Reinforced soil by using kenaf fibers

Abstract

The objective of this research is to investigate the beneficial effects of reinforcing silty sand soil specimens using randomly distributed kenaf fibers of lengths ranged between 20-25 mm. The strength and deformation characteristics were examined in the laboratory under three loading conditions mainly, Proctor, California Bearing Ratio and Unconfined Compression Tests. For research objectives, the soil used in the investigation was sourced from Soba east Khartoum and the kenaf fibers were purchased from the local market. The Optimum Moisture Content (OMC), California Bearing Ratio (CBR) and Unconfined Compression Strength (UCS) were investigated and thereby, the optimum value of kenaf fiber content has been determined. The results of tests indicated that CBR Values of reinforced silty sand were 5.3 times their unreinforced value and the inclusion of kenaf fibers increased the unconfined compressive strength and residual strength of the specimens by approximately 88% and can change significantly the brittle behavior of the silty sand soil to more ductile one. Also, the results indicated that; the reinforced soils exhibited higher failure stresses in unconfined compression strength tests than the unreinforced ones due to the bond developed between soil particles and the fiber. The use of the kenaf fiber for soil reinforcement means that in many areas of the world there is a readily available, effective local source of material for improving the strength of locally available soils that can be used in soil stabilization.