JP2020066854A - Wooden building component - Google Patents

Abstract

To provide a wooden building component capable of forming the outer dimensions of the cross-section compact while ensuring the fire resistance performance.SOLUTION: A pillar 100 as an example of a wooden building component includes: a load-bearing part 120 made of long wood with rectangular cross-section; and at least two non-burning layers 140 that cover the entire circumference of the load-bearing part 120. The pillar 100 is further provided an air layer 160 between the two non-burning layers 140. As for beams, which are another example of a wooden building component, the outer circumference of the load-bearing part is covered with non-burning layers on at least three sides.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a wooden building member such as a pillar or a beam for constructing a framework of a wooden building.

  In order to satisfy the performance required for a wooden fireproof building, as described in “Guidelines for maintenance of wooden fireproof buildings in government facilities” (Non-Patent Document 1), a load supporting portion that is a main part in terms of structural strength. It is well known to cover the periphery of the with a fireproof coating (stop flame layer) made of gypsum board or the like.

"Guideline for the maintenance of wooden fireproof buildings in government facilities", [online], March 29, 2013, Ministry of Land, Infrastructure, Transport and Tourism, Ministry of Public Affairs, Government Department, [October 9, 2018 search], Internet <URL: http : //www.mlit.go.jp/common/000993924.pdf>

  By the way, the Building Standard Law stipulates fire resistance (fire resistance time) according to the number of floors of a building. When constructing a large-scale wooden building that complies with the Building Standards Law, in order to delay the burnout of the load-bearing portion that secures structural strength, the anti-combustion layer that covers the load-bearing portion must be thickened. If the flame-retardant layer is thickened, the outer size (cross-sectional area) of the wooden building member also becomes large, which may lead to a decrease in workability and an increase in weight.

  Therefore, it is an object of the present invention to provide a wooden building member that can have a compact outer dimension in a cross section even when ensuring fire resistance.

  The wooden building member has a load supporting part made of wood having a long rectangular cross section and at least two non-burning layers covering at least three sides of the load supporting part along the entire length thereof. . In the wooden building member, an air layer is further provided between at least two non-burning layers.

  According to the present invention, the outer dimensions in the cross section can be made compact even if the fire resistance is secured.

It is a perspective view of the pillar mentioned as an example of a wooden building member. It is a perspective view which shows the internal structure of a pillar. It is a cross-sectional view showing a pillar. It is a cross-sectional view of 1st Embodiment of the beam given as another example of a wooden construction member. It is a cross-sectional view of 2nd Embodiment of the beam given as another example of a wooden building member. It is a perspective view which shows the 1st modification of the spacer which forms an air layer. It is a perspective view which shows the 2nd modification of the spacer which forms an air layer. It is a perspective view which shows the 3rd modification of the spacer which forms an air layer.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the accompanying drawings.
1 to 3 show a pillar 100 that is an example of a wooden building member.

  The pillar 100 whose material axis extends in the vertical direction has a load supporting portion 120 that supports a load, and at least two non-burning layers 140 that cover the outer periphery of the load supporting portion 120 over its entire length. . In the pillar 100 shown in FIGS. 1 to 3, two flame-retardant layers 140 are provided, but the number of layers is not limited to two and, for example, the number of layers is appropriately determined according to the required fire resistance performance. be able to. Here, “vertical” is not limited to complete vertical, but may be such that it can be visually recognized as vertical (hereinafter, the same applies to directions).

  The load support portion 120 is made of wood having a long and rectangular cross section, and has a cross-sectional area capable of ensuring the strength required according to the scale of a wooden building. Here, the “rectangle” is a rectangle in which all the corners are right angles, but it may be a rectangle that can be visually recognized (hereinafter, the same applies to the shape). Further, as the wood, solid wood or laminated wood, which is generally used in wooden structures, can be used.

  The flame-retardant layer 140 is made of a non-combustible material or a flame-retardant material specified by the Building Standards Law. Here, as the "non-combustible material", a gypsum board having a thickness of 9 mm or more (a board base paper having a thickness of 0.6 mm or less), a wood wool cement board having a thickness of 15 mm or more, a thickness of 9 mm or more Hard wood chip cement board (having a bulk specific gravity of 0.9 or more), wood chip cement board having a thickness of 30 mm or more (bulk specific gravity of 0.5 or more), pulp cement board having a thickness of 6 mm or more can do. As the "flame-retardant material", flame-retardant plywood with a thickness of 5.5 mm or more, gypsum board with a thickness of 7 mm or more (board raw paper having a thickness of 0.5 mm or less), etc. can be used. . When gypsum board is used as the non-combustible material or the flame-retardant material, the flame-retardant layer 140 can be constructed using a material that is widely used in buildings and that is inexpensive and has high fire resistance. In addition, the flame-retardant layer 140 disposed inward is a weak joining method that does not transmit various loads acting on the load supporting portion 120, specifically, nailing, a synthetic adhesive, or the like. Can be fixed around.

  The flame-retardant layer 140 can be formed, for example, by joining the ends of a rectangular plate material at right angles by a stabbing, a staking, a mortar insertion, or the like. Here, "Tsumugi" is a joining method that cuts and joins the openings of two plate materials at 45 °, and "dashing patch" is a method of processing the openings of two plate materials at a right angle and one of the plate materials. The joining method of butting and joining one plate material to the other plate material, "Ootsugi" is a joining method of digging a groove on the side surface of one plate material and inserting the mouth of the other plate material into the groove to join. In any joining method, the two plate materials are fixed by using a nail or an adhesive.

  On the premise of such a pillar 100, an air layer 160 filled with air that exhibits a heat insulating performance superior to that of a metal by 10,000 times is provided between the two non-burning layers 140. Specifically, a plurality of spacers 180 extending in the material axis direction over the entire length of the pillar 100 are arranged between the two layers of the flameproof layer 140, and the two layers of the flameproof layer 140 have a thickness of the spacer 180. The air layer 160 filled with air is provided by being separated from each other. In the pillar 100 shown in FIGS. 1 to 3, for each surface of the flame-retardant layer 140 having the rectangular outer shape arranged inward, a pair of spacers 180 spaced apart from each other and extending in parallel at both ends of the surface, The air layer 160 is formed between the flame-retardant layer 140 arranged outside, but the number and the position of the air layer 160 can be arbitrarily determined. As the spacer 180, it is preferable to use a material that does not generate toxic gas even when exposed to a flame, such as wood or the same member as the flame-retardant layer 140.

Next, the operation of the pillar 100 will be described.
When a fire occurs in a wooden building and the fire spreads from the outside of the pillar 100, the unstoppable layer 140 is first exposed to the flame. Since the flame-retardant layer 140 is made of a non-combustible material or a flame-retardant material, even if it is exposed to a flame, it does not burn out easily and in a short time, and the load supporting portion 120 arranged inside thereof is exposed to the flame. Can slow down the time.

  Even if the non-burning layer 140 arranged on the outside is exposed to flames and the temperature rises, the air layer 160 arranged on the inner side functions as a heat insulating material and is arranged on the inner side of the air layer 160. The temperature rise of the burnout layer 140 is moderate. Therefore, the fire resistance performance of the pillar 100 can be improved as compared with the pillar 100 in which the air layer 160 is not provided. Further, since the upper end and the lower end of the pillar 100 are joined to other building members by a known joint metal, when the air in the air layer 160 is heated by the flame, the flow of air from the lower end to the upper end of the pillar 100. Occurs. Therefore, the air in the air layer 160 is replaced, and the temperature rise can be suppressed. Since the air filled in the air layer 160 exhibits good heat insulation performance, it is possible to improve the fire resistance performance of the pillar 100 without increasing the thickness of the air insulation. Can be made compact.

  When a gypsum board is used as the burn-out layer 140, since the gypsum board contains crystal water corresponding to about 21% of the weight, when the gypsum board is exposed to a flame or heat, thermal decomposition occurs and water vapor is generated. The temperature of the load supporting portion 120 is limited to the boiling point of water or less, because the temperature is maintained at the boiling point of water (about 100 ° C.) until all the crystal water of the gypsum board is discharged. Then, since the temperature rise of the gypsum board arranged inside is suppressed, the generation of crystal water becomes slow, and the function as the unburnt layer 140 can be sufficiently exerted. Therefore, the progress of carbonization of the load support portion 120 can be moderated for the temperature limitation time of the gypsum board.

  Therefore, even if the fire resistance of the pillar 100 is ensured, the outer dimension of the pillar 100 in the cross section can be made compact. Further, since the load supporting portion 120 mainly supports the load of the wooden building, the design of the structural yield strength is facilitated, and the wooden building does not collapse until the unburnt layer 140 is completely burned down.

FIG. 4 shows a beam 300 as another example of the wooden building member.
Similar to the pillar 100, the beam 300 whose material axis extends in the horizontal direction includes a load supporting portion 320 that supports a load, and at least two layers of burning that cover three sides of the cross section of the load supporting portion 320 over the entire length thereof. And a dead layer 340. That is, the beam 300 has a functionally similar configuration to the pillar 100, but since the beam 300 supports various loads on one surface (upper surface) of the cross section of the load supporting portion 320, the non-combustion layer 340 forms the load supporting portion. Only the both side surfaces and the lower surface of 320 are covered. At this time, the upper surface of the load supporting portion 320 is joined to the floor material 500 made of an incombustible material or the like and is not directly exposed to the flame at the time of a fire, and therefore the beam 300 of the beam 300 is not provided here even if it is not provided. There is no effect on fire resistance.

  On the premise of such a beam 300, an air layer 360 filled with air that exhibits a heat insulating performance superior to that of a metal by 10,000 times is provided between the two layers of the non-combustion layer 340. Specifically, a plurality of spacers 380 extending in the material axis direction over the entire length of the beam 300 are arranged between the two layers of the flame-retardant layer 340, and the two layers of the flame-retardant layer 340 have a thickness of the spacer 380. The air layer 360 filled with air is provided by being separated from each other. In the beam 300 shown in FIG. 4, the three surfaces (both side surfaces and the lower surface) of the flame-retardant layer 340 arranged inward are outwardly extended by a pair of spacers 380 which are parallel to each other at both ends of the surface. Although the air layer 360 is formed between the arranged flame-retardant layer 340, the number and installation position of the air layer 360 can be arbitrarily determined. As the spacer 380, it is preferable to use a material that does not generate toxic gas even when exposed to flames, such as wood and the same member as the flame-retardant layer 340.

  In addition, in the beam 300, in order to prevent the flame-retardant layer 340 from easily falling off from the load supporting portion 320 due to gravity, for example, a well-known fastener such as a bolt and a nut is used, and the load supporting portion 320 and the flame-retarding portion are stopped. It is desirable to integrate layer 340. Although the beam 300 shown in FIG. 4 is provided with the two flame-retardant layers 340, the number of layers is not limited to two and, for example, the number of layers may be appropriately determined according to the required fire resistance performance. You can

  Since the load supporting portion 320 and the non-burning layer 340 of the beam 300 are similar to the load supporting portion 120 and the non-burning layer 140 of the column 100, detailed description thereof will be omitted for the purpose of eliminating redundant description. Further, the action and effect of the beam 300 are also similar to the action and effect of the column 100, and therefore detailed description thereof will be omitted for the purpose of eliminating duplicate description. See pillar 100 description if necessary.

  The beam 300 is not limited to the configuration shown in FIG. 4, and as shown in FIG. 5, the cross section of the load supporting portion 320 may be covered with the non-burning layer 340 in all directions. In short, in the beam 300, it is sufficient that at least three sides of the cross section of the load supporting portion 320 are covered with the non-burn layer 340.

  Here, the spacer 180 of the pillar 100 is not limited to the structure that extends in the material axis direction over the entire length of the pillar 100, and may have a structure in which a part thereof is cut off, as shown in FIG. 6. In addition, the spacer 180 of the pillar 100 extends around the flame-retardant layer 140 in the cross section of the pillar 100 as shown in FIG. 7 (that is, the structure extending over the cross section of the load supporting portion 120), and in FIG. As shown, a part of it may be cut away. In short, the spacer 180 may have any shape and arrangement as long as the air layer 160 can be formed between the two non-burning layers 140. The beam 300 may also be a spacer similar to the pillar 100.

  In each of the embodiments, in order to further improve the fire resistance of the wooden building member, the load supporting portions 120 and 320 may be formed of non-combustible liquid agent cancer invasion. Alternatively, an aluminum foil (not shown) may be attached to the outer peripheral surfaces of the flame-retardant layers 140 and 340 arranged inward. By doing so, a part of the heat acting on the flame-retardant layers 140, 340 arranged inward is reflected by the aluminum foil, and the progress of carbonization of the load supporting portions 120, 320 can be made more gradual. Furthermore, in order to improve the appearance of the pillars 100 and the beams 300, for example, fireproof coating may be applied or a cloth having fireproof performance may be attached to the outer peripheral surfaces of the flameproof layers 140 and 340.

  The present invention can be applied not only to the pillars 100 and the beams 300 as wooden building members but also to braces and joists.

100 columns (wooden building components)
120 Load-bearing part 140 Non-combustion layer 160 Air layer 180 Spacer 300 Beam (wooden building member)
320 Load-bearing part 340 Flame-retardant layer 360 Air layer 380 Spacer

The wooden building member has a load supporting portion made of wood having a long rectangular cross section and at least two non-burning layers covering at least three sides of the outer periphery of the load supporting portion over the entire length thereof. . Further, in the wooden building member, an air layer that penetrates from one end to the other end in the longitudinal direction is further provided between at least two non-burning layers.

Claims (6)

A load supporting part made of wood with a long and rectangular cross section,
At least two non-combustion layers covering at least three sides of the outer periphery of the load supporting portion over the entire length thereof;
A wooden building member having
An air layer is further provided between the at least two non-burning layers,
Wooden building material. The flame-retardant layer is made of gypsum board,
The wooden building member according to claim 1. The air layer is formed by a plurality of spacers,
The wooden building member according to claim 1 or 2. The spacer extends in the material axis direction of the load supporting portion,
The wooden building member according to claim 3. The spacer extends on a cross section of the load support,
The wooden building member according to claim 3. A part of the spacer is cut off,
The wooden building member according to claim 4 or 5.