Behavior of Full-Scale Shear Deficient Corner RC Beam- Column Connections Retrofitted with CFRP Sheets

In moment resisting reinforced concrete framed buildings, corner joints are found at the roof level. These joints, if designed for gravity loads and are based on pre-seismic codes, may suffer substantial damage during earthquakes particularly under opening cycles, i.e. those causing flexural tension on the inside of the joint. Several techniques of repair and strengthening of reinforced concrete joints, damaged by earthquakes, have been reported in earthquake prone countries such as Japan, Mexico, and Peru. Of the various repair techniques used, the most common involved were RC or steel jackets. Plain or corrugated steel plates have also been tried. These techniques cause various difficulties in practical implementation at the joint, namely intensive labor, artful detailing, increased dimensions, corrosion protection and special attachments. To overcome the difficulties associated with these techniques recent research efforts have focused on the use of epoxy-bonded Fiber Reinforced Polymer (FRP) sheets or strips with fibers oriented properly so as to carry tension forces due to shear.