预处理方法对聚氨酯再生沥青混合料性能的影响

To explore the feasibility of polyurethane used in recycled asphalt mixtures (RAM), the strength and road performance of polyurethane recycled asphalt (PRA) were studied. RAMs were recycled with polyurethane using three treatment methods: RAM with extracted bitumen, RAM with hot mixing treatment, and RAM with hot mixing + rejuvenator, which were named PRA-1, PRA-2, and PRA-3. They were compared with porous polyurethane mixtures (PPM) and open-graded friction course (OGFC) mixtures. Split strength, porosity, anti-freeze capacity, Marshall stability, and adhesion were measured to characterize the performance of mixtures. The results indicate that the performance of PRA-1 is close to that of PPM, which shows good Marshall stability with the split strength of 1.8 MPa. However, the anti-freeze capacity and adhesion property of PRA-1 are lower than those of OGFC. The performance of PRA-2 is close to that of OGFC. The Marshall stability and split strength (1.0 MPa) of PRA-2 are insufficient due to the asphalt, but the anti-freeze capacity and adhesion property are better than those of PRA-1. The strength and stability of PRA-3 are the worst due to asphalt and rejuvenator, which is not recommended in engineering. Therefore, the feasibility of polyurethane used in RAM is closely related to pretreatment methods. The RAM with extracted bitumen and RAM with hot mixing treatment have some application significance. However, it is not recommended to add rejuvenator to PRA.