Alcuni aspetti del comportamento flessionale di travi di cemento armato con fogli di CFRP

This paper deals with the flexural strengthening of reinforced concrete beams with Carbon FRP sheets. In particular, referring to Replark, the mechanical characteristics of the material and some aspects of the flexural design are discussed, especially involving the check of stress under working loads. The influence of the state of stress of the structure at the time of the renovation on the utlimate bending moment and on the stress under working loads is evaluated. The unloading branches of moment – curvature diagrams are also considered in order to evaluate the influence of the state of stress on the residual deformations. Two examples of application of CFRP sheets for repair and strengthening of a concrete structure are briefly described. First example refers to a prestressed concrete structure; second example refers to the beams of a reinforced concrete structure.