Innovative Triaxially Braided DuctileFRP Fabric for Strengthening Structures

Synopsis: This paper deals with the effectiveness of a new triaxially braided ductile Fiber Reinforced Polymer (FRP) fabric for flexural strengthening of continuous reinforced concrete beams. The tested continuous beams had two spans strengthened in flexure along their positive and negative moment regions and loaded with a concentrated load at the middle of each span. One beam was not strengthened and was tested as a control beam. The behaviors of the beams strengthened with the new fabric were investigated and compared with the behaviors of similar beams strengthened using a commercially available carbon fiber sheet. The responses of the beams were examined in terms of deflections, strains, and failure modes. The beams strengthened with the new fabric showed greater ductility than those strengthened with the carbon fiber sheet. The new fabric provided reasonable ductility due to the formation of plastic hinges that allowed for the redistribution of moment between the positive and negative moment zones of the strengthened continuous beam. Redistribution of the moment enabled the full utilization of the strength of the beam at cross sections of maximum positive and negative bending moments.