Optimisation of Mix Design of Cemented Stone Column Material Using Steel Slag as Aggregate

The stone column is an effective ground improvement technique that uses a large quantity of conventional aggregates. Replacing the usual aggregate with industrial waste, such as steel slag, is a sustainable approach for stone columns. Steel slag is a by-product of steel making that can be used as a substitute for coarse aggregate. It has a higher impact and crushing strength, better anti-skid capacity due to its angularity, higher resistance to abrasion, and good bonding with the cement matrix. In the current experiment, steel slag was combined with cementitious materials including cement and fly ash, and it was employed as stone column material. The features of the steel slag–cement mix, such as its compressive strength and permeability, affect the degree to which it performs. Cemented stone columns were made using different combinations of fine aggregate, coarse aggregate, cement, and fly ash. The sample had been optimised to balance compressive strength and permeability. The results showed that with an increase in finer content and cementitious content, the crushing strength increased however the permeability decreased. The mixed design that was proposed is the most appropriate design for achieving the best performance of stone columns in terms of bearing capacity and consolidation acceleration.