Case Evaluation of Structural Strength Improvement of Lateritic Soil Using Selected Binders

Abstract

The research investigated the potential use of sisal fiber and plastic waste strips as a partial replacement for cement to enhance the geotechnical characteristics of lateritic soils. Various laboratory experiments were conducted, encompassing tests such as specific gravity determination, grain size distribution analysis, compaction assessment, Atterberg limit evaluation, unconfined compressive strength (UCS) testing, and microscopic analysis. Sisal fiber and plastic strips were each varied at 0, 0.5, 1.0, 1.5, 2.0 and 2.5% while maintaining a constant 5% cement added to all the mix proportions. Result of investigations revealed an enhancement in plasticity of the soils for both treatment methods. Liquid limit shows a steady drop from 43% in its natural state to 42% and 41% at 1% sisal fiber and 1% plastic strips content respectively, while plasticity index showed a decline from 14.8% in its natural form to 12.69% and 10.8% at 2% sisal fiber and 1% plastic strips content respectively. There is a considerable development in the compaction and strength properties of the treated soil. The analysis of the results via one-way analysis of variance (ANOVA) and regression recorded a significant effect on most of the measured parameters. Microanalysis of the natural and optimally modified soils showed alteration in the fabric arrangement of the particles of soils. Based on the results of the study, optimally 1-1.5% sisal fiber/5% cement and 1-1.5% plastic strips/5%cement meaningfully improved the soil strength and can both be used as sub-base materials for light trafficked roads.