Search Articles

Home / Articles

Effect of expanded polystyrene beads and fly ash on the strength and deformation characteristics of soil

. Sharafat Ali, Feng Yong, Amanullah Marri, Farhad Jamil & Mudassir Mehmood


Abstract

In the field of geotechnics, silty soil is not preferred as the best geotechnical material. However, the growing interest in utilizing waste, raw, and lightweight materials in civil engineering applications has opened the possibility of using modified soils as an alternative to unconventional materials for various geotechnical purposes. In this study, silt as a base material is mixed with fly ash as a pozzolanic material and expanded polystyrene beads (EPS) as a lightweight material to produce a lightweight soil (LWS) that can be used as a construction material. Various EPS bead sizes and fly ash were considered to evaluate their effects on maximum dry density (MDD), optimum water content (OWC), and unconfined compressive strength (UCS). The finding shows that as the size of the EPS beads increases at a given content, the ductility and deformation increase, and the strength and density decrease significantly. It was revealed that increasing fly ash concentration increases the stiffness and unconfined compressive strength (UCS) of lightweight soil from 165 kPa to 215 kPa but decreases, as the size of expanded polystyrene pellets increases. Studies have also shown that a mixture of tiny expanded polystyrene beads and fly ash is suitable for increasing strength. In contrast, heavily expanded polystyrene pellets weaken the fly ash bead combination. 15% and 20% fly ash, particularly in 1mm to 3mm sizes with an EPS bead content of 0.5%, are useful for construction materials. The advantages of each size of expanded polystyrene pellet depend on the requirements of the engineering application and the conditions in the field. The purpose of this study is to determine the effect of EPS beads and fly ash on the strength and deformation characteristics of soil and to ascertain an optimum content that can be adequate for improving the strength and deformation characteristics

Keywords: EPS beads, light weighted soil, Fly ash, unconfined compression test, strength and deformation, stress-strain

Download :