Study On Mechanical Properties Of Grouting Connection Of High-strength Steel Sleeve

Building industrialization is the main development direction of the future construction industry,and prefabricated concrete structure is the main form of building industrialization.Among them,the effective connection between prefabricated concrete components is the key to ensure the stability and reliability of the overall structural stability.At present,steel sleeve grouting connection is the most widely used connection method between precast concrete components,and a large number of engineering practices and research projects have also verified the feasibility and reliability of this connection method.At present,with the improvement of seismic fortification requirements for buildings in China,high-strength reinforcement has been applied in prefabricated building,and high-strength joints are needed as the support for structural stability.However,the majority of ordinary steel bars of 400 MPa grade used in current engineering projects for grouting connections with steel sleeves also restrict the development of prefabricated concrete structures to a certain extent.Therefore,this article proposes a sleeve grouting connection of500 MPa and 600 MPa high-strength steel bars based on 120 MPa ultra-high strength grouting material,and studies its mechanical properties through experimental and finite element analysis methods.The research work is as follows:(1)Through extensive literature review in the early stage,the main methods of steel bar connection between prefabricated components and the current research status at home and abroad were briefly described.Combined with the research results of domestic and foreign experts,the stress mechanism between various parts of the grouting sleeve was analyzed.(2)Design and manufacture 10 specimens of 16 mm and 500 MPa grade steel bar sleeve grouting joints,and study the effects of factors such as steel bar anchorage length,grouting material strength,and load loading system on the mechanical properties of the joints.The interaction between the sleeve,steel bar,and grouting material is reflected through the force displacement curve,steel bar strain,sleeve circumferential strain,and sleeve axial strain,and the data results are substituted into the theoretical formula for verification.Establish a grouting sleeve model using finite element software,verify the consistency of test results,and conduct parametric analysis.(3)Design and manufacture four 20 mm and 500 MPa grade steel bar sleeve grouting joint specimens,compare the force displacement curves,steel bar strain,and sleeve strain of the four specimens,and analyze the mechanical properties of the joint under different steel bar anchoring lengths and grouting material strength.Calibrate the force displacement curve and failure mode of the experiment through finite software to ensure the accuracy of the simulation results.At the same time,establish a parameterized model for parameterized analysis of high-strength steel sleeve grouting connection specimens.(4)Design and manufacture 6 specimens of 16 mm and 600 MPa grade steel bar sleeve grouting joints,study the mechanical properties of the specimens at anchorage lengths of 6d,8d,10 d,and grouting material strengths of 85 MPa and 120 MPa,and reflect the bonding effect of each part of the joint through force displacement curves,strain and other data.Continue to study the mechanical properties of joints under different grouting material strengths,steel bar anchorage lengths,and the number of sleeve ring ribs using finite element software.