Multiscale Interfacial Interactions in Graphene-Asphalt Nanocomposites: Implications for Asphalt Pavement Material Applications

Graphene-asphalt nanocomposites are considered to be the next generation of major pavement materials. At present, the rheological properties of graphene-asphalt nanocomposites are basically clear, but the mechanism of performance evolution is not well understood, especially the multiscale interaction mechanism at the interface, which has not been reported. In this study, density functional theory, molecular dynamics simulation, microstructure characterization, and property evaluation were used to explore the interfacial mechanism and multiscale correlation of graphene-asphalt nanocomposite. The results show that graphene and asphalt have excellent compatibility and that there is no chemical reaction between them. There are three interactions at the interface: mechanical entanglement, van der Waals force, and benzene ring stacking, and there is no hydrogen bond. Graphene significantly improves the shear resistance, deformation resistance, rutting resistance, and elasticity of asphalt because graphene and asphalt have good interface properties. The graphene interfacial shear stress barrier is 248.93 MPa, and the interfacial bonding energy barrier is 6.634 kcal/mol/A2, which ensure the integrity and stability and promote stress transfer at the interface of graphene-asphalt nanocomposites. Graphene also improves the aging resistance of asphalt because graphene has a wrapping effect on aromatics and saturates. This study can provide a theoretical basis for the application of 2D nanomaterials to asphalt pavements.