Experimental Study on Iron Ore Tailings and Bottom Ash as Fine Aggregates in Concrete

Abstract

Iron ore tailings (IOT) are waste produced during mining of iron from its ore. Thus sustainable handling of iron ore tailings is of prime concern to all stakeholders who are into iron ore mining. Bottom ash is the waste material, which drops into the bottom of the furnace in latest large thermal power plants. The consumption and demand of construction materials has resulted in the extraction of sand from rivers. The extraction of sand is having adverse effects on rivers, causing degradation of rivers. Hence, in this thesis the effectiveness of iron ore tailings and bottom ash as fine aggregates in concrete is taken for study. Initially replacement of fine aggregate with 10%, 20%, 30%, 40% and 50% iron ore tailings was done. Then replacement of fine aggregate with 10%, 20%, 30%, 40% and 50% bottom ash was also done. The fresh and hardened state properties of concrete in both cases were studied and compared. The various tests have done include slump test, compacting factor test, compressive strength test, split tensile strength test and flexural strength test.

Iron Ore Tailings as Partial Replacement for Fine Aggregate in Concrete Production – Review

“…The workability of IOT concrete decreases as the percentage of fine aggregate replaced with IOT increases, which could be owing to the fineness and large specific surface area of the IOT, which necessitates a substantial amount of water to wet all particles in the mix. Several studies such as [37][14], [15], [36], [38] have reported the reduction in the workability of IOT concrete as the percentage replacement fine aggregate with IOT increases. In the same vein, [16] found that adding IOT to the mix increased water demand while lowering the flowability of the fresh material due to the IOT's high specific surface area and rough surface.…”

“…However, it was also observed that the strength of the concrete with IOT was decreased as the percentage of IOT was increased and concluded that the optimum replacement of sand with IOT is 25%. [37] carried out an experimental study on iron ore tailings and bottom ash as fine aggregates in concrete. They replaced fine aggregate with 10%, 20%, 30%, 40%, and 50% iron ore tailings and with 10, 20, 30, 40, and 50% bottom ash for concrete cubes.…”

“…In research carried out by [45], it was concluded that the Split tensile strength of 10, 20, 30, 40, and 50% IOT mix decreased by 1.38, 2.79, 14.10, 33.9, and 42.03% respectively from that of the control mix and that the flexural strength of 10, 20, 30, 40 and 50% IOT replacements for fine aggregate decreases by 21.14, 24.95, 26.19, 30.95, and 32.86% respectively from control mix.…”