Shear strengthening of concrete beams with FRP laminates

The aim of the present work is the study of the optimal arrangement of FRP sheets in order to increase the shear strength of reinforced concrete beams. For this reason various arrangements of FRP sheets and beams with shear strength less than the bending one are considered for the experimental program. An increment of the shear strength between 50% and 90% with respect to the initial strength of the beam is obtained. A ductile failure mechanism occurs for the beams with FRP reinforcement. The FRP laminates, in fact, allow to influence in a positive way the cracking and the failure mechanisms of the considered beams. Some formulas which allow to estimate the contribution of the composite to the shear strength are proposed.