Influence of types and contents of nano cellulose materials as reinforcement on stability performance of cementitious tailings backfill

This study explores the quality of cemented tailings backfill (CTB) reinforced with diverse nano cellulose materials (NCMs) such as micro-fibrillated cellulose (MFC), hydroxylated cellulose nanofiber (CNF), and cellulose crystal (CNC) at macroscopic/microscopic levels. Uniaxial compressive strength (UCS), cracking/failure patterns, deformation analysis, and microstructure of NCM-reinforced CTB samples were thoroughly explored. The results are as follows: the addition of CNF, CNC and MFC to samples augmented its UCS values by 0.95 MPa to 1.39 MPa, 1.43 MPa and 1.29 MPa, respectively. A two-aspect effect on UCS of CNF-, CNC-, and MFC-based samples was observed, namely an escalation followed by a reduction. The optimal concentration of NCM-reinforced CTB samples is 0.9 kg/m(3), and the strengthening effect of CNC on CTB is better than CNF and MFC. The cracks witnessed in CTB were created in the stress clouds after loading. NCM-reinforced CTB's failure pattern was portrayed by tensile/shear failure. Addition of NCMs to CTB well-inhibited crack propagations. Three types of nano cellulose showed diverse morphologies at 2000X, but CNF, CNC and MFC on cracks capably upgraded CTB's strength characteristics. It was lastly proven that unlike synthetic fibers, incorporating NCMs as a reinforcing material in fill could be a wise solution for boosting CTB recipes in terms of cost-efficiency, operational ease, and sustainability.