约束浆锚连接极限搭接长度试验研究

发布时间：2018-05-14 16:58

本文选题：钢筋搭接连接 + 极限搭接长度　；参考：《哈尔滨工业大学》2014年硕士论文

【摘要】：预制混凝土结构关键在于解决预制构件之间的钢筋连接和混凝土界面连接，只有预制构件之间的连接得到保证，结构才能做到良好的整体性。哈尔滨工业大学课题组自主研发了约束浆锚钢筋搭接连接，并将其应用到预制混凝土剪力墙结构的钢筋连接中，形成了约束浆锚预制混凝土剪力墙结构体系，这种体系在工程应用中取得了良好的效果。从2008年起，哈尔滨工业大学课题组对约束浆锚钢筋搭接连接方法做了大量试验和理论研究，确定钢筋的搭接长度为1.0倍的基本锚固长度。前期试验表明增大螺旋箍筋配箍率可以减小钢筋搭接长度，但未能确定最短搭接长度，钢筋搭接长度越短，，越有利于工程使用以及预制构件运输和安装，但搭接长度越短，搭接性能越不能得到保证，存在更大的安全隐患，在使用之前必须验证其搭接性能。本文在前期研究成果的基础上，研究约束浆锚钢筋搭接连接的极限搭接长度，极限搭接长度是指合理配箍构造下的钢筋最短搭接长度。本文设计了一系列试件进行探索不同直径钢筋的极限搭接长度，以钢筋直径、螺旋箍筋配箍率、搭接长度为参数，共完成54个搭接连接试件。试验加载方法参考《钢筋机械连接通用技术规程》（JGJ107），并将试验方法加以改进。对直径、、纵筋，改变搭接长度和配箍率，通过试件破坏现象和试验数据确定三种直径钢筋的极限搭接长度，最终给出了三种直径钢筋的极限搭接长度。将极限搭接长度研究试验结果应用到预制混凝土剪力墙结构中，来验证剪力墙钢筋搭接连接的性能。本文设计了三片边缘约束区纵筋直径分别为、、的足尺约束浆锚预制混凝土剪力墙试件，纵筋搭接长度根据极限搭接长度来确定，并按照现行规范来配筋。同时制作三片与预制剪力墙对应的现浇混凝土剪力墙试件，钢筋配筋、试件尺寸、加载工况均与对应的预制剪力墙相同。通过对试件进行拟静力试验，得出预制试件滞回曲线、骨架曲线、退化刚度、延性和耗能等指标，并与现浇试件进行对比。通过滞回曲线、骨架曲线发现，承载力方面，预制试件与现浇试件几乎相同，而在延性以及耗能方面，预制试件要优于现浇试件，表现出良好的抗震性能。试验证明了钢筋搭接性能良好，同时表明了钢筋采用极限搭接长度是安全可行的。在极限搭接长度试验和预制剪力墙拟静力试验的基础上，并结合理论分析，给出了钢筋极限搭接长度的设计建议使用公式。
[Abstract]:The key of precast concrete structure is to solve the connection of steel bar and concrete interface between prefabricated members. Only when the connection between prefabricated members is ensured can the structure achieve good integrity. The project team of Harbin University of Technology has independently developed the restrained mortar anchor steel bar lap connection, and applied it to the steel bar connection of the precast concrete shear wall structure, and formed the restrained slurry anchor precast concrete shear wall structure system. The system has achieved good results in engineering application. Since 2008, the research group of Harbin University of Technology has done a lot of experiments and theoretical studies on the method of lapping connection of restrained grouted anchor bars, and determined the basic anchoring length of steel bar with lapped length of 1.0 times. The preliminary tests show that increasing the ratio of screw stirrups can reduce the length of the lapped steel bar, but the shortest lapping length can not be determined. The shorter the lapping length of the steel bar is, the more favorable it is to the engineering use and the transportation and installation of the prefabricated members, but the shorter the lapping length is, the shorter the lapping length is. The more the lapping performance can not be guaranteed, the greater the safety risk exists, and the lapping performance must be verified before use. On the basis of the previous research results, this paper studies the limit lapping length of restrained grouted anchor bars, which refers to the shortest lapped length of steel bar under reasonable collocation structure. In this paper, a series of specimens are designed to explore the ultimate lap length of steel bars with different diameters. Taking the diameter of steel bar, the ratio of spiral stirrups and the length of lap joint as parameters, 54 lap joint specimens are completed. The test loading method refers to the General Technical Specification for reinforcement Mechanical connection and improves the test method. The ultimate lap length of three kinds of diameter steel bar is determined by the failure phenomenon of specimen and the test data. Finally, the ultimate lap length of three kinds of diameter steel bar is given. The experimental results of the ultimate lap length are applied to the precast concrete shear wall structure to verify the performance of the shear wall reinforced lap connection. In this paper, the diameter of the longitudinal stiffeners in the three edge restraint zones is designed respectively. The length of longitudinal reinforcement lapping is determined according to the limit length of concrete shear wall, and the reinforcement is made according to the current code. At the same time, three cast-in-place concrete shear wall specimens corresponding to prefabricated shear walls, reinforced bars, specimen sizes and loading conditions are all the same as the corresponding precast shear walls. The hysteretic curve, skeleton curve, degenerative stiffness, ductility and energy dissipation of prefabricated specimens were obtained by quasi-static test, and compared with cast-in-place specimens. From the hysteretic curve and skeleton curve, it is found that the prefabricated specimen is almost the same as the cast-in-place specimen in terms of bearing capacity, while the prefabricated specimen is superior to the cast-in-situ test piece in ductility and energy dissipation, showing good seismic performance. The test results show that the lapping performance of steel bar is good, and it is safe and feasible to use the ultimate lapping length of steel bar. On the basis of ultimate lap length test and pseudo-static test of precast shear wall and theoretical analysis, the formula for the design of ultimate lap length of steel bar is given.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU375

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