Experimental investigation of change in shear resistance on clayey soil randomly reinforced with alkali resistant glass fiber

In this thesis, the effect of glass fiber additive with high alkali resistance on the undrained shear strength of high plasticity clay soil was investigated. First of all, the physical and mechanical properties of the clay soil taken from the Sapanca District of Sakarya Province were determined. Then, glass fibers with high alkali resistance produced in 30 and 42 mm lengths were divided into 10 mm, 20 mm, 30 mm, and 40 mm lengths. These fibers were added to the natural soil at rates of 0.25%, 0.5%, 1%, 1.5%, and 2% by dry weight, randomly distributed, and soil-fiber-water mixtures were prepared in optimum water content. The prepared mixtures were compacted in sample molds of two sizes with a constant energy corresponding to twice the Standard Proctor energy. In the study, unconfined compression tests (UCS) were carried out on a total of 370 cylindrical samples, 20 of which are natural and 350 of which are glass fiber reinforced samples. The macroscopic structure of the glass fiber reinforced clay samples was examined, and Scanning Electron Microscopy (SEM) analysis was made to examine the microscopic structure. When the results of the UCS tests performed on all samples were interpreted, it was determined that the glass fiber additive with high alkali resistance increased the undrained shear strength of the clay soil by providing a positive effect and ductility by spreading the failure over a long period. The results are interpreted as alkali-resistant glass fiber that can be used as an alternative material for soil reinforcement.