Rheological properties and aging resistance of self‐healing polyurea elastomer modified asphalt

Abstract

Polymer modified asphalt containing dynamic chemical bonds has the potential to increase the service life of asphalt pavement due to its excellent self‐healing ability. The effect of this self‐healing accelerator with dynamic chemical bond on the rheological properties and aging resistance of asphalt binder is still unclear. In this study, a self‐healing polyurea elastomer (PUA) modified asphalt containing dynamic disulfide bonds was prepared. The high‐ and low‐temperature performance and fatigue resistance of PUA modified asphalt were studied through multiple stress creep, low‐temperature bending beam rheometer, mechanical glass transition temperature, and linear amplitude scanning tests. Moreover, considering the service environment of asphalt over a wide temperature range (−30–70°C), three rheological aging indices (RAI) were proposed. At the same time, the aging resistance of PUA modified asphalt was evaluated by chemical aging index (CAI) based on carbonyl and sulfoxide groups. Finally, a linear relationship is established between RAI and CAI over a wide temperature range. The experimental results show that self‐healing accelerators can increase the resistance to permanent deformation of asphalt by 47.41% and the fatigue resistance by 88.54%. The S value of PUA modified asphalt decreased by at most 33.21% and the m value increased by at most 35.23% compared with BA at −18°C. Moreover, PUA can improve the long‐term thermal oxygen aging resistance of asphalt binders by at least 38.33% over a wide temperature range.Highlights Rheological properties of self‐healing polyurea elastomer modified asphalt. Aging resistance of self‐healing polyurea elastomer modified asphalt. Proposed rheological aging indices for different temperature ranges. Clarified the correlation between chemical–rheological aging indices.