Effect of grains roughness on waves velocities in granular packings

International audienceThe effect of particles roughness on wave velocities is investigated in granular materials using bender-extender elements. The roughness of the particles was modified by a chemical degradation process of initially smooth beads. Wave velocities were calculated along isotropic stress paths from 100 to 500 kN/m 2 in order to compare these experimental results to theoretical predictions by Hertz or previous results presented in the literature. Our results show a little effect of the surface roughness on the longitudinal wave velocities but a notable effect on the shear wave velocities