ABSTRACT
Concrete-filled FRP tubes with round cross sections are more popular than the rectangular ones due to their higher confinement effectiveness. Also, the totally filled tubes are the most commonly used due to the fact that the entire cross section is utilized in compression. However, in some cases,
General ........................................................................................................................................... 513 Design Considerations ................................................................................................................... 513
Axial Members with Round FRP Tubes ................................................................................... 513 Stress-Strain Curve of FRP-Confined Concrete .................................................................. 514 Confinement Models ............................................................................................................ 516 Axial Strength of the Member .............................................................................................. 517
Axial Members with Rectangular FRP Tubes ........................................................................... 517 Slenderness Effects ................................................................................................................... 517
Summary of the Experimental Work on Axial Members ............................................................... 518 Comparison of FRP-Confined Concrete and Steel-Confined Concrete .................................... 519 Effect of Geometry and Configuration of Cross Section .......................................................... 520 Effect of Slenderness and Eccentricity of Load ........................................................................ 522 Sustained Loading ..................................................................................................................... 522 Bond Effects .............................................................................................................................. 522
References ...................................................................................................................................... 523
partially filled tubes with central holes are used to reduce the self-weight of the member, as in large diameter piles. In principle, the FRP shells required for this type of members need to be designed to provide the maximum strength and stiffness in the transverse direction for optimum confinement of concrete.
