Studies on Desiccation Cracking Behavior of Geofiber Reinforced Clay

Abstract

Expansive clays undergo large volumetric changes with varying moisture content inducing desiccation cracks. Desiccation cracks increase the hydraulic conductivity and reduce the strength of the soil substantially. This can be a setback when expansive clays are used as landfill liners and covers where low hydraulic conductivity is mandatory to ensure a safe barrier. In this study, the effect of discrete and randomly distributed fiber (DRDF) reinforcement on desiccation cracking of soil with varying fiber lengths was investigated. Black cotton soil, a locally available expansive clay, was reinforced with polypropylene fibers of lengths 6, 12, and 18 mm, at 0.5% fiber content (% by dry weight of soil). The slurry samples were allowed to dry at uniform temperature and relative humidity. Various physical and morphological parameters such as cell area, crack width, and moisture content were observed over time. The crack parameters were quantified using digital image analysis (DIA). It was observed that fiber inclusion efficiently reduces desiccation cracking by increasing the tensile strength of the clay.