The interaction of magnesium in hydration of C3S and CSH formation using 29Si MAS-NMR
The interaction of magnesium in hydration of C3S and CSH formation using 29Si MAS-NMR
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DOI：
10.1007/s10853-008-2889-2
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发表时间：
2008-08
影响因子：
4.5
通讯作者：
L. Fernández;C. Alonso;C. Andrade;A. Hidalgo
中科院分区：
文献类型：
--
作者：
L. Fernández;C. Alonso;C. Andrade;A. Hidalgo
在水热条件下，在氧化镁的存在下，硅酸三钙的水合作用显示出CSH凝胶结构（硅酸钙水合物）形成的变化。新的CSH结合镁离子，水镁石，但存在一个弱的波特兰。氧化镁会阻碍氢氧化镁的析出。通过~（29）Si MAS-NMR对不同CaO/SiO_2比的CSH凝胶的表征表明：（1）在低CaO/SiO_2 < 1时，CSH凝胶具有dreierketten结构，并存在Q_3缺陷和Q_2v缺陷。一些镁离子结合在八面体位置，在dreierketten图案的层间空间中。(2)对于CaO/SiO2比> 1的CSH凝胶，镁离子将以四面体配位的形式掺入CSH凝胶的硅酸盐链中。尽管如此，CSH凝胶的低MgO/CaO比表明CSH链中的镁掺入低。
Hydration of tricalcium silicate in hydrothermal conditions in the presence of magnesium oxide has shown changes in the formation of CSH gel structure (Calcium silicate hydrates). The new CSH incorporates magnesium ions, brucite, but a weak presence of portlandite. The magnesium oxide would hinder the precipitation of portlandite. The characterization of CSH gel by 29Si MAS-NMR with various CaO/SiO2 ratios would point out that: (1) A dreierketten structure of the CSH for low CaO/SiO2 < 1, with some defects (Q3 defect and Q2v) in its structure is confirmed. Some magnesium ions are incorporated in the octahedral sites, in the interlayer space of the dreierketten pattern. (2) For the CSH gels with CaO/SiO2 ratios > 1, magnesium ions would be incorporated in the silicate chains of the CSH gel in a tetrahedral coordination. Although, the low MgO/CaO ratios of CSH gels indicate that the magnesium incorporation in CSH chain is low.