Research on 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 indicates a better fatigue performance. Rutting test also is 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 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 make the AR super high performance, gap gradation make the mixture accommodate high asphalt content, high asphalt content and high crumb rubber content in asphalt make the AR mixture excellent fatigue performance.