Experimental investigation on the microstructural and mechanical properties of sandcrete blocks made with geopolymer binder
manufacturing process contributes heavily to CO2 emission which is a challenge to the environment. Geopolymer with good physical and mechanical properties is a promising substitute for Portland limestone cement. This research investigates the microstructural and mechanical properties of geopolymer sandcrete blocks produced using fly ash, ground granulated blast furnace slag (GGBS), and alkaline solution as binder. The hollow sandcrete blocks were formed with a mould of dimensions 230 × 100 × 100 mm. The results indicate that geopolymer sandcrete blocks cured at a lower temperature of 60 °C had higher strength compared to those cured at 105 °C. Furthermore, the optimal combination of 8 mol sodium hydroxide solution and fly ash to GGBS ratio of 55 % to 45 % yielded the maximum compressive strength at both curing temperatures. While the findings highlight the environmental viability of geopolymer sandcrete blocks as low-carbon alternatives to Portland sandcrete blocks, their compressive strength remained lower under the tested curing conditions, indicating that further optimization is required to achieve mechanical performance comparable to conventional sandcrete blocks.