Alkali activation of metakaolins: parameters affecting mechanical, structural and microstructural properties

Granizo, M. L.; Blanco-Varela, María Teresa; Martínez-Ramírez, S.

doi:10.1007/s10853-006-0565-y

Cited by 147 publications

(69 citation statements)

References 14 publications

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“…Strengths of the order of 36 MPa were attained at 28 days and, up to that point, no reduction in strength was detected. These two gels have also been observed coexisting in alkali-activated mixtures in other studies [32][33][34].…”

Section: Compressive Strength Of Alkali-activated Mortarsupporting

confidence: 65%

Strength development of alkali-activated fly ash produced with combined NaOH and Ca(OH) 2 activators

Vargas

Molin

Masuero

et al. 2014

Cement and Concrete Composites

107

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Section: Compressive Strength Of Alkali-activated Mortarsupporting

confidence: 65%

Strength development of alkali-activated fly ash produced with combined NaOH and Ca(OH) 2 activators

Vargas

Molin

Masuero

et al. 2014

Cement and Concrete Composites

107

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“…The XRD pattern of the metakaolin used in this study shows a product of low crystallinity due to the presence of an amount of quartz (SiO 2 ), which is identified by a peak at~25 • (2θ) [51,52]. The XRD pattern for sample 16 before and after casting belongs to the crystalline SiO 2 phase, which proves that traces of quartz are already present in MK precursor in MK-based geopolymers [53,54]. The reason for the small shift from 26.84 • (2θ) to 26.62 • (2θ) could be due to the reaction of SiO 2 during the casting and forming of another silica phase (Folder S1).…”

Section: Fourier Transform Infrared Spectroscopy (Ftir)mentioning

confidence: 55%

“…The XRD pattern for sample 16 before and after casting belongs to the crystalline SiO2 phase, which proves that traces of quartz are already present in MK precursor in MK-based geopolymers [53,54]. The reason for the small shift from 26.84° (2θ) to 26.62° (2θ) could be due to the reaction of SiO2 during the casting and forming of another silica phase (Folder S1).…”

Section: X-ray Diffraction (Xrd)mentioning

confidence: 67%

Development of Green Geopolymer Using Agricultural and Industrial Waste Materials with High Water Absorbency

et al. 2017

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Abstract:Geopolymer is a promising porous material that can be used for evaporative cooling applications. Developing a greener geopolymer using agricultural and industrial wastes is a promising research area. In this study, we utilize rice husk (RH), rice husk ash (RHA), metakaolin (MK), ground granulated blast furnace slag (GGBS), and palm oil fuel ash (POFA) to prepare geopolymer pastes, with alkali liquid as an activator. Many geopolymer samples have been prepared as per the Design of Experimental software (DOE), and its corresponding response surface mode and central composite design and later they were characterized. The samples were cured in an oven for 2 h at 80 • C, and thereafter stored at room temperature (~25-30 • C) prior to being tested for its water absorption and compressive strength. The effect of the different composition of precursors on water absorption, density, porosity, and the compressive strength of the prepared geopolymers have been investigated. The results showed that the compressive strength of geopolymers is directly proportional to the ratio of the alkali liquid. Post-optimization, the best geopolymer paste mixture was confirmed to contain 10% of RH, 15% RHA, 35% MK, 10% POFA and 30% of GGBS, with 72% desirability for maximum water absorption (~38%) and compressive strength (4.9 MPa). The results confirmed its applicability for evaporative cooling.

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“…The 27 Al NMR spectra for MK contain signals indicative of the presence of octahedral, pentahedral, and tetrahedral Al. [17] Blended cement pastes containing 10% MK at 20 • C The hydrated phase formation in 10/90 MK/white cement paste cured at 20 • C for 3, 28, 90 and 360 days were studied by microRaman spectroscopy. The Raman spectra for pastes cured for 3 and 360 days in the 4000-3000 cm −1 and 2000-200 cm −1 range are shown in Fig.…”

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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Alkali activation of metakaolins: parameters affecting mechanical, structural and microstructural properties

Cited by 147 publications

References 14 publications

Strength development of alkali-activated fly ash produced with combined NaOH and Ca(OH) 2 activators

Strength development of alkali-activated fly ash produced with combined NaOH and Ca(OH) 2 activators

Development of Green Geopolymer Using Agricultural and Industrial Waste Materials with High Water Absorbency

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

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