打撃試験によるコンクリートの浮き検査

抄録

We investigated the method of detecting a void in the concrete structure by the impact test. The shock waves generated by hitting the concrete propagates along a surface and through the inside of a concrete. Sensors placed on several locations apart from the impact point measure both a surface wave and a wave passing through internal concrete. We separated a internal wave from a surface wave by the method of the independent component analysis to detect a void.

At first, we checked the effectiveness of the method by simulation. Then we made a test system. Our system was composed of a impact part and sensor parts. At a impact part, a steel ball was shot by a spring to a concrete surface. At sensor parts, a small block attached an acceleration sensor was pressed to a concrete surface by a heavy mass. By this way, high frequency components of a shock wave were measured. At last, our test equipment showed a good performance to detect a void in a concrete structure.