Study On The Influence Of Steel-concrete Composite Structure Stud Connectors On The Shrinkage Of Concrete During Construction

As the span of the bridge becomes larger and the structure becomes more and more complex,the steel-concrete composite structure has been considered by scholars.Steel-concrete composite structures give full play to the compressive properties of concrete,steel tensile properties and bending properties.In order to meet such requirements,various steel-concrete composite structures have emerged,such as Stud connectors,PBL type Shear connectors,PZ Shear connectors,embedded corrugated steel plate shear connectors and high-strength concrete composite structures,among them,the combination structure of Stud Nail and high-strength concrete is used more.In a large number of practical projects,the cracking of the composite structure of Stud and high-strength concrete is serious,because high-strength concrete is widely used in the composite structure of Stud and high-strength concrete,also,the combination of Stud and high-strength concrete is more complex than reinforced concrete.The serious concrete cracking of the composite structure of Stud Nail and high-strength concrete not only affects the applicable function of the structure,but also reduces the bearing capacity and durability of the steel-concrete composite structure.There are few researches on the shrinkage of high-strength concrete confined by single-row studs,especially those confined by multiple-row studs.Therefore,in the background of a certain project,this paper designs the shrinkage test of high strength concrete confined by single row studs,establishes and analyzes the model of high strength concrete confined by single row studs,and compares the results with the test results to ensure the feasibility of the model,the shrinkage of high strength concrete(HSC)confined by multi-row studs is studied and compared with the model of HSC confined by single-row studs.The main conclusions of this paper are as follows:(1)The shrinkage of HSC was restrained by different types of single row studs,the height of studs>the distance of studs>The diameter of studs.In the early stage(7d age),the shrinkage is the fastest,and the single row studs have the best inhibition effect on the shrinkage of high strength concrete from 0d to 3d.(2)The effect of oil-brush studs on the shrinkage of high-strength concrete is greatly reduced.The middle shrinkage and the end shrinkage can be regarded as the same,and the difference between the middle shrinkage and the end shrinkage caused by HSC itself can be neglected.With the increase of the bolt restraint,the shrinkage difference between the middle and the end of the specimen decreases gradually,which shows that the restraint of the restraint band is enhanced.(3)The ANSYS finite element analysis software is used to model a group of test blocks,and the parameters,boundary conditions and temperature corresponding to the test blocks are inputted,verify the feasibility of the model.In the same way,the models of high-strength concrete confined by multi-row studs can be established,and the shrinkage and stress of high-strength concrete can be analyzed,by comparing the shrinkage and stress diagram of concrete confined by single-row studs and multi-row studs,it is concluded that multi-row studs are more effective in restraining the shrinkage of high strength concrete.