Confining concrete cover of GFRP tube reinforced concrete columns with polymer grids

This study presents the results of an experimental investigation on the behaviour of glass fibre reinforced polymer (GFRP) tube reinforced concrete columns under axial compression. The polymer grids were embedded into the concrete cover of glass fibre reinforced polymer (GFRP) tube reinforced concrete columns to reduce the spalling of concrete cover. A total of four column specimens were prepared and tested under axial compression. The columns were 150 mm in diameter and 300 mm in height. The first column was the reference column without any reinforcement. The second column was reinforced with GFRP tube without cover confinement. For the third and fourth GFRP tube reinforced concrete columns, concrete cover was confined with one layer and two layers of polymer grids, respectively. The test results show that FRP tube reinforced concrete columns can obtain much higher strength and ductility than reference column. Confining the concrete cover by polymer grids can effectively reduce the spalling of concrete cover.