*Member, The American Ceramic Society.
Cement–Dispersant Incompatibility due to Ettringite Bridging
Article first published online: 26 AUG 2010
© 2010 The American Ceramic Society
Journal of the American Ceramic Society
Volume 94, Issue 1, pages 200–208, January 2011
How to Cite
Chen, C.-T. and Struble, L. J. (2011), Cement–Dispersant Incompatibility due to Ettringite Bridging. Journal of the American Ceramic Society, 94: 200–208. doi: 10.1111/j.1551-2916.2010.04030.x
H. Jennings—contributing editor
This study was supported by the Center for Advanced Cement-Based Materials (ACBM).
- Issue published online: 5 JAN 2011
- Article first published online: 26 AUG 2010
- Manuscript No. 26803. Received September 18, 2009; approved July 13, 2010.
Sulfonated naphthalene formaldehyde, a common dispersant for portland cement, was found to be incompatible with some cements, the incompatible combinations producing gelation rather than dispersion of cement–water mixtures. The gelation was found to be prevented by the addition of alkali hydroxide or alkali sulfate. The objective of this study was to explore the mechanism behind these incompatibilities. Three hypotheses were tested: ettringite bridging, superplasticizer consumption, and polymer bridging. Results showed that the ettringite formation was responsible for the gelation and that alkali addition inhibited the ettringite formation.