Abstract:In this paper, the freezing and thawing properties of concrete in sodium sulphate solution were investigated. The experimental results showed that the influence of sodium sulphate solution is different for concrete with different m w/ m c. For concrete with higher m w/ m c, the decrease of relative dynamic modulus of elasticity exhibites a slight slower in sulphate solution than that in fresh water during the process of freezing and thawing cycles. In sulphate solution, the concrete can take more cycles of freezing and thawing than that in water. However, for high strength concrete with lower m w/ m c, the failure of concrete occurs earlier in solution than that in fresh water due to the sulphate attack. The failure mode is brittle crack.