Environmental protection by using waste copper slag as a coarse aggregate in self-compacting concrete

• Published in: Journal of environmental management 2020-10, Vol.271, p.111013-111013, Article 111013
• Main Authors: Sharifi, Yasser, Afshoon, Iman, Asad-Abadi, Saman, Aslani, Farhad
• Format: Article
• Language: English
• Subjects: Coarse aggregate; Environmental protection; Low-cost concrete; Self-compacting concrete; Waste copper slag
• ISSN: 0301-4797; 1095-8630
• DOI: 10.1016/j.jenvman.2020.111013

The copper production process causes waste and by-products called waste copper slag (WCS). A considerable amount of WCS is produced globally. This research aims to utilise WCS as an alternative to natural coarse aggregate in self-compacting concrete (SCC). To achieve this goal, WCS was utilised in different percentages (0%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, and 100%) as a natural coarse aggregate replacement in SCC production. Following this, the fresh, mechanical, and durability characteristics of SCCs incorporating WCS as a partial replacement of coarse aggregates were investigated in-depth. Incorporating 100% WCS as coarse aggregates in SCCs showed 27%, 29%, and 26% growth in compressive, split, and flexural strengths in 28 days, respectively. The reduction of free drying shrinkage of the mixture containing 100% WCS compared to the control mixture was approximately 36%, and the water absorption of all the specimens was less than 6%. Further, the increase in weight for the mixture containing 100% WCS as coarse aggregates was less than 15% compared to the control mixture. A cost analysis of the SCCs showed that incorporating WCS for all coarse aggregates reduced production costs by 19%. Investigating the economic index of concrete containing WCS as a coarse aggregate showed that utilising the WCS in green SCC was feasible. •This study investigated the fresh and mechanical properties of SCC with and without WCS.•WCS has been used in different percentages of 0–100 as coarse aggregate to produce SCC.•The addition of WCS into SCCs led to an increase in the workability.•By reducing the W/C ratio, the increasing WCS percentage is more effective for mechanical properties.•Cost analysis shows a 19% reduction in the cost of production of SCC with 100% WCS.