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    王立成

    • 教授     博士生导师   硕士生导师
    • 性别:男
    • 毕业院校:大连理工大学
    • 学位:博士
    • 所在单位:土木工程系
    • 学科:结构工程. 水工结构工程. 港口、海岸及近海工程
    • 办公地点:建设工程学部4号楼316
    • 联系方式:wanglich@dlut.edu.cn
    • 电子邮箱:wanglich@dlut.edu.cn

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    Mesoscale simulation of chloride diffusion in concrete considering the binding capacity and concentration dependence

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    论文类型:期刊论文

    发表时间:2011-04-01

    发表刊物:COMPUTERS AND CONCRETE

    收录刊物:Scopus、SCIE、EI

    卷号:8

    期号:2

    页面范围:125-142

    ISSN号:1598-8198

    关键字:mesoscale simulation; chloride diffusion; binding capacity; concentration dependence; truss network model

    摘要:In the present paper, a numerical simulation method based on mesoscopic composite structure of concrete, the truss network model, is developed to evaluate the diffusivity of concrete in order to account for the microstructure of concrete, the binding effect of chloride ions and the chloride concentration dependence. In the model, concrete is described as a three-phase composite, consisting of mortar, coarse aggregates and the interfacial transition zones (ITZs) between them. The advantage of the current model is that it can easily represent the movement of mass (e.g. water or chloride ions) through ITZs or the potential cracks within concrete. An analytical method to estimate the chloride diffusivity of mortar and ITZ, which are both treated as homogenious materials in the model, is introduced in terms of water-to-cement ratio (w/c) and sand volume fraction. Using the newly developed approaches, the effect of cracking of concrete on chloride diffusion is reflected by means of the similar process as that in the test. The results of calculation give close match with experimental observations. Furthermore, with consideration of the binding capacity of chloride ions to cement paste and the concentration dependence for diffusivity, the one-dimensional nonlinear diffusion equation is established, as well as its finite difference form in terms of the truss network model. A series of numerical analysises performed on the model find that the chloride diffusion is substantially influenced by the binding capacity and concentration dependence, which is same as that revealed in some experimental investigations. This indicates the necessity to take into account the binding capacity and chloride concentration dependence in the durability analysis and service life prediction of concrete structures.