0000000000296901
AUTHOR
Thibault Charpentier
showing 5 related works from this author
Study of the hydration of cement with high slag content
2014
International audience; The physico-chemical properties of cementitious materials, such as transport properties or porosity are established during the hydration process. The latter which involves dissolution and precipitation reactions, is characterized by the mineralogical and structural changes associated to water state (evolution from evaporable water to chemically bound water and physically absorbed water) and chemical shrinkage. These physico-chemical properties are modified by the addition of supplementary cementitious materials like slag. Powers' model, based on the water state repartition, was initially developed to describe the hydration of Portland cement. This work aims to apply …
Triple-Quantum Two-Dimensional 27Al Magic Angle Nuclear Magnetic Resonance Study of the Aluminum Incorporation in Calcium Silicate Hydrates
1998
Triple-quantum two-dimensional 27Al magic angle spinning nuclear magnetic resonance (27Al 3Q-MAS NMR) was used to characterize the substitution of Si4+ by Al3+ into the Te−Oc−Te structure of calcium silicate hydrates (C−S−H). This substitution was studied with C−S−H having an Oc/Te ratio of 1 and in equilibrium with Al(OH)3 in aqueous suspensions. In the absence of NaOH, no substitution into the C−S−H structure occurred. Addition of NaOH in the preparation increased the concentration of Al(OH)4- and favored substitution. The deficit of charge resulting from this substitution was compensated by the accommodation of sodium in the interlayer space of the C−S−H. Increasing levels of substituted…
Al-27 and Si-29 Solid-State NMR Characterization of Calcium-Aluminosilicate-Hydrate
2012
International audience; Calcium silicate hydrate (C-S-H) is the main constituent of hydrated cement paste and determines its cohesive properties. Because of the environmental impact of cement industry, it is more and more common to replace a part of the clinker in cement by secondary cementitious materials (SCMs). These SCMs are generally alumina-rich and as a consequence some aluminum is incorporated into the C-S-H. This may have consequences on the cohesion and durability of the material, and it is thus of importance to know the amount and the location of Al in C-S-H and what the parameters are that control these features. The present paper reports the Si-29 and Al-27 MAS NMR analyses of …
Characterization by solid-state NMR and selective dissolution techniques of anhydrous and hydrated CEM V cement pastes.
2010
International audience; The long term behaviour of cement based materials is strongly dependent on the paste microstructure and also on the internal chemistry. A CEM V blended cement containing pulverised fly ash (PFA) and blastfurnace slag (BFS) has been studied in order to understand hydration processes which influence the paste microstructure. Solid-state NMR spectroscopy with complementary X-ray diffraction analysis and selective dissolution techniques have been used for the characterization of the various phases (C3S, C2S, C3A and C4AF) of the clinker and additives and then for estimation of the degree of hydration of these same phases. Their quantification after simulation of experime…
Hydration of a CEM V Blended Cement: Characterization of PFA and BFS Reactivity and Evolution of the Porosity
2007
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 characterizat…