Composition of C-S-H in the Hydration Products of Fly-Ash Cement System

This paper describes the effect of fly ash on the composition of C-S-H gel. The CaO/SiO2 ratio and chemical bonding water of C-S-H gel were estimated by the combination of the Rietveld analysis by XRD, the selective dissolution analysis and loss of ignition measurement. The results indicated that the CaO/SiO2 ratio of hydrate gel in fly ash-portland cement paste decreases as the hydration of fly ash proceeds, while the CaO/SiO2 ratio of C-S-H gel in portland cement paste did not vary with the progress of hydration. At the same amount of produced C-S-H gel, bonding water in C-S-H gel of paste prepared with 50% fly ash was higher than those of pastes prepared with prepared with of fly ash 25% and 0%. The corresponded results can be seen from decreasing of density of C-S-H gel when replacement ratio of fly ash increases. The paper describes how the bonding water in C-S-H gel decreases as its CaO/SiO2 ratio increases. The effect of chemical bonding water in C-S-H gel can be applied to modify the gel/space-strength model.

Language

  • English

Media Info

  • Media Type: Print
  • Features: Figures; References; Tables;
  • Pagination: pp 361-374
  • Monograph Title: Ninth CANMET/ACI International Conference on Fly Ash, Silica Fume, Slag and Natural Pozzolans in Concrete

Subject/Index Terms

Filing Info

  • Accession Number: 01053868
  • Record Type: Publication
  • ISBN: 139780870312410
  • Report/Paper Numbers: SP-242-28
  • Files: TRIS
  • Created Date: Jul 17 2007 2:26PM