Repair of fire damaged circular reinforced concrete columns with FRP composites

An experimental study was undertaken to investigate the axial capacity of post-heated circular reinforced concrete columns repaired with glass and carbon fibre reinforced polymers. The series of tests comprised columns which were un-heated, post-heated, post-heated seriously spalled and repaired with mortar, post-heated and wrapped with either glass or carbon fibre reinforced polymer, and post-heated seriously spalled and repaired with both mortar and either glass or carbon FRP. The post-heated columns were repaired with unidirectional glass and carbon fibre reinforced polymer jackets. All columns were tested under axial compression to determine their ultimate axial strength, stiffness and ductility. The results indicated that repairing heat damaged circular columns with a single layer of unidirectional glass or carbon fibre reinforced polymer has a significant effect on the axial strength and the ductility of circular columns. It was shown that the load-carrying capacity of post-heated columns can be restored up to the original level or greater than those of un-heated columns. However, it was shown that the effect of a single layer of glass or carbon fibre reinforced polymer on the axial stiffness was not significant.