交变荷载对硫酸盐侵蚀混凝土速率影响研究

Study on the Influence of Alternation Loading to the Speed of Sulfate Corrosion Concretes

为了研究交变荷载对硫酸盐侵蚀混凝土腐蚀速率的影响,引入受交变荷载影响的硫酸根离子有效扩散系数Dt,采用有限差分法通过matlab软件求解不同交变荷载应力水平、加载频率作用下的有效扩散系数Dt,并与已知的单一硫酸根离子在混凝土中扩散系数D进行比对分析。结果表明:有效扩散系数Dt的引入可以有效地表征交变荷载对硫酸盐侵蚀混凝土速率的影响,交变荷载作用明显地提高了硫酸根离子的有效扩散系数,加速了硫酸根离子的侵蚀速率,侵蚀速率随交变荷载应力水平、加载频率的增加而呈现不同程度的提高。

In order to study the influence of fatigue loading to the speed of the sulfate corrosion concrete,introduced effective diffusion coefficient of sulfate ion（Dt）on the basis of the Fick second law in unsteady state diffusion,used the finite difference method to solve effective diffusion coefficient of sulfate ion（Dt） under different stress level of alternation loading and loading frequency,and contrasted with the known sole sulfate ion＇s diffusion coefficient D in concretes.The result indicated： the effective diffusion coefficient Dt is a good way to token the influence of fatigue loading to sulfate ion diffusion,and the alternation loading has enhanced distinctly effective diffusion coefficient of sulfate ion and the speed of the sulfate corrosion concrete,the speed of the sulfate corrosion concrete increased with the enhancement of stress level and loading frequency of fatigue loading.