非饱和混凝土中氯离子传输机理

发布时间：2018-04-18 17:24

本文选题：非饱和混凝土 + 氯离子传输　；参考：《建筑材料学报》2016年01期

【摘要】：基于Fick第一定律和质量守恒定律,在水的质量守恒方程中考虑对流作用引起的水的改变量,建立了扩散和对流完全耦合的非饱和状态混凝土中的氯离子传输理论模型;采用交替方向隐式有限差分法(ADI)对传输控制方程进行数值求解,与Ababneh等提出的氯离子传输理论模型以及美国道路与运输协会的试验数据进行了对比.另外,基于物质守恒定律,通过定义容量矩阵、传递矩阵和氯离子通过率向量,并与瞬态热平衡方程中的各参量进行等效,给出了基于ANSYS热分析模块模拟非饱和状态混凝土中氯离子传输的数值方法.结果表明,所提出的非饱和状态混凝土中氯离子传输理论模型与美国道路与运输协会的试验数据之间的吻合程度要比Ababneh模型更好,但2种传输理论模型与试验数据之间的差距都非常小.因此,考虑对流作用引起的水的改变量对于实际工程不会起到太大影响,但能更好地与氯离子传输的物理过程相吻合,有助于完善非饱和状态混凝土中氯离子传输的理论体系.基于ANSYS的非饱和状态混凝土中氯离子传输模拟方法的精度不如氯离子传输理论模型高,但计算代价较小,适用于实际工程.
[Abstract]:Based on the first law of Fick and the law of mass conservation, a theoretical model of chloride ion transport in unsaturated concrete with fully coupled diffusion and convection is established by considering the quantity of water change caused by convection in the mass conservation equation of water.The alternating direction implicit finite difference method (ADI) is used to numerically solve the transmission control equation, which is compared with the theoretical model of chloride ion transport proposed by Ababneh et al and the experimental data of the American Road and Transportation Association.In addition, based on the conservation law of matter, the capacity matrix, transfer matrix and chloride passing rate vector are defined, and are equivalent to the parameters in the transient heat balance equation.A numerical method for simulating chloride transport in unsaturated concrete based on ANSYS thermal analysis module is presented.The results show that the proposed theoretical model of chloride transport in unsaturated concrete is in better agreement with the experimental data of the American Road and Transportation Association than the Ababneh model.However, the gap between the two transmission theory models and experimental data is very small.Therefore, the amount of water change caused by convection will not have much effect on practical engineering, but it can better coincide with the physical process of chloride ion transport, which is helpful to improve the theoretical system of chloride ion transport in unsaturated concrete.The simulation method of chloride ion transport in unsaturated concrete based on ANSYS is less accurate than the theoretical model of chloride ion transport, but the calculation cost is relatively small, so it is suitable for practical engineering.
【作者单位】：哈尔滨工业大学土木工程学院;
【基金】：国家重点基础研究发展计划(973计划)项目(2011CB013600) 国家自然科学基金资助项目(51308166) 山东省自然科学基金资助项目(ZR2011EEQ028)
【分类号】：TU528

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