弾性波法による外壁タイルの剥離およびコンクリートのひび割れ評価に関する実験的研究

Abstract

The waveform of elastic wave propagating through concrete contains various informations related to the internal structure of concrete. It may be possible to clarify the defects in concrete, such as tile separations and cracks, by analyzing the detected elastic wave in detail. The elastic wave method was applied to evaluate the tile separation and crack depth, as the fundamental investigation to establish a new non-destructive technique predicted from the frequency characteristics of elastic wave propagating throug hconcrete. Following results were obtained in this study : 1) The frequency characteristics of measured wave are very affected by the setting locations of transducers to emit and detect the elastic wave, even if the width of tile separation is same. In general, when both transducers are setted on the separate portion of tile, the measured wave is most sensitively affected by the change of sparating widthof tile. 2) The amplitude and energy of the measured waveform increase, and the frequency components lower than 150kHz of the frequency transfer function become prominent significantly with the increase of separating width of tile. 3) The amplitude and energy of the measured waveform decrease, and the frequency components lower than 50kHz of the frequency transfer function become prominent significantly with the increase of crack depth.