受泥浆浸泡影响的钢筋混凝土黏结特性试验研究  

Experimental study on bond characteristics of reinforced concrete immersed by slurry

作　　者：陈逸伟 李东[1] 庄欠伟 张弛 CHEN Yiwei;LI Dong;ZHUANG Qianwei;ZHANG Chi(School of Mechanics and Engineering Science,Shanghai University,Shanghai 200444,China;Shanghai Shield Design and Experimental Research Centre Co.,Ltd.,Shanghai 200137,China)

机构地区：[1]上海大学力学与工程科学学院,上海200444 [2]上海盾构设计试验中心有限公司,上海200137

出　　处：《上海大学学报(自然科学版)》2025年第1期143-156,共14页Journal of Shanghai University:Natural Science Edition

摘　　要：为了探究地下连续墙支护结构的稳定性是否会受泥浆浸泡影响后钢筋混凝土握裹力的影响,以苏州河段深层排水调蓄管道系统工程为背景,基于自研的大载荷中心拉拔试验装置和自下而上的泥浆替换方式,采用大尺寸试样和与实际工程相同的混凝土和浆液配比进行拉拔破坏性试验.通过分析钢筋、玻璃纤维筋与混凝土界面的黏结特性,揭示浇筑方式、黏结长度、主筋材质等因素对2种浇筑环境下钢筋、玻璃纤维筋与混凝土界面黏结强度的影响规律.结果表明:正常环境与浸泡在护壁泥浆2种不同环境下浇筑试块混凝土抗压强度均值差距在3%以内;对于钢筋和玻璃纤维筋,两种环境下的荷载-位移曲线均有所差异,其中钢筋和玻璃纤维筋界面荷载-位移曲线均可以分为弹性变形阶段、塑性变形阶段和破环阶段;受泥浆浸泡影响后的握裹力均小于正常浇筑环境下的握裹力,随着黏结长度的增加,泥浆对于钢筋-混凝土界面握裹力的影响程度逐渐变大,而对于玻璃纤维筋-混凝土界面握裹力的影响程度逐渐减小,其中泥浆浸泡后的平均黏结强度显著减小,钢筋减小了19.2%,玻璃纤维筋减小了44.5%,且泥浆浸泡影响后的滑移值小于正常环境下的滑移值;试样表面产生的裂纹形式分为径向裂纹、圆形裂纹及周边试块掉落,且裂纹的形成主要集中在正常浇筑环境下.In order to investigate whether the stability of the underground diaphragm wall is affected by the grip strength of reinforced concrete wrapped by slurry,this paper takes the Deep Drainage Pipeline System of Suzhou River project as the background.The pull-out destructive tests were carried out based on the self-developed high-power central pull-out test device and the bottom-up mud replacement method by using large-size specimens and the same concrete and slurry ratios as the actual project.The bonding characteristics of the interface between steel,glassfibre reinforcement and concrete were analysed to reveal the effect of casting method,bond length and main reinforcement material on the bond strength under two casting environments.The results show that:(1)There is no significant difference on the concrete compressive strength of specimens cast in normal environment and in slurry,and the mean difference on the concrete compressive strength of specimens cast in the two different environments is within 3%.(2)For both steel and glassfibre reinforcement,the load-displacement curves differed between the normal environment and the mud-soaked environment;it can be divided into elastic deformation phase,plastic deformation phase and broken phase.(3)The grip force after mud immersion is less than that under normal casting conditions.As the bond length increases,the influence of mud on the grip force at the reinforcement-concrete interface gradually becomes greater,and the influence of mud on the grip force at the glassfibre reinforcement-concrete interface gradually decreases.The average bond strength after slurry immersion was significantly reduced by 19.2%for steel and 44.5%for glassfibre reinforcement.The slip values after the effect of mud immersion were less than those under normal conditions.(4)The forms of cracks produced on the specimen surfaces were classified as radial cracks,circular cracks and falling-offs of the surrounding specimens,and the formation of cracks was mainly concentrated in the normal p

关 键 词：钢筋混凝土 中心拉拔试验 地下连续墙 玻璃纤维筋 黏结强度 

分 类 号：TU375[建筑科学—结构工程]