Reactive Transport Modelling of Chloride Ingress in Saturated Coral Aggregate Concrete
Reactive Transport Modelling of Chloride Ingress in Saturated Coral Aggregate Concrete
复制标题
饱和珊瑚骨料混凝土中氯离子侵入的反应传输模型
DOI：
10.3389/fmats.2021.755241
复制
发表时间：
2021-10-12
影响因子：
3.2
通讯作者：
Niu, Ditao
中科院分区：
文献类型：
--
作者：
Guo, Bingbing;Li, Zhenming;Niu, Ditao
利用珊瑚骨料混凝土(CAC)在偏远岛屿上建设，可以显著降低建设成本和工期，减少二氧化碳排放，并减少不可再生能源的消耗。钢筋混凝土结构的抗氯离子侵蚀能力是影响其耐久性的重要因素。在这项研究中，开发了一个反应输运模型来研究氯离子在CAC中的进入，其中基于MatLab语言建立了COMSOL-PHREEQC接口。将文献中的实验作为基准例子。结果表明，所建立的数值模型能较准确地预测氯离子在CAC中的运移。与普通骨料混凝土(OAC)不同，CAC的水泥水化产物在氯离子进入过程中不会出现库泽尔盐。数值结果表明，随着曝光时间的延长，氯离子在CAC中的穿透深度逐渐增大。当CAC暴露在外部氯化物溶液中时，孔溶液pH的下降影响了Friedel盐的沉淀，这不利于氯的化学结合。
Utilizing coral aggregate concrete (CAC) for construction on remote islands can significantly reduce construction cost and period, CO2 emission, and consumption of non-renewable energy. The durability of reinforced CAC structures is critically influenced by their resistance to chloride attack. In this study, a reactive transport modelling was developed to investigate chloride ingress in CAC, in which a COMSOL-PHREEQC interface based on MATLAB language was established. The experiment from the literature was taken as a benchmark example. The results show that the developed numerical model can accurately predict chloride transport in CAC. Differing from ordinary aggregate concrete (OAC), Kuzel's salt does not appear in cement hydrate compounds of CAC during chloride ingress. The numerical results indicate that the penetration depth of chloride in CAC gradually increases as the exposure time is prolonged. When CAC is exposed to an external chloride solution, the decrease in the pH of the pore solution affects the precipitation of Friedel's salt, which is detrimental to the chemical binding of chloride.