采用冷弯薄壁方型钢管和胶合竹板通过横向约束拉杆和结构胶黏剂复合成顺纹抗压的组合空芯短柱(thin-walled steel tube/bamboo-plywood composite hollow short column with binding bars,SBCCB),采用9个试件研究SBCCB试件的偏心抗压破坏模式、抗压承载力和影响规律。结果表明,SBCCB试件受压破坏形态主要为柱端开胶破坏、横向约束拉杆之间基体胶合界面开胶剥离破坏和胶合竹板局部压屈破坏;SBCCB抗压极限荷载随胶合竹净横截面积增大而提高,随着长细比和荷载偏心率的增大而降低,随空心率增大而增大;约束拉杆可有效延迟SBCCB的开胶剥离破坏,改变屈曲破坏模式,有助于试件抗压承载力的提高;相对于不带约束拉杆试件,SBCCB抗压极限应力提高约17.64%;局部翘曲随约束拉杆间距减小而减小,相对拉杆间距比3.0以下能确保较小的局部翘曲变形。薄壁钢管和胶合竹板能形成较好的复合抗压结构单元,该批试件平均值抗压强度达到18.54 MPa,展现了优异的抗压性能。SBCCB可作为绿色建筑材料广泛应用于现代装配式工程结构,同时拓展竹材的应用途径,实现"以竹代木,以竹代钢",具有很好的工程价值和应用前景。
The development of laminated-bamboo has broadened the application range of bamboo material in the field of structural engineering. An assembling hollow column parallel to the fiber texture is composed of square thin-walled cold-formed steel-tube and bamboo-plywood by the fastening of the transverse binding bars and structural adhesive. The thin-walled steel-tube/bamboo-plywood assembling short hollow column with binding bars(SBCCBs) are a new type of steel/bamboo composite with excellent physical and mechanical properties. Multi- layered high- strength bamboo plywood forms the primary body in the SBCCB that is subjected to compressive forces, and the square thin-walled steel tube only serves as a liner. Large numbers of bamboo are used, which reduce the manufacturing cost of the composite columns and result in a relatively high load-bearing capacity. The failure modes, bearing capacity and influence factors of SBCCB subjected to eccentric compression loading, were investigated by the test of nine short specimens. The test results indicated that the compressive failure of specimens were primarily the gluing failure at the column end and the tension side of specimen, the gluing and debonding failure of the matrix interfaces in the middle of column between binding bars and the compressive broken of bamboo plywood material. The ultimate bearing capacity of SBCCB generally increased as the net cross- sectional area of gluing bamboo and hollow ratio increased, decreased as the slenderness ratio and the loading eccentricity increased. The thin-walled steel-tube embedded in the laminated bamboo column can enlarge the cross sectional area of composite column, and reduce the slenderness ratio and the loading eccentricity increased, which effectively improved the stability and ultimate bearing capacity of SBCCBs subjected to compression loading. The transverse binding bars forming the ferrule effect with the thin- walled steel- tube can effectively slow the gluing failure of SBCCB, changed the ultimate buckling mode and