Seismic Upgrading Of Square And RectangularRC Columns Using FRP Wrapping

This paper presents the results of an experimental study to evaluate the effectiveness of using FRP wrapping for repair and seismic upgrading of square and rectangular RC columns in buildings. The factors affecting the performance of FRP wrapping in rectangular columns under the action of both axial and combined axial and lateral loads are considered in this paper. These factors include the rectangularity ratio of the column cross section, the thickness of the FRP jacket, and the use of carbon verses glass FRP for column jacketing. Techniques to improve the performance of strengthening rectangular columns were also proposed and evaluated in the paper. Such techniques include rounding the sharp edges of the columns, and transferring square into circular columns using mortar. A total of fourteen half-scale reinforced concrete columns, divided into two groups, are tested in this research. The first group of columns consists of three square columns and three rectangular columns which are tested under axial loads. The second group consists of four square columns and four rectangular columns tested under combined axial and lateral loads.