| With the advancement of urbanization in China,the government vigorously promotes the development of prefabricated buildings.Floor slabs are an important part of building structure.And various types of composite slabs are currently used in prefabricated buildings.However,in the actual engineering application,the structure of all kinds of precast slabs is complicated,the degree of standardization is low and the mold versatility is poor,which make the production cost of precast slab increase and prevent mass production.Therefore the development of a new type of composite slab with simple structure,low cost and high degree of standardization has the prospect of widespread.In view of this,this paper proposed concrete composite slab with detachable structural steel and carried out static loading tests and finite element analysis to obtain its flexural capacity of this new type of composite slab,which provides reference for the promotion and application of this kind of composite slab.The paper’s research work and results are as follows:1.Three precast slabs and four composite slabs were designed,the three precast slabs respectively were a none steel bar truss concrete precast slab with detachable structural steel(DB-C),a steel bar truss concrete precast slab(DB-H)and a concrete precast slab(DB-N)as the control group,and then,four composite slabs were formed by recasting concrete on different precast slabs,the four composite slabs respectively were two concrete composite slab with detachable structural steel(DHB-C5,DHB-C10),a steel bar truss concrete composite slab(DHB-H)and a concrete composite slab(DHB-N)as the control group.This paper introduces the plane size and thickness,reinforcement,embedded parts,bolts and structural steel of seven slabs.2.Static loading test was conducted on each of the seven slab.The test device and loading method of the slab are introduced,the test position and method of strain and deflection of the slab are described,and the test results of concrete,reinforcement,bolt strength and elastic modulus are presented.3.Record the crack development and different damage forms of each slab,and analyze and compare the cracking load,flexural ultimate bearing capacity,reinforcement strain,concrete strain,load-deflection curve of each slab.The test showed that the flexural ultimate load carrying capacity of DB-N,DB-C and DB-H was 7.36k N/m~2,9.28k N/m~2,11.07k N/m~2 respectively,and the mid-span defection of the new precast slab DB-C was 14.5mm which under the standard value of the load in the construction stage and as 1/207 of calculated span,less than 1/200,meet the requirements of the specification,and the slab is still in the elastic stage.The flexural ultimate load carrying capacity of DHB-N,DHB-C5,DHB-C10 and DHB-H was23.00k N/m~2,22.56k N/m2,25.10k N/m~2,36.76k N/m~2 respectively,and the mechanical properties of each slab in the use stage meet the specifications.4.Taking seven test slabs as the object FEM analysis of each slab was carried by using ABAQUS,and the finite element simulation results were fitted well with the test results.The correctness and reliability of finite element modeling method for composite slabs and precast slabs with detachable structural steel is verified,which can provide reference for product application and promotion in the later stage.5.Then,Finite element node stress analysis was performed for the embedded parts of two specifications.After that,the analysis of the model parameter changes was conducted to study the influence of the number of embedded parts and the type steel size on the bending bearing capacity of the slab,Some helpful conclusions have been obtained.Through the above experimental study and finite element analysis,this paper obtains the mechanical properties of the new concrete composite slab with detachable structural steel and the influence of various factors on the slab which provides the basis and guidance for the application and promotion of the new composite floor. |
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