Laboratory performance of recycled polyethylene modified epoxy asphalt binders

This paper deals with the impact of polymer loading on the microstructure, viscosity, thermal properties and mechanical performance of recycled polyethylene (rPE) modified epoxy asphalt binder. With this aim, rPE was used as a modifier to improve the toughness of a hot-mix epoxy asphalt binder. rPE particles were found to be highly swollen by the asphalt. Double phase separation was observed in rPE modified epoxy asphalt binders: asphalts dispersed in the continuous epoxy phase and rPE particles distributed in the discontinuous asphalt phase. The viscosity of epoxy asphalt binders increased with more rPE contents but the allowable construction time for pavement remained long. Results revealed that the thermal stability of epoxy asphalt binders was slightly improved with the addition of rPE. Furthermore, rPE lowered the glass transition temperature and increased the storage modulus at the rubbery state. All rPE modified epoxy asphalt binders performed better damping behaviours. In addition, at low rPE concentrations, the mechanical properties of epoxy asphalt binders were improved while at rPE loading higher than 2%, the results were opposite.