Rheology of dense granular suspensions across flow regimes

Dense granular suspensions that consist of concentrated mixtures of non-Brownian particles suspended in a liquid are ubiquitous in many natural phenomena (e.g. landslides, debris flows, and sediment transport) and industrial processes (e.g. concrete and pastes). Their rheology is not fully understood, and establishing a unified theoretical framework across the different flow regimes is still challenging. The present work describes rheological measurements of granular suspensions in the dense regime undertaken at imposed volume fractions but also at imposed values of the particle normal stress. It addresses the transition from a Newtonian rheology in the Stokes limit to a Bagnoldian rheology when inertia is increased. It also examines the critical behavior near the jamming transition of suspensions of particles that can be rigid and rough but also soft and smooth.