Research On The Technology And Mechanical Properties Of Precast Concrete Slabs By Suturing Connection

In recent years,China has actively promoted the reform of industrialization of construction and vigorously developed prefabricated buildings.Among them,the most important thing is how to improve the prefabrication rate of assembly structures.In order to improve the low assembly rate of prefabricated floor slabs,scholars have focused their attention on the research and development of fully prefabricated floor slabs connection structure.As far as fully prefabricated floor slabs,the most important thing is the overall mechanical properties of the prefabricated structure after assembly.In order to solve this problem,this paper proposes a method of stitching butt connection of prefabricated floor slabs structure.This method can enhance the integrity and mechanical properties of the structure by tension the steel wire rope to produce a certain pre-compression stress at the adjacent plate seam.The main works and results of this paper are as follows:(1)Invented a suture-type butt connection technology for prefabricated floor slabs structure,and the connection effect of the method is analyzed by theory.Through the analysis of the prestress loss of the steel wire rope,the theoretical calculation formula of the prestressed friction loss is derived.Then,the concrete stress on the internal splicing surface of the steel wire rope is analyzed theoretically and the design proposal is given.The feasibility of the suture butt joint method to establish a certain pre compression stress in the prefabricated floor assembly part is preliminarily verified.(2)Using ABAQUS to analyze two prefabricated floor slabs for stitching butt joint,also the prestressed joint effects of two preloaded prefabricated were tested.Through the simulation results,it can be seen that the friction loss of the prestressed steel wire rope after tension is large.Through the analysis of the prestressed connection effect,the stress-strain diagram of the concrete section at the joint of the prefabricated floor slabs in the tension stage,the normal use load state and the bearing capacity limit state is obtained.The results show that the stitched butt joint method can effectively establish a sufficient pre-compressive stress at the spliced part of the prefabricated floor slabs.(3)Using the ABAQUS finite element analysis software,13 different parameters of prefabricated floor are simulated and analyzed.The characteristics of prestress loss of steel wire rope and the stress distribution of concrete in the joint surface of steel wire rope contour are studied.The influence of post pouring joint width,friction coefficient and pretension on the prestressed connection effect of joint type butt joint precast floor is analyzed.The results show that the stitched butt joint method can establish the prestress at the assembly joint;the width of the post pouring joint has no effect on the prestressed connection effect;the smaller the friction coefficient and the larger the pretension,the better the prestressed connection effect of the stitched butt joint method.(4)Based on the calculation model of friction loss of steel wire rope in suture butt joint method,the theoretical calculation results and ABAQUS simulation results are compared and analyzed.The theoretical model of friction loss of steel wire rope is modified by introducing correction coefficient and origin fitting,which provides a more reliable basis for engineering application.The paper has 72 figures,3 tables,and 93 references.