Recycling copper slag in steel fibre concrete for sustainable construction

Although industrialization has raised the living standard of human beings but now it is also becoming threat to the environment. The manufacturing industries are producing waste material in large volumes and are emitting greenhouse gases. These waste materials are being dumped on open land that pollute the soil, water, and air. On the other hand, construction industry is using natural resources on large scale to create infrastructures. This has put some natural resources on the verge of fading. River sand is one of the such stressed natural resource which needs immediate researcher's attention. Through this research work, utilization of copper industry waste material called copper slag has been tried as a substitute of sand in fibre concrete containing 1% hook end steel fibres. The aspect ratio of steel fibre used in this work was 80. It was found that workability of fresh steel fibre concrete increased linearly on inclusion of copper slag. The compressive strength of steel fibre concrete enhanced on inclusion copper slag as replacement of sand. At 28 days, concrete mixture containing 1% hook end steel fibre and 80% copper slag displayed optimum compressive strength of 44.25 MPa against 31.04 MPa of control concrete. At 7, 28 and 56 days, compressive strength of concrete mixture made with 100% copper slag was 32.64, 26.71 and 24.71% higher than that of reference concrete, respectively. Similar trend of enhancement in split tensile strength of fibre concrete with copper slag was observed. At 28 days, concrete mixture containing 80% copper slag displayed 48% and 14.72% higher split tensile strength and bond strength than that of control concrete, respectively. On use of 80% copper slag as substitute of sand, water penetration depth and capillary water absorption of fibre concrete reduced by 25.5% and 42.65%, respectively. Water penetration depth and capillary water absorption reduce almost linearly with increment in copper slag content. The present work establishes that inclusion of copper slag as replacement of sand densify the microstructure of fibre concrete. (C) 2020 Elsevier Ltd. All rights reserved.