Análise do reforço à flexão com fibras de carbono em vigas de concreto armado: abordagem numérica

Abstract

The reinforcement of reinforced concrete structures with concrete fibers reinforced polymers (CFRP) can be used in new structures or rehabilitation of them. The method was consolidated as an attractive alternative for civil works, due to the fact of the characteristics of this material, such as its high tensile strength and corrosion, small specific weight, ease and speed of application. The development of this technique and the increasing use of it, requires more refined methods of analysis. In this context, the present work aimed to analyze numerically the resistant capacity of the flexural reinforcement with carbon fiber reinforced polymers (PRFC) externally bonded, in reinforced concrete beams facing different degrees of deterioration. For this, initially, a reference beam was dimensioned, having as guideline the beams tested experimentally by Beber (1999). The deterioration was applied to the reference beam using the methodology proposed by Paliga (2008), where the steel area of the longitudinal bars is reduced in order to reduce the flexural strength of the structure. Then, the reinforcement with the PRFC was dimensioned based on international normative prescriptions (ACI 440.2R) and due to the reinforcement area necessary for each deterioration situation. Finally, the efficiency of the reinforcement application was analyzed using carbon fiber composites through by the Finite Element Method (MEF) analysis using the ANSYS Mechanical APDL 19.2 software, manipulating the programming script provided by Medeiros (2019) and validated in that work. The reinforcement with PRFC adhered externally proved to be efficient, reaching satisfactory last loads. In all of the cases analyzed, the failure of the structure was due to excessive plastic deformation of the reinforcement, not having the maximum use of the strength of the reinforcement fiber. [resumo fornecido pelo autor]