  We show that mixing a colloidal gel with larger, non-Brownian grains
generates novel flow-switched bistability. Using a combination of confocal
microscopy and rheology, we find that prolonged moderate shear results in
liquefaction by collapsing the gel into disjoint globules, whereas fast shear
gives rise to a yield-stress gel with granular inclusions upon flow cessation.
We map out the state diagram of this new `mechanorheological material' with
varying granular content and demonstrate that its behavior is also found in
separate mixture using different particles and solvents.
