HRB400钢筋与UHPC锚固可靠度分析及锚固设计研究  

HRB400 Rebar-UHPC Anchoring Reliability Analysis and Anchoring Design

作　　者：陈留剑 高立强 CHEN Liujian;GAO Liqiang(State Key Laboratory of Bridge Intelligent and Green Construction,Wuhan 430034,China;China Railway Bridge Science Research Institute,Ltd.,Wuhan 430034,China)

机构地区：[1]桥梁智能与绿色建造全国重点实验室,湖北武汉430034 [2]中铁大桥科学研究院有限公司,湖北武汉430034

出　　处：《世界桥梁》2024年第1期103-109,共7页World Bridges

基　　金：湖北省交通运输厅科技项目(2020-186-2-8);中国中铁股份有限公司科技开发计划项目(2019-重大-05,2021-专项-02)。

摘　　要：为给桥梁工程中HRB400钢筋与超高性能混凝土(Ultra-High Performance Concrete,UHPC)锚固设计提供依据,对两者间的粘结性能及锚固长度进行研究。根据中心拔出试验中54个不同参数HRB400钢筋与UHPC锚固试件的粘结强度结果,回归得到粘结强度计算公式;在此基础上利用中心点法进行锚固可靠度分析与基本锚固长度计算,并与国内外规范基本锚固长度计算结果进行对比。结果表明:《混凝土结构设计规范》(GB 50010-2010)和CEB-FIB Model Code 2010计算的基本锚固长度接近,与中心点法相比偏大、偏安全;基于锚固长度计算结果,给出不同保护层厚度下基本锚固长度和钢筋断裂最小锚固长度建议值;提出UHPC相对保护层厚度为0.5时,可采用《混凝土结构设计规范》计算HRB400钢筋与UHPC基本锚固长度和钢筋断裂最小锚固长度;UHPC相对保护层厚度为1.0、1.5、2.0时,可通过修正《混凝土结构设计规范》计算结果取值,基本锚固长度修正系数分别可取0.8、0.65、0.55,钢筋断裂最小锚固长度修正系数分别可取0.85、0.7、0.6。The study focuses on the anchoring reliability between the HRB400 rebars and UHPC.The bonding properties of rebars and UHPC as well as the development length of rebars were analyzed.The bonding strengths of fifty-four HRB400 rebar-UHPC anchoring specimens in the central pull-out test were regressed to derive a bonding strength calculation formula.Afterwards,the anchoring reliability was predicted by the center point method and the basic development lengths of rebars are calculated and compared with the values obtained by using the suggested formulas in the Code for Design of Concrete Structures(GB 50010-2010)and CEB-FIB Model Code 2010.It is shown that the anchoring reliability is relatively bigger and has larger safety margin than that predicted by the center point method.On the basis of the development length calculations,the basic development length as well as minimum anchoring length associated with rebar fracture in the contexts of varying UHPC cover thickness are suggested.When the relative UHPC cover thickness is at 0.5,it is suggested to consult GB 50010-2010 to calculate HRB400 rebar-UHPC basic development length and minimum development length associated with rebar fracture.When the relative UHPC cover thickness is at 1.0,1.5 and 2.0,the values gained by using the formulas in the GB 50010-2010 can be modified,with a basic development length correction coefficient of 0.8,0.65 and 0.55,respectively,and a correction coefficient for the minimum development length at rebar failure of 0.85,0.7 and 0.6,respectively.

关 键 词：桥梁工程 HRB400钢筋 超高性能混凝土 粘结性能 锚固长度 可靠度 锚固设计 中心拔出试验 

分 类 号：U448[建筑科学—桥梁与隧道工程] TU528[交通运输工程—道路与铁道工程]