ABSTRACT
As large quantity of iron ore is being produced around the world, accordingly large quantity of overburden waste and tailings are produced which needs to be disposed in an environmental friendly manner. Utilization of such waste and tailings in concrete as a building material is beneficial for mining industry as well as construction industry. This chapter presents a systematic research study carried out to investigate the potential use of iron ore waste rock (WR) and iron ore tailings (IOT) as coarse and fine aggregates in concrete. Two different mixes were considered, one set of concrete mixes with WR as coarse aggregates and other set of concrete mixes with IOT as fine aggregates were replaced partially by 10%, 20%, 30%, 40% and 50% with varying water–cement (w/c) ratio for each composition by 0.35, 0.40 and 0.45 and tested for 3, 7 and 28 curing days. Around 162 cubes, 54 cylinders and 54 beams were casted for each mix composition and tested for their strength properties. Optimum strength was obtained at 40%, 30% and 20% replacement of WR in concrete at 28 days cured specimen for 0.35, 0.40 and 0.45 w/c, respectively. Similarly, optimum percentage of IOT for 0.35, 0.40 and 0.45 w/c is 30%, 20% and 10%, respectively for 28 days cured specimens. Concrete mix with IOT was workable with higher w/c compared to 0.35 and 0.40 w/c; this is due to the high specific gravity of IOT. In case of WR concrete, workability was found to satisfy the design criteria. Flexural strength observed for IOT and WR concrete mixes ranged between 4.50 and 5.10 MPa. Similar trend was observed in case of compressive and splitting tensile strength.
