Thaumasite form of sulfate attack in limestone cement concrete: The effect of cement composition, sand type and exposure temperature

Three cements were examined: (i) Portland cement, (ii) limestone cement containing 15% limestone and (iii) limestone cement containing 30% limestone. Concrete specimens, prepared with siliceous or calcareous sand, were immersed in a 1.8% MgSO4 solution and cured at 5 °C and 25 °C for 3 years. Limestone cement concrete is susceptible to thaumasite form of sulfate attack at 5 °C. In concrete with siliceous sand the damage is greater, the higher the limestone content of the cement. In concrete with calcareous sand the sulfate resistance seems to be independent on the limestone content. Concrete with calcareous sand showed better performance than concrete with siliceous sand. No damage was observed in the specimens exposed to sulfate solution at 25 °C.

► Limestone cement concrete (LCC) suffers from thaumasite sulfate attack at 5 °C.
► In LCC with siliceous sand the damage is greater, the higher the limestone content.
► In LCC with calcareous sand the damage is independent on the limestone content.
► LCC with calcareous sand showed better performance than LCC with siliceous sand.
► No damage was observed in specimens exposed to sulfates at 25 °C for 36 months.