Research On The Performance Of Assembly Type Monolithic Prefabricated Floor L Tongue-and-groove And Wall Joint

With the slowdown in my country’s economic growth,the population dividends have gradually disappeared,and the construction industry is facing the difficulty of reducing labor,rapid labor costs.At the same time,traditional cash-in-in-place construction has produced a large number of construction waste,which has caused serious impact on the environment.Therefore,assembled buildings ushered in the development opportunity and continuously promotes the building industry to achieve green sustainable development.The connection structure of prefabricated assembled concrete floor and prefabricated walls is an important guarantee for achieving efficient and reliable performance of assembly buildings.Suitable connection makes the load effectively between prefabricated components,and improves the bearing capacity and ductility of nodes,it is necessary for the prefabricated structural system.In order to improve the assembler composite wall structural system assembly rate,reduce construction period,Based on the construction design idea of prefabricated structure,and combined with the existing multi-ribbed composite wall structure system and the actual engineering application requirements,this paper designed a new connection node of the whole prefabricated floor slab and prefabricated multi-ribbed composite wall.In this node as the research object,it is studied the effects of L tongueand-groove,Additional bending reinforcement and Micro-expansion concrete to its anti-bending and anti-cutting performance.A total of two groups of three different structures in two groups were designed,and the anti-bending and anti-punching test were performed,and the finite element simulation analysis was combined,and the following conclusions were obtained:(1)Bending performance:The test piece is bending damage.When all the test pieces are damaged,the rolled steel bars near the floor node meet the yield strength,and the damage to the assembly prefabricated slab without additional steel bars is mainly concentrated in the tongue-and-groove;After adding additional steel bars,the destruction of the prefabricated slab is concentrated at the tongue-and-groove and the wall node,similar to the destruction of the current casting.The ductility coefficient of the test piece is greater than 3,the peak angle is about 1/10,and the deformation ability is better.According to the relevant specification,the measured load of 3 test pieces is greater than the standard design value,and the yield load and extreme bearing capacity of the additional steel prefabricated slab are larger than the current casting,and there is no additional steel prefabricated slab.The feasibility of the bending resistance of the precast slab post-cast joint is illustrated.(2)In terms of anti-punching performance:all the test pieces are shear destruction,the construction of the Pouring nodes of the L tongue-and-groove have proven to be effective in punching test mode,and the test piece can be effectively improved by adding additional curved steel bars.At the same time,the shear performance of the tongue-and-groove is significantly improved,effectively makes up for the shear performance at the seam,delaying the occurrence of cracks at the tongue-and-groove seam.(3)Finite element analysis:the stress distribution of each test piece stress cloud in the anti-bending test and the digestive test is similar;The simulated loaddisplacement curve is basically the same as the trend of the test;Compared with the experimental value,the ultimate bearing capacity analog value is within 15%;The simulation results were highly high,confirmed the rationality of finite element analysis and the reliability of finite element models.Through the additional analysis of parameters,the increase in the increase in the diameter of the additional steel bar is more obvious;Although the strength of the steel bar can improve the carrying capacity of the test piece,the effect is not obvious;Within a certain range,with the improvement of the concrete strength,the strength of each node has increased,but the level is increasing.