Stabilization of Medium Expansive Soils in Pakistan Using Marble Industrial Waste and Bagasse Ash

This paper reports an investigation of suitability of industrial and agricultural waste (i.e. marble waste and bagasse ash) on the geotechnical properties of medium expansive soils, located across Kohat city, of Khyber Pakhtunkhwa Pakistan. As most part of Pakistan falls in semi-arid zone, the geology and climatic conditions in Kohat produce widespread distribution of swelling clays. Such soils possesses a variety of undesirable characteristics i.e. immensely affect the pavements, boundary walls, slab-on-grade members and other infrastructure. Soil samples were collected, cataloged, subjected to multitude of geotechnical tests and submitted to anti-expansive treatment using prescribed percentages of stabilizers. The investigation includes chemical analysis i.e. X-Ray Diffraction (XRD) Analysis, Scanning Electron Microscopy (SEM), X-Ray Fluorescence (XRF) tests, and evaluation of geotechnical properties such as moisture-density relationships, Atterberg limits, unconfined compressive strength, swell pressure and free swell. When blended with both stabilizer materials, the compatibility and strength characteristics are improved and plasticity is significantly reduced. From the viewpoint of economy, blending of soil using 4-6% bagasse ash and/or 8-10% marble industrial waste is recommended. This paper summarizes the results of identification, characterization and stabilization techniques to eliminate the expansively of swelling soils.