Crack resistance of asphalt mixture with steelrnslag powder

摘要

Steel slag is a kind of industrial waste generated during steelmaking. It has been widely used in asphalt mixtures asrnaggregate in previous research. The utilisation of steel slag in asphalt mixtures as filler is rarely reported. The primaryrnobjective of this research was to evaluate the effect of steel slag powder (SSP) on the crack resistance of asphaltrnmixtures. Two types of fillers – namely, SSP and limestone powder (LP) – were used, and LP functioned as the controlrngroup. The characteristics of SSP and LP, including surface texture, chemical composition and particle size gradation,rnwere first investigated. Then, asphalt mixtures containing SSP and LP were designed by the Superpave procedure.rnFinally, the indirect tensile strength (ITS) and fracture energy of asphalt mixtures were determined to evaluate therncrack resistance of asphalt mixtures. Results suggest that the particles in SSP and LP both possess obvious edges andrncorners and coarse surface textures. The average chemical compositions indicate that SSP is a high-alkalinity slag filler.rnDetermining the crack resistance of asphalt mixtures by ITS value is not sufficient because of the similar results causedrnby SSP and LP. The fracture energy parameter suggests that SSP improves the crack resistance of asphalt mixtures.