Enhanced strength and durability with sustainable geopolymer concrete with copper slag as fine aggregate replacement

The production of Ordinary Portland Cement (OPC) contributes significantly to CO2 emissions globally, making the quest for sustainable building materials imperative. The research focuses on creating geopolymer concrete with jute fiber reinforcing, copper slag as a partial substitute for natural fine aggregate, and metakaolin (MK) and ground granulated blast furnace slag (GGBS) as geopolymer binders. The research intends to assess the combined effects of MK-GGBS geopolymer binder, copper slag replacement (10–40% with cement), and jute fiber on the mechanical, durability, and microstructural properties of ambient-cured geopolymer concrete. Workability, flexural strength, split tensile strength, water absorption, sulphate resistance, acid resistance, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) analysis were among the experimental investigations. With a 28-day compressive strength of 38.95 MPa, the geopolymer concrete with 40% copper slag (as partial fine aggregate) outperformed the control mixes in terms of mechanical characteristics, durability, and denser microstructure. SEM, FTIR, and XRD investigations revealed that the formation of a denser geopolymer matrix with decreased porosity improved water absorption as well as resistance to sulphate and acid attacks. Copper slag substitution and OPC elimination reduce waste and carbon emissions, making geopolymer concrete a sustainable structural material.