JP4801449B2 - Reinforcing methods and structures for concrete structures. - Google Patents

Description

The present invention relates to a method for reinforcing a concrete structure such as a beam supported by a column, and a reinforcing structure.

A method of increasing the thickness by winding concrete or a method of increasing the strength by winding a steel plate has been developed as a reinforcement method when a concrete structure that supports a beam with a column deteriorates, such as a railway overpass. Yes.

The conventional method for reinforcing a concrete structure as described above has the following problems.
<1> In the method in which concrete is wound around an existing structure to increase the thickness, a bottom formwork for placing new concrete must be disposed under the beam. For this purpose, a formwork supporter must be installed on the underside of the beam. (The temporary material that supports the load from the bottom is called a support.) If you try to construct this bottom formwork without using a support, you will need to work many anchors on the lower surface of the beam in an upward position. .
<2> In particular, when concrete is placed, a strong support work is required. Moreover, when constructing without supporting work, it is necessary to drive a large number of anchors into the lower surface of the beam in an upward posture.
<3> Further, the shear reinforcement bars arranged on the side surfaces of the beam require laborious work of bending the shear reinforcement bars in an L shape on the lower surface of the beam and welding the bent end on the lower surface of the beam.
<4> The method of winding the periphery of a concrete beam with a steel plate is expensive in construction costs and maintenance costs.
<5> In order to attach the steel plate to the beam, the position of the bolt hole installed in the beam and the position of the bolt hole opened in the steel plate must be exactly matched, and high accuracy is required.
<6> It is necessary to attach the divided steel plates with bolts, and then weld and integrate them, and painting after welding and maintenance thereof are required.
<7> Furthermore, the method of winding a steel plate around concrete is a structure which expects a shear reinforcement effect on the steel plate on the side surface fixed by the anchor. Therefore, a large number of anchors that can sufficiently withstand such demands are required.

The present invention, which has solved the above-described conventional problems, is a method for reinforcing a concrete structure supported on both sides by a support such as a column with a beam main bar anchor and a shear reinforcement bar, and the position to be reinforced. Brackets are attached to the support members on both sides of the beam, and the other end of the beam main bar anchor with one end attached to the support member such as a column is projected hollow toward the opposite support member, between the brackets on both sides, and An arch-shaped arch plate is placed under the beam main bar anchor, and one end of the shear reinforcement bar is inserted into this arch plate into the notch of the reinforcing steel plate attached to the upper surface of the arch plate. fixedly attached to the mold steel by thread portion and the nut, the other end of the shear reinforcement is attached to the concrete reinforcing target, and arch plate, the interior of the side mold disposed on the outer side of the shear reinforcement Method for reinforcing a concrete structure performed by Da設 concrete under a state including a beam main reinforcement anchor is characterized in.
It is characterized by.

Further, the present invention is a method of reinforcing a concrete structure supported on both sides by a support such as a column with a beam main bar anchor and a shear reinforcing bar, the main bar is arranged in the vertical direction outside the support, In a state where this main bar is avoided, a bracket is attached to the support body, and the other end of the beam main bar anchor with one end attached to the support body such as a column is projected into the hollow toward the opposite support body. And, an arch-shaped arch plate is arranged at the lower part of the beam main bar anchor, and one end of a shear reinforcement bar is inserted into this arch plate in a notch of a reinforcing steel plate attached to the upper surface of the arch plate, fixedly attached to the mold steel by shear reinforcement screw and nut, the other end of the shear reinforcement is attached to the concrete reinforcing subject sided arranged and arch plate, on the outside of the shear reinforcement Inside the performed by Da設 concrete under a state including beam main reinforcement anchor, it is characterized in the reinforcing method of the concrete structure.

Further, the present invention is a reinforcing structure in which a concrete structure supported on both sides by a support such as a column is reinforced by a beam main bar anchor and a shear reinforcement, and is attached to the support on both sides of the position to be reinforced. One end is attached to the bracket and the support body such as a column, and the other end is hollowed out toward the opposite support body, and between the brackets on both sides and at the bottom of the beam main bar anchor The arch plate placed on the arch plate, the steel mold for reinforcement attached to the upper surface of the arch plate, one end is inserted into the notch of the steel mold, and the other end is fixed to the concrete to be reinforced with a screw and a nut. Reinforcement structure of a concrete structure composed of installed shear reinforcement and concrete placed on top of the arch board in a state surrounding the arch board and the shear reinforcement It is an feature.

Since the concrete structure reinforcing method and reinforcing structure of the present invention are as described above, the following effects can be obtained.
<1> Since it is the structure which attaches a bracket to the support body of the both sides of the position which should be reinforced, and arrange | positions an arch board in this arch shape between this bracket, the operation | work which assembles a support work under a beam is unnecessary.
<2> Similarly, the operation of driving a large number of anchors for supporting the bottom formwork on the lower surface of the beam is unnecessary and economical.
<3> Since the beam main bar anchor with one end attached to the support is arranged inside the reinforced concrete, the reinforced concrete is surely integrated with the concrete to be reinforced to improve the strength of the structure to be reinforced. be able to.
<4> The tensile force acting on the structure after reinforcement acts on the arch plate in the middle of the reinforcement part and is transmitted to the structure to be reinforced via the beam main bar anchor at the end of the reinforcement part. A part and the structure before reinforcement can be integrated completely, and a yield strength can be improved.
<5> If the structure which attaches the end of a shear reinforcement to a part of arch board with a volt | bolt is employ | adopted, welding will become unnecessary and workability will improve.
<6> Since the shear reinforcement has a structure that supports the arch plate, the arch plate can be reliably supported.

  Embodiments of the reinforcing method for concrete structures of the present invention will be described below with reference to the drawings.

<1> Overall configuration.
The method for reinforcing a concrete structure according to the present invention is a reinforcing method in which a reinforced concrete is thickly wound around the lower surface of a concrete structure that is supported on both sides by a support such as a support column 1. And place shear reinforcement.
The object to be reinforced is not limited to the concrete beam 2 but can be the lower surface of a concrete slab.
The supports on both sides are not limited to the support columns 1 and can be beams, slabs or the like supported by wall surfaces or the like.

<2> Attaching the bracket 3.
For example, the brackets 3 are attached to the surfaces of the pillars 1 on both sides supporting the beam 2.
For example, an angle member having an L-shaped cross section can be used for the bracket 3.
The bracket 3 is fixed to the surface of a support such as the support 1 via bolts.
An end portion of an arch plate 4 to be described later is mounted on the bracket 3, but the concrete tensile force acting on the arch plate 4 after the concrete is placed, that is, after reinforcement, is applied to the structure by a beam main bar anchor 6 to be described later. It is the structure which transmits, and is not the structure which transmits via the bracket 3. FIG.
Therefore, the bracket 3 may have a simple structure, and the bracket 3 and the column 1 need not be attached with a strong structure such as an anchor, and need only be fixed with a simple bolt.

<3> Attachment of beam main bar anchor 6.
A hole is drilled in the horizontal direction above the bracket mounting position of a support such as a support.
Then, one end of the beam main bar anchor 6 is inserted into this drilling hole, and mortar or adhesive is injected into the drilling hole and fixed.
The beam main bar anchor 6 is composed of a reinforcing bar, a steel bar or the like.
The other end of the beam main bar anchor 6 projects in a hollow toward the opposite support body.
As a result, the beam main bar anchor 6 is located in the upper space of the arch plate described later.
This beam main reinforcement anchor 6 performs the effect | action which transmits the tensile force which acts on the reinforced concrete to original structure main bodies, such as a support | pillar.

<4> Arrangement of the arch plate 4.
An arch plate 4 formed by bending upward in an arch shape is disposed between the brackets 3 on both sides and under the beam main bar anchor 6.
As this arch plate 4, for example, a galvanized steel plate is bent upward and curved.
On both edges of the upper surface of the arch plate 4 made of this steel plate, a steel plate 41 such as H steel is attached and reinforced along the longitudinal direction.
Of course, this steel plate 41 is also bent and formed into a curved surface with the same curvature as the arch plate.
The reinforcing steel plate 41 attached to both edges of the arch plate 4 is formed with notches 41a at a number of locations from the outside.
Since the cutout 41a is open on the outside, a shear reinforcing bar 5 described later can be inserted from the outside.
Both ends of the arch plate 4 are mounted on the bracket 3 and the end portions thereof are simply welded or fixed with bolts.
On the arch plate 4, a shift stopper 42 such as L-shaped steel can be attached in the transverse direction of the beam.
The slip stopper 42 ensures adhesion between the arch plate 4 and the concrete placed thereon.
Further, the deflection in the beam transverse direction can be suppressed by the presence of the misalignment stopper 42 when the concrete is placed.

<5> Attaching the shear reinforcement 5.
The shear reinforcing bar 5 is a reinforcing bar arranged at a portion to be reinforced.
The shear reinforcing bar 5 is formed in an L shape by a horizontal part 51 that is inserted horizontally during mounting and a vertical part 52 that is vertically arranged.
In order to attach the shear reinforcement 5 to the beam 2, an anchor hole is drilled in the beam 2 from the horizontal direction, and the upper horizontal portion of the shear reinforcement 5 is inserted into the anchor hole from the side surface and fixed with an adhesive. .
On the other hand, a thread for stopping the nut 53 is formed at the lower end of the vertical portion 52 of the shear reinforcing bar 5.
In this case, if an off-the-shelf product that does not require threading and has a spiral groove is used, it is economical because no cross-sectional defects are caused by threading and the threading operation is unnecessary.
Then, the lower end of the shear reinforcement 5 is inserted into the notch 41a of the reinforcing steel plate 41 of the arch plate 4 from the outside.
As described above, since the cutout 41a is open on the outside, the shear reinforcing bar 5 can be inserted from the outside.
Then, by tightening the nut 53 to the thread of the shear reinforcement bar 5, the shear reinforcement bar 5 and the mold steel 41 can be integrated by tightening the flange of the steel mold 41 from both the upper and lower sides.
If the arch plate 4 is attached to the beam 2 with the combination of the bolt and the nut 53 as described above, a rapid work can be performed without requiring a welding work by a skilled worker.
If a large number of shear reinforcement bars 5 having such a configuration are arranged, the arch plate 4 can be suspended from the beam 2 to be reinforced by the shear reinforcement bars 5 at a large number of locations.
The shear reinforcing bar 5 is not limited to the L-shaped orthogonal shape as shown in FIG. 3, but as shown in FIG. 4, the anchor hole 21 is drilled upward or vertically or at an angle close thereto. It is also possible to use the shear reinforcing bar 5 in a shape corresponding to it.
In that case, the shear reinforcement 5 is constituted by the vertical portion 52 and the non-horizontal portion 54.

<6> Placing concrete.
Side molds 7 are attached to both sides of the arch plate 4 attached to the beam 2 with the above-described configuration.
The side mold 7 is arranged outside the shear reinforcement 5.
Then, reinforcing concrete is placed inside the arch plate 4 and the side form frame 7 arranged outside the shear reinforcing bar 5 so as to surround the beam main bar anchor 6.
When placing concrete, both ends of the arch plate 4 are supported by the bracket 3 as described above, and the middle is also supported by a large number of shear reinforcement bars 5, so that the bottom formwork can be securely supported. It is possible to safely place concrete.
In this way, the concrete structure can be reinforced by increasing the thickness of the lower part and the side part of the beam 2 with the reinforced concrete. However, the arch plate 4 is an embedded formwork and is not only a support work but also a bending reinforcement. It also functions as a, and contributes to the improvement of strength.
The shear reinforcement 5 functions as a support member that supports the arch plate 4 and at the same time functions as a shear reinforcement, contributing to an improvement in the strength of the concrete member.
Further, at the end of the reinforcing portion, the beam main bar anchor 6 performs an action of transmitting a tensile force acting on the concrete to a structure such as a support.

Explanatory drawing of the Example of the reinforcement method of the concrete structure of this invention. Explanatory drawing from the side of the state which attached the arch board and the beam main bar anchor to the support | pillar. Explanatory drawing from the cross section of the state which attaches an arch board, a shear reinforcement, and a shape steel to a support | pillar. Explanatory drawing of the other shape of a shear reinforcement.

Explanation of symbols

1: Prop
2: Beam
3: Bracket
4: Arch board
41: Shape steel
41a: Notch
5: Shear reinforcement
6: Beam main bar anchor

Claims (4)

A method of reinforcing a concrete structure supported on both sides by a support such as a column with a beam main bar anchor and a shear reinforcing bar,
Attach the bracket to the support on both sides of the position to be reinforced,
The other end of the beam main bar anchor with one end attached to a support such as a column is projected into the hollow toward the opposite support,
An arched arch plate is disposed between the brackets on both sides and at the lower part of the beam main bar anchor,
Insert one end of the shear reinforcement bar into this arch plate into the notch of the reinforcing steel plate attached to the upper surface of the arch plate, and fix it to the steel plate with the screw and nut of the shear reinforcement bar ,
Attach the other end of the shear reinforcement to the concrete to be reinforced,
Concrete is placed inside the arch plate and the side formwork placed outside the shear reinforcement bar, including the beam main bar anchor.
A method of reinforcing concrete structures. A method of reinforcing a concrete structure supported on both sides by a support such as a column with a beam main bar anchor and a shear reinforcing bar,
Place the main bars in the vertical direction outside the support,
In a state that avoids this main bar, attach the bracket to the support,
The other end of the beam main bar anchor with one end attached to a support such as a column is projected into the hollow toward the opposite support,
An arched arch plate is disposed between the brackets on both sides and at the lower part of the beam main bar anchor,
Insert one end of the shear reinforcement bar into this arch plate into the notch of the reinforcing steel plate attached to the upper surface of the arch plate, and fix it to the steel plate with the screw and nut of the shear reinforcement bar ,
Attach the other end of the shear reinforcement to the concrete to be reinforced,
Concrete is placed inside the arch plate and the side formwork placed outside the shear reinforcement bar, including the beam main bar anchor.
A method of reinforcing concrete structures. The upper surface of the arch plate is constructed by attaching a reinforcing steel plate.
The method for reinforcing a concrete structure according to claim 1 or 2. A reinforcing structure in which a concrete structure supported on both sides by a support such as a column is reinforced by a beam main bar anchor and a shear reinforcing bar,
Brackets attached to supports on both sides of the position to be reinforced,
A beam main bar anchor that has one end attached to a support such as a post and the other end projecting hollow toward the opposite support,
An arch plate disposed between the brackets on both sides and arranged in an arch shape below the beam main bar anchor;
A reinforcing steel plate attached to the upper surface of this arch plate,
Insert one end into the notch of this steel, and fix it to the steel with the screw and nut.
A shear reinforcement with the other end attached to the concrete to be reinforced,
Constructed by concrete placed on top of the arch plate in a state surrounding the arch plate and the shear reinforcement,
Reinforcement structure for concrete structures.

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