JP2983466B2 - Reinforcement grid material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reinforcing grid material used in a method for reinforcing an existing structure such as a floor slab of a concrete bridge.

[0002]

2. Description of the Related Art A floor slab of a concrete bridge or the like is a portion which receives the severest load among the main members of a road bridge because a wheel load of an automobile is directly and repeatedly applied.
For this reason, in particular, on the lower surface of a floor slab or the like, vertical and horizontal cracks are generated from one-way cracks, and further, these cracks grow and become fine mesh, which eventually causes concrete to fall off. .

[0003] If such damage is left untreated, the cracks may progress further into the deeper part, leading to corrosion of the reinforcing steel, and eventually to the destruction of the structure. In order to avoid such a situation, the lower surface of the concrete bridge floor slab has been repaired at the stage when a fine crack has occurred.

For example, as a repair method, a resin injection method for injecting epoxy resin into a crack of a floor slab or the like to integrate it with concrete, a sheet or a coating to prevent rainwater or the like from entering the floor slab or the like. Waterproof construction method to form waterproof layer such as membrane, FRP (Fib
er Reinforced Plastics), and a cross section repairing method of filling a bean plate such as a floor slab, a cavity, and peeling with a cement mortar or a resin mortar.

[0005] These techniques can be expected to prevent concrete deterioration to a certain degree and to prevent rusting of reinforcing steel, but they only repair existing structures and do not improve the strength of the structures.

Therefore, the present inventors have disclosed in Japanese Patent Application Laid-Open No. 61-14 / 1986.
No. 6904 proposes a method of repairing and reinforcing a bridge floor slab in which a surface coating material is applied to the surface of a cleaned existing structure, a wire mesh is attached thereon, and the coating material is further applied on the wire mesh. As a result, the reinforced structure has the same strength from the beginning as the structure in which the reinforcing bar is inserted in an amount corresponding to the wire mesh.

Further, the present inventors have disclosed in Japanese Patent Application Laid-Open No. 7-423.
No. 78 discloses a method for reinforcing a concrete structure obtained by improving and developing the above method. This method is used to fix the reinforcement grid material to the lower surface of the concrete structure.
It uses a fixture with a tapered part whose cross section expands toward the head side, thereby providing tension in the surface direction of the reinforcing grid material and integrating the existing structure with the reinforcing grid material. To obtain a reinforcing effect.

[0008]

Problems to be Solved by the Invention Japanese Patent Laid-Open No. 7-42378
In the method disclosed in Japanese Patent Application Laid-Open Publication No. H10-209, a mesh reinforcing bar is used as a reinforcing grid material, and this mesh reinforcing bar is formed by arranging reinforcing bars horizontally and vertically and fixing an intersection thereof by welding or the like. Therefore, at the intersection, the vertical and horizontal reinforcing bars are vertically overlapped. Therefore, the thickness of the entire reinforcing bar is about twice as large as the diameter of the reinforcing bar, so when coating the reinforcing bar fixed to the lower surface of the slab of a concrete structure with a coating such as polymer concrete mortar, a large amount of the coating is required. I need.

[0009] Further, in fixing the reinforcing steel bar as a reinforcing grid material to the lower surface of the existing structure, a fixing device having a tapered portion whose cross section increases toward the head side is used. In doing so, it is necessary to prepare a fixture having a special shape separately from the mesh reinforcing bar.

The problem to be solved by the present invention is to provide a reinforcing grid material which can be easily fixed, does not require a large amount of covering material, and provides an excellent reinforcing effect in the reinforcement work of a concrete structure. Is to provide.

[0011]

In order to solve the above-mentioned problems, a reinforcing grid member of the present invention is a reinforcing grid member fixed to the lower surface of a concrete structure to reinforce the structure, and forms a grid material. The vertical member and the horizontal member are on the same plane. Since the vertical member and the horizontal member do not vertically overlap at the intersection, the thickness of the entire reinforcing lattice member can be reduced.

Here, the reinforcing lattice member is made of a steel material. By using a steel material as a material, workability is good, so that various sizes and shapes can be accommodated, and adhesion to concrete mortar and the like is also good.

Further, the reinforcing lattice member is made of a fiber reinforced resin material. By using a fiber reinforced resin material as a material, the weight of the reinforcing grid material can be reduced, and the corrosion resistance and chemical resistance are greatly improved.

Glass fibers and carbon fibers can be used as the fibers constituting the fiber reinforced resin material.
Resins include vinyl ester (Vi
nylEster) can be used.

As a commercially available product, Nefcom (registered trademark) sold by Nefcom Co., Ltd. can be suitably used. This Nefcom is designed to impregnate a continuous fiber such as carbon fiber, glass fiber, or aramid fiber with a resin while maintaining a spacing of 5%.
It is integrally molded in a grid shape of 0, 100, 150 mm, etc., has a specific gravity of 1.3 to 1.7, and is 1/4 to 1/1 / of steel material.
6. Tensile strength is about the same as that of PC steel strands and is 4 to 5 times that of rebar, and tensile elasticity is 2/3 to 1 times that of steel.
/ 4, and the area of elastic deformation is 2-5 of the PC steel stranded wire.
It is twice.

Since the intersection has a so-called laminate structure in which fibers are alternately superposed, it has excellent binding power and can secure sufficient strength even when a tension is applied to the intersection by a fixing tool. Further, since the intersections are on the same plane, the thickness of the entire reinforcing grid material can be reduced.

Further, the reinforcing grid member has fixing means for fixing the reinforcing grid member to the lower surface of the concrete structure in a state where tension is generated in the reinforcing grid member.
Since the reinforcing grid material is to be integrated with the structure by fixing it to the lower surface of the concrete structure in a state where tension is generated, and reinforcing the grid material, it is necessary to provide such a fixing means to the reinforcing grid material. Thereby, the work of fixing to the lower surface of the concrete structure becomes easy and reliable.

Here, the fixing means is characterized by comprising a guide slope formed on the reinforcing grid member and an auxiliary tool which comes into contact with the guide slope and has an anchor mounting hole.
When fixing the reinforcing grid to the bottom of the concrete structure,
When the anchor inserted into the anchor mounting hole of the auxiliary tool is driven into the concrete structure, the auxiliary tool moves along the guide slope formed on the reinforcing grid material, generating surface tension in the reinforcing grid material. It can be fixed in the state where it has been made.

Since the grid member is fixed to the lower surface of the concrete structure in a state where a tensile force is applied in the surface direction, so-called prestress is introduced into the grid member.
The existing structure and the lattice material are firmly integrated. Therefore, even when the concrete structure to which the reinforcing grid is attached is bent, the grid follows the displacement,
A reliable reinforcing effect can be obtained.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view showing the first embodiment, and FIG. 2 is a cross-sectional view near the line AA in FIG.

The reinforcing grid member 5 of the present embodiment is for fixing an existing structure by fixing it to the lower surface of a concrete bridge or the like, and the vertical member 5a and the horizontal member 5b forming the grid member 5 are formed by a reinforcing member. Both are on the same plane. For this reason, the vertical member 5a and the horizontal member 5b do not overlap vertically at the intersection 5c, and the thickness of the entire reinforcing grid member 5 is reduced to the vertical member 5a.
Alternatively, the thickness can be set to the thickness of the horizontal member 5b.

Here, the reinforcing lattice member 5 is formed of a steel material. Since it is made of a steel material, it has good workability, can correspond to various sizes and shapes, and has good adhesion to concrete mortar and the like. The method of manufacturing the reinforcing grid member 5 is not particularly limited. For example, the reinforcing grid member 5 can be formed into a grid by punching out a single steel plate by pressing to remove a portion corresponding to the opening 5k.

Further, the reinforcing grid member 5 has a guide slope 10 formed at the intersection 5c of the reinforcing grid member 5 in order to fix the grid member 5 to the lower surface of the concrete structure while generating tension. , And an auxiliary tool 12 having an anchor mounting hole 11 in contact with the guide slope 10.

Therefore, when fixing the reinforcing lattice member 5 to the lower surface of the concrete structure, the anchor 13 inserted into the anchor mounting hole 11 of the auxiliary member 12 is driven into the concrete structure, so that the auxiliary member 12 Intersection 5
Since the grid member 5 moves along the guide inclined surface 11 formed in c, the grid member 5 can be fixed in a state where a tension in the surface direction is generated. At this time, the tension applied to the lattice member 5 can be finely adjusted by adjusting the driving depth of the anchor 13.

Since the grid member 5 is fixed in a state where a tensile force is applied to the grid member 5 in a plane direction, so-called prestress is introduced into the grid member 5.
Are firmly integrated. Therefore, even when the concrete structure to which the grid member 5 is attached is bent, the grid member follows the displacement, so that a reliable reinforcing effect can be obtained.

Here, a concrete bridge reinforced by fixing the reinforcing grid member 5 to the lower surface will be described with reference to FIGS. 3 and 4. FIG. FIG. 3 is a vertical cross-sectional view of the concrete bridge, and FIG. 4 is a view taken along line BB of FIG.

In FIG. 3, reference numeral 1 denotes a floor slab of a concrete bridge, and ground covers 2 are formed at both ends.
A row of bridge girders 3 is provided. D indicates a track as a live load.

As shown in FIG. 3, a reinforcing grid member 5 is fixed to the entire lower surface of the floor slab 1. The means for fixing the reinforcing grid member 5 to the lower surface of the floor slab 1 is the same as that shown in FIG. As shown in FIG.
Of the grid material 5
, A tension in the direction of the arrow is applied to the entire surface. At this time, by adjusting the driving depth of the anchor, the tension applied to the grid member 5 can be finely adjusted, so that the construction can be performed according to the situation at the site.

In the reinforcing work of the floor slab 1 of the concrete bridge, if the reinforcing grid member 5 provided with such fixing means is used, the tension in the surface direction is generated over the entire surface of the grid member 5. Can be fixed to the lower surface of the floor slab 1 with the
In this state, so-called prestress is introduced, and the floor slab 1 and the lattice member 5 are firmly integrated. Therefore, even when the floor slab 1 to which the reinforcing grid member 5 is attached is bent,
Since the lattice member 5 follows the displacement, a reliable reinforcing effect can be obtained. In the present embodiment, the tension is applied from the center of the span of the floor slab 1, that is, from the portion having the largest deflection to the outside.

Further, from this state, a coating layer is formed by pouring a polymer cement mortar so as to cover the entire surface of the lattice member 5, whereby the reinforcing work is completed. At this time, since there is no overlapping portion in the intersection 5c of the grid member 5, the coating layer can be made thinner than the conventional reinforcing method, and the amount of the coating material such as polymer cement mortar can be greatly reduced. it can.

Next, a second embodiment will be described with reference to FIG. FIG. 5 is a perspective view showing a reinforcing grid member 20 according to the second embodiment. The reinforcing grid member 20 is made of a fiber reinforced resin material. By using the fiber reinforced resin material as a material, the reinforcing grid member 20 is reduced in weight, and the corrosion resistance and chemical resistance are greatly improved. Nefcom (registered trademark) sold by Nefcom Co., Ltd. is used as the fiber-reinforced resin material. Since the reinforcing grid material 20 is a fiber reinforced resin material,
Lighter and stronger than steel materials.

Since the intersections 20c of the grid member 20 have a so-called laminate structure in which fibers are alternately superposed, they have excellent binding power, and have sufficient strength even when a tension is applied to the intersections by a fixture. Can be secured. Also, since the intersections are on the same plane, the entire reinforcing grid material could be made thinner. For this reason, the coating layer can be made thinner than the conventional reinforcing method, and the amount of polymer cement mortar and the like can be significantly reduced.

The reinforcing grid member 20 includes a grid member 20.
The guide slope 21 formed at the intersection 20c is fixed to the lower surface of the concrete structure in a state where tension is generated in the cross section.
And an auxiliary tool 23 which is in contact with the guide slope 21 and has an anchor mounting hole 22.

When fixing the reinforcing grid member 20 to the lower surface of the concrete structure, the auxiliary tool 23 is driven into the concrete structure by driving the anchor 24 inserted into the anchor mounting hole 22 of the auxiliary tool 23 so that the auxiliary tool 23 intersects the intersection of the grid material 20. In order to move along the guide slope 21 formed in 20c, the grid material 2
A zero tension can be generated in the plane direction. Therefore, by dispersing and providing the guide slope 21 and the auxiliary tool 23 at a plurality of locations of the grid member 20, it is possible to fix the grid member 20 in a state where tension is generated over the entire surface of the grid member 20. At this time, the tension applied to the lattice member 20 can be finely adjusted by adjusting the driving depth of the anchor 24.

[0035]

According to the present invention, the following effects can be obtained.

(1) Both the vertical and horizontal members forming the grid member are on the same plane, and the vertical and horizontal members do not overlap each other at the intersection, so that the thickness of the entire reinforcing grid member is reduced. it can.

(2) Since the reinforcing grid material is made of a steel material, the workability is good, so that it is possible to cope with various sizes and shapes, and the adhesion to concrete mortar and the like is also good. .

(3) By using a fiber-reinforced resin material for the reinforcing grid material, the weight can be reduced, and the corrosion resistance and chemical resistance are greatly improved.

(4) By providing a fixing means for fixing the reinforcing grid material to the lower surface of the concrete structure in a state where tension is generated, the fixing work to the lower surface of the concrete structure becomes easy and reliable, and the reinforcement is performed. The effect is also improved.

(5) The fixing means is constituted by a guide slope formed on the reinforcing grid material and an auxiliary tool which comes into contact with the guide slope and has an anchor mounting hole. At the time of fixing, the reinforcing grid member can be fixed in a state where a tensile force in the surface direction is generated simply by driving the anchor inserted into the anchor mounting hole of the auxiliary tool into the concrete structure.

[Brief description of the drawings]

FIG. 1 is a plan view showing a first embodiment.

FIG. 2 is a sectional view in the vicinity of line AA in FIG.

FIG. 3 is a vertical sectional view of a concrete bridge.

FIG. 4 is a view taken along line BB of FIG. 3;

FIG. 5 is a perspective view showing a reinforcing grid member of a second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Floor slab 2 Ground covering 3 Bridge girder D track 5, 20 Reinforcement grid material 5a Vertical member 5b Horizontal member 5c, 20c Intersection 5k Opening 10,21 Guide slope 11,22 Anchor mounting hole 12,23 Auxiliary tool 13,24 anchor

Claims (2)

(57) [Claims] 1. A reinforcing lattice member the concrete structure is fixed to the lower surface to reinforce the structure, Ri longitudinal member and transverse member on both the same plane near to form the grating material,
Concrete structure with tension generated in the grid material
As the fixing means for fixing to the underside of the structure,
Guide slope formed on the
A reinforcing grid member having fixing means constituted by an auxiliary tool . 2. The reinforcing grid material is a steel material or a fiber.
The reinforcing grid material according to claim 1, wherein the reinforcing grid material is a material.