Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
The impact-echo method recently draws a remarkable attention for nondestructive evaluation of defects in concrete structures. Extracting resonance frequencies responsible for the locations of reflectors, depth and presence of defects are estimated. However, there exist still problems by applying the technique to concrete structures in service. Particularly, estimation of ungrouted sheath in prestressed concrete beams is limitedly successful. In order to solve the problems, the method was studied theoretically on basis of elastodynamics. A new device to apply an impact to concrete has been developed. Then, in order to circumvent the difficulty to identify peak frequencies in the conventional procedure, a new procedure has been investigated, applying an imaging procedure. Thus, stack imaging of spectral amplitudes based on impact-echo (SIBIE) is developed. Here, numerical analyses are conducted to confirm and study the performance of SIBIE. In order to identify the voids in concrete, based on the BEM analysis, SIBIE procedure is studied. It is clarified that the reflector near the duct containing a void is effectively visualized. The stress distribution and dynamic deformations at the peak frequency fvoid confirm the presence of reflections at the duct hole.
The impact-echo method recently draws a remarkable attention for nondestructive evaluation of defects in concrete structures. Extracting resonance frequencies responsible for the locations of reflectors, depth and presence of defects are estimated. However, there exist still problems by applying the technique to concrete structures in service. Particularly, estimation of ungrouted sheath in prestressed concrete beams is limitedly successful. In order to solve the problems, the method was studied theoretically on basis of elastodynamics. A new device to apply an impact to concrete has been developed. Then, in order to circumvent the difficulty to identify peak frequencies in the conventional procedure, a new procedure has been investigated, applying an imaging procedure. Thus, stack imaging of spectral amplitudes based on impact-echo (SIBIE) is developed. Here, numerical analyses are conducted to confirm and study the performance of SIBIE. In order to identify the voids in concrete, based on the BEM analysis, SIBIE procedure is studied. It is clarified that the reflector near the duct containing a void is effectively visualized. The stress distribution and dynamic deformations at the peak frequency fvoid confirm the presence of reflections at the duct hole.
Void detection in grouted sheath in post-tensioning prestressed concrete by SIBIE
Nachweis von Hohlräumen in geschlämmten Umhüllungen in nachgespanntem Spannbeton durch Spektralamplituden basierter Impakt-Echountersuchung
2004
7 Seiten, 7 Bilder, 2 Tabellen, 5 Quellen
(nicht paginiert)
Aufsatz (Konferenz)
Datenträger
Englisch
Void detection in grouted sheath in post-tensioning prestressed concrete by SIBIE
| British Library Conference Proceedings | 2004
| British Library Online Contents | 2007