Compressive behavior of CFFT with inner steel wire mesh

A new concrete filled FRP tube (CFFT) with inner steel wire mesh (WM), termed as CFFT-WM, is proposed in this paper. Uniaxial compression tests were carried out on 27 CFFT-WM specimens to investigate the compressive behavior of the composite structure. The considered experimental variables are number of GFRP layers (1, 2 and 3 layers) and volumetric ratios of WM (0.31, 0.60 and 0.89%). Their effects on the failure mode, compressive stress-strain response, confinement effectiveness and ratio, and the Poisson ratio of the specimens are discussed. The test results show that GFRP tube and WM increase the ultimate compressive strength, strain and ductility of the concrete remarkably. The increase in strength is proportional to an increase in number of GFRP layer. Specimen with higher WM volumetric ratio corresponds to a lower ultimate axial strain but larger strength. In addition, the presence of WM results in a post-peak response showing more ductile compared with the conventional CFFT. Based on the experimental results, confinement stress and strain models were proposed to predict the ultimate compressive behavior of CFFT-WM confined concrete.