Abstract
The construction sector significantly contributes to global carbon emissions, largely due to the widespread use of Ordinary Portland Cement (OPC). This study investigates fly ash, ground granulated blast furnace slag (GGBFS), and calcium carbide residue (CCR) as sustainable precursors for one-part alkali-activated binders. Paste and mortar specimens were prepared using a single activator comprising 4% sodium hydroxide by precursor weight, with CCR incorporated as both an additive and partial replacement at dosages of 0-10%. The results show that a CCR content of 2.5% yields an optimal mechanical performance in GGBFS-based and fly ash–GGBFS blended systems. The effects of ambient and heat curing at 60 °C on geopolymerization and strength development were evaluated. Microstructural analyses using SEM and XRD confirmed the formation of C-S-H and C-A-S-H gels, which supports the strength trends observed. Overall, the study demonstrates that CCR can serve as an effective, low-cost auxiliary activator, which enables the development of sustainable and low-carbon construction materials while offering environmental, social, and economic benefits.