Seismic Retrofitting of RC Columns Using Prestressed Aramid Fiber Belts

A new seismic retrofit technique, in which aramid fiber belts are prestressed and used as external transverse reinforcement, is proposed in this paper. Six shear critical columns with shear span to depth ratio of 1.5 and poor steel hoops, were retrofitted and tested under reversed cyclic lateral forces and constant axial load, simultaneously. The test results indicated that the proposed method could be a highly effective retrofit technique for RC columns with inadequate shear resistance or poor bond strength. While the original non-retrofitted column exhibited shear failure, the retrofitted column developed ductile flexural response. Moreover, the experimental results for an earthquake-damaged column showed that the proposed method, as an emergency retrofit technique, could restore the lateral strength of initially damaged column.