The main objective of the study is to examine the effect of size segregation on the rheology of granular assemblies subjected to triaxial loading. We employ Discrete Element Method (DEM) to simulate the triaxial loading of assemblies which consist of alternating layers of particles of different sizes, with sharp segregations separating them. The macroscopic data obtained from DEM simulations are verified against experimental tests. A triangulation-based discretisation is utilised to obtain the strain distribution in the assembly. Broadly, strain localisation seems to be restricted to the layer to which it belongs, which indicates that the interface acts as a barrier to strain localisation. Further, the macroscopic load-bearing characteristics are largely unaffected by strain localisation. Investigating the lateral deformation of the assembly reveals a local minimum in lateral displacement at the interface. This suggests that the particles at the interface have a higher load-bearing capacity when compared to the individual layers.