Axial Compression Testing of Bamboo-Laminated Encased Steel Tube Composite Columns

Abstract

To resolve the problem of premature glue failure in square, thin-walled steel tube/bamboo-laminated composite hollow columns (SBCCs) under compression, a new type of SBCC with transverse binding bars (SBCCB) is proposed. An axial compression test was performed on nine SBCCBs to observe the compressive failure mode and analyse the influence of the net cross-sectional dimension, slenderness ratio and cross-sectional composition on the glue failure and the ultimate bearing load; the results were compared with the known limit stress of SBCCs without transverse binding bars. The experimental results indicate that the compressive damage to SBCCBs is primarily the breaking of the bamboo plywood material and glue failure between the matrix interfaces at the end and middle of the column between the binding bars. The ultimate bearing load is not only related to the dimensions of the cross section and the slenderness ratio but also impacted by the cross-sectional composition. Installing transverse binding bars can effectively reduce glue failure in the test specimens, alter the limit failure mode and significantly increase the ultimate bearing load. Compared to the limiting compressive stress on an SBCC, the limiting compressive stress on an SBCCB is 26% higher on average. A formula for calculating the axial compressive load capacity of an SBCCB was established using nonlinear regression analysis.