An Ultimate Drift Based Design Method for FRP Retrofitted RC Columns

摘要

Seismic retrofitting of RC columns by external bonding of FRPs has been proven to be a cost-effective and simple technique in recent years. In this study, the ultimate drift capacity of FRP retrofitted columns were predicted by selecting design parameters as the ratios of confinement, axial load, longitudinal reinforcement and plastic damage with a database consisting flexure dominated RC columns with and without damage. The database consisted of 28 strengthened and 6 repaired specimens, representing typical deficient building columns with poor transverse reinforcement detailing, that were tested under cyclic displacement excursions and constant axial load. For the strengthened columns, a drift based design equation was proposed and this equation was modified regarding the damage amount and axial load level for the repaired columns. The deformation capacities were predicted with a good accuracy and the simplified design equations gave reliable results considering safe design regulations.