Study On Viscoelastic Continuum Damage Fatigue Characters Of Asphalt Mixtures

The asphalt concrete mixture is characterized as a viscoelastic material, as well as the most significant engineering material widely adopted in road pavement constructions. Meanwhile, fatigue cracking of asphalt pavement is known to be one of the most dominated distresses, which results in the emphasizingon pavement maintenances and operation managements. The research focuses on viscoelastic character of asphalt mixture and switches the hackneyed theories that based on static modulus to a different perspective, which devotes to improve the performance and life span of asphalt pavement as well as the design progress of pavement structure and response under loads.Firstly, this paper conducted a series of dynamic modulus test with AC-13 and AC-13 mix together carbon black of asphalt mixtures on a Simplified Performance Tester machine, and processed nonlinear fitting utilizing Origin software. Based on its data analysis, the dynamic modulus and phase angle master curves were determined, then viscoelastic dynamic parameters were obtained and viscoelastic characters and effect of modifiers on various asphalt mixtures were analyzed. Secondly, this paper also conducted dynamic modulus test with AC-13, AC-16 and AC-20 of asphalt mixtures, determined the master curves, and contrastively studied viscoelastic characters. Finally, this paper obtained elastic constitutive equations according to simplify the Schapery model that based on elastic-viscoelastic theories etc. Accordingly Linear Viscoelastic Continuum Damage Model integrated with Continuum Damage Model was established, and a new approach based on Viscoelastic Continuum Damage Mode to testify the fatigue cracking was innovated.