Ground granulated blast furnace slag effect on the durability of ternary cementitious system exposed to combined attack of chloride and sulfate

- Durability of the ternary system exposed to combined NaCl and Na2SO4 attacks is tested.
- GGBS can improve the resistance to sulfate and chloride attacks of the ternary system.
- The optimum amount of GGBS in 5% NaCl, 5% Na2SO4, and 5% NaCl-5% Na2SO4 solutions were 35%, 25%, and 25%.

This paper presents a study on the durability of the ternary cementitious system (TCS) containing ordinary Portland cement, calcium aluminate cement and calcium sulfate with different content of ground granulated blast furnace slag (GGBS) when subjected to 5% NaCl, 5% Na2SO4, and 5% NaCl-5% Na2SO4 attacks. The results showed that the partial replacement of TCS by GGBS increased bound chloride, enhanced compressive strength, and decreased apparent porosity. Besides, the presence of chloride mitigated sulfate attack. The presence of sulfate decreased the contents of free and total chloride, and limited the formation of Friedel's salt.