- Author
- Gert Baert (UGent) , Nele De Belie (UGent) , J. Kratky, A. Ivens, Isabel Van Driessche (UGent) and Geert De Schutter (UGent)
- Organization
- Abstract
- To increase the early compressive strength of high volume fly ash concrete, activators are added to the concrete mix. The influence of the type of activator on the hydration of cement as well as on the mechanical performance of the final concrete product is investigated in the current study. From isothermal calorimetric measurements, performed on activated fly ash - cement paste, it can be seen that high concentrations of especially sodium or potassium hydroxide accelerated the second peak, but decreased the total heat release. Calcium hydroxide had a similar effect, but the total heat slightly increased. Intergrinding cement with fly ash increased the total heat release as well as the height of the third peak and accelerated its time of occurrence. A third peak was not noticed in the pastes activated with potassium carbonate. Potassium carbonate slightly increased the total heat. The highest heat release was found with 1 mol sulfate per liter solution. Waterglass decreased the setting time significantly, as well as sodium or potassium hydroxides. A small reduction in the initial and final setting was found when sodium sulfate was added to the mix. Calcium hydroxide did not influence the setting behaviour, while potassium hydroxide caused a small delay in setting behaviour. At one day, the highest compressive strength was found for the mortars activated with a small amount of sodium hydroxide and on the mortars containing mechanically activated fly ash and portland cement mix. At 7 days mechanical activation resulted in the highest compressive strength (but still close to the reference) while other methods studied gave considerably lower results. At 28 days, the mechanical and sodium sulfate activation raised the compressive strength most.
- Keywords
- setting behaviour, compressive strength, heat of hydration, activation, fly ash
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Citation
Please use this url to cite or link to this publication: http://hdl.handle.net/1854/LU-667073
- MLA
- Baert, Gert, et al. Mechanical and Thermal Behaviour of Alkali-Activated High Volume Fly Ash Concrete. Edited by Vlastimil Bilek and Zbynek Kersner, 2008, pp. 57–66.
- APA
- Baert, G., De Belie, N., Kratky, J., Ivens, A., Van Driessche, I., & De Schutter, G. (2008). Mechanical and thermal behaviour of alkali-activated high volume fly ash concrete (V. Bilek & Z. Kersner, Eds.).
- Chicago author-date
- Baert, Gert, Nele De Belie, J. Kratky, A. Ivens, Isabel Van Driessche, and Geert De Schutter. 2008. “Mechanical and Thermal Behaviour of Alkali-Activated High Volume Fly Ash Concrete.” In , edited by Vlastimil Bilek and Zbynek Kersner, 57–66.
- Chicago author-date (all authors)
- Baert, Gert, Nele De Belie, J. Kratky, A. Ivens, Isabel Van Driessche, and Geert De Schutter. 2008. “Mechanical and Thermal Behaviour of Alkali-Activated High Volume Fly Ash Concrete.” In , ed by. Vlastimil Bilek and Zbynek Kersner, 57–66.
- Vancouver
- 1.Baert G, De Belie N, Kratky J, Ivens A, Van Driessche I, De Schutter G. Mechanical and thermal behaviour of alkali-activated high volume fly ash concrete. In: Bilek V, Kersner Z, editors. 2008. p. 57–66.
- IEEE
- [1]G. Baert, N. De Belie, J. Kratky, A. Ivens, I. Van Driessche, and G. De Schutter, “Mechanical and thermal behaviour of alkali-activated high volume fly ash concrete,” presented at the Third International Symposium Non-Traditional Cement & Concrete, Brno, 2008, pp. 57–66.
@inproceedings{667073,
abstract = {{To increase the early compressive strength of high volume fly ash concrete, activators are added to the concrete mix. The influence of the type of activator on the hydration of cement as well as on the mechanical performance of the final concrete product is investigated in the current study. From isothermal calorimetric measurements, performed on activated fly ash - cement paste, it can be seen that high concentrations of especially sodium or potassium hydroxide accelerated the second peak, but decreased the total heat release. Calcium hydroxide had a similar effect, but the total heat slightly increased. Intergrinding cement with fly ash increased the total heat release as well as the height of the third peak and accelerated its time of occurrence. A third peak was not noticed in the pastes activated with potassium carbonate. Potassium carbonate slightly increased the total heat. The highest heat release was found with 1 mol sulfate per liter solution.
Waterglass decreased the setting time significantly, as well as sodium or potassium hydroxides. A small reduction in the initial and final setting was found when sodium sulfate was added to the mix. Calcium hydroxide did not influence the setting behaviour, while potassium hydroxide caused a small delay in setting behaviour. At one day, the highest compressive strength was found for the mortars activated with a small amount of sodium hydroxide and on the mortars containing mechanically activated fly ash and portland cement mix. At 7 days mechanical activation resulted in the highest compressive strength (but still close to the reference) while other methods studied gave considerably lower results. At 28 days, the mechanical and sodium sulfate activation raised the compressive strength most.}},
author = {{Baert, Gert and De Belie, Nele and Kratky, J. and Ivens, A. and Van Driessche, Isabel and De Schutter, Geert}},
editor = {{Bilek, Vlastimil and Kersner, Zbynek}},
isbn = {{9788021436428}},
keywords = {{setting behaviour,compressive strength,heat of hydration,activation,fly ash}},
language = {{eng}},
location = {{Brno}},
pages = {{57--66}},
title = {{Mechanical and thermal behaviour of alkali-activated high volume fly ash concrete}},
year = {{2008}},
}