Energy dissipation due to breakage during confined compaction of granular materials

The dissipation of energy during the compaction of granular materials was studied by performing confined drop tower experiments on Ottawa sand. Energy dissipated due to breakage was quantified by evaluating the creation of new surfaces at varying drop heights. Post-compaction particle size distributions (PSD) were measured and the amount of breakage was quantified by the position of the current PSD relative to the pre-compaction and ultimate PSD. Our observations revealed that the percentage of input energy dissipated due to breakage accounted for less than 0.5% of the total energy budget and was a constant proportion regardless of the total energy applied to the system. We also evaluated the effects of die wall friction by measuring post-compaction PSD in various positions within the sample.