Performance improvement and aging property of oil/SBS modified asphalt

Abstract

The main objective of this work is to use the oil to improve the low- and intermediate- temperature performance of styrene–butadienestyrene (SBS) modified asphalt, and how long the benefits of adding oils can stay (aging property) was also evaluated. In this study, one bio-oil and one re-refined engine oil bottom (REOB) were selected to blend with two types of SBS modified asphalt to prepare oil/SBS modified asphalt. The performance improvement, rheological and chemical evolution upon aging process were characterized and tracked by performance grading, master curve, Linear Amplitude Sweep (LAS) test, Bending Beam Rheometer (BBR) test and Fourier Transform Infrared (FTIR) scanning, and the aging indices were calculated, subsequently. The results confirm the performance-improving effect of adding oils, while the bio-oil exhibits higher efficiency than REOB in terms of changing performance-related characteristics. BBR test results at various aging states show that the low-temperature performance mostly depended on the ability of relaxing the internal stress (m-value) other than stiffness. The addition of bio-oil was proved to have an effect of slowing down the deteriorating rate of low-temperature performance. FTIR scanning and aging indices results show that performance-related characteristics and chemical changes mostly occurred at the long-term aging period, and the oil addition would not influence the SBS degradation during aging.