Experimental study on mechanical properties and microscopic mechanism of solidified slit soil with nanocomposite fibers

Solid waste management and utilization are pivotal to the operation of a circular economy. Within the present study, nano-silica and nano-graphene composite fibers were incorporated as modifiers into solidified silt soil specimens, with the aim of examining how these fibrous additives affect the specimens’ mechanical performance and microstructural evolution. The findings indicate that at the 28-day curing stage, the compressive strength of glass fiber-reinforced soil specimens is 75.6% greater than that of the unmodified control group; furthermore, the addition of 1.0% silica particles results in a further 118.3% enhancement in compressive strength. Additionally, the correlation between graphene content and material toughness exhibits a nonlinear trend: as the graphene dosage increases, the toughness of specimens modified with nano-graphene composite fibers rises initially before declining thereafter. In the early hardening phase, the introduction of nano-graphene composite fibers exerts a notable promotional effect on the tensile strength development of the soil specimens. Microstructural analysis results demonstrate that elevated silica particle concentrations enhance the interfacial adhesion between flocculent reaction products, crystalline phases, and the fiber-reinforced matrix. More specifically, acicular crystalline structures fill the interfacial gaps between glass fibers and matrix constituents, forming a strong mechanical interlocking mechanism between the fibers and their adjacent matrix. Collectively, this research lays a theoretical and experimental foundation for the stability control of solidified silt soil.