Laboratory study on mechanical properties of composite pavement under partial compression-shear load

Abstract

To investigate the mechanical characteristics of asphalt pavement over rigid base, a loading device with an inclined indenter was designed to simulate the partial compression-shear of moving traffic loading. A series of tests were conducted to comparatively study the mechanical properties, including compression-shear strength and fatigue life of composite pavement. Temperature and asphalt overlay thickness were identified as the two most influencing factors on compression-shear strength, based on which a strength model was proposed. Substantial differences were found between asphalt pavement with and without rigid base in energy distribution and damage evolution. Due to the support and confinement provided by the rigid base, the mechanical properties and resilience of asphalt pavement are significantly improved: the fatigue life of composite pavement specimen was nearly 35% higher than that asphalt pavement specimen without rigid base. Fatigue life was significantly reduced by heavy load, whilst proportionally increased with asphalt overlay thickness. Fatigue life prediction model of asphalt layer over rigid base was characterized and validated by the multi-stress fatigue test. The results can provide reference for the design and promotion of composite pavement.