TY - CONF A1 - Wiggenhauser, Herbert T1 - A European research project for the condition assessment of railway bridges, on-site investigation techniques for the structural evaluation of historic masonry buildings T2 - Advanced Course on Non-Destructive Testing and Evaluation of Concrete Structures CY - Chennai, India DA - 2007-02-15 PY - 2007 AN - OPUS4-14766 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wiggenhauser, Herbert T1 - Improvement and Validation of Foundation NDT Methods T2 - Advanced Course on Non-Destructive Testing and Evaluation of Concrete Structure, SERC CY - Chennai, India DA - 2007-01-25 PY - 2007 AN - OPUS4-14729 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Helmerich, Rosemarie A1 - Niederleithinger, Ernst A1 - Algernon, Daniel A1 - Streicher, Doreen A1 - Wiggenhauser, Herbert T1 - Bridge inspection and condition assessment in Europe T2 - TRB 87th annual meeting CY - Washington, D.C., USA DA - 2008-01-13 KW - Construction KW - Environment and Energy PY - 2008 IS - CD-ROM (Paper 08-1450 / Session 568) SP - 1 EP - 13 PB - TRB CY - Washington, DC AN - OPUS4-16651 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wiggenhauser, Herbert T1 - Bridge inspection and condition assessment in Europe T2 - Transportation Research Board (TRB) 87th Annual Meeting, Session 660 CY - Washington, D.C., USA DA - 2008-01-13 PY - 2008 AN - OPUS4-16594 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Helmerich, Rosemarie A1 - Niederleithinger, Ernst A1 - Algernon, Daniel A1 - Streicher, Doreen A1 - Wiggenhauser, Herbert T1 - Bridge Inspection and Condition Assessment in Europe N2 - The European infrastructure asset has developed historically and is characterized by nation-specific construction processes. Inspection, condition assessment, and maintenance procedures differ from country to country. Because of historical and political circumstances, national infrastructure assets are maintained at different levels, too. Since the budget for maintaining the bridge infrastructure less and less meets the demands of a growing bridge stock, bridge inspection, maintenance, and life-cycle considerations gain higher importance. The need exists to develop effective diagnosis tools for early detection of construction faults, defects, and deterioration processes during inspection, to keep the bridge infrastructure at an acceptable level, from structural safety and economic viewpoints. An overview on the latest research projects and integrated bridge management systems in Europe is given. The potentials of nondestructive testing (NDT) are presented, with special focus on technical advances of NDT applications to reinforced concrete (RC) and posttensioned concrete bridges. Although NDT is not regularly integrated in these processes, the application brings valuable information on the current condition of the inner structure in called-in special inspections. NDT-automation and the application of imaging echo methods, combined with advanced data processing, produce a surprising level of information about the inner structure of massive RC slabs up to a depth of about 60 cm. Detected inhomogeneity and scatterers of acoustic or electromagnetic waves can be visualized in vertical or horizontal slices through the structure or animations. The fusion of different three-dimensional data sets of processed data improves the interpretability and accuracy of the results. KW - Category IIIC PY - 2008 DO - https://doi.org/10.3141/2044-04 SN - 0361-1981 VL - 2044 SP - 31 EP - 38 PB - National Research Council CY - Washington, DC AN - OPUS4-18037 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Niederleithinger, Ernst A1 - Wiggenhauser, Herbert A1 - Taffe, Alexander T1 - The NDT-CE test and validation center in Horstwalde T2 - NDTCE ´09 - 7th International symposium on nondestructive testing in civil engineering CY - Nantes, France DA - 2009-06-30 KW - Foundations KW - Bridges KW - Piles KW - Slabs KW - Integrity KW - Ultrasonics KW - Parallel seimics PY - 2009 SN - 978-2-7208-2542-5 SN - 1628-4704 SP - 1 EP - 6 AN - OPUS4-20140 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Wiggenhauser, Herbert A1 - Helmerich, Rosemarie A1 - Krause, Martin A1 - Mielentz, Frank A1 - Niederleithinger, Ernst A1 - Taffe, Alexander A1 - Wilsch, Gerd ED - Naus, D. T1 - Non-destructive Testing of Nuclear Power Plant Concrete Structures State of the Art Report N2 - Nuclear Power Plants have been in operation for ca. 50 years. Based on this experience, non-destructive testing tasks specific to thick and highly reinforced nuclear containment structures have materialized. The performance based Service life extension of existing NPPs also needs a measurement based decision to support continuing the service of the concrete part of the installations. By nature, concrete is a very durable material and any natural Deterioration processes may take a long time to become critical to the structure. The experience of more than 50 years of service limits the testing tasks to a few ones which are not yet solved. Research in NDT of concrete structures is performed by many research institutions all over the world with different technical and systematic approaches. Results are mainly obtained on laboratory specimens, sometimes additional field studies are reported. This research takes place independently without coordination and as a result, the outcomes mostly lack full comparability. Software for data analysis has become indispensable and very powerful. This part of testing needs more attention when it comes to evaluate test results. Validation of NDE solutions is becoming a critical part in concrete structure testing. Validation is by definition the proof that a customer´s requirements in the test are being met by the testing solution. This includes equipment, personnel qualification and data analysis. In the following tables, the research recommendation Validation is used in the sense, that proof of the performance of existing solutions needs to be adressed. In general, a validation methodology for NDE solutions for concrete testing in itself needs to be researched and established. Comparability of research also needs an accepted and easily accessible reference. From experience, it is almost impossible to manufacture exact copies of test specimens at different locations. Round Robin tests are therefore needed to evaluate the performance of a test. Data evaluation is generally done using dedicated software, sometimes Hardware dependant and not interchangeable between systems. Software is ever more increasingly becoming more powerful and sophisticated. An in-depth evaluation needs to address the comparability and validation of Software used for data analysis and evaluation. The vision of a unified software pool for NDE investigations would undoubtedly support research tremendously. Quantitative NDE is mostly recommended to assess the condition of a structure. However, qualitative data can be very useful, especially for processes which change the material properties or deteriorate the structure (e.g. corrosion of reinforcement). The need for reliable baseline data is a key factor for such monitoring tasks. KW - Nuclear structures KW - Non-destructive testing KW - State of the art KW - Research needs PY - 2013 SP - 1 EP - 120 PB - BAM CY - Berlin AN - OPUS4-51049 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wolf, Julia A1 - Niederleithinger, Ernst A1 - Mielentz, Frank A1 - Grothe, Sven A1 - Wiggenhauser, Herbert T1 - Überwachung von Betonkonstruktionen mit eingebetteten Ultraschallsensoren N2 - Die immer komplexere Konstruktionsweise von Neubauten einerseits und die alternde Infrastruktur andererseits erfordern in manchen Fällen eine dauerhafte Überwachung, um besondere Einwirkungen und gegebenenfalls Schädigungen rechtzeitig und genau zu erkennen. Hierfür ist eine Vielzahl von Methoden und Sensoren verfügbar. Das Portfolio weist aber insbesondere bei der Detektion langsamer, räumlich begrenzter Veränderungen Lücken auf. Hierfür sind bisher sehr aufwändige Untersuchungen oder Installationen notwendig. In der vorliegenden Arbeit werden Sensoren und zugehörige Auswertemethoden für die Ultraschalltransmission vorgestellt, die sich für die zerstörungsfreie, dauerhafte Überwachung von Beton eignen. Direkt oder nachträglich in Betonkonstruktionen eingebaut, ermöglichen sie eine nicht nur lokale, sondern größere Raumbereiche umfassende Dauerüberwachung von Änderungen der Materialeigenschaften. Das Prinzip der Ultraschalltransmission und die verschiedenen Einflussparameter werden vorgestellt. Zu letzteren gehören neben der Belastung und Schädigung auch Umweltparameter wie Temperatur und Feuchte. Verschiedene Methoden zur Datenanalyse, wie z. B. die Codawelleninterferometrie, ermöglichen eine Detektion kleinster Veränderungen. Die in den Beton einzubettenden Ultraschallsensoren werden vorgestellt und ihr Einbau und Betrieb beschrieben. Als Beispiele für Anwendungen werden Frost-Tauwechsel-Experimente im Labor, die Detektion von lokalen Lasten im Technikumsmaßstab und der Einsatz an realen Brücken diskutiert. Die Sensoren sind zum Teil bereits seit mehreren Jahren in Probeobjekte eingebettet und liefern zuverlässig wertvolle Daten.------------------------------------------------------------------------------------------------------------------------------------------------------------- Monitoring of concrete constructions by embedded ultrasonic sensors: Challenging new constructions and the ageing infrastructure are increasing the demand for permanent monitoring of loads and damages. Various methods and sensors are used for this purpose. But the technologies available today have difficulties in detecting slowly progressing locally confined damages. Extensive investigations or instrumentations are required so far for this purpose. In this study we present new sensors and data processing methods for ultrasonic transmission, which can be used for non-destructive permanent monitoring of concrete. They can be mounted during construction or thereafter. Larger volumes can be monitored by a limited number of sensors for changes of material properties. The principles of ultrasonic transmission and influencing factors are presented. This latter include load, damages as well as environmental parameters as temperature or moisture. Various methods for data processing, e. g. coda wave interferometry are introduced. They allow the detection of very small changes in the medium. The embedded sensors are shown including mounting and operation. Application examples so far include small scale laboratory freeze-thaw experiments, localizing loads in larger concrete models and monitoring load effects on real structures. Some sensors are operating already for several years. KW - Beton KW - Ultraschall KW - Transmission KW - Monitoring KW - Codawelleninterferometrie KW - Frost-Tauwechsel KW - Ultraschallsensoren, eingebettete KW - Lastconcrete KW - Ultrasound KW - Coda wave interferometry KW - Embedded sensors KW - Freeze-thaw KW - Load KW - Neue Verfahren/Versuchstechnik KW - New Processes/Experimental Techniques PY - 2014 DO - https://doi.org/10.1002/bate.201400073 SN - 0932-8351 SN - 1437-0999 SN - 0005-6820 SN - 0341-1052 SN - 0932-6359 VL - 91 IS - 11 SP - 783 EP - 796 PB - Ernst & Sohn CY - Berlin AN - OPUS4-32077 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Sens-Schönfelder, C. A1 - Grothe, Sven A1 - Wiggenhauser, Herbert T1 - Coda wave interferometry used to localize compressional load effects on a concrete specimen N2 - Coda Wave Interferometry (CWI), a method to evaluate subtle changes of elastic wave velocity in a medium, has been proven to be effective to detect small changes or ultrasonic velocity in concrete caused by load, temperature, moisture, damage or other means. While classical CWI is just able to determine velocity changes globally in relatively large areas between and around pairs of transmitters and receivers, several approaches have been proposed to identify the area affected by the changes more precisely. Most of them are based on the calculation of sensitivity kernels for de-correlation of signals measured at a specific state against a reference. Others follow simplified approaches. In a laboratory setup a concrete specimen of 1:5 x 1:5 x 0:5 m3 was compressed at a certain point. Maximum loads of 20 to 100 kN have been applied in 5 to 10 kN steps in various cycles. The specimen is equipped with 18 embedded ultrasonic broadband piezo transceivers (60 kHz central frequency). Ten of these receivers have been connected to a multiplexer and ultrasonic transmitting and receiving equipment in a way that allowed almost continuous two way measurements between all sensor pairs. Even simple ways to evaluate the data (e.g. crosscorrelation between signals at different load states) allowed pinpointing the load center at least approximately. A more detailed data evaluation either using CWI or even more one of the more sophisticated localization algorithms gave “sharper” results in terms of localization and a better correlation between load and velocity change/de-correlation. The results are used in upcoming monitoring systems for concrete structures. T2 - 7th European workshop on structural health monitoring CY - Nantes, France DA - 08.07.2014 KW - Concrete KW - Ultrasound KW - Coda wave inteferometry KW - Tomography KW - Correlation KW - Stress KW - Monitoring PY - 2014 SP - Paper WeBT6.3, 1427 EP - 1433 AN - OPUS4-31204 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wiggenhauser, Herbert A1 - Niederleithinger, Ernst A1 - Milmann, Boris T1 - Zerstörungsfreie Ultraschallprüfung dicker und hochbewehrter Betonbauteile T1 - Nondestructive testing of thick and highly reinforced concrete structures with ultrasound N2 - Ein Ultraschallsystem mit großer Apertur, genannt LAUS – Large Aperture UltraSound, wird vorgestellt und die technischen Eigenschaften erläutert. Es besteht aus zwölf Prüfköpfen, die beliebig auf Betonoberflächen mit Unterdruck befestigt und jeweils als Sender oder Empfänger genutzt werden. Alle möglichen Kombinationen ergeben 132 Einzelmessungen, die zur Rekonstruktion des durchschallten Volumens genutzt werden. Das System wurde an zwei Bauwerken erfolgreich erprobt. Die Dicke einer sehr stark bewehrten Fundamentplatte eines Fallturms wurde bestimmt. Die Messungen erfolgten in einem Raster auf einer Fläche von 2,0 × 1,8 m2 und die Rückseite konnte eindeutig abgebildet werden. Weitere Anzeigen aus dem Inneren der Platte zeigen das Potenzial des Systems. An einem Brückenbauwerk wurden indirekt Verdichtungsmängel lokalisiert. Dazu wurden mit dem LAUS-System die im Brückenträger verlaufenden Spannkanäle durch fast 2 m Beton abgebildet. N2 - An ultrasound system with a large aperture, called LAUS - Large Aperture UltraSound, is presented and the technical characteristics are explained. It consists of twelve sensor units which can be attached independently on concrete surfaces with vacuum and which are used as transmitters or receivers respectively. All possible combinations result in 132 individual measurements which are used to reconstruct the insonificated volume. The system has been successfully tested on two structures. The thickness of a very heavily reinforced foundation slab of a drop tower was determined. The measurements were carried out in a grid on a surface of 2.0 x 1.8 m(2) and the back side could be clearly imaged. Further indications from inside the foundation show the potential of the system. Voids in concrete were indirectly located in a bridge structure. For this purpose, the LAUS system was used to image the tendon ducts running in the bridge beam through almost 2 m of concrete. KW - Ultraschall KW - Beton KW - Brücke KW - Fundament KW - LAUS PY - 2017 DO - https://doi.org/10.1002/bate.201700040 SN - 0932-8351 VL - 94 IS - 10 SP - 682 EP - 688 PB - Ernst & Sohn CY - Berlin AN - OPUS4-42614 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst A1 - Wiggenhauser, Herbert A1 - Milmann, Boris T1 - LAUS - Erste praktische Erfahrungen mit einem neuartigen Ultraschallsystem großer Eindringtiefe N2 - Konventionelle Systeme zur Ultraschall-Echo-Prüfung von Betonbauteilen sind in ihrer Eindringtiefe auf etwa einem Meter begrenzt. Zur Prüfung stärkerer Objekte war die Entwicklung eines neuartigen Prüfsystems notwendig. Das LAUS-System (Large Aperture UltraSound) besteht aus 12 einzelnen Arrays, die mit jeweils 32 Einzelprüfköpfen (Scherwellen, 25 – 50 kHz) als Sender oder Empfänger betrieben werden können. Sie werden unabhängig auf Betonoberflächen mit Unterdruck befestigt und kommunizieren drahtlos untereinander und mit der Zentraleinheit. Alle möglichen Kombinationen ergeben 132 Einzelmessungen, die zur Rekonstruktion des durchschallten Volumens genutzt werden. Mehrere dieser Datensätze lassen sich zu einer 3D-Auswertung kombinieren. Das System wurde an mehreren Testobjekten und Bauwerken erfolgreich erprobt. So konnte die fünf Meter dicke, sehr stark bewehrte Fundamentplatte des Fallturms auf dem BAM-Testgelände bei Horstwalde durchschallt werden. Ein zweites Beispiel ist die erfolgreiche Detektion von Spannkanälen in 1,8 m Tiefe in einem massiven Brückenbauwerk. T2 - Bauwerksdiagnose 2018 CY - Berlin, Germany DA - 15.2.2018 KW - Ultraschall KW - Beton KW - LAUS KW - Brücke KW - Fundament PY - 2018 AN - OPUS4-44577 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wiggenhauser, Herbert T1 - Bauwerksdiagnostik – Indikatoren für die Zukunft T1 - Building Diagnostics - Indicators for the Future N2 - Vor dem Hintergrund der alternden Verkehrsinfrastruktur und des großen Bauwerksbestands allgemein gewinnt deren Zustandserfassung an Bedeutung. Durch die Einführung von Bauwerksmanagementsystemen und die Digitalisierung der Wirtschaft im Rahmen von Industrie 4.0 wird diese Entwicklung noch mehr Dynamik entfalten. Die Vernetzung von Zustandsdaten mit der Belastung, Wartung und Instandsetzung sowie der politischen Planung, wird eine hohe Bedeutung bekommen. Angesichts der Altersstruktur der Verkehrsinfrastruktur und begrenzter öffentlicher Gelder wird zukünftig eine selektive Instandsetzung von Bauwerken nach deren Zustandsnoten notwendig sein. Zerstörungsfreie Untersuchungsverfahren für Bauwerke nehmen in diesem Kontext eine wichtige Rolle ein, sie sollen die quantitativen Zustandsdaten erbringen und in die Datenbanken für Managementsysteme mit zuverlässigen und objektiven Messdaten füllen. KW - Bauwerksdiagnostik KW - Zerstörungsfreie Prüfung KW - Infrastruktur PY - 2017 DO - https://doi.org/10.1002/bate.201771003 SN - 1437-0999 VL - 94 IS - 10 SP - 675 EP - 675 PB - Ernst & Sohn CY - Berlin AN - OPUS4-42618 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Maierhofer, Christiane A1 - Krause, Martin A1 - Niederleithinger, Ernst A1 - Wiggenhauser, Herbert T1 - Non-destructive testing methods at BAM for damage assessment and quality assurance in civil engineering N2 - The structural safety, durability and performance of the infrastructure is of primary interest in every country. An efficient system for early and regular structural assessment as well as for quality assurance during and after the construction of new structures and of reconstruction processes is urgently required. At BAM, NDT methods to be applied in civil engineering are developed and their application improved. From the experience of on-site assessments, quality assurance systems and methodologies for regular inspections are elaborated. This work is mainly performed in the frame of externally funded research projects. T2 - 6th International Symposium Non-Destructive Testing in Civil Engineering (NDT-CE) CY - Berlin, Germany DA - 2003-09-16 KW - Non-destructive testing in civil engineering KW - Radar KW - Ultrasonics KW - Impact-echo KW - Impulse thermography KW - Concrete KW - Masonry PY - 2003 UR - http://www.ndt.net/article/ndtce03/papers/v068/v068.htm SN - 3-931381-49-8 PB - DGZfP CY - Berlin AN - OPUS4-3160 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wiggenhauser, Herbert T1 - Quality Control of Hydrophobic Coatings with an Integrated Marker Element by Laser-Induced Breakdown Spectroscopy (LIBS) T2 - International Congress on Durability of Concrete CY - Trondheim, Norway DA - 2012-06-18 PY - 2012 AN - OPUS4-27414 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -