TY - GEN A1 - Maack, Stefan A1 - Niederleithinger, Ernst T1 - Imaging of Ultrasonic Echo Measurements for Reconstruction of Technical Data of Bridges – Possibilities, Limitations and Outlook N2 - When reassessing existing concrete bridges, the challenge is often to obtain missing or incomplete information on the internal structure. In particular, the number and position of the existing reinforcement as well as the geometric dimensions of the components are of interest. Non-destructive testing methods, like radar or ultrasound, which work on the basis of the pulse-echo method, have been established for this purpose, as they only require access to the component from one side. The measurement data recorded on the structure require pre-processing to be able to reproduce the internal structure geometrically accurately. Besides different steps of data processing, the geometrical reconstruction of the measured data based on the Synthetic Aperture Focusing Technique (SAFT) is state of the art today. In this paper, the technical possibilities of the ultrasonic echo method are presented based on measurements in the laboratory and on a real bridge structure. The precision of the reconstruction and its limitations are shown. In addition to the state of the art SAFT technique, open questions and the latest research approaches, such as imaging by reverse time migration (RTM) including initial results are discussed. T2 - 13th German-Japanese Bridge Symposium CY - Osaka, Japan DA - 29.08.2023 KW - Bridge KW - Non destructive testing and evaluation KW - Concrete KW - Validation PY - 2023 UR - https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/58328 AN - OPUS4-58328 AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany