Sulfate resistance of steam cured ferronickel slag blended cement mortar

The performance of steam cured (80 degrees C for 7 h) and standard cured ferronickel slag (FNS) cement mortar (0%, 20% replacement of cement with FNS) subjected to sodium sulfate attack were investigated. The results show that the incorporation of FNS improves the sulfate resistance of cement mortar on both early age standard curing condition and early age steam curing condition, however, the impact of early age steam curing on the sulfate resistance of FNS blended cement mortar under dry-wet cycles and partial immersion is the opposite. It is noted that early age steam curing promotes the formation of hemicarbonate and C-A-S-H, which accounts for the enhanced sulfate resistance of steam cured FNS blended cement mortar. The influence of (Mg, Fe)(2)SiO4 and MgSiO3 in FNS on the hydration products is found to be very limited regardless of early age curing condition.