Effects of settlement and drainage on strength development within mine paste backfill

Paste backfill mixture with binder was poured and cast into rigid PVC moulds especially designed to permit load application to the paste in both drained and undrained conditions. After 28 days of curing, uniaxial compression tests and microstructure analysis through the measurements of specific surface area were accomplished to investigate the mechanical strength development within paste backfill samples. The results of the study showed that external loading leads to an increase in compressive strength (UCS) when paste backfill sample is drained, but a reduction of UCS when paste backfill sample is undrained.