FRP confined concrete columns: Behaviour under extreme conditions

The behaviour of concrete columns wrapped with fibre reinforced polymer (FRP) materials when exposed to several extreme conditions is evaluated. Cold regions environments, FRP repair of corroding reinforced concrete columns, and fire resistance are all considered. For the cold regions exposure, FRP wrapped cylinders (152 × 305 mm) are exposed to temperatures as low as −40 °C or to up to 300 cycles of freeze-thaw (−18 °C to +15 °C). The combination of freeze-thaw exposure with sustained loading is also examined. For FRP wrapping of corroding reinforced concrete columns, the results of tests on cylinders and larger-scale circular columns (300 × 1200 mm) are presented. The specimens are corroded and then wrapped with FRP sheets. The rate of corrosion is monitored both before and after wrapping. The final extreme condition that is considered is fire exposure. Tests on full-scale reinforced concrete columns (400 × 3800 mm) exposed to a standard fire are described and discussed. Overall, the results demonstrate that FRP confined concrete columns tested in concentric axial compression have adequate performance under several extreme conditions such as low temperature, freeze-thaw action, corrosion of internal reinforcement, and fire exposure.