Strength, mineralogical and microstructural studies on clayey soil stabilized by bio-stabilized waste ash with lime

Clayey soils can be strengthened and stabilized primarily using a variety of binder materials, such as lime, cement, fly ash, etc., which have been extensively researched. Despite that, recent studies focus on solid waste as binary and tertiary additives along with the activators to improve the strength of clay by considering the aspect of the environment and economy. In this study, bio-stabilized waste ash (BSWA) is considered as a binary additive which was added in the range of 0–25% (% by weight) with 4.5% (% by weight) initial consumption of lime (ICL) into the clay and cured for 0, 7, 14, and 28 days to enhance the index properties and compressive strength of untreated clay. The compressive strength of soil with an optimum percentage of BSWA (15%) and ICL shows a fourfold increase when compared to the virgin soil's strength cured for 28 days. Scanning Electron Microscopy, Fourier Transform Infrared, and X-ray Diffraction analysis depict the noticeable changes in microstructure and mineralogical composition of BSWA-amended clay.