超音波スペクトロスコピー法を適用したコンクリートの劣化度評価に関する研究(その1) : 高応力繰返し荷重を受けたコンクリートの場合

Abstract

The waveform of ultrasonic pulses through concrete contains various informations related to the internal structure of concrete. It may bepossible to clarify the internal structure of concrete by analyzing the measured waves in detail. Thus, an ultrasonic spectroscopy is useful to evaluate the quality of concrete by measuring the frequency characteristics of ultrasonic pulse through concrete. The ultrasonic spectroscopy technique was applied to evaluating the quality of concrete damaged by the cyclic loading, as the fundamental investigation to establish a new non-destructive testing technique for concrete. The ultrasonic pulse velocity, energy and maximum amplitude of the measured waveform decreased, but the energy moment and energy dispersion increased with the progress of accumulative damage of concrete subjected to the cyclic loading. The frequency components higher than 150kHz gradually diminished, and those lower than 150kHz of the frequency transfer function became prominent significantly with the progress of damage of concrete during the cyclic loading.