Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7885700 | Cement and Concrete Research | 2014 | 10 Pages |
Abstract
We used in-situ XRD and heat flow calorimetry to investigate the first 44Â h of hydration of Ordinary Portland Cement (OPC) blended with siliceous fly ash (FA). By recalculating the heat flow using XRD data it was possible to establish the direct influence of FA on the silicate and aluminate reaction of the OPC hydration in combination with absolute phase quantities. A retarding effect of FA on the silicate reaction was detected, probably induced by the adsorption of Ca2Â + ions on the FA surface. The aluminate reaction proved to be influenced by FA. Thereby the filler effect produces an acceleration of the reaction by providing additional nucleation sites. Additionally the reaction itself is very sensitive to the chemical composition of FA. Readily available SO3 seems to be the factor responsible for retarding the aluminate reaction. The increasing of the effective w/s-ratio seems to have only a slight influence on the hydration behavior.
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Authors
S. Dittrich, J. Neubauer, F. Goetz-Neunhoeffer,