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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. [ABSTRACT FROM AUTHOR]

Sasobit has been widely applied as warm-mix asphalt (WMA) additive in an environment friendly and energy saving pavement construction. Epoxy asphalt (EA) has been extensively used on the pavement of steel bridge decks. In the present paper, Sasobit was introduced into warm-mix epoxy asphalt binder (WEAB) to prepare Sasobit modified WEAB. The effect of Sasobit on the viscosity, thermal, damping and mechanical properties and morphology of the neat WEAB were investigated using various characterisation techniques. Sasobit significantly lowered the viscosity of the neat WEAB and prolonged the operational lifetime for mixture pavement. Sasobit lowered the glass transition temperature of the neat WEAB. Sasobit slightly decreases the damping properties and thermal stability of the neat WEAB. However, Sasobit increased the tensile strength of the neat WEAB. The crystalline network structures of Sasobit formed in asphalts were clearly observed. The lamellar crystalline structure of Sasobit turned to gel-like structure in curly ribbon shape with an increase of the WMA additive contents. Reaction-induced phase separation occurred in the neat WEAB and Sasobit modified WEABs. No crystalline network structures of Sasobit were observed in the dispersed asphalt phase of the modified WEABs. Sasobit decreased the size of asphalt particles in the continuous epoxy phase. [ABSTRACT FROM AUTHOR]