Effect of Fly ash powder on the physical properties of expansive soils

Abstract

Expansive soils have a large variation in volume depending on the quantity of water in them, causing structural and geotechnical problems. Fly ash powder could be used as a stabilizing material for high-plasticity clay in five different locations in Erbil city that has caused damage to different buildings and roads. Grain size analysis, specific gravity, and Atterberg limit were the main methods of physical testing of soils. The expansive soil was stabilized by adding three different percentages of Fly Ash Powder (5%, 10%, and 15%). The results show that liquid limit, plastic limit, and plasticity index were decreased with increasing Fly ash powder to expansive soil. Mineralogically these soils are composed of Montmorillonite, Chlorite, Chlorite- swelling, Kaolinite, Illite, Palygoriskite, and mixed layer - dominated clay mineral components ,and the non-clay minerals consisting of calcite, muscovite, and quartz, and Fly ash powder composed of Muscovite and Calcite.