Evaluation of fatigue behavior of high reclaimed asphalt binder mixes modified with rejuvenator and softer bitumen

Reclaimed asphalt binder (RAB) is aged bitumen extracted from milling of deteriorated asphalt pavement materials. The objective of this study was to analyze the effect of a new rejuvenator as well as softer bitumen on regenerating fatigue characteristics of the RAB-containing binder mixes as compared to the virgin (control) binder. In this study, firstly fatigue resistance of binder mixes containing different percentages of RAB was evaluated by temperature sweep, linear amplitude sweep (LAS) and time sweep tests. Secondly, correlations between different fatigue test methods were established. Results showed that use of rejuvenating agent improved fatigue performance of binder mixes containing up to 100% RAB to the level of that of the control binder. On the other hand, the softer bitumen improved fatigue behavior of asphalt binders containing up to 50% RAB in comparison with the control binder. Based on the obtained results, the current fatigue Superpave criteria (G*.sin delta) correlated well with parameter B (LAS parameter). In addition, the fatigue lives obtained from the LAS test have good correlation with strains at peak stress in stress-strain curve. Furthermore, Results indicated that there was a fair agreement between fatigue lives obtained using the LAS and the time sweep tests. (C) 2018 Published by Elsevier Ltd.