Stabilization of physical and mechanical properies of Kutlubey-Yazıcılar clays with Çatalağzı fly ash

The safety of soils in terms of safety stress is especially important for infrastructure works such as stream improvement, pipelines, sewer line or for the soils under the bases where the structures are located. Mechanical properties of clayey soils can cause problems due to mechanical insufficiencies in clayey soils such as bearing capacity failure, swelling and shrinkage tendency, shear strength failure, consolidation and stability problems. This study focused on the improvement of mechanical properties of a high plasticity clayey soils mixed with fly ashes of thermal power plant waste. For this purpose, the fly ash obtained from Çatalağzı Thermal Power Plants and the clayey soils belonging to Kutlubey region of Bartın were used. These fly ash-clay mixtures, which are compacted in optimum water contents, were stored in the cure (1-8-16-32 days) for the triaxial pressure test. The samples completed for curing time were tested without consolidation and drainage (UU) conditions by using the triaxial test machine. In order to better determine the engineering behavior of fly ash-clay mixtures, the Scanning Electron Microscopy (SEM) and X-ray Powder Diffraction (XRD) analyses were performed at the final stage of the experimental part of the study. From the tests results, significant increases were observed in the strength values of mixtures which were formed the fly ash percentages added between 5% and 20% to clayey soils. However, it was determined that the addition of fly ash to clayey soils more than a certain percentage of additives did not significantly affect shear strength.