Laboratory Comparison of Rejuvenated 50% Reclaimed Asphalt Pavement Hot-Mix Asphalt with Conventional 20% RAP Mix

The Maine Department of Transportation (DOT) currently allows 20% reclaimed asphalt pavement (RAP) in base and intermediate courses. To help the Maine DOT decide whether RAP could be increased to 50%, this study evaluated the critical laboratory properties of hot-mix asphalt with 50% RAP materials and rejuvenator. The scope of work consisted of preparing 20% and 50% RAP mixes with and without rejuvenators and testing compacted specimens for their volumetric properties, moduli, indirect tensile strength, moisture susceptibility, and low- and intermediate-temperature cracking potential. Two rejuvenators were used: (a) generic waste vegetable oil and (b) proprietary, commercially available rejuvenator. Virgin binder, extracted RAP binder, and extracted binder from recycled mixes were tested for continuous performance grading. The results showed that rejuvenators improved the properties of high RAP mixes, and the performance of rejuvenated 50% RAP mixes was equal to that of the currently allowed 20% RAP mixes. Results from semicircular bending tests were used to evaluate and quantify the effect of rejuvenators on mixes with high RAP content. Field trials of 50% RAP mixes were recommended as a result of the study.