A lightweight concrete for mine filling and its preparation method

Abstract

This invention discloses a lightweight concrete for mine filling and its preparation method, relating to the field of lightweight building materials technology. The method includes sequentially subjecting chopped polypropylene fibers to chromic acid oxidation etching, nano-alumina coating deposition, and aminosilane grafting to obtain modified polypropylene fibers; sequentially subjecting fumed silica nano-coating to methyltriethoxysilane hydrophobic grafting, hexadecyltrimethoxysilane secondary reinforcement, and stearic acid co-assembly treatment to obtain a composite hydrophobic modifier; mixing mine tailings, cement, fly ash, slag powder, the modified fibers, the composite hydrophobic modifier, polyvinyl alcohol, and nano-calcium carbonate to form a slurry, adding foam, and then pouring and curing to obtain the final product. This invention, through the synergistic effect of multi-level fiber modification and the superhydrophobic structure of nanoparticles, solves the problem of the shielding interference of hydrophobic components on the fiber interface, achieving simultaneous optimal improvement in the mechanical strength and impermeability of concrete.

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