Seismic Performance of Large Rupture Strain (LRS) FRP-Wrapped Circular RC Columns

Yu Feng Zhang, Yu Lei Bai, Peng Xuan Sun, Jian Guo Dai

Research output: Chapter in book / Conference proceedingConference article published in proceeding or bookAcademic researchpeer-review


This paper presents an experimental study on seismic retrofit of circular reinforced concrete (RC) columns with FRP composites. Three RC columns strengthened with Polythylene Naphthalate (i.e., PEN) FRP composite, which has a much larger rupture strain than conventional FRPs, were tested under combined axial loading and cyclic lateral loading. Three conventional CFRP-confined RC columns and one un-strengthened control column were also tested for comparison. The control column was found to fail due to the buckling of the longitudinal steel reinforcement and be of shortage of ductility, while the major role of FRP confinement in cases of slender circular RC columns is to prevent the spalling of concrete cover and the buckling of longitudinal reinforcement. Use of different FRP jackets and FRP stiffness had a marginal effect on the overall load-deformation responses particularly under a lower axial load ratio. Numerical simulations based on OpenSees, into which a cyclic stress-strain model for longitudinal reinforcement previously developed by the authors was implemented, were conducted to facilitate an in-depth understanding of the test results and the corresponding strengthening mechanisms. The cyclic stress-strain model takes into account the buckling effect of steel reinforcement and the lateral confinement effect of FRP jackets. Further parametric studies revealed that under a high axial load ratio (e.g., 0.4), the consideration of buckling of longitudinal reinforcement is of more significance.

Original languageEnglish
Title of host publication10th International Conference on FRP Composites in Civil Engineering - Proceedings of CICE 2020/2021
EditorsAlper Ilki, Medine Ispir, Pinar Inci
PublisherSpringer Science and Business Media Deutschland GmbH
Number of pages9
ISBN (Print)9783030881658
Publication statusPublished - 2022
Event10th International Conference on Fibre-Reinforced Polymer (FRP) Composites in Civil Engineering, CICE 2021 - Virtual, Online
Duration: 8 Dec 202110 Dec 2021

Publication series

NameLecture Notes in Civil Engineering
Volume198 LNCE
ISSN (Print)2366-2557
ISSN (Electronic)2366-2565


Conference10th International Conference on Fibre-Reinforced Polymer (FRP) Composites in Civil Engineering, CICE 2021
CityVirtual, Online


  • Buckling
  • FRP
  • Large rupture strain (LRS)
  • Seismic performance

ASJC Scopus subject areas

  • Civil and Structural Engineering

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