Investigation of particle breakage under one-dimensional compression of sand using X-ray microtomography

Particle breakage alters particle-scale properties of granular soils including particle size, shape, and contact conditions, and changes macroscale properties including soil compressibility, shear strength, and permeability. This study monitors the crushing of natural quartz sands under one-dimensional compression with in situ X-ray tomography, i.e., X-ray scans during loading. We use the assembly-scale and particle-scale images to characterize particle failure patterns, e.g., chipping, major splitting, and comminution. Image processing and analysis enable us to determine the failure patterns around the yield stress, and the influence of initial density and particle morphology on the particle survival probability. We further quantify the degree of particle breakage with fractal dimension, breakage factor, and specific surface. Particle shape and coordination number both show a scale-dependent evolution pattern.