EXPERIMENTAL INVESTIGATION ON SEISMIC BEHAVIOR OF RECTANGULAR CONCRETE COLUMNS RETROFITTED WITH HYBRIDIZED FRP METHOD

A new retrofit method for improving the seismic behavior of reinforced concrete columns is developed in which the embedded bars and fiber-reinforced-plastics (FRP) sheets are used in the retrofitted area. Five reinforced concrete square columns were tested to examine the effect of GFRP (glass FRP)-bars, CFRP (carbon FRP) sheets and their hybridized method on seismic behavior, as well as that on the increase of displacement ductility ratio, stiffness degradation, and energy dissipation. Experimental results show that the new retrofit method of combining embedding FRP-bars and wrapping CFRP sheets is very effective in improving the seismic behavior of concrete columns compared with the other two methods.