Effect of cockle shell powder as sustainable additive on geotechnical engineering properties of stabilized soil

The problematic soils such as marine clay old alluvium/ soft soil, ex-mining lands, and man-made fills are commonly found in coastal and river shores areas which require soil stabilization techniques by using sustainable materials. The sustainable materials from recycled and waste products are rapidly gaining attention in construction, infrastructure, and transportation as alternate materials for sustainable development due to their low negative impact on resources, environment, and people. This paper investigates the effect of Anadara granosa, better known as cockle shell, as a natural admixture as well as a sustainable material, on the physical and mechanical characteristics of stabilized marine soil. The effect of cockle shell powder (CSP) as a natural waste additive on soil properties in the stabilization techniques is not well understood by many researchers especially in mixing design and its effectiveness on the stabilized properties. In this study, twenty-five samples were prepared at five different percentages of CSP (0%, 2.5%, 5%, 7.5%, and 10% based on dry unit weight) which were added into original soils to investigate the effects of different percentages of CSP on Atterberg limit properties, compaction characteristics, and unconfined compressive strength of marine soils. The findings indicate that the geotechnical properties were improved and influenced by the different percentages of CSP. The significant percentage of additives added into the soil mixture was 5–10%. The correlations of the geotechnical properties of stabilized soils with different percentages of CSP are proposed as a guide for laboratory experiments as well as fieldwork in determining the right proportions in mixing CSP with soil for stabilization purposes.