高强钢丝布增强UHPC约束混凝土柱轴压性能  

Axial Compression Performance of Concrete Columns Confined by Ultra-High Performance Concrete Reinforced with High-Strength Steel Wire Cloth

作　　者：邓宗才[1] 王天宇 DENG Zongcai;WANG Tianyu(The Key Laboratory of Urban Security and Disaster Engineering,Ministry of Education,Beijing University of Technology,Beijing 100124,China)

机构地区：[1]北京工业大学城市与工程防灾减灾省部共建教育部重点实验室,北京100124

出　　处：《西南交通大学学报》2025年第1期72-82,共11页Journal of Southwest Jiaotong University

基　　金：北京市教委科技重点项目(KZ201810005008)。

摘　　要：为掌握新型高强钢丝布增强超高性能混凝土(UHPC)的约束效应,研究高强钢丝布面密度和层数变化对约束混凝土柱轴压性能的影响规律.首先,利用混凝土泊松比、延性指数和韧性指数对高强钢丝布增强UHPC的约束效应进行评估;其次,考虑高强钢丝布与UHPC提供的约束力,建立复合约束层的侧向约束力模型;最后,基于Ottosen破坏准则和有效约束指标,建立约束混凝土轴压本构模型.研究结果表明:约束柱受压时呈明显的延性破坏,高强钢丝布增强UHPC约束体系可有效抑制裂缝发展,减缓加载后期试件刚度退化;与未约束柱相比,约束柱极限承载力、峰值压应变和峰值应力的最大增幅分别为147.0%、104.0%和58.0%;当高强钢丝布层数从1层增加至2层,面密度增加至3.3倍时,约束柱极限承载力、峰值压应变和峰值应力分别提高了8.4%、29.3%和15.8%,延性指数和韧性指数分别提高了50.3%和44.2%.对比经典约束混凝土轴压本构模型,本文建立的模型结果与试验结果吻合度较高.In order to master the constraint effect of new high-strength steel wire cloth reinforced ultra-high performance concrete(UHPC),a study was conducted on the influence of the surface density and number of layers of high-strength steel wire cloth on the axial compression performance of confined concrete columns.Firstly,the constraint effect of high-strength steel wire cloth reinforced UHPC was evaluated using Poisson’s ratio,ductility index,and toughness index.Secondly,a lateral constraining force model of the composite constraining layer was established considering the constraining force provided by high-strength steel wire cloth and UHPC.Finally,a constitutive model of axial compression of confined concrete was established based on the Ottosen failure criterion and an effective constraint index.The results show that the confined column exhibits obvious ductile failure under compression,and the high-strength steel wire cloth reinforced UHPC confinement system can effectively suppress crack development and slow down the stiffness degradation of the specimen in the later stage of loading.Compared with the unconfined column,confined columns have maximum increases of 147.0%,104.0%,and 58.0% in ultimate bearing capacity,peak compressive strain,and peak stress,respectively.When the number of layers of high-strength steel wire cloth increases from 1 to 2,and the surface density increases to 3.3 times,the ultimate bearing capacity,peak compressive strain,and peak stress of the confined column increase by 8.4%,29.3%,and 15.8%,respectively,while the ductility index and toughness index increase by 50.3%and 44.2%,respectively.The model established in this paper highly agrees with the experimental results compared with the classical constitutive model of axial compression of confined concrete.

关 键 词：高强钢丝布 轴压性能 超高性能混凝土 约束混凝土 本构模型 

分 类 号：TU375.3[建筑科学—结构工程]