Research on Influence Factors of AR Mixture Fatigue Performance

Abstract:

According to AASHTO TP8 in American standard specification,threepointbendingfatigueloading test method was modified to evaluate the fatigue performance of asphalt rubber(AR)gapgraded mixture.Material test system(MTS)and straincontrol mode were used to evaluate influence factors of fatigue performance of AR mixture.According to the research,the fatigue life of AR mixture increases with the asphalt content when the asphalt content is between 7.0%~8.5%.The decrease of air voids will also improve the fatigue performance if VFA is within a reasonable extent.The best fatigue performance comes out when the crape rubber modifier(CRM)content in AR is 19%.Air voids have the greatest influence on fatigue property of AR mixture and VFA(voids filled with asphalt),asphalt content and CRM content also influence the property obviously.When AR mixture based on fatigue performance is designed,lower air voids first be confirmed according to the engineering requirement and then higher asphalt content and higher CRM content is advised.