Behavior of Steel Fiber Reinforced High Strength Concrete FRP Confined Columns under Axial Loads

Abstract

As concrete is of brittle nature, different materials have been used to improve this inherent behavior of concrete. This research studies the effects of use of steel fibers and confinement simultaneously on high strength concrete and studies the post peak response of confined Steel Fiber reinforced Concrete. A total of 39 circular unreinforced and steel fiber reinforced high-strength concrete columns were casted. The steel fiber volume (Vf) was varied as 0.5%, 1.5% and 2.5%. 12 samples were unconfined, 18 samples were confined with CFRP sheet and 9 samples were casted in steel pipe confinement. The samples were tested under axial compressive loads on 200Kn capacity UTM at Sarhad University, Peshawar. The results confirmed that the use of steel fiber had little effect on the compressive strength of concrete but it increased the ductility and enhanced the post peak behavior of concrete to an observable extent. The use of confinement increased the compressive strength. The combined use of steel fibers and confinement in concrete columns can be viewed as extremely beneficial as it not only increases the compressive strength of concrete but also solves the problem of brittleness in concrete to an appreciable extent.