SEISMIC UPGRADE OF CONCRETE COLUMNS

This paper presents a summary of the work from an extensive research program underway at the University of Toronto on strengthening deficient and repairing damaged concrete columns with fibre reinforced polymer (FRP) jackets. The specimens consisted of either a 305 mm square or 356 mm diameter and 1.47 m long column connected to a 508 × 762 × 813 mm stub. Each specimen was tested under lateral cyclic displacement excursions and simultaneous constant axial load to simulate seismic forces. Results indicate that added confinement with FRP at plastic hinge locations significantly enhanced ductility, energy dissipation capacity and strength of columns. Efficiency of FRP confinement was much superior in circular columns than in square columns. A procedure is presented for the design of confining FRP reinforcement in columns required to achieve a certain ductility performance given the applied axial load and the properties of the FRP.

کلیدواژه ها:

columns ، confinement ، ductility ، earthquake ، energy dissipation ، retrofitting