Shear behaviour and shear analysis of reinforced concrete beams containing steel fibres

Abstract

An investigation of the shear behaviour of reinforced concrete beams containing steel fibres is presented. The major test variables were the amount of steel fibres and the volume of shear stirrups. The fibre content was varied from 0% to 2% by volume, and the amount of stirrups from zero to full reinforcement using code-required values. The test results show that the cracking shear strength increases significantly as the fibre content increases, and that improvement in ultimate shear strength is also achieved. It is seen that the steel fibres play an important role in reinforced concrete beams by curbing crack occurrence and reducing the crack width. This effect greatly enhances the serviceability and durability of reinforced concrete structures. The mode of failure changed from shear to flexure when the volume fraction of fibres exceeded 1%. This means that fibre reinforcement greatly increases the shear capacity. The ductility is also enhanced remarkably by the addition of fibres. The present study indicates that fibre reinforcement can reduce the amount of shear stirrups required, and that a combination of fibres and stirrups may be used to achieve both strength and ductility requirements. An analytical method for predicting the shear strength of reinforced concrete beams containing steel fibres is proposed. Good correlation was obtained between calculated and test data. The proposed method allows a more realistic shear analysis of reinforced concrete structural members containing steel fibres.