Non-Destructive Inspection of Concrete Structures by Noncontact Acoustic Inspection Technology Using Acoustic Irradiation Induced Vibration

Abstract

Tapping inspection is generally used for the inspection of concrete structures, but as the number of skilled workers decreases, the efficiency of inspection work must be improved. Various methods have been developed, but only a few of them have been linked to the improvement of work efficiency, because they must be used close to the inspection surface. Therefore, a noncontact acoustic inspection technique using acoustic-irradiation-induced vibration and a laser Doppler vibrometer has been developed, which enables a noncontact inspection similar to a hitting inspection from a long distance. Since verification experiments on specimens and actual structures have already been conducted and the effectiveness of this technique has been clarified, the latest trends will be introduced.