基于侵蚀损伤演化的硫酸根离子在混凝土中的扩散模型研究

Based on Fick's second law and the mechanism of damage evolution caused by sulfate attack, a new nonlinear diffusion model considering the damage evolution is proposed. Moreover, damage evolution and hydration are introduced into diffusion coefficient, and a sulfate ionic consumption item due to chemical reaction will be put into Fick's equation. The damage evolution is a function related to the initial porosity of sample and erosion time, as well as the concentration of sulfate solution, and it can be obtained from the ultrasonic experiment. This differential diffusion equation is then solved by numerical method. The numerical result shows that initial porosity and erosion damage, as well as the sulfate concentration can significantly affect the diffusion of sulfate ions in concrete.