Road performance, VOCs emission and economic benefit evaluation of asphalt mixture by incorporating steel slag and SBS/CR composite modified asphalt

Abstract

To promote the comprehensive utilization of solid waste in highway engineering, asphalt rubber hot mixture (ARHM-13) was prepared with steel slag and SBS/CR modified asphalt. The pavement performance of steel slag and basalt asphalt mixtures, including Marshall stability, moisture susceptibility, high temperature and low temperature performance, were evaluated in the laboratory. Combined with the project case of the trial pavement section in Beijing-Qinhuangdao Expressway, and the compactness, flatness, skid resistance and seepage resistance of the asphalt pavements were tested. And volatile organic compounds (VOCs) emissions and economic performance of asphalt mixtures were analyzed. The results showed that steel slag asphalt mixture reveals more excellent pavement performance than basalt asphalt mixture. The compactness, skid resistance and anti-seepage performance of asphalt mixture with steel slag are superior than basalt in contrast to the surface flatness. The VOCs emission concentrations of the steel slag asphalt mixture during mixing plant, spreading and rolling are higher than that of basalt asphalt mixture. Replacing basalt with steel slag can reduce by about 56.7% of aggregate cost and increase by 6.2% of asphalt cost. The total cost of raw materials for 1 km asphalt mixture with steel slag is reduced by about 10.5%. The research conclusion of this study provides the theoretical support for the promotion and utilization of steel slag and crumb rubber in road engineering.