Shear behaviour of prestressed beams reinforced with steel fibres: Fid-Bau Portal

Shear behaviour of prestressed beams reinforced with steel fibres

Belletti, B. / Bernardi, P. / Meda, A.

The use of Fibre Reinforced Concrete (FRC) can be attractive if the higher cost due to the material is compensate by a reduction in the labour cost and an optimisation of the production process. The aim of this paper is to improve the knowledge of the behaviour of prestressed FRC and RC beams when shear failure occurs. A set of experimental tests on full-scale beams was carried out, taking particular attention to the design of the beam geometry, so as to provide information about the mechanical response of the beams both near and away from the transfer length of the strands. The performed tests were simulated by means of a finite element procedure able to predict the non linear behaviour of prestressed FRC and RC beams. A modified version of PARC stiffness matrix, in which the FRC constitutive response has been suitably modelled, has been implemented into the FE code ABAQUS. This constitutive relationship enables to model plain or reinforced concrete beams by means ofmembrane elements, allowing to consider the reinforcement due to both steel rebars and fibres. By means of the proposed numerical procedure, the contribution of the main phenomena occurring after cracking (such as aggregate interlock, bridging effect due to concrete and fibres, etc.) on the final shear capacity has been evaluated by means of an energetic approach. The different mechanisms will be analysed on the basis of the obtained results with particular regard to the effect of fibres.