Numerical Simulation of the Effect of Freeze–Thaw Cycles on the Durability of Concrete in a Salt Frost Environment

摘要

In order to improve the accuracy of the analysis of the impact of freeze–thaw cycle on concrete durability in a salt freezing environment, the numerical simulation of the impact of the freeze–thaw cycle on concrete durability in a salt freezing erosion environment is studied in this paper. Firstly, considering the influence of axial force and bending moment on the relationship between bending moment and curvature, a concrete fiber beam column model is established. Then, according to the joint influence of temperature field, stress field and seepage field on concrete in the process of freezing and thawing, the control differential equation of the freezing and thawing cycle is established. The freeze–thaw damage section is divided, the non-uniform distribution of freeze–thaw damage is determined, and the division of the freeze–thaw damage section is completed. According to the linear relationship between freeze–thaw damage degree, relative dynamic elastic modulus, freeze–thaw cycle times and position variables, the durability of concrete is numerically simulated, and the attenuation law of bond strength at different section depths after freeze–thaw is determined. The results show that the temperature curve simulated by the design method is consistent with the actually measured temperature curve, which can better reduce the temperature change of the inner core of the test block during freezing and thawing, and the relative dynamic elastic modulus is in good agreement with the actual value, which can prove that the method in this paper has certain practical application value. It is expected to provide some reference for solving the durability problem of concrete in a salt frost erosion environment and the optimal design of concrete structures.