Coda Wave Interferometry 기법을 이용한 콘크리트 응력 상태에 따른 초음파 거동 특성 분석

Abstract

In this study, acoustoelastic effect of ultrasonic coda wave in concrete is analyzed using coda wave inteferometry technique. Static stress state in concrete structures should be monitored for safety assessment as it can be changed due to physical and environmental actions during their service life. In current static stress monitoring techniques for concrete structures, reference stress should be reset with sensor replacement, which is problematic in quantitative assess ment of static stress change. Coda wave means a reverberation components of ultrasonic waves appearing after large dominant wave component passed. The study did ultrasonic-measurements on a water cement ratio and find aggregate ratio depending on the state of static stress. It showed that time delay increased in the water cement ratio and rate of increase of time delay was almost the same in the find aggregate ratio. The result showed that it is applicable for the Coda wave iterferometry technique to find out behavioral characteristics for ultrasonic waves depending on the concrete stress state.