Achieving lower temperature modification and its mechanism of SBS modified asphalt based on pre-swelling/extraction process and compositing with C9 petroleum resin

Abstract

Achieving lower temperature modification of SBS modified asphalt is of vital significance in energy conservation and carbon emission reduction. The compatibility between styrene–butadiene–styrene (SBS) and base asphalt is a crucial factor for the excellent performance of SBS modified asphalt (SBSMA), however the compatibility improvement under lower temperature faces challenges and its modification mechanism has little scientific backing. In this study, SBS was firstly pretreated with naphthenic oil as swelling agent and petroleum ether as extractant to prepare pre-swelling SBS (npSBS), and the effects of SBS pre-swelling/extraction process combined with C9 petroleum resin on the conventional properties, compatibility, rheological and thermodynamic properties of SBSMA prepared at a lower shear temperature (150 °C) were studied by physical properties, storage stability, DSR, MSCR and DSC characterization. The results demonstrated that SBS pre-swelling/extraction treatment improved the low temperature performance as well as compatibility of SBSMA while reduced its high temperature performance. However, C9 petroleum resin could effectively compensate for the loss of high temperature and rutting resistance performance, and the pre-swelling/extraction process combined with C9 resin has synergistic effect in improving the compatibility of SBS in modified asphalt under lower modification temperature, which can effectively reduce the modification temperature of SBSMA by 30 °C. This work provides a feasible strategy for environmentally benign and low-carbon modification of SBSMA.