Aging Property of Oil Recycled Asphalt Binders with Reclaimed Asphalt Materials

The reuse of high content of reclaimed asphalt pavement and reclaimed asphalt shingles in hot mixtures by adding recycling oils has attracted wide attention and interest in the paving industry. However, the aging property and the durability of oil recycled asphalt binders with reclaimed asphalt materials are not well understood. This study prepared 12 oil recycled asphalt binders with base binder, extracted binders from reclaimed asphalt pavement and reclaimed asphalt shingles, and three types of oils, including two bio-oils and one re-refined engine oil bottom oil. Multiple stress creep recovery and oscillation tests were performed to evaluate the rheological change with aging, and Fourier-transform infrared spectroscopy was used to track the chemical evolution. Aging performance of these blends was evaluated using the aging indexes. Results showed that the recovery and nonrecoverable creep compliance were highly related. The aging indexes of nonrecoverable creep compliance at 3.2 kPa and complex modulus indicated that adding oils may impair the durability of asphalt binders with reclaimed asphalt materials. However, the aging index of carbonyl suggested that the oils do not have much effect on the chemical reaction (oxidation). The correlating analysis indicated that rheological and chemical change had a good correlation relationship, but also showed material dependency.