Ionic transport features in concrete composites containing various shaped aggregates: a numerical study
Ionic transport features in concrete composites containing various shaped aggregates: a numerical study
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含有各种形状骨料的混凝土复合材料中的离子输运特征：数值研究
DOI：
10.1016/j.compstruct.2017.03.088
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发表时间：
2018-01-01
影响因子：
6.3
通讯作者：
Li, Long-yuan
中科院分区：
文献类型：
--
作者：
Liu, Qing-feng;Feng, Gan-lin;Li, Long-yuan
氯离子引起的耐久性问题严重缩短了混凝土基础设施和建筑物的使用寿命。为了阐明夹杂物结构响应的输运机制，将混凝土视为砂浆、骨料和界面过渡区（ITZ）的三相复合体，数值研究了各相的形态和非均匀性对夹杂物结构响应的影响.建立了一系列具有不同形状和体积分数的团聚体的细观数值模型，研究团聚体对离子迁移的影响。与大多数现有的已发表的研究工作在这一领域，多组分离子传输理论，考虑到离子相互作用已被用于本研究。通过耦合质量守恒和泊松方程，得到了单个离子的时空浓度分布结果。其他重要的因素，如外加电场，混凝土的异质性，离子结合和ITZ也被认为是在这项研究中和检查。通过这种相对彻底的数值分析，一些重要的功能，聚集体形状的影响，基于多物种建模，这是以前没有得到适当的研究，突出显示。(C)2017爱思唯尔有限公司版权所有
The service life of concrete-based infrastructure and buildings is seriously shortened due to the chloride-induced durability problems. In order to clarify the transport mechanism associated with the response of inclusion structures, this paper presents a numerical study on the influence caused by morphology and heterogeneity of individual phases, in which the concrete is treated as a three-phase composite including mortar, aggregates and interfacial transition zone (ITZ). A series of meso-scale numerical models with different shapes and volume fractions of aggregates are developed for examining the effects of aggregates on ionic migration. Unlike in most of the existing published research work in this area, a multi-component ionic transport theory which takes ionic interactions into consideration has been utilised in this study. By coupling mass conservation and Poisson's equations, the time-spatial concentration distribution results for individual ionic species are obtained. Other important factors such as the externally applied electric field, concrete heterogeneity, ionic binding and ITZ are also considered and examined in this study. Through this relatively thorough numerical analysis, some important features about the effect of aggregate shape based on multi-species modelling, which have previously not been properly investigated, are highlighted. (C) 2017 Elsevier Ltd. All rights reserved.