Synergy between sodium lactate and basic oxygen furnace slag in supersulfated cement: hydration and properties

Supersulfated cement (SSC), a low carbon dioxide binder utilising 80–90% ground granulated blast-furnace slag (GGBS), faces a critical challenge in balancing mechanical performance and carbon dioxide footprint reduction when incorporating basic oxygen furnace slag (BOFS) – a steelmaking byproduct with underutilised potential. However, adding more than 10% BOFS to SSC causes a significant reduction in strength, which limits both its broader application and its potential for further reducing carbon dioxide emissions. This study explores the synergistic effect of sodium lactate in BOFS-modified SSC (BSC) to address this limitation. The results show that even a small addition of 0.5% sodium lactate significantly improves the 7-day and 28-day strength of BSC. Hydration heat tests reveal that the combined use of BOFS and…