Effect of incorporating discarded facial mask fiber on mechanical properties of MICP–treated sand

Responding to environmental challenges associated with the waste generated from discarded facial mask fiber (DFMF), this study introduces an innovative approach to integrate DFMF as a beneficial additive to Microbial-induced calcium carbonate precipitation (MICP) technology - an eco-friendly soil stabilization method. Despite its merit of enhancing soil strength and permeability, MICP often incurs substantial soil brittleness. The incorporation of DFMF, a material conventionally destined for landfill, demonstrates an enhancement in the ductility of MICP–treated sand. Various proportions of DFMF were incorporated (0%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5% by weight), leading to an observable improvement in unconfined compressive strength (UCS), splitting tensile strength (STS) and in the microstructural configuration of MICP-treated sand. The presence of DFMF fostered bacterial immobilization, catalyzed CaCO3 production, and culminated in an optimum DFMF content at 0.2%. This not only mitigated soil brittleness by introducing ductility via calcite precipitation but also culminated in a “sand particles-fibers-sand particles” spatial configuration, reducing the weakening effect of water on MICP-treated sand samples. This study, therefore, highlights the potential of DFMF as a promising additive in MICP-treated sand, thereby offering an effective method for recycling and reusing discarded facial mask fibers.