Fatigue Performance Of Asphalt Mixes

Fatigue cracking is one of main destruction forms of asphalt pavement. Research on fatigue performance of asphalt mixture can improve the anti-fatigue performance of asphalt mixture and prolong the service life of asphalt pavement. The phenomenological fatigue model is mainly used to study asphalt mixture fatigue performance both indoor and abroad. Fatigue life is often different under different test methods and test conditions for the same asphalt mixture, which will affect the objectivity of evaluation. This paper based on the asphalt beam bending, for preliminary explore the fatigue equivalent temperature of asphalt pavement in Chongqing area , and fatigue life prediction model with different levels of confidence and reliability of the asphalt mixture as well as the fatigue life correction factor F of asphalt pavement.First of all, analyse the road structure's temperature field of the Chongqing area using the Finite Element method, preliminary get the temperature field in summer and winter of asphalt pavement in Chongqing area and and then determine the equivalent fatigue temperature of asphalt pavement in Chongqing area; and carry out the temperature damage analysis of asphalt pavement in Chongqing area.Then, experiments of constant strain controlled beam bending fatigue under different conditions for AC13, AC16, AC20 asphalt mixture were carried on, fatigue performance prediction model with different levels of confidence and reliability of the asphalt mixture are established. Provide theoretical and experimental basis for the establishment of the strain design indicators as a design system for asphalt pavement and use of gray system theory to analyse the factors that impacting asphalt mixture fatigue life.Finally, making use of Elastic Fracture Mechanics theory and Finite Element method to calculate crack stress intensity factor and account the semi-rigid asphalt pavement fatigue life using the Paris formula., then get the fatigue life correction factor F of semi-rigid asphalt pavement.