FREEZING-THAWING FAILURE EVOLUTION MODEL OF CONCRETE BASED ON HYDROSTATIC PRESSURE THEORY

Quantitative analysis of frost resistance of concrete materials is one of the basic requirements of digital concrete era. Based on the comprehensive analysis of the factors affecting the frost resistance of concrete and the existing hypothesis of freeze-thaw damage of concrete, the theoretical model of freeze-thaw damage of concrete is deduced. The model uses internal and external independent variables, and takes the micro-structure evolution of the material as the core, so as to realize the quantitative analysis of the frost resistance of concrete. The calculation analysis of the model shows that the physical and mechanical properties, bubble content and pore size distribution, minimum temperature, cooling rate, stress level, material overflow distance and other internal and external factors of cement hydration products affect the freeze-thaw damage characteristics of cement-based materials from different angles and to different degrees. Reasonable design of bubble content and bubble aperture can effectively improve the frost resistance durability of concrete. The above analysis is in good agreement with the existing research results. The research results can provide reference for the freezing resistance design of concrete.