Influence of Alkali on Early-Age Hydration Process and Microstructure of Low-Heat Cement

被引：0
|
作者：
Li Y. [1 ]
He Z. [2 ]
Guo W. [1 ]
Yin H. [1 ]
Wang S. [1 ]
机构：
[1] Changjiang River Scientific Research Institute of Changjiang Water Resources Commission, Wuhan
[2] School of Water Resources and Hydropower Engineering, Wuhan University, Wuhan
来源：
Jianzhu Cailiao Xuebao/Journal of Building Materials | 2018年 / 21卷 / 04期
关键词：
Calcium silicate hydrate; Hydration process; Low-heat cement; Microstructure;
D O I：
10.3969/j.issn.1007-9629.2018.04.004
中图分类号：
学科分类号：
摘要：
The alkali content(by mass, the same below) of low-heat cement was adjusted to 0.80%, 1.20% and 1.60% by adding Na2SO4. Isothermal calorimetry test was used to investigate the influence of alkali on early age hydration process of low-heat cement. The influence of alkali on the hydration stage of low-heat cement was analyzed by the hydration kinetic model. The structure of silicon phase and migration form of the aluminum phase in low-heat cement hydration products were observed by 29Si and 27Al magic angle spinning nuclear magnetic resonance. The results show that alkali can promote hydration process of low-heat cement, but the hydration process does not increase with the increment of alkali content in certain content. The promotion effect of alkali on low-heat cement is mainly due to increase of nucleation and crystal growth rate of low-heat cement and the stage of interaction at phase boundaries is prolonged. Besides, alkali is more likely to increase aluminum substitution ratio in calcium silicate hydrate(C-S-H) chain and the degree of polymerization of C-S-H. However, with the increment of alkali content, aluminum tends to shift to ettringite(AFt) rather than to C-S-H chain. © 2018, Editorial Department of Journal of Building Materials. All right reserved.
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页码：549 / 555
页数：6
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