TY - JOUR A1 - Maierhofer, Christiane A1 - Zacher, Gerhard A1 - Kohl, Christoph A1 - Wöstmann, Jens T1 - Evaluation of Radar and Complementary Echo Methods for NDT of Concrete Elements N2 - Non-destructive testing (NDT) of concrete structures plays an increasing role in civil engineering. This paper presents the results of systematic measurements carried out in the laboratory at BAM and on-site at several bridges using reconstructed and fused radar and ultrasonic echo data sets. For investigating the influence of concrete mixture, radar and ultrasonic measurements were performed at test specimens consisting of concrete mixtures with different pore content and distribution as well as with steel fibres. Further, it is demonstrated how the fusion of data sets recorded with different methods at the same structure (here: concrete bridges) enhances the information content in the fused data set. Different approaches for data fusion algorithms are discussed. The results of these investigations show the high potential of reconstruction and data fusion for the improvement and simplification of the interpretability of large data sets measured with impulse-echo methods. The presented results are based on the research project FOR384 funded by the DFG (Deutsche Forschungsgemeinschaft). KW - Radar KW - Ultrasonic KW - Data fusion KW - Pixel level KW - Evidence theory KW - Concrete KW - Bridges KW - Reinforcement KW - Pores KW - Steel fibres PY - 2008 DO - https://doi.org/10.1007/s10921-008-0030-8 SN - 0195-9298 SN - 1573-4862 VL - 27 IS - 1-3 SP - 47 EP - 57 PB - Plenum Press CY - New York, NY AN - OPUS4-17711 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Maierhofer, Christiane A1 - Kohl, Christoph A1 - Wöstmann, Jens ED - Maierhofer, C. ED - Reinhardt, H.-W. ED - Dobmann, G. T1 - Combining the results of various non-destructive evaluation techniques for reinforced concrete: data fusion KW - Non-destructive testing KW - Concrete KW - Data fusion KW - Radar KW - Ultrasonic techniques PY - 2010 SN - 978-1-84569-950-5 VL - 2 IS - Chapter 5 SP - 95 EP - 107 PB - Woodhead Publ. AN - OPUS4-22607 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Kohl, Christoph A1 - Krause, Martin A1 - Maierhofer, Christiane A1 - Mayer, K. A1 - Wöstmann, Jens A1 - Wiggenhauser, Herbert T1 - 3D-Visualisation of NDT-Data using Data Fusion Technique N2 - Non-destructive testing (NDT) of concrete structures is performed using pulse-echo methods. According to the type of the applied waves it can be classified as acoustic (Impact-Echo, Ultrasonics) and electromagnetic methods (Radar). The results are visualised through different imaging processes. This work is performed in the frame of a research project promoted by Deutsche Forschungsgemeinschaft (FOR384).The objective of data fusion is to use the complementary information of the different methods. Radar can detect metallic reflectors in concrete (metallic ducts and concrete reinforcement) very well. This method is not able to locate defects behind these reflectors (injecting defects, defects behind close concrete reinforcement), because the electromagnetic waves are completely reflected at metals. The acoustic methods are able to compensate this deficit i.e. acoustic waves can penetrate through metal. But acoustic waves in the ultrasonic range are completely reflected by air layers. Air layers have smaller influence on radar propagation, so that both methods complement each other.In order to be able to combine the NDT-data from several methods records at the same volume, the different data setsmodes of signals must be adapted. The ultrasonic and radar data have to be reconstructed with programs based on the Synthetic Aperture Focusing Technique (SAFT) before data fusion. Subsequently, a conversion of the data into a uniform format has to be carried out. This is a prerequisite in order to keep the data exchange between the project partners as simple as possible. After the data sets are imported and transferred into a common reference system, they can be processed with operations according to the purpose of the investigation. Results, which have been achieved in concrete test specimen with radar and ultrasonics, will be presented and will show the feasibility of the data fusion method. T2 - 6th International Symposium Non-Destructive Testing in Civil Engineering (NDT-CE) CY - Berlin, Germany DA - 2003-09-16 KW - Radar KW - Ultrasonic KW - Data Fusion PY - 2003 UR - http://www.ndt.net/article/ndtce03/papers/v023/v023.htm SN - 3-931381-49-8 SP - 1 EP - 11(?) PB - DGZfP CY - Berlin AN - OPUS4-3053 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Kohl, Christoph A1 - Maierhofer, Christiane A1 - Krause, Martin A1 - Streicher, Doreen A1 - Wiggenhauser, Herbert ED - Mazal, P. T1 - Data fusion of complementary NDT methods applied in civil engineering T2 - 2nd International Workshop of NDT Experts CY - Prague, Czech Republic DA - 2003-10-06 KW - Non-destructive testing in civil engineering KW - Data fusion KW - Radar KW - Ultrasonics KW - Concrete PY - 2003 SN - 80-2142475-3 SP - 1 EP - 11(?) PB - Univ. of Technology CY - Brno AN - OPUS4-3054 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Mayer, K. A1 - Zimmer, A. A1 - Langenberg, K. J. A1 - Kohl, Christoph A1 - Maierhofer, Christiane T1 - Non-Destructive Evaluation of Embedded Structures in Concrete - Modeling and Imaging N2 - We concentrate on appropriate algorithmic processing of microwave Ground Penetrating Radar (GPR) data obtained from concrete specimens containing tendon ducts below steel reinforcement bars either via simulations or via experiments. The goal is to understand the physical phenomena of electromagnetic wave propagation and scattering in detail in order to optimize imaging algorithms like SAFT (Synthetic Aperture Focusing Technique as the NDT version of SAR) in its 3D diffraction tomographic FT-SAFT formulation (Fourier-Transform-SAFT). Therefore we start with the simulation of a "simple" specimen and switch to a more realistic one in order to check whether simulation and experiment can give comparable results. Basically, this could be confirmed, but, nevertheless, various parametric studies will still have to be performed in the future. 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 - Modelling KW - SAFT KW - SAR PY - 2003 UR - http://www.ndt.net/article/ndtce03/papers/v022/v022.htm SN - 3-931381-49-8 VL - 85-CD PB - DGZfP CY - Berlin AN - OPUS4-3159 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kohl, Christoph A1 - Krause, Martin A1 - Maierhofer, Christiane A1 - Mayer, K. A1 - Wöstmann, Jens A1 - Wiggenhauser, Herbert T1 - 3D-visualisation of NDT data using a data fusion technique KW - Non-destructive testing KW - Radar KW - Ultrasonic KW - Data fusion KW - SAFT PY - 2003 SN - 0007-1137 VL - 45 IS - 12 SP - 800 EP - 808 PB - British Institute of Non-Destructive Testing CY - Northampton AN - OPUS4-4585 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Kohl, Christoph A1 - Krause, Martin A1 - Maierhofer, Christiane A1 - Wöstmann, Jens A1 - Wiggenhauser, Herbert T1 - Datenfusion komplementärer Impuls-Echo Verfahren zur zerstörungsfreien Untersuchung von Betonbauteilen T2 - Jahrestagung Zerstörungsfreie Materialprüfung 2004 CY - Salzburg, Österreich DA - 2004-05-17 KW - Zerstörungsfreie Prüfung im Bauwesen KW - Radar KW - Ultraschall KW - Impact-Echo KW - Datenfusion KW - SAFT PY - 2004 UR - http://www.ndt.net/article/dgzfp04/papers/p37/p37.htm SN - 3-931381-55-2 SP - 1 EP - 15(?) PB - DGZfP CY - Berlin AN - OPUS4-5603 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maierhofer, Christiane A1 - Kohl, Christoph A1 - Mayer, K. T1 - Radar in der DFG-Forschergruppe FOR384 T2 - DAfStb-Fachtagung 2005 "Zerstörungsfreie Prüfverfahren und Bauwerksdiagnose im Betonbau" CY - Berlin, Deutschland DA - 2005-03-10 KW - Zerstörungsfreie Prüfung im Bauwesen KW - Radar KW - Datenfusion KW - Bewehrung KW - Spannkanal KW - Hohlkastenbrücke PY - 2005 SP - A19 EP - A24 PB - BAM CY - Berlin AN - OPUS4-7208 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maierhofer, Christiane A1 - Krause, Martin A1 - Mielentz, Frank A1 - Streicher, Doreen A1 - Milmann, Boris A1 - Gardei, André A1 - Kohl, Christoph A1 - Wiggenhauser, Herbert T1 - Complementary application of radar, impact-echo and ultrasonics for testing concrete structures and metallic tendon ducts T2 - 83rd Annual Meeting Transportation Research Board of the National Academies CY - Washington, D. C., USA DA - 2004-01-11 KW - Non-destructive testing KW - Tendon duct KW - Concrete bridge KW - Radar KW - Ultrasonic KW - Impact-echo PY - 2004 SP - 18 pages CY - Washington AN - OPUS4-4909 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kohl, Christoph A1 - Streicher, Doreen T1 - Results of reconstructed and fused NDT-data measured in the laboratory and on-site at bridges N2 - Non-destructive testing (NDT) of concrete structures plays an increasing role in civil engineering. This paper presents the results of measurements carried out in the laboratory at BAM and on-site at several bridges using reconstructed and fused radar and ultrasonic echo data sets. In this context different scanning systems, developed for the on-site application of NDT-methods (e.g. reinforced concrete bridges) are introduced. The main object was the demonstration of the improved effectiveness of radar and ultrasonic pulse echo technique due to the automated measurements and the application of new software for the data processing and data visualisation. The results of these measurements show the high potential of reconstruction and data fusion for the improvement and simplification of the interpretability of large data sets measured with impulse-echo methods. KW - Non-destructive testing KW - Prestressed concrete bridges KW - Radar KW - Ultrasonic pulse echo technique KW - Data fusion KW - Scanning system PY - 2006 DO - https://doi.org/10.1016/j.cemconcomp.2006.02.005 SN - 0958-9465 SN - 1873-393X VL - 28 IS - 4 SP - 402 EP - 413 PB - Elsevier CY - Barking, Essex AN - OPUS4-12307 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Streicher, Doreen A1 - Kohl, Christoph A1 - Wiggenhauser, Herbert A1 - Petz, J. T1 - Assessment of post tensioned box girder bridges applying automated non-destructive testing methods T2 - 85th TRB Annual Meeting CY - Washington D.C., USA DA - 2006-01-22 KW - Automatisierte ZfPBau-Verfahren KW - Radar KW - Ultraschallecho KW - Impact-Echo KW - Spannbetonbrücken PY - 2006 SP - 1 EP - 13(?) PB - TRB CY - Washington, D.C. AN - OPUS4-12238 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -