Speaker
Description
Abstract. Re-refined engine oil bottom (REOB) is a non-distillable residuum of waste engine oil that has been used as a softening agent for asphalt binders since the 1980s. While some researchers believe in the positive effect of REOB on pavement performance, many state agencies are concerned with the potential detrimental effect of REOB. Thus, a clear understanding of the effects of REOB on the rheological properties of asphalt binder is necessary. This study blended a REOB from a single source with an unmodified PG 64-22 binder at various REOB contents (0%, 3%, 6%, 9%, and 12%). An X-ray Fluorescence (XRF) test was used to measure the metallic component contents in the blended binders. The blended binders were also tested to evaluate the rheological properties using the dynamic shear rheometer (DSR) and bending beam rheometer (BBR). The results showed that adding REOB reduced the stiffness of the blended binders at both high and low temperatures, indicating that REOB can be used as a softener. Considering the small fraction of metallic wastes (i.e., 0.67%) detected by XRF in the REOB used in this study, the softening effect of the REOB on asphalt binder was solely due to the oil (99.33%) present in the REOB.
