Sustainable Soil Stabilization: Strength And Microstructural Analysis Of Calcium Lignosulfonate Treated Black Cotton Soil

Abstract

The current study considered the calcium lignosulfonate as a stabilizing material to stabilize black cotton soil as it do not release CO₂ upon reacting with soil, unlike traditional stabilizers and can be a sustainable material that helps to achieve Sustainable Development Goals as it is an eco-friendly, non-traditional stabilizer and organic polymer. In addition to that, it is vital to understand the micro-structural properties of treated soil to have a comprehensive knowledge on strength improvement mechanism. To examine the optimum calcium lignosulfonate content, black cotton soil was mixed with different dosages of calcium lignosulfonate ranging from 1 to 5% with an increment of 1% and the optimum content of 4%. The densely packed structure contributed by formation of Calcium Silicate Hydrate in treated soil enhanced the soaked California Bearing Ratio up to 8.13% and Unconfined Compressive Strength up to 203.80 kPa. This enhanced strength characteristics in the black cotton soil appraised by the X-Ray Diffraction, Field Emission Scanning Electron Microscopy and Energy Dispersive X-ray Spectroscopy analyses. The optimum CBR value and decreased thickness of the pavement made the stabilized BC soil suitable for subgrade material for pavement construction.