Evaluation of stabiliser material using a waste additive mixture

Abstract

AbstractTo eliminate problems caused by gypsum soil in Iraq (due to gypsum salt under building foundations and projects), this study evaluates the effect of using the proposed stabiliser additives (vehicle waste oil and asphalt powder) to produce a composite enhancement material as a novel solution by examining the shear strength of the gypseous soil using the direct shear and constant head permeability tests. Three burned-oil weights were used (3%, 5%, and 7% by dry soil weight), which were mixed with a constant quantity of asphalt powder (10% of the sample weight) to investigate the shear strength of the composite material. Several factors were considered in this study, including soaking time and moisture content.The main findings reveal that composite material could improve the strength of the gypseous soil. The stabiliser reduces water leakage and percolation by forming an impermeable layer with a very fine texture, causing a significant reduction in the permeability coefficient, which improves the gypseous soil and reduces the collapse phenomenon.