圆形配筋钢管混凝土桥柱受压力学性能的试验研究

Experimental Study on Compression Performance of Reinforced Concrete Filled Circular Steel Tubular Bridge Columns

为研究圆形配筋钢管混凝土桥柱的受压力学性能,对中空圆钢管柱、圆钢管混凝土(CFT)柱及配筋圆钢管混凝土(RCFT)柱进行轴压试验,探讨混凝土强度、钢筋配置的数量和位置、加强肋、钢管的径厚比等对配筋圆钢管混凝土柱的承载力和变形性能等力学性能的影响。研究表明:(1)对于CFT柱,柱破坏时核心高强混凝土表现出明显的脆性,柱的极限受压承载力提高,变形性能降低。(2)钢筋的配置提高了核心混凝土的抗剪承载力,柱破坏时核心混凝土未发生剪切破坏。RCFT柱比中空钢管柱和CFT柱具有更高的承载力和更优的变形性能。(3)带加强肋的柱破坏时核心混凝土与加强肋密不可分,加强肋对于钢管和核心混凝土的一体化性能有明显的促进作用,加强肋可提高约束效果,柱的极限受压承载力和延性都有所提高。(4)钢管径厚比越大,对核心混凝土的约束效果越好。

In order to study mechanical behavior of reinforced concrete filled circular steel tubular columns,axi-al compression experiments have been performed on hollow steel tube,CFT （concrete filled steel tube）and RCFT（reinforced concrete filled steel tube）columns to investigate the influences of the concrete strength,ar-rangement and number of reinforcing bars,ribs and width-thickness ratio on mechanical performance such as bearing capacity and deformation.The experimental results indicate that：（1 ）In the case of CFT columns, when column failure occurs,the core high strength concrete shows obvious brittle nature .The ultimate com-pression bearing capacity of the columns increased,while the deformation behavior decreased.（2）In the case of RCFT columns,reinforcements can effectively increase the shear bearing capacity of core concrete,shear failure of core concrete has not occurred when column failure occurs.The RCFT columns show better compres-sion bearing capacity and deformation performance than hollow steel tube and CFT columns.（3 ）If the steel tube of RCFT/CFT columns is reinforced with ribs,the core concrete and steel tubes are inseparable upon col-umn failure.The reinforced ribs can significantly increase the integration performance between the steel tubes and the core concrete,and improve the confinement effect,ultimate compression bearing capacity and ductility of columns.（4）The greater the width-thickness ratio of steel tubes is,the better confinement effect the core concrete will have.