Enhancing the Performance of Asphalt Mixtures Containing High RAP Content with the Use of Different WMA Technologies

The production of Warm-mix asphalt mixtures in conjunction with reclaimed asphalt pavement (RAP) has received considerable interest in recent years for economic and environmental reasons. The primary objective of this project is to enhance the performance of asphalt mixtures containing RAP in Region 6 using different WMA technologies. In this project, the effect of utilizing 0%, 25%, and 35% RAP contents on the performance of different WMA mixtures against rutting, moisture damage, and fatigue cracking are evaluated. The effects of the WMA technologies on the rutting performance of the asphalt mixtures and recovered binders were investigated using loaded wheel tracker (LWT) and multiple stress creep recovery (MSCR), respectively. Further, the influences of these technologies on the cracking performance of the asphalt mixtures and recovered binders were evaluated using Semi-Circular Bending (SCB) and linear amplitude sweep (LAS) test, respectively. Based on the results, WMA mixtures containing no RAP have a lower value of the Jnr compared to the HMA control mixture. This is an indication of the better performance of the WMA mixtures against the permanent deformation. Moreover, findings from the LWT test completely agree with the results from the MSCR test. On the other hand, the fracture resistance is found to be enhanced with the incorporation of a higher percentage of RAP and WMA technologies. Overall fracture resistance performance of WMA-RAP mixtures is observed to be better compared to HMA-RAP mixtures. Moreover, the results of the LAS test show that the incorporation of RAP materials and WMA technologies is associated with improved fatigue life of the WMA-RAP mixtures.