▎ 摘　　要

Epoxy asphalt mixtures have been extensively used in the construction of steel deck bridges. The fatigue cracking formed during long-term service has become the main failure of epoxy asphalt mixtures due to the inherent brittleness of epoxy resin. To improve the toughness of the mixture to resist fatigue cracking, graphene nanoplatelets (GNPs) were used to modify the warm-mix epoxy asphalt binder (WEAB). The thermal stability, viscosity-curing time behavior, phase separation, dynamic mechanical properties and mechanical performance of GNP modified WEABs were investigated by various techniques. The presence of GNPs enhanced the thermal stability of the neat WEAB. The addition of GNPs increased the viscosity of the neat WEAB at the later stage of cure reaction and thus shortened the allowable construction time of epoxy asphalt mixtures. However, the viscosities of all modified WEABs containing less than 1.0 wt% GNPs meet the general specifications of epoxy asphalt materials for paving roads and bridges. Confocal microscopy observation revealed that GNPs dispersed in the discontinuous asphalt phase of epoxy asphalt binder. Meanwhile, the existence of GNPs altered the phase-separated morphology of the neat WEAB. GNPs slightly lowered the glass transition temperatures of both epoxy and asphalt and the damping ability of the neat WEAB. GNPs significantly improved the mechanical properties of the neat WEAB, especially for their tensile strength and toughness, increased by 46% and 41%, respectively, with the addition of 0.2 wt% GNPs.