Lattice modeling of chloride diffusion in sound and cracked concrete
Lattice modeling of chloride diffusion in sound and cracked concrete
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DOI：
10.1016/j.cemconcomp.2013.05.003
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发表时间：
2013-09
影响因子：
10.5
通讯作者：
B. Šavija;J. Pacheco;E. Schlangen
中科院分区：
文献类型：
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作者：
B. Šavija;J. Pacheco;E. Schlangen
钢筋混凝土结构经常暴露在恶劣的环境条件下。最值得注意的是，来自海水或除冰盐的氯离子是潜在有害的，因为它们促进钢筋的腐蚀。足够质量和深度的混凝土保护层可确保对钢筋的保护。然而，有必要研究材料非均匀性和裂缝对混凝土中氯离子侵入的影响。这是通过提出一个三维晶格模型，能够模拟氯离子在饱和的声音和开裂的混凝土中的传输。计算确定运输性能的各个阶段在非均质混凝土（骨料，砂浆，界面），知道混凝土的组成和平均运输性能的手段，提出和讨论。在数值试验和文献研究的基础上，采用了裂纹网格单元有效扩散系数与裂纹宽度的关系式。该模型与晶格断裂模型相结合，使氯离子侵入裂缝混凝土的模拟。该模型进行了验证，从文献中的数据，显示出良好的协议与实验结果。
Reinforced concrete structures are frequently exposed to aggressive environmental conditions. Most notably, chloride ions from sea water or de-icing salts are potentially harmful since they promote corrosion of steel reinforcement. Concrete cover of sufficient quality and depth can ensure protection of the steel reinforcement. However, it is necessary to study the effects of material heterogeneity and cracking on chloride ingress in concrete. This is done herein by proposing a three-dimensional lattice model capable of simulating chloride transport in saturated sound and cracked concrete. Means of computationally determining transport properties of individual phases in heterogeneous concrete (aggregate, mortar, and interface), knowing the concrete composition and its averaged transport properties, are presented and discussed. Based on numerical experimentation and available literature, a relation between the effective diffusion coefficient of cracked lattice elements and the crack width was adopted. The proposed model is coupled with a lattice fracture model to enable simulation of chloride ingress in cracked concrete. The model was validated on data from the literature, showing good agreement with experimental results.