Published Paper Details:

This research investigates the development of low-grade geopolymer concrete (GPC) using Ground Granulated Blast Furnace Slag (GGBS) as a complete replacement for Ordinary Portland Cement (OPC), focusing on compressive and splitting tensile strength. Three nominal grades--M15, M20, and M25--were prepared using alkaline activation with sodium hydroxide (8M) and sodium silicate in a 2.5:1 ratio. The mixes were cured under ambient conditions, eliminating the need for external heat or steam curing, and their mechanical behavior was assessed at 7, 14, and 28 days. The M25 mix achieved the highest compressive strength of 33.64 MPa at 28 days, followed by M20 at 28.35 MPa and M15 at 23.87 MPa, while in terms of tensile strength, M25 also performed best with a splitting tensile value of 3.12 MPa, followed by M20 with 2.76 MPa and M15 with 2.43 MPa at 28 days. Strength gain increased gradually over time across all mixes, confirming the pozzolanic and long-term hydration effects of GGBS. These results demonstrate that GGBS-based low-grade geopolymer concrete exhibits sufficient strength characteristics for structural applications and offers a sustainable alternative to conventional OPC concrete, confirming that replacing cement entirely with GGBS is feasible without compromising mechanical integrity. Additionally, this approach significantly contributes to reducing CO? emissions and promoting eco-friendly construction, setting a foundation for large-scale adoption of GGBS-based GPC in civil infrastructure.