Graphene oxide-enabled reactive bridging networks in high-performance epoxy asphalt

Achieving efficient structural integration in epoxy asphalt remains challenging because the cured epoxy phase is prone to forming heterogeneous domains within the asphalt matrix, limiting the connectivity of the cured epoxy domains and overall performance. Here, we report a graphene oxide (GO)-assisted reactive bridging strategy that enables the molecular-level integration of epoxy resin (ER) and asphalt through a continuous GO-ER/asphalt crosslinked network. GO acts as a multifunctional reactive platform, where its oxygen-containing groups covalently anchor ER chains and provide active sites for subsequent curing with methyl tetrahydrophthalic anhydride (MTHPA). This sequential grafting and curing process transforms the epoxy asphalt system from a loosely dispersed multiphase structure into a chemically connected network with enhanced continuity and compatibility. The resulting GO-ER crosslinked network suppresses free volume, restricts molecular mobility, strengthens interfacial interactions, and improves thermal stability, thereby promoting more effective stress transfer and deformation resistance. Consequently, the GO-ER modified asphalt exhibits improved storage stability, high-temperature rutting resistance, elastic recovery, fatigue resistance, and tensile performance, while maintaining a favorable balance between strength and deformability. This work reveals a molecular-level reactive bridging mechanism and provides a general strategy for designing high-performance epoxy asphalt materials through GO-assisted interfacial regulation.