Full-scale experimental and numerical analysis of pavement surface layers responses to different loading conditions

While base pavement layers have been often studied due to their main contribution to fatigue resistance, less studies have focused on surface layers. This study investigates the mechanical response of surface layers under different loading conditions, including single and tridem axles and different interface bonding conditions, using experimental and numerical approaches. Two full-scale pavements with different types of surface layer materials, were subjected to those loading configurations. Strain gauges and optical fibres embedded at different depths were used to analyse strain responses under varying surface layer temperatures. Results show that tridem axle generates higher strains, due to interaction between the closely spaced wheels. In addition, one structure presented a well bonded surface layer, leading to compressive strains in the surface layer; on the other structure interface debonding developed tensile strains at the bottom of the surface layer. Numerical predictions using Viscoroute©2.0 captured the effects of axle configurations and interface conditions.