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Highly Reactive β‐Dicalcium Silicate: II, Hydration Behavior at 25°C Followed by 29 Si Nuclear Magnetic Resonance
Author(s) -
Ishida Hideki,
Okada Yoshihiko,
Mitsuda Takeshi
Publication year - 1992
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1992.tb08187.x
Subject(s) - silicate , hydrate , magic angle spinning , calcium silicate hydrate , chemistry , magic angle , analytical chemistry (journal) , crystallography , chemical composition , nuclear magnetic resonance , nuclear magnetic resonance spectroscopy , materials science , stereochemistry , cement , organic chemistry , metallurgy , physics
The hydration behavior at 25°C of highly reactive β‐dicalcium silicate synthesized from hillebrandite (Ca 2 (SiO 3 )(OH) 2 ) was studied over a period of 7 to 224 d using 29 Si magic‐angle spinning nuclear magnetic resonance (MAS NMR). The hydration product, C‐S‐H, contains Q 2 and Q 1 silicate tetrahedra, the chemical shifts of which are independent of the water/solid (w/s) ratio and curing time. Until the reaction is completed, the amounts of Q 1 and Q 2 formed are independent of the w/s ratio, being determined only by the degree of reaction. The ratio Q 2 /Q 1 increases as the reaction progresses and as the curing time becomes longer. From the values of Q 2 /Q 1 , it appears that the hydrate is a mixture of dimers and short single‐chain polymers. The Ca/Si ratio of the hydrate is high, taking values close to 2.0, but the Ca/Si ratio does not influence the Q 2 /Q 1 ratio. It was also found that the NMR peak intensities allow quantitative assessment similar to XRD.