Development and Experimental Verification of Underwater Concrete Defect Detection Device Using Impact Echo Method

To address the challenges of non-destructive testing of underwater concrete structures, an innovative underwater impact echo detection device is introduced and its performance is evaluated through experiments on indoor underwater concrete samples with defects. In the process of device development, this study compares electric excitation and pneumatic excitation and explores the applicability of the ICP accelerometer and the hydrophone in underwater impact echo concrete testing. According to the results, (1) the combination of electric excitation and ICP accelerometers enables the precise identification of defect areas, depths, and the sample's thickness; (2) electric excitation demonstrates superior signal stability and consistency over pneumatic excitation, while the latter potentially leads to signal distortion; (3) hydrophones can identify the defect areas, but provide insufficient precision for determining their depth. A scientific foundation and technical support are provided for underwater concrete defect detection, and a reference is offered for related engineering practice.