Sustainable engineered geopolymer composites: A study on the potential of fly ash, BOF slag, and iron ore tailings

Industrial residues like Basic Oxygen Furnace (BOF) slag and Iron Ore Tailings (IOT) in the construction sector conserves natural resources by reducing carbon emissions and enhancing sustainability. However, it is crucial to establish significant research findings to build confidence among end users and stakeholders to facilitate the adoption of the same for practical applications. This study aims to investigate the feasibility of using BOF slag and Fly ash (FA) as primary precursors in the development of steel fibre (SF) reinforced Engineered Geopolymer Composites (EGC) with IOT replacing M-Sand as fine aggregate. Trial mixes (600 No.s) were conducted to synthesize EGC with BOF slag, FA, IOT, and SF. Compressive strength was measured and IOT was found to significantly improve the strength of EGC, following SF and BOF levels. Six optimized mixes were identified and subjected for water absorption, flexure, impact resistance and leaching toxicity of heavy metals. The mix comprising 40% BOF, 1.5% SF and 45% IOT showed the highest strength characteristics viz., 41.8 MPa, 5.78 MPa and 313.92 Nm correspondingly for compression, flexure and impact. The obtained results have implications for sustainable construction involving BOF slag and FA as viable precursors, alongside IOT as a partial substitute for fine aggregate.