Improving the performance of RET modified asphalt with the addition of polyurethane prepolymer (PUP): Fid-Bau Portal

Improving the performance of RET modified asphalt with the addition of polyurethane prepolymer (PUP)

Xu, Cheng / Zhang, Zhengqi / Zhao, Fuqiang / Liu, Feifei / Wang, Jiarong

Highlights • RET modified asphalt was modified with polyurethane prepolymer (PUP). • Performance and its influencing factors of PUP/RET modified asphalt were studied. • The chemical reaction between PUP and RET modified asphalt was studied by FTIR. • PUP can improve the performance of RET modified asphalt and its mixture. • The optimal preparation of PUP/RET modified asphalt was put forward.

Abstract To improve the performance of Reactive Elastomeric Terpolymer (RET) modified asphalt and give full play to its role, the chemically modified material, polyurethane prepolymer (PUP), was used for composite modification. The effect of PUP content, RET content, preparation equipment, rotation speed and shear time on the performance of PUP/RET modified asphalt (PUP/RETMA) was investigated using asphalt tests. The chemical reaction between PUP and RET modified asphalt (RETMA) was confirmed using FTIR test. The high-temperature rutting resistance, low-temperature crack resistance and moisture susceptibility of several asphalt mixtures were evaluated and compared using mixture tests. The results show that PUP can improve the performance of RETMA and its mixture, especially the low-temperature performance. RET content and PUP content have the positive effect on the high and low temperature performance of PUP/RETMA, respectively. To obtain excellent performance, sufficient shearing and proper shear time are needed for the preparation of PUP/RETMA. The chemical reaction exists in the modification process of PUP and RETMA. Based on experimental study, the proper RET content and PUP content are recommended 1.5% and 8%–10% by weight of base asphalt respectively. The high-speed shear emulsifying mixer is recommended, 5000 rpm of shear speed and at least one hour of shearing are suggested. PUP can improve the performance of RETMA, thus, using PUP for composite modification is able to promote the application and popularization of RETMA.