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Undispersed Granulated Silica Fume in Concrete - Chemical System and Durability Problems

Published online by Cambridge University Press:  21 February 2011

Björn Lagerblad
Affiliation:
Swedish Cement and Concrete Research Institute, 100 44 Stockholm, Sweden
Peeter Utkin
Affiliation:
Tallin Technical University, Building Materials Lab, Akadeemia tee 1, 200108 Tallin, Estonia
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Abstract

Granulated condensed silica fume is not easily dispersed. In contact with the pore fluids of the cement paste the granulates rapidly turn into alkali-silica gel nodules. With time this gel absorbs Ca and at least the rim of the AS-nodules transforms into a C-S-H product. The gel by itself does not cause expansion as it forms before the cement paste hardens. However, if exposed to alkali salts the AS-nodules may become further enriched in alkalies, which in turn may trigger an expansive reaction and cracking.

Type
Research Article
Copyright
Copyright © Materials Research Society 1995

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References

1. Lagerblad, B. & Utkin, P.Silica granulates in concrete-dispersion and durability aspects. CBI-report 3:93, 44 p, (1993).Google Scholar
2. Shayan, A., Quick, G.W. & Lancucki, C.J., “Morphological, mineralogical and chemical features of steam-cured concretes containing densified silica fume and varios alkali levels”, Advances in Cement Research, 5, No 20, 151162, (1993)Google Scholar
3. Lagerblad, B. & Trägårdh, J., “Slowly reacting aggregates in Sweden,” Mechanism and conditions for reactivity in concrete”, Proceedings, 9th International conference on alkali-aggregate reactions, London, 570578, (1992).Google Scholar
4. Wang, H. & Gillot, J.E., “Mechanism of alkali-silica reaction and the significans of calcium hydroxide”, Cement and Concrete Research, vol 21, 647654, (1991)Google Scholar
5. Wang, H. & Gillot, J.E., “Effect of Ca(OH)2 on the alkali-silica reaction, Magazine of Concrete Research, 43, 156, 215218 (1991)Google Scholar