The depth of a surface-breaking crack in a concrete slab is characterized by using non-contact surface wave transmission measurements. Two air-coupled sensors are used to measure surface waves across surface-breaking cracks with varying depths from 0mm to 100mm in a concrete slab (1500X1500X180mm3). Resulting transmission coefficient and crack depth relation from a series of experimental studies shows a good agreement with theoretical results previously obtained by the author.

• 기성훈(동아대학교 건축공학과 조교수, 공학박사) | Kee, Seong-Hoon