JP7427709B2 - Fireproof coating structure for steel frame members - Google Patents

Description

The present invention relates to a fireproof coating structure for steel frame members.

Wooden structural materials are known that include a load support part made of wood, a fireproof layer placed outside the load support part, and a fuel layer made of wood and placed outside the fireproof layer. (For example, see Patent Documents 1 to 3).

Furthermore, a fireproof covering structure is known that includes a steel column, a plurality of studs erected around the steel column, and a fireproof board attached to the plurality of studs and surrounding the steel column (for example, see Patent Document 4). .

Japanese Patent Application Publication No. 2014-129669 Japanese Patent Application Publication No. 2005-048585 Japanese Patent Application Publication No. 2005-053195 Japanese Patent Application Publication No. 2012-041749

By the way, it is conceivable to cover a steel frame member such as a steel frame column with fireproof coating using a plurality of wooden fireproof coating materials. In this case, for example, the ends of adjacent wood fireproof coverings are butted against each other at the corners and screwed to a base material placed around the steel member.

Here, in the event of a fire, the corners where the ends of adjacent wood fireproof covering materials abut are heated from two directions (two-sided heating), so they are more likely to burn down than other parts. If the end portion of the wood fireproof covering material screwed to the base material is burned out at the corner, there is a possibility that the wood fireproof covering material may fall off.

The present invention has been made in consideration of the above-mentioned facts, and an object of the present invention is to suppress the falling off of the wooden fireproof covering material in the event of a fire.

The fireproof coating structure for a steel frame member according to the first aspect includes a steel frame member, a base material disposed around the steel frame member, and a metal plate facing the steel frame member, which are attached to the inner surface, and are abutted against each other at an angle. a plurality of wood fireproof sheathing materials, the end portions of which form a section are screwed together with the metal plate to the base material; It is fastened with screws.

According to the fireproof covering structure for a steel frame member according to the first aspect , the base material is arranged around the steel frame member. Further, a metal plate facing the steel member is attached to the inner surface of the wood fireproof covering material.

Here, the ends of adjacent wood fireproof coverings are butted against each other to form a corner. The ends of this wood fireproof covering are screwed together with the metal plate to the base material. Thereby, the steel frame member is fireproof coated with the wood fireproof sheathing material and the metal plate.

Further, the metal plate is screwed to a general part of the wood fireproof covering material that is removed from the end. That is, the general portion of the wood fireproof covering material is supported by the base material through the metal plate.

As a result, even if the end portion of the wood fireproof sheathing material screwed to the base material at the corner is destroyed by fire in the event of a fire, the general portion of the wood fireproof sheathing material is supported by the base material via the metal plate. Therefore, in the event of a fire, the general portion of the wood fireproof covering material is prevented from falling off.

In the fireproof coating structure for a steel frame member according to a second aspect , in the fireproof coating structure for a steel frame member according to the first aspect , the end portion of the wood fireproof coating material is arranged such that the thickness of the wood fireproof coating material is measured from the outer surface of the corner portion. It is screwed together with the metal plate to the base material within an area 1.5 times larger than .

According to the fireproof covering structure for a steel frame member according to the second aspect , the end portion of the wooden fireproof covering material is attached to the base together with the metal plate within an area 1.5 times the thickness of the wooden fireproof covering material from the outer surface of the corner. It is screwed to the material.

In this way, by screwing the ends of the wood fireproof sheathing together with the metal plate to the base material within an area 1.5 times the thickness of the wood fireproof sheathing from the outer surface of the corner, in the event of a fire, the adjacent wood Opening of the joints at the ends of the fireproof coating is suppressed.

On the other hand, in a region 1.5 times the thickness of the wood fireproof sheathing from the outer surface of the corner, the ends of the wood fireproof sheathing are likely to be burned down in the event of a fire.

On the other hand, in the present invention, the metal plate is screwed to a general portion of the wood fireproof covering material that is separated from the end. That is, the general portion of the wood fireproof covering material is supported by the base material through the metal plate.

As a result, even if an area 1.5 times the thickness of the wood fireproof sheathing is destroyed from the outside surface of the corner in the event of a fire, the general part of the wood fireproof sheathing will be supported by the base material through the metal plate. . Therefore, in the event of a fire, the general portion of the wood fireproof covering material is prevented from falling off.

As described above, in the present invention, in the event of a fire, it is possible to suppress the general portion of the wooden fireproof covering material from falling off, and to suppress the opening of the joints at the ends of adjacent wooden fireproof covering materials.

In the fireproof coating structure for a steel frame member according to a third aspect , in the fireproof coating structure for a steel frame member according to the first aspect , the density of the end portion of the wood fireproof coating material is the density of the general portion of the wood fireproof coating material. higher than

According to the fireproof covering structure for a steel frame member according to the third aspect , the density of the end portion of the wood fireproof covering material is higher than the density of the general portion of the wood fireproof covering material. This makes the ends of the wood fireproof covering more difficult to burn than the general parts of the wood fireproof covering.

Therefore, in the event of a fire, the end portions of the wood fireproof covering material screwed to the base material are prevented from being burned down at the corners formed when the ends of adjacent wood fireproof covering materials abut against each other.

The fireproof coating structure for a steel frame member according to a fourth aspect is attached to the outer surface of the wooden fireproof coating material in the fireproof coating structure for a steel frame member according to any one of the first to third aspects , and the fireproof coating structure is attached to the outer surface of the wooden fireproof coating material. A wood sheathing material having a higher density than the end portion of the material is provided.

According to the fireproof covering structure for a steel frame member according to the fourth aspect , a wooden sheathing material having a higher density than an end portion of the wooden fireproof covering material is attached to the outer surface of the wooden fireproof covering material. This prevents the wooden fireproof coating from being burnt down in the event of a fire.

A fire-resistant covering structure for a steel frame member according to a fifth aspect is a fire-resistant covering structure for a steel frame member according to a fourth aspect , in which the wooden exterior material is provided so as to straddle the joint between the adjacent wooden fire-resistant covering materials.

According to the fireproof covering structure for a steel frame member according to the fifth aspect , the wooden exterior material is provided so as to straddle the joint between adjacent wooden fireproof covering materials. This suppresses the intrusion of fire heat from the joints of adjacent wooden fireproof covering materials to the steel frame member side. Therefore, the fire resistance performance of the steel frame member is improved.

As explained above, according to the present invention, it is possible to suppress the wooden fireproof covering material from falling off in the event of a fire.

It is a cross-sectional view showing a concrete-filled steel pipe column to which the fireproof structure of the steel frame member according to the first embodiment is applied. 2 is a partially enlarged sectional view of FIG. 1. FIG. FIG. 3 is a sectional view corresponding to FIG. 2 showing a modification of the fireproof structure of the steel frame member according to the first embodiment. FIG. 2 is a sectional view corresponding to FIG. 1 showing a concrete-filled steel pipe column to which the fireproof structure of the steel frame member according to the second embodiment is applied. 5 is a partially enlarged sectional view of FIG. 4. FIG. FIG. 6 is a sectional view corresponding to FIG. 5 showing a modification of the fireproof structure of the steel frame member according to the second embodiment. FIG. 3 is a sectional view corresponding to FIG. 2 showing a concrete-filled steel pipe column to which the fireproof structure of the steel frame member according to the third embodiment is applied.

(First embodiment)
First, a first embodiment will be described. Note that the arrow X direction and the arrow Y direction appropriately shown in each figure indicate two horizontal directions orthogonal to each other.

FIG. 1 shows a concrete-filled steel pipe column (hereinafter referred to as "CFT column") 10 to which the fireproof structure of the steel frame member according to the first embodiment is applied. The CFT column 10 includes a steel pipe 12 and concrete 14 filled inside the steel pipe 12.

The steel pipe 12 is, for example, a square steel pipe. A plurality of corner base materials 20 are arranged around the steel pipe 12. Note that the steel pipe 12 is not limited to a square steel pipe, but may be a round steel pipe. Moreover, the steel pipe 12 is an example of a steel frame member.

(corner base material)
The plurality of corner base materials 20 are arranged around the steel pipe 12 along the axial direction of the steel pipe 12. Each corner base material 20 is formed of a lightweight steel frame or the like having an L-shaped cross section, and is disposed outside each corner of the steel pipe 12. Note that the corner base material 20 is an example of a base material.

The corner base material 20 is arranged with the longitudinal direction of the material axis of the steel pipe 12 extending from the column base to the column head of the steel pipe 12. Further, the upper and lower ends of the corner base material 20 are supported by runners (not shown).

The corner base material 20 has a pair of flange portions 20A. The pair of flange portions 20A are bent along the corners of the wood fireproof covering material 30, which will be described later. End portions 30E and 40E of the wooden fireproof covering material 30 and the metal plate 40 are attached to the pair of flange portions 20A.

(Wood fireproof covering material)
A plurality of (four in this embodiment) wooden fireproof covering materials 30 are arranged to surround the steel pipe 12. More specifically, the plurality of wooden fireproof covering materials 30 are arranged in a rectangular frame shape surrounding the steel pipe 12 when viewed from the axial direction of the steel pipe 12, and provide fireproof covering of the steel pipe 12.

Each wood fireproof covering material 30 is arranged with a space between it and the outer surface of the steel pipe 12. The interval functions as a heat insulating layer (insulating space). Further, by leaving a space between the outer surface of the steel pipe 12 and the wooden fireproof sheathing material 30, interference between irregularities such as weld beads formed on the outer surface of the steel pipe 12 and the wooden fireproof sheathing material 30 is suppressed, and The spacing makes it possible to absorb errors in the construction of the wood fireproof covering material 30.

Each wood fireproof covering material 30 is formed of a wood board such as CLT (Cross Laminated Timber), LVL (Laminated Veneer Lumber), laminated wood, or plywood, for example. Note that as the adhesive used for laminated wood etc., thermoplastic resin adhesives and thermosetting resin adhesives can be used, but thermosetting resin adhesives are preferable from the viewpoint of fire resistance.

The wood fireproof covering material 30 functions as a fireproof covering material. Specifically, the wood fireproof coating material 30 functions as a burnt layer that coats the steel pipe 12 with fireproof coating. The burning layer is a layer that suppresses the infiltration of fire heat into the steel pipe 12 side by burning during a fire and forming a carbonized layer (insulating layer).

The thickness (board thickness) t (see FIG. 2) of the wooden fireproof covering material 30 is appropriately set according to the required fireproof performance. More specifically, in the case of one-sided heating, wood (wooden material) is carbonized by 40 mm to 60 mm when heated for 1 hour, 70 mm to 90 mm when heated for 2 hours, and 100 mm to 120 mm when heated for 3 hours.

In addition, when wood (wooden material) is heated on two sides, an allowance of 10% to 20% is required for the thickness, and the thickness of the wood for pillars, beams, etc. (thickness t of the wood fireproof covering material 30) is 1 hour. It is set to 44 mm to 72 mm when heated, 77 mm to 108 mm when heated for 2 hours, and 110 mm to 144 mm when heated for 3 hours.

Examples of the tree species (wood) used for the wooden fireproof covering material 30 include larch, Douglas fir, and cedar. Here, depending on the tree species, the burning state of the outer surface (locating surface) 30B of the wooden fireproof covering material 30 may differ after heating. For example, in the case of cedar, combustion tends to continue over the entire outer surface 30B of the wood fireproof covering 30.

On the other hand, in the case of larch and Douglas fir, combustion continues partially on the outer surface 30B of the wood fireproof covering material 30, but as a whole it is easy to stop burning. Therefore, as the tree species (wood) used for the wooden fireproof covering material 30, larch and Douglas fir are preferable.

Further, the steel pipe 12 has high thermal conductivity. Therefore, even if combustion continues partially on the outer surface 30B of the wooden fireproof covering 30 during a fire, the heat of the fire is diffused throughout the steel pipe 12, so a local temperature rise in the steel pipe 12 is suppressed. Furthermore, since the concrete 14 inside the steel pipe 12 has a large heat capacity, the rise in temperature of the steel pipe 12 is further suppressed.

Therefore, even if larch or Douglas fir is used as the wooden fireproof sheathing material 30 and burning continues partially on the outer surface 30B of the wooden fireproof sheathing material 30 in the event of a fire, the fireproof performance of the CFT column 10 is ensured. be done.

When viewed from the axial direction of the steel pipe 12, adjacent wooden fireproof covering materials 30 are arranged along directions (arrow X direction, arrow Y direction) that are substantially orthogonal to each other. Moreover, the end portions 30E of the adjacent wooden fireproof covering materials 30 abut against each other in an L-shape when viewed from the axial direction of the steel pipe 12, and form a corner portion 30C. Further, a joint 32 is formed between the end portions 30E of adjacent wooden fireproof covering materials 30. The ends 30E of these wood fireproof coverings 30 are attached to the corner base material 20 via metal plates 40.

(metal plate)
The metal plate 40 is made of a steel plate, iron plate, or the like having high thermal conductivity. Further, the metal plate 40 is approximately the same size as the wooden fireproof covering material 30, and is overlapped over substantially the entire surface of the inner surface 30A of the wooden fireproof covering material 30.

The metal plate 40 is attached (fastened with screws) to a portion separated from the end 30E of the wooden fireproof coating 30 (hereinafter referred to as the "general portion 30M") from the steel pipe 12 side. . Moreover, the metal plate 40 is attached to the inner surface 30A of the wooden fireproof covering material 30 and is disposed facing the outer surface (side surface) of the steel pipe 12.

The wood fireproof covering material 30 and the metal plate 40 are arranged over the outer surface of the flange portion 20A of the corner base material 20 adjacent to each other, and the ends 30E and 40E on both sides thereof are attached to the flange portion 20A with a plurality of screws 34. (fastened with screws).

The plurality of screws 34 are arranged at intervals in the longitudinal direction of the flange portion 20A. In addition, in this embodiment, a counterbore 36 for the screw 34 is formed on the outer surface 30B of the wooden fireproof covering material 30. However, the counterbore 36 can be omitted as appropriate.

(Two-sided heating area, one-sided heating area)
As shown in FIG. 2, the corner portion 30C where the end portions 30E of the adjacent wooden fireproof covering materials 30 abut against each other is heated from two directions (two-sided heating) in the event of a fire. The area of the wooden fireproof sheathing material 30 that is heated from two directions in the event of a fire (hereinafter referred to as "two-sided heating area R2") is, for example, the area from the outer surface 30C1 of the corner 30C to the thickness t of the wood fireproof sheathing material 30. The area is said to be 1.5 times larger.

Specifically, for example, in the case of 2-hour fire resistance, the thickness t of the wood fireproof covering material 30 is set to 70 mm to 90 mm. In this case, an area 105 mm to 135 mm (70 mm x 1.5 to 90 mm x 1.5) from the outer surface 30C1 of the corner 30C is the two-sided heating area R2.

As described above, the thickness t of the wood fireproof covering material 30 in the case of one hour fire resistance is set to 40 mm to 60 mm, and the thickness t of the wood fireproof covering material 30 in the case of three hour fire resistance is set to 100 mm to 120 mm. Set.

Further, the area of the wood fireproof covering material 30 other than the two-sided heating area R2 is an area that is heated from one direction in the event of a fire (hereinafter referred to as "one-sided heating area R1").

In the present embodiment, in the two-sided heating region R2, the end portion 30E of the wood fireproof covering material 30 is attached to the corner base material 20 together with the metal plate 40 by a plurality of screws 34. Further, in the one-sided heating region R1, the general portion 30M of the wooden fireproof covering material 30 is attached to the metal plate 40 with a plurality of screws 42.

(effect)
Next, the operation of the first embodiment will be explained.

As shown in FIG. 1, according to this embodiment, a corner base material 20 is arranged around the steel pipe 12 of the CFT column 10. Further, a metal plate 40 facing the steel pipe 12 is attached to the inner surface 30A of the wooden fireproof covering material 30.

As shown in FIG. 2, the ends 30E of adjacent wooden fireproof coverings 30 are butted against each other to form a corner 30C. The end portion 30E of this wood fireproof covering material 30 is screwed together with the metal plate 40 to the corner base material 20. As a result, the steel pipe 12 of the CFT column 10 is fireproof coated with the wood fireproof coating material 30 and the metal plate 40 . Therefore, the fire resistance performance of the steel pipe 12 of the CFT column 10 is improved.

Further, the metal plate 40 is screwed to the general portion 30M of the wood fireproof covering material 30, which is separated from the end portion 30E. That is, the general portion 30M of the wooden fireproof covering material 30 is supported by the corner base material 20 via the metal plate 40.

As a result, even if the end portion 30E of the wood fireproof sheathing material 30 screwed to the corner base material 20 is burned down at the corner portion 30C in the event of a fire, the general portion 30M of the wood fireproof sheathing material 30 can be protected by the metal plate 40. and is supported by the corner base material 20. Therefore, in the event of a fire, the general portion 30M of the wooden fireproof covering material 30 is prevented from falling off.

Here, in the event of a fire, the joints 32 between the ends 30E of adjacent wooden fireproof coverings 30 are likely to open. In order to suppress the opening of the joint 32, it is preferable to screw the end 30E of the wood fireproof covering material 30 to the corner base material 20 at a position close to the joint 32.

Therefore, in the present embodiment, from the viewpoint of suppressing the opening of the joints 32 in the event of a fire, in a two-sided heating area R2 of 1.5 times the thickness of the wooden fireproof covering material 30 from the outer surface 30C1 of the corner 30C, An end 30E of the covering material 30 is screwed together with a metal plate 40 to the corner base material 20. That is, the screw 34 is arranged within the two-sided heating region R2. This prevents the joints 32 at the ends 30E of adjacent wooden fireproof coverings 30 from opening in the event of a fire.

On the other hand, since the two-sided heating region R2 is heated from two directions in the event of a fire, the end portion 30E of the wood fireproof covering material 30 is likely to be burned down.

On the other hand, in this embodiment, the general portion 30M of the wooden fireproof coating 30 is screwed to the metal plate 40 in the one-sided heating region R1. In other words, the screw 42 is disposed within the one-sided heating region R1. Thereby, the general portion 30M of the wooden fireproof covering material 30 is supported by the corner base material 20 via the metal plate 40.

Therefore, even if the two-sided heating region R2 is burnt down in the event of a fire, the general portion 30M of the wooden fireproof covering material 30 is supported by the corner base material 20 via the metal plate 40. Therefore, in the event of a fire, the general portion 30M of the wooden fireproof covering material 30 is prevented from falling off.

In this way, in this embodiment, in the event of a fire, it is possible to suppress the general portion 30M of the wooden fireproof covering material 30 from falling off, and to suppress the opening of the joints 32 of the end portions 30E of the adjacent wooden fireproof covering materials 30. Can be done.

(Modified example of first embodiment)
Next, a modification of the first embodiment will be described.

In the modification shown in FIG. 3, the density of the end portion 30E of the wood fireproof covering 30 is higher than the density of the general portion 30M of the wood fireproof covering 30. Specifically, the wooden fireproof covering material 30 is formed of laminated wood. This wood fireproof covering material 30 includes a plurality of low-density wooden boards 50L and a plurality of high-density wooden boards 50H, which are laminated and bonded.

Note that the low-density wood board 50L and the high-density wood board 50H are examples of wood boards (lamina).

The density of the high-density wood board 50H is higher than the density of the low-density wood board 50L. These high-density wooden boards 50H form an end portion 30E of the wood fireproof covering material 30. This prevents the end portion 30E of the wood fireproof covering material 30 from being burned down in the event of a fire. On the other hand, the general portion 30M of the wooden fireproof covering material 30 is formed by a plurality of low-density wooden boards 50L.

Note that the high-density wooden board 50H may be formed of the same tree species as the low-density wooden board 50L. In this case, for example, the density is calculated from the weight and volume of the wood, and a wood board whose density is less than a predetermined value is defined as a low-density wood board 50L, and a wood board whose density is greater than or equal to a predetermined value is defined as a high-density wood board 50H.

Further, the high-density wood board 50H may be formed of a tree species having a higher density than the low-density wood board 50L. In this case, examples of the low-density wooden board 50L include cedar, and examples of the high-density wooden board 50H include larch and Douglas fir.

Further, in the first embodiment, in the two-sided heating region R2, the end portion 30E of the wood fireproof covering material 30 is screwed to the corner base material 20 together with the end portion 40E of the metal plate 40. However, the thickness t of the wooden fireproof covering material 30 is set according to the fireproof performance (fireproof time) required of the CFT column 10. Moreover, the one-sided heating area R1 and the two-sided heating area R2 are set according to the thickness t of the wooden fireproof covering material 30.

Therefore, depending on the thickness t of the wood fireproof covering material 30, the end portion 30E of the wood fireproof covering material 30 is screwed to the corner base material 20 together with the end portion 40E of the metal plate 40 in the one-sided heating region R1.

(Second embodiment)
Next, a second embodiment will be described. In addition, in the second embodiment, members having the same configuration as those in the first embodiment are given the same reference numerals, and description thereof will be omitted as appropriate.

FIG. 4 shows a CFT column 10 to which the fireproof structure of a steel frame member according to the second embodiment is applied. In the second embodiment, a plurality of low-density wooden exterior materials 60L and a plurality of high-density wooden exterior materials 60H are attached to the outer surface 30B of the wooden fireproof covering material 30. Note that the low-density wooden exterior material 60L and the high-density wooden exterior material 60H are examples of wooden exterior materials.

(Wood exterior material)
The low-density wooden exterior material 60L and the high-density wooden exterior material 60H are formed of, for example, laminated wood or wooden boards such as plywood, and are stacked on the outer surface 30B of the wooden fireproof sheathing material 30 with screws or screws (not shown). It is attached with adhesive or the like.

The density of the low-density wooden exterior material 60L and the high-density wooden exterior material 60H is higher than the density of the wooden fireproof covering material 30. The outer surface 30B of the wooden fireproof covering material 30 is covered with the low-density wooden exterior material 60L and the high-density wooden exterior material 60H. This enhances the design of the CFT column 10.

As shown in FIG. 5, the density of the high-density wooden exterior material 60H is higher than the density of the low-density wooden exterior material 60L. This high-density wooden sheathing material 60H is attached to the outer surface 30B of the end portion 30E of the wooden fireproof sheathing material 30.

Further, the high-density wooden exterior material 60H is attached to the outer surface 30B of the two-sided heating region R2 of the wooden fireproof covering material 30. Furthermore, the high-density wooden exterior material 60H is arranged across the boundary between the one-sided heating area R1 and the two-sided heating area R2 of the wooden fireproof covering material 30, and extends between the two-sided heating area R2 and the one-sided heating area R1. .

On the other hand, the low-density wooden exterior material 60L is attached to the outer surface 30B of the general portion 30M of the wooden fireproof covering material 30. Furthermore, the low-density wooden exterior material 60L is attached to the outer surface 30B of the one-sided heating region R1 of the wooden fireproof covering material 30.

(effect)
Next, the operation of the second embodiment will be explained.

According to this embodiment, a low-density wooden exterior material 60L and a high-density wooden exterior material 60H are attached to the outer surface 30B of the wooden fireproof covering material 30. This prevents the wooden fireproof covering material 30 from being burned down in the event of a fire. Therefore, it is possible to improve the fire resistance of the steel pipe 12 in the CFT column 10 while enhancing the design of the CFT column 10.

Further, the density of the low-density wooden exterior material 60L and the high-density wooden exterior material 60H is higher than the density of the wooden fireproof covering material 30. This further prevents the wooden fireproof covering material 30 from being burned down in the event of a fire.

Furthermore, the density of the high-density wooden exterior material 60H attached to the outer surface 30B of the end 30E of the wooden fireproof covering 30 is higher than the density of the end 30E of the wooden fireproof covering 30. Thereby, it is possible to more reliably prevent the end portion 30E of the wooden fireproof covering material 30 from being burnt down in the event of a fire.

Furthermore, the high-density wooden exterior material 60H is arranged across the boundary between the two-sided heating region R2 and one-sided heating region R1 of the wooden fireproof covering material 30, and extends between the two-sided heating region R2 and one-sided heating region R1. . Thereby, when the two-sided heating region R2 of the wooden fireproof covering material 30 is destroyed by fire, one end side of the high-density wooden exterior material 60H is supported by the one-sided heating region R1. Therefore, falling off of the high-density wooden exterior material 60H is suppressed.

(Modified example of second embodiment)
Next, a modification of the second embodiment will be described.

In the second embodiment, the density of the low-density wooden exterior material 60L and the high-density wooden exterior material 60H is higher than the density of the wooden fireproof covering material 30. However, the density of at least one of the low-density wooden exterior material 60L and the high-density wooden exterior material 60H may be made higher than the density of the wooden fireproof covering material 30.

Further, in the second embodiment, two types of low-density wooden exterior material 60L and high-density wooden exterior material 60H are attached to the outer surface 30B of the wooden fireproof covering material 30. However, one type of wood exterior material having a higher density than the wood fireproof sheathing material 30 may be attached to the outer surface 30B of the wood fireproof sheathing material 30. Moreover, a wooden exterior material having the same density as the wooden fireproof covering material 30 or a density lower than that of the wooden fireproof covering material 30 may be attached to the outer surface 30B of the wooden fireproof covering material 30.

Moreover, in the modification shown in FIG. 6, a high-density wooden exterior material 60H is attached to the outer surface 30B of the wooden fireproof covering material 30 so as to straddle the joints 32 and 38 of the adjacent wooden fireproof covering materials 30.

Specifically, a plurality of corner base materials 20 and a plurality of intermediate base materials 22 are arranged around the steel pipe 12. The intermediate base material 22 is formed of, for example, a lightweight steel frame having an L-shaped cross section, and is disposed between adjacent corner base materials 20 along the axial direction of the steel pipe 12.

The intermediate base material 22 is arranged with the longitudinal direction of the steel pipe 12 in the material axis direction, and extends from the column base to the column head of the steel pipe 12. The upper and lower ends of this intermediate base material 22 are supported by runners (not shown).

The wood fireproof covering material 30 is arranged across the corner base material 20 and the intermediate base material 22 that are adjacent to each other, and its ends on both sides are attached to the corner base material 20 and the intermediate base material 22, respectively, with a plurality of screws 34. It is being Further, on the intermediate base material 22, a joint 38 formed between the end portions of the adjacent wooden fireproof covering materials 30 is arranged.

Here, the high-density wooden exterior material 60H is attached to the outer surface 30B of the wooden fireproof covering material 30 so as to straddle the joints 32 and 38 of the adjacent wooden fireproof covering materials 30. This suppresses the intrusion of fire heat into the steel pipe 12 side of the CFT column 10 from the joints 32 and 38 of the adjacent wooden fireproof coverings 30. Therefore, the fire resistance performance of the steel pipe 12 of the CFT column 10 is improved. Note that a low-density wooden exterior material 60L is attached to other parts of the outer surface 30B of the wooden fireproof covering material 30.

(Third embodiment)
Next, a third embodiment will be described. In addition, in the third embodiment, members having the same configuration as those in the first embodiment are given the same reference numerals, and description thereof will be omitted as appropriate.

FIG. 7 shows a CFT column 10 to which the fireproof structure of the steel frame member according to the third embodiment is applied. In the third embodiment, the wood fireproof covering material 30 is formed of CLT (Cross Laminated Timber).

Specifically, the wood fireproof covering material 30 has a plurality of wood layers 72 in the thickness direction. Each wooden layer 72 is formed by a plurality of wooden boards (laminas) 74. Adjacent wooden layers 72 are laminated and bonded together with the wooden boards 74 intersecting (orthogonal to) each other when viewed from the thickness direction.

The wooden layer 72 located closest to the steel pipe 12 is arranged such that the longitudinal direction of the wooden board 74 is along the axial direction of the steel pipe 12 . Furthermore, in the wooden layer 72 located closest to the steel pipe 12, the wooden board (high-density wooden board) 74H through which the screw 34 is penetrated has a higher density than the other wooden boards 74.

(effect)
Next, the operation of the third embodiment will be explained.

As shown in FIG. 7, the wood fireproof covering material 30 is formed of CLT. In the wood layer 72 of the wood fireproof covering material 30 located closest to the steel pipe 12, the wood board (high-density wood board) 74H through which the screw 34 is penetrated has a higher density than the other wood boards (low-density wood board) 74. There is.

This prevents the wooden board 74H from being burned down in the event of a fire. Therefore, the wooden fireproof covering material 30 is prevented from falling off in the event of a fire.

(Modifications of the first to third embodiments above)
Next, modified examples of the first embodiment, second embodiment, and third embodiment described above will be described. Note that various modifications will be described below using the first embodiment as an example, but these modifications can also be applied to the second and third embodiments as appropriate.

In the first embodiment, the corner base material 20 is formed to have an L-shaped cross section. However, the base material is not limited to an L-shaped cross section, but may also be a stud with a C-shaped cross section, a stud with a rectangular cross section, or the like.

Further, in the first embodiment, the corner base material 20 is supported by a runner (not shown). However, the base material may be supported (or attached) to the steel pipe 12 of the CFT column 10.

Further, in the first embodiment described above, the steel frame member is the steel pipe 12 of the CFT column 10. However, the steel frame member is not limited to the steel pipe 12, but may also be a shaped steel member. Further, in the first embodiment, the steel member is a column (CFT column 10). However, the steel members are not limited to columns, and may also be steel beams.

Although one embodiment of the present invention has been described above, the present invention is not limited to such an embodiment, and the embodiment and various modifications may be used in combination as appropriate, and the gist of the present invention may be It goes without saying that the invention can be implemented in various ways without departing from the scope.

12 Steel pipes (steel members)
20 Corner base material (base material)
30 Wooden fireproof covering material 30A inner surface (inner surface of wood fireproof covering material)
30B External surface (outer surface of wood fireproof covering material)
30C corner 30C1 outer surface (outer surface of corner)
30E End (end of wood fireproof covering material)
30M General section (general section of wood fireproof covering material)
32 Joint 38 Joint 40 Metal plate 60H High-density wood exterior material (wood exterior material)
60L Low density wood exterior material (wood exterior material)
t Thickness (thickness of wood fireproof covering material)
R2 Two-sided heating area (area 1.5 times the thickness of the wood fireproof coating from the outer surface of the corner)

Claims (5)

steel members,
a base material erected around the steel frame member or attached to the steel frame member ;
A plurality of wood fireproof covering materials, wherein metal plates facing the steel frame member are attached to the inner surface, and ends of which abut each other to form corners are screwed together with the metal plates to the base material;
Equipped with
The metal plate is screwed to a general part of the wood fireproof covering that is removed from the end.
Fireproof coating structure for steel frame members. The end portion of the wood fireproof covering material is screwed to the base material together with the metal plate within an area 1.5 times the thickness of the wood fireproof covering material from the outer surface of the corner portion.
A fireproof covering structure for a steel frame member according to claim 1. The density of the end portion of the wood fireproof coating is higher than the density of the general portion of the wood fireproof coating.
A fireproof covering structure for a steel frame member according to claim 1. comprising a wood sheathing material attached to the outer surface of the wood fireproof sheathing material and having a higher density than the end portion of the wood fireproof sheathing material;
A fireproof coating structure for a steel frame member according to any one of claims 1 to 3. steel members,
a base material disposed around the steel member;
A plurality of wood fireproof covering materials, wherein metal plates facing the steel frame member are attached to the inner surface, and ends of which abut each other to form corners are screwed together with the metal plates to the base material;
A wood sheathing material that is attached to the outer surface of the wood fireproof sheathing material and has a higher density than the end portion of the wood fireproof sheathing material;
Equipped with
The metal plate is screwed to a general part of the wood fireproof covering material that is removed from the end part,
The wooden exterior material is provided so as to straddle the joints of the adjacent wooden fireproof covering materials,
Fireproof coating structure for steel frame members.