STRUCTURAL CHARACTERISTIC OF RC COLUMNS RETROFITTED WITH A COMBINATION OF ARAMID FIBER SHEETS AND STEEL PLATES

Abstract

We have developed a new seismic reinforcing method that combines aramid fiber sheets and steel plates for existing RC columns. In order to investigate structure characteristic of RC columns retrofitted with this technique, cyclic lateral loading test was carried out. As a test results, the tendency of hysteretic loops were generally similar for all specimens;longitudinal bar was yielding at drift angle of 1/100rad, the strength started to decrease when the maximum strength was achieved at drift angle of about 1/50rad. Flexural cracks after the test were observed at the top and bottom of column. However, the strength decrease was very small and cracks was few. Furthermore, it was found that this method can be used for enhancing the flexural strength compared with RC columns retrofitted only by aramid fiber sheets. Therefore, the calculated values by current ultimate flexural capacity formula were underestimate test results. This paper was discussed about the flexural strength and the ductile behavior obtained form the skeleton curve, which was converted into the elastic-plastic restoring force characteristics based on principle of the ultimate energy equilibrium. In conclusion, the experimental evaluation methods of seismic performance for columns retrofitted with this technique was estimated considering the increasing effect of flexural strength and equivalent viscous damping factor.