JP7174514B2 - Wooden fireproof member - Google Patents

Description

TECHNICAL FIELD The present invention relates to a wooden fire-resistant member provided with a fire-resistant coating layer and a finishing wood layer on the outside of a wooden load-bearing part.

With the enactment of the "Act on Promotion of Use of Wood in Public Buildings, etc." in 2010, there is a growing trend toward the use of wood in buildings. On the other hand, when wood, which is a combustible material, is used for structural members such as pillars and beams, it is desirable that the wood has fire resistance to ensure safety in the event of a fire.
For the purpose of ensuring the fire resistance of wooden structural members, a large number of fire-resistant structures have been developed in which wooden load-bearing parts are covered with a fire-resistant coating. It should be noted that the fire-resistant structure is required to prevent the wooden load-bearing part from being carbonized even when the fire ends. The fire-resistant coating layer is generally formed by attaching a board such as a mortar board, a gypsum board, or a wooden structural member impregnated with a flame retardant agent to the load-bearing layer. For example, Patent Literature 1 discloses a wooden structural member in which a fire-stopping layer made of flame-retardant-treated wood is interposed between a decorative wood made of wood and a wooden load-bearing portion. .
As described above, the refractory coating layer needs to have a thickness that does not allow ambient heat to be transmitted to the wooden load-bearing part during or after a fire. Therefore, simply forming a fire-resistant coating layer on the outer surface of the wooden load-bearing portion increases the cross-sectional area of the wooden structural member. Therefore, if the cross-sectional area of the wooden structural member becomes large, the degree of freedom of utilization of shared space (living space, etc.) is restricted. Therefore, as a fireproof coating layer, the wooden load-bearing part is covered with a foam material that maintains a thin layer during normal use, but foams when exposed to heat, thereby minimizing the cross-sectional area of the member during normal use. Also disclosed is a wooden structural member capable of securing a layer thickness necessary for a flame stop layer by foaming a foam material after a fire occurs. For example, Patent Literature 2 discloses a wooden structural member in which a heat-shielding portion formed by laminating an incombustible material and a foam layer is interposed between a wooden load-bearing portion and a finished wood layer. Further, Patent Document 3 discloses a wooden structural member in which a heat shielding portion formed by laminating a foam layer and a film-like incombustible material is interposed between a wooden load-bearing portion and a finished wood layer. there is Further, in Patent Documents 2 and 3, the wooden load support portion and the heat shield portion are adhered with an adhesive, and the heat shield portion and the finished wood layer are adhered with an adhesive. On the other hand, since the surface of the foam material is not flat, it has been difficult to directly bond the finishing wood layer to the surface of the foam material.

JP 2015-025245 A JP 2010-236255 A Japanese Unexamined Patent Application Publication No. 2012-180700

The present invention, as a wooden fire-resistant member to be placed in the main structural part that bears the vertical load and seismic load, has the texture of wood in the outer covering, has good workability, and is mainly exposed to heat in the event of a fire. An object of the present invention is to propose a wooden fire-resistant member that prevents a structural part from being affected.

As a wooden fire-resistant member, the present inventors laminated a moisture blocking layer, a fire-resistant coating layer, and a finishing wood layer on the outer peripheral surface of the wooden load-bearing part in order toward the outside, so that the fire-resistant coating layer provided a predetermined heat insulation performance. Focusing on the fact that can be ensured, it led to the wooden fire-resistant member of the present invention.
In order to solve the above-mentioned problems, the wooden fire-resistant member of the first invention includes a fire-resistant member on the outer peripheral surface and both side outer surfaces of the wooden load-bearing portion (opposed outer surfaces such as the upper and lower surfaces and the left and right side surfaces of the wooden load-bearing portion). A wooden fire-resistant member provided with a coating layer and a finishing wood layer, the wooden load-bearing part having a rectangular or circular cross-sectional shape, and a moisture blocking layer provided on the outer surface of the wooden load-bearing part. , a fireproof coating layer made of a wet fireproof coating material covering the moisture barrier layer, and a finishing wood layer provided on the outside of the fireproof coating layer , wherein the moisture barrier layer comprises a moisture barrier coating film and a moisture barrier. It is characterized by being formed of either a sheet or waterproof paper .
According to such a wooden fire-resistant member, a moisture blocking layer is formed between the wooden load-bearing part and the fire-resistant coating layer, and the wet-type fire-resistant coating material is used for the fire-resistant coating layer. Since moisture can be prevented from penetrating into the wooden load-bearing part, it is possible to suppress the influence on the strength characteristics of the wooden load-bearing part. In addition, a finished wood layer is provided on the outer skin portion, and a fireproof coating layer and a wooden load supporting portion are provided toward the inside of the finished wood layer to form a wooden fire-resistant member, thereby arranging the wood on the outer skin portion. , a wooden fire-resistant member with a wooden load-bearing part in the center of the cross section was realized. In addition, since the outer peripheral surface of the wooden load-bearing part is covered with a moisture-blocking layer formed of one of a moisture-blocking coating film, a moisture-blocking sheet, and waterproof paper, moisture in the refractory coating layer is prevented from is prevented from penetrating into Therefore, the wooden load-bearing part made of wood does not suffer from deterioration in strength or discoloration due to moisture in the wet-type fire-resistant coating material forming the fire-resistant coating layer, and structural performance and fire-resistant performance can be ensured.

Furthermore, the present inventors arranged a connecting member as a spacer function on the outer peripheral surface of the wooden load-bearing part, and fixed the position of the finishing wood layer, so that even a fireproof coating layer with an uneven surface can achieve high performance. Focusing on the fact that a finished wood layer can be formed with good quality, the wooden fire-resistant member of the second invention was developed. A wooden fire-resistant member of the second invention is a wooden fire-resistant member in which a fire-resistant coating layer and a finishing wood layer are provided on the outer peripheral surface or both side outer surfaces of the wooden load-bearing part, and has a rectangular or circular cross-sectional shape. a moisture barrier layer provided on the outer surface of the wooden load support part; a fire resistant coating layer comprising a wet fire resistant coating material covering the moisture barrier layer; and a connecting member disposed through the fireproof coating layer, wherein the connecting member is formed of a columnar or plate-like mortar member or gypsum board. and
According to such a wooden fire-resistant member, the fire-resistant coating layer arranged on the outer peripheral surface and the outer surface of the wooden load-bearing part is fixed by screwing from the outer surface of the finishing wood layer or by bonding it to the inner surface of the finishing wood layer. Instead, a plurality of connecting members are installed on the outer peripheral surface of the wooden load-bearing part at predetermined intervals, and both edge surfaces of the connecting members are adhered to the wooden load-bearing part and the finishing wood layer, and the wooden load-bearing part and the finish are bonded. An installation space for the fire-resistant coating layer was secured between the wooden layer and the fire-resistant coating layer was arranged in the installation space. Therefore, even on the outer peripheral surface of the refractory coating layer where it is difficult (uneven) to flatten the surface, the finishing material can be installed with high quality.

A wooden fire-resistant member according to a third aspect of the invention is a wooden fire-resistant member that constitutes a pillar or a wall pillar, and is characterized in that the fire-resistant coating layer is arranged on the upper end and the lower end (timber end) of the finished wood layer. do.
In this way, in addition to the above effects, by arranging the fireproof coating layer on both ends of the finishing timber layer arranged along the wooden load-bearing part where the wooden fireproof member contacts the building frame, fire In some cases, the spread of fire between the building frame and the finished wood layer that constitutes the wooden fire-resistant member can be suppressed. In addition, by providing a fire-resistant coating layer with lower compressive rigidity than the finished wood layer on the end of the finished wood layer that constitutes the wooden fire-resistant member, even if the wooden fire-resistant member is greatly deformed during an earthquake, Since the exposed portion of the covering layer can absorb the displacement, it is possible to prevent damage at the contact portion between the wooden fireproof member and the building frame.

According to the present invention, it is possible to provide a wooden fire-resistant member that has the texture of wood in the outer covering portion, has good workability, and has excellent fire-resistant performance.

(a) is a plane cross-sectional view schematically showing the wooden fire-resistant member according to the first embodiment, and (b) is a cross-sectional view of the wooden fire-resistant member. (a) to (c) are plan cross-sectional views showing examples of forming a moisture blocking layer according to another embodiment. 2(a) to 2(c) are plan cross-sectional views schematically showing a method of forming the wooden fire-resistant member of FIG. 1. FIG. (a) Appearance of a test specimen for heating experiment of the covered wooden fire-resistant column used in the heating experiment conducted on the wooden fire-resistant member of the present embodiment, and (b) wooden load constituting the wooden fire-resistant member according to the result of the same heating experiment. It is a cut cross section of a support part. It is a plane cross section containing the fireproof coating layer after foaming of the wooden fireproof member by the heating experiment result. It is a steady heat transfer model of the wooden fireproof member of this embodiment. It is a plane sectional view which shows typically the wooden fireproof member which concerns on 2nd embodiment. (a) and (b) are cross-sectional design examples of wooden fire-resistant members for ensuring two-hour fire-resistant performance.

The present invention is a wooden fire-resistant member in which a moisture barrier layer, a fire-resistant coating layer, and a finishing wood layer are sequentially provided on the outer peripheral surface of a wooden load-bearing portion toward the outside. Wooden fire-resistant members are characterized by having a finishing wood layer corresponding to the margin for burning, and a fire-resistant coating layer corresponding to the stop-burning portion that can stop burning and carbonization during the spread of fire or after heating. The point is to provide a moisture blocking layer between the part and the refractory coating layer. By providing a moisture blocking layer between the wooden load-bearing part and the refractory coating layer, it is possible to prevent moisture from moving between the wooden load-bearing part and the refractory coating layer made of foaming fireproof paint or wet refractory coating material. . Therefore, moisture does not permeate the wooden load-bearing portion, and corrosion of the wood forming the wooden load-bearing portion can be prevented.
FIG. 1 shows a first embodiment of the present invention, FIG. 7 shows a second embodiment, and FIG. 8 shows a cross-sectional design example of a wooden fire-resistant member for ensuring two-hour fire resistance performance.
Hereinafter, with reference to the accompanying drawings, each configuration of the wooden fire-resistant member according to the present invention, the results of heating experiments and the results of heat conduction analysis relating to fire-resistant performance will be described.

<First embodiment>
A wooden fire-resistant member 1 of the first embodiment is a member that constitutes a pillar of a building, and has a square cross section as shown in FIG. 1(a). In addition, the cross-sectional shape of the wooden fire-resistant member 1 is not limited, and may be, for example, a rectangular shape or a circular shape.
The wooden fire-resistant member 1 comprises a wooden load-bearing part 2 , a moisture barrier layer 3 , a fire-resistant coating layer 4 and a finishing wood layer 5 .

The wooden load support part 2 is a so-called structural member, and as shown in FIG. It has a cross-sectional dimension (600 x 600 mm in this embodiment) that can be used. The wooden load supporting portion 2 of the present embodiment is made of laminated larch wood having a square cross section. It should be noted that the material constituting the wooden load supporting portion 2 is not limited to larch, and may be, for example, Japanese cedar, Japanese cypress, hemlock, or the like. Moreover, the wooden load supporting portion 2 is not limited to laminated lumber, and may be formed by combining a plurality of small-diameter lumbers and joining them together. Furthermore, the cross-sectional dimensions and cross-sectional shape of the wooden load-bearing part 2 are not limited, and may be appropriately determined according to the stress acting on the wooden fire-resistant member 1 .

The moisture blocking layer 3 covers the periphery of the wooden load support portion 2 . That is, the wooden fire-resistant member 1 of this embodiment has the moisture barrier layer 3 formed between the wooden load-bearing portion 2 and the fire-resistant coating layer 4 . The water blocking layer 3 is formed by winding a metal plate 31 having a thickness of 0.3 mm around the outer surface of the wooden load supporting portion 2 and screwing the ends. The moisture barrier layer 3 is not a structural member. Note that the thickness of the metal plate 31 is not limited. Also, the method of fixing the metal plate 31 is not limited, and for example, it may be adhered. The method of forming the moisture barrier layer 3 is not limited. For example, as shown in FIG. Alternatively, as shown in FIG. 2B, it may be formed by abutting a pair of metal plates 31 having a U-shaped cross section. As shown in FIG. 2(c), two or four (two in the drawing) metal plates 31 having an L-shaped cross section may be fixed to the outer surface of the wooden load support portion 2. FIG. In addition, the material constituting the moisture blocking layer 3 is not limited to a metal plate as long as it can block the permeation of moisture. (trade name), etc.), a moisture blocking sheet (eg, Air Dry (registered trademark), etc.), or waterproof paper. When a moisture barrier coating is employed, a predetermined coating is provided on the outer peripheral surface of the wooden load support portion 2 by a spraying method or a coating method using a brush. When a moisture blocking sheet or waterproof paper is used, it is fixed to the outer peripheral surface of the wooden load support portion 2 using a fixing pin or an adhesive.

The fireproof coating layer 4 covers the outer periphery of the moisture barrier layer 3, as shown in FIG. 1(a). The fire-resistant coating layer 4 of this embodiment is formed to have a predetermined thickness (2 to 10 mm in this embodiment) by applying or spraying an expandable fire-resistant paint on the outer surface of the moisture blocking layer 3 . The fireproof coating layer 4 may be formed by placing a plate-like material (foamable fireproof board) coated with a foamable fireproof paint on the outside of the moisture blocking layer 3 at a factory. The thickness of the fireproof coating layer 4 is determined according to the desired fireproof time. The refractory coating layer 4 is not a structural member. As shown in FIG. 1(a), the fireproof coating layer 4 is applied (chamfered) so as not to form corners. That is, in the portions corresponding to the corners of the wooden fire-resistant member 1, the foaming fire-resistant paint is applied in an arc shape. By doing so, foam failure such as cracking of the refractory coating layer 4 at the corners can be prevented. In addition, corners of the fireproof coating layer 4 may be corner-cut. The foamable fire-resistant paint used is one that foams before it reaches the temperature at which wood begins to carbonize in the event of a fire (carbonization initiation temperature of 260° C.). The present embodiment uses an intumescent refractory coating that begins to foam at relatively low temperatures of about 150° C. or less. The foamable fireproof coating material used for the fireproof coating layer 4 is not limited to this, and for example, a commonly used material that starts foaming at about 200 to 300°C may be used. . Foaming fire-resistant paint is a fire-resistant coating material that exhibits fire-resistant performance for about 1 to 3 hours with a coating film that is several mm to several tens of mm thick, and forms a carbonized layer by foaming 20 to 100 times in the event of a fire. By doing so, the wooden load support portion 2 is protected from fire. Examples of foaming fire-resistant coatings include foaming acrylic resin coatings and SK Taica Coat (registered trademark), which is a water-based foaming fire-resistant coating manufactured by SK Kaken Co., Ltd. The material constituting the fire-resistant coating layer 4 is not limited to the foamable fire-resistant paint, and may be, for example, a plate-like fire-resistant coating material or a sheet-like fire-resistant coating material. A plate-like or sheet-like fireproof coating material is attached or wound around the outer peripheral surface of the wooden load support portion 2 to ensure a predetermined layer thickness. The plate-like or sheet-like refractory covering material is a heat-resistant rock wool material having a colored nonwoven fabric on its surface, or a xonotlite-based calcium silicate refractory covering material. For example, the heat-resistant rock wool material is Makibee (registered trademark) of fire-resistant coating material manufactured by NICHIAS Corporation.

Also, the fireproof coating layer 4 may be formed of a wet fireproof coating material by spraying. Specifically, the wet refractory coating material includes rock wool and cement, sprayed rock wool mainly composed of water, or sprayed ceramic refractory coating mainly composed of white cement, aluminum hydroxide, and calcium carbonate. is. Blasted rockwool is a refractory coating mixed with 6:4:8 rockwool:cement:water by weight, with a moisture content of 44%. The spray-on ceramic refractory coating material is mainly composed of aluminum hydroxide, calcium carbonate, and cement, which have a high heat absorption effect.

As shown in FIG. 1(b), the fireproof coating layer 4 of the present embodiment has a U-shaped cross-section by having a concave portion that opens outward. That is, the fireproof coating layer 4 is thicker at the ends (column ends) of the wooden fireproof members 1 than at the other portions.

The finishing wood layer 5 is provided around the outside of the fireproof coating layer 4 so as to cover the outer surface of the wooden fireproof member 1 . Finishing wood layer 5 is not a structural member. In this embodiment, the finishing wood layer 5 is arranged in a recess formed in the outer surface of the fireproof coating layer 4 . Therefore, the fireproof coating layer 4 is exposed to the outer surface at the ends (pillar ends) of the wooden fireproof member 1 . The exposed portions of the fireproof coating layer 4 at the ends of the wooden fireproof member 1 may be formed as required, and are not necessarily formed.
As shown in FIG. 1(a), the finishing wood layer 5 of this embodiment is composed of four finishing plate members 51 arranged in a frame shape in a cross-sectional view. The end portions of the finishing plate members 51 are in contact with each other, and the finishing plate members 51 may be joined by an adhesive, screws, or the like, if necessary. A cedar board having a thickness of 10 mm is used as the finishing board material 51 of the present embodiment. It should be noted that the material constituting the finishing board material 51 is not limited to the cedar board. The thickness of the finishing wood layer 5 and the thickness of the finishing plate material 51 are not limited and may be determined as appropriate. ≤ 0.004). The finishing plate material 51 is supported by the wooden load support portion 2 via the connecting member 6 .

The connecting member 6 is a column-shaped or plate-shaped member arranged at the center of each surface (four surfaces) of the wooden load-bearing part 2. As shown in FIG. A plurality of them are arranged at predetermined intervals in the direction (vertical direction). The shape of the connecting member 6 is not limited, and may be, for example, a prismatic shape, a cylindrical shape, or a rectangular flat plate. Moreover, although the dimension of the connection member 6 is not limited, it has a height (thickness) equal to or greater than the thickness of the fireproof coating layer 4 . The connecting member 6 is made of a material that has low thermal conductivity and is not easily combustible (for example, mortar, gypsum board, etc.). The connecting member 6 uses an adhesive for concrete, metal, and wood (for example, PM165R P50ml RE-220 manufactured by Cemedine Co., Ltd., Concrebond K10A manufactured by Konishi Co., Ltd.), and attaches one end to the wooden load support portion 2. The other end of the connecting member 6 is fixed to the finishing plate material 51 (finishing wood layer 5). That is, as shown in FIG. 1, in the case of the wooden load-bearing portion 2 having a rectangular cross section, the connecting members 6 are installed on each outer peripheral surface of the wooden load-supporting portion 2 and at predetermined intervals along the vertical direction. Spacer.

Next, a method for forming the wooden fire-resistant member 1 of this embodiment will be described.
First, as shown in FIG. 3(a), one end surface of the connecting member 6 is adhered to the wooden load supporting portion 2 made of laminated lumber using an adhesive for concrete, metal and wood. The connection member 6 may be fixed to the wooden load support portion 2 after the metal plate 31 is fixed to the outer surface of the wooden load support portion 2 .
Next, as shown in FIG. 3(b), the water blocking layer 3 is formed by fixing the metal plate 31 to the outer surface of the wooden load support portion 2. Next, as shown in FIG. The metal plate 31 is screwed to the outer surface of the wooden load support portion 2 . An opening (not shown) is formed in the metal plate 31 according to the position of the connecting member 6 . The metal plate 31 is installed on the outer surface of the wooden load support portion 2 with the connecting member 6 inserted through the opening.
Subsequently, as shown in FIG. 3(c), a fire-resistant coating layer 4 is formed by applying an expandable fire-resistant paint to the outer surface of the moisture barrier layer 3. As shown in FIG. The thickness of the fireproof coating layer 4 is controlled with reference to the height of the connecting member 6 . The thickness of the refractory coating layer 4 is increased at the end of the column of the wooden load-bearing portion 2 as shown in FIG.
Finally, a finish board 51 is placed on the outer surface of the fireproof coating layer 4 to form the finish wood layer 5 (see FIG. 1). At this time, the finish plate member 51 is fixed by being brought into contact with the edge end face of the connection member 6 after applying an adhesive for concrete/metal/wood between the edge end face of the connection member 6 . In addition, the finishing wood layer may be arranged outside the fireproof coating layer 4 on each side of the wooden load supporting part 2 and adhered to the connecting member 6, and the finishing wood layer 5 formed in a concave shape may be placed on the outside of the fireproof coating layer 4. It may be arranged outside the covering layer 4 and adhered to the connecting member 6 . A water blocking material (water blocking paint, water blocking sheet, etc.) may be provided on the back surface of the finishing plate material 51 (the side facing the fireproof coating layer 4), if necessary.
Specifically, in the embodiment of the wooden fire-resistant member 1, the wooden member is manufactured by providing the moisture blocking layer 3, the fire-resistant coating layer 4, and the finishing wood layer 5 on the outer surface of the wooden load-bearing portion 2 in the factory. It is transported to the construction site, erected on the floor slab or on the top of the column, and the beam-column structure is constructed. Alternatively, a semi-factory product (half-precast product) of the wooden fire-resistant member 1 manufactured in a factory up to the fire-resistant coating layer 4 on the outer surface side of the wooden load-bearing part 2 is brought to the construction site, erected in a predetermined position, and then covered with fire-resistant coating. A finish wood layer 5 may be formed on the outer side of the layer 4 without gaps.

Below, the effects of the wooden fire-resistant member 1 of the present embodiment will be described.
According to the wooden fire-resistant member 1 of the present embodiment, it is possible to contribute to a low-carbon society by realizing a fire-resistant structure of a wooden structural member. In the event of a fire, the finished wood layer 5 burns from the outer surface and carbonization progresses. However, since the fireproof coating layer 4 is provided between the finished wood layer 5 and the wooden load bearing portion 2, the wooden structural member is formed. Even if the finishing wood layer of the outer skin part burns and falls off, the wooden load supporting part 2 is placed outside, and the fireproof performance is secured by the two-layer structure consisting of the moisture blocking layer 3 and the fireproof coating layer 4, thereby maintaining the wooden load supporting part. Combustion and carbonization of 2 can be prevented. Therefore, it is possible to construct the wooden fire-resistant member 1 having fire-resistant performance, and eventually it is possible to realize a fire-resistant structure that satisfies the Building Standards Act. In addition, since the finishing wood layer 5 is fixed to the outer edge face of the connecting member 6 with an adhesive, when the finishing wood layer is burned or falls off at the carbonization stage, the burning of the wood load bearing portion is prevented. 2 is prevented from catching fire. Therefore, even when a fire breaks out, the function as a structural member can be maintained.
Since the finishing wood layer 5 is supported by the wooden load supporting portion 2 via the connecting member 6, the finishing plate material 51 can be accurately installed even on the outer periphery of the fireproof coating layer 4 whose surface is uneven (not flat). can do.
In addition, since the wooden fire-resistant member 1 is a factory product in which all layers including the wooden load-bearing part 2 or up to the fire-resistant coating layer 4 are formed at a factory, the fire-resistant coating layer 4 and the finishing wood layer 5 can be easily formed. In addition, it is possible to easily ensure various fire resistance performances (1 hour fire resistance, 2 hour fire resistance, etc.) required for each building frame 7 using the wooden fire-resistant member 1 of the present invention. In addition, the wooden fire-resistant member 1 has good workability, can be covered with a fire-resistant coating material (expandable fire-resistant paint, foamed fire-resistant board, wet fire-resistant coating material) without gaps even at joints between plate materials, and is wooden. The fireproof coating layer 4 and the finishing wood layer 5 can be integrated on the outer surface side of the load bearing part 2 under high quality control. Moreover, the wooden fire-resistant member 1 can be mass-produced in a short time.

Further, since the fireproof coating layer 4 is formed on the ends of the wooden fireproof member 1, it is possible to prevent the fire from spreading to the finishing wood layer 5 via the building frame 7 in contact with the wooden fireproof member 1. - 特許庁In addition, since the fireproof coating layer 4 having a lower compressive rigidity than the finished wood layer 5 is provided at the ends of the wood, the fireproof coating layer 4 will not be exposed when the wooden fireproof member 1 is greatly deformed during an earthquake. Since the portion can absorb the displacement, it is possible to prevent breakage at the contact portion between the wooden fireproof member 1 and the building frame 7 .
In addition, by using the foamable fire-resistant coating for the fire-resistant coating layer 4, the foamable fire-resistant coating is in an unfoamed state during normal use, the layer thickness of the foamable fire-resistant coating is thin, and the cross-sectional dimension of the wooden fire-resistant member 1 is can be made smaller. In addition, by providing the moisture blocking layer 3 between the wooden load-bearing part 2 and the fireproof coating layer 4, moisture released from the wet fireproof coating material forming the fireproof coating layer 4 is prevented from reaching the wooden load-bearing part 2. It can prevent permeation. Therefore, the wooden load-bearing part 2 is not immersed in water, and its strength is not lowered by corrosion or the influence of water, so that structural performance and fireproof performance can be maintained. It should be noted that, when steam is generated from the wooden load support portion 2 due to the heat of a fire or the like, it is possible to prevent the foaming failure from occurring in the foamable fireproof paint. That is, since the water barrier layer 3 prevents water vapor from coming into contact with the fire-resistant coating layer 4, it is possible to prevent the fire-resistant coating layer 4 from being cooled by water vapor.
Moreover, the fireproof coating layer 4 of the wooden fireproof member 1 can be formed by a wet fireproof coating material (for example, spray rock wool) by a spraying method in addition to the foaming fireproof paint. The wet refractory coating material has a water content of about 40%, which is higher than that of general wooden members. For example, the moisture content of a cypress pillar is about 18%, that of a cypress flooring material is about 15%, that of a cedar pillar is about 20-30%, and that of a cedar flooring material is about 15-22%. Therefore, when using a wet fire-resistant coating material, a moisture-blocking layer 3 made of a moisture-blocking coating film or a moisture-blocking sheet is installed between the wooden load-bearing part 2 and the fire-resistant coating layer 4 to support the wooden load. It prevents permeation of moisture into the part 2 and secures structural performance and fireproof performance.

(Heating performance test of wooden fireproof coated column)
Below, an outline of a test body of a heating experiment of a covered wooden fireproof column simulating the wooden fireproof member 1 of the present embodiment and the results of the experiment are shown.
Fig. 4(a) shows the external appearance of the wooden fireproof coated column used in the heating experiment. The test specimen was a laminated cedar (wood load bearing part) with a rectangular cross section of 120 mm x 120 mm and a height of 1200 mm, which was made by reconstructing a plurality of plate materials with an adhesive in the central part of the cross-sectional view. The outer peripheral surface of the column is coated with a 0.3 mm thick metal sheet (moisture blocking layer) and a foaming fireproof paint panel (fireproof coating layer). Foaming fire-resistant paint panels were made by pouring epoxy-based fire-resistant paint into a formwork. In addition, in this performance confirmation experiment, in addition to uniformly foaming the foaming fire-resistant paint due to the heat of the fire and the spread of fire, in order to clearly measure the layer thickness of the foaming fire-resistant paint after foaming, the foaming fire-resistant paint The panel was 50 mm thick. The thin metal plate was adhered to the outer peripheral surface of the laminated cedar lumber with an adhesive for concrete/metal/wood (for example, PM165R P50ml RE-220 manufactured by Cemedine Co., Ltd.).
In the heating experiment, after placing the test specimen in the heating furnace, the temperature inside the furnace was raised to 1049 ° C. after 2 hours from the start of heating according to the standard heating curve (ISO834), which is an international standard. The change in the surface temperature of the supporting portion was measured, and after leaving the panel for 24 hours, the foaming state of the fireproof paint panel and the carbonization state of the test specimen were observed.

Fig. 4(b) shows a cross section (600 mm in height) of the wooden load bearing part from which the refractory paint panel and the thin metal plate were removed after the specimen was left in the heating furnace for 24 hours after the heating test. After the heating test, no charring or cracks were observed in the wooden load-bearing part, as evidenced by the fact that the surface temperature was 260° C. or less at the start of carbonization.
In addition, FIG. 5 shows the state of foaming of the fireproof paint panel covering the wooden load-bearing part of the wooden fireproof coated column body after the heating test. The fire-resistant paint panel had a layer thickness of 50 mm before foaming, but after the heating experiment, the panel was uniformly foamed to a panel thickness of about 220 mm, and the foaming ratio reached about 4.4 times.
Therefore, according to the results of a two-hour fire resistance performance test on a wooden fire-resistant coated column body simulating the wooden fire-resistant member of this embodiment, it is possible to form a moisture blocking layer and a fire resistant coating layer on the outer peripheral surface of the wooden load-bearing part. , the outer skin temperature of the wooden load-bearing part did not reach 260° C., which is the carbonization starting temperature of wood, and it was confirmed that the wooden load-bearing part had a fire resistance performance of 2 hours.

(Verification of heating performance test results by steady heat transfer model)
FIG. 6 shows a calculation example based on a steady-state heat transfer model for a heating test specimen of a covered wooden fireproof column simulating the wooden fireproof member 1 of the present embodiment.
_In this calculation example, in the steady heat transfer model shown in FIG. Considering that the temperature at the central portion of the cross section of the wooden load-bearing portion 2 was not carbonized in the results of the heating experiment, the temperature was set to 20°C at room temperature. The outer surface temperature T2 of the wooden load-bearing part is estimated using the layer thickness d, the thermal conductivity λ, and the heat transfer coefficient α of the refractory coating layer 4 and the wooden load-bearing part ₂ , respectively. Specifically, the heating test specimen is a stationary heat transfer model composed of the fireproof coating layer 4 and the wooden load support portion 2 without modeling the moisture blocking layer 3 . The fireproof coating layer 4 has a layer thickness d of 220 mm after foaming, which is measured in a heating experiment, and α=0.06 W/(m ² ·k). The wooden load supporting portion 2 has a layer thickness of 60 mm up to the center of the cross section, and λ=0.107 W/(m·k).
As for the temperature distribution at each part of the column, the temperature difference at each part and the magnitude of the thermal resistance (heat transfer resistance, heat conduction resistance) are in the relationship of the following formula (formula 1). Therefore, the outer surface temperature T2 of the wooden load supporting portion ₂ is estimated by the following equation.
1000 _- T2: _T2-20 =1/α:d/λ (Formula 1)
1000 _- T2: _T2-20 =1/0.06:0.06/0.107
_18.45T2 = 894
T2 ₌ 48.5
As described above, the outer surface temperature T2 of the wooden load-bearing part ₂ estimated using the steady-state heat transfer model of the heating performance test results is 48.5°C. As confirmed by the results, the result was lower than the carbonization start temperature of wood of 260°C.
According to the heating performance experiment and the verification results shown above, according to the wooden fire-resistant member 1 of the present embodiment, even if the temperature of the outside air of the wooden fire-resistant member 1 rises to 1000° C. in the event of a fire or the like, , A moisture blocking layer 3 and a fireproof coating layer 4 are provided around the outer circumference of the wooden load support part 2, and the fireproof coating layer 4 is foamed to reduce heat conduction in the event of a fire, and the wood fireproof has a fireproof performance of 2 hours. It can be seen that the member 1 is feasible.

<Second embodiment>
A wooden fire-resistant member 1 of the second embodiment is a member constituting a pillar of a building, as in the first embodiment, and has a square cross section as shown in FIG. In addition, the cross-sectional shape of the wooden fire-resistant member 1 is not limited, and may be, for example, a square shape or a circular shape.
The wooden fire-resistant member 1 comprises a wooden load-bearing part 2 , a moisture barrier layer 3 , a fire-resistant coating layer 4 and a finishing wood layer 5 . The details of the wooden load support portion 2, the moisture blocking layer 3, and the finished wooden layer 5 are the same as those described in the first embodiment, and detailed descriptions thereof will be omitted.

The fireproof coating layer 4 covers the periphery of the moisture blocking layer 3 . The fireproof coating layer 4 of the present embodiment is formed by individually attaching a plate-shaped fireproof coating material (hereinafter referred to as "fireproof panel 41") to each surface (four surfaces) of the moisture blocking layer 3. . The plate thickness of the fireproof panel 41 is not limited, and may be appropriately determined according to the desired fireproof time. The refractory coating layer 4 is not a structural member. In addition, openings are formed in the fireproof panel 41 according to the positions of the connecting members 6 . The fireproof panel 41 is attached to the outer surface of the moisture blocking layer 3 with the connecting member 6 inserted through the opening. The four corners of the fire-resistant coating layer 4 are coated with a fan-shaped fire-resistant coating paint 42 (for example, foamable fire-resistant paint). That is, the fireproof panels 41 adjacent to each other are connected via the fireproof coating paint 42 , and the moisture blocking layer 3 is covered with the four fireproof panels 41 and the fireproof coating paint 42 . In addition, the fireproof coating paint 42 may be applied in a triangular cross-sectional view.
The refractory coating layer 4 of the present embodiment has a U-shaped cross-section by having an outwardly opening concave portion (see FIG. 1(b)). That is, the fireproof coating layer 4 is thicker at the ends (column ends) of the wooden fireproof members 1 than at the other portions. In addition, the cross-sectional shape of the fireproof coating layer 4 is not limited, and may be, for example, a flat plate shape.

〔Example〕
FIG. 8 shows cross-sectional design examples (Examples 1 and 2) of the wooden fire-resistant members 1 intended for buildings that require two-hour fire resistance.
FIG. 8(a) shows Example 1, in which the wooden fire-resistant member 1 is a column having a square cross section, and the wooden load-bearing part 2 is 600 mm×600 mm. In Example 1, the wooden load-bearing part 2 is made of larch material, and the moisture blocking layer 3, the fireproof coating layer 4, and the finishing wood layer 5 are laminated in order from the wooden load-bearing part 2 toward the outside. The moisture blocking layer 3 was formed by adhering a waterproof sheet such as waterproof paper to the outer surface of the wooden load support portion 2 . The fire-resistant coating layer 4 was formed by applying a foamable fire-resistant paint having a foaming temperature of 200° C. or less to a thickness of about 2 to 10 mm. The finished wood layer 5 was formed by combining flat plates with a thickness of 10 mm supported by the wooden load support portion 2 via connecting members 6 in the form of a frame.
The larch material that forms the wooden load-bearing part 2 is a coniferous tree that is distributed from Hokkaido to northern Honshu in Japan, and has a specific gravity of about 0.53 when dry. ^2. Tensile strength is about 85 N/mm ² and shear strength is about 8 N/mm ² . In addition, when compared with concrete, which has the same compressive strength as larch wood, larch wood, which is wood, varies in strength depending on the presence or absence of a core material and in a dry state. It is a structural material that exhibits strength characteristics greater than 10 times. Therefore, the wooden fire-resistant member 1 using the larch material according to Example 1 for the wooden load-bearing portion 2 can bear up to a vertical load equivalent to a concrete column of about Fc=45 N/mm ² .

FIG. 8(b) shows Example 2, in which the wooden fire-resistant member 1 is a wall pillar, and the wooden load-bearing part 2 is a cross laminated timber (CLT: Cross Laminated Timber) having a thickness of 220 mm, or a veneer laminate ( LVL: Laminated Veneer Lumber). A moisture blocking layer 3, a fireproof coating layer 4, and a finishing wood layer 5 were laminated in order toward the opposing outer side surfaces such as the upper side or the lower side with the wooden load bearing portion 2 sandwiched therebetween. The materials and dimensions of the moisture blocking layer 3, the fireproof coating layer 4, and the finished wood layer 5 were the same as in Example 1.

[Other Modifications]
Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and the constituent elements described above can be modified as appropriate without departing from the scope of the present invention.
For example, a corrugated sheet may be used for the moisture barrier layer 3 and a gap may be formed between the wooden load support portion 2 and the moisture barrier layer 3 to form an escape path for water vapor.
In each of the above embodiments, a pillar (woody fireproof pillar) has been described, but the use of the woody fireproof member 1 is not limited, and may be, for example, a beam (woody fireproof beam). In the case of wooden fire-resistant beams, the wooden load-bearing part 2 becomes the beam main body, and a floor slab is often provided on the upper surface of the wooden load-bearing part 2. In the case of wooden fire-resistant beams with floor slabs, the rectangular shape that forms the wooden fire-resistant beam Moisture blocking layer 3, refractory coating layer 4, and finishing wood layer 5 are formed on three U-shaped surfaces on the lower side of .
Although a flat plate is used as the finishing plate material 51 in each of the above-described embodiments, the finishing plate material 51 is not limited to a flat plate. For example, the finished wood layer 5 may be formed by combining molded wood having a U-shaped cross section or molded wood having an L-shaped cross section.

1 Wooden fireproof members (wooden fireproof columns, wooden fireproof beams)
2 wooden load bearing part 3 moisture barrier layer 4 fireproof coating layer 5 finished wood layer 6 connecting member 7 building frame

Claims (3)

A wooden fire-resistant member having a fire-resistant coating layer and a finishing wood layer on the outer peripheral surface or both side outer surfaces of the wooden load-bearing part,
the wooden load support portion having a rectangular or circular cross-sectional shape;
a moisture blocking layer provided on the outer surface of the wooden load support;
The refractory coating layer made of a wet refractory coating material covering the moisture barrier layer;
said finish wood layer provided outside said fire resistant coating layer;
A wooden fire-resistant member, wherein the water-blocking layer is formed of any one of a water-blocking coating film, a water-blocking sheet, and waterproof paper. A wooden fire-resistant member having a fire-resistant coating layer and a finishing wood layer on the outer peripheral surface or both side outer surfaces of the wooden load-bearing part,
the wooden load support portion having a rectangular or circular cross-sectional shape;
a moisture blocking layer provided on the outer surface of the wooden load support;
The refractory coating layer made of a wet refractory coating material covering the moisture barrier layer;
said finish wood layer outside said fire resistant coating layer;
and a connecting member disposed through the fireproof coating layer,
A wooden fire-resistant member, wherein the connecting member is formed of a column-shaped or plate-shaped mortar member or a gypsum board. A wooden fireproof member constituting a pillar or wall pillar,
3. The wooden fire-resistant member according to claim 1, wherein the fire-resistant coating layer is arranged on the upper end and the lower end of the finishing wood layer.

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