Ex) Article Title, Author, Keywords
New Phys.: Sae Mulli 2021; 71: 310-315
Published online March 31, 2021 https://doi.org/10.3938/NPSM.71.310
Copyright © New Physics: Sae Mulli.
Yeong-Won CHOI1, Yun-Taek YEOM1, Hak-Joon KIM1, Sung-Jin SONG1, Sung-Woo RYU2, Hun-Hee KIM3, Jae-Suk PARK3, Sung-Duk KWON4*
1School of Mechanical Engineering, Sungkyunkwan University, Suwon 16419, Korea
Multiple layers formed by multiple objects can be easily found in concrete structures. Defects occurring on the exterior of the structure are typically cracks and leaks in the outer wall, and defects occurring at multiple layers hidden on the back of the outer wall are known as corrosion of reinforcement and the occurrence of voids in concrete. Among them, studies on inspecting voids in concrete at multiple layers are insufficient. Therefore, in this paper, an inspection study was conducted using a microphone, which is a non-contact sensor, to check the differences in signals caused by voids at various void depth. For this purpose, a specimen and blocks capable of implementing various void depths were produced, and an actuator was used as an impact source. For the acoustic signals collected according to void depth, after signal processing to improve the S/N ratio, the acoustic energy for each void depth in the frequency domain was calculated, and an evaluation of voids occurring in the multiple layers was performed through comparison and analysis
Keywords: Multiple layer, Void, Impact echo method, Microphone, Acoustic signal