@article {13363, title = {Refor{\c c}o de vigas em bet{\~a}o armado com armaduras exteriores de FRP}, journal = {Revista Internacional TechITT}, volume = {15}, number = {40}, year = {2017}, note = {

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}, month = {Jan. 2017}, pages = {48-60}, abstract = {

A utiliza{\c c}{\~a}o de Pol{\'\i}meros Refor{\c c}ados com Fibras (FRP) no refor{\c c}o de estruturas de Bet{\~a}o Armado (BA) tem tido cada vez mais aceita{\c c}{\~a}o devido {\`a} sua elevada resist{\^e}ncia e rigidez, baixo peso espec{\'\i}fico e excelente resist{\^e}ncia aos efeitos dos agentes ambientais. No entanto, actualmente, {\'e} comum utilizarem-se t{\'e}cnicas de refor{\c c}o que dificilmente permitem tirar partido da resist{\^e}ncia total destes materiais. Com o objectivo de explorar a capacidade total de Pol{\'\i}meros Refor{\c c}ados com Fibras de Carbono (CFRP), foram estudadas e desenvolvidas duas novas t{\'e}cnicas de refor{\c c}o de vigas {\`a} flex{\~a}o designadas por Continuous Reinforcement Embedded at Ends (CREatE) e Horizontal Near Surface Mounted Reinforcement (HNSMR). Posteriormente realizou-se um estudo comparativo entre o desempenho destes sistemas de refor{\c c}o e o de duas outras t{\'e}cnicas j{\'a} estudadas e usuais, nomeadamente os sistemas Externally Bonded Reinforcement (EBR) e Near Surface Mounted Reinforcement (NSMR). A t{\'e}cnica CREatE provou ser a mais eficaz de todas as alternativas testadas mobilizando a totalidade do comp{\'o}sito de CFRP e dotando as vigas de BA com uma maior capacidade resistente e com uma ductilidade mais elevada.Como complemento deste trabalho experimental, desenvolveu-se tamb{\'e}m um programa de c{\'a}lculo em MATLAB, capaz de simular o problema em estudo atrav{\'e}s de um modelo num{\'e}rico de an{\'a}lise n{\~a}o linear atrav{\'e}s do equil{\'\i}brio de sec{\c c}{\~o}es. A representatividade dos dados obtidos foi verificada atrav{\'e}s de uma an{\'a}lise comparativa entre os valores num{\'e}ricos e os obtidos experimentalmente.The use of Fiber Reinforced Polymers (FRP) in order to strengthen Reinforced Concrete (RC) structures has been increasingly accepted due to their strength and stiffness, low weight and excellent resistance to the effects of environmental aggressive agents. However, the bonding techniques available and described in the literature can not allow the full use of the mechanical properties of these materials and premature failures are often observed and described by several researchers. In order to explore the full capacity of CFRP composites, two new bonding strengthening techniques of RC beams when subjected to 4-point bending tests were studied and developed. For these new techniques, the designation of Continuous Reinforcement Embedded at Ends (CREatE) and Horizontal Near Surface Mounted Reinforcement (HNSMR) has been assigned. Posteriorly, a comparative study has been carried out between those strengthening systems performance and two traditional techniques, namely, the Externally Bonded Reinforcement (EBR) and Near Surface Mounted Reinforcement (NSMR). The CREatE technique has proved to be the most effective of all alternatives tested, with the full utilization of the CFRP composite and the highest strength, combined with the highest ductility. A code using MATLAB software was developed as a complement of this experimental work, which is able to simulate the problem under study through a nonlinear numerical model based on the equilibrium of sections. The representativeness of the numerical data has been verified afterwards through a comparative analysis between those and the experimental results.

}, keywords = {Beams, CFRP composites, Nonlinear Numerical modelling, Reinforced Concrete, Strengthening, Bet{\~a}o Armado, Comp{\'o}sitos de CFRP, Modela{\c c}{\~a}o Num{\'e}rica N{\~a}o Linear, Refor{\c c}o, Vigas}, isbn = {1645-5576}, url = {https://issuu.com/techitt/docs/rit40}, author = {Ant{\'o}nio Monteiro and Chastre, Carlos and Biscaia, Hugo and Franco, Noel} }