Influence of Eggshell Ash and Stone Powder on Geotechnical Properties of Expansive Clay in Dukem Town

Expansive clays exhibit a distinctive swelling–shrinkage behavior, leading to structural distress and damage when subjected to varying moisture levels during different seasons. So, to mitigate these issues, stabilization techniques are commonly employed, aiming to diminish swelling tendencies and enhance the strength characteristics of expansive clays. This study delves into the transformative impact of utilizing eggshell ash (ESA) and stone powder (SP) as stabilizing agents on both the index properties and strength parameters of expansive clays. The selection of these stabilizing agents is guided by criteria encompassing cost-effectiveness, availability, and environmental compatibility. Through comprehensive analysis utilizing scanning electron microscopy (SEM) and X-ray diffraction (XRD), the mineralogical compositions of both soil and additives are meticulously examined. The XRD analysis of the expansive clay unveils the presence of minerals such as quartz, sanidine (potassium or sodium feldspar), and magnetite. Incorporating ESA into the expansive clay matrix yields substantial improvements across various soil index values, encompassing the free swell index, free swell ratio, linear shrinkage, and unconfined compressive strength value. To further amplify these benefits, the study extends its focus to the influence of SP while maintaining a consistent 6% ESA content. Notably, the addition of SP exhibits a significant enhancement in compressive strength, alongside other crucial properties. Synthesizing these findings, the laboratory results point to an optimal combination ratio of 6% ESA and 15% SP, as a recommended approach to achieve superior stabilization effects. This research contributes to a deeper understanding of the interplay between stabilizing agents and expansive clays, paving the way for improved engineering practices and more resilient structural designs.