Effect of Partial Replacement of Fine Aggregates by Cupola Furnace Slag on Properties of Concrete

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 good quality aggregates is also 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 fine aggregates in the concrete mix and to study the effect on mechanical and durability properties 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 fine aggregate. The results show that the compressive strength as well as the split tensile strength of the concrete is increased by partial replacement of fine aggregate up to 30% replacement level with cupola furnace slag whereas a continuous increasing trend is observed in case of durability properties. The percentage increase in the strength values is higher for lower water-cement ratios indicating its suitability for use in concrete mixes. Highest increase in strength values, both compressive as well as split tensile, is achieved for a 30% replacement of fine aggregates with cupola furnace slag, indicating that 30% cupola slag is the optimum replacement percentage of fine aggregates in the concrete mixtures. The compressive and tensile strength of the concrete decreases beyond 30% replacement of fine aggregate with cupola slag whereas same is not observed in case of durability properties.