TY - JOUR A1 - Alver, Ninel A1 - Wiggenhauser, Herbert T1 - Modified SIBIE procedure for ungrouted tendon ducts applied to scanning impact-echo JF - Construction and building materials N2 - The impact-echo method has been successfully applied to identify defects inside concrete. In addition, to detect ungrouted tendon ducts in a large concrete slab, a scanning impact-echo technique is developed. However, since resonant frequencies in the spectrum responsible for the travel paths via defects are only taken into account, the method could lead to erroneous results due to complicated spectra obtained in the tests. Consequently, Stack Imaging of spectral amplitudes Based on Impact-Echo (SIBIE) procedure has been developed to improve the data interpretation. Conventionally, SIBIE is applied to a single measurement data and a point information of defects is obtained at the area, where the impact test is performed. In this study, SIBIE is applied to scanning impact-echo data. Locations of ungrouted tendon ducts embedded in a large concrete specimen are investigated. In order to visualize the whole cross-section tested, the SIBIE analysis is modified, introducing an elliptical integration mode. It is demonstrated that ungrouted tendon ducts are successfully located by the modified SIBIE analysis, whereas results of the conventional B-scan analysis are not so good as the modified SIBIE analysis. KW - Impact echo KW - Scanning procedure KW - SIBIE PY - 2010 DO - https://doi.org/10.1016/j.conbuildmat.2010.05.012 SN - 0950-0618 VL - 24 IS - 12 SP - 2388 EP - 2392 PB - Elsevier Science CY - Amsterdam AN - OPUS4-23961 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -