Flexibility of C-S-H sheets and stacks from molecular simulations

Tulio Honorio (1) , Laurent Brochard (1)

1 navier umr 8205 - Laboratoire Navier

The flexibility of C-S-H solid sheets may play, as is the case of other phyllosilicates, an important role in the structuration of "bulk" C-S-H. In this paper, we determine, for the first time to the author's knowledge, the bending modulus of tobermorite single sheets by the combination of molecular simulations and Kichhoff-Love plate theory. Further, using the results for laminates, we compute the bending modulus of stacks of solid layers, which are a larger structural unit in the nanotexture of phyllosilicates. Tobermorite single layers are more rigid than other phyllosilicates such as montmorillonites and kaolinites. Our estimation of shear stresses within a stack of layers, confronted to the yield strength of tobermorite computed by other authors, indicates that these stacks might exfoliate if the number of solid layers exceeds few tens. Stacks of this thickness are quite rigid, which justifies the choice of rigid grains in mesocale investigations of calcium silicate hydrates.

Mots clés: Calcium silicate hydrates; Molecular simulation; Bending modulus; Nanotexture

Domaines: Mécanique des matériaux [physics.class-ph]

Tulio Honorio, Laurent Brochard. Flexibility of C-S-H sheets and stacks from molecular simulations. EAC-02 - 2nd International RILEM/COST Conference on Early Age Cracking and Serviceability in Cement-based Materials and Structures, Sep 2017, Brussels, Belgium. ⟨hal-01986296⟩