Experimental Study on the Expansion Behavior of Full Aggregate Steel Slag Concrete

To improve the utilization rate of steel slag, this paper investigates the expansion behavior of Full Aggregate Steel Slag Concrete (FASSC). Orthogonal experiment was performed to analyze the effects of sand ratio, water-cement ratio, steel slag sand content, replacement particle size of steel slag sand, coarse steel slag content, and replacement particle size of coarse steel slag on the expansion rate of FASSC. Test results demonstrated that the expansion rate of FASSC decreased with a gradual increase in the replacement particle size of steel slag sand or the coarse steel slag content. With a gradual increase in the water-cement ratio or the steel slag sand content, the expansion rate of FASSC first increased and then decreased. As the sand ratio increased, the expansion rate of FASSC first decreased and then increased. Among these, the steel slag sand content and the replacement particle size of steel slag sand significantly affected the expansion rate of FASSC. The mix proportions of SSC for self-stressing CFST and shrinkage compensating SSC were suggested according to the experimental research. Additionally, a formula for approximately predicting the expansion rate of FASSC was proposed based on the single factor weighted fitting.