Particle-morphology-based characterization of the breakage behavior of particle assemblies under one-dimensional compression

In this study, a series of one-dimensional compression tests are conducted to study the particle breakage behavior of carbonate sands, with a focus on the effect of particle grading. Advanced image processing techniques (i.e., the QICPIC imaging system and the X-ray micro-tomography) are employed to analyse the particle crushing phenomenon by tracing the evolution of particle morphology features which include the particle size and shape. The results show that particle shape tends to become more irregular with increasing overburden pressure. The evolution of the cumulative distribution of overall particle shape index (overall regularity, OR) will reach a steady state, which is analogous to the evolution of particle size distribution during the compression process. A new shape-dependent particle breakage index, termed relative shape breakage index (S_r), has been proposed to quantify the breakage degree, and its correlation with the particle size-dependent breakage index is analysed. Finally, the X-ray micro-tomography (μCT) data are utilized to explore the shape variation of child particles during the fragmentation of a single particle from a micromechanical perspective. The particle size effect on the breakage behavior of particle assemblies under one-dimensional compression is also schematically clarified.