Compressive behavior of PET FRP-confined concrete encased CFST columns

• Published in: Journal of constructional steel research Vol. 202; p. 107732
• Main Authors: Zhou, Jie-Kai, Zeng, Jun-Jie, Liang, Qi-Jin, Dai, Hai-Shuan, Fan, Tian-Hui
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.03.2023
• Subjects: Axial compression; Confinement; High strength steel (HSS); Polyethylene terephthalate (PET) FRP; Steel encased concrete; Polyethylene terephthalate (PET) FRP; High strength steel (HSS); Steel encased concrete; Confinement; Axial compression
• ISSN: 0143-974X; 1873-5983
• DOI: 10.1016/j.jcsr.2022.107732

Environmental friendly construction materials such as polyethylene terephthalate (PET) fiber-reinforced polymer (FRP) and high-strength materials such as high-strength steel (HSS) are attracting wide attentions. In this study, a total of ten novel circular PET FRP-confined Concrete Encased Concrete-filled steel tube columns (PFCECs) with a Q690 steel tube and a PET FRP tube are tested to understand their axial compressive behavior, with the investigated variables covering the thickness of the outer PET FRP tube and the diameter ratio. The experimental results demonstrate that the load-carrying capacity of PFCECs with a given inner steel tube increase with an increase in the diameter ratio, but the ultimate axial strains and the residual axial loads do not necessarily increase with the increase of the diameter ratio. In the end, this paper compares the test results against the predictions from two existing models, and the comparisons show that the models give comparatively accurate predictions on the ultimate axial stresses/strains of the core concrete in PFCECs, but they are unable to capture complete axial stress-axial strain responses of the core concrete in PFCECs accurately. •Novel circular PET FRP-confined Concrete Encased Concrete-filled steel tube columns (PFCECs) are developed.•The load-carrying capacity of PFCECs with a given inner steel tube increase with an increase in the diameter ratio.•The ultimate axial strains and the residual axial loads do not necessarily increase with the increase of the diameter ratio.