Investigation of the mechanical and durability properties of sustainable high performance concrete based on calcium sulfoaluminate cement

Calcium sulfoaluminate (CSA) cement could be a promising alternative to ordinary Portland cement (OPC) to reduce environmental impact of concrete production. This paper investigates the performance of high performance concretes produced with CSA cement in total or partial substitution of OPC (or OPC with ground granulated blast-furnace slag (GGBS)) at water-binder ratio of 0.35. Mechanical, physical, durability, and microstructural properties of different concretes were assessed. The results show that substitution of OPC with CSA cement improves the mechanical properties of concrete. The addition of CSA cement results in a reduced shrinkage deformation, while it increases the risk of carbonation and corrosion of steel rebars. Combination of CSA cement with OPC and GGBS in the binary and ternary systems causes a reduction of the strengths of concrete, and adversely affects the durability properties. The SEM observation show that ettringite crystals decomposed in the CSA-blended mixes and resulted in the formation of carbonated phases.