Application des propriétés thermodynamiques du système CaO-Al2O3-CO2-H2O. A l'hydratation des ciments alumineux.

National audienceThe thermodynamical study of the CaO-Al2O3-CO2-H2O system, applied to the hydration of monocalcium aluminate at ambient temperature, allows to explain both the experimental precipitation of unstable hydrates (C2AH8 and C4ACH11) and the apparent complexity of conductimetric curves, by the manifestation of supersaturation phenomena. The role of some anhydrous phases (C12A7 and CA2) present in aluminous cements, and particularly their influence on the acceleration or delay in the precipitation process, are also clearly pointed out from the observation of phase diagrams