Study on a high strength ternary blend containing calcium sulfoaluminate cement/calcium aluminate cement/ordinary Portland cement

Repair mortars containing calcium sulfoaluminate cement (CSA), calcium aluminate cement (CAC) and ordinary Portland cement (OPC) was prepared. The effects of binder proportion on the mechanical properties of ternary blends were researched. Moreover, the hydration products and microstructure of that were observed by XRD, TG, and SEM. Results showed that the addition of CAC-OPC can accelerate the setting of CSA and enhance its early strength, which is mainly contributed to the rapid formation of massive ettringite. The strength of ternary blends continues to increase with time resulted from the decrease of porosity. Moreover, the microstructure of ettringite in CSA is significantly affected by the presence of CAC and OPC.