竹胶板-薄壁钢管约束收尘石粉混凝土组合柱轴压性能

Axial compression performance of bamboo-plywood and thin-walled steel tube-encased dust-powder concrete composite column

提出一种新型的竹胶板-薄壁钢管复合约束收尘石粉混凝土组合柱(BSDCC),对10根BSDCC试件进行轴压试验,考察试件的破坏特点和形态,调查收尘石粉混凝土的含量率和强度、试件长细比、截面组合与拉杆约束方式、拉杆间距比对试件承载能力和变形的影响规律。结果表明,BSDCC试件的受压破坏形态主要为试件中部约束拉杆之间竹胶板的层间开胶剥离和材料压折破坏、竹胶板与钢管的开胶剥离破坏。相同条件下,收尘石粉混凝土含量率对试件的极限承载力无明显影响,对变形有重要影响,改变试件的破坏模式;混凝土强度、截面组合与拉杆约束方式对约束作用的影响大;承载力随着长细比、拉杆间距比增大而降低。通过回归分析建立了BSDCC的极限承载力计算模型。

A new type of bamboo-plywood and thin-walled steel tube-encased dust-powder concrete composite column(BSDCC) was proposed.Ten BSDCC specimens were used to perform the axial compression test.The damage and failure mode were investigated,and the influences of dust-powder concrete(DPC) content ratio,concrete strength,slenderness ratio,restraint mode of sectional combination and binding-bars,and spacing ratio of binding-bars on the ultimate bearing capacity and deformation of specimens were analyzed.The results show that the compressive failure modes of BSDCC are mainly glue failure of the bamboo plywood and the thin-walled steel tube between the binding bars,and the material broken damage of the bamboo plywood in the middle of the specimen.The concrete content ratio has no significant effect on the ultimate bearing capacity,but has an important effect on the deformation under the same condition,which leads to the change of the failure mode of the specimen.The bearing capacity of specimens decreases with the increase of the slenderness ratio and the spacing ratio of the binding bars,and increases with the increasing concrete strength and the constraint of sectional combination and binding bars restraint mode on the bamboo plywood.A calculating model for the axial compression bearing-capacity of BSDCC is proposed through the regression analysis.