Steel Slag Expansion Inhibition Method and Basic Performance Analysis

Abstract Steel slag contains a large amount of free calcium oxide, which undergoes hydration reaction when it meets water. This causes a significant increase in the volume of the active material in the steel slag, posing a potential risk of expansion and destruction when used in road engineering. This study adopts single mixed silicon powder, single mixed sodium citrate, mixed solution of silicon powder and sodium citrate to treat steel slag to inhibit the volume expansion of steel slag. The effectiveness of the expansion inhibition before and after treatment is confirmed through an immersion expansion rate test. The results show that: silicon powder and sodium citrate solution have inhibited the expansion of steel slag, with the mixed solution of silicon powder and sodium citrate showing the best expansion inhibition effect, reducing the steel slag’s expansion rate by 81.8%. The mixed solution treatment results in a significant reduction of free calcium oxide in the slag, and the pores on the surface of the slag are filled with silica powder, forming a dense layer structure.