Resistant Capacity And Failure Modes Of Reinforced Concrete Beams Strengthened In Flexure With Externally Bonded Carbon Fiber Reinforced Plastic [capacidade Resistente E Modos De Ruptura De Vigas De Concreto Armado Reforçadas à Flexão Com Fibras De Carbono]

To design an externally bonded fiber reinforced plastic reinforcement for a reinforced concrete beam, it is necessary that the engineer responsible chooses to work without the use of mechanisms to increase the anchoring within safe levels, or make use of artifacts to ensure that the deformation in the fiber reaches ultimate state value supplied by the manufacturer. This article shows the basis for the calculation of the two methodologies under the existing criteria more expressively and also makes comparisons with laboratory tests. For enhancement without anchoring, it was found that to prevent unwanted premature and abrupt ruptures, the methods proposed by ACI and FIB showed to be adequate. To ensure the ultimate deformation of the fiber, a mechanism for anchoring in the form of a bow 45° made by the material of the fiber was studied. In this case, the process of balanced sections to foresee the mode of collapse were verified and then the appropriate comparisons were made between the expected values with the tests results found in the laboratory.653297303(1996) State-of-the-art report on fiber reinforcing plastic reinforcement for concrete structures-ACI 440R-96, p. 68. , AMERICAN CONCRETE INSTITUTE. Reported by ACI Committee 440. Detroit, MichiganArduini, M., Tommaso, A.D., Nanni, A., Brittle failure in FRP plate and sheet bonded beams (1997) ACI Structural Journal, 94 (4), pp. 363-370Ashour, A.F., Family, M., Tests of concrete flanged beams reinforced with CFRP bars (2006) Magazine of Concrete Research, 58 (9), pp. 627-639Barros, J.A.O., Dias, S.J.E., Near surface mounted CFRP laminates for shear strengthening of concrete beams (2006) Cement & Concrete Composites, (28), pp. 276-292Chaallal, O., Nollet, M.J., Perraton, D., Strengthening of reinforced concrete beams with externally bonded fiber-reinforced-plastic plates: Design guidelines for shear and flexure (1998) Canadian Journal of Civil Engineering, 2 (25), pp. 692-704. , Montreal(2001) Externally bonded FRP reinforcement for RC structures-Technical Report-FIB Bulletin, (14), p. 130. , FÉDERATION INTERNATIONALE DU BÉTON. LausanneNg, S.C., Lee, S., A study of flexural behavior of reinforced concrete beam strengthened with carbon fiber-reinforced plastic (CFRP) (2002) Journal of Reinforced Plastics and Composites, 21, pp. 919-938Norris, T., Saadatmanesh, H., Ehsani, M.R., Shear and flexural strengthening of R/C beams with carbon fiber sheets (1997) ASCE Journal of Structural Engineering, 123 (7), pp. 903-911Papanicolaou, C.G., Textile reinforced mortar (TRM) versus FRP as strengthening material of URM walls: Out-of-plane cyclic loading (2008) Materials and Structures, 41, pp. 143-157Roberts, T.M., Approximate Analysis of Shear and Normal Stress Concentrations in the Adhesive Layer of Plated RC Beams (1989) The Structural Engineer, 67 (12), pp. 229-233Saadatmanesh, H., Ehsani, M.R., RC beams strengthened with GFRP plates. I: Experimental study (1991) ASCE Journal of Structural Engineering, 117 (11), pp. 3417-3432Si-Larbi, A., Ferrier, E., Hamelin, P., Flexural behaviour of MRBC beams (multi-reinforcing bars concrete beams), promoting the use of FRHPC (2006) Composite Structures, 74, pp. 163-174Silva, A.O.B., (2001) Reforço à flexão de vigas de concreto de elevada resistência por meio da colagem de manta polimérica reforçada com fibras de carbono, p. 405. , São Paulo: Faculdade de Engenharia Civil, Universidade Estadual de Campina