Stability of calcium sulphoaluminate hydrates in water solutions with various pH values

Gabrišová, A.; Havlica, Jaromír; Sahu, Sadananda

doi:10.1016/0008-8846(91)90062-m

Cited by 160 publications

(57 citation statements)

References 3 publications

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“…A relação entre as alterações do pH da fase líquida existente nos poros da matriz cimentícia e a instabilidade dos produtos de hidratação conforme o grau de solubilidade foi estudada por diversos autores (GABRISOVA et al, 1991;LAGERBLAD, 2005;TAYLOR, 1997). O Ca(OH) 2 é o composto com maior grau de solubilidade e, portanto, o que reage mais rapidamente com o CO 2 para a formação do CaCO 3 (PADE;GUIMARAES, 2007).…”

Section: Introductionunclassified

Carbonatação acelerada efetuada nas primeiras idades em compósitos cimentícios reforçados com polpas celulósicas

Almeida

Tonoli²,

Santos

et al. 2010

Ambient. constr.

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O objetivo deste trabalho foi avaliar o efeito carbonatação acelerada nas propriedades físicas e desempenho mecânico de compósitos cimentícios reforçados com altos teores de polpas celulósicas. Os compósitos foram moldados em laboratório pelo processo de sucção a vácuo do excesso de água e posterior prensagem, e a carbonatação acelerada foi realizada em diferentes estágios de cura. O estudo das propriedades microestruturais foi realizado por microscopia eletrônica de varredura ambiental e difração de raios X. Os resultados obtidos mostraram que a carbonatação acelerada nos primeiros dias de cura resultou em maiores resultados de propriedades mecânicas e melhora na interface fibra-matriz. A carbonatação acelerada reduziu o conteúdo de portlandita [Ca(OH)2] e aumentou o teor de calcita [CaCO3] que é o principal composto resultante da carbonatação. Consequentemente, ocorreu a redução da alcalinidade na matriz cimentícia, o que pode favorecer a durabilidade das fibras celulósicas que se destacam como alternativas às fibras minerais e sintéticas, e podem contribuir para o desenvolvimento sustentável na tecnologia dos materiais de construção.

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Section: Introductionunclassified

Carbonatação acelerada efetuada nas primeiras idades em compósitos cimentícios reforçados com polpas celulósicas

Almeida

Tonoli²,

Santos

et al. 2010

Ambient. constr.

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“…According to Gabrisova's research [13], ettringite can produce when the value of pH is more than 10.7 and gypsum can produce when the value of pH is less than 10.7 as shown in Fig.2. In addition, considering expansion crack due to ettringite, the reaction of monosulfate and gypsum should be focused [1] as shown in Fig.2.…”

Section: Sulfate Attack Analysismentioning

confidence: 99%

“…(b) Precipitation condition It is known that the precipitations such as gypsum and ettringite were influenced by the value of pH [13]. Then, in this analysis, precipitations condition was introduced by pH.…”

Section: Sulfate Attack Analysismentioning

confidence: 99%

Fundamental Study of Crack Propagation of External Sulfate Attack with Mesoscale Analysis System for Coupled Chemo-Mechanical Behaviours

Miura

Yamamoto

Nakamura

2016

Proceedings of the 9th International Conference on Fracture Mechanics of Concrete and Concrete Structures

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Abstract:In this study, three dimensional numerical analysis systems, which can consider the change in physico-chemical property and expansive strain due to external sulfate attack, was constructed in order to evaluate the process of expansion cracking behavior. This analysis was coupled with cement hydration model, sulfate attack analysis and Rigid Body Spring Model. In this paper, this analysis was conducted to evaluate the expansive crack propagation in association with cement source and mix proportion. As results, it was confirmed that this analysis can describe signature expansion cracking behavior.

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“…This model takes into account the sulfate ion diffusion, and the reactions of ettringite and gypsum by a reaction rate constant related to portlandite. In addition, the stability of ettringite due to the value of pH suggested by Gabrisova et al (1991) is introduced in order to take into account for dissolution of ettringite at near surface. These dissolution and precipitation processes, however, should be evaluated by chemical equilibrium condition in solid-liquid phase.…”

Section: Diffusion-reaction Model For Sulfate Attackmentioning

confidence: 99%

Feedback System of Ion Transfer through Cracks During Deterioration of Mortar Due to Sulfate Attack Evaluated by RBSM-Truss Network Model

Miura

Maruyama

Nakamura

et al. 2017

ACT

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In this paper, the transformation of solid phase and expansion cracking behaviors due to sulfate attack were evaluated by using RBSM-Truss Network Model. This analysis was constructed by combining a hydration model, a diffusionreaction model, and a crack propagation model in order to evaluate the influence of feedback system of ion transfer through cracks on transformation of solid phase and expansion cracking behavior due to sulfate attack. As a result, the proposed model can predict the change in phase assemblage and physical properties due to hydration process and the change in the transformation of solid phase and the distribution of sulfate ion due to sulfate attack. It was found that expansion crack can affect the diffusion process and expansion cracking behavior as the crack behaves as a buffer of sulfate ion.

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Stability of calcium sulphoaluminate hydrates in water solutions with various pH values

Cited by 160 publications

References 3 publications

Carbonatação acelerada efetuada nas primeiras idades em compósitos cimentícios reforçados com polpas celulósicas

Carbonatação acelerada efetuada nas primeiras idades em compósitos cimentícios reforçados com polpas celulósicas

Fundamental Study of Crack Propagation of External Sulfate Attack with Mesoscale Analysis System for Coupled Chemo-Mechanical Behaviours

Feedback System of Ion Transfer through Cracks During Deterioration of Mortar Due to Sulfate Attack Evaluated by RBSM-Truss Network Model

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