Author : Magdy Nabih Salib

The objective of this investigation is to study the effect of using different configurations of CFRP laminates externally bonded to the tension side of RC T-beams on the behavior, flexural strength, stiffness, failure mode and ductility of the RC T-beams, and determine the most suitable configuration of the CFRP laminates to strengthen the beams. Two series of RC T-beams were strengthened for flexure with CFRP laminates. The axial stiffness of the CFRP laminates in each series was kept constant. The CFRP laminates in series II have twice the axial stiffness of that in series I. All beams were strengthened for shear with externally bonded CFRP sheet straps with the same configuration (U-wraps) along the shear span to prevent shear failure. Width, arrangements along the beam span and the number of plies of CFRP laminates were the main parameters that were investigated during experimental study. The test results showed that the externally bonded CFRP laminates used for flexural strengthening of the RC T-beams have enhanced the cracking load and showed a significant increase in the flexural load-carrying capacity but exhibited lower ductility compared with the corresponding unstrengthened control beam depending on the configuration and the axial stiffness of CFRP laminates that were used for strengthening.

Keywords: RC T-beams; strengthening; flexural strength; deflection ductility; CFRP laminates.

Article published in International Journal of Current  Engineering  and Technology, Vol.2,No.4 (Dec- 2012)