Axial compressive behavior of bamboo slices twining tube-confined concrete

Bamboo continues to be of interest in buildings and structures owing to its good mechanical properties and sustainability. In this study, a new method of bamboo use is proposed, which is to twine laminated bamboo lumber (LBL) slices to form a bamboo-fiber-reinforced composite tube (bamboo slices twining tube, BST). Considering the high tensile strength of bamboo fiber, BST is proposed to replace steel and FRP as the confining jacket acting on concrete. A total of 10 BST and BST-confined concrete (BCC) short columns were subjected to axial compressive tests using the BST wall thickness as a variable. The test results show that the mechanical properties of BSTs are close to those of engineered bamboo under tension and compression. The failure mode of the BCC specimens is the rupture of the BST wall in the middle of the columns. BSTs can effectively confine the concrete.The BST with a wall-thickness of 5 - 12 mm can enhance the compressive strength and the ultimate strains of the plain concrete (PC) column by more than 1/4 and 3 times, respectively. Finally, an analysis-oriented stress-strain model for the BCCs is proposed, and the predictions of the proposed model can reproduce the experimental curves well.

Automated summary

BSTs exhibit mechanical properties similar to engineered bamboo under tension and compression, effectively confining concrete and improving the compressive strength and ultimate strains of plain concrete columns when the BST wall thickness is between 5-12 mm. The proposed stress-strain model for BST-confined concrete can accurately predict experimental results.