TY - CONF A1 - Millar, Steven A1 - Gottlieb, Cassian A1 - Wilsch, Gerd A1 - Günther, Tobias A1 - Völker, Tobias T1 - Chemische Zustandsanalyse von Stahlbetonbauwerken mit der laserinduzierten Plasmaspektroskopie (LIBS) N2 - Die chemische Analyse von Beton gehört bei der Ermittlung des Ist-Zustandes von Stahl- und Spannbetonbauwerken zu den grundlegenden Untersuchungen bei der Zustandserfassung. Der tiefenabhängige Chloridgehalt sowie der Karbonatisierungsfortschritt müssen bei der Bewertung des Ist-Zustandes, beim Instandsetzungsbedarf und ggf. bei der Planung eines erforderlichen Instandsetzungskonzeptes mit einbezogen werden. Seit Mitte der 1990er Jahre wird an der Bundesanstalt für Materialforschung und -prüfung die laserinduzierte Plasmaspektroskopie (engl. Laser-induced Breakdown Spectroscopy) – kurz LIBS – stetig für die chemische Analyse von Beton weiterentwickelt. In diesem Beitrag wird der aktuelle Stand der Forschung/ Technik und der Normungsarbeit präsentiert, sowie zukünftig mögliche Anwendungen vorgestellt. Mit den aktuellen LIBS-Systemen (mobiles LIBS-System sowie kommerziell erhältliche Laborsysteme) ist es möglich den Chloridgehalt ortsaufgelöst in wenigen Minuten zu quantifizieren, sogenannte Elementlandkarten zu erstellen und somit die Elementverteilung innerhalb des Betons zu visualisieren. Durch das Scannen eines Bohrkernquerschnittes und der simultanen Erfassung von mehreren Elementen mit einer Messung, ist es zudem möglich, die Gesteinskörnung in den Messdaten zu identifizieren und den Chloridgehalt auf die Zementsteinmatrix zu beziehen. Fehlerquellen aus der Umrechnung der betonbezogenen Chloridgehalte können dadurch minimiert werden. Neben den Grundlagen von LIBS werden vor allem aktuelle Praxisbeispiele vorgestellt, die die aktuellen Möglichkeiten des Verfahrens veranschaulichen. T2 - 9. Kolloquium Parkbauten CY - Esslingen, Germany DA - 04.02.2020 KW - LIBS KW - Chemische Analyse KW - Spektroskopie KW - Beton PY - 2020 UR - https://elibrary.narr.digital/article/99.125005/kpb202010305 SN - 2510-7763 VL - 9 IS - 1 SP - 305 EP - 319 AN - OPUS4-50615 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Epple, Niklas T1 - Monitoring of bridges with coda waves - first steps towards an imaging strategy N2 - Monitoring of concrete structures is of utmost importance in maintenance and preservation of infrastructure. As a part of the DFG research group CoDA (Concrete Damage Assessment by Coda Waves), the works within this PhD project aim for identification of damage sensitive parameters extracted from ultrasonic measurements obtained with embedded sensors, the determination of environmental (reversible) influences on the signal and the localisation of damaged areas. The main technique used for the detection of changes in the monitored material is the so-called Coda Wave Interferometry (CWI). It uses the later part of the ultrasonic recording for the detection of small changes in the sensed area and the calculation of a relative velocity change. Using this technique we can show that we are able to detect changes in concrete temperature with ultrasound measurements. This enables temperature correction for ultrasound monitoring with embedded sensors. The crucial point for imaging and localisation with coda waves is the calculation of the so-called sensitivity kernels. We propose the application of numerical wave simulations for the kernel calculations instead of the commonly used diffusivity equation. Using finite-difference wave modelling code from our DFG project partners we are able to calculate those Kernels and first results are shown in this presentation. The major task for the second year will be the development and implementation of the inversion algorithm as well as the preparation of validation experiments. T2 - Doktorandenseminar BAM Abt. 8 CY - Berlin, Germany DA - 30.03.2020 KW - Ultrasound KW - Non-destructive testing KW - Numerical modelling KW - Structural health monitoring PY - 2020 AN - OPUS4-50624 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Strangfeld, Christoph A1 - Kruschwitz, Sabine T1 - Determination of readiness for laying based on material moisture, corresponding relative humidity, and water release N2 - The moisture content of the subfloor has to be determined before installation to avoid damages of the floor covering. Only if the readiness for layering is reached, an installation without damages can be expected in all cases. In general, three different approaches exist to measure the residual water content: determination of the moisture content, determination of the water release, or determination of the corresponding relative humidity. All three approaches are tested in laboratory at eight different screed types including two different samples thicknesses in each case. The moisture content and the water release are measured by sample weighing, the corresponding relative humidity is measured by embedded sensors. All three approaches are compared and correlated to each other. The evaluations show only weak correlation and, in several cases, contradicting results. Samples are considered as being ready for layering and not-being ready for layering at the same time, depending on the chosen approach. Due to these contradicting results, a general threshold for the risk of damage cannot be derived based on these measurements. Furthermore, the experiment demonstrates that the measurement of corresponding relative humidity is independent of the considered screed type or screed composition. This makes the humidity measurement to very promising approach for the installation of material moisture monitoring systems in the future. KW - Material moisture KW - Readiness for laying KW - Screed KW - Corresponding relative humidity KW - Partially saturated pores PY - 2020 DO - https://doi.org/10.3139/120.111581 VL - 62 IS - 10 SP - 1033 EP - 1040 PB - Carl Hanser Verlag GmbH & Co. KG CY - München AN - OPUS4-51405 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gottlieb, Cassian A1 - Bohling, Christian A1 - Wilsch, Gerd T1 - New possibilities for concrete analysis 4.0 with the Laser-Induced Breakdown Spectroscopy (LIBS) N2 - In civil engineering the damage assessment of concrete infrastructures is an important task to monitor and ensure the estimated life-time. The aging of concrete is caused by different damage processes like the chloride induced pitting corrosion of the reinforcement. The penetration depth and the concentration of harmful species are crucial factors in the damage assessment. As a highly cost and time-consuming standard procedure, the analysis of concrete drill cores or drilling by wet-chemistry is widely used. This method provides element concentration to the total mass as aggregates and binder are homogenized. In order to provide a method that is capable to detect the element concentration regarding the cement content only, the laser-induced breakdown spectroscopy (LIBS) will be presented. The LIBS method uses a focused pulsed laser on the sample surface to ablate material. The high-power density and the laser-material interaction causes a laser-induced plasma that emits elemental and molecular line emission due to energy transition of the excited species in the plasma during the cooling phase. As each element provides element-specific line emission, it is in principle possible to detect any element on the periodic table (spectroscopic fingerprint) with one laser shot. In combination with a translation stage the sample under investigation can be spatially resolved using a scan raster with a resolution up to 100 µm (element mapping). Due to the high spatial resolution, the element distribution and the heterogeneity of the concrete can be evaluated. By using chemometrics the non-relevant aggregates can be excluded from the data set and the element concentration can be quantified and referred to a specific solid phase like the binding matrix (cement) only. In order to analyze transport processes like diffusion and migration the twodimensional element distributions can provide deep insight into the transport through the pore space and local enrichments of elements. As LIBS is a multi-elemental method it is also possible to compare the ingress and transport process of different elements like Cl, Na, K, S, C, and Li simultaneously and evaluate cross-correlations between the different ions. Furthermore, the element mapping allows to visualize the transport along cracks. This work will show the state of the art in terms of hardware and software for an automated LIBS system as well as different application for a concrete analysis 4.0. Focus will be the application of LIBS for a fast concrete analysis. T2 - SMAR 2019 CY - Potsdam, Germany DA - 27.08.2019 KW - Damage KW - LIBS KW - Concrete KW - Mapping KW - Chlorine PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-517282 UR - https://www.ndt.net/?id=24963 SN - 1435-4934 VL - 25 IS - 1 SP - 1 EP - 8 PB - NDT.net CY - Kirchwald AN - OPUS4-51728 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bühling, Benjamin T1 - Entwicklung eines luftgekoppelten Ultraschall-Echo-Prüfverfahrens mittels fluidischer Anregung N2 - In vielen technischen Bereichen werden Ultraschallverfahren zur zerstörungsfreien Werkstoffprüfung (ZfP) eingesetzt um auf Basis der Signalstärke und der Laufzeit Einbauteile und Beschädigungen zu orten. Luftgekoppelter Ultraschall spielt bisher in kommerziellen Anwendungen vor Allem im Bauwesen eine untergeordnete Rolle, da die Differenz der akustischen Impedanzen von Luft und Festkörpern immense Verluste beim Übergang des Schallsignals hervorruft. Im Rahmen des Promotionsvorhabens soll die Eignung eines neuartigen Anregungsprinzip untersucht werden, mit dem ein Großteil dieser Verluste vermieden werden soll. Anstelle eines Festkörpers soll mit Hilfe einer fluidischen Düse Druckluft zur Signalerzeugung eingesetzt werden. Die Impedanzverluste zwischen Aktuatormembran und Umgebungsluft entfallen daher. Die gezielte Schallerzeugung durch einen pulsierenden Freistrahl ist weitgehend unerforscht. Es ist daher notwendig, den so erzeugten Schallpuls in der Interaktion mit dem transienten Strömungsfeld zu untersuchen. Das kompressible Medium Luft und die geringen räumlichen Dimensionen einer hochfrequenten Pulsdüse werfen darüber hinaus einige Herausforderungen hinsichtlich der eingesetzten Messtechnik auf. Hier sollen geeignete Verfahren weiterentwickelt und validiert werden, um die Eignung des fluidisch erzeugten Pulses zu überprüfen. In diesem Vortrag werden erste Messungen an einem fluidischen Schalter mit denen an einem kommerziellen Luftultraschallprüfkopf verglichen. T2 - Doktorandenseminar BAM Abt. 8 CY - Berlin, Germany DA - 17.02.2020 KW - ZfP KW - Ultraschall KW - NDT KW - Ultrasound KW - Air-coupled KW - Non-Contact KW - Luftgekoppelt KW - Kontaktlos PY - 2020 AN - OPUS4-51120 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gottlieb, C. A1 - Bohling, C. A1 - Millar, S. A1 - Günther, Tobias A1 - Wilsch, Gerd ED - Krieger, J. ED - Isecke, B. T1 - Schnelle ortsaufgelöste Chloridbestimmung mit der laserinduzierten Plasmaspektroskopie (LIBS) N2 - Im Zuge der Ist-Zustandserfassung von Stahl- und Spannbetonbauwerken spielt die chemische Analyse von Beton eine zentrale Rolle. Durch den externen Eintrag von schädigenden Substanzen wie Chlorid oder Alkalien aus Tausalzen oder Meerwasser, kann u.U. der Beton und/oder die Stahlbewehrung angegriffen werden. Bei Überschreitung kritischer korrosionsauslösender Chloridgehalte, z.B. bei Stahlbeton 0,4 M.-% (bzw. 0,5 M.-%) und Spannbeton 0,2 M.-% bezogen auf den Zement, erhöht sich das Risiko für eine Chlorid-induzierte Korrosion. Für die Beurteilung eines Instandsetzungsbedarfs und, sofern notwendig, der Erarbeitung eines Instandsetzungskonzeptes muss nach der Rili-SIB1 ein sachkundiger Planer herangezogen werden. Standardmäßig werden für die chemische Analyse Bohrkerne bzw. Bohrmehlproben aus dem zu untersuchenden Bauwerk entnommen und nach aufwendiger Probenvorbereitung nasschemisch analysiert (nach DAfStb Heft 401 oder DIN 14629). Dabei wird der Gesamtchloridgehalt bezogen auf die Einwaage angegeben. Eine Umrechnung auf den Zementgehalt erfolgt i.d.R. durch Schätzwerte. Der Einsatz der laserinduzierten Plasmaspektroskopie (LIBS) wird seit Mitte der 90er Jahren an der Bundesanstalt für Materialforschung und -prüfung erforscht, um den Chloridgehalt durch eine ortsaufgelöste Elementanalyse an einer Betonprobe möglichst genau zu ermitteln. Die zweidimensionale LIBS-Messung mit einer lateralen Auflösung von 100 µm x 100 µm erlaubt die Berücksichtigung der Heterogenität von Beton. Dabei lassen sich die Bindemittelmatrix und die Gesteinskörnung separat betrachten, wodurch sich die Aussagekraft der Ergebnisse und somit die Sicherheit der chemischen Zustandserfassung erhöht. Durch die stetige Weiterentwicklung von Komponenten wie Laser, Spektrometer und analytischer Auswerteroutinen sind mittlerweile automatisierte Systeme für die schnelle LIBS-Analyse auf dem Markt verfügbar. In diesem Vortrag wird der aktuelle Stand der Technik anhand von Praxisbeispielen präsentiert und entscheidende Vorteile gegenüber dem Standardverfahren herausgestellt. Aufgrund der Möglichkeit für eine simultane Multielementanalyse mit LIBS werden weitere Anwendungen, wie z.B. die Ermittlung der Karbonatisierungstiefe, Untersuchungen von Transportprozessen, Chlorideintrag entlang von Rissen oder Untersuchungen von Elementverteilungen im Kontext einer AKR vorgestellt. T2 - 4. Brückenkolloquium CY - Online meeting DA - 08.09.2020 KW - Chloride KW - Beton KW - LIBS KW - Schädigung PY - 2020 SN - 978-3-8169-3518-6 SP - 465 EP - 471 PB - Narr Francke Attempto Verlag GmbH + Co. KG CY - Tübingen AN - OPUS4-51681 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gottlieb, C. T1 - Schnelle ortsaufgelöste Chloridbestimmung mit der laserinduzierten Plasmaspektroskopie N2 - Im Zuge der Ist-Zustandserfassung von Stahl- und Spannbetonbauwerken spielt die chemische Analyse von Beton eine zentrale Rolle. Durch den externen Eintrag von schädigenden Substanzen wie Chlorid oder Alkalien aus Tausalzen oder Meerwasser, kann u.U. der Beton und/oder die Stahlbewehrung angegriffen werden. Bei Überschreitung kritischer korrosionsauslösender Chloridgehalte, z.B. bei Stahlbeton 0,4 M.-% (bzw. 0,5 M.-%) und Spannbeton 0,2 M.-% bezogen auf den Zement, erhöht sich das Risiko für eine Chlorid-induzierte Korrosion. Für die Beurteilung eines Instandsetzungsbedarfs und, sofern notwendig, der Erarbeitung eines Instandsetzungskonzeptes muss nach der Rili-SIB1 ein sachkundiger Planer herangezogen werden. Standardmäßig werden für die chemische Analyse Bohrkerne bzw. Bohrmehlproben aus dem zu untersuchenden Bauwerk entnommen und nach aufwendiger Probenvorbereitung nasschemisch analysiert (nach DAfStb Heft 401 oder DIN 14629). Dabei wird der Gesamtchloridgehalt bezogen auf die Einwaage angegeben. Eine Umrechnung auf den Zementgehalt erfolgt i.d.R. durch Schätzwerte. Der Einsatz der laserinduzierten Plasmaspektroskopie (LIBS) wird seit Mitte der 90er Jahren an der Bundesanstalt für Materialforschung und -prüfung erforscht, um den Chloridgehalt durch eine ortsaufgelöste Elementanalyse an einer Betonprobe möglichst genau zu ermitteln. Die zweidimensionale LIBS-Messung mit einer lateralen Auflösung von 100 µm x 100 µm erlaubt die Berücksichtigung der Heterogenität von Beton. Dabei lassen sich die Bindemittelmatrix und die Gesteinskörnung separat betrachten, wodurch sich die Aussagekraft der Ergebnisse und somit die Sicherheit der chemischen Zustandserfassung erhöht. Durch die stetige Weiterentwicklung von Komponenten wie Laser, Spektrometer und analytischer Auswerteroutinen sind mittlerweile automatisierte Systeme für die schnelle LIBS-Analyse auf dem Markt verfügbar. In diesem Vortrag wird der aktuelle Stand der Technik anhand von Praxisbeispielen präsentiert und entscheidende Vorteile gegenüber dem Standardverfahren herausgestellt. Aufgrund der Möglichkeit für eine simultane Multielementanalyse mit LIBS werden weitere Anwendungen, wie z.B. die Ermittlung der Karbonatisierungstiefe, Untersuchungen von Transportprozessen, Chlorideintrag entlang von Rissen oder Untersuchungen von Elementverteilungen im Kontext einer AKR vorgestellt. T2 - 4. Brückenkolloquium CY - Online meeting DA - 08.09.2020 KW - Beton KW - LIBS KW - Schädigung KW - Chloride PY - 2020 AN - OPUS4-51683 LA - mul AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kruschwitz, Sabine T1 - Evaluation of Advanced NDT-Methods for Measurement of Fibre Orientation in Concrete N2 - Integration of fibre reinforcement in high-performance cementitious materials has become widely applied in many fields of construction. One of the most investigated advantages of steel fibre reinforced concrete (FRC) is the deceleration of crack growth and hence it’s improved sustainability due to e.g. decrease of permeability of concrete by aggressive substances. Additional benefits are associated with the structural properties of FRC, where fibres can significantly increase the ductility and the tensile strength of concrete. In some applications, such as tunnel linings or industrial slabs, it is even possible to entirely replace the conventional reinforcement, leading to significant logistical and environmental benefits. Fibre reinforcement can, however, have critical disadvantages and even hinder the performance of concrete, since it can induce an anisotropic material behaviour of the mixture if the fibres are not appropriately oriented. For a safe use of FRC in the future, reliable non-destructive methods need to be identified to assess the fibres’ orientation in hardened concrete. In this study, ultrasonic material testing, electrical impedance testing, and X-ray computer tomography have been investigated for this purpose using specially produced samples with biased or random fibre orientations. This paper demonstrates the capabilities of each of these NDT techniques for fibre orientation measurements and draws conclusions based on these results about the most promising areas for future research and development using these techniques. T2 - fib2020 Shanghai CY - Online meeting DA - 22.11.2020 KW - Ultrasonic testing KW - Steel fibre reinforced concrete (FRC) KW - Fibre orientation KW - X-ray computed tomography (CT) KW - Electrical impedance PY - 2020 AN - OPUS4-51651 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Munsch, Sarah Mandy T1 - Ermittlung der Porosität von Sandsteinen - Vergleich von Quecksilberporosimetrie, Tauchwägung und NMR N2 - Die Porosität sowie die Porengrößenverteilung (PSD) eines Baustoffs sind wichtige petrophysikalische Eigenschaften, die Transportprozesse im Material beeinflussen und im direkten Zusammenhang mit der Schadensanfälligkeit stehen (Frost-Tau-Schäden, Schäden durch Salzeinträge und sauren Regen). Verfahren zur Ermittlung der Porosität stellen die Quecksilberporosimetrie (MIP), das Prinzip der Tauchwägung nach Archimedes (triple weighing method, TWM) und die Nuklear Magnetische Resonanz (NMR) dar. Das Hauptziel dieser Arbeit ist der Vergleich der drei Methoden für die Porositätsbestimmung. Als Untersuchungsmaterial wurde Sandstein gewählt. Als Baustoff wird Sandstein trotz einer teilweise geringen Festigkeit, aber aufgrund seiner Farbvielfalt häufig für Kulturbauten, Gehwegmaterial und Fassaden eingesetzt. Sandsteine weisen zudem meist eine hohe effektive Porosität (bis zu ca. 30 %) und teilweise breite Porengrößenspektren auf, wodurch Feuchte- und Ioneneinträge begünstigt werden und zu z. B. langfristigen Verfärbungen an Sandsteinfassaden führen können. Im Rahmen dieser Arbeit werden die Porositäten von 10 verschiedenen Sandsteinen aus Deutschland und Tschechien bestimmt. Für die Untersuchungen mittels TWM und NMR wurden für jede Sandsteinart zwei zylinderförmige Proben unter Unterdruck mit Leitungswasser aufgesättigt. Beim Vergleich der Verfahren liegt der Fokus insbesondere auf NMR und der verwendeten Gerätetechnik, die mit einer minimalen Echozeit von 50 µs ein Wasserstoffsignal in Sandsteinen aus bis zu ca. 2 nm kleine Poren erfassen kann. Darüber hinaus wird das Auflösungsvermögen von MIP und NMR bezüglich der Poren- bzw. Poreneingangsgrößen diskutiert. Für den Vergleich von NMR und MIP werden an ausgewählten Sandsteinproben ebenfalls die zusätzlich ermittelten PSD in Korrelation zueinander gebracht. Erste Ergebnisse zeigen eine gute Korrelation von NMR- und TWM-Daten, aber teilweise starke Abweichungen zu den mit MIP bestimmten Porositäten. Ergebnisse zu den PSD zeigen teilweise nahezu identische Kurvenverläufe. Jedoch ist die Abschätzung des Umrechnungsfaktors für die NMR-Daten ohne Hinzuziehen von zusätzlichen Referenzverfahren wie Röntgen-Computer-Tomographie oder Spektral Induzierte Polarisation teilweise sehr schwierig. T2 - Bauwerksdiagnose CY - Berlin, Germany DA - 13.02.2020 KW - NMR KW - Porosität KW - Sandsteine KW - Quecksilberporosimetrie KW - Tauchwägung PY - 2020 N1 - Geburtsname von Munsch, Sarah Mandy: Nagel, S. M. - Birth name of Munsch, Sarah Mandy: Nagel, S. M. AN - OPUS4-50405 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maack, Stefan T1 - Nutzung von ZfP-Daten bei der Nachrechnung von Brücken - Beispiel Regenbrücke Roding N2 - Im Laufe des Lebenszyklus einer Brücke kann es erforderlich sein, diese hinsichtlich der Tragfähigkeit neu zu bewerten. Ursächlich hierfür sind beispielsweise sich ändernde Einwirkungen, wie steigende Verkehrslasten oder auch neuere Erkenntnisse, die beim ursprünglichen Bauwerksentwurf noch nicht berücksichtigt wurden. Die aufgeführten Ursachen treten hierbei meisten nach mehreren Jahrzehnten der Nutzung des Bauwerkes auf. In Deutschland findet eine planmäßige Neubewertung für Brückenbauwerken des Bundes und der Länder auf Basis der im Mai 2011 eingeführten Nachrechnungsrichtline statt. Neben der Neubewertung zur Gewährleistung der Zuverlässigkeit im laufenden Betrieb ist es insbesondere im Rahmen des Abbruches von Bauwerken wichtig Resttragfähigkeiten beurteilen zu können. Die Zuverlässigkeit der Berechnungsergebnisse hängt insbesondere von der Anzahl und von der Qualität der einbezogenen Informationen ab. Durch die Anwendung von zerstörungsfreien Prüfmethoden können quantitative Informationen gesammelt werden, die für die Beurteilung der Tragwerke sowohl relevant als auch ausreichend genau sind. Die gemessenen Daten können explizit in probabilistische Berechnungsmodelle für die Nachrechnung einer Brücke einfließen. Dadurch wird das Modell sukzessive an die Realität angenähert — in anderen Worten: "zugeschärft". Die Zuverlässigkeit der Ergebnisse der Nachrechnung steigt. In diesem Beitrag wird an einem konkreten Beispiel der gegenwärtige Stand von Technik und Forschung für ausgewählte Fragstellungen gezeigt. Im Rahmen der erstellten Abbruchstatik einer vorgespannten Brücke aus Beton wurden Ergebnisse der zerstörungsfreien Prüfung verwendet, um Spanngliedlagen für eine Beprobung zu detektieren. Darüber hinaus wurden die Messergebnisse mit wissenschaftlichen Methoden (Phasenauswertung) ausgewertet, um den Zustand der Verpressung der Spannglieder beurteilen zu können. Weiterhin werden die gewonnenen Messdaten der zerstörungsfreien Prüfung verwendet, um den Nachweis zu erbringen, dass auf deren Grundlage eine zuverlässigere Beurteilung der Tragfähigkeit des Bauwerkes erfolgen kann. Hierfür werden die ersten Ergebnisse der Voruntersuchungen für den Biegenachweis der vorgespannten Brücke präsentiert. T2 - Fachtagung Bauwerksdiagnose 2020 CY - Berlin, Germany DA - 13.02.2020 KW - Zerstörungsfreie Prüfung KW - Brückenbauwerke KW - Nachrechnungsrichtlinie KW - Abbruchstatik PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-504471 AN - OPUS4-50447 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Küttenbaum, Stefan T1 - Beurteilung von Bestandsbauwerken mit zerstörungsfrei gemessenen Daten - Erprobung eines neuen Konzepts an der Regenbrücke Roding N2 - Fortwährend besteht ein wesentlicher Bedarf an Nachrechnungen von bestehenden Brückenbauwerken. Die Zuverlässigkeit der Berechnungsergebnisse hängt insbesondere von der Anzahl und von der Qualität der einbezogenen Informationen ab. Durch die Anwendung von zerstörungsfreien Prüfmethoden können quantitative Informationen gesammelt werden, die für die Beurteilung der Tragwerke sowohl relevant als auch ausreichend genau sind. Die gemessenen Daten können explizit in probabilistische Berechnungsmodelle für die Nachrechnung einer Brücke einfließen. Dadurch wird das Modell sukzessive an die Realität angenähert — in anderen Worten: "zugeschärft". Die Zuverlässigkeit der Ergebnisse der Nachrechnung steigt. In diesem Posterbeitrag wird ein entwickeltes Konzept für die Verwendung von Messergebnissen (anstelle von deterministischen Informationen und Annahmen) im statischen Nachweis zusammengefasst. Am Fallbeispiel einer Spannbetonbrücke werden die Vorteile des dargestellten Ansatzes aufgezeigt. Die Messgrößen (hier die Positionen der Längsspannglieder) und die Messstrategien können anhand von Sensitivitätsanalysen definiert und die Anforderungen an die Messergebnisse aus der statischen Berechnung spezifiziert werden. Die Auswirkungen a) der Messunsicherheit auf die Tragwerkszuverlässigkeit sowie b) von gegenüber den vor den Messungen verfügbaren Informationen abweichenden Messwerten sind am Beispiel der Lokalisierung der Längsspannglieder durch Ultraschall- und Radarmessungen dargestellt. T2 - Fachtagung Bauwerksdiagnose 2020 CY - Berlin, Germany DA - 13.02.2020 KW - Spannbetonbrücke KW - Zerstörungsfreie Prüfung KW - Messung KW - Nachrechnung PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-504014 AN - OPUS4-50401 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Munsch, Sarah Mandy T1 - Ermittlung des Flüssigwasseranteils an voll- und teilgesättigten Sandsteinen mittels 1H-NMR und Hygrometrie N2 - Da Feuchte insbesondere in Form von Flüssigwasser ein hohes Schadenspotential für Baustoffe und Konstruktionen darstellt, finden zerstörungsfreie Verfahren wie die Kernspinresonanz (NMR) zunehmend Einsatz im Bauwesen. Auch wenn zur qualitativen Lokalisierung möglicher Schad- und Risikostellen bereits zahlreiche zerstörungsfreie Verfahren in der Praxis Anwendung finden, so besteht beispielweise bei der Porenraumcharakterisierung und dem Verständnis von Feuchtetransportmechanismen weiterhin Forschungsbedarf. Eine besondere Herausforderung stellt in diesem Zusammenhang die (ortsaufgelöste) Erfassung und Quantifizierung von Feuchteverteilungen bei Teilsättigung dar. Mittels 1H-NMR lassen sich der Wassergehalt sowie die Relaxationszeiten der Wasserstoffprotonen in Abhängigkeit von ihrer Bindungsart und der Porenumgebung messen. In vollgesättigten porösen Baustoffen kann somit das NMR-Signal als Porengrößenverteilung interpretiert werden. Da aber in der Praxis nur selten bis nie vollgesättigte Zustände vorliegen, befasst sich eine laufende Forschungsarbeit mit dem Verständnis der NMR-Signale teilgesättigter Porensysteme, die teilweise multimodale Porengrößenverteilungen aufweisen. Im Rahmen dieser Arbeit werden insgesamt 19 Sandsteine aus Deutschland, Tschechien und Italien sowohl im voll- als auch im teilgesättigten Zustand mit NMR untersucht. Definierte teilgesättigte Zustände werden durch Aufsättigen der Proben in Exsikkatoren mit verschiedenen relativen Luftfeuchten (z. B. 33 %, 75 %, 96%) erzeugt. Die Regulierung der Luftfeuchten erfolgt mit Hilfe von gesättigten Salzlösungen. Als Ergebnis wird die Veränderung der Signalamplitude und der T2-Relaxationszeitenverteilungen in Abhängigkeit von dem Feuchtezustand näher betrachtet. Des Weiteren erfolgt die Berechnung des Flüssigwasseranteils bzw. der adsorbierten Wasserfilmdicke einzelner Poren aus der mit Quecksilberporosimetrie bestimmten Porengrößenverteilung und der Annahme einer Porengeometrie (z.B. Schlitz-, Zylinderpore, etc.). Am Ende dieser Arbeit soll der Zusammenhang des NMR-Signals (Amplitude und Relaxationszeiten) mit dem Porensättigungsgrad in einem Porensystem mit multimodaler Porengrößenverteilung bei Teilsättigung aufgezeigt werden. T2 - Jahrestagung der Deutschen Geophysikalischen Gesellschaft CY - Online meeting DA - 18.05.2020 KW - NMR KW - Sandstein KW - Flüssigwasser KW - Teilsättigung KW - Hygrometrie PY - 2020 N1 - Geburtsname von Munsch, Sarah Mandy: Nagel, S. M. - Birth name of Munsch, Sarah Mandy: Nagel, S. M. AN - OPUS4-50861 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Strangfeld, Christoph T1 - Determination of the diffusion coefficient and the hydraulic conductivity of porous media based on embedded humidity sensors N2 - Reinforced concrete and several other building materials deteriorate during their service life. Almost all deterioration processes are related to moisture. For understanding those processes, knowing the exact amount of the moisture content and the moisture transport characteristics is crucial. In fact, the moisture transport in porous materials is a two-phase flow; consisting of the vapour and the liquid phase. The two corresponding parameters are the diffusion coefficient and the hydraulic conductivity. By means of an inverse approach, these two coefficients are experimentally determined. The moisture transport of eight different screed types during hydration and evaporation is monitored based on embedded humidity sensors. The measured humidity profiles are converted into a pore saturation by adapting the approach of Hillerborg to the measured pore volume distribution. The summation of all pore saturations yields the total moisture content including the ink-bottle effect during desorption. The pore volume distribution was determined by mercury intrusion porosimetry as well as by gas adsorption. The measurement of the humidity and the pore saturation in the entire sample enables to invert the mass balance in order to extract the diffusion coefficient and the hydraulic conductivity. The determined diffusion coefficients of the eight investigated screeds are between m2s-1 and m2s-1. KW - Material moisture KW - Moisture transport KW - Embedded sensors KW - Diffusion coefficient KW - Partially saturated pores PY - 2020 DO - https://doi.org/10.1016/j.conbuildmat.2020.120092 VL - 263 SP - 120092 PB - Elsevier Ltd. AN - OPUS4-51029 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bartelmeß, Jürgen A1 - Zimmek, David A1 - Bartholmai, Matthias A1 - Strangfeld, Christoph A1 - Schäferling, M. T1 - Fibre optic ratiometric fluorescence pH sensor for monitoring corrosion in concrete N2 - In this communication a novel concept for pH sensing is introduced which is specifically adapted to monitor carbonation induced corrosion in concrete structures. The method is based on a ratiometric measurement principle, exploiting the pH sensitive colour switching of thymol blue in the basic pH regime and the emissive properties of two different (Zn)CdSe/ZnS core shell quantum dots. The transition point of thymol blue in a Hydrogel D4 matrix was determined to be at around pH 11.6, which fits ideally to the intended application. Next to the fundamental spectroscopic characterization of the ratiometric response, a new design for a sensor head, suitable for the incorporation into concrete matrices is presented. Toward this, a manufacturing process was developed which includes the preparation of a double layer of polymers containing either thymol blue or a quantum dot mixture inside a porous ceramic tube. Results of a proof-of-priciple performance test of the sensor head in solutions of different pH and in cement specimens are presented, with encouraging results paving the way for future field tests in concrete. KW - Fiber optic sensing KW - PH monitoring in concrete KW - Embedded sensors KW - Ratiometric fluorescence PY - 2020 DO - https://doi.org/10.1039/c9an02348h VL - 145 IS - 6 SP - 2111 EP - 2117 PB - Royal Society of Chemistry AN - OPUS4-50381 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Küttenbaum, Stefan T1 - Zerstörungsfreie Prüfung im Bauwesen - eine zuverlässige Informationsquelle N2 - Inhalt der Präsentation: - Einführung in das Prinzip der Laufzeitmessung - Vorteile bei der Anwendung von Volumenverfahren an Spannbetonbrücken - Möglichkeiten zur Beurteilung der Leistungsfähigkeit von ZfP-Verfahren und zur Verwendung der Messergebnisse in probabilistischen Nachweisen von Bestandstragwerken T2 - Fachtagung ZfPStatik 2020 CY - Munich, Germany DA - 18.02.2020 KW - Zerstörungsfreie Prüfung im Bauwesen KW - Messunsicherheit KW - Nachrechnung KW - Beurteilung von Bestandstragwerken PY - 2020 AN - OPUS4-50417 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Völker, Tobias A1 - Millar, Steven A1 - Strangfeld, Christoph A1 - Wilsch, Gerd T1 - Identification of type of cement through laser-induced breakdown spectroscopy N2 - The composition of concrete determines its resistance to various degradation mechanisms such as ingress of ions, carbonation or reinforcement corrosion. Knowledge of the composition of the hardened concrete is therefore helpful to assess the remaining service life of an existing structure or evaluate the damage observed during inspections. For example, for most existing concrete structures the type of cement originally used is not known and must therefore be determined afterwards. This paper presents a preliminary study on the application of laser-induced breakdown spectroscopy (LIBS) to identify the type of cement. For this purpose, ten different types of cement were investigated. For every type, three cement paste prisms were produced: (i) prisms dried, ground and pressed into tablets, (ii) prisms dried and (iii) prisms untreated. LIBS measurements were performed with a diode-pumped low energy laser (1064 nm, 3 mJ, 1.5 ns, 100 Hz) in combination with two compact spectrometers which cover the UV and NIR spectral range. A reduced subset of spectral features was used to build a classification model based on linear discriminant analysis. The results show that the classification of homogenized pressed cement powder samples provides a high accuracy, however, factors such as a different sample matrix and moisture content can affect the accuracy of the classification. The study demonstrates that LIBS is a promising tool to identify the type of cement. KW - Spectroscopy KW - LIBS KW - Cement KW - Classification KW - Identification PY - 2020 DO - https://doi.org/10.1016/j.conbuildmat.2020.120345 VL - 258 SP - 120345 PB - Elsevier Ltd. AN - OPUS4-51157 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Küttenbaum, Stefan A1 - Maack, Stefan T1 - Nutzung von ZfP-Daten bei der Nachrechnung von Spannbetonbrücken N2 - Der Vortrag umfasst methodische Ansätze sowie Fallbeispiele zur Nachrechnung von Betonbrücken unter Einbeziehung von gütebewerteten, zerstörungsfreien Inspektionsergebnissen. T2 - Seminar "Zerstörungsfreie Prüfung" der Technischen Universität München CY - Online meeting DA - 09.07.2020 KW - ZfPStatik KW - Ultraschall KW - Radar KW - Nachrechnung PY - 2020 AN - OPUS4-50999 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Oesch, Tyler T1 - Analysis of the porosity of alkali-sensitive aggregates for the assessment of microstructure-dependent solubility in the context of ASR N2 - Intensified Alkali-Silica Reaction (ASR) damage has occurred on German roadways in recent years, leading to requirements for compulsory pre-construction investigation of aggregate alkali sensitivity using concrete tests with external alkali supply. However, since these tests are time-consuming and cost-intensive, there is interest in replacing them with a solubility test on pure aggregate in 0.1 M KOH solution at 80°C with a defined NaCl content (1wt.-%). In this context, the influence of aggregate pore structure on SiO2 and Al2O3 solubility was investigated in this project. This paper compares the results of porosity studies with X-ray Computed Tomography (3D-CT) and the Brunauer-Emmett-Teller (BET) method on individual quarried and river gravel granules of both rhyolite and greywacke. For visualization and quantification of both externally accessible and fully enclosed surfaces of granules using X-ray 3D-CT, special software tools were developed. The results demonstrated that the river gravel granules had significantly larger externally accessible surfaces than the quarried granules. BET measurements on individual stones showed, as expected, that measured surfaces were about three orders of magnitude larger than those from the X-ray 3D-CT analyses due to the higher spatial resolution of BET. There was no apparent correlation between the X-ray 3D-CT and BET surface areas. Mercury porosimetry measurements indicate that this may be due to the presence of significant porosity below the spatial resolution of the X-ray 3D-CT. A comparison of SiO2 and Al2O3 solubility measurements with the X-ray 3D-CT and BET surface area data resulted only in weak, inconclusive correlations, indicating the need for further experimental investigation. T2 - Microdurability Webinar CY - Online meeting DA - 12.10.2020 KW - X-ray Computed Tomography (CT) KW - Brunauer-Emmett-Teller (BET) Method KW - Alkali-Silica Reaction (ASR) KW - Porosity KW - Solubility PY - 2020 AN - OPUS4-51429 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bühling, Benjamin T1 - OsciCheck - Fluidic Generation of Ultrasound N2 - The OsciCheck project is presented. The working principle and sound field of a fluidic switch is described. Future goals of the project are presented. T2 - CoDA Summer School 2020 CY - Berchtesgaden, Germany DA - 28.09.2020 KW - Fluidic Switch KW - Air-coupled ultrasound KW - Ultrasound KW - Non-destructive testing KW - Fluidischer Schalter KW - Luftgekoppelter Ultraschall KW - Ultraschall KW - Zerstörungsfreie Prüfung PY - 2020 AN - OPUS4-51380 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Bühling, Benjamin T1 - Acoustic and flow data of an ultrasonic fluidic switch and an ultrasonic piezoelectric transducer N2 - This dataset contains acoustic and flow data of an ultrasonic fluidic switch, which have been acquired using a microphone, a hot-wire anemometer and a pitot tube. Furthermore, acoustic data of a commercial piezoelectric transducer is provided. KW - Fluidics KW - Air-coupled ultrasound KW - Ultrasound KW - Non-destructive testing KW - Acoustic-flow interaction KW - Piezoelectric transducer PY - 2020 DO - https://doi.org/10.7910/DVN/OQYPC9 PB - Harvard College CY - Cambridge, MA, USA AN - OPUS4-52392 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 DO - 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 - Ulbricht, Alexander A1 - Gollwitzer, Christian A1 - Kupsch, Andreas A1 - Léonard, Fabien A1 - Müller, Bernd R. A1 - Oesch, Tyler A1 - Onel, Yener A1 - Thiede, Tobias A1 - Zscherpel, Uwe ED - Puente León, F. ED - Zagar, B. T1 - Moderne Methoden der CT-gestützten Strukturanalyse T1 - Modern techniques of CT based structure analysis N2 - Durch den großflächigen Einsatz der Computertomographie (CT) in unterschiedlichen Industriebereichen steigen auch die Anforderungen an die quantitative Bildanalyse. Subjektive Bildwahrnehmung muss durch objektive Algorithmen ersetzt werden. In diesem Artikel stellt die Bundesanstalt für Materialforschung und -prüfung (BAM), die seit den 1980er Jahren an der Entwicklung der industriellen CT beteiligt ist, anhand ausgewählter Beispiele den aktuellen Stand ihrer Analysemethoden an verschiedenen Anwendungsbeispielen der CT vor. N2 - The increasing use of computed tomography (CT) in various industrial sectors requires more sophisticated techniques of quantitative image analysis. Subjective image perception needs to be replaced by objective algorithms. The German Federal Institute for Materials Research and Testing (BAM) has been involved in the development of industrial CT since the 1980s. This paper summarizes the current status of quantitative 3D image analysis techniques based on selected examples. KW - Computed tomography KW - Computertomographie KW - Röntgen-Refraktion KW - X-Ray refraction KW - Schadensanalyse KW - Damage analysis KW - Normung KW - standardization PY - 2020 DO - https://doi.org/10.1515/teme-2019-0125 SN - 0171-8096 SN - 2196-7113 VL - 87 IS - 2 SP - 81 EP - 91 PB - de Gruyter CY - Berlin AN - OPUS4-50337 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gottlieb, Cassian A1 - Gojani, Ardian A1 - Völker, Tobias A1 - Günther, Tobias A1 - Gornushkin, Igor B. A1 - Wilsch, Gerd A1 - Günster, Jens T1 - Investigation of grain sizes in cement-based materials and their influence on laser-induced plasmas by shadowgraphy and plasma imaging N2 - The effect of particle grain sizes in different cement-based mixtures on the laser-induced plasma evolution is studied using two experimental methods: (i) temporal and spatial evolution of the laser-induced shock wave is investigated using shadowgraphy and two-dimensional plasma imaging, and (ii) temporal and spatial distribution of elements in the plasma is investigated using two-dimensional spectral imaging. This study is motivated by the interest in applying laser-induced breakdown spectroscopy (LIBS) for chemical analysis of concrete, and subsequently obtain information related to damage assessment of structures like bridges and parking decks. The distribution of grain sizes is of major interest in civil engineering as for making concrete different aggregate grain sizes defined by a sieving curve (64mm to 0.125 mm) are needed. Aggregates up to a size of 180 μm can be excluded from the data set, therefore only the amount of small aggregates with a grain size below 180 μm must be considered with LIBS. All components of the concrete with a grain size smaller than 0.125mm are related to the flour grain content. Tested samples consisted of dry and hardened cement paste (water-cement ratio w/z=0.5), which served as a reference. Aggregate mixtures were made by adding flour grains (size 40 μm) and silica fume (size 0.1 μm) in different ratios to cement: 10%, 30%, 50% and 60%, all combined to the remaining percentage of dry or hydrated cement. The visualization results show that a dependance in the evolution of the plasma as a function of sample grain size can be detected only in the initial stages of the plasma formation, that is, at the initial 3 μs of the plasma life. Spectral information reveals the elemental distribution of the silicon and calcium in plasma, in both neutral and ionized form. Here also, a significant effect is observed in the first 1 μs of the plasma lifetime. KW - LIBS KW - Cement-based materials KW - Particle size KW - Shadowgraphy KW - Plasma imaging PY - 2020 DO - https://doi.org/10.1016/j.sab.2020.105772 VL - 165 SP - 105772 PB - Elsevier B.V. AN - OPUS4-50319 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Maack, Stefan A1 - Bertovic, Marija A1 - Radtke, Martin A1 - et al., ED - Wahlster, W. ED - Winterhalter, C. T1 - Deutsche Normungsroadmap künstliche Intelligenz N2 - Rund ein Jahr haben DIN und DKE in einem gemeinsamen Projekt mit dem Bundesministerium für Wirtschaft und Energie und zusammen mit ca. 300 Fachleuten aus Wirtschaft, Wissenschaft, öffentlicher Hand und Zivilgesellschaft an der Normungsroadmap Künstliche Intelligenz gearbeitet. Eine hochrangige Steuerungsgruppe unter dem Vorsitz von Prof. Wolfgang Wahlster hat die Erarbeitung koordiniert und begleitet. Ziel der Roadmap ist die frühzeitige Entwicklung eines Handlungsrahmens für die Normung und Standardisierung, der die internationale Wettbewerbsfähigkeit der deutschen Wirtschaft unterstützt und europäische Wertmaßstäbe auf die internationale Ebene hebt. KW - Künstliche Intelligenz KW - Normung KW - Roadmap PY - 2020 UR - https://www.din.de/resource/blob/772438/ecb20518d982843c3f8b0cd106f13881/normungsroadmap-ki-data.pdf VL - 2020 SP - 1 EP - 232 PB - Deutsches Institut für Normung (DIN) CY - Berlin ET - 1. AN - OPUS4-51733 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd A1 - Völker, Tobias T1 - Laser-based building material sorting for the processing of construction and demolition waste for the circular economy N2 - A joint project of partners from industry and research institutions for the research and construction of an analysis system for an automated, sensor-supported sorting of construction and demolition waste will be presented. This is intended to supplement or replace the previously practiced manual sorting, which harbors many risks and dangers for the staff and only enables obvious, visually detectable differences for separation. The method of laser-induced breakdown spectroscopy is to be used in combination with hyperspectral sensors. Due to the jointly processed information (data fusion), this should lead to a significant improvement in the separation of types. In addition to the sorting of different materials (concrete, main masonry building materials, organic components, glass, etc.), impurities such as SO3-containing building materials (gypsum, aerated concrete, etc.) could also be detected and separated. The subsequent recycling and sales opportunities are examined, such as the use of recycled aggregates in concrete, the recycling of building materials containing sulphate as a gypsum substitute for the cement industry or the agglomeration of synthetic lightweight aggregates for lightweight concrete or as a substrate for green roofs. At the same time, it is investigated whether soluble components (sulfates, heavy metals, etc.) can be detected by LIBS without a wet chemical analysis and what impact the recycling materials have on the environment. The entire value chain is examined using the example of the Berlin location in order to minimize economic / technological barriers and obstacles on a cluster level and to sustainably increase the recovery and recycling rates. T2 - Materials Week 2021 CY - Online meeting DA - 07.09.2021 KW - Laser induced breakdown spectroscopy KW - Building waste KW - Circular economy KW - Material sorting PY - 2021 AN - OPUS4-53286 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - THES A1 - Küttenbaum, Stefan T1 - Zur Validierung von zerstörungsfreien Messverfahren für die probabilistische Beurteilung von Bestandsbauwerken mit gemessenen Daten T1 - Validation of non-destructive measurement procedures for reliability assessments of existing structures using measured data N2 - The aging of existing bridge structures coincides with the progressing degradation and increasing requirements on the bridge stock caused by increasing traffic densities as well as heavy traffic. The resulting demand for structural assessments of existing bridges is of substantial importance, both nationally and internationally. The information available about the considered system provides the basis for reassessments. Both the structural reliability and the validity of the computation results depend primarily on the condition, i.e. the quality and the relevance of this information. The purposeful measurement of quality-evaluated and relevant information can significantly increase the engineer’s power of judgement regarding the structural reliability. It is advisable to keep the destructive structural interventions necessary to obtain such information to a minimum. The purpose of the present thesis is the development and evaluation of a methodology for the probabilistic reassessment of existing structures using non-destructively measured data and for the validation of the suitability of non-destructive measurement procedures for the application in the context of reassessments. For this purpose, the applicability of the rules established within the Guide to the Expression of Uncertainty (GUM)-framework for evaluating the quality of the measured information to be used later in the reassessment is emphasized. The requirements on measured data-based basic variables are derived from the First Order Reliability Method (FORM), a probabilistic approximation procedure. Based on this, the metrology and the reassessment are brought together. The measurement-based basic variables are explicitly appreciated as random variables in reliability analyses. The developed methodology is evaluated by means of two prestressed concrete bridges and four basic variables. Geometrical measurement results gathered by radar and ultrasound measurements are incorporated into reassessments regarding the limit states ULS bending, ULS shear and SLS decompression. The modelling of the measurements is an essential part in order to calculate the measurement results, each consisting of a measured value and the attributed measurement uncertainty. It is shown that the incorporation of the non-destructively collected measurement results reduces the uncertainty to be covered and increases the level of approximation of the considered models. The measurement results are reliable and comparable. Extensive sensitivity analyses provide information about crucial structure parameters to be measured, since they significantly influence the structural reliability. This way, the relevance of the information is derived. Such analyses are suitable for the design and commissioning of investigations meeting the demands as well as for the purposeful refinement of initially insufficient computation models. Furthermore, the appreciation of measured data-based basic variables can increase the robustness of structural analyses. Measurement-based reliability reassessments are particularly useful if required information is missing or doubts have arisen about the available information. In the best case, the incorporation of non-destructively measured data results in the extension of estimated remaining service lives, in the enhancement of infrastructural availabilities and in the optimization of the consumption of resources. N2 - Die Alterung bestehender Brückenbauwerke fällt mit dem sich verschlechternden Zustand und zunehmenden Anforderungen an die Bausubstanz zusammen, die eine Folge von steigenden Verkehrszahlen und der Zulassung des Schwerlastverkehrs sind. Der daraus erwachsende Bedarf an Beurteilungen von bestehenden Brücken ist national und international fortwährend groß. Die Grundlage für Nachrechnungen sind die über das System verfügbaren Informationen. Sowohl die rechnerische Zuverlässigkeit eines Tragwerks als auch die Validität der Ergebnisse hängen im Wesentlichen vom Zustand, also von der Qualität und der Relevanz dieser Informationen ab. Die gezielte Messung von gütebewerteten, relevanten Informationen kann die Urteilsfähigkeit des Beurteilenden über die Zuverlässigkeit eines Tragwerks signifikant steigern. Wünschenswert ist die Erhebung derartiger Informationen ohne signifikante Eingriffe in die Bausubstanz. Das Ziel der vorliegenden Arbeit ist die Entwicklung und Erprobung einer Vorgehensweise für die probabilistische Beurteilung von bestehenden Bauwerken mit zerstörungsfrei gemessenen Daten und einer Methodik zum objektiven Nachweis der Eignung von zerstörungsfreien Messverfahren zur Anwendung im Zuge einer Nachrechnung. Herausgestellt wird die Eignung der im Guide to the Expression of Uncertainty in Measurement (GUM) publizierten Regeln zur Bewertung der Qualität der gemessenen Informationen, die später im statischen Nachweis verwendet werden sollen. Die Anforderungen an die Basisvariablen, d. h. an die Eingangsgrößen im probabilistischen Nachweis, werden aus den Vorschriften zur Zuverlässigkeitsanalyse mit dem probabilistischen Näherungsverfahren FORM, der First Order Reliability Method, abgeleitet. Darauf basiert die Entwicklung der Schnittstelle zwischen der Messtechnik und der Nachrechnung. Im Kern werden die messdatenbasierten Basisvariablen explizit als Zufallsgrößen bei der Zuverlässigkeitsanalyse berücksichtigt. Die entwickelte Vorgehensweise wird am Beispiel von zwei Spannbetonbrücken und vier Basisvariablen erprobt. In die Nachweise der Biege- und der Querkrafttragfähigkeit sowie in einen Nachweis der Dekompression fließen geometrische Messergebnisse ein, die mithilfe von Radar- und Ultraschallmessungen generiert werden. Ein wichtiger Bestandteil ist die Bildung von Modellen zur Auswertung der Messungen und zur Berechnung der Messergebnisse. Es wird gezeigt, dass die Einbeziehung der zerstörungsfrei generierten Messergebnisse die Unsicherheit in den Berechnungsmodellen reduzieren und den Grad der Annäherung der Modelle an die Realität steigern kann. Die Messergebnisse sind zuverlässig und vergleichbar. Umfassende Sensitivitätsanalysen geben Aufschluss über sinnvollerweise zu messende Bauwerksparameter, die einen maßgeblichen Einfluss auf die Tragwerkszuverlässigkeit ausüben. Auf diese Weise wird die Relevanz der Informationen ermittelt. Das Potential derartiger Analysen für die gezielte Planung und Beauftragung von Messungen sowie für die bedarfsgerechte Zuschärfung von initial unzureichenden Berechnungsmodellen erscheint groß. Die messdatenbasierten Modelle können darüber hinaus die Robustheit einer Tragwerksanalyse steigern. Die Berücksichtigung von Messergebnissen ist dann besonders nützlich, wenn zur Beurteilung erforderliche Informationen fehlen oder Zweifel an den verfügbaren Informationen aufgekommen sind. Im besten Fall resultiert daraus die Verlängerung von rechnerischen Restnutzungsdauern, die Steigerung der Verfügbarkeit der Infrastruktur, die Optimierung des Ressourcenverbrauchs und insgesamt eine realitätsnahe Bauwerksbewertung. KW - Zerstörungsfreie Prüfung im Bauwesen KW - Nachrechnung KW - Spannbetonbrücken KW - Zuverlässigkeitsanalyse KW - Messunsicherheit PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:bvb:706-7686 SN - 1431-5122 VL - 21/2 SP - I EP - 314 PB - Universität der Bundeswehr München CY - Neubiberg AN - OPUS4-53851 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lay, Vera A1 - Buske, S. A1 - Townend, J. A1 - Kellett, R. A1 - Savage, M. A1 - Schmitt, D. R. A1 - Constantinou, A. A1 - Eccles, J. D. A1 - Gorman, A. A1 - Bertram, M. A1 - Hall, K. A1 - Lawton, D. A1 - Kofman, R. T1 - 3D Active Source Seismic Imaging of the Alpine Fault Zone and the Whataroa Glacial Valley in New Zealand N2 - The Alpine Fault zone in New Zealand marks a major transpressional plate boundary that is late in its typical earthquake cycle. Understanding the subsurface structures is crucial to understand the tectonic processes taking place. A unique seismic survey including 2D lines, a 3D array, and borehole recordings, has been performed in the Whataroa Valley and provides new insights into the Alpine Fault zone down to ∼2 km depth at the location of the Deep Fault Drilling Project (DFDP)-2 drill site. Seismic images are obtained by focusing prestack depth migration approaches. Despite the challenging conditions for seismic imaging within a sediment filled glacial valley and steeply dipping valley flanks, several structures related to the valley itself as well as the tectonic fault system are imaged. A set of several reflectors dipping 40°–56° to the southeast are identified in a ∼600 m wide zone that is interpreted to be the minimum extent of the damage zone. Different approaches image one distinct reflector dipping at ∼40°, which is interpreted to be the main Alpine Fault reflector located only ∼100 m beneath the maximum drilled depth of the DFDP-2B borehole. At shallower depths (z < 0.5 km), additional reflectors are identified as fault segments with generally steeper dips up to 56°. Additionally, a glacially over-deepened trough with nearly horizontally layered sediments and a major fault (z < 0.5 km) are identified 0.5–1 km south of the DFDP-2B borehole. Thus, a complex structural environment is seismically imaged and shows the complexity of the Alpine Fault at Whataroa. KW - Imaging KW - Signal processing KW - Seismic KW - Borehole KW - DAS PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-539163 DO - https://doi.org/10.1029/2021JB023013 VL - 126 IS - 12 SP - 1 EP - 21 PB - American Geophysical Union AN - OPUS4-53916 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Küttenbaum, Stefan T1 - Zur Validierung von ZfP-Verfahren für die Nachrechnung von Brücken N2 - "Die effiziente Verwendung von Messergebnissen bei der Nachrechnung und von Ergebnissen aus zerstörungsfreien Prüfungen im Speziellen setzt voraus, dass die Relevanz der messbaren Informationen beziffert, die Qualität der gemessenen Information berechnet und die Anforderungen an die Genauigkeit der Inspektionen aus der statischen Berechnung abgeleitet werden können. Der Vergleich der Anforderungen an eine zu messende Information mit der Qualität der gemessenen Information wird in diesem Aufsatz als Validierung eines Messverfahrens aufgefasst. Es wird gezeigt, wie zerstörungsfreie Prüfverfahren für die Nachrechnung validiert werden können. Die Methodik wird anhand einer mit der Ultraschallecho- und Impulsradarmethode untersuchten Spannbetonbrücke demonstriert." KW - Bestandsbauwerke KW - Zuverlässigkeitsbewertung KW - Messunsicherheit PY - 2021 UR - https://www.dgzfp.de/Portals/24/Zeitung/Ausgaben/Zeitung176.pdf SN - 1616-069X IS - 176 SP - 41 EP - 48 PB - Deutsche Gesellschaft für Zerstörungsfreie Prüfung e.V. (DGZfP), Österreichische Gesellschaft für Zerstörungsfreie Prüfung (ÖGfZP), Schweizerische Gesellschaft für Zerstörungsfreie Prüfung (SGZP) AN - OPUS4-53470 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gottlieb, C. T1 - Optimization of LIBS experiments using Design of experiment (DoE) N2 - To conduct a reliable, repeatable and accurate LIBS analysis, the optimization of the experimental setup is an important task. Hardware parameters of lasers and spectrometers used in the setup as well as additionally required components such as optics or process gas pipes must be carefully aligned and adjusted because factors like (i) focal conditions of the optics, (ii) alignment of the sample, (iii) process purge gas (types, flow rate) or (iv) measurement settings (integration time, accumulation of pulses) have a big impact on the signal quality. Therefore, in most cases the effect of different factors is evaluated empirically due to changing one factor at a time while keeping the overall configuration the same. In the end, the optimal configuration is selected based on the best parameters for each influencing factor. During optimization, a configuration of the experimental setup is aimed at, which allows e.g. the highest signal intensity or the lowest variation. In most cases, cross-correlation, interference and interaction among the various factors are not considered. For this reason, the possibilities of using Design of Experiment (DoE) to optimize a LIBS experiment will be shown and advantages of (i) reduction of testing plans using a feature space, (ii) identifying and considering cross-correlations and interactions, (iii) evaluating individual impacts on the measurement (e.g. contour and surface plots) as well as (iv) multivariate models for prediction of impacts will be presented. T2 - 11th Euro-Mediterranean Symposium on Laser-Induced Breakdown Spectroscopy (EMSLIBS) CY - Online meeting DA - 29.11.2021 KW - LIBS KW - Chlorine KW - DoE PY - 2021 AN - OPUS4-53899 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Aßmann, Norman A1 - Bühling, Benjamin T1 - Impact-echo dataset "Radarplatte" N2 - This dataset contains raw data resulting from Impact-Echo measurements at the reference conrete block "Radarplatte", located at BAM (German Federal Institute for Materials Research and Testing). This specimen has been described in detail by Niederleithinger et al. (2021), who applied muon tomography, ultrasonic echo measurements, radar and X-ray laminography to visualize its internal structure. The Impact-Echo method is based on the excitation of the zero-group-velocity frequency of the first symmetric Lamb mode of a plate-like structure, in order to assess its thickness. Numerous publication elaborate on Impact-Echo theory, examples are (Gibson and Popovics 2005, Schubert and Köhler 2008 , Abraham and Popovics 2010). The measurements have been conducted using a setup that contains only commercially available components. The setup consists of an Olson CTG-2 concrete thickness gauge (Olsen Instruments, USA) for actuation and sensing and an 8-bit NI USB-5132 digital storage oscilloscope (National Instruments, USA) combined with the Echolyst software (Schweizerischer Verein für technische Inspektionen (SVTI), Switzerland) for data acquisition. Measurements were conducted using a grid of 23x23 points with a spacing of 50 mm. At each point 8192 samples were recorded at a sampling rate of 1 MS/s. The dataset contains the (X,Y) location in mm of the individual measurement points as well as the raw measurement data at those points. The data is provided in the formats *.mir/*.mhdr (Echolyst), *.npy (Python) and *.mat (Matlab) and *.csv to ease the import in various post-processing tools. KW - Nondestructive testing KW - Impact-echo KW - S1-ZGV mode KW - Concrete PY - 2021 DO - https://doi.org/10.7910/DVN/UNOH2U PB - Harvard College CY - Cambridge, MA, USA AN - OPUS4-53886 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schweitzer, T. A1 - Hörmann, M. A1 - Bühling, Benjamin A1 - Bobusch, B. T1 - Switching Action of a Bistable Fluidic Amplifier for Ultrasonic Testing N2 - Air-coupled ultrasonic testing is widely used in the industry for the non-destructive testing of compound materials. It provides a fast and efficient way to inspect large concrete civil infrastructures for damage that might lead to catastrophic failure. Due to the large penetration depths required for concrete structures, the use of traditional piezoelectric transducer requires high power electric systems. In this study, a novel fluidic transducer based on a bistable fluidic amplifier is investigated. Previous experiments have shown that the switching action of the device produces a high-power broadband ultrasonic signal. This study will provide further insight into the switching behaviour of the fluidic switch. Therefore, parametric CFD simulations based on compressible supersonic RANS simulations were performed, varying the inlet pressure and velocity profiles for the control flow. Switching times are analyzed with different methods, and it was found that These are mostly independent of the slope of the velocity profile at the control port. Furthermore, it was found that an inversely proportional relationship exists between flow velocity in the throat and the switching time. The results agree with the theoretical background established by experimental studies that can be found in the literature. KW - Ultrasound KW - Non-destructive testing KW - Fluidic devices KW - Computational fluid dynamics KW - Concrete KW - Bistable fluidic amplifier PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-525115 DO - https://doi.org/10.3390/fluids6050171 SN - 2311-5521 VL - 6 IS - 5 SP - 171 PB - MDPI CY - Basel, Switzerland AN - OPUS4-52511 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lay, Vera T1 - 3D seismic imaging of the Alpine Fault and the glacial valley at Whataroa, New Zealand N2 - The Alpine Fault at the West Coast of the South Island (New Zealand) is a major plate boundary that is expected to rupture in the next 50 years, likely as a magnitude 8 earthquake. The Deep Fault Drilling Project (DFDP) aimed to deliver insight into the geological structure of this fault zone and its evolution by drilling and sampling the Alpine Fault at depth. Here we present results from a seismic survey around the DFDP-2 drill site in the Whataroa Valley where the drillhole almost reached the fault plane. This unique 3D seismic survey includes several 2D lines and a 3D array at the surface as well as borehole recordings. Within the borehole, the unique option to compare two measurement systems is used: conventional three-component borehole geophones and a fibre optic cable (heterodyne Distributed Vibration Sensing system (hDVS)). Both systems show coherent signals but only the hDVS system allowed a recording along the complete length of the borehole. Despite the challenging conditions for seismic imaging within a glacial valley filled with sediments and steeply dipping valley flanks, several structures related to the valley itself as well as the tectonic fault system are imaged. The pre-processing of the seismic data also includes wavefield separation for the zero-offset borehole data. Seismic images are obtained by prestack depth migration approaches. Within the glacial valley, particularly steep valley flanks are imaged directly and correlate well with results from the P-wave velocity model obtained by first arrival travel-time tomography. Additionally, a glacially over-deepened trough with nearly horizontally layered sediments is identified about 0.5 km south of the DFDP-2B borehole. With regard to the expected Alpine fault zone, a set of several reflectors dipping 40-56° to the southeast are identified in a ~600 m wide zone between depths of 0.2 and 1.2 km that is interpreted to be the minimum extent of the damage zone. Different approaches image one distinct reflector dipping at 40°, which is interpreted to be the main Alpine Fault reflector. This reflector is only ~100 m ahead from the lower end of the borehole. At shallower depths (z<0.5 km), additional reflectors are identified as fault segments and generally have steeper dips up to 56°. About 1 km south of the drill site, a major fault is identified at a depth of 0.1-0.5 km that might be caused by the regional tectonics interacting with local valley structures. A good correlation is observed among the separate seismic data sets and with geological results such as the borehole stratigraphy and the expected surface trace of the fault. In conclusion, several structural details of the fault zone and its environment are seismically imaged and show the complexity of the Alpine Fault at the Whataroa Valley. Thus, a detailed seismic characterization clarifies the subsurface structures, which is crucial to understand the transpressive fault’s tectonic processes. T2 - EGU 2021 General Assembly CY - Online meeting DA - 19.04.2021 KW - Imaging KW - Signal processing KW - Seismic KW - Borehole KW - DAS PY - 2021 AN - OPUS4-52614 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Küttenbaum, Stefan T1 - Validierung von ZfP-Verfahren für die Nachrechnung von Brücken N2 - Vortrag über die Bewertung der Zuverlässigkeit von bestehenden Brücken mit gezielt am Bauwerk erhobenen ZfP-Ergebnissen im Rahmen der Verleihung des DGZfP-Nachwuchspreises 2021 auf der Jahrestagung der DGZfP. T2 - DGZfP-Jahrestagung 2021 CY - Online meeting DA - 10.05.2021 KW - Zuverlässigkeit KW - Messunsicherheit KW - Reliability assessment KW - Existing structures PY - 2021 AN - OPUS4-52630 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd T1 - Condition assessment of concrete infrastructure with LIBS N2 - Due to the ageing of the infrastructure facilities, a reliable assessment of the condition of concrete structures is of great interest to plan timely and appropriate measures. In concrete structures, pittingcorrosion of the reinforcement is the predominant deterioration mechanism affecting serviceability and eventually structural performance. Determination of quantitative chloride ingress is not only necessary to obtain valuable information on the current condition of a structure, but the data obtained can also be used to predict future developments and the associated risks. An overview of the progress and the possibilities of the application of laser-induced breakdown spectroscopy for concrete analysis in daily civil engineering practice is given. High-resolution 2D measurements of drill cores to determine the penetration of harmful species into concrete is presented. Furthermore, the application of a mobile LIBS system in a parking garage is shown. The system consists of a diode-pumped low-energy laser (3 mJ, 1.5 ns, 100 Hz) and a compact NIR spectrometer. A scanner allows two-dimensional element mapping. Progress towards the establishment of LIBS in a leaflet for the analysis of chlorine ingress into concrete in civil engineering is presented. T2 - Euro-Mediterranean Symposium on Laser-Induced Breakdown Spectroscopy 2021 CY - Gijón, Spain DA - 29.11.2021 KW - LIBS KW - Concrete KW - Chlorine KW - Civil engineering PY - 2021 AN - OPUS4-56536 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Küttenbaum, Stefan A1 - Braml, T. A1 - Taffe, A. A1 - Keßler, S. A1 - Maack, Stefan T1 - Reliability assessment of existing structures using results of nondestructive testing N2 - Making optimal decisions about the reliability of existing structures requires that the information used in assessment adequately represents the properties and the condition of the structures. The knowledge gap regarding a structure to be assessed can be successively filled by individually purposeful observations on site. This paper gives an overview of an approach for utilizing nondestructively gathered measurement results in reliability assessment of existing structures. An essential part of measurement-based stochastic modeling of basic variables is the calculation of measurement uncertainties, which serves to establish confidence in measurement, to ensure the comparability of unambiguously expressed measurement results, and to quantify the quality of the measured information. Regarding the current discourse on how to treat information collected on-site in the context of assessment, the authors recommend that measurement uncertainty becomes an uncertainty component mandatorily to be represented in measurement-based stochastic models. The main steps of the proposed concept are presented, and the advantages of its application are emphasized by means of a prestressed concrete bridge as case study. The bridge is assessed regarding the serviceability limit state decompression using ultrasonic and radar data measured at the structure. KW - Bridge KW - Measurement uncertainty KW - Prestressed concrete KW - Stochastic modeling KW - Probabilistic methods PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-529927 DO - https://doi.org/10.1002/suco.202100226 SN - 1751-7648 VL - 22 IS - 5 SP - 2895 EP - 2915 PB - John Wiley & Sons Ltd CY - Oxford AN - OPUS4-52992 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bühling, Benjamin A1 - Maack, Stefan A1 - Schönsee, Eric A1 - Schweitzer, Thorge A1 - Strangfeld, Christoph T1 - Acoustic and flow data of fluidic and piezoelectric ultrasonic transducers N2 - This data article presents characteristic acoustic and flow data of a fluidic ultrasonic transducer as well as acoustic data of a commercial piezoelectric ultrasonic transducer used in non-destructive testing for civil engineering. The flow data has been acquired using hot-wire anemometry and a Pitot tube. The three-dimensional acoustic data of both devices has been acquired using a calibrated microphone. The distribution of characteristic acoustic properties of both transducers are extracted and given in addition to the raw data. The data presented in the article will be a valuable source for reference and validation, both for developing fluidic and alternate ultrasound generation technologies. Furthermore, they will give additional insight into the acoustic-flow interaction phenomena of high speed switching devices. This article is accompanying the paper Experimental Analysis of the Acoustic Field of an Ultrasonic Pulse Induced by a Fluidic Switch (Bühling et al., 2021) published in The Journal of the Acoustical Society of America, where the data is interpreted in detail and the rationale for characteristic sound properties of the fluidic transducer are given. KW - Ultrasound KW - Non-destructive testing KW - Air-coupled ultrasound KW - Fluidics KW - Acoustic-flow interaction KW - Piezoelectric transducer PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-531308 DO - https://doi.org/10.1016/j.dib.2021.107280 VL - 38 SP - 1 EP - 8 PB - Elsevier CY - Amsterdam AN - OPUS4-53130 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Strangfeld, Christoph A1 - Wiehle, Philipp A1 - Munsch, Sarah Mandy T1 - About the dominance of mesopores in physisorption in amorphous materials N2 - Amorphous, porous materials represent by far the largest proportion of natural and men-made materials. Their pore networks consists of a wide range of pore sizes, including mesoand macropores. Within such a pore network, material moisture plays a crucial role in almost all transport processes. In the hygroscopic range, the pores are partially saturated and liquid water is only located at the pore fringe due to physisorption. Therefore, material parameters such as porosity or median pore diameter are inadequate to predict material moisture and moisture transport. To quantify the spatial distribution of material moisture, Hillerborg’s adsorption Theory is used to predict the water layer thickness for different pore geometries. This is done for all pore sizes, including those in the lower nanometre range. Based on this approach, it is shown that the material moisture is almost completely located in mesopores, although the pore network is highly dominated by macropores. Thus, mesopores are mainly responsible for the moisture storage capacity, while macropores determine the moisture transport capacity, of an amorphous material. Finally, an electrical analogical circuit is used as a model to predict the diffusion coefficient based on the pore-size distribution, including physisorption. KW - Physisorption KW - Mesopores KW - Amorphous materials KW - Macropores KW - Adsorbed water layer thickness KW - Material moisture KW - Moisture distribution PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-538525 UR - https://dataverse.harvard.edu/dataset.xhtml?persistentId=doi:10.7910/DVN/NILGW2 DO - https://doi.org/10.3390/molecules26237190 VL - 26 IS - 23 SP - 1 EP - 22 PB - MDPI AN - OPUS4-53852 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Strangfeld, Christoph T1 - Quantification of the Knudsen Effect on the Effective Gas diffusion Coefficient in Partially Saturated Pore Distributions N2 - The effective gas diffusion coefficient describes the process of gas diffusion in porous materials. Several materials have a significant number of micropores in the lower nanometre range leading to a reduction of gas diffusion (Knudsen effect). In the case of partial pore saturation during adsorption, the available pore space is further reduced, as is the gas diffusion. In this study, the influence of partially saturated pores on the Knudsen effect and on the gas diffusion is quantified. Three different pore geometries are investigated (slit, cylindrical and spherical pores) and three different types of pore size distribution, including a broad equal distribution, three narrow normal distributions and two measured distributions of concrete. Besides the intensive computation of the exact pore saturation, a simplified model with low computational requirements is suggested. This study shows that the influence of the water layer thickness on the effective diffusion becomes significant for pore radii below 50 nm and the assumed pore geometry is important. At the end, the overall effect is quantified for an amorphous material with most pore radii below 30 nm. At a moisture level of 50% relative humidity, the effective diffusion is reduced by 35% due to partial saturation. KW - Effective gas diffusion coefficient KW - Gas transport in porous media KW - Knudsen diffusion KW - Moisture transport KW - Nanopores PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-528509 DO - https://doi.org/10.1002/adem.202100106 VL - 23 IS - 10 SP - 2100106 PB - Wiley AN - OPUS4-52850 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Munsch, Sarah Mandy A1 - Strangfeld, Christoph A1 - Kruschwitz, Sabine T1 - Application of 1H proton NMR relaxometry to building materials - A review N2 - Since nuclear magnetic resonance with focus on 1H protons is highly sensitive to pore filling fluids, it is nowadays often applied for the investigation of porous media. Mainly in materials research and especially in the field of non-destructive testing in civil engineering it is increasingly used. Scientific questions about and based on NMR meanwhile cover a broad spectrum. To give an overview, we have reviewed various studies dealing with the determination of moisture contents and parameters such as the pore-size distribution, surface relaxivity, porosity, etc. In some papers, the monitoring of moisture transport in connection with degradation processes or admixtures was the main objective. In other papers, NMR was used for pore space analysis or even applied on site to assess the state of conservation of cultural heritage. Building materials that have been investigated in the presented studies are for example cement, concrete, woods, sandstones etc. In this paper, short descriptions and the significant results of the reviewed articles are summarized and their measurement problems and discrepancies are pointed out. A special feature of this review article is the concise tabular compilation of determined 𝑇1 and 𝑇2 relaxation times, as well as of surface relaxivity values for various materials and components. Finally, relevant aspects are summed up and conclusions about the increasing potential of NMR relaxometry for investigations of porous building materials are drawn, followed by an outlook about future applications and the need for technical development. KW - NMR relaxometry KW - Building materials KW - Natural stones KW - Relaxation times KW - Surface relaxivities KW - Moisture KW - Pore space characterization PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-521888 DO - https://doi.org/10.1016/j.jmro.2021.100012 N1 - Geburtsname von Munsch, Sarah Mandy: Nagel, S. M. - Birth name of Munsch, Sarah Mandy: Nagel, S. M. VL - 6-7 SP - 100012 PB - Elsevier Inc. CY - Amsterdam AN - OPUS4-52188 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Küttenbaum, Stefan A1 - Maack, Stefan A1 - Braml, T. A1 - Taffe, A. A1 - Strübing, T. T1 - Bewertung von Bestandsbauwerken mit gemessenen Daten - Teil 2: Berechnung der Tragwerkszuverlässigkeit unter Einbeziehung der ZfP-Messergebnisse T1 - Reassessment of existing structures based on measured data - Part 2: Structural reliability analyses using NDT results N2 - Durch die Einbeziehung von gemessenen Daten bei der Bewertung von bestehenden Bauwerken können Unsicherheiten bei der Beurteilung des Tragverhaltens reduziert werden, ohne das normative Zuverlässigkeitsniveau einzuschränken. Informationen sind die wesentliche Grundlage für die Analyse der Zuverlässigkeit von Tragwerken. Umso wichtiger ist die Kenntnis über die Präzision und die Richtigkeit der verwendeten Informationen. Aus messtechnischer Sicht kann ein Messwert, dem keine Messunsicherheit beigeordnet wurde, als wertlos erachtet werden. Liegt ein vollständig dokumentiertes Messergebnis vor, so ist die Qualität der gemessenen Information bekannt und deren Vergleichbarkeit gewährleistet. In diesem Beitrag wird am Beispiel einer Spannbetonbrücke und zweier Grenzzustände gezeigt, wie Messergebnisse aus der zerstörungsfreien Prüfung in probabilistische Nachweise von Bestandsbauwerken einfließen können und welche Auswirkungen die Implementierung von gemessenen Daten bei der Bewertung von Bestandsbauwerken haben kann. N2 - Every decision about the reliability of a structure is associated with uncertainties. The reassessment of existing structures remains a major challenge. The decisive difference compared to the design of new structures is the possibility and necessity to collect individual information about the actual condition and properties of the structure. Such knowledge should be appreciated in the reassessment in order to reduce uncertainties and increase the validity of the results. Reliability analyses using measured data require the comparability of measurement results and the evaluation of the quality of the measured information. Both requirements can be met by adequate measurement uncertainty considerations. Besides, the destructive interventions necessary for the measurements should be kept to a minimum. This paper shows how non-destructively gathered measurement results can be incorporated into probabilistic reassessments and which effects the implementation of measured data can have when evaluating existing structures, using a prestressed concrete bridge as a case-study. KW - Nachrechnung KW - Zerstörungsfreie Prüfung KW - Zuverlässigkeitsanalyse KW - Messung KW - Spannbetonbrücke PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-519480 DO - https://doi.org/10.1002/best.202000087 SN - 0005-9900 SN - 1437-1006 VL - 116 IS - 3 SP - 183 EP - 199 PB - Ernst & Sohn CY - Berlin AN - OPUS4-51948 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Maack, Stefan A1 - Küttenbaum, Stefan A1 - Epple, Niklas A1 - Aligholizadeh, M. T1 - Die Ultraschall-Echomethode – von der Messung zur bautechnischen Kenngröße T1 - Ultrasonic Echo Method - Deriving structural parameters from measured values N2 - Zerstörungsfreie Prüfverfahren liefern wichtige Informationen zur Beurteilung von Bauwerken. Mit ihnen können Materialeigenschaften bestimmt oder die innere Struktur von Bauteilen beschrieben werden. Für letzteres werden in der Regel Volumenverfahren angewandt. Einen besonderen Stellenwert haben in der Praxis die Radar- und die Ultraschall-Echoverfahren. Ihre Anwendung erfordert lediglich eine einseitige Zugänglichkeit zum Bauteil. Zudem lassen sich zahlreiche unterschiedliche Prüfaufgaben lösen. Zum Stand der Technik gehören beispielsweise die Ortung von Bewehrung und Spannkanälen, die Bestimmung der Dicke von Bauteilen oder die Fehlerlokalisierung. In diesem Beitrag wird gezeigt, wie mithilfe von Ultraschall-Echomessungen gesammelte Messwerte in ein quantitatives Messergebnis überführt werden können, das wiederum in ingenieurtechnische Berechnungen einfließen kann. Einleitend werden die Prüfmethode und die Messtechnik erläutert. Anschließend wird das Vorgehen von der Auswertung der Messergebnisse bis zur Bestimmung der bautechnischen Kenngröße – Bauteildicke – gezeigt. Abschließend wird die Methodik an einem Referenzprüfkörper aus Polyamid demonstriert und den Ergebnissen von Messungen an Beton gegenübergestellt. KW - Zerstörungsfreie Prüfung KW - Ultraschall-Echoverfahren KW - Messunsicherheit KW - Bildgebende Darstellung KW - Schallgeschwindigkeit PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-521113 DO - https://doi.org/10.1002/best.202000091 VL - 116 IS - 3 SP - 200 EP - 211 PB - Ernst & Sohn AN - OPUS4-52111 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bühling, Benjamin A1 - Strangfeld, Christoph A1 - Maack, Stefan A1 - Schweitzer, T. T1 - Experimental analysis of the acoustic field of an ultrasonic pulse induced by a fluidic switch N2 - Ultrasonic inspection is a common tool for non-destructive testing in civil engineering (NDT-CE). Currently, transducers are coupled directly to the specimen surface, which makes the inspection time-consuming. Air-coupled ultrasound (ACU) transducers are more time-efficient but need a high pressure amplitude as the impedance mismatch between the air and the concrete is high and large penetration depth is needed for the inspection. Current approaches aim at eliminating the impedance mismatch between the transducer and the air to gain amplitude; however, they hardly fulfill the NDT-CE requirements. In this study, an alternative approach for ultrasound generation is presented: the signal is generated by a fluidic switch that rapidly injects a mass flow into the ambience. The acoustic field, the flow field, and their interaction are investigated. It is shown that the signal has dominant frequencies in the range of 35–60 kHz, and the amplitude is comparable to that of a commercial ACU transducer. KW - Air-coupled ultrasound KW - Non-destructive testing KW - Ultrasonic transducer KW - Acoustic-flow interaction PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-523862 DO - https://doi.org/10.1121/10.0003937 VL - 149 IS - 4 SP - 2150 EP - 2158 AN - OPUS4-52386 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Munsch, Sarah Mandy T1 - Möglichkeiten und Grenzen der zerstörungsfreien Erfassung niedriger Feuchtegehalte in teilgesättigten Sandsteinen mit 1H-NMR N2 - Die zerstörungsfreie Ermittlung der Materialfeuchte in Baustoffen ist für das Bauwesen von großer Bedeutung, denn ein erhöhter Feuchteeintrag kann zu Schimmelbildung, Alkali-Kieselsäure-Reaktionen, Korrosion etc. führen und somit ein hohes Schadenspotential mit sich bringen. Auch wenn zur qualitativen Lokalisierung möglicher Schad- und Risikostellen bereits zahlreiche zerstörungsfreie Verfahren in der Praxis Anwendung finden, besteht ein Mangel an quantitativen Verfahren, die auch bei niedrigen Feuchtegehalten sensitiv sind. Eine Methode zur zerstörungsfreien und quantitativen Bestimmung des Feuchtegehaltes und der effektiven Porosität ist die 1H-Kernspinresonzanzmethode (NMR). Da NMR sensitiv für die molekulare Beweglichkeit von Wasserstoffprotonen ist, lassen sich Informationen über die Bindungsform und -stärke sowie der Umgebung (Porengröße und Mineralzusammensetzung) der Wasserstoffprotonen gewinnen. Obwohl es bereits seit über 20 Jahren mobile NMR-Messeräte gibt, wird NMR heutzutage immer noch weitestgehend im Labor eingesetzt. Dies liegt daran, dass sie aufgrund der verwendeten Permanentmagnete schwer sind und nur äußerst geringe Eindringtiefen ermöglichen. In einer derzeit laufenden Forschungsarbeit wird deshalb ein speziell für Bohrkerne entworfener NMR-Tomograph eingesetzt. Mit seiner minimalen Echozeit von 50 µs lässt sich (abhängig von der Oberflächenrelaxivität) Wasser bis in nanometergroßen Poren erfassen. Um die Sensitivität von NMR bei Teilsättigung zu untersuchen, wurden verschiedene Sandsteinproben in Exsikkatoren mit relativen Luftfeuchten im Bereich von 33 % bis 96 % gelagert. Als Referenzen dienen zum einen das NMR-Signal bei Vollsättigung und zum anderen die Porengrößenverteilung aus Quecksilberporosimetriemessungen (MIP). Um die NMR-Sensitivität zu bewerten, wird die Korrelation der NMR-Amplitude mit den gravimetrisch ermittelten Feuchtegehalten sowie ein Vergleich der Porosität aus NMR und MIP betrachtet. Zu beachten ist in diesem Zusammenhang, dass sowohl die Reduzierung der Wasserfilmdicke als auch die Verkleinerung von Porengrößen zu einer ähnlichen Verkürzung der T2-Relaxationszeit führt. Als Ausblick wird ein Lösungsansatz vorgestellt, bei dem die NMR-Signale mit der Wasserfilmdickenberechnung basierend auf der relativen Luftfeuchte im Material korreliert werden. T2 - 81. Jahrestagung der Deutschen Geophysikalischen Gesellschaft CY - Online meeting DA - 01.03.2021 KW - NMR KW - Sandsteine KW - Porosität KW - Oberflächenrelaxivität KW - Feuchtegehalt PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-522271 DO - https://doi.org/10.23689/fidgeo-3957 N1 - Geburtsname von Munsch, Sarah Mandy: Nagel, S. M. - Birth name of Munsch, Sarah Mandy: Nagel, S. M. AN - OPUS4-52227 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maack, Stefan T1 - CASPAR - FKZ: 19F2178A "Plattform für die beweissichere und rückführbare Datennutzung im Bauwesen" N2 - Bestandsunterlagen von älteren Bauwerken sind oft nicht in ausreichendem Umfang verfügbar. Soll jedoch der Zustand von z.B. Gebäude oder Brücken bewertet werden, stellen Bestandsunterlagen die Grundlage dafür dar. Ansonsten muss die Bauweise des Bauwerkes kostenintensiv nachvollzogen und mit nachträglichen Untersuchungsverfahren bewertet werden. Heute spielt die digitale Planung im Bauwesen eine immer größere Rolle und Bauvorhaben werden in sogenannten BIM Modellen (Building Information Modelling) geplant. Diese Daten müssen langfristig und manipulationssicher gespeichert werden. In diesem Projekt erarbeiten wir die technologischen Grundlagen, um Daten effizient und sicher zu speichern. Wir erarbeiten eine digitale Schnittstelle, um Daten aus unterschiedlichsten Quellen sicher zusammenzuführen und Informationen semantisch zu verknüpfen. Um den Nachweis für die Nutzbarkeit unserer Technologie zu erbringen, entwickeln wir im Rahmen des beantragten Projekts eine prototypische objektbezogene Datenablage in Form eines Demonstrators, in die digitale Informationen einer realen Brücke überführt werden. T2 - Kick-Off-Meeting Förderprogramm mFUND CY - Online meeting DA - 05.08.2021 KW - Digitalisierung KW - Messdaten KW - Brücken KW - Qualitätssicherung KW - Bauwesen PY - 2021 AN - OPUS4-53220 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Küttenbaum, Stefan A1 - Feistkorn, S. A1 - Braml, T. A1 - Taffe, A. A1 - Maack, Stefan ED - Rizzo, P. ED - Milazzo, A. T1 - Methods to Quantify the Utility of NDT in Bridge Reassessment N2 - The purpose of this contribution is to introduce and to apply the developed approach of incorporating non-destructively gathered measurement results (instead of deterministic information and assumptions) into a reassessment model of a typical prestressed concrete road bridge and to outline the advantages. An essential part is the quality evaluation of the non-destructively measured information, that deals primarily with two questions. Could the object or parameter to be obtained reliably detected and if, how accurate are the inspection results achieved? Therefore, the importance of the combination of a probability of detection (POD)-approach and measurement uncertainty calculations is emphasized. With regard to the introduced case-study it is shown, for which structure parameters an assumption deviating from the actual (and measurable) situation has a particularly strong (and possibly arithmetically unfavorable) influence on the structural reliability. Measurements on such parameters are particularly beneficial for a reliable and robust reassessment. In conclusion, the individual reassessment results without consideration and with consideration of evaluated non-destructive inspection results are compared. KW - Non-destructive testing (NDT) KW - Structural safety KW - Concrete bridges KW - Measurement uncertainty KW - Probability of detection (POD) PY - 2021 SN - 978-3-030-64593-9 DO - https://doi.org/10.1007/978-3-030-64594-6_40 SN - 2366-2557 VL - 127 SP - 403 EP - 413 PB - Springer Nature Switzerland CY - Cham, Switzerland AN - OPUS4-52009 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maack, Stefan T1 - CASPAR - FKZ: 19F2178A "Plattform für die beweissichere und rückführbare Datennutzung im Bauwesen" N2 - Bestandsunterlagen von älteren Bauwerken sind oft nicht in ausreichendem Umfang verfügbar. Soll jedoch der Zustand von z.B. Gebäude oder Brücken bewertet werden, stellen Bestandsunterlagen die Grundlage dafür dar. Ansonsten muss die Bauweise des Bauwerkes kostenintensiv nachvollzogen und mit nachträglichen Untersuchungsverfahren bewertet werden. Heute spielt die digitale Planung im Bauwesen eine immer größere Rolle und Bauvorhaben werden in sogenannten BIM Modellen (Building Information Modelling) geplant. Diese Daten müssen langfristig und manipulationssicher gespeichert werden. In diesem Projekt erarbeiten wir die technologischen Grundlagen, um Daten effizient und sicher zu speichern. Wir erarbeiten eine digitale Schnittstelle, um Daten aus unterschiedlichsten Quellen sicher zusammenzuführen und Informationen semantisch zu verknüpfen. Um den Nachweis für die Nutzbarkeit unserer Technologie zu erbringen, entwickeln wir im Rahmen des beantragten Projekts eine prototypische objektbezogene Datenablage in Form eines Demonstrators, in die digitale Informationen einer realen Brücke überführt werden. T2 - Online-Fachaustausch der mFUND-Begleitforschung Move Mobility | iRights.Lab CY - Online meeting DA - 07.05.2021 KW - Digitalisierung KW - Messdaten KW - Brücken KW - Qualitätssicherung KW - Bauwesen PY - 2021 AN - OPUS4-53221 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Strangfeld, Christoph T1 - Non-destructive testing at BAM N2 - A brief introduction to non-destructive testing at BAM, Department 8 and its Divisions. T2 - AK Post Docs Symposium CY - BAM Berlin, Germany DA - 02.02.2021 KW - Non-destrucitve testing PY - 2021 AN - OPUS4-52063 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Küttenbaum, Stefan A1 - Maack, Stefan T1 - ZfP Statik – Zuverlässigkeitsbewertung von Bestandsbauwerken mit ZfP-Ergebnissen N2 - Messen heißt wissen. Dieses Wissen spiegelt die Realität wider und soll den Statiker eines bestehenden Bauwerkes bei der Entscheidungsfindung über die Sicherheit und Zuverlässigkeit der Konstruktion unterstützen. Gegenüber dem Neubauentwurf können bei der Bewertung von bestehender Bausubstanz Sicherheitsreserven genutzt werden, da Unsicherheiten, die beim Bau auftreten können, besser bekannt oder nicht mehr vorhanden sind. Können solche Unsicherheiten genauer bewertet werden, z. B. durch die Feststellung der genauen Lage der Spannglieder bei einer Spannbetonbrücke, so können Sicherheitsbeiwerte reduziert werden, ohne dass es dabei zu Auswirkungen auf das normativ festgelegte Zuverlässigkeitsniveau kommt. Mittlerweile sind Prüfmethoden an Bauwerken wirtschaftlich einsetzbar und auch so leistungsfähig, dass die für die Tragfähigkeit und Gebrauchstauglichkeit wesentlichen Parameter identifiziert werden können. Ein wesentlicher Punkt ist hierbei die Integration derartiger Messergebnisse in Rechenmodelle, die für die Nachrechnung des Bauwerks verwendet werden. Dies können sowohl semiprobabilistische Rechenmodelle als auch vollprobabilistische Modelle sein. Bei semiprobabilistischen Methoden können aus den Messergebnissen Teilsicherheitsbeiwerte berechnet und abgeleitet werden, die dann in den bekannten Nachweisformaten gemäß den Eurocodes und der Nachrechnungsrichtlinie berücksichtigt werden. Bei vollprobabilistischen Nachweisen können die Messdaten in Form von Verteilungsdichtefunktionen mit gemessenen Variationskoeffizienten direkt in das Rechenmodell eingehen. T2 - Abteilungsseminar der Abteilung 8 CY - Online meeting DA - 28.04.2021 KW - Bestandsbauwerke KW - Zuverlässigkeitsbewertung KW - Nachrechnung KW - Zerstörungsfreie Prüfung KW - Messunsicherheit PY - 2021 AN - OPUS4-52531 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Strangfeld, Christoph T1 - Adaption of fluidic devices for SHM of hydrogen tanks N2 - Frequency analysis of the tank during every filling Passive actuator is integrated inside filling nozzle/ pressure vessel Frequency from 5 kHz to 150 kHz Frequency sweep (Chirp) can be performed Works with every fluid: air, hydrogen, oxygen, argon, water. T2 - H2Safety Kompetenzzentrum CY - BAM Berlin, Germany DA - 07.07.2021 KW - Fluidic device KW - Structural health monitoring KW - Hydrogen tank KW - Ultrasound PY - 2021 AN - OPUS4-52930 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Munsch, Sarah Mandy A1 - Strangfeld, Christoph A1 - Kruschwitz, Sabine T1 - Interpretation of NMR signals from partly saturated sandstones N2 - The development of prevention methods and the detection of moisture related damages in buildings and transport infrastructure at an early stage are current issues in the field of non-destructive testing in civil engineering. Especially the subject of partial saturation requires further research since it is more likely to occur than full saturation of the material. In fact, partial saturation in porous media is even more complicated because both fully and partly saturated pores (i.e. pores in which the surfaces are covered with thin water layers) are present. As the non-destructive method nuclear magnetic resonance (NMR) enables the measurement and quantification of relative low moisture contents, it is suitable for the investigation of partly saturated porous building materials. Nevertheless, the differentiation between partly and fully saturated pores is still a challenge. Therefore, in this study, we investigate two sandstones types (Bozanov and Schönbrunner sandstone) at various defined saturation states by using NMR. Furthermore, we measure the relative humidities within the samples and compute the water layer thicknesses (WLT) along the pore walls of all pore sizes to calculate the corresponding degree of pore saturation. To finally assign the NMR signals to pore sizes and to differentiate between partly and fully saturated pores, the water content distribution obtained from the WLT calculation is used for calibration of the relaxation-time distribution. In this extended abstract, selected results only for Schönbrunner sandstone are presented. T2 - ISEMA 2021 CY - Online meeting DA - 26.07.2021 KW - NMR KW - Relative humidity KW - Water layer thickness KW - Partial pore saturation KW - Pore-size distribution PY - 2021 SN - 978-1-7281-8736-5 VL - 2021 SP - 111 EP - 115 PB - IEEE AN - OPUS4-53045 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Braml, T. A1 - Wimmer, J. A1 - Maack, Stefan A1 - Küttenbaum, Stefan A1 - Kuhn, T. A1 - Reingruber, M. A1 - Gordt, A. A1 - Hamm, J. ED - Krieger, J. T1 - Datenablage als Grundlage für den digitalen Zwilling eines Bauwerks – Verwaltungsschale BBox N2 - Der Beitrag stellt die Entwicklung und die Systemarchitektur der BBox am Beispiel von 2 Projekten dar. T2 - 1. Fachkongress Digitale Transformation im Lebenszyklus der Verkehrsinfrastruktur CY - Esslingen, Germany DA - 29.06.2021 KW - Digitaler Zwilling KW - Bestandsbauwerke KW - Physikalisches Modell PY - 2021 SN - 978-3-8169-3530-8 SP - 75 EP - 84 PB - expert Verlag CY - Tübingen AN - OPUS4-52938 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Braml, T. A1 - Wimmer, J. A1 - Maack, Stefan A1 - Küttenbaum, Stefan A1 - Kuhn, T. A1 - Reingruber, M. A1 - Gordt, A. A1 - Hamm, J. ED - Krieger, J. T1 - Datenablage als Grundlage für den digitalen Zwilling eines Bauwerks – Verwaltungsschale BBox N2 - Der Weg zur digitalen Brücke ist eingeschlagen. Im Bereich der Planung, Bauüberwachung und -ausführung wird aktuell das Building Information Modelling (BIM) eingeführt. Ist eine Brücke in der Baulast von Bund und Ländern errichtet, wird ihr Zustand im Zuge von wiederkehrenden Bauwerksprüfungen nach DIN 1076 lückenlos überwacht. Abgespeichert werden die Informationen der Überwachung in einer Datenbank (ASB-ING Teilsystem Bauwerksdaten). Aus dieser Datenbank können anschließend relevante Informationen in ein objektspezifisches Bauwerksbuch überführt werden. In dieser Datenbank werden im Vorfeld definierte Daten abgespeichert. Reine Messdaten oder aber auch die verwendeten ingenieurtechnisch-physikalischen Modelle verbleiben in der Regel bei den beauftragen Dienstleistern. Zusammengefasst existieren verschiedene parallele Insellösungen der Informationsablage. Gegenstand verschiedener Forschungsanstrengungen ist es nun Lösungen zu finden, die einen ganzheitlichen Ansatz für den Informationsfluss von der Errichtung über den Betrieb bis hin zum Abbruch eines Bauwerkes sicherstellen. Im Rahmen einer prototypischen Entwicklung wird auf Grundlage, des für die Industrie 4.0 entwickelten open source Software Framework Eclipse BaSyx, ein möglicher Lösungsansatz – die Verwaltungsschale BBox (Bridge Box) - präsentiert. Dieser Lösungsansatz stellt das physikalisch-ingenieurtechnische Modell zur Zustandsbewertung der Brücke gedanklich in den Mittelpunkt. Unter der Voraussetzung einer durchgängigen Digitalisierung der gesamten Prozessschritte innerhalb der Lebensdauer der Brücke, kann jeder Planungs- und Fertigungsschritt, die Instandhaltung einschließlich des Rückbaus erfasst werden. Das Besondere hierbei ist, dass auch die Grundlagen der Bewertung, wie Messdaten, mit abgespeichert werden. Die Modellstruktur der Verwaltungsschale erlaubt hierbei eine bedarfsgerechte Granularität hinsichtlich der Messdaten auf allen virtuellen Ebenen, um das physikalisch-ingenieurtechnisch Modell mit Daten zu versorgen. Die gewählte Form der Datenablage bildet den Grundstein für zukünftige KI-Auswertungen z.B. mit den Methoden des Maschinellen Lernens (ML). Der Zugriff auf die dafür jeweils benötigten Daten wird durch die Ablage der Daten einschließlich Metadaten und den Einsatz einer Standard S3 Schnittstelle stark vereinfacht. Der Beitrag stellt die Entwicklung und die Systemarchitektur der BBox am Beispiel von 2 Projekten dar. T2 - 1. Fachkongress Digitale Transformation im Lebenszyklus der Verkehrsinfrastruktur CY - Esslingen, Germany DA - 29.05.2021 KW - Brücke KW - Digitalisierung KW - Digitaler Zwilling KW - Datenablage PY - 2021 UR - https://elibrary.narr.digital/article/99.125005/dtv202110075 SN - 2748-9221 IS - 1 SP - 75 EP - 84 PB - expert verlag AN - OPUS4-56159 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Braml, T. A1 - Wimmer, J. A1 - Varabei, Y. A1 - Maack, Stefan A1 - Küttenbaum, Stefan A1 - Kuhn, T. A1 - Reingruber, M. A1 - Gordt, A. A1 - Hamm, J. T1 - Digitaler Zwilling: Verwaltungsschale BBox als Datenablage über den Lebenszyklus einer Brücke T1 - Digital twin: Asset administration shell BBox as data storage over the life cycle of a bridge N2 - Auf dem Weg zur digitalen Brücke existieren bereits erste Lösungen, die den Lebenszyklus einer Brücke abbilden können. Für die Planung, den Bau und den Unterhalt stehen unterschiedlichste Werkzeuge, z. B. BIM, DIN 1076, SIB-Bauwerke, Monitoring etc. zur Verfügung, die jeweils mit unterschiedlichen Datenformaten arbeiten. Für ein intelligentes Erhaltungsmanagement müssen aber alle Daten mit den verschiedenen Datenformaten zusammengeführt, abgelegt und so verwaltet werden können, dass über den gesamten Lebenszyklus einer Brücke die Abbildung eines ganzheitlichen digitalen Zwillings eines Bauwerks möglich ist. Die Autoren haben dafür mit BBox den Prototyp einer Verwaltungsschale (VWS) auf Grundlage von Industrie 4.0 entwickelt. Damit wird das physikalisch-ingenieurtechnische Modell zur Zustandsbewertung der Brücke in den Mittelpunkt gestellt und der gesamte Lebenszyklus einer Brücke kann unabhängig von Datenformaten digital erfasst werden. Da der Aufbau der VWS durch die Granularität optimal strukturiert ist, bietet die Ablage und Einspeisung von Messdaten sowohl die Grundlage eines Live-Monitorings als auch den Grundstein für maschinelles Lernen (ML). Der Datenzugriff via S3-Schnittstelle erleichtert die Entwicklung von eigenen Prognosemodellen mit Informationsmustern (SHIP – Structural Health Information Pattern). Am Beispiel der Heinrichsbrücke Bamberg wird die praktische intelligente Umsetzung des Bauwerksmonitorings inkl. VWS mit Informationsmustern und ML gezeigt. N2 - On the way to the digital bridge, initial solutions already exist that can map the life cycle of a bridge. A wide variety of tools are available for planning, construction and maintenance, e. g. BIM, DIN 1076, SIB structures, monitoring etc., each of which works with different data formats. For an intelligent maintenance management, however, all data with the different data formats must be merged, stored, and managed in such a way that the mapping of a holistic digital twin of a structure is possible over the entire life cycle of a bridge. For this purpose, the authors have developed BBox, a prototype of an asset administration shell (AAS) based on Industry 4.0. This places the physical-engineering model for assessing the condition of the bridge at the center, and the entire life cycle of a bridge can be digitally recorded independently of data formats. Since the structure of the AAS is optimally structured through granularity, the storage and feeding of measurement data provides both the basis of live monitoring and the cornerstone for machine learning (ML). The data access via S3 interface facilitates the development of own prognosis models with information patterns (SHIP – Structural Health Information Pattern). Using the Heinrichsbrücke Bamberg as an example, the practical intelligent implementation of structural monitoring incl. AAS with information patterns and ML is shown. KW - Digitaler Zwilling KW - Lebenszyklus KW - Bauwerksmonitoring KW - Industrie 4.0 KW - Maschinelles Lernen KW - Digital twin KW - Life cycle KW - Structural health monitoring KW - Industry 4.0 KW - Machine learning PY - 2021 DO - https://doi.org/10.1002/bate.202100094 SN - 1437-0999 SP - 1 EP - 9 PB - Ernst & Sohn CY - Berlin AN - OPUS4-54017 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Strangfeld, Christoph A1 - Klewe, Tim ED - Rizzo, P. ED - Milazzo, A. T1 - Hygrometric Moisture Measurements Based on Embedded Sensors to Determine the Mass of Moisture in Porous Building Materials and Layered Structures N2 - Subfloors are layered structures, consisting largely of porous building materials, such as screed. They are often suffering damage from tap water leakage, which is a typical problem in buildings, and which has largely contributed to repair costs of almost 3 billion Euro in 2018 alone in Germany. In this context, especially mould plays a role, which is both destroying the structure and posing severe health risks. To determine the damaging effects of moisture, it is necessary to know the respective processes occurring in building materials, especially to quantify the amount of moisture and its progress in the material. In this study, humidity sensors are used to derive the material moisture experimentally. Capacitive sensors recording the relative humidity are embedded into the screed and in the insulation materials such as expanded polystyrene, extruded polystyrene, perlite and glass wool. For the application in screed, the sensors need to be shielded against the aggressive alkaline materials. To ensure an appropriate exchange with the environment, a permeable membrane is requested. Different membrane materials have been investigated regarding their robustness and their permeability. In the first experimental setup, two humidity sensor arrays with seven individual sensors are embedded in homogeneous screed samples. The measured corresponding relative humidity of the screed is converted to the material moisture based on the approach of Hillerborg. In a second experimental setup, a layered structure of a complete subfloor is built in a box of 0.8 m times 0.8 m. The humidity sensors are positioned in the different insulation materials of various thicknesses. By adding water, leakage damage is simulated and its progress and effect is investigated experimentally. The investigations point at the question if the observed moisture is able to generate damage such as mould. The moisture and corresponding humidity values are discussed. It will be shown that this low-cost hygrometric approach can be used easily for moisture monitoring of screed and insulation materials as well KW - Moisture monitoring KW - Material moisture KW - Building materials KW - Embedded humidity sensors PY - 2021 DO - https://doi.org/10.1007/978-3-030-64594-6_22 VL - 1 SP - 213 EP - 225 PB - Springer Nature CY - Cham AN - OPUS4-52013 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Strangfeld, Christoph T1 - TC 286-GDP STAR - chapter: Modelling moisture transport in porous media N2 - The current content and structure of the chapter "Modelling moisture transport in porous media" of the state of the art report is presented. T2 - RILEM Spring Convention 2021 CY - Online meeting DA - 06.04.2021 KW - Moisture transport KW - Porous media KW - Modelling mass transfer KW - Gas diffusion KW - Concrete PY - 2021 AN - OPUS4-52405 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Schönsee, Eric T1 - Entwicklung eines Prüfstandes zur Erfassung von Frischbetoneigenschaften während der additiven Fertigung T1 - Development of a test rig for detecting parameters of fresh concrete during additive manufacturing N2 - In den vergangenen Jahren ist die Entwicklung additiver Fertigungsverfahren branchenübergreifend fortgeschritten. In der Industrie ist die Verarbeitung von Polymeren wie z. B. Polylactide (PLA) oder Acrylnitril-Butadien-Styrol-Copolymer (ABS) am weitesten verbreitet, aber auch die Verarbeitung von Metallen nimmt zu. Umfragen des Fraunhofer-Institut für Produktionstechnik und Automatisierung IPA aus dem Jahr 2016 verdeutlichen, wie hoch das Potential additiver Fertigungsverfahren eingeschätzt wird und auch die Anzahl der jährlich angemeldeten Patente im Bereich des 3D-Drucks hat sich in den letzten Jahren vervielfacht. KW - Additive Fertigung KW - 3D Druck von Beton KW - Prozessüberwachung PY - 2021 SP - 1 EP - 145 CY - Berlin AN - OPUS4-52550 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Munsch, Sarah Mandy T1 - Interpretation of NMR signals from partly saturated sandstones N2 - The development of prevention methods and the detection of moisture related damages in buildings and transport infrastructure at an early stage are current issues in the field of non-destructive testing in civil engineering. Especially the subject of partial saturation requires further research since it is more likely to occur than full saturation of the material. In fact, partial saturation in porous media is even more complicated because both fully and partly saturated pores (i.e. pores in which the surfaces are covered with thin water layers) are present. As the non-destructive method nuclear magnetic resonance (NMR) enables the measurement and quantification of relative low moisture contents, it is suitable for the investigation of partly saturated porous building materials. Nevertheless, the differentiation between partly and fully saturated pores is still a challenge. Therefore, in this study, we investigate two sandstones types (Bozanov and Schönbrunner sandstone) at various defined saturation states by using NMR. Furthermore, we measure the relative humidities within the samples and compute the water layer thicknesses (WLT) along the pore walls of all pore sizes to calculate the corresponding degree of pore saturation. To finally assign the NMR signals to pore sizes and to differentiate between partly and fully saturated pores, the water content distribution obtained from the WLT calculation is used for calibration of the relaxation-time distribution. T2 - ISEMA 2021 CY - Online meeting DA - 26.07.2021 KW - NMR KW - Relative humidity KW - Water layer thickness KW - Partial pore saturation KW - Pore-size distribution PY - 2021 N1 - Geburtsname von Munsch, Sarah Mandy: Nagel, S. M. - Birth name of Munsch, Sarah Mandy: Nagel, S. M. AN - OPUS4-53044 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Küttenbaum, Stefan T1 - From uncertainty in measurement to certainty in bridge assessment N2 - In this contribution, an approach is outlined to process non-destructively gath-ered measurement data in a comparable way in order to include the measured information in probabilistic reliability assessments of existing structures. An es-sential part is the calculation of measurement uncertainties. The effect of incor-porating evaluated NDT-results is demonstrated by means of a prestressed con-crete bridge and GPR measurements conducted on this bridge as a case-study. The bridge is assessed regarding SLS Decompression using the NDT-results. T2 - 1st Conference of the European Association on Quality Control of Bridges and Structures – EUROSTRUCT2021 CY - Padova, Italy DA - 29.08.2021 KW - Reliability KW - Assessment KW - Existing structures KW - NDT KW - Concrete PY - 2021 AN - OPUS4-53173 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bühling, Benjamin A1 - Schweitzer, T. A1 - Maack, Stefan A1 - Strangfeld, Christoph T1 - Influence of operating conditions on the fluidic ultrasonic transducer signal N2 - While contact and immersion ultrasonic testing are established methods in non-destructive testing (NDT), generating high power air-coupled ultrasound remains a challenging task. Solutions often involve setups that are restricted to lab environments. When field measurements are required, such as in NDT for civil engineering, a handy, robust and safe transducer is needed. For this purpose, an ultrasonic transducer based on a fluidic switch has been developed. A sonic air flow inside the device is switched rapidly so that an ultrasonic signal is generated. Both theory and previous flow simulations suggest that the control flow pressure ramp has only little influence on the switching time of the device. This publication gives an overview over the operating principle of the fluidic ultrasonic transducer and investigates the influence of control tube length and pulsing repetition rate on the ultrasonic pressure amplitude. High repetition rates are found to reduce the signal amplitude, whereas long tubing has only little negative influence on the amplitude while improving signal quality. T2 - 47. Jahrestagung für Akustik (DAGA 2021) CY - Vienna, Austria DA - 15.08.2021 KW - Ultrasound KW - Non-destructive testing KW - Fluidic devices PY - 2021 UR - https://pub.dega-akustik.de/DAGA_2021 SN - 978-3-939296-18-8 SP - 48 EP - 51 CY - Berlin, Germany AN - OPUS4-53493 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bühling, Benjamin T1 - Recent Developments of Fluidic Ultrasonic Transducers at BAM N2 - Ultrasonic measurement technology has become indispensable in NDT. In order to reduce measurement time and extend the application to other materials, contactless ultrasound is the subject of many different research groups. Department 8 has been researching successfully in this field for years. A novel approach is based on so-called fluidic devices. These devices can be used to perform binary logic operations with the help of natural flow instabilities. Hence the abbreviated name, Fluidic (FLUID+LogIC). Only a pressure reservoir of the used fluid is required as energy supply. This enables the production of very robust actuators that generate ultrasonic signals in an extremely energy efficient way. The presentation includes the research results of the ZIM innovation project OsciCheck. The original idea will be presented and its application on different building materials is validated. Beyond this, the possible application areas are much larger and a detailed outlook is given to discuss the future potential of fluidic ultrasonic actuators. T2 - Abteilungsseminar Abteilung 8 CY - Berlin, Germany DA - 23.09.2021 KW - Uultrasound KW - Non-destructive testing KW - Fluidic devices KW - Hydrogen KW - Ranging KW - Harsh environments PY - 2021 AN - OPUS4-53356 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bühling, Benjamin T1 - Influence of Operating Conditions on the Fluidic Ultrasonic Transducer Signal N2 - Motivation: • Air-coupled ultrasound (AC-US) enables faster measurements in non-destructive testing for civil engineering • Current state of the art: piezo and capacitive transducers are mostly used for AC US • Currently >99.9% sound intensity loss due to impedance mismatches Innovation: • Fluidic transducers generate US (30-60 kHz) by rapid switching of a supersonic jet • Fluidic transducers rely on external components such as solenoid valves and tubing --> How do repetition time and tube length influence the signal? T2 - DAGA 2021 CY - Vienna, Austria DA - 15.08.2021 KW - Ultrasound KW - Non-destructive testing KW - Fluidic devices PY - 2021 AN - OPUS4-53408 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 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-546756 DO - https://doi.org/10.3390/inventions6020036 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 - 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 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-529974 DO - https://doi.org/10.1007/s10921-021-00797-3 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 - 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 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-537956 DO - https://doi.org/10.1007/s10921-021-00824-3 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 - CONF A1 - Maack, Stefan T1 - Testing to reasses - Corrosion activity assessment based on NDT using a prestressed concrete bridge as case study N2 - Corrosion of concrete reinforcement is one of the major damage mechanisms affecting both the load-bearing capacity and the serviceability of reinforced concrete structures significantly. The challenge of detecting corrosion is that the corrosion process in its various forms is not immediately visible, especially in the corrosion initiation phase inside the concrete. When externally discernible damages are observed during visual inspections on the structure, the extent of the damage inside the concrete is often already significant. Corrosion caused by carbonation often leads to severe discoloration of the surface or even large-area spalling of the concrete cover. In contrast, chloride-induced corrosion is usually difficult to observe visually, but can cause much more serious damage in less time. The effect occurs locally and can lead to weakening of the cross-section of the reinforcement. This, in turn, can cause sudden structural collapses without prior notice. Therefore, it is important to investigate whether there is protection against corrosion of the reinforcement in the concrete and to detect active corrosion in the structure at an early stage. In the meanwhile, various non-destructive and minimally invasive testing methods are available to evaluate the resistance to penetration of corrosion-promoting pollutants and to detect active corrosion. In this paper, a bridge crossing the river Regen (Germany) is used as a case-study to demonstrate how the information obtained applying different testing methods can be combined and evaluated in the context of structural reassessments. Both the results of the permeability testing (Torrent tester) and the electrical resistance measurement (Wenner probe) are considered, as well as active corrosion areas are localized using the half-cell potential mapping combined with the concrete cover measurement with the eddy current method and ground penetrating radar (GPR). The results are evaluated using drill cores and in addition laser-induced breakdown spectroscopy (LIBS) was applied to obtain information about possible ion transport in the concrete. T2 - EUROSTRUCT 2021 - 1st Conference of the European Association on Quality Control of Bridges and Structures - EUROSTRUCT CY - Padova, Italy DA - 30.08.2021 KW - Nondestructive testing KW - Corrosion KW - Bridge KW - Durability assessment KW - Civil engineering PY - 2021 AN - OPUS4-53222 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst 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 - 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 DO - 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 - 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 DO - 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 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 - Niederleithinger, Ernst 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 DO - 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 - Niederleithinger, Ernst 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 - 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 DO - 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 - 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 DO - 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 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 - Maack, Stefan T1 - Zerstörungsfreie Prüfung an Bestandsbrücken aus Beton - Fallbeispiele aus Nachrechnung und Ertüchtigung N2 - Präsentation der Ergebnisse von zerstörungsfreien Bauwerksprüfungen an Bestandsbrücken. Stand der Technik - Stand der Wissenschaft T2 - Koordinierungsausschuss Erhaltung (KoA-Erh 21/038) CY - Online meeting DA - 02.11.2021 KW - Zerstörungsfreie Prüfung KW - Messdaten KW - Brücken KW - Bildgebende Darstellung KW - Bauwesen KW - Qualitätssicherung PY - 2021 AN - OPUS4-53685 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kruschwitz, Sabine A1 - Oesch, T. A1 - Mielentz, Frank A1 - Meinel, Dietmar A1 - Spyridis, P. T1 - Non-Destructive Multi-Method Assessment of Steel Fiber Orientation in Concrete N2 - Integration of fiber reinforcement in high-performance cementitious materials has become widely applied in many fields of construction. One of the most investigated advantages of steel Fiber reinforced concrete (SFRC) is the deceleration of crack growth and hence its improved sustainability. Additional benefits are associated with its structural properties, as fibers can significantly increase the ductility and the tensile strength of concrete. In some applications it is even possible to entirely replace the conventional reinforcement, leading to significant logistical and environmental benefits. Fiber reinforcement can, however, have critical disadvantages and even hinder the Performance of concrete, since it can induce an anisotropic material behavior of the mixture if the fibers are not appropriately oriented. For a safe use of SFRC in the future, reliable non-destructive testing (NDT) methods need to be identified to assess the fibers’ orientation in hardened concrete. In this study, ultrasonic material testing, electrical impedance testing, and X-ray computed tomography have been investigated for this purpose using specially produced samples with biased or random Fiber orientations. We demonstrate the capabilities of each of these NDT techniques for fiber orientation measurements and draw conclusions based on these results about the most promising areas for future research and development. KW - Spectral induced polarization KW - Steel fiber reiniforced concrete KW - Fiber orientation KW - Non-destructive testing KW - Micro-computed tomography KW - Ultrasound PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-543520 DO - https://doi.org/10.3390/app12020697 VL - 12 IS - 2 SP - 1 EP - 14 PB - MDPI CY - Basel Switzerland AN - OPUS4-54352 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Grotelüschen, Bjarne A1 - Bühling, Benjamin T1 - Impact-Echo Dataset "IE Platte" N2 - This dataset contains raw data resulting from Impact-Echo measurements at the reference concrete block "IE Platte", located at BAM (German Federal Institute for Materials Research and Testing). The specimen contains three polystyrene slabs and one polyethylene foil to act as reflectors. The specimen was produced in a three-step process. First, the base plate was cast. Second, the reflectors were taped to the base plate. Finally, the upper layer was cast on top of base plate and reflectors. A drawing is contained in the dataset. The Impact-Echo method is based on the excitation of the zero-group-velocity frequency of the first symmetric Lamb mode of a plate-like structure, in order to assess its thickness. Numerous publications elaborate on Impact-Echo theory, examples are (Gibson and Popovics 2005, Schubert and Köhler 2008 , Abraham and Popovics 2010). The measurements have been conducted using a setup that contains only commercially available components. The setup consists of an Olson CTG-2 concrete thickness gauge (Olsen Instruments, USA) for actuation and sensing and an 8-bit NI USB-5132 digital storage oscilloscope (National Instruments, USA) combined with the Echolyst software (Schweizerischer Verein für technische Inspektionen (SVTI), Switzerland) for data acquisition. Measurements were conducted using a grid of 29x29 points with a spacing of 50 mm. At each point 8192 samples were recorded at a sampling rate of 1 MS/s. The dataset contains the (X,Y) location in mm of the individual measurement points as well as the raw measurement data at those points. The data is provided in the formats *.mir/*.mhdr (Echolyst), *.npy (Python) and *.mat (Matlab) and *.csv to ease the import in various post-processing tools. KW - Concrete KW - Impact-Echo KW - Nondestructive testing PY - 2022 DO - https://doi.org/10.7910/DVN/EH4E9G PB - Harvard College CY - Cambridge, MA, USA AN - OPUS4-55279 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Völker, Tobias T1 - Application of LIBS to identify construction and demolition waste for circular economy N2 - Responsible treatment of the environment and resources is a key element of sustainability. The building and construction industry is one of the largest consumers of natural resources. Consequently, there is a particular need for regulations and technologies that help to create closed material cycles. From the technological point of view, such efforts are complicated by the growing material diversity and the amount of composites contained in present and future construction and demolition waste (CDW). Nowadays, simple but proven techniques like manual sorting are mainly used. However, this practice not only poses health risks and dangers to the staff performing the work, but also relies on merely obvious, visually striking differences. Automated, sensor-based sorting of these building materials could complement or replace this practice to improve processing speed, recycling rates, sorting quality, and prevailing health conditions. The preliminary results for the identification of a wide variety of building materials with LIBS are presented. T2 - XII Laser Induced Breakdown Spectroscopy (LIBS 2022) CY - Bari, Italy DA - 04.09.2022 KW - LIBS KW - Construction and demolition waste KW - Circular economy PY - 2022 AN - OPUS4-55679 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Völker, Tobias T1 - Interlaboratory comparison for quantitative chlorine analysis in cement pastes with LIBS N2 - Concrete structures often show severe damage during their lifetime. One such damage is pitting corrosion of the steel reinforcement caused by chloride ingress into the porous concrete structure. Laser-induced breakdown spectroscopy (LIBS) is a promising method in civil engineering, which is used for detection of chlorine in concrete structures in addition to conventional methods of wet chemistry. To assess LIBS as a trustful analytical technique, its accuracy and robustness is carefully tested. The presentation will outline the results of the interlaboratory comparison of chlorine quantification in cement paste samples, which was carried out by 12 laboratories in 10 countries. Two sets of samples with chloride content ranging from 0.06-1.95 wt.% in the training set and 0.23-1.51 wt.% in the test sample set (“unknowns”), with additional variations in the type of cement and chlorine source (salt type) were sent to the laboratories. The overall result demonstrates that LIBS is suitable for the quantification of the investigated sample compositions: average relative bias was mostly below 15 %. Considering that the laboratories did not receive instructions on how to perform the analysis or how to process the data, the results can be evaluated as a true status quo of the LIBS technique for this type of analysis. T2 - XII Laser Induced Breakdown Spectroscopy (LIBS 2022) CY - Bari, Italy DA - 04.09.2022 KW - LIBS KW - Chlorine KW - Cement pastes KW - Interlaboratory comparison PY - 2022 AN - OPUS4-55680 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Völker, Tobias A1 - Gornushkin, Igor B. T1 - Importance of physical units in the Boltzmann plot method N2 - The Boltzmann plot is one of the most widely used methods for determining the temperature in different types of laboratory plasmas. It operates on the logarithm as a function of the dimensional argument, which assumes that the correct physical units are used. In many works using the Boltzmann method, there is no analysis of the dimension of this argument, which may be the cause of a potential error. This technical note offers a brief description of the method and shows how to correctly use physical units when using transcendental functions like the logarithm. KW - Boltzmann plot KW - Laser induced plasma PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-558039 DO - https://doi.org/10.1039/d2ja00241h SP - 1 EP - 3 PB - Royal Society of Chemistry AN - OPUS4-55803 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Völker, Tobias T1 - Laser Induced Breakdown Spectroscopy A Tool for Imaging the Chemical Composition of Concrete N2 - One of the most common causes of damage is the ingress of harmful ions into the concrete, which can lead to deterioration processes and affect structural performance. Therefore, the increasingly aging infrastructure is regularly inspected to assess durability. Regular chemical analysis can be useful to determine the extent and evolution of ion ingress and to intervene in a timely manner. This could prove more economical than extensive repairs for major damage, particularly for critical infrastructure. In addition to already established elemental analysis techniques in civil engineering such as potentiometric titration or X-ray fluorescence analysis, laser-induced breakdown spectroscopy (LIBS) can provide further important complementary information and benefits. The possibilities of LIBS are demonstrated using the example of a drill core taken from a parking garage. T2 - 6th International Conference on Concrete Repair, Rehabilitation and Retrofitting CY - Cape Town, South Africa DA - 03.10.2022 KW - LIBS KW - Concrete KW - Cement KW - Chlorine PY - 2022 AN - OPUS4-56061 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd A1 - Völker, Tobias A1 - Klewe, Tim A1 - Kruschwitz, Sabine T1 - Laser Induced Breakdown Spectroscopy – A Tool for Imaging the Chemical Composition of Concrete N2 - One of the most common causes of damage is the ingress of harmful ions into the concrete, which can lead to deterioration processes and affect structural performance. Therefore, the increasingly aging infrastructure is regularly inspected to assess durability. Regular chemical analysis can be useful to determine the extent and evolution of ion ingress and to intervene in a timely manner. This could prove more economical than extensive repairs for major damage, particularly for critical infrastructure. In addition to already established elemental analysis techniques in civil engineering such as potentiometric titration or X-ray fluorescence analysis, laser-induced breakdown spectroscopy (LIBS) can provide further important complementary information and benefits. The possibilities of LIBS are demonstrated using the example of a drill core taken from a parking garage. T2 - 6th International Conference on Concrete Repair, Rehabilitation and Retrofitting CY - Kapstadt, South Africa DA - 03.10.2022 KW - LIBS KW - Concrete KW - Chlorine PY - 2022 UR - https://iccrrr2022.org/downloads SP - 126 EP - 127 AN - OPUS4-56062 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd T1 - Application of LIBS in civil engineering – status, trends and challenges N2 - The main application of LIBS in civil engineering is the detection of harmful ions in concrete, which can penetrate the component through the porous concrete structure. The advantages of LIBS over standard methods are the possibility of multi-element analysis, measurement speed, spatially resolved measurements, and minimal sample preparation. The spatially resolved measurements of LIBS allow the assessment of the heterogeneity of the concrete by measuring separately the chemical composition of the aggregates and the binder matrix. The latter is particularly relevant because the determined elemental distribution can be directly related to the binder matrix. This is not possible with standard methods, since the material is homogenized to powder during sample preparation stage and the determined concentration is thus related to the total mass. In addition to the use of LIBS for the specific analysis of individual harmful ions, LIBS can also be used to estimate the concrete composition and thus determine, for example, the type of cement used. Corresponding information are relevant for the estimation of the remaining service life and for the preparation of a maintenance concept. In recent years, LIBS has been increasingly used in civil engineering. Currently, however, it is primarily used in research institutions and only occasionally in building materials laboratories. Special commercial devices have also been developed, which greatly simplify the application due to the high degree of automation. Mobile LIBS systems allow on-site application. A central point, which limits the use of LIBS in the commercial sector, is the lack of norms and standards. Therefore, within the framework of a project funded by the German government, work has been carried out on the preparation of a leaflet on quantitative chlorine determination in concrete, which will be published this year. In interlaboratory comparisons the robustness and accuracy for the practical application was demonstrated. LIBS also has great potential in the recycling of construction waste in conjunction with hyperspectral sensors. This issue is currently being addressed in a national project. During the presentation, the state of the art of LIBS in civil engineering will be presented, next steps will be discussed, and future challenges will be outlined. T2 - XII international conference on laser induced breakdown spectroscopy (LIBS 2022) CY - Bari, Italy DA - 04.09.2022 KW - LIBS KW - Concrete KW - Chlorine KW - Civil engineering PY - 2022 AN - OPUS4-56535 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd T1 - Laser Induced Breakdown Spectroscopy – A Tool for the Chemical Investigation of Concrete N2 - LIBS is a complementary method to XRF and can detect all elements without the need for vacuum conditions. Automated systems are already commercially available capable of scanning surfaces with a resolution of up to 0.1 mm within a few minutes. In addition to possible applications in R&D, LIBS is also used for practical applications in building materials laboratories and even on-site. In view of ageing infrastructure facilities, a reliable assessment of the condition of concrete structures is of increasing interest. For concrete structures, the ingress of potential harmful ions is affecting the serviceability and eventually structural performance. Pitting corrosion induced by penetrating chlorides is the dominant deterioration mechanism. Condition assessment based on frequently performed chloride profiling can be useful to identify the extent and evolution of chloride ingress. This could prove to be more economical than extensive repairs, especially for important infrastructure facilities. Currently the most common procedure for determining the chloride content is wet chemical analysis with standard resolution of 10 mm. The heterogeneity is not considered. LIBS is an economical alternative for determining the chloride content at depth intervals of 1 mm or less. It provides 2D distributions of multiple elements and can locate spots with higher concentrations. The results are directly correlated to the mass of binder and can also be performed on-site with a mobile LIBS-System. The application of a LIBS-system is presented. Calibration is required for quantitative analysis. Concrete cores were drilled, sliced and analyzed to determine the 2D-distribution of harmful elements. By comparing the chloride ingress and the carbonation, the interaction of both processes can be visualized in a measurement that takes less than 10 minutes for a 50 mm x 100 mm drill core. A leaflet on the use of LIBS for the chloride ingress assessment has been completed. T2 - NDT-CE 2022 - The International Symposium on Nendestructive Testing in Civil Engineering CY - Zurich, Switzerland DA - 16.08.2022 KW - Chlorides KW - Corrosion KW - Imaging KW - Service life KW - Damage assessment KW - LIBS PY - 2022 AN - OPUS4-56540 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Küttenbaum, Stefan T1 - Imaging of results in NDT-CE: Strength and limitations in the use of Radar vs. Ultrasonic Echo N2 - Presentation on behalf of the co-author specified in BAM-Publica. Study on capabilities of volume methods (GPR, Ultrasonic Echo) regarding lateral and depth localisation of reinforcement and tendons in concrete components. Varied boundary conditions: spacing and diameter of both the near surface rebars of the mesh, and the reflectors of interest, as well as component thickness and concrete cover. Please find corresponding references on slide 2. T2 - 6th International Conference on Concrete Repair, Rehabilitation and Retrofitting (ICCRRR2022) CY - Cape Town, South Africa DA - 03.10.2022 KW - Reinforcement KW - Tendon duct KW - Concrete KW - NDT KW - Localisation PY - 2022 AN - OPUS4-55987 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Strangfeld, Christoph A1 - Klewe, Tim T1 - Comparison of the Calcium Carbide Method and Darr Drying to Quantify the Amount of Chemically Bound Water in Early Age Concrete N2 - Hydration is the exothermic reaction between anhydrous cement and water, which forms the solid cement matrix of concrete. Being able to evaluate the hydration is of high interest for the use of both conventional and more climate-friendly building materials. The experimental monitoring is based on temperature or moisture measurements. The first needs adiabatic conditions, which can only be achieved in laboratory. The latter is often measured comparing the weight of the material sample before and after oven drying, which is time-consuming. This study investigates the moisture content of two cement-based and two calcium sulphate based mixtures for the first 90 days by using the calcium carbide method and oven drying at 40 °C and 105 °C (Darr method). Thereby, the amount of chemically bound water is determined to derive the degree of hydration. The calcium carbide measurements highly coincide with oven drying at 40 °C. The calcium carbide method is therefore evaluated as a suitable alternative to the time-consuming Darr drying. The prompt results are seen as a remarkable advantage and can be obtained easily in laboratory as well as in the field. KW - Concrete KW - Hydration KW - Material moisture KW - Calcium carbide method KW - Bound water KW - Darr method KW - Oven drying KW - Chemisorption KW - Physisorption PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-564519 DO - https://doi.org/10.3390/ma15238422 VL - 15 IS - 23 SP - 1 EP - 16 PB - MDPI AN - OPUS4-56451 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bühling, Benjamin A1 - Maack, Stefan A1 - Schweitzer, T. A1 - Strangfeld, Christoph T1 - Enhancing the spectral signatures of ultrasonic fluidic transducer pulses for improved time-of-flight measurements N2 - Air-coupled ultrasonic (ACU) testing has proven to be a valuable method for increasing the speed in non-destructive ultrasonic testing and the investigation of sensitive specimens. A major obstacle to implementing ACU methods is the significant signal power loss at the air–specimen and transducer–air interfaces. The loss between transducer and air can be eliminated by using recently developed fluidic transducers. These transducers use pressurized air and a natural flow instability to generate high sound power signals. Due to this self-excited flow instability, the individual pulses are dissimilar in length, amplitude, and phase. These amplitude and angle modulated pulses offer the great opportunity to further increase the signal-to-noise ratio with pulse compression methods. In practice, multi-input multi-output (MIMO) setups reduce the time required to scan the specimen surface, but demand high pulse discriminability. By applying envelope removal techniques to the individual pulses, the pulse discriminability is increased allowing only the remaining phase information to be targeted for analysis. Finally, semi-synthetic experiments are presented to verify the applicability of the envelope removal method and highlight the suitability of the fluidic transducer for MIMO setups. KW - Air-coupled ultrasound KW - Fluidics KW - Signal processing KW - Pulse compression KW - MIMO KW - Hilbert transform PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-537853 DO - https://doi.org/10.1016/j.ultras.2021.106612 SN - 0041-624X VL - 119 SP - 1 EP - 12 PB - Elsevier B.V. CY - Amsterdam, Netherlands AN - OPUS4-53785 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bühling, Benjamin A1 - Küttenbaum, Stefan A1 - Maack, Stefan A1 - Strangfeld, Christoph T1 - Development of an Accurate and Robust Air-Coupled Ultrasonic Time-of-Flight Measurement Technique N2 - Ultrasonic time-of-flight (ToF) measurements enable the non-destructive characterization of material parameters as well as the reconstruction of scatterers inside a specimen. The time-consuming and potentially damaging procedure of applying a liquid couplant between specimen and transducer can be avoided by using air-coupled ultrasound. However, to obtain accurate ToF results, the waveform and travel time of the acoustic signal through the air, which are influenced by the ambient conditions, need to be considered. The placement of microphones as signal receivers is restricted to locations where they do not affect the sound field. This study presents a novel method for in-air ranging and ToF determination that is non-invasive and robust to changing ambient conditions or waveform variations. The in-air travel time was determined by utilizing the azimuthal directivity of a laser Doppler vibrometer operated in refracto-vibrometry (RV) mode. The time of entry of the acoustic signal was determined using the autocorrelation of the RV signal. The same signal was further used as a reference for determining the ToF through the specimen in transmission mode via cross-correlation. The derived signal processing procedure was verified in experiments on a polyamide specimen. Here, a ranging accuracy of <0.1 mm and a transmission ToF accuracy of 0.3μs were achieved. Thus, the proposed method enables fast and accurate non-invasive ToF measurements that do not require knowledge about transducer characteristics or ambient conditions. KW - Air-coupled ultrasound KW - Laser Doppler vibrometer KW - Refracto-vibrometry KW - Acousto-optic effect KW - Time-of-flight measurements KW - In-air ranging KW - Non-destructive testing PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-544711 DO - https://doi.org/10.3390/s22062135 VL - 22 IS - 6 SP - 1 EP - 17 PB - MDPI CY - Basel, Switzerland AN - OPUS4-54471 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bühling, Benjamin A1 - Maack, Stefan A1 - Strangfeld, Christoph T1 - OsciCheck - A Novel Fluidic Transducer for Air-Coupled Ultrasonic Measurements N2 - Ultrasonic measurement technology has become indispensable in NDT-CE. Air-coupled ultrasonic (ACU) measurement techniques promise to reduce measurement time. However, the signal quality suffers from large specific impedance mismatch at the transducer-air and air-specimen interface. Additionally, large pressure amplitudes are necessary for the penetration depth required in NDT-CE applications. To address the specific requirements of ultrasonic testing in NDT-CE, a robust ACU transducer was developed, that generates ultrasound by quickly switching a pressurized air flow. The simple design of the fluidic transducer makes the device maintenance free and resilient against harsh environmental conditions. Since the signal is generated by aeroacoustics, there is no specific impedance mismatch between the transducer and the surrounding air. The ultrasonic signal exhibits frequencies in the 30-60 kHz range and is therefore well suited to penetrate heterogenous materials such as concrete. This contribution gives an introduction in the working principle and signal characteristics of the fluidic transducer. Its applicability to measurements in concrete is verified. A detailed outlook is given to discuss the future potential of fluidic ultrasonic actuators. T2 - NDT-CE 2022 CY - Zurich, Switzerland DA - 16.08.2022 KW - Air-coupled ultrasound KW - Nondestructive testing KW - Fluidics KW - Bistable amplifier KW - Aeroacoustics PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-555271 UR - https://www.ndt.net/search/docs.php3?id=27319 VL - 2022/09 SP - 1 EP - 9 PB - NDT.net CY - Bad Breisig AN - OPUS4-55527 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Munsch, Sarah Mandy T1 - Ermittlung der Oberflächenrelaxivität in Sandsteinen - ein Methodenvergleich N2 - Mit dem zerstörungsfreien Verfahren der nuklear magnetischen Resonanz (NMR) mit Fokus auf 1H-Protonen lässt sich der Feuchtegehalt in porösen Materialien bestimmen und bei einem vollgesättigten Medium eine Porengrößenverteilung ableiten. Für die Ermittlung der Porengrößenverteilung muss die gemessene T2-Relaxationszeitenverteilung mit dem Parameter Oberflächenrelaxivität (OR) umgerechnet werden. Ist dieser Parameter für das zu untersuchende Medium unbekannt, kann dieser mithilfe von Vergleichsverfahren abgeschätzt werden. Dabei kommen z. B. Gassorption, Quecksilberporosimetrie (MIP), Dünnschliff-Mikroskopie oder µ-Computer-Tomographie (µ-CT) zum Einsatz. Da die verschiedenen Verfahren allerdings unterschiedliche Auflösungsgrenzen aufweisen und auf verschiedenen physikalischen Prinzipien beruhen, können die ermittelten ORs für ein Medium stark variieren. Um ein besseres Verständnis für die OR und die Einflüsse der Vergleichsverfahren zu bekommen, wurden 19 verschiedene Sandsteintypen untersucht. Die OR wurde zum einen basierend auf der spezifischen inneren Oberfläche aus der dynamischen Dampfsorption (DVS) und der Gassorption abgeleitet. Zum anderen wurden die Relaxationszeitenverteilungen durch manuelles Anpassen der OR derart in Porengrößenverteilungen umgerechnet, sodass es eine Übereinstimmung mit den Porengrößenverteilungen aus MIP und/oder µ-CT gibt. Die Umrechnung von Relaxationszeitverteilungen in eine Porengrößenverteilung berücksichtigt dabei sowohl fast- als auch slow-diffusion. Insgesamt ergab sich für die Sandsteine ein breites Spektrum an ORs, bei dem die über die innere spezifische Oberfläche ermittelten ORs andere Größenordnungen aufwiesen (< 10 µm/s), als bei dem Vergleich mit MIP oder µ-CT (bis 600 µm/s). Die mit MIP und µ-CT ermittelten Werten lagen dabei um einen Faktor von 1 bis 30 auseinander. Dieser umfangreiche Datensatz, der vier verschiedene Vergleichsverfahren einbezieht, soll neue Erkenntnisse in der Charakterisierung von porösen Materialien (z. B. bezüglich der Oberflächenrauigkeit) und in der Ursache für die starke Variation der OR ermöglichen. Durch das Berücksichtigen von fast- als auch slow-diffusion, können dabei sogar Daten in eine Porengrößenverteilung umgerechnet werden, bei denen das fast-diffusion-Kriterium nach Brownstein und Tarr nicht erfüllt ist. Außerdem ergibt sich aus der Berücksichtigung des slow-diffusion-Regimes ein neues Verständnis für die obere Auflösungsgrenze von NMR. T2 - 82. Jahrestagung der Deutschen Geophysikalischen Gesellschaft CY - Online meeting DA - 07.03.2022 KW - NMR KW - Sandsteine KW - Oberflächenrelaxivität KW - Porengrößenverteilung PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-544721 UR - https://e-docs.geo-leo.de/handle/11858/9672 DO - https://doi.org/10.23689/fidgeo-5330 AN - OPUS4-54472 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Küttenbaum, Stefan A1 - Maack, Stefan A1 - Taffe, A. A1 - Braml, T. ED - Sykora, M. ED - Lenner, R. ED - de Koker, N. T1 - On the Treatment of Measurement Uncertainty in Stochastic Modeling of Basic Variables N2 - The acquisition and appropriate processing of relevant information about the considered system remains a major challenge in assessment of existing structures. Both the values and the validity of computed results such as failure probabilities essentially depend on the quantity and quality of the incorporated knowledge. One source of information are onsite measurements of structural or material characteristics to be modeled as basic variables in reliability assessment. The explicit use of (quantitative) measurement results in assessment requires the quantification of the quality of the measured information, i.e., the uncertainty associated with the information acquisition and processing. This uncertainty can be referred to as measurement uncertainty. Another crucial aspect is to ensure the comparability of the measurement results.This contribution attempts to outline the necessity and the advantages of measurement uncertainty calculations in modeling of measurement data-based random variables to be included in reliability assessment. It is shown, how measured data representing time-invariant characteristics, in this case non-destructively measured inner geometrical dimensions, can be transferred into measurement results that are both comparable and quality-evaluated. The calculations are based on the rules provided in the guide to the expression of uncertainty in measurement (GUM). The GUM-framework is internationally accepted in metrology and can serve as starting point for the appropriate processing of measured data to be used in assessment. In conclusion, the effects of incorporating the non-destructively measured data into reliability analysis are presented using a prestressed concrete bridge as case-study. T2 - International Probabilistic Workshop 2022 (IPW2022) CY - Stellenbosch, South Africa DA - 09.09.2022 KW - Reliability KW - Assessment KW - Existing structures KW - Measurement uncertainty PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-556580 DO - https://doi.org/10.14311/APP.2022.36.0109 SN - 2336-5382 VL - 36 SP - 109 EP - 118 PB - Czech Technical University CY - Prague AN - OPUS4-55658 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Küttenbaum, Stefan A1 - Maack, Stefan A1 - Taffe, A. T1 - Approach to the development of a model to quantify the quality of tendon localization in concrete using ultrasound N2 - Each engineering decision is based on a number of more or less accurate information. In assessment of existing structures, additional relevant information collected with on-site inspections facilitate better decisions. However, observed data basically represents the physical characteristic of interest with an uncertainty. This uncertainty is a measure of the inspection quality and can be quantified by expressing the measurement uncertainty. The internationally accepted rules for calculating measurement uncertainty are well established and can be applied straightforwardly in many practical cases. Nevertheless, the calculations require the occasionally time-consuming development of an individually suitable measurement model. This contribution attempts to emphasize proposals for modelling the non-destructive depth measurement of tendons in concrete using the ultrasonic echo technique. The proposed model can serve as guideline for the determination of the quality of the measured information in future comparable inspection scenarios. T2 - International Conference on Concrete Repair, Rehabilitation and Retrofitting (ICCRRR 2022) CY - Kapstadt, South Africa DA - 03.10.2022 KW - Reliability KW - Measurement Uncertainty KW - Non-Destructive Testing KW - Existing Concrete Structures PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-559927 DO - https://doi.org/10.1051/matecconf/202236403007 SN - 2261-236X VL - 364 SP - 1 EP - 8 PB - EDP Sciences CY - Les Ulis, France AN - OPUS4-55992 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Büyüksahin, Kaan T1 - Weiterentwicklung und Automatisierung einer Ultraschallbohrlochsonde zur zerstörungsfreien Prüfung untertägiger Verschlussbauwerke N2 - Im Jahre 2011 wurde in Deutschland nach 50 Jahren der Ausstieg aus der kommerziellen Kernenergie beschlossen. Fünf Jahre später war Deutschland mit 80.000 GWh immer noch unter den zehn größten Atomstromproduzenten. Im darauffolgenden Jahr wurden weltweit 2.500.000 GWh Atomstrom produziert. Durch die Atomstromproduktion fallen große Mengen an radioaktiven Reststoffen an, die bis zu mehrere tausend Jahre für einen vollständigen Abbau benötigen. Aus dieser Problematik geht die Debatte über den Verbleib der Reststoffe hervor. Die Endlagerung in tiefen Gesteinsschichten ist eine Lösung für das Problem. Voraussetzung ist hierbei allerdings die Gewährleistung eines dauerhaften Schutzes vor ionisierender Strahlung, die durch Verschlüsse der tiefen Gesteinsschichten in Form von Verschlussbauwerken erzielt werden sollen. Es gilt die bauliche Integrität sowie die Dichtwirkung der Verschlussbauwerke dauerhaft zu überwachen und zu prüfen, um eine langfristige Verzögerung der Radionuklidfreisetzung zu gewährleisten. KW - Bohrlochsonde KW - Beton KW - ZfP im Bauwesen KW - Abschlussbauwerke KW - Ultraschall PY - 2022 SP - 1 EP - 77 CY - Berlin AN - OPUS4-54942 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Strangfeld, Christoph T1 - Bore hole probe for ultrasound-based quality control of sealing constructions N2 - Several countries, which use or used nuclear power, started to destruct nuclear power plants. Thus, large amounts of radioactive waste have to be stored safely during the next decades. Large underground caverns will be used a nuclear waste disposal. Once the cavern is full, a sealing construction is required. The sealing should avoid the contact to any fluids or substances of the storage barrels and reduce hazardous radiation. T2 - International Symposium Non-Destructive Testing in Civil Engineering CY - Zurich, Switzerland DA - 16.08.2022 KW - Ultrasonic testing KW - Nuclear waste PY - 2022 AN - OPUS4-55530 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Maack, Stefan A1 - Benner, Philipp A1 - Kröll, Mirco A1 - Prager, Jens A1 - Daum, Werner A1 - Casperson, Ralf A1 - Heckel, Thomas A1 - Spaltmann, Dirk A1 - et al., ED - Wahlster, W. ED - Winterhalter, C. T1 - Deutsche Normungsroadmap künstliche Intelligenz T1 - German standardization roadmap on artificial intelligence N2 - Im Auftrag des Bundesministeriums für Wirtschaft und Klimaschutz haben DIN und DKE im Januar 2022 die Arbeiten an der zweiten Ausgabe der Deutschen Normungsroadmap Künstliche Intelligenz gestartet. In einem breiten Beteiligungsprozess und unter Mitwirkung von mehr als 570 Fachleuten aus Wirtschaft, Wissenschaft, öffentlicher Hand und Zivilgesellschaft wurde damit der strategische Fahrplan für die KI-Normung weiterentwickelt. Koordiniert und begleitet wurden diese Arbeiten von einer hochrangigen Koordinierungsgruppe für KI-Normung und -Konformität. Mit der Normungsroadmap wird eine Maßnahme der KI-Strategie der Bundesregierung umgesetzt und damit ein wesentlicher Beitrag zur „KI – Made in Germany“ geleistet. Die Normung ist Teil der KI-Strategie und ein strategisches Instrument zur Stärkung der Innovations- und Wettbewerbsfähigkeit der deutschen und europäischen Wirtschaft. Nicht zuletzt deshalb spielt sie im geplanten europäischen Rechtsrahmen für KI, dem Artificial Intelligence Act, eine besondere Rolle. N2 - On behalf of the German Federal Ministry of Economic Affairs and Climate Action, DIN and DKE started work on the second edition of the German Standardization Roadmap Artificial Intelligence in January 2022. With the broad participation and involvement of more than 570 experts from industry, science, the public sector and civil society, the strategic Roadmap for AI standardization was thus further developed. This work was coordinated and accompanied by a high-level coordination group for AI standardization and conformity. The standardization roadmap implements a measure of the German government’s AI Strategy and thus makes a significant contribution to “AI – Made in Germany”. Standardization is part of the AI Strategy and is a strategic instrument for strengthening the innovation and competitiveness of the German and European economies. Not least for this reason, standardization plays a special role in the planned European legal framework for AI, the Artificial Intelligence Act. KW - Digitalisierung KW - Künstliche Intelligenz KW - Datenwissenschaft KW - Normung Roadmap KW - Data science KW - Artificial intelligence KW - Standardization roadmap KW - Digitization PY - 2022 UR - https://www.din.de/resource/blob/1072988/20bf33d405710a703aa26f81362493bb/ausgabe-2-nrm-ki-data.pdf UR - https://www.dke.de/de/arbeitsfelder/core-safety/normungsroadmap-ki SP - 1 EP - 448 PB - Deutsches Institut für Normung (DIN) CY - Berlin ET - 2. AN - OPUS4-56576 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Küttenbaum, Stefan A1 - Braml, T. A1 - Taffe, A. A1 - Maack, Stefan ED - Pellegrino, C. ED - Faleschini, F. ED - Zanini, M.A. ED - Matos, J.C. ED - Casas, J.R. ED - Strauss, A. T1 - From Uncertainty in Measurement to Certainty in Bridge Reassessment N2 - "The reassessment of bridges continues to take great importance both nationally and internationally. A major challenge is to find computation models reflecting the actual properties of the considered structures sufficiently accurate. Besides regular inspections, the conduction of advanced measurements is suitable to generate reliable information about a structure to be assessed. Prior to incorporating measurement results in reassessment, the relevance, the trueness, and the precision of the measured information needs to be stated. On the one hand, the use of information whose quality has not been assessed can lead to errors with serious consequences. On the other, the measurement of irrelevant information is inefficient. Although the use of measured data in assessment is currently mostly unregulated, their appreciation in reliability analyses is beneficial since the built environment can be assessed more realistically. Utilizing NDT in reassessment has the potential to extend remaining lifetimes of a structure, save resources, and improve infrastructural availabilities. The power of judgment regarding the decision on the reliability of an existing structure can be increased. In this contribution, an approach is outlined to process non-destructively gathered measurement data in a comparableway in order to include themeasured information in probabilistic reliability assessments of existing structures. An essential part is the calculation of measurement uncertainties. The effect of incorporating evaluated NDT-results is demonstrated by means of a prestressed concrete bridge and GPR measurements conducted on this bridge as a case-study. The bridge is assessed regarding SLS Decompression using the NDT-results." KW - Reliability KW - Assessment KW - Existing structures KW - NDT KW - Concrete PY - 2022 DO - https://doi.org/10.1007/978-3-030-91877-4_58 VL - 200 SP - 509 EP - 517 PB - Springer CY - Cham AN - OPUS4-54019 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Jansen, D. A1 - Bald, S. A1 - Birbaum, J. A1 - Küttenbaum, Stefan A1 - Krause, J. A1 - Maack, Stefan A1 - Pichottka, S. A1 - Scherkenbach, M. A1 - Strangfeld, Christoph A1 - Villaret, K. A1 - Wöllenstein, J. T1 - Sensorik zur Substanzbewertung von Straßen N2 - Das vorliegende Arbeitspapier stellt den Stand des Wissens und der Forschung zum Einsatz von Sensorik in Straßenbefestigungen zur Erfassung von Eingangsgrößen und Merkmalen für die Substanzbewertung zusammenfassend dar. Unter Sensorik versteht dieses Arbeitspapier ganz allgemein technische Einrichtungen, mit denen man die Werte von physikalischen Größen erfassen und zur Interpretation darstellen kann. KW - Sensorik KW - Beton KW - Asphalt KW - Messkette KW - Zustandsbewertung PY - 2022 SN - 978-3-86446-314-3 SP - 1 EP - 28 PB - Forschungsgemeinschaft für Straßen- und Verkehrswesen e.V. CY - Köln AN - OPUS4-54530 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -