Strengthening Design Limitations of an RC Frames Using FRP Column Wrapping Considering Column-to-Beam Strength Ratio

Abstract

The aim of this paper is to study the influence of the column-to beam strength ratio on the seismic strengthening of a column with a Fiber Reinforced Plastic (FRP) wrapping system. FRP wrapped Reinforced Concrete (RC) columns are analyzed to obtain moment-curvature curves using FRP confined concrete characteristics. A pushover analysis of a 2D model was performed on one and three-story moment-resisting frames, with different column-to-beam strength ratios. The results indicate that FRP strengthening is more efficient in frames with a low ratio of column-to-beam strength, due to the type of lateral failure mechanism of the frame. Also, high values of the column-to-beam strength ratio can be benefited by low values of the confining pressure. In case of a column strength greater than a beam strength, beyond a certain confining pressure ratio, further enhancement in performance will not be achieved. Therefore, the level of effective wrapping on frame performance enhancement is controlled by the column-to-beam strength ratio.