Image created by stack imaging spectral amplitudes based on the impact-echo (SIBIE) method is largely one-dimensional because a single frequency domain spectrum for wave reflected below a single point of impact is used to create the image. The method has limitations for representing defects in a cross section of a concrete structural element using two-dimensional coordinates. This study focused on defect detection and visualization in a concrete structural element using multiple impacts and accumulated SIBIE. An impactor was used to induce energy at multiple points at positioned at prescribed intervals along the structural element. A modified SIBIE method was applied to the collected data of each point and the modified SIBIE images were accumulated to generate one image (an accumulated SIBIE image).

• Lee, Sanghun(Member, Tohoku Gakuin University, Dept. of Civil and Environ. Eng., Professor) | 이상훈
• Shishido, Hiroki(Member, Sin Nippon Giken Engineering, Dept. of Design) | 시시도히로키
• Kamada, Toshiro(Osaka University, Dept. of Civil Eng., Professor) | 카마다토시로
• Uchida, Shinya(Ritsmeikan University, Dept. of Civil Eng., Assistant Professor) | 우치다신야
• Lee, Weoncheol(Member, Sambo Engineering, Dept. of Structure, Senior Managing Director) | 이원철