“Enhancing Road Construction Sustainability: Clayey Soil Stabilization with Cement and Volcanic

This study focuses on a residual clay soil collected from Bako village along the Gwagwalada-Garki road in the Federal Capital Territory of Nigeria using disturbed sampling. The clay was subjected to comprehensive characterization, including X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Electron Dispersive Spectroscopy (EDS) tests. Additionally, the clay soil was compacted at the Standard Proctor energy level to determine its Maximum Dry Density (MDD) and Optimum Moisture Content (OMC).

Subsequently, Unconfined Compressive Strength (UCS) tests were performed on both the natural clay and the clay mixed with varying percentages (0%, 2%, 4%, and 6%) of cement. Each cement mixture was further admixed with different percentages (0%, 3%, 6%, 9%, 12%, and 15%) of Volcanic Ash (VA). The mineral composition of the clay was found to predominantly include montmorillonite, ankerite, calcium silicide, anorthite, anothoclase, and orthoclase.

The SEM test revealed a flaky nature of the clay with visible pore spaces. When the natural clay specimen, compacted at the standard proctor energy level, was mixed with different proportions of VA, it exhibited a remarkable 2.5 times increase in UCS compared to its natural state. Furthermore, when 6% cement was mixed with varied percentages of VA, the UCS increased by 80% compared to specimens containing 6% cement with 0% VA.

The study identified that the optimal percentage range of VA, which resulted in maximum UCS values, lies between 6% and 9%. These findings provide valuable insights into enhancing the engineering properties of clay soil using cement and volcanic ash admixtures.

Enhancing Road Construction Sustainability: Clayey Soil Stabilization with Cement and Volcanic.