Sand particle breakage under high-pressure and high-rate loading

Abstract

Under intensive loading, either hydrostatic or dynamic shear, sand particles are broke up to smaller particles. In this study, we randomly embedded color-coated sand grains of five different initial sizes inside cylindrical sand specimens under dynamic tri-axial loading. The quasi-static pressure was varied from 25 to 150 MPa at 25 MPa intervals and then unloaded. The embedded particles were retrieved and found fractured particles increased with increasing pressure. However, many of the colored particles remained intact. Under 100-MPa hydrostatic pressure, additional axial load was added at three different strain rates, 0.01, 500, and 1000 s-1. It was found that, under additional dynamic loading nearly all the colored particles were fractured. In addition, to the attention on the embedded colored particles, the overall size change of the sand from the loaded specimens were also quantified.