Hydration of a CEM V Blended Cement: Characterization of PFA and BFS Reactivity and Evolution of the Porosity
Résumé
The long term behaviour of cement based materials is strongly influenced by the internal chemistry and the paste microstructure. The industrial byproduct additives like pulverised fly ash (PFA) or blastfurnace slag (BFS) used in blended cement influence together the paste microstructures and the chemistry. A blended cement, designated CEM V in the European standard, containing PFA and BFS has been studied in order to understand processes involved during hydration. Several techniques as Xrays diffraction (XRD), solid-state NMR, thermogravimetry analysis (TGA) have been used to characterize the hydration of the PFA, BFS and the components (C2S, C3S) of the clinker. Such types of characterization have been performed both on old (10 years) and recent samples (from 28 days to 2 years old). Microstructure characterisations, mainly by mercury intrusion porosimetry (MIP), have been also done. Interpretations of all these characterizations allow to build a sketch for the hydration of CEM V cement.