Experimental study of reinforced concrete beams strengthened for flexure with steel plates

Abstract

There is often a need to reinforce a structural element, as it may not always support an increase on the applied load. Because of that, the objective of this work was to accomplish a study on the flexural reinforcement technique, with glued steel plates on reinforced concrete beams, to verify changes on the behavior of the reinforced beams when utilizing different approaches for this technique. For the objectives of this research to be achieved, an experimental program was performed, which consisted on the execution of flexural tests on five beams, of which one was not strengthened and the four other beams were strengthened with plates of two different thicknesses. Two were strengthened with glued steel plates only, and the other two with glued steel plates anchored by parabolts on their extremities. Per the experimental results obtained, the increase in resistance and bending stiffness of the reinforced beams in relation to the control beam was observed. Besides that, it was found that the plate thickness influenced the practical performance of the reinforcement, and that the parabolt anchoring if of extreme importance for improving this system. The increase in resistance was not reach the percentage proposed by the calculation methodology, showing that the necessary care must be taken on the preparation of the application surface for the plate and the concrete. It is concluded that characterization studies must be performed on the epoxy resin and anchoring utilized to obtain a better performance from the strengthened beams.