Effect of an Ultrafine Powder on the Properties of a Fast Hardening Sulfoaluminate Cement Mortar

Considering the problem that sulfoaluminate cement easily collapses due to its late strength and insufficient bonding strength, ultrafine powder is used to replace part of it.The effects of an ultrafine powder with different dosages on the compressive and flexural strength, bonding strength, wear resistance, frost resistance, hydration heat release and microstructure of a fast hardening sulfoaluminate cement mortar were investigated.The results show that adding 20 % and 30 % ultrafine powder can improve the early strength of the cement mortar and maintain the later-age strength.Also, it has good bonding performance, excellent frost resistance and no cracking or peeling after 300 freeze-thaw cycles.It can also reduce the early hydration heat release of the cement mortar and improve the microstructure of the matrix.