Use of GPR for thickness measurement and quality control of flexible pavements

The performance of ground penetrating radar (GPR) in estimating the layer thicknesses of flexible pavements was evaluated. The results were based on field data collected from the Virginia Smart Road's pavement test facility, from a newly built section of a state highway (Route 288, VA), and from a section of an in-service interstate highway (I-81). Based on the collected data, current GPR analysis approach failed to detect layer interfaces in some circumstances because of physical limitations (such as low dielectric constant contrast between the layers combined with relatively high material loss or the presence of thin layers, compared to the GPR resolution, within the surveyed pavement system). However, GPR was feasible nondestructive tool for estimating the layer thicknesses of hot-mix-asphalt layers, provided that the appropriate data analysis technique for the type of surveyed pavement is used. The type of GPR system and the suitable data analysis technique depended on the application and the level of accuracy needed in the project. This is an abstract of a paper presented at the Association of Asphalt Paving Technologists 2004 Technology Sessions (Baton Rouge, LA 3/10-18/2004).