Behaviour of CFRP-confined concrete-filled circular steel tube stub columns under axial loading

Behavior of CFRP-confined reactive powder concrete-filled steel tubes under axial compression

“…Relative to RPCFST specimens from the same group, the increase factor of the maximum ultimate load of the CF-RPCFST specimens was 32.8% and the minimum increase factor was 2.2%. In Ding et al (2018), the maximum and minimum enhancements of CFSTs strengthened by CFRP were 76.89% and 19.11%, respectively. This indicates that CFRP-reinforced RPCFSTs are less effective at improving ultimate load than CFRP-reinforced CFSTs.…”

“…Most of the CF-CFSTs exhibited drum-shaped failure (Ding et al, 2018; Lu et al, 2014; Tao et al, 2007; Wei et al, 2014), while the CF-RPCFSTs often showed compression shear failure. This is mainly due to the high rate of brittle failure of RPC compared to ordinary concrete.…”

“…During this process, the steel tube imparted a good restraining effect on the core RPC. According to the Ding et al (2018), the strength of concrete confined by steel tubes is C50. When the confinement between the steel tube and concrete took effect, the strain ratio exceeded 0.5, which was higher than the strain ratio range of 0.295∼0.4; this indicated that less confinement occurred in the case of RPC confined by steel tubes than in that of ordinary concrete confined by steel tubes, and also suggested that the lateral expansion of RPC in confined concrete is less complete than that of ordinary concrete (Wu and Lin, 2005).…”

“…Over the past 20 years, many researchers have carried out exploratory work on the performance of CFRP-confined concrete-filled steel tubes (CF-CFSTs). Extensive investigations have been performed into the compressive behavior of concrete-filled steel tubes (CFSTs) confined by CFRP (Ding et al, 2018; Hu et al, 2011; Liu et al, 2018; Lu et al, 2014; Tao et al, 2007; Wei et al, 2014; Xiao et al, 2005). Studies on CF-CFSTs stress-strain models have also been conducted, by Choi and Xiao (2010), Teng et al (2013) and Zhang et al (2019).…”

“…The studies (Choi and Xiao, 2010; Ding et al, 2018; Hu et al, 2011; Liu et al, 2018; Lu et al, 2014; Tao et al, 2007; Teng et al, 2013; Wei et al, 2014; Xiao et al, 2005; Yu et al, 2014; Zhang et al, 2019) mentioned above shows that imposing constraints on CFRPs can effectively improve the bearing capacity of CFSTs and postpone local buckling of steel tubes. However, their experimental research focused on the behavior of CFRP-confined ordinary concrete-filled steel tubes, and the core concrete strength was between 30 MPa and 70 MPa.…”