REPAIR OF R.C. BEAMS SUBJECTED TO TORSION USING CFRP SHEETS

Abstract

Experimental and analytical programs have been carried out to investigate the behavior of repair of rectangular reinforced concrete beams subjected to torsion using Carbon Fiber Reinforced Polymer (CFRP) sheets. Five specimens have been tested with various parameters such as the effect of configurations and orientation of CFRP sheets and spacing of the strips. The ultimate load carrying capacity, ultimate torque, and twisting angle of the specimens. The results showed that using CFRP strengthening technique improves the ultimate load carrying capacity of all the repaired beams, where Full wrapping is the most effective configuration. In addition, CFRP strips applied in 45 degrees with axis of the beam give higher torsional strength than strips applied in 90 degrees with the axis of the beam. The results show that spacing of the strips play a vital role in strengthening, where the smaller spacing increase in effective confinement provided by full strips and hence, result in greater post cracking stiffness compared to the larger spacing.