Experiments and Theoretical Modelling for FRP-confined Concretefilled Steel Tubes under Axial Compression
Teng J. G. and Hu Y. M.
ABSTRACT
Fibre-reinforced polymer (FRP) jackets have been widely used to confine reinforced
concrete (RC) columns for enhancement in both strength and ductility. More recently,
the benefit of FRP confinement of concrete-filled steel tubes has been explored by
researchers. In this paper, gap is introduced between steel tube and FRP jacket. It is
believed that a balanced enhancement of both strength and ductility could be realized if a
proper gap scheme is applied. The main aim of this paper is to present and verify a
theoretical model for FRP-confined concrete-filled steel tubes based on a recent
analysis-oriented model for FRP-confined concrete. To this end, results of a series of
tests on FRP-confined concrete-filled steel tubes with different gap scheme are first
presented. The theoretical model is next presented and verified using these test results.
Both the test and the theoretical results show that only FRP jacketing can significantly
enhance the ultimate load but may reduce the ductility of concrete-filled FRP columns.
However, a proper gap scheme could yield a balanced enhancement.