JP2023003711A - Fireproof structure of steel column - Google Patents

Abstract

To provide a fireproof structure of a steel column improved in workability, without impairing fire resistance.SOLUTION: A fireproof structure 1 of a steel column 2 has the steel column 2 and a fireproof plate 3 arranged with a space in relation to the steel column 2 and covering the steel column 2. The fireproof structure 1 of the steel column 2 has an opening 32 formed to the fireproof plate 3, a wiring box 4 having an opening face on one face and fitted to the fireproof plate 3 with the opening face facing the opening 32 and positioned between the fireproof plate 3 and the steel column 2, and a fireproof covering material 7 covering the wiring box 4 between the fireproof plate 3 and the steel column 2. The fireproof covering material 7 has a pair of side covering materials 71 fitted to a left side plate 42 and a right side plate 43 of the wiring box 4 and extending to the steel column 2, and an upper covering material 72 jointing the upper ends of the pair of side covering materials 71 with each other, and the parts corresponding to a back plate 45 and a bottom plate 44 of the wiring box 4 are opened.SELECTED DRAWING: Figure 3

Description

The present invention relates to a fire-resistant structure for steel columns.

Patent Literature 1 describes a conventional fire-resistant structure for steel columns. A fire-resistant structure of a steel column described in Patent Document 1 includes a steel column and a board member covering the steel column. An opening is formed in the board member over the entire length in the vertical direction.

For example, a switch box, an outlet box, and the like are arranged in the opening, and the opening is closed by a cover member. A fireproof plate having a substantially U-shaped cross section is attached between the board member and the steel frame column in the opening. By covering the opening with the fireproof plate having a substantially U-shaped cross section, it is possible to suppress deterioration in fire resistance of the board member having the opening.

JP 2012-062683 A

However, in the fire-resistant structure described in Patent Document 1, it takes time and effort to construct a pair of left and right side surfaces and a back surface using a fire-resistant plate between the board member and the steel frame column. There is In particular, in recent years, there are many structures in which a steel frame column surrounded by a board member is finished as small as possible, and the space between the steel frame column and the board member is narrow, so there is a problem that construction is even more difficult.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a fire-resistant structure for steel columns that can improve workability without impairing fire resistance.

A fire-resistant structure for a steel-frame column according to one aspect of the present invention is a fire-resistant structure for a steel-frame column that includes a steel-frame column and a fire-resistant plate disposed with a gap from the steel-frame column and covering the steel-frame column. The fireproof plate has an opening formed in the fireproof plate and an opening surface on one side, and the fireproof plate is arranged so that the open surface faces the opening and is positioned between the fireproof plate and the steel frame column. and a fireproof covering material covering the wiring box between the fireproof plate and the steel frame column. The fireproof covering material includes a pair of side covering materials attached to the left side plate and the right side plate of the wiring box and extending to the steel frame column, and an upper covering material connecting the upper ends of the pair of side covering materials. and a portion corresponding to the back plate and the bottom plate of the wiring box is open.

A fire-resistant structure for a steel-frame column according to one aspect of the present invention is a fire-resistant structure for a steel-frame column that includes a steel-frame column and a fire-resistant plate disposed with a gap from the steel-frame column and covering the steel-frame column. The fireproof plate has an opening formed in the fireproof plate and an opening surface on one side, and the fireproof plate is arranged so that the open surface faces the opening and is positioned between the fireproof plate and the steel frame column. and a thermally expansible refractory material provided on the inner surface of the wiring box and expanded by heating to form a refractory and heat insulating layer.

The fire-resistant structure of the steel frame column according to the above aspect of the present invention has an advantage that workability can be improved without impairing fire resistance.

FIG. 1(A) is a cross-sectional view of a fireproof structure of a steel column according to one embodiment of the present invention. FIG. 1(B) is an enlarged view of part B of FIG. 1(A). FIG. 2(A) is a front view of the fireproof structure of the same steel column, with the fireproof plate on the front side omitted. FIG. 2(B) is an enlarged view of part A of FIG. 2(A). FIG. 3(A) is a side view of the same fire-resistant structure of steel columns, omitting the side-side fire-resistant plate. FIG. 3(B) is an enlarged view of part C of FIG. 3(A). FIG. 4 is a perspective view showing the lid portion of the same. FIG. 5A is an enlarged view of part A according to Modification 1. FIG. FIG. 5(B) is a cross-sectional view taken along line X1-X1 of FIG. 5(A). FIG. 6 is an enlarged view of part C according to Modification 2. As shown in FIG. FIG. 7 is a cross-sectional view of a fireproof structure of a steel column according to Modification 3. FIG. 8A and 8B are cross-sectional views of a fireproof structure of a steel column according to Modification 4. FIG.

<Embodiment>
(1) Overall In the fire-resistant structure 1 of the steel-frame column 2 according to the present embodiment, the steel-frame column 2 of the building is surrounded and covered with fire-resistant plates 3, so that when a fire occurs, the steel-frame column 2 becomes hot. It is a structure to prevent the strength from decreasing due to The building is not particularly limited, and examples thereof include commercial facilities, office buildings, distribution facilities, gymnasiums, housing complexes, and the like. The fireproof structure 1, as shown in FIG. 1, covers a steel column 2, a plurality of fireproof plates 3, a plurality of spacers 8, a wiring box 4, a lid 6 (FIG. 2), and a wiring box 4. refractory covering material 7;

(2) Steel column The steel column 2 is a metal column. The longitudinal direction of the steel column 2 is substantially parallel to the vertical direction. Examples of the steel frame columns 2 include rectangular steel pipe columns, circular steel pipe columns, H-shaped steel columns, CFT (Concrete Filled Steel Tubes), etc. In this embodiment, square steel pipe columns are used. The steel column 2 is a hollow column, but may be a solid column.

(3) Fireproof board The fireproof board 3 is a board|plate material which has fire resistance. A steel frame column 2 is covered with a plurality of fireproof plates 3. Each fireproof plate 3 is arranged with a gap with respect to the steel frame column 2. - 特許庁A gap between the fireproof plate 3 and the steel frame column 2 is maintained by a plurality of spacers 8, and the fireproof plate 3 is installed so as not to come into contact with the steel frame column 2. - 特許庁The dimension H1 of the gap between the fireproof plate 3 and the steel frame column 2 is not particularly limited, but when the wiring box 4 is installed, it becomes larger than the thickness dimension of the wiring box 4, and is usually 40 mm or more and 300 mm or less. Yes, and is set to 100 mm in this embodiment.

As shown in FIG. 1(A), the steel column 2 is surrounded by a plurality of fireproof plates 3 . However, in the present invention, the steel frame column 2 is constructed of an outer wall plate (for example, ALC, PC plate, etc.) facing one surface of the steel frame column 2 and three fireproof plates 3 facing the other three surfaces of the steel frame column 2. Alternatively, the steel frame column 2 may be surrounded by a pair of external wall plates forming an outward corner and two fireproof plates 3. That is, the fireproof plate 3 should be included in at least a part of the elements surrounding the steel column 2 .

Further, the dimension H1 of the gap between the fireproof plate 3 and the steel frame column 2 may be the same dimension over the entire circumference of the steel frame column 2, or may be different depending on the part.

The fireproof board 3 is at least one selected from the group consisting of a calcium silicate board, a gypsum board, a reinforced gypsum board, a rock wool board, a ceramic fiber board, a PC board, an extruded cement board, an ALC panel, and a GRC panel. It is configured. Among these, from the viewpoint of fire resistance, the fireproof board 3 preferably contains a calcium silicate board.

Adjacent fireproof boards 3 are fixed to each other by fastening members 31 in a state of being arranged substantially at right angles in a plan view. The fastening member 31 is composed of, for example, a screw, a nail, a bolt, a fixture, or the like. However, the fireproof board 3 may be attached to other structures (for example, steel columns 2, ceiling boards, floor boards, etc.) using spacers 8 or other fixtures.

The thickness dimension of the fireproof plate 3 is not particularly limited, and is appropriately determined according to the required fireproofness. The thickness dimension of the fireproof board 3 is, for example, 25 mm.

The fireproof plate 3 is formed with an opening 32 for exposing the front surface of the instrument body 5 housed in the wiring box 4 . The opening 32 penetrates the fireproof plate 3 . The opening 32 is formed in a substantially rectangular shape in a front view in this embodiment. Although the opening 32 is configured as a substantially rectangular through-hole in the present embodiment, it may have a shape cut out from the edge of one fireproof plate 3, for example.

(4) Wiring Box The wiring box 4 is a box for housing the appliance main body 5 . The wiring box 4 is composed of a metal box, and as shown in FIG. 2(B), includes a top plate 41, a left side plate 42, a right side plate 43, a bottom plate 44 and a back plate 45 (FIG. 3(B)). and has an opening on the front side. A cover 47 that covers the opening on one side of the wiring box 4 and the opening 32 of the fireproof plate 3 is attached to the wiring box 4 . An opening is formed in the central portion of the cover 47 to expose the instrument main body 5 .

Examples of the device main body 5 include a power supply device for inserting a plug, a switch device having a switch, and a device combining these. The switch is not particularly limited, and examples thereof include rocker switches, slide switches, toggle switches, push button switches, and the like.

Examples of the wiring box 4 include a switch box, an outlet box, an outlet box, a pull box, and the like. In this embodiment, as the wiring box 4, an outlet box and a switch box arranged above the outlet box are used as shown in FIG. 2(A). The method of forming the wiring box 4 is not particularly limited, and it may be formed into a box shape by bending a metal plate, may be formed by casting, or may be formed by drawing.

As shown in FIG. 3B, the wiring box 4 is installed so that the front opening face faces the opening 32 of the fireproof plate 3 and is positioned between the fireproof plate 3 and the steel frame column 2. . A gap L1 is interposed between the back plate 45 of the wiring box 4 and the steel frame column 2. - 特許庁The wiring box 4 is attached to the fireproof board 3 . Attachment of the wiring box 4 to the fireproof plate 3 is not particularly limited, and can be achieved by, for example, screwing, fitting, sandwiching, adhesion, or the like.

The wiring box 4 has a connection connector 46 . The connecting connector 46 is connected to a flexible tube 52 in which an electric cable 51 is arranged, and the electric cable 51 can be routed inside the wiring box 4 through the inside of the connecting connector 46 . The connecting connector 46 is formed in a cylindrical shape and attached to the top plate 41 . It should be noted that the connecting connector 46 may be attached to the bottom plate 44, as will be described later in a modified example.

The electric cable 51 is connected to the appliance main body 5 inside the wiring box 4 . As shown in FIG. 3A, the electric cable 51 passes between the steel frame column 2 and the fireproof plate 3, passes through the cover portion 6 provided at the upper end of the fireproof plate 3, and extends between the steel frame column 2 and the fireproof plate 3. It is taken out from between the fireproof board 3 and the outside.

(5) Lid Portion The lid portion 6 closes the gap between the fireproof plate 3 and the steel frame column 2, as shown in FIG. The lid portion 6 includes a plate body 61 having a notch portion 611 , a filler 62 made of a biosoluble fiber and an inorganic adhesive, and a cylindrical body 63 .

The plate main body 61 is a portion that constitutes the main body of the lid portion 6 . A notch 611 is formed in the end surface of the plate body 61 facing the fireproof plate 3 . The plate body 61 preferably has fire resistance and is preferably made of the same material as the fire-resistant plate 3 .

The filling material 62 is filled between the cylindrical body 63 and the notch 611 while the cylindrical body 63 is placed in the notch 611 . The filling material 62 is configured, for example, by stuffing biosoluble fibers between the cylindrical body 63 and the notch 611 and then solidifying the biosoluble fibers with an inorganic adhesive. Here, the biosoluble fiber means an amorphous inorganic fiber that dissolves in vivo. According to the biosoluble fiber, even if the biosoluble fiber is taken into the body, the risk of carcinogenicity in the body can be reduced. Examples of biosoluble fibers include AES. AES is an artificial mineral fiber heat insulating material made from silica, calcia, magnesia, etc., and includes alkaline earth silicate wool and alkaline earth silicate fiber.

The cylindrical body 63 is formed in a cylindrical shape, one end of which opens below the plate body 61 and the other end of which opens above the plate body 61 . As a result, the flexible tube 52 is passed through the cylindrical body 63 along the central axis. That is, the inner peripheral surface of the cylindrical body 63 constitutes the through hole of the lid portion 6 .

The cylindrical body 63 is preferably made of a thermal expansion material. The thermal expansion material is a material that expands in volume and closes the opening of the cylinder 63 when exposed to high temperatures due to fire. The thermally expansive material is not particularly limited, but is, for example, a synthetic resin mixed with expansive graphite. The thermally expansive material includes, for example, a synthetic resin as a base material, expansive graphite, and an inorganic filler. Synthetic resins include, for example, thermoplastic resins, rubber substances, thermosetting resins, and the like.

(6) Fireproof Covering Material The fireproof covering material 7 covers the wiring box 4 between the fireproof plate 3 and the steel frame column 2, as shown in FIG. 1(B). However, the fireproof covering material 7 according to the present embodiment does not cover the entire outer surface of the wiring box 4, but rather covers the back plate 45 and the bottom plate 44 of the wiring box 4 as shown in FIGS. 2(B) and 3(B). The part corresponding to is open. That is, the back plate 45 and the bottom plate 44 of the wiring box 4 are exposed in the space between the fireproof plate 3 and the steel frame column 2 without being covered. As a result, it is possible to improve workability by reducing the ease and difficulty of construction of the fireproof covering material 7 while ensuring a certain level of fire resistance, and also to reduce material costs. The fireproof covering material 7 is composed of a pair of side covering materials 71 and an upper covering material 72, as shown in FIG. 2(B).

The side covering material 71 is attached to the outer surface of each of the left side plate 42 and the right side plate 43 of the wiring box 4 . The side covering material 71 has an upper end surface positioned at the same level as the upper surface of the top plate 41 of the wiring box 4 and a lower end surface positioned at the same level as the lower surface of the bottom plate 44 of the wiring box 4 . However, the lower end surface of the side covering material 71 may be positioned below the lower surface of the bottom plate 44 of the wiring box 4 .

The side covering material 71 extends from the fireproof plate 3 to the steel frame column 2 as shown in FIG. 3(B). In this embodiment, the surface facing the fireproof plate 3 extends to the position where it hits the fireproof plate 3 , and the surface facing the steel frame column 2 extends to the steel frame column 2 . However, in the present invention, the side covering material 71 only needs to cover about half of the ends of the left and right side plates 42 and 43 on the steel frame 2 side. , does not need to extend until it hits the fireproof plate 3.

Here, "the side covering material 71 extends to the fireproof board 3" means not only that the surface facing the fireproof board 3 is in contact with the fireproof board 3, but also that the side covering material 71 extends to the fireproof board 3. It also includes extending to a position close to the fireproof board 3. The same applies to the expression "the side covering material 71 extends to the steel frame column 2".

The side covering material 71 may be attached to each of the left side plate 42 and the right side plate 43 of the wiring box 4 by adhesion, or may be attached to the fireproof plate 3 with a fastener F1 such as a nail. Alternatively, it may be attached by both adhesive and fixture F1.

The upper covering member 72 connects the upper ends of the pair of side covering members 71, as shown in FIG. 2(B). The upper covering member 72 may be formed over the entire length of the upper end surfaces of the pair of side covering members 71, including the upper surface of the top plate 41. In this embodiment, the connecting connector 46 is attached to the top plate 41. Therefore, as shown in FIG. 3B, it is not provided at a position corresponding to the top plate 41 of the wiring box 4 among the upper end faces of the pair of side covering members 71 . The upper covering member 72 prevents the heat radiated from the back plate 45 of the wiring box 4 from moving above the upper ends of the side covering members 71 .

The upper covering material 72 preferably extends to the steel column 2 . "The upper covering material 72 extends to the steel frame column 2" includes not only extending to a position where the surface facing the steel frame column 2 touches the steel frame column 2, as in the case of the side covering material 71, but also the steel frame column 2 The surface facing to extends to a position close to the fireproof board 3.

The refractory coating material 7 (that is, the side coating material 71 and the upper coating material 72) includes calcium silicate board, gypsum board, reinforced gypsum board, rock wool board, ceramic fiber board, ceramic fiber blanket, PC board, It is preferably composed of at least one selected from the group consisting of an extruded cement board, an ALC panel and a GRC panel. Among these, it is preferable that the fireproof covering material 7 contains a calcium silicate board from the viewpoint of fire resistance.

As described above, the fireproof covering material 7 is composed of the side covering material 71 and the upper covering material 72, and the positions corresponding to the back plate 45 and the bottom plate 44 are opened, so that the fireproof covering material 7 can be easily constructed. It is possible to improve the workability by reducing the difficulty of the construction, and to reduce the material cost.

On the other hand, since the fireproof covering material 7 that covers the back plate 45 and the bottom plate 44 is omitted as the fireproof covering material 7, there is a concern that the fire resistance will be lowered. Then, when the space between the wiring box 4 and the steel frame column 2 is covered from the sides and above, a certain level of fire resistance can be obtained. As a result, it is possible to improve workability and reduce material costs while ensuring a certain level of fire resistance.

The following is considered as one of the reasons why the decrease in fire resistance was suppressed. In the fireproof structure 1 of the present embodiment, even if a fire breaks out and the wiring box 4 is heated, the heat is dissipated from the back plate 45 to between the fireproof plate 3 and the steel frame column 2, so that the heat is generated in the wiring box 4. Even if the wiring box 4 is heated by flames of fire or the like, the heat is radiated between the fireproof plate 3 and the steel frame column 2 from the back plate 45, so that the heat is transferred between the top plate 41 of the wiring box 4 and the top plate 41 of the wiring box 4. It is possible to suppress the danger of concentrating on the connecting connector 46 installed on the plate 41 and the electric cable 51 connected to the connecting connector 46 and eventually causing the fire to spread to the electric cable 51 . Moreover, since the heat radiated from the back plate 45 is prevented from rising by the upper covering member 72, it is possible to prevent the connecting connector 46 and the electric cable 51 from being heated intensively in the same manner as described above. Note that the heat conducted to the bottom plate 44 is radiated from the bottom plate 44 . However, due to the upward nature of flames, the heating by the flames is much more intense in heating the back plate 45 than in heating the bottom plate 44 .

In addition, in this embodiment, since the space inside the wiring box 4 is not filled with a filler such as rock wool or ceramic fiber for imparting fire resistance, the space inside the wiring box 4 can be widely used. . Therefore, the electrical work for connecting the electric cable 51 to the device main body 5 is easy, and the filling material does not retain moisture inside the wiring box 4, so that the filling material does not cause electric leakage. It also has the advantage of being avoidable.

<Modification>
The above embodiment is but one of the various embodiments of the present invention. The embodiment can be modified in various ways according to the design etc., as long as the object of the present invention can be achieved. Modifications of the embodiment will be described below. Modifications described below can be applied in combination as appropriate.

(1) Modification 1
In the above embodiment, the connecting connector 46 is attached to the top plate 41 of the wiring box 4, but the connecting connector 46 is attached to the bottom plate 44 of the wiring box 4 as shown in FIGS. may An electric cable 51 is connected to the connecting connector 46 from the floor slab through between the fireproof plate 3 and the steel frame column 2 .

As shown in FIG. 5, the point that the fireproof covering material 7 is composed of a pair of side covering materials 71 and an upper covering material 72 is the same as in the above-described embodiment, but in this modified example, the upper covering material 72 extends from the fireproof plate 3 to the steel frame column 2. Therefore, the upper covering material 72 covers the upper surface of the top plate 41 of the wiring box 4 .

As a result, even if the wiring box 4 is heated, the heat can be radiated from the back plate 45 without immediately rising upward. Since the connecting connector 46 attached to the bottom plate 44 is located below the wiring box 4, heat is less likely to concentrate.

(2) Modification 2
In the above embodiment, the wiring box 4 is covered with the fireproof covering material 7, but in this modification, as shown in FIG. Attach to the inner surface of box 4.

The thermally expandable refractory material 9 expands in volume to form a refractory insulating material and fills the inside of the wiring box 4 when exposed to a high temperature caused by a fire. The thermally expandable fireproof material 9 is not particularly limited, and examples thereof include synthetic resin mixed with expandable graphite. The thermally expandable fireproof material 9 contains, for example, a synthetic resin as a base material, expandable graphite, and an inorganic filler. Synthetic resins include, for example, thermoplastic resins, rubber substances, thermosetting resins, and the like. The thermally expandable fireproof material 9 may be, for example, a fireproof sheet or fireproof paint.

As the fire-resistant sheet, a two-layered fire-resistant sheet consisting of a thermal expansion layer and an adhesive layer (for example, “Suributasuke” (registered trademark) manufactured by Nippon Insulation Co., Ltd.) can be preferably used.

The coefficient of expansion of the thermally expandable refractory material 9 is not particularly limited as long as it can fill most of the inside of the wiring box 4 when expanded. is preferably 250%, more preferably 300%.

The thermally expandable fireproof material 9 may be provided on any of the top plate 41, the left side plate 42, the right side plate 43, the back plate 45 and/or the bottom plate 44 of the wiring box 4; From the viewpoint of suppressing heat transfer to 2, it is preferable to provide it inside the back plate 45 . Although it is provided only on the inner surface of the back plate 45 in this modification, it may be provided on another surface in addition to the inner surface of the back plate 45 . As a result, the expanded thermally expandable fireproof material 9 can fill most of the inside of the wiring box 4 .

The thermally expandable fireproof material 9 is fixed to the back plate 45 by means of coating, adhesion, screwing, riveting, or the like, for example. Since the heat-expandable fireproof material 9 is provided on the inner surface of the back plate 45, it can be constructed from the outside of the fireproof plate 3, and workability is good.

(3) Modification 3
In the above-described embodiment, the steel column 2 is made of a rectangular steel pipe column, but as shown in FIG. 7, the steel column 2 may be made of H-section steel. When the steel column 2 is made of H-section steel, the wiring box 4 is arranged between the H-section steel flange 21 and the fireproof plate 3 . Since the rest of the configuration is the same as that of the above embodiment, description thereof is omitted.

Even when the steel frame column 2 is made of H-shaped steel, as shown in Modification 2, instead of the fireproof covering material 7, the thermally expandable fireproof material 9 may be attached to the inner surface of the wiring box 4.

(4) Modification 4
In the above-described embodiment, the steel column 2 is a square steel pipe column, but as shown in FIGS. 8A and 8B, the steel column 2 may be a circular steel pipe column. When the steel frame column 2 is configured by a circular steel pipe column, the wiring box 4 is arranged between any portion of the circular steel pipe column in the circumferential direction and the fireproof plate 3 . Since the rest of the configuration is the same as that of the above embodiment, description thereof is omitted.

As shown in FIG. 8(A), the fireproof plate 3 may be formed concentrically with the steel frame column 2 and arranged at a constant interval with respect to the steel frame column 2 . In this case, a plurality of arc-shaped fireproof boards 3 may be connected to form a circular fireproof board 3, or a cylindrical fireproof board 3 may be used. Moreover, as shown in FIG. 8B, the fireproof plate 3 may be formed to have a rectangular cross section as in the above-described embodiment even when the steel frame column 2 is a circular steel pipe column.

Also in the case of Modification 4, as shown in Modification 2, instead of the fireproof covering material 7, the thermally expandable fireproof material 9 may be attached to the inner surface of the wiring box 4. FIG.

(5) Other Modifications Modifications of the embodiment are listed below.

In the above embodiment, the fireproof coating material 7 corresponding to the back plate 45 of the wiring box 4 is not provided, but if there is concern about local heating of the portion facing the back plate 45 of the steel column 2, A refractory material, a thermally expandable refractory material 9, or the like may be attached to the relevant portion of the steel frame column 2 as necessary.

Further, in the above embodiment, the connecting connector 46, the electric cable 51 and the flexible tube 52 are not provided with measures to prevent the spread of fire. . For example, the connecting connector 46 and the electric cable 51 may be covered with a fireproof sheet, or coated with fireproof paint, or the connecting connector 46 itself may be made of the thermally expandable fireproof material 9 .

In the above-described embodiment, the electric cable 51 is passed through the lid portion 6 provided at the upper end of the fireproof plate 3 and taken out from between the steel frame column 2 and the fireproof plate 3 . It is also possible to provide the lid portion 6 on the side surface of the intermediate portion and let the electric cable 51 go out from the intermediate portion of the fireproof plate 3 .

In this specification, expressions with "substantially" such as "substantially parallel" or "substantially orthogonal" may be used. For example, "substantially parallel" means substantially "parallel", and includes not only a strictly "parallel" state but also an error of several degrees. The same applies to expressions with other "abbreviations".

In addition, in this specification, expressions such as "end" and "end" are used to distinguish between the presence or absence of "... portion". For example, "edge" refers to the distal portion of an object, while "edge" refers to an area of definite extent that includes the "edge". Any point within a certain range including the edge is regarded as an "edge". The same applies to other expressions with "... part".

<Summary>
As described above, the fire-resistant structure 1 of the steel-frame column 2 according to the first aspect includes the steel-frame column 2, the fire-resistant plate 3 arranged with a gap from the steel-frame column 2 and covering the steel-frame column 2, It is a fire-resistant structure 1 of a steel column 2. The fire-resistant structure 1 of the steel frame column 2 has an opening 32 formed in the fire-resistant plate 3 and an opening surface on one side, the opening surface facing the opening 32 and between the fire-resistant plate 3 and the steel frame column 2 and a fireproof coating material 7 covering the wiring box 4 between the fireproof plate 3 and the steel frame column 2. The fireproof covering members 7 are a pair of side covering members 71 attached to the left side plate 42 and the right side plate 43 of the wiring box 4 and extending to the steel frame column 2, and an upper covering member connecting the upper ends of the pair of side covering members 71. 72, and the portions corresponding to the back plate 45 and the bottom plate 44 of the wiring box 4 are open.

According to this aspect, the workability of the fireproof coating material 7 of the wiring box 4 can be improved while the fireproof property of the steel frame column 2 is kept constant, and the material cost can be reduced. can be done. As a result, workability and material costs can be reduced without impairing fire resistance.

In the fire-resistant structure 1 of the steel frame column 2 according to the second aspect, the pair of side covering materials 71 extends to the fire-resistant plate 3 in the first aspect.

According to this aspect, the heat entering the wiring box 4 due to the fire is radiated laterally from the left and right side plates 42, 43 of the wiring box 4, thereby preventing the temperature inside the fireproof structure of the steel frame column 2 from rising immediately. can be prevented.

In the fire-resistant structure 1 of the steel column 2 according to the third aspect, the wiring box 4 has the connection connector 46 through which the electric cable 51 is passed on the top plate 41 or the bottom plate 44 in the first or second aspect.

According to this aspect, the connecting connector 46 can be attached to the top plate 41 or the bottom plate 44 which is less affected by heat, and the electrical cable 51 can be prevented from being damaged by heat.

In the fireproof structure 1 of the steel frame column 2 according to the fourth aspect, in any one of the first to third aspects, the fireproof covering material 7 is a calcium silicate board, a gypsum board, a reinforced gypsum board, or a rock wool board. , a ceramic fiber board, a ceramic fiber blanket, a PC board, an extruded cement board, an ALC panel, and a GRC panel.

According to this aspect, the fire resistance of the opening 32 can be obtained more effectively.

In the fireproof structure 1 of the steel frame column 2 according to the fifth aspect, in any one of the first to fourth aspects, the fireproof board 3 is a calcium silicate board, a gypsum board, a reinforced gypsum board, a rock wool board, It is composed of at least one selected from the group consisting of a ceramic fiber board, a PC board, an extruded cement board, an ALC panel and a GRC panel.

According to this aspect, the fire resistance of the steel column 2 can be effectively obtained.

A fire-resistant structure 1 of a steel column 2 according to a sixth aspect includes a steel column 2 and a fireproof plate 3 disposed with a gap from the steel column 2 and covering the steel column 2. Fire resistant structure 1. The fire-resistant structure 1 of the steel frame column 2 has an opening 32 formed in the fire-resistant plate 3 and an opening surface on one side, the opening surface facing the opening 32 and between the fire-resistant plate 3 and the steel frame column 2 and a thermally expandable fireproof material 9 which is provided on the inner surface of the wiring box 4 and expands when heated to form a fireproof insulation layer.

According to this aspect, fire resistance can be obtained by providing the thermally expandable fire resistant material 9 without using the fire resistant coating material 7, so that the fire resistant coating material of the wiring box 4 can be used while maintaining the fire resistance constant. In addition to improving the workability of 7, the material cost can be reduced. As a result, workability and material costs can be reduced without impairing fire resistance.

In the fire-resistant structure 1 of the steel frame column 2 according to the seventh aspect, the thermally expandable fire-resistant material 9 is provided on the inner surface of the back plate 45 of the wiring box 4 in the sixth aspect.

According to this aspect, in the event of a fire, the thermally expandable refractory material 9 can be expanded with good reactivity, and heat radiated from the back plate 45 to the steel frame column 2 can be effectively suppressed.

In the fire-resistant structure 1 of the steel frame column 2 according to the eighth aspect, in the sixth or seventh aspect, the thermally expandable fire-resistant material 9 contains at least one of sheet material and paint.

According to this aspect, it is possible to improve workability when providing the thermally expandable fireproof material 9 .

REFERENCE SIGNS LIST 1 refractory structure 2 steel column 3 fireproof plate 32 opening 4 wiring box 41 top plate 42 left plate 43 right plate 44 bottom plate 45 back plate 46 connecting connector 7 fireproof covering material 71 side covering material 72 upper covering material 9 thermally expandable fireproof material

Claims (8)

steel columns and
a fireproof plate disposed with a gap with respect to the steel column and covering the steel column;
A steel column fireproof structure comprising
an opening formed in the fireproof plate;
a wiring box having an open surface on one side, the open surface facing the opening and attached to the fireproof plate so as to be positioned between the fireproof plate and the steel frame column;
a fireproof covering material that covers the wiring box between the fireproof plate and the steel frame column;
with
The fireproof coating material is
a pair of side covering members attached to the left side plate and the right side plate of the wiring box and extending to the steel column;
an upper covering member connecting the upper end portions of the pair of side covering members;
and a portion corresponding to the back plate and the bottom plate of the wiring box is open,
Fireproof structure of steel columns. the pair of side claddings extending to the fire plate;
The fireproof structure of the steel column according to claim 1. The wiring box has a connecting connector on the top plate or the bottom plate for passing an electric cable,
The fire-resistant structure of the steel frame column according to claim 1 or claim 2. The refractory coating material is selected from the group consisting of calcium silicate board, gypsum board, reinforced gypsum board, rock wool board, ceramic fiber board, ceramic fiber blanket, PC board, extruded cement board, ALC panel, GRC panel. consists of at least one
The fireproof structure of the steel column according to any one of claims 1 to 3. The fireproof board is at least one selected from the group consisting of calcium silicate board, gypsum board, reinforced gypsum board, rock wool board, ceramic fiber board, PC board, extruded cement board, ALC panel and GRC panel. It is configured,
The fireproof structure of the steel column according to any one of claims 1 to 4. steel columns and
a fireproof plate disposed with a gap with respect to the steel column and covering the steel column;
A steel column fireproof structure comprising
an opening formed in the fireproof plate;
a wiring box having an open surface on one side, the open surface facing the opening and attached to the fireproof plate so as to be positioned between the fireproof plate and the steel frame column;
a thermally expansible fireproof material provided on the inner surface of the wiring box, which expands when heated to form a fireproof and heat insulating layer;
comprising
Fireproof structure of steel columns. The thermally expandable refractory material is provided on the inner surface of the back plate of the wiring box,
The fireproof structure of the steel column according to claim 6. The thermally expandable refractory material includes at least one of sheet material and paint,
The fireproof structure of the steel column according to claim 6 or 7.

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