干湿循环作用下钢筋混凝土氯离子侵蚀与寿命预测

Chloride Erosion and Life Prediction of Steel Reinforced Concrete Under Dry and Wet Cycles

在已有水泥混凝土氯离子侵蚀模型基础上,综合考虑外部环境因素(温度、湿度、风速)与混凝土自身条件(龄期、氯离子吸附效应)对非饱和混凝土氯离子侵蚀的影响,建立干湿循环下混凝土氯离子传输模型并进行实验验证。根据运算的复杂程度对Fib Model Code模型进行优化,建立干湿循环作用下钢筋混凝土寿命预测模型,可为实际工况下受氯离子侵蚀钢筋混凝土材料设计与寿命预估提供参考。

A mathematical model was presented to predict chloride ion migration in cement concrete under drywet cycles.In consideration of the effect of external environmental factors（temperature,humanity and wind speed）and the concrete conditions（age,chloride ion adsorption effect）on the chloride ion diffusion of unsaturated concrete was studied.The Fick′s law was adopted to describe the diffusion of chloride.A solution of the diffusion equation was proposed to determine the chloride concentration under dry-wet cycles as a function of time and space.The chloride concentration responses were obtained and compared with a variety of available test data.Model simulations indicated a reasonable agreement with experimental data available in the literature.To simplify the model,a facilitate model was put forward to predict the corrosion life of concrete.