Ground Penetrating Radar: Pavement Layer Thickness Evaluation

Abstract

The following report demonstrates the accuracy of using Ground Penetrating Radar (GPR) to determine the surface layer thickness for both asphalt and concrete pavements. In addition, tests were conducted to identify GPR's repeatability on dry pavements and GPR's ability to determine pavement layer thicknesses in wet conditions. An attempt was made to determine the number of actual field cores necessary to accurately post-process radar data into thickness values. The equipment used to perform these evaluations was Geophysical Survey Systems Inc.'s model SIR 10B with the model 4108 (1 GHz) air-launched horn antenna. Preliminary results indicate that when ground truth cores were used, GPR calculated thicknesses varied from actual core thicknesses by the following: Asphalt less than 2 in. (+/-10.32% to +/-0.40%; +/-0.20 to +/-0.01 in.); Asphalt bases of 8 to 9 in. (+/-2.73% to +/-1.34%; +/-0.24 to +/-0.12 in.); and Concrete 9 to 12 in. (+/-14.24% to +/-0.05%; +/-1.66 to +/-0.01 in.).