DESIGN AND PERFORMANCE EVALUATION OF FLEXIBLE PAVEMENT USING INDUSTRIAL WASTE FOR SUBGRADE SOIL STABILIZATION

Abstract

The increasing demand for sustainable highway infrastructure has encouraged the utilization of industrial waste materials in pavement construction to improve engineering performance while minimizing environmental pollution. Weak subgrade soils often possess low bearing capacity, excessive compressibility, and poor load distribution characteristics, leading to premature pavement failures such as rutting, settlement, cracking, and excessive maintenance costs. Conventional soil stabilization techniques generally require large quantities of cement or lime, which increase construction costs and contribute to carbon emissions. Therefore, the use of industrial waste materials such as fly ash, ground granulated blast furnace slag (GGBS), quarry dust, rice husk ash, steel slag, silica fume, and construction demolition waste has emerged as an economical and environmentally sustainable alternative for improving subgrade properties. This project presents the Flexible Pavement Design Using Industrial Waste for Subgrade Soil Stabilization by investigating the effectiveness of industrial waste materials in enhancing the engineering characteristics of weak subgrade soil. Laboratory investigations including the California Bearing Ratio (CBR) test, Atterberg Limits test, Standard Proctor Compaction test, Unconfined Compressive Strength (UCS) test, Grain Size Analysis, and Specific Gravity test were conducted to evaluate the stabilized soil. The improved CBR values obtained after stabilization were used for the structural design of flexible pavement according to IRC:37-2018 guidelines. The stabilized subgrade exhibited increased bearing capacity, improved compaction characteristics, higher shear strength, reduced plasticity, and enhanced resistance to settlement compared with untreated soil. The designed flexible pavement demonstrated improved structural performance, longer service life, and reduced pavement thickness, resulting in significant savings in construction cost. The study confirms that industrial waste materials provide an environmentally friendly, technically reliable, and economically viable solution for subgrade stabilization while promoting sustainable highway construction and effective waste utilization.