长期荷载作用对钢管约束的组合短柱变形及承载力的影响  

Effect of Long-Term Loading on Deformation and Bearing Capacity of Steel Tube-Constrained Composite Columns

作　　者：李艳华 张素梅 王焰 王玉银[2] LI Yanhua;ZHANG Sumei;WANG Yan;WANG Yuyin(Civil and Environmental Engineering,Harbin Institute of Technology(Shenzhen),Shenzhen 518000,China;School of Civil Engineering,Harbin Institute of Technology,Harbin 150090,China)

机构地区：[1]哈尔滨工业大学(深圳)土木与环境工程学院,广东深圳518000 [2]哈尔滨工业大学土木工程学院,哈尔滨150090

出　　处：《工业建筑》2023年第1期151-159,19,共10页Industrial Construction

基　　金：深圳市高层次人才项目。

摘　　要：为研究长期荷载作用对钢管约束钢管混凝土柱、钢管约束钢筋混凝土柱和钢管约束型钢混凝土柱变形和承载力的影响,设计并制作了12个钢管约束钢管混凝土短柱、9个钢管约束型钢混凝土短柱和6个钢管约束钢筋混凝土短柱试件,对其中的4个钢管约束钢筋混凝土短柱、6个钢管约束型钢混凝土短柱和8个钢管约束钢管混凝土短柱进行了760 d的持荷试验,随后对所有试件进行了轴压承载力试验。主要研究参数混凝土强度等级为C50和C70,加载时核心混凝土龄期分别为7,14,28 d。对比分析了各类试件长期变形性能和持荷760 d对试件轴压性能的影响,结果表明:1)3类试件的长期变形均主要发生在加载前期,呈现出前期增长较快、后期随时间增长而逐渐减慢的趋势,其中钢管约束钢管混凝土试件的长期变形最小;2)低应力长期荷载作用、核心混凝土及夹层混凝土的长期变形对此3类试件的轴压承载力几乎无影响;试件类型、加载龄期和混凝土强度等级对试件承载力的影响较小;3)是否预先受载对试件破坏模式没有显著影响,钢管约束钢筋混凝土和钢管约束型钢混凝土试件均表现为明显的剪切破坏,而加载龄期较早或混凝土强度中等的钢管约束钢管混凝土试件呈现较好的腰鼓型截面压溃破坏。12 steel-tube-confined concrete-filled steel tube columns(TCFST),6 tubed reinforced concrete columns(TRC)and 9 tubed steel reinforced concrete columns(TSRC)were designed to study the effect of long-term loading on the deformation and bearing capacity.Among them,8 TCFST,6 TSRC and 4 TRC short columns were loaded for a total of 760 days.Then the axial compression tests were conducted on all the above columns.The main concerned parameters were concrete strength grade(C50 and C70),and core concrete ages at the time of loading application(7 d,14 d and 28 d).The long-term deformation properties of the columns and the influence of 760-day sustained loading on their mechanical properties were compared and analyzed.The results showed that:1)the long-term deformation of the three types of short columns occurred mainly in the early stage of the loading,showing a rapid increase in the early stage and a gradual slowdown in the later stage.The long-term deformation of the TCFST columns was the smallest comparing with the other two;2)the low-stress long-term loading,long-term deformation of core concrete,as well as interlayer concrete had almost no effect on the bearing capacity of the columns under axial compression;the type of specimens,loading age and concrete strength grade had little effect on the bearing capacity;3)the column failure modes were not influenced by the existence of long-term loading.TSRC columns and TRC columns showed an obvious shear failure,while the TCFST columns with loading in early age or moderate concrete strength grade occurred ductile squash failure.

关 键 词：长期荷载 钢管约束组合短柱 长期变形 收缩徐变 承载力 轴压试验 

分 类 号：TU398.9[建筑科学—结构工程]