Evaluating Mechanical and Durability Properties of Electric Arc Furnace Aggregate Concrete

Abstract

Every year, the world generates roughly 240 kilos of steel for every person on the planet, reaching about 1800 million tons. On average, the production of one ton of steel results in around 200 kg of by-products for the electric arc furnace (EAF) slag and 400 kg for the basic oxygen furnace (BOF) slag. Instead of being disposed of in landfills causing environmental problems, residues of the steel industry could be applied in the construction sector as raw materials for road pavements, cement production, soil stabilization, building materials among other applications. The benefits obtained through the reuse of these resources in the economy include saving non-renewable natural resources and reducing CO2 emissions in environment. Electric arc furnace (EAF) is a non-metallic industrial by-product created by melting iron ore to make molten pig iron in blast furnaces. Every year, around 500 million tons of blast furnace slag are produced around the world. Slag aggregate has not been widely investigated in concrete as a substitute for natural coarse and fine aggregate instead of extra cementitious material. As a result of this application, aggregate grinding is no longer required, lowering production costs. Natural aggregates are usually less porous than EAF. As a result, using EAF as a natural aggregate substitute could result in a higher water absorption of the mix, and direct aggregate substitution must be thoroughly investigated. In this study, the Electric Arc Furnace (EAF) coarse and fine aggregate were procured from “ArcelorMittal Nippon Steel India Limited Pvt. Ltd.”. Physical parameters of EAF aggregates were examined, including fineness modulus, specific gravity, water absorption, moisture content, bulk density, and aggregate impact value. EAF aggregate showed an increase in water absorption of 8.78% for coarse and 2.3% for fine aggregate as compare to natural coarse and fine aggregate, which is attributed to the extra pores on the surface of EAF aggregate due to which the slump also increases with increase in replacement percentage. EAF coarse aggregate has 22% higher aggregate Impact value than natural coarse aggregate which can be attributed to the aggregate’s toughness. The Bulk density of EAF coarse and fine aggregate increases by 6.5% and 6%, respectively, due to their specific gravity. Indian standard code, IS:383-2016 was used to replace the slag percentage, which allows for a maximum of 25% replacement. As a result, volumetric replacement of 15%, 20%, and 25% of coarse and fine aggregate in M20 grade concrete was performed, and mechanical and durability properties were investigated. Mechanical properties shows that when the percentage replacement is raised, mechanical properties also tends to raise with the maximum strength gain occurring at 25%. Compressive strength increased by 19.4% for coarse and 17.7% for fine, flexural strength grew by 7.9% for coarse and 6.53% for fine, split tensile strength grew by 8% for coarse and 7.6% for fine, and modulus of elasticity increased by 11.7% for coarse and 10.6% for fine. This is due to the EAF aggregate’s porous and rough surface, which strengthens the bond between the matrix and aggregate, resulting in increased strength. Durability properties like Rapid chloride penetration test (RCPT) and Water Impermeability has no significant change in coarse and fine slag aggregate concrete as compare to control concrete. This is due to the micro structure’s compactness, which prevents Ion and water penetration in concrete.