Fatigue Properties of Asphalt Rubber Mixtures

Abstract:

According to AASHTO TP8 in American standard specification,three point bending fatigue loading test method was modified to evaluate the fatigue properties of asphalt rubber (AR) mixture according to Arizona specification.Material test system was used to straincontrol mode.Test result shows that the relation between fatigue life and strain level of AR gapgraded mixture is in a good linearity.Compared to traditional AC-13 gradation mixture which two conventional binders including polymermodified asphalt (PMA) and conventional asphalt are used,AR gapgraded mixture presents a better fatigue performance.Rutting test is also used to evaluate the high temperature performance,AR gapgraded mixture whose asphalt content is 1.6 times higher than PMA mixture’s still shows the same high temperature performance as PMA mixture.The excellent fatigue performance and high temperature performance of AR mixture is mainly due to three reasons: high crumb rubber content in asphalt makes the AR super high performance;gap gradation makes the mixture accommodate high asphalt content;high asphalt and crumb rubber contents in asphalt make the AR mixture excellent fatigue performance.