Performance Characteristics of Self Compacting Concrete Containing Iron Slag

Abstract

In India, an approximate production of iron and steel slag is 10 million tons annually. Large quantity of slag is used in cement industry but except that it is dumped on land adjoining sites of iron and steel mills and becoming environmental hazard to the community. The constructive use of iron slag is the better way to mitigate the issue associated with disposal. The utilization of such material in self compacting concrete helps in reducing the disposal problem. Hence in this study, perceptions for using iron slag as replacement of fine aggregates are explored. The current study has been carried out to evaluate the feasibility of the use iron slag as fine aggregates in self-compacting concrete (SCC). Control SCC was made with fly ash (10% addition as supplementary cementing material) designed to achieve 28-day compressive strength of 30 40MPa. In control SCC, fine aggregates were replaced with iron slag at 10, 25 and 40% contents. A total four SCC mixtures SCC-CM, SCC-IS10, SCC-IS25 and SCC-IS40 were developed; SCC-CM (control mix) was developed without replacement of iron slag with fine aggregates, SCC-IS10 with 10% replacement of iron slag, SCC-IS25 with 25% replacement of iron slag and SCC-IS40 with 40% replacement of iron slag. Slump flow, L-box, U-box and V-funnel tests were performed to evaluate passing and filling abilities of SCC in fresh state. Tests for compressive strength, splitting tensile strength, flexural strength, modulus of elasticity, water absorption, sorptivity, sulphate resistance, rapid chloride permeability, abrasion resistance and ultra-sonic pulse velocity were conducted up to the age of 365 days. Test results indicate that fresh properties such as slump flow, L-box, U-box and V-funnel of SCC mixes with or without replacement of iron slag were within the specified range as specified by EFNARC. Compressive strength of SCC mixtures increased with the inclusion of iron slag as well as with age. At the age of 7 days, SCC mixes with iron slag achieved higher compressive strength.