Reinforced concrete beams externally strengthened in flexure using hybrid systems

This paper presents the experimental results of nine full scale RC beams externally strengthened in flexure with different combinations of Aluminum, CFRP and galvanized steel mesh (GSM) hybrid laminates. Three groups of three beams were built with different flexural reinforcement ratios, and two beams in each group were strengthened with hybrid laminates in addition to control specimen. Coupon tests were conducted also to obtain the mechanical properties of the composite laminates. All the beams were tested under four-point bending and the load-deflection response had been recorded until the failure of the specimens. All the specimens failed in flexure and delamination was the controlling failure mode for all the strengthened specimens. Load carrying capacity of strengthened specimens increased from 27%–128% over the unstrengthened control specimen. It was also observed that the ductility and stiffness of the specimens increased due to the use of optimum hybrid laminates.