TY - GEN A1 - Niederleithinger, Ernst A1 - Niederleithinger, Ernst A1 - Katzenbach, R. A1 - Hillmann, S. A1 - Schallert, M. A1 - Unseld, H. A1 - Willmes, M. ED - Bullock, P. ED - Verbeek, G. ED - Paikowsky, S. ED - Tara, D. T1 - A Framework for Nondestructive Testing Used in Foundation Reuse Projects N2 - The reuse of existing foundations is considered in various construction Projects to save time and costs while avoiding unnecessary interference with other underground objects. Because the design and as-built drawings might not be complete and questions may arise regarding the condition of the foundations, a detailed investigation is a prerequisite for the planning process in most cases. Nondestructive testing (NDT) techniques are a core part of this endeavor. The processes and procedure for foundation reuse planning are not yet standardized, and the possibilities and limitations of NDT methods are not known to many planners and stakeholders. The German research Project REFUND (2014–2016) has developed charts for the planning and Investigation process that consider available standards and the current state of the art in NDT. These charts are separately available for single and strip, slab, and pile foundations. Available NDT methods have been compiled and evaluated for specific tasks at these foundation types, including their respective limitations. The procedures have been successfully tested in two real-world projects. The results from these projects enable planners to improve the reliability of the process while potentially saving significant resources. This paper discusses the procedures for pile foundations and demonstrates the use of various NDT methods in a project on the reuse of electrical tower foundations. KW - Foundation reuse KW - Pile integrity testing KW - Parallel seismic PY - 2019 SN - 978-0-8031-7667-6 U6 - https://doi.org/10.1520/STP161120170159 VL - 1611 SP - 238 EP - 253 PB - ASTM International CY - West Conshohoken, PA, USA AN - OPUS4-48795 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Niederleithinger, Ernst A1 - Olofsson, J. A1 - Elfgren, L. A1 - Bell, B. A1 - Paulsson, B. A1 - Jensen, J. A1 - Feltrin, G. A1 - Täjlsten, B. A1 - Cremona, Ch. A1 - Kiviluoma, R. A1 - Bien, J. T1 - Sustainable bridges - A European integrated research project. background and overview T2 - International Conference Sustainable Bridges CY - Wroclaw, Poland DA - 2007-10-10 PY - 2007 AN - OPUS4-16146 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Weller, Andreas A1 - Lewis, Ronald A1 - Niederleithinger, Ernst T1 - Geophysikalische Verfahren zur Strukturerkundung und Schwachstellenanalyse von Flussdeichen – ein Handbuch N2 - Geophysikalische Verfahren zur Strukturerkundung und Schwachstellenanalyse von Flussdeichen – ein Handbuch ISBN: ISBN 978-3-981 07 - 4 Vor dem Hintergrund der seit Mitte der 90er Jahre in Deutschland gehäuft auftretenden Hochwasserereignisse (Rhein 1993/1995, Saale 1994, Oder 1997, Donau, Elbe und Mulde 2002/2005/2006) und den damit verbundenen umfangreichen Schäden, die ursächlich auf das Versagen von Hochwasserschutzanlagen (Deichbrüche) zurückzuführen waren, wird deutlich, dass die teilweise mehrere hundert Jahre alten Flussdeiche den Belastungen, bedingt durch ihre Bauart, die eingesetzten Baustoffe und die Bauhöhen, zum Teil nicht mehr gewachsen sind. Vor einer schutzzielabhängigen Entscheidung, ob eine Deichanlage künftigen Belastungen standhält oder ggf. zu ertüchtigen bzw. neu zu errichten ist, bedarf es als grundlegender Voraussetzung einer detaillierten Untersuchung des Tragsystems Bauwerk (Deich) und Untergrund. Ziel dieser Untersuchungen ist es, Schwachstellen des Tragsystems nach Umfang und Lage zu ermitteln, um daraus gezielt mögliche Sanierungsstrategien ableiten zu können. Für eine systematische Schwachstellenanalyse bieten sich in Kombination mit konventionellen geotechnischen Untersuchungsmethoden geophysikalische Messverfahren an. Einschlägige Normen und Richtlinien (DWA-M 507, DIN 19712) empfehlen zwar den Einsatz von geophysikalischen Verfahren, geben aber kaum praktische Hinweise für die Anwendung dieser Methoden. So erfolgt der Einsatz zerstörungsfreier geophysikalischer Verfahren zur Strukturerkundung an Deichen in Kombination mit geotechnischen Untersuchungen bisher regional differenziert und teilweise unsystematisch. Zudem werden von den für den Hochwasserschutz verantwortlichen Behörden zumeist keine oder sehr unterschiedliche Anforderungen an derartige Untersuchungen formuliert. Dadurch mangelt es den mit der Ausführung beauftragten Dienstleistern (Ingenieurbüros) zumeist an eindeutigen Vorgaben. Dies führt in der Regel dazu, dass die Qualität der aus diesen Untersuchungen abgeleiteten Aussagen höchst unterschiedlich ausfällt und vielfach nicht als optimal bezeichnet werden kann. Eine Hilfe zur Methoden- und Parameterwahl sowie eine systematische Bewertung der Eignung geophysikalischer Verfahren zur Strukturerkundung von Deichen gab es bisher nicht. Nach den Hochwasserereignissen des Jahres 2002 an Elbe und Mulde initiierte das Bundes- ministerium für Bildung und Forschung (BMBF) das Forschungsprogramm „Rimax“ (Risi- komanagement extremer Hochwasserereignisse). Mit diesem Programm werden zahlreiche Projekte auf ganz unterschiedlichen Gebieten der Hochwasserforschung gefördert [8]. Eines dieser Projekte ist das Verbundprojekt „Systematische Evaluierung existierender und innovativer Methoden zur Schwachstellenanalyse und Strukturerkundung von Deichen“ (DEISTRUKT). Ziel war es, möglichst viele erfolgversprechende oberflächen- und bohrlochgeophysikalische Methoden auf ihre Eignung für die Deichstrukturerkundung und Schwachstellenanalyse zu prüfen. Besondere Aufmerksamkeit wurde dabei auf die Umsetzung in geotechnisch verwertbare Ergebnisse gelegt. Mit dem Vorhaben DEISTRUKT sollte die Grundlage für einen effektiven Einsatz dieser Verfahren gelegt werden. Behörden und ausführende Ingenieurbüros sollen ein Werkzeug für die Entscheidungsfindung bei Konzeption, Ausschreibung, Durchführung und Bewertung geophysikalischer Messungen in Verbindung mit den geotechnischen Untersuchungsergebnissen erhalten. Basierend auf einer intensiven Recherche und praktischen Tests wurde eine systematische Evaluierung durchgeführt. Die Darstellung der Ergebnisse erfolgt als Richtlinie in diesem Handbuch. Berührungsfreie Methoden der Aerogeophysik oder der Fernerkundung waren nicht Gegenstand der Untersuchungen und bleiben daher im vorliegenden Handbuch unberücksichtigt. Das vorliegende Handbuch soll sowohl dem Praktiker aus Geophysik und Geotechnik als auch Behördenvertretern, die geophysikalische Leistungen zu beauftragen haben, als Hilfe zur Auswahl geeigneter Methoden und Messparameter dienen. Insoweit ist es auch als Ergänzung zu den Richtlinien DIN 19712, DIN 4020 und DWA-M 507 zu sehen. Sinngemäß können die in diesem Handbuch gegebenen Empfehlungen und Hinweise auch für die Erkundung von Trassen für den Deichneubau bzw. für Deichrückverlegungen, Seedeiche sowie für Flussseiten- bzw. Kanalseitendämme im Sinne von [36] gelten. Im Kapitel 2 werden insbesondere die Bauweise (Struktur) von Flussdeichen und die damit verbundenen Schwachstellen des Tragsystems sowie die daraus abgeleiteten Untersuchungsmethoden beschrieben. Kapitel 3 behandelt die Anforderungen und den Ablauf der geophysikalischen Deicherkundung und zeigt die Verknüpfungen zu den geotechnischen Untersuchungen auf. Eine kurze Beschreibung der wichtigsten bei der Deicherkundung eingesetzten geophysikalischen Methoden enthält Kapitel 4. In Kapitel 5 erfolgt die Bewertung der Eignung dieser Methoden. Schließlich werden im Anhang Hinweise zur Ausschreibung geophysikalischer Leistungen gegeben. T3 - BAM Forschungsberichtreihe - 281 PY - 2008 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-1700 SN - 978-3-9812072-2-4 SN - 0938-5533 VL - 281 SP - 1 EP - 29 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-170 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Meggyes, Tamás A1 - McDonald, C. A1 - Roehl, K. E. A1 - Witt, K. J. A1 - Debreczeni, Á. A1 - Niederleithinger, Ernst ED - Annokkée, G. J. T1 - Reducing the risk for tailings facilities T2 - 8th International FZK/TNO Conference on Contaminated Soil ; 8th ConSoil 2003 CY - Gent, Belgium DA - 2003-05-12 PY - 2003 SN - 0947-8620 N1 - Serientitel: Wissenschaftliche Berichte / Forschungszentrum Karlsruhe in der Helmholtz-Gemeinschaft – Series title: Wissenschaftliche Berichte / Forschungszentrum Karlsruhe in der Helmholtz-Gemeinschaft IS - 6943 SP - E3239 EP - E3247 PB - Forschungszentrum CY - Karlsruhe AN - OPUS4-2808 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Giese, Lutz A1 - Weritz, Friederike A1 - Weimann, Karin A1 - Niederleithinger, Ernst A1 - Ulbricht, J.P. ED - Dincer, I. T1 - Bricks made of sludge from the Izmir bay - an integrative approach for the recycling of sludge - preliminary results T2 - 1st International Exergy, Energy and Environment Symposium ; IEEES-1 CY - Izmir, Turkey DA - 2003-07-13 PY - 2003 SN - 975-288440-7 SP - 995 EP - 1003 CY - Izmir AN - OPUS4-2829 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Taffe, Alexander A1 - Maierhofer, Christiane A1 - Krause, Martin A1 - Gardei, André A1 - Niederleithinger, Ernst A1 - Hasenstab, Andreas A1 - Hemmleb, Matthias A1 - Wiggenhauser, Herbert A1 - Borchardt, Kerstin T1 - ZfPBau-Kompendium 2004 N2 - Dieses Kompendium ist ein kurzgefasster Abriss, ein Leitfaden und auch ein Handbuch der für den Einsatz im Bauwesen geeigneten zerstörungsfreien Prüfverfahren. In strenger, stets gleicher Gliederung wird jede der mehr als 100 Untersuchungsmethoden in einem eigenen Geräteblatt beschrieben. Hinzu kommen Querverweise zu alternativen Prüfmethoden sowie zahlreiche Hinweise auf einschlägige Fachliteratur und zu bekannt gewordenen Geräteherstellern, Lieferanten und Dienstleistern. PY - 2007 N1 - Das "ZfPBau-Kompendium 2004" war eine Datenbank, die von 2007 bis 2015 im Internet verfügbar war; sie wurde ersatzlos vom Netz genommen, als sie nicht mehr aktuell war – The "ZfPBau-Kompendium 2004" was a database that was accessible on the internet from 2007 to 2015; it was deleted without replacement when it wasn't up-to-date anymore PB - Bundesanstalt für Materialforschung und -prüfung CY - Berlin AN - OPUS4-1497 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Niederleithinger, Ernst A1 - Weller, Andreas T1 - SIP: Messung des komplexen elektrischen Widerstandes von Beton und Mauerwerk - Ansätze zu einer neuen Prüfmethode N2 - Zusammenfassung In der Geophysik wird seit einiger Zeit das Verfahren der "Spektralen Induzierten Polarisation (SIP)"eingesetzt, um nähere Informationen über die Art, die Struktur und den Zustand des Bodens zu erhalten. Die Methode beruht auf der Messung des komplexen spezifischen elektrischen Widerstands im Frequenzbereich zwischen 1 mHz und 10 kHz. Die SIP kann neue Möglichkeiten beim Einsatz elektrischer Verfahren in der Bauwerksuntersuchung eröffnen. So lassen sich beispielsweise Materialunterschiede von Feuchteinhomogenitäten trennen, was mit konventioneller Widerstandsmessung nicht möglich ist. Ebenfalls denkbar ist eine Detektion kontaminierter Bereiche (z. B. bei starker Belastung durch organische Substanzen oder Salze) im Mauerwerk. Vorgestellt werden das Verfahrensprinzip, die Messtechnik und erste Ergebnisse von Messungen an Mauerwerksziegeln. T2 - Jahrestagung Zerstörungsfreie Materialprüfung 2002 CY - Weimar, Deutschland DA - 2002-05-06 KW - Bauwesen KW - Elektrik KW - Spektrale Induzierte Polarisation KW - Feuchtigkeit KW - Mauerwerk PY - 2002 UR - http://www.ndt.net/article/dgzfp02/papers/v47/v47.htm SN - 3-931381-39-0 N1 - Serientitel: Berichtsband / Deutsche Gesellschaft für zerstörungsfreie Prüfung e. V. – Series title: Berichtsband / Deutsche Gesellschaft für zerstörungsfreie Prüfung e. V. IS - 80-CD PB - DGZfP CY - Berlin AN - OPUS4-1821 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Maierhofer, Christiane A1 - Krause, Martin A1 - Niederleithinger, Ernst A1 - Wiggenhauser, Herbert T1 - Non-destructive testing methods at BAM for damage assessment and quality assurance in civil engineering N2 - The structural safety, durability and performance of the infrastructure is of primary interest in every country. An efficient system for early and regular structural assessment as well as for quality assurance during and after the construction of new structures and of reconstruction processes is urgently required. At BAM, NDT methods to be applied in civil engineering are developed and their application improved. From the experience of on-site assessments, quality assurance systems and methodologies for regular inspections are elaborated. This work is mainly performed in the frame of externally funded research projects. T2 - 6th International Symposium Non-Destructive Testing in Civil Engineering (NDT-CE) CY - Berlin, Germany DA - 2003-09-16 KW - Non-destructive testing in civil engineering KW - Radar KW - Ultrasonics KW - Impact-echo KW - Impulse thermography KW - Concrete KW - Masonry PY - 2003 UR - http://www.ndt.net/article/ndtce03/papers/v068/v068.htm SN - 3-931381-49-8 PB - DGZfP CY - Berlin AN - OPUS4-3160 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Gardei, André A1 - Behrens, Matthias T1 - Non Destructive Testing of Concrete Railway Tracks by Impulse Response and Impact Echo Techniques T2 - Proceedings of Test 2003 International Conference on Material Testing (CD), Exhibition Centre Nuremberg CY - Nuremberg, Germany DA - 2003-05-13 PY - 2003 AN - OPUS4-3228 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Gardei, André A1 - Behrens, Matthias T1 - Non Destructive Testing of Concrete Railway Tracks by Impulse Response and Impact Echo Techniques T2 - International Conference on Materials Testing ; TEST Kongress ; TEST Conference CY - Nuremberg, Germany DA - 2003-05-13 KW - Impakt-Echo KW - Impulse-Response KW - Beton KW - Feste Fahrbahn KW - Qualitätskontrolle KW - Schwellen KW - Verbund KW - Zerstörungsfreie Prüfung PY - 2003 IS - A 7.2 SP - 153 EP - 156 PB - AMA Service GmbH CY - Wunstorf AN - OPUS4-3229 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kruschwitz, Sabine A1 - Niederleithinger, Ernst T1 - Mehrkanalige SIP - erste Erfahrungen T2 - 64. Jahrestagung der Deutschen Geophysikalischen Gesellschaft (DGG) CY - Berlin, Deutschland DA - 2004-03-08 KW - SIP KW - Geotechnik KW - Geoelektrik KW - Baustoffe KW - Feuchtigkeit KW - Porosität KW - Spülhalden PY - 2004 SP - 571 EP - 572 PB - Deutsche Geophysikalische Gesellschaft CY - Berlin AN - OPUS4-3440 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Weller, Andreas T1 - SIP: Messung des komplexen elektrischen Widerstandes von Beton und Mauerwerk - Ansätze zu einer neuen Prüfmethode T2 - DGZfP-Jahrestagung 2002: ZfP in Anwendung, Entwicklung und Forschung CY - Weimar, Germany DA - 2002-05-06 PY - 2002 AN - OPUS4-3893 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Maierhofer, Christiane A1 - Krause, Martin A1 - Weritz, Friederike A1 - Gardei, André T1 - Zerstörungsfreie Bauwerksdiagnose T2 - Jahrestagung Deutsche Geophysikalische Gesellschaft (DGG) CY - Hanover, Germany DA - 2002-03-18 PY - 2002 AN - OPUS4-3878 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Entwicklung und Anwendung von Umweltmessverfahren T2 - Fachausschusssitzung ZfP Bauwesen (FA B), DGZfP CY - Berlin, Germany DA - 2002-11-26 PY - 2002 AN - OPUS4-3866 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Meggyes, Tamás A1 - McDonald, C. A1 - Debreczeni, Á. T1 - TAILSAFE: Investigation and Improvement of Tailings Facilities T2 - XIIIth European Conference on Soil Mechanics and Geotechnical Engineering CY - Prague, Czech Republic DA - 2003-08-25 PY - 2003 AN - OPUS4-3833 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Taffe, Alexander T1 - Concept for a reference pile testing site for the development and improvement of NDT-CE T2 - XIIIth European Conference on Soil Mechanics and Geotechnical Engineering CY - Prague, Czech Republic DA - 2003-08-25 PY - 2003 AN - OPUS4-3834 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Taffe, Alexander T1 - Concept for a reference pile testing site for the development and improvement of NDT-CE T2 - NDT-CE 2003, International Symposium Non-Destructive Testing in Civil Engineering CY - Berlin, Germany DA - 2003-09-16 PY - 2003 AN - OPUS4-3841 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Brink, Arne A1 - McDonald, C. A1 - Meggyes, Tamás A1 - Roehl, K.E. A1 - Witt, K. J. T1 - TAILSAFE: Investigation and Improvement of Tailings Facilities T2 - NDT-CE 2003, International Symposium Non-Destructive Testing in Civil Engineering CY - Berlin, Germany DA - 2003-09-16 PY - 2003 AN - OPUS4-3827 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Spectral Induced Polarization - a Tool for Non-Destructive Testing of Soils and Building Materials T2 - NDT-CE 2003, International Symposium Non-Destructive Testing in Civil Engineering CY - Berlin, Germany DA - 2003-09-16 PY - 2003 AN - OPUS4-3828 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Taffe, Alexander T1 - Horstwalde - Konzeption für einen Teststandort zur Pfahlprüfung T2 - Pfahl-Symposium 2003 CY - Braunschweig, Germany DA - 2003-02-20 PY - 2003 AN - OPUS4-3831 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Meggyes, Tamás A1 - Niederleithinger, Ernst T1 - Improving the safety of tailings ponds and dams PY - 2002 SN - 1219-008X N1 - Serientitel: A Miskolci Egyetem közleménye : A sorozat, Bányászat – Series title: A Miskolci Egyetem közleménye : A sorozat, Bányászat IS - 62 SP - 47 EP - 56 PB - Egyetemi Kiadó CY - Miskolc AN - OPUS4-1598 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Niederleithinger, Ernst T1 - Spectral Induced Polarization - a Tool for Non-Destructive Testing of Soils and Building Materials N2 - The Spectral Induced Polarization (SIP) is a newly developed non-destructive geophysical method. It is an extension of conventional electrical resistivity measurements. By measuring additional parameters a more detailed investigation of the subsurface is possible. Up to now SIP is mainly used in mineral exploration, but the number of application examples from near surface geophysics and civil engineering is increasing. Results are presented from the investigation of slag heaps and measurements on bricks. T2 - 6th International Symposium Non-Destructive Testing in Civil Engineering (NDT-CE) CY - Berlin, Germany DA - 2003-09-16 PY - 2003 UR - http://www.ndt.net/article/ndtce03/papers/v060/v060.htm SN - 3-931381-49-8 SP - 1(?) EP - 8(?) PB - DGZfP CY - Berlin AN - OPUS4-2755 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Niederleithinger, Ernst A1 - Taffe, Alexander T1 - Concept for a reference pile testing site for the development and improvement of NDT-CE N2 - Pile testing as a NDT-CE (non-destructive-testing in civil engineering) method provides information about the condition of foundations. It is also used as a tool for quality control. Real size test fields with sound piles, piles with flaws and piles connected with a foundation allow calibration of measurement devices and method comparison under "real" conditions. Such a site is planned on a BAM testing area south of Berlin. The joint use facilitates the establishment of the testing site as a national or European reference site. T2 - 6th International Symposium Non-Destructive Testing in Civil Engineering (NDT-CE) CY - Berlin, Germany DA - 2003-09-16 PY - 2003 UR - http://www.ndt.net/article/ndtce03/papers/v026/v026.htm SN - 3-931381-49-8 SP - 1 EP - 6(?) PB - DGZfP CY - Berlin AN - OPUS4-2757 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Niederleithinger, Ernst A1 - Meggyes, Tamás A1 - McDonald, C. A1 - Roehl, K. E. A1 - Witt, K. J. A1 - Debreczeni, Á. T1 - TAILSAFE - Investigation and improvement of tailings facilities N2 - Improperly built or managed tailing dams pose major risks to human lives and the environment. Research for risk reduction by new technologies including slurry handlings, stochastic modelling, development of a parameter framework as well as work on legislation and authorisation procedures will be done in the EC-funded project TAILSAFE. Focus of this paper is on geophysial techniques for structure investigation and monitoring. T2 - 13th European Conference on Soil Mechanics and Geotechnical Engineering ; 13e Congrès Européen de Mécanique des Sols et de la Géotechnique CY - Prague, Czech Republic DA - 2003-08-25 KW - Tailing dams KW - Hazards KW - Geotechnics KW - Stochastics KW - Geophysics KW - Monitoring PY - 2003 SN - 80-8676904-6 N1 - Serientitel: DGZfP-Proceedings BB – Series title: DGZfP-Proceedings BB IS - 85-CD SP - 179 EP - 182 CY - Praha AN - OPUS4-2758 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Niederleithinger, Ernst A1 - Taffe, Alexander T1 - Concept for a reference pile testing site for the development and improvement of NDT-CE T2 - 13th European Conference on Soil Mechanics and Geotechnical Engineering ; 13e Congrès Européen de Mécanique des Sols et de la Géotechnique CY - Prague, Czech Republic DA - 2003-08-25 KW - Pile testing KW - Assessment KW - Quality control KW - Testing site KW - Reference testing PY - 2003 SN - 80-8676904-6 N1 - Serientitel: DGZfP-Proceedings BB – Series title: DGZfP-Proceedings BB IS - 13-2 SP - 763 EP - 766 CY - Praha AN - OPUS4-2759 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Niederleithinger, Ernst A1 - Taffe, Alexander ED - Stahlmann, J. T1 - Horstwalde - Konzeption für einen Teststandort zur Pfahlprüfung T2 - 7. Pfahl-Symposium CY - Braunschweig, Deutschland DA - 2003-02-20 PY - 2003 SN - 3-927610-62-3 N1 - Serientitel: Mitteilung des Instituts für Grundbau und Bodenmechanik - Technische Universität Braunschweig – Series title: Mitteilung des Instituts für Grundbau und Bodenmechanik - Technische Universität Braunschweig IS - 71 SP - 1(?) EP - 6(?) CY - Braunschweig AN - OPUS4-2760 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Niederleithinger, Ernst A1 - Taffe, Alexander A1 - Behrens, Matthias ED - Stahlmann, J. T1 - RUFUS - Re-Use of Foundations on Urban Sites - Ein EU-Projekt zur Wiedernutzung von Fundamenten T2 - 7. Pfahl-Symposium CY - Braunschweig, Deutschland DA - 2003-02-20 PY - 2003 SN - 3-927610-62-3 N1 - Serientitel: Mitteilung des Instituts für Grundbau und Bodenmechanik - Technische Universität Braunschweig – Series title: Mitteilung des Instituts für Grundbau und Bodenmechanik - Technische Universität Braunschweig IS - 71 SP - 1(?) EP - 2(?) CY - Braunschweig AN - OPUS4-2761 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Kruschwitz, Sabine A1 - Behrens, Matthias A1 - Brink, Arne T1 - Multichannel Spectral Induced Polarization (SIP) - Application to Geotechnics and Construction Materials T2 - Near Surface 2004, 10th European Meeting of Environmental and Engineering Geophysics CY - Utrecht, Netherlands DA - 2004-09-06 PY - 2004 AN - OPUS4-3973 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Kruschwitz, Sabine T1 - Elektrische Widerstandsmessungen mit Spektraler Induzierter Polarisation T2 - Feuchtetag 2004 mit Workshop ONSITEFORMASONRY CY - Berlin, Germany DA - 2004-11-18 PY - 2004 AN - OPUS4-5703 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Kruschwitz, Sabine A1 - Behrens, Matthias A1 - Brink, Arne T1 - Multichannel Spectral Induced Polarization (SIP) - Application to Geotechnics and Construction Materials T2 - 10th European Meeting of Environmental and Engineering Geophysics (Near Surface 2004) CY - Utrecht, Niederlande DA - 2004-09-06 KW - SIP KW - Geotechnik KW - Geoelektrik KW - Baustoffe KW - Feuchtigkeit KW - Porosität KW - Spülhalden PY - 2004 SP - 4 pages PB - EAEG CY - Houten AN - OPUS4-4053 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Helmerich, Rosemarie A1 - Niederleithinger, Ernst ED - Alexander, M. T1 - Non-destructive techniques for the condition assessment of railway bridges T2 - International Conference on Concrete Repair, Rehabilitation and Retrofitting (ICCRRR) CY - Cape Town, South Africa DA - 2005-11-21 KW - Sustainable bridges KW - Non-destructive Testing KW - Quality assurance KW - Repair PY - 2005 SN - 0-415-39654-9 N1 - Serientitel: Balkema proceedings and monographs in engineering, water and earth sciences – Series title: Balkema proceedings and monographs in engineering, water and earth sciences SP - 163-165 / 429-435 (CD-ROM) PB - Taylor & Francis CY - London AN - OPUS4-11679 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Taffe, Alexander A1 - Krause, Martin A1 - Milmann, Boris A1 - Niederleithinger, Ernst ED - Alexander, M. T1 - Assessment of foundation slabs with US-echo in the re-use process N2 - During the re-use process of existing concrete memebers like foundations information about geometry and location of piles or strip foundation is necessary. Ultrasonic echo with a need of only one-sided access may provide this information and help the engineer to assess foundations. Cost effectiveness by the re-use of foundations gains an increasing economic role due to decreasing average economic lifetime of buildings on urban sites. Results of systematic ultrasonic echo investigations at a slab from 75 cm to 125 cm thickness with ten different reinforcement ratios are presented. The influence of the varying reinforcement ratio and thickness on the reliability of the results is shown. Available data-processing algorithms based on reconstruction calculation and imaging of results to reveal the geometry of a slab and the location of piles or strip foundations are introduced. Practical guidance for the application of ultrasonic echo and its limits are presented to ensure reliable results. T2 - International Conference on Concrete Repair, Rehabilitation and Retrofitting (ICCRRR) CY - Cape Town, South Africa DA - 2006-11-21 KW - Ultraschallecho KW - Fundamentdicke KW - Bildgebende Darstellung KW - Wiedernutzung von Fundamenten KW - SAFT KW - ZfP im Bauwesen KW - Objektortung PY - 2006 SN - 0-415-39654-9 N1 - Serientitel: Balkema proceedings and monographs in engineering, water and earth sciences – Series title: Balkema proceedings and monographs in engineering, water and earth sciences SP - 525 EP - 530 PB - Taylor & Francis CY - London AN - OPUS4-11681 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Taffe, Alexander A1 - Niederleithinger, Ernst A1 - Krause, Martin A1 - Milmann, Boris T1 - Zerstörungsfreie Untersuchungen an Fundamentplatten mit Ultraschallecho KW - Zerstörungsfreie Prüfung im Bauwesen KW - ZfPBau KW - Ultraschallecho KW - Dickenmessung KW - Fundamente KW - Baustellenscanner KW - Wiedernutzung PY - 2004 SN - 0005-9900 SN - 1437-1006 VL - 99 IS - 12 SP - 1000 EP - 1004 PB - Ernst CY - Berlin AN - OPUS4-5284 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Kruschwitz, Sabine A1 - Niederleithinger, Ernst A1 - Behrens, Matthias A1 - Mittag, Kornelia T1 - Zerstörungsfreie Strukturuntersuchung von Spülhaldendämmen mittles SIP T2 - Jahrestagung Deutsche Geophysikalische Gesellschaft (DGG) CY - Graz, Österreich DA - 2005-02-21 KW - Spektrale Induzierte Polarisation KW - Spülhalden KW - Dammstabilität PY - 2005 SN - 0344-7251 SP - 113 EP - 114 PB - DGG CY - wechselnde Verlagsorte AN - OPUS4-7214 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Kruschwitz, Sabine A1 - Niederleithinger, Ernst T1 - Spektrale Induzierte Polarisation zur Charakterisierung von Baumaterial T2 - Jahrestagung Deutsche Geophysikalische Gesellschaft (DGG) CY - Graz, Österreich DA - 2005-02-21 KW - Spektrale Induzierte Polarisation KW - Baumaterial KW - Holz KW - CNM KW - Hg-Porosimetrie PY - 2005 SN - 0344-7251 SP - 296 EP - 297 PB - DGG CY - wechselnde Verlagsorte AN - OPUS4-7215 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Niederleithinger, Ernst A1 - Taffe, Alexander A1 - Behrens, Matthias T1 - Pfahlprüfung - Grenzbereich zwischen Bauingenieurwesen und Geophysik T2 - Jahrestagung Deutsche Geophysikalische Gesellschaft (DGG) CY - Graz, Österreich DA - 2005-02-21 KW - Fundamente KW - Bohrpfähle KW - Pfahlprüfung KW - Pfahlintegritätsprüfung KW - Parallel Seismic Verfahren KW - Geophysik PY - 2005 SN - 0344-7251 SP - 287 PB - DGG CY - wechselnde Verlagsorte AN - OPUS4-7239 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Taffe, Alexander A1 - Niederleithinger, Ernst ED - Butcher, A. ED - Powell, J. ED - Skinner, H. T1 - NDT investigation methods KW - Re-use of foundations KW - NDT KW - Pile integrity testing KW - Parallel seismic KW - Ultrasonic KW - Sustainability KW - Piles KW - Foundations PY - 2006 SN - 1-86081-938-9 N1 - Serientitel: Building Research Establishment X – Series title: Building Research Establishment X IS - 414 SP - 47 EP - 55 PB - IHS BRE Press CY - Bracknell AN - OPUS4-13925 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Helmerich, Rosemarie A1 - Niederleithinger, Ernst A1 - Wiggenhauser, Herbert T1 - A toolbox with non-destructive testing methods for the condition assessment of railway bridges N2 - The unified economic structure of the European market requires a unified transport infrastructure to ensure seamless and barrierfree transportation of passengers and goods. The European commission is funding the European Integrated Project Sustainable Bridges to comply with future traffic demands. The main objective of the project is to reliably assess and upgrade the bridge infrastructure for the required increase of axle loads and transport volume. 32 Institutes from 12 countries develop unified procedures for the assessment and improvement of the existing railway bridge stock under the guidance and review of six major European railway companies. Non destructive testing (NDT) is given a high priority. One of the work packages concentrates on the potential of advanced NDT-methods and creates a toolbox with advisable methods for the condition assessment of all types of railway bridges. Although NDT-methods are implemented in the quality assurance process in many industries, their application in the railway infrastructure is not common. Only a few countries have included selected NDT-methods into advanced condition assessment procedures for the management of their bridge stock. This paper describes also current activities to enhance pulse-phase thermography, impulse-radar and acoustic methods. The advanced methods enable infrastructure owners to verify construction plans, to assess structures, repair and strengthening quality or to identify in-service damages. Latest development is an automated scanning system for combined acoustic and electromagnetic measurements. The results are then combined through data fusion techniques to further increase their value for the bridge owners. T2 - 85th TRB Annual Meeting CY - Washington, DC, USA DA - 2006-01-22 KW - Non-Destructive Testing KW - Thermography KW - Railway Bridges KW - NDT-toolbox PY - 2006 SP - 1 EP - 12(?) PB - TRB CY - Washington, D.C. AN - OPUS4-12037 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - New Concepts from Geophysics - New Possibilities for NDT T2 - Construction Materials Seminar, University of Illinois CY - Urbana-Champaign, IL, USA DA - 2013-04-10 PY - 2013 AN - OPUS4-28063 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Wunderlich, Carolin T1 - Ultrasonic Monitoring of Concrete Using Concepts from Seismology T2 - SAGEEP 2013 CY - Denver, CO, USA DA - 2013-03-17 PY - 2013 AN - OPUS4-28056 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Weller, Andreas A1 - Lewis, R. T1 - Evaluation of Geophysical Techniques for Dike Inspection T2 - SAGEEP 2013 CY - Denver, CO, USA DA - 2013-03-17 PY - 2013 AN - OPUS4-28058 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Data Fusion in Geophysics/NDT T2 - SmartGeo Seminar, Colorado School of Mines CY - Golden, CO, USA DA - 2013-02-25 PY - 2013 AN - OPUS4-28059 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Ultrasonic Crosshole Logging for Quality Assurance of Pile and Diaphragm Walls Joints T2 - SmartGeo Seminar, Colorado School of Mines CY - Golden, CO, USA DA - 2013-01-29 PY - 2013 AN - OPUS4-28060 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Geophysics at BAM' NDT Department: Same Physics, Different Scale T2 - Heiland Lecture, Colorado School of Mines CY - Golden, CO, USA DA - 2013-01-17 PY - 2013 AN - OPUS4-28061 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Niederleithinger, Ernst T1 - Improvement and extension of the parallel seismic method for foundation depth measurement KW - Parallel seismic KW - Length KW - Piles KW - Interpretation KW - Foundations PY - 2012 U6 - https://doi.org/10.1016/j.sandf.2012.11.023 SN - 0038-0806 VL - 52 IS - 6 SP - 1093 EP - 1101 PB - Soc. CY - Tokyo AN - OPUS4-27908 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Stähler, S.C. A1 - Sens-Schönfelder, C. A1 - Niederleithinger, Ernst T1 - Monitoring stress changes in a concrete bridge with coda wave interferometry N2 - Coda wave interferometry is a recent analysis method now widely used in seismology. It uses the increased sensitivity of multiply scattered elastic waves with long travel-times for monitoring weak changes in a medium. While its application for structural monitoring has been shown to work under laboratory conditions, the usability on a real structure with known material changes had yet to be proven. This article presents experiments on a concrete bridge during construction. The results show that small velocity perturbations induced by a changing stress state in the structure can be determined even under adverse conditions. Theoretical estimations based on the stress calculations by the structural engineers are in good agreement with the measured velocity variations. KW - Bridges (structures) KW - Concrete KW - Interferometry KW - Structural acoustics PY - 2011 U6 - https://doi.org/10.1121/1.3553226 SN - 0001-4966 SN - 1520-8524 VL - 129 IS - 4 SP - 1945 EP - 1952 PB - AIP CY - Melville, NY, USA AN - OPUS4-28588 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bienert, K. A1 - Schalk, H. A1 - Molkenthin, A. A1 - Wilsch, Gerd A1 - Goldschmidt, Sebastian A1 - Niederleithinger, Ernst ED - Grantham, M. ED - Mechtcherine, V. ED - Schneck, U. T1 - Quality control of hydrophobic coatings with an integrated marker element by laser-induced breakdown spectroscopy (LIBS) T2 - Concrete solutions 2011 - 4th International conference on concrete repair CY - Dresden, Germany DA - 2011-09-26 KW - Laser induced breakdown spectroscopy (LIBS) KW - Hydrophobic coating KW - Quality control KW - Depth of penetration KW - Concrete repair KW - Chloride PY - 2012 SN - 978-0-415-61-622-5 SP - 805 EP - 811 PB - Taylor & Francis CY - London AN - OPUS4-25151 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Niederleithinger, Ernst A1 - Kruschwitz, Sabine A1 - Martin, Tina A1 - Trela, Christiane T1 - Geophysical investigation of tailings dams - the TAILSAFE challenge N2 - One of the main problems in the assessment of the operability, stability and contamination potential of tailings facilities is the lack of data on subsurface materials, properties and structures. One key task in the use of geophysics is the selection of the proper methods for a given site/problem combination. Interpretation of the acquired and processed physical data (e.g. electrical resistivity distribution) into something useful for site assessment (e.g. contamination distribution) is another. In the TAILSAFE project (funded by the European Commission) we have worked with partners on the use of geophysics for tailings facilities inspection. DC and complex resistivity, ground penetrating radar, and spectral analysis of surface waves and multichannel analysis of surface waves have been used on dams and beaches. In most cases, our methods provided useful information on the subsurface structure, but the translation of geophysical values into geotechnical or other parameters is still challenging. KW - Geophysics KW - Geoelectrics KW - Ground penetrating radar KW - Spectral analysis of surface waves KW - Tailings PY - 2007 SN - 0967-0513 VL - 15 IS - 2 SP - 157 EP - 162 PB - EPP Publ. CY - Richmond AN - OPUS4-25080 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Kruschwitz, Sabine A1 - Martin, Tina T1 - SIP - Komplexe elektrische Widerstandstomographie T2 - DACH-Jahrestagung 2008 CY - St. Gallen, Switzerland DA - 2008-04-28 PY - 2008 AN - OPUS4-25016 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Kruschwitz, Sabine A1 - Martin, Tina T1 - SIP@BAM: Spectral Induced Polarisation used at masonry, wood and concrete T2 - Workshop des Arbeitskreises Induzierte Polarisation CY - Denver, CO, USA DA - 2011-10-31 PY - 2011 AN - OPUS4-25018 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kemna, A. A1 - Binley, A. A1 - Cassiani, G. A1 - Niederleithinger, Ernst A1 - Revil, A. A1 - Slater, L. A1 - Williams, K. H. A1 - Orozco, A.F. A1 - Haegel, F.-H. A1 - Hördt, A. A1 - Kruschwitz, Sabine A1 - Leroux, V. A1 - Titov, K. A1 - Zimmermann, E. T1 - An overview of the spectral induced polarization method for near-surface applications N2 - Over the last 15 years significant advancements in induced polarization (IP) research have taken place, particularly with respect to spectral IP (SIP), concerning the understanding of the mechanisms of the IP phenomenon, the conduction of accurate and broadband laboratory measurements, the modelling and inversion of IP data for imaging purposes and the increasing application of the method in near-surface investigations. We summarize here the current state of the science of the SIP method for near-surface applications and describe which aspects still represent open issues and should be the focus of future research efforts. Significant progress has been made over the last decade in the understanding of the microscopic mechanisms of IP; however, integrated mechanistic models involving different possible polarization processes at the grain/pore scale are still lacking. A prerequisite for the advances in the mechanistic understanding of IP was the development of improved laboratory instrumentation, which has led to a continuously growing data base of SIP measurements on various soil and rock samples. We summarize the experience of numerous experimental studies by formulating key recommendations for reliable SIP laboratory measurements. To make use of the established theoretical and empirical relationships between SIP characteristics and target petrophysical properties at the field scale, sophisticated forward modelling and inversion algorithms are needed. Considerable progress has also been made in this field, in particular with the development of complex resistivity algorithms allowing the modelling and inversion of IP data in the frequency domain. The ultimate goal for the future are algorithms and codes for the integral inversion of 3D, time-lapse and multi-frequency IP data, which defines a 5D inversion problem involving the dimensions space (for imaging), time (for monitoring) and frequency (for spectroscopy). We also offer guidelines for reliable and accurate measurements of IP spectra, which are essential for improved understanding of IP mechanisms and their links to physical, chemical and biological properties of interest. We believe that the SIP method offers potential for subsurface structure and process characterization, in particular in hydrogeophysical and biogeophysical studies. KW - Induced polarisation KW - Review KW - Moisture KW - Soil KW - Masonry resistivity PY - 2012 U6 - https://doi.org/10.3997/1873-0604.2012027 SN - 1569-4445 VL - 101 IS - 6 SP - 453 EP - 468 PB - EAGE - European Association of Geoscientists & Engineers CY - Houten AN - OPUS4-27433 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Niederleithinger, Ernst A1 - Weller, Andreas A1 - Lewis, R. T1 - Evaluation of geophysical techniques for dike inspection N2 - After some river embankment failures during recent floods in Germany, major investigation and improvement programs for river embankments have been implemented. Presently, the investigation mainly relies on existing documentation, visual inspection, and drilling and sampling. Geophysical techniques, which are applied non-destructively from the surface, have the potential to cover the gaps between sampling points and to enhance the reliability of subsurface information. This paper describes the evaluation results for resistivity, electromagnetic, seismic and GPR techniques acquired at a test site along the Mulde River in eastern Germany. The work was carried out under the government funded project DEISTRUKT. Each geophysical method has its own specific advantages and limitations. Keeping the requirements posed by current German guidelines for river embankments in mind, 2–D electrical resistivity tomography (ERT) is the method of first choice. However, all geophysical results have to be calibrated carefully using information, such as material properties and depth of structures, determined from boreholes. Although some recommendations are provided here, a set of detailed recommendations have been compiled in a handbook. KW - Dikes KW - Embankments KW - Flood KW - Geophysics KW - Geotechnics KW - Evaluation PY - 2012 U6 - https://doi.org/10.2113/JEEG17.4.185 SN - 1083-1363 VL - 17 IS - 4 SP - 185 EP - 195 PB - EEGS CY - Denver, Colo., USA AN - OPUS4-27490 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst ED - Coutinho, R.Q. ED - Mayne, P.W. T1 - Two in one: parallel seismic for foundation length determination and downhole seismic for soil properties using a single borehole N2 - Parallel Seismic was introduced about four decades ago for foundation length estimation. As the borehole required by this test is in most cases more expensive than the test itself, the usage is limited so far. In addition the graphical Interpretation technique which is still state of the art tends to overestimate the length and neglects several geometrical Parameters. New Interpretation algorithms have been recently introduced rely on model based travel time curve Utting. They improve the accuracy and extend the maximum ränge (distance pile to borehole) of the method. Borehole or pile inclination as well as soil layering can be considered. If the location is properly chosen, several piles can be tested using a single borehole. The capabilities and limitations of the methods have been tested using simulations and measurements at the BAM-TTS test site in Horstwalde south of Berlin and several commercial projects involving piles, pile secant walls and sheet piles. To improve the accuracy of the method as well as to provide additional Parameters to the geotechnical engineer it is recommended to use the borehole for Downhole Seismic measurements. Determination of compressional and shear wave velocities can be used to determine the dynamic elastic properties of the subsoil. The approach is evaluated again on the BAM-TTS test site. The affectivity of this kind of combiuation can be further enhanced by using a seismic cone. T2 - ISC-4 - 4th International conference on site characterization - Geotechnical and geophysical site characterization 4 CY - Pernambuco, Brazil DA - 17.09.2012 KW - Parallel seismic KW - Downhole seismic KW - Foundation piles KW - Length KW - Shear wave velocity PY - 2013 SN - 978-0-415-62136-6 VL - I SP - 453 EP - 458 PB - CRC Press AN - OPUS4-27491 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd A1 - Schalk, H. A1 - Bienert, K. A1 - Molkenthin, A. A1 - Goldschmidt, Sebastian A1 - Niederleithinger, Ernst T1 - Quality control of hydrophobic coatings with an integrated marker element by laser-induced breakdown spectroscopy (LIBS) T2 - 2nd International conference Micro Durability - Microstructural-related durability of cementitious composites CY - Amsterdam, The Netherlands DA - 2012-04-11 KW - Hydrophobierung KW - Laser Induced Breakdown Spektroskopie (LIBS) KW - Qualitätskontrolle PY - 2012 SN - 978-2-35158-129-2 N1 - Serientitel: RILEM proceedings – Series title: RILEM proceedings VL - PRO83 SP - 1 EP - 10(?) AN - OPUS4-27534 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd A1 - Goldschmidt, Sebastian A1 - Niederleithinger, Ernst A1 - Bienert, K. A1 - Schalk, H. A1 - Molkenthin, A. ED - Jacobsen, S. ED - Justnes, H. ED - Cepuritis, R. ED - Hornbostel, K. ED - Peng, Y. T1 - Quality control of hydrophobic coatings with an integrated marker element by laser-induced breakdown spectroscopy (LIBS) T2 - ICDC 2012 - International congress on durability of concrete CY - Trondheim, Norway DA - 2012-06-18 KW - Hydrophobic coating KW - Marker element KW - Quality control KW - Depth of penetration KW - Concrete repair KW - Pitting corrosion KW - Chloride KW - Exposure KW - Freeze-taw cycles KW - Laser-induced breakdown spectroscopy KW - Hydrophobierung KW - Laser Induced Breakdown Spektroskopie KW - Qualitätskontrolle PY - 2012 SN - 978-82-8208-031-6 SP - Session B 1, 1 EP - 14(?) AN - OPUS4-27527 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bienert, K. A1 - Schalk, H. A1 - Molkenthin, A. A1 - Wilsch, Gerd A1 - Goldschmidt, Sebastian A1 - Niederleithinger, Ernst T1 - Qualitätskontrolle von Hydrophobierungen mit einem integrierten Markerelement durch die laser-induced breakdown spectroscopy (LIBS) T2 - 18. Ibausil - Internationale Baustofftagung CY - Weimar, Germany DA - 2012-09-12 KW - Hydrophobierung KW - Markerelement KW - Qualitätskontrolle KW - Eindringtiefe KW - Betonreparatur KW - Lochfraßkorrosion KW - Chloride KW - Frost-Tausalz-Wechsel KW - LIBS PY - 2012 SN - 978-3-00-034075-8 VL - 2 IS - 3.07 SP - 2-0398 - 2-0409 AN - OPUS4-27601 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Müller, Sabine A1 - Niederleithinger, Ernst A1 - Bohlen, T. T1 - Reverse time migration: a seismic imaging technique applied to synthetic ultrasonic data N2 - Ultrasonic echo testing is a more and more frequently used technique in civil engineering to investigate concrete building elements, to measure thickness as well as to locate and characterise built-in components or inhomogeneities. Currently the Synthetic Aperture Focusing Technique (SAFT), which is closely related to Kirchhoff migration, is used in most cases for imaging. However, this method is known to have difficulties to image steeply dipping interfaces as well as lower boundaries of tubes, voids or similar objects. We have transferred a processing technique from geophysics, the Reverse Time Migration (RTM) method, to improve the imaging of complicated geometries. By using the information from wide angle reflections as well as from multiple events there are fewer limitations compared to SAFT. As a drawback the required computing power is significantly higher compared to the techniques currently used. Synthetic experiments have been performed on polyamide and concrete specimens to show the improvements compared to SAFT. We have been able to image vertical interfaces of step-like structures as well as the lower boundaries of circular objects. It has been shown that RTM is a step forward for ultrasonic testing in civil engineering. KW - Beton KW - Ultraschall KW - Concrete KW - Imaging KW - Ultrasonics KW - Reverse time migration PY - 2012 U6 - https://doi.org/10.1155/2012/128465 SN - 1687-8868 SN - 1687-885X VL - 2012 IS - Article ID 128465 SP - 1 EP - 7 PB - Hindawi Publishing Corporation CY - New York, NY, USA AN - OPUS4-26295 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Kruschwitz, Sabine A1 - Niederleithinger, Ernst T1 - Untersuchung voll- und teilgesättigter Baustoffe mit Spektral Induzierter Polarisation - Wege zu einem zerstörungsfreien Prüfungsverfahren? T2 - Workshop 2007 "Innovative Feuchtemessung in Forschung und Praxis" CY - Karlsruhe, Deutschland DA - 2007-10-17 KW - Spektral Induzierte Polarisation KW - Baumaterial KW - Feuchte KW - Salz KW - FD Modellierung PY - 2007 SN - 978-3-931681-91-3 SP - 149 EP - 155 PB - Aedificatio AN - OPUS4-16369 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Helmerich, Rosemarie A1 - Niederleithinger, Ernst A1 - Algernon, Daniel A1 - Streicher, Doreen A1 - Wiggenhauser, Herbert T1 - Bridge inspection and condition assessment in Europe T2 - TRB 87th annual meeting CY - Washington, D.C., USA DA - 2008-01-13 KW - Construction KW - Environment and Energy PY - 2008 IS - CD-ROM (Paper 08-1450 / Session 568) SP - 1 EP - 13 PB - TRB CY - Washington, DC AN - OPUS4-16651 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Niederleithinger, Ernst ED - Jaime Alberto dos Santos, T1 - Numerical simulation of low strain dynamic pile tests T2 - 8th International Conference on the Application of Stress Wave Theory to Piles - Science, Technology and Practice CY - Lisbon, Portugal DA - 2008-09-08 KW - Pile integrity testing KW - Parallel seismic KW - Simulation KW - EFIT PY - 2008 SN - 978-1-58603-909-7 SP - 315 EP - 320 PB - IOS Press BV AN - OPUS4-17916 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Niederleithinger, Ernst T1 - The Parallel Seismic Technique for Determination of Foundation Pile Length T2 - Near Surface 2008 - 14th European Meeting of Environmental and Engineering Geophysics (EAGE) CY - Kraków, Poland DA - 2008-09-15 KW - Piles KW - Parallel seismic KW - Length KW - Quality assurance PY - 2008 SN - 978-90-73781-56-6 SP - 1 EP - 5 AN - OPUS4-17917 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Meggyes, Tamás A1 - Niederleithinger, Ernst A1 - Witt, K. J. A1 - Csövári, M. A1 - Kreft-Burman, K. A1 - Engels, J. A1 - McDonald, C. A1 - Roehl, K.E. T1 - Enhancing the safety of tailings management facilities N2 - Unsafe tailings management facilities (TMFs) have caused serious accidents in Europe (e.g., Baia Mare, Romania, in 2000, Aznalcóllar, Spain, in 1998, and Stava, Italy, in 1985), threatening human health/life and the environment. While advanced design, construction and management procedures are available, their implementation requires greater emphasis. An integrated research project funded by the European Union was carried out between 2002 and 2005 with the overall goal of improving the safety of TMFs (Sustainable Improvement in Safety of Tailings Facilities-TAILSAFE, http://www.tailsafe.com/). The objective of TAILSAFE was to develop and apply methods of parameter evaluation and measurement for the assessment and improvement of the safety state of tailings facilities, with particular attention to the stability of tailings dams and slurries, the special risks inherent when such materials include toxic or hazardous wastes, and authorization and management procedures for tailings facilities. Aspects of tailings facilities design, water management and slurry transport, non-destructive and minimally intrusive testing methods, monitoring and the application of sensors, intervention and remediation options were considered in TAILSAFE. A risk reduction framework (the TAILSAFE Parameter Framework) was established to contribute to the avoidance of catastrophic accidents and hazards from tailings facilities. Tailings from the mining and primary processing of metals, minerals and coal were included within the scope of TAILSAFE. The project focused on the avoidance of hazards by developing procedures and methods for investigating and improving the stability of tailings dams and tailings bodies. KW - Mining KW - Extractive industry KW - Tailings KW - Tailings management facility KW - Tailings pond KW - Non-destructive testing KW - Site-investigation KW - Neutron logging KW - Parameter framework PY - 2008 U6 - https://doi.org/10.1080/15320380802143922 SN - 1532-0383 SN - 1549-7887 VL - 17 IS - 4 SP - 323 EP - 345 PB - Taylor & Francis CY - Philadelphia, Pa. AN - OPUS4-17918 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Kruschwitz, Sabine A1 - Niederleithinger, Ernst A1 - Trela, Christiane A1 - Wöstmann, Jens T1 - Complex resistivity (CR) behavior of building material - first results of field scale measurements T2 - Near Surface 2008 - 14th European Meeting of Environmental and Engineering Geophysics (EAGE) CY - Kraków, Poland DA - 2008-09-15 KW - Building materials KW - Damage KW - Non-destructive testing KW - Complex resistivity PY - 2008 SN - 978-90-73781-56-6 SP - 1 EP - 4 AN - OPUS4-17908 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Taffe, Alexander A1 - Behrens, Matthias A1 - Stoppel, Markus T1 - Pfahlprüfung: Grenzbereich zwischen Bauingenieurwesen und Geophysik T2 - Jahrestagung Deutsche Geophysikalische Gesellschaft (DGG) CY - Graz, Austria DA - 2005-02-21 PY - 2005 AN - OPUS4-7177 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Taffe, Alexander A1 - Katzenbach, R. A1 - Klingmüller, O. A1 - Niederleithinger, Ernst T1 - Untersuchungen an Fundamentalplatten und Pfahlgründungen im Hinblick einer Wiedernutzung N2 - The re-use of foundations on urban sites contributes to the Sustainable Development in construction. Investigations at potential parts to be re-used should be performed in time to influence the planning process. Non-destructive testing methods in civil engineering (NDT-CE) provide necessary information about location, dimension and condition of existing foundations. Thickness measurement of foundation slabs, imaging of their geometry is dealt with as well as localisation of voids and reinforcement beyond surface-near layers. For pile foundations this article introduces NDT-CE methods to measure the pile length or deviation of an expected length as well as to determine the pile integrity. Practical examples of typical testing problems are given and show the possibilities as well as limits of a method. This guidance enables the planning engineer to consider the use of NDT-CE methods and to assure their successful application. KW - Wiedernutzung KW - Fundamente KW - Pfahlgründungen KW - Dickenmessung KW - Pfahlintegrität KW - ZfPBau KW - Zerstörungsfreie Prüfung KW - RuFUS PY - 2005 U6 - https://doi.org/10.1002/best.200590207 SN - 0005-9900 SN - 1437-1006 VL - 100 IS - 9 SP - 757 EP - 770 PB - Ernst CY - Berlin AN - OPUS4-10892 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Kruschwitz, Sabine A1 - Niederleithinger, Ernst T1 - Multi-channel Spectral Induced Polarization (SIP) Measurements on Tailings Dams T2 - Near Surface 2005 CY - Palermo, Italy DA - 2005-09-05 KW - Spectral Induced Polarization KW - Tailings Facilities KW - Dam Stability KW - SASW PY - 2005 SN - 90-73781-91-4 SP - 4 pages PB - Co Productions CY - Houten AN - OPUS4-10911 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Kruschwitz, Sabine A1 - Behrens, Matthias T1 - Spectral induced polarization (SIP) measurements for stability assessment of tailings dams T2 - 18th Annual Meeting SAGEEP, Symposium on the Application of Geophysics to Engineering and Environmental Problems, "Geophysical Solutions for Today´s Challenges" CY - Atlanta, GA, USA DA - 2005-04-03 KW - Geophysik KW - Geotechnik KW - Halden KW - Umwelt KW - Bergbau PY - 2005 SP - 298 EP - 305 PB - Environmental and Engineering Geophysical Society CY - Atlanta AN - OPUS4-11469 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Taffe, Alexander A1 - Fechner, Th. T1 - Improved parallel seimic technique for foundation assessment T2 - 18th Annual Meeting SAGEEP, Symposium on the Application of Geophysics to Engineering and Environmental Problems, "Geophysical Solutions for Today´s Challenges" CY - Atlanta, GA, USA DA - 2005-04-03 KW - Parallel Seismik KW - Fundamente KW - Pfahlprüfung KW - Baugrund PY - 2005 SP - 1004 EP - 1011 PB - Environmental and Engineering Geophysical Society CY - Atlanta AN - OPUS4-11470 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Niederleithinger, Ernst T1 - Neuer Arbeitskreis Induzierte Polarisation (IP) der DGG KW - Induzierte Polarisation KW - Geophysik KW - Arbeitskreis KW - Kalibrierung KW - Referenzmaterialien PY - 2005 SN - 1618-8721 IS - 1 SP - 19 PB - Deutsche Glastechnische Gesellschaft CY - Offenbach AN - OPUS4-7489 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Numerical simulation of low strain dynamic pile tests T2 - Stresswave 2008, Application of Stress Wave Theory to Piles CY - Lisbon, Portugal DA - 2008-09-08 PY - 2008 AN - OPUS4-18038 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Krause, Martin A1 - Dérobert, X. A1 - Hugenschmidt, J. A1 - Moczko, A. A1 - Niederleithinger, Ernst A1 - Taffe, Alexander ED - L. Binda, ED - M. di Prisco, ED - R. Felicetti, T1 - Benchmark for thickness measurement of concrete elements T2 - 1st International RILEM Conference, on Site Assessment of Concrete, Masonry and Timber Structures (SACoMaTiS 2008) CY - Varenna, Italy DA - 2008-09-01 KW - Thickness measurement KW - Radar KW - Ultrasonic Echo KW - Impact-Echo and Low Strain Techniques PY - 2008 SN - 978-2-35158-062-2 VL - 1 IS - PRO 59 SP - 357 EP - 366 PB - RILEM Publications AN - OPUS4-18030 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Kruschwitz, Sabine A1 - Wiggenhauser, Herbert T1 - Charakterisierung von Feuchte- und Salzbelastungen in Baumaterial mit Impedanzspektroskopie T2 - Workshop Innovative Feuchtemessung in Forschung und Praxis 2 (Feuchtetag 2006) CY - Karlsruhe, Germany DA - 2006-10-17 PY - 2006 AN - OPUS4-14116 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Kruschwitz, Sabine A1 - Martin, Tina A1 - Trela, Christiane A1 - Berta, Z. A1 - Prohany, Z. T1 - Geophysical methods for the investigation of tailings sites T2 - Materials Congress 2006, Carlton House Terrace CY - London, England DA - 2006-04-05 PY - 2006 AN - OPUS4-14118 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Niederleithinger, Ernst A1 - Taffe, Alexander T1 - Early stage elastic wave velocity of concrete piles N2 - The low-strain pile integrity testing method is used for quality control of new piles as well as length and integrity check for old piles. If no other methods for calibration are available, the accuracy and reliability of the techniques depend on a good estimation of the elastic wave velocity. In practice it is assumed that piles can be tested 7 days after casting and that the velocity is almost constant in all piles of one kind in a construction project. Recent measurements at the BAM test site in Horstwalde, Germany, showed that the 7 day criterion is not generally applicable. KW - Non-destructive testing KW - Concrete piles KW - Pile integrity testing KW - Foundation PY - 2006 U6 - https://doi.org/10.1016/j.cemconcomp.2006.02.013 SN - 0958-9465 SN - 1873-393X VL - 28 IS - 4 SP - 317 EP - 320 PB - Elsevier CY - Barking, Essex AN - OPUS4-14039 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Taffe, Alexander T1 - Pfahl- und Fundamentprüfung T2 - Bauwerksdiagnose 2006 CY - Berlin, Germany DA - 2006-02-23 PY - 2006 AN - OPUS4-14086 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Numerical simulation of non-destructive foundation pile tests T2 - ECNDT Berlin 2006, 9th European Conference on NDT CY - Berlin, Germany DA - 2006-09-25 PY - 2006 AN - OPUS4-14087 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Taffe, Alexander T1 - Validation of NDT methods for foundation testing at the BAM site Horstwalde T2 - RuFUS Conference CY - Watford, England DA - 2006-10-19 PY - 2006 AN - OPUS4-14088 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Taffe, Alexander T1 - NDT methods in the foundation re-use process T2 - RuFUS Conference CY - Watford, England DA - 2006-10-19 PY - 2006 AN - OPUS4-14089 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Taffe, Alexander T1 - Improvement and validation of foundation NDT methods T2 - 2006 NDE Conference on Civil Engineering CY - St. Louis, MO, USA DA - 2006-08-14 PY - 2006 AN - OPUS4-14180 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Numerical Simulation of Non-Destructive Foundation Pile Tests T2 - 9th European Conference on NDT CY - Berlin, Germany DA - 2006-09-25 KW - NDT KW - Foundation KW - Pile KW - Integrity testing KW - Parallel seismics KW - Numerical KW - CEFIT KW - Simulation PY - 2006 UR - http://www.ndt.net/article/ecndt2006/doc/P17.pdf SN - 3-931381-86-2 SP - 1(?) EP - 8(?) PB - European Federation for Non-Destructive Testing CY - Berlin AN - OPUS4-14213 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Niederleithinger, Ernst A1 - Taffe, Alexander ED - Butcher, A. ED - Powell, J. ED - Skinner, H. T1 - Validation of NDT methods for foundation testing at the BAM site Horstwalde T2 - International Conference "Reuse of Foundations for Urban Sites" CY - Watford, England, UK DA - 2006-10-19 KW - NDT KW - Ultrasonics KW - Pile KW - Slab KW - Test site KW - Integrity testing KW - Parallel seismics PY - 2006 SN - 1-86081-938-9 N1 - Serientitel: Building Research Establishment X – Series title: Building Research Establishment X IS - 414 SP - 123 EP - 132 PB - IHS BRE Press CY - Bracknell AN - OPUS4-14214 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Niederleithinger, Ernst A1 - Taffe, Alexander ED - Butcher, A. ED - Powell, J. ED - Skinner, H. T1 - NDT methods in the foundation reuse process T2 - International Conference "Reuse of Foundations for Urban Sites" CY - Watford, England, UK DA - 2006-10-19 KW - NDT KW - Foundation KW - Pile KW - Slab KW - Ultrasonics KW - Integrity testing KW - Parallel seismics PY - 2006 SN - 1-86081-938-9 N1 - Serientitel: Building Research Establishment X – Series title: Building Research Establishment X IS - 414 SP - 115 EP - 122 PB - IHS BRE Press CY - Bracknell AN - OPUS4-14215 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Niederleithinger, Ernst A1 - Taffe, Alexander T1 - Zerstörungsfreie Pfahl- und Fundamentprüfung im Hinblick auf Wiedernutzung T2 - DGZfP-Fachtagung Bauwerksdiagnose "Praktische Anwendungen Zerstörungsfreier Prüfungen" CY - Berlin, Deutschland DA - 2006-02-22 KW - Zerstörungsfreie Prüfung KW - Fundament KW - Pfahl KW - Platte KW - Ultraschall KW - Integritätsprüfung KW - Parallel Seismic PY - 2006 SN - 3-931381-71-4 SP - 1(?) EP - 8(?) PB - DGZfP CY - Berlin AN - OPUS4-14216 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Kruschwitz, Sabine A1 - Zacher, Gerhard T1 - Mauerwerksuntersuchungen mit spektraler induzierter Polarisation (SIP) T2 - XII. Arbeitsseminar Hochauflösende Geoelektrik, Kloster Nimbschen CY - Leipzig, Germany DA - 2006-10-09 PY - 2006 AN - OPUS4-14247 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Kruschwitz, Sabine T1 - Charakterisierung von Feuchte- und Salzbelastungen in Baumaterial durch Impedanzspektroskopie T2 - 1. Symposium Impedanzspektroskopie, Grundlagen und Anwendungen CY - Essen, Germany DA - 2006-05-16 PY - 2006 AN - OPUS4-14248 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Niederleithinger, Ernst A1 - Taffe, Alexander T1 - Improvement and Validation of Foundation NDT Methods T2 - NDE Conference on Civil Engineering CY - St. Louis, Missouri, USA DA - 2006-08-14 KW - Foundations KW - Piles KW - Slabs KW - NDT KW - Integrity testing KW - Ultrasonics KW - Parallel seismics PY - 2006 SN - 1-57117-148-7 SP - 506 EP - 512 PB - ASTM CY - St. Louis AN - OPUS4-14271 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Helmerich, Rosemarie T1 - Sustainable Bridges - NDT as a tool to assist railway bridge management T2 - 2006 NDE Conference on Civil Engineering CY - St. Louis, MO, USA DA - 2006-08-14 PY - 2006 AN - OPUS4-14276 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kruschwitz, Sabine A1 - Niederleithinger, Ernst A1 - Wiggenhauser, Herbert ED - Nüesch, R. T1 - Charakterisierung von Feuchte- und Salzbelastungen in Baumaterial durch Impedanzspektroskopie T2 - Charakterisierung von Feuchte- und Salzbelastungen in Baumaterial durch Impedanzspektroskopie CY - Karlsruhe, Deutschland DA - 2006-10-17 KW - Impedanzspektroskopie KW - Spektrale Induzierte Polarisation KW - SIP KW - Feuchte KW - Mauerwerk KW - Salzgehalt PY - 2006 SP - 185 EP - 192 PB - Aedificatio Verl. CY - Karlsruhe AN - OPUS4-14378 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Numerische Simulation von Fundamentpfahlprüfungen T2 - Jahrestagung Deutsche Geophysikalische Gesellschaft CY - Aachen, Germany DA - 2007-03-26 PY - 2007 AN - OPUS4-14680 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Weller, Andreas A1 - Stötzner, U. A1 - Fechner, Th. A1 - Lorenz, B. A1 - Lewis, R. A1 - Nießen, J. T1 - Schwachstellenanalyse an Flussdeichen T2 - Jahrestagung Deutsche Geophysikalische Gesellschaft CY - Aachen, Germany DA - 2007-03-26 PY - 2007 AN - OPUS4-14682 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Helmerich, Rosemarie A1 - Casas, J. T1 - New methods for inspection and condition assessment T2 - International Conference Sustainable Bridges CY - Wroclaw, Poland DA - 2007-10-10 PY - 2007 AN - OPUS4-16145 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - The parallel seismic technique for determination of foundation pile lenght T2 - Near Surface 2008 - 14th European Meeting of Environmental and Engineering Geophysics CY - Kraków, Poland DA - 2008-09-15 PY - 2008 AN - OPUS4-17876 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Weller, Andreas A1 - Lewis, R. T1 - Evaluierung geophysikalischer Verfahren zur Strukturuntersuchung von Flussdeichen T2 - 68. Jahrestagung der Deutschen Geophysikalischen Gesellschaft (DGG) CY - Freiberg, Germany DA - 2008-03-03 PY - 2008 AN - OPUS4-17829 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Das Parallel-Seismic-Verfahren zur Bestimmung der Länge von Fundamentpfählen T2 - 68. Jahrestagung der Deutschen Geophysikalischen Gesellschaft (DGG) CY - Freiberg, Germany DA - 2008-03-03 PY - 2008 AN - OPUS4-17830 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Kruschwitz, Sabine A1 - Niederleithinger, Ernst T1 - Assessment of salt and moisture stone damages using complex resistivity measurements T2 - International Conference on Salt Weathering on Buildings and Stone Sculptures CY - Copenhagen, Denmark DA - 2008-10-22 KW - Complex resistivity KW - Bricks KW - Sandstone KW - Salt decay KW - Moisture content PY - 2008 SN - 9788778772732 SP - 177 EP - 185 AN - OPUS4-18246 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Kruschwitz, Sabine A1 - Niederleithinger, Ernst T1 - Charaktersierung von Feuchte- und Salzbelastungen in Baumaterial durch Impedanzspektroskopie T2 - DGZfP-Fachtagung Bauwerksdiagnose "Praktische Anwendungen Zerstörungsfreier Prüfungen" CY - Berlin, Deutschland DA - 2006-02-22 KW - Spektrale Induzierte Polarisation KW - Baumaterial KW - Feuchte KW - Salz PY - 2006 SN - 3-931381-71-4 SP - 1 EP - 8(?) PB - DGZfP CY - Berlin AN - OPUS4-12210 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Systematische Evaluierung existierender und innovativer Methoden zur Schwachstellenanalyse und Strukturerkennung von Deichen - Das Projekt DEISTRUKT T2 - RIMAX-Seminar (Risikomanagement extremer Hochwasserereignisse, BMBF-Förderaktivität) auf der "acqua alta" 3. Internationale Fachmesse und Kongress für Hochwasserschutz, Klimafolgen und Katastrophenmanagement CY - Hamburg, Germany DA - 2006-09-14 PY - 2006 AN - OPUS4-13992 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wiggenhauser, Herbert A1 - Niederleithinger, Ernst T1 - Innovative ultrasonic techniques for inspection and monitoring of large concrete structures N2 - Ultrasonic echo and transmission techniques are used in civil engineering on a regular basis. New sensors and data processing techniques have lead to many new applications in the structural investigation as well as quality control. But concrete structures in the nuclear sector have special features and parameters, which pose problems for the methods and instrumentation currently available, e.g. extreme thickness, dense reinforcement, steel liners or special materials. Several innovative ultrasonic techniques have been developed to deal with these issues at least partly in lab experiments and pilot studies. Modern imaging techniques as multi-offset SAFT have been used e. g. to map delaminations. Thick concrete walls have successfully been inspected, partly through a steel liner. Embedded ultrasonic sensors have been designed which will be used in monitoring networks of large concrete structures above and below ground. In addition, sensitive mathematical methods as coda wave interferometry have been successfully evaluated to detect subtle changes in material properties. Examples of measurements and data evaluation are presented. KW - Automated scanning systems KW - Multi-Offset Array KW - Enhanced Imaging KW - Embedded ultrasonic sensors PY - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-290513 SN - 2100-014X VL - 56 SP - 04004-1 EP - 04004-9 PB - EDP Sciences CY - Les Ulis AN - OPUS4-29051 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Wunderlich, Carolin T1 - Influence of small temperature variations on the ultrasonic velocity in concrete N2 - Ultrasonic methods are valuable tools for quality assessment and structural imaging of concrete. In such applications, accurate and reliable determination of ultrasonic wave velocities is essential, as they are affected by various experimental and environmental factors. In this research coda wave interferometry (CWI) was used to determine the influence of temperature (0 to 50 °C) on ultrasonic wave velocity in concrete samples. A resolution of better than 10-4 was achieved in the measurement of relative velocity changes. Reversibility and repeatability as well as the influence of moisture were taken into account. In addition the influence of sensor (transmitter and receiver) positioning errors on the results of the interferometric algorithm was evaluated as well as the benefit of newly developed, permanently embedded sensors. The presented results can be used to evaluate and refine data from ultrasonic monitoring systems. T2 - 39th Annual review of progress in quantitative nondestructive evaluation CY - Denver, Colorado, USA DA - 15.07.2012 KW - Ultrasonic KW - Concrete KW - Scattering KW - Coda wave interferometry KW - Temperature PY - 2013 SN - 978-0-7354-1129-6 U6 - https://doi.org/10.1063/1.4789074 SN - 0094-243X SN - 1551-7616 N1 - Serientitel: AIP conference proceedings – Series title: AIP conference proceedings VL - 1511 SP - 390 EP - 397 AN - OPUS4-29052 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kruschwitz, Sabine A1 - Niederleithinger, Ernst A1 - Trela, Christiane A1 - Wöstmann, Jens T1 - Use of complex resistivity tomography for moisture monitoring in a flooded masonry specimen N2 - Moisture ingress is one of the major deteriorating factors for building materials. Today, the only approved way to assess such damage is the gravimetric Darr method, which is essentially destructive. Substantial progress has been made using the geophysical complex-resistivity method, which can be applied non-destructively and provides spatial information along two-dimensional sections, rather than punctual along one borehole. Considerable advantages of complex resistivity are its sensitivity to textural properties, as well as the pore-fluid chemistry of wet, porous media. In a comprehensive laboratory study, and later in field scale experiments, it could be shown that complex resistivity may even be able to distinguish between salt content and saturation degree in a single measurement. A comparison with complementary nondestructive testing techniques points to the benefit and further research to be explored in multimethodical approaches. KW - Moisture KW - Salt KW - Masonry KW - Damage KW - Electrical resistivity KW - Radar KW - Radiography KW - Microwaves KW - Ground-penetrating radar KW - Microwave transmission PY - 2012 U6 - https://doi.org/10.1061/(ASCE)IS.1943-555X.0000053 SN - 1076-0342 SN - 1943-555X VL - 18 IS - 1 (Special issue) SP - 2 EP - 11 CY - New York, NY AN - OPUS4-29536 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Geophysikalische Deichuntersuchungen: Evaluierung von Verfahren und Anwendungshinweise T2 - 2. Internationales Symposium zur Wasserwirtschaft CY - Berlin, Germany DA - 2009-04-01 PY - 2009 AN - OPUS4-19223 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Tronicke, J. T1 - Inversion von Laufzeitdaten des Parallel-Seismik Verfahren T2 - Jahrestagung Deutsche Geophysikalische Gesellschaft CY - Kiel, Germany DA - 2009-03-23 PY - 2009 AN - OPUS4-19225 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Niederleithinger, Ernst A1 - Klingmüller, O. A1 - Schallert, M. A1 - Bobbe, A. ED - Petrukhin, V.P. ED - Ulitsky, V.M. ED - Kolybin, I.V. ED - Lisyuk, M.B. ED - Kholmyansky, M.L. T1 - Quality assurance of a secant pile wall using three different non-destructive test methods T2 - International geotechnical conference "Geotechnical challenges in megacities" CY - Moscow, Russia DA - 2010-06-07 KW - Bohrpfahlwand KW - Integritätsprüfung KW - Ultraschallmethode KW - Parallel Seismik KW - Pile wall KW - Integrity testing KW - Cross-hole sonic logging KW - Parallel seismics PY - 2010 SN - 978-5-9902005-2-4 VL - 3 SP - 1131 EP - 1136 PB - GRF AN - OPUS4-21620 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Amir, J. M. A1 - Hübner, M. T1 - Crosshole sonic logging of secant pile walls a feasibility study T2 - 23rd SAGEEP Symposium on the application of geophysics to engineering and environmental problems CY - Keystone, Colorado, USA DA - 2010-04-11 KW - Bohrpfahlwand KW - Pile wall KW - Ultraschallmethode KW - Cross-hole sonic logging PY - 2010 SN - 1554-8015 SP - 685 EP - 693 AN - OPUS4-21677 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Klingmüller, O. A1 - Schallert, M. A1 - Bobbe, A. T1 - Quality assurance of a secant pile wall using three different non-destructive test methods T2 - ISSMGE International Geotechnical Conference, Geotechnical Challenges in Megacities CY - Moscow, Russia DA - 2010-06-07 PY - 2010 AN - OPUS4-21687 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Müller, S. A1 - Krause, Martin A1 - Bohlen, T. T1 - Reverse Time Migration: A Seismic Imaging Technique Applied to Ultrasound Data T2 - NDE/NDT for Highway & Bridges: Structural Materials Technology (SMT) 2010 CY - New York City, NY, USA DA - 2010-08-16 PY - 2010 AN - OPUS4-21835 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Hübner, M. A1 - Amir, J. M. A1 - Müller, H. T1 - Qualitätssicherung von Pfahlwänden mit der Ultraschallmethode - eine Machbarkeitsstudie T2 - Fachtagung Bauwerksdiagnose CY - Berlin, Germany DA - 2010-02-18 PY - 2010 AN - OPUS4-20951 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Wunderlich, C. A1 - Fischer, J. A1 - Niederleithinger, Ernst A1 - Schallert, M. A1 - Klingmüller, O. T1 - Auswertung von Ringversuchen zur Vergleichbarkeit von Pfahlintegritätsprüfungen T2 - Fachtagung Bauwerksdiagnose - Praktische Anwendungen zerstörungsfreier Prüfungen und Zukunftsaufgaben CY - Berlin, Deutschland DA - 2010-02-18 KW - Bohrpfähle KW - Ringversuch KW - Integritätsprüfung PY - 2010 SN - 978-3-940283-24-5 IS - DGZfP-BB 121 SP - 1 EP - 8 CY - Berlin AN - OPUS4-20978 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Niederleithinger, Ernst A1 - Hübner, M. A1 - Amir, J. M. A1 - Müller, H. T1 - Qualitätssicherung von Pfahlwänden mit der Ultraschallmethode - eine Machbarkeitsstudie T2 - Fachtagung Bauwerksdiagnose - Praktische Anwendungen zerstörungsfreier Prüfungen und Zukunftsaufgaben CY - Berlin, Deutschland DA - 2010-02-18 KW - Bohrpfahlwand KW - Ultraschallmethode PY - 2010 SN - 978-3-940283-24-5 IS - DGZfP-BB 121 SP - 1 EP - 9 CY - Berlin AN - OPUS4-20979 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Fritsche, M. T1 - Measurement of Sheet Pile Length by Pile Integrity Testing and the Parallel Seismic Method T2 - Symposium on Engineering and Environmental Geophysics (SAGEEP) CY - Keystone, CO, USA DA - 2010-04-11 PY - 2010 AN - OPUS4-21166 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Amir, J. M. A1 - Hübner, M. T1 - Crosshole Sonic Logging of Secant Pile Walls - A Feasibility Study T2 - Symposium on Engineering and Environmental Geophysics (SAGEEP) CY - Keystone, CO, USA DA - 2010-04-11 PY - 2010 AN - OPUS4-21165 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Fritsche, M. T1 - Measurement of sheet pile length by pile integrity testing and the parallel seismic method T2 - 23rd SAGEEP Symposium on the application of geophysics to engineering and environmental problems CY - Keystone, Colorado, USA DA - 2010-04-11 KW - Spundwand KW - Sheet piles KW - Parallel seismic KW - Parallel-Seismik KW - Integrity testing KW - Integritätsprüfung PY - 2010 SN - 1554-8015 SP - 675 EP - 691 AN - OPUS4-22542 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Müller, Sabine A1 - Niederleithinger, Ernst A1 - Krause, Martin A1 - Bohlen, T. T1 - Reverse time migration: A seismic imaging technique applied to ultrasound data T2 - NDE/NDT for highways and bridges - Structural materials technology (SMT) CY - New York, USA DA - 2010-08-16 KW - Ultraschall KW - Rekonstruktion KW - Migration PY - 2010 SN - 978-1-57117-211-2 SP - 554 EP - 559 CY - Columbus, OH, USA AN - OPUS4-22543 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Niederleithinger, Ernst A1 - Tronicke, J. T1 - Travel-time inversion of parallel-seismic data for foundation length estimation T2 - Near Surface 2010 - 16th European Meeting of Environmental and Engineering Geophysics CY - Zurich, Switzerland DA - 2010-09-06 KW - Parallel Seismik KW - Fundamente KW - Pfähle KW - Inversion KW - Simulated annealing KW - Levenberg-Marquardt PY - 2010 SN - 978-90-73781-88-7 IS - P08 SP - 1 EP - 5 AN - OPUS4-22544 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Grandemenge, Julien A1 - Wilsch, Gerd T1 - Spatial clustering of LIBS data from concrete samples T2 - 6th International Conference on Laser-Induced Breakdown Spectroscopy CY - Memphis, TN, USA DA - 2010-09-13 PY - 2010 AN - OPUS4-22789 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Hübner, M. A1 - Kauther, R. T1 - Qualitätssicherung überschnittener Bohrpfahlwände mit der Ultraschallmethode am Beispiel der Schleuse Dörverden T2 - Bauwerksdiagnose 2012 an BAM Berlin, Praktische Anwendungen Zerstörungsfreier Prüfungen und Zukunftsaufgaben CY - Berlin, Germany DA - 2012-02-23 PY - 2012 AN - OPUS4-26887 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - The parallel seismic method for foundation length measurement: Useful also to check pile integrity? T2 - 9th International Conference on Testing and Design Methods for Deep Foundations CY - Kanazawa, Japan DA - 2012-09-18 PY - 2012 AN - OPUS4-26888 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Weller, Andreas A1 - Lewis, R. T1 - Geophysikalische Verfahren zur Strukturerkundung im Deichbau T2 - Jahreskongress 2012 Bund der Ingenieure für Wasserwirtschaft, Abfallwirtschaft und Kulturbau (BWK) e.V., Landesverband Brandenburg und Berlin e.V. CY - Frankfurt (Oder), Germany DA - 2012-06-01 PY - 2012 AN - OPUS4-26889 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Wunderlich, Carolin T1 - Influence of small Temperature Variations on the Ultrasonic Velocity in Concrete T2 - Quantitative Nondestructive Evaluation (QNDE) 2012 CY - Denver, CO, USA DA - 2012-07-15 PY - 2012 AN - OPUS4-26890 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Baeßler, Matthias A1 - Georgi, Steven A1 - Herten, M. T1 - Evaluation of the dynamic load test on bored piles in sandy soil T2 - IS-Kanazawa: The 9th International Conference on Testing and Design Methods for Deep Foundations CY - Kanazawa, Japan DA - 2012-09-18 PY - 2012 AN - OPUS4-27019 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Wunderlich, Carolin T1 - Temperature influence on ultrasonic velocity in concrete T2 - Noise and Diffuse Wavefields 2012 CY - Neustadt an der Waldnaab, Germany DA - 2012-11-11 PY - 2012 AN - OPUS4-27058 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Niederleithinger, Ernst A1 - Wunderlich, Carolin ED - Meßinger, J. T1 - Temperature influence on ultrasonic velocity in concrete T2 - 2nd Neustadt workshop CY - Neustadt a.d. Weinstraße DA - 2012-11-11 KW - Coda wave interferometry KW - Concrete KW - Temperature KW - Ultrasound KW - Velocity PY - 2012 SN - 0947-1944 VL - IV SP - 60 EP - 61 PB - Dt. Geophysikalische Ges. CY - Potsdam AN - OPUS4-27224 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst ED - Matsumoto, T T1 - The parallel seismic method for foundation length measurement: useful also to check pile integrity? T2 - 9th International conference on testing and design methods for deep foundations CY - Kanazawa, Japan DA - 2012-09-18 KW - Parallel seismic KW - Bored piles KW - Integrity KW - Low strain testing PY - 2012 SN - 978-4-89010-597-7 SP - 217 EP - 222 AN - OPUS4-27336 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Hübner, M. A1 - Müller, H. A1 - Kauther, R. T1 - Qualitätssicherung überschnittener Bohrpfahlwände mit der Ultraschallmethode am Beispiel der Schleuse Dörverden N2 - Überschnittene Bohrpfahlwände sind eine bewährte Konstruktionsmethode zur Herstellung tragender, hydraulisch dichter, tiefreichender Wände im Spezialtiefbau. Anders als bei Einzelpfählen gibt es bisher für die zerstörungsfreie Prüfung von Pfahlwänden keine etablierte Vorgehensweise. Erste Versuche an Baustellen und Modellkörpern zeigten das Potential der Ultraschallmethode (cross-hole sonic logging) zur Prüfung der Fugen über mehrere Pfähle hinweg. An der Schleusenbaustelle Dörverden ergab sich die Möglichkeit, das Verfahren unter Realbedingungen einzusetzen und die Ergebnisse visuell durch Kernbohrungen und nach Aushub zu evaluieren. Dabei wurden die meisten der prognostizierten Fehlstellen bestätigt. Die Resultate wurden in einer Neuauflage der entsprechenden Regelwerke berücksichtigt. T2 - Fachtagung Bauwerksdiagnose 2012 - Praktische Anwendungen zerstörungsfreier Prüfungen und Zukunftsaufgaben CY - Berlin, Deutschland DA - 2012-02-23 KW - Bohrpfahlwand KW - Ultraschallmethode PY - 2012 UR - http://www.bauwerksdiagnose2012.de/Portals/bwd2012/Dokumente/bb/v17.pdf SN - 978-3-940283-40-5 IS - Vortrag 17 SP - 1 EP - 11 CY - Berlin AN - OPUS4-27337 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Geophysical Methods for Non-Destructive Testing in Civil Engineering T2 - AGU Fall Meeting CY - San Francisco, CA, USA DA - 2013-12-09 PY - 2013 AN - OPUS4-29843 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Cotic, P. A1 - Jaglicic, Z. A1 - Niederleithinger, Ernst A1 - Effner, Ute A1 - Kruschwitz, Sabine A1 - Trela, Christiane A1 - Bosiljkov, V. T1 - Effect of moisture on the reliability of void detection in brickwork masonry using radar, ultrasonic and complex resistivity tomography N2 - The influence of moisture on the reliability of detection of larger voids in brickwork masonry was investigated using three non-destructive techniques: radar, ultrasonic and complex resistivity (CR). Radar and ultrasonic travel time tomography, as well as CR tomography, were performed over a specific cross section of a specimen containing a large void at a known position to determine the influence of different levels of moisture content in the brickwork on the wave velocities and the CR magnitude. We defined a numerical estimator to quantitatively determine the void detection efficiency from the images obtained when exposing the specimen to moisture. The results showed radar to be the most reliable technique for void detection in both dry and wet masonry, while CR performed much better in detecting larger air voids in wet masonry. KW - Radar KW - Ultrasonic and complex resistivity KW - Tomography KW - Masonry KW - Moisture KW - Void detection KW - Ultrasound PY - 2013 U6 - https://doi.org/10.1617/s11527-012-0011-3 SN - 1359-5997 SN - 1871-6873 VL - 46 IS - 10 SP - 1723 EP - 1735 PB - Springer CY - Dordrecht AN - OPUS4-29991 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Müller, Sabine T1 - Geophysik und Zerstörungsfreie Prüfung im Bauwesen T2 - Bauwerksdiagnose 2014 CY - Berlin, Germany DA - 2014-02-13 PY - 2014 AN - OPUS4-30195 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Algernon, D. A1 - Arndt, R. A1 - Ebsen, B. A1 - Feistkorn, S. A1 - Friese, M. A1 - Große, C. A1 - Kathage, S. A1 - Keßler, S. A1 - Kurz, J. A1 - Küttenbaum, Stefan A1 - Lohse, C. A1 - Maack, Stefan A1 - Niederleithinger, Ernst A1 - Schickert, M. A1 - Schröder, G. A1 - Taffe, A. A1 - Walther, A. A1 - Wilcke, M. A1 - Wolf, J. A1 - Wöstmann, Jens T1 - Richtlinie B-LF 01: Leitfaden zur Erstellung von Prüfanweisungen für die Zerstörungsfreie Prüfung im Bauwesen (ZfP Bau) N2 - Der vorliegende Leitfaden dient zur Unterstützung der Entwicklung und Umsetzung von Prüfanweisungen für ZfP-Verfahren im Bauwesen. Er gibt einen Überblick über Verwendungszweck, Erstellung und Inhalte von Prüfanweisungen unter Berücksichtigung einheitlicher Standardisierungsziele. KW - Prüfanweisung KW - Beton KW - Leitfaden PY - 2022 SN - 978-3-947971-23-7 SP - 1 EP - 9 PB - Deutsche Gesellschaft für Zerstörungsfreie Prüfung e.V. (DGZfP) CY - Berlin ET - 1. Aufl., April 2022 AN - OPUS4-54985 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Grohmann, Maria A1 - Niederleithinger, Ernst A1 - Buske, B. T1 - Application of Elastic Reverse Time Migration to Ultrasonic Echo Data in Civil Engineering N2 - To improve ultrasonic imaging of concrete structures, we transferred a seismic migration technique, the Reverse Time Migration (RTM), to non-destructive testing. A 2D elastic RTM algorithm was tested on synthetic ultrasonic echo data. Compared to the typically used synthetic aperture focusing technique (SAFT) as well as our acoustic RTM algorithm, the presented elastic RTM results show an enhancement in imaging vertical reflectors and complex features inside the 2D numerical concrete model. T2 - The International Symposium on Nondestructive Testing in Civil Engineering CY - Zurich, Switzerland DA - 16.08.2022 KW - Ultrasonic Echo Technique KW - Reverse Time Migration KW - Synthetic Aperture Focusing Technique PY - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-561147 UR - https://www.ndt.net/article/ndtce2022/paper/60699_manuscript.pdf SP - 1 EP - 6 AN - OPUS4-56114 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Epple, Niklas A1 - Niederleithinger, Ernst A1 - Fontoura Barroso, Daniel T1 - Coda Wave Interferometry for Monitoring Bridges with Embedded Ultrasonic Transducers – Lessons Learned at the Gänstorbrücke Bridge Ulm, Germany N2 - Ultrasonic Coda Wave interferometry has the potential to detect minute changes in scattering materials like concrete. By permanently installing ultrasonic transducers in concrete, DFG Research unit CoDA aims to develop methods for concrete damage assessment in Germany's aging infrastructure. To test the methods developed in simulations and laboratory experiments on a large scale, we have implemented several ultrasonic transducers at the Gänstorbrücke Ulm, one of Germany's most monitored road bridges. Since fall 2020 we are monitoring parts of the center of the Bridge, as well as an abutment, and compare the results to the commercial monitoring system. All data is recorded with a self-made data collection device, the so-called W-Box, and analyzed with different coda wave-based algorithms to detect signal and volumetric velocity changes. The long-term measurements show that the influence of temperature changes on strains and therefore ultrasound velocity changes calculated with coda waves can be monitored. The capabilities and limitations of the coda wave-based monitoring system are tested in a controlled experiment. Static loading using a truck with varying loads at several positions allows the calibration of the system to improve the detectability of possibly damaging loads and changes induced by this loading. A map of velocity change analyzing data from this load experiment shows that the influence of load on the material and strain distribution can be detected with array measurements. T2 - NDT-CE 2022 - The International Symposium on Nondestructive Testing in Civil Engineering CY - Zurich, Switzerland DA - 16.08.2022 KW - Coda Wave Interferometry KW - Ultrasound KW - Embedded sensors KW - Bridge Monitoring KW - Load Experiment PY - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-564531 SP - 1 EP - 8 AN - OPUS4-56453 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zhang, T. A1 - Sens-Schönfelder, C. A1 - Epple, Niklas A1 - Niederleithinger, Ernst T1 - Imaging of Small-Scale Heterogeneity and Absorption Using Adjoint Envelope Tomography: Results From Laboratory Experiments N2 - To complement the information provided by deterministic seismic imaging at length scales above a certain resolution limit we present the first application of adjoint envelope tomography (AET) to experimental data. AET uses the full envelopes of seismic records including scattered coda waves to obtain information about the distribution of absorption and small-scale heterogeneity which provide complementary information about the investigated medium. Being below the resolution limit this small-scale structure cannot be resolved by conventional tomography but still affects wave propagation by attenuating ballistic waves and generating scattered waves. Using ultrasound data from embedded sensors in a meter-sized concrete specimen we image the distribution of absorption and heterogeneity expressed by the intrinsic quality factor Q−1 and the fluctuation strength ɛ that characterizes the strength of the heterogeneity. The forward problem is solved by modeling the 2-D multiple nonisotropic scattering in an acoustic medium with spatially variable heterogeneity and attenuation using the Monte-Carlo method. Gradients for the model updates are obtained by convolution with the back-propagated envelope misfit using the adjoint formalism in analogy to full waveform inversion. We use a late coda time window to invert for absorption and an earlier time window to infer the distribution of heterogeneity. The results successfully locate an area of salt oncrete with increased scattering and concentric anomalies of intrinsic attenuation. The resolution test shows that the recovered anomalies constitute reasonable representations of internal structure of the specimen. KW - Ultrasound KW - Scattering KW - Tomography KW - Concrete KW - Heterogeneity PY - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-563163 SN - 2169-9313 VL - 127 IS - 11 SP - 1 EP - 21 PB - American Geophysical Union AN - OPUS4-56316 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lay, Vera A1 - Effner, Ute A1 - Niederleithinger, Ernst A1 - Arendt, J. A1 - Hofmann, M. A1 - Kudla, W. T1 - Ultrasonic quality assurance at magnesia shotcrete sealing structures N2 - Engineered barriers are a key element to enable safe nuclear waste disposal. One method currently under research for their construction is magnesia concrete applied in a shotcrete procedure. In this study, the ultrasonic echo method is evaluated as a means for quality assurance. Imaging of internal structures (backwall, boreholes) and defects, such as delamination, has successfully been achieved in the shotcrete. Additionally, detailed information about the potential cause of selected reflectors are obtained by phase analysis. In several test blocks of various sizes, no consistent concrete section boundaries have been found by ultrasonic imaging, which was verified by subsequent drilling and complementary tests. An experiment with artificial defects imitating cracks, air-filled voids, and material with lower density has been challenging and shows the limitations of the current methods. Although significant defects, such as a large delamination, are reliably identified, several smaller defects are not identified. Generally, ultrasonic imaging provides a suitable base as a mean for quality assurance during and after the construction of sealing structures. However, further developments are required to enhance the reliability of the method and a full validation is still pending. Still, the method has potential to increase the safety of nuclear waste repositories. KW - Ultrasound KW - Imaging KW - Engineered barrier systems KW - Underground KW - Shotcrete PY - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-563170 SN - 1424-8220 VL - 22 IS - 22 SP - 1 EP - 16 PB - MDPI CY - Basel AN - OPUS4-56317 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - PREDIS The pre-disposal management of radioactive waste N2 - This presentation summarizes the opbjectives and the progress of the EURATOM project PREDIS (pre-disposal management of radioactive waste) and its workpackage 7 in particular. Focus is on the development of wireless sensors for monitoring radioactive waste packages, measuring radiation, temperature, pressure and humidity. T2 - DigiDecom 2022 CY - Halden, Norway DA - 18.10.2022 KW - Radioactive waste KW - Monitoring KW - Wireless KW - RFID PY - 2022 AN - OPUS4-56321 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Guangliang, Y. A1 - Mahon, D. A1 - Gardner, S. T1 - Muon tomography applied to assessment of concrete structures: First experiments and simulations. N2 - Non-destructive techniques for reinforced or prestressed concrete inspection such as ultrasound or radar have found regular, successful practical application but sometimes suffer from limited resolution and accuracy, imaging artefacts or restrictions in detecting certain features. Until the 1980s X-ray transmission was used in case of special demands and showed a much better resolution than other NDT techniques. However, due to safety concerns and cost issues, this method is almost never used anymore. Muon tomography has received much attention recently. Novel detectors for cosmic muons and tomographic imaging algorithms have opened new fields of application. As a first step towards practical application in civil engineering and as a proof of concept we used an existing system to image the interior of a reference reinforced 600 kg concrete block. Even with a yet not optimized setup for this kind of investigation, the muon imaging results are at least of similar quality compared to ultrasonic and radar imaging, potentially even better. In a second step, we have performed simulations to assess the potential for a set of important testing problems such as grouting defects in tendon ducts. The next steps include the development of mobile detectors and optimizing acquisition and imaging parameters. T2 - NDT-CE 2022 CY - Zurich, Switzerland DA - 16.08.2022 KW - Muon tomography KW - Concrete KW - Inspection KW - Simulation PY - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-563224 UR - https://www.ndt.net/article/ndtce2022/paper/60943_manuscript.pdf SP - 1 EP - 8 PB - NDT.net AN - OPUS4-56322 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Guangliang, Y. A1 - Mahon, D. A1 - Gardner, S. T1 - Muon tomography applied to assessment of concrete structures: First experiments and simulations. N2 - Non-destructive techniques for reinforced or prestressed concrete inspection such as ultrasound or radar have found regular, successful practical application but sometimes suffer from limited resolution and accuracy, imaging artefacts or restrictions in detecting certain features. Until the 1980s X-ray transmission was used in case of special demands and showed a much better resolution than other NDT techniques. However, due to safety concerns and cost issues, this method is almost never used anymore. Muon tomography has received much attention recently. Novel detectors for cosmic muons and tomographic imaging algorithms have opened new fields of application. As a first step towards practical application in civil engineering and as a proof of concept we used an existing system to image the interior of a reference reinforced 600 kg concrete block. Even with a yet not optimized setup for this kind of investigation, the muon imaging results are at least of similar quality compared to ultrasonic and radar imaging, potentially even better. In a second step, we have performed simulations to assess the potential for a set of important testing problems such as grouting defects in tendon ducts. The next steps include the development of mobile detectors and optimizing acquisition and imaging parameters. T2 - NDT-CE 2022 CY - Zurich, Switzerland DA - 16.08.2022 KW - Muon tomography KW - Concrete KW - Inspection KW - Simulation PY - 2022 AN - OPUS4-56323 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schumacher, T. A1 - Niederleithinger, Ernst T1 - Combining Passive and Active Ultrasonic Stress Wave Monitoring Techniques: Opportunities for Condition Evaluation of Concrete Structures N2 - Concrete structures are invaluable assets to a society and managing them efficiently and effectively can be supported by information gathered through structural health monitoring (SHM). In this paper, a combined approach based on passive, i.e., acoustic emission (AE), and active, i.e., ultrasonic stress wave (USW) monitoring techniques for application to concrete structures is proposed and evaluated. While AE and USW are based on the same underlying physics, i.e., wave motion in solids, they differ fundamentally with respect to the nature of the source. For the former, external stimuli such as mechanical loads or temperature cause the rapid release of energy from initially unknown locations. As a result, AE events are unique and cannot be repeated. For the latter, a known source at a known location is employed at a specified time. This approach is thus controlled and repeatable. It is argued that a combination of these two techniques has the potential to provide a more comprehensive picture of ongoing fracture processes, damage progression, as well as slowly occurring aging and degradation mechanisms. This combined approach does thus promise new opportunities to support condition assessment of concrete structures. After providing an overview and comparison of the two techniques, results, and observations from a full-scale laboratory experiment and an in-service bridge monitoring study are discussed to demonstrate the promise of the proposed combined monitoring approach. Finally, suggestions for further work are presented. T2 - NDT-CE 2022 CY - Zurich, Switzerland DA - 16.08.2022 KW - Ultrasound KW - Acoustic emission KW - Concrete structures KW - Monitoring PY - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-563242 UR - https://www.ndt.net/article/ndtce2022/paper/61607_manuscript.pdf SP - 1 EP - 11 PB - NDT.net AN - OPUS4-56324 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Landis, E. A1 - Hassefras, Emiel A1 - Oesch, Tyler A1 - Niederleithinger, Ernst T1 - A Microstructural Basis for Diffuse Ultrasound in Concrete N2 - Attenuation of ultrasonic signals in concrete has the potential to carry much information about the microstructure of the material. In this work a series of concrete specimens of varying porosities and pore size distributions were internally imaged with x-ray computed tomography (CT), and then subsequently examined with throughtransmission ultrasound. The CT images were used to quantify both capillary porosity of cement paste as well as internal interfaces that are likely to produce elastic wave scattering. Ultrasound signals were represented as a diffusion process such that absorption and scattering attenuation could be isolated. As implemented, the diffusion model was a poor predictor of capillary porosity, while diffusivity was a reasonable predictor of scattering interfaces. Diffusivity was found to scale extremely well with small scale porosity, which made it a good predictor of compressive strength. T2 - NDT-CE 2022 CY - Zurich, Switzerland DA - 16.08.2022 KW - Concrete KW - X-ray tomography KW - Ultrasound PY - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-563371 UR - https://www.ndt.net/article/ndtce2022/paper/61592_manuscript.pdf SP - 1 EP - 4 PB - NDT.net AN - OPUS4-56337 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Imani, A. A1 - Niederleithinger, Ernst A1 - Brown, M. C. T1 - Nondestructive Evaluation of Bridges without Structural Plans for Load Rating Purposes N2 - According to the NBI database, more than 21,000 in-service U.S. bridges lack sufficient structural documentation necessary for analytical load rating. Among these are a significant proportion of older prestressed concrete bridges. Given the lack of documentation on the reinforcing layout, such structures cannot be load rated analytically and are often subject to engineering judgement as the basis for rating. Otherwise, the typical approach for load rating such bridges is to conduct costly proof load testing and destructive probing together with making conservative assumptions. Therefore, any improvement to current practices will benefit DOTs and taxpayers alike. Accurately reconstructed 3D images of the girders to reflect the internal reinforcement could mitigate the need for costly, if not impractical, destructive testing and proof load testing, and help reduce dependency on conservative assumptions. This study examines a comprehensive NDE approach using ultrasonic tomography and GPR to aid in gathering structural information for load rating purposes. Different types of AASHTO and hollow core girders were tested. T2 - NDT-CE 2022 CY - Zurich, Switzerland DA - 16.08.2022 KW - Ultrasound KW - Radar KW - Bridges KW - Load rating PY - 2022 AN - OPUS4-56356 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Abraham, O. A1 - Niederleithinger, Ernst A1 - Schmidt, F. A1 - Sörensen, J.D. A1 - Thöns, S. A1 - Chapeleau, X. A1 - Ferria, H. T1 - Infrastar Training School on Fatigue and Reliability Analysis of Structures - Training for Assessment of Risk N2 - The Infrastar training school provides lectures and hands-on training to Master and PhD students, early-stage researchers and (young) professionals on all aspects of asset management of civil infrastructures with respect to fatigue of materials. It is organized yearly since 2019 and up to 20 profiles are selected to attend the 3.5-day training. A team of 7 teachers provides insight in multi-disciplinary and intersectoral basic concepts in three core fields, ranging from the design to the dismantling of the structures (bridges and wind turbines): 1. Monitoring and auscultation, 2. Structural and action models, 3. Reliability, risk and decision analyses. Each year, a recognized expert is invited to deliver a keynote lecture to raise interest in a specific aspect of one of the fields covered. The presentation is recorded and published on the training school website. T2 - NDT-CE 2022 CY - Zurich, Switzerland DA - 16.08.2022 KW - Doctoral School KW - Multidisciplinary KW - Fatigue KW - Reliability PY - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-563253 UR - https://www.ndt.net/article/ndtce2022/paper/61021_manuscript.pdf SP - 1 EP - 3 PB - NDT.net AN - OPUS4-56325 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Arndt, R.W. A1 - Grosse, C.U, A1 - Maehner, D. A1 - Niederleithinger, Ernst A1 - Taffe, A. A1 - Algernon, D. A1 - Berger, J. A1 - Kessler, S. A1 - Krueger, M. A1 - Kruschwitz, Sabine A1 - Ufermann-Wallmeier, D. A1 - Walther, A. T1 - Non-destructive testing in civil engineering: A memorandum for teaching at German-speaking universities N2 - This contribution summarizes actual developments and draft fundamental teaching topics in the field of nondestructive testing in civil engineering (NDT-CE). It is based on the first memorandum on teaching and research in the field of NDT-CE at German speaking universities and provides an overview of the academic education and highlights possible focuses, especially in teaching but also takes into account noteworthy developments and topics in research in the field of NDT-CE. Suggestions are given for the development and advancement of the teaching curricula in regards to a comprehensive and sound professional education of students in civil engineering and adjacent disciplines. T2 - NDT-CE 2022 CY - Zurich, Switzerland DA - 16.08.2022 KW - Curriculum KW - NDT-CE KW - University KW - Competencies PY - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-563269 UR - https://www.ndt.net/article/ndtce2022/paper/61547_manuscript.pdf SP - 1 EP - 10 PB - NDT.net AN - OPUS4-56326 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rabe, U. A1 - Pudovikov, S. A1 - Herrmann, H.-G. A1 - Wiggenhauser, H. A1 - Prabhakara, Prathik A1 - Niederleithinger, Ernst T1 - Evaluation of retroreflective corner echo for detection of surface breaking cracks in concrete by ultrasound N2 - The retroreflective corner echo is used, for example, in ultrasonic non-destructive testing of metals to find fatigue cracks in tubes or shafts. If the much weaker crack tip signal is additionally detected, the crack length can also be determined. A corner reflection occurs in cases of surface breaking cracks with predominantly perpendicular orientation to the surface. The intensity of the corner reflection depends on the angle of incidence and on the ultrasonic wave mode used. For the reliable detection of vertical surface breaking cracks in metals, transversal waves are commonly used, which propagate at an angle of 37° to 53° to the inspection surface. As shown in this contribution, the wide spread low frequency ultrasonic arrays with dry point contact sources available for ultrasonic testing of concrete also allow to receive corner echoes. These devices generate transversal waves in concrete structures with a large divergence of the sound field. A series of experiments was carried out with such dry point contact arrays on concrete specimens with artificial test defects and controlled induced cracks of different depths. The ultrasonic time-of-flight signals were recorded, exported and reconstructed utilising the SAFT (Synthetic Aperture Focusing Technique) algorithm. The SAFT reconstruction parameters were adjusted to visualize the corner echo indication. As will be shown, with this targeted processing, the reproducible detection of surface breaking cracks in concrete is possible. The retroreflective corner echo can thus be exploited in civil engineering for non-destructive inspection of concrete. T2 - NDT-CE 2022 CY - Zurich, Switzerland DA - 16.08.2022 KW - Concrete KW - Crack depth KW - Ultrasound KW - SAFT PY - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-563365 UR - https://www.ndt.net/article/ndtce2022/paper/27256_manuscript.pdf IS - 27256 SP - 1 EP - 4 PB - NDT.net AN - OPUS4-56336 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Prabhakara, Prathik A1 - Mielentz, Frank A1 - Stolpe, Heiko A1 - Behrens, Matthias A1 - Lay, Vera A1 - Niederleithinger, Ernst T1 - Validation of novel ultrasonic phased array borehole probe by using simulation and measurement N2 - Low-frequency ultrasonic testing is a well-established non-destructive testing (NDT) method in civil engineering for material characterization and the localization of cracks, reinforcing bars and delamination. A novel ultrasonic borehole probe is developed for in situ quality assurance of sealing structures in radioactive waste repositories using existing research boreholes. The aim is to examine the sealing structures made of salt concrete for any possible cracks and delamination and to localize built-in components. A prototype has been developed using 12 individual horizontal dry point contact (DPC) shear wave transducers separated by equidistant transmitter/receiver arrays. The probe is equipped with a commercially available portable ultrasonic flaw detector used in the NDT civil engineering industry. To increase the sound pressure generated, the number of transducers in the novel probe is increased to 32 transducers. In addition, the timed excitation of each transducer directs a focused beam of sound to a specific angle and distance based on the previously calculated delay time. This narrows the sensitivity of test volume and improves the signal-to-noise ratio of the received signals. In this paper, the newly designed phased array borehole probe is validated by beam computation in the CIVA software and experimental investigations on a half-cylindrical test specimen to investigate the directional characteristics. In combination with geophysical reconstruction methods, it is expected that an optimised radiation pattern of the probe will improve the signal quality and thus increase the reliability of the imaging results. This is an important consideration for the construction of safe sealing structures for the safe disposal of radioactive or toxic waste. KW - Ultrasound KW - Phased array KW - Concrete KW - Borehole PY - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-565722 SN - 1424-8220 VL - 22 IS - 24 SP - 1 EP - 16 PB - MDPI CY - Basel AN - OPUS4-56572 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fontoura Barroso, Daniel A1 - Epple, Niklas A1 - Niederleithinger, Ernst T1 - A Portable Low-Cost Ultrasound Measurement Device for Concrete Monitoring N2 - This paper describes a new ultrasonic measuring device called “W-Box”. It was developed based on the requirements of the DFG Forschergruppe (research unit) CoDA for a portable device for monitoring of concrete specimens, models and actual structures using embedded ultrasonic transducers as well as temperature and humidity sensors. The W-Box can send ultrasonic pulses with a variable frequency of 50–100 kHz to one selectable transducer and records signals from up to 75 multiplexed channels with a sample rate of 1 MHz and a resolution of 14 bits. In addition, it measures temperature and humidity with high accuracy, adjustable amplification, restarts automatically after a power failure and can be fully controlled remotely. The measured data are automatically stored locally on-site data quality checks and transferred to remote servers. The comparison of the W-Box with a laboratory setup using commercial devices proves that it is equally reliable and precise, at much lower cost. The W-Box also shows that their measurement capacities, with the used embedded ultrasonic transducers, can reach above 6 m in concrete. KW - Low-cost KW - Coda wave interferometry KW - Ultrasound KW - IoT KW - Non-destructive testing PY - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-546756 SN - 2411-5134 VL - 6 IS - 2 SP - 1 EP - 17 PB - MDPI CY - Basel, Switzerland AN - OPUS4-54675 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Mielentz, Frank A1 - Effner, Ute A1 - Oesch, Tyler A1 - Prabhakara, Prathik T1 - Ultraschallprüfung von Verschlussbauwerken im Salinar N2 - Zu jedem Endlager gehört die Entwicklung eines Verschlusskonzept. Im Endlager Morsleben und an anderer Stelle werden in Abhängigkeit vom Wirtsgestein verschiedene Materialien und Bauweisen für Streckenverschlüsse entwickelt und in großem Maßstab erprobt. Hierzu gehören auch Maßnahmen der Qualitätssicherung, die Informationen über Ausführung und Zustand der Versuchsbauwerke liefern. Hierzu werden von der Bundesanstalt für Materialforschung und -prüfung (BAM) für verschiedene Forschungsvorhaben und Prüfaufträge Methoden und Geräte getestet, verbessert und vor Ort unter Tage eingesetzt Die hier beschriebenen Verfahren lassen sich auch zu Untersuchungen im Wirtsgestein anwenden. T2 - Tage der Standortauswahl CY - Freiberg/S., Germany DA - 11.02.2021 KW - Endlager KW - Verschlussbauwerke KW - Qualitätssicherung KW - Ultraschall PY - 2021 AN - OPUS4-54166 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Wang, Xin A1 - Epple, Niklas A1 - Schumacher, T. A1 - Ahmend, S. A1 - Klikowicz, P. T1 - Ultrasonic coda wave monitoring of concrete structures: First experiences with large-scale experiments and real structures N2 - Ultrasonic monitoring, making use of the sensitivity of the coda of repeated transmission meas-urements to changes in stress, temperature, moisture, as well as localized or distributed damage, has gotten at-tention in structural health monitoring (SHM) research recently. Analysis methods such as coda wave inter-ferometry (CWI), including its nonlinear extension, have been shown to be able to measure ultrasonic wave velocity changes with a 1∙10-5 resolution, while indicators such as cross-correlation or cross-coherence have been used to distinguish between reversible and irreversible changes. Several small- and large-scale laboratory experiments have demonstrated that stress changes in structures can be captured or damage detected in a very early stage. The use of this technique for pre-warning before failure are currently under investigation, as well as detailed research on the physical causes and the connection between ultrasonic wave properties and materi-al/structural behavior. Recently, several of large-scale laboratory and real structures have been instrumented with embedded ultrasonic transducers to gather experience and evidence on how to use this technology in re-al-world applications. Preliminary results from installations on a new bridge, an existing bridge, a tunnel, a la-boratory earthquake test as well as a historic stadium in Germany, Poland, and the United States, respectively, are presented. Environmental influences (mainly temperature) and validation by load tests are discussed. T2 - IABMAS 2020 CY - Online meeting DA - 11.04.2021 KW - Ultrasound KW - Monitoring KW - Coda wave interferometry KW - Concrete KW - Bridges PY - 2021 AN - OPUS4-54167 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Niederleithinger, Ernst A1 - Wang, Xin A1 - Epple, Niklas A1 - Schumacher, T. A1 - Ahmend, S. A1 - Klikowicz, P. ED - Yokota, H. ED - Frangopol, D. W. T1 - Ultrasonic coda wave monitoring of concrete structures: First experiences with large-scale experiments and real structures N2 - Ultrasonic monitoring, making use of the sensitivity of the coda of repeated transmission meas-urements to changes in stress, temperature, moisture, as well as localized or distributed damage, has gotten at-tention in structural health monitoring (SHM) research recently. Analysis methods such as coda wave inter-ferometry (CWI), including its nonlinear extension, have been shown to be able to measure ultrasonic wave velocity changes with a 1∙10-5 resolution, while indicators such as cross-correlation or cross-coherence have been used to distinguish between reversible and irreversible changes. Several small- and large-scale laboratory experiments have demonstrated that stress changes in structures can be captured or damage detected in a very early stage. The use of this technique for pre-warning before failure are currently under investigation, as well as detailed research on the physical causes and the connection between ultrasonic wave properties and materi-al/structural behavior. Recently, several of large-scale laboratory and real structures have been instrumented with embedded ultrasonic transducers to gather experience and evidence on how to use this technology in re-al-world applications. Preliminary results from installations on a new bridge, an existing bridge, a tunnel, a la-boratory earthquake test as well as a historic stadium in Germany, Poland, and the United States, respectively, are presented. Environmental influences (mainly temperature) and validation by load tests are discussed. KW - Coda wave interferometry KW - Structural health monitoring KW - Ultrasound KW - Concrete KW - Bridges PY - 2021 SN - 978-0-367-23278-8 U6 - https://doi.org/10.1201/9780429279119-345 SP - 2525 EP - 2531 PB - Taylor & Francis CY - London, UK AN - OPUS4-54168 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Strangfeld, Christoph A1 - Hindersmann, I. A1 - Niederleithinger, Ernst T1 - Smart Bridge The duraBASt test bridge equipped with RFID-based sensors N2 - The duraBASt area at the highway intersection “Köln-Ost” is a large test field for road testing. It includes the duraBASt test bridge which is approximately 66 m long and 14.25 m broad. This bridge is part of the “road in the 21st Century” project and is equipped with several sensors for structural health monitoring. This feasibility study is carried out to investigate the prerequisites necessary for the constraction of intelligent bridges in the foture. Embedded sensors are able to measure quantities such as temperature, strain, moisture, corrosion, etc. In the presented work, the focus is set on passive RFID-based sensors. The communication and energy supply are realised by a mobile transmitter through the concrete cover. Hence, no cables or batteries are required. The sensors are designed to withstand the alkaline environment in concrete. Thus, moisture and corrosion values are measurable for several decades. T2 - 10th International Conference on Bridge Maintenance, Safety and Management CY - Online meeting DA - 11.04.2021 KW - RFID based sensors KW - Embedded sensors KW - Bridge Monitoring PY - 2021 U6 - https://doi.org/10.1201/9780429279119-321 VL - 2021 SP - 2353 EP - 2358 PB - Taylor & Francis Group CY - London AN - OPUS4-53816 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Epple, Niklas A1 - Fontoura Barroso, Daniel A1 - Hau, Julia A1 - Niederleithinger, Ernst ED - Cunha, A. ED - Caetano, E. T1 - Accounting for Long Term Environmental Influences on Ultrasonic Monitoring Measurements of Reinforced Concrete Constructions with Embedded Transducers N2 - Ultrasound measurements in concrete are a well-known technique in civil engineering and non-destructive testing. For consistent monitoring of a concrete structure, the common techniques, using external sensors can often not provide the appropriate degree of repeatability, as the surface of structures changes, and comparable coupling conditions cannot be guaranteed when a measurement is repeated after some time. By embedding ultrasound transducers in concrete, we aim to develop a strategy for long-term monitoring of infrastructure, especially bridges, as a supplement and extension to other techniques. Applying the so-called coda wave interferometry to these measurements we can detect subtle changes in the medium far beyond the Resolution limit of traditional time of flight methods. A smart sensor layout enables cost-efficient sensing of the entire area of interest. Embedding the transducers might remove uncertainties like coupling or positioning changes, while other challenges remain. Temperature and moisture content influence the structure and the transducers. These drifts need to be recorded and removed and good coupling must be ensured while not being able to visually inspect the sensor. In a multidisciplinary research group funded by the German Research Foundation, we aim to solve these problems on the way towards an ultrasound monitoring system for reinforced concrete structures. In various experiments in the lab and field, we determine the influence of temperature variations on the measurements and the equipment. As the monitoring task is the detection of irreversible damages - not reversible changes - a smart system requires a smart way of discrimination between permanent damages and reversible changes. With the data collected in these experiments, we present an approach to an environmental correction to ultrasound data to avoid a misinterpretation of these environmental changes as damage indicators. T2 - 10th International Conference on Structural Health Monitoring of Intelligent Infrastructure CY - Porto, Portugal DA - 30.06.2021 KW - Ultrasound KW - Coda Wave Interferometry (CWI) KW - Structural Health Monitoring KW - Embedded Sensors PY - 2021 SP - 1 EP - 7 AN - OPUS4-54007 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Lay, Vera A1 - Köpp, Christian A1 - Holt, E. A1 - Oksa, M. T1 - PREDIS: Innovative ways for pre disposal treatment and monitoring of low and medium radioactive waste N2 - The EURATOM PREDIS project (http://www.predis-h2020.eu, last access:TS1) targets the development and implementation of activities for predisposal treatment of radioactive waste streams other than nuclear fuel and high-level radioactive waste. It started on 1 September 2020 with a 4 year duration. The consortium includes 47 partners from 17 member states. The overall budget of the project is EUR23.7 million, with EC contribution of EUR 14 million. The PREDIS project develops and increases the technological readiness level (TRL) of treatment and conditioning methodologies for wastes for which no adequate or industrially mature Solutions are currently available, including metallic materials, liquid organic waste and solid organic waste. The PREDIS project also develops innovations in cemented waste handling and predisposal storage by testing and evaluating. The technical work packages align with priorities formulated within the Roadmap Theme 2 of EURAD (https://www.ejp-eurad.eu/TS2), Nugenia Global Vision (https://snetp.eu/nugenia/TS3) and with those identified by the project’s industrial end users group (EUG). The PREDIS will produce tools guiding decision making on the added value of the developed technologies and their impact on the design, safety and economics of waste management and disposal. Four technical work packages are focusing on specific waste types: metallic, liquid organic, solid organic, and cemented wastes. For the first three, the main aim lies in processing, stabilizing, and packaging the different waste streams, e.g. by using novel geopolymers, to deliver items which are in line with national and international waste acceptance criteria. In contrast, the fourth technical work package has a different focus. To provide better ways for a safe and effective monitoring of cemented waste packages including prediction tools to assess the future integrity development during predisposal activities, several digital tools are evaluated and improved. Safety enhancement (e.g. less exposure of testing personnel) and cost-effectiveness are part of the intended impact. The work includes but is not limited to inspection methods, such as muon imaging, wireless sensors integrated into waste packages as well as external package and facility monitoring, such as remote Fiber optic sensors. The sensors applied will go beyond radiation monitoring and include proxy parameters important for long-term integrity assessment (e.g. internal pressure). Sensors will also be made cost-effective to allow the installation of many more sensors compared to current practice. The measured data will be used in digital Twins of the waste packages for specific simulations (geochemical, integrity) providing a prediction of future behavior. Machine learning techniques trained by the characterization of older waste packages will help to connect the models to the current data. All data (measured and simulated) will be collected in a joint database and connected to a decision framework to be used at actual facilities. The presentation includes detailed information about the various tools under consideration in the Monitoring of cemented waste packages, their connection and first results of the research. T2 - Safety of Nuclear Waste Disposal CY - Berlin, Germany DA - 10.11.2021 KW - Radioactive waste disposal KW - RFID KW - Monitoring KW - Cemented waste PY - 2021 AN - OPUS4-54157 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - NDT CE from simple detectors to deep insight and quantitative structural assessment N2 - Non-destructive testing methods are available in civil engineering for decades to estimate concrete properties or to detect flaws and features. But recently we have seen the dawn of next-generation tools, methods, and applications. Some of them will be discussed in the web talk: – Better tools: deeper and more detailed insight into concrete constructions – Better methods: Quantitative use in probabilistic structural assessment – Better rules: Towards standardization, qualification, and certification – Better application: Digitalization and Elimination of the boundaries between NDT, SHM, and BIM: NDT-CE 4.0 Not enough? I might show, how cosmic rays might become a game-changer in NDT-CE. This live webinar record was provided by https://eurostruct.org T2 - Eurostruct Live Talk CY - Online meeting DA - 12.05.2021 KW - NDT-CE KW - Concrete KW - Ultrasound KW - Muons PY - 2021 AN - OPUS4-54158 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Sodeikat, C. A1 - Epple, Niklas A1 - Liao, Chun-Man A1 - Hindersmann, I. T1 - Acoustic emission and ultrasonic monitoring of a prestressed concrete bridge in its final years N2 - Many European bridges built in the 1950s, 60s and 70s must be re-placed in the next decade due to structural deficiencies, insufficient load capacity or other issues. However, the existing bridges must be used for another couple of years even if flaws and damages already have been detected. In Germany, several prestressed concrete bridges have been instrumented with acoustic emission detection systems to detect wire breaks and to provide early warning signs before failure. To evaluate and interpret the consequences of wire breaks additional instrumentation and accompanying measures as finite element modeling are required. At a bridge in southern Germany we have complemented such a system with active ultrasonic monitoring. Repeated ultrasonic measurements are evaluated with a very sensible algorithm called coda wave interferometry. This method, inspired by seismology, has been shown to deliver early warning signs in lab experiments. Large volumes of concrete can be monitored with a limited network of ultrasonic transducers. We will report on the installation, capabilities, and lim-itations as well as first results. T2 - 1st Conference of the European Association on Quality Control of Bridges and Structures (Eurostruct) CY - Padua, Italy DA - 29.08.2021 KW - Bridge KW - Concrete KW - Acoustic emission KW - Ultrasound KW - Monitoring PY - 2021 AN - OPUS4-54160 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Niederleithinger, Ernst ED - Meyendorf, N. ED - Ida, N. ED - Singh, R. ED - Vrana, J. T1 - NDE 4.0 in Civil Engineering N2 - Civil engineering industry is one of the most important industry sectors in the worldwide economy. It contributes significantly to the gross economic product and general employment. Even more important, it provides many of the basic needs of the society (e.g., housing, infrastructure, and protection from natural hazards). The concept of “Industry 4.0” or “Smart Production” has not yet made significant progress in the civil engineering industry. The designing, building, and operating processes are still widely dominated by the exchange of printed documents and drawings. Most objects (buildings and other constructions) are unique, and a large part of the production still requires a large amount of manual labor. As-built documentation and quality assurance are often neglected. Civil engineering is among the industry sectors with the lowest level of digitalization and the lowest gain in productivity. However, this is going to change. In the past decade, several drivers have challenged the ways clients, contractors, and authorities currently operate. These drivers include but are not limited to an increasing demand for serialization and automatization or the mandatory introduction of “Building Information Modeling” (BIM) in public procurement as well as the upcoming use of digital twins. NDE plays an increasing role in quality assurance, condition assessment, and monitoring of structures. However, with very few exceptions, applications are mostly nonstandardized and performed only at selected sites. To change this, the NDT-CE community including manufacturers, service providers, clients, and the scientific community must work consistently on open data formats, interfaces to BIM, standardization, and validated ways for a quantitative use of the results in the assessment of constructions. KW - NDE 4.0 KW - Civil engineering KW - BIM KW - IFC PY - 2021 SN - 978-3-030-48200-8 U6 - https://doi.org/10.1007/978-3-030-48200-8 SP - 1 EP - 14 PB - Springer Nature CY - Cham, Switzerland AN - OPUS4-54161 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Mielentz, Frank A1 - Effner, Ute A1 - Oesch, Tyler A1 - Prabhakara, Prathik T1 - Ultraschallprüfung von Verschlussbauwerken im Salinar N2 - Zu jedem Endlager gehört die Entwicklung eines Verschlusskonzept. Im Endlager Morsleben und an anderer Stelle werden in Abhängigkeit vom Wirtsgestein verschiedene Materialien und Bauweisen für Streckenverschlüsse entwickelt und in großem Maßstab erprobt. Hierzu gehören auch Maßnahmen der Qualitätssicherung, die Informationen über Ausführung und Zustand der Versuchsbauwerke liefern. Hierzu werden von der Bundesanstalt für Materialforschung und -prüfung (BAM) für verschiedene Forschungsvorhaben und Prüfaufträge Methoden und Geräte getestet, verbessert und vor Ort unter Tage eingesetzt. Die hier beschriebenen Verfahren lassen sich auch zu Untersuchungen im Wirtsgestein anwenden. T2 - Tage der Standortauswahl CY - Freiberg/S., Germany DA - 11.02.2021 KW - Endlager KW - Verschlussbauwerke KW - Qualitätssicherung KW - Ultraschall PY - 2021 AN - OPUS4-54165 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Zerstörungsfreie Prüfung von Fundamenten vor der Wiedernutzung N2 - Für die Qualitätssicherung von neuen Fundamenten steht eine Reihe von zerstörungsfreien Prüfverfahren zur Verfügung. Das Portfolio reicht von der einfachen Hammerschlagmethode („Pfahlintegritätsprüfung“) bis zu aufwändigen Ultraschallverfahren für meterstarke Fundamentplatten. Aber funktionieren die Verfahren auch im Bestand? Lassen sich die für Wieder-, Um- und Weiternutzung notwendigen Daten erfassen? Und wie werden die zerstörungsfreien Prüfverfahren erfolgreich in Untersuchungskonzepte integriert? Dies wird vor allem am Beispiel der Fundamente von Freileitungsmasten diskutiert. T2 - RWTH Forum Geotechnik CY - Online meeting DA - 20.1.2022 KW - Fundamente KW - Wiedernutzung KW - Zerstörungsfreie Prüfung KW - Parallelseismik KW - Pfahlgründung PY - 2022 AN - OPUS4-54236 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lay, Vera A1 - Baensch, Franziska A1 - Johann, Sergej A1 - Sturm, Patrick A1 - Mielentz, Frank A1 - Prabhakara, Prathik A1 - Hofmann, Detlef A1 - Niederleithinger, Ernst A1 - Kühne, Hans-Carsten T1 - SealWasteSafe: materials technology, monitoring techniques, and quality assurance for safe sealing structures in underground repositories N2 - Within the project SealWasteSafe, we advance construction materials and monitoring concepts of sealing structures applied for underground disposal of nuclear or toxic waste. As these engineered barriers have high demands concerning integrity, an innovative alkali-activated material (AAM) is improved and tested on various laboratory scales. This AAM has low reaction kinetics related to a preferential slow release of the heat of reaction in comparison to alternative salt concretes based on Portland cement or magnesium oxychloride cements. Hence, crack formation due to thermally induced strain is reduced. After successful laboratory scale analysis (Sturm et al., 2021), the AAM is characterised on a larger scale by manufacturing test specimens (100–300 L). Conventional salt concrete (DBE, 2004) and the newly developed AAM are compared using two specimen geometries, i.e. cylindrical and cuboid. A comprehensive multisensor monitoring scheme is developed to compare the setting process of AAM and salt concrete for these manufactured specimens. The analysed parameters include temperature and humidity of the material, acoustic emissions, and strain variations. Passive sensor systems based on radiofrequency identification technology (RFID) embedded in the concrete, enable wireless access to temperature and humidity measurements and are compared to conventional cabled systems. Additionally, fibre-optic sensors (FOS) are embedded to record strain, but also have potential to record temperature and moisture conditions. Part of this project aims at demonstrating the high reliability of sensors and also their resistance to highly alkaline environments and to water intrusion along cables or at sensor locations. Further technical improvements were implemented so that first results clearly show the scalability of the setting process from previous small-scale AAM experiments and particularly the high potential of the newly developed approaches. Furthermore, ultrasonic methods are used for quality assurance to detect obstacles, potential cracks and delamination. On the one hand, both active and passive ultrasonic measurements complement the results obtained from the multisensor monitoring scheme for the produced specimens. On the other hand, the unique large aperture ultrasonic system (LAUS) provides great depth penetration (up to nearly 10 m) and can thus be applied at in situ sealing structures built as a test site in Morsleben by the Federal Company for Radioactive Waste Disposal (Bundesgesellschaft für Endlagerung, BGE) as shown by Effner et al. (2021). An optimised field lay-out identified from forward modelling studies and advanced imaging techniques applied to the measured data will further improve the obtained results. To characterise the inside of the test engineered barrier and achieve a proof-of-concept, an ultrasonic borehole probe is developed to enable phased arrays that can further improve the detection of potential cracks. Modelling results and first analysis of semispherical specimens confirmed the reliability of the directional response caused by the phased arrays of the newly constructed ultrasonic borehole probe. Overall, the project SealWasteSafe improves the construction material, multisensor monitoring concepts and ultrasonics for quality assurance. This will help to develop safe sealing structures for nuclear waste disposal. The outcomes are particularly valuable for salt as a host rock but partly also transferrable to alternative conditions. T2 - Safe ND Interdisciplinary research symposium on the safety of nuclear disposal practices CY - Berlin, Germany DA - 10.11.2021 KW - Borehole probe KW - SealWasteSafe KW - Engineered barrier KW - Materials technology KW - Monitoring KW - AAM KW - Ultrasound PY - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-539172 VL - 1 SP - 127 EP - 128 PB - Copernicus AN - OPUS4-53917 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Büttner, C. A1 - Niederleithinger, Ernst A1 - Buske, S. A1 - Friedrich, C. T1 - Ultrasonic Echo Localization Using Seismic Migration Techniques in Engineered Barriers for NuclearWaste Storage N2 - In the framework of non-destructive-testing advanced seismic imaging techniques have been applied to ultrasonic echo data in order to examine the integrity of an engineered test-barrier designed to be used for sealing an underground nuclear waste disposal site. Synthetic data as well as real multi-receiver ultrasonic data acquired at the test site were processed and imaged using Kirchhoff prestack depth migration reverse time migration (RTM). In general, both methods provide a good Image quality as demonstrated by various case studies, however deeper parts within the test barrier containing inclined reflectors were reconstructed more accurately by RTM. In particular, the image quality of a specific target reflector at a depth of 8 m in the test-barrier has been significantly improved compared to previous investigations using synthetic aperture Focusing technique, which justifies the considerable computing time of this method. KW - Radioactive waste disposal KW - Engineered barrier KW - Ultrasound KW - Imaging KW - Crack detection PY - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-537956 SN - 0195-9298 VL - 40 IS - 4 SP - 1 EP - 10 PB - Springer AN - OPUS4-53795 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wang, Xin A1 - Chakraborty, J. A1 - Niederleithinger, Ernst T1 - Noise Reduction for Improvement of Ultrasonic Monitoring Using Coda Wave Interferometry on a Real Bridge N2 - Reinforced concrete bridges are iconic parts of modern infrastructure. They are designed for a minimum service life of 100 years. However, environmental factors and/or inappropriate use might cause overload and accelerate the deterioration of bridges. In extreme cases, bridges could collapse when necessary maintenance lacks. Thus, the permanent monitoring for structure health assessment has been proposed, which is the aim of structural health monitoring (SHM). Studies in laboratories have shown that ultrasonic (US) coda wave interferometry (CWI) using diffuse waves has high sensitivity and reliability to detect subtle changes in concrete structures. The creation of micro-cracks might be recognized at an early stage. Moreover, large-volume structures can be monitored with a relatively small number of US transducers. However, it is still a challenge to implement the CWI method in real SHM practical applications in an outdoor environment because of the complex external factors, such as various noise sources that interfere with the recorded signals. In this paper, monitoring data from a 36-m long bridge girder in Gliwice, Poland, instrumented with embedded US transducers, thermistors, and vibrating wire strain gauges, is presented. Noise estimation and reductionmethods are discussed, and the influence of traffic, as well as temperature variation, are studied. As a result, the relative velocity variation of US waves following the temperature change with a very high precision of 10−4% is shown, and a good bridge health condition is inferred. The influence of lightweight real traffic is negligible. The study verified the feasibility of the implementation of the CWI method on real bridge structures. KW - Ultrasound KW - Coda Wave Interferometry KW - Noise KW - Concrete KW - Bridge PY - 2021 U6 - https://doi.org/10.1007/s10921-020-00743-9 VL - 40 IS - 1 SP - Article number: 14 PB - Springer Nature AN - OPUS4-52052 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - News from NDT@BAM N2 - The presentation summarizes some recent research at BAM in the field of NDT in civil engineering. the firste xample decribes lab experiments on the degardation of concrete during tunnel fires. Radar measuremenst were sucessfully used to detect interior damage. The second example decribes the first ever experiment on using muon imaging to evaluate concrete constructions. T2 - TRB 100th Annual Meeting, Subcommittee AKB40(1) CY - Online meeting DA - 05.01.2021 KW - Non-destructive testing KW - Civil engineering KW - Tunnel fire KW - Radar KW - Muon imaging PY - 2021 AN - OPUS4-52053 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Vrana, J. T1 - ZfPBau 4.0 - Herausforderungen an die ZfP im Bauwesen im Rahmen der Digitalisierung N2 - Die ZfP ist im Bauwesen bisher deutlich weniger reguliert (und auch akzeptiert) als in anderen Industriebereichen. Zum Beispiel gibt für die meisten Prüfverfahren weder Normen noch ein allgemein akzeptiertes Ausbildungs- und Zertifizierungssystem. Dies hat auch Konsequenzen für die Digitalisierung. Im Gegensatz dazu wird im Bauwesen derzeit für viele Bereiche verbindlich ein neues Verfahren zur Unterstützung von Design, Planung, Herstellung und Betrieb eingeführt: BIM (Building Information Modeling). Der Vortrag beleuchtet das Spannungsfeld zwischen dem geringen Organisations- und Standardisierungsgrad und den neuen digitalen Möglichkeiten und stellt den neuen Arbeitskreis zur ZfP 4.0 im Bauwesen vor. Er beleuchtet auch, in welchen Bereichen die ZfP im Bauwesen von Entwicklungen aus „Industrie 4.0“ und der zerstörungsfreien Prüfung in anderen Anwendungsbereichen profitieren kann - z. B. bei Datenformaten, Datenarchivierung und Schnittstellen. T2 - TAE Fachkongress Digitale Transformation im Lebenszyklus der Verkehrsinfrastruktur CY - Esslingen, Germany DA - 29.06.2021 KW - ZfPBau KW - SHM KW - Industrie 4.0 KW - BIM KW - Datenbank PY - 2021 AN - OPUS4-52914 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Vrana, J. ED - Krieger, J. T1 - ZfPBau 4.0 – Herausforderungen an die ZfP im Bauwesen im Rahmen der Digitalisierung N2 - Die ZfP ist im Bauwesen bisher deutlich weniger reguliert (und auch akzeptiert) als in anderen Industriebereichen. Zum Beispiel gibt für die meisten Prüfverfahren weder Normen noch ein allgemein akzeptiertes Ausbildungs- und Zertifizierungssystem. Dies hat auch Konsequenzen für die Digitalisierung. Im Gegensatz dazu wird im Bauwesen derzeit für viele Bereiche verbindlich ein neues Verfahren zur Unterstützung von Design, Planung, Herstellung und Betrieb eingeführt: BIM (Building Information Modeling). Der Vortrag beleuchtet das Spannungsfeld zwischen dem geringen Organisations- und Standardisierungsgrad und den neuen digitalen Möglichkeiten und stellt den neuen Arbeitskreis zur ZfP 4.0 im Bauwesen vor. Er beleuchtet auch, in welchen Bereichen die ZfP im Bauwesen von Entwicklungen aus „Industrie 4.0“ und der zerstörungsfreien Prüfung in anderen Anwendungsbereichen profitieren kann - z. B. bei Datenformaten, Datenarchivierung und Schnittstellen. T2 - Fachkongress Digitale Transformation im Lebenszyklus der Verkehrsinfrastruktur CY - Esslingen, Germany DA - 29.06.2021 KW - ZfPBau KW - BIM KW - Datenbank KW - SHM KW - Industrie 4.0 PY - 2021 SP - 187 EP - 190 PB - expert CY - Esslingen AN - OPUS4-52915 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liao, Chun-Man A1 - Hille, Falk A1 - Fontoura Barroso, Daniel A1 - Niederleithinger, Ernst ED - Papadrakakis, M. ED - Fragiadakis, M. T1 - Monitoring of a prestressed bridge model byultrasonic measurement and vibration recordings N2 - The aim of this work is to improve the current structural health monitoring (SHM) methods for civil structures. A field experiment was carried out on a two-span bridge with a built-in un-bonded prestressing system. The bridge is a 24-metre long concrete beam resting on three bear-ings. Cracks were formed subsequently when a prestressing force of 350 kN was changed to 200 kN, so that different structural states could be demonstrated. The structural assessment of this reference bridge was accomplished by the non-destructive testing using ultrasonic devices and vibration measurements. The ultrasonic velocity variations were investigated by using the coda wave interferometry method. The seismic interferometry technique was applied to the vi-bration recordings to reconstruct the wave propagation field in the bridge. This investigation shows that the wave velocity is sensitive to the current structural state and can be considered as the damage indicator. Overall, the implementation of coda cave interferometry and seismic interferometry technique facilitates structural health monitoring (SHM) in civil engineering. T2 - COMPDYN 2021 8th ECCOMAS Thematic Conference on Computational Methods in Structural Dynamics and Earthquake Engineering CY - Online meeting DA - 28.06.2021 KW - Structural health monitoring KW - Non-destructive testing KW - Coda wave interferometry KW - Seismic interferometry KW - Ultrasonic measurement KW - Prestress PY - 2021 SP - 1 EP - 9 PB - European Community on Computational Methods in Applied Sciences (ECCOMAS) AN - OPUS4-52957 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wang, Xin A1 - Niederleithinger, Ernst A1 - Hindersmann, Iris T1 - The installation of embedded ultrasonic transducers inside a bridge to monitor temperature and load influence using coda wave interferometry technique N2 - This article presents a unique method of installing a special type of embedded ultrasonic transducers inside a 36-m-long section of an old bridge in Germany. A small-scale load test was carried out by a 16 ton truck to study the temperature and load influence on the bridge, as well as the performance of the embedded transducers. Ultrasonic coda wave interferometry technique, which has high sensitivity in detecting subtle changes in a heterogeneous medium, was used for the data evaluation and interpretation. The separation of two main influence factors (load effect and temperature variation) is studied, and future applications of wave velocity variation rate Φ for structural health condition estimation are discussed. As a preliminary research stage, the installation method and the performance of the ultrasonic transducer are recognized. Load- and temperature-induced weak wave velocity variations are successfully detected with a high resolution of 10−4%. The feasibility of the whole system for long-term structural health monitoring is considered, and further research is planned. KW - Ultrasound KW - Bridge KW - Monitoring KW - coda wave interferometry KW - embedded PY - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-527978 SN - 1475-9217 VL - 21 IS - 3 SP - 913 EP - 927 PB - SAGE AN - OPUS4-52797 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Towards digital tools for waste package and facility monitoring and prediction N2 - To provide better means for a safe and effective monitoring of cemented waste packages including prediction tools to assess the future integrity development during pre-disposal activities, several digital tools are evaluated and improved in the frame of the EC funded project PREDIS. Safety enhancement (e. g. less exposure of testing personnel) and cost effectiveness are part of the intended impact. The work includes but is not limited to inspection methods such as muon imaging, wireless sensors integrated into waste packages as well as external package and facility monitoring such as remote fiber optical sensors. The sensors applied will go beyond radiation monitoring and include Proxy parameters important for long term integrity assessment (e. g. internal pressure). Sensors will also be made cost effective to allow the installation of much more sensors compared to current practice. The measured data will be used in digital twins of the packages for specific simulations (geochemical, integrity) providing a prediction of future behavior. Machine Learning techniques trained by the characterization of older packages will help to connect the models to the actual data. All data (measured and simulated) will be collected in a joint data base and connected to a decision framework to be used at actual facilities. The presentation includes detailed information about the various tools under consideration, their connection and first results of our research. T2 - DigiDecom 2021 DIGITAL – Online event focusing on innovation within nuclear decommissioning CY - Online Meeting DA - 23.03.2021 KW - Radioactive waste KW - Waste package KW - Monitoring KW - Digital twin PY - 2021 AN - OPUS4-52622 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - NDE4.0 in civil engineering - obstacles and opportunities N2 - Civil engineering industry is one of the most important industry sectors in the world-wide economy. It contributes significantly to the gross economic product and general employment. Even more important, it provides many of the basic needs of the society (e. g. housing, infrastructure, protection from natural hazards). The concept of “Industry 4.0” or “Smart Production” has not yet made significant progress in the civil engineering industry. The design, build and operate processes are still widely dominated by the exchange of printed documents and drawings. Most objects (buildings and other constructions) are unique, and a large part of the production still requires a large amount of manual labor. As-built documentation and quality assurance are often neglected. Civil engineering is among the industries sectors with the lowest level of digitalization and the lowest gain in productivity. However, this is going to change. In the past decade, several drivers have challenged the ways clients, contractors, and authorities currently operate. These drivers include but are not limited to an increasing demand for serialization and automatization, the mandatory introduction of “Building Information Modeling” (BIM) in public procurement, the availability of construction equipment with sensors and digital interfaces or emerging automated construction technologies such as 3D-printing. NDE (referred to as NDT-CE in this sector), after a rapid technological development in the last two decades, plays an increasing role in quality assurance, condition assessment and monitoring of structures. However, with very few exceptions, applications are mostly non-standardized and performed only at selected sites. To change this, the NDT-CE community including manufacturers, service providers, clients and the scientific community must work consistently on open data formats, interfaces to BIM, standardization and validated ways for a quantitative use of the results in the assessment of constructions. T2 - International Virtual Conference on NDE 4.0 CY - Online Meeting DA - 14.04.2021 KW - NDT KW - BIM KW - SHM KW - NDE 4.0 PY - 2021 AN - OPUS4-52623 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Long term monitoring of concrete structures using innovative NDT and SHM approaches: NDT-CE 4.0 N2 - In Germany, a large amount of reinforced and/or prestressed concrete structures are approaching the end of their life cycle. Many of them already show a significant reduction of operability or capacity. The issue is most obvious, but not limited to traffic or energy related infrastructure. These structures have to be inspected and assessed on a regular basis. More and more permanent monitoring systems are installed to follow the degradation and to give pre-warning before failure. While the basic mandatory inspection (e. g. of bridges) is still limited to visual examination and tap tests, more advanced investigation tools as ultrasound or radar are used more and more often. Monitoring e. g. by acoustic emission systems is increasingly used e.g. for detection of wire breaks in prestressed structures. The presentation gives an overview on the state of the art and an outlook on innovative systems, including the integration in modern data processing, evaluation, display and archive systems. T2 - European NDE Symposium for NPP CY - Online Meeting DA - 04.05.2021 KW - NDT KW - Nuclear KW - Concrete PY - 2021 AN - OPUS4-52624 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maack, Stefan A1 - Küttenbaum, Stefan A1 - Niederleithinger, Ernst T1 - Practical procedure for the precise measurement of geometrical tendon positions in concrete with ultrasonic echo N2 - Existing concrete structures were usually designed for lifetimes of several decades. The current and urgently required efforts to increase sustainability and protect the environment will likely result in extended service lives up to 100 years. To achieve such objectives, it is required to assess structures over their entire lifecycles. Non-destructive testing (NDT) methods can reliably support the assessment of existing structures during the construction, operational, and decommissioning phases. One of the most important and safety-relevant components of a prestressed concrete structure are the tendons. NDT methods such as the ultrasonic echo method are suitable for both the detection and the localization of the tendons, i.e., the measurement of their geometrical position inside the component. The uniqueness of structures, concrete heterogeneity, and varying amounts of secondary components such as the reinforcement represent obstacles in the application of these methods in practice. The aim of this contribution is to demonstrate a practicable procedure, that can be used in the field to determine the parameters required for the measuring data analysis without extensive knowledge about the investigated components. For this purpose, a polyamide reference specimen is used to show which steps are required to obtain reliable imaging information on the position of tendons from the measurement data. The procedure is then demonstrated on a concrete test specimen that covers various relevant and practice-oriented test scenarios, such as varying tendon depths and component thicknesses. T2 - International Conference on Concrete Repair, Rehabilitation and Retrofitting (ICCRRR 2022) CY - Cape Town, South Africa DA - 03.10.2022 KW - Validation KW - Non-destructive testing KW - Ultrasonic KW - Reconstruction KW - Concrete KW - Tendon duct PY - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-559979 SN - 2261-263X SP - 1 EP - 8 AN - OPUS4-55997 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lay, Vera A1 - Niederleithinger, Ernst A1 - Köpp, Christan T1 - Monitoring and digital tools for pre-disposal handling of cemented wastes N2 - Multifaceted developments for pre-disposal management of low and intermediate level radioactive waste are undertaken in the EC funded project PREDIS. In work package 7, innovations in cemented waste handling and pre-disposal storage are advanced by testing and evaluating. To provide better means for safe and effective monitoring of cemented waste packages including prediction tools to assess the future integrity development during pre-disposal activities, several monitoring and digital tools are evaluated and improved. Both safety enhancement (e. g. less exposure of testing personnel) and cost effectiveness are part of the intended impact. Current methods to pack, store, and monitor cemented wastes are identified, analysed and improved. Innovative integrity testing and monitoring techniques applied to evaluate and demonstrate package and storage quality assurance are further developed. The work includes but is not limited to inspection methods such as muon imaging, wireless sensors integrated into waste packages as well as external package and facility monitoring such as remote fiber optical sensors. The sensors applied will go beyond radiation monitoring and include proxy parameters important for long term integrity assessment (e. g. internal pressure). The measured data will be used in digital twins of the packages for specific simulations (geochemical, integrity) providing a prediction of future behaviour. Machine Learning techniques trained by the characterization of older packages will help to connect the models to the actual data. As data handling, processing and fusion are crucial for both the monitoring and the digital twin model, all data (measured and simulated) will be collected in a joint data base and connected to a decision framework. Finally, the implementation of the improved techniques will be tested at actual facilities. An overview about various relevant tools, their interconnections, and first research results will be shown. T2 - 9th IGD-TP Symposium CY - Zurich, Switzerland DA - 20.09.2022 KW - Predis KW - Monitoring KW - Sensors KW - Simulation KW - Digital twin PY - 2022 AN - OPUS4-55827 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Epple, Niklas A1 - Fontoura Barroso, Daniel A1 - Niederleithinger, Ernst A1 - Hindersmann, I. A1 - Sodeikat, C. A1 - Groschup, R. ED - Rizzo, P. ED - Milazzo, A. T1 - From the Lab to the Structure: Monitoring of a German Road Bridge Using Embedded Ultrasonic Transducers and Coda Waves N2 - The ‘Gänstorbrücke’ bridge between the cities of Ulm and Neu-Ulm is one of the best-monitored bridges all over Germany. In addition to an already active bride monitoring system, we have equipped the bridge with 30 ultrasonic transducers to explore the monitoring possibilities at an in-service large-scale reinforced concrete structure with continuous active ultrasonic measurements. The monitoring system is based on the detection of small changes in the entire signal, especially the multiply scattered parts of the recording, the so-called coda. Applying Coda Wave Interferometry (CWI), subtle changes in the signal can be detected and related to changing velocities in the area between source and receiver. A comparison of the results from coda wave interferometry with the strain measurements of the permanent monitoring system shows a correlation between strain measurements and CWI results. We discuss the challenges of changing environmental conditions, pose for interpretation of the results, and highlight the advantages of embedded versus externally attached ultrasonic transducers in permanent bridge monitoring, especially when coda wave interferometry is applied. KW - Bridge monitoring KW - Ultrasound KW - Embedded sensors KW - Coda wave interferometry PY - 2022 SN - 978-3-031-07258-1 U6 - https://doi.org/10.1007/978-3-031-07258-1_83 VL - 254 SP - 824 EP - 832 PB - Springer Cham CY - Cham AN - OPUS4-55385 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liao, Chun-Man A1 - Niederleithinger, Ernst A1 - Bernauer, F. A1 - Igel, H. A1 - Hadziioannou, C. T1 - Real time bridge monitoring using ultrasonic techniques combined with six component (6-c) measurements N2 - This study aims to develop a real-time monitoring method for the structural performance by ultrasonic testing in combination with six-component (6-C) translation and rotation measurements. So far, the recordings of the velocity and acceleration response in the translation direction have been used to obtain the eigenfrequencies of structures. Recently, measurement of rotation has been used to fully characterize the dynamic behavior of structures. In this research, 6-C sensors consisting of a three-component rotational seismometer and a three-component broadband seismometer are evaluated for their suitability for bridge monitoring. Since changes in environmental conditions such as temperature during vibration recordings affect the structural evaluation results, cross-correlation function is applied here to the 6-C ambient vibration signals to reconstruct the wave propagation on the one hand, and coda wave interferometry (CWI) is applied to obtain the internal velocity variation from waveforms on the other hand. In field tests on a large-scale prestressed concrete bridge model, it was verified whether the prestress loss can also be determined in presence of temperature effects. For this purpose, measurements were performed in two scales, ultrasonic and output-only vibration measurements. The change in structural properties due to the prestress loss should be detected by the pulse velocity change. The results demonstrate both the performance and advantages of ultrasonic techniques and the capabilities of 6-C sensors. Thus, the application of CWI to wave signals can contribute comprehensively to bridge monitoring. T2 - NDT-CE 2022 CY - Zurich, Switzerland DA - 16.08.2022 KW - 6-C vibration signals KW - Coda wave interferometry KW - Cross-correlation function KW - Prestressed bridge KW - Structural health monitoring KW - Ultrasonic PY - 2022 AN - OPUS4-55646 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liao, Chun-Man A1 - Hicke, Konstantin A1 - Bernauer, F. A1 - Igel, H. A1 - Hadziioannou, C. A1 - Niederleithinger, Ernst ED - Isecke, B. ED - Krieger, J. T1 - Multi-Sensor measurements on a large-scale bridge model N2 - This contribution introduces an investigation of a large-scale prestressed concrete bridge model (“BLEIB” structure at the BAM-TTS open air test site) by means of on-site cooperative measurements. This bridge has an external post-tensioning system and has been instrumented with the ultrasonic transducers, temperature sensors and optical fibers for Distributed Acoustic Sensing (DAS). Our experiment was designed to test the suitability of the novel 6C sensors developed within the framework of the GIOTTO project – the IMU50. The IMU50 sensor enables vibration measurements in translation along three axes and rotation around three axes. The geophone sensors were considered for complementary measurements of vertical velocity response. In the experiment, several perturbations were achieved by controlling the external influence factors such as loading and prestressing changes. The aim of the integrated measurement strategy was to fully observe the results of the condition change and to verify the effectiveness of multiple sensors for bridge monitoring. T2 - 5. Brückenkolloquium CY - Ostfildern, Germany DA - 06.09.2022 KW - Concrete KW - Bridge KW - Monitoring KW - Rotation KW - Distributed acoustic sensing PY - 2022 SN - 978-3-8169-3549-0 SP - 223 EP - 230 PB - Expert Verlag CY - Tübingen AN - OPUS4-55625 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liao, Chun-Man A1 - Niederleithinger, Ernst A1 - Hicke, Konstantin A1 - Bernauer, F. A1 - Igel, H. A1 - Hadziioannou, C. T1 - Multi-Sensor measurements on a large-scale bridge model N2 - This contribution introduces an investigation of a large-scale prestressed concrete bridge model (“BLEIB” structure at the BAM-TTS open air test site) by means of on-site cooperative measurements. This bridge has an external post-tensioning system and has been instrumented with the ultrasonic transducers, temperature sensors and optical fibers for Distributed Acoustic Sensing (DAS). Our experiment was designed to test the suitability of the novel 6C sensors developed within the framework of the GIOTTO project – the IMU50. The IMU50 sensor enables vibration measurements in translation along three axes and rotation around three axes. The geophone sensors were considered for complementary measurements of vertical velocity response. In the experiment, several perturbations were achieved by controlling the external influence factors such as loading and prestressing changes. The aim of the integrated measurement strategy was to fully observe the results of the condition change and to verify the effectiveness of multiple sensors for bridge monitoring. T2 - 5. Brückenkolloquium CY - Ostfildern, Germany DA - 06.09.2022 KW - Concrete KW - Bridge KW - Monitoring KW - Rotation KW - Distributed acoustic sensing PY - 2022 AN - OPUS4-55626 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Hille, Falk A1 - Hofmann, Detlev A1 - Kind, Thomas ED - Isecke, B. ED - Krieger, J. T1 - Überwachung der Brücke Altstädter Bahnhof, Brandenburg./H. Begleituntersuchungen mit moderner Sensorik und zerstörungsfreier Prüfung N2 - Die B1 Brücke am Altstädter Bahnhof in Brandenburg an der Havel wurde im Dezember 2019 aufgrund von während einer turnusmäßigen Inspektion entdeckten Rissen und Hohlstellen entlang der vorgespannten Längsträger gesperrt und im Mai 2021 abgebrochen. In der Zwischenzeit wurde die Brücke detailliert überwacht. Vor dem Abriss wurden zudem umfangreiche Untersuchungen zur Bestandsaufnahme und Schadensanalyse sowie Tests moderner Sensorik vorgenommen. Dabei konnte sowohl die richtige, zuvor nicht sicher bekannte Anzahl von Spanngliedern in den Querträgern sicher ermittelt werden als auch durch moderne Varianten der Schwingungsmessungen und der faseroptischen Sensorik zusätzliche Kenntnisse püber das Bauwerksverhalten ermittelt werden . In dem Beitrag werden die Verfahren mit ihren Möglichkeiten und Grenzen vorgestellt, die Ergebnissee an der Brücke in Brandenburg erläutert und zukünftige Einsatzmöglichkeiten diskutiert. T2 - 5. Brückenkolloquium CY - Ostfildern, Germany DA - 06.09.2022 KW - Monitoring KW - Brücke KW - Radar KW - Vibration KW - Faseroptik PY - 2022 SN - 978-3-8169-3549-0 SP - 555 EP - 566 PB - Expert Verlag CY - Tübingen AN - OPUS4-55627 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Hille, Falk A1 - Hofmann, Detlev A1 - Kind, Thomas T1 - Überwachung der Brücke Altstädter Bahnhof, Branden-burg./H. N2 - Die B1 Brücke am Altstädter Bahnhof in Brandenburg an der Havel wurde im Dezember 2019 aufgrund von während einer turnusmäßigen Inspektion entdeckten Rissen und Hohlstellen entlang der vorgespannten Längsträger gesperrt und im Mai 2021 abgebrochen. In der Zwischenzeit wurde die Brücke detailliert überwacht. Vor dem Abriss wurden zudem umfangreiche Untersuchungen zur Bestandsaufnahme und Schadensanalyse sowie Tests moderner Sensorik vorgenommen. Dabei konnte sowohl die richtige, zuvor nicht sicher bekannte Anzahl von Spanngliedern in den Querträgern sicher ermittelt werden als auch durch moderne Varianten der Schwingungsmessungen und der faseroptischen Sensorik zusätzliche Kenntnisse püber das Bauwerksverhalten ermittelt werden . In dem Beitrag werden die Verfahren mit ihren Möglichkeiten und Grenzen vorgestellt, die Ergebnissee an der Brücke in Brandenburg erläutert und zukünftige Einsatzmöglichkeiten diskutiert. T2 - 5. Brückenkolloquium CY - Ostfildern, Germany DA - 06.09.2022 KW - Monitoring KW - Brücke KW - Radar KW - Vibration KW - Faseroptik PY - 2022 AN - OPUS4-55628 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liao, Chun-Man A1 - Bernauer, F. A1 - Igel, H. A1 - Hadziioannou, C. A1 - Niederleithinger, Ernst T1 - Real-time bridge monitoring using ultrasonic techniques combined with six-component (6-C) measurements N2 - This study aims to develop a real time structural health monitoring method by ultrasonic tests combined with advanced six component (6C) translation and rotation measurements. Conventionally, the investigation of the velocity and acceleration response in the translation direction is used to obtain the eigenfrequencies of structures. Recently the measurement of rotation has been considered to fully characterize the dynamic behavior of structures. This research undertakes the evaluation of a novel 6C sensor (IMU50-iXblue) with components originally developed for navigation for the purpose of bridge monitoring. However, as for all vibration recordings, there is a certain influence of environmental conditions (mainly temperature) which may affect evaluation and the results of structural assessment. We propose applying the cross-correlation function to the 6C ambient vibration signals to reconstruct wave propagation and using coda wave interferometry (CWI) to obtain internal velocity variation from waveforms. A field experiment on a large-scale prestressed concrete bridge model is presented. To verify that we are able to identify the pre-stress loss even in presence of temperature effects, we perform measurements in two different scales: the ultrasonic and output-only, vibration measurements. The change in the structural properties due to the pre-stress loss should be detected by the pulse velocity change. The results reveal both the performance and advantages of ultrasonic techniques and the capabilities of 6C sensors. To conclude, the application of CWI to wave signals contributes to a comprehensive assessment for bridge monitoring. T2 - NDT-CE 2022 CY - Zurich, Switzerland DA - 16.08.2022 KW - Structural health monitoring KW - Ultrasonic KW - Coda wave interferometry PY - 2022 SP - 1 EP - 10 AN - OPUS4-55660 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Diewald, F. A1 - Epple, Niklas A1 - Kraenkel, T. A1 - Gehlen, C. A1 - Niederleithinger, Ernst T1 - Impact of External Mechanical Loads on Coda Waves in Concrete N2 - During their life span, concrete structures interact with many kinds of external mechanical loads. Most of these loads are considered in advance and result in reversible deformations. Nevertheless, some of the loads cause irreversible, sometimes unnoticed changes below the macroscopic scale depending on the type and dimension of the impact. As the functionality of concrete structures is often relevant to safety and society, their condition must be known and, therefore, assessed on a regular basis. Out of the spectrum of non-destructive monitoring methods, Coda Wave Interferometry using embedded ultrasonic sensors is one particularly sensitive technique to evaluate changes to heterogeneous media. However, there are various influences on Coda waves in concrete, and the interpretation of their superimposed effect is ambiguous. In this study, we quantify the relations of uniaxial compression and uniaxial tension on Coda waves propagating in normal concrete. We found that both the signal correlation of ultrasonic signals as well as their velocity variation directly reflect the stress change in concrete structures in a laboratory environment. For the linear elastic range up to 30% of the strength, we calculated a velocity variation of −0.97‰/MPa for compression and 0.33%/MPa for tension using linear regression. In addition, these parameters revealed even weak irreversible changes after removal of the load. Furthermore, we show the time-dependent effects of shrinkage and creep on Coda waves by providing the development of the signal parameters over time during half a year together with creep recovery. Our observations showed that time-dependent material changes must be taken into account for any comparison of ultrasonic signals that are far apart in time. The study’s results demonstrate how Coda Wave Interferometry is capable of monitoring stress changes and detecting even small-size microstructural changes. By indicating the stated relations and their separation from further impacts, e.g., temperature and moisture, we anticipate our study to contribute to the qualification of Coda Wave Interferometry for its application as an early-warning system for concrete structures. KW - Ultrasound KW - Coda Wave Interferometry (CWI) KW - Mechanical Load KW - Microstructure KW - Concrete PY - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-556878 SN - 1996-1944 VL - 15 IS - 16 SP - 1 EP - 15 PB - MDPI AN - OPUS4-55687 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baensch, Franziska A1 - Hofmann, Detlef A1 - Johann, Sergej A1 - Tiebe, Carlo A1 - Basedau, Frank A1 - Sturm, Patrick A1 - Lay, Vera A1 - Niederleithinger, Ernst T1 - Multi-sensor conception for safe sealing structures in underground repositories N2 - The project "SealWasteSafe" of the Bundesanstalt für Materialforschung und -prüfung (BAM, Berlin) deals with sealing structures applied for underground disposal of nuclear waste from two perspectives: (1) material improvement for application in sealing constructions and (2) feasibility study regarding multi-sensor approaches to ensure quality assurance and long-term monitoring. One specimen of 150 l made of alkali-activated material, which was found innovative and suitable for sealing constructions based on preliminary laboratory studies, and, for comparison purpose, another one made of salt concrete, are manufactured with an integrated multi-sensory setup for quality assurance and long-term-monitoring. The specimens were left in their cast form and additionally thermally insulated to simulate the situation in the repository. The multi-sensory concept comprises RFID technology embedded in the specimens suppling material temperature and moisture measurements, integrated fibre optic sensing allowing strain measurement and acoustic emission testing for monitoring possible crack formation. Overall, the suitability and the functionality of the sensors embedded into and attached to strongly alkaline (pH > 13 for the AAM) and salt corrosive (NaCl) environment was proven for the first 672 h. First temperature measurement based on RFID succeeded after 626 h for the alkali-activated material and after 192 h for the conventional salt concrete. Strain measurement based on distributed fibre optic sensing turned out the alkali-activated material with > 1 mm m-1 undergoing approximately twice the compression strain as the salt concrete with strains < 0.5 mm m-1. In contrast, the acoustic emission first and single hits representing crack formation in numbers, was found for alkali-activated material half of that detected at the salt concrete. T2 - SMIRT 26 CY - Berlin/Potsdam, Germany DA - 10.07.2022 KW - SealWasteSafe KW - Monitoring KW - Acoustic emission KW - Fibre optic sensing KW - RFID technology KW - alkali-activated material PY - 2022 SP - 1 EP - 10 AN - OPUS4-55371 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Geophysical methods delivering input to geostatistical methods for geotechnical site characterization N2 - Geophysical methods are able to contribute significantly to geotechnical site characterization. In-situ parameters are collected and gaps between boreholes or other direct tests are filled with information. However the limited resolution has to be considered and the indirect geophysical parameters have to be translated into something geotechnically useful. Moreover, the limitations have to be evaluated when including geophysical data into geostatistical models. If done properly, the use of geophysics will help in an efficient and effective site characterization. A comprehensive overview on existing geophysical (mostly seismic) methods is given as well as information on the calibration of geophysical against geotechnical parameters, pitfalls and limitations and some hints how to include these data into geostatistical/geotechnical models. T2 - ICGoES International Conference on Geologicalk Engineering and Geosciences CY - Yogyakarta, Indonesia DA - 21.09.2022 KW - Geophysics KW - Geostatistics KW - Geotechnics PY - 2022 AN - OPUS4-55806 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lay, Vera A1 - Effner, Ute A1 - Niederleithinger, Ernst A1 - Arendt, J. A1 - Kudla, W. T1 - Ultrasonic quality assurance for underground salt shotcrete sealing structures in Teutschenthal mine, Germany N2 - Underground sealing structures are necessary to seal radioactive or toxic waste in underground repositories. A special version of MgO concrete is used in the mine in Teutschenthal and applied at a large-scale test with the aim to provide a low permeability barrier. The test structures (up to 10 m long) were created by shotcreting. Besides destructive tests, non-destructive ultrasonic measurements have been evaluated for quality assurance to monitor potential anomalies such as cracks, concrete inhomogeneities, and delamination. We show results of ultrasonic measurements with a multi-transducer system used at the front and from the side of the concrete structure. Images are obtained by synthetic aperture focusing techniques. The boundaries between concreting sections are not visible in the ultrasonic images systematically so that a successful concreting is assumed, which is confirmed by the low permeabilities observed. Several reflectors up to a depth of 1.2 m are identified and interpreted as potential damages in the concrete. Phase analysis of prominent reflectors reveal a negative impedance contrast thus indicating air filled voids, cracks or delamination. Boreholes through some of the identified reflectors are used to verify the results from ultrasonic measurements. Additionally, an experiment with incorporated artificial defects was undertaken to analyse the reliability of the applied methods. Overall, the conducted tests show the potential of ultrasonic measurements to detect critical anomalies. Despite challenges at small-scale structures (cm-order), large-scale anomalies can be identified. Consequently, implementing ultrasonic monitoring during and after the construction of concrete sealing structures has shown its potential as a tool for quality assurance, but needs further development and validation. T2 - NDT-CE 2022 CY - Zurich, Switzerland DA - 16.08.2022 KW - Ultrasound KW - Ultrasonic imaging KW - Magnesia shotcrete KW - Underground KW - Engineered barrier systems PY - 2022 UR - https://www.ndt.net/events/proceedings/topic.php?eventID=292&TopicID=27209 SP - 1 EP - 4 PB - NDT.net AN - OPUS4-55824 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Prabhakara, Prathik A1 - Mielentz, Frank A1 - Stolpe, Heiko A1 - Behrens, Matthias A1 - Lay, Vera A1 - Niederleithinger, Ernst T1 - Construction and validation of a novel phased array borehole probe for ultrasonic investigations at sealing structures in radioactive repositories N2 - A new type of ultrasonic borehole probe is currently under development for the quality assurance of sealing structures in radioactive waste repositories using existing research boreholes. The goal is to examine the sealing structures made of salt concrete for possible cracks, delamination, and embedded objects. Earlier prototype probes use 12 or 16 individual dry point contact (DPC) horizontal shear wave transducers grouped into a transmitter and a receiver array, each made up of six or eight individual transducers. They are operated with a commercially available portable ultrasonic flaw detector used in the civil engineering industry. To increase the generated sound pressure of the borehole probe, the number of transducers in the novel probe is increased to 32. In addition, timed excitation of each probe is used to direct a focused sound beam to a specific angle and distance based on calculated time delays. Hence, the sensitive test volume is limited, and the signal-to-noise ratio of the received signals is improved. This paper presents the validation of the newly developed phased array borehole probe by beam computation in CIVA software and experimental investigations on a semi-cylindrical test specimen to investigate the directional characteristics. In combination with geophysical reconstruction techniques, an optimised radiation pattern of the probe is expected to improve the signal quality and thus increase the reliability of the imaging results. This is of great importance for the construction of safe sealing structures needed for the disposal of radioactive or toxic waste. T2 - NDT-CE 2022 CY - Zurich, Switzerland DA - 16.08.2022 KW - Borehole probe KW - Phased array technique KW - SealWasteSafe KW - Monitoring KW - Engineered barrier; PY - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-568016 SN - 1435-4934 SP - 1 EP - 4 PB - NDT.net AN - OPUS4-56801 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Prabhakara, Prathik A1 - Mielentz, Frank A1 - Stolpe, Heiko A1 - Behrens, Matthias A1 - Lay, Vera A1 - Niederleithinger, Ernst T1 - Ultrasonic Investigation for the Quality Assurance of Sealing Structures in Radioactive Waste Repositories N2 - The structural integrity of sealing structures in underground repositories for radioactive waste is a major concern regarding safe disposal. Non-destructive testing plays a very important role in the safety of this sealing structures. Ultrasonic pulse echo technology has been established in the construction industry as a non-destructive testing method for locating potential defects and material characterization of concrete structures. A borehole probe is an ultrasonic pulse-echo device used to investigate the internal structures of salt concrete. A prototype borehole probe is successfully demonstrated with the existing research borehole in the test site using a commercially available flaw detector. A novel phased array borehole probe that allows the beam to be focused based on the delay law was constructed and tested. The directivity measurements on the semi-cylindrical concrete sample agree well with the simulation results for the different focusing angles. In combination with geophysical reconstruction methods, the optimized radiation pattern of the probe is expected to improve the signal quality and thus increase the reliability of the imaging results. In addition, a unique large aperture ultrasound system (LAUS) is expected to provide enhanced images of possible cracks and embedded objects in in-situ structures. LAUS will be optimized to reliably detect objects at depths greater than 9 m and, at the same time, provide good resolution. Modeling studies show the potential to increase the distance between the transducer arrays further, and the same configuration has been successfully tested on a thick concrete wall. Overall, the paper shows that quality assurance using ultrasonic testing is crucial for constructing safe sealing structures to dispose of radioactive or toxic waste. T2 - NDE 2022 CY - Gandhinagar, India DA - 24.12.2022 KW - Ultrasonic Testing KW - Engineered barrier KW - Phased array technique KW - Non-destructive testing civil engineering KW - Quality assurance PY - 2022 AN - OPUS4-56802 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Amir, J. M. A1 - Schneider, N. T1 - New Possibilities for Quality Assurance of Diaphragm Wall Joints T2 - International Conference on Piling & Deep Foundations CY - Stockholm, Sweden DA - 2014-05-21 PY - 2014 AN - OPUS4-30751 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Baeßler, Matthias A1 - Georgi, Steven A1 - Herten, M. T1 - Geotechnical and Geophysical Characterization of a Pile Test Site in Post-glacial Soil T2 - International Conference on Piling & Deep Foundations CY - Stockholm, Sweden DA - 2014-05-21 PY - 2014 AN - OPUS4-30752 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Müller, Sabine T1 - Interpolation von Ultraschalldaten durch seismische Interferometrie T2 - 74. Jahrestagung der Deutschen Geophysikalischen Gesellschaft (DGG) CY - Karlsruhe, Germany DA - 2014-03-10 PY - 2014 AN - OPUS4-30697 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wolf, Julia A1 - Niederleithinger, Ernst A1 - Mielentz, Frank A1 - Grothe, Sven A1 - Wiggenhauser, Herbert T1 - Überwachung von Betonkonstruktionen mit eingebetteten Ultraschallsensoren N2 - Die immer komplexere Konstruktionsweise von Neubauten einerseits und die alternde Infrastruktur andererseits erfordern in manchen Fällen eine dauerhafte Überwachung, um besondere Einwirkungen und gegebenenfalls Schädigungen rechtzeitig und genau zu erkennen. Hierfür ist eine Vielzahl von Methoden und Sensoren verfügbar. Das Portfolio weist aber insbesondere bei der Detektion langsamer, räumlich begrenzter Veränderungen Lücken auf. Hierfür sind bisher sehr aufwändige Untersuchungen oder Installationen notwendig. In der vorliegenden Arbeit werden Sensoren und zugehörige Auswertemethoden für die Ultraschalltransmission vorgestellt, die sich für die zerstörungsfreie, dauerhafte Überwachung von Beton eignen. Direkt oder nachträglich in Betonkonstruktionen eingebaut, ermöglichen sie eine nicht nur lokale, sondern größere Raumbereiche umfassende Dauerüberwachung von Änderungen der Materialeigenschaften. Das Prinzip der Ultraschalltransmission und die verschiedenen Einflussparameter werden vorgestellt. Zu letzteren gehören neben der Belastung und Schädigung auch Umweltparameter wie Temperatur und Feuchte. Verschiedene Methoden zur Datenanalyse, wie z. B. die Codawelleninterferometrie, ermöglichen eine Detektion kleinster Veränderungen. Die in den Beton einzubettenden Ultraschallsensoren werden vorgestellt und ihr Einbau und Betrieb beschrieben. Als Beispiele für Anwendungen werden Frost-Tauwechsel-Experimente im Labor, die Detektion von lokalen Lasten im Technikumsmaßstab und der Einsatz an realen Brücken diskutiert. Die Sensoren sind zum Teil bereits seit mehreren Jahren in Probeobjekte eingebettet und liefern zuverlässig wertvolle Daten.------------------------------------------------------------------------------------------------------------------------------------------------------------- Monitoring of concrete constructions by embedded ultrasonic sensors: Challenging new constructions and the ageing infrastructure are increasing the demand for permanent monitoring of loads and damages. Various methods and sensors are used for this purpose. But the technologies available today have difficulties in detecting slowly progressing locally confined damages. Extensive investigations or instrumentations are required so far for this purpose. In this study we present new sensors and data processing methods for ultrasonic transmission, which can be used for non-destructive permanent monitoring of concrete. They can be mounted during construction or thereafter. Larger volumes can be monitored by a limited number of sensors for changes of material properties. The principles of ultrasonic transmission and influencing factors are presented. This latter include load, damages as well as environmental parameters as temperature or moisture. Various methods for data processing, e. g. coda wave interferometry are introduced. They allow the detection of very small changes in the medium. The embedded sensors are shown including mounting and operation. Application examples so far include small scale laboratory freeze-thaw experiments, localizing loads in larger concrete models and monitoring load effects on real structures. Some sensors are operating already for several years. KW - Beton KW - Ultraschall KW - Transmission KW - Monitoring KW - Codawelleninterferometrie KW - Frost-Tauwechsel KW - Ultraschallsensoren, eingebettete KW - Lastconcrete KW - Ultrasound KW - Coda wave interferometry KW - Embedded sensors KW - Freeze-thaw KW - Load KW - Neue Verfahren/Versuchstechnik KW - New Processes/Experimental Techniques PY - 2014 U6 - https://doi.org/10.1002/bate.201400073 SN - 0932-8351 SN - 1437-0999 SN - 0005-6820 SN - 0341-1052 SN - 0932-6359 VL - 91 IS - 11 SP - 783 EP - 796 PB - Ernst & Sohn CY - Berlin AN - OPUS4-32077 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kruschwitz, Sabine A1 - Niederleithinger, Ernst T1 - Untersuchung des Einflusses der Porenhalsgröße auf SIP-Spektren N2 - Das Sorptionsverhalten und die Frost-Tau-Beständigkeit von Baustoffen hängen maßgeblich von ihrer Porengrößenverteilung ab. Ein zerstörungsfreies, räumlich visualisierendes Messverfahren, das diese abschätzen könnte, wäre für die Bau- und Sanierungsindustrie sehr hilfreich. Scott und Barker (2003) berichteten über einen deutlichen Zusammenhang zwischen dominanter Porenhalsgröße und der SIP-Relaxationszeit an Sandsteinen. Diese Korrelation wird seit einiger Zeit für Baustoffe, insbesondere Sandsteine, an der BAM untersucht. T2 - 74. Jahrestagung der Deutschen Geophysikalischen Gesellschaft CY - Karlsruhe, Germany DA - 10.03.2014 KW - Spektral induzierte Polarisation KW - Sandsteine KW - Baustoffe KW - Porenhalsgröße KW - Feuchte PY - 2014 SN - 0344-7251 SP - IP GE EP - 1.002, 162 AN - OPUS4-31174 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Sabine A1 - Niederleithinger, Ernst T1 - Anwendung der Reverse Time Migration auf Ultraschall-Echo-Messungen in der zerstörungsfreien Prüfung im Bauwesen N2 - Ultraschall-Echo-Messungen dienen im Bauwesen zur Dickenbestimmung von Bauteilen sowie der Lokalisierung und Charakterisierung von Einbauteilen, Einlagerungen und anderen Inhomogenitäten. Zur Rekonstruktion werden bisher Abbildungsverfahren wie z.B. 3D-SAFT genutzt. Diese setzen aber voraus, dass direkte Reflexionen am Abbildungsobjekt erfolgen. Deshalb können keine zuverlässigen Aussagen über den Durchmesser von eingebauten Spannkanälen oder z. B. Seitenkanten von Objekten getroffen werden. Ziel laufender Forschungsarbeiten ist es, die Abbildungsqualität zu verbessern. Mit der aus der Geophysik stammenden Reverse Time Migration, die bereits häufig in der Erdölexploration genutzt wird, lassen sich auch steilere Strukturen über 70° abbilden und somit auch die Unterseite von Einbauten oder Stufen in Bauteilen darstellen. Um die Leistungsfähigkeit des Algorithmus für die zerstörungsfreie Prüfung zu untersuchen, wurden verschiedene Simulationsrechnungen durchgeführt. Dabei wurden typische Prüfprobleme unterschiedlicher Komplexität zunächst in Polyamid nachgestellt. Die Schwerpunkte lagen bei der Darstellung senkrechter Grenzflächen und Hohlstellen. Die Rechnungen dienten neben der Evaluierung und Optimierung des Verfahrens auch der Planung von Experimenten an Probekörpern mit verschiedenen Einbauten. Die Simulationsergebnisse wurden an einem dem synthetischen Modell entsprechenden Polyamidprobekörper überprüft, an dem rauscharme Ultraschalldaten aufgenommen werden konnten. In einer Messreihe wurde in den Probekörper eine Bohrung eingebracht und schrittweise vergrößert. Mit diesen Messungen konnte die Leistungsfähigkeit der Reverse Time Migration auch an realen Ultraschalldaten nachgewiesen werden. Untersuchungen mit an Beton aufgenommenen Ultraschalldaten werden folgen. T2 - DGZfP-Jahrestagung 2014 CY - Potsdam, Germany DA - 26.05.2014 KW - Ultraschall KW - Reverse Time Migration KW - Zerstörungsfreie Prüfung PY - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-319311 SN - 978-3-940283-61-0 IS - DGZfP-BB 148 SP - Di.1.C.4, 1 EP - 8 PB - Deutsche Gesellschaft für Zerstörungsfreie Prüfung (DGZfP) AN - OPUS4-31931 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Sens-Schönfelder, Ch. A1 - Grothe, Sven A1 - Wiggenhauser, Herbert T1 - Coda Wave Interferometry used to Localize Compressional Load Effects in a Concrete Specimen T2 - 7th European Workshop on Structural Health Monitoring CY - Nantes, France DA - 2014-07-08 PY - 2014 AN - OPUS4-31060 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Sens-Schönfelder, Ch. A1 - Gassenmeier, M. A1 - Thiemann, K. A1 - Köllner, F. T1 - Monitoring and Imaging based on Interferometric Concepts T2 - 7th European Workshop on Structural Health Monitoring CY - Nantes, France DA - 2014-07-08 PY - 2014 AN - OPUS4-31061 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Borehole based methods for length determination of existing piles T2 - Seminar Dynamic Pile Testing CY - Berlin, Germany DA - 2009-02-18 PY - 2009 AN - OPUS4-18984 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Shokouhi, Parisa A1 - Niederleithinger, Ernst A1 - Zoëga, Andreas A1 - Barner, Andreas A1 - Schöne, Dieter T1 - Using ultrasonic coda wave interferometry for monitoring stress-induced changes in concrete T2 - 23rd SAGEEP Symposium on the application of geophysics to engineering and environmental problems CY - Keystone, Colorado, USA DA - 2010-04-11 KW - Coda wave interferometry KW - Concrete KW - Beton KW - Stress KW - Ultrasonics KW - Ultraschall PY - 2010 SN - 1554-8015 SP - 650 EP - 654 AN - OPUS4-21570 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Fritsche, M. T1 - Nachträgliche Bestimmung von Spundbohlenlängen mit dem Parallel-Seismik-Verfahren T2 - Pfahlsymposium CY - Braunschweig, Germany DA - 2009-02-19 PY - 2009 AN - OPUS4-18960 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Niederleithinger, Ernst A1 - Wiggenhauser, Herbert A1 - Taffe, Alexander T1 - The NDT-CE test and validation center in Horstwalde T2 - NDTCE ´09 - 7th International symposium on nondestructive testing in civil engineering CY - Nantes, France DA - 2009-06-30 KW - Foundations KW - Bridges KW - Piles KW - Slabs KW - Integrity KW - Ultrasonics KW - Parallel seimics PY - 2009 SN - 978-2-7208-2542-5 SN - 1628-4704 SP - 1 EP - 6 AN - OPUS4-20140 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Kruschwitz, Sabine A1 - Niederleithinger, Ernst T1 - Complex resistivity tomography in laboratory and field studies - a promising NDT tool T2 - NDTCE ´09 - 7th International symposium on nondestructive testing in civil engineering CY - Nantes, France DA - 2009-06-30 KW - Electrical resistivity KW - Moisture KW - Salt KW - Damage PY - 2009 SN - 978-2-7208-2542-5 SN - 1628-4704 SP - 1 EP - 6 AN - OPUS4-20141 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Fritsche, M. T1 - Nachträgliche Bestimmung der Länge von Spundbohlen an Schiffsanlegern T2 - Bauwerksdiagnose 2008 CY - Berlin, Germany DA - 2008-02-21 PY - 2008 AN - OPUS4-20116 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Wiggenhauser, Herbert A1 - Taffe, Alexander T1 - The NDT-CE test and validation center in Horstwalde T2 - NDT-CE 2009 CY - Nantes, France DA - 2009-06-30 PY - 2009 AN - OPUS4-20117 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Kruschwitz, Sabine T1 - Complex resistivity tomography in laboratory and field studies - a promising NDT tool T2 - NDT-CE 2009 CY - Nantes, France DA - 2009-06-30 PY - 2009 AN - OPUS4-20118 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Martin, Tina T1 - Multiparameter investigations on wood samples T2 - International Workshop on Induced Polarization in Near-Surface Geophysics CY - Bonn, Germany DA - 2009-09-30 PY - 2009 AN - OPUS4-20146 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Shokouhi, Parisa A1 - Stähler, S. A1 - Nowak, Thomas Rudolf T1 - Detection of Subtle Changes in Materials by Coda Wave Interferometry T2 - 10th European Conference on NDT (ECNDT) CY - Moscow, Russia DA - 2010-06-07 PY - 2010 AN - OPUS4-21448 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Shokouhi, Parisa A1 - Stähler, S. A1 - Nowak, Thomas Rudolf T1 - Detection of subtle changes in materials by Coda Wave interferometry T2 - 10th European conference on non-destructive testing CY - Moscow, Russia DA - 2010-06-07 KW - Cold wave interferometry KW - Beton KW - Concrete KW - Stress PY - 2010 IS - Paper 4.02.18 SP - 1 EP - 9 AN - OPUS4-21468 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Tronicke, J. T1 - Traveltime inversion of parallel-seismic data for foundation lenght estimation T2 - EAGE Near Surface 2010 CY - Zurich, Switzerland DA - 2010-09-06 PY - 2010 AN - OPUS4-21920 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Linder, S. A1 - Paasche, H. A1 - Tronicke, J. A1 - Niederleithinger, Ernst A1 - Vienken, T. T1 - Zonal cooperative inversion of crosshole P-wave, S-wave, and georadar traveltime data sets N2 - In this study, we use and extend a recently developed zonal cooperative inversion approach and apply it to the inversion of three independent geophysical field data sets. We invert crosshole P-wave, S-wave, and georadar data sets acquired in sand and gravel dominated unconsolidated sediments to detect and characterize different sedimentary units relevant for an engineering or hydrological site characterization. The zonal cooperative inversion of the three traveltime data sets results in a single subsurface model, which is a geophysical three-parameter model (P-wave, S-wave, and georadar velocity) outlining the major subsurface zonation while explaining all input data sets. Comparing our zonal model to direct push (DP) logging data (tip resistance, sleeve friction, and dielectric permittivity) shows good agreement; i.e., the zones in our geophysical model largely correspond to major DP parameter changes. Furthermore, we demonstrate how the sparse DP data can be inter- and extrapolated to the entire tomographic plane which allows for further geotechnical and hydrological interpretations. This study illustrates that the zonal cooperative inversion approach is highly flexible and an excellent tool to characterize a variety of environments in terms of multiple physical parameters. KW - Seismic KW - Georadar KW - Direct push techniques KW - Crosshole tomography KW - Cooperative inversion KW - Site characterization PY - 2010 U6 - https://doi.org/10.1016/j.jappgeo.2010.10.003 SN - 0926-9851 VL - 72 IS - 4 SP - 254 EP - 262 PB - Elsevier CY - Amsterdam [u.a.] AN - OPUS4-23266 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Wunderlich, Carolin T1 - Evaluation of temperature influence on ultrasound velocity in concrete by coda wave interferometry T2 - International Symposium on Nondestructive Testing of Materials and Structures, NDTMS-2011 CY - Istanbul, Turkey DA - 2011-05-15 PY - 2011 AN - OPUS4-24111 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - The BAM Site for Non-Destructive Testing Methods (NDT) in Civil Engineering T2 - International Foundations Congress and Equipment Exhibition (IFCEE) CY - Orlando, FL, USA DA - 2009-03-15 PY - 2009 AN - OPUS4-20248 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Stähler, S. A1 - Niederleithinger, Ernst A1 - Pirskawetz, Stephan A1 - Nowak, Thomas Rudolf A1 - Weise, Frank ED - Sens-Schönfelder, Christoph ED - Ritter, Joachim ED - Wegler, Ulrich ED - Große, Christian T1 - Detection of subtle changes in materials by Coda Wave interferometry T2 - Noise and diffuse wavefields workshop CY - Neustadt an der Weinstraße, Germany DA - 2009-07-05 KW - Coda wave interferometry Beton KW - Schädigung KW - Ultraschall-Transmission PY - 2009 SN - 978-3-00-027952-2 SN - 0947-1944 VL - II SP - 59 EP - 61 AN - OPUS4-20574 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kruschwitz, Sabine A1 - Niederleithinger, Ernst A1 - Trela, Christiane A1 - Wöstmann, Jens T1 - Complex resistivity and radar investigation of building material: First results of field scale measurements N2 - Moisture ingress is one of major damaging factors for masonry buildings. As the complex resistivity (CR) is sensitive to textural properties as well as to the pore fluid chemistry of wet porous media, its non-destructive application can provide helpful information for conservators. In a comprehensive laboratory study it has been shown that CR might even be able to distinguish between salt content and saturation degree in only one measurement. The combined use of electrical and electromagnetic measurement techniques in two field-scale flooding experiments has shown some unexpected differences. Possible reasons are discussed and it is shown that bringing together the information of both methods leads to a clearer picture. KW - Complex resistivity KW - Ground penetrating radar KW - Non-destructive testing KW - Masonry KW - Salt and moisture damage PY - 2010 U6 - https://doi.org/10.2478/s11600-009-0019-4 SN - 1895-6572 SN - 1895-7455 VL - 58 IS - 1 SP - 96 EP - 113 PB - Springer CY - Warsaw AN - OPUS4-20575 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ertel, Jens-Peter A1 - Niederleithinger, Ernst A1 - Grohmann, Maria T1 - Advances in pile integrity testing N2 - For decades, the low-strain impact integrity testing using a hammer blow is well established as a method of quality assurance for various pile types. However, this method has its limitations. Our research and development focuses on improving the excitation signal using a shaker system in contrast to the standard hammer method. Another approach is to increase the amount of sensors used during testing. The purpose is to identify the direction of wave propagation which gives advantages under difficult conditions, such as piles below structures. Pile integrity testing (PIT) using a shaker system was performed on two 11 m long piles of 90 cm in diameter. While one pile was intact, the other one showed a flaw at approx. 3.5 m below pile top, which was confirmed by standard PIT in 2012. A logarithmic sweep between 500 Hz and 1 KHz of 0.1 s was used as the input signal, being vertically injected into the pile. Prior to that, simulations on similar pile geometries showed that the depth of the pile toe as well as flaws within the pile can be extracted by applying regularized deconvolution. The result is the impulse response in the time domain. The application of deconvolution on the measured signals shows that it is possible to identify the pile length but it is more difficult to clearly extract the flaw’s position in the pile. Additional digital signal processing techniques and the improvement of the regularized deconvolution method as well as the experimental setup need to be investigated. Another way to improve the PIT method is to use a multichannel sensor arrangement. By arranging several accelerometers vertically along the accessible part of the pile shaft, it is possible to distinguish between downward and upward traveling waves. Furthermore, it is possible to estimate the unknown wave speed, which gives the possibility of more accurate pile length calculations. The method was evaluated successfully during a measurement campaign of a slab foundation with subjacent piles. In 20 of 28 cases the pile length could be detected accurately. KW - Pile integrity testing KW - Pile length KW - CEFIT KW - Deconvolution KW - Simulation PY - 2016 UR - http://nsg.eage.org/publication/publicationdetails/?publication=86879 SN - 1569-4445 SN - 1873-0604 VL - 14 IS - 6 SP - 503 EP - 512 PB - EAGE Publications AN - OPUS4-37837 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Ertel, Jens-Peter A1 - Sochor, M. A1 - Unseld, H. T1 - Nachbestimmung von Pfahllängen am Beispiel von Masten N2 - Im Rahmen der Lebensdauerverlängerung oder der Umnutzung von Bauwerken (z. B. Brücken, Bürogebäude oder Maste) müssen diese zum Teil neu bewertet werden. Dafür ist eine Nachrechnung für statische und dynamische Lastfälle erforderlich. Dies betrifft zum einen die Struktur selbst, die gegebenenfalls verstärkt werden muss. Aber auch die Gründung (oft Pfähle verschiedenster Typen) muss neu beurteilt werden. Nach mehreren Jahrzehnten sind jedoch für einige Bauwerke keine zuverlässigen Bestandsunterlagen verfügbar. Eine vollständige Freilegung der Pfähle verbietet sich aus Kostengründen sowie Verlust an Widerstand gegen Zug. Lediglich der Pfahlanschluss kann visuell begutachtet werden, um Pfahlzahl, -typ und Durchmesser zu bestimmen. Für die Bestimmung der Pfahllänge müssen zerstörungsfreie Verfahren eingesetzt werden. In einer Machbarkeitsstudie wurden von den Autoren teils im Blindversuch drei Verfahren evaluiert: die klassische Pfahlintegritätsprüfung nach der Hammerschlagmethode, eine mehrkanalige Variante hierzu und das Parallel-Seismik-Verfahren. Die ersten beiden Methoden lieferten an den untersuchten Pfählen nur in Einzelfällen verwertbare Ergebnisse. Die Parallel-Seismik-Methode lieferte auch im Blindversuch an Fundamenten, bei denen die Pfahllänge dem Eigentümer bekannt war, Ergebnisse mit einer Abweichung von max. 0,5 m. Diese Toleranz lässt sich bei der Standfestigkeitsbeurteilung berücksichtigen. Die Mehrkosten des Verfahrens (anders als bei den anderen Verfahren wird ein verrohrtes Bohrloch im Boden nahe dem Pfahl benötigt) halten sich in Grenzen, wenn man es in die geotechnische Untersuchung integriert. Daher wurde es inzwischen auch in der Praxis eingesetzt. Auch liegen die Gesamtkosten für die Untersuchung deutlich unter denen für eventuell notwendigen Ersatz – oder Verstärkungsmaßnahmen, die notwendig werden, wenn keine Daten zur Pfahllänge verfügbar sind. Der Vortrag erläutert die Ergebnisse der Machbarkeitsstudie, zeigt erste Praxisfälle und weist auf Möglichkeiten hin, das Parallel-Seismik Verfahren in Zukunft noch genauer und effizienter einzusetzen. T2 - Baugrundtagung 2016 CY - Bielefeld, Germany DA - 15.09.2016 KW - Mast KW - Pile KW - Pfahl KW - Länge KW - Parallel-Seismik KW - Integritätsprüfung KW - Tower KW - Length KW - Parallel-seismic KW - Integrity-testing PY - 2016 AN - OPUS4-37647 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Ertel, Jens-Peter A1 - Sochor, M. A1 - Unseld, H. T1 - Nachbestimmung von Pfahllängen am Beispiel von Masten N2 - Im Rahmen der Lebensdauerverlängerung oder der Umnutzung von Bauwerken (z. B. Brücken, Bürogebäude oder Maste) müssen diese zum Teil neu bewertet werden. Dafür ist eine Nachrechnung für statische und dynamische Lastfälle erforderlich. Dies betrifft zum einen die Struktur selbst, die gegebenenfalls verstärkt werden muss. Aber auch die Gründung (oft Pfähle verschiedenster Typen) muss neu beurteilt werden. Nach mehreren Jahrzehnten sind jedoch für einige Bauwerke keine zuverlässigen Bestandsunterlagen verfügbar. Eine vollständige Freilegung der Pfähle verbietet sich aus Kostengründen sowie Verlust an Widerstand gegen Zug. Lediglich der Pfahlanschluss kann visuell begutachtet werden, um Pfahlzahl, -typ und Durchmesser zu bestimmen. Für die Bestimmung der Pfahllänge müssen zerstörungsfreie Verfahren eingesetzt werden. In einer Machbarkeitsstudie wurden von den Autoren teils im Blindversuch drei Verfahren evaluiert: die klassische Pfahlintegritätsprüfung nach der Hammerschlagmethode, eine mehrkanalige Variante hierzu und das Parallel-Seismik-Verfahren. Die ersten beiden Methoden lieferten an den untersuchten Pfählen nur in Einzelfällen verwertbare Ergebnisse. Die Parallel-Seismik-Methode lieferte auch im Blindversuch an Fundamenten, bei denen die Pfahllänge dem Eigentümer bekannt war, Ergebnisse mit einer Abweichung von max. 0,5 m. Diese Toleranz lässt sich bei der Standfestigkeitsbeurteilung berücksichtigen. Die Mehrkosten des Verfahrens (anders als bei den anderen Verfahren wird ein verrohrtes Bohrloch im Boden nahe dem Pfahl benötigt) halten sich in Grenzen, wenn man es in die geotechnische Untersuchung integriert. Daher wurde es inzwischen auch in der Praxis eingesetzt. Auch liegen die Gesamtkosten für die Untersuchung deutlich unter denen für eventuell notwendigen Ersatz – oder Verstärkungsmaßnahmen, die notwendig werden, wenn keine Daten zur Pfahllänge verfügbar sind. Der Vortrag erläutert die Ergebnisse der Machbarkeitsstudie, zeigt erste Praxisfälle und weist auf Möglichkeiten hin, das Parallel-Seismik Verfahren in Zukunft noch genauer und effizienter einzusetzen. T2 - 34. Baugrundtagung CY - Bielefeld, Germany DA - 15.09.2016 KW - Mast KW - Pfahl KW - Länge KW - Parallel-Seismik KW - Integritätsprüfung PY - 2016 SN - 9783946039013 SP - 31 EP - 36 PB - DGGT CY - Essen AN - OPUS4-37648 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Geophysik im Bauwesen - ein Überblick N2 - Überblick über den Einsatz verschiedener geophysikalischer Verfahren in der zerstörungsfreien Prüfung im Bauwesen T2 - Workshop Geophysikalische Untersuchungen an Bauwerken CY - Neustadt/W., Germany DA - 05.10.2016 KW - Geophysik KW - ZfP KW - Bauwesen PY - 2016 AN - OPUS4-37719 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Ertel, Jens-Peter A1 - Sochor, M. A1 - Unseld, H. T1 - Nachbestimmung von Pfahllängen am Beispiel von Masten. N2 - Im Rahmen der Lebensdauerverlängerung oder der Umnutzung von Bauwerken (z. B. Brücken, Bürogebäude oder Maste) müssen diese zum Teil neu bewertet werden. Dafür ist eine Nachrechnung für statische und dynamische Lastfälle erforderlich. Dies betrifft zum einen die Struktur selbst, die gegebenenfalls verstärkt werden muss. Aber auch die Gründung (oft Pfähle verschiedenster Typen) muss neu beurteilt werden. Nach mehreren Jahrzehnten sind jedoch für einige Bauwerke keine zuverlässigen Bestandsunterlagen verfügbar. Eine vollständige Freilegung der Pfähle verbietet sich aus Kostengründen sowie Verlust an Widerstand gegen Zug. Lediglich der Pfahlanschluss kann visuell begutachtet werden, um Pfahlzahl, -typ und Durchmesser zu bestimmen. Für die Bestimmung der Pfahllänge müssen zerstörungsfreie Verfahren eingesetzt werden. In einer Machbarkeitsstudie wurden von den Autoren teils im Blindversuch drei Verfahren evaluiert: die klassische Pfahlintegritätsprüfung nach der Hammerschlagmethode, eine mehrkanalige Variante hierzu und das Parallel-Seismik-Verfahren. Die ersten beiden Methoden lieferten an den untersuchten Pfählen nur in Einzelfällen verwertbare Ergebnisse. Die Parallel-Seismik-Methode lieferte auch im Blindversuch an Fundamenten, bei denen die Pfahllänge dem Eigentümer bekannt war, Ergebnisse mit einer Abweichung von max. 0,5 m. Diese Toleranz lässt sich bei der Standfestigkeitsbeurteilung berücksichtigen. Die Mehrkosten des Verfahrens (anders als bei den anderen Verfahren wird ein verrohrtes Bohrloch im Boden nahe dem Pfahl benötigt) halten sich in Grenzen, wenn man es in die geotechnische Untersuchung integriert. Daher wurde es inzwischen auch in der Praxis eingesetzt. Auch liegen die Gesamtkosten für die Untersuchung deutlich unter denen für eventuell notwendigen Ersatz – oder Verstärkungsmaßnahmen, die notwendig werden, wenn keine Daten zur Pfahllänge verfügbar sind. Der Vortrag erläutert die Ergebnisse der Machbarkeitsstudie, zeigt erste Praxisfälle und weist auf Möglichkeiten hin, das Parallel-Seismik Verfahren in Zukunft noch genauer und effizienter einzusetzen. T2 - Workshop Geophysikalische Untersuchungen an Bauwerken CY - Neustadt/W., Germany DA - 05.10.2016 KW - Parallel-Seismik KW - Mast KW - Pfahl KW - Länge PY - 2016 AN - OPUS4-37720 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Wiggenhauser, Herbert T1 - Coda wave interferometry used for monitoring of concrete constructions N2 - Ultrasonic transmission measurements on concrete; embedded transducers; coda wave interferometry to check for subtle chnages in velocity as indicator for various loads or deterioration. T2 - 76. Jahrestagung der Deutschen Geophysikalischen Gesellschaft CY - Münster, Germany DA - 14.03.2016 KW - Ultrasound KW - Transmission KW - Coda wave interferometry KW - Concrete KW - Load PY - 2016 AN - OPUS4-37721 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Inspection and monitoring of massive concrete structures by innovative ultrasonic methods N2 - Presentation on recent progress in ultrasinic testing and monitoring of concrete for massive structures. First, a new instrument (LAUS) for ultrasonic echo testing of thicknesses up to 5 m is shown. A new method to provide better images of the concrete interior, Reverse Mitem Migration (RTM)is presented. Second, the use of embedded ultrasonic transducers and data processing methods borrowed from seismology to detect subtle changes in concrete are documented. T2 - NUCCON 2016 CY - Helsinki, Finland DA - 31.10.2016 KW - Ultrasound KW - Concrete KW - Imaging KW - Monitoring KW - Nuclear PY - 2016 AN - OPUS4-38181 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Grohmann, Maria A1 - Müller, Sabine A1 - Niederleithinger, Ernst T1 - Reverse time migration: Introduction of a new imaging technique for ultrasonic measurements in civil engineering N2 - Ultrasonic echo testing is widely used in non-destructive testing in civil engineering to investigate concrete structures, to measure thickness, and to locate and characterise built-in components or inhomogeneities. Currently, synthetic aperture focusing techniques are mostly used for imaging. These algorithms are highly developed but have some limitations. For example, it is not possible to image the lower boundary of built-in components like tendon ducts or vertical reflectors. We adopted reverse time migration for non-destructive testing in civil engineering in order to improve the imaging of complicated structures in concrete. By using the entire wavefield, including waves reflected more than once, there are fewer limitations compared to synthetic aperture focusing technique algorithms. As a drawback, the required computation is significantly higher than that for the techniques currently used. Simulations for polyamide and concrete structures showed the potential for non-destructive testing. The simulations were followed by experiments at a polyamide specimen. Here, having acquired almost noise-free measurement data to test the algorithm, we were able to determine the shape and size of boreholes with sufficient accuracy. After these successful tests, we performed experiments at a reinforced concrete foundation slab. We obtained information from the data by reverse time migration, which was not accessible by traditional imaging. The imaging of the location and structure of the lower boundary of the concrete foundation slab was improved. Furthermore, vertical reflectors inside the slab were imaged clearly, and more flaws were found. It has been shown that reverse time migration is a step forward in ultrasonic testing in civil engineering. T2 - NDT-CE 2015 - International symposium non-destructive testing in civil engineering CY - Berlin, Germany DA - 15.09.2015 KW - Ultrasound KW - Imaging KW - Reverse time migration KW - Reflection seismics KW - Concrete PY - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-345406 SN - 1435-4934 SP - 1 EP - 10 PB - Technische Universität Berlin / Bundesanstalt für Materialforschung und -prüfung AN - OPUS4-34540 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Niederleithinger, Ernst A1 - Wolf, Julia A1 - Mielentz, Frank A1 - Wiggenhauser, Herbert A1 - Pirskawetz, Stephan T1 - Embedded ultrasonic transducers for active and passive concrete monitoring N2 - Recently developed new transducers for ultrasonic transmission, which can be embedded right into concrete, are now used for non-destructive permanent monitoring of concrete. They can be installed during construction or thereafter. Large volumes of concrete can be monitored for changes of material properties by a limited number of transducers. The transducer design, the main properties as well as installation procedures are presented. It is shown that compressional waves with a central frequency of 62 kHz are mainly generated around the transducer's axis. The transducer can be used as a transmitter or receiver. Application examples demonstrate that the transducers can be used to monitor concrete conditions parameters (stress, temperature, …) as well as damages in an early state or the detection of acoustic events (e.g., crack opening). Besides application in civil engineering our setups can also be used for model studies in geosciences. KW - Ultrasound KW - Transmission KW - Concrete KW - Damages KW - Cracks KW - Stress KW - Monitoring KW - Acoustic emission KW - Transducers KW - Coda wave interferometry PY - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-345632 SN - 1424-8220 VL - 15 IS - 5 SP - 9756 EP - 9772 PB - MDPI CY - Basel AN - OPUS4-34563 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Wolf, Julia A1 - Mielentz, Frank A1 - Wiggenhauser, Herbert A1 - Pirskawetz, Stephan T1 - Active and passive ultrasonic experiments with transducers embedded in concrete T2 - CARGESE summer School: "Passive Imaging and monitoring in wave physics: from seismology to ultrasound" CY - Cargese, France DA - 2015-05-11 PY - 2015 AN - OPUS4-34376 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wiggenhauser, Herbert A1 - Niederleithinger, Ernst T1 - NDT-CE 2015: International symposium non-nestructive testing in civil engineering N2 - The legend continued: The International Symposium NonDestructive Testing in Civil Engineering (NDT-CE) had returned to Berlin. The Bundesanstalt für Materialforschung und -prüfung (BAM) and the Technical University of Berlin (TUB) hosted this prestigious event in the industrial landmark building Peter-Behrens-Halle and the Test Site Technical Safety (TTS) in Horstwalde in September 2015. Almost 300 participants from more than 35 countries gathered to present recent research, exchange knowledge and to lest the newest equipment in NDT-CE. This symposium, held regularly in various locations all over the world, was organized for the third time in Berlin and is by far the largest of its kind. KW - Non-destructive testing KW - Civil engineering KW - Conference PY - 2015 SN - 0934-6554 IS - 3 SP - 53 EP - 54 PB - Deutsche Geophysikalische Gesellschaft CY - Münster AN - OPUS4-35097 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Ertel, Jens-Peter A1 - Grohmann, Maria ED - Stahlmann, J. T1 - Low-Strain-Pfahlintegritätsprüfung reloaded: Geht nicht doch ein bisschen mehr? N2 - Die beiden in dieser Arbeit dargestellten Beispiele zeigen, dass sich die Low-strain-Pfahlintegritätsprüfung noch über den bisherigen, schon sehr erfolgreichen Stand hinaus entwickeln kann. Der Einsatz von Vibratortechnik und passender mathematischer Methoden bietet das Potential, Prüfungen auch unter bisher nicht lösbaren Randbedingungen durchzuführen. Dazu gehören sehr schlanke Pfähle und Messungen bei hohem Störpegel. Der erhöhte Mess- und Auswerteaufwand ist jedoch im Einzelfall gegenüber dem erzielbaren Erfolg abzugleichen. Apparativ müssen noch Entwicklungsarbeiten geleistet werden, um einen einfachen und zuverlässigen Einsatz in der Praxis zu ermöglichen. Die Messung mit mehreren Sensoren entlang des Pfahls kann schon heute in der Praxis eingesetzt werden. In vielen Fällen lassen sich damit auch Messungen an Pfählen im Bestand durchführen, bei denen die konventionelle Pfahlprüfung aufgrund von überlagernden Signalen aus der aufgehenden Struktur versagt. T2 - Pfahl-Symposium 2015 - Fachseminar CY - Braunschweig, Germany DA - 19.02.2015 KW - Pfahlprüfung KW - Integritätsprüfung KW - Vibrator KW - Mehrkanalmethode KW - Dekonvolution PY - 2015 SN - 3-927610-92-5 N1 - Serientitel: Mitteilung des Instituts für Grundbau und Bodenmechanik - Technische Universität Braunschweig – Series title: Mitteilung des Instituts für Grundbau und Bodenmechanik - Technische Universität Braunschweig IS - 99 SP - 117 EP - 135 PB - TU Braunschweig, Institut für Grundbau und Bodenmechanik AN - OPUS4-32643 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Neue Ideen für die zerstörungsfreie prüfung von beton: Seismische Interferometrie und mehr T2 - DGZfP Jahrestagung 2014 CY - Potsdam DA - 2014-05-26 PY - 2014 AN - OPUS4-33708 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Sens-Schönfelder, Ch. A1 - Flores, H. A1 - Köllner, F. A1 - Müller, Sabine A1 - Parolai, S. A1 - Pilz, M. A1 - Pomponi, E. A1 - Schuck, A. T1 - MIIC - Monitoring and Imaging based on Interferometric Concepts T2 - Jahrestagung der Deutschen Geophysikalischen Gesellschaft 2013 CY - Leipzig DA - 2013-03-04 PY - 2013 AN - OPUS4-33710 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Cotic, P. A1 - Jaglicic´, Z. A1 - Bosiljkov, V. T1 - GRP and IR Thermography for near-surface defect detection in building structures T2 - The 12th International Conference of the slovenian Society for non-Destructive Testing CY - Ljubljana, Slovenia DA - 2013-09-04 PY - 2013 AN - OPUS4-33704 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Cotic, P. T1 - Unsupervised Fusion of Scattered data Collected by a Multi-Sensor Robot on Concrete T2 - DGZfP Jahrestagung 2014 CY - Potsdam DA - 2014-05-26 PY - 2014 AN - OPUS4-33705 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Douma, J. A1 - Snieder, R. T1 - Improved Focusing Using Deconvolution within a Concrete Block T2 - DGZfP Jahrestagung 2014 CY - Potsdam DA - 2014-05-26 PY - 2014 AN - OPUS4-33706 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Krompholz, R. A1 - Müller, Sabine A1 - Lautenschläger, R. A1 - Kittler, J. T1 - 36 Jahre Talsperre Eibenstock - 36 Jahre Überwachung des Betonzustands durch Ultraschall N2 - Ultraschall-Transmissionsmessungen werden seit Jahrzehnten bei der Qualitätssicherung von Betonkonstruktionen eingesetzt. Aus den Wellengeschwindigkeiten lassen sich dynamische Elastizitätsmoduln und – nach lokaler Kalibrierung – auch Druckfestigkeiten ermitteln. Zudem ergeben sich Hinweise auf Risse und andere Materialschwächungen. Der Einsatz erfolgt vor allem im Labor oder an der Bauwerksoberfläche. Neuerdings werden auch Monitoringsysteme mit eingebetteten Sensoren auf Ultraschallbasis erfolgreich getestet. Die Talsperre Eibenstock dient als größte Sperre in Sachsen der Trinkwasserversorgung und dem Hochwasserschutz. Hier wurden während der Bauphase im Jahr 1979 im Fußbereich des Mauerkörpers Ultraschallsensoren eingebracht, die in Verbindung mit einem Messoszilloskop eine Überwachung der Erhärtung des Mauerbetons ermöglichten. Der für die Sensorauswahl eingesetzte Messstellenumschalter wurde im September 2011 grundlegend instand gesetzt. Danach zeigte sich, dass die eingebetteten Sensoren selbst sowie die Verkabelung auch nach über fünfunddreißig Jahren in einwandfreiem Zustand sind. Eine nunmehr aufgelegte Messserie mit modernem Gerät von über einem Jahr mit ein- bis zweimonatigen Intervallen zeigte, dass die Wellengeschwindigkeit seit der Bauphase noch einmal um gut 10 % zugenommen hat, was für eine erhöhte Druckfestigkeit spricht. Innerhalb des Jahres zeigten sich auch bei Einsatz neuer, sehr sensibler Auswertemethoden (sog. Codawelleninterferometrie) nur geringfügige Schwankungen. Diese waren auch nicht zu erwarten, da sich die Füllhöhe zu den Messzeitpunkten nur gering unterschied, die Temperatur im Bauwerksinneren nur wenig schwankte und der Bauwerkszustand sehr gut ist. Die Aussagen zur Betongüte sind direkt vergleichbar mit den früheren Mess- und Untersuchungsergebnissen an der Talsperre Gottleuba, die im gleichen Zeitraum errichtet wurde und ebenfalls mit einem Ultraschallsystem ausgerüstet war. Die Experimente zeigten, dass ein Einsatz von Ultraschallsystemen für die Bauwerksüberwachung auch über Jahrzehnte möglich ist. Dies war im vorliegenden Fall nie geplant, aber durch den Einsatz der Mitarbeiter vor Ort und der Herstellerfirma möglich. Bei zukünftigen Systemen ist eine langfristige Planung unter Einbeziehung aller Beteiligten sowie eine Einbindung in Überwachungs- und Wartungspläne notwendig, damit die qualitätsgesichert gewonnen Daten gewinnbringend genutzt werden können. T2 - 38. Dresdner Wasserbaukolloquium CY - Dresden, Germany DA - 05.03.2015 KW - Talsperre KW - Ultraschall KW - Beton KW - Überwachung KW - Monitoring PY - 2015 SN - 978-3-86780-420-2 SN - 0949-5061 N1 - Serientitel: Dresdner Wasserbauliche Mitteilungen – Series title: Dresdner Wasserbauliche Mitteilungen IS - 53 SP - 171 EP - 180 AN - OPUS4-32754 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Ertel, Jens-Peter A1 - Grohmann, Maria T1 - 36 Jahre Talsperre Eibenstock - 36 Jahre Überwachung des Betonzustands durch Ultraschall T2 - 38. Dresdner Wasserbaukolloquium 2015 CY - Dresden, Deutschland DA - 2015-03-05 PY - 2015 AN - OPUS4-32720 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Cotic, Patricia A1 - Jaglicic, Z. A1 - Niederleithinger, Ernst A1 - Stoppel, Markus A1 - Bosiljkov, V. T1 - Image fusion for improved detection of near-surface defects in NDT-CE using unsupervised clustering methods N2 - The capabilities of non-destructive testing (NDT) methods for defect detection in civil engineering are characterized by their different penetration depth, resolution and sensitivity to material properties. Therefore, in many cases multi-sensor NDT has to be performed, producing large data sets that require an efficient data evaluation framework. In this work an image fusion methodology is proposed based on unsupervised clustering methods. Their performance is evaluated on ground penetrating radar and infrared thermography data from laboratory concrete specimens with different simulated near-surface defects. It is shown that clustering could effectively partition the data for further feature level-based data fusion by improving the detectability of defects simulating delamination, voids and localized water. A comparison with supervised symbol level fusion shows that clustering-based fusion outperforms this, especially in situations with very limited knowledge about the material properties and depths of the defects. Additionally, clustering is successfully applied in a case study where a multi-sensor NDT data set was automatically collected by a self-navigating mobile robot system. KW - Non-destructive testing KW - Concrete KW - Defect detection KW - Data fusion KW - Cluster analysis KW - Image fusion KW - Thermography KW - Radar KW - Ultrasonics KW - Defects PY - 2014 U6 - https://doi.org/10.1007/s10921-014-0232-1 SN - 0195-9298 SN - 1573-4862 VL - 33 IS - 3 SP - 384 EP - 397 PB - Plenum Press CY - New York, NY AN - OPUS4-33831 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Cotic, P. A1 - Jaglicic, Z. A1 - Bosiljkov, V. A1 - Niederleithinger, Ernst T1 - GPR an IR thermography for near-surface defect detection in building structures N2 - Ground penetrating radar (GPR) and infrared (IR) thermography techniques have been used in many civil engineering applications for the structural visualization and defect detection. However, validation tests of the methods performance for the defection of defects in the nearsurface region with respect to the defects different material and depth below the surface are lacking. To overcome this, we performed GPR and IR thermography tests where the different material properties, shape and depth of defects were studied on concrete and the evaluation of seismic related damage propagation was assessed on stone masonry walls. The results showed that IR thermography, though being greatly affected by the presence of water in the specimen, outperformed GPR in the detection of defects very close to the surface. However, already at the depth of 3 cm and further up till almost 7.5 cm, the performance of GPR resembles the one of IR thermography for the detection of polystyrene (air) voids. On the plastered masonry walls, IR thermography could detect an air gap resulting from plaster delamination as small as 2 mm. Moreover, structural cracking resulting from the induced lateral load could be detected at an early stage. T2 - 12th International conference of the Slovenian society for non-destructive testing - Application of contemporary non-destructive testing in engineering CY - Ljubljana, Slovenia DA - 04.09.2013 KW - Radar KW - Thermography KW - Defects KW - Non-destructive testing validation KW - Concrete KW - Masonry KW - Near-surface defects KW - Ground PY - 2013 UR - http://www.ndt.net/article/ndt-slovenia2013/papers/225.pdf SP - 1 EP - 8 AN - OPUS4-33793 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Cotic, P. A1 - Niederleithinger, Ernst A1 - Stoppel, Markus T1 - Unsupervised fusion of scattered data collected by a multi-sensor robot on concrete N2 - At BAM a multi-sensor robot system BetoScan is used for the investigation of reinforced concrete floors affected by corrosion in parking garages. Potential maps, as well as the distribution of concrete cover and moisture can be assessed simultaneously and data can be collected contactlessly. In order to evaluate the extent of degradation adequately and to divide the investigated structure into zones with defined damage classes, large data sets have to be collected and interpreted manually. Thus, to promote an efficient data evaluation framework, which could speed up and simplify the evaluation of large data sets, an unsupervised data fusion is of major interest. However, taking into account that collected data do not certainly coincide in space, a scattered data interpolation method should be applied prior data fusion. In the paper, a case study involving a BetoScan data set acquired from a reinforced concrete floor of a parking garage in Germany is presented. The data set includes potential mapping, covermeter based on eddy current, as well as microwave moisture measurements. Among the examined methods for interpolation of scattered data, kriging shows to yield smooth interpolated data plots even in the case of very sparse data. In the post-processing step, the investigated structure is efficiently segmented into zones using clustering based data fusion methods, which prove to be robust enough also for handling noisy data. Based on the minimization of the XB validity index, an unsupervised selection of optimal segmentation into damage classes is derived. T2 - DGZfP-Jahrestagung 2014 CY - Potsdam, Germany DA - 26.05.2014 KW - Robot KW - Data fusion KW - Ultrasonics KW - Radar KW - Potential method PY - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-337943 UR - http://www.ndt.net/article/dgzfp2014/papers/di2c1.pdf SN - 978-3-940283-61-0 IS - DGZfP-BB 148 SP - Di.2.C.1, 1 EP - 8 PB - Deutsche Gesellschaft für Zerstörungsfreie Prüfung (DGZfP) AN - OPUS4-33794 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Douma, J. A1 - Niederleithinger, Ernst A1 - Snieder, R. T1 - Improved focusing using deconvolution within a concrete block N2 - Time reversal techniques are used in ocean acoustics, medical imaging and non-destructive evaluation to backpropagate recorded signals to the source of origin. We demonstrate experimentally a technique which improves the temporal focus achieved at the source location. The experiment consists of propagating a signal from a transducer within a concrete block to a single receiver on the surface, and then applying time reversal or deconvolution to focus the energy back at the source location. The results show that we are able to generate a focus in time at the correct location. The proposed method is simple and proven to be robust. Additionally, its costs are negligible due to deconvolution being a preprocessing step to the recorded data. The technique can be applied for detailed investigation of the source mechanisms (e. g. cracks) but also for monitoring purposes. T2 - DGZfP-Jahrestagung 2014 CY - Potsdam, Germany DA - 26.05.2014 KW - Ultrasonics KW - Acoustic emission KW - Time reversal KW - Deconvolution PY - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-337953 UR - http://www.ndt.net/article/dgzfp2014/papers/di2c2.pdf SN - 978-3-940283-61-0 IS - DGZfP-BB 148 SP - Di.2.C.2, 1 EP - 8 PB - Deutsche Gesellschaft für Zerstörungsfreie Prüfung (DGZfP) CY - Berlin AN - OPUS4-33795 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Neue Ideen für die zerstörungsfreie Prüfung von Beton: Seismische Interferometrie und mehr N2 - Ultraschallverfahren haben sich im Bauwesen in den letzten Jahren immer mehr in der Praxis etabliert. Echomessungen zur Geometriebestimmung sind Stand der Technik. In der Wissenschaft gibt es zahlreiche Ideen, die Messmethodik und die Auswertung weiter zu verbessern sowie den Einsatzbereich zu erweitern. Erste eingebettete Ultraschallsysteme zum Langzeitmonitoring sind installiert, Mehrkanalgeräte ermöglichen immer größere Aperturen und Eindringtiefen, verbesserte Abbildungsverfahren zeigen immer mehr Details. Zusätzlich lassen sich Verfahren aus der Geophysik adaptieren, die weiteren Fortschritt versprechen. Die Seismische Interferometrie dient klassisch dazu, Materialeigenschaften des Erduntergrundes mittels seismischer Wellen zu bestimmen. Derzeitige Anwendungsbereiche sind die Verbesserung seismischer Abbildungsverfahren, Interpolation seismischer Spuren (A-Scans), Bestimmung von Quellparametern oder die Eliminierung unerwünschter Signale in passiven und aktiven Experimenten, hauptsächlich durch Kreuzkorrelation und Bestimmung Greenscher Funktionen. Diese Techniken können auch auf Ultraschalldaten, die an Betonkonstruktionen erfasst wurden, angewendet werden. Moderne Abbildungsverfahren benötigen eine möglichst hohe A-Scan-Dichte und eine genaue Kenntnis des Quellsignals. Beides ist nicht unbedingt gegeben, z. B. wegen der physischen Größe der Sensoren und wechselnder Ankopplungsbedingungen. In simulierten und realen Experimenten wurden interferometrische Methoden zur Lösung dieser Aufgabenstellungen evaluiert. Es zeigt sich, dass fehlende A-Scans kinematisch korrekt interpoliert werden können, wenn ausreichend viele Sender- und Empfängerpositionen genutzt wurden. Amplituden und Signalform sind verändert, können aber durch adaptive Filterung angepasst werden. Die Quellsignalform kann mit hoher Genauigkeit rekonstruiert werden. Die Ergebnisse können potentiell zu einer Verbesserung der Abbildung des Inneren der untersuchten Objekte genutzt werden. T2 - DGZfP-Jahrestagung 2014 CY - Potsdam, Germany DA - 26.05.2014 KW - Zerstörungsfreie Prüfung KW - Geophysik PY - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-337967 UR - http://www.ndt.net/article/dgzfp2014/papers/di1c1.pdf SN - 978-3-940283-61-0 IS - DGZfP-BB 148 SP - Di.1.C.1, 1 EP - 8 PB - Deutsche Gesellschaft für Zerstörungsfreie Prüfung (DGZfP) CY - Berlin AN - OPUS4-33796 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - State-of-the-art of ultrasonic monitoring of concrete N2 - Ultrasonic methods are well established in various aspects of concrete testing. They are used for imaging the interior geometry of constructions, estimation of concrete strength or monitoring lab investigations. However, so far the detection of distributed damages, especially in an early stage, has been almost impossible. The arrival of new technologies as embedded transducers and sensitive data processing techniques adopted from seismology has opened new field of work. Recent research has been focused to detect changes in concrete elements induced by stress, temperature, moisture or chemical attacks by permanent monitoring. Techniques as Coda Wave Interferometry can resolve changes in ultrasonic velocity in the order of 1*10-5. In addition, many researchers believe that the investigation of nonlinear effects can be used to characterize damages. The workshop will give a wrap up of ultrasonic techniques currently used in practice. This will include echo based methods as multi-channel/multi-offset imaging of structural elements using commercial and prototype devices. Imaging methods as SAFT and RTM will be shortly discussed. The focus will be on the emerging techniques used for monitoring. New types of sensors will be presented as well as the devices used in laboratory and field applications. Insight will be given on the various influence factors on ultrasonic signals and various ways of feature extraction and data processing. The results of lab experiments will be shown to demonstrate the detection of various kind of damages from mechanical load, ASR, corrosion to fatigue. The experiences with or first installations in real constructions (bridges, tunnel) will also be presented. T2 - The 8th Australian Network of Structural Monitoring Annual Workshop CY - Melbourne, Australia DA - 29.11.2016 KW - Ultrasound KW - Concrete KW - Monitoring KW - Imaging PY - 2016 AN - OPUS4-38727 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Progress in non-destructive testing and monitoring of concrete N2 - The presentation will give an overview on non-destructive testing techniques being developed at the Federal Institute for Materials Research and Testing, Germany (BAM). This includes ultrasonic methods, ground penetration radar, Laser-Induced Breakdown Spectroscopy (LIBS), infrared thermography, pile testing, sensor technology and building scanner. A focus of the talk will be ultrasonic methods, which are well established in various aspects of concrete testing. They are used for imaging the interior geometry of constructions, estimation of concrete strength or monitoring lab investigations. However, so far the detection of distributed damages, especially in an early stage, has been almost impossible. The arrival of new technologies as embedded transducers and sensitive data processing techniques adopted from seismology has opened new field of work. Recent research has been focused to detect changes in concrete elements induced by stress, temperature, moisture or chemical attacks by permanent monitoring. Techniques as Coda Wave Interferometry can resolve changes in ultrasonic velocity in the order of 1*10-5. In addition, many researchers believe that the investigation of nonlinear effects can be used to characterize damages. The presentation will give a wrap up of ultrasonic techniques currently used in practice. This will include echo based methods as multi-channel/multi-offset imaging of structural elements using commercial and prototype devices. Imaging methods as SAFT and RTM will be shortly discussed. The focus will be on the emerging techniques used for monitoring. New types of sensors will be presented as well as the devices used in laboratory and field applications. Insight will be given on the various influence factors on ultrasonic signals and various ways of feature extraction and data processing. The results of lab experiments will be shown to demonstrate the detection of various kind of damages from mechanical load, ASR, corrosion to fatigue. The experiences with our first installations in real constructions (bridges, tunnel) will also be presented. T2 - CIES Research Seminar, University of New South Wales CY - Sydney, Australia DA - 13.12.2016 KW - Ultrasound KW - Concrete KW - Monitoring KW - Imaging PY - 2016 AN - OPUS4-38731 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Progress in non-destructive testing and monitoring of concrete N2 - The presentation will give an overview on non-destructive testing techniques being developed at the Federal Institute for Materials Research and Testing, Germany (BAM). This includes ultrasonic methods, ground penetration radar, Laser-Induced Breakdown Spectroscopy (LIBS), infrared thermography, pile testing, sensor technology and building scanner. A focus of the talk will be ultrasonic methods, which are well established in various aspects of concrete testing. They are used for imaging the interior geometry of constructions, estimation of concrete strength or monitoring lab investigations. However, so far the detection of distributed damages, especially in an early stage, has been almost impossible. The arrival of new technologies as embedded transducers and sensitive data processing techniques adopted from seismology has opened new field of work. Recent research has been focused to detect changes in concrete elements induced by stress, temperature, moisture or chemical attacks by permanent monitoring. Techniques as Coda Wave Interferometry can resolve changes in ultrasonic velocity in the order of 1*10-5. In addition, many researchers believe that the investigation of nonlinear effects can be used to characterize damages. The presentation will give a wrap up of ultrasonic techniques currently used in practice. This will include echo based methods as multi-channel/multi-offset imaging of structural elements using commercial and prototype devices. Imaging methods as SAFT and RTM will be shortly discussed. The focus will be on the emerging techniques used for monitoring. New types of sensors will be presented as well as the devices used in laboratory and field applications. Insight will be given on the various influence factors on ultrasonic signals and various ways of feature extraction and data processing. The results of lab experiments will be shown to demonstrate the detection of various kind of damages from mechanical load, ASR, corrosion to fatigue. The experiences with our first installations in real constructions (bridges, tunnel) will also be presented. T2 - CIE Research Seminar, University of Western Sydney, New South Wales CY - Sydney, Australia DA - 15.12.2016 KW - Ultrasound KW - Concrete KW - Monitoring KW - Imaging PY - 2016 AN - OPUS4-38732 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Niederleithinger, Ernst A1 - Abraham, O. A1 - Mooney, M. T1 - Special Issue on Geophysics for Non-destructive Testing in Civil Engineering Foreword N2 - Foreword to a special issue of "Near Surface Geophysics" on the application of geophysical techniques to non-destructive testing in civil engineering KW - geophysics non-destructive testing PY - 2016 U6 - https://doi.org/10.3997/1873-0604.2016043 SN - 1569-4445 VL - 14 IS - 6 SP - 479 EP - 480 PB - EAGE CY - Houton, NL AN - OPUS4-38984 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kruschwitz, Sabine A1 - Niederleithinger, Ernst T1 - ERT Measurements on tailings dams using multi-channel spectral induced polarization (SIP) N2 - The often poor construction and low maintenance level of tailings dams has caused serious accidents. The EC funded Project TAILSAFE is aimed at the non-destructive assessment of tailings facilities for stabilization analyses and the development of better management methods. The focus of geophysical field studies was on the discrimination of different layering and construction steps as well as the determination of the spatial (relative) water content in the dams. SIP measurements at three tailings facilities different in their geological backgrounds, composition and age have been conducted. T2 - 11th European Meeting of Environmental and Engineering Geophysics CY - Palermo, Italy DA - 04.09.2005 KW - TAILSAFE KW - Non-destructive assessment KW - Stabilization analyses PY - 2005 AN - OPUS4-36560 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Coelho Lima, Isabela A1 - Grohmann, Maria A1 - Niederleithinger, Ernst T1 - Alternative imaging conditions for reverse-time migration N2 - Poster on the evaluation of several imaging conditions for reverse time migration, applied to ultrasonic echo data, tested with synthetic (simulated) dat and real data from a polyamide model. T2 - Jahrestagung der Deutschen geophysikalischen Gesellschaft CY - Leoben, Austria DA - 12.2.2018 KW - Ultrasound KW - Reverse time migration KW - Imaging condition KW - Concrete KW - Polyamide PY - 2018 AN - OPUS4-44583 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Ultrasound: From Imaging to Monitoring N2 - Review of ultrasonic echo imaging and ultrasonic monitoring techniques applied to concrete structures, especially bridges. Includes newest research results from BAM. T2 - Transport Research Board Annual Meeting, Workshop 1647 CY - Washington, DC, USA DA - 6.1.2018 KW - Ultrasound KW - Imaging KW - Monitoring KW - Concrete KW - Bridges PY - 2018 AN - OPUS4-44587 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Der Blick in die Brücke N2 - Populärwissenschaftlicher Vortrag zu jüngeren Entwicklungen beim Ultraschall für das Bauwesen. T2 - Berliner Industriegespräch der DPG CY - Berlin, Germany DA - 7.3.2018 KW - Beton KW - Ultraschall KW - Brücke PY - 2018 AN - OPUS4-44574 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Progress in non-destructive testing and monitoring of concrete N2 - Überblicksvortrag zu Aktivitäten von BAM-8.2 T2 - Seminar der Universität Lund, Fakultät, Technische Geologie und NDT CY - Lund, Sweden DA - 8.3.2018 KW - Concrete KW - Non-Destructive Testing PY - 2018 AN - OPUS4-44575 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Wiggenhauser, Herbert A1 - Milmann, Boris T1 - LAUS - Erste praktische Erfahrungen mit einem neuartigen Ultraschallsystem großer Eindringtiefe N2 - Konventionelle Systeme zur Ultraschall-Echo-Prüfung von Betonbauteilen sind in ihrer Eindringtiefe auf etwa einem Meter begrenzt. Zur Prüfung stärkerer Objekte war die Entwicklung eines neuartigen Prüfsystems notwendig. Das LAUS-System (Large Aperture UltraSound) besteht aus 12 einzelnen Arrays, die mit jeweils 32 Einzelprüfköpfen (Scherwellen, 25 – 50 kHz) als Sender oder Empfänger betrieben werden können. Sie werden unabhängig auf Betonoberflächen mit Unterdruck befestigt und kommunizieren drahtlos untereinander und mit der Zentraleinheit. Alle möglichen Kombinationen ergeben 132 Einzelmessungen, die zur Rekonstruktion des durchschallten Volumens genutzt werden. Mehrere dieser Datensätze lassen sich zu einer 3D-Auswertung kombinieren. Das System wurde an mehreren Testobjekten und Bauwerken erfolgreich erprobt. So konnte die fünf Meter dicke, sehr stark bewehrte Fundamentplatte des Fallturms auf dem BAM-Testgelände bei Horstwalde durchschallt werden. Ein zweites Beispiel ist die erfolgreiche Detektion von Spannkanälen in 1,8 m Tiefe in einem massiven Brückenbauwerk. T2 - Bauwerksdiagnose 2018 CY - Berlin, Germany DA - 15.2.2018 KW - Ultraschall KW - Beton KW - LAUS KW - Brücke KW - Fundament PY - 2018 AN - OPUS4-44577 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Wiggenhauser, Herbert A1 - Milmann, Boris T1 - LAUS - Erste praktische Erfahrungen mit einem neuartigen Ultraschallsystem großer Eindringtiefe N2 - Konventionelle Systeme zur Ultraschall-Echo-Prüfung von Betonbauteilen sind in ihrer Eindringtiefe auf etwa einem Meter begrenzt. Zur Prüfung stärkerer Objekte war die Entwicklung eines neuartigen Prüfsystems notwendig. Das LAUS-System (Large Aperture UltraSound) besteht aus 12 einzelnen Arrays, die mit jeweils 32 Einzelprüfköpfen (Scherwellen, 25 – 50 kHz) als Sender oder Empfänger betrieben werden können. Sie werden unabhängig auf Betonoberflächen mit Unterdruck befestigt und kommunizieren drahtlos untereinander und mit der Zentraleinheit. Alle möglichen Kombinationen ergeben 132 Einzelmessungen, die zur Rekonstruktion des durchschallten Volumens genutzt werden. Mehrere dieser Datensätze lassen sich zu einer 3D-Auswertung kombinieren. Das System wurde an mehreren Testobjekten und Bauwerken erfolgreich erprobt. So konnte die fünf Meter dicke, sehr stark bewehrte Fundamentplatte des Fallturms auf dem BAM-Testgelände bei Horstwalde durchschallt werden. Ein zweites Beispiel ist die erfolgreiche Detektion von Spannkanälen in 1,8 m Tiefe in einem massiven Brückenbauwerk. T2 - Fachtagung Bauwerksdiagnose 2018 CY - Berlin DA - 15.2.2018 KW - Beton KW - Ultraschall KW - LAUS KW - Brücke KW - Fundament PY - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-445786 UR - https://www.bauwerksdiagnose2018.de/Portals/bauwerksdiagnose2018/BB/16.pdf SP - Paper 16, 1 EP - 8 CY - Berlin AN - OPUS4-44578 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Buildings: Seismology and Strctural Health Monitoring N2 - Overview of seismological concepts unsed in nondestructive testing in civil engineering T2 - Fourth TIDES Advanced Training School CY - Prague, Czech Repubilc DA - 01.07.2018 KW - Geophysics KW - Seismology KW - Interferometry KW - Structural health monitoring KW - Nondestructive testing PY - 2018 AN - OPUS4-45361 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Ertel, J.-P. T1 - Foundations N2 - Overview on NDT methods for foundations as a preparation for the practical training T2 - NDT&E Advanced Training Workshop CY - Berlin, Germany DA - 27.06.2018 KW - Nondestructive testing KW - Foundations KW - Pile KW - Integrity PY - 2018 AN - OPUS4-45362 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Vössing, Konrad A1 - Niederleithinger, Ernst ED - Faix, O. T1 - Nondestructive assessment and imaging methods for internal inspection of timber. A review. N2 - This paper reviews state-of-the-art in nondestructive testing (NDT) and semidestructive testing (SDT) methods applicable for imaging the condition of structural timber. Both NDT and SDT imaging reveal defects, damages, and decay, while the extent of wood decay can also be quantified. Combined with an appropriate data interpretation concerning the internal defects, the mechanical properties of the material can also be assessed. The possibilities and limitations of the most relevant individual NDT and SDT methods, also in combination with each other, are outlined and compared. To facilitate comparison, many observations are reported based on the same test specimen. KW - Drilling resistance KW - Electrical resistivity KW - Radar KW - Radiography KW - Sonic stress wave KW - Ultrasound KW - Non destructive testing KW - Timber structure PY - 2018 U6 - https://doi.org/10.1515/hf-2017-0122 SN - 0018-3830 SN - 1437-434X VL - 72 IS - 6 SP - 467 EP - 476 PB - De Gruyter CY - Berlin AN - OPUS4-44445 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Niederleithinger, Ernst A1 - Wang, Xin A1 - Herbrand, M. A1 - Müller, M. T1 - Processing ultrasonic data by coda wave interferometry to monitor load tests of concrete beams N2 - Ultrasonic transmission measurements have been used for decades to monitor concrete elements, mostly on a laboratory scale. Recently, coda wave interferometry (CWI), a technique adapted from seismology, was introduced to civil engineering experiments. It can be used to reveal subtle changes in concrete laboratory samples and even large structural elements without having a transducer directly at the place where the change is taking place. Here, several load tests until failure on large posttensioned concrete beams have been monitored using networks of embedded transducers. To detect subtle effects at the beginning of the experiments and cope with severe changes due to cracking close to failure, the coda wave interferometry procedures had to be modified to an adapted step-wise approach. Using this methodology, we were able to monitor stress distribution and localize large cracks by a relatively simple technique. Implementation of this approach on selected real structures might help to make decisions in infrastructure asset management. KW - Ultrasound KW - Concrete KW - Monitoring KW - Coda wave interferometry KW - Embedded transducers PY - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-452328 SN - 1424-8220 VL - 19 IS - 1 SP - Article 147, 1 EP - 13 PB - MDPI CY - Basel AN - OPUS4-45232 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Abraham, O. A1 - Ferria, H. A1 - Niederleithinger, Ernst A1 - Brühwiler, E. A1 - Dalsgard Sörensen, J. A1 - Klikowicz, P. A1 - Kirsch, F. A1 - Niedermayer, H. A1 - Yalamas, T. T1 - INFRASTAR - Innovation and networking for fatigue and reliability analysis of structures - Training for assessment of risk - H2020 N2 - "INFRASTAR aims to develop knowledge, expertise and skills for optimal and reliable management of structures. The generic methodology is applied to bridges and wind turbines in relation to fatigue offering the opportunity to deal with complementary notions (such as old and new asset management, unique and similar structures, wind and traffic actions) while addressing 3 major challenges: 1/ advanced modelling of concrete fatigue behaviour, 2/new non destructive testing methods for early aged damage detection and 3/probabilistic approach of structure reliability under fatigue. Benefit of cross-experience and inter-disciplinary synergies creates new knowledge. INFRASTAR proposes innovative solutions for civil infrastructure asset management so that young scientists acquire a high employment profile in close dialogue between industry and academic partners. Modern engineering methods, including probabilistic approaches, risk and reliability assessment tools, will take into account the effective structural behaviour of existing bridges and wind turbines by exploiting monitored data. Existing methods and current state-of -the art is based on excessive conservatism which produces high costs and hinders sustainability. INFRASTAR improves knowledge for optimising the design of new structures, for more realistic verification of structural safety and more accurate prediction of future lifetime of the existing structures. That is a challenge for a sustainable development because it reduces building material and energy consumption as well as CO2 production. Within the global framework of optimal infrastructure asset management, INFRASTAR will result in a multi-disciplinary body of knowledge covering generic problems from the design stage process of the new civil infrastructures up to recycling after dismantlement. This approach and the proposed methods and tools are new and allow a step forward for innovative and effective process." KW - Concrete KW - Fatigue KW - Wind turbine KW - Bridge PY - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-447016 UR - http://www.ingentaconnect.com/content/sil/impact/2018/00002018/00000001/art00023 SN - 2398-7073 VL - 2018 IS - 1 SP - 70 EP - 72 PB - Science Impact Ltd. CY - Bristol, UK AN - OPUS4-44701 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Herbrand, Martin A1 - Müller, Matthias T1 - Codawelleninterferometrie zur Detektion von Spannungszuständen in Betonbauteilen N2 - Informationen zu in Betonbauteilen stattfindenden Umlagerungsprozessen sowie Druckspannungsverteilungen können mit konventioneller Messtechnik bislang nicht zweifelsfrei beantwortet werden. Ultraschallmessungen mit eingebetteten Sensoren könnten hier eine sinnvolle Ergänzung zur konventionellen Messtechnik sein. Durch Einsatz der Codawelleninterferometrie (CWI) sind hiermit schon sehr kleine Änderungen im Material detektierbar. Um diese neue Methodik zu evaluieren, wurde das Forschungsprojekt „Querkrafttragfähigkeit von Spannbetonbrücken – Erfassung von Spannungszuständen in den Spannbetonversuchsträgern mit Ultraschallsensoren“ durch die Bundesanstalt für Straßenwesen (BASt) initiiert. In diesem Projekt wurden durch die Bundesanstalt für Materialforschung und –prüfung (BAM) Ultraschall-Transducer in mehrere Spannbetonträger des Instituts für Massivbau der RWTH Aachen eingebettet, die anschließend bis zum Bruch belastet wurden. Der Belastungsversuch an einem der Spannbetondurchlaufträger zeigte das große Potential dieser Methodik. Die im Netzwerk erfassten Änderungen der Ultraschallwellengeschwindigkeit geben die Spannungsverhältnisse im Längsschnitt des Trägers schon bei sehr niedrigen Belastungen qualitativ richtig wieder und zeigen bei hohen Belastungen eine gute Korrelation zum Rissbild. Dabei weisen räumliche Anomalien und Änderungen in der Charakteristik der Geschwindigkeitsänderungen oft schon auf Rissbildung hin, wenn diese noch nicht an der Oberfläche sichtbar ist. Dies zeigt das Potential im Hinblick auf eine Frühwarnung. Hierfür und ebenso in Bezug auf eine Quantifizierung der Effekte ist aber noch Entwicklungsarbeit notwendig. Ein Vorteil der Methodik ist, dass die Transducer nicht direkt am Ort der Änderung platziert werden müssen und einen relativ großen Bereich um die Transducer herum erfassen. T2 - DGZfP Jahrestagung CY - Leipzig, Germany DA - 07.05.2018 KW - Ultraschall KW - Monitoring KW - Codawelleninterferometrie KW - Brückenträger PY - 2018 AN - OPUS4-44863 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Herbrand, Martin A1 - Müller, Matthias T1 - Codawelleninterferometrie zur Detektion von Spannungszuständen in Betonbauteilen N2 - Informationen zu in Betonbauteilen stattfindenden Umlagerungsprozessen sowie Druckspannungsverteilungen können mit konventioneller Messtechnik bislang nicht zweifelsfrei beantwortet werden. Ultraschallmessungen mit eingebetteten Sensoren könnten hier eine sinnvolle Ergänzung zur konventionellen Messtechnik sein. Durch Einsatz der Codawelleninterferometrie (CWI) sind hiermit schon sehr kleine Änderungen im Material detektierbar. Um diese neue Methodik zu evaluieren, wurde das Forschungsprojekt „Querkrafttragfähigkeit von Spannbetonbrücken – Erfassung von Spannungszuständen in den Spannbetonversuchsträgern mit Ultraschallsensoren“ durch die Bundesanstalt für Straßenwesen (BASt) initiiert. In diesem Projekt wurden durch die Bundesanstalt für Materialforschung und –prüfung (BAM) Ultraschall-Transducer in mehrere Spannbetonträger des Instituts für Massivbau der RWTH Aachen eingebettet, die anschließend bis zum Bruch belastet wurden. Der Belastungsversuch an einem der Spannbetondurchlaufträger zeigte das große Potential dieser Methodik. Die im Netzwerk erfassten Änderungen der Ultraschallwellengeschwindigkeit geben die Spannungsverhältnisse im Längsschnitt des Trägers schon bei sehr niedrigen Belastungen qualitativ richtig wieder und zeigen bei hohen Belastungen eine gute Korrelation zum Rissbild. Dabei weisen räumliche Anomalien und Änderungen in der Charakteristik der Geschwindigkeitsänderungen oft schon auf Rissbildung hin, wenn diese noch nicht an der Oberfläche sichtbar ist. Dies zeigt das Potential im Hinblick auf eine Frühwarnung. Hierfür und ebenso in Bezug auf eine Quantifizierung der Effekte ist aber noch Entwicklungsarbeit notwendig. Ein Vorteil der Methodik ist, dass die Transducer nicht direkt am Ort der Änderung platziert werden müssen und einen relativ großen Bereich um die Transducer herum erfassen. T2 - DGZfP Jahrestagung 2018 CY - Leipzig, Germany DA - 07.05.2018 KW - Ultraschall KW - Monitoring KW - Codawelleninterferometrie KW - Brückenträger PY - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-448642 SP - Mo.3.A.4, 1 EP - 8 PB - DGZfP AN - OPUS4-44864 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Coelho Lima, Isabela A1 - Grohmann, Maria A1 - Niederleithinger, Ernst T1 - Advanced ultrasonic imaging for concrete: Alternative imaging conditions for reverse time migration N2 - Ultrasound echo is a widely used NDT technique for determining the internal geometry of structures. Reverse-time migration (RTM) has been recently introduced to NDT applications, as an imaging method for ultrasound data, to overcome some of the limitations (e.g. imaging steeply dipping reflector) experienced by the Synthetic Aperture Focusing Technique (SAFT), the most commonly used imaging algorithm for these measurements. The standard implementation of RTM also experiences some drawbacks caused by its imaging condition, which is based on the zero-lag of the cross-correlation between source and receiver wavefields and generates high-amplitude low-frequency artifacts. Three alternative imaging conditions, developed for seismic data applications, were tested for their ability to provide better images than the standard cross-correlation: illumination compensation, deconvolution and wavefield decomposition. A polyamide specimen was chosen for the simulation of a synthetic experiment and for real data acquisition. The migrations of both synthetic and real data were performed with the software Madagascar. The illumination imaging condition was able to reduce the low-frequency noise and had a good performance in terms of computing time. The deconvolution improved the resolution in the synthetic tests, but did not showed such benefit for the real experiments. Finally, as for the wavefield decomposition, although it presented some advantages in terms of attenuating the low-frequency noise and some unwanted reflections, it was not able to image the internal structure of the polyamide as well as the cross-correlation did. Suggestions on how to improve the cost-effectiveness of the implementation of the deconvolution and wavefield decomposition were presented, as well as possible investigations that could be carried out in the future, in order to obtain better results with those two imaging conditions. T2 - DGZfP Jahrestagung 2018 CY - Leipzig DA - 07.05.2018 KW - Ultrasound KW - Reverse time migration KW - Imaging condition KW - Concrete PY - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-448704 SP - Mi.3.A.4, 1 EP - 10 PB - DGZfP AN - OPUS4-44870 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Coelho Lima, Isabela A1 - Niederleithinger, Ernst A1 - Grohmann, Maria T1 - Alternative imaging conditions for reverse time migration N2 - Ultrasound echo is a widely used NDT technique for determining the internal geometry of structures. Reverse-time migration (RTM) has been recently introduced to NDT applications, as an imaging method for ultrasound data, to overcome some of the limitations (e.g. imaging steeply dipping reflector) experienced by the Synthetic Aperture Focusing Technique (SAFT), the most commonly used imaging algorithm for these measurements. The standard implementation of RTM also experiences some drawbacks caused by its imaging condition, which is based on the zero-lag of the cross-correlation between source and receiver wavefields and generates high-amplitude low-frequency artifacts. Three alternative imaging conditions, developed for seismic data applications, were tested for their ability to provide better images than the standard cross-correlation: illumination compensation, deconvolution and wavefield decomposition. A polyamide specimen was chosen for the simulation of a synthetic experiment and for real data acquisition. The migrations of both synthetic and real data were performed with the software Madagascar. The illumination imaging condition was able to reduce the low-frequency noise and had a good performance in terms of computing time. The deconvolution improved the resolution in the synthetic tests, but did not showed such benefit for the real experiments. Finally, as for the wavefield decomposition, although it presented some advantages in terms of attenuating the low-frequency noise and some unwanted reflections, it was not able to image the internal structure of the polyamide as well as the cross-correlation did. Suggestions on how to improve the cost-effectiveness of the implementation of the deconvolution and wavefield decomposition were presented, as well as possible investigations that could be carried out in the future, in order to obtain better results with those two imaging conditions. T2 - DGZfP Jahrestagung 2018 CY - Leipzig, Germany DA - 07.05.2018 KW - Ultrasound KW - Reverse time migration KW - Imaging condition KW - Concrete PY - 2018 AN - OPUS4-44873 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zheng, H. A1 - Ertel, Jens-Peter A1 - Kourmpetis, M. A1 - Kanfoud, J. A1 - Niederleithinger, Ernst A1 - Gan, T.-H. T1 - Integrity testing of cast in situ concrete piles based on an impulse response function method using sine‑sweep excitation by a shaker N2 - In this study, an Impulse Response Function analysis of pile response to sine-sweep excitation by a low cost, portable Shaker was used to identify defects in piles. In straightforward impact-echo methods, echoes from the pile toe and defects are visible in the time domain measurements. However, these echoes are not present in the time domain records of piles subjected to sine-sweep excitations, due to interactions between the input and output signals. For this reason, the impulse response function in the time domain has been calculated and is able to identify the echoes from pile impedance changes. The proposed methodology has been evaluated both numerically and experimentally. A one-dimensional pile-soil interaction system was developed, and a finite difference method used to calculate the pile response to sine-sweep excitation. The numerical simulations indicate that impulse response measurements with a synthesized logarithmic, sine-sweep excitation could be an effective tool for detecting defects in piles. The methodology was further tested with field trials on 6 cast in situ concrete test piles including 1 intact pile and 5 defective piles subjected to sine-sweep excitations by a shaker. In 5 of the 6 cases the echoes from the pile toe could be identified in the deconvoluted waveforms—the impulse Response functions. Damage detection is more difficult and dependent on the selection of the optimal regularization parameter. Further research and optimization of the deconvolution process is needed to evaluate the effectiveness compared to standard pile integrity testing methods. KW - Pile testing KW - Shaker KW - Deconvolution PY - 2019 U6 - https://doi.org/10.1007/s10921-019-0595-4 SN - 0195-9298 SN - 1573-4862 VL - 38 IS - 2 SP - 55, 1 EP - 18 PB - Springer CY - Cham, Switzerland AN - OPUS4-48185 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Wiggenhauser, Herbert A1 - Helmerich, Rosemarie A1 - Krause, Martin A1 - Mielentz, Frank A1 - Niederleithinger, Ernst A1 - Taffe, Alexander A1 - Wilsch, Gerd ED - Naus, D. T1 - Non-destructive Testing of Nuclear Power Plant Concrete Structures State of the Art Report N2 - Nuclear Power Plants have been in operation for ca. 50 years. Based on this experience, non-destructive testing tasks specific to thick and highly reinforced nuclear containment structures have materialized. The performance based Service life extension of existing NPPs also needs a measurement based decision to support continuing the service of the concrete part of the installations. By nature, concrete is a very durable material and any natural Deterioration processes may take a long time to become critical to the structure. The experience of more than 50 years of service limits the testing tasks to a few ones which are not yet solved. Research in NDT of concrete structures is performed by many research institutions all over the world with different technical and systematic approaches. Results are mainly obtained on laboratory specimens, sometimes additional field studies are reported. This research takes place independently without coordination and as a result, the outcomes mostly lack full comparability. Software for data analysis has become indispensable and very powerful. This part of testing needs more attention when it comes to evaluate test results. Validation of NDE solutions is becoming a critical part in concrete structure testing. Validation is by definition the proof that a customer´s requirements in the test are being met by the testing solution. This includes equipment, personnel qualification and data analysis. In the following tables, the research recommendation Validation is used in the sense, that proof of the performance of existing solutions needs to be adressed. In general, a validation methodology for NDE solutions for concrete testing in itself needs to be researched and established. Comparability of research also needs an accepted and easily accessible reference. From experience, it is almost impossible to manufacture exact copies of test specimens at different locations. Round Robin tests are therefore needed to evaluate the performance of a test. Data evaluation is generally done using dedicated software, sometimes Hardware dependant and not interchangeable between systems. Software is ever more increasingly becoming more powerful and sophisticated. An in-depth evaluation needs to address the comparability and validation of Software used for data analysis and evaluation. The vision of a unified software pool for NDE investigations would undoubtedly support research tremendously. Quantitative NDE is mostly recommended to assess the condition of a structure. However, qualitative data can be very useful, especially for processes which change the material properties or deteriorate the structure (e.g. corrosion of reinforcement). The need for reliable baseline data is a key factor for such monitoring tasks. KW - Nuclear structures KW - Non-destructive testing KW - State of the art KW - Research needs PY - 2013 SP - 1 EP - 120 PB - BAM CY - Berlin AN - OPUS4-51049 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Clauß, F. A1 - Epple, Niklas A1 - Ahrens, M. A. A1 - Niederleithinger, Ernst A1 - Mark, P. T1 - Comparison of Experimentally Determined Two-Dimensional Strain Fields and Mapped Ultrasonic Data Processed by Coda Wave Interferometry N2 - Due to the high sensitivity of coda waves to the smallest structural alterations such as strain, humidity or temperature changes, ultrasonic waves are a valid means to examine entire structures employing networks of ultrasonic transducers. In order to substantiate this ex ante assessment, the viability of measuring ultrasonic waves as a valid point of reference and inference for structural changes is to be further scrutinized in this work. In order to investigate the influence of mechanical strain on ultrasonic signals, a four-point bending test was carried out on a reinforced concrete beam at Ruhr University Bochum. Thus, measurements collected from a network of selected transducer pairings arranged across the central, shear-free segment of the test specimen, were correlated to their respective strain fields. Detected ultrasonic signals were evaluated employing Coda Wave Interferometry. Such analysis comprised the initial non-cracked state as well as later stages with incremental crack depth and quantity. It was to ascertain that the test specimen can in fact be qualitatively compartmentalized into areas of compression and tension identified via Relative Velocity Changes presented in Attribute Maps. However, since results did not entail a zero crossing, i.e., neither positive nor negative values were to be calculated, only relative changes in this work displayed staggered over the height of the object under test, are discussed. Under the given methodological premises, additional information is currently required to make quantitative assertions regarding this correlation of ultrasonic and strain results. This holds true for the comparability of the ultrasonic and strain results for both non-cracked and even the cracked state. KW - Digital image correlation KW - Fiber optic sensors KW - Coda Wave Interferometry KW - Ultrasound KW - Concrete PY - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-510501 SN - 1424-8220 VL - 20 IS - 14 SP - Paper 4023, 1 PB - MDPI CY - Basel AN - OPUS4-51050 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Progress in using geophysical methods in foundation quality assurance and inspection N2 - Modern geophysical methods might be either directly applied to foundations or integrated into existing testing schemes to assist in quality assurance and inspections. This paper gives an overview on available ideas and some more detailed examples from the author `s work including: - Vibrator technologies to improve pile integrity testing. - Ideas from vertical seismic profiling used in multichannel pile inspection - Cross- and downhole seismics to check the diameter of jet grouting columns - Improving the parallel seismic methods for precise length measurement of piles and foundation walls - Seismic migration methods to improve ultrasonic imaging of foundation slabs - Seismological tools to monitor subtle changes in concrete constructions The author strongly believes that the cooperation between geophysics and civil engineering, which is obviously becoming stronger and stronger, will lead to a large number of innovative approaches for investigations tasks currently still unresolved. A lot of challenges and chances for science and technology are right here. T2 - SAGEEP CY - Denver, CO, USA DA - 20.03.2016 KW - Non-destructive testing KW - Piles KW - Foundations KW - Slabs KW - Parallel seismic KW - Vibrator KW - Integrity PY - 2016 SP - paper 45, 1 EP - 7 AN - OPUS4-35704 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Levee inspection - geophysics between science, standards, reliability and budgets N2 - Numerous case histories show evidence that geophysical methods are valuable tools for levee inspection and monitoring. National and international standards and recommendations recommend the use of geophysics for a variety of tasks. However, in some cases reported have been flaws missed or false indications given. Due to the larger variety in type, size and construction of levees and the even larger variety of potential tasks and targets the success of geophysical surveys still pretty much depends on the available budget and the experience and capabilities of the clients and contractors involved. It is strongly recommended that all relevant parties agree on the detailed objectives of the survey, required accuracy and reliability of the results and any follow up measures. For the most common tasks more research and practical work using techniques as POD (probability of detection), which are well established in other fields of non-destructive testing, would be of benefit. T2 - SAGEEP 2016 CY - Denver, CO, USA DA - 20.03.2016 KW - Levee KW - Geophysics KW - Inspection PY - 2016 SP - paper levees 07, 1 EP - 4 AN - OPUS4-35705 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Progress in using geophysical methods for foundation quality assurance and inspection N2 - Modern geophysical methods might be either directly applied to foundations or integrated into existing testing schemes to assist in quality assurance and inspections. This paper gives an overview on available ideas and some more detailed examples from the author `s work including: - Vibrator technologies to improve pile integrity testing. - Ideas from vertical seismic profiling used in multichannel pile inspection - Cross- and downhole seismics to check the diameter of jet grouting columns - Improving the parallel seismic methods for precise length measurement of piles and foundation walls  Seismic migration methods to improve ultrasonic imaging of foundation slabs  Seismological tools to monitor subtle changes in concrete constructions The author strongly believes that the cooperation between geophysics and civil engineering, which is obviously becoming stronger and stronger, will lead to a large number of innovative approaches for investigations tasks currently still unresolved. A lot of challenges and chances for science and technology are right here. T2 - SAGEEP 2016 CY - Denver, CO, USA DA - 20.03.2016 KW - Non-destructive testing KW - Piles, foundations KW - Slabs KW - Parallel seismic KW - Vibrator KW - Integrity PY - 2016 AN - OPUS4-35706 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Levee inspection - geophysics between science, standards, reliability and budgets N2 - Numerous case histories show evidence that geophysical methods are valuable tools for levee inspection and monitoring. National and international standards and recommendations recommend the use of geophysics for a variety of tasks. However, in some cases reported have been flaws missed or false indications given. Due to the larger variety in type, size and construction of levees and the even larger variety of potential tasks and targets the success of geophysical surveys still pretty much depends on the available budget and the experience and capabilities of the clients and contractors involved. It is strongly recommended that all relevant parties agree on the detailed objectives of the survey, required accuracy and reliability of the results and any follow up measures. For the most common tasks more research and practical work using techniques as POD (probability of detection), which are well established in other fields of non-destructive testing, would be of benefit. T2 - SAGEEP 2016 CY - Denver, CO, USA DA - 20.03.2016 KW - Levee KW - Inspection KW - Geophysics PY - 2016 AN - OPUS4-35707 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Bearce, R. A1 - Mooney, M. A1 - Galindo Guerreros, Julio Cesar A1 - Mackens, S. A1 - Fechner, T. T1 - Innovative seismic and resistivity tools for determining the diameter of jet grouting columns N2 - Jet grouting is used for soil improvement, foundation support and groundwater low control all over the world. It is well accepted and subject of standardization in many countries. However, some issues with the method remain. As the grout columns are produced in the subsurface without visual control in an often inhomogeneous soil, the prediction of the column’s diameter is still a challenge. All methods applied so far have their limitations. The approach presented in this study is twofold. At Colorado School of Mines a resistivity probe has been developed, which is pushed into the fresh grout directly after production. ERT sections are measured and inverted. Given some background information is available, the diameter of the columns can be evaluated. At BAM the focus has been on post-production investigations using seismic borehole methods. After hardening of the concrete seismic waves are sent through the column downhole (sensors placed in a casing in the column’s axis, source on top) and crosshole (source and sensor in boreholes on opposite sides of the column). We have developed a scheme to evaluate the diameter of the column based on travel time measurements without calibration. As this method is eventually more time and cost intensive we assume its application mainly for test columns. These are casted and dug out for visual inspection to determine appropriate grouting parameters. Our method would replace the often very cost intensive visual inspection. Both approaches have been tested at three test columns produced at BAM’s test site at Horstwalde, Germany and on an actual constructions site. Both methods have been in good agreement with the diameters predicted by the jet grouting contractors, which were confirmed in one case by mechanical measurements. T2 - SAGEEP 2016 CY - Denver, CO, USA DA - 20.03.2016 KW - Jet grouting KW - Diameter KW - Quality assurance KW - Seismic PY - 2016 AN - OPUS4-35708 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Wiggenhauser, Herbert T1 - Coda wave interferometry used for monitoring of concrete constructions N2 - Concrete is known to be a very useful, flexible and durable construction material. However, due to excess load, fatigue, chemical processes, freeze-thaw or reinforcement corrosion concrete may suffer from degradation. If detected too late, repair is difficult and expensive. The propagation of ultrasonic waves is influenced by changes in the properties and structure of the material, including, but not limited to, stress, temperature, moisture content and microcracking. Ultrasonic velocieties thus may serve as indicators for structural health. Traditional ultrasonic methods as transmission time of flight measurements are used since decades, but are not sensible enough to show subtle changes. Coda Wave Interferometry (CWI), originally developed in seismology to detect stress changes in the earth's crust uses the information in the late part of ultrasonic signals originating from multiple reflections and scattering. Since a few years it is used by several researchers for lab experiments on concrete. Meanwhile specialized sensors to be embedded in concrete have been developed. We have conducted several lab and a few field experiments, which will be reported here. The capabilities and limitations of CWI are summarized. T2 - Jahrestagung der DGG CY - Münster DA - 14.03.2016 KW - Coda wave interferometry KW - Concrete KW - Monitoring KW - Ultrasound PY - 2016 AN - OPUS4-35710 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Abraham, O. A1 - Mooney, M. T1 - Geophysical methods in civil engineering: Overview and new concepts T2 - NDT-CE 2015 - International Symposium Non-destructive Testing in Civil Engineering CY - Berlin, Germany DA - 2015-09-15 PY - 2015 AN - OPUS4-35205 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Wolf, Julia A1 - Mielentz, Frank A1 - Pirskawetz, Stephan A1 - Wiggenhauser, Herbert T1 - Using embedded ultrasonic sensors for active and passive concrete monitoring T2 - NDT-CE 2015 - International Symposium Non-destructive Testing in Civil Engineering CY - Berlin, Germany DA - 2015-09-15 PY - 2015 AN - OPUS4-35206 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Grohmann, Maria A1 - Niederleithinger, Ernst A1 - Buske, S. T1 - Geometry Determination of a Foundation Slab Using the Ultrasonic Echo Technique and Geophysical Migration Methods N2 - The ultrasonic echo technique is a frequently used method in non destructive testing for geometry Determination of concrete building elements. Important tasks are thickness measurements as well as the localization and characterization of built-in components and inhomogeneities. Currently mainly the synthetic aperture focusing family of techniques (SAFT) is used for imaging. These algorithms have difficulties in imaging steeply dipping interfaces and complicated structures such as steps and lower boundaries of voids. As an alternative two geophysical migration methods, pre-stack Kirchhoff depth migration and pre-stack Reversetimemigration (RTM)were tested in this paper at a reinforced concrete foundation slab. The slab consists of various reinforcement contents, different thicknesses and two pile heads. In a first step, both methods were evaluated with synthetic 2D data. In the second step, ultrasonic measurement data recorded with shear wave transducers on a line profile on the foundation slab were processed. The use of an automatic scanner simplified the measurements. A comparison of the geophysical migration results with those of SAFT shows, in particular for RTM, a significant improvement in the Imaging of the geometry of the foundation slab. Vertical borders were reconstructed and the location and structure of the lower boundary of the foundation slab were reproduced better. Limitations still exist in imaging the piles below the slab. KW - Kirchhoff migration KW - Ultrasonic echo technique KW - Synthetic aperture focusing technique (SAFT) KW - Reverse-time migration PY - 2016 U6 - https://doi.org/10.1007/s10921-016-0334-z SN - 0195-9298 (Print) 1573-4862 (Online) VL - 2016/Band 1 IS - 35:1 SP - 1 EP - 13 PB - Springer CY - New York AN - OPUS4-35838 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Douma, J. A1 - Niederleithinger, Ernst A1 - Snieder, R. T1 - Locating events using time reversal and deconvolution: experimental application and analysis N2 - Time reversal techniques are used in ocean acoustics, medical imaging, seismology, and non-destructive evaluation to backpropagate recorded signals to the source of origin. We demonstrate experimentally a technique which improves the temporal focus achieved at the source location by utilizing deconvolution. One experiment consists of propagating a signal from a transducer within a concrete block to a single receiver on the surface, and then applying time reversal or deconvolution to focus the energy back at the source location. Another two experiments are run to study the robust nature of deconvolution by investigating the effect of changing the stabilization constant used in the deconvolution and the impact multiple sources have upon deconvolutions’ focusing abilities. The results show that we are able to generate an improved temporal focus at the source transducer using deconvolution while maintaining the robust nature of time reversal. Additionally, deconvolution’s costs are negligible due to it being a preprocessing step to the recorded data. The technique can be applied for detailed investigation of the source mechanisms (e.g. cracks) but also for monitoring purposes. KW - Time reversal KW - Deconvolution KW - Concrete KW - Acoustic emission KW - Ultrasound PY - 2015 U6 - https://doi.org/10.1007/s10921-015-0276-x SN - 0195-9298 SN - 1573-4862 VL - 34 IS - 2 SP - 1 EP - 9 PB - Plenum Press CY - New York, NY AN - OPUS4-33017 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Ertel, Jens-Peter A1 - Grohmann, Maria T1 - Low-Strain-Pfahlintegritätsprüfung reloaded – geht nicht doch ein bisschen mehr? T2 - Pfahl-Symposium 2015 an der TU Braunschweig CY - Braunschweig, Deutschland DA - 2015-02-19 PY - 2015 AN - OPUS4-32660 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bearce, R.G. A1 - Mooney, M.A. A1 - Niederleithinger, Ernst A1 - Revil, A. T1 - Characterization of simulated soilcrete column curing using acoustic tomography N2 - Implementation of soilcrete columns via jet grouting or deep soil mixing to stabilize problematic subsurface soils is common in underground construction. However, industry is faced with limited options to characterize column geometry and quality of the resulting soilcrete without excavation or destructive testing. Laboratory-scale experiments were conducted on simulated soilcrete columns using crosshole ultrasonic testing to evaluate the feasibility of acoustic tomography to characterize soilcrete geometry and quality. Data were acquired on multiple columns immediately after placement up to a curing time of 120 hours. Jet grout compressional wave velocity (VP) was estimated using a first arrival time approach and inverted to construct acoustic tomograms. Acoustic tomograms indicate that crosshole ultrasonic testing is able to characterize the changes in acoustic properties that result from jet-grout curing, locate contrasts between weaker/stronger regions in the jet grout, and estimate geometry of the column. T2 - Geo-congress 2014 CY - Atlanta, Georgia, USA DA - 23.02.2014 KW - Jet grouting KW - Ultrasound KW - Tomography KW - Ray tracing KW - Simulation PY - 2014 SN - 978-0-7844-1327-2 U6 - https://doi.org/10.1061/9780784413272.044 N1 - Serientitel: Geotechnical Special Publication (GSP) – Series title: Geotechnical Special Publication (GSP) VL - 234 SP - 465 EP - 474 AN - OPUS4-32601 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Niederleithinger, Ernst A1 - Abraham, O. A1 - Mooney, M. T1 - Geophysical methods in civil engineering: Overview and new concepts N2 - Geophysical methods have been used in civil engineering for decades. The main field of application is - to no surprise – in geotechnical projects from site characterization to foundation quality assurance. For more than 25 years, ground penetrating radar (GPR) and seismic methods have found applications in structural engineering. Recently introduced geophysical methods have been adopted to ultrasonic investigations in various fields. They help to improve the quality of structural imaging and to detect small changes in concrete. An overview of the history and current use of geophysics in civil engineering is given. Selected examples of new concepts include advances in wave based imaging, quality assurance for foundations, detecting small changes in concrete as well as moisture and corrosion detection are discussed. T2 - NDT-CE 2015 - International symposium non-destructive testing in civil engineering CY - Berlin, Germany DA - 15.09.2015 KW - Nondestructive testing KW - Civil engineering KW - Geophysics PY - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-344666 UR - https://www.ndt.net/?id=18260 SN - 1435-4934 VL - 20 IS - 11 SP - 1 EP - 6 PB - NDT.net CY - Kirchwald AN - OPUS4-34466 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - 3G - Geophysical Methods Delivering Input to Geostatistical Methods for Geotechnical Site Characterization T2 - Fifth International Symposium on Geotechnical Safety and Risk (ISGSR) CY - Rotterdam, Netherlands DA - 2015-10-13 PY - 2015 AN - OPUS4-34427 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Galindo Guerreros, Julio Cesar A1 - Mackens, S. A1 - Fechner, Th. T1 - Quality Assurance of Jet Grouting Columns Using Seismic Methods T2 - EAGE Near Surface Geoscience CY - Torino, Italy DA - 2015-09-06 PY - 2015 AN - OPUS4-34428 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zheng, H. A1 - Kappatos, V. A1 - Niederleithinger, Ernst A1 - Ertel, Jens-Peter A1 - Grohmann, Maria A1 - Selcuk, C. A1 - Gan, T.-H. T1 - Defect detection in concrete pile using impulse response measurements with sine sweep excitations N2 - For pile integrity inspection, a low cost and portable shaker was used to create the sine sweep signal for pile excitation. The impulse response function, calculated by the deconvolution of pile response from the sine sweep excitation, was proposed to identify the echoes in the piles due to the pile’s impedance changes. The proposed methodology has been evaluated and validated both numerically and experimentally. Based on the results from the simulations and experiments, it was found that the impulse response measurement with sine sweep excitation could be an effective tool to detect the echoes of the pile toe and the defects in the pile. T2 - NDT-CE 2015 - International symposium non-destructive testing in civil engineering CY - Berlin, Germany DA - 15.09.2015 KW - Impulse response function KW - Sine sweep excitation KW - Pile integrity KW - Damage detection PY - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-347157 SN - 1435-4934 SP - 1 EP - 4 PB - Technische Universität Berlin / Bundesanstalt für Materialforschung und -prüfung AN - OPUS4-34715 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ertel, Jens-Peter A1 - Niederleithinger, Ernst A1 - Grohmann, Maria T1 - Old ideas to improve pile integrity testing revisited and optimized N2 - Low strain pile integrity testing is an established method in QA of foundation piles. The technique is very effective and well accepted for larger flaws and length determination. It is part of standards and recommendations. Challenges exist for more complicated structures (e. g. pile walls, diaphragm walls, and pile under structures) and small flaws. Interpretation is subjective in many cases. Possible solutions, e.g. the use of vibrators instead of a hammer or application of several sensors instead of one have been proposed decades ago, but not used much in practice. In several projects we are working on the extension and optimizations of these ideas, based on input from other engineering disciplines. In the frame of the project PileInspect we are working with an international consortium on the use of vibrators instead of a hand held hammer. This allows the full control of input signals as well as the use of (semi)automatic classification routines from machine diagnosis. At BAM we are using a low cost vibrator and deconvolution routines to improve the results of classical low strain testing. In another project we are working on multichannel measurements with sensor placement along the pile axis. This can be used to determine the travel direction of certain waves (downwards or upwards) to improve the interpretation of measurements on piles below constructions or pile walls. The use of ideas adapted from geophysics („vertical seismic profiling“) are helpful. Both concepts are proven by simulations results and first field tests. T2 - NDT-CE 2015 - International symposium non-destructive testing in civil engineering CY - Berlin, Germany DA - 15.09.2015 KW - Pile inspect KW - Ultraseismic KW - Low strain pile integrity testing KW - Piles KW - Shaker KW - Deconvolution KW - Vertical seismic profiling PY - 2015 SN - 1435-4934 SP - 1 EP - 4 AN - OPUS4-34716 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Amir, J. M. A1 - Schneider, N. T1 - New possibilities for quality assurance of diaphragm wall joints N2 - Diaphragm walls are used to provide a stable and watertight confinement for the construction of tunnels, Underground railway stations, deep basements and other structures requiring deep excavations. Water seepage and soil loss through the joints have occurred on several occasions, causing extensive damage. This may have been due to uncontrolled concrete flow between the joints, unexpected geologic conditions or just poor workmanship. Different ways of quality assurance are applied on construction sites. Most of them rely on recording Parameters of the construction equipment and conventional concrete quality control. In the frame of the EUREKA/ZIM project DiWaQ we have looked at several ways to perform non-destructive Quality control. Some methods are to be applied after excavation before concreting (phase 1); others after the wall is completed (phase 2). For phase 1 we have used two different principles for checking the shape of the excavation, especially the joint to existing panels. A mechanical device which can be adapted to the excavating Equipment was developed; field tested and validated on test and construction sites. It is described in detail in another paper in the same volume. A sonar-based device with a 10 mm resolution has shown good performance in the lab, but is still under development. For phase 2 different temperature sensors have been lowered into access holes to monitor the hydration heat developed during concrete curing. The same tubes can also be used to perform electromagnetic and ultrasonic crosshole measurements across or along joints to detect flaws. Especially the ultrasonic method has shown promising results on Validation specimen at the BAM test site at Horstwalde, but limitations as well. Success substantially depended on the joint type, flaw size and distance of the sensors to the joint. T2 - International conference on piling & deep foundations CY - Stockholm, Sweden DA - 21.05.2014 KW - Diaphragm walls KW - Joints KW - Integrity KW - Crosshole sonic logging KW - Sonar PY - 2014 UR - http://www.piletest.com/papers/Niederleithinger_et_al_2014_Stockholm_2014.pdf SP - 911 EP - 918 AN - OPUS4-31201 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Niederleithinger, Ernst T1 - DGZfP-Merkblatt B08 zur seismischen Baugrunderkundung - Informationen zu Verfahren, Einsatzbereichen, Beauftragung und Qualitätssicherung N2 - Seismische Methoden, die mithilfe elastischer Wellen Informationen über den Untergrund liefern, spielen in der Baugrunderkundung eine immer größere Rolle. Die einschlägigen Regelwerke weisen zwar auf diese Methoden hin, geben aber keine näheren Hinweise zu Methodenauswahl oder Einsatzbereichen. Das neue Merkblatt B08 'Seismische Baugrunderkundung', das seit Kurzem bei der DGZfP (Deutsche Gesellschaft für Zerstörungsfreie Prüfung) online und gedruckt auf Deutsch und Englisch erhältlich ist, will diese Lücke schließen. Die Grundlagen der Seismik werden kurz und knapp beschrieben, ebenso wie die zahlreichen Einzelmethoden mit ihren Anwendungsmöglichkeiten und Grenzen. Dabei wird sowohl auf Anwendungen von der Erdoberfläche aus wie auch auf Bohrlochmethoden und Offshore-Techniken eingegangen. Eine Applikationsmatrix hilft bei der Methodenauswahl. Hinweise zu Ausschreibungen fehlen ebenso wenig wie Maßnahmen zur Qualitätssicherung. Das Merkblatt richtet sich an alle, die seismische Messungen zur Baugrunderkundung ausschreiben oder anbieten bzw. mit den Ergebnissen arbeiten.---------------------------------------------------------------------------Information on methods, applications, contracting and quality assurance: Seismic methods, which are acquiring information about the subsurface using elastic waves, are more and more used in site investigation. These techniques and their fields of application are mentioned in standards and regulations but not described or explained in detail. The new guideline B08 'Site Investigation by Seismic methods' has been published by DGZFP (German Society for Non-Destructive Testing) recently and is available in print and online in German and English. Basic concepts of seismic exploration are described shortly as well as the numerous techniques including fields of application and limitations. This includes surface, borehole and offshore methods. Hints on fields of application are given in a matrix like structure. Comments on tendering and bidding are included as well as measures for quality assurance. This guideline is for all, who need or offer geophysical services. KW - Baugrund KW - Seismik KW - Merkblatt KW - Baugrunderkundung KW - Boden KW - Elastische Parameter KW - Normen/Vorschriften/Richtlinien KW - Bauausführung PY - 2014 U6 - https://doi.org/10.1002/best.201400029 SN - 0005-9900 SN - 1437-1006 VL - 109 IS - 7 SP - 500 EP - 502 PB - Ernst CY - Berlin AN - OPUS4-31203 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Sens-Schönfelder, C. A1 - Grothe, Sven A1 - Wiggenhauser, Herbert T1 - Coda wave interferometry used to localize compressional load effects on a concrete specimen N2 - Coda Wave Interferometry (CWI), a method to evaluate subtle changes of elastic wave velocity in a medium, has been proven to be effective to detect small changes or ultrasonic velocity in concrete caused by load, temperature, moisture, damage or other means. While classical CWI is just able to determine velocity changes globally in relatively large areas between and around pairs of transmitters and receivers, several approaches have been proposed to identify the area affected by the changes more precisely. Most of them are based on the calculation of sensitivity kernels for de-correlation of signals measured at a specific state against a reference. Others follow simplified approaches. In a laboratory setup a concrete specimen of 1:5 x 1:5 x 0:5 m3 was compressed at a certain point. Maximum loads of 20 to 100 kN have been applied in 5 to 10 kN steps in various cycles. The specimen is equipped with 18 embedded ultrasonic broadband piezo transceivers (60 kHz central frequency). Ten of these receivers have been connected to a multiplexer and ultrasonic transmitting and receiving equipment in a way that allowed almost continuous two way measurements between all sensor pairs. Even simple ways to evaluate the data (e.g. crosscorrelation between signals at different load states) allowed pinpointing the load center at least approximately. A more detailed data evaluation either using CWI or even more one of the more sophisticated localization algorithms gave “sharper” results in terms of localization and a better correlation between load and velocity change/de-correlation. The results are used in upcoming monitoring systems for concrete structures. T2 - 7th European workshop on structural health monitoring CY - Nantes, France DA - 08.07.2014 KW - Concrete KW - Ultrasound KW - Coda wave inteferometry KW - Tomography KW - Correlation KW - Stress KW - Monitoring PY - 2014 SP - Paper WeBT6.3, 1427 EP - 1433 AN - OPUS4-31204 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sens-Schönfelder, C. A1 - Niederleithinger, Ernst A1 - Gassenmeier, M. A1 - Thiemann, K. A1 - Köllner, F. T1 - Monitoring and imaging based on interferometric concepts N2 - Utilization of coherent phase information in complex wave fields forms the basis of interferometric time series analysis. The concept is known since decades, but until about 15 years ago there have been no practical implementations. Meanwhile seismic interferometry is used in a wide range from investigations of the earth’s deep crust to engineering applications. Focused on monitoring and imaging the MIIC (Monitoring and Imaging based on Interferometric Concepts) project as part of the German GeoTechnologien program has contributed to this development. Special attention was given to the transfer of methodology to different length scales that range from centimeters, in laboratory applications, over geotechnical scales to even kilometers in seismological applications. General purpose methods and open source software was developed, which can be used on all scales. The core of the MIIC software is a Python library organized in different modules for various processing tasks. A graphical user interface facilitates the creation of processing routines by visualizing connections and dependencies of variables and by checking the consistency of data types. Example applications have included carbon sequestration, salt mine and railroad embankment monitoring as well as imaging changes in concrete constructions. T2 - 7th European workshop on structural health monitoring CY - Nantes, France DA - 08.07.2014 KW - Ultrasound KW - Seismics KW - Interferometry KW - Monitoring KW - Tomography KW - Concrete KW - Correlation KW - Stress KW - Coda wave interferometry PY - 2014 SP - Paper WeBT6.5, 1441 EP - 1448 AN - OPUS4-31205 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Spruit, R. A1 - Van Tol, F. A1 - Broere, W. A1 - Slob, E. A1 - Niederleithinger, Ernst T1 - Detection of anomalies in diaphragm walls with crosshole sonic logging N2 - Crosshole sonic logging (CSL) can be used to determine the quality of joints in a diaphragm wall. Tests conducted on laboratory models have provided reference information for interpretation of field data. During two large construction projects, CSL has been implemented for quality control of diaphragm walls. The field experiences have shown the benefits of the tests and the predictive value of the reference measurements. KW - Crosshole sonic logging (CSL) KW - Diaphragm wall KW - Joint KW - Quality control PY - 2014 U6 - https://doi.org/10.1139/cgj-2013-0204 SN - 0008-3674 SN - 1208-6010 VL - 51 IS - 4 SP - 369 EP - 380 CY - Toronto, Ont. AN - OPUS4-31192 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Niederleithinger, Ernst A1 - Ranz Garcia, J. T1 - Quality assurance of diaphragm walls by sonar measurements - model study N2 - Diaphragm walls are used to provide a stable and water-tight confinement for the construction of tunnels, underground railway stations, deep basements and other structures requiring deep excavations. These walls consist of individual panels, cast piece-wise in the ground, separated by water-tight joints. There are several methods to improve the water tightness of these joints, including rubber bands, metal sheets or precast concrete elements. In most cases, diaphragm walls perform very well. Quality problems, which occur in a few occasions, may be due to uncontrolled concrete flow between the joints, unexpected geological conditions or poor workmanship. Different methods of quality assurance are applied on construction sites. Sonar instruments can be used in a bentonite-filled trench to evaluate the shape of the excavation. An improved prototype instrument has been developed, including digital data-processing features, which allow the detection of even small anomalies at the stop-end surface before concreting the adjacent panel. The sonar sensor can be used in depths up to 200 m. Model experiments show that a centimetre resolution can be achieved. Set-up, model experiments and their results are shown. The prototype might be the basis of an easy-to-use commercial device. KW - Diaphragm walls KW - Field testing & monitoring KW - Quality control KW - Sonar KW - Quality assurance KW - Deconvolution KW - Betonite PY - 2014 U6 - https://doi.org/10.1680/geng.13.00038 SN - 1751-8563 SN - 1353-2618 VL - 166 SP - GE 1, Article 1300038, 1 EP - 10 PB - Telford CY - London AN - OPUS4-31193 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wang, Xin A1 - Chakraborty, J. A1 - Bassil, A. A1 - Niederleithinger, Ernst T1 - Detection of Multiple Cracks in Four-Point Bending Tests Using the Coda Wave Interferometry Method N2 - The enlargement of the cracks outside the permitted dimension is one of the main causes for the reduction of service life of Reinforced Concrete (RC) structures. Cracks can develop due to many causes such as dynamic or static load. When tensile stress exceeds the tensile strength of RC, cracks appear. Traditional techniques have limitations in early stage damage detection and localisation, especially on large-scale structures. The ultrasonic Coda Wave Interferometry (CWI) method using diffuse waves is one of the most promising methods to detect subtle changes in heterogeneous materials, such as concrete. In this paper, the assessment of the CWI method applied for multiple cracks opening detection on two specimens based on four-point bending test is presented. Both beams were monitored using a limited number of embedded Ultrasonic (US) transducers as well as other transducers and techniques (e.g., Digital Image Correlation (DIC), LVDT sensors, strain gauges, and Fiber Optics Sensor (FOS)). Results show that strain change and crack formation are successfully and efficiently detected by CWI method even earlier than by the other techniques. The CWI technique using embedded US transducers is undoubtedly a feasible, efficient, and promising method for long-term monitoring on real infrastructure. KW - Coda wave interferometry KW - Reinforced concrete KW - Cracks KW - SHM KW - Damage detection PY - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-506666 VL - 20 IS - 7 SP - 1 EP - 17 PB - MDPI CY - Basel AN - OPUS4-50666 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Recent advances in NDE of concrete structures at BAM N2 - This talk gives an introduction to BAM and its NDT-CE division. Specific challenges in NDT-CE are discussed as well as recent research results. T2 - NDE 2019 Pre-Conference Tutorial PCT 4 CY - Bangalore, India DA - 03.12.2019 KW - NDT KW - Civil engineering PY - 2019 AN - OPUS4-50168 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - NDE of foundations N2 - This talk teaches the basic princioles and applications of NDT methods for deep foundations, sprecifically piles. A variety of testing methods are discussed (integrity testing, ultrasonic crosshole logging, parallel seismic and others). Capabilities and limitations are given as well as specific hints for practical use. T2 - NDE 2019 Pre-Conference Tutorial PCT 4 CY - Bangalore, India DA - 03.12.2019 KW - NDT KW - Foundation KW - Pile KW - Integrity testing PY - 2019 AN - OPUS4-50169 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Ultrasonic methods for concrete: To boldly see, what we have not seen before N2 - This keynote talk at NDE 2019 discusses specific progress in ultrasonic testing of concrete structures. A deep penetration instrument (LAUS) is introduced as well as advanced imaging methods adopted from geophysics and new approaches to ultrasonic monitoring. T2 - NDE 2019 CY - Bangalore, India DA - 05.12.2019 KW - NDT KW - Concrete KW - Ultrasound KW - Imaging KW - Monitoring PY - 2019 AN - OPUS4-50170 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Vössing, Konrad A1 - Gaal, Mate A1 - Niederleithinger, Ernst ED - Ross, R. ED - Sauter, U. T1 - Contactless testing of wood-based materials with novel air-coupled ultrasonic transducers N2 - The detection of delamination, rot and cracks causing a decrease of strength in wooden construction elements is a key task for nondestructive testing (NDT). Air-coupled ultrasound (ACU) is used to detect flaws without having to provide contact to the surface or otherwise affect the object. Novel ferroelectric transducers with a high signal-to-noise ratio enable an accurate flaw detection. Transducers made of cellular polypropylene (PP) are suitable for characterizing wood-based materials (WBM) because their extremely low Young’s modulus and low density mean a favorable acoustic impedance for the transmission of ultrasonic waves between the transducer and air. The transducers can be applied during the production of WBM and during its service life. The device enables a fast in-situ recognition of defects with frequencies between 90 kHz and 250 kHz. Measurements can be performed in through transmission for a high resolution or in pulse-echo technique in case of one-sided access at the expense of reduced signal strength. Ultrasonic quality assurance for wood is an important attempt to increase the acceptance of wooden structures and towards sustainability in civil engineering in general. T2 - 21. International Nondestructive Testing and evaluation of Wood Symposium CY - Freiburg, Germany DA - 24.09.2019 KW - Air-coupled ultrasound KW - Defect detection KW - Nondestructive Testing KW - Timber PY - 2019 SP - 100 PB - FVA CY - Freiburg AN - OPUS4-49169 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Abraham, Odile A1 - Larose, Eric T1 - A review on ultrasonic monitoring of concrete: coda wave interferometry and beyond N2 - The propagation of ultrasonic waves in concrete is affected by its micro- and macro-structure, geometry and properties as well as external influences as stress, temperature or moisture. In addition, age and degradation have a strong influence. Therefore, Ultrasound has been used to monitor concrete samples and structures since decades. However, early applications using conventional techniques as time-of flight or changes in amplitudes have been limited to detect changes in a late stage close to serviceability or ultimate load states. Around 2000, several new, more sensitive techniques adopted from geophysics or other field of material sciences have been introduced to research in ultrasonic monitoring of concrete. The most discussed methodologies are coda wave interferometry, a technique which allows to detect very subtle changes from repeated ultrasonic measurements. Nonlinear acoustic techniques help to identify e. g. cracks even in an inhomogeneous background. Both techniques can be combined. This paper reviews methods and results achieved so far on the laboratory scale and with full scale models the directions for future research and application is given as well. T2 - QNDE 2019 CY - Portland, OR, USA DA - 14.07.2019 KW - Ultrasound KW - Coda wave interferometry KW - Concrete KW - Nonlinear KW - Monitoring PY - 2019 SP - Paper 1234 AN - OPUS4-48686 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Abraham, O. A1 - Larose, E. T1 - A review on ultrasonic monitoring of concrete: coda wave interferometry and beyond N2 - The propagation of ultrasonic waves in concrete is affected by its micro- and macro-structure, geometry and properties as well as external influences as stress, temperature or moisture. In addition, age and degradation have a strong influence. Therefore, Ultrasound has been used to monitor concrete samples and structures since decades. However, early applications using conventional techniques as time-of flight or changes in amplitudes have been limited to detect changes in a late stage close to serviceability or ultimate load states. Around 2000, several new, more sensitive techniques adopted from geophysics or other field of material sciences have been introduced to research in ultrasonic monitoring of concrete. The most discussed methodologies are coda wave interferometry, a technique which allows to detect very subtle changes from repeated ultrasonic measurements. Nonlinear acoustic techniques help to identify e. g. cracks even in an inhomogeneous background. Both techniques can be combined. This paper reviews methods and results achieved so far on the laboratory scale and with full scale models the directions for future research and application is given as well. T2 - QNDE 2019 CY - Portland, OR, USA DA - 14.07.2019 KW - Ultrasound KW - Coda wave interferometry KW - Concrete KW - Nonlinear KW - Monitoring PY - 2019 AN - OPUS4-48688 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Mielentz, Frank A1 - Effner, Ute A1 - Maack, Stefan A1 - Scott, David A1 - Villalobos, Salvador T1 - Ultrasonic methods for quality assurance and condition assessment in nuclear concrete structures – lessons learned N2 - Ultrasonic non-destructive testing methods have found various applications in quality assurance and condition assessment of nuclear concrete structures. This includes but is not limited to the localization of construction features (thickness measurements, reinforcement, tendon ducts, and others) and damage detection (e. g. corrosion or cracks). However, there are still limitations, e. g. limited penetration depth and resolution, issues when testing hybrid steel/concrete structures as well as absence of standards and regulations. This presentation will show progress in some of these issues and will focus on advanced instrumentation and validation of ultrasonic NDT for concrete structures. Ultrasonic echo testing has been limited to a penetration depth of less than one meter in reinforced concrete. The development of the LAUS (Large Aperture Ultrasonic System), using a large array of ultrasonic transducers and wider offsets between transmitter and receiver, allows to reach up to 5 m in reinforced concrete and 9 m in unreinforced concrete. This capability has been demonstrated by collecting data from an engineered salt concrete barrier in an underground nuclear waste storage facility. Due to an increasingly competitive environment, commercial manufacturers will continue to develop equipment with enhanced penetration and/or increased resolution. To quantify the capabilities and reliability of ultrasonic tests, validation mockups with engineered flaws are required. EPRI and BAM have built a large-scale mockup at a test site close to Berlin (BAM-TTS, Horstwalde) using a design which is repeated at other places. This presentation will also cover the methods deployed on engineered flaws and the repeatability of the test results. T2 - NDE in Nuclear CY - Charlotte, NC, USA DA - 25.7.2019 KW - Concrete KW - Nuclear Structures KW - Ultrasound PY - 2019 AN - OPUS4-48690 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Ertel, Jens-Peter A1 - Niederleithinger, Ernst ED - Bullock, P. ED - Verbeek, G. ED - Paikowsky, S. ED - Tara, D. T1 - Impulse Response Measurement for Pile Integrity Testing Using a Shaker as Excitation Source and Regularized Deconvolution N2 - Concrete piles are used as a foundation when the load capacity of the soil is insufficient or when the sustainable soil is found at a higher depth. Among other impact factors, the load capacity depends on the pile’s integrity and length. Therefore, verifying these parameters using adequate methods is recommended. The most common procedure is the low-strain integrity test using the hammer impact method. Developed and established in the 1970s, this method uses stress waves induced by a hammer impact at the pile head and its reflections at impedance changes (length, defects, geometry changes) to estimate the length and defect locations. Although this method is widely used due to its low cost and fast conduction in situ, one disadvantage is its inability to classify the exact type of defect, i.e., crack, change in diameter, or concrete quality. Furthermore, very long and slender piles are difficult to test and small defects cannot be detected. In addition, it is necessary for the test engineer to hold a high level of experience and expertise in this field. The European Union–funded PileInspect project (2013–2016) aimed to compensate for these disadvantages by using a low-cost shaker as the excitation source and sophisticated artificial intelligence algorithms for damage detection (higher-order spectra method). Because this technology lacks the capacity to localize damages and verify the pile length, an additional impulse response (IR) measurement technique was developed using vibrational excitation and regularized deconvolution to extract the depth information from the data in a similar manner as the hammer method. Simulations and subsequent experiments conducted at a test facility on 90-cm-diameter bored piles 11 m in length and containing cracks at approximately 4 m below the pile head confirmed the capacity to determine the pile length. Damage diagnosis and localization, however, are more difficult than for the hammer method. Although the damaged piles could be distinguished from the intact piles, in a blind test, this method might lead to misinterpretations caused by perturbations arising from the deconvolution process. The results also indicated that the low-cost shaker used for these measurements might be inappropriate for the transferal of sufficient energy. Although the IR method cannot compensate for the disadvantages of the hammer method by itself, it may enable the possibility of using long and fully controllable and repeatable signals (chirp, synthetic impacts, even noise, etc.) for pile integrity testing in the future. KW - Pile integrity testing KW - L-curve KW - Tikhonov regularization KW - NDT PY - 2019 SN - 978-0-8031-7667-6 U6 - https://doi.org/10.1520/STP161120170162 VL - 1611 SP - 184 EP - 204 PB - ASTM International CY - West Conshohoken, PA, USA AN - OPUS4-48794 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Effner, Ute A1 - Behrens, Matthias A1 - Smith, Sean A1 - Büttner, C. A1 - Friedrich, C. A1 - Mauke, R. T1 - Application of ultrasonic techniques for quality assurance of salt concrete engineered barriers: Shape, cracks and delamination N2 - The closure of underground nuclear waste disposal facilities requires reliable gas- and watertight engineered barriers. In Germany, barriers made from salt concrete have been evaluated in full scale. While the barriers seem to fulfill the requirements regarding permeability, some unexpected cracks have been detected at the surface and at depth. In cooperation between the Federal Company for Radioactive Waste Disposal (BGE) and the Federal Institute for Materials Research and Testing (BAM), several experiments have been carried out to evaluate the applicability for ultrasonic measurements in crack detection and general quality assurance. Both commercial instruments and specially developed devices have been tested on site. Using commercial ultrasonic echo devices designed for concrete inspection it was possible to detect cracks and object in salt concrete up to a depth of 2 m. The check for delamination in shotcrete is another field of application. A unique device available at BAM, the wide aperture, deep penetration instrument LAUS, was able to locate cracks and objects up to a depth of 8 m so far, which is thought to be a record for ultrasonic echo measurements in concrete. Adapted imaging procedures, partly adopted from geophysics, helped to reveal 3D structure at depth. In addition, we have developed ultrasonic probes to be deployed in boreholes, currently at up to 20 m depth. They can collect information on cracks and other features in a radius of about 1.5 m around the borehole in the current version and might be used in echo or transmission mode. Evaluation experiments have been performed at an experimental barrier at the ERAM site in Morsleben, Germany. The results showed several empty and injected cracks as well as built in instrumentation. The results have been verified using borehole endoscopy as well as core examination and will be used to set up a reliable quality assurance system for engineered barriers. All instruments are based on ultrasonic shear wave transducers with a frequency range between 25 kHz and 100 kHz. Current research focuses on the improvement of the hardware (e. g. optimization of array characteristics) and imaging techniques as Reverse Time Migration, both aiming at the improvement of depth of penetration, resolution and probability of detection. T2 - Modern 2020, 2nd International Conference about Monitoring in Geological Disposal of Radioactive Wast CY - Paris, France DA - 09.04.2019 KW - REverse Time Migration (RTM) KW - Engineered Barrier System (EBS) KW - Non-Destructive Testing KW - Ultrasonic Echo KW - Large Aperture Ultrasonic System (LAUS) KW - Synthetic Aperture Focusing Technique (SAFT) PY - 2019 AN - OPUS4-48974 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Ertel, Jens-Peter T1 - PileInspect N2 - The EC funded project PileInspect (2013-2016) has tried to improve the traditional low strain pile integrity test by using a shaker instead of a hamm and sophisticated higher order spectra analysis methods to provide automated, reliable interpretation. However, the results, even if promising, have not seen full validation yet. A second module, providing depth information by regularized deconvolution, was developed and tested successfully, but doesn't deliver additional information compared tomteh traditioanl test. T2 - DFI Seminar Pile Integrity Testing CY - Bruxelles, Belgium DA - 12.09.2019 KW - Pile integrity testing KW - Shaker KW - Higher order spectra KW - Deconvolution PY - 2019 AN - OPUS4-48948 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Advances in ultrasonic testing and monitoring of concrete structures N2 - Recent years have seen extended use of ultrasonic techniques for concrete infrastructure assessement. They are applied for quality assurance and condition assessement at bridges, power plants, dams and other important objects. However, there are still a couple of significant limitations. They include, but are not limited to depth of penetration, imaging complex structures or early stage detections of distributed damage. The talk will give information on recent research in this area. Specifically, the application of the unique deep penetration system LAUS is shown. Ultrasonic monitoring using embedded transducers to check for subtle and sudden changes in the material is introduced as well. Comments on initiatives for validation, standardization and certification will be given. T2 - 341e Conférence CERES CY - Online meeting DA - 26.10.2020 KW - Concrete KW - Ultrasound KW - Imaging KW - Monitoring PY - 2020 AN - OPUS4-51463 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Landis, E. A1 - Hassfras, Emiel A1 - Oesch, Tyler A1 - Niederleithinger, Ernst T1 - Relating ultrasonic signals to concrete microstructure using X-ray computed tomography N2 - With a goal to improve our understanding of the relationships between microstructural features and ultrasonic signal behavior, concrete specimens of varying water-to-cement ratio were imaged using X-ray computed tomography (CT), and subsequently subjected to ultrasonic testing. From the CT scans, measurements were made of cement paste density and number of interfaces. Ultrasonic signals produced using a through-transmission configuration were analyzed and fit to a diffusion model to separate absorption from scattering attenuation. The results showed that at the frequencies tested, ultrasonic dissipation rate correlated weakly with paste density, while diffusivity correlated well with number of interfaces, but only if entrained air is considered separately. Cement paste density was found to be very well predicted by diffusivity, leading to a clear power-law relationship between diffusivity and compressive strength. KW - Concrete KW - Ultrasound KW - Strength KW - CT PY - 2021 U6 - https://doi.org/10.1016/j.conbuildmat.2020.121124 SN - 0950-0618 VL - 268 SP - Paper 121124, 1 EP - 12 PB - Elsevier Ltd. AN - OPUS4-52073 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Vössing, Konrad A1 - Gaal, Mate A1 - Niederleithinger, Ernst T1 - Imaging wood defects using air coupled ferroelectret ultrasonic transducers in reflection mode N2 - Air-coupled ultrasound (ACU) is used to detect defects in wood panels without physically contacting the sample and with a quick scanning rate. Transducers made of cellular polypropylene (PP) with a high signal-to-noise ratio are quite suitable for ACU testing of wood. The extremely low modulus of elasticity and low density of PP transducers results in a small difference in acoustic impedance for the Transmission of ultrasonic waves between the transducer and air, allowing new areas of application to become possible. To demonstrate the suitability of the reflection technique, measurements are shown on the three samples Multiplex, LVL, and MDF and compared with transmission measurements. Due to this acoustic barrier and the use of cellular PP transducers, an exact detection of delamination and cavities is possible in wood panels up to 40 mm thick. If only one side of an object is accessible and the depth of the defect is of interest, the reflection technique is preferred at the expense of a reduced measuring accuracy and Penetration depth. KW - Wood KW - Ultrasound KW - Air coupled KW - Defects PY - 2020 U6 - https://doi.org/10.1016/j.conbuildmat.2020.118032 VL - 241 SP - 118032, 1 EP - 8 PB - Elsevier Ltd. AN - OPUS4-50235 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Effner, Ute A1 - Mielentz, Frank A1 - Niederleithinger, Ernst A1 - Friedrich, C. A1 - Mauke, R. A1 - Mayer, K. T1 - Prüfung von Abdichtbauwerken für Endlager auf Risse – eine Herausforderung N2 - Im Jahr 2011 hat der Bundestag in Deutschland den Ausstieg aus der Kernenergie beschlossen. Der angefallene Abfall wird mehr als hunderttausend Jahre eine derartig hohe Aktivität besitzen, dass er eine erhebliche Gefahr für nachfolgende Generationen darstellen kann. Dieser radioaktive Abfall soll in tiefen geologischen Formationen (z.B. Salz, Ton oder Kristallin) sicher endgelagert werden. Die Endlager werden mittels sogenannter geotechnischer Abdichtbauwerke (Schachtbzw. Streckenverschlüsse) verschlossen, wofür u.a. Zement- oder Sorel-basierte Baustoffe (Betone) in Frage kommen. Die Beschreibung des Dichtvermögens dieser Bauwerke ist unabdingbar. In der Forschungsphase werden verschiedene Werkstoffe untersucht und Methoden für die zerstörungsfreie Untersuchung der Bauwerke als Mittel der Qualitätsprüfung entwickelt. Hierbei ist der Nachweis der Rissfreiheit bzw. die Detektion möglicher Risse ein vorrangiges Thema. In den letzten Jahren konnten bereits umfangreiche Erfahrungen mit der Untersuchung von in-situ-Versuchsobjekten in Realmaßstab gesammelt werden. Die Messungen wurden im Endlager für radioaktive Abfälle Morsleben am in-situ-Versuch “Abdichtbauwerk im Steinsalz” und in der Grube Teutschenthal am Großversuch GV2 durchgeführt. Es ist gelungen mit einem neu entwickelten Ultraschall-Messsystem Eindringtiefen bis ca. 9,0 m zu realisieren. Die Messungen mit dem Large Aperture Ultrasonic System in Kombination mit der Rekonstruktion-Methode Synthetic Aperture Focusing Technique zeigen, dass die zerstörungsfreie Prüfung von Abdichtbauwerken möglich und die Nutzung des Messsystems zur Qualitätssicherung bei der Erstellung der Verschlussbauwerke vielversprechend ist. N2 - In 2011, the German Bundestag decided to phase out nuclear energy. The resulting waste will remain highly radioactive for many hundreds of thousands of years and represents a considerable danger for future generations. This radioactive waste is to be safely disposed of in deep geological formations (e.g. salt, clay or crystalline). The repositories will be sealed by means of engineered barrier systems. The impermeability of these structures is indispensable. In the current research phase, various materials are being investigated and methods for monitoring the structures are being developed. In this context, the investigation of cracks is a priority topic. In recent years, BAM has gained extensive experience in the investigation of in-situ test objects in full scale. The measurements were performed in the Morsleben repository for radioactive waste at the test structure for the in-situ experiment "Sealing structure in rock salt" and in the Teutschenthal mine at the large-scale GV2 test structure. With a newly developed ultrasonic measuring system it has been possible to achieve penetration depths of up to approx. 9.0 m. Measurements with the Large Aperture Ultrasonic System in combination with the Synthetic Aperture Focusing Technique reconstruction method show that the non-destructive testing of sealing structures is possible and the use of the measuring system for quality assurance in the construction of sealing structures is promising. KW - Abdichtbauwerk / Verschlussbauwerk KW - Zerstörungsfreie Prüfung KW - Large Aperture Ultrasonic System KW - Synthetic Aperture Focusing Technique KW - Ultraschall-Echo-Verfahren PY - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-520298 SN - 1521-4052 VL - 52 IS - 1 SP - 19 EP - 31 PB - Wiley-VCH GmbH CY - Weinheim AN - OPUS4-52029 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Epple, Niklas A1 - Fontoura Barroso, Daniel A1 - Niederleithinger, Ernst ED - Rizzo, P. ED - Milazzo, A. T1 - Towards Monitoring of Concrete Structures with Embedded Ultrasound Sensors and Coda Waves – First Results of DFG for CoDA N2 - Due to the importance of reinforced concrete structures for modern society, damage assessment during the entire life-cycle of such structures has become a special interest in non-destructive testing. Using embedded ultrasound sensors in combination with other measurement methods, numerical modeling and self-made data collectors, tailored specifically for monitoring tasks, the German research group DFG FOR CoDA aims to investigate and develop novel methods for damage detection and rapid model updating in reinforced concrete structures. In the first stage of the project, besides the development of custom-built, low-cost data collectors, ultrasonic transducers are embedded in a large, reinforced concrete specimen on a BAM test site near Berlin. In this experiment, the influence of changing environmental conditions (mainly temperature) on the ultrasound signal is investigated using coda-wave interferometry. The results show a correlation between changes in temperature and ultrasonic velocity. Such changes must be taken into consideration in a long-term monitoring setup to distinguish between reversible and permanent changes. By correcting the data using a linear relation between concrete temperature and velocity change to remove the seasonal trends and by low-pass filtering the data to remove daily variations can remove most of the temperature influence on the ultrasound measurements. KW - Ultrasound KW - Coda Wave Interferometry (CWI) KW - Embedded sensors KW - Structural health monitoring PY - 2021 SN - 978-3-030-64593-9 SN - 978-3-030-64594-6 U6 - https://doi.org/10.1007/978-3-030-64594-6_27 VL - 127 SP - 266 EP - 275 PB - Springer Nature CY - Cham, Switzerland AN - OPUS4-52012 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Current Trends in SHM of German Prestressed Concrete Road bridges N2 - Due to increasing ageing, deterioration and loading , several prestressed concrete bridges bulit in the 1950ies and 1960ies need monitoring. Recently several bridges have sucesssfully equipped with acoustic emission sensing system. BAM works together with several universities on an add onn: Active ultrasonic monitoring combined with coda wave interferometry will help to detect subtle changes and precursors fo failure earlier than other methods. T2 - TRB 100th Annual Meeting, Subcommittee AKT40(3) CY - Online meeting DA - 05.01.2021 KW - Bridges KW - Monitoring KW - Acoustic emission KW - Ultrasound KW - Coda wave interferometry PY - 2021 AN - OPUS4-51972 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Towards digital tools for waste package and facility monitoring and prediction N2 - The workpackage 7 of the EC funded project PREDIS deals with cemented low and intermediate level radioactive waste. The focus is on NDT/monitoring technologies, digiutal twins and data/decision frameworks to optimize facilitay and waste package management. The talk describes the project setup and planned activities. T2 - DigiDecom 2021 CY - Online meeting DA - 22.03.2021 KW - Nuclear waste KW - Waste package KW - Predisposal KW - storage KW - monitoring PY - 2021 AN - OPUS4-52334 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dackermann, U. A1 - Yu, Y. A1 - Niederleithinger, Ernst A1 - Li, J. A1 - Wiggenhauser, Herbert T1 - Condition Assessment of Foundation Piles and Utility Poles Based on Guided Wave Propagation Using a Network of Tactile Transducers and Support Vector Machines N2 - This paper presents a novel non-destructive testing and health monitoring system using a network of tactile transducers and accelerometers for the condition assessment and damage classification of foundation piles and utility poles. While in traditional pile integrity testing an impact hammer with broadband frequency excitation is typically used, the proposed testing system utilizes an innovative excitation system based on a network of tactile transducers to induce controlled narrow-band frequency stress waves. Thereby, the simultaneous excitation of multiple stress wave types and modes is avoided (or at least reduced), and targeted wave forms can be generated. The new testing system enables the testing and monitoring of foundation piles and utility poles where the top is inaccessible, making the new testing system suitable, for example, for the condition assessment of pile structures with obstructed heads and of poles with live wires. For system validation, the new system was experimentally tested on nine timber and concrete poles that were inflicted with several types of damage. The tactile transducers were excited with continuous sine wave signals of 1 kHz frequency. Support vector machines were employed together with advanced signal processing algorithms to distinguish recorded stress wave signals from pole structures with different types of damage. The results show that using fast Fourier transform signals, combined with principal component analysis as the input feature vector for support vector machine (SVM) classifiers with different kernel functions, can achieve damage classification with accuracies of 92.5% ± 7.5%. KW - Structural Health Monitoring KW - Non-Destructive Testing KW - Sensor network KW - Support vector machine KW - Utility poles PY - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-434868 UR - http://www.mdpi.com/1424-8220/17/12/2938 SN - 1424-8220 VL - 17 IS - 12 SP - Article 2938, 1 EP - 16 PB - MDPI CY - Basel, Schweiz AN - OPUS4-43486 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Seismic methods for ultrasonic testing in Civil Engineering N2 - Invited presentation on the use of seismic imaging and monitoring technologies in civil engineering T2 - Geophysikalisches Kolloquium der ETH CY - Zürich, Switzerland DA - 17.03.2017 KW - Seimic KW - Ultrasound KW - Monitoring KW - Imaging KW - Concrete PY - 2017 AN - OPUS4-39428 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Katzenbach, Rolf A1 - Klingmüller, Oswald A1 - Molkenthin, Andre A1 - Willmes, Michael T1 - REFUND: Untersuchung von Bestandsfundamenten und Entscheidungsbäume zur optimierten Weiter- und Nachnutzung N2 - Vor einer geplanten Weiter- oder Wiedernutzung von Bestandsfundamenten stellt sich die Frage nach deren Lage, Geometrie und Zustand im Untergrund. Hierfür gibt es verschiedene Prüfverfahren. Im Projekt REFUND (2014-2016) wurden unter Berücksichtigung der aktuellen Normen und des Standes der Technik Ablaufdiagramme für die Planung der Wiedernutzung und die Untersuchung des Bestandes entwickelt. Dies geschah getrennt für Einzel- und Streifenfundamente, Platten und Pfähle. An zwei Praxisbeispielen wurden die Abläufe getestet und optimiert. Die Ergebnisse wurden in einem Handbuch kompiliert, das bei der TU Darmstadt erscheint. T2 - 24. Darmstädter Geotechnik-Kolloquium CY - Darmstadt, Germany DA - 16.03.2017 KW - Fundamente KW - Wiedernutzung KW - Ablaufdiagramme KW - Planung KW - Prüfung PY - 2017 AN - OPUS4-39429 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Bertschat, Anja A1 - Mierschke, Vivien A1 - Wang, Xin T1 - Bridge monitoring using embedded ultrasonics First results from the BLEIB reference structure N2 - The BLEIB reference structure The structure is a two-span, 24 m long inverse u-shaped post-tensioned concrete beam. Fibre optic sensing cables, RFID sensors and ultrasonic transducers are permanently embedded. Other sensing techniques (vibrational, optical, ultrasonic, mechanical) are applied externally. Tension can be adjusted. Loads can be placed at arbitrary locations. Limited damage is introduced to one span. The BLEIB reference structure is located at BAM‘s test site in Horstwalde, south of Berlin. Ultrasonic transducer before concreting. Embedded ultrasonic transducers 14 piezo transducers have been embedded before concreting. They are located in five sections, two close to the centers of both spans respectively and one above the central bearing. Load experiment and data evaluation In a first experiment load 2 (weight 2 t) was moved three times along the southern (right) span. The tension forces were modified as well. Ultrasonic transmission measurements were repeated over time and evaluated using Coda Wave Interferomerry (CWI), which determines correlation coefficients and relative velocity changes as subtle indicators for loads and other changes in the material. T2 - New mathematics for a safer world: wave propagation in heterogeneous materials CY - Edinburgh, UK DA - 12.06.2017 KW - Bridge monitoring KW - Ultrasound KW - Embedded transducers KW - Coda wave interferometry PY - 2017 AN - OPUS4-40578 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Detecting subtle changes in concrete with coda wave interferometry N2 - Subtle changes in concrete, caused by stress, temperature or deterioration can be detected by ultrasonic transmission measurements evaluated by coda wave interferometry. Background and examples are presented as well as possibilities to locate damages. T2 - New mathematics for a safer world: wave propagation in heterogeneous materials CY - Edinburgh, UK DA - 12.06.2017 KW - Concrete KW - Ultrasound KW - Coda wave interferometry KW - Monitoring PY - 2017 AN - OPUS4-40580 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Bridge Monitoring by Passive Seismic Data, First tests at the BLEIB reference structure N2 - Seismic wave velocities are related to elastic moduli and other properties and can serve as indicators for changes in the material. They are conventionally determined by active measurements. Using ideas from seismic interferometry Determination from stacked cross-correlations of registrations of man- made and natural noise (“passive seimics“) is an effective alternative, as these data might be available from vibration monitoring anyway. The validity of this approach is demonstrated by a simple experiment based on recordings of man made noise using accelerometers at the reference structure. The s-wave (or more probable. guided wave) velocity was determined to be 2100 m/s in both active and passive experiments. T2 - Passive Imaging and monitoring in wave physics: from seismology to ultrasound CY - Cargese, France DA - 05.06.2017 KW - Passive Seismics KW - Bridge monitoring KW - Elastic wave velocity PY - 2017 AN - OPUS4-40575 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Bridge Monitoring by Passive Seismic Data, First tests at the BLEIB reference structure N2 - Seismic wave velocities are related to elastic moduli and other properties and can serve as indicators for changes in the material. They are conventionally determined by active measurements. Using ideas from seismic interferometry determination from stacked cross-correlations of registrations of man-made and natural noise (“passive seimics“) is an effective alternative, as these data might be available from vibration monitoring anyway. The validity of this approach is demonstrated by a simple experiment based on recordings of man made noise using accelerometers at the reference structure. The s-wave (or more probable. guided wave) velocity was determined to be 2100 m/s in both active and passive experiments. T2 - Passive Imaging and monitoring in wave physics: from seismology to ultrasound CY - Cargese, France DA - 05.06.2017 KW - Bridge monitoring KW - Passive seismics KW - Ambient noise KW - Interferometry KW - Elastic wave velocity PY - 2017 AN - OPUS4-40577 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Wiggenhauser, Herbert A1 - Mielentz, Frank A1 - Bertschat, Anja-Sophie A1 - Mierschke, Vivien A1 - Werner, Andreas T1 - Untersuchung von Veränderungen in Beton mit Ultraschall-Codawelleninterferometrie N2 - Die Coda transmittierter Ultraschallsignale in Beton enthält Informationen zu Struktur und Zustand des Materials bzw. deren Änderung. Relevant sind u. a. Temperatur, Stress, Feuchtigkeit und verschiedene Schädigungsmechanismen. Die zahlreichen Einflussfaktoren sind nur schwer zu trennen und die Messeffekte oft zu Beginn sehr klein.Die CWI ermöglicht die Detektion kleinster Geschwindigkeitsveränderungen durch den Vergleich, der in kleinen Schritten gestauchten oder gestreckten Signalen mit eine Referenzmessung. Andere Indikatoren für Änderungen im Material sind: • Kreuzkorrelation • Laufzeit direkte Welle • Energie/Amplitude • Änderungen im Frequenzspektrum Die beschriebene Technik wird von uns bisher primär in klein- und großskaligen Laborversuchen genutzt. Die Forschung konzentriert sich auf die Untersuchung und Trennung verschiedener Einflusseffekte. Aber auch erste reale Bauwerke wurden schon instrumentiert, z. B. Brücken und eine Tunneldecke. T2 - 77. Jahrestagung der Deutschen Geophysikalischen Gesellschaft CY - Potsdam, Germany DA - 27.03.2017 KW - Beton Ultraschall Monitoring PY - 2017 AN - OPUS4-39661 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - König, Markus A1 - Grohmann, Maria A1 - Niederleithinger, Ernst T1 - Anwendung der Reverse-Time Migration auf Ultraschall-Echo-Daten zur Detektion von verdeckten Rissen in Betonkörpern N2 - Das Ultraschall-Echo-Verfahren ist eine wichtige Methode der zerstörungsfreien Prüfung (ZfP). Prüfaufgaben im Bauwesen beinhalten unter anderem die korrekte Dickenbestimmung von Konstruktionen, sowie die Lokalisierung von Einbauteilen und Fehlstellen. Das Abbildungsverfahren RTM (Reverse Time Migration) liefert oft bessere Bilder als konventionelle Verfahren. Die Datenaufnahme am Betonprobekörper erfolgte mit einem Scannersystem der BAM, bei dem jeweils ein Ultraschall-Prüfkopf als Sender bzw. Empfänger diente. Es wurden senkrecht zur Profilrichtung horizontal polarisierte Scherwellen genutzt. Die RTM wurde mit dem Softwarepaket Madagascar gerechnet. Die Ergebnis zeigt das Potential dieser Methode im Bezug auf komplexe Strukturen. Die lateralen Positionen der Risse im RTM-Bild sowie deren Höhe innerhalb des Probekörpers, entsprechen recht genau dem visuellen Befund. T2 - 77. Jahrestagung der Deutschen Geophysikalischen Gesellschaft CY - Potsdam, Germany DA - 27.03.2017 KW - Ultraschall KW - Beton KW - Riss KW - Reverse Time Migration PY - 2017 AN - OPUS4-39662 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ertel, Jens-Peter A1 - Niederleithinger, Ernst A1 - Grohmann, Maria ED - Stahlmann, J. T1 - Das PileInspect-Projekt: Pfahlintegritätsprüfung durch Schwinganregung mittels eines elektrodynamischen Shakers N2 - Pfahlintegritätsprüfung von Bohrpfählen durch Messung der Impulsantwort mittels Schwinganregung und regularisierter Dekonvolution. T2 - Pfahlsymposium 2017 CY - Braunschweig, Germany DA - 23.02.2017 KW - Pfahlintegritätsprüfung KW - Tikhonov KW - Dekonvolution KW - PileInspect KW - Shaker PY - 2017 VL - 2017 IS - 102 SP - 217 EP - 235 PB - Eigenverlag Institut für Grundbau und Bodenmechanik - Technische Universität Braunschweig CY - Braunschweig AN - OPUS4-39272 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Heckel, Thomas A1 - Brackrock, Daniel T1 - Vorversuche zur Ultraschallprüfung an Groutverbindungen N2 - Im rahmen des themenfeldprojektes LEBEWIND wurden Vorversuche zur Ultraschallprüfung von Groutverbindungen an Offshore-Windenergieanlagen gemacht. Die Experimente mit kommerzieller Prüftechnik in Echo und Transmission durch die Stahlwandung hindurch bestätigten, dass diese Bauweise so nicht prüfbar ist. T2 - Workshop "Grout in der Betriebsphase" CY - Berlin, Germany DA - 22.03.2017 KW - Windenergieanlagen KW - Grout KW - Ultraschall PY - 2017 AN - OPUS4-39541 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Wiggenhauser, Herbert T1 - The LAUS: First applications of a new system for ultrasonic imaging of very concrete structures N2 - The LAUS (Large Aperture Ultrasonic System) has been developed to image very thick concrete structures, which are not accessible for commercial systems. The device and the corresponding software is the result of joint research of BAM, an ultrasonic instrument manufacturer and University of Kassel, Germany. It consists of 12 separate arrays of 32 point-contact shear wave transducers each, which can be deployed in flexible configurations. Each array is combined with battery and transmitter, receiver and wireless communication electronics. Three case histories are presented. First the system was deployed on a 5-m thick heavily reinforced foundation slab. The reflection of the slab’s bottom was imaged clearly. In addition, a multiple reflection was registered, thus giving hope that even thicker elements might be imaged by the instrument. Second, the LAUS was used to investigate a massive bridge girder where a heavy rainstorm during concreting had led to imperfections that were visible after removing the formwork was removed. The LAUS could image tendon ducts in 1.8m depth and the backwall closely behind them. Some limited areas showed blurred reflections and were checked by drill holes; these areas were affected by diffuse damage which could be repaired by injections. Third, a large retaining wall was checked for thickness. Meanwhile, the LAUS has been used in underground waste deposits (nuclear and other) for quality assurance of sealing plugs. A confirmed penetration depth of about 7 m has been reached. T2 - ASNT SMT/NDT-CE 2018 CY - New Brunswick, NJ, USA DA - 27.8.2018 KW - LAUS KW - Ultrasound KW - Imaging KW - Concrete PY - 2018 AN - OPUS4-45828 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Abraham, O. A1 - Niederleithinger, Ernst A1 - Chapeleau, B. A1 - Klikowicz, P. A1 - Brühwiler, E. A1 - Bassil, A. A1 - Wang, Xin A1 - Chakraborty, J. A1 - Bayane, I. A1 - Leduc, D. A1 - Salamak, M. A1 - Katunin, A. A1 - Sörensen, J. D. T1 - Addressing the need to monitor concrete fatigue with non destructive testing: preliminary results of infrastar European project N2 - Fatigue is one of the most prevalent issues, which directly influences the service life expectancy of concrete structures. Fatigue has been investigated for years for steel structures. However, recent findings suggest that concrete structures may also be significantly subjected to the fatigue phenomena that could lead to premature failure of certainfatigue prone structural elements. To date, fatigue of reinforced concrete has been given little focus. and Kknowledge on the influence factors and durability/capacity effects on this material should be improved. Current technological means to measure fatigue in civil structures like bridges and wind turbines (both onshore and offshore) are outdated, imprecise and inappropriate. Meanwhile, this topic has got much more attention as dynamic loading on concrete structures plays an increasing role, e.g. in bridges with increasing traffic and heavier trucks, in wind energy production due to inherent vibrations e.g. in offshore wind turbine support structures affected by wind and waves. The European Innovative Training Networks (ITN) Marie Skłodowska-Curie Actions project INFRASTAR (Innovation and Networking for Fatigue and Reliability Analysis of Structures - Training for Assessment of Risk) provides research training for 12 PhD students. The project aims to improve knowledge for optimizing the design of new structures as well as for more realistic verification of structural safety and more accurate prediction of the remaining fatigue lifetime of existing structures. First, the INFRASTAR research framework is detailed. Then it will be exemplified through the presentation of the major results of the four PhD students involved in the work package dealing with auscultation and monitoring. This includes the development and improvement of Fiber Optics (FO) and Coda Wave Interferometry (CWI) for crack sizing and imagery, new sensor technologies and integration, information management, monitoring strategy for fatigue damage investigation and lifetime prediction. T2 - ASNT SMT/NDT-CE 2018 CY - New Brunswick, NJ, USA DA - 27.8.2018 KW - Concrete KW - Fatigue KW - Non-destructive testing KW - Reliabiilty PY - 2018 AN - OPUS4-45862 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Vössing, Konrad A1 - Gaal, Mate A1 - Niederleithinger, Ernst T1 - Air‑coupled ferroelectret ultrasonic transducers for nondestructive testing of wood‑based materials N2 - Air-coupled ultrasound (ACU) is used in through transmission to detect delamination, rot, and cracks in wood without altering the structure permanently. Novel ferroelectret transducers with a high signal-to-noise ratio enable high-precision structure recognition. Transducers made of cellular polypropylene are quite suitable for ACU testing due to their extremely low Young’s modulus and low density resulting in a favorable acoustic impedance for the transmission of ultrasonic waves between the transducer and air. Thus, structures with great dimensions, with a thickness of up to 300 mm and material densities below 500 kg/m3, can be inspected. Promising results were obtained under laboratory conditions with frequencies ranging from 90 to 200 kHz. The advantage of ACU transducers is that they do not equire contact to the sample; they are accurate and cost-effective. Ultrasonic quality assurance for wood is an important avenue to increase the acceptance of wooden structures and toward sustainability in civil engineering in general. KW - Ultrasound KW - Wood KW - Defect KW - Air-coupled PY - 2018 U6 - https://doi.org/10.1007/s00226-018-1052-8 VL - 52 IS - 6 SP - 1527 EP - 1538 PB - Springer AN - OPUS4-46653 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bassil, A. A1 - Wang, Xin A1 - Chapeleau, X. A1 - Niederleithinger, Ernst A1 - Abraham, O. A1 - Leduc, D. T1 - Distributed fiber optics sensing and coda wave interferometry techniques for damage monitoring in concrete structures N2 - The assessment of Coda Wave Interferometry (CWI) and Distributed Fiber Optics Sensing (DFOS) techniques for the detection of damages in a laboratory size reinforced concrete beam is presented in this paper. The sensitivity of these two novel techniques to micro cracks is discussed and compared to standard traditional sensors. Moreover, the capacity of a DFOS technique to localize cracks and quantify crack openings is also assessed. The results show that the implementation of CWI and DFOS techniques allow the detection of early subtle changes in reinforced concrete structures until crack formation. With their ability to quantify the crack opening, following early detection and localization, DFOS techniques can achieve more effective monitoring of reinforced concrete structures. Contrary to discrete sensors, CWI and DFOS techniques cover larger areas and thus provide more efficient infrastructures asset management and maintenance operations throughout the lifetime of the structure. KW - Distributed fiber optic sensors KW - Coda wave interferometry KW - Reinforced concrete KW - Cracks KW - Damage detection KW - Structural health monitoring PY - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-472549 SN - 1424-8220 VL - 19 IS - 2 SP - 356, 1 EP - 15 PB - MDPI AN - OPUS4-47254 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Abraham, O. A1 - Niederleithinger, Ernst A1 - Chapeleau, X. A1 - Klikowicz, P. A1 - Brühwiler, E. A1 - Bassil, A. A1 - Wang, Xin A1 - Chakraborty, J. A1 - Bayane, I. A1 - Leduc, D. A1 - Salamak, M. A1 - Katunin, A. A1 - Sørensen, J.D. T1 - Addressing the need to monitor concrete fatigue with nondestructive testing: Results of infrastar European project N2 - Fatigue is one of the most prevalent issues, which directly influences the service life expectancy of concrete structures. Fatigue has been investigated for years for steel structures. However, recent findings suggest that concrete structures may also be significantly subjected to fatigue phenomena that could lead to premature failure of certain structural elements. To date, fatigue of reinforced concrete has been given little focus. Knowledge on the influence factors and durability/capacity effects on this material should be improved. Current technological means to measure fatigue in civil structures like bridges and wind turbines (both onshore and offshore) are outdated, imprecise and inappropriate. Meanwhile, this topic has got much more attention as time-variant loading on concrete structures plays an increasing role, e.g. in bridges with increasing traffic and heavier trucks, and for wind turbines for renewable energy production, e.g. for offshore wind turbine support structures affected by wind and waves. The European Innovative Training Networks (ITN) Marie Skłodowska-Curie Actions project INFRASTAR (Innovation and Networking for Fatigue and Reliability Analysis of Structures - Training for Assessment of Risk) provides research training for 12 PhD students. The project aims to improve knowledge for optimizing the design of new structures as well as for more realistic verification of structural safety and more accurate prediction of the remaining fatigue lifetime of existing concrete structures. First, the INFRASTAR research framework is detailed. Then it will be exemplified through the presentation of the major results of the four PhD students involved in the work package dealing with auscultation and monitoring. This includes the development and improvement of Fiber Optics (FO) and Coda Wave Interferometry (CWI) for crack sizing and imagery, new sensor technologies and integration, information management, monitoring strategy for fatigue damage investigation and lifetime prediction. T2 - SMT and NDT-CE 2018 CY - New Brunswick, NJ, USA DA - 27.08.2018 KW - Concrete KW - Fatigue KW - Crack KW - Monitoring KW - Non-destructive testing PY - 2019 UR - https://asnt.org/smt18papers SN - 978-1-57117-456-7 VL - 11/19 SP - 2 EP - 13 PB - The American Society for Nondestructive Testing, Inc. CY - Columbus, OH, USA AN - OPUS4-47237 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Wiggenhauser, Herbert T1 - The LAUS: First Applications of a New System for Ultrasonic Imaging of Very Concrete Structures N2 - The LAUS (Large Aperture Ultrasonic System) has been developed to image very thick concrete structures, which are not accessible for commercial systems. The device and the corresponding software is the result of joint Research of BAM, an ultrasonic instrument manufacturer and University of Kassel, Germany. It consists of 12 separate Arrays of 32 point-contact shear wave transducers each, which can be deployed in flexible configurations. Each array is combined with battery and transmitter, receiver and wireless communication electronics. Three case histories are presented. First the system was deployed on a 5-m thick heavily reinforced foundation slab. The reflection of the slab’s bottom was imaged clearly. In addition, a multiple reflection was registered, thus giving hope that even thicker elements might be imaged by the instrument. Second, the LAUS was used to investigate a massive bridge girder where a heavy rainstorm during concreting had led to imperfections that were visible after removing the formwork was removed. The LAUS could image tendon ducts in 1.8m depth and the backwall closely behind them. Some limited areas showed blurred reflections and were checked by drill holes; these areas were affected by diffuse damage which could be repaired by injections. Third, a large retaining wall was checked for thickness. Meanwhile, the LAUS has been used in underground waste deposits (nuclear and other) for quality assurance of sealing plugs. A confirmed penetration depth of about 7 m has been reached. T2 - SMT and NDT-CE 2018 CY - New Brunswick, NJ, USA DA - 27.08.2018 KW - LAUS (Large Apertur Ultrasonic System) KW - Ultrasonic echo KW - Deep penetration KW - Concrete PY - 2019 UR - https://asnt.org/smt18papers SN - 978-1-57117-456-7 VL - 11/19 SP - 208 EP - 213 PB - The American Society for Nondestructive Testing, Inc. CY - Columbus, OH, USA AN - OPUS4-47238 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Grohmann, Maria A1 - Ertel, Jens-Peter T1 - Geophysical methods in quality assurance and inspection of foundations N2 - Modern geophysical methods might be either directly applied to concrete structures or integrated into existing testing schemes to assist in quality assurance and inspections. This paper gives an overview on some ideas and developments from the author’s work: • Vibrator technologies to improve pile integrity testing. • Ideas from vertical seismic profiling used in multichannel pile inspection • Cross- and downhole seismics to check the diameter of jet grouting columns • Improving the parallel seismic methods for precise length measurement of piles and foundation walls • Seismic migration methods to improve ultrasonic imaging of foundation slabs • Seismological tools to monitor subtle changes in concrete constructions The authors strongly believe that the cooperation between geophysics and civil engineering, which is obviously becoming stronger and stronger, will lead to a large number of innovative approaches. T2 - ICEG 2017 CY - Al Ain, United Arab Emirates DA - 09.10.2017 KW - Foundations KW - NDT KW - Geophysics PY - 2017 AN - OPUS4-42551 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Grohmann, Maria A1 - Ertel, Jens-Peter T1 - Using geophysical methods in quality assurance and inspection of foundations N2 - Modern geophysical methods might be either directly applied to concrete structures or integrated into existing testing schemes to assist in quality assurance and inspections. This paper gives an overview on some ideas and developments from the author’s work: • Vibrator technologies to improve pile integrity testing. • Ideas from vertical seismic profiling used in multichannel pile inspection • Cross- and downhole seismics to check the diameter of jet grouting columns • Improving the parallel seismic methods for precise length measurement of piles and foundation walls • Seismic migration methods to improve ultrasonic imaging of foundation slabs • Seismological tools to monitor subtle changes in concrete constructions The authors strongly believe that the cooperation between geophysics and civil engineering, which is obviously becoming stronger and stronger, will lead to a large number of innovative approaches. T2 - ICEG 2017 CY - Al Ain, United Arab Emirates DA - 09.10.2017 KW - Foundations KW - NDT KW - Geophysics PY - 2017 SP - Paper EG02, 1 EP - 5 PB - UAE University CY - Al Ain, United Arab Emirates AN - OPUS4-42552 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wiggenhauser, Herbert A1 - Niederleithinger, Ernst A1 - Milmann, Boris T1 - Zerstörungsfreie Ultraschallprüfung dicker und hochbewehrter Betonbauteile T1 - Nondestructive testing of thick and highly reinforced concrete structures with ultrasound N2 - Ein Ultraschallsystem mit großer Apertur, genannt LAUS – Large Aperture UltraSound, wird vorgestellt und die technischen Eigenschaften erläutert. Es besteht aus zwölf Prüfköpfen, die beliebig auf Betonoberflächen mit Unterdruck befestigt und jeweils als Sender oder Empfänger genutzt werden. Alle möglichen Kombinationen ergeben 132 Einzelmessungen, die zur Rekonstruktion des durchschallten Volumens genutzt werden. Das System wurde an zwei Bauwerken erfolgreich erprobt. Die Dicke einer sehr stark bewehrten Fundamentplatte eines Fallturms wurde bestimmt. Die Messungen erfolgten in einem Raster auf einer Fläche von 2,0 × 1,8 m2 und die Rückseite konnte eindeutig abgebildet werden. Weitere Anzeigen aus dem Inneren der Platte zeigen das Potenzial des Systems. An einem Brückenbauwerk wurden indirekt Verdichtungsmängel lokalisiert. Dazu wurden mit dem LAUS-System die im Brückenträger verlaufenden Spannkanäle durch fast 2 m Beton abgebildet. N2 - An ultrasound system with a large aperture, called LAUS - Large Aperture UltraSound, is presented and the technical characteristics are explained. It consists of twelve sensor units which can be attached independently on concrete surfaces with vacuum and which are used as transmitters or receivers respectively. All possible combinations result in 132 individual measurements which are used to reconstruct the insonificated volume. The system has been successfully tested on two structures. The thickness of a very heavily reinforced foundation slab of a drop tower was determined. The measurements were carried out in a grid on a surface of 2.0 x 1.8 m(2) and the back side could be clearly imaged. Further indications from inside the foundation show the potential of the system. Voids in concrete were indirectly located in a bridge structure. For this purpose, the LAUS system was used to image the tendon ducts running in the bridge beam through almost 2 m of concrete. KW - Ultraschall KW - Beton KW - Brücke KW - Fundament KW - LAUS PY - 2017 U6 - https://doi.org/10.1002/bate.201700040 SN - 0932-8351 VL - 94 IS - 10 SP - 682 EP - 688 PB - Ernst & Sohn CY - Berlin AN - OPUS4-42614 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Niederleithinger, Ernst A1 - Katzenbach, R. A1 - Klingmüller, O. A1 - Hillmann, S. A1 - Willmes, Michael T1 - REFUND: Untersuchung von Bestandsgründungen für eine Entscheidung zur Wiedernutzung T1 - REFUND: Investigation of existing foundations and decision making before re-use N2 - Vor einer geplanten Weiter- oder Wiedernutzung von Bestandsgründungen stellt sich die Frage nach deren Lage, Geometrie und Zustand im Untergrund. Hierfür gibt es verschiedene Prüfverfahren. Die Abläufe bei Planung und Prüfung sind jedoch bisher nicht standardisiert und die Möglichkeiten bzw. Grenzen der Prüfverfahren den Planern wenig bekannt. Im Forschungsprojekt REFUND (2014–2016) wurden unter Berücksichtigung der aktuellen Normen und des Stands der Technik Ablaufdiagramme für die Planung der Wiedernutzung sowie die Untersuchung des Bestands entwickelt. Dies geschah getrennt für Einzel- und Streifenfundamente, Platten und Pfähle. An zwei Praxisbeispielen wurden die Abläufe getestet und optimiert. Die Ergebnisse wurden in einem Handbuch zusammengefasst. Es soll Planer und andere Verantwortliche bei der wirtschaftlich und technisch optimierten Durchführung von Wiedernutzungsprojekten unterstützen. N2 - Before re-using existing foundations they have to be investigated for position, geometry and condition in the subsurface. The procedures and protocols haven't been standardized yet. Capabilities and limitations of appropriate testing methods are not known to all stakeholders. In the frame of the research project REFUND (2014-2016) we have developed decision trees for the planning and the investigation process, separately for single and strip foundations, slabs and piles. The protocols were tested in line with two actual projects. The results have been compiled in a handbook, which will support planners and other participants in a technical and economical optimized way to perform re-use of foundations. KW - Fundament KW - Wiedernutzung KW - Entscheidung KW - Zerstörungsfrei PY - 2017 U6 - https://doi.org/10.1002/bate.201700038 SN - 1437-0999 VL - 94 IS - 10 SP - 676 EP - 681 PB - Ernst & Sohn CY - Berlin AN - OPUS4-42615 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Grohmann, Maria A1 - Müller, Sabine A1 - Niederleithinger, Ernst A1 - Sieber, S. T1 - Reverse time migration: introducing a new imaging technique for ultrasonic measurements in civil engineering N2 - Ultrasonic echo testing is widely used in non-destructive testing in civil engineering to investigate concrete structures, to measure thickness, and to locate and characterise built-in components or inhomogeneities. Currently, synthetic aperture focusing techniques are mostly used for imaging. These algorithms are highly developed but have some limitations. For example, it is not possible to image the lower boundary of built-in components like tendon ducts or vertical reflectors. We adopted reverse time migration for non-destructive testing in civil engineering in order to improve the imaging of complicated structures in concrete. By using the entire wavefield, including waves reflected more than once, there are fewer limitations compared to synthetic aperture focusing technique algorithms. As a drawback, the required computation is significantly higher than that for the techniques currently used. Simulations for polyamide and concrete structures showed the potential for non-destructive testing. The simulations were followed by experiments at a polyamide specimen. Here, having acquired almost noise-free measurement data to test the algorithm, we were able to determine the shape and size of boreholes with sufficient accuracy. After these successful tests, we performed experiments at a reinforced concrete foundation slab. We obtained information from the data by reverse time migration, which was not accessible by traditional imaging. The imaging of the location and structure of the lower boundary of the concrete foundation slab was improved. Furthermore, vertical reflectors inside the slab were imaged clearly, and more flaws were found. It has been shown that reverse time migration is a step forward in ultrasonic testing in civil engineering. KW - Ultrasonic echo technique KW - Reverse time migration PY - 2017 U6 - https://doi.org/10.3997/1873-0604.2017006 SN - 1569-4445 SN - 1873-0604 VL - 15 IS - 3 SP - 242 EP - 258 PB - Wiley AN - OPUS4-41921 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Niederleithinger, Ernst A1 - Herbrand, M. A1 - Müller, M. T1 - Monitoring von Querkraftversuchen an Spannbetondurchlaufträgern mit Ultraschall und Codawelleninterferometrie T1 - Monitoring of shear tests on prestressed concrete continuous beams using ultrasound and coda wave interferometry N2 - Zusammenfassung Im Rahmen eines Forschungsvorhabens an der RWTH Aachen wurden mehrere Spannbetondurchlaufträger bis zum Versagen belastetet. Neben umfangreicher konventioneller Messtechnik wurden zusätzlich innovative Messmethoden durch die Bundesanstalt für Materialforschung und –prüfung (BAM) getestet. Darunter waren eingebettete Ultraschall-Transducer, deren Daten mit einer neuartigen Methode, der Codawelleninterferometrie (CWI), ausgewertet wurden. Dieses Verfahren detektiert auch kleinste Änderungen im Signal und in der Wellengeschwindigkeit gegenüber einer Referenzmessung. Hiermit können Belastungs- und Strukturänderungen sowie Schäden sehr viel sensibler angezeigt werden als bei konventionellen Ultraschallmessungen. Durch eine Modifikation des Verfahrens mit gleitender Referenz können aber auch starke Veränderungen im Material, wie sie bei Bruchversuchen auftreten, erfasst werden. In den Versuchen gelang es mit Netzwerken aus bis zu 20 Ultraschall-Transducern, Spannungskonzentrationen und Rissbildungen qualitativ zu detektieren und zu verfolgen, ohne dass die Sensoren direkt am Ort der Änderung angebracht sein müssen. N2 - Abstract In the framework of a research project at RWTH Aachen University, a set of large scale post-tensioned concrete continuous beams has been loaded until failure. In addition to conventional measurement techniques, innovative methods like embedded ultrasonic transducers have been applied by the Bundesanstalt für Materialforschung und -prüfung (BAM). The data acquired with theses transducers has been processed with a novel method called coda wave interferometry (CWI). This technique is able to detect even very small changes in the ultrasonic signal and in wave velocity. Loads or structural changes as well as damages can be detected with a much higher sensitivity compared to conventional measurements. Using a modification of the technique with step-wise referencing larger changes in the material can be followed as well. In the experiments, networks of up to 20 ultrasonic transducers have been used. Stress concentrations and crack formation have been detected and monitored qualitatively, without having to place the transducers directly at the place of interest. KW - Ultraschall KW - Codawelleninterferometrie KW - Brücken KW - Belastung KW - Monitoring PY - 2017 SN - 0005-6650 SN - 1436-4867 VL - 92 IS - November SP - 474 EP - 481 PB - Springer CY - Düsseldorf AN - OPUS4-42677 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Non-destructive Evaluation for Nuclear Power Plant concrete infrastructure N2 - The ageing and decommissioning of nuclear concrete infrastructure (e. g. safety containments) as well as the building and closure of waste repositories gives new challenges to non-destructive testing. For example, the quality assurance of very thick concrete structures is beyond the limitations of commercial ultrasonic instrumentation. The presentation introduces typical testing tasks and the application of state of the art NDT techniques. In addition, it describes some new developments in ultrasonic testing and monitoring. Specifically, the application of the unique deep penetration system LAUS is shown. Ultrasonic monitoring using embedded transducers to check for subtle and sudden changes in the material is introduced as well. T2 - Aalto University Special Guest Seminar CY - Espoo, Finland DA - 25.10.2018 KW - Ultrasound KW - Concrete KW - Nuclear PY - 2018 AN - OPUS4-46425 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Niederleithinger, Ernst T1 - Ultrasonic monitoring of concrete constructions using embedded transducers N2 - Ultrasonic transmission measurements are used to monitor concrete elements mostly on a laboratory scale since decades. Recently, coda wave interferometry, a technique adapted from seismology, has been introduced to civil Engineering experiments. It can be used to reveal subtle changes in concrete samples and even large construction elements without having a transducer directly at the location where the change is taking place. The methodology works best with embedded transducers to avoid coupling issues or excessive environmental influence. These transducers can be used for newly built and existing structures. Recently, large concrete beams have been equipped with a network of transducers and loaded until failure. Using code wave interferometry, it was possible to visualize stress fields and damaged areas. T2 - International Symposium on Structural Health Monitoring and Nondestructive Testing CY - Saarbrücken, Germany DA - 4.10.2018 KW - Ultrasound KW - Monitoring KW - Concrete PY - 2018 UR - http://www.ndt.net/?id=23542 SN - 1435-4934 VL - 23 IS - 12 SP - 1 EP - 6 PB - NDT.net CY - Kirchwald AN - OPUS4-46842 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Wang, Xin A1 - Mierschke, Vivien A1 - Bertschat, Anja Sophie T1 - Concepts from seismic interferometry transferred to sonic and ultrasonic concrete inspection and monitoring N2 - Seismic interferometry (SI) deals either with the sensible detection of changes in the subsurface or with the reconstruction of virtual signals between two receivers by crosscorrelation of signals from diffuse sources. These concepts can be applied in NDT in civil engineering for various purposes, e. g. to detect changes in bridges. Here it is demonstrated using data from a reference structure on our test site. Practical applications can be expected in the very near future. T2 - European Conference on Non-Destructive Testing (ECNDT) CY - Gothenburg, Sweden DA - 11.6.2018 KW - Ultrasound KW - Monitoring KW - Concrete KW - Interferometry KW - Coda PY - 2018 AN - OPUS4-46844 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Von der Ölsuche zum Beton - Geophysikalische Methoden für die ZfP im Bauwesen N2 - Nutzung geophysikalischer Methoden für die zerstörungsfrei Prüfung von Betonbauwerken; Beispiel 1: Reverse Time Migration zur Verbesserung der Abbildungsqualität von Ultraschall-Echo-Prüfungen; Beispiel 2: Eingebettete Transducer und Codawelleninterferometrie für die Bauwerksüberwachung. T2 - DGZfP Arbeitskreis Berlin, 389. Sitzung CY - Berlin, Germany DA - 05.09.2017 KW - Geophysik KW - Zerstörungsfreie Prüfung KW - Monitoring KW - Beton KW - Ultraschall PY - 2017 AN - OPUS4-41849 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst ED - Gabrijel, Ivan ED - Grosse, Christian ED - Skazlić, Marijan T1 - Ultrasonic monitoring of structural concrete elements N2 - Ultrasonic transmission measurements are used to monitor concrete elements mostly on a laboratory scale since decades. Recently, coda wave interferometry, a technique adapted from seismology, has been introduced to civil engineering experiments. It can be used to reveal subtle changes in concrete samples and even large construction elements without having a transducer directly at the location where the change is taking place. The methodology works best with embedded transducers to avoid coupling issues or excessive environmental influence. These transducers can be used for newly built and existing structures. Recently, large concrete beams have been equipped with a network of transducers and loaded until failure. Using code wave interferometry, it was possible to visualize stress fields and damaged areas. This paper gives an overview of the state of the art, recent results achieved at BAM and a task list for further results and development. T2 - International Conference on Sustainable Materials, Systems and Structures (SMSS 2019) CY - Rovinj, Croatia DA - 20.3.2019 KW - Concrete KW - Ultrasound KW - Monitoring KW - coda wave interferometry PY - 2019 SN - 978-2-35158-227-5 SP - 1 EP - 11 PB - RILEM Publications S.A.R.L. CY - Paris, France AN - OPUS4-47677 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schumacher, T. A1 - Murtuz, A. K. M. G. A1 - Hafiz, A. A1 - Dusicka, P. A1 - Niederleithinger, Ernst ED - Gabrijel, I. ED - Grosse, C. ED - Skazlić, M. T1 - Post-earthquake damage evaluation of concrete structures using ultrasonic monitoring: A proof-of concept laboratory study N2 - In earthquake-prone regions such as the Pacific Northwest, damage assessment tools are needed to enable safety evaluations to support recovery. Currently, damage assessment is performed primarily by visual inspection and is often impossible for structural members that are inaccessible, such as deep foundations or interior members hidden by cladding. This study explores the possibility of using embedded ultrasonic transducers to monitor reinforced concrete members for damage progression under earthquake loading. A novel methodology is proposed where changes in the member condition due to an increase in the earthquake-type loading of a full-scale column-foundation specimen are correlated with changes in the recorded ultrasonic waveforms. The discussed preliminary analysis of the ultrasonic signals is based on wave propagation velocity, changes in the coda wave portion, and maximum amplitude of the signals. Three embedded transducers were used to continuously monitor the laboratory specimen during destructive testing. This paper provides an overview of the proposed methodology, outlines the laboratory experiment, and discusses some preliminary observations. T2 - International Conference on Sustainable Materials, Systems and Structures (SMSS 2019) CY - Rovinj, Croatia DA - 20.3.2019 KW - Concrete KW - Monitoring KW - Ultrasound KW - earthquake PY - 2019 SN - 978-2-35158-227-5 U6 - https://doi.org/10.1007/978-3-031-07258-1_84 SP - 112 EP - 119 PB - RILEM Publications S.A.R.L. CY - Paris, France AN - OPUS4-47679 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Vössing, Konrad A1 - Gaal, Mate A1 - Niederleithinger, Ernst T1 - Air-coupled ferroelectret ultrasonic transducers for nondestructive testing of wood in through transmission and reflection mode N2 - The necessity and demand for nondestructive testing of wood-based materials which can automatically scan huge areas of wood is increasing. Air-coupled ultrasound (ACU) is used to detect defects and damage without altering the structure permanently. Using through transmission it is possible to detect even small holes and missing adhesive. If only one side of an object is accessible the reflection mode is preferred at the expense of a reduced resolution and penetration depth. Novel ferroelectret transducers with a high signal-to-noise ratio (SNR) enable a high-precision structure recognition. The transducers made of cellular polypropylene (PP) are quite suitable for ACU testing due to their extremely low Young’s modulus and low density which result in a favorable acoustic impedance for the transmission of ultrasonic waves between the transducer and air. Thus, defects such as delamination, rot, and cracks can be detected. Promising results were obtained under laboratory conditions with frequencies from 90 kHz to 200 kHz. The advantage of these ACU transducers is that they do not require contact to the sample, are accurate, and cost effective. Ultrasonic quality assurance for Wood is an important attempt to increase the acceptance of wooden structures and towards sustainability in civil engineering in general. T2 - International Conference on Sustainable Materials, Systems and Structures CY - Rovinj, Croatia DA - 20.03.2019 KW - Air-coupled ultrasound KW - Cellular polypropylene KW - Wood KW - Nondestructive Testing KW - Defect detection PY - 2019 SP - 28 EP - 33 AN - OPUS4-47682 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Azari, H. A1 - Shams, S. A1 - Köpp, Christian A1 - Timofeev, Juri A1 - Niederleithinger, Ernst T1 - Development of reference specimens for nondestructive evaluation of concrete bridge decks N2 - Decades of non-destructive evaluation (NDE) for the quality assurance of concrete bridges revealed the necessity of developing procedures for building reference specimens for different defects. External objects have been widely used in specimen construction to represent defects. However, embedded materials can alter the actual defect characteristics, interrupting the NDE responses. This study proposes new approaches to fabricating reference specimens for reinforced concrete that feature substantial defects, including cracks, delamination, honeycombing and rebar corrosion, without external objects. As a result, realistic responses can be acquired to identify promising NDE methods for characterising actual deteriorations. The procedures were produced with the intent of being reproducible in any laboratory. Destructive and non-destructive testing methods were performed to verify the effectiveness of the processes in creating defects. This study provides research laboratories with techniques for fabricating reference specimens for characterising defects and assessing the performance of NDE technologies. KW - Concrete structures KW - Reference KW - Specimen KW - Non-destructive testing KW - Laboratory tests PY - 2023 U6 - https://doi.org/10.1680/jfoen.21.00030 SN - 2043-9911 SP - 1 EP - 12 PB - ICE Publishing AN - OPUS4-56957 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lay, Vera A1 - Mielentz, Frank A1 - Prabhakara, Prathik A1 - Baensch, Franziska A1 - Johann, Sergej A1 - Hofmann, Detlef A1 - Sturm, Patrick A1 - Stamm, Michael A1 - Niederleithinger, Ernst T1 - Multi-sensory monitoring and ultrasound for quality assurance at underground sealing structures N2 - Within the safety concepts of underground disposal sites of nuclear waste, engineered barriers play an important role. As these sealing structures have high demands concerning integrity, we aim at advancing the available construction materials, monitoring, and inspection techniques within the project SealWasteSafe. A specifically developed alkali-activated material is compared to classical salt concrete. A comprehensive multi-sensory monitoring scheme is used at 150-340 l specimens to monitor setting and hardening of both materials. All sensors are demonstrated to resist the highly alkaline environments. Besides cabled and wireless temperature and humidity of the materials, strain variations using fibre optic sensors and acoustic emissions are recorded over periods of at least 28 days, partly for more than eight months. After hardening of the specimens, further nondestructive evaluations using ultrasonic echo and thermographic measurements are conducted. Preliminary results proof the suitability of the tested sensors and clearly highlight differences between the tested materials. Particularly, the newly developed alkali-activated material shows lower acoustic emission activity indicating less cracking activity. Additionally, unique ultrasonic methods will enable better images of potential internal objects and cracks at in-situ sealing structures. A largescale ultrasonic system is optimised to reliably detect objects at a depth exceeding 9 m while still obtaining a good resolution. Modelling studies show the potential of further increasing the distance between individual transducer arrays. Additionally, a new ultrasonic borehole probe using phased arrays allowing for beam focussing is constructed and tested. Laboratory measurements at a halfcylindrical concrete specimen coincide well with the previous modelling. In total, the presented safe materials, detailed monitoring approaches and ultrasonic quality assurance methods will help to obtain safe sealing structures within salt as a host rock. The concepts can partly be transferred to sealing structures in alternative host rocks and will also be valuable for non-nuclear waste repositories. T2 - NDE NucCon CY - Espoo, Finland DA - 25.01.2023 KW - SealWasteSafe KW - Engineered barriers KW - Monitoring KW - Embedded sensors KW - Ultrasonic imaging PY - 2023 SP - 2 EP - 10 AN - OPUS4-56928 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kolditz, O. A1 - Jacques, D. A1 - Claret, F. A1 - Bertrand, J. A1 - Churakov, S. V. A1 - Debayle, C. A1 - Diaconu, D. A1 - Fuzik, K. A1 - Garcia, D. A1 - Graebling, N. A1 - Grambow, B. A1 - Holt, E. A1 - Idiart, A. A1 - Leira, P. A1 - Montoya, V. A1 - Niederleithinger, Ernst A1 - Olin, M. A1 - Pfingsten, W. A1 - Prasianakis, N. I. A1 - Rink, K. A1 - Sampier, J. A1 - Szöke, I. A1 - Szöke, R. A1 - Theodon, L. A1 - Wendling, J. T1 - Digitalisation for nuclear waste management: predisposal and disposal N2 - Data science (digitalisation and artificial intelligence) became more than an important facilitator for many domains in fundamental and applied sciences as well as industry and is disrupting the way of research already to a large extent. Originally, data sciences were viewed to be well-suited, especially, for data-intensive applications such as image processing, pattern recognition, etc. In the recent past, particularly, data-driven and physics-inspired machine learning methods have been developed to an extent that they accelerate numerical simulations and became directly usable for applications related to the nuclear waste management cycle. In addition to process-based approaches for creating surrogate models, other disciplines such as virtual reality methods and high-performance computing are leveraging the potential of data sciences more and more. The present challenge is utilising the best models, input data and monitoring information to integrate multi-chemical-physical, coupled processes, multi-scale and probabilistic simulations in Digital Twins (DTw) able to mirror or predict the performance of its corresponding physical twins. Therefore, the main target of the Topical Collection is exploring how the development of DTw can benefit the development of safe, efficient solutions for the pre-disposal and disposal of radioactive waste. A particular challenge for DTw in radioactive waste management is the combination of concepts from geological modelling and underground construction which will be addressed by linking structural and multi-physics/chemistry process models to building or tunnel information models. As for technical systems, engineered structures a variety of DTw approaches already exist, the development of DTw concepts for geological systems poses a particular challenge when taking the complexities (structures and processes) and uncertainties at extremely varying time and spatial scales of subsurface environments into account. KW - Data science KW - Digitalization KW - Nuclear waste KW - Disposal KW - Predisposal PY - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-569387 SN - 1866-6280 VL - 82 IS - 1 SP - 1 EP - 11 PB - Springer AN - OPUS4-56938 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Holt, E. A1 - Oksa, M. A1 - Nieminen, M. A1 - Abdelouas, A. A1 - Banford, A. A1 - Fournier, M. A1 - Mennecart, T. A1 - Niederleithinger, Ernst T1 - Predisposal conditioning, treatment, and performance assessment of radioactive waste streams N2 - Before the final disposal of radioactive wastes, various processes can be implemented to optimise the waste form. This can include different chemical and physical treatments, such as thermal treatment for waste reduction, waste conditioning for homogenisation and waste immobilisation for stabilisation prior to packaging and interim storage. Ensuring the durability and safety of the waste matrices and packages through performance and condition assessment is important for waste owners, waste management organisations, regulators and wider stakeholder communities. Technical achievements and lessons learned from the THERAMIN and PREDIS projects focused on low- and intermediate-level waste handling is shared here. The recently completed project on Thermal Treatment for Radioactive Waste Minimization and Hazard Reduction (THERAMIN) made advances in demonstrating the feasibility of different thermal treatment techniques to reduce volume and immobilise different streams of radioactive waste (LILW) prior to disposal. The Pre-Disposal Management of Radioactive Waste (PREDIS) project addresses innovations in the treatment of metallic materials, liquid organic waste and solid organic waste, which can result from nuclear power plant operation, decommissioning and other industrial processes. The project also addresses digitalisation solutions for improved safety and efficiency in handling and assessing cemented-waste packages in extended interim surface storage. KW - Radioactive waste KW - Predisposal KW - Treatment KW - Monitoring PY - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-567276 SN - 2491-9292 VL - 8 SP - 1 EP - 6 PB - EDP Sciences CY - Les Ulis AN - OPUS4-56727 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Introduction to BAM and ultrasonics (and GPR) in civil engineering N2 - This presentation gives anoverview about BAM, its department 8 and in particular its division 8.2 "NDT methods for civil engineering". The focus is on methods and applications with a geoscientific context, such as methods adopted from geophysics or NDT method applied in a geological environment. T2 - GTK (Geological Survey of Finland) Semninar CY - Espoo, Finland DA - 20.01.2023 KW - NDT KW - Ultrasound KW - Radar KW - Geophysics KW - Concrete PY - 2023 AN - OPUS4-56911 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Nuclear concrete, and how to live with it more easy using NDE N2 - This keynote presentation compiles the specialities of civil engineering compared to other disciplines, of NDT in civil engineering compared to other filds of NDT and the specific challenges of applications in the nuclear energy and disposal sector. T2 - NucCon 2023 CY - Espoo, Finland DA - 25.01.2023 KW - NDT KW - Concrete KW - Nuclear PY - 2023 AN - OPUS4-56912 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Grohmann, Maria A1 - Niederleithinger, Ernst A1 - Buske, S. A1 - Büttner, C. T1 - Application of Elastic P-SV Reverse Time Migration to Synthetic Ultrasonic Echo Data from Concrete Members N2 - The ultrasonic echo technique is frequently used in non-destructive testing (NDT) of concrete structures for thickness measurements, geometry determinations as well as localization of built-in components. To improve ultrasonic imaging of complex structures in concrete, we transferred a geophysical imaging technique, the reverse time migration (RTM), to NDT in civil engineering. In contrast to the conventionally used synthetic aperture focusing technique (SAFT) algorithms, RTM is a wavefield continuation method in time and uses the full wave equation. Thus, RTM can handle complicated wave propagations in any direction without dip limitation. In this paper, we focused on the application and evaluation of a two-dimensional (2D) elastic RTM algorithm considering compressional waves, vertically polarized shear waves, and Rayleigh waves. We tested the elastic RTM routine on synthetic ultrasonic echo data generated with a 2D concrete model consisting of several steps and circular air inclusions. As these complex structures can often be found in real-world NDT use cases, their imaging is especially important. By using elastic RTM, we were able to clearly reproduce vertical reflectors and lower edges of circular air voids inside our numerical concrete model. Such structures cannot be imaged with conventional SAFT algorithms. Furthermore, the used elastic RTM approach also yielded a better reconstruction of a horizontal reflector and upper boundaries of circular air inclusions. Our encouraging results demonstrate that elastic RTM has the potential to significantly improve the imaging of complex concrete structures and, thus, is a step forward for detailed, high-quality ultrasonic NDT in civil engineering. KW - Concrete KW - Ultrasound KW - Imaging KW - Reverse time migration KW - Elastic PY - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-580680 SN - 0195-9298 VL - 42 IS - 3 SP - 1 EP - 18 PB - Springer Nature AN - OPUS4-58068 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Maack, Stefan A1 - Küttenbaum, Stefan A1 - Bühling, Benjamin A1 - Borchardt-Giers, Kerstin A1 - Aßmann, Norman A1 - Niederleithinger, Ernst T1 - Low frequency ultrasonic pulse-echo datasets for object detection and thickness measurement in concrete specimens as testing tasks in civil engineering N2 - The dataset contains raw data gathered with the ultrasonic pulse-echo method on concrete specimens. The surfaces of the measuring objects were automatically scanned point by point. Pulse-echo measurements were performed at each of these measuring points. The test specimens represent two typical testing tasks in construction industry: the detection of objects and the determination of dimensions to describe the geometry of components. By automating the measurement process, the different test scenarios are examined with a high repeatability, precision and measuring point density. Longitu- dinal and transversal waves were used and the geometrical aperture of the testing system was varied. The low-frequency probes operate in a range of up to approximately 150 kHz. In addition to the specification of the geometrical dimensions of the individual probes, the directivity pattern and the sound field characteristics are provided. The raw data are stored in a universally readable format. The length of each time signal (A-scan) is two milliseconds and the sampling rate is two mega-samples per second. The provided data can be used for comparative studies in signal analysis, imag- ing and interpretation as well as for evaluation pur- poses in different, practically relevant testing scenarios. KW - Validation KW - Puls-echo method KW - Ultrasonic KW - Non-destructive testing KW - SAFT KW - Reconstruction algorithm PY - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-575185 SN - 2352-3409 VL - 48 SP - 1 EP - 16 PB - Elsevier Inc. AN - OPUS4-57518 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maack, Stefan A1 - Niederleithinger, Ernst T1 - Low frequency ultrasonic dataset for comparison and validation of signal processing and imaging techniques in civil engineering N2 - The evaluation of technical components and materials in terms of condition and quality with the aid of non-destructive testing methods plays an outstanding role both in industrial serial production and in the individual assessment of components. The ultrasonic echo method is used for a wide variety of testing tasks, such as measuring the thickness of a component. At the Bundesanstalt für Materialforschung und -prüfung (BAM) in Berlin, test methods are developed and their performance is demonstrated. For this purpose, references such as materials, test procedures or data sets are generated, which are used to evaluate these developed test methods. An important component of these references are data sets that are created according to the BAM Data Policy and made available to the scientific community and users of test methods in practice on the basis of the FAIR principles (Findability, Accessibility, Interoperability, and Reuse). T2 - The International Symposium on Nondestructive Testing in Civil Engineering (NDT-CE) 2022 CY - Zurich, Switzerland DA - 16.08.2022 KW - Reference data KW - Non destructive testing and evaluation KW - Ultrasonic KW - Civil engineering PY - 2022 AN - OPUS4-58440 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maack, Stefan A1 - Niederleithinger, Ernst T1 - Imaging of Ultrasonic Echo Measurements for Reconstruction of Technical Data of Bridges – Possibilities, Limitations and Outlook N2 - When reassessing existing concrete bridges, the challenge is often to obtain missing or incomplete information on the internal structure. In particular, the number and position of the existing reinforcement as well as the geometric dimensions of the components are of interest. Non-destructive testing methods, like radar or ultrasound, which work on the basis of the pulse-echo method, have been established for this purpose, as they only require access to the component from one side. The measurement data recorded on the structure require pre-processing to be able to reproduce the internal structure geometrically accurately. Besides different steps of data processing, the geometrical reconstruction of the measured data based on the Synthetic Aperture Focusing Technique (SAFT) is state of the art today. In this paper, the technical possibilities of the ultrasonic echo method are presented based on measurements in the laboratory and on a real bridge structure. The precision of the reconstruction and its limitations are shown. In addition to the state of the art SAFT technique, open questions and the latest research approaches, such as imaging by reverse time migration (RTM) including initial results are discussed. T2 - 13th German-Japanese Bridge Symposium CY - Osaka, Japan DA - 29.08.2023 KW - Bridge KW - Non destructive testing and evaluation KW - Concrete KW - Validation PY - 2023 AN - OPUS4-58328 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Morichi, M. A1 - Fanchini, E. A1 - Bruggemann, C. A1 - Perot, B. A1 - Ricard, D. A1 - Niederleithinger, Ernst T1 - Developments and experiences of the CHANCE, MICADO and PREDIS projects in radioactive waste characterization N2 - Characterization is a very important step in dealing with materials and waste streams generated during the operational and decommissioning phases of nuclear installations, including nuclear power plants. Characterization allows differentiation between materials that can be released from regulatory control and those that require further treatment and conditioning to become a stable waste form suitable for future storage and final disposal according to its waste classification. Characterization is also needed in the pre-disposal stages of radioactive waste management to demonstrate compliance with the waste acceptance criteria of the facilities that will accept the different waste forms. This work will present the strategies developed and implemented by the three projects for in-depth and accurate waste characterization and investigation of the different radioactive waste packages considered. CHANCE, MICADO, and PREDIS will present their goals, the methods developed, the technologies used and the (preliminary) results contributing to the improvement of the safety and the data and information quality of the waste packages analyzed at the different stages of the waste management process. Special emphasis will also be given to complementary approaches highlighting the usability of the technologies, the accessibility of the data, and the problem-solving of the three projects within the European panorama. KW - Waste management KW - Radioactive waste KW - Waste chracterization PY - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-571872 SN - 2491-9292 VL - 9 IS - 12 SP - 1 EP - 11 PB - EPJ Nuclear Sci. Technol. AN - OPUS4-57187 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Zerstörungsfreie Prüfung von Betonkonstruktionen N2 - Der Vortrag behandelt den Stand der Technik bei der zerstörungsfreien Prüfung von Betonkonstruktionen und insbesondere den Stand und die Herausforderungen bei der Digitalisierung. Es werden Prüfaufgaben sowie etablierte Prüfmethoden und die passende Auswahl diskutiert. Ein weitere Schwerpunkt liegt bei der Genauigkeit und Verlässlichkeit und dem Konzept ZfPStatik. Abschließend werden Schnittstellen zu BIM, SIB-Bauwerke und anderen System kurz angerissen und ein Katalog offener Fragen aufgestellt. T2 - Workshop Digitale Bauwerkserhaltung inklusive Bauwerksdiagnose CY - Bonn, Germany DA - 20.02.2024 KW - ZfP-Bau KW - Beton KW - Bauwerksprüfung KW - Digitalisierung KW - ZfPStatik PY - 2024 AN - OPUS4-59547 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Epple, Niklas T1 - ridge Monitoring by Ultrasonic Coda Wave Interferometry N2 - The built infrastructure ages and requires regular inspection and, when in doubt, monitoring. To ensure that older concrete bridges showing signs of deterioration can be used safely, several innovative monitoring tools have been introduced, including but not limited to optical, fiber-optic, or acoustic emission techniques. However, there are gaps in the portfolio. A sensing technique that covers a wide range of damage scenarios and larger volumes, while still being sensitive and specific, would be beneficial. For about 15 years, research has been conducted on ultrasonic monitoring of concrete structures that goes beyond the traditional ultrasonic pulse velocity test (PV test), mostly using a very sensitive data evaluation technique called coda wave interferometry. At BAM we have developed sensors and instrumentation specifically for this method. We have instrumented a 70-year-old, severely damaged prestressed concrete bridge in Germany in addition to a commercial monitoring system. We have now collected data for almost 3 years. We can show that we can provide information about the stress distribution in the bridge. We have also been able to confirm that there has been no significant additional damage to the bridge since the installation. T2 - ISNT NDE 2023 CY - Pune, India DA - 07.12.2023 KW - Coda wave interferometry KW - Structural health monitoring KW - Ultrasound KW - Concrete KW - Bridges PY - 2023 AN - OPUS4-59346 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - X-rays without X-rays: Can muon tomography provide pictures from within concrete objects? N2 - Until the 1980s radiography was used to inspect civil structures in case of special demands and showed a much better resolution than other NDT techniques. However, due to safety concerns and cost issues, this method is almost never used anymore. Meanwhile, non-destructive techniques such as ultrasound or radar have found regular, successful practical application but sometimes suffer from limited resolution and accuracy, imaging artefacts or restrictions in detecting certain features when applied to reinforced or prestressed concrete inspection. Muon tomography has received much attention recently. Muons are particles generated naturally by cosmic rays in the upper atmosphere and pose no risk to humans. Novel detectors and tomographic imaging algorithms have opened new fields of application, mainly in the nuclear sector, but also in spectacular cases such as the Egyptian pyramids. As a first step towards practical application in civil engineering and as a proof of concept we used an existing system to image the interior of a reference reinforced 600 kg concrete block. Even with a yet not optimized setup for this kind of investigation, the muon imaging results have been at least of similar quality compared to ultrasonic and radar imaging, potentially even better. Recently, the research was expanded to more realistic testing problems such as the detection of voids in certain structural elements. However, before practical implementation, more robust, mobile, and affordable detectors would be required as well as user-Friendly imaging and simulation software. T2 - ISNT NDE 2023 CY - Pune, India DA - 07.12.2023 KW - Muon tomography KW - Concrete KW - Civil engineering PY - 2023 AN - OPUS4-59347 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Prabhakara, Prathik A1 - Lay, Vera A1 - Mielentz, Frank A1 - Niederleithinger, Ernst A1 - Behrens, Matthias T1 - Enhancing the Performance of a Large Aperture Ultrasound System (LAUS): A Combined Approach of Simulation and Measurement for Transmitter–Receiver Optimization N2 - The Large Aperture Ultrasound System (LAUS) developed at BAM is known for its ability to penetrate thick objects, especially concrete structures commonly used in nuclear waste storage and other applications in civil engineering. Although the current system effectively penetrates up to ~9 m, further optimization is imperative to enhance the safety and integrity of disposal structures for radioactive or toxic waste. This study focuses on enhancing the system’s efficiency by optimizing the transducer spacing, ensuring that resolution is not compromised. An array of twelve horizontal shear wave transducers was used to find a balance between penetration depth and resolution. Systematic adjustments of the spacing between transmitter and receiver units were undertaken based on target depth ranges of known reflectors at depth ranges from 5 m to 10 m. The trade-offs between resolution and artifact generation were meticulously assessed. This comprehensive study employs a dual approach using both simulations and measurements to investigate the performance of transducer units spaced at 10 cm, 20 cm, 30 cm, and 40 cm. We found that for depths up to 5 m, a spacing of 10 cm for LAUS transducer units provided the best resolution as confirmed by both simulations and measurements. This optimal distance is particularly effective in achieving clear reflections and a satisfactory signal-to-noise ratio (SNR) in imaging scenarios with materials such as thick concrete structures. However, when targeting depths greater than 10 m, we recommend increasing the distance between the transducers to 20 cm. This increased spacing improves the SNR in comparison to other spacings, as seen in the simulation of a 10 m deep backwall. Our results emphasize the critical role of transducer spacing in achieving the desired SNR and resolution, especially in the context of depth imaging requirements for LAUS applications. In addition to the transducer spacing, different distances between individual sets of measurement positions were tested. Overall, keeping the minimal possible distance between measurement position offsets provides the best imaging results at greater depths. The proposed optimizations for the LAUS in this study are primarily relevant to applications on massive nuclear structures for nuclear waste management. This research highlights the need for better LAUS efficiency in applications such as sealing structures, laying the foundation for future technological advances in this field. KW - Engineered barrier system KW - Phased array technique KW - Ultrasonic testing KW - Non-destructive testing in civil engineering KW - Seismic migration PY - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-592426 VL - 24 IS - 1 SP - 1 EP - 23 PB - MDPI CY - Basel, Switzerland AN - OPUS4-59242 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Baeßler, Matthias A1 - Georgi, Steven A1 - Herten, M. T1 - Comparison of static and dynamic load tests on bored piles in glacial soil N2 - BAW and BAM have performed a large scale comparison and calibration test on static and dynamic load capacity evaluation of bored piles in glacial sandy soil. The test was performed using eight piles at the BAM test site for technical safety at Horstwalde 50 km south of Berlin. The test area has been prepared and investigated in great detail using boreholes, cone penetration tests, pore pressure sensors and geophysical methods to assure controlled conditions for all piles and tests. The piles (10 m length, 0.9 m diameter) are mainly friction piles (low toe resistance) and have been checked by integrity testing. Five piles have been tested by five contractors using the dynamic method in a blind experiment, the other ones piles by static load and/or later on by the dynamic method. Some piles have been equipped with additional fibre optic Instrumentation which proved to be robust and helpful in interpreting the results of static, dynamic and integrity tests. We have experienced a deviation of the dynamic load test results gathered in the blind experiment from the static values of up to 20% in most cases, sometimes even up to 30%. This can be related to the known soil inhomogeneities, interpretation and modelling in CAPWAP and method inherent uncertainties. In cases where the static values were known by the testers for calibration, the deviations were significantly smaller. It has to be taken into account, that the two static load tests showed different results as well. Due to the low toe resistance, use of a big drop weight (11 tons) and large drop heights most piles suffered from cracking, which was clearly seen in follow up integrity tests and confirmed by excavation. The piles are available for further research. T2 - International conference on piling & deep foundations CY - Stockholm, Sweden DA - 21.05.2014 KW - Piles KW - Static load test KW - Dynamic load test KW - Integrity PY - 2014 SP - 1 EP - 8 AN - OPUS4-31202 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Niederleithinger, Ernst A1 - Wang, Xin A1 - Mierschke, Vivien A1 - Bertschat, Anja Sophie T1 - Concepts from seismic interferometry transferred to sonic and ultrasonic concrete inspection and monitoring N2 - Seismic interferometry (SI) deals either with the sensible detection of changes in the subsurface or with the reconstruction of virtual signals between two receivers by crosscorrelation of signals from diffuse sources. These concepts can be applied in NDT in civil engineering for various purposes, e. g. to detect changes in bridges. Here it is demonstrated using data from a reference structure on our test site. Practical applications can be expected in the very near future. T2 - 12th European Conference on Non-Destructive Testing (ECNDT 2018) CY - Gothenburg, Sweden DA - 11.6.2018 KW - Ultrasound KW - Concrete KW - Monitoring KW - Coda KW - Interferometry PY - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-468465 UR - http://www.ndt.net/?id=22760 SN - 1435-4934 VL - 23 IS - 8 SP - 1 EP - 2 PB - NDT.net CY - Kirchwald AN - OPUS4-46846 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Herten, M. A1 - Baeßler, Matthias A1 - Niederleithinger, Ernst A1 - Georgi, Steven T1 - Bewertung dynamischer Pfahlprobebelastungen an Bohrpfählen T2 - Pfahl-Symposium 2013 CY - Braunschweig, Germany DA - 2013-02-21 KW - Ringversuch KW - Statische Pfahlprobebelastung KW - Dynamische Pfahlprobebelastung KW - Bohrpfähle PY - 2013 SN - 3-927610-88-7 N1 - Serientitel: Mitteilung des Instituts für Grundbau und Bodenmechanik - Technische Universität Braunschweig – Series title: Mitteilung des Instituts für Grundbau und Bodenmechanik - Technische Universität Braunschweig IS - 96 SP - 79 EP - 100 AN - OPUS4-28072 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - THES A1 - Niederleithinger, Ernst T1 - Optimierung und Erweiterung der Parallel-Seismik-Methode zur Bestimmung der Länge von Fundamentpfählen N2 - Das Parallel-Seismik-Verfahren dient vor allem der nachträglichen Langenmessung von Fundamentpfählen oder ähnlichen Elementen zur Gründung von Bauwerken. Eine solche Messung wird beispielsweise notwendig, wenn ein Gebäude verstärkt, erhöht oder anders als bisher genutzt werden soll, aber keine Unterlagen mehr über die Fundamente vorhanden sind. Das Messprinzip des schon seit einigen Jahrzehnten bekannten Verfahrens ist relativ einfach: Auf dem Pfahlkopf wird meist durch Hammerschlag eine Stoßwelle erzeugt, die durch den Pfahl nach unten lauft. Dabei wird Energie in den Boden abgegeben. Die abgestrahlten Wellen werden von Sensoren in einem parallel zum Pfahl hergestellten Bohrloch registriert. Aus den Laufzeiten lassen sich die materialspezifischen Wellengeschwindigkeiten im Pfahl und im Boden sowie die Pfahllange ermitteln. Bisher wurde meist ein sehr einfaches Verfahren zur Datenauswertung verwendet, das die Lange der Pfahle systematisch überschätzt. In der vorliegenden Dissertation wurden die mathematisch-physikalischen Grundlagen beleuchtet und durch Computersimulation die Wellenausbreitung in Pfahl und Boden genau untersucht. Weitere Simulationen klarten den Einfluss verschiedener Mess- und Strukturparameter, beispielsweise den Einfluss von Bodenschichtung oder Fehlstellen im Pfahl. So konnte geklärt werden, in welchen Fällen mit dem Parallel-Seismik-Verfahren gute Ergebnisse erzielt werden können (z. B. bei Fundamenten in Sand oder Ton) und wo es an seine Grenzen stößt (z. B. bei Gründung im Fels). Auf Basis dieser Ergebnisse entstand ein neuer mathematischer Formalismus zur Auswertung der Laufzeiten. In Verbindung mit einem Verfahren zur Dateninversion, d. h. der automatischen Anpassung der Unbekannten in den Gleichungen an die Messergebnisse, lassen sich sehr viel genauere Werte für die Pfahllange ermitteln als mit allen bisher publizierten Verfahren. Zudem kann man nun auch mit relativ großen Abstanden zwischen Bohrloch und Pfahl (2 - 3 m) arbeiten. Die Methode wurde an simulierten Daten ausführlich getestet. Die Messmethode und das neue Auswerteverfahren wurden in einer Reihe praktischer Anwendungen getestet – und dies fast immer erfolgreich. Nur in einem Fall komplizierter Fundamentgeometrie bei gleichzeitig sehr hoher Anforderung an die Genauigkeit war schon nach Simulationen klar, dass hier ein Einsatz nicht sinnvoll ist. Dafür zeigte es sich, dass auch die Lange von Pfahlwanden und Spundwanden ermittelt werden kann. Die Parallel-Seismik-Methode funktioniert als einziges verfugbares Verfahren zur Fundamentlangenermittlung zugleich in den meisten Bodenarten sowie an metallischen und nichtmetallischen Fundamenten und kommt ohne Kalibrierung aus. Sie ist nun sehr viel breiter einsetzbar und liefert sehr viel genauere Ergebnisse. Die Simulationen zeigten noch Potential für Erweiterungen, zum Beispiel durch den Einsatz spezieller Sensoren, die zusätzliche Wellentypen empfangen und unterscheiden können. N2 - The Parallel Seismic (PS) method is used for determination of the unknown or undocumented depth/length of foundations, mostly piles. PS is an established but rather not commonly used geophysical technique, which has been developed several decades ago. Currently, this method is standardized in France and included in the FHWA method catalog. The principle behind PS is quite simple: an impulse is generated on top of the pile by a hammer stroke, generating elastic waves (mainly compressional) traveling downward through the pile. Due to the high impedance contrast between pile and soil, the main part of the energy remains in the pile, but some is transmitted as guided waves into the surrounding soil. After reaching the pile toe, transmitted/diffracted waves of nearly spherical front are generated. These waves are recorded by sensors (hydrophones or geophones) in a nearby borehole. From the first arrival times registered at the sensors, the apparent wave velocity is calculated, which is different above the pile toe (pile velocity) and below (soil velocity). In the conventional data analysis, the pile length is estimated based on the intersection of the two travel time branches, leading to a systematic overestimation of the length of the pile. This thesis provides a systematic treatise of the mathematical and physical foundations of wave propagation in piles and soil. Extensive numerical simulations and parametric studies have been carried out to investigate the nature of the wave-field and influence of measurement and structural parameters. The results revealed the range of applicability of Parallel Seismic, but also some limitations, e. g. in the case of rock socketed foundations or piles containing flaws. A new formalism for data interpretation was developed based on the simulation results, which takes into account the soil layers and the borehole inclination. This novel data interpretation scheme was used in combination with different data inversion methods. A comparison of the results showed that the commonly used Levenberg-Marquardt type least squares approach gives sufficiently accurate estimations in most common scenarios. The VFSA (very fast simulated annealing) method offers some advantages (e. g. avoiding local minima under certain conditions) but is much more time consuming. The new interpretation method was successfully validated using several sets of simulated data. It proved to be not only more accurate than all other available methods, but also to extend the maximum allowable pileborehole distance to 2 – 3 m. Besides the numerical study, several field investigations have been carried out for the purpose of this study and also in the framework of real world projects. The foundation types included secant pile walls and sheet piles. The method performed successfully in all cases but one: a highly accurate determination of the connection of a T-shaped footing. In this particular case, the inapplicability of the method was concluded after some preliminary simulations, thus avoiding unnecessary costs to the client. Performing simulations prior to the actual testing is recommended in dealing with all non-standard cases. Today, Parallel Seismic is the only method applicable on metallic and non metallic foundations which can be used without calibration. It has the largest range of all borehole methods. T3 - BAM Dissertationsreihe - 70 KW - Parallel-Seismik KW - Fundament KW - Inversion KW - Bohrpfahl KW - Längenbestimmung PY - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-883 SN - 978-3-9813853-5-9 SN - 1613-4249 VL - 70 SP - 1 EP - 221 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-88 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Helmerich, Rosemarie A1 - Niederleithinger, Ernst A1 - Stoppel, Markus A1 - Wiggenhauser, Herbert ED - Mencik, J. T1 - The role of advanced non-destructive techniques in condition assessment of existing bridges T2 - 2nd International Conference "Reliability, Safety and Diagnostics of Transport Structures and Means 2005" CY - Parduce, Czech Republic DA - 2005-07-07 KW - Condition assessment KW - Non-destructive testing (NDT) KW - Scanning system KW - Impulse radar KW - Ultrasonic echo KW - Impact echo KW - Active thermography KW - LIBS PY - 2005 SN - 80-7194-769-5 SP - 111 EP - 118 PB - University of Pardubice CY - Pardubice AN - OPUS4-7695 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Helmerich, Rosemarie A1 - Niederleithinger, Ernst A1 - Trela, Christiane A1 - Bien, J. A1 - Bernardini, G. ED - Hyun-Moo Koh, ED - Dan M. Frangopol, T1 - Complex multi-tool inspection of a masonry arch bridge using non-destructive testing T2 - Bridge Maintenance, Safety, Management, Health Monitoring and Informatics - IABMAS 2008 CY - Seoul, South Korea DA - 2008-07-13 PY - 2008 SN - 978-0-415-46844-2 SP - 1 EP - 8 PB - CRC Press CY - Boca Raton AN - OPUS4-17744 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Niederleithinger, Ernst A1 - Gardner, S. A1 - Kind, Thomas A1 - Kaiser, R. A1 - Grunwald, Marcel A1 - Yang, G. A1 - Redmer, Bernhard A1 - Waske, Anja A1 - Mielentz, Frank A1 - Effner, Ute A1 - Köpp, Christian A1 - Clarkson, A. A1 - Thompson, F. A1 - Ryan, M. A1 - Mahon, D. T1 - Muon Tomography of the Interior of a Reinforced Concrete Block: First Experimental Proof of Concept N2 - Quality assurance and condition assessment of concrete structures is an important topic world-wide due to the aging infrastructure and increasing traffic demands. Common topics include, but are not limited to, localisation of rebar or tendon ducts, geometrical irregularities, cracks, voids, honeycombing or other flaws. Non-destructive techniques such as ultrasound or radar have found regular, successful practical application but sometimes suffer from limited resolution and accuracy, imaging artefacts or restrictions in detecting certain features. Until the 1980s X-ray transmission was used in case of special demands and showed a much better resolution than other NDT techniques. However, due to safety concerns and cost issues, this method is almost never used anymore. Muon tomography has received much attention recently. Novel detectors for cosmic muons and tomographic imaging algorithms have opened up new fields of application, such as the investigation of freight containers. Muon imaging also has the potential to fill some of the gaps currently existing in concrete NDT. As a first step towards practical use and as a proof of concept we used an existing system to image the interior of a reference reinforced 600 kg concrete block. Even with a yet not optimized setup for this kind of investigation, the muon imaging results are at least of similar quality compared to ultrasonic and radar imaging, potentially even better. The data acquisition takes more time and signals contain more noise, but the images allowed to detect the same important features that are visible in conventional high energy X-ray tomography. In our experiment, we have shown that muon imaging has potential for concrete inspection. The next steps include the development of mobile detectors and optimising acquisition and imaging parameters. KW - Concrete KW - Muon KW - Radar KW - Ultrasound KW - X-ray PY - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-529974 VL - 40 IS - 3 SP - 1 EP - 14 PB - Springer Nature AN - OPUS4-52997 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Maak, Stefan A1 - Mielentz, Frank A1 - Effner, Ute A1 - Strangfeld, Christoph A1 - Timofeev, Juri T1 - Review of recent developments in ultrasonic echo testing of concrete N2 - Ultrasonic methods are used in concrete investigations since decades. While being limited to transmission testing in the laboratory for a while, in-situ echo measurements for structural investigations and condition assessment have made their way into practical application in the past 20 years. However, several challenges remain. On one side, there are technical issues as limitations in depth of penetration, resolution and imaging capabilities. On the other side there are still gaps in validation, standardization and certification, which are limiting the applicability in condition/load capacity assessment. This review reports a couple of developments which will help to overcome these issues. This includes technical developments as new devices which are easier to handle on site or giving a much deeper penetration depth (e.g. the LAUS device at BAM) as well as improvements in imaging by hardware update (e. g. air coupled ultrasound or coded signals) or new software (e. g. RTM imaging). To foster the application in real world projects we are as well working on standardization by developing new reference specimen with international partners which will ensure world-wide comparability of ultrasonic and other methods and quality assurance codes. Further, non-destructive methods are being used to update probabilistic models used for the reassessment of existing structures to support the structural engineer’s decisions. T2 - SMAR 2019 CY - Potsdam, Germany DA - 27.08.2019 KW - Engineered Barrier System (EBS) KW - Ultraschall KW - NDT KW - Re-assessment of exiting bridges PY - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-489686 SP - 1 EP - 6 AN - OPUS4-48968 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Helmerich, Rosemarie A1 - Niederleithinger, Ernst A1 - Wiggenhauser, Herbert T1 - Toolbox with Nondestructive Testing Methods for Condition Assessment of Railway Bridges KW - Non-destructive testing KW - Automated scanning KW - Condition assessment KW - Bridge assessment KW - Ultrasonicecho KW - Impulse radar KW - Impact echo PY - 2006 SN - 0361-1981 IS - 1943 SP - 65 EP - 73 PB - National Research Council CY - Washington, DC AN - OPUS4-14293 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Algernon, D. A1 - Arndt, R.W. A1 - Denzel, W. A1 - Ebsen, B. A1 - Feistkorn, S. A1 - Friese, M. A1 - Große, C.U. A1 - Kathage, S. A1 - Keßler, S. A1 - Köpp, Christian A1 - Küttenbaum, Stefan A1 - Lohse, C. A1 - Maack, Stefan A1 - Niederleithinger, Ernst A1 - Schickert, M. A1 - Schröder, G. A1 - Taffe, A. A1 - Timofeev, Juri A1 - Walther, A. A1 - Wilcke, M. A1 - Wolf, J. A1 - Wöstmann, Jens T1 - Test specimen concepts in regard to quality assurance and validation of nondestructive testing in civil engineering N2 - The process of ensuring reliability of NDT applications contains various aspects, such as determining the performance and probability of success, the uncertainty in measurement, the provision of clear and functional procedures and ensuring the correct application accordingly. Test specimens have become powerful elements in supporting many of these aspects. Within the committee for NDT in Civil Engineering (NDT-CE) of the German Society for Nondestructive Testing (DGZfP), the subcommittee on Quality Assurance (UA-QS) therefore addresses the design and the integration of test specimens in the quality assurance process. Depending on the specific purpose, the requirements on test specimens can vary significantly based on the defined simulated scenario. The most prominent purposes of test specimens might be seen in providing references for inspection systems in regard to function control, calibration and validation. Further aspects can be parametric studies, basic investigation of physical principles related to NDT or a simplified and therefore comprehensive demonstration of inspection concepts (e.g. for teaching purposes). The specific purpose of a test specimen dictates the requirements regarding its conception, including the exact design, the material or the fabrication accuracy and the conditioning. In the development of a general guideline by the UA-QS for application-specific procedures and their validation, the use of test specimens is addressed and specific concepts for the design of test specimens are made. This includes the analysis of the measurement process regarding any given application, deriving an adequate calibration approach for it and designing test specimens (calibration specimens) accordingly. Furthermore, it includes the validation of the procedure taking into account all conditions related to the specific application in the field. The validation requires a statistically sufficient number of trials. Thorough evaluation of each trial can only be established if the ground-truth is known. Therefore, test specimens providing a realistic but controlled simulation of the inspection problem are valuable and indispensable elements in the validation process. The requirement of being fully realistic will often not be possible to fulfill due to practical restrictions. Any aspect that cannot be included in the simulation realistically needs to be simulated conservatively. This again, requires a sufficient understanding of the inspection principle and technique to ensure conservativeness. Among other quality-assurance-related aspects, the UA-QS establishes concepts and guidelines regarding sound and efficient approaches for the specific purposes of test specimens. This subcommittee brings together representatives of different Groups along the entire value chain of NDT-CE, including researchers, practitioners, manufacturers and clients. They all work together in establishing a common understanding and level of quality assurance in the industry. T2 - SMT and NDT-CE 2018 CY - New Brunswick, NJ, USA DA - 27.08.2018 KW - Quality assurance KW - Procedure KW - Reliability KW - Validation KW - Reference specimen PY - 2019 UR - https://asnt.org/smt18papers SN - 978-1-57117-456-7 VL - 11/19 SP - 39 EP - 48 PB - The American Society for Nondestructive Testing, Inc. CY - Columbus, OH, USA AN - OPUS4-47240 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mielentz, Frank A1 - Stolpe, Heiko A1 - Effner, Ute A1 - Behrens, Matthias A1 - Bernstein, Thomas A1 - Niederleithinger, Ernst T1 - Entwicklung einer Bohrlochsonde für Ultraschalluntersuchungen an Abschlussbauwerken in Endlagern N2 - Für die Qualitätssicherung von Abschlusswerken für Endlager wird eine Ultraschall-Bohrlochsonde entwickelt. Mithilfe dieser Sonde, die aus einer Vielzahl von einzelnen koppelmittelfreien Ultraschall-Punktkontaktprüfköpfen besteht, soll die Rissfreiheit der Versuchsbauwerke überprüft werden. Ein erster Prototyp der Sonde wurde mit einem kommerziellen Ultraschallgerät betrieben und bestand aus 12 Transversalwellen-Punktkontaktprüfköpfen von denen jeweils sechs als Sender und sechs als Empfänger parallelgeschaltet waren. Um den erzeugten Schalldruck der Bohrlochsonde zu steigern, wurde bei der Neuentwicklung die Prüfkopfanzahl erhöht und zusätzlich die laufzeitgesteuerte Anregung der einzelnen Prüfköpfe vorgesehen. Für die Anregung der Prüfköpfe mit programmierten Zeitverzögerungen wurde ein neuartiger mehrkanaliger Sender für bipolare Rechtecksignale entwickelt. Durch die Entwicklung der Bohrlochsonde soll eine dynamische Anpassung der Prüfkopf-Apertur sowie eine Fokussierung des Schallfeldes in Abhängigkeit der zu untersuchenden Tiefe erfolgen. Mithilfe entsprechender Anregungsfunktionen kann das Schallfeld der Bohrlochsonde unterschiedlich geformt werden, z. B. ist auch ein Schwenken des fokussierten Schallbündels möglich. Dadurch wird das erfasste Prüfvolumen begrenzt und auf diese Weise das Signal-Störverhältnis der Empfangssignale verbessert. In Kombination mit SAFT-Rekonstruktionsrechnungen wird durch eine optimierte Abstrahlcharakteristik der Sonde mit einem hohen Schalldruck unter verschiedenen Winkeln eine verbesserte Signalqualität und damit eine erhöhte Aussagesicherheit der Ergebnisse in der Objektabbildung erwartet. T2 - DGZfP-Jahrestagung 2021 CY - Online meeting DA - 10.05.2021 KW - Abdichtbauwerk KW - Bohrlochsonde KW - Ultraschall-Echoverfahren KW - Verschlussbauwerk KW - Zerstörungsfreie Prüfung KW - Ultraschall-Messtechnik PY - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-526746 UR - https://jahrestagung.dgzfp.de/portals/jt2021/bb176/inhalt/poster.htm SN - 978-3-947971-18-3 VL - 176 SP - 1 EP - 7 PB - Deutsche Gesellschaft für Zerstörungsfreie Prüfung (DGZfP) CY - Berlin AN - OPUS4-52674 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rabe, U. A1 - Pudovikov, S. A1 - Herrmann, H.-G. A1 - Wiggenhauser, H. A1 - Prabhakara, Prathik A1 - Niederleithinger, Ernst T1 - Using the Corner Reflection for Depth Evaluation of Surface Breaking Cracks in Concrete by Ultrasound N2 - The corner echo is a well-known effect in ultrasonic testing, which allows detection of surface breaking cracks with predominantly perpendicular orientation to the surface as, for example, corrosion cracks in metal pipes or shafts. This echo is formed by two planes, the surface of the crack and the surface which the crack breaks. It can also be classified as a half-skip method, since a reflection of the pulse occurs on the backwall before the reflection at the defect takes place. In combination with the diffraction from the crack tip, the corner echo also allows crack sizing. As shown in this paper, the corner reflection can be used in civil engineering for nondestructive inspection of concrete. Commercially available low frequency ultrasonic arrays with dry point contact sources generate SH transversal waves with sufficient divergence of the sound field in order to detect corner reflections. Ultrasonic line-scans and area-scans were acquired with a linear array on flat concrete specimens, and the data were reconstructed by the Synthetic aperture focusing technique. If the angles and the area of reconstruction are chosen accordingly, the corner echo reflection can be distinguished from other ultrasonic information. The corner echo can thus be used as a method for deciding whether a crack is a partial-depth crack or a full-depth crack and thus for obtaining a statement about crack depth. This paper presents corresponding experimental results obtained on concrete specimens with artificial test defects and cracks induced under controlled conditions. KW - Ultrasound KW - Crack depth KW - Concrete KW - Corner echo PY - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-574631 SN - 0195-9298 VL - 42 IS - 2 SP - 1 EP - 19 PB - Springer Nature AN - OPUS4-57463 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Epple, Niklas A1 - Fontoura Barroso, Daniel A1 - Clauß, F. A1 - Ahrens, M. A. A1 - Mark, P. ED - Krieger, J. ED - Isecke, B. T1 - Ultraschallbasierte Überwachung von Stahl- und Spannbeton-konstruktionen – erste Ergebnisse der DFG-Forschungsgruppe 2825 CoDA N2 - Die Überwachung von Bauteilen aus Stahl- oder Spannbeton mit Ultraschall hat in Labor- und Technikumsversuchen schon vielversprechende Ergebnisse gezeigt. Besonders gute Resultate wurden dabei mit eingebetteten Ultraschalltrans-ducern und bei Auswertung der Daten mit der hochsensiblen Codawelleninterferometrie erzielt. Erfasst werden können neben Temperatur- und Feuchteeffekten auch Belastungszustände und jegliche Art von Schädigung, die mit Mikro- oder Makrorissbildung einhergeht. Seit 2019 untersucht die DFG-Forschergruppe 2825 „CoDA“ (Sprecher: Prof. Christoph Gehlen, TU München) ver-schiedenste Aspekte dieser innovativen Technologie mit dem Ziel, Einflussgrößen quantitativ zu erfassen, Umweltein-flüsse zu korrigieren und 3D-Auswerteverfahren zu verbessern. Final soll eine am Bauwerk einsatzfähige Methode ent-stehen, die klassische Monitoringverfahren ergänzt und erweitert sowie Input zu einem Update des statischen Systems liefert. Aufgaben der BAM in der Forschergruppe ist neben Verbesserung und Adaptierung der Messsystem und Sensorik auch Langzeitversuche an einem Großobjekt und Testinstallationen an Realbauwerken. Hierzu liegen erste Ergebnisse vor, die zeigen, dass die Technologie auch außerhalb des Labors einsatzfähig ist. T2 - 4. Brückenkolloquium CY - Online meeting DA - 08.09.2020 KW - Brücke KW - Monitoring KW - Ultraschall KW - Codawelleninterferometrie PY - 2020 SN - 978-3-8169-3518-6 SP - 473 EP - 480 PB - expert CY - Tübingen AN - OPUS4-51205 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Algernon, D. A1 - Arndt, R.W. A1 - Denzel, W. A1 - Ebsen, B. A1 - Feistkorn, S. A1 - Friese, M. A1 - Große, C.U. A1 - Kathage, S. A1 - Keßler, S. A1 - Köpp, Christian A1 - Küttenbaum, Stefan A1 - Lohse, C. A1 - Maack, Stefan A1 - Niederleithinger, Ernst A1 - Schickert, M. A1 - Schröder, G. A1 - Taffe, A. A1 - Timofeev, Juri A1 - Walther, A. A1 - Wilcke, M. A1 - Wolf, J. A1 - Wöstmann, Jens T1 - NDT procedures in relation to quality assurance and validation of nondestructive testing in civil engineering N2 - The field of non-destructive testing of civil structures (NDT-CE) has been continuously growing. Due to the complexity and diversity of civil constructions as well as the heterogeneity of concrete, specific standards or guidelines for the application of modern NDT-CE are still missing. The development of individual solutions is the current approach, which is just as challenging as it is common for NDT-CE. With the increasing development and commercialization of NDT-CE technology, the group of practitioners is growing. To ensure a good level of quality in the industry, it appears necessary to establish adequate means. Naturally, the performance of NDT-CE methods regarding a specific application is strongly dependent on choosing the most suitable inspection technique and applying it correctly, generally referred to as the inspection procedure in the field of NDT. There are well-defined guidelines regarding procedure documentation and handling in many fields of NDT (e.g. nuclear, aerospace or automotive) according to the high importance of procedures in assuring a successful and reliable application. For a long time, this has not always been the case with NDT-CE, which is still considered a unique discipline of NDT. Part of the reason for that might be the young development state of NDTCE, the heterogeneity of building materials like concrete, timber or masonry as a material and the diversity of civil structures. In consequence, NDT-CE procedure development is considered challenging. Among other aspects, addressed in the subcommittee on Quality Assurance (UA-QS) within the committee for NDT-CE of the German Society for Nondestructive Testing (DGZfP), part of its work aims at establishing an adequate basis for NDT-CE procedure development. While some of the highly developed approaches from other industries are taken into consideration, they need to be analyzed regarding their suitability for NDT-CE and adapted accordingly. For a procedure to be as defined as possible, it needs to contain sufficient information, such as the scope and limitations regarding material, geometry and condition of the test object, inspection parameters, calibration, data acquisition, analysis criteria as well as requirements regarding the inspection personnel. For a successful implementation in the field, it is important to define the specific procedure as precisely as possible. Despite the necessity of a great amount of information to be included, the procedure needs to be suitable for efficient field application. The UA-QS is developing a guideline for NDT-CE procedures suitable for application in this field of NDT to ensure correct and reproducible application. To demonstrate and evaluate this concept, specific examples of procedures are also produced. In particular, the UA-QS has developed a procedure for the detection and positioning of tendon ducts using Ground Penetrating Radar (GPR). This procedure is tested regarding the practical applicability in a roundrobin on a defined type of reference test block. T2 - SMT and NDT-CE 2018 CY - New Brunswick, NJ, USA DA - 27.08.2018 KW - Quality assurance KW - Procedure KW - Reliability KW - Validation KW - Reference specimen PY - 2019 UR - https://asnt.org/smt18papers SN - 978-1-57117-456-7 VL - 11/19 SP - 31 EP - 38 PB - The American Society for Nondestructive Testing, Inc. CY - Columbus, OH, USA AN - OPUS4-47239 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Maack, Stefan A1 - Küttenbaum, Stefan A1 - Bühling, Benjamin A1 - Niederleithinger, Ernst T1 - Low frequency ultrasonic dataset for pulse echo object detection in an isotropic homogeneous medium as reference for heterogeneous materials in civil engineering N2 - The dataset presented contains ultrasonic data recorded in pulse echo mode. The investigated specimen is made of the isotropic homogeneous material polyamide and has a drill hole of constant diameter running parallel to the surface, which was scanned in a point grid using an automatic scanner system. At each measuring position, a pitch-catch measurement was performed using a sampling rate of 2 MHz. The probes used are arrays consisting of a spatially separated receiving and in-phase transmitting unit. The transmitting and receiving sides each consist of 12 point-shaped single probes. These dry-point contact (DPC) probes operate according to the piezoelectric principle at nominal frequencies of 55 kHz (shear waves) and 100 kHz (longitudinal waves), respectively, and do not require a coupling medium. The measurements are performed with longitudinal (100 kHz) and transverse (55 kHz) waves with different geometric orientations of the probe on the measurement surface. The data presented in the article provide a valid source for evaluating reconstruction algorithms for imaging in the low-frequency ultrasound range. KW - Non-destructive testing KW - Ultrasound KW - Pulse-echo method KW - Reference material KW - Reconstruction algorithm KW - Validation PY - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-547326 VL - 42 SP - 1 EP - 11 PB - Elsevier Inc. AN - OPUS4-54732 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Niederleithinger, Ernst A1 - Wolf, Julia A1 - Mielentz, Frank A1 - Wiggenhauser, Herbert T1 - Using embedded ultrasonic sensors for active and passive concrete monitoring N2 - Challenging new constructions and ageing infrastructure are increasing the demand for permanent monitoring of loads and condition. Various methods and sensors are used for this purpose. But the technologies available today have difficulties in detecting slowly progressing locally confined damages. Extensive investigations or instrumentations are required so far for this purpose. In this study we present new sensors and data processing methods for ultrasonic transmission, which can be used for non-destructive long term monitoring of concrete. They can be mounted during construction or thereafter. Larger volumes can be monitored by a limited number of sensors for changes of material properties. The principles of ultrasonic transmission and influencing factors are presented. This latter include load, damages as well as environmental parameters as temperature or moisture. Various methods for data processing, e. g. coda wave interferometry are introduced. They allow the detection of very small changes in the medium. The embedded sensors are shown including mounting and operation. Application examples so far include small scale laboratory freeze-thaw experiments, localizing loads in larger concrete models, monitoring load effects on real structures as well as detecting acoustic events. Some sensors are operating already for several years. The sensors can be used as transmitter or receivers or switched between both roles. While most of the previous experiments have been active (at least one sensor serving as transmitter), new studies show that the sensors are useful as well for passive measurements, e. g. in acoustic emission or time reversal experiments. Besides application in civil engineering our setups can also be used for model studies in geosciences. T2 - NDT-CE 2015 - International symposium non-destructive testing in civil engineering CY - Berlin, Germany DA - 15.09.2015 KW - SHM KW - Monitoring KW - Ultrasound concrete KW - Embedded sensors PY - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-344652 UR - http://www.ndt.net/?id=18408 SN - 1435-4934 VL - 20 IS - 11 SP - 1 EP - 4 PB - NDT.net CY - Kirchwald AN - OPUS4-34465 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wohlgemuth, V. A1 - Niederleithinger, Ernst A1 - Helmerich, Rosemarie A1 - Hieksch, Torsten A1 - Stülpner, Doreen T1 - Entscheidung vor Ort: Eine Software unterstützt bei der Prüfung von Eisenbahnbrücken - Mit effektiveren Untersuchungs-, Bewertungs- und Verstärkungsmaßnahmen lassen sich zahlreiche europäische Brücken ertüchtigen KW - Infrastruktur KW - Zerstörungsfreie Prüfung KW - Inspektion KW - Brücke PY - 2008 SP - 74 EP - 79 CY - Berlin AN - OPUS4-17995 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Feistkorn, S. A1 - Algernon, D. A1 - Arndt, R. A1 - Ebell, Gino A1 - Friese, M. A1 - Grosse, C. U. A1 - Holstein, R. A1 - Niederleithinger, Ernst A1 - Schickert, M. A1 - Schulze, S. A1 - Taffe, A. A1 - Walther, A. A1 - Wolf, J. A1 - Zoega, A. A1 - Zwanzig, M. T1 - Introduction to DIN 4871: Qualification of NDT Personnel in Civil Engineering (NDT-CE) N2 - Recently, non-destructive testing in civil engineering (NDT-CE), in particular of concrete components, has successfully mastered the leap from research to practice. Several methods have been established for field inspections to determine the concrete cover of reinforcement or to estimate the compressive strength as well as other parameters related to the concrete material. In addition, the application of nondestructive testing is indispensable, if information about the inner structure - such as the location of rebars and tendon ducts or the damage-related condition assessment to detect grouting defects, honeycombs, delamination, or corrosion - is required. Besides the selection of a suitable NDT method and an appropriate inspection system, the reliability of the results depends largely on the person who applies the non-destructive inspection technique and evaluates the inspection results. To ensure a high quality of non-destructive concrete evaluation as well as to keep the uncertainty caused by the inspection personnel to a minimum, structured, consistent and regulated theoretical as well as practical training of inspection personnel is essential. To close this gap, the subcommittee of education (UA-A) within the committee for NDT-CE of the German Society for Nondestructive Testing (DGZfP) has been reactivated in 2018 to establish uniform training standards for nondestructive concrete inspections in the long term. The subcommittee consists of scientists, practitioners, authorities, and clients. So far, the national standard DIN 4871 “Non-destructive testing - Qualification and Certification of NDT personnel in Civil Engineering (NDT-CE)” was developed and is currently under review. This standard considers the civil-industry-specifics, for example, that standards for NDT of concrete, as well as related product standards with a few exceptions, still do not exist at the moment. Within this presentation, the concept, the connection to ISO 9712 and other standards as well as an overview of the developed German standard DIN 4871 will be presented. T2 - NDT-CE 2022 CY - Zurich, Switzerland DA - 16.08.2022 KW - Non-destrucive testing KW - Civil engineering PY - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-555250 UR - https://www.ndt.net/article/ndtce2022/paper/66594_manuscript.pdf VL - 2022/09 SP - 1 EP - 12 PB - NDT.net CY - Bad Breisig AN - OPUS4-55525 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baeßler, Matthias A1 - Niederleithinger, Ernst A1 - Georgi, Steven A1 - Herten, M. ED - Matsumoto, T. T1 - Evaluation of the dynamic load test on bored piles in sandy soil N2 - This paper summarizes the detailed planning of an evaluation project for dynamic load tests on bored piles in sandy soil. A test site had to be prepared, which ensures comparable conditions at all pile locations as well as a detailed knowledge on soil parameters and other boundary conditions. A detailed site investigation program was performed at a dedicated area on the BAM test site near Horstwalde south of Berlin, Germany. The site consists mainly of well graded, partly well compacted medium sands. A test program is designed that aims to give full responsibility for the testing performance to the operating consulting engineers. While each consultant is responsible for the testing of one of eight similar virgin piles, the test results will be compared to static load tests performed after the pile capacity analysis. The tests aim at a better understanding of the reliability of dynamic load tests and the necessary precautions for a good quality result. T2 - IS Kanazawa 2012 - 9th International conference on testing and design methods for deep foundations CY - Kanazawa, Japan DA - 18.09.2012 KW - Pile capacity KW - Bored pile KW - Evaluation study KW - Dynamic load test KW - Static load test PY - 2012 SN - 978-4-89010-597-7 IS - Paper 017 SP - 155 EP - 162 PB - Kanazawa e-Publishing Co., Ltd. AN - OPUS4-26901 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Seismic methods to test concrete strcutures N2 - Seismic methods are increasingly used to improve ultrasonic imaging and monitoring of concrete. At BAM, we are research mainly the use of Reverse Time Migration to get better images from ultrasonic echo data of thick, complex concrete structures. Coda wave interferometry is used to detect subtle changes in concrete constructions, e. g. using embedded ultasonic transducers. T2 - Geophysikalisches Seminar der Universität Potsdam CY - Potsdam,. Germany DA - 25.01.2019 KW - Concrete KW - Ultrasound KW - Monitoring KW - Imaging PY - 2019 AN - OPUS4-47302 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Grohmann, Maria A1 - Niederleithinger, Ernst A1 - Maack, Stefan A1 - Buske, Stefan T1 - Application of iterative elastic SH reverse time migration to synthetic ultrasonic echo data N2 - The ultrasonic echo technique is widely used in non-destructive testing (NDT) of concrete objects for thickness measurements, geometry determinations and localization of built-in components. To improve ultrasonic imaging of complex concrete structures, we transferred a seismic imaging technique, the Reverse Time Migration (RTM), to NDT in civil engineering. RTM, in contrast to the conventionally used synthetic aperture focusing technique (SAFT) algorithms, considers all wavefield types and thus, can handle complex wave propagations in any direction with no limit on velocity variations and reflector dip. In this paper, we focused on the development, application and evaluation of a two-dimensional elastic RTM algorithm considering horizontally polarized shear (SH) waves only. We applied the elastic SH RTM routine to synthetic ultrasonic echo SH-wave data generated with a concrete model incorporating several steps and circular cavities. As these features can often be found in real-world NDT use cases, their imaging is extremely important. By using elastic SH RTM, we were able to clearly reproduce almost all reflectors inside the concrete model including the vertical step edges and the cross sections of the cavities.We were also capable to show that more features could be mapped compared to SAFT, and that imaging of complex reflectors could be sharpened compared to elastic P-SV (compressional-vertically polarized shear) RTM. Our promising results illustrate that elastic SH RTM has the potential to significantly enhance the reconstruction of challenging concrete structures, representing an important step forward for precise, high-quality ultrasonic NDT in civil engineering. KW - Ultrasonic echo technique KW - Concrete structures KW - Elastic reverse time migration KW - Synthetic aperture focusing technique KW - Horizontally polarized shear waves PY - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-591716 SN - 1573-4862 VL - 43 SP - 1 EP - 16 PB - Springer Science and Business Media CY - Dordrecht AN - OPUS4-59171 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Große, Christian A1 - Arndt, Ralf A1 - Mähner, Dietmar A1 - Niederleithinger, Ernst A1 - Taffe, Alexander T1 - Zerstörungsfreie Prüfung im Bauwesen: Memorandum zur Lehre an deutschsprachigen Hochschulen N2 - Dieses erste Memorandum zur Lehre und Forschung an deutschsprachigen Hochschulen auf dem Gebiet der zerstörungsfreien Prüfung im Bauwesen gibt einen Überblick hinsichtlich der akademischen Ausbildung und zeigt mögliche Schwerpunkte vor allem in der Lehre auf. Diese Schwerpunkte berücksichtigen auch aktuelle Entwicklungen und Themen auf dem Gebiet der Forschung. Es werden Anregungen zur Entwicklung bzw. Weiterentwicklung der Lehr-Curricula im Hinblick auf eine umfassende und solide fachliche Ausbildung der Studierenden des Bauwesens und angrenzender Fachrichtungen gegeben. Inhaltlich und formal lehnt sich der Beitrag an dem Memorandum der Hochschullehrer im Fachgebiet „Werkstoffe im Bauwesen“ (Breit et al., 2012) an und beruht auf einer Initiative des Unterausschusses Ausbildung – Arbeitsgruppe Ausbildung in der Hochschule – des Fachausschusses ZfP im Bauwesen der Deutschen Gesellschaft für zerstörungsfreie Prüfung (DGZfP). Die Hauptredaktion wurde übernommen von Prof. Christian U. Grosse (TU München) und Prof. Ralf W. Arndt (FH Erfurt). KW - Zerstörungsfreie Prüfung KW - Lehrplan KW - Bauwesen PY - 2019 UR - https://onlinelibrary.wiley.com/doi/epdf/10.1002/bate.201900008 U6 - https://doi.org/10.1002/bate.201900008 SN - 1437-0999 SN - 0932-8351 VL - 96 IS - 4 SP - 360 EP - 368 PB - Ernst & Sohn CY - Berlin AN - OPUS4-47606 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Ultrasonic monitoring of structural concrete elements N2 - Ultrasonic transmission measurements are used to monitor concrete elements mostly on a laboratory scale since decades. Recently, coda wave interferometry, a technique adapted from seismology, has been introduced to civil engineering experiments. It can be used to reveal subtle changes in concrete samples and even large construction elements without having a transducer directly at the location where the change is taking place. The methodology works best with embedded transducers to avoid coupling issues or excessive environmental influence. These transducers can be used for newly built and existing structures. Recently, large concrete beams have been equipped with a network of transducers and loaded until failure. Using code wave interferometry, it was possible to visualize stress fields and damaged areas. This paper gives an overview of the state of the art, recent results achieved at BAM and a task list for further results and development. T2 - International Conference on Sustainable Materials, Systems and Structures (SMSS 2019) CY - Rovinj, Croatia DA - 20.03.2019 KW - Concrete KW - Ultrasound KW - Monitoring KW - coda wave interferometry PY - 2019 AN - OPUS4-47676 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bien, J. A1 - Helmerich, Rosemarie A1 - Niederleithinger, Ernst A1 - Kubiak, Z. T1 - Condition assessment of old railway bridges, a scientific cooperation between Berlin and Wroclaw N2 - Two years ago, the East Prussian and the Low-Silesian Railway lines celebrated their 160th anniversaries. The history of both first railway connections in the Eastern railway network development in the whole region in the 19th century is presented together with information about the railway between Berlin and Wroclaw. Special attention is paid to the railway bridges built in this period. The first large iron bridges and typical masonry arch structures are presented. Special attention is paid to masonry arches. The condition appraisal of existing masonry arches requires new developed technical methodologies, effective tools and procedures for the description of the bridges current state and function. Their current technical condition as well as service-ability is described. T2 - 3rd international congress on construction history CY - Cottbus, Germany DA - 2009-05-20 KW - Historische Eisenbahnlinien KW - Infrastruktur KW - Erhaltung KW - Wissenschaftliche Zusammenarbeit PY - 2009 VL - 1 SP - 205 EP - 211 AN - OPUS4-19532 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Niederleithinger, Ernst A1 - Helmerich, Rosemarie A1 - Streicher, Doreen ED - Vincentsen, L. T1 - NDT Methods for Condition Assessment of Railway Bridges T2 - International Association for Bridge and Structural Engineering (IABSE) Conference on Operation, Maintenance and Rehabilitation of Large Infrastructure Projects, Bridges and Tunnels CY - Copenhagen, Denmark DA - 2006-05-15 KW - Condition assessment KW - Non-destructive testing KW - Automation KW - Method combination PY - 2006 SN - 87-91044-03-0 SP - 1(?) PB - IABSE CY - Zürich AN - OPUS4-14038 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Niederleithinger, Ernst A1 - Helmerich, Rosemarie A1 - Wiggenhauser, Herbert ED - Cruz, P. ED - Frangopol, D. T1 - Trends in bridge condition assessment using non-destructive testing methods T2 - Bridge Maintenance, Safety, Management, Life-Cycle Performance and Cost CY - Porto, Portugal DA - 2006-07-16 KW - NDT KW - Condition assessment KW - Automation of measurement KW - Data fusion PY - 2006 SN - 0-415-40315-4 N1 - Serientitel: Balkema proceedings and monographs in engineering, water and earth sciences – Series title: Balkema proceedings and monographs in engineering, water and earth sciences SP - 933 EP - 934 PB - Taylor & Francis CY - London AN - OPUS4-14037 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Niederleithinger, Ernst A1 - Helmerich, Rosemarie T1 - Sustainable Bridges - NDT as a Tool to Assist Railway Bridge Management T2 - NDE Conference on Civil Engineering CY - St. Louis, Missouri, USA DA - 2006-08-14 KW - Railways KW - Bridges KW - NDT KW - Condition assessment PY - 2006 SN - 1-57117-148-7 SP - 196 EP - 204 PB - ASTM CY - St. Louis AN - OPUS4-14436 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Unger, Jörg F. A1 - Gründer, Klaus-Peter A1 - Hille, Falk A1 - Liehr, Sascha A1 - Maack, Stefan A1 - Niederleithinger, Ernst A1 - Pirskawetz, Stephan A1 - Rogge, Andreas A1 - Said, Samir A1 - Viefhues, Eva A1 - Zorn, Sebastian ED - Baeßler, Matthias ED - Möller, G. ED - Rogge, Andreas ED - Schiefelbein, N. T1 - Innovative Messsysteme zum Brückenmonitoring am Beispiel einer Versuchsbrücke – vom Sensor bis zur Zustandsprognose N2 - In der aktuellen Projektphase liegt der Fokus auf der Datenaufnahme, -bearbeitung und -speiche-rung mit dem Ziel, automatisierte Auswerteverfahren einsetzen zu können. Aktuell wurden primär punktuelle Messungen an ausgewählten Messtagen aufgenommen. Die Systeme sollen so weiter-entwickelt werden, dass sie sich auch für kontinuierliche Messungen im Rahmen von Monitoring-aufgaben eignen. Ein wichtiger Fokus bei der Auswertung ist die Kombination mit numerischen Modellen, die mithilfe von Bayesian Update Verfahren und den aufgenommenen Messdaten kalibriert und im Verlauf der Monitoringaufgabe angepasst werden sollen. Insbesondere sollen auch zeitabhängige Modelle, die eine zeitliche Entwicklung von Struktureigenschaften beinhalten (Kriechen, Schwinden, Ermüdung, Korrosion) dazu verwendet werden, die zukünftige Performance der Struktur bewerten zu können. Basierend darauf werden dann Konzepte zur Planung von Inspektion und Wartung erstellt. T2 - Messen im Bauwesen 2017 CY - Berlin, Germany DA - 14.11.2017 KW - Brückeninfrastruktur KW - Innovative Messverfahren KW - Stereofotogrammetrie PY - 2017 SN - 978-3-9818270-8-8 VL - 2017/1 SP - 7 EP - 19 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-44306 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schilder, Constanze A1 - Kohlhoff, Harald A1 - Hofmann, Detlef A1 - Basedau, Frank A1 - Habel, Wolfgang A1 - Baeßler, Matthias A1 - Niederleithinger, Ernst A1 - Georgi, Steven A1 - Herten, M. ED - Jaroszewicz, L.R. T1 - Static and dynamic pile testing of reinforced concrete piles with structure integrated fibre optic strain sensors N2 - Static and dynamic pile tests are carried out to determine the load bearing capacity and the quality of reinforced concrete piles. As part of a round robin test to evaluate dynamic load tests, structure integrated fibre optic strain sensors were used to receive more detailed information about the strains along the pile length compared to conventional measurements at the pile head. This paper shows the instrumentation of the pile with extrinsic Fabry-Perot interferometers sensors and fibre Bragg gratings sensors together with the results of the conducted static load test as well as the dynamic load Tests and pile integrity tests. T2 - EWOFS 2013 - 5th European workshop on optical fibre sensors CY - Kraków, Poland DA - 19.05.2013 KW - Static load test KW - Dynamic load test KW - Pile integrity test KW - Extrinsic Fabry-Perot interferometer KW - Fibre Bragg grating KW - Structure integrated sensor KW - Fibre optic strain sensor PY - 2013 SN - 978-0-81949-634-8 U6 - https://doi.org/10.1117/12.2026813 SN - 0277-786X N1 - Serientitel: Proceedings of SPIE – Series title: Proceedings of SPIE VL - 8794 IS - Paper 8794 - 181 SP - 700 EP - 703 AN - OPUS4-28854 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Epple, Niklas A1 - Fontoura Barroso, Daniel A1 - Clauß, F. A1 - Ahrens, M. A. A1 - Mark, P. T1 - Ultraschallbasierte Überwachung von Stahl- und Spannbeton-konstruktionen – erste Ergebnisse der DFG-Forschungsgruppe 2825 CoDA N2 - Die Überwachung von Bauteilen aus Stahl- oder Spannbeton mit Ultraschall hat in Labor- und Technikumsversuchen schon vielversprechende Ergebnisse gezeigt. Besonders gute Resultate wurden dabei mit eingebetteten Ultraschalltrans-ducern und bei Auswertung der Daten mit der hochsensiblen Codawelleninterferometrie erzielt. Erfasst werden können neben Temperatur- und Feuchteeffekten auch Belastungszustände und jegliche Art von Schädigung, die mit Mikro- oder Makrorissbildung einhergeht. Seit 2019 untersucht die DFG-Forschergruppe 2825 „CoDA“ (Sprecher: Prof. Christoph Gehlen, TU München) ver-schiedenste Aspekte dieser innovativen Technologie mit dem Ziel, Einflussgrößen quantitativ zu erfassen, Umweltein-flüsse zu korrigieren und 3D-Auswerteverfahren zu verbessern. Final soll eine am Bauwerk einsatzfähige Methode ent-stehen, die klassische Monitoringverfahren ergänzt und erweitert sowie Input zu einem Update des statischen Systems liefert. Aufgaben der BAM in der Forschergruppe ist neben Verbesserung und Adaptierung der Messsystem und Sensorik auch Langzeitversuche an einem Großobjekt und Testinstallationen an Realbauwerken. Hierzu liegen erste Ergebnisse vor, die zeigen, dass die Technologie auch außerhalb des Labors einsatzfähig ist. T2 - 4. Brückenkolloquium CY - Online meeting DA - 08.09.2020 KW - Ultraschall KW - Monitoring KW - Brücke KW - Codawelleninterferometrie PY - 2020 AN - OPUS4-51206 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Helmerich, Rosemarie A1 - Niederleithinger, Ernst A1 - Algernon, Daniel A1 - Streicher, Doreen A1 - Wiggenhauser, Herbert T1 - Bridge Inspection and Condition Assessment in Europe N2 - The European infrastructure asset has developed historically and is characterized by nation-specific construction processes. Inspection, condition assessment, and maintenance procedures differ from country to country. Because of historical and political circumstances, national infrastructure assets are maintained at different levels, too. Since the budget for maintaining the bridge infrastructure less and less meets the demands of a growing bridge stock, bridge inspection, maintenance, and life-cycle considerations gain higher importance. The need exists to develop effective diagnosis tools for early detection of construction faults, defects, and deterioration processes during inspection, to keep the bridge infrastructure at an acceptable level, from structural safety and economic viewpoints. An overview on the latest research projects and integrated bridge management systems in Europe is given. The potentials of nondestructive testing (NDT) are presented, with special focus on technical advances of NDT applications to reinforced concrete (RC) and posttensioned concrete bridges. Although NDT is not regularly integrated in these processes, the application brings valuable information on the current condition of the inner structure in called-in special inspections. NDT-automation and the application of imaging echo methods, combined with advanced data processing, produce a surprising level of information about the inner structure of massive RC slabs up to a depth of about 60 cm. Detected inhomogeneity and scatterers of acoustic or electromagnetic waves can be visualized in vertical or horizontal slices through the structure or animations. The fusion of different three-dimensional data sets of processed data improves the interpretability and accuracy of the results. KW - Category IIIC PY - 2008 U6 - https://doi.org/10.3141/2044-04 SN - 0361-1981 VL - 2044 SP - 31 EP - 38 PB - National Research Council CY - Washington, DC AN - OPUS4-18037 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Olofsson, J. A1 - Elfgren, L. A1 - Bell, B. A1 - Paulsson, B. A1 - Niederleithinger, Ernst A1 - Jensen, J. A1 - Feltrin, G. A1 - Täljsten, B. A1 - Cremona, C. A1 - Kiviluoma, R. A1 - Bien, J. ED - Jan Bien, ED - Lennart Elfgren, ED - Jan Olofsson, T1 - Sustainable Bridges - A European Integrated Research Project. Background and overview KW - Brücken KW - Inspektion KW - Monitoring KW - Zerstörungsfreie Prüfung KW - Eisenbahn KW - Verstärkung KW - Reparatur PY - 2007 SN - 978-83-7125-161-0 SP - 29 EP - 49 PB - Dolnoslaskie Wydawnictwo Edukacyjne CY - Wroclaw, Poland AN - OPUS4-16181 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Clauß, F. A1 - Epple, Niklas A1 - Ahrens, M. A. A1 - Niederleithinger, Ernst A1 - Mark, P. T1 - Correlation of Load-Bearing Behavior of Reinforced Concrete Members and Velocity Changes of Coda Waves N2 - The integral collection of information such as strains, cracks, or temperatures by ultrasound offers the best prerequisites to monitor structures during their lifetime. In this paper, a novel approach is proposed which uses the collected information in the coda of ultrasonic signals to infer the condition of a structure. This approach is derived from component tests on a reinforced concrete beam subjected to four-point bending in the lab at Ruhr University Bochum. In addition to ultrasonic measurements, strain of the reinforcement is measured with fiber optic sensors. Approached by the methods of moment-curvature relations, the steel strains serve as a reference for velocity changes of the coda waves. In particular, a correlation between the relative velocity change and the average steel strain in the reinforcement is derived that covers 90% of the total bearing capacity. The purely empirical model yields a linear function with a high level of accuracy (R 2 =0.99, R2=0.99, RMSE≈90μ RMSE≈90μ strain). KW - Ultrasound KW - Coda Wave Interferometry (CWI) KW - Structural Health Monitoring KW - Reinforced Concrete KW - Embedded Sensors PY - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-542316 VL - 15 IS - 3 SP - 738 PB - MDPI AN - OPUS4-54231 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Lay, Vera A1 - Effner, Ute A1 - Niederleithinger, Ernst A1 - Arendt, J. A1 - Hofmann, M. A1 - Kudla, W. T1 - Correction: Lay et al. Ultrasonic quality assurance at magnesia shotcrete sealing structures. Sensors 2022, 22, 8717 N2 - The authors wish to correct the following errors in the original paper Lay, V.; Effner, U.; Niederleithinger, E.; Arendt, J.; Hofmann, M.; Kudla, W. Ultrasonic Quality Assurance at Magnesia Shotcrete Sealing Structures. Sensors 2022, 22, 8717, https://doi.org/10.3390/s22228717. PY - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-584969 SN - 1424-8220 VL - 23 IS - 18 SP - 1 EP - 3 PB - MDPI CY - Basel AN - OPUS4-58496 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Baeßler, Matthias A1 - Herten, M. A1 - Rumpf, M. A1 - Tronicke, J. ED - Coutinho, R.Q. ED - Mayne, P.W. T1 - Geotechnical and geophysical characterization of a pile test site in post-glacial soil N2 - Two research institutes are currently evaluating dynamic pile load testing methods on bored piles in a sandy environment. A test site has been prepared, which ensures comparable conditions at all pile locations and provides detailed knowledge on soil and other boundary conditions. A detailed site investigation program was performed at a dedicated area on the BAM test site south of Berlin, Germany. Undisturbed soil samples have been collected from boreholes. In addition several CPTs and geophysical surveys have been performed. The site consists mainly of well graded, partly well compacted medium sands. But at depth an inhomogeneous gravel layer was detected in some parts of the site. This has led to a redesign of the test piles. They are now shorter than originally intended to avoid gravel layers at depth and to ensure that the drop weight available for dynamic test is capable to mobilize the required load. T2 - ISC-4 - 4th International conference on site characterization - Geotechnical and geophysical site characterization 4 CY - Pernambuco, Brazil DA - 17.09.2012 KW - Dynamic pile testing KW - Test site KW - CPT KW - Seismic tomography KW - Seismic crosshole PY - 2013 SN - 978-0-415-62136-6 VL - I SP - 459 EP - 464 PB - CRC Press AN - OPUS4-27492 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Foundations N2 - NDT-CE methods for foundations. T2 - NDT&E Advanced Training Workshop CY - Berlin, Germany DA - 05.07.2017 KW - NDT KW - Foundations KW - Pile integrity testing KW - Parallel seismic KW - Crosshole sonic logging PY - 2017 AN - OPUS4-42663 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - State-of-the-art ultrasonic monitoring of concrete N2 - Ultrasonic methods are well established in various aspects of concrete testing. They are used for imaging the interior geometry of constructions, estimation of concrete strength or monitoring lab investigations. However, so far the detection of distributed damages, especially in an early stage, has been almost impossible. The arrival of new technologies as embedded transducers and sensitive data processing techniques adopted from seismology has opened new field of work. Recent research has been focused to detect changes in concrete elements induced by stress, temperature, moisture or chemical attacks by permanent monitoring. Techniques as Coda Wave Interferometry can resolve changes in ultrasonic velocity in the order of 1*10-5. In addition, many researchers believe that the investigation of nonlinear effects can be used to characterize damages. The presentation will give a wrap up of ultrasonic techniques currently used in practice. This will include echo based methods as multi-channel/multi-offset imaging of structural elements using commercial and prototype devices. Imaging methods as SAFT and RTM will be shortly discussed. The focus will be on the emerging techniques used for monitoring. New types of sensors will be presented as well as the devices used in laboratory and field applications. Insight will be given on the various influence factors on ultrasonic signals and various ways of feature extraction and data processing. The results of lab experiments will be shown to demonstrate the detection of various kind of damages from mechanical load, ASR, corrosion to fatigue. The experiences with or first installations in real constructions (bridges, tunnel) will also be presented. T2 - CBIR Research Seminar, University of Technology Sydney CY - Sydney, Australia DA - 05.12.2016 KW - Ultrasound KW - Concrete KW - Monitoring KW - Imaging PY - 2016 AN - OPUS4-38730 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Helmerich, Rosemarie A1 - Streicher, Doreen A1 - Stoppel, Markus A1 - Wiggenhauser, Herbert ED - Forde, M. T1 - Automated non-destructive investigation of railway bridge condition T2 - 11th International Conference and Exhibiton "Structural Faults and Repair - 2006" CY - Edinburgh, Scotland, UK DA - 2006-06-13 KW - Non-Destructive Testing KW - Automated scanning device KW - Combination of methods KW - Ultrasonic-echo KW - Impact-echo KW - Impulse radar PY - 2006 SN - 0-947644-59-8 SP - 1 EP - 8(?) PB - Engineering Technics Pr., CY - Edingburgh AN - OPUS4-12530 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baeßler, Matthias A1 - Niederleithinger, Ernst A1 - Herten, M. A1 - Georgi, Steven ED - Dietzel, M. ED - Kieffer, S. ED - Marte, R. ED - Schubert, W. ED - Schweiger, H.F. T1 - Dynamische Pfahlprobebelastungen an Bohrpfählen in einem Testfeld: Ein Ringversuch T2 - 28. Christian Veder Kolloquium - Tiefgründungskonzepte - Vom Mikropfahl zum Großbohrpfahl CY - Graz, Austria DA - 2013-04-04 KW - Ringversuch KW - Statische Pfahlprobebelastung KW - Dynamische Pfahlprobebelastung KW - Bohrpfähle PY - 2013 SN - 978-3-900484-66-8 IS - 49 SP - 229 EP - 244 AN - OPUS4-28073 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Galindo Guerreros, Julio Cesar A1 - Mackens, S. A1 - Niederleithinger, Ernst A1 - Fechner, T. ED - Manzanal, D. ED - Sfriso, A. O. T1 - Numerical simulations of crosshole and downhole seismic measurements as quality control tool for jet grout columns N2 - Sealing and strengthening of the subsoil by injection is a major issue in the field of geotechnical engineering. This involves also jet grouting, which allows creating columns of grouted soil by eroding and mixing the in-situ soil with a thin cement suspension. A general difficulty of this method is to predict the column diameter and its material strength. Here, we present two-dimensional finite-difference numerical simulation results of a promising non-destructive quality assurance testing tool to evaluate the diameter of jet grout columns. This approach incorporates crosshole and downhole seismic measurements. Preliminary tests showed that this tool is applicable under real site conditions. T2 - 15th Pan-American Conference on Soil Mechanics and Geotechnical Engineering CY - Buenos Aires, Argentina DA - 15.11.2015 KW - Jet grout KW - Diameter KW - Seismic KW - Crosshole KW - Downhole KW - FD KW - Quality control tool PY - 2015 SN - 978-1-61499-603-3 SN - 978-1-61499-602-6 U6 - https://doi.org/10.3233/978-1-61499-603-3-985 SP - Part 1, 985 EP - 992 PB - IOS Press AN - OPUS4-37706 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Galindo Guerreros, Julio Cesar A1 - Niederleithinger, Ernst A1 - Mackens, S. A1 - Fechner, Th. T1 - Crosshole and downhole seismics: a new quality assurance tool for jet grout columns N2 - Sealing and strengthening of the subsoil by grout injection is a major issue in the field of geotechnical engineering. One commonly applied method is jet grouting, which allows creating columns of grouted soil by eroding and mixing the in-situ soil with a thin cement suspension. A general difficulty linked with this method is in predicting the resulting column diameter and its material strength. In this paper, we illustrate the application of a newly developed non-destructive quality assurance tool used to determine the diameter of jet grout columns. This approach incorporates standard crosshole and downhole seismic measurements. To demonstrate its effectiveness, we tested the new approach within two-dimensional finite-difference numerical simulations. Additional field tests showed that this tool is also applicable in real site conditions. For this purpose, three jet grout columns were produced with different process parameters in a depth between 3 and 10 m. The evaluated diameters were within 1 and 1.5 m, slightly deviating from the previously predicted range by the jet grouting contractor. Moreover, we were able to detect the base of the columns at a 10-m depth with no significant difficulties. On the other hand, unsaturated, less compacted sands between the groundwater level and surface considerably affected the seismic data, hence complicating the detection of the top of the columns. KW - Jet grouting KW - Quality assurance PY - 2016 U6 - https://doi.org/10.3997/1873-0604.2016042 SN - 1569-4445 IS - 14 SP - 493 EP - 501 PB - EAGE CY - Houton, NL AN - OPUS4-38977 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Niederleithinger, Ernst T1 - State-of-the-art of Ultrasonic Monitoring of Concrete N2 - Ultrasonic methods are well established in various aspects of concrete testing. They are used for imaging the interior geometry of constructions, estimation of concrete strength or monitoring lab investigations. However, so far the detection of distributed damages, especially in an early stage, has been almost impossible. The arrival of new technologies as deep penetration ultrasonic echo devices, new imaging techniques, embedded transducers for permanent monitoring and sensitive data processing techniques adopted from seismology have opened new fields of work. Recent research has been focused to detect changes in concrete elements induced by stress, temperature, moisture or chemical attacks. KW - Ultrasound KW - Concrete KW - Monitoring KW - Imaging PY - 2016 IS - 10 SP - 15 EP - 18 AN - OPUS4-38728 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maack, Stefan A1 - Niederleithinger, Ernst T1 - Imaging of Ultrasonic Echo Measurements for Reconstruction of Technical Data of Bridges – Possibilities, Limitations and Outlook N2 - When reassessing existing concrete bridges, the challenge is often to obtain missing or incomplete information on the internal structure. In particular, the number and position of the existing reinforcement as well as the geometric dimensions of the components are of interest. Non-destructive testing methods, like radar or ultrasound, which work on the basis of the pulse-echo method, have been established for this purpose, as they only require access to the component from one side. The measurement data recorded on the structure require pre-processing to be able to reproduce the internal structure geometrically accurately. Besides different steps of data processing, the geometrical reconstruction of the measured data based on the Synthetic Aperture Focusing Technique (SAFT) is state of the art today. In this paper, the technical possibilities of the ultrasonic echo method are presented based on measurements in the laboratory and on a real bridge structure. The precision of the reconstruction and its limitations are shown. In addition to the state of the art SAFT technique, open questions and the latest research approaches, such as imaging by reverse time migration (RTM) including initial results are discussed. T2 - 13th German-Japanese Bridge Symposium CY - Osaka, Japan DA - 29.08.2023 KW - Bridge KW - Non destructive testing and evaluation KW - Concrete KW - Validation PY - 2023 SP - 1 EP - 8 AN - OPUS4-58327 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Al-Neshawy, F. A1 - Ferreira, M. A1 - Bohner, E. A1 - Ojala, T. A1 - Sjöblom, V. A1 - Niederleithinger, Ernst A1 - Effner, Ute A1 - Puttonen, J. T1 - Design, Construction and NDT of a Mock-up for Reinforced Concrete Walls in NPP N2 - Construction methods, environmental stressors, and aging factors are the main causes for defects of reinforced concrete in nuclear power plants (NPP). These defects are typically occurred as corrosion of reinforcement steel, delamination, cracks, malfunction of post-tensioning or steel composite systems etc. Some of the challenges for assessing the performance of these structures by nondestructive testing methods (NDT) are that the assessment could be performed only during the annual overhauls when testing is time-limited and uncertainty of the accuracy and reliability of the available NDT testing devices combined with the lack of the international uniformity of the methods used for NDT tests. To overcome these challenges, a mock-up wall representing a section of the concrete containment of the NPP was built. The mock-up wall included simulated defects, which mimic the most common types of defects in NPP concrete structures such as dimensional errors, honeycombing, delamination, defects adjacent to the steel liner and voids in grouted tendon ducts for the post-tensioned structures. This paper introduces the design and construction of the wall including the concrete properties, reinforcement, tendon ducts and the types of the simulated defects. The paper also introduces the NDT methods and techniques that are suitable for assessing the condition of the mock-up wall under the real environmental conditions. These techniques include mechanical methods as rebound hammer, ultrasonic and electromagnetic methods. This mock-up wall will enable to investigate reliably available NDT methods and experts’ skills providing also an important and very much need educational platform for future NDE experts. T2 - SMIRT-25 CY - Charlotte, NC, USA DA - 04.08.2019 KW - NDE KW - Defects KW - Thick-walled KW - Concrete KW - Deterioration KW - Steel liner PY - 2019 SP - 1 EP - 12 AN - OPUS4-48965 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Galindo Guerreros, Julio Cesar A1 - Niederleithinger, Ernst A1 - Mackens, S. A1 - Fechner, T. T1 - Quality assurance of jet grout columns with borehole seismic measurements N2 - Sealing and strengthening of the subsoil by injection is a major issue in the field of geotechnical engineering. One commonly applied method is jet grouting, which allows creating columns of grouted soil by eroding and mixing the in-situ soil with a thin cement suspension. A general difficulty linked with this method is to predict the resulting column diameter and its material strength. In this paper we illustrate the application of a newly developed non-destructive quality assurance testing tool used to determine the diameter of jet grout columns. This approach incorporates standard crosshole and downhole seismic measurements. To demonstrate its effectiveness, we tested the new approach within two-dimensional finite-difference numerical simulations. Additional field tests showed that this tool is also applicable in real site conditions. For this purpose, three jet grout columns were produced with different process parameters in a depth between 3.0 and 10 m. The evaluated diameters were within 1.0 and 1.5 m, slightly deviating from the previously predicted range by the jet grouting contractor. Moreover, we were able to detect the base of the columns at 10 m depth with no significant difficulties. On the other hand, unsaturated, partly unconsolidated sands between ground water level and surface considerably affected the seismic data, hence complicating the detection of the top of the columns. T2 - NDT-CE 2015 - International symposium non-destructive testing in civil engineering CY - Berlin, Germany DA - 15.09.2015 KW - Jet grout KW - Seismics KW - Crosshole KW - Downhole PY - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-346753 UR - https://www.ndt.net/?id=18277 SN - 1435-4934 VL - 20 IS - 11 SP - 1 EP - 7 PB - NDT.net CY - Kirchwald AN - OPUS4-34675 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mackens, S. A1 - Fechner, T. A1 - Rios, N.I.C. A1 - Tweeton, D. A1 - Galindo Guerreros, Julio Cesar A1 - Niederleithinger, Ernst T1 - A new approach to determine the diameter of a jet grouted column using seismic methods N2 - Jet grouting is a geotechnical method of ground improvement to increase shear strength and stiffness of soils. The method is typically used to construct in-situ geometries of grouted soil such as panels or columns. The diameter of grouted columns and its material strength depend on various process parameters and the subsurface soil properties. It is only vaguely possible to predict the final column diameter. Therefore, it is a general practice to excavate a test column and perform a visual examination. However, an excavation to control the in situ diameter is often impossible, especially under complex site conditions, such as a high ground water table. Therefore, as part of a research project, borehole seismic measurements (crosshole, downhole and tomography) were tested as a quality control to verify the extent of the column and to monitor the influence of the jet grout injection on the soil over time. The field surveys were conducted before and after the jet grouting process at different time intervals. The acquired seismic data show clear traveltime differences which allow the determination of the specific column depth and diameter. The tomogram measured in the natural soil and the tomograms of the measurements after the injection process were used to visualize the time dependent effects of the jet grout injection on the soil. T2 - SAGEEP 2015 - 28th Symposium on the application of geophysics to engineering and environmental problems CY - Austin, TX, USA DA - 22.03.2015 KW - Jet grouting KW - Grouted column KW - Column diameter KW - Seismic tomography KW - Quality assurance KW - Diameter PY - 2015 U6 - https://doi.org/10.4133/SAGEEP.28-021 SP - 142 EP - 146 AN - OPUS4-33678 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Lay, Vera A1 - Köpp, Christian T1 - Digital tools for cemented waste package and facility monitoring and prediction N2 - To provide better means for a safe and effective monitoring of cemented waste packages including prediction tools to assess the future integrity development during pre-disposal activities, several digital tools are evaluated and improved in the frame of the EC funded project PREDIS. Safety enhancement (e. g. less exposure of testing personnel) and cost effectiveness are part of the intended impact. The work includes but is not limited to inspection methods such as muon imaging, wireless sensors integrated into waste packages as well as external package and facility monitoring such as remote fiber optical sensors. The sensors applied will go beyond radiation monitoring and include proxy parameters important for long term integrity assessment (e. g. internal pressure). Sensors will also be made cost effective to allow the installation of much more sensors compared to current practice. The measured data will be used in digital twins of the packages for specific simulations (geochemical, integrity) providing a prediction of future behavior. Machine Learning techniques trained by the characterization of older packages will help to connect the models to the actual data. All data (measured and simulated) will be collected in a joint data base and connected to a decision framework to be used at actual facilities. The paper includes detailed information about the various tools under consideration, their connection and first results of our research. T2 - International Conference on Radioactive Waste Management: Solutions for a Sustainable Future CY - Vienna, Austria DA - 01.11.2021 KW - Radioactive waste disposal KW - Monitoring KW - Cemented waste PY - 2021 AN - OPUS4-54163 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Grohmann, Maria A1 - Niederleithinger, Ernst A1 - Buske, S. T1 - Bestimmung der Geometrie einer Fundamentplatte mit dem Ultraschall-Echo-Verfahren unter Anwendung geophysikalischer Migrationsmethoden N2 - Das Ultraschall-Echo-Verfahren ist ein klassisches Verfahren in der zerstörungsfreien Prüfung zur Bestimmung der Geometrie von Bauteilen. Die Prüfaufgaben beinhalten unter anderem die korrekte Dickenbestimmung der Baukörper sowie die Lokalisierung von Einbauteilen und Fehlstellen. Stand der Technik bei den Abbildungsverfahren ist die SAFT–Rekonstruktion (Synthetic Aperture Focusing Technique). Diese Verfahrensfamilie hat Schwierigkeiten bei der Darstellung von steilen Grenzflächen und komplizierten Strukturen, wie beispielsweise Stufen oder Unterkanten von Hohlräumen und Hüllrohren. Als Alternative werden seit einiger Zeit geophysikalische Migrationsmethoden evaluiert. Am Beispiel eines Stahlbetonfundamentes mit verschiedenen Bewehrungsgehalten, unterschiedlichen Dicken sowie zwei Pfahlköpfen wurden die Kirchhoff-Migration und die Reverse-Time Migration (RTM) getestet. Die strahlenbasierte Kirchhoff-Migration arbeitet ähnlich wie die SAFT-Rekonstruktion. Die RTM basiert auf der vollständigen Wellengleichung. In einem ersten Schritt wurden die Methoden an einem synthetischen, auf der akustischen Wellengleichung basierenden zweidimensionalem Modell getestet. Im zweiten Schritt wurden reale Messdaten, die mit Scherwellenprüfköpfen an der Fundamentplatte aufgenommen wurden, bearbeitet. Der Einsatz eines Scannersystems vereinfachte die Messungen. Die Experimente, die in diesem Manuskript vorgestellt werden, sind von bedeutendem Interesse für die Evaluierung geophysikalischer Migrationsmethoden an analogen Modellen. Ein Vergleich der Migrationsergebnisse mit den bisherigen SAFT-Ergebnissen zeigt insbesondere für die RTM eine deutliche Verbesserung in der Abbildung der Bauteilgeometrie. Vertikale Kanten konnten dargestellt sowie die Lage und Struktur der Rückwände exakter reproduziert werden. Grenzen bestehen noch bei der Darstellung der Pfahlköpfe, da die von dem zylinderförmigen Pfahl kommenden Signale verrauscht sind. Ursachen dafür sind u.a. die Bewehrung, Randeffekte sowie Mehrfachreflexionen an dem Pfahlschaft. T2 - DGZfP-Jahrestagung 2014 CY - Potsdam, Germany DA - 26.05.2014 PY - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-320249 SN - 978-3-940283-61-0 IS - DGZfP-BB 148 SP - Poster 10, 1 EP - 8 PB - Deutsche Gesellschaft für Zerstörungsfreie Prüfung (DGZfP) AN - OPUS4-32024 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Niederleithinger, Ernst A1 - Brink, Arne A1 - McDonald, C. A1 - Meggyes, Tamás A1 - Roehl, K. E. A1 - Witt, K. J. T1 - TAILSAFE - Investigation and improvement of tailings facilities N2 - Tailings are the fine residue of the milling process in the mining industry and appear in slurry form being mixed with water during this process. Large tailings ponds are required to contain them, usually confined by man-made dams. Such tailings facilities pose considerable risk both to the environment and human lives. A major interdisciplinary research project ('TAILSAFE') supported by European Union has been initiated with the aim to increase attention towards and reduce the risk posed by tailings facilities. Methods of parameter evaluation and measurement are being developed within the project and applied for the detection, assessment and improvement of the safety state of tailings dams and ponds. One of the workpackages has his focus on non-destructive geophysical investigation methods. Geoelectrical (SIP), seismic and radar methods will be used to get information on the tailings dam structure and water content. T2 - 6th International Symposium Non-Destructive Testing in Civil Engineering (NDT-CE) CY - Berlin, Germany DA - 2003-09-16 PY - 2003 UR - http://www.ndt.net/article/ndtce03/papers/p014/p014.htm SN - 3-931381-49-8 SP - 1 EP - 6(?) PB - DGZfP CY - Berlin AN - OPUS4-2756 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Helmerich, Rosemarie A1 - Niederleithinger, Ernst A1 - Trela, Christiane A1 - Bien, J. A1 - Kaminski, T. A1 - Bernardini, G. T1 - Multi-tool inspection and numerical analysis of an old masonry arch bridge N2 - Complex special inspection of an old masonry arch bridge according to the Guideline on Inspection and Condition Assessment of Railway Bridges and numerical analysis of the structure are presented. The guideline summarises recommendations for the step-by-step investigation of railway bridges applying enhanced methods developed during the EU-funded project Sustainable Bridges. For the investigation of the arch barrel, the ballast parameters and the inner structure of the backfill behind the arch barrel a number of various advanced non-destructive and minor-destructive testing methods were applied. Deformation of the structure during load tests was measured using three independent measuring systems: laser vibrometer, LVDT and microwave radar. Results of calculations performed with 2D and 3D models based on FEM are compared with the field load tests. Sensitivity of the ultimate load of the structure to investigated parameters is studied in FE model. Some general conclusions according to methods of testing and modelling of masonry arch bridges are presented and discussed. KW - Masonry bridges KW - Non-destructive testing KW - Bridge inspection KW - Finite element method PY - 2010 U6 - https://doi.org/10.1080/15732471003645666 SN - 1573-2479 SN - 1744-8980 IS - NSIE_A_465075 SP - 1 EP - 13 PB - Taylor & Francis CY - London AN - OPUS4-22838 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Helmerich, Rosemarie A1 - Niederleithinger, Ernst A1 - Trela, Christiane A1 - Bien, J. A1 - Kaminski, T. A1 - Bernardini´, G. T1 - Multi-tool inspection and numerical of an old masonry arch bridge N2 - Complex special inspection of an old masonry arch bridge according to the Guideline on Inspection and Condition Assessment of Railway Bridges and numerical analysis of the structure are presented. The guideline summarises recommendations for the step-by-step investigation of railway bridges applying enhanced methods developed during the EU-funded project Sustainable Bridges. For the investigation of the arch barrel, the ballast parameters and the inner structure of the backfill behind the arch barrel a number of various advanced non-destructive and minor-destructive testing methods were applied. Deformation of the structure during load tests was measured using three independent measuring systems: laser vibrometer, LVDT and microwave radar. Results of calculations performed with 2D and 3D models based on FEM are compared with the field load tests. Sensitivity of the ultimate load of the structure to investigated parameters is studied in FE model. Some general conclusions according to methods of testing and modelling of masonry arch bridges are presented and discussed. KW - Masonry bridges KW - Non-destructive testing KW - Bridge inspection KW - Finite element method PY - 2012 SN - 1573-2479 VL - 8 IS - 1 SP - 27 EP - 39 PB - Taylor & Francis CY - London [u.a.] AN - OPUS4-27425 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Bien, J. A1 - Helmerich, Rosemarie A1 - Kubiak, Z. A1 - Niederleithinger, Ernst T1 - Ocena Kondycji Starych Mostów Kolejowych Przy Uz.yciu Zaawansowanych Metod - Naukowa Wspólpraca Berlina i Wroclawia / Condition assessment of old railway bridges using advanced methods - scientific cooperation between Berlin and Wroclaw T2 - 160 Lat Polaczenia Kolejowego Wroclaw - Berlin / 160 Jahre Eisenbahnverbindung Berlin-Breslau Konferenz CY - Wroclaw, Poland DA - 2006-12-15 KW - Mosty kolejowe KW - Metody diagnostyczne KW - Metody zaawansowane KW - Historische Eisenbahnlinien KW - Infrastruktur KW - Erhaltung KW - Wissenschaftliche Zusammenarbeit PY - 2006 SN - 83-7085-995-X SP - 183 EP - 199 PB - Oficyna Wydawnicza Politechniki Wroclawskiej CY - Wroclaw AN - OPUS4-14456 LA - pol AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Taffe, Alexander A1 - Behrens, Matthias T1 - RUFUS - Re-Use of Foundations on Urban Sites - Ein EU-Projekt zur Wiedernutzung von Fundamenten T2 - Pfahl-Symposium 2003 CY - Braunschweig, Germany DA - 2003-02-20 PY - 2003 AN - OPUS4-3830 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - X-rays without X-rays: Can muon tomography provide pictures from within concrete and other objects? N2 - Until the 1980s radiography was used to inspect civil structures in case of special demands and showed a much better resolution than other NDT techniques. However, due to safety concerns and cost issues, this method is almost never used anymore. Meanwhile, non-destructive techniques such as ultrasound or radar have found regular, successful practical application but sometimes suffer from limited resolution and accuracy, imaging artefacts or restrictions in detecting certain features when applied to reinforced or prestressed concrete inspection. Muon tomography has received much attention recently. Muons are particles generated naturally by cosmic rays in the upper atmosphere and pose no risk to humans. Novel detectors and tomographic imaging algorithms have opened new fields of application, mainly in the nuclear sector, but also in spectacular cases such as the Egyptian pyramids. As a first step towards practical application in civil engineering and as a proof of concept we used an existing system to image the interior of a reference reinforced 600 kg concrete block. Even with a yet not optimized setup for this kind of investigation, the muon imaging results have been at least of similar quality compared to ultrasonic and radar imaging, potentially even better. Recently, the research was expanded to more realistic testing problems such as the detection of voids in certain structural elements. However, before practical implementation, more robust, mobile, and affordable detectors would be required as well as user-Friendly imaging and simulation software. The talk also discusses other applications , such as volcanology, mining and geothermal exploration. T2 - RWTH Aachen, Geophysikalisches Seminar CY - Aachen, Germany DA - 11.01.2024 KW - Muon tomography KW - Civil engineering KW - Mining KW - Geothermal engineering PY - 2024 AN - OPUS4-59349 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Ultrasonic monitoring of full-scale load experiments N2 - Previous work has shown that ultrasonic monitoring using externally applied or embedded transducers and imaging methods based on coda wave interferometry are able to detect subtle changes in concrete elements. In this study, a limited number of embedded transducers has been used to monitor changes in several 12 m long two-span concrete beams subjected to point or linear loads until failure. The ultrasonic results showed the high sensitivity to stress changes and the nonlinear character of the associated effects. However, the ultrasonic features showed a very good correlation to several conventional monitoring parameters. For higher loads (significant amount of cracking), the technique had to be modified to cope with large wave velocity variations and high decorrelation compared to the reference signal. Using a very simple imaging procedure, the 2D stress field inside the beam has been visualized including inhomogeneities and artifact at places where cracking occurred at higher loads. The technique has the potential to be included in real time monitoring systems. T2 - ASNT SMT/NDT-CE 2018 CY - New Brunswick, NJ, USA DA - 27.8.2018 KW - Concrete KW - Monitoring KW - Ultrasound KW - Coda wave interferometry PY - 2018 AN - OPUS4-45827 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Baeßler, Matthias A1 - Georgi, Steven A1 - Herten, M. A1 - Tronicke, J. A1 - Rumpf, M. T1 - Geotechnical and Geophysical Characterization of a Pile Test Site in Postglacial Soil T2 - SAGEEP 2013 CY - Denver, CO, USA DA - 2013-03-17 PY - 2013 AN - OPUS4-28057 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Niederleithinger, Ernst A1 - Helmerich, Rosemarie A1 - Casas, J. ED - Jan Bien, ED - Lennart Elfgren, ED - Jan Olofsson, T1 - New methods for inspection and condition assessment KW - Brücken KW - Inspektion KW - Monitoring KW - Zerstörungsfreie Prüfung KW - Eisenbahn PY - 2007 SN - 978-83-7125-161-0 SP - 83 EP - 91 PB - Dolnoslaskie Wydawnictwo Edukacyjne CY - Wroclaw, Poland AN - OPUS4-16182 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Helmerich, Rosemarie A1 - Niederleithinger, Ernst A1 - Milmann, Boris A1 - Wöstmann, Jens A1 - Röllig, Mathias A1 - Feldmann, Rüdiger A1 - Täljsten, B. ED - Masoud Motavalli, T1 - Near surface mounted CFRP-rods - preparation of reinforcing measures and quality control by means of non-destructive testing T2 - 4th International Conference on FRP Composites in Civil Engineering (CICE2008) CY - Zurich, Switzerland DA - 2008-07-22 PY - 2008 SN - 978-3-905594-50-8 SP - 1 EP - 6 AN - OPUS4-17747 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -