TY - GEN A1 - Streicher, Doreen A1 - Krause, Martin A1 - Kohl, Christoph A1 - Schickert, M. A1 - Kroggel, O. A1 - Müller, W. T1 - Parameters for the Quantitative Assessment of Ulrasonic Imaging for Concrete Elements N2 - Ultrasonic investigation is an established non-destructive testing method for detection of defects and material characterisation. In the last years scanning ultrasonic echo methods were developed especially for the application in civil engineering. The different scanning ultrasonic echo methods are modified with respect to the type of the transducer applied, the number and the arrangement of transducers and the frequency used. Also different algorithms are used to analyse the measured data, for instance SAFT (Synthetic Aperture Focusing Technique) reconstruction. The results are typically presented as B- and C-scans, obtained from raw data or the SAFT reconstructed data. Since 2001 several German research institutes co-operate within the scope of the research initiative Non-destructive Evaluation of Concrete Structures Using Acoustic and Electromagnetic Echo-Methods (FOR 384) supported by the Deutsche Forschungsgemeinschaft (DFG). One of the tasks is to investigate these ultrasonic echo methods for special applications like the detection of cavities in concrete structures or faults in tendon ducts. Concrete test specimens with intentional faults have been manufactured and investigated. Parameters were defined to assess the results more objectively. Currently three parameters -signal/noise-ratio, lateral edge resolution and uniformity- are considered. For the first time results of different working groups on the same imaged objects are compared quantitatively. It should help to get more knowledge about the ultrasonic inspection of typical faults in civil engineering structures. T2 - 6th International Symposium Non-Destructive Testing in Civil Engineering (NDT-CE) CY - Berlin, Germany DA - 2003-09-16 PY - 2003 UR - http://www.ndt.net/article/ndtce03/papers/p050/p050.htm SN - 3-931381-49-8 SP - 1(?) EP - 12(?) PB - DGZfP CY - Berlin AN - OPUS4-2751 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Krause, Martin A1 - Mielentz, Frank A1 - Milmann, Boris A1 - Streicher, Doreen A1 - Müller, W. T1 - Ultrasonic Imaging of Concrete Elements - State of the Art Using 2D Synthetic Aperture N2 - Since several years ultrasonic imaging techniques are used for testing concrete elements. Combined with a reconstruction calculation they lead to an acoustic imaging of scatterers and reflectors from the inside of the concrete element. For several testing problems it is an advantage to use a two dimensional synthetic aperture and to combine it with a three-dimensional reconstruction calculation (3D-SAFT, Synthetic Aperture Focussing Technique). This enables the analysis of the tested volume by means of B-scans in two directions and C-scans (projections parallel to the surface), respectively. Using the 2D-scanning technique, especially the disturbing influence of the reinforcing rebars can be minimised. In this contribution the state of the art of this method is demonstrated and analysed. Examples of the application are presented, concerning Localisation of honeycombing and compaction faults Characterisation of cracks (especially measuring the crack depth) Investigation of tendon ducts The results presented are obtained in the frame of a research initiative Non-destructive Evaluation of Concrete Structures Using Acoustic and Electromagnetic Echo-Methods supported by the German Science Council (FOR 384 of DFG, Deutsche Forschungsgemeinschaft). The methods are assessed and improved in cooperation with the partners participating in the project. T2 - 6th International Symposium Non-Destructive Testing in Civil Engineering (NDT-CE) CY - Berlin, Germany DA - 2003-09-16 PY - 2003 UR - http://www.ndt.net/article/ndtce03/papers/v051/v051.htm SN - 3-931381-49-8 PB - DGZfP CY - Berlin AN - OPUS4-2606 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Hasenstab, Andreas A1 - Krause, Martin A1 - Hillger, w. A1 - Bühling, L. A1 - Ilse, D. A1 - Hillemeier, B. A1 - Rieck, C. T1 - Luftultraschall und Ultraschall-Echo-Technik an Holz T2 - DGZfP Jahrestagung CY - Rostock, Deutschland DA - 2005-05-02 KW - ZfP an Holzbauteilen KW - Fehlstellen KW - Minderdicken KW - Ultraschallecho-Experimente an Probekörpern KW - Ultraschall-Echo KW - Fäulnis KW - Bauwesen KW - Luftultraschall PY - 2005 SN - 3-931381-64-1 N1 - Serientitel: Berichtsband / Deutsche Gesellschaft für zerstörungsfreie Prüfung e. V. – Series title: Berichtsband / Deutsche Gesellschaft für zerstörungsfreie Prüfung e. V. IS - 94-CD SP - 1(?) EP - 15(?) PB - DGZfP CY - Berlin AN - OPUS4-11961 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Mielentz, Frank A1 - Milmann, Boris A1 - Wöstmann, Jens A1 - Krause, Martin A1 - Maierhofer, Christiane A1 - Römer, A. A1 - Völkel, W. T1 - Untersuchungen zur zerstörungsfreien Bestimmung des Hohlraumgehaltes von Asphaltschichten T2 - DGZfP-Fachtagung Bauwerksdiagnose "Praktische Anwendungen Zerstörungsfreier Prüfungen" CY - Berlin, Deutschland DA - 2006-02-22 KW - Asphalt KW - Hohlraumgehalt KW - Zerstörungsfreie Prüfung KW - Ultraschallverfahren KW - Ultraschall-Rückstreuung KW - Radarverfahren PY - 2006 SN - 3-931381-71-4 SP - 1(?) EP - 9(?) PB - DGZfP CY - Berlin AN - OPUS4-12116 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Krause, Martin A1 - Bärmann, R. A1 - Frielinghaus, R. A1 - Kreschmar, F. A1 - Krogge, O. A1 - Langenberg, K. A1 - Maierhofer, Christiane A1 - Müller, W. A1 - Neisecke, J. A1 - Schickert, M. A1 - Schmitz, V. A1 - Wiggenhauser, Herbert A1 - Wollbold, F. ED - Schickert, G. T1 - Comparison of pulse-echo-methods for testing concrete T2 - International Symposium Non-Destructive Testing in Civil Engineering (NDT-CE) CY - Berlin, Germany DA - 1995-09-26 KW - Beton KW - Radar KW - Aufprallecho KW - Ultraschall KW - Prüfung PY - 1995 SN - 3-931381-02-1 N1 - Serientitel: BB / DGZfP – Series title: BB / DGZfP SP - 281 EP - 295 PB - DGZfP, Dt. Ges. für Zerstörungsfreie Prüfung e.V. CY - Berlin AN - OPUS4-593 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -