Life Cycle Assessment of Concrete Using Copper Slag as a Partial Cement Substitute in Reinforced Concrete Buildings

Abstract

Cement, one of the main components of concrete, poses environmental risks, accounting for 7% of total global carbon emissions. To alleviate the environmental hazards related to cement manufacturing, supplementary cementitious materials (SCM) are employed to reduce the usage of cement in concrete. One SCM used is copper slag (CS). In this study, a life cycle assessment (LCA) is conducted by investigating the environmental impacts of concrete replacing different percentage of cement with CS. As a case study, the LCA was performed for low-rise and mid-rise structures designed with varying concrete strengths, and a cost analysis was performed for these structures when replacing different percentages of cement with CS. Based on the results, the usage of CS was established as being beneficial to the impact categories ADP (Abiotic Depletion Potential (Fossil)) and GWP (Global Warming Potential), but exerted damaging effects on ADP (Abiotic Depletion Potential) and HTP (Human Toxicity Potential). On the basis of the cost analysis, the use of CS as a partial cement replacement was found to reduce building costs by a maximum of 1.4%, which is statistically significant. When evaluating the risk in comparison to the benefit of using CS in buildings, it was found that the negative environmental influence outweighed the favorable influence and cost savings resulting from the use of CS as a cement alternative. However, when only considering GWP, which is the standard procedure for environmental assessment in buildings, the use of CS as a partial cement substitute in buildings was regarded as being beneficial, yielding a 12.80% reduction in carbon emissions.