Investigation of FRP Strengthening Design Rules for Insufficient RC Columns

Abstract

Increasing the deformation capacities of code-incompliant RC columns by wrapping their potential plastic hinge regions with fiber-reinforced polymer (FRP) has become a rather popular strengthening technique in recent years. FRP design guidelines are included in the 7 th chapter of the Turkish Earthquake Code (TEC-07) that became effective in 2007. This study intends to scrutinize the design approach of TEC-07 in light of the test results of 10 columns tested under axial load and cyclic displacement excursions at METU and the test results of 18 columns gathered from literature. After careful investigations, it was clearly seen that in TEC-07, the FRP wrapped column performance limits were over conservative and led to uneconomical designs. Two different design methods were developed. The first one is compatible with the current code procedure and the other is based on interstory drifts in order to obtain simpler and more economical FRP design in addition to its accuracy.