Prediction of shear strength of steel fibre based concrete beams without shear stirrups

Abstract

Seventy Seven tests were conducted on reinforced concrete beams with four steel fibre volume fractions (0, 0.5, 0.75, 1.0%), two aspect ratios of fibres (66.6 and 80.0), five shear span-depth ratios (1, 1.3, 1.6, 2.6 and 4.0) and three concrete strengths (23.30, 29.72 and 34.23). the results demonstrate that ultimate shear strength increases with increasing fibre volume, decreasing shear span to depth ratio, and increasing concrete compressive strength. It has been seen that as the fibre content increased, the failure mode changed from shear to flexure mode for the beams with moderate amount of longitudinal tension steel. The test results were used to evaluate existing and proposed empirical equations for estimating shear strength. It was found that the equations proposed herein and the equations developed by Narayanan and Darwish provide a good accuracy for the estimation of shear strength