Mean shear resistance at steady-state for wet glass beads impact of liquid content and particle size

Haithem Louati (1) , Driss Oulahna (1) , Alain de Ryck (1)

1 RAPSODEE - Centre de recherche d'Albi en génie des procédés des solides divisés, de l'énergie et de l'environnement

The flow behaviour of a granular media is due to their weight, frictional contact forces between them, and external forces exerted by the walls. If their size is lower than 50 microns, the Van-der-Waals forces between them may also influence their flowability. When adding some wetting liquid, we introduce attractive forces between the particles, whose order of magnitude may overcome the particle weight and V-d-W interactions. This leads to a cohesive behaviour. The shear stress to start the flow is greater than in the dry case but the steady-state flow is also perturbed by the presence of liquid bridges. This later phenomenon has been recently quantitatively studied for 70-110 μm glass beads with a non-volatile liquid, with experimental results for different normal stresses (up to 12 kPa) and liquid content (up to 20 % in volume). These results have been compared to a heuristic model, based on the model for capillary bridges and the simplest hypothesis for the granular bed texture depending on the stresses applied. We extend this study with new results concerning smaller glass beads 12-40 μm in diameter and larger liquid fraction for 70-110 μm glass beads using experimental and theoretical approaches.

Mots clés: dimension particule; resistance traction; perle de verre

Domaines: Sciences de l'ingénieur [physics]

Haithem Louati, Driss Oulahna, Alain de Ryck. Mean shear resistance at steady-state for wet glass beads impact of liquid content and particle size. Powders and grains 2017 - 8th International Conference on Micromechanics on Granular Media, Jul 2017, Montpellier, France. art. 08010 - 4 p., ⟨10.1051/epjconf/201714008010⟩. ⟨hal-01626932⟩