| A systematic review of the available research on seismic behavior of circular steel-confined columns is presented. The limitations of the available experimental results are discussed. Based on the available results, the existing design approaches for confinement reinforcement, several confinement models, and the ACI Code's confinement provisions for circular columns are critically evaluated. It is concluded that the Code's requirements are insufficient to provide ductile behavior in circular columns under certain circumstances. Several areas in which the Code's provisions need revisions and the direction of future research are identified accordingly. A review was also conducted on the previous research on FRP-confined columns tested under simulated seismic loading. Based on these results, procedures for the design of confining FRP for square and circular columns are proposed. The procedures relate the required amount of confining FRP to axial load level and column performance. The research areas needed for FRP-confined columns are also suggested. |
