Performance and Modification Mechanism of Polyurethane Semi-prepolymer Modified Asphalt

【摘要】 A polyurethane semi-prepolymer was introduced as a new modifier for asphalt. The performance of the polyurethane semi-prepolymer-modified asphalt were compared with SBS-modified asphalt. The results of infrared spectroscopy and fluorescence microscopy indicate that there is a chemical reaction between the polyurethane semi-prepolymer and the asphalt, while the SBS and the asphalt are physically cross-linked.The dynamic shear rheometer(DSR) tests indicate that the polyurethane semi-prepolymer-modified asphalt exhibits resistance to deformation at high temperatures, remarkable elastic recovery, minimal stress sensitivity,and higher viscosity. However, its low-temperature performance is inferior to that of SBS-modified asphalt.Based on the asphalt mixture rutting test, the study confirms the excellent rutting resistance of polyurethane semi-prepolymer-modified asphalt. Moreover, the three-point beam bending test and semi-circular bending test(SCB) indicate that the low-to-medium temperature cracking resistance of the polyurethane semi-prepolymermodified asphalt mixture is inferior to that of SBS-modified asphalt. Therefore, polyurethane semi-prepolymermodified asphalt exhibits significant application potential in high-temperature regions and on heavy-duty roadways.更多还原

【Abstract】 A polyurethane semi-prepolymer was introduced as a new modifier for asphalt. The performance of the polyurethane semi-prepolymer-modified asphalt were compared with SBS-modified asphalt. The results of infrared spectroscopy and fluorescence microscopy indicate that there is a chemical reaction between the polyurethane semi-prepolymer and the asphalt, while the SBS and the asphalt are physically cross-linked.The dynamic shear rheometer(DSR) tests indicate that the polyurethane semi-prepolymer-modified asphalt exhibits resistance to deformation at high temperatures, remarkable elastic recovery, minimal stress sensitivity,and higher viscosity. However, its low-temperature performance is inferior to that of SBS-modified asphalt.Based on the asphalt mixture rutting test, the study confirms the excellent rutting resistance of polyurethane semi-prepolymer-modified asphalt. Moreover, the three-point beam bending test and semi-circular bending test(SCB) indicate that the low-to-medium temperature cracking resistance of the polyurethane semi-prepolymermodified asphalt mixture is inferior to that of SBS-modified asphalt. Therefore, polyurethane semi-prepolymermodified asphalt exhibits significant application potential in high-temperature regions and on heavy-duty roadways.更多还原