Laboratory Evaluation of Green Concrete Mixes Containing High Percentages of Steel Slag Coarse Aggregate

Abstract

Sustainability in the built environment is of increasing importance, particularly in the concrete structures. Slag from iron and steel industries can be used in some cases to replace natural aggregates in construction. Steel slag aggregate is an engineered product with great potential as replacement to naturally occurring aggregates in construction projects due to its distinctive physical and chemical properties. It is a 100% recyclable material.  In this research, a comprehensive laboratory evaluation of the use of steel slag as a Portland Cement Concrete (PCC) aggregate was conducted. The performance of steel slag aggregates as a construction material in comparison to dolomite aggregates was evaluated. PCC mixtures with 0/100, 25/75, 50/50, 75/25, 100/0 percentages of steel slag/dolomite aggregates were prepared in the laboratory. All parameters in the mixes were kept constant except the coarse aggregate proportions. Test results revealed that steel slag has great potential as a construction material.  The resulted concrete with steel slag showed relatively high compressive, splitting, flexural and bond strength as well as higher modulus of elasticity and lower permeability. Finally, the optimum amount of steel slag replacement was found to be 50% of the coarse aggregate.