Modelling the tension stiffening effect in SFR-RC

The understanding of the performance and cracking behaviour of steel fibre reinforced concrete (SFRC) has developed greatly in recent times. Many of these studies, however, are limited to SFRC without conventional reinforcement. This paper reports on the tensile behaviour of SFRC members co-reinforced with conventional reinforcing bars (SFR-RC). A physical description of the behaviour of the specimens is presented and an analytical model is derived. The model adopts the load-sharing concept between the tensile stresses resisted by the steel fibres and the steel reinforcing bar as well as the bond between the concrete and reinforcing bar to the tension stiffening effect of these members. The model is founded upon a previously reported tension chord model and allows for explicit identification of the three components to the tension stiffening effect. An experimental programme is reported here and the model is shown to correlate well with the experimental data and test data reported elsewhere.