Tricalcium silicate Ca<sub>3</sub>O[SiO<sub>4</sub>]: The monoclinic superstructure

Nishi, F.; Takéuchi, Yoshio; Maki, Iwao

doi:10.1524/zkri.1985.172.3-4.297

“…No evidence of Ca(OH) 2 was found, suggesting that the sample container seals remained intact. The C 3 S structure used was the monoclinic structure described by Nishi [17], and the β-C 2 S that described by Mumme [18]. Refined parameters for each phase were lattice parameters and crystallite size.…”

Section: Methodsmentioning

confidence: 99%

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Whitfield

¹

,

Mitchell

²

2003

Journal of Materials Science

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/npsi/ctrl?lang=en http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/ctrl?lang=fr Access and use of this website and the material on it are subject to the Terms and Conditions set forth at http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/jsp/nparc_cp.jsp?lang=en NRC Publications Archive Archives des publications du CNRCThis publication could be one of several versions: author's original, accepted manuscript or the publisher's version. / La version de cette publication peut être l'une des suivantes : la version prépublication de l'auteur, la version acceptée du manuscrit ou la version de l'éditeur. For the publisher's version, please access the DOI link below./ Pour consulter la version de l'éditeur, utilisez le lien DOI ci-dessous.http://dx.doi.org/10.1023/A:1026363906432 Science, 38, 21, pp. 4415-4421, 2003-11-01 Quantitative Rietveld analysis of the amorphous content in cements and clinkers Whitfield, P. S.; Mitchell, L. D. Journal of Materials AbstractThe potential presence of an amorphous content in OPC clinker and cements is usually overlooked when studying their phase composition. This is largely because of the difficulty in determining amorphous content experimentally. Despite this difficulty, the study of amorphous content and composition in these materials has merit due to the likely effects on the reactivity of the resulting cement.This paper applied the Rietveld method using X-ray powder diffraction data to determine the amorphous content of a number of materials, including clinker, cements and single phases. The cementitious materials were found to contain widely varying, but significant, amorphous contents. The addition of amorphous slag to change the amorphous content by a known amount, gave results as expected from the calculated results for the pure cement and clinker amorphous contents. The results are discussed in relation to other studies published on the issue of amorphous content in cementitious materials.2

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“…Such a broadening is commonly observed in situations where the distribution of NMR parameters such as chemical shifts and quadrupolar constants is present. Since the monoclinic crystal structure of C 3 S has 36 non-equivalent sites for Ca, 48 it wouldn't be too surprising if some small deviations from the perfect lattice produced the observed broadening in the spectrum. The NMR spectrum of the triclinic C 3 S, however, has relatively well-separated 43 Ca signals appearing in the range between 40 to 140 ppm.…”

Section: Cement Compoundsmentioning

confidence: 99%

“…C 3 S is known to have 29 distinct Ca sites in its triclinic form 47 and 36 sites in the monoclinic superstructure. 48 Even if some of these sites incidentally have indistinguishable signals and completely overlap, the overall 43 Ca NMR spectrum is expected to be very complicated. The hydrated calcium silicate, i.e.…”

Section: Introductionmentioning

confidence: 99%

Natural abundance high field 43Ca solid state NMR in cement science

Moudrakovski

¹

,

Alizadeh

²

,

Beaudoin

³

2010

Phys. Chem. Chem. Phys.

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/npsi/ctrl?lang=en http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/ctrl?lang=fr Access and use of this website and the material on it are subject to the Terms and Conditions set forth at http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/jsp/nparc_cp.jsp?lang=en NRC Publications Archive Archives des publications du CNRCThis publication could be one of several versions: author's original, accepted manuscript or the publisher's version. / La version de cette publication peut être l'une des suivantes : la version prépublication de l'auteur, la version acceptée du manuscrit ou la version de l'éditeur. For the publisher's version, please access the DOI link below./ Pour consulter la version de l'éditeur, utilisez le lien DOI ci-dessous.http://dx.doi.org/10.1039/c000353kPhysical Chemistry Chemical Physics, 12, pp. 6961-6969, 2010-06-01 Natural abundance high field 43Ca NMR solid state NMR in cement science Moudrakovski, I.; Alizadeh, R.; Beaudoin, J. J. The material in this document is covered by the provisions of the Copyright Act, by Canadian laws, policies, regulations and international agreements. Such provisions serve to identify the information source and, in specific instances, to prohibit reproduction of materials without written permission. For more information visit http://laws.justice.gc.ca/en/showtdm/cs/C-42Les renseignements dans ce document sont protégés par la Loi sur le droit d'auteur, par les lois, les politiques et les règlements du Canada et des accords internationaux. Ces dispositions permettent d'identifier la source de l'information et, dans certains cas, d'interdire la copie de documents sans permission écrite. Pour obtenir de plus amples renseignements : http://lois.justice.gc.ca/fr/showtdm/cs/C-42 Natural abundance high field 43 Ca solid state NMR in cement sciencew This work is a systematic attempt to determine the possibilities and the limitations of the 43 Ca high field solid state NMR in the study of cement-based materials. The low natural abundance (0.135%) and small gyromagnetic ratio of 43 Ca present a serious challenge even in a high magnetic field. The NMR spectra of a number of cement compounds of known structure and composition are examined. The spectra of several phases important in cement science, e.g., anhydrous beta di-calcium silicate (b-C 2 S) and tri-calcium (C 3 S) silicate were obtained for the first time and the relation of spectroscopic and structural parameters is discussed. The method was also applied to the hydrated C 3 S and synthetic calcium silicate hydrates (C-S-H) of different composition in order to understand the state of calcium and transformations in the structure during hydrolysis. The spectra of hydrated C 3 S reveals a calcium environment similar to that of the C-S-H samples and 11 Å Tobermorite. These observations support the validity of using layered crystalline C-S-H systems as structural models for the C-S-H that forms in the hydration of Portland cement.

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“…The Rietveld refinement was performed by taking into account polymorphs of each clinker mineral phase. The starting structural parameters were taken for cubic C3A from Reference [54], for C2S-γ from Reference [55], for C2S-β from Reference [56], for monoclinic C3S from References [57] and [58], for triclinic C3S from Reference [59], for C4AF from Reference [60], for ghelenite from Reference [61], for CaO from Reference [62], and for Ca(OH) 2 from Reference [52]. Since the analysis of polymorphs abundance was not an objective of the present work, polymorphs of the same phase were summed up by giving the total abundance of the mineral.…”

Section: Resultsmentioning

confidence: 99%

Effect of the Nano-Ca(OH)2 Addition on the Portland Clinker Cooking Efficiency

Zucchini

¹

,

Comodi

²

,

Michele

³

et al. 2019

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A new technology was tested to improve the cooking efficiency of the raw mixture for Portland clinker production by the use of nano-Ca(OH)2. A decrease in the free lime concentration after the firing of approximately 35% and 55% in the nano-added clinkers burned at 1350 °C and 1450 °C, respectively, with respect to the standard Portland clinkers was observed. Moreover, in the nano-added clinkers, a slight decrease in alite (C3S), of approximately 2–4 wt%, and increase in belite (C2S), of approximately 5–6 wt%, were observed. Despite these variations, the C2S and C3S abundance lies within the ranges for standard Portland clinkers. The results showed that the nano-addition leads to an increase of the raw mixtures’ cooking efficiency. The relatively low energy required for the clinker firing could be used to increase the plant productivity and decrease the CO2 emissions during clinker burning. The decrease of the work index of the clinkers produced by the use of the nano-Ca(OH)2 also contributes to the energy saving during clinker grinding. Differences were also found in the pore size distribution among nano-added clinkers and the standard Portland clinker. The smallest porosities with the modal volume lying in the class of 3 × 10−6 mm3 were found to increase by the use of nano-Ca(OH)2. However, the pore volumes higher than 2.0 × 10−5 mm3 decreased in the nano-added clinkers.

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Tricalcium silicate Ca₃O[SiO₄]: The monoclinic superstructure

Cited by 108 publications

References 3 publications

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Natural abundance high field 43Ca solid state NMR in cement science

Effect of the Nano-Ca(OH)2 Addition on the Portland Clinker Cooking Efficiency

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Tricalcium silicate Ca3O[SiO4]: The monoclinic superstructure

Cited by 108 publications

References 3 publications

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Natural abundance high field 43Ca solid state NMR in cement science

Effect of the Nano-Ca(OH)2 Addition on the Portland Clinker Cooking Efficiency

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Tricalcium silicate Ca₃O[SiO₄]: The monoclinic superstructure