TY - JOUR A1 - Maierhofer, Christiane A1 - Brink, Arne A1 - Röllig, Mathias A1 - Wiggenhauser, Herbert T1 - Detection of shallow voids in concrete structures with impulse thermography and radar T2 - NDT & E international N2 - New thermography systems enable the application of active investigation techniques, i.e. the observation of the cooling down process after heating the surface of a structure under investigation. Defects like voids in concrete having a different thermal diffusivity in comparison to the bulk material are visualised by different surface temperatures. The differences between temperature transient curves above sound regions and above inhomogeneities are expected to include information about the defect parameters. Experimental investigations with impulse thermography and radar on a concrete test specimen containing voids were analysed. Radar was used to determine the depth of the voids. The influence of size and depth of the voids on the temperature transient curves was studied for different heating times. The transient curves were also fitted with a simple semi-empirical model. PB - Butterworth-Heinemann CY - Oxford KW - Impulse thermography KW - Radar KW - Non-destructive testing KW - Concrete KW - Civil engineering PY - 2003 UR - https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/11867 AN - OPUS4-11867 SN - 0963-8695 VL - 36 IS - 4 SP - 257 EP - 263 AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany