Effects of Relative Density and Grading on the Particle Breakage and Fractal Dimension of Granular Materials

Particle breakage was reported to have great influence on the mechanical property of granular materials. However, limited studies were conducted to quantify the detailed effects of relative density and initial grading on the particle breakage behaviour of granular materials under different confining pressures. In this study, a series of monotonic drained triaxial tests were performed on isotropically consolidated granular materials with four different initial gradings and relative densities. It is observed that particle breakage increases as the confining pressure or relative density increases, whereas it decreases with the increasing coefficient of uniformity. Due to particle breakage, the grading curves of granular materials after triaxial tests can be simulated by a power-law function with fractal dimension. As the confining pressure increases, the fractal dimension approaches the limit of granular materials, i.e., 2.6. A unique normalized relation between the particle breakage extent and confining pressure by considering relative density and grading index was found.

Automated summary

Particle breakage has a significant impact on the mechanical properties of granular materials. This study investigated the effects of confining pressure, relative density, and initial grading on the particle breakage behavior of granular materials. The results show that particle breakage increases with increasing confining pressure or relative density, but decreases with increasing coefficient of uniformity. The grading curves of the granular materials after triaxial tests can be simulated by a power-law function with fractal dimension. A normalized relation between the particle breakage extent and confining pressure considering relative density and grading index was also found.