ELUCIDATION OF MICP PROCESS MECHANISM OF SHORT FIBER REINFORCED SANDS

Abstract

 Soil toughness can be enhanced by mixing short fibers into the soil. Short fibers include natural, artificial, and mineral fibers, yet there is concern that the reinforcement function deteriorates as the fibers degrade over time. Therefore, some techniques to control the degradation are needed to sustain the effects of the fiber in soil. In this study, microorganisms were added to sand samples mixed with naturally occurring and artificial fibers, respectively, and their effects on fiber degradation were investigated. As a result, laboratory experiments revealed that large amounts of carbonate precipitated on/in the fibers in the cases of sand samples mixed with naturally occurring fibers, and that the carbonate protected the fibers. Additionally, numerical simulations based on reaction-diffusion theory clarified that the inhibition of ion diffusion in the solvent is closely related to the protective effect observed in naturally occurring fibers.