Structural models of random packing of spheres extended to bricks. Simulation of the nanoporous Calcium-Silicate-Hydrates.

Victor Morales-Florez (1) , Fabrice Brunet (1)

1 TAO - Département Terre-Atmosphère-Océan (Paris, France)

Structure simulation algorithms of random packing of spheres and bricks have been developed. These algorithms were used to reproduce the nanostructure of the cementitius calcium-silicate-hydrates. The textural parameters (specific surface area, porosity, pore size, etc.) of a C-S-H sample, the main binding phase of cements, have been derived from N2-physisorption experiments. In the same time, these parameters have been simulated by using a sphere-based structural model where the spheres are randomly packed according to several hierarchical levels. The corresponding algorithm has been extended for managing cuboids instead of spheres. The C-S-H sample density is successfully predicted by considering the presence of water in pores defined by the sphere network within 10 nm-size globules and assuming a tobermorite-like skeleton. Simulations with bricks (3x2x1.4 nm3) yield also textural parameters which are consistent with N2-physisorption data but with a globule size (22 nm) twice as big as that obtained when using spheres.

Mots clés: Physical Sciences

Domaines: Planète et Univers [physics]

Victor Morales-Florez, Fabrice Brunet. Structural models of random packing of spheres extended to bricks. Simulation of the nanoporous Calcium-Silicate-Hydrates.. Molecular Simulation, 2009, 35 (12-13), pp.1001-1006. ⟨10.1080/08927020903033117⟩. ⟨hal-00530455⟩