Seismic Retrofitting of Reinforced Concrete Columns with Wing Walls Using Carbon Fiber Reinforced Plastic Walls

The effective retrofitting method applicable to reinforced concrete columns connected with monolithically cast wing walls by CFRP (Carbon Fiber Reinforced Plastics) sheet jacketing is presented. To clarify the improving mechanism of deformation capacity under earthquake loading by applying CFRP sheet jacketing, eight column specimens with or without wing walls were tested under reversals of horizontal load mainly in the large deformation zone. Test results show that CFRP sheet jacketing methods proposed in this paper are useful for retrofitting works of existing apartment buildings designed in accordance with the old building code. Base on the test evidence, a proposal for estimating the ultimate strength and the deformation capacity of columns with wing walls strengthened by CFRP sheet jacketing are presented.