Analytical investigation of reinforced concrete beams strengthened by carbon fiber reinforced polymer

Strengthening reinforced concrete beams with carbon fiber reinforced polymer CFRP is considered as comparatively fast and practical solution. The objective of this research is to investigate the performance of strengthened reinforced concrete beams by using a non-linear finite element program which is called ABAQUS and the influence of different parameters on strengthened beams' performance. The studied parameters included the number of beam side to be jacketed, the number of layers and Length of CFRP. The obtained results from finite element analyses are presented by the load-deflection curve at the center of beams and show very close to the experimental data obtained from literature to verify the generated models. For flexural critical beams strengthened only at the tensile side, the maximum increase in the ultimate load capacity is obtained when three layers of fibers are used. In this case the flexural strength of the beam increases 52.72% and the mid‐span deflection at failure reduces 18.90% compared to un-strengthened control beam. While strengthening flexural critical beams by using U-shape, the maximum increase in the ultimate load capacity when four layers of fibers are used. In this case the flexural strength of the beam increases 113.5% and the deflection value decrease by 20.09% compared to control beam. On the other hand, the ultimate strength and deflection values of strengthened RC beams at tension side with CFRP length 75% and 100% are very close. For shear critical beams strengthened by U-shape method showed that the maximum increase in the ultimate capacity is obtained when four layers of fibers are used. In this case the shear strength of the beam increases by 16.10% and the deflection decreases by 37.58%. While, shear beams strengthened by wrapped method, the maximum increasing in the ultimate load capacity is obtained when four layers of fibers are used.