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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

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