82 publications from this institution
Extensive research has been conducted on fiber-reinforced polymer (FRP)-confined plain and RC columns, leading to a large number of stress–strain models. Most of these models have been developed for FRP-confined plain concrete and are thus applicable only to concrete in FRP-confined RC columns with a negligible amount of transverse steel reinforcement. The few models that have been developed for concrete under the combined confinement of FRP and transverse steel reinforcement are either inaccurate or too complex for direct use in design. This paper presents an accurate design-oriented stress–strain model for concrete under combined FRP-steel confinement in FRP-confined circular RC columns. The proposed model is formulated on the basis of extensive numerical results generated using an analysis-oriented stress–strain model recently proposed by the authors and properly captures the key characteristics of FRP-steel-confined concrete as revealed by existing test results. The model strikes a good balance between accuracy of prediction and simplicity of form and is shown to provide close predictions of test results and perform significantly better than existing stress–strain models of the same type.
An important application of fiber-reinforced polymer (FRP) composites is to provide confinement to reinforced concrete (RC) columns to enhance their load-carrying capacity. However, this application is generally restricted to short columns as existing design guidelines do not contain provisions for the design of FRP jackets for slender columns. This situation has been due to both the scarcity of test data and the lack of rigorous theoretical studies into the behavior of slender FRP-confined RC columns. This paper presents a theoretical model for slender FRP-confined circular RC columns based on the numerical integration method; Lam and Teng’s stress–strain model is employed to describe the behavior of FRP-confined concrete in the column. Predictions from the theoretical column model are compared with existing test results, which demonstrates that the theoretical model is reasonably accurate in reproducing the experimental results of FRP-confined circular RC columns. These comparisons also demonstrate the need to conduct careful tests on large-scale columns to eliminate some uncertainties associated with the existing test data to enable a more conclusive verification of the proposed theoretical column model.
