A comprehensive review on polyurethane modified asphalt: Mechanism, characterization and prospect

Polyurethane (PU), with excellent physical and chemical properties and high designability, is one of the ideal materials for asphalt modification in the future. In this paper, based on the limitations of traditional asphalt modifiers, the preparation process, relative advantages and development prospects of PU as asphalt modifiers are described. Subsequently, the spatial structure, physical and chemical properties of PU synthetic raw materials were combined with the modification properties of PU to analyze the effect and influence of PU on asphalt modification. Specifically, polyurethane modified asphalt (PUMA) is divided into thermoplastic polyurethane modified asphalt (TP-PUMA) and thermosetting polyurethane modified asphalt (TS-PUMA). The gain effect of TP-PUMA in high-temperature performance, low-temperature performance, aging resistance, fatigue resistance, weathering performance and bonding performance is obvious. In addition, it has good storage stability. With excellent road performance, TS-PUMA makes up for the shortcomings of epoxy asphalt in terms of low-temperature performance and compatibility. Finally, due to the development trend of functional diversification of modified asphalt, the research basis and status of several new modified asphalts based on PU properties are described. Because the systematic study of PUMA is insufficient, this paper proposes corresponding research. To provide guidance and ideas for the research of PU modified asphalt.