  We study the flow of equal-volume binary granular mixtures of spheres and
dumbbells with different aspect ratios down a rough inclined plane, using the
discrete element method. We consider two types of mixtures -- in the first type
the particles of the two species have equal volume but different aspect ratios
(EV) and in the second type they have variable volumes and aspect ratios (VV).
We also use mixtures of spheres of two different sizes (SS) with the same
volume ratios as in the mixtures of the second type, as the base case. Based on
the study of Guillard, Forterre and Pouliquen [\textit{J. Fluid Mech.}
\textbf{807}, R1--R11 (2016)], the inclination angle of the base for each
mixture is adjusted and maintained at a high value to yield the same pressure
and shear stress gradients for all mixtures and a high effective friction
($\mu$) for each. This ensures that the segregation force and resulting extent
of segregation depend only the size and shape of the particles. The species
with larger effective size, computed in terms of the geometric mean diameter,
floats up in all cases and the dynamics of the segregation process for all the
mixtures are reported. The concentration profiles of the species at steady
state agree well with the predictions of a continuum theory. The $\mu-I$ and
$\phi-I$ scaling relations, where $I$ is the inertial number and $\phi$ is the
solid volume fraction, extended to the case of mixtures, are shown to describe
the rheology for all the cases.
