Compatibility between polyurea resin modifier and asphalt binder based on segregation and rheological parameters

Abstract Polyurea (PUA) resin exhibits excellent flexibility and stress dispersion, and its application has been widely explored across various fields in recent years. To assess the potential of PUA materials in asphalt binder pavement applications, both the PUA modifier and the modified asphalt binder were prepared in this study. The interactions between PUA and asphalt binder were investigated using scanning electron microscopy and storage stability tests, focusing on the interaction effects and segregation phenomena. The optimal particle size of the PUA modifier for use in asphalt binder was identified. Rheological models, including the Han curve and Cole-Cole plots, were employed to examine the phase separation behavior of PUA-modified asphalt binder. Additionally, the compatibility of the modified binder was analyzed in relation to its thermal properties. The correlation between the mechanical properties and the compatibility of the PUA-modified asphalt binder was explored. The results demonstrated that PUA modifiers with smaller particle sizes exhibited stronger integration with the base asphalt binder, showing improved compatibility. Increasing the particle size and content of the modifier exacerbated phase separation and segregation phenomena in the asphalt binder system. A strong correlation was observed between the macroscopic properties and the compatibility of the PUA-modified asphalt binder. To achieve favorable macroscopic mechanical properties while minimizing segregation, comprehensive consideration of the particle size and dosage parameters of PUA is necessary for optimizing the compatibility and performance of modified asphalt binders.