Ground-Penetrating Radar Signal Characterization for Non-destructive Evaluation of Low-Range Concrete Sub-surface Boundary Conditions

The use of nondestructive sensing technologies is critical in the evaluation of concrete conditions and structural integrity. In our previous experimental studies, we showed the use of the ground-penetrating radar (GPR)-based nondestructive evaluation method to examine low-range concrete subsurface boundary conditions. As the characterization of GPR signals based on multiple factors is crucial for furthering the accurate conditions of concrete subsurfaces, we investigate the GPR signals in this letter by simulating electromagnetic wave propagation on concrete models through the use of the finite-difference time-domain method. The effects of concrete relative permittivity, the standoff distance of GPR from the top surface of concrete, the operating frequency of GPR, and the depth height of multilayered concrete on the GPR measurements were all investigated, and conclusions were established. Through the outcomes of this investigation, we will be able to choose the most appropriate operating frequency for the GPR for collecting measurements on concrete infrastructures at the most effective standoff distance to the surface and subsurface depths under a variety of relative permittivity conditions in various locations.