Polyethylene terephthalate fibre-reinforced polymer-confined concrete encased high-strength steel tube hybrid square columns: Axial compression tests

A State-of-the-Art Review of FRP-Confined Steel-Reinforced Concrete (FCSRC) Structural Members

“…Such buckling failure should be avoided in structures because it portends that the yield strength of high-strength steel cannot be fully utilized and the ductility of the structural member can be greatly compromised. Efforts have been made to prevent or delay the local and overall buckling of steel in structural columns, such as (i) filling a steel tube with concrete [69][70][71], (ii) filling the annular space between the steel tube and the FRP tube for double-skin tubular columns (DSTCs) [16][17][18][19][20], (iii) implementing an FRP wrap on the concrete-filled steel tubes [72][73][74][75][76], and iv) encasing a steel section (e.g., tube shape or I-section) by concrete [77][78][79][80] or FRPconfined concrete [21][22][23][24][25][26][27]. However, each technique may have limitations: (i) for the first one, the local outward buckling of the steel tube still occurs due to incompatibility with concrete (the Poisson's ratios of concrete and steel are 0.18 and 0.3, respectively); (ii) for the second one, the possible inward buckling of the steel tube remains a potential issue for DSTCs; and (iii) for the third and fourth ones, the steel section may be less likely to buckle prior to the cracking of concrete (or the FRP tube rupture) because it is surrounded by the concrete or constrained by the FRP jacket.…”

“…Therefore, it is generally not an economic option to construct pure FRP structures in practical applications. To this end, the combined usage of FRP composites and traditional construction materials (including steel and concrete) has attracted more and more attention in the research community [16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31], with the aim to establish cost-effective and novel forms of structures with excellent structural performance.…”

“…However, the DSTMs-which consist of an FRP tube as an external confining device and protective skin against environmental attacks, a steel tube as internal reinforcement, and concrete sandwiched between the two tubes-may experience the inward buckling of the steel tube under compression. To address this concern, some investigators have proposed filling the inner void of DSTMs to form the hybrid double-tube concrete members (DTCMs; see Figure 2b) [21][22][23][24][25][26][27]. Additionally, an emerging form of hybrid systems with FRP composites termed as FRP-confined steel-reinforced concrete structural members (FCSRCs; see Figure 3) -which consist of a steel section as internal reinforcement, an external FRP confining tube, and concrete filled between them-has recently attracted increasing research interest.…”

“…(a) (b) Polymers 2022, 14, x FOR PEER REVIEW 2 of void of DSTMs to form the hybrid double-tube concrete members (DTCMs; see Figure [21][22][23][24][25][26][27]. Additionally, an emerging form of hybrid systems with FRP composites termed FRP-confined steel-reinforced concrete structural members (FCSRCs; see Figure 3) [3 57]-which consist of a steel section as internal reinforcement, an external FRP confin tube, and concrete filled between them-has recently attracted increasing research interest (a) (b) The concept of FCSRC structural members was first proposed by Liu et al [32] with the aim to strengthen/repair steel structures.…”

Behaviour of Hybrid fibre in RC column with basalt and E-glass fibre under axial loading

“…The FRP was very much used in the construction field for the retrofitting of the damaged columns as a confined device (Zhao et al, 2020;Wang, 2019;Lin, 2020). In the recent research, the column as a confined tube was tested to determine different structural behaviour.…”