摘要: |
采用超高性能混凝土(UHPC)修复普通混凝土(NSC)基体时可以获得优异的界面黏结强度,其值甚至高于基体强度,导致界面性能测试时容易发生基体失效,从而不能准确评价界面性能及其影响因素.针对上述问题,提出了基体约束加强的方法,将失效位置控制在修复界面,测得了真实的UHPC-NSC界面黏结强度,分析了基体强度和修复面粗糙度对界面性能的影响与机理,克服了传统测试方法的评价结果过于保守且难以反映粗糙度等影响因素的不足.UHPC-NSC界面较NSC-NSC界面更加致密,界面过渡区的钙硅比更低,宽度和孔隙率分别降低了91%和70%. |
关键词: 混凝土修复 超高性能混凝土 界面抗拉强度 界面微观结构 |
DOI:10.3969/j.issn.1007-9629.2023.11.011 |
分类号:TU528.58 |
基金项目:中国博士后创新人才支持计划(BX20230205);山东博士后科学基金资助项目(SDBX2023006);“十三五”国家重点研发计划项目(2018YFC0705404) |
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Evaluation Method of UHPC-NSC Interface Bond Performance |
FENG Shuo1,2,3, SHI Xinbo4, WANG Wei4, XU Fan4, XIAO Huigang2,3
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1.School of Civil Engineering, Shandong University, Jinan 250061, China;2.School of Civil and Engineering, Harbin Institute of Technology, Harbin 150090, China;3.Key Lab of Structures Dynamic Behavior and Control of the Ministry of Education, Harbin Institute of Technology, Harbin 150090, China;4.Heilongjiang Construction Engineering Group Co., Ltd., Harbin 150000, China
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Abstract: |
Ultra-high performance concrete (UHPC) combined with normal strength concrete (NSC) has excellent interface tensile strength, and the interface tensile strength is even more than substrate strength. Thus substrate failure is easy to occur in interface tensile tests, and the interface performance and its influencing factors can not be evaluated accurately. A method of substrate constraint strengthening is proposed to control the failure location at the repair interface, and accurate interface tensile strength is obtained. The effects of substrate strength and repair surface roughness on the interface tensile strength are analyzed, which overcomes the shortcoming of the traditional test method. The UHPC-NSC interface is denser than the NSC-NSC interface, the n(Ca)/n(Si) in the overlays transition zone is lower, and the width and porosity of the overlays transition zone are reduced by 91% and 70%, respectively. |
Key words: concrete repair ultra-high performance concrete interface tensile strength interface microstructure |