Evaluation of effect of moisture on fatigue performance of pavement designed with recycled asphalt mixtures

The moisture resistance of dense- and gap-graded bituminous mixes prepared with the replacement of virgin aggregates and fresh bitumen with reclaimed asphalt pavement (RAP) was evaluated using indirect tensile strength (ITS) and resilient modulus ( M r ). The mechanistic analysis was performed to estimate the effect of moisture resistance on the fatigue performance of thin and thick pavement sections designed with dense- and gap-graded bituminous mixes. The ITS ratio and M r ratio results indicate that the resilient modulus ratio is more sensitive to moisture damage in bituminous mixes than the ITS ratio. In addition, the results of the fatigue life ratio indicated that the gap-graded mix prepared with different RAP content has better resistance to moisture-related cracking in thick pavement sections than the dense-graded mix. However, the effectiveness of gap-graded and dense-graded mixes prepared with different RAP content on moisture-related cracking depended on the subgrade strength for thin pavement sections.