DUCTILITY AND TOUGHNESS CHARACTERISTICS OF STEEL FIBRE HIGH STRENGTH CONCRETE

High strength concrete is considered to be a relatively brittle material. To improve its ductility, and ability to absorb energy prior to failure, steel fibres are added to the concrete mix. Experimental research was conducted to investigate the mechanical properties of steel fibre high strength concrete (SFHSC). The experimental tests were carried out on 150 mm × 300 mm cylindrical moulds to study both the ductility and toughness characteristics of SFHSC. The main variable in this research includes the volumetric ratio Vf of the steel fibre; four different values of Vf were used (0.5%, 0.75%, 1.0%, and 1.5%) in order to establish the effect on ductility and toughness of SFHSC. In this study, a wide range of high strength is covered, specifically from 40 MPa up to 80 MPa specified strength. Ductility ratios and toughness indices were used to quantify the post peak behaviour of SFHSC. The results showed that introducing steel fibres within the concrete mix enhances the stress-strain characteristics, and improves the post peak behaviour of high strength concrete, and this is reflected in the increase in ductility and toughness of the resulting concrete. The improvement being better for larger volumetric ratios of the steel fibre. INTRODUCTION THEORETICAL BACKGROUND EXPERIMENTAL PROGRAM EXPERIMENTAL RESULTS ANALYSIS AND DISCUSSION OF RESULTS CONCLUSIONS REFERENCES