1. The influence of slightly and highly soluble carbonate salts on phase relations in hydrated calcium aluminate cements
- Author
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Melanie Rivera, Narayanan Neithalath, Gwenn Le Saout, Aditya Kumar, Guillermo Puerta-Falla, Gabriel Falzone, Magdalena Balonis, Gaurav Sant, Department of Civil and Environmental Engineering [UCLA - Los Angeles], University of California [Los Angeles] (UCLA), University of California-University of California, University of California, Centre des Matériaux des Mines d'Alès (C2MA), IMT - MINES ALES (IMT - MINES ALES), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), and Arizona State University [Tempe] (ASU)
- Subjects
chemistry.chemical_classification ,Sodium aluminate ,Mechanical Engineering ,Inorganic chemistry ,0211 other engineering and technologies ,Salt (chemistry) ,02 engineering and technology ,021001 nanoscience & nanotechnology ,6. Clean water ,law.invention ,[SPI.MAT]Engineering Sciences [physics]/Materials ,chemistry.chemical_compound ,Calcium carbonate ,chemistry ,Mechanics of Materials ,law ,021105 building & construction ,Carbonate ,General Materials Science ,Solubility ,0210 nano-technology ,Sodium carbonate ,Calcium aluminate cements ,Dissolution - Abstract
International audience; The addition of slightly (CaCO3) and highly soluble (Na2CO3) carbonate salts is expected to favor the formation of carboaluminate phases in hydrated calcium aluminate cements (CACs). A multi-method approach including X-ray diffraction, thermogravimetric analysis, and thermodynamic calculations is applied to highlight that the “conversion phenomena” in CACs cannot be mitigated by the formation of carboaluminate phases (monocarboaluminate: Mc and hemicarboaluminate: Hc) which are anticipated to form following the addition of carbonate salts. Here, carboaluminate phase formation is shown to depend on three factors: (1) water availability, (2) carbonate content of the salts, and their ability to mobilize CO3 2− species in solution, and (3) lime content associated with the carbonate salt. The latter two factors are linked to the composition and solubility of the carbonate agent. It is concluded that limestone (CaCO3), despite being a source of calcium and carbonate species, contributes only slightly to carboaluminate phase formation due to its low solubility and slow dissolution rate. Soluble carbonate salts (Na2CO3) fail to boost carboaluminate phase formation as the availability of Ca2+ ions and water are limiting. Detailed thermodynamic calculations are used to elucidate conditions that affect the formation of carboaluminate phases.
- Published
- 2016
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