Effect of BaCO3 on C3A hydration
Ba ions are known to immobilise sulfates by forming BaSO4. The use of BaCO3 as a full or partial substitute for gypsum to regulate C3A (3CaO·Al2O3) hydration was consequently studied with a view to establishing its correct dosage in sulfate-resistant cements presently under development. The hydratio...
| Autores: | , , , |
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| Formato: | artículo |
| Estado: | Versión aceptada para publicación |
| Fecha de publicación: | 2015 |
| País: | España |
| Recursos: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/121938 |
| Acesso em linha: | http://hdl.handle.net/10261/121938 |
| Access Level: | acceso abierto |
| Palavra-chave: | Hydration Calorimetry |
| Resumo: | Ba ions are known to immobilise sulfates by forming BaSO4. The use of BaCO3 as a full or partial substitute for gypsum to regulate C3A (3CaO·Al2O3) hydration was consequently studied with a view to establishing its correct dosage in sulfate-resistant cements presently under development. The hydration rate of synthetic C3A was determined in the presence of varying percentages of gypsum, BaCO3, and gypsum + BaCO3 by running conduction calorimetry analyses on early age (up to 20 h) samples. The hydration products were subsequently identified with XRD, FTIR and DTA/TG. The addition of (20–42 wt.%) BaCO3 to C3A neither regulated the speedy reaction of the latter with water nor reacted with the aluminate. Gypsum + BaCO3 blends proved able to regulate C3A hydration; the heat flow curves for the mixes studied exhibited an induction period, an indication that gypsum acted as a C3A hydration regulator whilst at the same time reacting with BaCO3 to form barite. |
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