Evaluation of the Correlation between Performance Parameters of Asphalt Binder and Mixture in the RAP-Containing Asphalt Mixtures

In asphalt pavement hot recycling, reclaimed asphalt pavements called "RAP" and aged bitumen extracted from them are known as reclaimed asphalt binder (RAB). In this study, the performance of RAB-containing binder compounds with different percentages of recycled bitumen (0, 25%and 50%) and RAP-containing asphalt mixtures with varying contents of the RAP (0, 25% and 50%) were compared in two conditions (with and without a rejuvenating agent). The main purpose of this study was to evaluate the relationship between bitumen’s performance parameters and asphalt mixture’s performance parameters. Therefore, the correlation between the parameters obtained from the fatigue and the rutting tests of binder compounds (linear amplitude sweep test and multiple stress creep and recovery test, respectively) and parameters obtained from the fatigue and rutting tests of asphalt mixtures (four-point beam fatigue test and dynamic creep test, respectively) were investigated for the first time in RAP-containing asphalt mixtures. The results indicated that the behavior of asphalt mixtures in fatigue and rutting resistance was agreed with the behavior of the binder compounds in the linear amplitude sweep and multiple stress creep and recovery tests. Besides, there were statistically good correlations between the binder's fatigue life and asphalt mixtures' fatigue life and relatively good statistical correlations between binder's rutting resistance and asphalt mixtures' rutting resistance in the RAP-containing asphalt mixtures.