JP2001140217A - Concrete piece drop prevention construction in concrete structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure capable of preventing the drop of concrete pieces in a concrete construction and further concrete pieces drop prevention construction for a concrete structure to be prevented from the rusting of steel bars. SOLUTION: A surface from which a concrete piece 10 has dropped and/or a surface from which the falling of a concrete piece is predicted for a concrete structure 1 is covered with a plurality of plate-shaped members; a plurality of plate-shaped members are formed, jointed; a gap 3 is provided between a concrete structure and a plate-shaped member, and the gap is ventilated and a resin having transparency is adopted for a plate-shaped member, so that the dropping of a concrete piece is prevented, a concrete surface is ventilated and the occurrence of rust from inner reinforcing bars is prevented, the rupture of concrete is prevented, and also the changes in concrete surface can be visually inspected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for preventing falling of concrete pieces in a concrete structure, and more particularly to a method for preventing falling of concrete pieces in a concrete building which covers a concrete surface with a plurality of molded plate-shaped members to prevent falling. Regarding the structure.

[0002]

2. Description of the Related Art Recently, concrete pieces such as the inner walls of tunnels of Shinkansen bullet trains and viaducts of expressways have fallen seriously, causing a serious problem.

[0003] Although the causes are variously discussed, rust of reinforcing steel which explodes concrete and causes concrete pieces to fall is fundamentally unavoidable because steel reinforcing steel is generated as the concrete is denatured. . The rebar at the beginning of construction is protected from rust by being covered with alkaline concrete, but the concrete is neutralized from near the surface due to carbon dioxide and acid rain in the air. The speed is particularly high in areas where water is applied. Over the years, the neutralization reaches the interior of the concrete and rusts the internal reinforcement. Rusty rebar expands in volume, causing the concrete to explode and seeing concrete pieces fall.

As a countermeasure, in a concrete building such as an inner wall of a tunnel, a tapping is performed to judge from abnormal sound, or a peeling is visually found, and an angle corresponding to the shape is fixed at a problem portion to prevent the concrete from falling. ing. Also, at the spalling point, the concrete crack was knocked down with a hammer,
Repair measures have been taken to remove rust from the internal reinforcing steel, apply rust-preventive paint, and hit concrete.

[0005] In addition to the above-mentioned concrete buildings such as tunnels and bridge piers, falling of concrete pieces also poses a problem on the ceiling of an indoor pool made of reinforced concrete. Particularly in a heated pool, the reinforcing bar is easily rusted near the ceiling due to high temperature and humidity exceeding 40 degrees, and many places where concrete pieces are dropped from the surface of the beam with the passage of age are recognized. On the other hand, conventionally, the same repair means as in the above-described tunnel and bridges has been taken.

[0006]

However, a fall prevention measure for fixing the angle is reinforcement by wires, and concrete falling at a portion where there is no angle cannot be prevented unless the interval between the angles is reduced. Also,
Repairs such as rusting, rust-prevention painting, and concrete pouring at the point of fall are not fundamental improvements, so it is expected that the same accident will occur several years later.

[0007] In order to prevent the reinforcing steel from being rusted, there is a proposal to cover the reinforcing steel with thick concrete and delay the neutralization of the concrete near the reinforcing steel. However, it is impossible to adopt the method for existing concrete buildings.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and it is an object of the present invention to prevent concrete from exploding due to rust of reinforcing steel in an existing concrete building and dropping concrete pieces. It is an object of the present invention to provide a concrete piece falling prevention structure of a concrete building for preventing the falling of concrete pieces.

[0009]

According to the present invention, a concrete piece falling prevention structure for a concrete structure is provided with a plurality of surfaces on which concrete pieces fall and / or where concrete pieces are predicted to fall. Cover with a plate-like member.

Further, the concrete piece falling prevention structure of a concrete building according to the present invention comprises a plurality of plate-like members formed and connected in accordance with the shape of the concrete building. A gap is provided between them, and the space is ventilated.

The plate member is a resin having transparency.

A concrete piece falling prevention structure for a concrete building according to the present invention covers a surface on which a concrete piece has fallen and / or a surface on which a concrete piece is expected to fall by molding and connecting a plurality of plate-like members. The ventilation between the concrete and the plate-shaped member is provided to prevent the falling of concrete pieces at the plate-shaped member, and the ventilation prevents the internal rebar from rusting and prevents the explosion of concrete. it can. In addition, there is an advantage that a change in the concrete surface can be visually observed by using a transparent resin for the plate-shaped member.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a concrete piece falling prevention structure for a concrete building according to the present invention will be described below in detail with reference to the drawings.

With regard to the ceiling beams of the reinforced concrete indoor pool where the concrete pieces have fallen, the surrounding area where the concrete has fallen is crushed with a hammer to break the cracks in the concrete, the rust of the internal reinforcing steel is dropped, the rust preventive paint is applied, and the concrete is hit and repaired. As shown in FIGS. 1 (a) and 1 (b), a large number 20 of the plate-like members 2 shown in FIG. 2 (a) formed according to the shape of the beam as shown in FIG. Then, the entire surface of the concrete of the beam vertically fixed from the ceiling and fixed with bolts 5 is covered with the plate-shaped member 2 in a cover shape. Further, the horizontal portion of the ceiling can be entirely covered with the plate-shaped member 2 by using the connecting method described later.

The plate-like member 2 is light, has high mechanical strength, is water-resistant, has a high heat-resistant temperature, is resistant to acids and alkalis, has excellent electrical insulation properties, and has a self-extinguishing function (flame resistance). Polypropylene is preferred, but not limited to polypropylene, and synthetic resins such as carbon fiber reinforced plastics used in aircraft and the like are also suitable. Further, the material is not limited to a resin, and a metal such as stainless steel or lightweight aluminum is appropriately selected.

The molded resin 20 is applied to a concrete building 1
2A and 2B, drill holes 21, 21,... In advance in the plate-like resin 2.
Corresponding to the bolt holes 21, 21,... Drilled in the resin, as shown in FIG.
5,… The molded resin 20 is arranged at a predetermined position, the upper part of the anchor bolt 5 is projected from the bolt hole 21, and the bolt cover 6, which is made of a resin of the same quality as the molded resin 20 and has a thread therein, is screwed therein. (Figure 1
(C)).

The concrete piece falling prevention structure of a concrete building according to the present invention covers a large area,
It is composed according to the shape of the building and the size with a large number of plate-like resins 2, 2,... (FIG. 1B). For example, 25m wide beam
When covering one piece, using fifteen plate-like resins 2, 2,..., Fifteen cover-shaped resins 20, 20,.
, And the 15 molded resins 20 are sequentially connected and covered.

Usually, the molding of the resin is performed by injection molding using a mold, but the molding of the plate-like resin 2 employed in the present invention is performed by bending the plate-like resin 2.

As shown in FIG. 2A, the bending process of the polypropylene resin is performed by bending the bending lines 22, 23, 2
A V-shaped groove is formed along 4, and an electric heater is heated close to the back of the V-shaped groove to melt the resin and crimp the groove surface.
A similar bending process is applied to a plurality of V-shaped grooves, and the cross section is
(FIG. 1 (a)) or its deformation (FIG. 1).
(C)) The resin 20 molded into a cover shape is obtained. V
By adjusting the angle of the groove, a molded resin (not shown) suitable for covering a gentle curved surface can be formed.

As shown in FIGS. 3 (a) and 3 (b), in order to connect a plurality of molded resins 20 molded so as to correspond to the shape of the building as described above, the moldings are sequentially connected. Connecting piece 2 in a certain direction (right side in the figure)
5 are fixed respectively. The connecting piece 25 is made of the same material (polypropylene resin) as the plate-like resin 2, and almost half of the connection piece 25 is welded to the plate-like resin 2 side, and the other half is in a state of overlapping with the resin 20 formed next.

When fixing the connecting piece 25 to the plate-like resin 2, hot air is blown to the welding portion, and the resin surface and the welding rod are simultaneously melted and welded. When a metal is selected as the plate-shaped member 2, the connecting piece 25 is also welded with a homogeneous metal.

The first molded resin 20 is fixed on the concrete surface of the building 1 with the anchor bolts 5, and the next molded resin 20 is fixed on the connecting piece 25 by repeating the same. A large number are connected according to the shape and size of.

When the molded resin 20 is fixed to a concrete building, as shown in FIG.
cm, more preferably between 20 and 50 cm, the gap 3 is created between the connected resin cover and concrete. Using the gap 3 as a duct, air can be circulated by a fan to prevent condensation on the concrete surface. Thereby, the effect of delaying the generation of rust of the reinforcing steel in the concrete is great.

By using a transparent resin as the plate-like resin 2, a visual inspection of the concrete surface is possible. In addition, since the molded resin 20 is detachable in units of blocks, when a stripped portion is visually found, the plate-shaped resin 2 of the corresponding block is removed and repaired, and the plate-shaped resin 2 is bolted again. Good.

In the embodiment, the indoor pool is exemplified as the concrete building. However, by changing the molding shape of the plate-like resin 2, it is possible to prevent concrete falling on the inner wall of a tunnel of a Shinkansen, a viaduct, a pier of a highway, and the like. However, it goes without saying that excellent effects can be similarly obtained.

[0026]

As is clear from the above description, the concrete piece falling prevention structure of the concrete building according to the present invention is expected to have a surface on which the concrete piece of the concrete building has fallen and / or to drop the concrete piece. The surface is covered with a plurality of plate members, and a plurality of plate members are formed and connected according to the shape of the concrete building, and a gap is provided between the concrete building and the plate member. Ventilation is applied to the gap, and a transparent resin is used for the plate-like member. Therefore, the surface on which the concrete piece has fallen and / or the surface where the concrete piece is expected to fall is covered with a plurality of molded plate-like members. In addition to preventing concrete pieces from falling, ventilation to the concrete surface prevents rust on the internal reinforcing steel and prevents explosion of concrete.
Further, it is possible to visually inspect the change of the concrete surface by employing a transparent resin.

[Brief description of the drawings]

FIG. 1A is a partial cross-sectional view illustrating a concrete piece falling prevention structure of a concrete building of the present invention. (B) A perspective view illustrating the present invention. (C) Partial sectional view explaining another example of the present invention.

FIG. 2A is a diagram illustrating a plate-like member used in the present invention. (B) The figure explaining shaping | molding of the plate-shaped member employ | adopted by this invention. (C) The figure explaining the concrete building where this invention is employ | adopted.

FIG. 3A is a side view for explaining connection of a plate-like member employed in the present invention. (B) The perspective view explaining the connection of the plate-shaped member employ | adopted by this invention.

[Explanation of symbols]

 1 ····· Concrete building 10 ····· Concrete piece 2 ···· Plate member 20 ···· Molded resin 21 ··· Bolt holes 22, 23, 24 ··· ... Bending line of plate-like member 25 ... Connection piece 3 ... Gap 5 ... Anchor bolt 6 ... Bolt cover

Claims (4)

[Claims] A surface of a concrete building (1) on which a concrete piece (10) has fallen and / or a surface on which the concrete piece is predicted to fall is provided with a plurality of plate-like members (2).
A concrete piece falling prevention structure for a concrete building, characterized by being covered with a coating. 2. The concrete piece falling prevention structure for a concrete building according to claim 1, wherein the plurality of plate-like members are formed and connected according to the shape of the concrete building. 3. A concrete building according to claim 1 or 2, wherein a gap (3) is provided between said concrete building and said plate-shaped member, and said gap is ventilated. Construction. 4. The concrete piece falling prevention structure for a concrete building according to claim 1, wherein the plate-like member is a resin having transparency.