JP3008795B2 - Joint structure of reinforced 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 joining structure for joining reinforced concrete beams in the middle of a column span when constructing an RC building.

[0002]

2. Description of the Related Art Conventionally, when a reinforced concrete beam is to be joined in the middle of a column span when constructing an RC building, for example, a construction method as shown in FIG. 5 is employed. That is, first, the reinforced concrete beams 50 and 5 to be joined are connected.
0 is built with the respective joint surfaces 50a, 50a facing the joints. At this time, the inner main bar 51 at the lower end of the beam is protruded from each joint surface 50a so that they abut against each other at the joint (FIG. 7A).

[0003] Next, the butting beam main reinforcement 51,
51 are joined to each other by a welded joint / mechanical joint. At the same time, the beam upper main bars 54 arranged on the reinforced concrete beams 50 are also welded or joined by a mechanical joint (FIG. 2B).

[0004] Thereafter, the ribs 5 are connected so that the beam lower main bar 51 and the beam upper main bar 54 are tied up and down at the joint.
In addition to arranging the reinforcements 3, a formwork 55 (indicated by a dashed line in the figure) for placing concrete for jointing is installed around the joint while supporting by a shoring work ((c) in the figure). ,
Here, concrete for jointing is cast, and the reinforced concrete beams 50 are integrated and joined.

[0005]

However, in the above-mentioned conventional method, the work of arranging the ribs 53 after the construction has to be performed on site, so that the number of on-site operations increases and the operation is performed at a high place. This task was complicated.

Further, a beam upper main bar 54 and a beam lower main bar 51 are provided.
Because the joints are made by welding or mechanical joints, in the former, work cannot be performed in rainy weather, and the construction period may be delayed due to weather, and in the latter,
There is a problem that the work is complicated due to an increase in man-hours such as arranging the sleeve and grouting.

[0007] Further, since it is necessary to install a formwork 55 for casting concrete for transfer, the provision of a supporter for supporting the formwork 55 increases temporary construction costs, and This was one of the causes of the prolonged construction period.

Accordingly, the present invention has been made to solve the above-mentioned problem, and the above-described operations such as the arrangement of the ribs, the joining of the main beams of the beams, and the installation of the formwork can be labor-saving, and the reinforced concrete beams can be connected to each other. It is an object of the present invention to provide a reinforced concrete beam joint structure capable of simplifying a joint operation and improving a building efficiency.

[0009]

SUMMARY OF THE INVENTION A joint structure of a reinforced concrete beam according to the present invention has been made to achieve the above object, and is a joint structure for joining reinforced concrete beams to each other in the middle of a column span. A U-shaped rib having a U-shaped cross section with an open upper portion formed along the longitudinal direction of the reinforced concrete beam at the joint end of the reinforced concrete beam and having an open top at the joint end. A beam reinforcing bar having a rib is projected, and a beam main reinforcing bar projecting at a joint end of the other reinforced concrete beam and the beam reinforcing bar are overlapped in the frame portion, and a cap tie is arranged above the rib bar. Then, concrete is cast into the frame portion.

[0010]

According to the joint structure of a reinforced concrete beam of the present invention, since the beam main reinforcement and the rib reinforcement are prearranged at the joint end, there is no need to perform a reinforcement operation on site and at a high place. Moreover, since the joints between the beam main reinforcements are lap joints, it is possible to easily perform the construction while securing a sufficient joint strength.

In addition, since the frame having a U-shaped cross section constitutes the outer layer of the reinforced concrete beam, it is not necessary to remove the frame after the concrete has hardened. Therefore, if concrete for jointing is cast in this frame part, it is not necessary to separately provide a formwork for casting concrete for jointing, and it is not necessary to install a supporting structure. as a result,
Temporary installation costs can be reduced and formwork installation work can be omitted.

Further, the frame portion and the beam reinforced cage of one reinforced concrete beam have a U-shape with an open top, so that when the other reinforced concrete beam is erected, the ribs impede the carrying in. Without this, the beam reinforcement of the other reinforced concrete beam can be inserted into the U-shaped frame portion and the beam reinforcement cage from above. Therefore, the work of positioning, construction, etc. becomes easy, the labor of erection of reinforced concrete beams can be saved, and the reinforced concrete beams can be built only by hanging them from above without moving them horizontally. It does not require a large space.
And since the upper part of a beam reinforced cage is tied with a cap tie after such a erection, the strength of the precast concrete beam as before can be ensured.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the accompanying drawings. FIGS. 1 to 3 show a procedure for joining reinforced concrete beams 10 and 20 by the reinforced concrete beam joining structure 1 of the present invention.

In FIG. 1, a reinforced concrete beam 10
Has one end joined to a column member (not shown),
It is composed of a beam main body 10a shown on the right side in the figure and a joint end 10b formed at the tip (left side in the figure) and located at the joint between the reinforced concrete beams 10 and 20 in the erected state. ing.

The beam main body 10a is a beam lower main bar 13 arranged along the longitudinal direction of the reinforced concrete beam 10.
And a rib 14 for connecting the beam upper main bar 12 and the beam lower main bar 13, and are formed solid by casting concrete 18.

On the other hand, the joint end 10b is located at the joint, is formed integrally with the beam main body 10a along the longitudinal direction of the reinforced concrete beam 10, and has a U-shaped cross section open at the top. It is roughly constituted by a frame portion 11 having a shape of a bar, and a beam reinforcing bar 19 protruding from the joint portion.

The frame 11 is provided with a reinforced concrete beam 10.
It is not necessary to remove it after the concrete for jointing, which is to be cast therein, hardens. The beam reinforcing bar 19 is formed of a beam main bar, a shear reinforcing bar, and the like normally required for an RC beam member. In the present embodiment, the beam reinforcing bar 19 extends to face the frame portion 11. The upper main bar 12 and the lower beam main bar 13, and the U-shaped rib bar 16 having an open upper portion and arranged to tighten the upper beam main bar 12 and the lower beam main bar 13 positioned above and below.
And an anchoring bar 17 arranged in parallel with the main bar 12 at the upper end of the beam so as to tightly connect the rib bars 16, 16 to each other. In this way, in order to arrange the beam upper main reinforcement 12, the beam lower main reinforcement 13, the rib reinforcement 16 and the like at the joint end 10b in advance, after the reinforced concrete beam 10 is erected, a reinforcing operation is performed on site and at a high place. No need.

The beam main body 10 facing the joint end 10b
A cotter 15 is formed on an end face of the end face a as a recess for increasing the joining strength between the concrete for piling into the frame 11 and the beam main body 10a.

As shown in FIG. 2, another reinforced concrete beam 20 is joined to the reinforced concrete beam 10 and, similarly to the reinforced concrete beam 10, is joined to the beam body 20a at the joint. And the end 20b. The beam body 20a has the same configuration as the beam body 10a of the reinforced concrete beam 10.

On the other hand, the joint end 20b is connected to the beam main body 2
Beam upper main bar 22 and beam lower main bar 23 arranged within 0a
Are provided so as to face the joint. In addition,
Similarly to the reinforced concrete beam 10, a cotter 25 is also formed on the end face of the beam body 20a facing the joint end 20b.

Then, the joint structure 1 of the reinforced concrete beam
Are reinforced concrete beams 10 and 2 by the following procedure.
0 The joining ends 10b and 20b are joined to each other at the joining portion.

First, as shown in FIG. 1, a reinforced concrete beam 10 is erected on a predetermined place to be erected, for example, on a predetermined column member. Next, as shown in FIG. 2, another reinforced concrete beam 20 is erected from above so that its joint end 20 a is located within the frame portion 11 of the joint end 10 b of the reinforced concrete beam 10. At this time, since the frame portion 11 and the beam reinforced basket 19 are in a U-shape with an open upper portion,
The beam main reinforcement 22 of the reinforced concrete beam 20 can be inserted into the frame portion 11 from above, and the reinforced concrete beam 20 can be easily built.

As shown in FIG. 3, in the frame portion 11, the beam upper main bar 22 and the beam lower main bar 23 of the reinforced concrete beam 20 and the beam reinforcing bar 19 are overlapped, and a cap Arrange tie 26.
This cap tie 26 is made of reinforced concrete beams 10, 20.
Reinforcing bars are arranged so as to be orthogonal to both beam upper main bars 12, 22, and are joined by welding or the like. After that, concrete for splicing is poured into the frame portion 11, and the joining operation is completed. In this manner, the joint between the beam upper main reinforcements 12 and 22 or the beam lower main reinforcements 13 and 23 is a lap joint, and the frame 1
Since the joints are collectively joined by the jointing concrete placed in the joint 1, the joint can be easily performed while securing sufficient joint strength.

In the present embodiment, the reinforced concrete beams 10 and 20 are structural members disposed inside a building, and are provided on the upper end surface of the side wall of the frame 11 as shown in FIG. The PC slab formwork 30, 30 is placed, and the floor slab concrete is cast up to the casting surface (two-dot chain line in the figure) above this.

According to the reinforced concrete beam joining structure 1 configured as described above, the U-shaped cross section 11 is a form for casting concrete for joining, and the frame 11 is an outer layer of the reinforced concrete beam 10. It is not necessary to remove it after the concrete for joining has hardened because it constitutes the part. Therefore, it is not necessary to separately provide a formwork for placing concrete for jointing, and it is not necessary to install a supporting structure. As a result, it is possible to reduce temporary construction costs, to omit the formwork installation work, and to save on-site work.

In this embodiment, the joint structure of the reinforced concrete beams is used to join the reinforced concrete beams 10 and 20 disposed inside the structure, but the present invention is not limited to this. Instead, as shown in FIG. 4, the present invention can be applied to a reinforced concrete beam 40 to be built at an outer peripheral position of a structure. In this case, the side wall 1 of the frame 11 is located outside the building.
The height of the side wall 11b is set to be equal to the height of the floor slab concrete (two-dot chain line in the figure), and the other side wall 11b is set low.
The end of the PC slab formwork 30 is placed on the upper end surface of the slab.

[0027]

As described above in detail, according to the joint structure of the reinforced concrete beam of the present invention, since the beam main reinforcement and the rib reinforcement are arranged in advance at the joint end, the arrangement at the site and at a high place is possible. Muscle work is not required, and work efficiency can be improved. In addition, since the joints between the beam main reinforcements are lap joints, they can be easily constructed while securing sufficient joint strength. At the same time, if concrete for jointing is cast in the U-shaped cross section, it is not necessary to separately provide a concrete formwork for concrete, and it is not necessary to install a supporting structure associated with this. As a result, temporary costs can be reduced, and on-site work can be saved.

Further, since the frame portion and the beam reinforced cage of one reinforced concrete beam have a U-shape with an open upper part, when the other reinforced concrete beam is built,
The upper ribs do not hinder loading, positioning,
Work such as construction is facilitated, and a large space for installing these reinforced concrete beams is not required. And since the upper part of a beam reinforced cage is tied with a cap tie after such a erection, the strength of the precast concrete beam as before can be ensured.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing only one reinforced concrete beam of a reinforced concrete beam joint structure according to one embodiment of the present invention, (a) is a top view thereof, and (b) is a longitudinal sectional view thereof. (C) is an AA cross-sectional view of (a).

FIG. 2 is an explanatory view showing a state in which both reinforced concrete beams are erected in the jointed structure of the reinforced concrete beams of the present invention, (a) is a top view thereof, and (b) is a longitudinal sectional view thereof. (C) is a sectional view taken along line BB of (a).

FIG. 3 is an explanatory view showing a state in which cap ties are arranged in the joint structure of a reinforced concrete beam of the present invention, (a) is a top view thereof, (b) is a longitudinal sectional view thereof, (c) is a CC sectional view of (a).

FIG. 4 is a sectional view showing a modified example of the joint structure of the reinforced concrete beam of the present invention.

FIG. 5 is an explanatory view showing a conventional method of joining reinforced concrete beams.

[Explanation of symbols]

 1 Joint Structure of Reinforced Concrete Beam 10, 20 Reinforced Concrete Beam 11 Frame 16 Rib 19 Beam Reinforcement Basket 22 Main Beam Top Bar 23 Beam Main Bar 26 Cap Tie

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Nobuhiko Suzuki 2-3-3 Kandaji-cho, Chiyoda-ku, Tokyo Obayashi Corporation Tokyo Head Office (56) References JP-A-5-321324 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) E04B 1/16 E04C 3/20

Claims (1)

(57) [Claims] 1. A joint structure for joining reinforced concrete beams to each other in the middle of a column span, wherein a reinforced concrete beam is provided with a U-shaped cross section having an open top at a joint end of one of the reinforced concrete beams in a longitudinal direction. And a beam main bar projecting at the joint end of the other reinforced concrete beam at the joint end of the other reinforced concrete beam. The reinforced concrete beam joining structure, wherein the beam reinforced cage is overlapped in the frame portion, a cap tie is arranged above the rib, and concrete is poured into the frame portion.