Generalization of Shear Truss Model to the Case of SFRC Beams with Stirrups

A theoretical model for shear strength evaluation of fibrous concrete beams reinforced withstirrups is proposed. The formulation is founded on the theory of plasticity and the stress field concepts,generalizing a known plastic model for calculating the bearing capacity of reinforced concrete beams, tothe case of fibrous concrete. The beneficial effect of steel fibres is estimated taking into account theresidual tensile strength of fibrous concrete, by modifying an analytical constitutive law which presents aplastic plateau as a post-peak branch. Around fifty results of experimental tests carried out on steelfibrous concrete beams available in the literature were collected, and a comparison of shear strengthestimation provided by other semi-empirical models is performed, proving that the numerical valuesobtained with the proposed model are in very good agreement with the experimental results.