Study On Mechanical Properties Of Large Diameter Reinforced Grouting Sleeve

With the development of domestic economy and reform and promoting of the construction industry,the weaknesses of traditional architecture has emerged,precast concrete structures can effectively improve the barriers in the development of construction industry,in line with the green concept of sustainable development in the present prefabricated buildings,often using lower cost construction convenient stress performance good grouting sleeve as important fittings mainly adopts ductile grouting sleeve,but due to its high cost,limits its application Seamless steel tube grouting sleeve has the advantages of convenient manufacture and low cost,but there is little research on the technology of seamless steel tube grouting sleeve,especially on the performance of large diameter steel bar grouting sleeve.In this paper,the grouting sleeve was simulated and analyzed mainly through experiments and abaqus software,and the force influencing factors of cold rolled grouting sleeve of large diameter steel bar with the diameter of 40 mm were studied.The structure of the sleeve was optimized and the main results were as follows:1.10 sets of 20 grouting sleeves in total were made with sleeves of two thicknesses and two lengths,and a single drawing test was carried out.The test results show that the yield strength of specimens with a wall thickness of 8mm,a length of 640 mm,a number of ribs of 6is 460 kN,and the ultimate strength is 730 kN.The yield strength and ultimate strength of the specimens with a wall thickness of 10 mm,a length of 700 mm and a number of ribs of 8 were463 kN and 755 kN respectively.The final failure form was the fracture failure of steel bar,which met the strength requirements of the specification for grouting sleeve connector.2.In order to study the influence of sleeve thickness on the bearing capacity of grouting sleeve,comparative analysis was conducted on the control variables of 10 groups of components.The results showed that the radial deformation of the sleeve with the thickness of10 mm was smaller,the radial constraint of the sleeve on grouting material was better,and the force was more reasonable.When the length of the deformation section is the same and the rib spacing is between 26 and 40 mm,the mechanical performance of the sleeve is inversely proportional to the rib spacing.When the length of the deformation section is the same,the length of the smooth section has little effect on the stress and deformation of the sleeve.3.Through the analysis of the influence of sleeve thickness,sleeve rib spacing and length of sleeve smooth section on sleeve deformation,it is found that sleeve thickness has the largest influence on sleeve deformation,while the length of smooth section has a small influence on sleeve deformation,and rib spacing and number have an influence on the deformation of sleeve.In the design of grouting sleeve specimens,the bearing capacity of specimens can be improved by increasing the wall thickness and decreasing the rib spacing if the grouting material strength is sufficient.4.Through the comparative analysis of the numerical simulation of 10 groups of components and the load-displacement curve of the test,it is found that the load-displacement curve of the finite element is slightly different from the load-displacement curve of the test.The simulation result is slightly lower than the test result.