The synergistic effect of silica fume and γ-C2S on the carbonation resistance of supersulfated cement

The poor carbonation resistance of supersulfated cement (SSC) is one of the key bottlenecks limiting its engineering applications. This paper investigates the synergistic effect of γ-C 2 S and silica fume (SF) on improving the carbonation resistance of SSC. The results show that γ-C 2 S can improve the compressive strength of SSC both before and after carbonation, and the strength improvement effect is more significant for the samples with both γ-C 2 S and SF. γ-C 2 S can reduce the porosity of SSC after 14 days of carbonation from ∼36% to ∼32%. SF can enhance the carbonation reaction degree of γ-C 2 S, strengthen the carbonation reinforcement effect, and reduce the porosity of carbonated SSC to ∼27%.This study provides a new method for improving the carbonation resistance of SSC. In addition, the promoting effect of SF on the carbonation reaction of γ-C 2 S also contributes to a new idea for improving the mechanical properties of γ-C 2 S-based carbonation-strengthened materials. • The combination of SF and γ-C 2 S improves the carbonization resistance of SSC; • The combination of SF and γ-C 2 S lowers the porosity of carbonated SSC; • The SF can promote the carbonation enhancing effect of γ-C 2 S in the hardened SSC.