Search

Slag-sulphoaluminate cement (G·SAC), an effective alternative to Portland cement, has garnered significant attention for its low hydration heat, good mechanical properties and durability. However, the role of slag fineness on the hydration of G·SAC remains unclear. To address this, the study employed three levels of slag fineness to evaluate its effects on G·SAC in terms of hydration heat, hydrates, mechanical properties and pore structure. Results indicate that increasing slag fineness from 400 m²/kg to 800 m²/kg shortens the induction period by 2 hours but does not significantly alter the hydration heat ∼ 110 J/g or 3-day strength (around 30 MPa). In contrast, slag with a specific surface area of 1300 m²/kg significantly enhances the hydration of G·SAC, evidenced by an increased hydration heat of 180 J/g and a higher degree of slag hydration from 24 % to 79 %. This leads to greater formation of hydrates and a higher polymerization degree of C-S-H, which in turn improves pore structure density and early strength, reaching 38.8 MPa at 3 days. To sum up, a slag fineness ∼ 400 m²/kg is optimal for engineering applications, offering a balance between performance and economic considerations. [Display omitted] • G·SAC with an S95 slag can serve as an effective alternative to PC. • G·SAC with an S105–1300 slag demonstrates an enhanced hydration and early strength. • The impact of slag refinement on G·SAC is notably enhanced at greater fineness. • G·SACs with varying slag fineness consistently meet the criteria for low hydration heat. [ABSTRACT FROM AUTHOR]