Mechanical, energy evolution, damage and microstructural behavior of cemented tailings-rock fill considering rock content and size effects

Abstract

Cemented tailings-rock fill (CTRF) is crucial for engineering intention and durability of re-filled stopes in deep underground mines. The current work examined the effects of fragment contents and sizes on the mechanical, energy evolution and microstructure of CTRF with 70 wt% solid. All CTRFs were subjected to uniaxial compression, energy dissipation and scanning electron microscopy experiments. Strength outcomes exhibit that adding rock fragments to CTRF had a clear mitigating influence on the backfill strength. Total/elastic-strain energy at peak point decreased with growing rock content in backfill. SEM-EDS studies demonstrate that backfill defects were chiefly micro-porosity and fractures. The findings are of great significance to guarantee the success and security of the CTRF fulfilled in deep underground hard rock and metalliferous mines.