Failure in porous granular aggregates

We use a 3D Lattice Element Method, based on the discretization of the particles and binding matrix on a regular lattice, to investigate the particle-scale origins of the strength and failure of porous granular aggregates under tensile loading. Damage growth is analyzed by considering the evolution of stress probability density and the number of broken bonds in the particle phase. We show that the stress probability density functions are increasingly broader for a decreasing matrix volume fraction, the stresses being more and more concentrated in the interparticle contact zones with an exponential distribution as in cohesionless granular media [4]. We carried out a detailed parametric study in order to evaluate the combined influence of the matrix volume fraction and particlematrix adherence. Our findings are in agreement with 2D results previously reported in the literature [6]. Three regimes of crack propagation are evidenced, corresponding to no particle damage, particle abrasion and particle fragmentation, respectively. The crack morphology (tortuosity...) is another important feature that we investigate for different distributions of the particles and pores within porous granular aggregates