Preparation of pavement base material by using steel slag powder and steel slag aggregate

ABSTRACT

The extensive use of cement has caused significant resource consumption and serious carbon emission problems. Recycling steel slag to partially replace cement presents a promising alternative. This study utilized steel slag powder (SSP) and steel slag aggregate (SSA) to prepare cement stabilized aggregate (CSA). The effects of different amounts of SSP and SSA on the road performance of CSA were studied, which was also compared with cement-fly ash (FA) stabilized aggregate (CFSA). The results demonstrated that adding SSP and SSA resulted in higher optimal moisture content and the maximum dry density of CSA. Adding 10% SSP enhances the mechanical properties of CSA. Compared to FA, SSP shows superior improvement effects at a 30% substitution rate. The dry shrinkage coefficient of CSA decreases as the SSP content increases. Further addition of SSA can further reduce shrinkage of CSA. The proper amount of SSP has no obvious effect on cement hydration, and the hydration degree of cement-SSP was higher than that of cement-FA. In addition, the higher the SSP blend, the lower the cost of the CSA and the lower the carbon emissions. Taking into account the performance, environmental impact, and cost of CSA, the optimal admixture of SSP is 30%.

Keywords:
Steel slag; Steel slag powder; Cement stabilized aggregate; Road performance; Microanalysis