6533b7dbfe1ef96bd126ffe3
RESEARCH PRODUCT
Early C3A hydration in the presence of different kinds of calcium sulfate.
Sylvie PourchetAndré NonatJean-philippe PerezLaure Regnaudsubject
Isothermal microcalorimetryEttringiteGypsumInorganic chemistry0211 other engineering and technologiesNucleationHydrationchemical and pharmacologic phenomena02 engineering and technologyengineering.materialEttringitechemistry.chemical_compound021105 building & constructionGeneral Materials ScienceTricalcium aluminateSulfateSupersaturationPrecipitation (chemistry)Chemistry[CHIM.MATE]Chemical Sciences/Material chemistryBuilding and ConstructionCa3Al2O6021001 nanoscience & nanotechnologyKinetics[ CHIM.MATE ] Chemical Sciences/Material chemistryengineering0210 nano-technologydescription
International audience; Hydration reactions of C3A with various amounts of calcium sulfate hemihydrate, gypsum or a mixture of two, were investigated by isothermal microcalorimetry, and a monitoring of the ionic concentrations of diluted suspensions. This study shows that sulfate type used modifies the early C3A-CaSO4 hydration products and the rate of this hydration. The fast initial AFm formation observed before ettringite precipitation in the C3A-gypsum system is avoided as soon as hemihydrate is present in the suspension. This was attributed to.higher super saturation degrees and then higher nucleation frequency with regard to the ettringite obtained in the presence of hemihydrate. Moreover, replacement of gypsum by hemihydrate also leads to an increase of the ettringite formation rate during at least the five first hours under experimental conditions.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2009-11-01 |