Seismic Behavior of RC Corroded Columns Strengthened With Hybrid FRP

In order to research the dynamic properties of strengthening the RC corroded columns with hybrid FRP sheets,ten RC columns were tested under cyclic load and constant axial.Among which four columns were tested as control specimens,three columns were tested after retrofitted with bonding hybrid FRP sheets,and the other three columns were pre-corroded and tested after retrofitted with bonding hybrid FRP sheets.Under low frequency cyclic loading,test phenomena are described.Experimental data are analyzed and compared,and the effects of the axial compression ratio and stirrup reinforcement ratio on the seismic behavior are studied.Resultsshow that the corrosion of steel bars may introduce the brittle failure for RC columns in some extent,and the seismic behavior can be reformed effectively for RC columns strengthened with hybrid FRP.Ductility and energy dissipation are improved significantly,but the bearing capacity can be only enhanced within limits.When the degree of corrosion is 5.1%,the displacement ductility factor and accumulated energy dissipation of the RC corroded columns strengthened with hybrid FRP are 123%and 12.5 times higher respectively than that of the RC corroded un-strengthened columns.