GPR research on damaged road pavements built in cut and fill sections

We present the GPR (Ground Penetrating Radar) results dealing with flexible road pavements located on cut and fill sections. The aim is to evaluate the road damage (particularly the ramified cracks) taking into consideration also the cut and fill sections height and the traffic load. GPR evaluation was carried out on 14 sites selected in the secondary non-urban road network of L’Aquila, a medium-size urban area of Central Italy. Stress induced by traffic load generally affects a road section thickness of about 1.5 m. A monostatic 1600 MHz GPR antenna was used because it is quite high-resolution when inspecting road damage. GPR acquisition was carried out in damaged and adjoining undamaged road sites, to compare GPR data of the two areas. GPR data analysis was based on the sweep-rectified power approach to evaluate the radar signal attenuation curve vs. depth, which permitted to single out different road types of damage and to discuss the factors which caused them.