Intrinsic Elastic Properties of Calcium Silicate Hydrates by Nanoindentation

Cédric Plassard (1) , Eric Lesniewska (1) , Isabelle Pochard (1) , André Nonat (1)

1 ICB - Laboratoire Interdisciplinaire Carnot de Bourgogne

To understand the mechanical properties of cement materials is obviously one of the main purposes of the material science. But the mechanical properties measures of a cement piece by conventional methods (vibration, compression, etc.) are largely dependent on the sample porosity. Hence, the result gives information about the sample density rather than on the intrinsic mechanical properties of the material itself. This work aims to present results on cement materials (alite and C-S-H) mechanical properties obtained by nanoindentation using an atomic force microscope (AFM). The material Young modulus in the z-direction is obtained by applying a force perpendicular to the sample surface using a diamond probe (spring constant = 40 kN/m). After checking the method with materials of known young modulus (mica, foshagite), results on compressed tricalcium (alite) samples will be presented for various hydration time, sample compressive strength and Ca/Si ratio. Then, nanoindentation results on calcium silicate hydrate (C-S-H) monocrystal will be shown. For C-S-H, the results exhibit Young modulus values increasing with the Ca/Si ratio and much greater as for porous alite samples especially for high Ca/Si ratio. All these results will be discussed and compared to theoretical and experimental works of the literature.

Domaines: Matériaux

Cédric Plassard, Eric Lesniewska, Isabelle Pochard, André Nonat. Intrinsic Elastic Properties of Calcium Silicate Hydrates by Nanoindentation. 12th International Congress on the Chemistry of Cement, Jul 2007, Montreal, Canada. pp.44. ⟨hal-00475195⟩