Influence of fiber type and content on the flexural strength of cemented lithium feldspar tailings backfill composites

In the realm of metal mine tailings management, enhancing the performance of Cemented Lithium Feldspar Tailings Backfill Composites (CTBC) is highly crucial. This study delved into the influence of fiber on the flexural strength of CTBC. Employing orthogonal three-point bending tests and numerical simulations, it examined how fiber type, content, solid content, and the cement-to-tailings ratio (c/t) affected CTBC flexural strength and post-peak toughness. Findings demonstrated that fiber content and c/t notably influenced flexural strength, with c/t being more significant (weights of 1.78 and 7.04 respectively via range). The flexural strength of CTBC changed with fiber content and c/t, and 70 % was the optimal solid content. PVA fibers exhibited the best enhancement. The yield deflection of fiber-reinforced CTBC exceeded that at the peak, and post-peak toughness was mainly affected by fiber content and type (relative values 2.25 and 3.625). CTBC beams cracked prior to peak load, and fiber addition postponed crack extension. The fitting model boasted high prediction reliability (correlation coefficients for flexural strength, deflection, and peak load regression models were 1, 0.988, and 0.999 respectively; correction coefficients were 1, 0.987, and 0.999 respectively) • Studied the flexural strength and toughness of lithium feldspar tailings cementitious filling materials. • The addition of fibers has a good effect on the toughness and crack resistance of the test block. • The post peak toughness of fiber reinforced CTBCs is mainly influenced by fiber content and type. • The fibers delay the crack propagation stage after the maximum applied load.