Strength Characteristics of Sandy Soil Reinforced with Kenaf Fiber and Natural Rubber Latex

Abstract

The construction industry continuously seeks sustainable and cost-effective alternatives for soil improvement to address the growing environmental concerns associated with cement-based stabilization methods. Sandy soils present significant challenges in construction due to their low cohesion, high permeability and prone to erosion and liquefaction. This study investigates the strength behaviour of reinforced sandy soil with kenaf fiber and bonded using natural rubber latex (NRL). An experimental program of 15 samples was conducted to evaluate the physical and mechanical properties of poorly graded sand samples treated with varying percentages of kenaf fiber and NRL. Physical properties tests included particle size distribution, Atterberg limits and specific gravity determination. Strength properties were determined through direct shear box tests while compaction characteristics were evaluated using standard Proctor compaction tests. The results demonstrated that the used of kenaf fiber as sustainable reinforcement and natural rubber latex stabilization agent significantly enhances the soil’s shear strength parameters. The optimum percentage of the soil mixture identified to be 1.0% kenaf fiber combined with 10% natural rubber latex achieved a cohesion of 16.03 kPa and friction angle of 22.80° representing improvements of 68.4% and 9.5% respectively compared to untreated sandy soil. The compaction properties showed that maximum dry density decreased from 1.74 g/cm³ to 1.59 g/cm³ while the optimum moisture content decrease from 15.72% to 15.50% for the best combination of soil mixture. The strength enhancement of soil cause from these two mechanisms: NRL provide interparticle bonding by coating soil particles and filling void spaces while randomly distributed kenaf fibers provide tensile reinforcement for soil.  The findings demonstrate that kenaf fibers and natural rubber latex effectively improve the strength properties of sandy soils which offer a sustainable alternative to cement-based stabilization methods.