Numerical Simulation of Flexible-Bonded Granular Assembly Using DEM

Abstract The present study explores the behaviour of flexible binding materials for bonded granular assembly using Discrete Element Method (DEM). Experimental and field results indicate that the addition of flexible polyurethane (PU) binder with geologic granular materials significantly enhances the constrained modulus of the assembly used in permeable pavements. It is noteworthy that PU binders exhibit distinct characteristics compared to cement-based binders, the latter possessing considerably higher stiffness and lower flexibility and hence a different bond breakage pattern. While numerical investigations on cement-based binders can be found in the existing literature, this study focuses on DEM simulations for flexible binders utilizing the soft-bond contact model inbuilt in the commercially available code PFC3D. The study addresses the calibration of bond parameters accounting for the contribution of bond materials in the overall porosity of the assembly. Subsequent particle-scale investigations are done to understand the influence of PU content in the mixture.