REPAIR OF EARTHQUAKE-DAMAGED RC COLUMNS WITH FRP WRAPS

A study was conducted on the flexural behavior of earthquake-damaged reinforced concrete columns repaired with prefabricated fiber reinforced plastic (FRP) wraps. Four column specimens were tested to failure under reversed inelastic cyclic loading to a level that is considered higher than would occur in a severe earthquake. The columns were repaired with prefabricated FRP wraps and retested under simulated earthquake loading. The test specimens were designed to model single-bent, nonductile concrete columns in existing highway bridges built prior to the modern seismic design provisions were in place. FRP composite wraps were used to repair damaged concrete columns in the critically stressed areas near the column footing joint. The physical and mechanical properties of FRP composite wraps are described. Seismic performance of repaired columns related to their hysteretic response is assessed and compared to those of the original and unretrofitted columns. The results suggest that the proposed repair technique is highly effective. Both flexural strength and displacement ductility of repaired columns were higher than those of the original columns.