SEISMIC PERFORMANCE OF GFRP RETROFITTING CORROSION DAMAGED CONCRETE FILLED STEEL TUBE

FRP (Fibre Reinforced Polymer) has potential in application of retrofitting for damaged concrete filled steel tube (CFST). This research studies the feasibility and effectiveness of GFRP (Glass Fibre Reinforced Polymer) seismic retrofitting for damaged CFSTs. Four corrosion damage modes created by electric accelerated corrosion were supplied on four series of CFSTs. One of two columns in each series was carried out quasi-static test directly and the other was firstly retrofitted by GFRP in proper way and then tested. The testing results showed that GFRP retrofitting can improve the seismic performance of damaged CFST. GFRP retrofitting can highly improve ductility and energy dissipation, but load bearing capacity improvement is not prominent. Circumferential corrosion crevice produces the most serious damage on seismic performance of CFST column and other material with higher stiffness are suggested to replace GFRP to prevent secondary failure in original damage zone.