Evaluation of Asphalt Overlay Permanent Deformation Based on Ground-Penetrating Radar Technology

Permanent deformation in materials can lead to rutting on an asphalt pavement. Rutting poses potential hazard to vehicles running on the pavement because of hydroplaning during wet weather conditions. To mitigate or remedy rutting, it is of critical importance to identify the sources and causes of the permanent deformation. Traditional methods mainly rely on cutting a trench to approach this issue. Despite the accuracy, it is labor intensive and time consuming, not to mention having a destructive characteristic. To improve on these, this study discusses the feasibility of potential use of a non-destructive technology with ground-penetrating radar (GPR). GPR is used to estimate the permanent deformation in an asphalt overlay on top of an existing concrete pavement. The GPR antenna mounted on a moving vehicle could detect pavement layer thickness at a fast speed. It also provides full coverage on the pavement along the driving direction. The permanent deformation is estimated by comparing the layer thicknesses between the right wheel path and lane center. In particular, the results could reveal the permanent deformation involving the following three critical aspects: (1) in which layer(s) the permanent deformation occurs; (2) where the permanent deformation is located along the driving direction; and (3) how significant the permanent deformation is.