Evaluation of Healing and Constitutive Modeling of Asphalt Concrete by Means of the Theory of Nonlinear Viscoelasticity and Damage Mechanics

摘要

Researchers have proved that existing fatigue failure criteria based on constant amplitude loading tests underpredict the fatigue life of asphalt concrete pavements. Two major differences between laboratory and field loading conditions were addressed in the study: the existence of rest periods and the random sequence of load applications of varying magnitudes. Three mechanisms were identified as influencing the behavior of asphalt concrete subjected to multi-level repetitive loads interrupted by various durations of rest periods: fatigue as a damage accumulation process, relaxation due to the fiscoelastic nature of asphalt concrete, and chemical healing across crack faces during rest periods. A uniaxial constitutive model, developed by employing the correspondence principle in concert with damage mechanics, shows potential as a means of predicting the stress strain behavior of asphalt concrete under realistic cyclic loading.