Dynamics of dense suspensions

Suspensions are common materials found in diverse applications from cosmetics (toothpaste), food products (coffee), to construction materials (cement) or even geophysical fluids (sludge). They are known to exhibit a wide variety of rheological regimes under flow. In particular, at high volume fraction, dense suspensions show a shear-thickening regime, i.e. a reversible increase of the viscosity with the shear stress. Such rheological properties affect dramatically the ability of complex fluids to flow. The formulation of many industrial suspensions is thus limited by the challenging mixing of dense suspensions due to the emergence of a yield stress and the shear-thickening observed at high volume fraction. In particular, the impossibility to mix a concentrated concrete suspension limits the mechanical performance of construction materials optimized for a maximum concentration of particles.

By tracking the local deformation and structure within a dense suspension under shear, the project aims to determine the flowing conditions of complex materials for construction to reduce the energetic cost necessary to make them flow.

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