The Research On Fatigue Damage Behavior Of Asphalt Mixture By Indirect Tensile Test

Fatigue cracing of asphalt concrete pavements is one of the major destruction in pavement engineering. Improving fatigue property of asphalt mix is the key of reducing the destruction. As result, the research on fatigue property of asphalt mix has always been the hot spot of the research on road materials and been paid a lot attention by the experts and scholars. Besides, the research on fatigue property of asphalt mix has an impotant engineering meaning to the design of asphalt pavement.The research conducted indirect tensile fatigue tests for six asphalt mixtures under four stress levels in the situation of 15 centi-degrees and 10Hz rate, and collected strain in those experiments by DY-3 to conduct the research on fatigue damage bBehavior of asphalt mixture.It also conducted indirect tensile fatigue tests for AC-13#2 asphalt mixture different rates, temperatures and slot time.Based upon the two-dimensional stress equation for material in indirect tensile testing mode, this paper derived three-dimensional elastic solution for indirect tensile tests. Combiating damage mechanics, this paper defined fatigue damage parameter by stiffness modulus, derived the damage function, and built the elastic damage model for asphalt mixture in indirect tensile test.Based on the elastic force analysis for asphalt mix in the indirect tensile test, this paper analysed the viscoelastic solution of fatigue for indirect tensile test considering the load mode in fatigue tests using elastic-viscoelatic correspondence principle. After processed data of fatigue tests,this paperderived the relationship between dissipated energy and load cycles.Based upon the rearch on the fatigue tests and damage mechanics of asphalt mix, this paper proposed the damage variable using the dissipated energy method, summarized and conclused the law of damage, and derived the non-lineal damage evolution equation.At last, this paper summarized the rearch work, and analysed the deficiency of the rearch that could be improved in the future and provides some advices.