Stochastic Damage Model of Concrete during Freeze-thaw Process

摘要

The anti-frost property of concrete is one of the major parts of study on the durability of concrete. By viewing all over the world, due to the alternation of external temperature upon and under zero centigrade, concrete structures located on the areas of high latitude are usually unavoidable to suffer the damage caused by freeze-thaw cycles. Due to the insufficiency of theoretical foundation and the complexity of freeze-thaw durability itself, the contemporary studies are far from integrity in respect to the theoretical consensus. What is more, the researching measures concentrate more on the experimental approach. Based on this, it would be necessary to carry out relevant theoretical study on the freeze-thaw durability of concrete. The freeze-thaw damage of concrete is equivalent to that when internally generated hydrostatic pressure during freezing thawing process is greater than the destruction produced by then tensile strength of concrete. Although hydrostatic pressure is uniform in all directions, concrete is a kind of uneven brittle material. When it's under the stress by three even directions, the final destruction always happens in the weakest section, which is very similar to tensile breakage. In this case, unilateral tensile can be used to simulate the internal hydrostatic pressure affection of concrete during freezing and thawing process. In this article, one-dimensional micromechanical model of random damage will be used to the research of freeze-thaw damage and try to quantify it.