First-Year Field Performance of Epoxy-Modified Asphalt

Pavement materials containing epoxy-asphalt are mainly used to enhance the fatigue cracking resistance of surfacing layers on bridges. These materials have also been proposed for roadways, but limited field data are available. In this research, a fully instrumented epoxy-modified asphalt surfacing layer was applied to measure strain responses in service conditions. Results over the first-year monitoring period indicated that the epoxy-modified asphalt behaves fundamentally similarly to a reference one with an asphalt mix of the same aggregate gradation. The epoxy-modified asphalt demonstrated the lowest transverse compressive strains at decreased temperatures, reflecting the potentially high material resistance against thermal cracking. After the summer period, the modified material showed lower tensile strains than the reference mix compared with the previous time period. Such an attribute could indicate the ongoing curing-induced stiffening of epoxy-modified asphalt at high temperatures during summer. The longitudinal and transverse strain measurements had inverse tendencies at all temperatures. Finally, the mechanical response of the studied materials after the summer has been examined using a classical fatigue cracking model and following a life cycle assessment methodology, and preliminary findings support the use of epoxy-asphalt for sustainable pavements.