Simplified analytical method for moment-curvature response of corroded prestressed concrete beams

Nowadays, the corrosion phenomenon is recognized as one of the main causes of deterioration of reinforced and prestressed concrete (PC) structures. Several experimental and numerical investigations have been proposed in the literature for the flexural and shear response of reinforced concrete structures. However, the lack of simplified yet accurate analytical models have been outlined, especially concerning the residual mechanical response of corroded pre stressed concrete members. To this aim, the present work focuses on the proposal of a simplified analytical model for the flexural resistance of prestressed concrete beams - subjected to chloride induced corrosion - in terms of moment-curvature response. Firstly, the basic assumptions of the approach and the validation against un-corroded PC beams are described by adopting a novel stress-strain relationship for corroded strands previously proposed by the authors. Secondly, the effect of the corrosion level on the moment-curvature response of deteriorated PC beams is in vestigated. Finally, outcomes are provided concerning: (i) the expected flexural failure mode, (ii) the evaluation of useful parameters for the assessment of flexural and shear resistances - the latter referring to the current formulation provided in the Model Code 2010