Behavior and Modeling of FRP-Confined Concrete: A State-of-the-Art Review

Over the past decade, fibre-reinforced polymer (FRP) composites have found wide applications in civil engineering, particularly in the retrofit of structures. One important application of FRP composites in the retrofit of reinforced concrete (RC) structures is to provide confinement to columns for enhanced strength and ductility. As a result, a large number of studies have been carried out on the compressive behavior of FRP-confined concrete. This paper provides a state-of-the-art review of existing studies on this subject, with the emphasis being on the revelation of the fundamental behavior of FRP-confined concrete and the modeling of this behavior. Both monotonic loading and cyclic loading are covered, although only a limited amount of work is available on the latter. The paper is explicitly limited to concrete confined with FRP jackets, in which the fibres are oriented only or predominantly in the hoop direction, but many of the observations made in this paper are also relevant to concrete confined with FRP jackets with a significant axial stiffness, as found in concrete-filled FRP tubes as new columns.