Numerical Study on the Influence of Rubber Content on the Mechanical Behaviour of Angular Aggregates

Abstract Railway tracks endure significant loads, with the ballast layer playing a crucial role in both damping and safely transmitting these forces to the subgrade. However, ballast degradation significantly impacts track maintenance costs. To mitigate this, tyre rubber crumbs could be mixed with the coarse aggregates. This study employs a coupled 2D - Discrete Element Method (DEM) - Element Free Galerkin (EFG) framework to evaluate the effect of including rubber with angular aggregates on the micromechanics during simple shear. The addition of deformable rubber particles to the granular ensemble enhances the coordination number of the assembly and stabilizes the strong force network between rigid particles. Notably, the addition of 20% rubber content does not significantly affect the anisotropy of the granular assembly. Furthermore, it is observed that the increased rubber content reduces the percentage of rattlers.