Flexural srengthening of RC beams using composite materials. End anchorage study

Abstract

Due to the excellent properties of fiber reinforced polymers (FRP), concrete beams retrofitted by bonding composite plates to its soffit have become an attractive structural strengthening method. The amount of external reinforcement is calculated assuming the ideal mode of failure, which is concrete crushing or plate rupture. However, the results of many experimental programs have shown premature failure due to high stresses at the end of the laminate or related to the crack mouth opening of flexural or shear cracks. A linear-elastic analysis at the end anchorage of the laminate is presented in this paper. Non Linear Fracture Mechanics Theory includes a post-peak behavior once concrete cracking is initiated. This fact implies an enhancement of the load transfer between concrete and FRP through the interface.