基于裂缝混凝土的修正氯离子迁移模型研究

通过研究裂缝混凝土内的氯离子运移，建立了混凝土内考虑扩散、结合和电迁移场作用以及裂缝影响的氯离子迁移耦合模型。预测混凝土寿命。模型从已有试验数据中得到了较好验证。在南通盐渍土环境，运用Comsol Multiphysics软件计算混凝土内氯离子随时间和空间的分布；随裂缝宽度、深度及保护层厚度变化的混凝土使用年限变化规律。研究表明：混凝土内氯离子浓度，随时间增加而增加，增速减小；随离子侵入混凝土深度增加而减小，减速趋缓。氯离子从裂缝运移到混凝土孔隙，浓度突降。混凝土使用年限，随保护层厚度增加呈近似线性增加；随裂缝深度增加而减小；随裂缝宽度增加呈指数型函数关系。

STUDY ON MODIFIED CHLORIDE LON MIGRATION MODEL IN CRACK CONCRETE

Through the study of chloride ion in cracked concrete, a coupling model is established, which considers diffusion, binding and electric potential and the crack influence. Predicting the concrete service life. The model was verified by experimental data. In Nantong saline soil, the chloride ion migration in different width and depth crack and the variation law of concrete service life was analyzed by Comol Multiphysics. The research shows that the chloride ion concentration decreases with the increase of intrusion depth, and increases over time. When moving into concrete, the chloride concentration dropping suddenly. The concrete service life increases with the increase of the protective cover thickness, and decreases with the increase of the crack depth, and the exponential function relation with the increase of the crack width.