UHPC圆形空心管柱轴压性能试验  

Experimental Study on Axial Compression Performance of UHPC Columns with Circular Hollow Section

作　　者：章世祥 王序 何迈杰 周权 刘钊[1] ZHANG Shi-xiang;WANG Xu;HE Mai-jie;ZHOU Quan;LIU Zhao(School of Civil Engineering,Southeast University,Nanjing 211189,Jiangsu,China;School of Urban Construction and Safety Engineering,Shanghai Institute of Technology,Shanghai 201418,China)

机构地区：[1]东南大学土木工程学院,江苏南京211189 [2]上海应用技术大学城市建设与安全工程学院,上海201418

出　　处：《中国公路学报》2023年第9期134-143,共10页China Journal of Highway and Transport

基　　金：国家重点研发计划项目(2019YFE0119800)。

摘　　要：为促进绿色桥梁建造与快速施工,充分发挥UHPC力学性能优势,将传统墩柱实心截面改变为UHPC圆形空心截面并加以研究。考虑到轴压是墩柱最基本的受力方式,设计并制作了6个UHPC和3个NC空心管柱试件,研究了不同材料、约束条件以及径厚比等因素对破坏形态与极限承载力的影响。在轴压试验前,通过多组材性试验测得所用UHPC的力学性能,并根据试验结果提出本构关系,用于后续的有限元分析。后续轴压试验表明:UHPC管柱试件中段无竖向裂缝,而NC管柱试件则出现了竖向贯穿裂缝;不同箍筋约束条件对试件初期刚度的影响较小,对极限承载力的影响较大,约束效应越强,极限承载力越高;对于面积相等的2组空心管柱试件,径厚比越小,极限承载力越高,当径厚比由9.5变为7时,试件的极限承载力平均提高了8.8%;其他条件相同时,提升材料强度并不能带来等比例极限承载力的提升。最后,根据实测本构关系建立有限元分析模型并与实测结果进行比对,荷载-位移曲线总体上吻合较好。研究成果可为后续预制拼装UHPC圆形空心管柱墩的设计与应用提供参考。To promote green bridge design and rapid construction,this study proposes using ultra-high-performance concrete(UHPC)hollow sections to replace conventional solid sections in pier columns,focusing on the basic axial compressive capacity.Six scaled UHPC and three NC hollow columns were designed and fabricated,considering the effects of different materials,restraint conditions,and diameter-thickness ratios on the load capacity and damage pattern.First,the mechanical properties of this batch of UHPC were tested,based on which a suitable constitutive law for UHPC was proposed and assigned to the subsequent finite element models.The subsequent axial compression experiment showed no cracking in the UHPC specimen and vertical cracks passed through the NC specimen.The influence of different stirrup restraints on the initial stiffness of the specimens was small,and the load capacity was relatively large;the better the restraint effect,the higher the load capacity.For the two groups of hollow column specimens with equal sectional areas,the smaller the diameter-thickness ratio,the higher the load capacity.When the diameter-thickness ratio changes from 9.5 to 7,the load capacity of the specimens increases by 8.8%on average.The increase in column load capacity is not proportional to the increase in material strength.Finally,a finite element analysis model was established according to the proposed constitutive law and compared with the measured results,which show that the load-displacement curves match well with the tests.The research findings can provide inputs for the design of prefabricated UHPC circular hollow piers for future applications.

关 键 词：桥梁工程 UHPC圆形空心管柱 轴压试验 约束效应 本构关系 承载能力 

分 类 号：U444[建筑科学—桥梁与隧道工程]