Comparative study of eccentrically loaded FRP wrapped columns

Studies undertaken in the past years concentrated on studying FRP-confined columns subjected to concentrated loads. Only a few of these studies addressed the engineering behaviour of such members when subject to eccentric load. In view of this scarcity in research on columns subjected to eccentric loads, this paper presents results of testing wrapped columns subjected to eccentric loads. Nine short columns with the same dimensions were cast and tested. Three columns were identically reinforced with steel bars, three columns were made of plain concrete and wrapped with three layers of carbon FRP strips, and the remaining three columns were made of plain concrete and wrapped with three layers of E-glass FRP strips. From each group, one column was tested under concentric load, one under a 25 mm eccentric load and one under 50 mm eccentric load. An eccentric load system was developed specifically for the application of the eccentric load. The experimental results showed that eccentric load could obviously lower down the maximum failure load of FRP-confined concrete columns, compared to the columns under concentric load. However, compared to the internally reinforced concrete columns, FRP-confined columns displayed a higher load capacity and ductility, both when tested concentrically and eccentrically.