Compression characteristics and particle scale stress distribution of sand-rubber mixtures with particle size disparity effect

This research investigates the particle-scale stress transmission characteristics at the end of isotropic consolidation stage for sand-rubber mixtures, focusing on the effects of particle size disparity, density, and stress levels. The discrete element method was adopted with total 450 simulations being conducted for sand-rubber mixtures with increasing size disparities to quantify the particle-scale stress distribution between sand and rubber materials. This study reveals that the variation of coordination number and void ratio for sand-rubber mixtures align with those observed in conventional gap-graded soils, while the inclusion of deformable rubber clumps significantly increases coordination number values. A complex interplay between packing density and stress level was evident, illustrating the nuanced role of rubber in stress transmission. As packing density and stress levels decrease, the efficacy of deformable rubber clumps in stress transfer increases. An inverse relationship between the efficiency of stress transmission and particle size disparity was observed for all these sand-rubber mixtures. The findings indicate that, despite variations in size disparity, the proportion of stress transferred by rubber remains consistently lower than their volumetric contribution. This study underscores the complexities of using sand-rubber mixtures and highlights that the effect of particle property disparity outweighs the that of particle property disparity.