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Abstract
This research paper presents the results of extensive experimental investigations and analytical results on the fresh and hardened properties of self-compacting concrete reinforced with hybrid hooked end fiber (HF) and crimped steel fiber (CF) in different fiber volume fractions. In this present investigation, the mixes were reinforced with different fiber combinations of hooked end fiber (0.25, 0.5 and 0.75%) and crimped fiber (0.25 and 0.5%). The fresh state properties of the mixes were characterized by using slump flow diameter, T50cm, and V-funnel test. The hardened properties of self-compacting concrete (SCC) mixes were assessed by using compressive strength, flexural strength and impact resistance test. Regression analysis was carried out in order to correlate the fresh and hardened state on the extensively large volume of collected experimental data. The results reported that adding hybrid hooked endcrimped steel fiber significantly improves the compressive strength, flexural strength and impact resistance. Addition of hooked end steel fiber led to improve the compressive strength when compared to crimped end fiber. Moreover, increasing the crimped fiber content decreased the effect of hooked end steel fiber in flexural strength improvement.
Introduction
In last two decades, the major research projects have focused on steel fiber reinforced concrete (FRC) for the construction of tunnels, airport runways, hydraulic structures, railway sleepers, underground works, earthquake resistance structures and highway projects like bridges [31]. The study of the fresh and hardened properties of FRC Akcay and Tesdemir [3] reported that length, diameter and shapes of fiber were extensively most important parameters that significantly affect the reinforcing capacity and toughening behavior of steel fiber reinforced concrete. Many Foreign researchers have manufactured fiber reinforced concretes by adding different geometries or shapes of single steel fiber. They produced concretes with better reinforcing capacity, compressive strength, flexural strength, toughness and fracture energy absorption capacity than single-fiber-reinforced concrete. Main drawback of concrete with fibers is its very low ductility property. Moreover, these plain concrete has low tensile characteristics, flexural strength and corresponding properties. Incorporation of steel fibers is a very effective way of producing plain concrete with enhanced hardened properties such as compressive, flexural strength properties and impact resistance.