Soil Improvement Using Blends of Coal Ash and Plantain Peel Ash as Road Pavement Layer Materials

Abstract

The management of waste and its environmental impact remains an issue. Thus, various strategies are being explored to mitigate this problem. For this research case, the ash of plantain peel and coal was harnessed to enhance soil for usage in designing road pavements. The form of the soil, as regards its plasticity and grain assortment, positions it as a sandy lean clay material. Geotechnical parameters of the natural soil were established before being treated with coal ash (CA) and plantain peel ash (PPA), and subjected to tests for the Atterberg limits, California bearing ratio (CBR) and compaction, as well as investigations pertaining to its crystallinity and morphology. These assessments showed that strength parameters of soil increased on adding CA and PPA. However, the inclusion of these admixtures should be conducted until optimal strength is achieved as seen in 9% CA + 6% PPA. The use of soil stabilised with CA and PPA is suitable for general fillings and embankments. These findings revealed that integrating CA and PPA together would have the potential of stabilising soil as pavement layer material while also eliminating the pollution that emerges from the improper disposal of coal and plantain peels from the environment.