Effect of particle size and shape on shear strength of sand–rubber granule mixtures

In this study, the effect of particle size and shape parameters on shear strength of sand–rubber mixture was investigated using repose angle, as an analogy to the constant volume response, maximum dilatancy, and peak internal friction angles for various mixture conditions. For this purpose, four different granulated rubber and sand sizes were used to include the particle size effect. The size ratio of rubber and sand was maintained as unity in the mixtures. The influence of particle shape was reflected using three different shape classes for sand and two different particle forms for rubber granules. The shape properties of particles were quantified using overall regularity parameter with image processing. The percentage of rubber in the mixtures was varied at five different rates by weight of total sample. As a result, it was observed that the soft-rubber inclusion affected the shear strength parameters distinctively. The geometrical properties of sand and rubber particles have leading roles in the evolution of shear strength.