装配式矮T梁UHPC湿接缝构造力学性能研究

Study on the Mechanical Properties of UHPC Wet Joints of Prefabricated Low T Beam

为解决装配式矮T梁湿接缝抗剪强度弱、耐久性差等工程技术问题,设计了一种新型锯齿超高性能混凝土(Ultra-High Performance Concrete)湿接缝,采用ABAQUS有限元软件分析湿接缝构造形式、配筋率和界面粗糙度对UHPC湿接缝界面力学性能的影响。研究结果表明:有限元模型能较好地模拟矮T梁湿接缝的界面力学性能;提出的新型锯齿形接缝整体力学性能和界面力学性能显著优于锯齿形接缝和平接缝,最大界面承载力较平接缝提升了83.8%;新型锯齿接缝界面承载力不随配筋率增高而同比增加,配筋率对界面切应力呈单峰效应,建议配筋率取4.0%;湿接缝界面处剥离位移随界面粗糙度变化较小,可减少在计算中的考虑。

In order to solve the engineering and technical problems such as weak shear strength and poor du-rability of prefabricated low T beam wet joints, a new type of sawtooth ultra-high performance con-crete (UHPC) wet joints was designed, and the effects of wet joint structure, reinforcement ratio and interface roughness on the interface mechanical properties of UHPC wet joints were analyzed by ABAQUS finite element software. The results show that the finite element model can better simu-late the interfacial mechanical properties of wet joints of low T beams. The overall mechanical properties and interfacial mechanical properties of the proposed new zigzag joint are significantly better than those of zigzag joints and flat joints, and the maximum interfacial bearing capacity is increased by 83.8% compared with flat joints. The bearing capacity of the new sawtooth joint inter-face does not increase year-on-year with the increase of reinforcement ratio, and the reinforcement ratio has a unimodal effect on the interface shear stress, so it is recommended that the reinforce-ment ratio is 4.0%, and the peeling displacement at the wet joint interface changes little with the interface roughness, which can reduce the consideration in the calculation.