高强钢管超高性能混凝土短柱轴压承载力性能试验研究

Experimental study on the axial compression load capacity performance of short UHPC columns with high-strength steel pipes

为研究高强钢管内填超高性能混凝土(UHPC)的钢管混凝土短柱轴压性能,该文设计22根高强钢管UHPC短柱进行轴压试验,从破坏模式、荷载-纵向应变关系对试件的轴压性能进行对比分析,旨在通过径厚比、混凝土强度、截面类型等变化来探究高强钢管UHPC短柱的实际承载力性能差异.试验结果表明:高强钢管UHPC短柱的轴压性能受径厚比、混凝土强度影响较大;试件承载力随钢管壁厚增加而增加,但相同钢管直径和不同钢管直径增幅呈现不同规律.该文从延性、核心混凝土强度提高程度两个角度进行分析并提出高强钢管混凝土试件的相关参数设计建议.最后,将高强钢管UHPC短柱的轴压试验承载力结果与国内外规范GB 50936—2014、AIJ计算承载力结果进行对比,并基于极限平衡理论推导出高强圆钢管UHPC试件的轴压承载力计算公式,同时结合该文试验数据对其进行验证,证明了公式的准确性.

To investigate the axial compression behavior of concrete-filled steel tube short columns filled with ultra-high performance concrete(UHPC)in high-strength steel tubes,22 high-strength steel tube UHPC short columns are designed for an axial compression test,comparison and analysis of the axial compression performance of the specimen from the failure mode.The purpose is to explore the difference in the actual bearing capacity of high-strength steel pipe UHPC short columns by changing the diameter-thickness ratio,concrete strength,section type.The test results show that the axial compression performance of high-strength steel tube UHPC short column is greatly influenced by the diameter-thickness ratio and concrete strength;the bearing capacity of the specimen increases with the increase of steel tube wall thickness,but the same steel tube diameter and different steel tube diameter increases show different regularity.This paper innovatively analyzes from two perspectives of ductility and core concrete strength improvement,and puts forward relevant parameter design suggestions for high-strength steel tube concrete specimens.Finally,the results of the axial compression test bearing capacity of the high-strength steel tube UHPC short column are compared with the results of the calculation bearing capacity of domestic and foreign standards GB50936-2014 and AIJ,and the calculation of the axial compression bearing capacity of the high-strength round steel pipe UHPC specimen is derived based on the extremely balance theory.The formula is verified by combining the experimental data in this paper,which proves the accuracy of the formula.