Enhancing the flexural load capacity of the reinforced concrete beams using Dramix 3D 80/60 BG steel fibres

Abstract

The purpose of this study was to investigate the effect of adding Dramix 3D 80/60 BG steel fibres to the reinforced concrete beams experimentally. The main specimens were 6 reinforced concrete beams (dimension of 150 x 180 x 1700 mm) with a variety of the flexural reinforcement (i.e. 2D6, 2D10 and 3D10) and the fibre volume fraction (i.e. 0%, 0.5%, 1% and 1.5%). The concrete compressive strength was 25 MPa, no superplasticizer was added in the concrete mix. The test set-up of the beam specimen is, the beam was simply supports at the distance of 1500mm, 2 concentrated loads gradually were applied until it collapses. During applying the loads, measurements were taken including the deflection in the mid-span of the beam, the crack propagation and crack width. The results showed that the increase of fibre content will increase the load capacity and stiffness without reducing the ductility of the reinforced concrete beams. The steel fibre volume fraction of 1% is the maximum content that can be used without using superplasticizer to maintain the workability of the fresh concrete. The addition of 0.5% steel fibre provides a similar flexural performance to the addition of one D10 (flexural reinforcement) in a reinforced concrete beam.