Ground penetrating radar assessment of flexible road pavement degradation

GPR method was applied on degraded road pavements built in cutting sections with the aims to find correlations between: (i) types of damage, (ii) depth of cutting sections, (iii) traffic load and (iv) GPR scans acquired with a 1600 MHz antenna. Five types of damages were investigated: (i) longitudinal and transversal cracks, (ii) longitudinal cracks only, (iii) transversal cracks only, (iv) ramified cracks and (v) failures. To determine the impact of cutting depth and traffic load on road pavement degradation, the study was focused on high (depth > 4 m) and low (depth < 2 m) cuttings, as well as on heavy traffic (average daily traffic > 4000) and low traffic (average daily traffic < 1000) road pavements. Twenty sites were selected in the non-urban road network of L’Aquila (central Italy). Road integrity was assessed via quantitative analysis of GPR signal attenuation vs. depth curves (rectified power diagram).