Solid-state 27Al and 29Si NMR characterization of hydrates formed in calcium aluminate–silica fume mixtures

Pena, P.; Mercury, José Manuel Rivas; Aza, Antonio H. De; Turrillas, X.; Sobrados, Isabel; Sanz, J.

doi:10.1016/j.jssc.2008.03.026

Cited by 70 publications

(59 citation statements)

References 25 publications

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“…The 27 Al NMR spectra of white cement contained signals for tetrahedrally coordinated aluminium at 78.6 ppm, with a shoulder at 84.1 ppm. Both resonances were ascribed to the Al in calcium aluminates [16] (Fig. S1, Supporting Information).…”

Section: Initial Phasesmentioning

confidence: 99%

Use of micro‐Raman spectroscopy to study reaction kinetics in blended white cement pastes containing metakaolin

Frías

Martínez-Ramírez

2009

J Raman Spectroscopy

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Curing temperature is known to play an important role in the formation, development, and stability of the hydrated phases appearing during pozzolanic reactions (chemical reaction between puzzolanic addition, metakaolin (MK), and calcium hydroxide from cement hydration). A typical example of this important reaction is to be found in metakaolin-bearing cement pastes, characterized by hexagonal phases whose thermodynamic stability declines with rising temperature. These phases cannot be exhaustively researched with traditional techniques (such as X-ray diffraction) due to their poor crystallinity. Consequently, micro-Raman spectroscopy was used in the present study to explore the behavior of white cement paste blends containing 0, 10, and 25% MK at two curing temperatures (20 and 60 • C). This led to the identification, for the first time using Raman spectroscopy, of phases C 2 ASH 8 1 (stratlingite) and C 3 ASH 6 , which appear in the MK-white cement reaction. The C-S-H gel formed was characterized by Q 1 dimers and a C/S ratio of 1.3-1.5. Raising the curing temperature favored the formation of C 4 AH 13 .

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Section: Initial Phasesmentioning

confidence: 99%

Use of micro‐Raman spectroscopy to study reaction kinetics in blended white cement pastes containing metakaolin

Frías

Martínez-Ramírez

2009

J Raman Spectroscopy

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“…They especially offered to use appropriate additions introduced into the cement system to avoid, or at least reduce, the hydrate conversion and its negative effect in CAC composites [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17].…”

Section: Introductionmentioning

confidence: 99%

“…There are opinions that silica reacts in the hydrating CAC to produce various crystalline hydrates with changing proportions of Ca, Al and Si, such as: C 3 AS 3-x H 2x , (0 \ x \ 3), and also different zeolite-type phases [4,6,13,14].…”

Section: Introductionmentioning

confidence: 99%

Studies on the influence of spent FCC catalyst on hydration of calcium aluminate cements at ambient temperature

Pacewska

Nowacka

Wilińska

et al. 2011

J Therm Anal Calorim

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The influence of spent catalyst from catalytic cracking in fluidized bed (FCC) on the hydration of two kinds of calcium aluminate cements (of about 40 and 70% content of alumina) was studied. Cement pastes were prepared with constant ratio of water/binder = 0.5 and with content of 0, 5 and 25% mass of addition as replacement of cement. The samples were stored at room temperature. Thermal analysis (TG, DTG), infrared absorption (FTIR) and X-ray diffraction methods were applied to investigate changes in various periods of hydration (up to 150 days). The compressive strength of cement mortars was also examined. On the basis of presented results it was affirmed that in studied conditions spent FCC catalyst is a reactive addition in calcium aluminate cement (CAC) pastes, which probably can create a new phase type C-A-S-H. It may be an interesting alternative for limitation of the negative phenomenon of conversion of aluminate hydrates, although the degree of the influence of the mineral additive depends on the composition of CAC and of the quantity of the used waste.

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“…Simultáneamente la sílice, al elevado pH desarrollado durante las reacciones de hidratación de los aluminatos de calcio, interacciona con la disolución formado grupos Si-OH y Ca-Si-OH sobre la superficie de la sílice amorfa como se ha observado en el estudio del proceso de hidratación de mezclas de sílice amorfa-aluminatos de calcio por RMN de 29 Si y 27 Al realizado por los autores (17,18).…”

Section: Discussionunclassified

“…Los resultados obtenidos por Análisis Térmico Diferencial (ATD) y Termogravimétrico (TG) y Microscopia Electrónica de Barrido de Emisión de Campo (MEB) han confirmado los resultados obtenidos por difracción de rayos X. El mecanismo de hidratación propuesto esta igualmente apoyado en datos de resonancia magnética nuclear de 29 Si obtenidos por los presentes autores (17,18). …”

Section: Introductionunclassified

Estudio por difracción de rayos X de la hidratación de mezclas de CaAl<sub>2</sub>O<sub>4</sub> - Humo de silice

Rivas-Mercury¹,

Turrillas²,

Aza³

et al. 2007

Bol. Soc. Esp. Ceram. Vidr.

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Se ha estudiado la influencia del humo de sílice sobre el mecanismo de hidratación del monoaluminato de calcio (CaAl 2 O 4 ) a temperatura ambiente y con una relación agua/sólidos de 0,5. La evolución de las fases hidratadas, que se forman en los primeros instantes de la reacción, se ha estudiado por difracción de rayos X de laboratorio con una resolución temporal de 36 min. In situ X-ray difraction study of hidration of CaAl 2 O 4 -amorphous silica mixturesThe influence of the amorphous silica on the mechanism of hydration of the calcium monoaluminate (CaAl 2 O 4 ) has been studied at ambient temperature with a water/solids ratio of 0.5. The evolution of the hydrated phases, formed in the first instants of the reaction, has been studied by laboratory X ray diffraction with a time resolution of 36 min. The integration of selected diffraction peaks of the phases: Ca 2 Al 2 O 5 ·8H 2 O (Ca 2 Al 2 (OH) 10 ·3H 2 O), CaAl 2 O 4 and Ca 4 Al 2 (OH) 12 (CO 3 )·5H 2 O, has allowed to establish the kinetics of the reaction. This way, it has been shown that the amorphous silica causes a drastic decrease in the period of induction of the hydration and accelerates the formation of the metastable crystalline hydrates Ca 2 Al 2 (OH) 10 ·3H 2 O and Ca 4 Al 2 (OH) 12 (CO 3 )·5H 2 O. These results have been confirmed by Thermogravimetry, Differential Thermal Analysis and Scanning Electric Microscopy. The hydration mechanism proposed confirms previous data of Nuclear Magnetic Resonance of Solids (RMN) of 29 Si of the authors of this paper.

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Solid-state 27Al and 29Si NMR characterization of hydrates formed in calcium aluminate–silica fume mixtures

Cited by 70 publications

References 25 publications

Use of micro‐Raman spectroscopy to study reaction kinetics in blended white cement pastes containing metakaolin

Use of micro‐Raman spectroscopy to study reaction kinetics in blended white cement pastes containing metakaolin

Studies on the influence of spent FCC catalyst on hydration of calcium aluminate cements at ambient temperature

Estudio por difracción de rayos X de la hidratación de mezclas de CaAl<sub>2</sub>O<sub>4</sub> - Humo de silice

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