Effect of utilization of fiber on the properties of self consolidating concrete

In this study, the effect of steel fibers having different aspect ratios on the fresh and mechanical properties of self-compacting concrete (SCC) mixtures was invatigated. In the mixtures containing fiber, three different twin-hook steel fibers with aspect ratios of 54, 64 and 50 were used as 0.6% of total volum. In all of the SCC mixtures water/cement ratio, cement dosage and slump-flow value were kept constant. The compressive, split-tensile and flexural strenghts as well as fracture enerjy, the load deflection relation under flexural load and load-crack opening displacement of SCC mixtures were also invatigated. Besides, the water absorption capacity and depth of penetration of water under pressure of mixtures were measured. As expected, regardless of fiber aspect ratio, water reducing admixture demand for desired slump-flow value increased by utilization of steel fiber. The mentioned effect was more pronunod by incresing length of fiber and elaspsing time. In the fibrous mixture, no measurment was taken beacausre the mixtures were not flow from th L and U boxes. The mixture containing fiber having aspect ratio of 50 showed the lowest performance in terms of slump-flow and J-ring tests. The fiber utilization and its aspect ratio had no significant effect on compressive strength and modulus of elastisity of the SCC mixtures. The split-tensile, flexural strengths and fracture energy of SCC mixtures increased by using of fiber. The permeability preperties of SCC mixture increased by fiber utilization. This effect was more pronunced by incresing utilization ratio of fiber.