The present study addresses the effect of different concentrations of Na2O on the structure of a composition of fresh C-S-H gels. The gels were synthesized from laboratory reagents, using calcium nitrate as the source of calcium and a sodium silicate solution for the silicon. A 10-M solution of NaOH was used to maintain a pH of over 13 throughout. The synthesized gels were exposed to different amounts of 8-M NaOH to determine their chemical stability and subsequently characterized with Fourier transform IR spectroscopy. The results showed that the addition of different concentrations of sodium leads to C-S-H gel modification even in the very short term. (C) 2009 Elsevier Ltd. All rights reserved.
Bibliographical noteThe present research was funded by the Ministry of Education and Science through project BIA2004-04835 and by the Spanish Council for Scientific Research in the form of the award of pre-doctoral grant I3P to Inés García-Lodeiro and a post-doctoral contract (ref. I3P-PC2004L) to Dr Ana Fernández-Jiménez.
- Calcium-Silicate-Hydrate (C-S-H)
- calcium silicate hydrate
- structural features
- part I