Shear strength characteristic of geopolymer fly ash and egg shell powder stabilized clay soil

Department of Civil Engineering, Universitas Muhammadiyah Yogyakarta, Jl. Brawijaya Tamantirto, Bantul, DI Yogyakarta, Indonesia

^* Corresponding author: willis.diana@umy.ac.id

Abstract

The clay soil can present various issues as a construction and infrastructure material. Clay soil is susceptible to shrinkage and swelling, limited bearing capacity, poor drainage, and erosion. Several techniques, including soil stabilization, drainage systems, and excavation techniques, may alleviate these issues and control the risks associated with clay soil. There is a growing interest in soil stabilization and developing environmentally friendly alternatives to Portland cement. Alternative utilization of waste with pozzolanic properties as a stabilizing material to replace cement and lime is increasing. In this field, the use of waste materials such as fly ash and eggshell powder is increasing. This study examines the properties of clay soil shear strength treated with a mixture of fly ash and eggshell powder geopolymer. The unconsolidated, undrained triaxial test was performed to determine the shear strength of the treated soil. In addition, the effects of sample variation, such as NaOH molarity, curing duration, and the ratio of eggshell powder to replaced fly ash, were studied. The results demonstrated that 5% eggshell powder might boost the shear strength of treated soil. In addition, increasing the NaOH molarity resulted in higher shear strength values, showing that the geopolymer has a more substantial binding effect. However, extending the curing period impacts the shear strength of stabilized soil. This study established the viability of eggshell powder geopolymer as a stabilizing agent for clay soil. Including 5% eggshell powder in the fly ash geopolymer mixture can enhance the shear strength of the soil.