Durability And Service Life Prediction Of Concrete Exposed To Environment With Saline Soil And Dry-cold In West Of China

Salty soil regions distribute widely in western China. Being exposed to low temperature and chlorate and sulfate environment, with over 0.5% gypsum, Glauber's salt and halite in the solum, the damage of concrete accelerates. Chemical erosion, rarely quoted in literatures, dominants the damage. The synergistic reaction of chlorate and sulfate needs to be definitely qualified.In order to explore the concrete durability under the harsh environment in the west, in this paper, based on the research of durability at home and abroad, cement specimens and mixed solutions of sulfate and chloride with different concentration, reasonable combinations was conducted by drying-immersion cycles and freezing-thawing cycles. By simulating the factors in western China that influence the erosion, the damage mechanism of concrete was investigated under the multiple destructive factors.Basing on measuring the mass property and dynamic elastic modulus of specimens using theoretical and experimental methods, this paper investigated the damage mechanism under synergistic reaction of chlorate and sulfate. Quantitative analysis of sulfate ion in mixed solutions with different concentration and under different drying-immersion cycles was conducted. Under the second law of Fick, The theoretical relativity of sulfate ion permeation, sulfate ion and the number of drying-immersion cycles was given studying the diffusivity of sulfate ion under sulfate environment inside specimens.