Steel-free hybrid reinforcing bars for concrete structures

J. G. Teng, Bing Zhang, Shishun Zhang, Bing Fu

Research output: Unpublished conference presentation (presented paper, abstract, poster)Conference presentation (not published in journal/proceeding/book)Academic researchpeer-review

2 Citations (Scopus)


Extensive research has been conducted on the replacement of steel rebars with FRP rebars to eliminate the steel corrosion problem in conventional steel bar-reinforced concrete structures. However, as the performance of FRP rebars is substantially inferior in compression (due to issues such as fibre micro-buckling) than in tension, their use in concrete columns is generally not recommended, which poses a significant challenge when a steel-free structure is needed. This paper presents the novel steel-free hybrid rebar developed at the Hong Kong Polytechnic University that overcomes the above-mentioned problem: such a hybrid rebar typically consist of a central FRP rebar, a thin external FRP confining tube and an annular layer of high strength cementitious material such as ultra-high performance concrete. To demonstrate the performance of these hybrid rebars, results from a series of preliminary tests and associated modelling work are presented in the paper. These results indicate that: (1) the FRP rebar at the centre is well supported against bar buckling and fibre micro-buckling; (2) the compressive strength of the FRP material can be fully mobilized; (3) the stress-strain response of hybrid rebars can be designed to resemble an elastic-plastic response with some post-yielding hardening.

Original languageEnglish
Publication statusPublished - 1 Jan 2017
Event6th Asia-Pacific Conference on FRP in Structures, APFIS 2017 - Singapore, Singapore
Duration: 19 Jul 201721 Jul 2017


Conference6th Asia-Pacific Conference on FRP in Structures, APFIS 2017


  • Confinement
  • FRP
  • Hybrid rebar
  • Steel-free rebar
  • Ultra-high performance concrete

ASJC Scopus subject areas

  • Civil and Structural Engineering
  • General Materials Science


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