António Monteiro

in

Reforço de Vigas de Betão Armado com Armaduras Exteriores de FRP

This thesis follows on from accomplished studies in the Civil Engineering Department of the Universidade Nova de Lisboa about the reinforcement to the bending of reinforced concrete beams with CFRP composites (reinforced composites with carbon fibers).

Initially, two new strengthening techniques using CFRP laminates were studied and developed in order to retrofit RC beams in bending. For these new techniques, the designation of Externally Bonded Reinforcement Anchorage (EBRA) and Horizontal Near Surface Mounted Reinforcement (HNSMR) has been assigned.

These strengthening systems have been studied and tested into five reinforced concrete T beams, which were taken at break through bending tests, considering a load application system into four points. For different loading patterns (monotonic and cyclic) several parameters related to the ability of mobilization of tensile strength of strengthening elements, system’s maximum resistance, their ductility and efficiency before service situations were analyzed. Therefore, a comparative study has been carried out between those strengthening systems performance and the one of two other techniques already studied, namely, the Externally Bonded Reinforcement (EBR) and Near Surface Mounted Reinforcement (NSMR) systems.

A code using MATLAB software was developed as a complement of this work, which is able to simulate the problem under study through a numeric model of nonlinear analysis of sections. The representativeness of obtained data by the numeric model has been verified afterwards through a comparative analysis between those and the obtained experimental ones.