基于有限元法的混凝土输水管内硫酸根离子扩散分析  

Numerical Analysis on Sulfate Ion Diffusion in Concrete Pipe Based on Finite Element Method

作　　者：殷光吉 温小栋 冯蕾 张振亚 王赛赛 YIN Guang-ji;WEN Xiao-dong;FENG Lei;ZHANG Zhen-ya;WANG Sai-sai(Ningbo University of Technology,School of Civil and Transportation Engineering,Ningbo 315000,China)

机构地区：[1]宁波工程学院建筑与交通工程学院,浙江宁波315000

出　　处：《数学的实践与认识》2022年第1期148-155,共8页Mathematics in Practice and Theory

基　　金：浙江省自然科学基金探索项目(LQ21E080008);国家自然科学基金(51569035);2020年宁波工程学院科研启动基金。

摘　　要：暴露于硫酸盐环境中的混凝土输水管易遭受硫酸盐化学侵蚀,导致其耐久性退化、提前失效;而环境中硫酸根离子传输进入混凝土是其化学侵蚀的前提.为获得混凝土内硫酸根离子的扩散进程,首先基于Fick定律及质量守恒定律,建立饱和混凝土管内硫酸根离子的扩散-反应模型.其次,将扩散-反应模型的边界条件齐次化,建立其有限元控制方程.然后,开展硫酸钠溶液中水泥砂浆圆柱试件的腐蚀试验,测定试件不同深度处的硫酸根离子浓度,与模型计算结果对比,以验证模型.最后,开展数值模拟研究,分析混凝土输水管外表面、内外表面暴露于浓度恒定或振荡的硫酸盐溶液情况下管内硫酸根离子浓度的时空分布.The concrete pipe exposed to sulfate environment suffers from the chemical sulfate attack,causing the durability deterioration and premature failure of the pipe.The transport of sulfate ion from outside environment into concrete is the premise of chemical sulfate attack.In order to predict the sulfate diffusion progress in concrete,firstly,a diffusionreaction model of sulfate ion in the saturated concrete pipe was established by using Fick ’s law and mass conservation law.Secondly,the boundary conditions of diffusion-reaction model were transformed into homogeneous conditions,and a finite element governing equation of the model is further established.Then,a corrosion experiment of cement mortar column specimens immersed into sodium sulfate solution was carried out to measure the sulfate concentrations in the different depths of the specimens.The sulfate concentrations calculated by the established model were compared with that from the corrosion experiment to validate the model.Finally,an numerical simulation is performed to analyze the spatial-temporal distribution of sulfate concentration in concrete pipe in the cases of its outside surface,the outside and inside surfaces exposed to sulfate solution with constant or oscillatory concentrations.

关 键 词：硫酸根离子 扩散-反应模型 有限元控制方程 数值模拟 

分 类 号：TU528.7[建筑科学—建筑技术科学]