Bituminous modifier selection and effects of dimethyl sulfoxide pretreated graphene contents on bituminous properties

To increase the graphene dispersity in bitumen, the dispersant solvent dimethyl sulfoxide (DMSO) pretreated graphene (DG) and N-methylpyrrolidone (NMP) pretreated graphene (NG) were first prepared, and were used as modifiers to prepare modified bitumen, respectively. After a comprehensive evaluation, it is found that DG is more uniformly dispersed in bitumen. DG modified bitumen shows better mechanical properties, and is selected to assess the impacts of DG contents on bituminous different properties after aging. Results indicate that DG effectively inhibits the formation of sulfoxide groups in the aging process of modified bitumen. The intercalation structure between DG and bitumen reduces the entry amount of oxygen, and slows down the transformation progress from micromolecular to macromolecular components in bitumen. Additionally, the modified bitumen with the DG content of 0.4 wt% has a weaker ultraviolet absorption ability and stronger ultraviolet reflection capacity, increasing the aging resistance of modified bitumen. Moreover, the ultraviolet absorption capacity of DG modified bitumen is decreased as the aging degree is increased. The DG content of 0.4 wt% is proposed to prepare modified bitumen, improving mechanical and anti-aging properties of bitumen.