Structural applications of fibre reinforced polymer (FRP) composite tubes: A review of columns members

Use of fibre reinforced polymer (FRP) in column applications is increased because it can act as a confining material, a reinforcement and a structural column. The application of FRP tubes is correlated with the fibre orientation since tube stiffness is mainly attributed to the stiffness of fibres. Thus, for confinement, the fibres should align in the transverse direction of the tube while they should align in the axial direction when tubes are used as compression members. FRP tubes with fibres mainly in axial direction may reach failure because the stiffness in the perpendicular direction to fibres depends only on the stiffness of the matrix. In order to boost the stiffness in the secondary direction while supporting fibres in the main direction, fibres should be in multidirections. This paper reviews and identifies gaps in knowledge on the use of FRP materials in column applications in new or existing construction regimes.