UTILIZING CEMENT AND FLY ASH FOR ENHANCEMENT IN SOFT IRAQI SOILS

Abstract

Problematic soil, especially soft clay, is widespread in the central and southern parts of Iraq, which is described via its low bearing capacity and settlement problems that occur either during or after construction because of low shear strength, high compressibility, and low permeability of this soil. This study aims to investigate the appropriateness of certain local materials to be utilized as stabilizers, like fly ash and cement, which are obtainable in Iraq at a lower cost. This work was carried out on a soil specimen brought from the Gramet Ali location (538 km) south of Baghdad in Al-Basra city. This study consists of three stabilization strategies using cement, fly ash, and their combination, aiming to systematically enhance shear strength and physical properties through rigorous testing protocols  (Specific gravity, Consistency limits, Compaction and Unconfined shear strength with curing time (immediately after preparation sample, 7 days & 28 days) that were carried out, it was determined how the soil's dry weight responded to the supplement of various amounts of fly ash and cement (3%, 5%, and 7% for each additive, respectively). Finding out how the soil reacted to adding varying amounts of each additive allowed us to calculate these percentages. The investigation revealed that incorporating fly ash and cement material into the clay soil resulted in a notable enhancement of the clay soil's shear strength and physical properties.