Research on reinforcement corrosion detection method based on the numerical simulation of ground-penetrating radar

Both the reinforcement depth and the electromagnetic properties of the concrete cover dramatically affect the steel reinforcement reflection wave amplitude in ground-penetrating radar (GPR), resulting in significant errors when evaluating the corrosion status of the reinforcement using the reflection wave amplitude. In response to this issue, this paper proposes a normalized amplitude-two-way travel time-relative permittivity (A-TWTT-epsilon r) method, which, compared to traditional single-shot detection methods, enhances the effectiveness of steel reinforcement corrosion detection through 3D space. The amplitude and TWTT parameters are extracted using the A-scan waveform at the vertex of the steel reinforcement, while epsilon r is determined through hyperbolic feature scatter fitting. Finally, the feasibility of the proposed method was verified using COMSOL numerical simulation data. The results showed that the proposed A-TWTT-epsilon r amplitude-correction method could simultaneously correct for the attenuation effect of differences in the reinforcement depth and concrete electromagnetic properties on the amplitude. The proposed method could enable single-shot corrosion detection by GPR, yet further validation is needed in complex experimental and on-site environments.