A Micro-Level Investigation of Optimum Lime-Content Stabilized Expansive Soil Amended with Organic Coconut Shell Powder

Abstract

The experimental investigation involved stabilizing an expansive soil using lime, amending the stabilization process with varying doses of coconut shell powder (CSP), and studying the effects of the amendment on the strength, index properties, mineralogy, and microstructure of the stabilized soil. The optimum lime content (OLC) for the maximum strength gain of the stabilized soil was determined by performing unconfined compressive strength (UCS) tests. The stabilization process was amended with four different proportions of CSP, and the UCSs of the amended specimens were evaluated and compared. The spent UCS samples were crushed and pulverized to perform index property tests as well as mineralogical (XRD) and micro-structural (SEM) tests. The results of the investigation revealed that amending the lime stabilization process with CSP yielded positive results only at a low dosage of 0.25%. It is concluded that materials of an organic origin such as CSP need to be adopted in low dosages to reap beneficial effects in the stabilization process.

Keywords

• expansivesoil
• lime
• coconut shell powder
• strength
• mineralogy
• microstructure
• plasticity
• swell-shrink