Search results for "Chemical reaction kinetics"
showing 3 items of 3 documents
Importance of the liquid to solid weight ratio in the powdered solid-liquid reactions Example drawn from cement constituent hydration
1997
Abstract It seems justified to wonder if the chemical processes which have been evidenced from diluted stirred suspensions are or are not in accordance with those involved in a stagnant paste. The present paper is aimed at clarifying this question which is in connection with the problem of the so called ‘dormant period’ or ‘induction period’ at the beginning of the hydration of Portland cement.
Investigation of Multicomponent Sorption in Polymers from Fluid Mixtures at Supercritical Conditions: The Case of the Carbon Dioxide/Vinylidenefluor…
2008
The simultaneous sorption of carbon dioxide and vinylidene fluoride (VDF) in poly(vinylidenefluoride) from their supercritical (sc) mixtures was studied using an experimental method, already described in a previous publication, based on the gas-chromatographic determination of the equilibrium composition of the fluid phase in contact with the polymer. Argon was added to the system as a nonabsorbable molecular probe in the polymer to take into account the effect of the volume swelling on the measurement. Sorption behavior has been studied at 50 °C by changing the composition and the density of the supercritical phase. We have found that VDF dissolves in its polymer with concentrations much l…
Hydration of cementitious materials, present and future
2011
This paper is a keynote presentation from the 13th International Congress on the Chemistry of Cement. It discusses the underlying principles of hydration and recent evidence for the mechanisms governing this process in both Portland cements and other cementitious materials. Given the overriding imperative to improve the sustainability of cementitious materials, routes to reducing CO2 emissions are discussed and the impact of supplementary materials on hydration considered. (C) 2011 Elsevier Ltd. All rights reserved.