Quantification of fabric in cemented granular materials

We perform a set of tomographic studies on polymer bonded frictional granular material to systematically characterize the structure through quantification of the relative orientation of its constituents. A three-dimensional network is constructed by considering the centroid of granules as vertex and polymer bridge as a link. We present the spatial distribution of coordination numbers in the network, which indicates the degree of bonding by the number of bridges per grain. Further, we quantify the network using microfabric tensors for each vertex. The spatial distribution of eigenvectors of these microfabric tensors suggests that the bridges align themselves, preferentially, along the direction of gravity. Further, a spherical distribution of direction of links is presented along with a second order polynomial fit. We construct ellipsoid fabric chains by traversing the path of optimally aligned dominant eigenvectors of microfabric tensors. This chain traverses the direction along which contacts orient themselves maximally.