Compatibility, Microstructure, and Mechanical Properties of a Dimethyl-Sulfoxide-Pretreated Graphene-Modified Asphalt Binder.

Abstract

The surface of graphene was pretreated with dimethyl sulfoxide to enhance its dispersion in asphalt. To investigate the compatibility, microstructure, and mechanical properties of a dimethyl-sulfoxide-pretreated graphene (DG)-modified asphalt (DG asphalt). The interaction between asphalt and DG, DG dispersion, functional groups, tensile performance, microscopic structures, and micromechanical properties of the DG asphalt were characterized. Results indicate that DG with a particle size range from 0 to 8 μm is uniformly dispersed in asphalt. The irregular distribution of DG enhances the stress transfer distance, thus improving the energy consumption and mechanical properties of the DG asphalt. The preparation process involves physical blending, which reduces the saturated hydrocarbon content and increases the chemical bond energy, ultimately enhancing mechanical properties. Additionally, the surface of the DG asphalt shows numerous smaller sized bee structures, which contribute to the hardening and smoothness of the asphalt surface. The stress is distributed uniformly across the surface of the DG asphalt, minimizing stress concentrations. Furthermore, the light components in asphalt are adsorbed by DG, forming intercalated structures that decrease the adhesion and energy dissipation when compared to base asphalt. The compressive stress within bee structures consumes more energy and enhances the anti-deformation capacity of the DG asphalt. However, at higher deformation levels, the slipping of intercalated DG decreases its anti-deformation capacity when compared to that of base asphalt. Nonetheless, the interaction between intercalated structures prevents rapid tensile failure in the DG asphalt.