Civil Engineering Department, Birla Institute of Technology and Science, Pilani 333031, India.
Civil Engineering Department, Birla Institute of Technology and Science, Pilani 333031, India.
Waste Manag. 2019 Nov;99:90-101. doi: 10.1016/j.wasman.2019.08.036. Epub 2019 Aug 29.
Fly ash (FA) and copper tailings (CT) both are, anthropogenic wastes, spread all over the globe due to rapid growth in thermal power plants and progressive increase in the demand of copper. This study examines the feasibility of combined utilization of FA and CT in concrete as a partial replacement of cement by assessing compressive strength, cost, and environmental impact. Morphology and constituent minerals of FA and CT have been identified to understand the utilization potential. Subsequently, the concrete has been designed for 30 MPa target strength as per IS 10262:2009 for different mix proportions of FA and CT. Improvement (up to 8.27% compared to the control mix) in the compressive strength has been observed at combined replacement of 10% FA and 5% CT. The cost of concrete can also be reduced up to 16% without compromising its compressive strength. The environmental impact assessment of the modified concrete mix proportions has also been performed using life cycle assessment (LCA) as per ISO 14040:2006. Effect of all raw materials, electricity, and water consumption have been considered from their cradle to grave approach. One cubic meter concrete has been taken as a functional unit in LCA. Notable reduction has been observed in the chosen midpoint categories up to 38% in climate change, up to 32.6% in human toxicity, up to 33.6% in ozone depletion, up to 31.9% in agriculture land occupation, water depletion up to 34.3%, fossil depletion up to 34.8%, particulate matter up to 35.4%, and metal depletion up to 25.2%.
粉煤灰（FA）和铜尾矿（CT）都是人为废弃物，由于火力发电厂的快速增长和对铜需求的不断增加，它们遍布全球。本研究通过评估抗压强度、成本和环境影响，考察了 FA 和 CT 在混凝土中作为部分替代水泥的综合利用的可行性。对 FA 和 CT 的形貌和组成矿物进行了鉴定，以了解其利用潜力。随后，根据 IS 10262:2009，为不同的 FA 和 CT 混合比例设计了抗压强度为 30 MPa 的目标强度的混凝土。在 10%FA 和 5%CT 的组合替代下，抗压强度提高了 8.27%（与对照混合物相比）。在不降低抗压强度的情况下，混凝土的成本也可以降低 16%。还使用生命周期评估（LCA）根据 ISO 14040:2006 对改性混凝土配合比的环境影响进行了评估。从摇篮到坟墓的方法考虑了所有原材料、电力和水的消耗。在 LCA 中，一立方米混凝土被视为一个功能单元。在所选的中点类别中，观察到了显著的减少，在气候变化方面减少了 38%，在人类毒性方面减少了 32.6%，在臭氧消耗方面减少了 33.6%，在农业土地占用方面减少了 31.9%，在水资源消耗方面减少了 34.3%，在化石燃料消耗方面减少了 34.8%，在颗粒物消耗方面减少了 35.4%，在金属消耗方面减少了 25.2%。
