Evaluation of the Effects of Waste Engine Oil on the Rheological Properties of Asphalt Binders

Abstract

This study evaluated the feasibility of using waste engine oil (WEO) to partially replace virgin asphalt binder. Two base asphalt binders (PG 64-28 and PG 76-22) were blended with three different WEO percentages of , 5, and 1%, respectively. First, the effects of WEO on two base asphalt binders were evaluated by the mass loss during rolling thin film oven (RTFO) and by performance grading (PG) test. Second, based on the developed WEO-PG formula, two binders were designed to have equivalent low temperature PG. Subsequently, the rheological properties of these two low-PG-equivalent binders were evaluated by PG, multiple stress creep recovery (MSCR), frequency sweep, and monotonic fracture tests. Results of the study showed that use of higher WEO content resulted in a decreased PG for base asphalt binder, but the amount of decrease was dependent on the base asphalt type. With the presence of WEO, the binders having equivalent low-temperature PG did not necessarily exhibit similar stiffness or fracture property. WEO had a softening effect, and an improved elasticity and recovery property on the base asphalt.