Reinforced concrete beams strengthened in shear with U-shaped PBO FRCM (Fabric Reinforced Cementitious Morta) composites: analysis of prediction models

FCRM composites consisting of fiber fabrics embedded into inorganic matrices (cement or lime mortars) , are suitable systems for strengthening and repair reinforced concrete structures. Shear strengthening is, generally, made with U-shaped strips bonded in different configurations (continuous or discontinuous). AS recognized by experimental investigations, shear capacity of FRCM strengthened beams is strongly influenced from strip debonding. Prediction models of strengthened beams shear capacity focus on the effective strain as the representative parameter of debonding. This paper provides an assessment of the commonly adopted models for predicting the shear capacity of FRCM strengthened reinforced concrete bemas. In addition, a new model founded on the evaluation of the effective strain by the results of bond tests is proposed. The comparison between models predictions and available experimental results allows to evaluate the effectiveness of the performed analysis