免蒸养超高性能混凝土-既有混凝土界面粘结性能试验研究  

Experimental Investigation of Interfacial Bond Behavior Between Non-autoclave Curing Ultra-high Performance Concrete and Existing Normal Concrete

作　　者：吴琛 储福玮 龚明子 曾志攀 WU Chen;CHU Fuwei;GONG Mingzi;ZENG Zhipan(Fujian Provincial Key Laboratory of Advanced Technology and Informatization in Civil Engineering,Fujian University of Technology,Fuzhou 350118,China;CCCC First Highway Xiamen Engineering Co.,Ltd.,Xiamen 361021,Fujian,China;Fujian Provincial Institute of Architectural Design and Research Co.,Ltd.,Fuzhou 350001,China)

机构地区：[1]福建理工大学福建省土木工程新技术与信息化重点实验室,福州350118 [2]中交一公局厦门工程有限公司,福建厦门361021 [3]福建省建筑设计研究院有限公司,福州350001

出　　处：《材料导报》2023年第24期159-166,共8页Materials Reports

基　　金：国家自然科学基金(52378494);福建省高校产学合作项目(2022H6032);福建省引导性科技计划项目(2021H0032)。

摘　　要：免蒸养超高性能混凝土(Ultra-high performance concrete,UHPC)在常温养护下具有超高强、超耐久等优异性能,其与普通混凝土(Normal concrete,NC)界面的粘结性能是保证免蒸养UHPC加固NC结构获得良好性能的重要因素。为研究免蒸养UHPC-NC界面粘结性能,设计直剪试验,分析免蒸养UHPC龄期、NC强度、NC表面处理方式和界面粘结剂对界面粘结性能的影响,提出了免蒸养UHPC-NC界面粘结-滑移本构模型,并给出相关刚度系数建议值。结果表明:免蒸养UHPC-NC试件界面破坏模式主要分为粘结界面破坏、粘结界面和NC破坏、NC破坏及NC和UHPC破坏;刻槽组较凿毛组试件具有明显的开裂阶段,表现出一定的延性且具有更高的粘结强度,最大提高量为183.7%;界面使用SiKa 32LP结构胶时,其粘结强度为4.91 MPa,是其他界面粘结剂试件粘结强度的两倍以上。因此,当采用免蒸养UHPC加固NC构件时建议NC表面刻槽和采用SiKa 32LP结构胶。Non-autoclave curing ultra-high performance concrete(UHPC)has excellent properties such as ultra-high strength and ultra-durability under normal curing.It is noted that,in strengthening normal concrete(NC)structure,the bonding property of UHPC-NC interface is an important factor to ensure the good performance of non-autoclave curing UHPC.In order to study the bonding properties of non-autoclave curing UHPC-NC interface,this paper designed the direct shear tests to analyze the influences of non-autoclave curing UHPC ages,NC strengths,NC surface treatments and interface binders.Furthermore,this paper proposed the bond-slip constitutive model of non-autoclave curing UHPC-NC interface.In addition,this paper presented the relative stiffness coefficient for further study.Experimental results show that:the failure modes of the interface for non-autoclave curing UHPC-NC specimens can be divided into bonding interface failure,bonding interface and NC failure,NC failure,and both NC and UHPC failure;compared with the specimens with roughing,the specimens with grooves have the obvious cracking stage and higher bond strength as well as ductility.Furthermore,the maximum bond strength increased 183.7%;when SiKa 32LP structural adhesive was used at the interface,specimens’bond strength was 4.91 MPa,which was 2 times than that with another structural adhesive.As a result,when the non-autoclave curing UHPC is used to strengthen the NC member,it is recommended to groove the NC surface and use SiKa 32LP structural adhesive.

关 键 词：免蒸养超高性能混凝土(免蒸养UHPC) 粘结性能 直剪试验 荷载-滑移曲线 粘结-滑移本构模型 

分 类 号：U444[建筑科学—桥梁与隧道工程]