A huge amount of waste tires is dumped at the landfill sites. Such a waste is posing an environmental hazard. It is high time to reduce their impact on the environment in a sustainable way and hence recycle them. One of the options is to recycle these waste tires, convert them into powdered form and use this granular rubber with other granular materials, e.g. soil to improve their properties. This study is based on the analysis of such sand-rubber mixtures. In particular, the focus of this study is to investigate the effect of quality of mixing on the mechanical response of such sand-rubber mixtures. The study began with characterizing the segregation of sand and rubber for specific conditions, i.e. mixing and under vertical taps. The experiments pointed out segregation in such mixtures. Hence, it was interesting to study its effect on the mechanical response of these mixtures by performing classic oedometer experiments and also with the help of Discrete Element Method (DEM) simulations. It was concluded that the segregation did not have a crucial effect on the mixtures, especially for important rubber volume fractions. For rubber volume fractions up to 25% however, it showed a considerable effect on the mechanical response of these mixtures. The use of DEM simulations helped to better understand the effect of mixing quality by relating the properties observed at the grainscale level such as contact forces, force distribution, etc. with the macroscopic response of these mixtures.