Abstract

The growth of the construction industry necessitates the development of sustainable and high-performance binders to reduce ordinary Portland cement (OPC) dependence. Among supplementary cementitious materials (SCMs), Ground granulated blast furnace slag (GGBFS) offers remarkable chemical reactivity, availability, and environmental benefits. This review synthesizes advances in GGBFS production, characteristics, and performance in concrete. At optimal replacement levels (30–50%), GGBFS enhances workability, strength, and durability against chloride ingress, sulfate attack, and alkali–silica reactivity through its pozzolanic and latent hydraulic reactivity. The formation of secondary C–S–H and C–A–S–H gels refines microstructure, lowers permeability, and improves long-term performance. Environmentally, GGBFS can reduce CO2 emissions by up to 40% and supports circular-economy principles through industrial by-product valorization. Although early-age strength and compositional variability pose challenges, GGBFS remains a key material for low-carbon, durable concrete and future sustainable infrastructure.