JP3329183B2 - Steel members - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steel member used for structural members such as columns and beams of a building, and more particularly to a member having a property of absorbing electromagnetic waves.

[0002]

2. Description of the Related Art With the advancement of information in recent years, it is expected that so-called wireless communication in which communication between OA devices is performed by electromagnetic waves, particularly in offices, will be advanced. Therefore,
For wireless communication, it is necessary to take measures against electromagnetic interference and electromagnetic interference caused by irregular reflection of electromagnetic waves on steel members constituting a building (electromagnetic shield).

Conventionally, as a countermeasure against the above-mentioned radio interference, especially in a steel-framed building, there is a method of covering a steel frame material used as a structural material such as a beam or a column with a radio wave absorbing material to prevent the reflection of radio waves. There, as an example, there is a radio wave absorbing curtain wall 10 ferrite green body (ferrite tile) 11 is embedded therein, as shown in FIG.

More specifically, the radio wave absorbing curtain wall 10 has a ferrite-based molded article (ferrite tile) 11 having a property of absorbing radio waves arranged in a concrete 14 corresponding to a position where a steel frame is provided. A precast concrete slab buried by embedding, a reinforcing bar 12 and a reinforcing mesh 13 which also functions as a reflector are disposed in the concrete 14.

According to the electromagnetic wave absorbing curtain wall 10, radio waves arriving at the building are absorbed by the ferrite tile 11 embedded in the concrete 14. Further, since the reinforcing mesh 13 as a reflector is buried in the concrete 14, the radio wave is transmitted twice through the ferrite tile 11 and absorbed by the reflection. The range of the reception failure to be performed can be narrowed.

On the other hand, in general, in a steel-framed building, means for securing the fire resistance of the steel frame material include, for example, spraying a fire-resistant coating (rock wool) on the surface of a steel frame, or silicic acid, separately from the above-mentioned measures against radio interference. This was done by attaching a calcium plate or the like.

[0007]

However, in the case of the conventional radio wave absorbing curtain wall 10 described above, the installation of the ferrite tile 11 and the arrangement of the reinforcing mesh 13 are required, resulting in an increase in construction work. . further,
In the radio wave absorbing curtain wall 10, the thickness (wall thickness) of the concrete 14 increases by the amount of the ferrite tile 11 buried inside, and accordingly, the curtain wall 1
In addition to the increase in the weight of 0, the design constraints increase,
Corresponding to this, there is a problem that the shapes of walls and beams are limited, and the degree of freedom in designing the appearance of the building is reduced.

Further, as described above, conventionally,
Work such as spraying rock wool and attaching calcium silicate plates, which are fire resistance measures for steel frames, was performed separately from the above-mentioned work to prevent radio interference, increasing the work required when constructing structures. However, this was one of the causes of the delay in the construction period and an increase in construction costs.

Accordingly, an object of the present invention is to provide a radio wave absorbing function and high fire resistance without being limited by design or design of wall thickness, weight, shape, etc., in addition to being able to be manufactured by simple construction work. It is an object of the present invention to provide a steel member which can be used.

[0010]

Means for Solving the Problems To achieve the above object, a steel member according to the present invention has a powder having a property of absorbing electromagnetic waves in mortar and a property of reflecting electromagnetic waves.
A coating layer formed by mixing powders to be formed is disposed on the surface of a steel frame (claim 1).

According to such a steel frame member, since the powder having the radio wave absorbing property is dispersed in the concrete, the radio wave incident on the concrete is absorbed and attenuated by the powder having the radio wave absorbing property. And a good radio wave absorption effect can be obtained. In particular, such a coating layer can be disposed on the surface of the steel frame by a simple construction work such as spraying or painting, so that its production is easy and the weight and shape of the steel frame member are significantly changed. Therefore, the degree of freedom in designing or designing the members can be ensured. In addition, electromagnetic waves incident on the coating layer
Therefore, while being irregularly reflected, it is absorbed by powder having radio wave absorption characteristics.
The transmission distance of radio waves within the coating layer
And increase the probability of radio wave absorption during that time
As a result, a higher radio wave absorption effect can be obtained.
You.

In the above-mentioned steel frame member, it is preferable that the powder is ferrite fly ash.

According to such a steel frame member, since the ferrite fly ash is manufactured by firing at a high temperature and has radio wave absorption characteristics, the coating layer formed by mixing the fly ash has electromagnetic wave absorption characteristics. Not only has it but also exhibits high fire resistance.

[0014]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a steel member according to an embodiment of the present invention. FIG. 1 is a perspective view showing a steel frame member 1 according to the present embodiment. The steel member 1 is a structural material constituting a steel-framed building, and is mainly used as a beam member or a column member. In the same figure, the steel frame member 1 is configured by disposing a coating layer 3 made by mixing powder having a property of absorbing electromagnetic waves with mortar on the surface of an H-shaped steel 2 which is a steel frame. Things.

In the present embodiment, the coating layer 3 is formed by spraying or applying a mortar containing the above-mentioned powder to the surface of the H-section steel 2 or by attaching a dry panel. In the present embodiment, ferrite fly ash is used as the powder mixed with the coating layer 3.

The ferrite fly ash is
For example, it is obtained by mixing iron oxide with fly ash generated when incinerating municipal garbage and firing it at a temperature of 500 to 800 ° C. The ferrite fly ash has good magnetic permeability, and when kneaded with a mortar having a predetermined composition, a coating material having an electromagnetic wave absorbing function can be obtained. The ferrite fly ash can be easily mixed into the mortar by blending it with a high-performance water reducing agent.

In the steel member 1 having such a configuration, the radio wave incident on the steel member 1 is absorbed when passing through the surface coating layer 3. That is, in the steel member 1, as schematically shown in FIG. 2, the ferrite fly ash 4, which is a powder having radio wave absorption characteristics, is dispersed in the mortar, so that it enters the coating layer 3. The incoming radio waves are absorbed by the fly ash 4 and attenuated. In addition, among the incident radio waves, those reflected on the steel frame 2 also pass through the fly ash 4 when passing through the coating layer 2 after the reflection.
Is absorbed by As a result, the radio wave incident on the steel frame member 1 can be absorbed by the steel frame member 1, and the radio wave interference in the building can be prevented.

Further, in the present embodiment, since the ferrite fly ash used as the powder for absorbing the electromagnetic waves has high fire resistance, the ferrite fly ash of the steel frame member 1 provided with the coating layer 3 formed by mixing them is disposed. Fire resistance can also be increased.

In this embodiment, ferrite fly ash is used as the powder for absorbing electromagnetic waves.
The present invention is not limited to this, and a reflective material having a property of reflecting electromagnetic waves, such as aluminum, steel, carbon, and whiskers, may be used as the powder.

In this case, the reflecting material can be used in a mixture with the above-mentioned ferrite fly ash. According to this, as shown in FIG. 2, the electromagnetic wave incident on the coating layer is absorbed in the fly ash 4 while being irregularly reflected by the reflective material 5, it is possible to increase the transmission distance of radio waves in the coating layer The probability of radio wave absorption during that period can be increased, and as a result, a higher radio wave absorption effect can be obtained.

[0021]

In summary, according to the steel member of the present invention, since the coating layer formed by mixing the powdery material having the property of absorbing radio waves is provided on the surface of the steel frame, it is incident on the steel member. The obtained radio waves are absorbed by the powdery material, and as a result, excellent radio wave absorption performance is obtained. Therefore, a building constructed using such a steel frame member,
By absorbing radio waves from inside and outside the building, subsequent reflections can be prevented to suppress radio interference in the building, and measures against electromagnetic interference can be ensured. Furthermore, electromagnetic waves incident on the coating layer are reflected by the reflective material.
Absorbed by powder with radio wave absorption characteristics while being diffusely reflected
Therefore, the transmission distance of radio waves in the coating layer can be lengthened.
The probability of radio wave absorption during that time can be increased.
As a result, a higher radio wave absorption effect can be obtained.

In particular, since such a coating layer can be disposed on the surface of the steel frame by a simple construction operation such as spraying or painting, its production is easy, and as a result,
The construction period can be shortened. Further, since the coating layer is merely provided on the surface of the steel frame, the weight and the shape of the steel frame member are not significantly changed, and the degree of freedom in design or design can be secured.

When ferrite fly ash is used as the powder in the above-mentioned steel frame member, since the ferrite fly ash has radio wave absorption characteristics, a coating layer formed by mixing them is provided. The steel member has the same effect as the above invention.

At the same time, since the ferrite fly ash is manufactured by firing at a high temperature, it has fire resistance, and therefore, the coating layer in which it is mixed not only has electromagnetic wave absorption but also has high fire resistance. Demonstrate performance. Therefore, the construction of the countermeasures against radio interference and the construction of the fire-resistant coating, which were separately performed in the past, can be performed by one work, so that the number of works can be reduced, the construction period can be shortened and the construction cost can be reduced. Rationalization and labor saving can be achieved.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of a steel frame member of the present invention.

FIG. 2 is a cross-sectional view schematically illustrating a surface portion of a steel member according to the present invention.

FIG. 3 shows a structural example of a conventional radio wave absorbing curtain wall.
FIG.

[Explanation of symbols]

1 steel member 2 H-section steel (steel) 3 covering material 4 ferritized the fly ash 5 reflective material

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) E04B 1/92

Claims (2)

(57) [Claims] 1. A coating layer formed by mixing a powder having a property of absorbing electromagnetic waves and a powder having a property of reflecting electromagnetic waves in a mortar, is provided on a steel frame surface. Steel frame members. 2. The steel frame member according to claim 1, wherein said powder is ferrite fly ash.