JP2021161653A - Fire resistant structure of wooden building and construction method therefor - Google Patents

Abstract

To provide a fire resistant structure of a wooden building which has small sectional area.SOLUTION: A fire resistant structure of a wooden building comprises: cedar laminate lumber (pillar) of 300×300 mm in cross-sectional size as load bearing lumber 2; sheet type rock wool of 1.5 mm in thickness as a sheet type inorganic fiber layer 3 provided outside the cedar laminate lumber; aluminum foil of 20 μm in thickness as a radiation heat reflection layer 4 which is provided outside the sheet type rock wool and reflects radiation heat; a sheet of 5 mm in thickness containing ammonium polyphosphate and vinyl acetate copolymer resin as a heat foaming layer provided outside the aluminum foil and foaming at 200°C to develop heat insulation; and (5) cypress lumbering of 19 mm in thickness as a decorative material provided outside the foaming type heat resistant coating sheet.SELECTED DRAWING: Figure 1

Description

The present invention relates to a fireproof structure of a wooden building and a wooden structural member used therein.

Conventionally, as a fireproof structure of a wooden building, for example, a core material made of laminated lumber that supports a load, a second burn-off layer made of an inorganic material provided outside the core material and having heat absorption and heat insulating properties, and the like. A sheet-shaped first burn-stop layer provided on the outside of the second burn-stop layer and thickened by heating to exhibit heat insulating properties, and a finishing material provided on the outside of the first burn-stop layer are provided. When it is composed of a structure (see Patent Document 1) and a wood material that supports a load, an air layer provided on the outside of the core material, an endothermic and heat insulating inorganic material provided on the outside of the air layer, and an inorganic material. There is a structure (see Patent Document 2) that includes a fireproof coating material provided on the outside of the fireproof coating material and a finishing material provided on the outside of the fireproof coating material.

However, these structures require a thick coating to protect the load-bearing members such as columns, beams, and walls from the heat of combustion during a fire, resulting in a large cross-sectional area of the structure of the building. There is a problem that the weight increases and the effective area in the building is reduced.

Japanese Unexamined Patent Publication No. 2015-129431 Japanese Unexamined Patent Publication No. 2017-179889

The problem to be solved is to provide a fireproof structure for a wooden building with a small cross-sectional area.

The fireproof structure of the wooden building of the present invention includes (1) a load-supporting wood that supports the load of the wooden building, (2) a sheet-like inorganic fiber layer provided outside the load-supporting wood, and (3). A radiant heat reflecting layer provided outside the sheet-shaped inorganic fiber layer that reflects radiant heat, and (4) a heated foam layer provided outside the radiant heat reflecting layer that foams at 200 ° C. or higher to exhibit heat insulating properties. , (5) The most important feature is to provide a decorative material provided on the outside of the heated foam layer.

According to the fireproof structure of a wooden building of the present invention, there is an advantage that a fireproof structure (column, beam, wall, etc.) having a small cross-sectional area can be obtained.

It is sectional drawing which showed the example of the fireproof structure (pillar) of this invention. It is sectional drawing which showed the example of the fireproof structure (wall) of this invention. It is sectional drawing which showed the example of the fireproof structure (beam) of this invention.

The fireproof structure 1 of the wooden building of the present invention is, for example, as follows.
As shown in FIG. 1, (1) a sugi laminated lumber (pillar) having a cross-sectional size of 300 mm × 300 mm as a load-supporting timber 2 and (2) provided outside the sugi laminated lumber to support the load of a wooden building. The sheet-shaped rock wool having a thickness of 1.5 mm as the sheet-shaped inorganic fiber layer 3 and (3) the aluminum having a thickness of 20 μm as the radiant heat-reflecting layer 4 provided on the outside of the sheet-shaped rock wool to reflect radiant heat. (4) Containing 5 mm thick ammonium polyphosphate and vinyl acetate copolymer resin as a heat-foamed layer provided on the outside of the aluminum wool and foaming at 200 ° C. or higher to exhibit heat insulating properties. A sheet and (5) a hinoki lumber having a thickness of 19 mm as a decorative material 5 provided on the outside of the foamed fireproof coating sheet are provided.

Examples of the load-bearing timber 2 include beams, walls, floors, and the like in addition to columns.
The load-bearing wood 2 is not limited to Sugi, and any tree species can be set. For example, coniferous trees such as Sugi, larch, Japanese cypress, and Japanese yew, and broad-leaved trees such as cherry, zelkova, beech, oak, and oak can be mentioned.

The load-bearing wood 2 is not limited to laminated lumber and can be arbitrarily set. For example, lumber, veneer laminated board (LVL), cross laminated board (CLT), plywood and the like can be mentioned.

The load-bearing wood 2 may be impregnated with a flame retardant such as phosphoric acid or boric acid to impart flame retardancy.

As the cross-sectional dimension of the load-bearing timber 2, the cross-sectional dimension necessary for indicating the load required for the building can be arbitrarily set.

The sheet-shaped inorganic fiber layer 3 needs to be provided on the outside of the load-indicating wood.

The sheet-shaped inorganic fiber layer 3 is provided to delay heat transfer due to convection, and is not limited to sheet-shaped rock wool, and can be arbitrarily set as long as it is a material having an effect of delaying heat transfer due to convection. For example, ceramic fiber, glass wool and the like can be mentioned. The inorganic fiber may be used by making a paper machine and molding it into a sheet. Of these, it is preferable to use sheet-shaped rock wool or ceramic fiber. As the ceramic fiber, it is preferable to use a bulk of the ceramic fiber in the form of a sheet. For example, Fineflex BIO Paper of Nichias Co., Ltd., 1260 Paper S of Isolite Industries, Ltd., 1600 Paper Isowool, 1260 Ace Paper, Isowool 1500 Ace paper and the like can be mentioned. By using the sheet-shaped inorganic fiber, the cross-sectional area of the fireproof structure 1 can be reduced as compared with the case of using a gypsum board, a calcium silicate board, wood impregnated with a flame retardant, or the like.

The thickness of the sheet-like inorganic fiber layer 3 per layer is preferably 0.3 to 5.0 mm, more preferably 0.5 to 3.0 mm, and 0.7 to 2.0 mm. Most preferably.

The method of fixing the sheet-shaped inorganic fiber layer 3 to the load-bearing wood 2 can be arbitrarily set. For example, it may be fixed with an adhesive, double-sided tape, building staples, nails, screws (hereinafter referred to as "tucker") or the like. The adhesive can be arbitrarily set as long as it adheres the sheet-shaped inorganic fiber layer 3 to the load-bearing wood 2. For example, ethylene vinyl acetate resin adhesive, vinyl acetate resin adhesive, acrylic resin adhesive, polyvinyl alcohol adhesive, urethane resin adhesive, epoxy resin adhesive and the like can be mentioned.

The sheet-shaped rock wool is formed into a sheet shape by making or pressurizing rock wool fibers, and may contain a synthetic resin such as polyvinyl alcohol, an acrylic resin, or a vinyl acetate resin as a binder. Further, another inorganic fiber such as glass fiber or an inorganic material containing water of crystallization such as aluminum hydroxide may be contained.

The radiant heat reflecting layer 4 needs to be provided on the outside of the sheet-shaped inorganic fiber layer 3.
The radiant heat reflecting layer 4 is not limited to aluminum foil, and can be arbitrarily set as long as it is a material that reflects radiant heat. For example, metals such as gold, silver and copper, and white oxides such as titanium oxide and magnesium oxide can be mentioned. Of these, the metal is preferably used in the form of a metal foil. Further, it is preferable to use a white oxide such as titanium oxide in the form of a paint or the like.

The thickness of the radiant heat reflecting layer 4 is preferably 5 to 50 μm, more preferably 10 to 35 μm, and most preferably 15 to 30 μm.

The method of fixing the radiant heat reflecting layer 4 to the sheet-shaped inorganic fiber layer 3 can be arbitrarily set. For example, it may be fixed with an adhesive, double-sided tape, building staples, nails, screws (hereinafter referred to as "tucker") or the like. The adhesive can be arbitrarily set as long as it adheres the sheet-shaped inorganic fiber layer 3 to the load-bearing wood 2. For example, ethylene vinyl acetate resin adhesive, vinyl acetate resin adhesive, acrylic resin adhesive, polyvinyl alcohol adhesive, urethane resin adhesive, epoxy resin adhesive and the like can be mentioned.

It is preferable that the radiant heat reflecting layer 4 and the sheet-shaped inorganic fiber layer 3 are laminated in advance for use. With such a configuration, the workability when the radiant heat reflection layer 4 is made of a metal foil is excellent.

The radiant heat reflecting layer 4 and the sheet-shaped inorganic fiber layer 3 may be repeatedly laminated. For example, sheet-shaped inorganic fiber layer / radiant heat reflecting layer / sheet-shaped inorganic fiber layer / radiant heat reflecting layer, sheet-shaped inorganic fiber layer / radiant heat reflecting layer / sheet-shaped inorganic fiber layer / radiant heat reflecting layer / sheet-shaped inorganic fiber layer / radiant heat reflection Layer, sheet-shaped inorganic fiber layer / radiant heat-reflecting layer / sheet-shaped inorganic fiber layer / radiant heat-reflecting layer / sheet-shaped inorganic fiber layer / radiant heat-reflecting layer / sheet-shaped inorganic fiber layer / radiant heat-reflecting layer, sheet-shaped inorganic fiber layer / radiant heat-reflecting Examples thereof include a layer / sheet-shaped inorganic fiber layer, a radiant heat-reflecting layer / sheet-shaped inorganic fiber layer / radiant heat-reflecting layer, and the like.

The heat foam layer needs to be provided on the outside of the radiant heat reflection layer 4.

The heated foam layer can be arbitrarily set as long as it foams at 200 ° C. or higher due to the heat of combustion during a fire to form the sheet-like inorganic fiber layer 3. For example, those containing ammonium polyphosphate and a synthetic resin, those containing expansive graphite and a synthetic resin, and the like can be mentioned.

The form of the heated foam layer can be arbitrarily set. For example, sheet-like, paint-like, and the like can be mentioned. Of these, when used in the form of a sheet, it is excellent in workability.

The thickness of the heated foam layer can be arbitrarily set according to the required fire resistance time.

The synthetic resin used for the heated foam layer can be arbitrarily set. For example, acrylic resin, vinyl chloride resin, vinyl acetate resin, polyethylene resin, urethane resin, silicone resin, natural rubber, butadiene rubber, butyl rubber and the like can be mentioned. Of these, it is preferable to use a vinyl acetate resin or a vinyl acetate copolymer resin obtained by copolymerizing a vinyl acetate resin with another synthetic resin.

The sheet containing ammonium polyphosphate and vinyl acetate copolymer resin preferably contains polyhydric alcohols such as pentaerythritol, dipentaerythritol and polyethylene glycol, titanium oxide, melamine and the like.

The decorative material 5 needs to be provided on the outside of the heated foam layer.

The decorative material 5 is provided to impart designability to the fireproof structure 1 such as columns, beams, and walls. The decorative material 5 is not limited to wood and can be arbitrarily set as long as it imparts design. For example, wallpaper, paint, etc. may be used.

When wood is used for the decorative material 5, the tree species is not limited to cypress and can be arbitrarily set. For example, coniferous trees such as Sugi, larch, Japanese cypress, and Japanese yew, and broad-leaved trees such as cherry, zelkova, beech, oak, and oak can be mentioned.

When wood is used for the decorative material 5, the grade is not limited to lumber and can be set arbitrarily. For example, a veneer, a single plate laminated plate (LVL), and the like can be mentioned. Further, the surface of the wood may be painted.

The fireproof structure 1 of the wooden building configured as described above holds the structure by the following mechanism in the event of a fire.

When the fireproof structure 1 of the present invention receives the heat of combustion at the time of fire, the outermost decorative material 5 burns. Subsequently, when the surface temperature reaches 200 ° C. or higher, the heated foam layer foams to form the sheet-like inorganic fiber layer 3, thereby delaying heat transfer. If the thickness of the heated foam layer is about 5 mm, when heating is performed in a refractory furnace according to the standard heating curve of ISO834, the load-bearing wood 2 can be withstood for about 1 hour without being ignited. Since the foaming temperature of the heated foam layer is 200 ° C. or higher, if the heated foam layer is left in the fireproof furnace after heating in a state where the heat foam layer is in direct contact with the load-supporting wood 2, the residual heat in the furnace is gradually loaded. It is transmitted to the supporting wood 2, and finally reaches the ignition temperature of the wood, which is around 260 ° C. However, in the fireproof structure 1 of the present invention, since the sheet-shaped rock wool and the aluminum foil are laminated between the load-bearing wood 2 and the heated foam layer, the residual heat in the furnace is transferred to the load-bearing wood 2. The inside of the furnace cools down before it is transmitted, and the load-bearing wood 2 does not ignite.

Hereinafter, the present invention will be described with reference to Examples and Comparative Examples. This is a configuration example of a fireproof structure of a wooden building required to obtain fireproof performance for one hour. The covering material is described so that the side closer to the load-bearing wood 2 is on the upper stage and the side farther from the load-bearing wood 2 is on the lower stage. The heated foam layer is a case where a sheet containing ammonium polyphosphate and a vinyl acetate copolymer resin is used. The fireproof structure of the present invention has the smallest cross-sectional area.

1 Fireproof structure 2 Load-bearing wood 3 Sheet-shaped inorganic fiber layer 4 Radiant heat reflection layer 5 Decorative material

Claims (5)

(1) Load-supporting wood that supports the load of a wooden building, (2) Sheet-shaped inorganic fiber layer provided outside the load-supporting wood, and (3) Provided outside the sheet-shaped inorganic fiber layer. On the outside of the radiant heat reflecting layer that reflects the radiant heat, (4) a heated foam layer that is provided outside the radiant heat reflecting layer and foams at 200 ° C. or higher to exhibit heat insulating properties, and (5) outside the heated foam layer. A fireproof structure of a wooden building characterized by being provided with decorative materials. The fireproof structure of a wooden building according to claim 1, wherein the sheet-shaped inorganic fiber layer and the radiant heat reflecting layer are repeatedly laminated. The fireproof structure of a wooden building according to claim 1 or 2, wherein the sheet-shaped inorganic fiber layer is sheet-shaped rock wool, and the radiant heat-reflecting layer is aluminum foil. The fireproof structure of a wooden building according to claim 1 to 3, wherein the heated foam layer is in the form of a sheet containing a vinyl acetate copolymer resin and ammonium polyphosphate. The method for constructing a fireproof structure of a wooden building according to claim 1, wherein the sheet-shaped inorganic fiber layer and the radiant heat reflective layer are laminated in advance as a radiant heat reflective heat insulating member.

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