Laboratory investigation on road performances of asphalt mixtures using steel slag and granite as aggregate

Shortages of natural stone resources and serious environmental pollution promote the utilization of low-grade resources and solid waste. Thus, steel slag and granite could be used to substitute conventional aggregates in constructing asphalt pavement. In this study, asphalt mixtures incorporating granite and steel slag (GSAM) are prepared and subsequently compared with asphalt mixture prepared by limestone aggregate to determine the road performance of asphalt mixture. Two kinds of asphalt mixture, asphalt concrete (AC), and stone matrix asphalt (SMA) are prepared by the molding methods of Marshall compaction. Marshall stability, dynamic modulus, moisture damage resistance, rutting resistance, permanent deformation resistance, and crack resistance are evaluated on all the prepared asphalt mixtures through laboratory tests. The results signify that the road performance of AC-GSAM and SMA-GSAM are enhanced such as high-temperature stability and low-temperature crack resistance. However, due to the characteristics of steel slag, the long-term moisture damage resistance of GSAM is still further improvement and research. Conclusively, the use of steel slag and granite as an aggregate substitute in asphalt mixture is technically appropriate.