Evaluation of the Impacts of Re-Refined Engine Oil Bottoms (ReOB) on Performance Graded Asphalt Binders and Asphalt Mixtures.

摘要

This report provides findings of a laboratory study that assessed the performance grade (PG) of asphalt binder modified with re-refined engine oil bottoms (ReOB), and the performance of hot-mix asphalt (HMA) using these modified binders. The selected asphalt binder PG for this study was PG 58-28. Asphalt binder was blended with two ReOB products from two different manufacturers (CC-type and SK-type) at various percentages of ReOB (3%, 6%, and 9%). All asphalt binders (six different blends in addition to the control) were characterized using the SuperPave asphalt binder PG system. Even though the final PG of all blended asphalt binders was PG 58-28, a reduction in the stiffness of binder at intermediate and low temperatures was observed with increasing ReOB content. Some of the critical engineering properties of asphalt mixtures prepared with CC- and SK-type ReOB were evaluated. The mixtures’ resistance to permanent deformation was evaluated using the Hamburg wheel track test (HWT). The HWT did not show any significant difference in permanent deformation of HMA with 9% ReOB compared with the control mix. The low- and intermediate-temperature cracking resistance was examined using the semi-circular bending beam (SCB) test at three aging levels: short-term, long-term, and extended long-term. Fracture energy and strength values obtained from the low-temperature SCB tests were comparable for all mixtures with increasing ReOB content. The SCB test results at 25°C (77°F) showed a consistent reduction in fracture energy and flexibility index (FI) with an increasing amount of ReOB at different levels of aging. Similar performance was observed for both CC- and SK-types of ReOB. The impact of ReOB in the mixes’ fracture properties including fracture energy and FI was evident at intermediate temperatures. 17. Key