Ethylene vinyl acetate copolymer modified epoxy asphalt binders: Phase separation evolution and mechanical properties.

As one of polymer modified asphalts (PMAs), epoxy asphalt (EA) has been extensively used in the pavement of steel bridge deck due to its excellent performances. Ethylene vinyl acetate copolymer (EVA) is one of most used polymer modifiers in PMAs. EA/EVA blends were prepared with the addition of EVA in asphalts. The effects of EVA on the morphology evolution of EA were investigated by laser scanning confocal microscopy (LSCM) and scanning electron microscopy (SEM). Furthermore, the rotational viscosity, thermal stability and mechanical properties of EA/EVA blends were studied. LSCM observed that epoxy resin was the continuous phase and EVA-asphalt was the disperse phase in EA/EVA blends. The presence of epoxy crosslinking network destroyed the physical interaction between EVA and asphalts. Both LSCM and SEM observations found that smaller and well-distributed EVA-asphalt particles formed in EA/EVA blends with lower EVA loadings. However, EVA-asphalt particles distributed inhomogeneously in the blends with higher EVA loadings. The addition of EVA increased the viscosity of the neat EA. Moreover, the presence of EVA improved both thermal stability and mechanical properties of the neat EA. [ABSTRACT FROM AUTHOR]