Damage and failure mechanism of basalt fiber-reinforced gangue-cemented backfill under uniaxial compression

The damage and fracture behaviors of basalt fiber-reinforced gangue-cemented backfill were studied. An appropriate amount of basalt fibers significantly improved the mechanical properties of the backfill, with the fiber content of 0.3% yielding the maximum compressive strength and peak strain. In addition, the acoustic emission activity of the fracture damage process was high, and the cumulative count increased. The internal crack propagation became dense with slow divergence; the macroscopic failure mode gradually transitioned to tensile–shear mixed failure. Excess fibers led to a dense spatial distribution, reducing the strengthening effect.