Effect of incorporating discarded facial mask fiber on mechanical properties of MICP

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

Han, Yi / Chen, Yumin / Chen, Runze / Liu, Hanlong / Yao, Xiaofei

Highlights • Reusing discarded facial mask fiber supports sustainability. • The absorbability of DFMF can increase the fixation rate of bacteria. • The addition of DFMF can improve the brittleness of MICP-cured sand.

Abstract 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.