JP2015200102A - Reinforcement structure between continuous holes on beam, and concrete structure thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a conventional problem with a reinforcement structure between continuous holes on a beam that has restricted the design, where the distance between the center of continuous holes must be thrice or larger than the hole diameter.SOLUTION: When a plurality of holes that pierces through a beam in the lateral direction is drilled at an interval in the longitudinal direction of the beam, the distance s between the center of adjacent holes is 2φ≤s<3φ when the radius φ of the holes is the same, and φ1+φ2≤s<1.5×(φ1+φ2)when the holes have different radii φ1, φ2, and a reinforcement structure 1 between the continuous holes of the beam has X-shaped reinforcing bars installed between the holes.

Description

  The present invention relates to a reinforcing structure between continuous holes in a reinforced concrete beam and a concrete structure having the reinforcing structure.

  Conventionally, in a beam of a reinforced concrete structure, when through holes such as sleeves that are penetrated in the beam width direction for piping are provided at a plurality of locations in the beam longitudinal direction, as shown in FIGS. 12 (A) and 12 (B) The distance between the centers of the openings is preferably set to be three times or more the opening diameter. Further, when an opening is provided on the beam end side, the center of the opening must be separated from the column end by at least the beam length.

  Therefore, as described in Patent Document 1, there is a reinforcing metal fitting in which a rectangular frame-shaped body is formed, the frame-shaped body is locked to the stirrup of the beam, and the frame-shaped body is fixed with a mounting rod. Are known. Furthermore, as described in Patent Document 2, a steel annular reinforcing member is formed around the through-hole of the beam so as to surround it with a covering thickness. A beam reinforcing structure is known in which concrete is placed between the through hole and the annular reinforcing member while being locked.

JP 2010-242482 A JP 2011-137335 A

  However, in the conventional perforated beam structure, when the number of through-holes is large when installing the beam through-holes, as shown in FIG. 12 (C), as shown in FIG. It will be necessary to deal with this, and it will be troublesome and uneconomical. In addition, the reinforcement structures described in Patent Documents 1 and 2 are time-consuming and expensive, and the construction period is long. The reinforcing structure between continuous openings of a beam and its concrete structure according to the present invention have been proposed in order to solve such problems.

The gist of the present invention for solving the above-mentioned problem of the reinforcing structure between the continuous openings of the beam according to the present invention is to provide a plurality of openings at appropriate intervals in the longitudinal direction of the beam. When penetrating in the short direction,
The spacing s between the centers of adjacent apertures is
If the diameters φ of the openings are the same, 2φ ≦ s <3φ,
Or
If the diameters of the openings are different diameters φ1, φ2,
φ1 + φ2 ≦ s <1.5 × (φ1 + φ2)
An X-shaped reinforcing bar in which a reinforcing bar is formed in an X shape is disposed between the openings.

  A flat portion that suppresses an increase in beam width is formed at an intersection where the reinforcing bars intersect in an X shape.

  The flat portion is a metal flat plate separate from the bar-shaped reinforcing bar.

  The flat portion is formed by laminating flat portions formed by partially pressing reinforcing bars.

  The flat portion is provided with a through hole through which the flat portion is overlapped and communicated with the rotation shaft so that the opening angle can be varied within a desired range at the intersecting portion.

  The flat portion is formed on one side with respect to a center line passing through the center point of the cross section in the cross-sectional shape of the reinforcing bar without exceeding the center line.

The X-shaped reinforcing bar is integrally formed with an X-shaped crossing portion and a horizontal connecting portion formed with the end of the crossing portion being horizontal,
It includes that a horizontal reinforcing portion is connected to the horizontal connecting portion by connecting means to form an X-shaped reinforcing bar.

  The gist of the concrete structure according to the present invention is to have a reinforcing structure between the continuous openings of the beam according to the present invention.

  According to the reinforcing structure between the continuous openings of the beam of the present invention, the X-shaped reinforcing bar exerts the same proof strength as that of the single-hole perforated beam, and the interval between the plurality of openings is at least the opening diameter. Can be reduced to, for example, about 2.5 to 2 times, and design constraints are eased.

  By forming a flat portion at the intersection of the X-shaped reinforcing bars, an increase in beam width can be suppressed, and planar fit can be improved. Further, this can be achieved by forming the flat portion on one side from the center line so that the overlapping flat portion does not become larger than the diameter of the reinforcing bar.

  The angle of the X-shaped reinforcing bar can be arbitrarily set, and it is not necessary to make a dedicated X-shaped reinforcing bar for each angle, and the X-shaped reinforcing bar can be formed efficiently.

  Further, if the X-shaped intersection is integrally formed in advance, mounting in the beam form is also facilitated.

  Since the restriction on the opening interval is relaxed, it is possible to aggregate the sleeves, etc., and it is possible to cancel the penetration under the beam, to stop the falling ceiling, and to prevent the sleeve from being detoured, and an economic effect can be obtained.

  By using a concrete structure with a reinforcement structure between the continuous openings of the beams, design costs can be reduced without having to struggle with piping, and there is no need for falling ceilings, making effective use of the space inside the building. Can do.

It is the longitudinal cross-sectional view (A) and (B) which show the schematic structure of the reinforcement structure 1 between the continuous openings of the beam which concerns on this invention. It is the longitudinal cross-sectional view which concerns on the Example of the typical dimension based on the reinforcement structure 1 between the continuous openings of the beam which concerns on the same invention. It is the longitudinal cross-sectional view (A) of the typical Example shown in the said FIG. 2 (B) based on the reinforcement structure 1 between the continuous openings of the beam based on this invention. In the reinforcing structure 1 between the continuous openings of the beam according to the present invention, there are embodiments (A) and (B) in the case where the intersecting portion 5 of the reinforcing bars is a flat portion 6. It is the partially expanded front view (A) and (B) which show the flat part 6 and other Example of X-shaped reinforcement in the reinforcement structure 1 between the continuous openings of the beam. It is a partially expanded front view which shows the shape of the flat part 4c of the X-shaped reinforcing bar 4 in the reinforcement structure 1 between the continuous openings of the beam. In the reinforcing structure 1 between the continuous openings of the beam, a cross-sectional view (A) in a state where the flat portion 4c of the intersecting portion is formed close to one side, a cross-sectional view showing a use state in which the flat portion 4c is overlapped to form an X shape (B). They are the front view (A) which shows the other Example which can change angle (theta) in the crossing part 5 in the reinforcement structure 1 between the continuous opening of a beam, and sectional drawing (B) of the crossing part 5 of this Example. It is the front view (A) which shows the Example of the strength test of the reinforcement structure 1 between the continuous openings of a beam, and the front view (B) which shows the structure example in the intensity test of the X-shaped reinforcement bar 4. FIG. FIG. 6 is a characteristic diagram (A) showing a load-deformation curve when there is an X-shaped reinforcing bar, and an explanatory diagram (B) showing a cracked state in stepwise beam deformation by a strength test. FIG. 6 is a characteristic diagram (A) showing a load-deformation curve without the X-shaped reinforcing bar, and an explanatory diagram (B) showing a cracked state in a stepwise beam deformation by a strength test. It is the longitudinal cross-sectional views (A) and (B) which show the Example between the continuous opening of the beam in a prior art example, and the top view (C) for rough description which shows the arrangement | positioning state of piping.

  The reinforcement structure between continuous openings of a beam according to the present invention is to arrange X-shaped reinforcing bars between a plurality of openings in the beam as shown in FIG.

  As shown in FIG. 1 (A), the reinforcing structure 1 between continuous openings of a beam according to the present invention includes a plurality of circular openings 3 having the same diameter in the longitudinal direction of the beam 2 at appropriate intervals. This is a reinforcing structure in the case of being. The opening 3 penetrates the beam 2 in the short direction.

  Between the openings 3 and 3, X-shaped reinforcing bars 4 and 4 are arranged. If the number of apertures 3 is 3 or more, as shown in FIG. 1 (B), the X shape is repeated to form, for example, a W-shaped reinforcing bar as a temporary name.

  The interval between the apertures 3 and 3 is less than 3 times the diameter of the aperture 3. In the illustrated example, for example, it is about twice.

  As shown in FIG. 2, when the diameters φ of the openings 3a and 3b are different, the distance s between the centers is, for example, the sum of the diameters φ of both the openings 3a and 3b, s = diameter φ1 + diameter φ2 is assumed.

  The horizontal portion of the X-shaped reinforcing bar 4 is formed by bending together with the X-shaped intersection 5. Considering the convenience of processing and handling of the horizontal portion, as another embodiment, as shown in FIG. 2, it is composed of a horizontal connecting portion 4a + horizontal reinforcing portion 4f, and an example of the length of the opening 3a It can be set to 40d (d is the diameter dimension of the X-shaped reinforcing bar 4) from the end position. Connection means such as welding or a mechanical joint is used to connect the horizontal connecting portion 4a and the horizontal reinforcing portion 4f.

  Further, as shown in FIGS. 3A and 3B, the bar arrangement structure of the X-shaped reinforcing bars 4 in the beam width direction in the cross section of the beam 2 is between the beam main bars or 1 of the beam main bars. It may be between the stepped streaks and the two staircases, or may be below the beam main bars, although not shown.

As shown in FIGS. 3A and 3B, the distance a between the beam main reinforcing bar and the reinforcing bar is, for example,
a ≧ max (a ₁ , a ₂ , a ₃ ),
Where a ₁ : 1.5 times the numerical value of the name of the reinforcing bar + outermost diameter,
a ₂ : 1.25 times the coarse aggregate maximum dimension + outermost diameter,
a ₃ : 25 mm + outermost diameter,
And

  Further, as shown in FIGS. 4 and 5A, in the crossing portion 5 where the X-shaped reinforcing bars 4 intersect with the X-shape, the beam width direction is suppressed in order to suppress the beam width increase in the beam width direction. Is a flat portion 6 having a “thickness”. The flat portion 6 is composed of a flat plate made of a metal such as an iron plate or steel having a thickness smaller than the diameter of the deformed bar, which is separate from the deformed bar serving as the reinforcing bar.

  As another embodiment of the flat portion 6, as shown in FIGS. 5B and 6, an X-shaped reinforcing bar 4 made of a deformed reinforcing bar having a round cross section is pressed and plastically deformed. The flat portion 4c can be obtained. And this flat part 4c is laminated | stacked so that the inner side may be match | combined, and the flat part 6 of the X-shaped intersection part 5 is comprised.

  As shown in FIG. 7A, the flat portion 4c has a cross-sectional shape of a round deformed reinforcing bar on one side without crossing the center line b with respect to the center line b passing through the center point 4d of the cross section. Is formed.

  Thus, by forming the flat portion 4c, as shown in FIG. 7B, in the X-shaped reinforcing bar 4, the flat portions 4c and 4c are laminated at the intersecting portion 5 intersecting with the X shape. In addition, the dimension of the deformed reinforcing bar in both X-shaped reinforcing bars 4 and 4 and the thickness of the laminated plate thicknesses of the flat portions 4c and 4c in the beam width direction overlap with each other at almost the same level. It does not swell in the hand direction).

  Therefore, the width in the beam width direction of the entire X-shaped reinforcing bars 4 and 4 does not increase, and even if a plurality of X-shaped reinforcing bars 4 are arranged in the beam 2 as shown in FIG. In the width direction, the distance between reinforcing bars (deformed bars) and between the beam main bar and the reinforcing bar is narrowed, so it is difficult to place the reinforcement work and the surroundings of the placed concrete deteriorate. .

  As another embodiment, as shown in FIGS. 8A and 8B, the flat portion 4 c has an X-shaped opening angle θ that can be varied within a desired angle range at the intersection portion 5. The flat part 4c is overlapped and communicated, and a through hole 4e through which a bolt 7 that is a rotation shaft is inserted is provided.

  The bolt 7 is communicated with the through holes 4e and 4e, and a nut (not shown) is attached to the protruding tip portion to tighten the laminated flat portions 4c and 4c. Once the X-shaped angle θ is determined by design, set it to the angle θ (about 30 ° to 60 °) and fix the X-shaped reinforcing bars 4 and 4 with bolts 7 and nuts. For example, it is fixed by welding or the like to form the intersecting portion 5 of the X-shaped reinforcing bar 4. Then, after the angle θ is determined and the X-shaped intersecting portion 5 is formed, the horizontal portion 4a is bent by a bending tool / device or the like.

  In this way, since the X-shaped reinforcing bar 4 is formed at an arbitrary angle θ, a dedicated X-shaped reinforcing bar 4 is formed for each angle θ designed according to the interval s between the openings 3 and 3. It is not necessary and can be manufactured flexibly. There is no waste of reinforcing bars as compared with the case where various types of X-shaped reinforcing bars are formed in advance.

  The X-shaped reinforcing bar 4 having the crossing portion 5 is formed in advance in a factory or the like before being installed in the beam formwork, and the end of the X-shaped reinforcing bar 4 is extended horizontally, That portion can be integrally formed as a horizontal connecting portion 4a.

  In this manner, if the X-shaped intersection 5 and the horizontal portion are integrally formed in advance, the bar arrangement work in the beam form can be facilitated. The horizontal portion is basically formed integrally with the X-shaped intersecting portion 5, but besides that, the horizontal portion is divided into a horizontal connecting portion 4a and a horizontal reinforcing portion 4f. The horizontal connecting portion 4a and the horizontal reinforcing portion 4f may be connected and fixed in advance in a factory or the like, and both members are connected on the site by a connecting means such as a mechanical joint, and then the beam You may make it arrange | position the X-shaped reinforcement bar | burr 4 in a use formwork.

With respect to the reinforcing structure 1 between the continuous apertures of the beam according to the present invention, as shown in FIGS. 9A and 9B, an X-shaped reinforcing bar 4 was formed, and the reinforcing effect was confirmed by experiments. In this experiment, the size of the beam is 300 (beam width) × 450 (beam beam) mm, the shear span ratio = 2.0 (= (beam span 1800 mm / 2) / 450 mm), the hole diameter of the opening 3 is 150 mm, and 2 Location, spacing s between apertures is 300 mm, concrete strength (σB) = 21 N / mm ² , aperture reinforcement is diamond-shaped reinforcing bars (for 150φ, 2-D10, 2 locations, Dialen: registered trademark), when opening The stirrup (2-D10), the X-shaped reinforcing bar 4, and the fracture type were shear fractures.

  FIG. 10 showing the load-deformation characteristic curve (NO.1) with the X-shaped reinforcing bar 4 and FIG. 11 showing the load-deformation characteristic curve (NO.2) without the X-type reinforcement, respectively. Shows cracks in the concrete surface at the stage. For example, the crack at the time of deformation of 1/100 is hardly cracked by the reinforcement of the X-shaped reinforcing bar 4 in FIG. However, in FIG. 11 without reinforcing bars, a clear crack occurs in the direction of about 45 ° from the opening 3.

  In the figure, Hirosawa min (without X) is the case where the effect of the X-type reinforcing bar 4 is ignored, and Hirosawa min (X average) is the load when the effect of the X-type reinforcing bar 4 is halved. The value is shown.

As described above, when there are a plurality of apertures 3 in the beam 2, the spacing s between the apertures 3 and 3 can be set to, for example, twice the diameter of the aperture 3 by using the X-shaped reinforcing bar 4. It can be relaxed to about 2.5 times.

  Therefore, conventionally, the interval s between the centers of the apertures 3 and 3 had to be three times or more the aperture diameter, but this can be relaxed and designed. Moreover, it is possible to construct a concrete structure having a reinforcing structure between continuous openings of such beams.

  The reinforcing structure 1 between continuous openings of a beam according to the present invention can widely use an X-shaped reinforcing bar when a plurality of openings for piping are provided in the beam. Also, it can be applied to RC and SRC concrete structures.

1 Reinforcement structure between continuous openings in the beam,
2 beams,
3 apertures, 3a, 3b apertures with different diameters,
4 Reinforcing bars, 4a Horizontal joint,
4b X-shaped bevel, 4c flat part,
4d center point, 4e through hole,
4f horizontal reinforcement,
5 intersections,
6 flat part,
7 volts,
8 pillars,
10 Reinforcing structure between continuous openings in conventional beams.

Claims (8)

When a plurality of apertures are provided at appropriate intervals in the longitudinal direction of the beam and penetrated in the lateral direction of the beam,
The spacing s between the centers of adjacent apertures is
If the diameters φ of the openings are the same, 2φ ≦ s <3φ,
Or
If the diameters of the openings are different diameters φ1, φ2,
φ1 + φ2 ≦ s <1.5 × (φ1 + φ2)
An X-shaped reinforcing bar having an X-shaped reinforcing bar is disposed between the openings,
Reinforcement structure between continuous openings of beams characterized by. At the intersection where the reinforcing bars intersect in the X shape,
A flat part that suppresses the beam width increase in the transverse direction of the beam is formed,
The reinforcing structure between continuous openings of the beam according to claim 1. The flat part is a metal flat plate that is separate from the bar-shaped reinforcing bar,
The reinforcing structure between continuous apertures of the beam according to claim 2. The flat portion is configured by laminating flat portions formed by pressing part of the reinforcing bars,
The reinforcing structure between continuous apertures of the beam according to claim 2. The flat portion is provided with a through hole through which the flat portion is overlapped and communicated with the rotation shaft so that the opening angle can be varied within a desired range at the intersection portion,
The reinforcing structure between continuous openings of the beam according to claim 4. The flat portion is formed on one side without crossing the center line with respect to the center line passing through the center point of the cross section in the cross-sectional shape of the reinforcing bar,
The reinforcing structure between continuous apertures of a beam according to claim 4 or 5. The X-shaped reinforcing bar is integrally formed with an X-shaped crossing portion and a horizontal connecting portion formed with the end of the crossing portion being horizontal,
An X-shaped reinforcing bar is formed by connecting a horizontal reinforcing portion to the horizontal connecting portion by connecting means,
The reinforcing structure between continuous openings of a beam according to any one of claims 2 to 6. The concrete structure according to any one of claims 1 to 7, having a reinforcing structure between continuous openings of the beam,
A concrete structure characterized by