Evaluation of air-coupled impact echo for the non-destructive monitoring of concrete structures

Non-destructive testing (NDT) technologies are a key asset for monitoring insidious changes in concrete structures, regardless of whether these originate from environmental conditions or intrinsic material degradation phenomena. NDT encompasses multiple complementary inspection methods capable of detecting different defects and features in structures and providing data-driven approach solutions to the maintenance of large infrastructures. Particularly, the impact-echo inspection method is effective in detecting embedded defects in concrete and in measuring the structure’s thickness. Yet, the application of this NDT method remains sporadic due to the time-consuming and laborious nature of the manual process involved in its data acquisition. The recent transition from contactbased impact-echo towards air-coupled impact-echo development provides new opportunities for improving the efficiency and automation level of the method. This research explores the recent developments in air-coupled IE technology and provides a comparison between different designs for the development of a portable and functional air-coupled impact-echo device.