Development of technology to accelerate SBS-modified asphalts swelling in dry modification mode

Abstract

Given that a polymer modifier cannot fully swell with asphalt in the existing dry modification mode, modified asphalt in most cases does not meet the standard of modification. This work aimed to develop an accelerant swelling agent to shorten the time of modified asphalt swelling. Molecular dynamics simulation technology was used to determine the diffusion and adhesion laws of asphalt components during swelling. The modification effect evaluation system was established to speculate on the promotion of polymer modifiers rapidly swelling molecular structure characteristics. The macro test was designed to determine the optimal pre-swelling time and to verify the rationality of bio-oil pre-swelling technology. At the micro level, the saturation with special long carbon chain structure diffuses best in SBS, and the adhesion strength of modifiers is stronger than that of the three other components. Linoleic acid, which is more similar to saturation, is suitable as an accelerant swelling component, and the adhesion between SBS-R and asphalt components is stronger than that of SBS-L and asphalt. Thus, SBS-R is more suitable than SBS-L as a pre-swelling modifier. At the macro level, the use of linoleic acid as a bio-oil pre-swelling agent is reasonable, and the optimal pre-swelling time is 30 min. The 5% pre-swelling SBS-L and 4% pre-swelling SBS-R meet the standards of wet modification processes.