Feasibility Study for Evaluating the Moisture Resistance of Asphalt Mixtures Containing RAP Using Pull-Off Test

摘要

Binder adhesion has an important effect on the properties of asphalt mixtures. In asphalt mixtures containing reclaimed asphalt pavement (RAP), rejuvenating agents have been used to restore the adhesive properties of an aged binder. In this study, a new rejuvenator was investigated to discover whether it can improve the moisture susceptibility of mixtures containing RAP. For this purpose, first, the effects of a new rejuvenator on the moisture resistance of binder compounds containing different percentages of aged binder were evaluated. Second, the moisture susceptibility of asphalt mixtures with different RAP contents (25, 50, 75, and 100 %) were investigated with and without rejuvenator utilization. The pull-off test was performed to evaluate the adhesion of binder compounds; indirect tensile strength and resilient modulus tests were utilized for evaluating the moisture susceptibility of the asphalt mixtures. Meanwhile, for the first time, the relationship between the pull-off test and the moisture susceptibility parameters of asphalt mixtures was established. The results indicate that the use of the rejuvenating agent improved the moisture resistance of the asphalt mixtures containing RAP as compared with the control mixture and mixtures without a rejuvenator. According to the obtained correlations, the pull-off test can be used as a rapid and economic test to estimate the moisture sensitivity of asphalt mixtures.