Study On The Effect Of Grout Repair On The Mechanical Properties Of Sleeve Connections Containing Defects

As the country attaches great importance to the strategy of "carbon peak and carbon neutral",the assembled building as an important means of construction industrialization has ushered in a new development opportunity.Grouting sleeve connection,as a more stable means of reinforcement connection in assembled buildings,is widely used for the connection of components such as wall-wall vertical connection and column-beam horizontal connection.However,in actual construction,the problem of diagnosing and dealing with defects brought about by the quality of grouting sleeve in the grouting process and the seating grout layer has become one of the reasons affecting the promotion of assembled buildings.With the increase of the market rate of assembled buildings,a large number of scholars at home and abroad have done a lot of research on the mechanical properties of defective specimens of grouting sleeves,and have come up with test data of grouting sleeve construction and defects.However,further research is needed for the management of defects after they appear,with a view to providing a reference for the project.In this paper,the feasibility of grout sleeve repair is studied based on test data and finite element analysis,taking the management of grout sleeve defects as an example.(1)Uniaxial tensile tests and repair tests were conducted on 39 specimens in 13 groups under different defective conditions to investigate the mechanical properties of grouted sleeves containing defective sleeves and repaired grouted sleeves.3 forms of damage occurred in the tests: reinforcement fracture damage,bond slip damage due to insufficient anchorage length,and threaded connection damage at the anchorage end.When the anchorage length is less than 6d the reinforcement slip of grouted sleeve increases,and the bond slip damage occurs when the anchorage length is reduced to 4d.(2)By analyzing the data of 468 strain gauges arranged at the grouting sleeve and the anchor end reinforcement,the strain distribution of the grouting sleeve specimens containing defects and the grouting sleeve specimens after repair were obtained,based on which the strain distribution law of the grouting sleeve specimens under different loads was analyzed,and the effect of the anchorage length and strength of the grouting material on the repair of the sleeve containing defects was examined.(3)A sleeve model with ribbed reinforcement,grouting material,grout patching material and reverse modeling was established,and the test members were simulated using finite element software.The stress distribution cloud diagram and damage cloud diagram were analyzed to investigate the stress distribution law,the stress mechanism of the reinforcement and grout sleeve,and the effect of different factors of grout repair on the mechanical properties of the grout sleeve containing defects.