Modeling of the chloride diffusivity of ultra-high performance concrete with a multi-scale scheme
Modeling of the chloride diffusivity of ultra-high performance concrete with a multi-scale scheme
复制标题
采用多尺度方案对超高性能混凝土的氯离子扩散率进行建模
DOI：
10.1088/1361-651x/ab1838
复制
发表时间：
2019-07-01
影响因子：
1.8
通讯作者：
Sun, Wei
中科院分区：
文献类型：
--
作者：
Gu, Chunping;Ye, Guang;Sun, Wei
超高性能混凝土(UHPC)的氯离子扩散系数是决定超高性能混凝土结构在氯离子环境中使用寿命的关键参数。在本研究中，提出了一个多尺度模型来预测超高性能混凝土的宏观性质，即氯离子扩散系数，该模型考虑了微观和细观尺度的结构信息。在微观尺度上，基于扩展的HYMOSTRUC3D模型和有限元方法对超高性能混凝土浆体的氯离子扩散系数进行了预测。在细观尺度上，采用ANM模型和有限元方法计算了超高性能混凝土砂浆的氯离子扩散系数。在宏观尺度上，用两相模型确定了超高性能混凝土的氯离子扩散系数。使用较低尺度的氯扩散系数作为输入，以预测较高尺度的氯扩散系数。进行了非稳态氯离子扩散试验，验证了模型的有效性。结果表明，所提出的多尺度模型给出的超高性能混凝土的氯扩散系数略高于实验结果。但该模型对氯离子环境下超高性能混凝土结构的耐久性设计仍有一定的参考价值。
The chloride diffusivity of ultra-high performance concrete (UHPC) is the key parameter that determines the service life of UHPC structures in chloride environments. In this study, a multi-scale model, which considered the structural information at micro and meso-scale, was proposed to predict macro property, i.e. chloride diffusivity, of UHPC. At micro-scale, the chloride diffusivity of UHPC paste was predicted based on an extended HYMOSTRUC3D model and a finite element method. At meso-scale, Anm model and finite element method were applied to calculate the chloride diffusivity of UHPC mortar. At macro-scale, the chloride diffusivity of UHPC was determined with a two phase model. The chloride diffusivity at a lower scale was used as input to predict the chloride diffusivity at the higher scale. Non-steady chloride diffusion tests were performed to validate the proposed model. The results showed that the proposed multi-scale model gave a little higher chloride diffusivity of UHPC than experiment results. However, the proposed model is still helpful for the durability design of UHPC structure in chloride environments.