Experimental Study On Mechanical Properties Of New Composite Plate With Removable Truss

With the economy of china developed,the construction structure is moving towards industrialization and standardization,a large number of prefabricated structures have emerged.The corresponding system is gradually established,with the development and popularization of prefabricated structure.This paper presents a brand new type of composite floor slab,which consists of prefabricated slabs,removable steel trusses and post-cast concrete.Due to the presence of the removable trusses,the rigidity of the prefabricated panels during construction can be improved.The prefabricated panels are equipped with stressed steel bars to eliminate the need to tie the steel bars on the construction site and prefabricated flooring can save the work of the field mold,which could speed up the construction of floor slabs.After the post-casting layer is formed integrally with the prefabricated plate,the section steel part of the prefabricated plate can be detached,it will achieve the purpose of reusing steel to save materials.The composite floor slab with truss is an innovation of the traditional laminated plate and the form of the composite floor slab.After the industrial design,the steel truss can produce great engineering effect and has broad development prospects.In order to obtain the static performance of composite slabs,static loading tests were carried out on a composite plate and a cast-in-place plate.The plate is placed on the support with linoleum and fine sand.Large reaction frame,hydraulic jack and two-stage distribution beam are used as loading tools.The plates are loaded at four points,and the uniform loading is simulated by four-point loading.After obtaining the data of component deflection,steel strain,and crack development under each stage of loading.From the test data,it is known that the composite slabs produces cracks similar to the cast-in-plate two-way plate at the end of the final loading.The cracks at the bottom of the plate first appeared below the four loading points,with subsequent loading,the four loading points extend to the four corners of the composite slabs,the tensile properties of the steel plates in the form of cracks are fully utilized during the failure.After the final loading is completed,the top concrete of the superposed plate is not crushed.And the relationship between the load and the strain of the steel bar shows that the direction of the oblique cracks in the laminated plate still has the steel bar which not reach the yield,indicating that composite slabs still has the ability tocontinue to bear.The bonding performance between the embedded parts and the concrete is good.There is no large-scale damage to the concrete surrounding the embedded parts,and the embedded parts do not affect the stress of the composite slabs.A number of vertical cracks were found on the side of the member,and no transverse cracks were found on the laminated surface,indicating that the surface shaving can meet the shearing requirements of the laminated surface.The finite element analysis of the laminated plate was carried out,and the results of the finite element analysis were compared with the results of the field test,and the finite element calculation results have good agreement with the real board,the two-way performance of the composite slab is good.It is found that the stress concentration occurs in both the concrete around the embedded parts and the embedded parts.Based on the test,suggestions are provided for the optimization of the truss during the preparation,transportation and on-site construction of the slab are recommended.