JP2791239B2 - Precast concrete beams - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a precast concrete beam having a stirrup protruding from an upper surface of the beam, which is a so-called half PC beam.

[0002]

2. Description of the Related Art In order to make up for the extreme labor shortage in recent years, or to improve the workability and work efficiency, pillars,
2. Description of the Related Art Precasting of building materials such as walls, floor slabs, beams, and the like, which are previously produced in factories, is in progress. Of these, the precast concrete beams have stirrups projecting from the upper surface, and the stirrups are integrated with the floor slab.

[0003] However, in such a precast concrete beam, in an experiment assuming a large deformation of a building due to an earthquake or the like, the joint boundaries are shifted or separated from each other, and the precast concrete beam and the floor slab are separated. There is a drawback that the predetermined strength and rigidity are lost due to loss of integrity. Therefore, as a means for preventing such a defect, a method of providing a small uneven portion 20 over the entire upper surface of the beam 10 or a method of arranging a slip preventing streak 30 as shown in FIG. 14 is conventionally used. .

[0004]

However, the method of providing small uneven portions on the entire upper surface of the beam as described above makes the work complicated due to the complexity of the formwork, and the arrangement of the reinforcement for preventing slippage is also troublesome. For this reason, there is a problem that both of them lack work efficiency and rationality. The present invention has been made in view of such a problem, and an object of the present invention is to easily manufacture a precast concrete beam for preventing displacement of a joint boundary surface during large deformation of a building due to an earthquake or the like, and preventing detachment. It is.

[0005]

A precast concrete beam according to the present invention for solving the above-mentioned problems is a precast concrete beam having a stirrup protruding from an upper surface thereof. Is buried, and part of the spiral muscle is
A semicircular shape you characterized in that projecting from the upper surface of the precast concrete beam with the adjacent state.

[0006]

According to the action this configuration, the spiral muscles are embedded in the longitudinal direction of the precast concrete beam upper surface, by a portion of the spiral muscle protrudes from the upper surface of the precast concrete beam adjacent state semicircular,
Precast concrete beams that prevent displacement and detachment of the joint interface can be easily manufactured , and the proof stress and toughness during large deformation of the building can be improved.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a sectional view of a use state of a precast concrete beam of the present invention, FIG. 2 is a perspective view of a precast concrete beam, FIG. 3 is a plan view of the precast concrete beam, and FIGS. FIG. The precast concrete beam 1 has stirrups 3 of the beam protruding from the upper surface and main bars 4 protruding from the end surfaces on both sides thereof. Precast concrete slab 5 on top
Are placed and the ready-mixed concrete 6 is cast thereon, whereby these are integrally formed.

A part of the spiral streaks is adjacent in a semicircular arc shape
Although conditions are <br/> buried projecting from the upper surface of the precast concrete beam in which after Da設raw concrete in the mold, or embedded by pressing on its upper surface, or in advance predetermined positions After fixing, the concrete is poured and buried.

FIGS. 4 to 6 show another embodiment of a precast concrete beam. FIG. 4 shows a precast concrete beam 1 buried in a central portion in which a spiral streak 2 is buried in the central portion. The figure also shows a precast concrete beam 1 buried at both ends with spiral streaks 2 buried at both ends. Further, FIG. 1 shows a distributed buried precast concrete beam 1 in which a spiral streak 2 having an appropriate length is appropriately divided and buried, and these are all manufactured by the same method as described above.

FIG. 5 shows not only one spiral streak 2 but also two spiral streaks 2 buried in parallel as described above. FIG. 5 shows a full length buried precast concrete beam buried over the entire length of the upper surface. It is one. The figure also shows a central buried type in which the spiral streaks 2 are buried only in the center of the upper surface.
Embedded type, or a distributed embedded type in which a pair of spiral streaks 2 of an appropriate length are appropriately divided and embedded,
These are superior in proof stress and toughness to the precast concrete beam 1 described above.

FIG. 6 shows a precast concrete beam 1.
A precast concrete beam 1 having a substantially U-shaped concave groove 7 having an open upper surface formed on the upper surface to reduce the weight. In the figure, one spiral streak 2 is embedded in the center of the upper surface. It is a notched end type precast concrete beam 1 having concave grooves 7 at both ends. In the same figure, one spiral streak 2 is embedded at both ends of the upper surface, and a groove 7 is formed at the center.
Is a central notched type precast concrete beam 1 in which is recessed.

Also, in FIG. 9 and FIG. 9, similarly to the above, the spiral streaks 2 of the precast concrete beam 1 with a notch at the end and the precast concrete beam 1 with a notch at the center.
And two precast concrete beams can be selected and used in accordance with the erection location and the purpose of erection, so that the right material in the right place can be realized. Furthermore, the end-cut type precast concrete beam 1 is reduced in weight and can be easily connected to another end-cut type precast concrete beam 1 by the concave groove 7.

FIG. 11 shows a precast concrete beam 1 in which a spiral streak 2 is provided at the center of the upper surface, and a notch 8 for attaching a small beam is provided at the center of both sides of the precast concrete beam 1. As shown in FIG. Beam 9 by beam cutout 8
Can be simply attached, and the weight of the precast concrete beam 1 can be reduced. In addition, the notch 8 for attaching the small beam is shown in FIGS.
5, 6, and 9 can be provided on each of the precast concrete beams 1. In FIGS. 6 and 9, further reduction in weight, simplification of workability, and efficiency can be achieved. By combining them, it is possible to achieve even more suitable materials and places.

[0014]

Spiral muscle in the longitudinal direction of the precast concrete beam upper surface according to the present invention is embedded, by a part of the spiral muscle protrudes from the upper surface of the precast concrete beam adjacent state semicircular, large deformation of the building precast concrete beam to prevent misalignment of the punching joint interface, and the detachment can be easily produced at the time.

A spiral streak is buried in the longitudinal direction of the upper surface of the precast concrete beam, and a part of the spiral streak is
Protrudes in a semicircular arc shape in the adjacent state from the upper surface of the precast concrete beam, by which the concave grooves provided on the upper surface thereof, to together to be able to reduce the weight of the precast concrete beam, the other precast concrete beam Can be concluded simply.

A spiral streak is buried in the longitudinal direction of the upper surface of the precast concrete beam, and a part of the spiral streak is
The precast concrete beam protrudes from the upper surface of the precast concrete beam in a semicircular shape adjacent to the upper surface, a concave groove is provided on the upper surface, and a notch portion for attaching a small beam is provided on the side surface, so that the weight of the precast concrete beam is reduced. to together to be able to achieve, attachment of joists can be easy.

[Brief description of the drawings]

FIG. 1 is a sectional view of a used state of a precast concrete beam of the present invention.

FIG. 2 is a perspective view of a precast concrete beam.

FIG. 3 is a plan view of a precast concrete beam.

FIG. 4 is a plan view of a precast concrete beam showing another embodiment.

FIG. 5 is a plan view of a precast concrete beam showing another embodiment.

FIG. 6 is a plan view of a precast concrete beam showing another embodiment.

FIG. 7 is a sectional view taken along line AA of FIG. 6;

FIG. 8 is a sectional view taken along the line BB of FIG. 6;

FIG. 9 is a plan view of a precast concrete beam showing another embodiment.

FIG. 10 is a sectional view taken along line CC of FIG. 9;

FIG. 11 is a plan view of a precast concrete beam showing another embodiment.

FIG. 12 is a sectional view taken along line DD of FIG. 11;

FIG. 13 is a sectional view showing a state in which a small beam is attached to a precast concrete beam.

FIG. 14 is a sectional view of a conventional precast concrete beam.

[Explanation of symbols]

 1 Precast concrete beam 2 Spiral bar 3 Stirrup bar 4 Main bar

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-2-236327 (JP, A) JP-A-63-1101 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) E04C 3/20 E04C 5/18

Claims (3)

(57) [Claims] 1. A precast concrete beam having a stirrup protruding from an upper surface thereof, wherein spiral beams are buried in a longitudinal direction of the upper surface of the precast concrete beam,
Precast concrete beam, wherein a portion of the spiral muscle protrudes from the upper surface of the precast concrete beam in adjacency to semicircular. 2. On the upper surface of the precast concrete beam
The precast concrete beam according to claim 1 , wherein a concave groove is provided . 3. A precast concrete beam according to claim 1 or 2, characterized in that is provided with notch for the beams mounted on the sides of the precast concrete beam.