Utilization of Cupola Furnace Slag as Partial Replacement to Coarse Aggregate in Concrete Mix

Abstract

In the present scenario, the emphasis is on the avoidance of waste generation, recycling and reuse of waste, and minimizing the adverse impact of waste disposal on the environment. With increasing capacities, disposal of large quantities of slag becomes a big environmental concern and a critical issue for foundry industries. The availability of good quality aggregates is depleting day by day due to tremendous growth in construction industry. Aggregates are the main ingredient of concrete occupying approximately 75% of its volume and directly affecting its fresh as well as hardened properties. The objective of the present work is to utilize the Cupola furnace slag as partial replacement to coarse aggregates in the concrete mix and to study the effect on compressive and split tensile strength of concrete. The chemical composition of cupola furnace slag varies widely depending upon the coke quality, contamination of charging material and quantity as well as quality of lime stone used in cupola furnace. The chemical composition of cupola furnace slag is analyzed from three different foundry clusters of Punjab before partially replacing it as coarse aggregate. The results show that the compressive strength as well as the split tensile strength of the concrete is increased by partial replacement of coarse aggregate up to 30% with cupola furnace slag. The percentage increase in the strength values is higher for higher water-cement ratios indicating its suitability for use in concrete mixes where strength requirements are low for all curing ages. Highest increase in strength values, both compressive as well as split tensile, is achieved for a 30% replacement of coarse aggregates with cupola furnace slag, indicating that 30% cupola slag is the optimum replacement percentage of coarse aggregates in the concrete mixtures. The compressive and tensile strength of the concrete decreases beyond 30% replacement of coarse aggregate with cupola slag.