Shear Behaviour of Ordinary Strength RC Slender Beams

Abstract

This experimental study was devised to ascertain the effects of longitudinal reinforcement on shear strength of RC slender beams under uniformly distributed load instead of concentrated two point loading which has so far been used to understand and formulate the shear design concept. Eight RC beams were divided into four groups of two beams each based on ACI minimum criteria, P.D. Zararis hypothesis, modified form of Zararis equation and beams without shear reinforcement for reference and comparison. These specimens were tested under uniformly distributed load with a constant moderate longitudinal reinforcement. Ultimate shear strengths obtained in this experimental program are compared to the analytical shear strengths calculated according to ACI code provisions, Zararis Equation and the Modified Zararis Equation. Test results show that ACI equation for calculating shear strength of RC beams is conservative. Zararis’ and Modified Zararis’ equations are appropriate for calculating shear capacity of beams. On an additional note a/d ratio was also ascertained for distributed loading which comes to about L/4 for this set of tests.