TY - JOUR
T1 - Behaviour of seawater and sea sand concrete filled FRP square hollow sections
AU - Li, Ying-Lei
AU - Zhao, Xiao-Ling
AU - Singh Raman, R. K.
PY - 2020/3/1
Y1 - 2020/3/1
N2 - 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.
AB - 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.
KW - Axial compression
KW - Bending
KW - FRP square hollow section
KW - Seawater and sea sand concrete (SWSSC)
KW - Theoretical model
UR - http://www.scopus.com/inward/record.url?scp=85077507168&partnerID=8YFLogxK
U2 - 10.1016/j.tws.2019.106596
DO - 10.1016/j.tws.2019.106596
M3 - Article
AN - SCOPUS:85077507168
VL - 148
JO - Thin-Walled Structures
JF - Thin-Walled Structures
SN - 0263-8231
M1 - 106596
ER -