Thermodynamic modelling of the effect of temperature on the hydration and porosity of Portland cement
- Empa, Laboratory for Concrete and Construction Chemistry, Uberlandstrasse 129, CH-8600 Duebendorf (Switzerland)
- University of Aberdeen, Department of Chemistry, Meston Walk, Old Aberdeen, AB24 3UE, Scotland (United Kingdom)
The composition of the phase assemblage and the pore solution of Portland cements hydrated between 0 and 60 deg. C were modelled as a function of time and temperature. The results of thermodynamic modelling showed a good agreement with the experimental data gained at 5, 20, and 50 deg. C. At 5 and at 20 deg. C, a similar phase assemblage was calculated to be present, while at approximately 50 deg. C, thermodynamic calculations predicted the conversion of ettringite and monocarbonate to monosulphate. Modelling showed that in Portland cements which have an Al{sub 2}O{sub 3}/SO{sub 3} ratio of > 1.3 (bulk weight), above 50 deg. C monosulphate and monocarbonate are present. In Portland cements which contain less Al (Al{sub 2}O{sub 3}/SO{sub 3} < 1.3), above 50 deg. C monosulphate and small amounts of ettringite are expected to persist. A good correlation between calculated porosity and measured compressive strength was observed.
- OSTI ID:
- 21033062
- Journal Information:
- Cement and Concrete Research, Vol. 38, Issue 1; Other Information: DOI: 10.1016/j.cemconres.2007.08.017; PII: S0008-8846(07)00199-8; Copyright (c) 2007 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0008-8846
- Country of Publication:
- United States
- Language:
- English
Similar Records
A thermodynamic approach to the hydration of sulphate-resisting Portland cement
Effect of temperature on the hydration of Portland cement blended with siliceous fly ash