Behaviour of GFRP tube reinforced concrete columns under eccentric loading

This study investigated the behaviour of glass fibre reinforced polymer (GFRP) tube reinforced concrete columns under eccentric loading. A total of four reinforced concrete columns with 240 mm in diameter and 800 mm in height were cast and tested under concentric or eccentric loading conditions. The first column was the reference column which was reinforced with steel helix and longitudinal steel bars, and the other three identical columns were reinforced with GFRP tubes. The cover thickness was 28 mm on the sides and 20 mm at the top and bottom ends. All the columns were made from normal strength concrete (compressive strength of 35 MPa). The reference column was subjected to concentric loading. For the other three GFRP tube reinforced concrete columns, one column was subjected to concentric loading, while the other two columns were subjected to eccentric loading with eccentricities of 25 mm and 50 mm. It has been shown that GFRP tube reinforced concrete column obtained higher load carrying capacity than steel reinforced concrete column under concentric loading. Eccentric loadings dramatically reduced the load carrying capacity of GFRP tube reinforced concrete columns.