Geotechnical Characteristics of HNPC Fly Ash

Abstract

Fly ash is the solid waste being produced in largest quantities from thermal power plants in India causing pollution of land and water. It requires bulk utilization which is possible in geotechnical applications such as embankments and subgrades. This necessitates the determination of the geotechnical properties of fly ash from different thermal power plants. The present paper investigates the geotechnical characteristics of fly ash from HNPC, Pedagantyada, Visakhapatnam. The physical and index properties of HNPC Fly ash (HNFA) and its OMC and MDD using I.S. Heavy compaction are first determined. The shear strength, CBR and permeability are then determined at OMC. The study also investigates the influence of polyester fibers and lime as admixture to HNFA in different percentages on Compaction and CBR properties to check their effectiveness in improving HNFA for use in embankments and subgrade. The chemical and morphological characteristics of HNFA, including its specific surface, XRD, SEM and FT-IR spectra have also been determined. The study confirms the suitability of HNFA for use in geotechnical applications and verifies the relative suitability of polyester and lime as admixtures for further improvement of the geotechnical properties of HNFA.