JP2003253753A - Anchoring method for main reinforcement for beam at the top floor or attic floor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an anchoring method for main reinforcement for a beam in a reinforced concrete building or in a steel framed reinforced concrete building capable of increasing anchoring forces of the main reinforcement for the beam without lengthening a vertical portion of the main reinforcement of the beam at the upper end portion. <P>SOLUTION: This is a method for anchoring the main reinforcement 12 for the beam in a column to beam joint portion at the top floor or attic floor of a reinforced concrete or a steel framed reinforced concrete building. The main reinforcement 12 is arranged at the top end side of a beam 11; and an almost reversed U-shaped beam restricting bars 14 comprising a pair of anchoring portions 14a and 14a extended to the lower side from the upper end side of the main reinforcement 12 of the beam and a connecting portion 14b connecting these anchoring portions 14a, 14a are hooked, and the anchoring portions 14a and 14a of the beam restricting bars 14 are anchored to concrete 15 in the column to beam jointing portion. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for fixing a main beam reinforcing bar on a top floor or a roof floor suitable for a reinforced concrete structure or a steel frame reinforced concrete structure.

[0002]

2. Description of the Related Art Conventionally, in a beam-column joint on the top floor or roof of a reinforced concrete or steel-framed reinforced concrete building, a reinforcing bar called a cage bar is attached to the upper end of the main pillar rebar on the outer peripheral side of the column. And put it on top,
By arranging the vertical part that extends downward from the outer peripheral edge of the bottom part along the inside of the shear reinforcement bar wound around the main rebar of the column, the concrete on the upper side of the column-beam joint is restrained by the cage bar. It was.

However, even when such a car reinforcement is covered on the column main rebar, the horizontal portion of the beam main rebar at the upper end has a weak anchoring force because the concrete covering thickness is small, and the beam main rebar at the upper end has a certain level or more. If the pulling force of
It cannot prevent splitting fracture of concrete.

Therefore, conventionally, the total fixing length is lengthened by bending the end portion of the main beam reinforcing bar at the upper end downward to provide a vertical portion to secure the fixing force of concrete.

[0005]

However, when the vertical portion of the beam main reinforcing bar is lengthened to increase the total fixing length as in the conventional case, the vertical portion has more chances of buffering with other reinforcing bars. There was a problem that the work of arranging becomes difficult.

[0006] Usually, the concrete of the column is placed in advance before joining the beams. However, when the vertical portion of the main reinforcing bar of the beam becomes long and extends through the beam-column joint to the inside of the column,
When the concrete of the pillar is placed in advance, the vertical part of the main rebar of the beam, which will be laid after that, will buffer the concrete, so it will not be possible to place it in advance and the process will be congested and the construction period will be extended. There was a problem.

An object of the present invention is to solve the above problems, and a reinforced concrete structure or a reinforced concrete structure capable of increasing the anchoring force of the beam main rebar without lengthening the vertical portion of the beam main rebar at the upper end. It is a technical object to provide a method for anchoring a beam main reinforcing bar in a steel reinforced concrete building.

[0008]

SUMMARY OF THE INVENTION The present invention is a method of fixing a beam main reinforcing bar on the top floor or a roof floor, and is configured as follows to solve the above-mentioned technical problems. That is, the present invention is a method of fixing the main beam reinforcement in the beam-column joint of the top floor or roof of a reinforced concrete structure or a steel-framed reinforced concrete structure, along the longitudinal direction of the beam at the upper end side of the beam. The beam restraining bar of substantially inverted U-shape, which is composed of a pair of fixing portions extending below the beam main reinforcing bar and a connecting portion connecting these fixing portions, is hooked on the beam main reinforcing bar arranged, The fixing portion of the beam restraint bar is fixed to the concrete in the beam-column joint.

The inverted U-shaped beam restraining bar can be hooked so as to cross one or more beam main reinforcing bars, for example, two adjacent beam main reinforcing bars.

According to the present invention, the connecting portion of the substantially U-shaped beam restraint bar is hooked on the beam main rebar on the upper end side, and the fixing portion of this beam restraint bar is vertically below the beam main rebar. Since it is reinforced in the concrete and anchored in the concrete, the anchoring force of the anchoring portion of the beam restraining bar restrains the beam main reinforcing bar, and as a result, the anchoring force of the beam main reinforcing bar increases.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an embodiment of a method for fixing a beam main rebar on a top floor or a floor according to the present invention will be described.
A detailed description will be given with reference to the drawings.

FIG. 1A is a cross-sectional view of a beam-column joint portion of the present invention, FIG. 1B is a cross-sectional view taken along the line AA of FIG. 1A, and FIG. 3 is a diagram for explaining the procedure for determining the number of beam restraint bars according to the present invention, FIG. 4 (a) is a diagram showing a substantially L-shaped hook portion, and FIG. 4 (b) is a diagram showing a substantially V-shaped hook portion. Figure showing,
FIG.4 (c) is a figure which shows a substantially U-shaped hook part.

As shown in FIG. 1A, according to the present invention, the upper and lower sides of a beam 11 fixed in a joint between a column 10 and a beam 11 are provided on a top floor or a floor of a reinforced concrete structure or a steel frame reinforced concrete structure. Of the beam main rebars 12 and 13 arranged along the longitudinal direction of the beam 11 on the end side, a horizontal portion 12a of the beam main rebar 12 on the upper end side is connected to a beam-reinforcing bar 14 having an inverted U-shape described later. The portion 14b is hooked and fixed, and the fixing portions 14a and 14a of the beam restraint bar 14 are fixed to the concrete 15 in the beam-column joint.

The pillar 10 has pillar main rebars 16, 16 on the outer peripheral side thereof.
... is arranged. These beam main rebar 16, 16
The upper end of ... is folded back in a U shape. Also,
A plurality of shear reinforcing bars 17, 1 are provided on the outer peripheral side of the column main reinforcing bar 16.
7 ... is wound.

Beam main reinforcing bar 12 arranged on the upper end side of beam 11.
Is bent downward to form a vertical portion 12b having a length that fits within the beam-column joint.
A shear reinforcing bar 18 is wound around the upper and lower beam main reinforcing bars 12 and 13 outside the column-beam joints.

As shown in FIG. 1B, the beam restraint bar 14 has two parallel fixing portions 14a, 14a and a connecting portion 1 for connecting the upper ends of the fixing portions 14a, 14a.
4b and is formed in a substantially inverted U shape. And
The connecting portion 14b is hooked so as to cross the horizontal portions 12a, 12a of the two main beam reinforcing bars 12, 12 adjacent to each other. As a result, the fixing portions 14a and 14a are vertically arranged below the beam main reinforcing bar 12.

Two fixing portions 14a, 1 of the beam restraint bar 14
The spacing L on the inside of 4a is such that both fixing parts 14a, 14a
The inner surface of the horizontal part of the beam main rebar 12,12
It is set so as to contact 2a. Further, the height H of the fixing portions 14a, 14a of the beam restraint bar 14 is determined by the beam restraint bar 1
4 is set to about 30 times the diameter d.

The height H of the fixing portions 14a, 14a
Can be appropriately set according to the specifications of the beam restraint bar 14 and the concrete 15 and the conditions of the use environment, but when the beam restraint bar 14 is hooked to the beam main rebars 12, 12, the fixing portion 14a,
14a is set within the beam-column joint.

This beam restraint bar 14 is, as shown in FIG.
A plurality of the main reinforcing bars 12 are hooked at predetermined intervals along the axial direction of the horizontal portion 12a. Incidentally, reference numeral 19 in FIG.
Is a beam orthogonal to the beam 11 having the beam main rebar 12 at the upper end,
Reference numeral 20 denotes main beam reinforcements above and below the beam 19. Beam 19
As shown in FIG. 1, the main beam reinforcing bar 20 is arranged so as to contact the lower beam main reinforcing bar 12 at the upper end and the lower beam main reinforcing bar 13 at the lower side.

The number of beam restraint bars 14 to be used can be set in the following manner. That is, as shown in FIG. 3, the length of the horizontal portion 12a of the beam main bar 12 at the upper end (the length arranged in the beam-column joint) Y1 is set, and the outer distance between the column main bars 12 and 12 at both ends is set to be the same. When Y2, the total X of the horizontal cross-sectional areas of the fixing portions 14a in all the beam restraint bars 14 is the area W
= (Y1 × Y2) is preferably about 7% (X / W = 0.07). However, the number of beam restraint bars 14 to be used can be appropriately set according to the conditions of the use environment such as the diameter and strength of the beam and the strength of concrete.

As described above, according to the present invention, the inverted U-shaped beam restraint bar 14 is hooked on the horizontal portion 12a of the beam main rebar 12 at the upper end, and the anchored portions 14a, 1 of the beam restraint bar 14 are secured.
Since 4a is fixed to the concrete 15, the horizontal portion 12a of the beam main reinforcing bar 12 is restrained by the fixing force of the fixing portions 14a and 14a of the beam restraining bar 14, and as a result, the horizontal portion 12a of the beam main reinforcing bar 12 is fixed. Power increases.

Therefore, even when a tensile force of a certain magnitude or more acts on the horizontal portion 12a of the beam main reinforcing bar 12 on the upper end side, the concrete 15 above the horizontal portion 12a is applied.
However, it can be prevented that the main reinforcing bars 12 and 12 are split and broken into continuous cracks.

Further, the beam main reinforcing bar 12 on the upper end side of the beam 11 on the top floor and the roof floor, which has not been conventionally recognized as a fixing portion,
Since the horizontal portion 12a in the section is effective for fixing, the total fixing length of the beam main reinforcing bar 12 in the beam-column joint can be shortened, and the reinforcing work becomes easy.

Further, the vertical portion 12 of the beam main rebar 12 at the upper end
Since it is not necessary to lengthen b and the vertical portion 12b can be housed in the column-beam joint, the beam main reinforcing bar 12 can be laid out after the concrete of the column 10 is placed ahead of the beam 11. As a result, the process can be simplified and the work period can be shortened. Further, since the beam restraint bar 14 is simply hooked on the horizontal portion 12a of the beam main rebar 12 on the upper end side from above, the bar arrangement work is very simple.

In the above-described embodiment, the beam restraining bar 14 is used.
The two main pillar rebars 1 whose connecting portions 14b are adjacent to each other.
2, 12 horizontal parts 12a, 12a were hung so as to cross, but one or more beam main reinforcing bars 12, 12 ...
It is also possible to hang it so as to cross the horizontal portions 12a, 12a ...

Further, although the lower end portions of the fixing portions 14a, 14a of the beam restraint bar 14 are made linear in the above-mentioned embodiment, as shown in FIG. 4A, the lower end portions of the fixing portions 14a, 14a are substantially formed. L-shaped hook portions 14c and 14c can be provided.

Further, as shown in FIG. 4B, the hook portions 14 having a substantially V shape are provided at the lower end portions of the fixing portions 14a, 14a.
d and 14d are provided, or as shown in FIG.
It is also possible to provide character-shaped hook portions 14e, 14e.

These hook portions 14c, 14d, 14e
Is secured to the beam main reinforcing bar 20 of the beam 19 that is orthogonal to the beam 11, and the beam restraining bar 14 can be temporarily fixed at the time of placing concrete.

[0029]

As described above, according to the present invention,
The inverted U-shaped beam restraint bar is hooked to the beam main rebar on the upper end side of the beam,
Since the anchoring portion of the beam restraint bar is vertically arranged below the main beam reinforcing bar and is anchored to the concrete, the anchoring force of the anchoring part of the beam restraint bar restrains the beam main reinforcing bar and increases its anchoring force. . Therefore, even when a tensile force of a certain magnitude or more is applied to the beam main rebar on the upper end side, the concrete above the beam main rebar can be prevented from splitting and breaking.

Further, since it is not necessary to provide a vertical portion on the beam main rebar on the upper end side in order to increase the fixing force, and even if a vertical portion is provided, it is not necessary to increase the length thereof, the concrete of the column is beamed. It is possible to place the structure in advance, which simplifies the process and shortens the construction period.

[Brief description of drawings]

1A and 1B are cross-sectional views illustrating a method of fixing a beam main reinforcing bar on a top floor or a floor according to the present invention, FIG. 1A is a cross-sectional view of a beam-column joint portion, and FIG. It is an AA sectional view of (A).

FIG. 2 is a view on arrow B in FIG.

FIG. 3 is a diagram illustrating a procedure for determining the number of beam restraint bars according to the present invention.

4A and 4B are views showing another embodiment of the beam restraint bar according to the invention, FIG. 4A shows a substantially L-shaped hook portion, and FIG. 4B shows a substantially V-shaped hook portion. FIG. 4C is a diagram showing a hook portion, and FIG. 4C is a diagram showing a substantially U-shaped hook portion.

[Explanation of symbols]

10 pillars 11 beams 12 Beam main rebar on the upper end of the beam 12a Horizontal part of beam main rebar 14 Beam restraint 14a Anchoring part of beam restraint 14b Connection part of beam restraint bar 15 concrete

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Tadashi Naruse             Maeda 2-1026 Fujimi, Chiyoda-ku, Tokyo             Construction Industry Co., Ltd. F term (reference) 2E125 AA03 AA13 AB12 AB13 AC04                       AC07 AC18 AG03 AG60 BA07                       BA45 BB08 BB37 BC09 BD01                       BE07 BE08 BF05 CA83 EA33                 2E164 AA02 BA12 BA34

Claims (3)

[Claims] 1. A method of fixing a main beam reinforcement in a beam-column joint on the top floor or roof of a reinforced concrete structure or a steel-framed reinforced concrete structure, wherein the beam main reinforcement is arranged on the upper end side of the beam along the longitudinal direction of the beam. The beam-reinforcing beam having a substantially inverted U shape, which is composed of a pair of fixing portions extending below the beam and a connecting portion connecting these fixing portions, is hooked on the reinforced main reinforcement of the beam. A fixing method of a main reinforcing bar of a beam on the top floor or a roof floor, characterized in that a fixing portion of a reinforcement is fixed to concrete in the column-beam joint. 2. The top floor or the roof floor according to claim 1, wherein the inverted U-shaped beam restraining bar is hooked so as to cross one or more of the beam main reinforcing bars. How to fix the main beam reinforcement. 3. The inverted U-shaped beam restraint bars are adjacent to each other.
3. It is hooked on each of the beam main reinforcing bars.
The method of fixing the beam main reinforcement on the top floor or the roof as described in.