Study On The Force Mechanism Of The Grout-Filled Pipe Splice

Nowadays,with the development of society,the status of the assembly structure in building structure is also rising,the mature assembly structure promotes the development of construction industry,this site for assembly,mass production,high efficiency and energy saving technology can greatly improve the quality of construction,saving a lot of time,but also facilitate the construction of assembly operation and so on.Type structure embodies the advantages of the most incisive.In this paper,improved technology reinforced grout sleeve for the assembly type structure of the connection are studied,and put forward a new type of welding sleeve,the sleeve is made of high quality seamless steel pipe as the material,the inner wall of the steel pipe welding rib and,compared with the market has a nodular cast iron sleeve sleeve,a new welding production process more simple.The cost is low,with stable performance,resource saving,green sustainable development conforms to the national modernization,has a good market prospects,will speed up the precast concrete structure in the promotion and development of domestic.This paper was studied by testing and analysis of the new type of surfacing sleeve,the test with 6 different anchorage length sleeve made of welding connection specimens were one-way drawing,with reinforced anchorage length as variables to study and analysis,the main contents of the research for the failure modes of specimens,the ultimate bearing capacity of specimen,the strain distribution of load displacement curve and reinforced and sleeve.The research shows that:(1)there are three kinds of failure modes for the reinforcement sleeve grouting connection specimens:(a)the pullout failure of the reinforcement before yielding;(b)the pull out failure of the reinforcement after yielding;(c)the tensile failure of the reinforcement after yielding.(2)the steel strain of anchorage segment decreases gradually from the end part of the sleeve to the middle sleeve,and two anchor bar at the strain value on the middle sleeve was symmetrical and the strain distribution;the surface of the sleeve is reduced gradually from the middle to the end of the sleeve,and the sleeve on the basic central symmetrical distribution.(3)the maximum stress of the steel bar in the anchorage section is located near the end of the sleeve,and gradually decreases to the position near the middle of the sleeve.The stress of the sleeve is minimum at both ends of the sleeve,and the stress accumulates gradually to the middle of the sleeve,and the maximum is in the middle.(4)the reinforcement sleeve grouting connection is achieved through the mutual bonding between steel bar grouting material and steel sleeve to achieve the connection connection of steel bar,and the bond strength of reinforcing bar is increased through the restraint of sleeve.In this paper,on the basis of the test,the connecting specimen is simulated and analyzed by ABAQUS finite element software,and the comparison is made with the test.By establishing 6 new finite element models of grouting deformation sleeve joints,the ultimate bearing capacity,load displacement relationship and sleeve stress distribution of sleeve joints under uniaxial tension are analyzed.The analysis results show that:(1)the failure mode obtained by ABAQUS software is consistent with the experimental results,and the load displacement curve is also very close,which shows that the simulation results are reasonable.(2)the ultimate bearing capacity obtained by the finite element analysis is basically the same as the ultimate bearing capacity of the test.(3)the stress distribution of the sleeve accords with the experimental rule.It is proved that the finite element model can better represent the mechanical properties of the reinforcement sleeve joint.