Axial Behaviour of Glass Fibre Reinforced Polymer- Confined Reinforced Concrete Short Columns

Fibre-reinforced polymer (FRP) jacketing is an effective confinement tool for reinforced concrete (RC) columns. To avoid the excessive stress concentration in square-shaped columns, a jacketing technique with rounded column edges needs to be practiced. The load-carrying capacity of RC square short columns wrapped with glass FRP (GFRP) on axial loading was investigated. The efficiency of confinement offered by improved jacketing schemes with different corner radii of the column, number of layers of FRP and various vertical distribution methods of jacketing are compared. The experimental study was conducted on 31 columns of size 140 mm x 140 mm x 1200 mm with one. two and three layers of FRP distributed over one-fourth. one-third and full length of the column. The corner radii of the columns were 0. 12.5, 25 and 37.5 mm. Specimens were loaded to the failure modes in concentric uniaxial compression, and the behaviour of the specimens was analysed. An analytical model for the ultimate load-carrying capacity of RC square columns confined by GFRP is proposed from the test results.