Enhancing geotechnical reinforcement: Exploring molybdenum tailings and basalt fibre-modified composites for sustainable construction

Abstract

Excessive tailings accumulation leads to secondary disasters and environmental pollution. Although the tailings used in this experiment have been filtered by beneficiation, the tailings soil itself has low strength and is not suitable for direct use as engineering materials. In order to make better secondary use of molybdenum tailings and improve the mechanical properties of tailings soil, the basalt fibre reinforcement method was used to improve the strength of tailings soil. We assessed the reinforcement embedding effect of fibre reinforcement in molybdenum tailings from macro and micro perspectives. Triaxial shear tests and numerical simulations of rigid fibre-modified tailings were performed and compared with indoor tests. We obtained the stress–strain curve, inter-particle displacement field, and soil particle friction cloud map. Tailings had fine- and medium-grained embedded particles with strong roughness and minimal agglomeration. Fibres exhibited good support and shear resistance. Microscopic analysis confirmed excellent tailings particle embedding. Under different confining pressures, the optimal combination of triaxial shear strength was as follows: water-cement ratio was 0.17, fibre content was 0.8% and fibre length was 9 mm. The results of laboratory triaxial test show that the peak strength of basalt modified tailings is increased by 21.70% compared with that of unmodified molybdenum tailings. By exploring the mechanical properties of fibre modified molybdenum tailings, it is found that basalt fibre can improve the strength of molybdenum tailings sand, and provide a reference for the application of fibre modified sand in civil engineering.