(97b) Effects of Waste Vegetable Oil in High Concentration Recycled Asphalt Pavement Binder Mixes

As the world’s focus has shifted toward environmental sustainability and the costs of roadwork have put economic stress on governments, researchers have been investigating viable ways to increase the use of Recycled Asphalt Pavement (RAP). Simultaneously, there is critical importance to find use for large quantities of waste cooking oil produced annually in the United States. The objective of this research is to investigate the rejuvenating effects of Waste Vegetable Oil (WVO) in high RAP binder concentration mixes, as well as the effects these mixes experience when aged. The ability to utilize WVO in high concentration RAP mixes would be incredibly beneficial because of the much lower costs of road materials, lower amounts of asphalt and vegetable oil waste, and the possibility of road conditions deteriorating less rapidly. The RAP binder used in this experiment was simulated using accelerated aging methods with a Rolling Thin Film Oven (RTFO) and Pressure Aging Vessel (PAV). A single type of vegetable oil (Mel-Fry Essential) was used to isolate the effects of chemical composition. Different ages of the oil during food preparation were collected to measure the changes in properties with use. Binder mixes were prepared with differing concentrations of oil (0 and 10%), RAP (0, 40, and 60%), and virgin binder. These mixes’ rheological properties were measured when unaged, RTFO aged, and PAV aged. The rheological properties of these RAP mixes were tested through the means of Rotational Viscometry (RV) and Dynamic Shear Rheometry (DSR). The results of these experiments have shown that the WVO used can effectively lower the viscosity and stiffness of high concentration RAP binder mixes. Further, WVO in RAP mixes has shown to provide significant resistance to effects of aging over time. Because of these findings, future research on WVO in binder mixes will be conducted to investigate the mechanism of this aging resistance, as well as the performance of the binder and mixes in other tests such as Bending Beam Rheometry (BBR), Dynamic Contact Angle (DCA), and moisture resistance.