Experiment and simulation of chloride ion transport and binding in concrete under the coupling of diffusion and convection
Experiment and simulation of chloride ion transport and binding in concrete under the coupling of diffusion and convection
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DOI：
10.1016/j.jobe.2021.103610
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发表时间：
2021-11-25
影响因子：
6.4
通讯作者：
Li, Huajian
中科院分区：
文献类型：
--
作者：
Liu, Zhiyong;Wang, Yuncheng;Li, Huajian
扩散和对流是影响氯离子在不饱和胶凝材料中传输的主要因素。本研究采用毛细管吸盐实验和稳态迁移实验研究了非饱和混凝土中氯离子的迁移情况，建立了考虑养护龄期、初始含水饱和度和氯离子综合影响的混凝土修正氯离子扩散对流模型。结果表明，非饱和混凝土中氯离子迁移可分为安全阶段、初始阶段、对流阶段、减速阶段、扩散阶段和稳定阶段6个阶段，氯离子结合系数与初始饱和度近似呈线性关系，粉煤灰掺量为40%或砂掺量为60%的混凝土对氯离子迁移的阻挡效果最好。
Diffusion and convection are the main factors affecting chloride ion transport in unsaturated cementitious materials. In this study, capillary salt absorption experiment and steady-state migration experiment were used to investigate the chloride ion migration in unsaturated concrete, and a modified chloride ion diffusion-convection model was established for concrete considering curing age, initial water saturation and the combined effect of chloride ion. The results show that the chloride ion migration in unsaturated concrete can be divided into six stages: safety stage, initial stage, convection stage, deceleration stage, diffusion stage and stablilization stage, the chloride ion binding coefficient is approximately linear with the initial saturation, and the concrete with fly ash content of 40% or sand content of 60% has the best blocking effect on chloride ion migration.