Beam structure

Abstract

To provide beam structure easily securing bending yield strength even when using arrangement reinforcement.SOLUTION: The beam structure is provided with: a plurality of stirrups 32 arranged in a longitudinal direction of beam main reinforcement 30 and wound up outside of the beam main reinforcement 30; arrangement reinforcement (upper cord material 46) placed in a longitudinal direction of a beam 10 below the stirrups 32; steel plates 42 of permanent forms forming a bottom surface of concrete 20 installed in the beam 10; and a spacer (lattice material 44) arranged on the steel plate 42 to set a height position of the arrangement reinforcement.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a beam structure. [Background technology]

[0002] The following Patent Document 1 describes a floor spacer that can hold the reinforcing bars and bottom reinforcing bars. When reinforcing bars are used in slabs or beams, spacers are sometimes used to ensure the cover thickness of the reinforcing bars. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-233723 Summary of the Invention [Problem to be solved by the invention]

[0004] As shown in the above-mentioned Patent Document 1, when using spacers to install step reinforcement in a beam, for example, the reinforcing bars are arranged in the following order from the side closest to the bottom end surface of the concrete: step reinforcement, stirrup reinforcement, and main beam reinforcement. If a sufficient cover thickness is secured from the surface of the step reinforcement, the main beam reinforcement viewed from the bottom end surface of the concrete is positioned higher than when step reinforcement is not installed. In this case, the bending strength is reduced compared to when step reinforcement is not installed.

[0005] In consideration of the above facts, the present invention aims to provide a beam structure that can easily ensure bending strength even when using step reinforcement. [Means for solving the problem]

[0006] The beam structure of claim 1 comprises: a plurality of stirrups arranged along the longitudinal direction of the beam main reinforcement and wound around the outside of the beam main reinforcement; step reinforcement arranged below the stirrups along the longitudinal direction of the beam; steel plates arranged below the step reinforcement and serving as temporary formwork that forms the underside of the concrete to be poured into the beam; and spacers installed on the steel plates to determine the height position of the step reinforcement.

[0007] In the beam structure of claim 1, steel plates are placed as temporary formwork for the concrete poured into the beam, so the concrete is protected and less likely to neutralize, and the reinforcement bars are less likely to rust. Therefore, the cover thickness provided by the spacers can be secured from the surface of the stirrups, not the surface of the reinforcement bars.

[0008] This allows the height of the main reinforcement to be lower than the bottom surface of the concrete, compared to when the cover thickness is secured from the surface of the reinforcement. This makes it easier to ensure the bending strength of the beam. Also, compared to when the reinforcement is rust-proofed without installing steel plates, construction work can be reduced.

[0009] The beam structure of claim 2 is the beam structure of claim 1, wherein the spacer is a lattice material, and the step reinforcement and the steel plate are welded to the lattice material and formed integrally.

[0010] According to the beam structure of claim 2, the lattice material increases the rigidity of the steel plate serving as a temporary formwork, so that shoring can be omitted.

[0011] The beam structure of claim 3 is the beam structure of claim 1 or 2, wherein the step reinforcement and the stirrup are spot welded.

[0012] According to the beam structure of claim 3, the stirrups are welded to the step bars arranged along the longitudinal direction of the beam. This allows the position of the stirrups in the longitudinal direction of the beam to be defined. This makes it possible to suppress the stirrups from becoming distorted. [Effects of the Invention]

[0013] According to the present invention, a beam structure can be provided that can easily ensure bending strength even when step reinforcement is used. [Brief explanation of the drawings]

[0014] [Figure 1] (A) is a cross-sectional view of a beam to which a beam structure according to an embodiment of the present invention is applied, (B) is a cross-sectional view of line BB in (A), and (C) is a cross-sectional view showing the state in which stirrups are placed on a formwork unit. [Figure 2] 1A is a partially enlarged cross-sectional view showing the cover thickness in a beam to which a beam structure according to an embodiment of the present invention is applied, and FIG. 1B is a partially enlarged cross-sectional view showing the cover thickness in a comparative example. [Figure 3] (A) is a cross-sectional view of a beam to which a modified example of a beam structure according to an embodiment of the present invention is applied, (B) is a cross-sectional view of line BB in (A), and (C) is a cross-sectional view showing the state in which spacers, step reinforcement bars, and stirrups are placed on a corrugated steel plate. [Figure 4] (A) is a cross-sectional view of a beam to which another modified example of the beam structure according to an embodiment of the present invention is applied, (B) is a cross-sectional view of line BB in (A), and (C) is a cross-sectional view showing the state in which spacers, step reinforcement bars, and stirrups are placed on the corrugated steel plate. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, a beam structure according to an embodiment of the present invention will be described with reference to the drawings. Components indicated by the same reference numerals in the various drawings are the same components. However, unless otherwise specified in the specification, each component is not limited to one, and may be present in multiple numbers.

[0016] Furthermore, descriptions of overlapping configurations and symbols in each drawing may be omitted. Note that the present disclosure is not limited to the following embodiments, and may be implemented by making appropriate modifications, such as omitting configurations, replacing them with different configurations, or combining one embodiment with various modified examples, within the scope of the purpose of the present disclosure.

[0017] In each drawing, the directions indicated by arrows X and Y are directions along the horizontal plane and are perpendicular to each other. The direction indicated by arrow Z is a direction along the vertical direction (up and down). In each drawing, the directions indicated by arrows X, Y, and Z are assumed to be consistent with each other.

[0018] <Beam structure> 1 shows an example of a beam 10 to which a beam structure according to an embodiment of the present invention is applied. The beam 10 is composed of concrete 20, main beam reinforcement 30, stirrups 32, and formwork units 40.

[0019] (beam) The concrete 20 is the concrete that constitutes the beam 10, and is poured using the form unit 40 as a throwaway form.

[0020] The beam main reinforcement 30 is a reinforcing bar arranged along the longitudinal direction (X direction) of the beam 10, and multiple bars are arranged in the beam width direction (Y direction). The beam main reinforcement 30 includes upper end reinforcement 30A arranged on the upper side of the beam and lower end reinforcement 30B arranged on the lower side.

[0021] The stirrups 32 are shear reinforcement bars arranged along the longitudinal direction of the beam main reinforcement 30 and wound around the outside of the beam main reinforcement 30. The stirrups 32 are arranged at predetermined intervals along the longitudinal direction of the beam main reinforcement 30. This interval may vary in the longitudinal direction of the beam 10.

[0022] (Formwork unit) The formwork unit 40 is configured to include steel plates 42, lattice members 44, upper chord members 46, and lower chord members 48. The steel plates 42 are temporary formwork that forms the lower surface of the concrete 20.

[0023] As shown in Figure 1(B), the lattice material 44 is a reinforcing bar formed in a corrugated shape with amplitude in the vertical direction along the longitudinal direction of the beam 10. The lower end of the lattice material 44 is welded to the steel plate 42.

[0024] As shown in Figure 1(A), the lattice members 44 are arranged at an angle when viewed from the longitudinal direction of the beam 10. This angle is formed so that the tops of two adjacent lattice members 44 come into contact. One upper chord member 46 is sandwiched between the tops of the two lattice members 44.

[0025] The upper chord member 46 is a reinforcing bar that runs along the longitudinal direction of the beam 10 and is welded to the top of each of the two lattice members 44. The lower chord member 48 is a reinforcing bar that runs along the longitudinal direction of the beam 10 and is welded to the bottom of each of the lattice members 44.

[0026] By joining the lattice members 44, the upper chord members 46 and the lower chord members 48 together in this way, the formwork unit 40 has a configuration in which a space truss is joined to the steel plate 42.

[0027] The upper chord members 46 function as step reinforcements for the beam 10. That is, the upper chord members 46 are arranged below the stirrups 32 in contact with the stirrups 32, and position the stirrups 32 in the vertical direction. In addition, the lattice members 44 function as spacers that position the height of the upper chord members 46.

[0028] The upper chord 46 and the stirrups 32 are spot welded to each other, and the stirrups 32 are positioned in the longitudinal direction of the beam 10. The stirrups 32 may be welded to the upper chord 46 either before or after the formwork unit 40 is delivered to the construction site where the beam 10 is constructed. Also, the upper chord 46 and the stirrups 32 do not necessarily have to be welded.

[0029] As shown in Figure 1(C), the steel plates 42, lattice members 44, upper chord members 46, and lower chord members 48 are welded together to form an integrated formwork unit 40 before constructing the beam 10. The stirrups 32 are then placed using the upper chord members 46 of the integrally formed formwork unit 40 as stepping reinforcements.

[0030] <Action and effect> In the beam structure according to an embodiment of the present invention, steel plates 42 are arranged as a formwork for the concrete 20 to be poured into the beam 10 (to form the beam 10), so that the concrete 20 is protected and less likely to become neutralized, and the upper chord 46 acting as a setting reinforcement is less likely to rust.

[0031] Therefore, as shown in Fig. 2(A), the cover thickness H1 of the lattice material 44 as a spacer is secured from the surface of the stirrup reinforcement 32, not from the surface of the upper chord member 46 as a preparation reinforcement. In contrast, as shown in the comparative example in Fig. 2(B), when the steel plate 42 is not used, the cover thickness H1 must be secured from the surface of the preparation reinforcement 50.

[0032] As a result, if the steel plate 42 is used as the temporary formwork, the height position of the beam main reinforcement 30 (bottom end reinforcement 30B) relative to the bottom end surface 20A of the concrete 20 can be lowered compared to when the steel plate 42 is not used. This makes it easier to ensure the bending strength of the beam 10. Alternatively, construction work can be reduced compared to when the steel plate 42 is not installed and the preparation reinforcement 50 is subjected to rust prevention treatment.

[0033] Furthermore, according to the beam structure of the embodiment of the present invention, the lattice material 44 increases the rigidity of the steel plates 42 serving as temporary formwork, so that shoring can be omitted.

[0034] Furthermore, in the beam structure according to the embodiment of the present invention, the stirrups 32 are welded to the upper chord members 46 as preparation reinforcements arranged along the longitudinal direction of the beam 10. This allows the position of the stirrups 32 in the longitudinal direction of the beam 10 to be defined. This makes it possible to suppress the disturbance of the stirrups 32.

[0035] <Other embodiments> In the above embodiment, a steel plate 42 was used as a disposable formwork, and a formwork unit 40 was used in which this steel plate 42 was integrated with a lattice material 44, an upper chord material 46, and a lower chord material 48, but embodiments of the present invention are not limited to this.

[0036] For example, as shown in FIG. 3(A), a corrugated steel plate 60 such as a deck plate may be used instead of the formwork unit 40. It is preferable that the grooves of the corrugated steel plate 60 are oriented along the longitudinal direction of the beam 10. When using the corrugated steel plate 60, a spacer 62 is placed on the corrugated steel plate 60. As shown in FIG. 3(B), a plurality of spacers 62 are arranged along the longitudinal direction of the beam 10.

[0037] At this time, the spacers 62 may be welded to the corrugated steel plate 60, but may not be welded as shown in Fig. 3(C). Also, the preparation reinforcement 50 may or may not be welded to the spacers 62.

[0038] The use of such corrugated steel plates 60 also increases the rigidity of the temporary formwork compared to when flat plates are used as the temporary formwork. Furthermore, by not integrating the corrugated steel plates 60, spacers 62, and preparation reinforcement bars 50 in advance, they can be more easily transported to the construction site compared to when these components are integrated.

[0039] In addition, in an embodiment in which the temporary formwork, spacers, and preparation reinforcement are not integrated, flat steel plates 64 may be used instead of the corrugated steel plates 60, as shown in Figures 4(A) to (C). The configuration is the same as the embodiment shown in Figures 3(A) to (C) except for replacing the corrugated steel plates 60 with flat steel plates 64. Even in this embodiment, by using steel plates as the temporary formwork, it is possible to obtain the effect of lowering the height position of the beam main reinforcement bars 30 (bottom end reinforcement bars 30B) relative to the bottom end surface 20A of the concrete 20. [Explanation of symbols]

[0040] 30 Beam main reinforcement 30A Top end reinforcement (beam main reinforcement) 30B Bottom reinforcement (beam main reinforcement) 32 Stirrups 42 Steel plate 44 Lattice material (spacer) 46 Upper chord (preparation reinforcement) 50 muscles 60 Corrugated steel plate (steel plate) 62 Spacer 64 Flat steel plate (steel plate)

Claims

1. A plurality of stirrups are arranged along the longitudinal direction of the beam main reinforcement and wound around the outside of the beam main reinforcement; A step reinforcement is arranged below the stirrups along the longitudinal direction of the beam; A steel plate that is a temporary formwork that is arranged below the step reinforcement and forms the bottom surface of the concrete to be poured into the beam; a spacer that is installed on the steel plate and that positions the height position of the reinforcing bars; Equipped with Beam structure.

2. The spacer is a lattice material, and the step reinforcement and the steel plate are welded to the lattice material and integrally formed. The beam structure of claim 1 .

3. The step reinforcement and the stirrup are spot welded. A beam structure according to claim 1 or 2.

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