Grafting waste rubber powder and its application in asphalt

Herein, rubber asphalt was modified to improve its comprehensive performance and the mechanism of its modification was investigated. Unmodified rubber powder was first treated with hydrogen peroxide, and then, grafted with prepolymer. The mechanism of modification of rubber powder and its effect on the structure and properties of rubber powder/asphalts were tested and characterized. Fourier transform infrared spectroscopy analysis proved that prepolymer was successfully grafted onto the surface of rubber particles. X-ray photoelectron spectrometer test revealed that graft modified rubber powder possessed high oxygen content along with the presence of nitrogen. These results indicated that rubber powder was successfully modified. The graft modified rubber powder was then applied to prepare rubber asphalt, significantly improving the low-temperature resistance to cracking and the stability performance, while it reduced high-temperature construction viscosity of rubber asphalt. The modification of rubber powder enhanced the dispersion of rubber powder in asphalt. The graft modified rubber powder/asphalt exhibited the highest weight fraction of restricted molecular layers, demonstrating the enhanced interfacial interaction between the graft modified rubber powder and asphalt matrix, which could be attributed to the simultaneous effect of physical entanglement and chemical bonding effect. (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

By modifying rubber powder, the overall performance of rubber asphalt was significantly improved, including enhanced low-temperature resistance to cracking and stability. The modified rubber powder exhibited better dispersion in asphalt and increased interfacial interaction with the asphalt matrix, leading to the enhanced performance of the composite material.