JP7600028B2 - Fire-resistant coating structure - Google Patents

Description

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

The strength of steel members used in structures decreases at high temperatures. Therefore, in order to prevent damage or collapse of steel-framed structures due to fire, measures have been taken to cover the surfaces of steel members with fire-resistant coating materials with thermal insulation properties. Conventionally, non-combustible and flame-retardant materials such as mortar coating, calcium silicate board coating, asbestos slate board coating, concrete coating, and sprayed asbestos coating have been used as fire-resistant coatings, and fire resistance for a specified period of time has been ensured.
Recently, on the other hand, technologies using wooden members have been developed from the viewpoints of improving workability, weight reduction, environmental measures, etc. For example, there exists a fireproof structure in which the surface of a steel member is covered with a fireproof coating material, and a wooden material is laminated on the surface of the fireproof coating material (Patent Document 1).

Japanese Patent Application Publication No. 2-58651

The allowable temperature of steel members on which long-term allowable loads act is limited to approximately 500°C to 550°C. For this reason, wooden members were previously thought to be unsuitable as fire-resistant covering materials, as they would carbonize as the temperature rose and could fall off due to their own weight.
However, the carbonization rate of wooden components is usually about 0.6 mm/min to 1.0 mm/min. It became apparent that if the wooden components have a certain thickness and remain until the required heating time, the temperature of the steel components can be suppressed and they can be used as fire-resistant coating materials, which led to the development of the conventional technology.

However, in conventional fire-resistant structures that use plate-shaped fire-resistant coating materials, gaps form in the joints where the fire-resistant coating materials meet. This creates weak areas through which heat can penetrate, making it impossible to achieve the required fire resistance, and so a solution was needed.

The present invention was made to solve the above problems, and aims to provide a fire-resistant coating structure that is simple in structure, inexpensive to install, and capable of achieving the required fire resistance.

In order to solve the above problems, the fire-resistant covering structure of the present invention (hereinafter sometimes referred to as "this fire-resistant covering structure") is characterized in that it uses wooden members as fire-resistant covering members for steel members, and the joints, which are weak points in terms of fire resistance, are blocked with a specified member, thereby improving fire resistance.

In other words, in this fire-resistant covering structure, a steel member is covered with a plurality of wooden members, each of the wooden members has a flat plate shape with at least one end face formed flat, and at least one location, the flat end faces of adjacent wooden members installed in the vertical direction are butted against each other to form a horizontal joint, and a blocking member for blocking the joint is provided on the steel member side of the joint, and rafters are extended on the surface of the steel member via a base material so as to be parallel to the vertical direction at a predetermined interval, and the rafters are provided at the position of the upper wooden member and the position of the lower wooden member , separated by a predetermined interval, and the blocking member is attached between the upper rafter and the lower rafter.
In addition, in this fire-resistant covering structure, a steel member is covered with a plurality of wooden members, each of the wooden members has a flat plate shape with at least one end face formed flat, and at least one location, the flat end faces of adjacent wooden members installed horizontally are butted against each other to form a vertical joint, and a blocking member for blocking the joint is provided on the steel member side of the joint, and rough girders are extended on the surface of the steel members at a predetermined interval and parallel to the vertical direction, and the blocking member is attached between each of the rough girders.

In addition, this fire-resistant covering structure is a fire-resistant covering structure in which a steel member is covered with a plurality of wooden members, each of the wooden members being formed from a flat plate formed in a rectangular shape and a backing square timber, and at least one location, a joint portion is formed in the vertical direction by abutting the wooden end face of one of the flat plates with the edge portion of the back surface of the other adjacent flat plate , and the backing square timber is provided on the steel member side of the joint portion for closing the joint portion, and rough girders are extended on the surface of the steel members at a predetermined interval via a base material so as to be parallel to the vertical direction, and the flat plates are attached to the rough girders .

Here, the end face of a wooden member having a flat plate shape refers to the butt end face (the side on the short side) and the end face (wooden side face) (the side on the long side), and it is sufficient that at least one end face of adjacent wooden members is formed flat.
In addition, the steel components to be coated can be of any type, including steel frame components such as H-shaped steel, square steel pipes, and circular steel pipes, and can be used in any manner, including as columns and beams.
Furthermore, each wooden member may have a flat plate shape with at least one end surface (end grain surface or end grain surface) formed flat, and the dimensions, etc., may be appropriately determined depending on the embodiment.
Furthermore, as long as the covering member is capable of blocking the joint, it can be made of plate material, square timber, etc., and its shape, dimensions, etc. can be appropriately determined depending on the embodiment.

Furthermore, in this fire-resistant covering structure, the steel members are covered with a plurality of wooden members. In this case, it is necessary to surround the entire periphery of the steel members so that they are not exposed to fire, etc., but the details of the wooden members in the surrounding area, such as the cross-sectional shape, number, installation mode, and number of joints, can be appropriately determined depending on the embodiment.
In particular, the cross-sectional shape of the wooden members in the enclosed area can be determined taking into consideration the shape of the steel members and their decoration, such as rectangular shapes and other polygonal shapes, and in terms of installation manner, multiple wooden members can be arranged side by side in the horizontal or vertical direction.

According to this fire-resistant coating structure, a blocking member is provided on the steel member side of the joints between the wooden members to block the joints. Therefore, even if a fire progresses and a gap forms in the joints, it is possible to prevent heat from entering through the gap, and it is possible to effectively demonstrate fire resistance even when wood is used as a fire-resistant coating material.

In the present fire-resistant covering structure, it is preferable that the blocking member is made of wood and is attached to the wooden member by a fastener.
Here, the fastener may be a metal fitting such as a screw, a nail, or the like.

According to this fire-resistant covering structure, the blocking member is made of wood and is attached to the wooden member with fasteners, so that the blocking member and the wooden member can work together to provide the effect of the fire-resistant covering material. In addition, because it can be easily attached to the wooden member, workability can be improved.

Furthermore, in this fire-resistant covering structure, if the blocking members are attached in advance to the specified positions of the wooden members, this is preferable because it further improves workability, shortens construction time, and reduces costs.

Furthermore, even if wooden components have cracks or knots, they can be easily repaired by filling the affected areas with various repair materials such as epoxy resin and acrylic resin.

The present invention provides a fire-resistant covering structure using wooden members that is simple in structure, inexpensive to install, and capable of providing a desired level of fire resistance.

FIG. 1 is a perspective view of a fire resistant covered structure of the present invention with some wood covering removed. FIG. 2 is a cross-sectional view taken along line I-I in FIG. FIG. 1 is a side view of a fire resistant covered structure of the present invention with some wood cladding removed. FIG. 2 is a perspective view of a fire-resistant covering structure according to another embodiment of the present invention with some of the wood covering removed. 5 is a cross-sectional view taken along line II-II in FIG. 4.

Below, with reference to the drawings, an example of an embodiment of the fire-resistant covering structure T will be described in detail, taking as an example a case in which a steel column 10 is used as the steel member and wooden covering materials 20, 20', 30' are used as the wooden member. In the description based on the drawings, the same elements are given the same reference numerals, and duplicate explanations will be omitted.

[Fireproof coating structure of the first embodiment]
In the fire-resistant covering structure T of the first embodiment, a square steel pipe steel column 10 is covered with a plurality of wooden covering materials 20. The wooden covering materials 20 are set in groups of four wooden covering materials 20 of the same shape, and the groups of four wooden covering materials 20 are installed in two tiers (total of eight wooden covering materials) in the vertical direction (height direction) (FIGS. 1 to 3).

On the surface of each side of the steel column 10, two elongated rafters 11 are provided parallel to the vertical direction at a predetermined interval via a small rectangular piece of base material 12. The rafters 11 are an upper rafter 11 provided at the position of the upper wooden covering material 20, and a lower rafter (not shown) provided at the position of the lower wooden covering material 20, and are provided at a predetermined interval. A backing plate 23 described below is attached between the upper and lower rafters 11.
The base material 12 is welded to appropriate positions on the surface of the steel column 10.

The wooden covering material 20 is formed of a flat plate 21 (wooden member) and a backing square timber (closing member) 22. The flat plate 21 has a rectangular shape and is formed so that the end grain surface 21a and the end grain surface 21b on all four sides are flat.
The backing square timber 22B (22) is attached in advance to the back surface of the flat plate 21B (22) (the surface that will face the steel column 10 when placed) with a screw 29 (fastening device) near one of the vertical edges of the flat plate 21B (21), with a gap from that edge that is the width of the wood end surface 21Ab (hereinafter sometimes simply referred to as the "wood end surface") of the flat plate 21A of the wooden covering material 20A (20) to be joined (for ease of explanation below, in Figure 1, only the necessary elements for each wooden covering material 20 will be distinguished by being given the symbols A, B, X).

The wooden covering material 20 is attached to the outer surface (the side not facing the steel column 10, the same below) of the rough girders 11 on each side of the steel column 10 at a predetermined position with screws 29. The entire wood end surface 21Ab of the wooden covering material 20 is abutted and joined to the rear edge of the adjacent wooden covering material 20 without leaving any gaps. With this structure, a joint 26 is arranged vertically at the corner, and the backing square timber 22B can close the joint 26 at the corner.

In addition, the wooden covering materials 20 adjacent in the height direction are butted against the lower end surface 21Aa (21a) (hereinafter sometimes simply referred to as the "end surface") of the flat plate 21A (21) of the upper wooden covering material 20A (20) and the upper end surface 21Xa (21a) of the lower wooden covering material 20X (20) in the entire surface so as not to create any gaps, thereby forming a horizontal joint 27A (27). A backing plate 23A (23) (closing member) is attached from the outer surface side with screws 29 to the surface of the joint 27A (27) facing the steel column 10 over the entire length of the joint 27A (27) so as to close the gap in the joint 27A (27).
In addition, the backing plate 23A may be attached to one of the wooden covering materials 20 in advance.

[Effects of the present fire-resistant coating structure]
According to this fire-resistant covering structure T, backing square timbers 22 and backing plates 23 for closing the joints 26, 27 are provided on the side of the steel column 10 at the joints 26, 27 of the wooden covering material 20. Therefore, even if gaps are formed at the joints 26, 27 due to the progression of a fire, it is possible to prevent heat from entering through the gaps, and it is possible to effectively exert fire resistance even when wood is used as the fire-resistant covering material.

Furthermore, according to this fire-resistant covering structure T, the wooden backing square timber 22 and the backing plate 23 are attached to the wooden covering material 20 with the screws 29, so that the backing square timber 22 and the backing plate 23 are integrated with the wooden covering material 20 to provide a fire-resistant covering effect. In addition, the backing square timber 22 and the backing plate 23 can be easily attached to the wooden covering material 20, which makes it possible to improve workability.
In particular, since the backing beam 22 is attached in advance to the back surface of the wooden covering material 20 with screws 29, workability is improved, and construction time can be shortened and costs can be reduced.

In this way, with this fire-resistant covering structure T, wood can be actively used as a fire-resistant covering material. As an associated effect, it can be made into an environmentally friendly structure by achieving a carbon dioxide reduction effect. In addition, it has excellent design, texture and visual effects, and a good tactile feel, and can also achieve various effects such as a relaxing scent, humidity control and deodorizing effects, a germicidal effect, and an immune system boosting effect.

[Fire-resistant coating structure of the second embodiment]
The fire-resistant covering structure T of the first embodiment comprises a set of four wooden covering materials 20 of the same shape, which are arranged in two rows (eight pieces in total) in the vertical direction (height direction).
On the other hand, the fire-resistant covering structure T' of the second embodiment has two wooden covering materials 20', 30' arranged side by side horizontally on each side of the steel column 10' (Figs. 4 and 5). The fire-resistant structure T' of the second embodiment differs from the fire-resistant structure T of the first embodiment only in the wooden covering materials 20, 30' (the steel column 10', girders 11' and base material 12' differ only in their dimensions). Below, only the differences will be described.

In the second embodiment of the fire-resistant covering structure T', two identical wooden covering materials 20', 30' (two types x four pieces) are used on each of the opposing surfaces (in the following description, one wooden covering material is referred to as the first wooden covering material 20' and the other wooden covering material is referred to as the second wooden covering material 30').

The first wooden covering material 20' comprises a flat plate 21' and a backing square timber 22'. The flat plate 21' is rectangular in shape and is formed so that the end grain and end wood surfaces on all four sides are flat. Each backing square timber 22' is attached vertically to the back surface of the flat plate 21' of the first wooden covering material 20' near one vertical edge of the flat plate 21' with a gap of the width of the end wood surface 30b' of the second wooden covering material 30' to be joined from the edge by a screw 29'.
The second real wooden covering material 30' is a flat plate formed so that the butt end surface and the end surface 21b' are flat.

The first wooden covering material 20' is attached to the two opposing faces of the steel column 10' at a predetermined position on the joist 11' from the outside with screws 29' so that each face is symmetrical. The first wooden covering material 20' adjacent in the left-right direction butts the opposing end faces 21b' of the flat plates 21' completely together to form a joint 27' in the vertical direction. A backing plate 23' is attached to the surface of the joint 27' facing the steel column 10' from the outside of the first wooden covering material 20' with screws 29' so as to close the gap in the joint 27' over the entire length of the joint 27'.

In addition, the left and right end faces 30b' of the second wooden covering material 30' are abutted against the rear edge of the first wooden covering material 20' at the other two opposing faces, and joined together without leaving any gaps. With this structure, a joining joint 26' is formed in the vertical direction at the corner.
On the other hand, a backing square member 22' is provided on the steel column 10' side of the corner joint 26', and this backing square member 22' is capable of closing the corner joint 26'.

The second wooden covering materials 30' adjacent in the left-right direction have their opposing wood end faces 30b' butted together completely so as to not create any gaps, thereby forming a vertical joint 37'. A backing plate 23' is attached to the surface of the joint 37' facing the steel column 10' over the entire length of the joint 37' from the outer surface side of the second wooden covering material 30' with screws 29' so as to close the gaps in the joint 37'.
Each backing plate 23' is provided in a space formed between two adjacent sills 11'.

The fire-resistant coating structure T' of the second embodiment described above can also achieve the same effect as the first embodiment due to the presence of the backing square timber 22' and backing plate 23' provided at the joints 26', 27', and 37'.

Although an example of a preferred embodiment of the present invention has been described above, the present invention is not limited to this embodiment, and appropriate design changes can be made to each element without departing from the spirit of the present invention.

As described above, there are no limitations on the various aspects of the wooden members and the blocking members, and the most suitable components can be used. In addition, the fire-resistant covering structure is exemplified by the minimum necessary components, and other necessary components may be added as long as they do not impede the effects of the present invention.
In particular, the shapes of the wooden members and the closing members, and the positions, shapes, numbers, etc. of the joints can be appropriately determined depending on the embodiment.

[Verification of the effectiveness of this fire-resistant coating structure]
A loaded heating experiment was conducted to verify the effectiveness of this fire-resistant covering structure.
(1) Test specimens The test specimens used were the fire-resistant covering structure of the first embodiment, in which two types of steel columns with different dimensions were covered with wooden covering materials. Note that two of each test specimen were prepared in consideration of the variability of the results, and a total of four specimens were tested.

The steel column of the first test specimen was a square steel pipe (STKR490) measuring 300 mm x 300 mm x 9 mm and had a length of 3000 mm.
Two wooden cladding sheets were placed on the top and bottom of each side. The wooden cladding sheets used for the steel columns of the first specimen had dimensions of 456 mm x 1500 mm x 36 mm, and the backing square timbers had dimensions of 32 mm x 32 mm and a length of 1500 mm.
A flat plate measuring 456 mm x 120 mm x 30 mm was used as the backing material provided at the joint between the upper and lower wooden covering materials.

The steel column of the second test specimen was a square steel pipe (STKR490) measuring 650 mm x 650 mm x 16 mm and having a length of 3000 mm.
Two wooden cladding sheets were placed on the top and bottom of each side. The flat wooden cladding sheets used for the steel columns of the second specimen had a flat surface dimension of 806 mm × 1500 mm × 36 mm, and the backing square timber had a dimension of 32 mm × 32 mm and a length of 1500 mm.
A flat plate measuring 806 mm x 120 mm x 30 mm was used as the backing material provided at the joint between the upper and lower wooden covering materials.
Cedar wood was used for the wooden covering material, backing timber and backing board.

(2) Experimental method and results The loaded heating experiment was carried out by placing each test specimen in the center of the heating furnace and applying a specified load (first test specimen: 2,072 kN, second test specimen: 8,378 kN) according to the standard heating curve in accordance with ISO 834. The steel column temperature at the specified location, the collapse time of the steel column, the collapse displacement of the steel column, etc. were measured.

[First test piece]
According to the test results of the first specimen, the upper wooden covering peeled off about 43 minutes after heating, exposing the steel pipe pole to the outside. After that, the steel temperature rose because part of the steel pipe pole was directly exposed to the flames, and when the average temperature of the upper part of the steel pipe pole reached about 800°C, it buckled locally and collapsed about 54 minutes after heating. The vertical expansion displacement at the time of collapse was -9.07 mm.
The second test specimen produced similar results.

[Second test piece]
According to the test results of the first specimen, about 36 minutes after heating, the upper wooden covering peeled off, exposing the steel pipe pole to the outside. After that, the steel temperature rose because part of the steel pipe pole was directly exposed to the flames, and when the average temperature of the upper part of the steel pipe pole reached about 700°C, it locally buckled and collapsed about 49 minutes after heating. The vertical expansion displacement at the time of collapse was -6.71 mm.
The second test specimen produced similar results.

According to the above experimental results, although the results varied depending on the dimensions and load of the steel column, it was confirmed that effective fire protection effects could be obtained at least for the 30 minutes required for fire protection and the 45 minutes required for the semi-fireproof structure of steel columns. The experimental results demonstrated that it is possible to further improve fire resistance by improving the quality and shape of the wooden protection material.

T, T' Fireproof coating structure (main fireproof coating structure)
10, 10' Steel column 11, 11' Rough frame 12, 12' Base material 20 Wooden covering material 20' First wooden covering material 30' Second wooden covering material 21, 21' Flat plate (wooden member)
21a End surface 21b, 21b', 30b End surface 22, 22' Backing square timber (closing member)
23, 23' Backing plate (blocking member)
26, 27, 26', 27', 37' Joint joint 29 Screw (fastener)

Claims (3)

In a fire-resistant structure in which steel members are surrounded by multiple wooden members,
Each of the wooden members has a flat plate shape with at least one end surface formed flat,
At least one location is formed by butting the flat end faces of the adjacent wooden members installed in the vertical direction against each other to form a horizontal joint portion;
A blocking member for blocking the joint portion is provided on the steel member side of the joint portion,
A fire-resistant coating structure characterized in that a furring strip is extended on the surface of the steel member with a base material interposed therebetween so as to be parallel to the vertical direction at a predetermined interval, the furring strip consisting of an upper furring strip provided at the position of the upper wooden member and a lower furring strip provided at the position of the lower wooden member , the upper furring strip being provided at the position of the upper wooden member and being spaced apart at a predetermined interval, and the blocking member being attached between the upper furring strip and the lower furring strip. In a fire-resistant structure in which steel members are surrounded by multiple wooden members,
Each of the wooden members has a flat plate shape with at least one end surface formed flat,
At least one location of the wooden members is formed in a vertical direction by butting the flat end faces of the wooden members that are adjacent to each other and are installed in a horizontal direction,
A blocking member for blocking the joint portion is provided on the steel member side of the joint portion,
A fire-resistant coating structure characterized in that rough sills are extended on the surface of the steel members at predetermined intervals and parallel to the vertical direction via a base material, and the blocking members are attached between each of the rough sills. In a fire-resistant structure in which steel members are surrounded by multiple wooden members,
Each of the wooden members is formed from a flat plate formed in a rectangular shape and a backing square timber,
At least one location is formed by abutting the edge of the wood end surface of one of the flat plates and the edge of the back surface of the adjacent other flat plate , forming a joint portion in the vertical direction ;
The backing square bar for closing the joint portion is provided on the steel member side of the joint portion ,
A fire-resistant coating structure characterized in that a rough sill is extended on the surface of the steel member at a predetermined interval and parallel to the vertical direction via a base material, and the flat plate is attached to the rough sill .