Retrofitting Method of RC Beams Using Tensioned Carbon Fiber Sheets

Abstract

Retrofitting methods for RC beams were proposed in the present work. Tensioned carbon fiber sheets were employed to improve the bending strength of the RC beams for both live and dead loads. A novel tensioning device was developed to apply the tensile stress to the carbon fiber sheets and to prevent the interfacial debonding between the carbon fiber sheets and RC beam. Experimental results showed that the proposed device could apply by far higher tensile stress to the carbon fiber sheets than the conventional methods. As a result, the bending strength of the beams retrofitted by the present method was higher than that of the beams retrofitted by the conventional methods. Especially, the critical load at the crack initiation in the concrete increased about 3.8 times comparing with that of the original RC beam and about 1.6 times comparing with that of the RC beams retrofitted by the conventional methods by using the present method.