CN1298945C - Unshored self supporting cast-in-situ concrete structure - Google Patents

Abstract

The unsupported self-supporting cast-in-place concrete structure relates to a self-supporting structure without support in the field of civil engineering. At present, in the construction of the bottom layer of the building structure and the construction of the giant concrete frame building structure, the amount of support and formwork required is large, and the construction is difficult. The built-in steel truss-concrete composite beam (1) of the present invention comprises a steel truss (1-1), a steel bottom formwork (1-2), a side formwork (1-3) and tensioned steel bars (1-4), the steel A group of tension reinforcement bars (1-4) are respectively welded on the lower chords (1-1-1) on both sides of the truss (1-1), and a steel base form ( 1-2), the side form (1-3) is fixedly connected to the steel base form (1-2). All the loads of the structure of the present invention are finally transmitted to the frame columns, which greatly reduces the number of supports required during the construction phase, avoids the disadvantages of directly transmitting the structure's self-weight and construction loads to the lower roof, and saves materials , The amount of support and formwork is small, the construction difficulty is reduced, and the construction speed is fast.

Description

Unsupported self-supporting cast-in-place concrete structure

Technical field: the present invention relates to a self-supporting structure for concrete frame houses without support in the field of civil engineering.

Background technology: At present: 1. When the outer layer concrete frame structure or frame-supported shear wall structure is used to add floors, the roof of the original building can hardly bear the self-weight, formwork load and construction load of the newly added floors during the construction stage. The traditional method is to use the steel truss hanging anti-beam enclosing construction technology. After the concrete structure is formed, the steel trusses used are cut and become waste products, resulting in huge waste and loss; 2. The giant concrete frame house structure consists of two parts: a giant frame and a substructure. From the perspective of simplifying construction and reducing cost, the mega frame should be constructed first, and then the substructure should be constructed. How to realize the unsupported self-supporting design and construction of the giant concrete frame structure floor (including beams and slabs) is the key to the smooth construction of the giant frame structure, because each layer of the giant frame structure is as high as tens to tens of meters. If the support and formwork are set according to the conventional method, the amount of formwork is large, the construction is difficult, the construction speed is slow, and the project investment is high.

Summary of the invention: The object of the present invention is to provide an unsupported self-supporting cast-in-place concrete structure that does not need support during the construction process. The present invention includes a steel truss whose two ends are fixed on the frame columns. It uses a built-in steel truss-concrete composite beam As the main girder during construction and use, the built-in steel truss-concrete composite beam 1 includes a steel truss 1-1, a steel base form 1-2, a side form 1-3 and tensioned reinforcement bars 1-4, the steel A set of tensile reinforcement bars 1-4 are respectively welded on the lower chords 1-1-1 on both sides of the truss 1-1, and a steel base form 1-2 is welded on the two sets of tensile reinforcement bars 1-4, and the side formwork 1 -3 is fixedly connected with the steel base mold 1-2. In the present invention, the steel truss is integrally arranged on the frame column, and the weight of the poured concrete is effectively transferred to the steel truss by connecting steel bars, steel bottom formwork and other structures. The joint structure of the beam and the main beam makes all the loads of the secondary beams act on the main beams and then transfer to the frame columns. The entire load of the structure of the present invention is finally transmitted to the frame columns through the steel truss-concrete composite beams. The number of required supports is greatly reduced, which avoids the disadvantages of directly transmitting the structure's self-weight and construction loads to the lower roof, and saves materials; the steel truss of the present invention is used during the construction process. The upper and lower chords of the steel truss are used as the longitudinal stress reinforcement of the concrete beam. Since the steel truss is no longer cut off to become waste products, it avoids waste and loss while improving the bearing capacity of the concrete beam; the support and formwork of the present invention The quantity is small, the difficulty of construction is reduced, the investment of the project is reduced, and the construction speed is fast, which is beneficial to popularization and application.

Description of drawings: Figure 1 is a schematic cross-sectional structure of steel truss-concrete composite beam, Figure 2 is a schematic cross-sectional structure of prestressed steel truss-concrete composite beam, Figure 3 is a schematic cross-sectional structure of steel box-concrete composite beam, and Figure 4 is a built-in steel truss - Schematic diagram of the connection structure between steel truss 1-1 of concrete composite beam 1 and built-in steel box - steel box 2-1 of concrete composite beam 2, Fig. 5 is the connection of steel truss 1-1, steel box 2-1 and main flute 3 Structural schematic diagram, Fig. 6 is a cross-sectional structural schematic diagram of the main flute 3.

Specific Embodiment 1: This embodiment includes a steel truss whose two ends are fixed on frame columns. During construction and use, a built-in steel truss-concrete composite beam is used as the main beam during construction and use. The built-in steel truss - The concrete composite beam 1 includes a steel truss 1-1, a steel base form 1-2, a side form 1-3 and tension reinforcement bars 1-4, and the lower chords 1-1-1 on both sides of the steel truss 1-1 A group of tensile reinforcement bars 1-4 are respectively welded, and a steel base form 1-2 is welded on the two sets of tensile reinforcement bars 1-4, and the tensile reinforcement bars 1-4 are evenly arranged along the length of the steel truss 1-1, and the The side form 1-3 is fixedly connected with the steel base form 1-2. During construction, the steel truss with the lower steel bottom formwork bears the self-weight of the concrete during the construction process, and the upper chord 1-1-2 and lower chord 1-1-1 of the steel truss 1 serve as the longitudinal stress reinforcement of the concrete beam during the use stage. The steel truss-concrete composite beam uses a steel plate as the bottom form 1-2, and is welded and connected with the lower chord 1-1-1 of the steel truss 1 through tie bars 1-4. Beam side formwork 1-3 adopts common formwork. The beam side form 1-3 is connected with the bottom form 1-2 by U-shaped clips, and the beam side forms 1-3 are connected with the steel strip 1-6 at the top by U-shaped clips 1-7. This ensures that the weight of the poured concrete is efficiently transferred to the steel trusses.

Specific embodiment 2: The difference between this embodiment and specific embodiment 1 is that when the load and span are large, prestressed steel trusses can be used in the construction stage, and prestressed steel trusses-concrete composite beams can be used in the use stage. The specific method In order to set the prestressed tendons 1-5 arranged in a straight line and the prestressed tendons 1-8 arranged in a curve inside the built-in steel truss-concrete composite beam, thereby forming a prestressed steel truss-concrete composite beam, the prestressed tendons are arranged along the The span direction of the steel truss-concrete composite beam is set, in which the two ends of the prestressed tendons 1-5 arranged in a straight line are riveted on the lower chord of the steel truss through riveted backing plates, and the two ends of the prestressed tendons 1-8 arranged in a curve The ends are riveted to the end of the steel truss-concrete composite beam.

Specific embodiment three: In this embodiment, a built-in steel box-concrete composite beam 2 is welded between two adjacent main beams as a secondary beam, and the built-in steel box 2-1 is two channel steels connected by butt welding , a group of tension reinforcement bars 2-2 are respectively welded at the lower ends of both sides of the built-in steel box 2-1, and a steel base form 2-3 is welded at the lower ends of the two sets of tension reinforcement bars 2-2, and the steel base form 2-3 passes through U-shaped card 2-5 is connected with side mold 2-4. In this embodiment, a steel bottom formwork 2-3 is set under the built-in steel box 2-1, and the steel box 2-1 bears the weight of the surrounding concrete in the construction phase, and the steel box 2-1 and its surrounding reinforced concrete jointly bear force in the use phase. The side of the steel box 2-1 is connected to the lower steel base form 2-3 through welding tie bars 2-2, and the side form 2-4 adopts a common formwork.

The welding method of the secondary beam and the main beam is a connection node structure, that is, a steel plate 4 is longitudinally welded on the side of the steel truss 1-1 of the main beam, and then the steel box 2-1 of the secondary beam is welded to the steel plate 4 to realize the built-in steel box - Connection of concrete composite beam 2 with built-in steel truss - concrete composite beam 1. In the construction stage, the load transfer is realized through the effective surrounding welding of the steel box 2-1 and the steel plate 4 connected to the side form of the steel truss. The pinning action of the longitudinal reinforcement of the secondary beam works together to realize the load transfer. A group of anchoring steel bars 5 is arranged on the steel plate 4, and the anchoring steel bars 5 are evenly arranged longitudinally along the steel plate 4, and the arrangement spacing is determined according to the force requirements and structural requirements.

Embodiment 4: The difference between this embodiment and Embodiment 1 is that it also includes a main flute 3 welded between two adjacent girders, and the cross section of the main flute 3 is "匚"shaped structure.

Embodiment 5: The difference between this embodiment and Embodiment 4 is that the main flute 3 is welded between two adjacent secondary beams. The construction of the unsupported self-supporting cast-in-place concrete floor slab supported by the wooden slab, the bottom formwork of the floor slab and the self-weight of the slab.

Claims (7)

1, a kind of nothing supports the self-supporting cast-in-place concrete structure, it comprises that two ends are fixed on the steel truss on the frame column, it is characterized in that with built-in steel truss-concrete combination beam as the girder in construction and the use, described built-in steel truss-concrete combination beam (1) comprises steel truss (1-1), steel bed die (1-2), side form (1-3) and socket reinforcing bar (1-4), be welded with one group respectively on the lower chord (1-1-1) of described steel truss (1-1) both sides and socket reinforcing bar (1-4), socket at two groups and to be welded with steel bed die (1-2) on the reinforcing bar (1-4), described side form (1-3) and steel bed die (1-2) Joint.

2, nothing according to claim 1 supports the self-supporting cast-in-place concrete structure, it is characterized in that being provided with in the inside of built-in steel truss-concrete combination beam the presstressed reinforcing steel (1-8) by arrangement of curves, thereby forms prestressed steel truss-concrete combination beam.

3, nothing according to claim 2 supports the self-supporting cast-in-place concrete structure, it is characterized in that it also comprises presstressed reinforcing steel (1-5) by straight line.

4, support the self-supporting cast-in-place concrete structure according to claim 1,2 or 3 described nothings, it is characterized in that between adjacent two girders, being welded with built-in steel-case-concrete combination beam (2) as secondary beam, two channel-section steels that built-in steel-case wherein (2-1) connects for butt welding, be welded with one group respectively in the lower end, both sides of built-in steel-case (2-1) and socket reinforcing bar (2-2), be welded with steel bed die (2-3) two groups of lower ends that socket reinforcing bar (2-2), steel bed die (2-3) is connected with side form (2-4) by U-shaped card (2-5).

5, nothing according to claim 4 supports the self-supporting cast-in-place concrete structure, the welding manner that it is characterized in that secondary beam and girder is the connected node structure, promptly in the lateral longitudinal of the steel truss (1-1) of girder to being welded with steel plate (4), the steel case (2-1) and the welding realization built-in steel-case-concrete combination beam (2) of steel plate (4) and being connected of built-in steel truss-concrete combination beam (1) by secondary beam again.

6, nothing according to claim 4 supports the self-supporting cast-in-place concrete structure, it is characterized in that it also comprises main stupefied (3), and main stupefied (3) are welded between adjacent two secondary beams, and described master's stupefied (3) cross section is " Contraband " shape structure.

7, support the self-supporting cast-in-place concrete structure according to claim 1,2 or 3 described nothings, it is characterized in that it also comprises main stupefied (3), main stupefied (3) are welded between adjacent two girders, and described master's stupefied (3) cross section is " Contraband " shape structure.

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