JP2020105733A - Reinforcing method and reinforcing structure of cylindrical structure - Google Patents

Abstract

To provide a reinforcing method and a reinforcing structure for a cylindrical structure improved in workability.SOLUTION: In a method of reinforcing an existing cylindrical structure 10, a step of arranging a linear bending reinforcing member 18 in a cylindrical axial direction along an inner wall surface 16 of the cylindrical structure 10; a film-like reinforcing coating material 24 is provided over the upper surface of the bending reinforcing material 18 and the inner wall surface 16 of the cylindrical structure 10, and a step of integrating the bending reinforcing material 18 and the inner wall surface 16 of the cylindrical structure 10 through the reinforcing coating material 24 are provided.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a reinforcing method and a reinforcing structure for a masonry tubular structure such as an existing chimney or an exhaust tower.

Conventionally, a method of reinforcing an existing masonry structure or the like masonry structure has been known (see, for example, Patent Document 1). At the time of reinforcement, it may be necessary to reinforce a tubular elongated structure portion (hereinafter referred to as a tubular structure) such as a chimney or an exhaust tower. In particular, in the case of a tubular structure made of brick, it is necessary to prevent the brick joint from being broken and falling apart, and also to prevent bending failure of the entire tubular structure.

As a conventional method for reinforcing such a structure, there are a method of additionally striking a reinforced concrete wall, a method of installing a steel frame and joining with a post-construction anchor, a method of adhering a continuous fiber reinforcing material such as a carbon fiber sheet, and the like. Are known.

JP, 2011-021422, A

However, reinforcement with reinforced concrete or steel frame has a problem that the construction work is large. Further, if reinforcement is performed inside the tubular structure in order to preserve the appearance of the structure, there is a problem that it becomes difficult to work in a narrow space. The reinforcing method using a carbon fiber sheet or the like also has the problem that it requires time and effort to smooth the surface before bonding. There is also a reinforcing method in which a vertical hole is made in a brick wall and tightened through a PC steel rod or embedded through a reinforcing bar, but there is a problem that it is difficult to make a hole when the wall thickness of the tubular structure is thin. Such a problem similarly occurs not only in a tubular structure made of brick but also in a tubular structure made of reinforced concrete having a small amount of reinforcing steel.

The present invention has been made in view of the above, and an object of the present invention is to provide a reinforcing method and a reinforcing structure for a tubular structure with improved workability.

In order to solve the above-mentioned problems and achieve the object, a method for reinforcing a tubular structure according to the present invention is a method for reinforcing an existing tubular structure, and is provided along an inner wall surface of the tubular structure. And arranging a linear bending reinforcement in the axial direction of the cylinder, and providing a film-like reinforcing covering over the upper surface of the bending strengthening and the inner wall surface of the cylindrical structure, and bending reinforcing through the reinforcing covering. A step of integrating the material and the inner wall surface of the tubular structure.

Further, another tubular structure reinforcing method according to the present invention is the above-described invention, in which a reinforcing coating material mainly composed of resin is sprayed onto the inner wall surface of the tubular structure from above the bending reinforcing material to perform bending reinforcement. The bending reinforcing material and the inner wall surface of the tubular structure are integrated by forming a reinforcing coating layer having a predetermined toughness on the upper surface of the material and the inner wall surface of the tubular structure.

Further, another method for reinforcing a tubular structure according to the present invention is, in the above-mentioned invention, arranged on the inner wall surface of the tubular structure by stacking a plurality of bending reinforcements in a direction orthogonal to the tubular axis. On the other hand, it is characterized in that the bending reinforcing material is continuously arranged in the cylinder axis direction without breaks.

Further, the reinforcing structure for a tubular structure according to the present invention is a structure for reinforcing an existing tubular structure, and has a linear shape arranged along the inner wall surface of the tubular structure in the cylinder axis direction. It comprises a bending reinforcement and a film-like reinforcement covering provided over the upper surface of the bending reinforcement and the inner wall surface of the tubular structure. The reinforcement covering integrally combines the bending reinforcement and the inner wall surface of the tubular structure. It is characterized by becoming.

Further, another reinforcing structure for a tubular structure according to the present invention is the above-described invention, wherein the reinforcing covering material is made of a material mainly composed of resin, and is provided on the upper surface of the bending reinforcing material and the inner wall surface of the cylindrical structure. It is characterized by forming a reinforcing coating layer having a predetermined toughness.

Further, another reinforcing structure for a tubular structure according to the present invention is, in the above-mentioned invention, arranged so as to be stacked in a direction orthogonal to the tubular axis, and is continuous in the tubular axis direction with respect to the inner wall surface of the tubular structure. It is characterized in that it is provided with a plurality of bending reinforcements arranged seamlessly.

According to the method for reinforcing a tubular structure according to the present invention, it is a method for reinforcing an existing tubular structure, in which a linear bending reinforcement is provided along the inner wall surface of the tubular structure in the cylinder axial direction. And the step of arranging the same, a film-like reinforcing covering material is provided over the upper surface of the bending reinforcing material and the inner wall surface of the tubular structure, and the bending reinforcing material and the inner wall surface of the cylindrical structure are integrated through the reinforcing covering material. Since it is provided with a step to perform, it can be installed even in a narrow space inside the tubular structure, and since it can be installed with only a relatively lightweight material, it can greatly improve the installability compared to the conventional reinforcing method. It has the effect of being able to. Also, since it can be reinforced only by the work inside the tubular structure, it has no effect on the appearance and is effective for the preservation of cultural properties. Unlike the carbon fiber sheet reinforcement, there is no need to make the surface smooth, so that the construction can be greatly simplified.

Further, according to another method for reinforcing a tubular structure according to the present invention, a reinforcing coating material mainly composed of resin is sprayed onto the inner wall surface of the tubular structure from above the bending reinforcement material to form an upper surface of the bending reinforcement material. And by forming a reinforcing coating layer having a predetermined toughness on the inner wall surface of the tubular structure, the bending reinforcing material and the inner wall surface of the tubular structure are integrated. It is possible to prevent such damage that the joints of the masonry material are broken and fall apart. Further, the tensile force of the tubular structure is transmitted to the bending reinforcing material via the reinforcing coating layer, so that bending failure of the entire tubular structure can be prevented.

Further, according to another method for reinforcing a tubular structure according to the present invention, by bending the plurality of bending reinforcements in a direction orthogonal to the tubular axis, bending is performed with respect to the inner wall surface of the tubular structure. Since the reinforcing material is continuously arranged in the axial direction of the cylinder without a break, it is possible to perform construction by using a lightweight and short bending reinforcing material, and thus it is possible to improve the workability.

Further, according to the reinforcing structure for a tubular structure according to the present invention, it is a structure that reinforces an existing tubular structure, and the line is arranged along the inner wall surface of the tubular structure in the cylinder axial direction. -Shaped bending stiffener, and a film-like reinforcing covering provided over the upper surface of the bending stiffener and the inner wall surface of the tubular structure, and the reinforcing covering material is the bending stiffener and the inner wall surface of the tubular structure. Since it is integrated, it can be installed even in a narrow space inside the tubular structure, and since it can be installed with only a relatively lightweight material, it can greatly improve the installability compared to the conventional reinforcement structure. It has the effect of being able to. Also, since it can be reinforced only by the work inside the tubular structure, it has no effect on the appearance and is effective for the preservation of cultural properties. Unlike the carbon fiber sheet reinforcement, there is no need to make the surface smooth, so that the construction can be greatly simplified.

Further, according to another reinforcing structure for a tubular structure according to the present invention, the reinforcing covering material is made of a resin-based material, and has a predetermined strength on the upper surface of the bending reinforcing material and the inner wall surface of the cylindrical structure. Since the reinforcing coating layer having the property is formed, it is possible to prevent the breakage such that the joints of the masonry material such as bricks forming the tubular structure are broken and fall apart. Further, the tensile force of the tubular structure is transmitted to the bending reinforcing material via the reinforcing coating layer, so that bending failure of the entire tubular structure can be prevented.

Further, according to the other reinforcing structure for a tubular structure according to the present invention, the tubular structures are arranged so as to be stacked in a direction orthogonal to the tubular axis, and are continuously continuous in the axial direction with respect to the inner wall surface of the tubular structure. Since the plurality of bending reinforcements to be arranged are provided, it is possible to perform construction using a lightweight and short bending reinforcement, and thus it is possible to improve the workability.

FIG. 1 is a diagram showing an embodiment of a method for reinforcing a tubular structure and a reinforcing structure according to the present invention, where (1) is a top view, (2) is a front sectional view, and (3) is a side sectional view. Is. 2A and 2B are views showing another embodiment of the method for reinforcing a tubular structure and the reinforcing structure according to the present invention, wherein (1) is a front sectional view and (2) is a side sectional view. 3A and 3B are explanatory diagrams regarding the overlapping length L, where FIG. 3A is a front sectional view and FIG. 3B is a horizontal sectional view.

Embodiments of a method for reinforcing a tubular structure and a reinforcing structure according to the present invention will be described below in detail with reference to the drawings. The present invention is not limited to the embodiments.

In the present embodiment, as a tubular structure to be reinforced, a brick tubular structure 10 as shown in FIG. 1 will be described as an example. The tubular structure 10 is a rectangular tubular body having an open upper end formed by stacking bricks 12 as masonry materials, and is constructed on a concrete foundation 20. The brick 12 is a rectangular parallelepiped building material made by baking or compressing clay, shale, and mud. Joints 14 made of mortar, grout, or the like are provided between the bricks 12 that are adjacent to each other vertically and horizontally. Incidentally, the tubular structure of the present invention is not limited to a brick tubular structure, for example, a concrete tubular structure stacked with concrete blocks as a masonry material, or a stone material as a masonry material. It may be a stacked cylindrical structure.

Further, in the present embodiment, the case where the bending reinforcement is a flat bar (flat steel) will be described as an example, but the bending reinforcement of the present invention is not limited to this, and for example, a reinforcing bar, a wire, or an FRP-made one. Any material such as a rod may be used as long as it has a constant tensile strength in the cylinder axis direction.

The reinforcing method of the present embodiment is performed in the construction procedure of steps 1 and 2. The details of the construction of each step will be described below.

(Step 1)
First, as shown in FIG. 1, along the inner wall surface 16 of the tubular structure 10, a flat bar 18 (bending reinforcement) is arranged in the vertical direction (cylindrical axis direction). As for the lowermost part, the flat bar 18 is fixed to the foundation 20 by post-installation anchors 22 or PC tightening. Note that the lowermost flat bar 18 is not limited to being fixed to the foundation 20 but may be fixed to a beam or a wall to which the tubular structure 10 is attached.

The flat bar 18 does not need to be connected by welding or bolt connection over the entire length of the reinforcing section of the tubular structure 10. The flat bar 18 is arranged in the horizontal direction (lateral direction) while having the overlapping length L as shown in FIG. May be. With this configuration, the flat bar 18 can be continuously arranged in the vertical direction on the inner wall surface 16 of the tubular structure 10 without interruption.

Here, the overlapping length L is preferably set to, for example, 10 times or more the flat bar width. The basis for this will be described. In the present embodiment, the tensile force of the flat bar 18 is transmitted by the shear stress of the polyurea resin (reinforcing coating layer 24) described later. Therefore, as shown in FIG. 3, assuming that the force is transmitted through the resin 24A attached to the upper surface 18A and the side surface 18B of the flat bar 18, the tensile force of the flat bar 18 can be expressed as follows.

t _f ·W ·σ _f
However, W: width of flat bar
σ _f : Tensile stress of flat bar
t _f : Thickness of flat bar (=t ₂ −t ₁ ).
t ₁ : resin thickness on the flat bar
t _2: resin thickness of the flat bar next to

The shearing force of the resin 24A can be expressed as follows.
t ₂ ·L ·τ _a
Where τ _{a is} the shear stress of the resin

The lap length L capable of transmitting sufficient stress can be obtained from the following relational expression.
t _f ·W ·σ _f ≦t ₂ ·L ·τ _a (1)

Assuming that the strength of the flat bar 18 is about 10 times that of the resin 24A, the above relational expression (1) can be modified as follows.
L/W≧(t _f /t ₂ )·(σ _f /τ _a )=(t _f /t ₂ )·10 (2)

Considering the case where the resin thickness on the flat bar 18 is 0, the above equation (2) can be modified as follows.
L/W≧10 (3)

Therefore, the overlapping length L may be 10 times or more the width W of the flat bar 18. By doing so, the tensile force of the flat bar 18 can be sufficiently transmitted by the shear stress degree of the polyurea resin (reinforcing coating layer 24) described later.

(Step 2)
Next, a polyurea resin (reinforcing coating material) is sprayed onto the inner wall surface 16 of the tubular structure 10 from above the flat bar 18 to reinforce the upper surface of the flat bar 18 and the inner wall surface 16 of the tubular structure 10 with a film-like reinforcement. The coating layer 24 is formed, and the inner wall surface 16 and the flat bar 18 of the tubular structure 10 are integrated via the reinforcing coating layer 24. By doing so, the reinforcing structure of the tubular structure according to the present embodiment can be obtained.

As shown in FIG. 2, when there is a rigid frame 26 around the lower part of the tubular structure 10 and fixing is possible, the flat bar 18 may be extended below and the polyurea resin may be similarly sprayed. In this case, the symbol T in FIG. 2 is the fixing length, and the symbol P is the bending fracture assumed position.

In the above-described embodiment, the flat bar 18 does not need to be directly adhered to the inner wall surface 16 of the tubular structure 10, and the flat bar 18 of the tubular structure 10 is connected so that the upper surface is connected by the reinforcing coating layer 24 of the sprayed polyurea resin. It suffices if it is in contact with or close to the inner wall surface 16.

The reinforcing coating material to be sprayed is not limited to polyurea resin, but is made of polyurethane resin, epoxy resin, or the like, and the bricks 12 are connected to each other to be integrated and bonded to the bricks 12 and the flat bar 18 to transmit a load (strength property). Properties) and elongation characteristics. The reinforcing coating material to be sprayed is preferably one mainly composed of the above resins, but may be one containing a mixture other than these resins.

When the inner wall surface 16 of the tubular structure 10 has a large step portion, the flat bar does not necessarily have to contact the entire inner wall surface, and the recessed portion 28 of the inner wall surface may have a gap. Also in that case, polyurea resin is sprayed on the recessed portion 28.

As described above, according to the reinforcing method of the present embodiment, by spraying the polyurea resin on the entire inner surface of the brick wall, it is possible to prevent the brick 12 of the tubular structure 10 from being broken at the joints 14 and being separated. It Further, the tensile force of the brick wall is transmitted to the flat bar 18 via the polyurea resin, and is transmitted to the foundation 20 by the post-installed anchor 22 or the fixing portion extending downward, so that the entire tubular structure 10 is bent and broken. Is prevented.

In addition, since it can be installed in a small space inside the tubular structure 10 and can be installed only with a relatively lightweight material such as a flat bar or polyurea resin, the installability is greatly improved compared to the conventional reinforcing method. can do. In addition, since it can be reinforced only by the work inside the tubular structure 10, it has no effect on the appearance and is effective for the preservation of cultural properties. Unlike the carbon fiber sheet reinforcement, there is no need to make the surface smooth, so that the construction can be greatly simplified.

As described above, according to the method for reinforcing a tubular structure according to the present invention, it is a method of reinforcing an existing tubular structure, and a linear bending is performed along the inner wall surface of the tubular structure. A step of arranging the reinforcing material in the cylinder axis direction, a film-like reinforcing covering material is provided over the upper surface of the bending reinforcing material and the inner wall surface of the cylindrical structure, and the bending reinforcing material and the cylindrical structure are provided through the reinforcing covering material. Since it has a step of integrating the inner wall surface of the tubular structure, it can be installed even in a narrow space inside the tubular structure, and it can be installed using only a relatively lightweight material. Can be greatly improved. Also, since it can be reinforced only by the work inside the tubular structure, it has no effect on the appearance and is effective for the preservation of cultural properties. Unlike the carbon fiber sheet reinforcement, there is no need to make the surface smooth, so the construction can be greatly simplified.

Further, according to another method for reinforcing a tubular structure according to the present invention, a reinforcing coating material mainly composed of resin is sprayed onto the inner wall surface of the tubular structure from above the bending reinforcement material to form an upper surface of the bending reinforcement material. And by forming a reinforcing coating layer having a predetermined toughness on the inner wall surface of the tubular structure, the bending reinforcing material and the inner wall surface of the tubular structure are integrated. It is possible to prevent such damage that the joints of the masonry material are broken and fall apart. Further, the tensile force of the tubular structure is transmitted to the bending reinforcing material via the reinforcing coating layer, so that bending failure of the entire tubular structure can be prevented.

Further, according to another method for reinforcing a tubular structure according to the present invention, by bending the plurality of bending reinforcements in a direction orthogonal to the tubular axis, bending is performed with respect to the inner wall surface of the tubular structure. Since the reinforcing material is continuously arranged in the axial direction of the cylinder without a break, it is possible to perform construction by using a lightweight and short bending reinforcing material, so that the workability can be improved.

Further, according to the reinforcing structure for a tubular structure according to the present invention, it is a structure that reinforces an existing tubular structure, and the line is arranged along the inner wall surface of the tubular structure in the cylinder axial direction. -Shaped bending stiffener, and a film-like reinforcing covering provided over the upper surface of the bending stiffener and the inner wall surface of the tubular structure, and the reinforcing covering material is the bending stiffener and the inner wall surface of the tubular structure. Since it is integrated, it can be installed even in a narrow space inside the tubular structure, and since it can be installed with only a relatively lightweight material, it can greatly improve the installability compared to the conventional reinforcement structure. it can. Also, since it can be reinforced only by the work inside the tubular structure, it has no effect on the appearance and is effective for the preservation of cultural properties. Unlike the carbon fiber sheet reinforcement, there is no need to make the surface smooth, so that the construction can be greatly simplified.

Further, according to another reinforcing structure for a tubular structure according to the present invention, the reinforcing covering material is made of a resin-based material, and has a predetermined strength on the upper surface of the bending reinforcing material and the inner wall surface of the cylindrical structure. Since the reinforcing coating layer having the property is formed, it is possible to prevent the breakage of the joint of the masonry material such as the brick constituting the tubular structure, which breaks and becomes disjointed. Further, the tensile force of the tubular structure is transmitted to the bending reinforcing material via the reinforcing coating layer, so that bending failure of the entire tubular structure can be prevented.

Further, according to the other reinforcing structure for a tubular structure according to the present invention, the tubular structures are arranged so as to be stacked in a direction orthogonal to the tubular axis, and are continuously continuous in the axial direction with respect to the inner wall surface of the tubular structure. Since the plurality of bending reinforcements to be arranged are provided, it is possible to perform construction by using a lightweight and short bending reinforcement, so that it is possible to improve workability.

As described above, the reinforcing method and the reinforcing structure for a tubular structure according to the present invention are useful for reinforcing an existing tubular structure such as a brick chimney or an exhaust tower, and particularly, for the reinforcement work. Suitable for improving workability.

10 tubular structure 12 bricks 14 joints 16 inner wall surface 18 flat bar (bending reinforcement material)
20 Foundation 22 Post-installed anchor 24 Reinforcement coating layer (reinforcement coating material)
26 Rigid body 28 Recessed part

Claims (6)

A method of reinforcing an existing tubular structure,
Along the inner wall surface of the tubular structure, a step of arranging the linear bending reinforcement in the tubular axis direction,
A step of providing a film-like reinforcing covering material over the upper surface of the bending reinforcing material and the inner wall surface of the tubular structure, and integrating the bending reinforcing material and the inner wall surface of the cylindrical structure through the reinforcing covering material. A method for reinforcing a tubular structure, characterized by: A reinforcing coating material composed mainly of resin is sprayed onto the inner wall surface of the tubular structure from above the bending reinforcement material to form a reinforcing coating layer having a predetermined toughness on the upper surface of the bending reinforcement material and the inner wall surface of the tubular structure. The method for reinforcing a tubular structure according to claim 1, wherein the bending reinforcement and the inner wall surface of the tubular structure are integrated by forming the bending reinforcement. By arranging a plurality of bending reinforcements in a direction orthogonal to the cylinder axis, the bending reinforcements are arranged continuously and seamlessly in the cylinder axis direction on the inner wall surface of the cylindrical structure. The method for reinforcing a tubular structure according to claim 1 or 2. A structure that reinforces an existing tubular structure,
A linear bending reinforcing material arranged along the inner wall surface of the tubular structure in the cylinder axis direction, and a film-like reinforcing covering material provided over the upper surface of the bending reinforcing material and the inner wall surface of the cylindrical structure. Equipped with
The reinforcing coating material is a reinforcing structure for a tubular structure, wherein the bending reinforcing material and the inner wall surface of the tubular structure are integrated. The reinforcing coating material is made of a resin-based material, and forms a reinforcing coating layer having a predetermined toughness on the upper surface of the bending reinforcing material and the inner wall surface of the tubular structure. The reinforcing structure for the tubular structure according to item 4. 5. A plurality of bending reinforcements, which are arranged to be stacked in a direction orthogonal to the cylinder axis, and which are arranged continuously and seamlessly in the cylinder axis direction with respect to the inner wall surface of the cylindrical structure. The reinforcing structure for the tubular structure according to 5.

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