UHPC-NC界面抗剪性能试验研究  

Experimental Study on Shear Performance of UHPC-NC Interface

作　　者：万志勇 陈健平 贺绍华 黄旭 孙向东 WAN Zhiyong;CHEN Jianping;HE Shaohua;HUANG Xu;SUN Xiangdong(College of Civil Engineering,Hunan University,Changsha,Hunan 410082,China;Guangdong Communication Planning&Design Institute Group Co.,Ltd.,Guangzhou,Guangdong 510507,China;Guangdong Construction Engineering Machinery Construction Co.,Ltd.,Guangzhou,Guangdong 510500,China;School of Civil and Transportation Engineering,Guangdong University of Technology,Guangzhou,Guangdong 510006,China)

机构地区：[1]湖南大学土木工程学院,湖南长沙410082 [2]广东省交通规划设计研究院股份有限公司,广东广州510507 [3]广东省建筑工程机械施工有限公司,广东广州510500 [4]广东工业大学土木与交通工程学院,广东广州510006

出　　处：《中外公路》2024年第4期138-147,共10页Journal of China & Foreign Highway

基　　金：国家自然科学基金资助项目(编号:52278161);广东省自然科学基金资助项目(编号:2023A1515010535)。

摘　　要：超高性能混凝土(UHPC)在工程结构加固领域应用前景广阔,新浇UHPC加固层与既有混凝土可靠的界面黏结性能,是确保加固结构服役性能的关键。为研究不同界面处理方式对UHPC与普通混凝土(NC)间黏结性能的影响,设计制作了6个Z形UHPC-NC界面抗剪试件,探究光滑、凿毛、凿毛+植筋3种不同UHPC-NC结合面黏结性能,并通过建立混凝土结合面非线性有限元模型,探讨剪切荷载作用下不同UHPC-NC结合面黏结应力的分布规律。结果表明:UHPC-NC界面黏结性能随结合面粗糙度增大不断提高,界面抗剪钢筋有利于延缓混凝土结合面脱黏和裂缝发展;相比光滑UHPC-NC结合面,平均凿毛深度为4 mm且植入4根直径8 mm抗剪钢筋的混凝土结合面,其抗剪强度、刚度及弹性刚度依次增大了156.1%、10.9%和101.0%,且随着界面裂缝不断发展,凿毛+植筋处理的UHPC-NC界面剪应力分布渐趋均匀,结合面残余黏结作用主要由界面抗剪钢筋提供。Ultra-high performance concrete(UHPC)has great application prospects in engineering structure reinforcement.The reliability of the bonding properties at the interface between the new UHPC reinforcement layer and the old concrete structure is critical for ensuring the serviceability of the reinforced structures.To determine the influence of different interface treatments on the bonding properties at the interface between the UHPC and normal concrete(NC),six Z-shaped UHPC-NC bonding specimens were designed,and the bonding properties of the UHPC-NC with three different kinds of interface,namely smooth,chisel,chisel+reinforced,were investigated.In addition,nonlinear finite element models for the concrete interface were established to determine the distribution law of bonding stresses of different UHPC-NC interfaces under shear loads.The results show that the bonding properties of the UHPC-NC interface increase with the increase in the interface roughness,and interfacial shear reinforcements can postpone the debonding and cracking of the concrete interface.Compared to the smooth UHPC-NC interface,the shear strength,stiffness,and elastic stiffness of the concrete interface with an average chisel depth of 4 mm and four shear reinforcements with a diameter of 8 mm are improved by 156.1%,10.9%,and 101.0%,respectively.With the continuous development of interfacial cracks,the shear stress distribution of the UHPC-NC interface treated with chisel and reinforcement becomes more and more uniform,and the residual bonding effect of the interface is mainly provided by the interfacial shear reinforcement.

关 键 词：UHPC-NC界面 加固 黏结性能 抗剪试验 数值模拟 

分 类 号：U441[建筑科学—桥梁与隧道工程]