3D GPR monitoring of artificial debonded pavement structures during accelerated tests
Résumé
The paper gives an overview of 3D GPR experiment to survey debonding areas within pavement structure during accelerated pavement testing on the IFSTTAR’s fatigue carrousel. Several artificial defects (tack-free, geotextile and sand-based) have been embedded during the construction phase between the top and the base layers. The data collection was organized in a two-stage experiments and covers the full life-cycle of the pavement structure. During the first stage that took place in 2012-13 leading to 300 kloading cycles, the structure revealed no clear degradation. Then, the second measurement campaign was performed in 2019 and lasted up to 720k loadings, until revealing a strongly degraded pavement surface. 3D GPR data were collected at 396, 500, 600 and 720 kloading cycles. They were completed by conventional 2D ground-coupled 1.5 and 2.6 GHz measurements in transverse and longitudinal directions. Radar data at 1.5 GHz are processed and compared on the three major defects.