Composite beam made of steel, common concrete and ultra-high performance concrete and construction method

Abstract

The invention discloses a composite beam made of steel, common concrete and ultra-high performance concrete and a construction method. The composite beam comprises a steel beam and a composite plate arranged on the steel beam. The composite board comprises prefabricated common concrete slabs and an ultra-high performance concrete board layer. The part, connected with the composite board, of each steel beam comprises a top surface, wherein the top surface is parallel to the horizontal plane; protruding parts extending downwards are arranged at the positions, corresponding to all the top surfaces, of the lower face of the ultra-high performance concrete board layer, wherein the width of the protruding part is smaller than that of the corresponding top surface, and the length is matched withthe corresponding top surface; the prefabricated common concrete slabs are arranged between every two protruding parts; and the lower faces of all the protruding parts are flush with the lower faces of all the prefabricated common concrete slabs. During construction, the method comprises the steps: firstly, preparing the prefabricated common concrete slabs, and erecting the steel beams; then, laying the prefabricated common concrete slabs, and installing a shear-resistant connector; and finally, pouring the ultra-high performance concrete board layer. The problem that concrete in the hogging moment area of the composite beam is prone to cracking is solved, and the method is particularly suitable for steel-concrete composite beams.

Description

technical field [0001] The invention relates to the technical field of structures, in particular to composite beams of steel, ordinary concrete and ultra-high-performance concrete and a construction method. Background technique [0002] Steel and concrete are the two largest structural engineering materials. Ordinary concrete has the characteristics of excellent compressive performance and poor tensile performance; although steel has the characteristics of excellent tensile and compressive properties, the steel plate is Therefore, when the steel is used in the compression zone, it is necessary to set up additional stiffeners to ensure the local stability of the steel plate. [0003] Concrete materials can be divided into many types, such as ordinary concrete, lightweight concrete, ultra-high performance concrete, etc. Different from ordinary concrete, ultra-high performance concrete is not a high-strength version of ordinary concrete, but a new type of cement-based structur...

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Problems solved by technology

my country's "Code for Design of Highway Steel Structure Bridges" JTGD64-2015 stipulates that the limit state of the bearing capacity of composite beams is controlled by the edge stress reaching the ultimate stress. Therefore, the traditional steel-concrete composite simply supported beam structure cannot give full play to the advantages of the two materials. performance, it can also be improved

[0006] In addition, there are two main construction methods for traditional steel-concrete composite beams. The first is the cast-in-place concrete bridge deck, that is, steel beams and shear connectors are made first, and then cast-in-place concrete bridge decks are supported by formwork. The advantage is that the force of the shear connector is relatively uniform, and the adaptability of the concrete slab pouring to the height difference of the steel beam is also good; the disadvantage is that the construction is more troublesome, and the formwork needs to be erected

[0007] The second is to use prefabricated concrete bridge decks, that is, to make steel beams and shear connectors first, install prefabricated concrete bridge decks with reserved slots for shear connectors, and finally pour the reserved slots to realize concrete slabs and steel beams. combination; the advantage of this construction method is that the construction is more convenient, and there is no need to erect formwork; the disadvantage is that the shear connectors need to be arranged in a centralized manner, resulting in uneven stress on the shear connectors, and the close adhesion between the precast concrete slab and the steel beam. Poor, requires high construction control precision, and the site often encounters the problem of large gaps between the concrete slab and the steel beam, which not only affects the mechanical performance of the structure as a whole, but also affects the durability of the shear connectors

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