JP6499435B2 - Outer insulation and fireproof outer wall structure of wooden building - Google Patents

Description

  The present invention relates to a heat-insulated fire-resistant outer wall structure for a wooden building.

  Recently, there have been many studies on wooden refractory buildings. The reasons include the promotion of further use of timber under the initiative of the country, further spread of wooden buildings, and improvement of fire resistance of buildings from the viewpoint of disaster prevention due to earthquakes in urban areas.

  In order to construct a wooden fireproof building, it is required to make the outer walls, floors, beams, columns, roofs, and stairs, which are the main structural parts of the building, have a fireproof structure. Also, wooden fireproof buildings are required to be self-supporting without collapsing after the fire has occurred and the fire has extinguished.

  In order for an outer wall of a building to be recognized as fireproof, it must pass a test that tests fireproof performance. The evaluation test method is defined in JIS-A-1304. In the test method, a test body having an outer wall structure is heated from the outdoor side or from the indoor side twice in total. The heating conditions are specified in ISO-834, and the condition is that the temperature in the furnace in which the test body is installed is raised to about 950 ° C. over 1 hour, and then the heating is stopped and left as it is for 3 hours. It is.

  As a conventional fireproof outer wall structure of a wooden building, there is a structure in which a structural member made of wood is covered with a noncombustible material so that the structural member made of wood is not carbonized or ignited when a fire occurs. In the structure, a nonflammable interior member is disposed on the indoor side of the structural member, and a nonflammable exterior member is disposed on the outdoor side. In particular, research and development has been conducted on exterior members. As a conventional fireproof outer wall structure of a wooden building, the structures described in Patent Document 1 and Patent Document 2 are known.

  Patent Document 1 discloses a first covering layer formed by pressing and joining a lightweight cellular concrete panel with an exterior exterior member of a structural member made of wood, and a second covering formed by pressing and joining a calcium silicate plate. A structure is disclosed in which the coating layer is laminated and the first coating layer is installed on the outdoor side so that the joint portion of the lightweight cellular concrete panel and the calcium silicate joint portion do not overlap each other. ing. The heat insulation method described in Patent Document 1 is a so-called filling heat insulation method in which glass wool or rock wool is filled in a structural member.

  Patent Document 2 discloses a fireproof outer wall structure of an outer-layer heat insulation method having excellent heat insulation performance. Patent Document 2 discloses a structure of an exterior portion in which one lath mortar layer, three slag gypsum plates, and two aluminum foil layers are laminated.

JP 2005-299194 A JP 2013-113033 A

  As an exterior member of a fireproof outer wall structure in a conventional wooden building, there are a structure in which a plurality of different types of materials are laminated together and a structure in which a plurality of the same materials are laminated together. In the fire-resistant outer wall structure of Patent Document 1, two types of exterior materials, a lightweight cellular concrete panel and a calcium silicate plate, are used, and the joint portions of the exterior member need to be shifted from each other. Moreover, in the fireproof outer wall structure of patent document 2, a lath mortar layer, a slag gypsum board, and an aluminum foil layer are overlaid, and several types and a plurality of exterior members are overlaid.

  However, when there are several types of exterior members, it takes much time to procure materials and quality control, leading to an increase in cost. Moreover, the number of man-hours increases and the construction period may be prolonged by constructing a plurality of exterior members. Furthermore, since the joint portions of the exterior member had to be shifted from each other, the design and construction were complicated and the construction period tended to be long.

  In addition, the case where the architectural style of the wooden building is an outer wall structure of a frame wall construction method will be described as an example. If there is a large temperature difference between the indoor side and the outdoor side, between the vertical frames of the frame assembly In a so-called filled thermal insulation specification in which a plurality of partitioned hollow regions are each filled with a heat insulating material, the heat insulating material is divided at the vertical frame portion, and the vertical frame portion becomes a thermal bridge. As a result, heat is easily transferred between the indoor side and the outdoor side, and there is a problem that the heat insulating performance is inferior. Therefore, it has been studied to adopt a heat insulation structure by so-called outer heat insulation in which the heat insulation performance is improved by continuously attaching the heat insulation material to the outdoor side of the frame assembly without dividing.

  SUMMARY OF THE INVENTION The present invention solves the problems of the prior art as described above, and can be applied at low cost and easily, and can be used as an outer covering for a wooden building that can exhibit excellent heat insulation performance. An object is to provide an adiabatic fireproof structure.

In order to solve the above problems, the present invention relates to the following [1] to [6].
[1] An exterior heat-resistant fireproof outer wall structure of a wooden building, which is attached to the outdoor surface of the structural surface material and the structural surface material attached to the outdoor side of the structural member made of wood A phenol foam heat insulating plate having a thickness of 12 mm or more and 80 mm or less, and a lightweight cellular concrete panel attached to a surface on the outdoor side of the phenol foam insulating plate, and the density of the lightweight cellular concrete panel is d (unit) Is kg / m ³ ), the thickness of the lightweight cellular concrete panel is t (unit is mm), and the ignition loss value of the lightweight cellular concrete panel is α (unit is wt%), 200 ≦ d ≦ 550, 45 ≦ t ≦ 100, 5 ≦ α ≦ 15, and 3000 ≦ d × t ³ × α ÷ 100000 ≦ 30000.
[2] The outer heat insulating and fireproof outer wall structure of a wooden building according to [1], wherein d satisfies 250 ≦ d ≦ 400.
[3] The outer heat insulating and fireproof outer wall structure of a wooden building according to [1] or [2], wherein t satisfies 45 ≦ t ≦ 75.
[4] α is an outer heat insulating fireproof outer wall structure of a wooden building according to any one of [1] to [3], which satisfies 8 ≦ α ≦ 13.
[5] The external heat insulating fireproof outer wall structure of a wooden building according to any one of [1] to [4], wherein d, t, and α satisfy 5000 ≦ d × t ³ × α ÷ 100000 ≦ 15000.
[6] A heat insulating material is filled between the vertical frame and the vertical frame constituting the structural member, or between the pillar and the stud and the pillar and the pillar constituting the structural member. [5] The outer heat insulating fireproof outer wall structure of the wooden building according to any one of [5].

The outer wall structure described above includes a lightweight cellular concrete panel as an exterior member. Since this lightweight cellular concrete panel has the design parameters described above, sufficient panel strength is ensured, and it is possible to exhibit high fire resistance while suppressing an increase in panel weight. Since the increase in the panel weight is suppressed, the deterioration of workability and the earthquake resistance of the building is suppressed. Further, since the exterior member is a lightweight lightweight concrete panel, the work of shifting the joints from each other is not necessary.
A phenol foam heat insulating plate is attached to the surface on the outdoor side of the structural face material. According to this phenol foam heat insulating plate, since the phenol foam heat insulating plate is continuously attached to the structural face material without being divided, the heat insulating performance of the outer wall structure can be improved. Therefore, there is provided an external heat insulating and fire resistant outer wall structure for a wooden building which has excellent fire resistance performance and heat insulation performance, is easy to construct and is low in cost.

  Here, the relationship between the design parameters of the lightweight cellular concrete and the fire resistance performance will be described in detail. In order to construct the exterior member of the outer heat insulating fireproof outer wall structure of a wooden building with one layer of lightweight cellular concrete panel, the lightweight cellular concrete is considered in consideration of the following three parameters that are largely related to the fire performance of the lightweight cellular concrete panel. You need to design a panel. The three parameters are (1) the density of the lightweight cellular concrete panel, (2) the thickness of the lightweight cellular concrete panel, and (3) the amount of “water” that the lightweight cellular concrete has, that is, the lightweight cellular concrete. It is the amount of “water” that calcium silicate hydrate has.

  The present inventors have intensively studied what factors determine the fire resistance of lightweight cellular concrete panels. As a result of the study, the present inventors have found that the fire resistance performance of the lightweight cellular concrete panel is determined by the amount of “water” possessed by the lightweight cellular concrete. The “water” described here is “water” of the calcium silicate hydrate constituting the lightweight cellular concrete. In other words, it is “water” hydrated with calcium silicate. The fire resistance performance of the lightweight cellular concrete panel improves as the amount of “water” contained in the calcium silicate hydrate increases.

  Here, if the density of the lightweight cellular concrete panel is increased, the absolute amount of calcium silicate hydrate increases, so that the fire resistance performance is improved. On the other hand, if the density of the lightweight cellular concrete panel is reduced, the absolute amount of calcium silicate hydrate is reduced and the fire resistance performance is lowered. On the other hand, if the density is increased too much, the panel weight increases, so that the workability may decrease or the seismic performance may decrease due to an increase in the building weight. Moreover, if the density is too small, the physical strength of the lightweight cellular concrete panel may be insufficient.

  Further, if the thickness of the lightweight cellular concrete panel is increased, the absolute amount of calcium silicate hydrate increases, so that the fire resistance performance is improved. On the contrary, if the thickness is reduced, the absolute amount of calcium silicate hydrate is reduced, so that the fire resistance performance is lowered. On the other hand, if the thickness of the lightweight cellular concrete panel is increased too much, the panel weight increases, so that the workability may be deteriorated or the seismic performance may be deteriorated due to an increase in the building weight. Moreover, if the thickness is too thin, the physical strength of the lightweight cellular concrete panel may be insufficient.

  Moreover, if the quantity of the water which lightweight aerated concrete has, ie, the quantity of the water which the calcium silicate hydrate which comprises a lightweight aerated concrete panel increases, fireproof performance will improve. Conversely, when the amount of water contained in the calcium silicate hydrate decreases, the fire resistance performance decreases. However, it is difficult to actually obtain quantitatively the water of calcium silicate hydrate in lightweight cellular concrete. Therefore, in the present invention, the amount of water contained in the lightweight cellular concrete is defined as the amount of water contained in the lightweight cellular concrete by reducing the weight of the lightweight cellular concrete by heating. This value is defined as “ignition loss value”. Therefore, it can be said that the greater the ignition loss value, the higher the fire resistance.

  As described above, it is not appropriate to design the lightweight cellular concrete panel used for the outer wall structure considering only the ignition loss value deeply related to the fire resistance performance. That is, it is necessary to comprehensively evaluate the density, thickness, and ignition loss value of the lightweight cellular concrete panel while taking into account the panel strength and panel weight related to seismic performance and workability.

As a result of intensive studies on the above-described parameters of density, thickness, and ignition loss value, the present inventors have (1) a density d of 200 kg / m ^{3 to} 550 kg / m ³ and (2) thickness. The thickness t is 45 mm or more and 100 mm or less, (3) the ignition loss value α is 5 wt% or more and 15 t% or less, and d (kg / m ³ ) × t ³ (mm ³ ) × α (wt%) ÷ It was found that when the value of 100,000 is 3000 or more and 30000 or less, it is possible to satisfy the requirements for all of the panel weight, panel strength, and fire resistance.

  Further, in the outer heat insulating fireproof outer wall structure of the wooden building of the present invention, between the vertical frame and the vertical frame constituting the structural member, or between the pillar and the stud and the stud and the stud constituting the structural member, It is preferable that the heat insulating material is filled. With such a configuration, better heat insulation performance can be obtained.

  The `` wooden building '' described here is a general term for buildings in which main structural members such as pillars, beams, girders, etc. are made of wood, and the construction method of the building is a wooden frame wall method, a wooden frame wall method, etc. Any construction method is acceptable. “Wood” refers to a wooden material, and includes a woody material formed by processing wood fibers. The “structural member” refers to a main part that supports the load and external force of a building, such as a frame member (a beam, a column, a brace, etc.) of a wooden frame structure method or a frame structure of a wooden frame wall method.

  The terms “fireproof structure” and “fireproof performance” used in this specification are synonymous with those defined in Article 2 of the Building Standards Act and Article 107 of the Building Standards Act Enforcement Ordinance.

  ADVANTAGE OF THE INVENTION According to this invention, it has fireproof performance and the outstanding heat insulation performance, and it can provide construction and the external heat insulation fireproof outer wall structure of a low-cost wooden building.

FIG. 1 is a perspective view showing a part of an outer heat insulating and fireproof outer wall structure of a wooden building according to an embodiment of the present invention. FIG. 2 is a horizontal cross-sectional view showing an outer heat insulating and fireproof outer wall structure of a wooden building according to an embodiment of the present invention.

DESCRIPTION OF EMBODIMENTS Hereinafter, a preferred embodiment of an outer heat insulating fireproof outer wall structure of a wooden building according to the present invention will be described in detail with reference to the drawings.
In addition, as this embodiment, it demonstrates using the example which applied the outer-layer heat insulation fireproof structure to the frame structure of the wooden frame wall construction method. FIG. 1 is a perspective view showing a part of an outer heat insulating fireproof outer wall structure according to an embodiment of the present invention. FIG. 2 is a horizontal cross-sectional view showing an outer heat insulating fireproof outer wall structure according to an embodiment of the present invention.

  Here, "wooden building" is a general term for buildings in which main structural members such as columns, beams, girders, etc. are made of wood, and the building construction method can be any of wooden frame wall construction methods, wooden frame construction methods, etc. Such a construction is also acceptable. “Wood” refers to a wooden material, and includes a woody material formed by processing wood fibers. The “structural member” refers to a main part that supports the load and external force of a building, such as a frame member (a beam, a column, a brace, etc.) of a wooden frame structure method or a frame structure of a wooden frame wall method. The meanings of the terms “fireproof structure” and “fireproof performance” are the same as those defined in Article 2 of the Building Standard Law and Article 107 of the Building Standard Law Enforcement Order.

<Outer wall structure 1>
As shown in FIG. 1 and FIG. 2, the outer wall structure 1 of the wooden building according to the present embodiment is a wall body that partitions the building indoors and outdoors, and in this embodiment, the structure used in the frame wall construction method is used. Adopted. The outer wall structure 1 mainly includes a structural member 2, an interior member 3 provided on the indoor side of the structural member 2, a heat insulating member 4 provided on the outdoor side of the structural member 2, and an outdoor side of the heat insulating member 4. The exterior member 5 is provided.

<Structural member 2>
The structural member 2 is a member that becomes a skeleton of the wall body, and supports the load and external force of the building. As shown in FIG. 1, the structural member 2 includes a plurality of vertical frames 21, an upper frame member 22 that connects upper ends of the vertical frames 21, and lower ends of the vertical frames 21. And a lower frame member 23. The structural member 24 is attached to the vertical frame 21 on the surface of the structural member 2 on the outdoor side.

  The vertical frame 21, the upper frame material 22, and the lower frame material 23 are all long wooden members having a cross-sectional dimension of, for example, 38 mm × 89 mm, which are known as wood for a frame wall construction method, such as nails or screws. Are fastened together. The vertical frames 21 are erected at equal intervals with an interval of 455 mm or less in the horizontal direction.

  The structural face member 24 is fixed by nailing to a frame composed of the vertical frame 21, the upper frame member 22, and the lower frame member 23, and is provided on the outdoor side with respect to the frame. Thus, the performance as the structural member 2 is exhibited by integrating the vertical frame 21, the upper frame member 22, the lower frame member 23, and the structural face member 24.

As the structural face material 24, for example, a structural plywood conforming to the Japanese Agricultural Standard having a thickness of 9 mm and a density of 0.55 g / cm ³ can be used. Further, as the structural face material 24, for example, a structural plywood having a thickness of 9 mm or more, a structural panel having a thickness of 9 mm or more, a particle board having a thickness of 9 mm or more, a shising board having a thickness of 12 mm or more, etc. Wood board, hard wood cement board with a thickness of 12mm to 25mm, pulp cement board with a thickness of 9mm or more, flexible board with a thickness of 9mm or more, calcium silicate board with a thickness of 9mm or more, thickness A volcanic glassy multilayer board of 9 mm or more, or a gypsum board having a thickness of 12 mm or more can be used.

<Filling insulation 25>
Since the architectural style of the outer wall structure 1 is a wooden frame wall construction method, it is preferable from the point of the further improvement of heat insulation performance that the filling heat insulating material 25 is filled between the adjacent frame frames 21. For example, glass wool having a density of 24 kg / m ³ or rock wool can be used as the filling heat insulating material 25. In addition, when the architectural style of the outer wall structure 1 is a wooden frame construction method, a heat insulating material may be filled between the columns and the inter-columns and between the inter-columns and the inter-columns.

<Interior member 3>
The interior member 3 constitutes a wall surface on the indoor side of the wall body, and protects the structural member 2 from a flame such as a fire generated indoors. The interior member 3 includes an interior underlayer 31 made of reinforced gypsum board attached to the indoor side of the structural member 2 and an interior overcoat layer 32 made of reinforced gypsum board laminated on the indoor side of the interior underlayer 31. doing.

  The interior underlayer 31 is configured by abutting and joining the small edge surfaces of a plurality of reinforced gypsum boards to each other. The interior underlayer 31 is fixed to the structural member 2 with a gypsum board nail.

  The interior overlying layer 32 is configured by butting and joining the small edge surfaces of a plurality of reinforced gypsum boards. The interior upper layer 32 penetrates the interior underlayer 31 and is fixed to the structural member 2 with a plaster board nail.

  These reinforced gypsum boards preferably have a thickness of 21 mm or more and a bulk specific gravity of 0.75 or more. According to such a reinforced gypsum board, the water in the reinforced gypsum board is vaporized by the heat of the fire when a fire occurs indoors, so it is possible to consume the heat of the fire and delay the transfer of heat. . Therefore, carbonization and ignition of the structural member 2 can be prevented, and fire resistance against heat from the indoor side can be ensured. The interior member 3 may have an aluminum foil that is sandwiched between the interior underlayer 31 and the interior overlayer 32.

<Insulation member 4>
The heat insulating member 4 has a role of imparting excellent heat insulating performance. The heat insulating member 4 is provided on the surface on the outdoor side of the structural face material 24. As the heat insulating member 4, a phenol foam heat insulating plate 41 according to JIS A 9511 can be used. The range of the thickness of the phenol foam heat insulating plate 41 is 12 mm or more and 80 mm or less, preferably 20 mm or more and 60 mm or less, more preferably 20 mm or more and 40 mm or less. When the thickness of the phenol foam heat insulating plate 41 is less than 12 mm, excellent heat insulation performance cannot be imparted. When the thickness of the phenol foam heat insulating plate 41 exceeds 80 mm, the wall thickness increases, which is not practical. The phenol foam heat insulating plate 41 is preferably attached to the outdoor side of the structural face material 24 using a tape or an adhesive.

<Exterior member 5>
The exterior member 5 is a member that constitutes a wall surface on the outdoor side of the wall body, and protects the structural member 2 from flames such as a fire that occurs outdoors. The exterior member 5 includes a waterproof layer 51 formed on the outdoor surface of the heat insulating member 4 and a lightweight cellular concrete panel layer 52 formed on the outdoor surface of the waterproof layer 51.

  The waterproof layer 51 protects the structural member 2 and the heat insulating member 4 from rain water or the like that has penetrated from the gaps in the exterior member 5, and is adhered to the outdoor side surface of the heat insulating member 4 with an adhesive, tape, staple, or the like. ing. The waterproof layer 51 is directly attached to the heat insulating member 4. As the waterproof layer 51, it is preferable to use an asphalt felt according to JIS A 6006 or a moisture-permeable waterproof sheet according to JIS A 6111.

  The lightweight cellular concrete panel layer 52 is configured by pressing and joining a plurality of lightweight cellular concrete panels 53.

  The lightweight cellular concrete panel 53 is a panel molded into a plate shape and has excellent characteristics such as light weight, high heat insulation, high workability, and high fire resistance. Therefore, lightweight cellular concrete panels are used in many buildings in a wide range of fields, from high-rise buildings to ordinary houses. For example, lightweight cellular concrete panels are used in parts such as outer walls, partitions, floors, and roofs. In the lightweight cellular concrete panel, a slurry obtained by mixing a siliceous raw material, a calcareous raw material, water, a foaming agent, and the like is poured into a mold to foam the mixture. Subsequently, the semi-cured mixture is obtained by curing at high temperature and high pressure steam in an autoclave.

The lightweight cellular concrete panel 53 is a plate-like panel. A screw or the like is passed through the lightweight cellular concrete panel 53, the waterproof layer 51, and the heat insulating member 4 to be fixed to the structural member 2. The lightweight cellular concrete panel 53 has a density d of 200 kg / m ³ or more and 550 kg / m ³ or less, a thickness t of 45 mm or more and 100 mm or less, and an ignition loss value α of 5 wt. % To 15 wt%. The value of density d (kg / m ³ ) × thickness t ³ × ignition loss value α ÷ 100,000 is not less than 3000 and not more than 30000. According to the lightweight cellular concrete 54 satisfying such parameters, the structural member 2 can be prevented from being carbonized or ignited even from an outdoor fire.

  It is preferable that the lightweight cellular concrete panel 53 has a reinforcing reinforcing bar and a reinforcing wire mesh embedded therein. Here, the reinforcing reinforcing bars are obtained by arranging reinforcing bars in a desired shape and welding the crossing contacts. Further, the reinforcing wire mesh is obtained by processing iron into a net shape, and a lath net or the like is a typical example. The shape, size, thickness of the reinforcing bar, size of the mesh of the reinforcing mesh, etc. are not limited. These reinforcing reinforcing bars or reinforcing wire meshes are preferably subjected to a rust preventive treatment effective for durability. A known synthetic resin material or the like can be used as the rust preventive material.

  As the density d of the lightweight cellular concrete panel 53 is larger, the absolute amount of calcium silicate hydrate constituting the lightweight cellular concrete is increased, and the fire resistance performance is improved. However, as the density d of the lightweight cellular concrete panel 53 increases, the panel weight increases. According to the increase in the panel weight, the workability is reduced, the building weight is increased, the seismic performance is reduced, and the raw material for manufacturing the lightweight cellular concrete panel 53 is increased, so that the manufacturing cost is increased. Cases can arise.

  On the other hand, the smaller the density d of the lightweight cellular concrete panel 53, the lighter the panel weight. Therefore, there are advantages that workability is improved, earthquake resistance is improved by reducing the weight of the building, and raw materials for manufacturing the lightweight cellular concrete panel 53 are reduced, thereby reducing manufacturing costs. However, as the density d of the lightweight cellular concrete panel 53 is lower, the absolute amount of calcium silicate is reduced, so that the fire resistance may be lowered or the panel strength may be lowered.

Accordingly, as a result of intensive studies, the inventors have determined that the range of the density d of the lightweight cellular concrete panel 53 is 200 kg / m ³ or more and 550 kg / m ³ or less, preferably 230 kg / m ³ or more and 500 kg / m ^3. It was found that it is not less than 250 kg / m ^{3 and not} more than 400 kg / m ³ . Here, when the density d is less than 200 kg / m ³ , the panel strength is low and the fire resistance is low, which is not practical. On the other hand, if the density of the lightweight cellular concrete panel 53 exceeds 550 kg / m ³ , the panel weight is heavy, so that the workability is reduced, and the building weight is increased and the seismic performance is lowered, which is not practical.

  Moreover, since the absolute amount of the calcium silicate hydrate which comprises the lightweight cellular concrete panel 53 increases, the fireproof performance improves, so that the thickness t of the lightweight cellular concrete panel 53 is large. However, as the thickness t of the lightweight cellular concrete panel 53 increases, the panel weight increases. According to the increase in the panel weight, the workability is reduced, the building weight is increased, the seismic performance is reduced, and the raw material for manufacturing the lightweight cellular concrete panel 53 is increased, so that the manufacturing cost is increased. Cases can arise.

  On the other hand, the smaller the thickness t of the lightweight cellular concrete panel 53, the lighter the panel weight. According to the weight reduction of the panel weight, the workability is improved, the building weight is lightened, the seismic performance is improved, and the raw material for manufacturing the lightweight cellular concrete panel 53 is reduced, so the manufacturing cost is reduced. There is a merit such as. However, there may be a case where the fire resistance performance decreases due to a decrease in the absolute amount of calcium silicate hydrate.

  Therefore, as a result of intensive studies, the present inventors have found that the range of the thickness t of the lightweight cellular concrete panel 53 is 45 mm or more and 100 mm or less, preferably 45 mm or more and 80 mm or less, more preferably 45 mm or more and 75 mm or less. I found out. Here, when the thickness t is less than 45 mm, the fire resistance is low, which is not practical. On the other hand, when the thickness t exceeds 100 mm, the workability deteriorates and is not practical.

  Further, as the ignition loss value α of the lightweight cellular concrete panel 53 is larger, the fire resistance performance of the lightweight cellular concrete panel 53 is higher. That is, when the ignition loss value α is large, the amount of water that the lightweight cellular concrete panel 53 has, that is, the “water” that the calcium silicate hydrate constituting the lightweight cellular concrete has is large in the lightweight cellular concrete. It is because it is doing. However, the production of the lightweight cellular concrete panel 53 containing a large amount of calcium silicate hydrate is technically difficult, so there is an upper limit to the amount of calcium silicate hydrate that can be present in the lightweight cellular concrete. On the other hand, the smaller the ignition loss value α, the lower the fire resistance performance of the lightweight cellular concrete panel 53.

  Therefore, as a result of intensive studies, the present inventors have determined that the range of the ignition loss value α of the lightweight cellular concrete panel 53 is 5 wt% or more and 15 wt% or less, preferably 7 wt% or more and 14 wt% or less, more preferably It was found to be 8 wt% or more and 13 wt% or less. Here, when the ignition loss value α is less than 5 wt%, the fire resistance is low, so the fire resistance required for the outer wall structure 1 cannot be satisfied.

However, in order to satisfy all of the panel weight, panel strength, and fire resistance required for the lightweight cellular concrete panel 53, the lightweight cellular concrete panel 53 has the above three parameters: (1) density d (kg / M ³ ), (2) thickness t (mm), and (3) ignition loss value α (wt%) may be insufficient even in the above numerical range.

  For example, even if the density d, the thickness t, and the ignition loss value α are within the above numerical range, the lightweight cellular concrete having the density d and the thickness t close to the upper limit of the numerical range. Although the panel 53 satisfies the fire resistance, the panel weight increases, so that the workability may be lowered and may not be practical.

  Moreover, although the density d is in the above numerical range, the lightweight cellular concrete panel 53 in which the density d is close to the lower limit of the numerical range may not satisfy the fire resistance. In that case, it is necessary to increase the thickness t of the lightweight cellular concrete panel 53 or the ignition loss value α.

Therefore, in order to satisfy all of the panel weight, panel strength, and fire resistance required for the lightweight cellular concrete panel 53, the lightweight cellular concrete panel 53 needs to comprehensively evaluate the above three parameters. . As a result of intensive studies on the evaluation method, the present inventors have conducted a new study of density d (kg / m ³ ) × (thickness t) ³ (mm ³ ) × ignition loss value α (wt%) ÷ 100,000. We found that it can be evaluated by parameters.

And the value of density d (kg / m ³ ) × (thickness t) ³ (mm ³ ) × ignition loss value α (wt%) ÷ 100,000, which is a new parameter, is 3000 to 30000, preferably It has been found that the panel weight, the panel strength, and the fire resistance can be satisfied satisfactorily when they are 4000 or more and 25000 or less, more preferably 5000 or more and 15000 or less.

  According to the outer wall structure 1 including the lightweight cellular concrete panel 53, it is possible to satisfy the panel weight, panel strength, and fire resistance performance required for the lightweight cellular concrete panel 53 in a well-balanced manner. Therefore, the exterior member 5 can be composed of only one kind of material and a single exterior member, that is, the lightweight cellular concrete panel 53. For this reason, construction is simple and low-cost fireproof outer wall structure 1 is realizable. For example, according to the outer wall structure 1, heating is performed for 1 hour under the heating conditions defined by ISO-834 from the outdoor side or indoor side, and after the heating is stopped, the structural member is carbonized or It has been confirmed that no ignition is observed. And according to the outer wall structure 1, it becomes possible to construct | assemble a wooden fireproof building easily, and the greater spread of wooden construction can be aimed at.

  The outer wall structure 1 includes an interior underlayer 31 made of reinforced gypsum board on the indoor side of the structural member 2 made of wood, and an interior overcoat layer 32 made of reinforced gypsum board on the indoor side of the interior underlayer 31. Has a two-layer structure. According to this two-layer structure, the heat of the fire transmitted to the structural member 2 made of wood can be reduced and the carbonization and ignition of the structural member 2 can be prevented against an indoor fire.

  Next, the Example at the time of performing a fireproof performance evaluation test is demonstrated using the outer wall structure 1 shown by FIG.1 and FIG.2. In addition, this invention is not limited to the specific dimension illustrated by a following example.

  First, the outer wall structure 1 will be described in detail. The outer wall structure 1 includes a structural member 2, an interior member 3, a heat insulating member 4, and an exterior member 5, and adopts a structure used in a wooden frame wall construction method.

<Structural member 2>
The structural member 2 includes a plurality of vertical frames 21, an upper frame member 22 that connects upper ends of the vertical frames 21, a lower frame member 23 that connects lower ends of the vertical frames 21, It is comprised from the structural surface material 24 attached to the surface of the frame 21 on the outdoor side. The vertical frame 21, the upper frame material 22, and the lower frame material 23 are all long wooden members having a cross-sectional dimension of 38 mm × 89 mm used as wood for the frame wall construction method. The vertical frame 21, the upper frame member 22, and the lower frame member 23 were fastened to each other with screws. The vertical frame 21 was erected at regular intervals of 455 mm. As the structural face material 24, a structural plywood having a thickness of 9 mm was used. The structural face material 24 was fixed to the vertical frame 21, the upper frame material 22, and the lower frame material 23 by hitting nails on the outdoor side surface of the vertical frame 21.

<Interior member 3>
The interior member 3 has a reinforcing gypsum board having a thickness of 21 mm which is an interior underlayer 31 on the indoor side of the structural member 2 and a thickness which is an interior upper layer 32 positioned on the indoor side of the interior underlayer 31. Is composed of a two-layer structure in which a 21 mm reinforced gypsum board is laminated. The interior underlayer 31 is configured by joining a plurality of reinforced gypsum boards together and joining them. The interior underlayer 31 was struck to the structural member 2 with a gypsum board nail. The interior overlying layer 32 is configured by a plurality of reinforced gypsum boards being butted together and joined together. The interior upper layer 32 was struck to the structural member 2 by passing a nail through the interior upper layer 32 and the interior underlayer 31. Moreover, the joint agent for gypsum boards according to JIS A 6914 was applied to the joint portion of the interior overlying layer 32 as a joint agent for interior material, and finished smoothly.

<Insulation member 4>
The heat insulating member 4 was affixed to the outdoor surface of the structural face material 24 using a tape. The heat insulating member 4 was configured by attaching and joining together a plurality of phenol foam heat insulating plates 41 (manufacturer: Asahi Kasei Construction Materials Co., Ltd., trade name: Neomafoam) having a thickness of 20 mm. A special tape was applied to the vertical and horizontal joints of the phenol foam heat insulating plate.

<Exterior member 5>
The exterior member 5 includes a waterproof layer 51 disposed on the outdoor surface of the heat insulating member 4 and a lightweight cellular concrete panel layer 52 disposed on the outdoor surface of the waterproof layer 51. The waterproof layer 51 is a moisture permeable waterproof sheet (manufacturer: Asahi, Deyupon, Flash, Span Product Co., Ltd., product name: Tyvek), and was attached to the outdoor side surface of the heat insulating member 4 using an adhesive. The seam of the moisture permeable waterproof sheet was overlapped at 90 mm both vertically and horizontally. The lightweight cellular concrete panel layer 52 was constituted by pressing and joining a plurality of lightweight cellular concrete panels 53. The lightweight cellular concrete panel 53 was fixed by passing a screw through the lightweight cellular concrete panel 53, the waterproof layer 51, and the heat insulating member 4 and hitting the structural member 2. An acrylic sealing material was applied to the joints of the lightweight cellular concrete panel layer 52.

  The outer wall structure 1 of the present embodiment was constituted by the structural member 2, the interior member 3, the heat insulating member 4, and the exterior member 5.

  Next, the measurement method of each value about the lightweight cellular concrete panel 53 and the fire resistance evaluation test method of the outer wall structure 1 will be described.

<Density of lightweight cellular concrete panel>
The lightweight cellular concrete panel 53 was cut out as a block having a size of 100 (mm) × 100 (mm) × 40 (mm), and the block was dried with a dryer at 105 ° C. until reaching a constant weight. The weight W (kg) after the drying and the volume V (m ³ ) of the block are measured, and the density d is calculated by the equation (1).
d (kg / m ³ ) = W / V (1)

<Thickness t of lightweight cellular concrete panel>
The thickness t was measured in units of 1 mm with a caliper.

<Light loss value α of lightweight cellular concrete panel>
The lightweight cellular concrete was pulverized until it became powdery. The powder was dried with a dryer at 105 ° C. until a constant weight was reached. The weight after drying is defined as A (g). Next, the powder which became the constant weight was heated for 1 hour using the electric furnace of 1000 degreeC. And the weight after a heating is measured and let the weight be B (g). The ignition loss value α is calculated by the equation (2).
α (wt%) = (A−B) × 100 / B (2)

<Moisture content β of lightweight cellular concrete panel>
The lightweight cellular concrete panel 53 is cut out as a block having a size of 600 (mm) × 600 (mm) × 40 (mm), and the weight C (kg) of the block is measured. The block was dried with a dryer at 105 ° C. until a constant weight was reached. The dried weight D (kg) is measured. The moisture content β of the lightweight cellular concrete panel is calculated by the equation (3).
β (wt%) = (C−D) × 100 / D (3)

<Firewall performance evaluation method for outer wall structure>
The test body of the outer wall structure 1 is heated for 1 hour from the outdoors or indoors according to the heating curve defined in ISO-834, and then the heating is stopped and the sample is allowed to stand for 3 hours. Thereafter, the test body is disassembled, and the structural member 2 is visually inspected for carbonization and ignition.

Example 1
In Example 1, fire resistance performance evaluation of the outer wall structure 1 comprised by the structural member 2, the interior member 3, the heat insulation member 4, and the exterior member 5 was performed. The following materials were used for the lightweight cellular concrete panel 53 constituting the lightweight cellular concrete panel layer 52.
d = 375 (kg / m ³ )
t = 50 (mm)
α = 11.5 (wt%)
d × t ³ × α ÷ 100000 = 5391
β = 2.6 (wt%)

(Fire resistance evaluation result of Example 1)
Indoor heating: No carbonization or ignition was observed in the structural member 2.
Heating from the outside: The structural member 2 was not carbonized or ignited.

(Example 2)
In Example 2, fire resistance performance evaluation of the outer wall structure 1 comprised of the structural member 2, the interior member 3, the heat insulating member 4, and the exterior member 5 was performed. The following materials were used for the lightweight cellular concrete panel 53 constituting the lightweight cellular concrete panel layer 52.
d = 490 (kg / m ³ )
t = 50 (mm)
α = 8.1 (wt%)
d × t ³ × α ÷ 100,000 = 4961
β = 2.8 (wt%)

(Fire resistance evaluation result of Example 2)
Indoor heating: No carbonization or ignition was observed in the structural member 2.
Heating from the outside: The structural member 2 was not carbonized or ignited.

(Example 3)
In Example 3, fire resistance performance evaluation of the outer wall structure 1 comprised by the structural member 2, the interior member 3, the heat insulation member 4, and the exterior member 5 was performed. The following materials were used for the lightweight cellular concrete panel 53 constituting the lightweight cellular concrete panel layer 52.
d = 350 (kg / m ³ )
t = 50 (mm)
α = 8.3 (wt%)
d × t ³ × α ÷ 100,000 = 3631
β = 2.5 (wt%)

(Fire resistance evaluation result of Example 3)
Indoor heating: No carbonization or ignition was observed in the structural member 2.
Heating from the outside: The structural member 2 was not carbonized or ignited.

Example 4
In Example 4, fire resistance performance evaluation of the outer wall structure 1 comprised by the structural member 2, the interior member 3, the heat insulation member 4, and the exterior member 5 was performed. The following materials were used for the lightweight cellular concrete panel 53 constituting the lightweight cellular concrete panel layer 52.
d = 275 (kg / m ³ )
t = 75 (mm)
α = 11.1 (wt%)
d × t ³ × α ÷ 100,000 = 1287
β = 2.5 (wt%)

(Fire resistance evaluation result of Example 4)
Indoor heating: No carbonization or ignition was observed in the structural member 2.
Heating from the outside: The structural member 2 was not carbonized or ignited.

(Example 5)
In Example 5, fire resistance performance evaluation of the outer wall structure 1 comprised by the structural member 2, the interior member 3, the heat insulation member 4, and the exterior member 5 was performed. The following materials were used for the lightweight cellular concrete panel 53 constituting the lightweight cellular concrete panel layer 52.
d = 500 (kg / m ³ )
t = 50 (mm)
α = 12.0 (wt%)
d × t ³ × α ÷ 100,000 = 7500
β = 2.5 (wt%)

(Fire resistance evaluation result of Example 5)
Indoor heating: No carbonization or ignition was observed in the structural member 2.
Heating from the outside: The structural member 2 was not carbonized or ignited.

(Example 6)
In Example 6, fire resistance performance evaluation of the outer wall structure 1 comprised by the structural member 2, the interior member 3, the heat insulation member 4, and the exterior member 5 was performed. Further, glass wool having a density of 24 kg / m ³ was filled between the vertical frame 21 and the vertical frame 21 constituting the structural member 2 as the filled heat insulating material 25. The following materials were used for the lightweight cellular concrete panel 53 constituting the lightweight cellular concrete panel layer 52.
d = 375 (kg / m ³ )
t = 50 (mm)
α = 11.0 (wt%)
d × t ³ × α ÷ 100000 = 5156
β = 2.6 (wt%)

(Fire resistance evaluation result of Example 6)
Indoor heating: No carbonization or ignition was observed in the structural member 2.
Heating from the outside: The structural member 2 was not carbonized or ignited.

(Comparative Example 1)
In Comparative Example 1, fire resistance performance evaluation of the outer wall structure 1 composed of the structural member 2, the interior member 3, the heat insulating member 4, and the exterior member 5 was performed. The following materials were used for the lightweight cellular concrete panel 53 constituting the lightweight cellular concrete panel layer 52.
d = 375 (kg / m ³ )
t = 37 (mm)
α = 11.1 (wt%)
d × t ³ × α ÷ 100,000 = 2108
β = 2.5 (wt%)

(Results of fire resistance evaluation of Comparative Example 1)
Indoor heating: No carbonization or ignition was observed in the structural member 2.
Heating from outside: Carbonization was observed in the structural member 2.

(Comparative Example 2)
In Comparative Example 2, fire resistance performance evaluation of the outer wall structure 1 composed of the structural member 2, the interior member 3, the heat insulating member 4, and the exterior member 5 was performed. The following materials were used for the lightweight cellular concrete panel 53 constituting the lightweight cellular concrete panel layer 52.
d = 500 (kg / m ³ )
t = 37 (mm)
α = 8.1 (wt%)
d × t ³ × α ÷ 100,000 = 2051
β = 2.5 (wt%)

(Fire resistance evaluation result of Comparative Example 2)
Indoor heating: No carbonization or ignition was observed in the structural member 2.
Heating from outside: Carbonization was observed in the structural member 2.

  As shown in Examples 1 to 6, as a result of heating from the indoor side and the outdoor side, the structural member 2 was not carbonized or ignited, so that the outer wall structure 1 is a “fireproof structure”. all right.

  It is an external heat insulation method that can provide excellent heat insulation performance for the outer wall structure of a wooden building, is easy to construct and low in cost, has only one type of exterior member, and is fireproof with only one exterior member. In order to achieve the structure, as a result of intensive studies, it was concluded that the exterior material was a lightweight cellular concrete panel. The outer wall structure 1 of the present embodiment has a structural face member 24 attached to the outdoor side of a structural member 2 made of wood, and a thickness of 12 mm attached to the outdoor side face of the structural face member 24. A lightweight foam concrete panel 53 is formed as an exterior member on the phenol foam heat insulating plate having a thickness of 80 mm or less and the outdoor side surface of the phenol foam heat insulating plate.

The density of the lightweight cellular concrete panel 53 is d (kg / m ³ ), the thickness of the lightweight cellular concrete panel 53 is t (unit: mm), and the ignition loss value of the lightweight cellular concrete panel 53 is α (wt%). Then, 200 ≦ d ≦ 550, 45 ≦ t ≦ 100, 5 ≦ α ≦ 15, and 3000 ≦ d × t ³ × α ÷ 100000 ≦ 30000 are satisfied.

  In order to give the thermal insulation outer wall structure of the wooden building of the present invention better thermal insulation performance, when the architectural style is a wooden framed wall construction method, between the pillars and the studs and between the pillars and the studs. The filling heat insulating material 25 may be filled. Further, when the architectural style is a wooden frame wall construction method, the filling heat insulating material 25 may be filled between the vertical frame 21 and the vertical frame 21 as described above.

  Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment. In this embodiment, although the case where this invention was applied to the wall body used for a wooden frame wall construction method was demonstrated as an example, you may apply to other wall bodies, such as a wooden frame construction method.

  According to the present invention, it is an external thermal insulation method capable of imparting excellent heat insulation performance, and the exterior member can be composed of only one type of material and a single layer exterior member, that is, the lightweight cellular concrete panel 53. It is possible to provide an easy, low-cost wooden building outer thermal insulation fireproof outer wall structure. Therefore, it becomes possible to easily construct a wooden fire-resistant building having excellent heat insulation performance, and the wooden construction can be more widely spread.

DESCRIPTION OF SYMBOLS 1 ... Outer wall structure, 2 ... Structural member, 3 ... Interior member, 4 ... Thermal insulation member, 5 ... Exterior member, 21 ... Vertical frame, 22 ... Upper frame material, 23 ... Lower frame material, 24 ... Structural surface material, DESCRIPTION OF SYMBOLS 31 ... Interior undercoat layer, 32 ... Interior overcoat layer, 41 ... Phenol foam thermal insulation board, 51 ... Waterproofing layer, 52 ... Lightweight cellular concrete panel layer, 53 ... Lightweight cellular concrete panel.

Claims (3)

It is an outer heat insulating fireproof outer wall structure of a wooden building,
A structural face material attached to the outdoor side of a structural member made of wood;
A phenol foam heat insulating plate attached to the surface on the outdoor side of the structural face material and having a thickness of 12 mm to 80 mm;
A lightweight cellular concrete panel attached as an exterior material to the outdoor side surface of the phenol foam heat insulating plate,
The density of the lightweight cellular concrete panel is d (unit is kg / m ³ ), the thickness of the lightweight cellular concrete panel is t (unit is mm), and the ignition loss value of the lightweight cellular concrete panel is α (unit is wt %),
250 ≦ d ≦ 400 ,
45 ≦ t ≦ 75 ,
8 ≦ α ≦ 13 , and
3000 ≦ d × t ³ × α ÷ 100,000 ≦ 15000
We meet the,
The ignition loss value α is calculated by α (wt%) = (weight A−weight B) × 100 / weight B, and the weight A is the weight of the lightweight cellular concrete panel powder dried to a constant weight. The weight B is a weight of the powder after heating the powder of the weight A at 1000 ° C. for 1 hour, and is an outer heat insulating fireproof outer wall structure of a wooden building. The outer heat insulating fireproof outer wall structure of a wooden building according to claim 1, wherein d, t, and α satisfy 5000 ≦ d × t ³ × α ÷ 100000 ≦ 15000. Between the vertical frame and the vertical frame constituting the structural member, or between the pillars and studs, and studs and studs constituting the structural member, the heat insulating material is filled, according to claim 1 or 2 Outer heat-insulated fire-resistant outer wall structure of wooden buildings.

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