Effect of interfacial transition zone on the transport of sulfate ions in concrete
Effect of interfacial transition zone on the transport of sulfate ions in concrete
复制标题
界面过渡区对混凝土中硫酸根离子输运的影响
DOI：
10.1016/j.conbuildmat.2018.10.140
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发表时间：
2018-12
影响因子：
7.4
通讯作者：
Zhang Lihai
中科院分区：
文献类型：
--
作者：
Sun D;an;Wu Kai;Shi Huisheng;Zhang Lintao;Zhang Lihai
长期的外部硫酸盐侵蚀会导致混凝土严重劣化。本研究的目的是发展一个实验验证的反应传输模型，以研究硫酸根离子在混凝土界面过渡区（ITZ）的传输行为。该模型考虑了界面处孔径的空间依赖性以及硫酸根离子与混凝土组分之间的化学反应在混凝土孔隙中形成钙矾石和石膏而引起的硫酸根离子扩散系数的变化。首先通过混凝土试件和硫酸钠溶液的试验对模型进行了验证。然后，进行了一系列的参数研究，以确定的关键参数，执政的硫酸根离子在混凝土中的传输。背散射电子显微镜（BSE）结果表明，界面区内混凝土的孔隙率相对较高，内部界面区（距骨料表面5 μm）的孔隙率是外部界面区（距骨料表面50 μm）的6倍。模型预测表明，硫酸根离子的浓度最初在混凝土中迅速增加，在第一个20天，然后增加的速率逐渐降低，由于离子的扩散系数的减少，作为一个结果的钙矾石和石膏形成在混凝土孔隙。此外，自感电场对硫酸根离子的迁移影响不大。
Long-term external sulfate attack can result in significant concrete degradation. The purpose of this study is to develop an experimentally validated reactive transport model to investigate the transport behaviour of sulfate ions in concrete containing interfacial transition zone (ITZ). The model takes into account the spatially dependent pore size in ITZ and the change of diffusion coefficient of sulfate ions due to the formation of ettringite and gypsum in concrete pores resulting from the chemical reaction between sulfate ions and concrete components. The developed model was firstly validated by performing a series of experiments involving concrete specimens and sodium sulfate solution. Then, a series of parametric studies were carried out to identify the critical parameters that govern the transport of sulfate ions in concrete. The backscattered electron microscopy (BSE) results show that the porosity of concrete within ITZ is relatively higher than that in bulk paste with a six-fold higher porosity in inner ITZ (5 µm from aggregate surface) than that in outer ITZ (50 µm from aggregate surface). The model predictions suggested that the concentration of sulfate ions initially increases rapidly in concrete during the first 20 days and then the rate of increase gradually decreases due to the reduction in the diffusion coefficient of ions as a result of the ettringite and gypsum formation in concrete pores. In addition, it demonstrates that self-induced electric field has little influence in the transport of sulfate ions.
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影响因子：
10.5
作者：
P. Gospodinov;R. Kazandjiev;M. Mironova
通讯作者：
P. Gospodinov;R. Kazandjiev;M. Mironova
模拟受到外部硫酸盐侵蚀的水泥浆体的损坏
影响因子：
4.1
作者：
Chuansheng Xiong（博士生）;Linhua Jiang;Yan Zhang;Hongqiang Chu
通讯作者：
Hongqiang Chu
DOI：
10.1088/0031-9112/7/10/004
发表时间：
2011-09
期刊：
Physics Bulletin
影响因子：
--
作者：
W. Ni
通讯作者：
W. Ni
影响因子：
7.4
作者：
Chen, Jian-kang;Qian, Chen;Song, Hui
通讯作者：
Song, Hui
DOI：
10.1023/b:ints.0000042339.92990.4c
发表时间：
2004-10-01
期刊：
INTERFACE SCIENCE
影响因子：
--
作者：
Scrivener, KL;Crumbie, AK;Laugesen, P
通讯作者：
Laugesen, P