TY - GEN A1 - Maierhofer, Christiane A1 - Zacher, Gerhard A1 - Kohl, Christoph A1 - Wöstmann, Jens ED - Christian U. Grosse, T1 - Radar and Fusion for Concrete Elements KW - NDT-CE KW - Concrete KW - Concrete bridge KW - Reinforcement bars KW - Radar KW - Ultrasonic KW - Data fusion PY - 2007 SN - 978-3-540-72447-6 SP - 631 EP - 638 PB - Springer CY - Heidelberg AN - OPUS4-15990 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - 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 U6 - 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 - JOUR A1 - Kohl, Christoph A1 - Krause, Martin A1 - Maierhofer, Christiane A1 - Wöstmann, Jens T1 - 2D- and 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. KW - Non-destructive testing KW - Radar KW - Ultrasonic KW - Impact-echo KW - Data fusion KW - SAFT PY - 2005 SN - 1359-5997 SN - 1871-6873 VL - 38 IS - 283 SP - 817 EP - 826 PB - Springer CY - Dordrecht AN - OPUS4-11591 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 -