弾性波法を適用したコンクリート内部の空隙および鉄筋位置の推定に関する実験的研究

Abstract

In this study, the elastic wave method was applied to estimate the location of void and steel bar, as the fundamental investigation to establish a new non-destructive technique predicted from the frequency characteristics of elastic wave propagating through concrete. Following results were obtained in the present study : 1) The locations of voids and steel bars can be most accurately estimated by using a resonance technique among three types of techniques applied in this experiment (resonance technique, ultrasonic pulse-echo technique and ultrasonic pitch-catch technique). 2) The frequency components in the range of 200-250kHz of the frequency transfer function become prominent with increasing the accuracy to predicte the thichness of cover mortar for steel bar. 3) The amplitude and energy of the measured waveform increase, and the ultrasonic pulse-echo is detected more easily with the increase of diameter and the decreae of thichness of cover mortar for void.