Seismic Behavior Of Square Thin-walled Steel-tube/bamboo Plywood Composite Hollow Column With Binding Bars

Lightweight and environmental protection is the important development tendency of the construction industry.There are a lot of disadvantages in production and application of traditional building materials,such as large energy loss,high carbon emissions,which is not conducive to sustainable development.It is necessary to develop of a new type of green building material.Currently,the bamboo resources in China is abundant,but the utilization rate is not high.Bamboo resource has a good performance of seismic.The steel—bamboo composite component is a hot spot in the current construction industry.Starting from the angle of seismic resistance,this paper designs the square thin-walled steel tube with transverse binding bars,namely SBCCB,and analyzes the seismic performance of composite columns by field experiment through improving the present steel — bamboo composite component under the study of axial compression or eccentric compression.By researching the physical and mechanical properties of bamboo and cold formed thin walled steel,this paper confirms the main factors that affects the seismic performance of SBCCB and designs the composite column.In this paper,a total of 9 SBCCB specimens were processed.SBCCBs were used to perform the low-cyclic reversed quasi-static loading tests.The damage process and failure modes of SBCCB were investigated.Through pseudo—static test,study the data of hysteretic curve? skeleton curve? strength degradation? stiffness degradation? ductility coefficient and energy dissipation.And the influence of the shear-span ratio,net cross-sectional area,sectional combination mode,binding-bar spacing of SBCCBs on the bearing capacity and seismic behavior were analyzed.Monitoring the strain of bamboo plywood in the process of pseudo—static test,and analysis the characteristics of bamboo plywood which under earthquake loads.The results indicate that the failures of SBCCBs are primarily the cracking damage between the gluing interfaces and the fracture damage of plywood material at the foot of column.The sectional combination mode has a significant influence on the failure mode,and the seismic behavior of SBCCB can be improved by increasing the net cross-sectional area and the slenderness ratio of the composite hollow columns.SBCCB has a good elastic deformation capacity and seismic energy dissipation capacity,and the binding-bars can effectively guarantee the integrity of SBCCB and suppress the gluing failure between the matrix interfaces.Bamboo plywood has good elastic and plastic properties.Along the height direction of the composite column,bamboo plywood's strain change uniform.Along the height of the composite column section,bamboo plywood's strain with a high degree of linear distribution.Thus,bamboo plywood's mechanical properties of combined column meet the plane—section assumption.