Abstract：The corrosion of concrete by seawater has many chemical characteristics, including sulfate ion, chloride ion and their coupling action. At present, there is no consensus on the evolution of concrete modulus under the corrosion of sulfate ion and chloride ion. First, the accelerated corrosion experiment of artificial seawater was carried out with concrete samples prepared in this paper. Then, non-destructive detection technology was used to explore the change of ultrasonic propagation speed in concrete under the joint corrosion of sulfate ions and chloride ions, and the evolution law of concrete modulus under corrosion conditions was obtained. On this basis, combined with the reaction equations of the chemical processes such as the continuous hydration of the material, the chemical reactions of sulfate ions with concrete in solid and liquid phase, the complexation reaction of chloride ions, and the corresponding chemical reaction rate equations, a mechanical-chemical model of the modulus evolution of concrete under the coupled sulfate-chloride erosion was established, and the competition mechanism of the two ions was elucidated. It provides theoretical support for the design of Marine concrete with better durability.
2025, Vol. 46 
