10 Pages

Nondestructive evaluation of horizontal cracks in RC slabs by impact elastic-wave methods

ByT. Kamada, S. Uchida, K. Nakayama, H. Mae & T. Tamakoshi

ABSTRACT: In this study, a reinforced concrete slab specimen with asphalt pavement and artificially simulated horizontal cracks in concrete was developed. Horizontal cracks in the specimen were detected by the impact elastic-wave method, and the validity of test results were verified by impact response analysis. An attempt was also made to identify the effects that the position of the center of crack relative to the points of input and receipt of elastic wave had on the propagation behavior of wave. As a result, the peak frequencies in the frequency spectrum obtained from the test and analysis were found to be nearly identical to the frequency of P-wave reflections from cracks. It was also revealed that if elastic wave is input and received on the pavement surface right above a crack, the existence and depth of the crack can be identified from the peak frequency.