Linear elastic fracture mechanics was used to investigate the mechanical properties of four model dry granule systems with porosities of between 35% and 55%. The deformation and fracture behaviour of the agglomerates varied according to their porosity, the identity and quantity of the binder component, and the nature of any substrate-binder interfacial interactions. All the agglomerates deformed elastically but failed by plastic deformation of the binder component, in agreement with previously reported theoretical predictions.