JP2014047530A - Reinforcement structure of concrete column - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reinforcement structure for a concrete column, of which reinforcement work has a little influence on floors other than a reinforcing object floor.SOLUTION: A reinforcement structure for a concrete column is constituted so that reinforcing bars 7 extending in the axial direction are arranged along the periphery of an existing concrete column 1 and the reinforcing bars are included in a grout material surrounding a surface of the concrete column. In the reinforcement structure: a top end 8 of each of the reinforcing bars 7 is fixed by a grout material 6 in a reinforcement part of a beam 3; a bottom end 9 thereof is placed on a top face of a slab 2 corresponding to a bottom end of the concrete column 1; near the bottom end 9 of the reinforcing bars 7, a plurality of axial direction anchor members 12 each having one end protruding from the top end of the slab or a plurality of lateral direction anchor members 13 protruding outward from a side face of the concrete column 1 are provided; and thus, the anchor members 12, 13 prevent the bottom ends of the reinforcing bars 7 from deviating.

Description

  The present invention relates to a reinforcing structure for reinforcing a concrete column of an existing building afterwards.

Conventionally, a reinforcing structure for reinforcing a concrete column is known.
In this reinforcing structure, the outer side of an existing concrete column is surrounded by a grout material to make it a thick column, and reinforcing bars extending in the axial direction are arranged in the grout material.
And the upper and lower ends of the reinforcing bars were inserted into the reinforcing part of the beam and the existing base part, respectively, and fixed inside thereof (Patent Document 1).

FIG. 5 of JP2008-240368A

In the above-described conventional reinforcing structure, the lower end of the reinforcing bar is inserted and fixed to the base portion, and thus the base portion has to be tampered with.
In other words, when reinforcing a concrete column, not only a floor having a column to be reinforced but also a construction under the floor is necessary.
The work under the floor often has a poor working environment, and there is a problem that workability is poor and it takes a work period and costs.
For example, in the case of a multi-story building, the construction of the foundation part of the reinforcement target floor must be performed from the lower floor as well as the target floor. For this reason, not only is the work complicated, but reinforcement work may not be possible depending on the situation of the lower floor.

Conversely, underfloor construction is possible, but it may be difficult to construct around the ceiling beam. For example, if the beam is not exposed in the room, it will be necessary to work on the back of the ceiling in order to provide a reinforcing part for the beam to fix the reinforcing bars. There is an impact on the floor. For this reason, depending on the situation on the upper floor, reinforcement work may not be possible.
An object of the present invention is to provide a concrete column reinforcing structure in which influences other than the target floor of reinforcement are reduced.

The first invention is a reinforcing structure of a concrete column in which reinforcing bars extending in the axial direction are arranged along the periphery of an existing concrete column, and the reinforcing bars are included in a grout material surrounding the surface of the concrete column. The upper end of the reinforcing bar is fixed in the grout material of the beam reinforcing portion provided on the outer periphery of the beam orthogonal to the concrete column, and the lower end of the reinforcing bar is connected to the lower end of the concrete column. A plurality of axial anchor members extending along the axial direction of the reinforcing bar, or one end thereof, with one end projecting upward from the upper surface of the slab in the vicinity of the lower end of the reinforcing bar. One or both of a plurality of transverse anchor members having a portion projecting outward from the side surface of the concrete column are provided, and the axial anchor member and the transverse anchor member The output portion, characterized in that is positioned in the grout with the reinforcement.
The upper end of the reinforcing bar is fixed in the grout material of the beam reinforcing portion provided on the outer periphery of the beam orthogonal to the concrete column. The upper end of the reinforcing bar is firmly fixed in the grout material. That's what it means. The fixing method is not particularly limited. For example, the upper end of the reinforcing bar is fixed to the beam surface using a dedicated metal fitting and then surrounded by a grout material.

The second invention is a reinforcing structure for a concrete column in which reinforcing bars extending in the axial direction are arranged along the periphery of an existing concrete column, and the reinforcing bars are enclosed in a grout material surrounding the surface of the concrete column. The lower end of the reinforcing bar is fixed under the floor, the upper end of the reinforcing bar is positioned under the beam corresponding to the upper end of the concrete column, and one end of the reinforcing bar is positioned near the upper end of the reinforcing bar. A plurality of lateral anchor members projecting from the side of the concrete column to the outside of the column are provided, and the projecting portions of the lateral anchor members are positioned in the grout material.
The underfloor is below the slab on the floor side of the floor to be reinforced, and any method for fixing the lower end of the reinforcing bar under the floor may be used.

  A third invention is characterized in that a reinforcing steel plate is provided surrounding the concrete column at a distance from the surface of the concrete column, and the grout material is filled between the reinforcing steel plate and the concrete column.

  The fourth invention is characterized in that a recess is formed around the concrete column on the upper surface of the slab, and the reinforcing steel plate is erected in the recess.

  The fifth invention is characterized in that a belt-like fiber sheet is bonded to the outer periphery of the reinforcing steel plate.

According to the first invention, since the lower end of the reinforcing bar is simply placed on the upper surface of the slab, work under the floor such as recreating the foundation is not necessary. Therefore, it is sufficient to work only on the floor that needs reinforcement, and it does not affect other floors. Therefore, workability is improved and the construction period can be shortened.
In addition, a plurality of axial anchor members extending in the axial direction of the reinforcing bars and a lateral anchor member protruding from the side surface of the concrete column are provided near the lower end of the reinforcing bars. The fixing force with the material is increased, and the displacement of the reinforcing bars on the upper surface of the slab can be prevented.
Further, both the axial anchor member and the lateral anchor member function as reinforcing bars, and improve the shear strength of the reinforcing structure.
That is, the above reinforcing bars can obtain a necessary reinforcing effect only by placing the lower end thereof on the upper surface of the slab.

According to the second invention, since the upper end of the reinforcing bar is stopped under the beam, the upper floor is not affected by the reinforcement work.
Further, a lateral anchor member protruding from the side surface of the concrete column is provided in the vicinity of the upper end of the reinforcing bar, and the fixing force of the grout material is increased, so that the upper end of the reinforcing bar can be prevented from shifting.
Further, the transverse anchor member also functions as a transverse reinforcing bar and improves the shear strength of the reinforcing structure.
In other words, the reinforcing bar has its upper end positioned under the beam, and a necessary reinforcing effect can be obtained without being particularly fixed.

According to the third invention, the reinforcing steel plate can be integrated with the grout material to further increase the reinforcing strength.
In addition, since the reinforcing steel plate also serves as a grout material mold, there is no need to disassemble or clean up the mold after the grout material is cured. As a result, the work time can be shortened.

  In 4th invention, the space | interval of a reinforcement steel plate and a concrete pillar can be kept constant by providing a reinforcement steel plate in contact with the inner wall of the recessed part formed in the slab surface, and the lower end of the standing reinforcement steel plate is a recessed part. Can be prevented from moving outward. In particular, during the filling and solidification of the grout material, it is possible to prevent the reinforcing steel plate from moving outward due to the pressure of the grout material, so there is a gap between the grout material and the concrete column or between the reinforcing steel plate and the grout material. It is possible to achieve sufficient reinforcing strength without being formed or forming a nest in the solidified grout material.

According to 5th invention, the connection of a reinforcement steel plate can be made easy and reliable with the strip | belt-shaped fiber sheet adhere | attached around the reinforcement steel plate.
Moreover, since a strip | belt-shaped fiber sheet unites with a reinforcement steel plate and hold | maintains a grout material and a reinforcement reinforcement, the reinforcement strength of a concrete pillar can be improved more.

FIG. 1 is a front view of a first embodiment of the present invention. FIG. 2 is a front view of the first embodiment with the front-side reinforcing steel plate and grout material omitted. FIG. 3 is a cross-sectional view of the column portion of the first embodiment. FIG. 4 is a cross-sectional view of the beam reinforcing portion of the first embodiment. FIG. 5 is a cross-sectional view of the column portion of the second embodiment. FIG. 6 is a front view of the third embodiment. FIG. 7 is a front view of the third embodiment with the front-side reinforcing steel plate and grout material omitted. FIG. 8 is a cross-sectional view of the column portion of the third embodiment.

The first embodiment of the present invention shown in FIG. 1 to FIG. 4 is a reinforcing structure that reinforces an existing concrete pillar 1 afterwards, and the portion to be reinforced is from the slab 2 to the beam 3 on the floor side in FIG. is there.
As shown in FIG. 1, reinforcing steel plates 4 are provided around the concrete pillars 1 at intervals, and reinforcing steel plates 5 are provided at intervals also at the beam 3 portions, inside the reinforcing steel plates 4, 5. The grout material 6 is filled (see FIGS. 3 and 4).

In the first embodiment, the reinforcing steel plate 4 surrounding the concrete pillar 1 is composed of four surrounding members 4a, 4b, 4c and 4d having an L-shaped cross section as shown in FIG. Yes. However, the reinforcing steel plate 4 is not limited to one constituted by four members. Any shape can be used as long as it can surround the concrete column 1.
Further, in FIG. 4, reference numeral 14 denotes a bolt, and the reinforcing steel plate 5 for beam reinforcement is fixed to the beam 3 by the bolt 14. The portion shown in FIG. 4 is a beam reinforcing portion of the present invention.

Further, a reinforcing bar 7 is disposed in the grout material 6 as a reinforcing bar of the present invention.
As shown in FIG. 2, the reinforcing bar 7 has plate nuts 8 and 9 attached to the upper and lower ends. Then, the upper end of the reinforcing bar 7 is brought into contact with the lower surface of the slab 10 on the beam 3 through the plate nut 8, and the lower end of the reinforcing bar 7 is placed on the upper surface of the floor-side slab 2 through the plate nut 9. Yes.
Further, a dedicated fastener (not shown) is attached near the upper end of the reinforcing bar 7 and the fastener is fixed to the beam 3. Therefore, the upper end of the reinforcing bar 7 is fixed at the beam reinforcement portion.
FIG. 2 is a view in which the front side portion and 5 of the reinforcing steel plate 4 are removed from FIG. 1 and the grout material 6 is omitted.

Moreover, as shown in FIG. 2, the recessed part 11 surrounding the said concrete pillar 1 is formed in the upper surface of the slab 2, The said reinforcing steel plate 4 is stood up in this recessed part 11, and the outer peripheral surface of the said reinforcing steel plate 4 is made. The inner wall of the recess 11 is brought into contact.
Thus, if the reinforcing steel plate 4 is provided in contact with the inner wall of the recess 11, the reinforcing steel plate 4 can be positioned, and the reinforcing steel plate 4 can be prevented from shifting outward. In particular, if the reinforcing steel plate is displaced when the grout material 6 is filled, a gap may be formed between the hardened grout material 6 and the concrete pillar 1 or the reinforcing steel plate, or a nest may be formed in the grout material 6. However, the recess 11 can easily prevent the reinforcing steel plate 4 from being displaced.

  Further, a plate nut 9 which is the lower end of the reinforcing bar 7 is placed on the bottom surface of the recess 11 and a plurality of anchor bolts 12 are driven. These anchor bolts 12 protrude from the upper surface of the slab 2 along the axial direction of the rebar 7 and constitute the axial anchor member of the present invention.

  These anchor bolts 12 increase the adhesiveness between the grout material 6 filled inside the reinforcing steel plate 4 and the slab 2 and maintain the adhesive force between the concrete column 1 and the slab 2. Then, by strengthening the fixing force between the slab 2 and the grout material 6, the reinforcing bars 7 in the grout material 6 are difficult to move in the recess 11.

In addition, a plurality of anchor bolts 13 are driven into the side surface of the concrete pillar 1 at a predetermined interval. These anchor bolts 13 are lateral anchor members of the present invention protruding in a direction perpendicular to the axis of the column, and exhibit a function of improving the adhesion between the grout material 6 and the side surface of the concrete column 1.
Although omitted in FIG. 2, the anchor bolt 13 is driven not only below the concrete pillar 1 but over the entire axial direction.
In particular, the anchor bolt 13 provided in the vicinity of the lower end of the reinforcing bar 7 enhances the fixing force of the grout material 6 corresponding to the lower end portion of the reinforcing bar 7 and makes it difficult to displace the reinforcing bar 7 just placed on the slab 2. .

Further, by providing the anchor bolt 13 on the side surface of the concrete column 1, it is not necessary to perform a roughening treatment on the surface of the concrete column 1.
The roughening treatment is to roughen the concrete surface of the concrete pillar 1 and improve the adhesion to the grout material 6, but it is difficult to perform this treatment uniformly and the work cost is increased. Alternatively, the sticking property with the grout material 6 may vary. However, if the anchor bolt 13 is used, uniform and high adhesiveness can be realized over the entire side surface of the concrete column 1.
Thus, if the adhesiveness of the existing concrete pillar 1 and grout material improves, the reinforcement effect by a reinforcement will also be exhibited and sufficient reinforcement strength can be maintained.
Further, the anchor bolt 13 also functions as a horizontal reinforcing bar, which contributes to an improvement in shear strength.

When the lower end of the reinforcing steel bar 7 is stopped on the upper surface of the slab 2 as in the first embodiment, a shear stress is applied to the lower end portion of the concrete column 2. The fixing force between the slab 2 and the grout material 6 is increased, and the anchoring force between the grout material 6 and the concrete column 1 is increased by the anchor bolts 13, so that the rebar 7 is prevented from being displaced and the shear strength can be improved.
In addition, if the number and diameter of the reinforcing bars 7, anchor bolts 12 and anchor bolts 13 are increased, the reinforcing strength is increased accordingly, but the installation space is required accordingly. Therefore, it is necessary to set the number, thickness, and arrangement according to the required shear strength.

As described above, since the reinforcement structure of the first embodiment is sufficient from the floor side slab 2 to the lower surface of the upper floor slab, the reinforcement work is completed only on the floor corresponding to the concrete column 1 to be reinforced. It is possible to do. Therefore, the necessary reinforcement work can be implemented regardless of the situation of the lower floor.
In addition, since work under the floor is unnecessary, it is possible to improve the work environment, workability, and shorten the construction period.

FIG. 5 is a cross-sectional view of the second embodiment, and shows a reinforcing structure in which a belt-like fiber sheet 15 indicated by a thick line is bonded to the outer periphery of the reinforcing steel plate 4. The belt-like fiber sheet 15 is made of a fiber having sufficient strength, such as an aramid fiber, and is impregnated with a resin adhesive and bonded to the reinforcing steel plate 4.
Other configurations are the same as those in the first embodiment. Accordingly, the same reference numerals are used for the same components as in the first embodiment, and FIGS. 1 to 4 of the first embodiment are also referred to in the following description.
In the second embodiment, the four enclosing members 4a, 4b, 4c, and 4d of the reinforcing steel plate 4 are connected by bonding the belt-like fiber sheet 15 to the outer periphery of the reinforcing steel plate 4 while being wound around the outer periphery.

Moreover, in this 2nd Embodiment, the strip | belt-shaped fiber sheet 15 is adhere | attached on the outer periphery across the reinforcement steel plate 5 and the said reinforcement steel plate 4 of the beam reinforcement part shown in FIG. You can also.
In this way, by adhering the belt-like sheet 15, the surrounding members 4 a, 4 b, 4 c, 4 d and the reinforcing steel plates 4 and 5 are connected, and the continuous parts thereof are opened by the pressure of the grout material 6. Can be prevented.

In the first and second embodiments, the anchor bolt 12 in the axial direction and the anchor bolt 13 in the lateral direction are used as the anchor member of the present invention in order to prevent the lower end portion of the reinforcing bar 7 from being displaced. Only one of them may be used.
When only the anchor bolts 13 in the horizontal direction are used, the side surface of the concrete pillar 1 is subjected to a roughing treatment or the like, and if the adhesion between the grout material 6 and the surface of the concrete pillar 1 is high, the anchor bolt 13 is It may be provided only in the vicinity of the lower end of the reinforcing bar 7 and other portions may be omitted.
In addition, in the said 1st, 2nd embodiment, although the reinforcement construction in one floor is demonstrated to the example, when the reinforcement object location of the concrete pillar 1 extends over several floors continuously, the said reinforcing bar 7 is A slab on the floor side of the intermediate floor may be provided so as to pass through, and the lower end thereof may be placed on the upper surface of the slab on the lowest floor.

The third embodiment shown in FIGS. 6 to 8 is a reinforcing structure that reinforces the existing concrete pillar 1 afterwards, and reinforcement under the floor is possible, but in order to reduce the influence on the upper floor, the reinforcing bar 7 is used. This is a reinforcing structure in which the upper end of the frame is stopped under the beam 3. And the reinforcement object part of this 3rd Embodiment is from the slab 2 by the side of the floor surface of FIG.
On the other hand, as shown in FIG. 7, the lower end side of the reinforcing bar 7 penetrates through the floor slab 2 and is fixed around a foundation (not shown) or a lower floor beam.
Note that in the third embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed descriptions of the individual components are omitted.

Also in the third embodiment, as shown in FIG. 8, reinforcing steel plates 4 are provided around the concrete pillars 1 at intervals, and the grout material 6 is filled inside the reinforcing steel plates 4.
As described above, the reinforcing steel plate 4 is provided around the concrete pillar 1, but unlike the first embodiment shown in FIG. 1, the reinforcing steel plate 5 is not provided in the beam 3 portion.
Further, a reinforcing bar 7 as a reinforcing bar of the present invention is arranged in the grout material 6.
As shown in FIG. 7, the reinforcing bar 7 has a plate nut 8 attached to the upper end thereof so that the plate nut 8 is in contact with the lower surface of the beam 3. However, a gap may be maintained between the upper end of the reinforcing bar 7 and the beam 3.
7 is a view in which the front side portion of the reinforcing steel plate 4 is removed from FIG. 6 and the grout material 6 is omitted.

A plurality of anchor bolts 13 which are lateral anchor members of the present invention are provided on the side surface of the concrete pillar 1. The function of these anchor bolts 13 is to enhance the adhesion between the concrete pillar 1 and the grout material 6 and to increase the bonding force of the surrounding grout material 6 as in the first embodiment. The anchor bolt 13 is provided particularly near the upper end of the reinforcing bar 7 so that the upper end of the reinforcing bar 7 is not easily displaced.
Although not shown in FIG. 7, the anchor bolt 13 is driven not only below the concrete column 1 but also in the entire axial direction, thereby eliminating the need for roughening the side surface of the concrete column 1.

Further, as in the first embodiment, a concave portion 11 surrounding the concrete column 1 is formed on the upper surface of the slab 2, and the reinforcing steel plate 4 is erected in the concave portion 11, and the outer periphery of the reinforcing steel plate 4 is The surface is in contact with the inner wall of the recess 11.
In the reinforcing structure of the third embodiment, necessary reinforcement work can be performed regardless of the situation of the upper floor by stopping the upper end of the reinforcing bar 7 under the beam.
In addition, since work behind the ceiling is not required, the work environment, workability, and construction period can be shortened.

Further, the reinforcing fiber sheet 15 of the second embodiment shown in FIG. 5 is bonded to the outer periphery of the reinforcing steel sheet 4 of the third embodiment to connect the reinforcing steel sheet 4, and a continuous portion of the reinforcing steel sheet 4 is a grout material. It can prevent opening with the pressure of 6.
In the above description, the reinforcement work on one floor is described as an example. However, when the reinforcement target portions of the concrete pillar 1 continuously extend over a plurality of floors, the reinforcing bars 7 are located on the floor side of the intermediate floor. A slab may be provided so as to penetrate the slab and be positioned below the beam on the top floor.

  In the first to third embodiments, the reinforcing steel plate 4 corresponding to the concrete pillar 1 is a member integrated in the axial direction, but a steel plate divided in the axial direction may be used as the reinforcing steel plate 4. . Thus, also when using the steel plate divided | segmented into the axial direction, a steel plate can be connected to an axial direction by adhesion | attachment of the said strip | belt-shaped fiber sheet 15. FIG.

Moreover, in the said embodiment, although the shift | offset | difference of the reinforcement steel plate 4 is prevented by forming the recessed part 11 in the upper surface of the slab 2, if the shift | offset | difference to the outward of the reinforcement steel plate 4 can be prevented by another means, the said recessed part will be provided. 11 may not be formed.
Further, the reinforcing steel plates 4 and 5 may not be provided, and the reinforcing bars 7 and the anchor bolts 12 and 13 may be surrounded only by the grout material 6.
In that case, a reinforcing frame is formed by providing a mold frame at a distance from the concrete pillar 1, injecting the grout 6 inside, and removing the mold frame after the grout material 6 has solidified.

  This is a particularly useful reinforcement structure in environments where it is difficult to work under the floor of concrete columns to be reinforced.

DESCRIPTION OF SYMBOLS 1 Concrete pillar 2 Slab 3 Beam 4 Reinforced steel plate 5 Reinforced steel plate 6 Grout material 7 (Reinforcing bar) Reinforcing bar 11 Recess 12 Anchor bolt 13 Anchor bolt 15 Strip-like fiber sheet

Claims (5)

Place reinforcing bars that extend axially around the perimeter of existing concrete columns,
A reinforcing structure of a concrete column in which the reinforcing bars are encapsulated in a grout material surrounding the surface of the concrete column,
The upper end of the reinforcing bar is fixed in the grout material of the beam reinforcing portion provided on the outer periphery of the beam orthogonal to the concrete column,
The lower end of the reinforcing bar is placed on the upper surface of the slab corresponding to the lower end of the concrete column,
Near the lower end of the reinforcing bar,
One end portion protrudes upward from the upper surface of the slab, and a plurality of axial anchor members along the axial direction of the reinforcing bar, or a plurality of one end portions protrude outward from the side surface of the concrete column. One or both of the transverse anchor members of
A concrete column reinforcing structure in which protruding portions of the axial anchor member and the lateral anchor member are positioned in the grout material together with the reinforcing bars. Place reinforcing bars that extend axially around the perimeter of existing concrete columns,
A reinforcing structure of a concrete column in which the reinforcing bars are encapsulated in a grout material surrounding the surface of the concrete column,
While the lower end of the reinforcing bar is fixed under the floor,
The upper end of the reinforcing bar is located under the beam corresponding to the upper end of the concrete column,
In the vicinity of the upper end of the reinforcing bar, a plurality of lateral anchor members are provided with one end protruding from the side of the concrete column to the outside of the column,
A concrete column reinforcing structure in which a protruding portion of the transverse anchor member is positioned in the grout material.   The reinforcement of the concrete pillar of Claim 1 or 2 with which the reinforcement steel plate surrounding the said concrete pillar was provided keeping the space | interval from the surface of the said concrete pillar, and the said grout material was filled between this reinforcement steel plate and the concrete pillar. Construction. Forming a recess around the concrete column on the top surface of the slab;
The reinforcing structure for a concrete pillar according to claim 3, wherein the reinforcing steel plate is erected in the recess.   The reinforcing structure for a concrete column according to claim 3 or 4, wherein a belt-like fiber sheet is bonded to the outer periphery of the reinforcing steel plate.

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