Compressive behavior of high-viscosity granular systems: Effects of viscosity and strain rate

The compressive behavior of granular materials has been evaluated under a variety of conditions. Granules were formulated using two size fractions of two different particulate materials prepared with a polydimethylsiloxane binder ranging in viscosity from 12–2413 Pa·s. The solids content of the granules was maintained constant at 90% in all cases studied. Granules were compressed at three different velocities (1, 10, and 100 mm/s). At these high viscosities, characteristics of the binder appear to have the greatest impact on granular behavior. Through ~ 300 Pa·s, the granule strength increases with increasing viscosity. Above this critical viscosity, however, the granular strength remains approximately constant within a given set of test parameters. The compression velocity also impacts the granular strength, as do the size and shape of the particulate inclusions (though to a lesser extent).