摘要
氯盐环境作为一种较为常见的化学侵蚀环境,研究其对超高性能混凝土(ultra-high performance concrete,UHPC)和普通混凝土(normal concrete,NC)界面耐久性能的影响对于UHPC加固混凝土结构和UHPC-NC组合结构的工程应用均具有重大的现实意义.基于此,通过在常规环境以及氯盐环境下的推出试验,获得了干湿循环次数(0次、25次、50次)、氯盐浸泡天数(0 d、50 d、100 d)及界面处理方式(钢丝刷刷毛、高压水射流冲毛、表面缓凝处理)对UHPC-NC界面黏结强度、界面黏结刚度及界面黏结滑移曲线的影响.结果表明:在100 d试验周期内,干湿循环及氯盐浸泡作用造成的界面黏结强度损失率不超过20%;氯盐环境作用时长的增加会导致界面黏结刚度的降低;随着界面粗糙度的增加,UHPC-NC试件的界面黏结强度以及界面黏结刚度均会增加;界面粗糙度的提高有助于界面抗氯盐侵蚀能力的提升.受到界面处理方法的影响,UHPC-NC试件经历干湿循环及氯盐浸泡后,荷载滑移曲线呈现2种不同的形式,分别对应光滑界面(钢丝刷刷毛界面)和其他界面(高压水射流冲毛界面和缓凝剂处理界面).各组试件的黏结滑移曲线在荷载到达峰值前趋于一致;荷载到达峰值后,前者存在荷载骤降段及持荷段,后者则随着滑移量的增加荷载不断降低.根据UHPC-NC黏结滑移曲线特征,提出了黏结滑移建议模型.
A chloride environment is a commonly used chemical attack environment.Investigating the interfacial durability between ultra-high performance concrete(UHPC)and normal concrete(NC)in a chloride environment is essential for potential engineering applications of UHPC reinforced concrete structures and UHPC-NC composite structures.Consequently,the effects of dry-wet cycles(0,25,and 50),salt immersion days(0,50,and 100 d),and different treatment methods(brushing,water-jet,and roughed with retarders)on the bonding strength,bonding stiffness,and bond-slip relationships were obtained based on push-out test results of UHPC-NC specimens in conventional and chloride environments.The results show that the loss rate of bonding strength caused by dry-wet cycles and salt immersion is not more than 20%during the test period of 100 d.In addition,the increased duration in a chloride environment leads to a decrease in bonding stiffness.With the increase in interface roughness,the bonding strength and bonding stiffness of UHPC-NC specimens,as well as the interfacial resistance to salt immersion,increase.Influenced by the interface treatment,the load-slip curves of UHPC-NC specimens in a chloride environment show two forms,corresponding to smooth interface(brushing)and other interfaces(water-jet and roughed with retarders).Before the load reached the peak,the bond-slip curves of each specimen were found to be consistent.After the peak value,the former has a load-holding section after a sudden drop in load,whereas the latter has a load-decreasing section with the increase of the slip.Finally,a bond-slip model was proposed based on the characteristics of UHPCNC bond-slip curves.
作者
谢剑
杨云涛
陈玉洁
杨荣伟
Xie Jian;Yang Yuntao;Chen Yujie;Yang Rongwei(School of Civil Engineering,Tianjin University,Tianjin 300350,China;Key Laboratory of Coast Civil Structure Safety of Ministry of Education(Tianjin University),Tianjin 300350,China;Beijing Engineering Research Center of Existing Building Renovation(Tianjin Branch),Tianjin 300350,China;Shanghai Architectural Design and Research Institute Co.,Ltd.,Shanghai 200092,China)
出处
《天津大学学报（自然科学与工程技术版）》
EI
CAS
CSCD
北大核心
2024年第1期11-20,共10页
Journal of Tianjin University：Science and Technology
基金
国家自然科学基金资助项目(51708404).
关键词
界面黏结性能
超高性能混凝土
普通混凝土
氯盐环境
界面处理
黏结滑移模型
interfacial bonding behavior
ultra-high performance concrete
normal concrete
chloride environment
interface treatment
bond-slip model
