考虑热湿影响的氯盐侵蚀下混凝土中多相传输与相变模拟

Numerical Simulation on Multiphase Transportation and Phase Transition in Chloride Contaminated Concrete with the Thermo-Hygro Coupled Effects

在富含氯化物的环境中,氯离子引起的钢筋锈蚀是导致钢筋混凝土结构性能退化的主要原因之一。如何预测氯离子侵蚀过程以及提高结构抗侵蚀能力是混凝土结构工程师所必须面临的最严峻挑战。为此,本实验建立了一个用于数值分析混凝土中氯离子传输过程的计算模型。为能再现混凝土结构在非饱和、非等温条件下的真实状况,模型控制方程中考虑了氯离子、湿分、空气、热量在混凝土中的耦合传输过程,以及相互间的耦合作用。控制方程中所涉及的耦合系数均来自已有的材料模型和实验数据,而方程的数值求解使用了有限单元法。模型计算结果与试验数据显示出良好的吻合度,研究结果可为混凝土结构的减防腐蚀灾害设计提供重要的参考。

Corrosion of reinforcing steel due to chloride attack is one of the main causes of deterioration process for reinforced concrete structures exposed to chloride-rich environment.How to predict the chloride penetration process into concrete structures and improve the penetration resistance of concrete to various chloride sources are the most serious challenges to concrete structural engineers that they have to face.Therefore,a theoretical and computational model for chloride transport in concrete was presented.The governing equations take into account the coupled transport process of chloride ions,moisture,air and heat.This represents the actual condition of concrete structures which are always found in non-saturated and non-isothermal conditions.The fully coupled effects among chloride,moisture,and heat diffusion were considered and included in the model.The coupling parameters evaluated based on the available material models and test data were proposed and explicitly incorporated in the governing equations.Then the coupled transport equations were solved numerically by the finite element method.The validation was performed by comparing the numerical results obtained from the present model with the available test data and a good agreement was observed.And the research results will provide important reference for the anticorrosion design of concrete structures in practical engineering application.