Research into the concrete freeze-thaw damage mechanism based on the principle of thermodynamics

摘要

Based on thermodynamic principles, this paper uses ANSYS to simulate thermal stress of the concrete piers and analyzes the main factors, namely, structure size, concrete strength, boundary conditions and freeze-thaw cycle system which affect thermal stress. We then draw the conclusion that the existence of thermal stress will make the concrete structure undertake cracking risk. Thermal stress difference in massive concrete structures is large and the influence of thermal stress on concrete structures is only limited to a certain size range; thermal stress inside the concrete increases with the increment of concrete strength grade; thermal stress inside the concrete decreases with the increment of boundary constraint conditions; the rate of change of thermal stress increases with the acceleration of freeze-thaw cycles. Meanwhile, we propose that through increasing the thickness of the protective layer and boundary constraint conditions properly, cracking risk of concrete structures can be reduced.