Factors affecting the delamination detectability in GPR images

摘要

Concrete delaminations are commonly-found defects in bridge decks and rigid pavements. While previous studies reported that ground-penetrating radar (GPR) could visualize those defects in many instances, it is still unclear about the factors that may affect such an application. For this reason, this study aimed to develop an understanding of the factors that influence the detectability of concrete delamination in GPR images/signals. Concerning the methodology, the study was conducted using both synthetic data generated from a GPR simulation program, and real data collected on a concrete bridge deck specimen. The analysis of such image data indicated the following. First, there is always some energy reflected from concrete delamination. However, its shape and strength are affected by the thickness of the delamination, the material (air or water) within it, and the peak (most energetic) frequency of the emitted signal. Second, the depth of delamination and its position relative to reinforcing steel bars might impact its visibility in GPR images.