Mechanical Properties and Flexural Behaviour of Copper Slag Based Geopolymer Concrete Beams

Objectives: The aim of this study is to evaluate the mechanical properties and flexural behaviour of Copper Slag (CS) Based Geopolymer Concrete (GPC) beams, emphasizing strength enhancement, structural performance, and sustainable material utilization. Methods: Copper slag is used to replace fine aggregate in the incremental way from 0% to 50% in the GPC with the binder as fly ash and GGBS. Sodium based alkaline solution with 8M, 10M and 12M concentrations have been used to assess the mechanical and flexural behaviour of the GPC beams through standard testing procedure. Findings: GPC mixture containing 70% fly ash and 30% GGBS as a binder and 40% copper slag replacement as a fine aggregate shows superior performance and selected as an optimum replacement to attain superior mechanical and flexural properties. The slag-based GPC showed maximum of 10.32% increase in compressive strength, 23.54% increase in flexural strength at 40% replacement. GPC beam of mix CS 40 with 12M shows ultimate load carrying capacity of about 65kN and ultimate deflection of 39.89mm which is 8.33% and 10.69% higher than mix CS 0 of 12M. Novelty: Utilizing fly ash, GGBS, and copper slag in geopolymer concrete reduces usage of cement and natural sand, lowers greenhouse gas emissions, and conserves resources. By eliminating the use of cement and fine aggregates, these structural members help to save natural resources and cut down on energy use, making construction more sustainable. Keywords: Geopolymer Concrete, Copper Slag, Fly ash, GGBS, Deflection, Load Carrying Capacity