The Sulfate Attack Of Concrete In The Environment And Diffusion Reaction Principles And Numerical Simulation

The durability damage of concrete not only shorten the service lifetime of concrte structures, but also reduce the safety and reliability of engineering structures. There are many factors which can cause concrete structure durability damage. Sulfate attack is one of the important environmental factors that causes the damage of concrete durability. Therefore, it is a matter of great significance for improving the safety on the design of concrete structures and predicting the service lifetime of concrete structures to study the durability of concrete structure under the environmental sulfate attacks. The main contexts in the present study include as follows:Firstly, the actuality of concrete structure durability and the damage mechanism of concrete under sulfate attack are introduced. Secondly, based on classical Fick's second law, the models reflecting on one, two and three dimension nonlinear and nonsteady diffusion-reaction laws of concrete under sulfate attack have been established, and the numerical solutions are obtained by the finite difference method. Finally, the diffusion-reaction law of sulfate ion in concrete are analyzed by numerical simulations under environmental sulfate attack, and the comparisons between modeling and experimental results for one dimension diffusion-reaction law of sulfate ion in concrete are carried out.The results show that, concentration distribution and concentration expended of the sulfate ion present ladder in concrete. With time increasing, diffusion and reaction trend to be dynamical equilibrium. The shorter distance from the diffusion source, the less time needed for reaching dynamical equilibrium, the higher concentration. The modeling results are in agreement with the experimental results for one dimension diffusion-reaction law of sulfate ion in concrete. Therefore, the established models in this paper may be used to analyze the diffusion-reaction law of sulfate ion in concrete under environmental sulfate attack.