Using Ground Penetrating Radar as an Assessment Methodology in Roadway Rehabilitation

In assessing the existing condition of a pavement structure, locations of past maintenance activities are often overlooked, or concealed by rehabilitation activities such as mill and overlays. Potential problem areas may not be evident at the time of evaluation, and if ignored could increase the rate of deterioration of the pavement structure. Proper identification of potential problem areas could provide a more accurate assessment of the existing pavement condition and better understanding of the performance of a pavement structure. Understanding the deterioration of a pavement structure, will in turn allow owner agencies to calibrate forecasting tools in their pavement/asset management systems. Ground penetrating radar (GPR) can be used as a tool for assessing the condition of the pavement structure at locations of surface distress, as well as identifying locations of previous subsurface maintenance activities that are not visible at the surface of the pavement. This paper presents and discusses the subsurface imagery obtained from a GPR survey, identifies several potential subsurface problem areas, and describes the benefits of applying this technology as an assessment tool for the rehabilitation of roadways.