BREAKAGE BEHAVIOR OF DESERT SAND, GLASS BEADS, AND HAIL SAND: MINERALOGY INFLUENCE AND PARTICLE MORPHOLOGY

Understanding the mechanisms and influencing factors behind particle breakage in granular soils is crucial for predicting soil behavior under high-stress geotechnical applications. This study examines the impact of particle morphology (shape and size), mineralogical composition, and applied compressive stress levels on the degree of breakage and the resulting changes in particle size distribution (PSD). Three distinct soils-sub-rounded desert sand, spherical glass beads, and angular Hail sand, were subjected to one-dimensional compression tests up to 500 MPa. Hail sand exhibited the highest breakage index despite being loaded to a lower maximum stress (400 MPa), due to its angularity and presence of weaker minerals such as albite, dolomite, and calcite. In contrast, glass beads and quartz-rich desert sand showed greater resistance to breakage. As stress increased, mean diameter (D50) decreased, and the coefficient of uniformity (Cu) increased for all materials, indicating fragmentation into finer particles and a transition to more graded, fractal-like distributions. These results confirm that particle shape, size, and mineral strength are critical in determining soil degradation under compression and have direct implications for geotechnical design and performance.