Grey relational evaluation on performance and mechanism of polyacrylonitrile fiber reinforced asphalt mixture

Aiming to improve pavement performance of polyacrylonitrile (PAN) fiber-asphalt mixture, five PAN fiber content was selected from 0% to 0.4% by 0.1% interval to evaluate the effect on the high temperature stability, crack resistance in low temperature and moisture stability of asphalt mixture. Then the enhancement mechanism of PAN fiber reinforcing asphalt mixture was revealed by SEM at the microscopic level. Based on the multi-index grey relational evaluation method, the optimum PAN fiber content is selected for the balance of both road performances and economic benefit. The results show that the PAN fiber significantly improves pavement performances of asphalt mixture, as it better infiltrates into the asphalt and forms higher interfacial strength. It also could be observed that the PAN fiber evenly distributed in the asphalt binder to form a spatial network structure, playing a significant role in bridging, reinforcement and toughening. When the amount of PAN fiber is 0.2%, the comprehensive performance of asphalt mixture is optimal on the basis of grey relational evaluation.