Study on the flexural performance and microstructure of lithium feldspar tailings cementitious filler using mixed fibers

The brittle fracture and toughness of cemented tailings backfill (CTB) are not conducive to underground mining projects. Incorporating fibers may enhance the flexural properties of the CTB. This study used glass (GS) and polypropylene (PP) fibers to fabricate fiber-reinforced cemented lithium feldspar tailing backfill (FCLTB) specimens. The flexural strengths and microstructures of the specimens were analyzed using a three-point flexure test and scanned electron microscopy (SEM). Following a three-point bending test, it was observed that Upon decreasing the amount of GS fiber, the bending strength of the FCLTB specimens initially decreased and then increased. However, with an increase in the PP fiber content, the average bending module of the FCLTB specimens initially reduced and then rose. The combined use of GS and PP fibers significantly improved the toughness of the CLTB samples after the peak. Composite fibers resist the formation of cracks under load.