TY - JOUR A1 - Helmerich, Rosemarie A1 - Mielentz, Frank A1 - Milmann, Boris A1 - Adam, Louisa A1 - Villalobos, S. A1 - Guimaraes, M. A1 - Wiggenhauser, Herbert T1 - Detection of cracks perpendicular to the surface using acoustic methods N2 - Cracks perpendicular to the surface may be initial indicators for a deterioration process of concrete structures. Moisture penetrates inside the structure and transports adverse chemicals. The paper presents an investigation about the reliability of available commercial non-destructive evaluation techniques to reliably estimate the depth of surface-breaking cracks in reinforced concrete structures. Aim of the study was the investigation of surface-braking cracks under laboratory conditions. Commercial acoustic devices as impact echo equipment, single ultrasonic transducers and arrays were applied even if they have not been developed for this purpose. The commercial software and descriptions for application was followed strictly to compare the function, precision and repeatability of the measurements. Both, perpendicular notches and cracks have been considered. The study was completed with a discussion about reference specimens. The study was the basis for formulation of gaps in research. The Electric Power Research Institute (EPRI) has initiated and funded a Project. T2 - NDT-CE 2015 - International symposium non-destructive testing in civil engineering CY - Berlin, Germany DA - 15.09.2015 KW - Acoustic test KW - Commercial acoustic devices KW - Ultrasonic test KW - Crack depth KW - Concrete specimens PY - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-345729 UR - https://www.ndt.net/?id=18412 SN - 1435-4934 VL - 20 IS - 11 SP - 1 EP - 9 PB - NDT.net CY - Kirchwald AN - OPUS4-34572 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Helmerich, Rosemarie A1 - Milmann, Boris A1 - Hong, S. T1 - Investigation of Reinforcement Corrosion using Automated Low-Frequency Ultrasonic Echo T2 - Danube Adria Symposium CY - Stary Smokovec, Slowakei DA - 2015-09-21 PY - 2015 AN - OPUS4-34449 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Helmerich, Rosemarie A1 - Milmann, Boris A1 - Hong, S. T1 - Reinforcement corrosion detection with ultrasonic echo before cracking T2 - Danube Adria Symposium CY - Stary Smokovec, Slowakei DA - 2015-09-21 PY - 2015 AN - OPUS4-34450 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Helmerich, Rosemarie A1 - Mielentz, Frank A1 - Milmann, Boris A1 - Adam, Louisa A1 - Wiggenhauser, Herbert A1 - Guimaraes, M. A1 - Villalobos, S. T1 - DETECTION OF CRACKS PERPENDICULAR TO THE SURFACE USING ACOUSTIC METHODS T2 - NDT-CE 2015 CY - Berlin, Germany DA - 2015-09-15 PY - 2015 AN - OPUS4-34451 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -