Effect of Particle Morphology on Strength of Glass Sands

Abstract

A series of drained triaxial tests were performed on sandy soils [crushed glass (CG) and glass bead (GB)] with different mean particle sizes in order to investigate the effect of both particle size and particle shape on the soil strength and dilatancy. Four groups of angular CG sands with mean particle sizes of 0.227 to 1.001 mm, four groups of rounded GB sands with mean particle sizes of 0.374 to 0.836 mm, and one special group of subrounded GB sands with a mean particle size of 0.181 mm were tested at the same initial relative density of 60%. It was observed that, as the mean particle size increased for a similar particle shape, both the maximum and critical-state friction angles of the rounded GB sands increased, albeit marginally, whereas the critical-state friction angle of the angular CG sands showed a decrease. The maximum dilation angle of both the angular CG and rounded GB sands increased with an increase in the mean particle size. In addition, a Bolton’s stress–dilatancy equation for glass sands was examined; the slope was found to be constant while the intercept varied slightly with different mean particle size. A comparison of the test results for the angular CG, rounded GB, and subrounded GB sands clearly demonstrated that the strength and friction angle of granular soils results directly from increased angularity where interparticle locking plays a crucial role.