Behaviour of seawater and sea sand concrete filled FRP square hollow sections

Ying-Lei Li, Xiao-Ling Zhao, R. K. Singh Raman

Research output: Contribution to journalArticleResearchpeer-review

30 Citations (Scopus)


FRP tube could serve as formwork in new constructions and the square cross-section is convenient for connections. This paper presents an experimental and theoretical study on seawater sea sand concrete (SWSSC)-filled glass/carbon/basalt FRP square hollow section (SHS) stub columns and beams. FRP SHS includes fibres oriented in ±15°, ±40° and ±75° with respect to the longitudinal axis so that the hoop and axial strengths are comparable. Both unfilled FRP SHS and SWSSC-filled FRP SHS were tested under axial compressive, three-point or four-point bending loads. SWSSC-filled FRP columns failed by FRP rupture, whereas the failure mode for beams was the crushing of compressive flanges. In this paper, the stress-strain behaviour of columns and moment-strain curves of beams were discussed and compared to the corresponding SWSSC-filled stainless steel (SS) SHS specimens. It was found that existing stress-strain models, which were originally derived for rectangular concrete confined by FRP wrap, cannot precisely capture the stress-strain response of SWSSC-filled FRP columns. Existing models are improved to more accurately predict the ultimate axial strains and stress-strain relationship. A theoretical model is proposed to estimate the moment capacity of SWSSC-filled FRP beams with reasonable accuracy.

Original languageEnglish
Article number106596
Number of pages18
JournalThin-Walled Structures
Publication statusPublished - 1 Mar 2020


  • Axial compression
  • Bending
  • FRP square hollow section
  • Seawater and sea sand concrete (SWSSC)
  • Theoretical model

Cite this