Flexural behaviour of steel fibre-reinforced concrete under cyclic loading

- The flexural behaviour of fibre reinforced concrete under cyclic loading was studied.
- The fibres orientation depends mainly upon the workability properties of the concrete mixture.
- The use of steel fibres in concrete improved the flexural tensile strength and the ductility.
- The fibre content and the aspect ratio have an important influence on the reversibility of FRC.
- The cumulative energy of FRC increases with the fibres content.

This paper presents the results of cyclic loading tests on fibre-reinforced concrete (FRC). The main objective of this research is to evaluate simultaneously the influence of the workability, the steel fibres and the compressive strength on the flexural behaviour of FRC under cyclic loading. Prismatic concrete specimens having dimensions of 150 × 150 × 700 mm were fabricated with concrete of various workability and different compressive strengths (30, 60 and 80 MPa) and reinforced with hooked end steel fibres of aspects ratios of 65 and 80 at contents of 0.5 and 1%. A four-point bending test with notched specimens was conducted using Digital Image Correlation technique. The orientation of the fibres, failure modes, hysteresis loops, flexural strength, local analysis, cumulative energy and ductility of FRC beams are presented and analyzed. The experimental results show that the cyclic flexural behaviour of FRC flexural strength and ductility of fibre-reinforced concrete are significantly improved by the fibre content, the aspect ratio, the fibres orientation and the concrete strength. The increase in flexural strength reaches 242%. The workability of concrete plays an important role on the orientation and distribution of the fibres in the matrix.