Crumb rubber-polyethylene glycol composite-modified asphalt integrated high performance and temperature regulation

This study employed chemical methods to prepare crumb rubber (CR) and polyethylene glycol (PEG) composite (CR-PEG) for the modification of asphalt with phase change temperature regulation function. The microstructure and composite mechanism of CR-PEG, properties and temperature regulation function of CR-PEG modified asphalt (CR-PEG-MA) were systematically investigated in details. The results demonstrate that hexamethylene diisocyanate (HDI)facilitated the chemical complexation between CR and PEG and altered the crystal structure of PEG. As PEG molecular weight increases, the onset temperature and enthalpy of phase transition initially increase before decreasing at molecular weight of 1000. The higher the PEG content, the lower the starting temperature of phase transition and the greater the enthalpy of phase transition. CR-PEG in asphalt begins to exhibit phase change temperature regulation around 50°C. CR-PEG-MA achieves optimal comprehensive performance with 3 wt% PEG6000. Moreover, it is an effective strategy to reduce PEG leakage risk by chemically fixing PEG in CR phase.