Mechanical properties of steel fibre reinforced concrete exposed at high temperatures

Steel fibre reinforced concrete (SFRC) is an advanced cementitious composite where fibres can act as a profitable replacement for diffused reinforcement, like welded steel mesh, especially for thin cross sections. In this case fire becomes a very important condition in the design. Previous experimental research has shown the benefits in fire resistance of steel fibres, when structural elements are bent. A careful mechanical characterization of a SFRC used for prefabrication after thermal cycles at high temperature is here presented. Three different tests are considered: four point bending, uniaxial compression and fixed-end uniaxial tension. In the paper the decay of peak and post-cracking strengths versus temperature increase for uniaxial compression, uniaxial tension and bending are discussed.