Effect of copper slag on recycled aggregate based self-compacting concrete

Abstract

The present research paper investigated experimentally the effective use of copper slag (CS) in recycled aggregate based self-compacting concrete (SCC). The work is carried out in two series. In the first series SCC mixes are prepared with recycled coarse aggregate (RCA) as a replacement of natural coarse aggregate of various proportions (0%, 33%, 66% and 100%). In the second series copper slag of various proportions (0%, 20%, 40%, 60%, 80% and 100%) is incorporated as fine aggregate in SCC mix made with 33% RCA and studied the behaviour of recycled aggregate based SCC mixes. Different properties of all mixes including fresh and hardened properties were determined according to EFNARC guidelines and IS code of practice and compared with the control concrete. The morphology of various SCC mixes is examined through scanning electron micrograph to verify the strength of SCC mix. The test results revealed that, with increased in RCA content the compressive strength of SCC decreased whereas the tensile strength of SCC is found marginal and comparable to control mix. However, by incorporating copper slag to the recycled aggregate concrete the compressive and split tensile strength of SCC enhanced up to 7% and 28% respectively in comparison to control SCC mix. The cost-effective and environmental impact analysis of RCA based SCC was carried out and it is revealed that, the combined use of RCA and copper slag could cut the cost of SCC by 8–11% and the maximum reduction in CO2 emission was about 3% which enables the construction sector to develop more sustainably and make a significant contribution towards the preservation of natural resources.