外包发泡混凝土帽钢龙骨组合立柱轴压承载力试验及分析

EXPERIMENTAL RESEARCH AND ANALYSIS ON AXIAL BEARING CAPACITY OF COMPOSITE COLUMN WITH LIGHT-GAUGE HAT-SECTION STEEL WRAPPED FOAMING CONCRETE

以立柱为帽形截面的轻钢龙骨（简称帽钢龙骨）和发泡混凝土共同构成的组合墙体为对象,研究组合墙体中由帽钢立柱和发泡混凝土共同构成的18个组合立柱的轴压承载能力。研究表明：组合立柱的轴压荷载-位移关系曲线包括明显的弹性和下降破坏两个阶段,其中弹性阶段基本为一条直线,且水平位移较小,说明发泡混凝土的包裹对组合立柱的水平位移有明显的束缚作用;外包发泡混凝土组合立柱的轴压承载力是单纯帽钢立柱的2～3倍;由于组合立柱两端帽钢的外露,当帽钢截面的厚度较小时,外露帽钢首先发生局部失稳,发泡混凝土的强度大小对组合立柱的轴压承载力几乎没有影响;而当帽钢厚度足够大时,随着外包发泡混凝土的强度增加,组合立柱的轴压承载力也随之增大,其破坏形式为发泡混凝土被压碎。

In this paper,the research object was the composite wall,which composed of hat-section steel column and foaming concrete. Based on the axial compression experiment,the compressive bearing capacities of 18 composite columns consisted of hat-section steel column and wrapped foaming concrete were studied. The research result showed that the axial load-displacement relationship curve of the composite column included two stages： elastic straight line and falling failure. In the elastic stage,the horizontal displacement of the composite columns was small,which indicated that the foaming curve had obvious restraint on the displacement of the composite column. Compared with pure hat-section steel column,the axial load bearing capacity of the composite column was 2 ～ 3 times as that of the steel column. Because there were two exposed hat-section steel segments at the two ends of each composite column,when the thickness of the hat-section steel was relatively small,the exposed segments occured local buckling,the strength of the foaming concrete almost had no effect on the axial load bearing capacity of the composite column. However,when the thickness of the hat-section steel was large enough,along with the increase of the strength of the concrete,the axial load bearing capacity of the composite column also increased and the failure mode of the composite column was the crushing of foaming concrete.