Experimental Investigation on Behaviour of Reinforced Concrete Beam Element Using Swimmer Bars as Shear Reinforcement

Abstract

A reinforced concrete beam may fail suddenly due to shear and therefore it is necessary to find some safe way to design the beam. The beams subjected to shear failure show different behaviour when compared with bending mode of failure. The width of cracks due to shear forces is more compared to bending forces. The shear failure may not give suitable warning before failure. Hence reinforcement has to be designed in a way that it can carry shear forces effectively. Previous studies show that swimmer bars are effective as shear reinforcement. Swimmer bar is a small bar inclined at some angle, and its either ends are bent horizontally for a small distance, it can be either welded or bolted accordingly, both at the top and bottom of flexural steel reinforcement. Due to the use of swimmer bars in an inclined plane, it forms plane-crack interceptor system, while in case of stirrups barcrack interceptor system is formed. This study is done by using two different shapes of swimmer bars. The purpose of this study is to find the most efficient shape of reinforcement to carry shear forces and also maintaining the economy of the structure. Reinforced concrete beam elements are casted and tested. The Load-Deflection variation for each beam is also plotted at a particular load. A close monitoring is also done on both flexural and shear cracks developed in the beam.