H. Jennings—contributing editor
First-Principles Study of Elastic Constants and Interlayer Interactions of Complex Hydrated Oxides: Case Study of Tobermorite and Jennite
Article first published online: 23 JUN 2009
© 2009 The American Ceramic Society
Journal of the American Ceramic Society
Volume 92, Issue 10, pages 2323–2330, October 2009
How to Cite
Shahsavari, R., Buehler, M. J., Pellenq, R. J.-M. and Ulm, F.-J. (2009), First-Principles Study of Elastic Constants and Interlayer Interactions of Complex Hydrated Oxides: Case Study of Tobermorite and Jennite. Journal of the American Ceramic Society, 92: 2323–2330. doi: 10.1111/j.1551-2916.2009.03199.x
Financial support by CIMPOR Corporation, Portugal, enabled through the MIT–Portugal program, is gratefully acknowledged.
- Issue published online: 25 SEP 2009
- Article first published online: 23 JUN 2009
- Manuscript No. 25826. Received February 4, 2009; approved May 7, 2009.
It is a common perception that layered materials are soft in the interlayer direction. Herein, we present results of first-principles calculations of the structure and elastic constants of a class for hydrated oxides, tobermorite, and jennite, which illustrate that this is not the case, if (1) the interlayer distance is such that coulombic interlayer interactions become comparable to the iono-covalent intralayer interactions and (2) the existence of interlayer ions and water molecules do not shield the coulombic interlayer interactions. In this case, the mechanically softest directions are two inclined regions that form a hinge mechanism. The investigated class of materials and results are relevant to chemically complex hydrated oxides such as layered calcium–silicate–hydrates (C–S–H), the binding phase of all concrete materials, and the principle source of their strength and stiffness. In addition, the first-principles results may serve as a benchmark for validating empirical force fields required for the analysis of complex calcio–silicate oxides.