Effect of the type of hooked-end steel fibers on the mechanical properties of concretes

The addition of fibers have been long termed and widely used application in order to increase of mechanical properties of concretes. Steel fibers are generally used when high performance is required, due to their superior mechanical properties. Effect of the amount, length, aspect ratio, and strength of fibers on the concrete properties are investigated by numerous studies. According to research results and development in technology, type of fibers were increased and new fibers with different hooked-ended were produced. In the scope of the thesis, an experimental study was carried out on the mechanical properties of concrete including hooked-ended steel fibers. In experiments, three different steel fibers which have a different type of hooked-ends and strengths were added in three different concretes (C40/50, C50/60 ve C80/95) in 4 different ratios (15, 30, 45, 60 kg/m3). The compressive, modulus of elasticity, splitting tensile and bending tests were conducted on concretes. Effects of type of steel fiber hooked-end on different concretes are revealed by the experiments. Also, image analyses were performed on the concrete sections and relationship between mechanical properties and the image analysis were investigated. Keywords: Concrete, steel fiber, hooked-end, mechanical properties, image analysis.