RU79908U1

RU79908U1 - Steel and concrete beam (options)

Info

Publication number: RU79908U1
Application number: RU2008130589/22U
Authority: RU
Inventors: Дмитрий Анатольевич Пекин
Original assignee: Дмитрий Анатольевич Пекин
Priority date: 2008-07-24
Filing date: 2008-07-24
Publication date: 2009-01-20

Abstract

The utility model relates to construction, namely to beams of floors or coatings of buildings and structures of various functional purposes and is aimed at increasing the bearing capacity, reliability, speed and manufacturability of the construction, reducing the consumption of steel and concrete. The specified technical result is achieved by the fact that in the proposed structural solution of the steel-reinforced concrete beam, the joint work of concrete, prestressed reinforcement, steel sheets forming a box beam is realized, in the cavity of which the prestressed reinforcement is then installed in the design position and concreted. Furthermore, in addition to steel sheets, shaped rolled or welded profiles can be used. A steel box-shaped steel beam is manufactured at the metal construction plant, consisting of horizontal sheets, vertical sheets and / or shaped elements connected by welding, with pre-made holes for the passage of prestressed reinforcement and subsequent concreting. Further, at the factory or directly at the construction site, pre-tensioned fittings are installed in pre-made holes, which is a certain number of rods or ropes coated with grease, located inside plastic pipes of a larger diameter and not having adhesion to concrete, which allows the reinforcement to be tensioned as supports (steel box-section beam) and concrete (after concreting the beam). The tension can be performed in one or several stages, depending on the assembly sequence and the application of loads. Concreting is carried out with fine-grained concrete or polymer concrete with maximum mixture mobility through pre-made holes in the upper beam shelf. Pre-stressed steel-reinforced concrete beam can be performed as a single-span articulated and multi-span continuous. A fundamentally new structural solution for steel-reinforced concrete beams is based on the joint work of steel and reinforced concrete structures described above and allows using the positive qualities of these building materials with maximum benefit. 4 ill.

Description

The utility model relates to construction, namely to beams of floors or coatings of buildings and structures of various functional purposes.

Known are traditional constructive solutions of prestressed reinforced concrete beams, trusses, arches, set forth in the book: “Baykov V.N., Sigalov E.E. Reinforced concrete structures. General course. Textbook for high schools. Ed. 3rd corrected. M., Stroyizdat, 1978, 767 pp. "On pages 489-509 of Fig. XIII.33-XIII.43.

The disadvantages of such structures for the option of erecting buildings and structures made of precast concrete are: limitations associated with the typical dimensions of structural elements (roof beams and ceilings, trusses, roof structures, arches); significant dead weight of structural elements; lack of manufacturers of some structural elements on the construction market. For the option of erecting buildings and structures from monolithic reinforced concrete, the disadvantages are associated with: the complexity of the manufacture and installation of formwork; the impossibility of high-quality concreting of supporting sections of structures in connection with a glut of reinforcement.

Also known are the traditional structural solutions of conventional and prestressed steel beams, trusses, arches, set forth in the book: “Metal structures. In 3 T.T. 2. Steel structures of buildings and structures. (Designer Handbook) / Under the general. ed. V.V. Kuznetsova (Central Research InstituteProjectstalconstruction named after N.P. Melnikov) - M.: Publishing House ASV, 1998, 512 pp., On pages 86-93, Fig. 6.1-6.7, on pages 150-159, Fig. .7.1-7.7, on pages 248-263 fig. 12.1-12.14.

The disadvantages of such structures are: lower overall stability of the beams, due to the lack of concrete in the cross section and the inappropriateness of developing the section from the plane; less static design uncertainty; lack of collaboration between steel and reinforced concrete structural elements, which reduces the reliability of the structure as a whole; the need to absorb compressive forces with steel elements, not concrete; the inappropriateness of the use of certain designs for floors and coatings with high loads.

The closest in technical essence is the constructive solution set forth in the book: “Baykov V.N., Sigalov E.E. Reinforced concrete structures. General course. Textbook for high schools. Ed. 3rd corrected. M., Stroyizdat, 1978, 767 pp. ”On pages 171-174 of Fig. XIII.17-XIII.18. In this design solution, a reinforced concrete beam consists of concrete, bar reinforcement and supporting (rigid) reinforcement in the form of a rolled or welded steel beam located inside the section.

The disadvantages of such a structural solution for reinforced concrete beams are: the complexity of the installation and subsequent permutation of the removable formwork; increase in the duration of construction, the complexity of high-quality concreting of the structure; there is no volumetric stress-strain state of concrete.

The utility model is aimed at increasing the bearing capacity, reliability, speed and manufacturability of the construction, reducing the consumption of steel and concrete of floor beams or coatings of buildings and structures.

This is achieved by the fact that in the proposed structural solution of steel-reinforced concrete beam, the joint work of concrete

reinforcement, steel sheets forming a box beam, in the cavity of which then tensioned reinforcement is installed in the design position and concreted.

Furthermore, in addition to steel sheets, shaped rolled or welded profiles can be used.

A steel box-shaped steel beam is manufactured at the metal construction plant, consisting of horizontal sheets, vertical sheets and / or shaped elements connected by welding, with pre-made holes for the passage of prestressed reinforcement and subsequent concreting. Then, at the factory or directly at the construction site, pre-tensioned fittings are installed in pre-made holes, which is a certain number of rods or ropes coated with grease, located inside plastic pipes of a larger diameter and not having adhesion to concrete, which allows the reinforcement to be tensioned as supports (steel box-section beam) and concrete (after concreting the beam). The tension can be performed in one or several stages, depending on the assembly sequence and the application of loads. Concreting is carried out with fine-grained concrete or polymer concrete with maximum mixture mobility through pre-made holes in the upper beam shelf. Pre-stressed steel-reinforced concrete beam can be performed as a single-span articulated and multi-span continuous.

A fundamentally new structural solution for steel-reinforced concrete beams is based on the joint work of steel and reinforced concrete structures described above and allows using the positive qualities of these building materials with maximum benefit.

An increase in the bearing capacity of a prestressed steel-reinforced concrete beam is achieved by the fact that the horizontal steel sheet is located below the concrete, thereby increasing the shoulder of the inner pair, using high-strength tensile reinforcement, which allows you to adjust the internal forces, also several vertical steel sheets are present in the cross section, which significantly increases the geometric characteristics of the whole cross section of the beam. The cross-sectional area of the horizontal sheet can vary widely and significantly exceed the possible area of the longitudinal reinforcement placed in a traditional reinforced concrete beam, due to the limitations of the light distances between the reinforcement, dictated by the need to lay the concrete mixture. The possibility of brittle fracture of the compressed concrete zone is excluded due to cramped working conditions and volumetric stress-strain state. Significantly increases the compressive strength of concrete.

The increase in reliability is due to the fact that the mechanism of brittle destruction of concrete is excluded, the static indeterminacy of the structure is increased, the influence of factors associated with a violation of the manufacturing and installation technology at the construction site is reduced, as a result, instead of one reinforced concrete or steel beam, a prestressed reinforced concrete beam inside the box-shaped steel beam is obtained . Steel sheets cannot lose stability, as they are in the body of concrete. The deformability of the structure as a whole changes, and it begins to work viscously. Concrete begins to play a subordinate role, preventing steel sheets inside concrete from losing stability. It excludes the possibility of changing the design position of the prestressed reinforcement due to the installation in pre-made holes in steel sheets.

Claims

1. Steel-reinforced concrete beam, including concrete, prestressed reinforcement, characterized in that it contains steel sheets forming a box-shaped beam, inside of which prestressed reinforcement and concrete are placed.

2. Steel-reinforced concrete beam, including concrete, prestressing reinforcement and shaped rolling or welded profiles, characterized in that it contains steel sheets and shaped rolling or welded profiles forming a box beam, inside of which prestressed reinforcement and concrete are placed.

3. Steel-reinforced concrete beam, including concrete and shaped rolled or welded profiles, characterized in that it contains steel sheets and shaped rolled or welded profiles, forming a box beam, inside of which concrete is placed.