Flexural modelling of steel-fibre-reinforced concrete member with conventional tensile rebars

This paper presents an analytical model for the determination of the ultimate flexural capacity of steel-fibre-reinforced concrete (SFRC) rectangular sections using the principles of strain compatibility and the force equilibrium. The proposed model considers an elastic-perfectly plastic model for the compression, and an elastic constant post-peak response of the SFRC in tension. Unlike other flexural models in the literature, the proposed model considers the random distribution and orientation of steel fibres at the cracked section in the analysis, and it is simple enough to find applications in routine practice. The model was verified using existing experimental results, and it predicts the flexural capacity of SFRC beams reasonably well. A parametric study using the proposed model was conducted to assess the effect of fibre parameters, conventional reinforcing bars and the strength of the concrete on the ultimate flexural capacity of a SFRC beam section. Normalised design charts are presented to simplify the analysis procedure, and these can be used for selection of the fibre and the quantity of conventional reinforcing steel during the flexural design of SFRC members.