Soil Stabilization Using Basic Oxygen Steel Slag Fines

The uses of byproducts such as blastfurnace slag and steel slag [electric arc furnace slag and basic oxygen steel (BOS) slag, and ground granulated blastfurnace slag] have long been established in a number of applications in the civil engineering industry. However, the use of ground BOS slag fines in the area of soil stabilization has not been fully investigated and developed despite having similar chemical composition and mineralogy to that of Portland cement. This paper describes a laboratory investigation for English China clay and Mercia mudstone, which are stabilized with three BOS slag fines from three different steel production sites in the United Kingdom. The investigation also included using mixture of BOS slag fines and two different activators: quicklime and sodium metasilicate. The results indicate that the use of BOS slag fines produce improvements in strength and durability, and also reduction in expansion. However, to achieve significant improvements in strength soils required a high percentage (15–20%) of BOS slag fines and a long curing period.