WO2024029210A1

WO2024029210A1 - Wooden structure load-bearing wall, construction method for wooden structure load-bearing wall, method for increasing wall magnification of wooden structure load-bearing wall, and gypsum-based load-bearing surface material

Info

Publication number: WO2024029210A1
Application number: PCT/JP2023/022235
Authority: WO
Inventors: 潮須藤; 克己新見; 知哉長谷川; 琢治山下; 晃三赤井; 洋介佐藤
Original assignee: 吉野石膏株式会社
Priority date: 2022-07-30
Filing date: 2023-06-15
Publication date: 2024-02-08

Abstract

The present invention increases the wall magnification of a wooden structure load-bearing wall without additionally attaching a reinforcing material or stiffener, and without increasing the specific gravity and/or sheet thickness of a gypsum-based surface material. A gypsum-based load-bearing surface material 10 for a wooden structure load-bearing wall is configured from: a main material or a core material comprising a plate-shaped gypsum cured body in which inorganic fibers and an organic-based strength-improving material are blended so as to exhibit a nail-side surface resistance of 500 N or greater; and a paper member covering at least front and back surfaces of the main material or core material. This load-bearing surface material: has a surface density that falls within a range of 6.5-8.9 kg/m2 and a compressive stiffness of 6.5 N/mm2 or greater; exhibits, in an in-plane shearing test of the load-bearing wall, an ultimate displacement (δu) greater than 20×10-3 rad and an initial stiffness (K) of 2.0 kN/10-3 rad or greater; and raises a plasticity rate (μ) due to a reduction in yield point displacement (δv), not only the ultimate displacement. As a result, the wall magnification and short-term standard shear stiffness (P0) of the wooden structure load-bearing wall are effectively and efficiently increased.

Description

Wooden load-bearing walls, construction methods for wooden load-bearing walls, methods for increasing the wall magnification of wooden load-bearing walls, and gypsum load-bearing facing materials

The present disclosure relates to a wooden structural load-bearing wall, a method for constructing a wooden structural load-bearing wall, a method for increasing the wall magnification of a wooden structural load-bearing wall, and a gypsum-based load-bearing wall material. More specifically, a relatively low-density gypsum-based load-bearing surface material with increased nail side resistance and reduced surface density is used, and reinforcing or stiffening materials such as metal plates are additionally installed. A wooden structural load-bearing wall, a construction method for a wooden structural load-bearing wall, a method for increasing the wall magnification of a wooden structural load-bearing wall, and a wooden structural load-bearing wall, which can effectively reduce the effects of destruction or breakage of nailed parts without causing damage. Concerning gypsum-based load-bearing surface materials.

In general, construction methods for wooden structures are broadly divided into wooden frame construction methods and wooden frame wall construction methods. Due to the effects of recent large-scale earthquakes, research on the earthquake resistance of wooden structures has recently attracted particular attention in Japan. As described in Patent Document 1 (International Publication WO2019/203148A1), in the practice of architectural design in Japan, the strength of wooden structures to withstand short-term horizontal loads (earthquake force, wind pressure, etc.) is The frame length of the load-bearing wall (the length of the wall in the architectural plan), which is effective in terms of structural strength, is generally used as an indicator. In calculating the frame length, a wall magnification that is appropriate for the structure of the load-bearing wall is used. Wall magnification is an index of seismic performance or load-bearing performance of a load-bearing wall, and the larger the value, the greater the seismic strength. A wall structure with a large wall magnification is advantageous in improving the design freedom and seismic resistance of the entire building.

The wall magnification of general-purpose wooden structural load-bearing walls that have been used in Japan for many years is based on Article 46 of the Enforcement Order of the Building Standards Act, Ministry of Construction Notification No. 1100 (June 1, 1980), and It is stipulated in Ministry of Land, Infrastructure, Transport and Tourism Notification No. 1541 (October 15, 2001). On the other hand, many recent load-bearing walls that do not belong to such general-purpose wall structures are constructed based on the certification of the Minister of Land, Infrastructure, Transport and Tourism as stipulated in Article 46, Paragraph 4, Table 1 (8) of the Enforcement Order of the Building Standards Act. It is necessary to determine the magnification. For this reason, it is necessary to set the wall magnification of a relatively large number of wooden structure load-bearing walls constructed in recent years based on performance tests conducted by designated performance evaluation organizations. It is described in detail in the "Wooden Load-bearing Walls and Their Magnification Performance Testing and Evaluation Procedures Manual" published by each testing and inspection organization.

Patent Document 1 discloses that, as a measure to increase the ultimate displacement of a load-bearing wall and improve the wall magnification, a reinforcing material or stiffening material such as a metal plate is provided in the nailed part, and the nailed part is destroyed or broken. A method of reinforcing face materials to prevent such problems is described. According to wooden structural load-bearing walls using such reinforcing materials or stiffening materials, the ultimate displacement can be reduced by improving the toughness and deformation followability of the load-bearing facing materials, without relying on an increase in the maximum load that the facing materials can withstand. It is thought that it will be possible to construct a wood structure load-bearing wall that exhibits a relatively high wall magnification. However, according to the load-bearing wall structure configured to increase the ultimate displacement etc. using such reinforcing materials or stiffening materials, the process of additionally attaching the reinforcing material or stiffening material to the surface of the load-bearing facing material is required. Such steps must be added to the manufacturing process or additionally performed during construction of the wood structural load-bearing wall. This type of process may complicate the manufacturing process of gypsum-based facing materials or may become a factor that worsens the workability of construction work.

On the other hand, "structural gypsum board" is known as a gypsum-based facing material that can be suitably used as a load-bearing facing material for wooden structural load-bearing walls. "Structural gypsum board" is a gypsum-based facing material that has strengthened the nail side resistance of "reinforced gypsum board" based on the technology of the applicant described in Patent No. 5,642,948 (Patent Document 2). Nail side resistance is the shear strength or shear strength of the nailed portion of the facing material measured by the nail side resistance test specified in JIS A 6901. Nail side resistance is described in relatively detail in Patent No. 7012405 (Patent Document 3) filed by the present applicant, so further detailed explanation will be omitted, but nail side resistance is is a physical property proposed by the present applicant as a strength determining factor for gypsum-based load-bearing surface materials in Patent Document 2, and is one of the strength factors that the present applicant has particularly focused on in recent years.

Structural gypsum board (GB-St) has improved overall strength as a load-bearing surface material compared to (ordinary) gypsum board (GB-R), and is more durable than reinforced gypsum board (GB-F). A gypsum-based facing material with improved side resistance. Structural gypsum board is currently defined in JIS A 6901 as a gypsum-based facing material having a nail side resistance of 750 N or more (Class A) or 500 N or more (Class B). A wooden structural load-bearing wall using structural gypsum board as a load-bearing facing material exhibits a relatively higher wall magnification than a wooden structural bearing wall using (usually) gypsum board or reinforced gypsum board as a load-bearing facing material. On the other hand, structural gypsum board, like reinforced gypsum board, requires a thickness of 12.5 mm or more and a specific gravity of 0.75 or more. For this reason, a wooden structural load-bearing wall to which structural gypsum board is fixed must have an areal density or areal weight (the mass of the load-bearing facing material per unit area of the wall surface (hereinafter referred to as "area density") of at least approximately 9.4 kg/ ^m2. .)) is required.

Patent Document 3 (Japanese Patent Publication No. 7012405) describes a gypsum-based shear strength that gives a load-bearing wall a short-term standard shear strength (P0) equivalent to that of structural gypsum board, but has a lower areal density than structural gypsum board. The facing material is listed. The gypsum-based facing material described in Patent Document 3 has a main material or core material made of a plate-shaped gypsum hardened body blended with inorganic fibers and an organic strength improving material so as to exhibit a nail side resistance of 500 N or more; It is composed of a paper member covering at least the front and back surfaces of the main material or core material, and has an areal density within the range of 6.5 to 8.9 kg/m ² . The gypsum-based facing material of Patent Document 3 can provide a load-bearing wall with a relatively high wall magnification even if the thickness is less than 12 mm. Compared to conventional gypsum-based load-bearing facing materials such as structural gypsum boards, this gypsum-based facing material reduces areal density and makes the facing material lighter, while suppressing the decline in yield strength through relatively high nail side resistance. This is a load-bearing facing material (hereinafter referred to as "low-density gypsum load-bearing facing material") that was developed with the intention of According to this low-density gypsum-based load-bearing surface material, it is possible to increase the ultimate displacement of the load-bearing wall and increase the plasticity ratio of the load-bearing wall, thereby increasing the wall magnification of the load-bearing wall. It becomes possible to provide a gypsum-based load-bearing surface material that is extremely advantageous in practice from the viewpoint of achieving both the desired load-bearing strength as well as its light weight and workability.

In this specification, the term "gypsum-based load-bearing surface material" refers not only to (ordinary) gypsum board, reinforced gypsum board, and structural gypsum board as defined in JIS A 6901 ("gypsum board products"). , the gypsum core part mainly made of gypsum, such as the low-density gypsum-based load-bearing facing material (Patent Document 3) and the gypsum-based load-bearing facing material described in Patent No. 6412431 (Patent Document 4), etc. This term is used to include gypsum-based facing materials in which the outer surface or outer layer of the core material (core material portion) is covered with a paper member such as base paper for gypsum board.

International Publication WO2019/203148A1 Publication published in Patent No. 5642948 Publication published in Patent No. 7012405 Publication published in Patent No. 6412431

The present inventors repeatedly conducted the above performance tests in order to further increase the wall magnification regarding the load-bearing wall using the low-density gypsum-based load-bearing surface material proposed in Patent Document 3, and found that punching out due to the punching shear phenomenon It was recognized that it is possible to further increase the wall magnification by preventing phenomena such as destruction and edge tearing. Destruction or breakage of the nailed part such as punching-out failure can be avoided by arranging a reinforcing material or stiffening material such as a metal plate in the nailed part, as in the face material reinforcement method described in Patent Document 1, for example. It is thought that this can be prevented by

However, as mentioned above, the process of additionally attaching such reinforcing materials or stiffeners to the surface of the load-bearing cladding may be added to the cladding manufacturing process, or such a step may be carried out during the construction of the wood-structured load-bearing wall. If implemented additionally, it is assumed that the manufacturing process of gypsum-based facing materials will become complicated or the workability of construction work will deteriorate.

The present disclosure has been made in view of the above circumstances, and its purpose is to provide a wooden structure that uses a low-density gypsum-based load-bearing facing material with increased nail side resistance and reduced surface density. In walls and their construction methods, it is possible to suppress the punching shear phenomenon or reduce the effects of punch-out failure without additionally installing reinforcing materials such as metal plates or stiffening materials, thereby preventing the failure of nailed parts or Provides a wooden structure load-bearing wall and its construction method, a method for increasing the wall magnification of a wooden structure load-bearing wall, and a gypsum-based load-bearing surface material that can further increase the wall magnification by suppressing breakage or reducing its effect. It's about doing.

In order to achieve the above object, the present disclosure provides a wooden structure load-bearing wall having a structure in which a gypsum-based load-bearing surface material is fastened to a wooden structure wall base using a wooden frame construction method or a wooden frame wall construction method using fasteners.
The load-bearing surface material is composed of a main material or core material made of a plate-shaped gypsum hardened body, and a paper member that covers at least the front and back surfaces of the main material or core material,
The load-bearing facing material has an areal density or areal weight within the range of 6.5 to 8.9 kg/m ² as the areal density or areal weight of the load-bearing facing material specified as the mass per unit area of the wall surface. At the same time, it exhibits a nail side resistance of 500N or more, and has a compressive strength of at least 6.5N/mm ² or more,
The fastener is made of a metal nail having a head and a body, and the area ratio of the area of the head/the cross-sectional area of the body is set to a value within the range of 6 to 13,
As the ultimate displacement of the load-bearing wall measured by an in-plane shear test using a load-bearing wall test piece with a wall length of 1.82 m, the load-bearing wall has an ultimate displacement (δu) of a value larger than 20 × 10 ^-3 rad. We provide wooden structural load-bearing walls featuring:

The present disclosure also provides a method for constructing a wooden structure load-bearing wall in which a gypsum-based load-bearing surface material is fixed to a wooden structure wall base of a wooden frame construction method or a wooden frame wall construction method,
A gypsum-based load-bearing surface material consisting of a main material or core material made of a plate-shaped hardened gypsum material and a paper member covering at least the front and back surfaces of the main material or core material, The areal density or areal weight specified as mass is within the range of 6.5 to 8.9 kg/ ^m2 , and the nail side resistance is 500 N or more and is at least 6.5 N/m2. A gypsum-based load-bearing surface material having a compressive strength of mm ² or more is fastened to the wooden structure wall base using fasteners, and the fasteners have an area ratio of 6 to 13 of the area of the head/cross-sectional area of the body. using a metal nail set to a value within the range of
The ultimate displacement (δu) of the load-bearing wall measured by an in-plane shear test using a load-bearing wall test piece with a wall length of 1.82 m is greater than 20 × 10 ^-3 rad. Provided is a method for constructing a wooden structure load-bearing wall, which is characterized by constructing the wooden structure load-bearing wall.

Preferably, the nail has a head diameter within the range of 6.0 to 10.0 mm and a body diameter within the range of 2.0 to 5.0 mm. More preferably, the nail has a head diameter within the range of 6.8 to 9.0 mm and a body diameter within the range of 2.2 to 4.2 mm, the area of the head being divided by the cross-sectional area of the body. The ratio (hereinafter referred to as "area ratio of head area/body cross-sectional area") is set to a value within the range of 7 to 11. Preferably, the body of the nail is a straight smooth body with a uniform circular cross-section and a spire-shaped tip, and the head of the nail has a circular profile in top view. The head has a flat head or a flat mesh head, and has an annular and flat seating surface that seats on the outer surface of the load-bearing surface material by nailing, and a wall surface constituted by the outer surface of the load-bearing surface material and substantially and a flat top surface constructed so as to be located in the same plane after nailing.

Preferably, the gypsum-based load-bearing surface material has inorganic fibers and organic strength-improving materials mixed into the main material or core material to ensure minimum physical properties (nail side resistance: 500 N or more) as a gypsum-based load-bearing surface material. On the other hand, the areal density of the facing material is rather reduced and set to a relatively low value (6.5 to 8.9 kg/m ² ). For example, the amount of inorganic fiber blended is 0.3 to 5 parts by weight, preferably 2 to 4 parts by weight, per 100 parts by weight of calcined gypsum. Examples of the inorganic fibers to be blended include glass fibers and carbon fibers. When using glass fibers, glass fibers having a diameter of 5 to 25 μm and a length of 2 to 25 mm can be suitably used. The amount of the organic strength improving material is 0.3 to 15 parts by weight, preferably 1 to 13 parts by weight, per 100 parts by weight of calcined gypsum. As the organic strength improving material, for example, starch, polyvinyl acetate, polyvinyl alcohol, polyacrylic, etc. can be suitably used. As starch, both unprocessed starch and processed starch can be used. The modified starch includes starch that has been subjected to physical treatment, chemical treatment, or enzymatic treatment. As the starch subjected to physical treatment, pregelatinized starch can be suitably used. Chemically treated starches include oxidized starch, phosphate starch, urea phosphate starch, hydroxypropylated phosphate cross-linked starch, hydroxyethylated starch, hydroxypropylated starch, cationized starch, and acetylated starch. Starch may be suitably used.

In the following description of this specification, "minimum physical properties as a gypsum-based load-bearing surface material" means a nail side resistance of 500N or more. In addition, the factors that change the compressive strength of gypsum-based load-bearing facing materials include the mixing condition of the gypsum slurry (mixing time, mixing temperature, etc.), the type and amount of impurities contained in the gypsum raw material, and the cross-sectional properties of the gypsum core. , density and uniformity, the amount, size and dispersion state of air bubbles contained in the gypsum core, water content or water content of the gypsum core, specific gravity of the gypsum core, etc. are known. These factors may be used as control factors to increase or decrease compressive strength, but manufacturing conditions (type of gypsum raw material, type and amount of additives such as foaming agents, temperature of mixing water, air temperature, etc.) It is not only a controlling factor closely related to humidity (e.g. humidity), but also to the overall quality of the gypsum core, with a relatively low areal density (areal density within the range of 6.5-8.9 kg/ ^m2 ). In this method, the desired compressive strength (compressive strength of 6.5 N/mm ² or more) is given to the gypsum-based load-bearing facing material, and in addition, the desired nail side resistance (nail side resistance of 500 N or more) is provided in cooperation with the inorganic fibers. It is not a property control factor that can be used specifically for the specific application of imparting to gypsum-based load-bearing facing materials. On the other hand, the above-mentioned organic strength-improving material can be used specifically for such applications, and can be added to the gypsum slurry during the manufacturing process, so it increases the compressive strength of the gypsum core. Provide practical and effective means.

The areal density value (6.5 to 8.9 kg/m ² ) of the gypsum-based load-bearing facing material according to the present disclosure is the same as the areal density (approximately 9.4 kg/m 2 ) of the conventional gypsum-based load-bearing facing material such as structural gypsum board. m ² ). According to such a surface density, the specific gravity and/or plate thickness of the gypsum-based load-bearing facing material can be reduced, thereby reducing the weight of the load-bearing wall or reducing the wall thickness. On the other hand, such a reduction in areal density can be achieved by increasing the short-term nominal shear strength (P0) of the load-bearing wall and by increasing the wall magnification (i.e., increasing the maximum yield strength (Pmax) by increasing specific gravity and/or plate thickness). This is a condition that is contrary to the conventional method of increasing wall magnification, which increases the short-term standard shear strength (P0). However, as described in Patent Document 3, if the areal density is lowered while ensuring the minimum physical properties (nail side resistance: 500N or more) for a gypsum-based load-bearing surface material, the gypsum-based load-bearing surface material has the potential to As a result, the ultimate displacement (δu) and plasticity ratio (μ) of the load-bearing wall increase, and as a result, the ultimate strength (corrected value) (Pu') of the load-bearing wall increases. , the short-term standard shear strength (P0) and wall magnification can be increased without necessarily increasing the maximum yield strength (Pmax).

Furthermore, the present inventors discovered through many experiments that the initial stiffness (K) of a load-bearing wall increases due to an increase in the compressive strength of a gypsum-based load-bearing surface material, and based on this knowledge, the inventors conducted extensive research. , increasing the compressive strength of the gypsum-based load-bearing surface material to a value of 6.5 N/mm ² or more to increase the initial stiffness (K) of the load-bearing wall, thereby greatly reducing the ultimate displacement (δu) of the load-bearing wall. We have come to realize that the yield point displacement (δv) can be lowered without causing any damage, resulting in a relatively large increase in the plasticity modulus (μ).

That is, according to the present disclosure, the initial stiffness (K) of the load-bearing wall is (preferably) 2.0 kN/10 ^-3 by increasing the compressive strength of the gypsum-based load-bearing facing material to a value of 6.5 N/mm ² or more. By increasing the yield point displacement (δv) to a value of, for example, 7.2×10 ^-3 rad or less, it is compatible with the relatively high value of the ultimate displacement (δu). As a result, the value of the plasticity modulus (μ) can be relatively greatly increased, and as a result, it is possible to relatively easily secure a value of 7.7 kN or more as the ultimate proof stress correction value (Pu'), for example. I can do it.

By the way, in the load-bearing wall using the low-density gypsum-based load-bearing face material of Patent Document 3, the initial stiffness (K) is a value less than 2.0 kN/10 ^-3 rad (for example, 1.9 kN/10 ^-3 rad). It is. In addition, the above-mentioned structural gypsum board has a load-bearing force called nail side resistance in order to suppress tear failure of the gypsum-based load-bearing facing material due to changes in the relative position of the gypsum-based load-bearing facing material and fasteners that may occur during vibration. This is a gypsum-based load-bearing facing material that was developed to increase the nail side resistance as desired by focusing on factors. By lowering the density, the toughness and deformation followability of the gypsum-based load-bearing surface material in the plastic region are brought to light, and the plasticity ratio (μ) and ultimate proof stress (corrected value) (Pu') are intended to be increased. However, none of these methods focuses on or considers the compressive strength of the gypsum-based load-bearing wall material or the initial stiffness that occurs in the elastic region as factors for improving the strength, but rather the initial stiffness of the load-bearing wall and the compressive strength of the gypsum-based load-bearing wall material. Nor did it examine or study the structural relationships between the two.

On the other hand, according to experiments conducted by the present inventors, the compressive strength can be increased as desired by increasing the areal density, but increasing the areal density not only increases the self-weight of the facing material but also reduces the ultimate displacement. Therefore, it is desirable to increase the compressive strength to an appropriate value mainly by using the effect of increasing the compressive strength using an organic strength-improving material or the like. That is, in the present disclosure, the compressive strength is set as desired mainly by setting an appropriate areal density and increasing the compressive strength by adding an organic strength improving material or the like.

Preferably, the yield point displacement (δv) of the load-bearing wall measured by an in-plane shear test is 7.2×10 ^-3 rad or less, or the initial stiffness (K) is 2.2 kN/10. In order to ensure a value of ^-3 rad or more and a value of 7.2×10 ^-3 rad or less as the yield point displacement (δv), the compressive strength is 7.5 N/mm ² or more. For example, in the gypsum-based load-bearing surface material according to the present disclosure, yield point displacement (δv) = 6.0 × 10 ^-3 rad, initial stiffness (K) = 2.5 kN/10 ^-3 rad, and ultimate yield strength Pu = 15. Assuming that 0 kN, ultimate displacement (δu) = 30 × 10 ^-3 rad, plasticity ratio (μ) = 5.0, and dispersion coefficient β = 1.0, the ultimate proof stress (corrected value) (Pu') is: It is 9.0kN. On the other hand, if the initial stiffness (K) is set to 1.9 kN/10 ^-3 rad (<2.0 kN/10 ^-3 rad), similar to the aforementioned low-density gypsum-based load-bearing surface material (Patent Document 3), In this case, even if the ultimate strength Pu = 15.0, the ultimate displacement (δu) = 30 × 10 ^-3 rad, and the dispersion coefficient β = 1.0, the yield point displacement (δv) = 7.8 × 10 ^-3 rad, plasticity ratio (μ) = 3.8, and ultimate proof stress (corrected value) (Pu') is only about 7.7 kN. In other words, by increasing the compressive strength of the load-bearing surface material and increasing the initial stiffness (K), the ultimate strength (corrected value) (Pu') increases relatively greatly, and the short-term standard shear strength (P0) and wall magnification increase. can be increased relatively significantly.

In the present disclosure, the compressive strength can be preferably set to a value within the range of 7.5 to 13.0 N/mm ² , more preferably 8.0 N/mm ² or more. Further, in the present disclosure, the initial stiffness is preferably a value within the range of 2.2 kN/10 ^-3 rad to 4.0 kN/10 ^-3 rad, more preferably 2.4 kN/10 ^-3 rad or more. Can be set to a value of Furthermore, according to the present disclosure, the yield point displacement (δv) is preferably a value within the range of 3.5×10 ⁻³ rad to 7.2×10 ⁻³ rad, more preferably 6.5 It can be set to a value of ×10 ⁻³ rad or less.

According to a load-bearing wall equipped with a gypsum-based load-bearing face material according to a preferred embodiment of the present disclosure, the plasticity modulus (μ) measured by an in-plane shear test is preferably 4.2 or more and 10.0 or less. A value of 4.3 or more is obtained, and the yield strength (Py) measured by an in-plane shear test is 7.7 kN or more, and moreover, it is higher than the ultimate yield strength (corrected value) (Pu') above. A large value, preferably 8.0 kN or more, is obtained. According to experiments conducted by the present inventors, as the initial stiffness (K) increases, the yield strength (Py) also tends to increase. Similarly, the yield strength (Py) was generally found to be larger than the ultimate yield strength (corrected value) (Pu').

In this way, the gypsum-based load-bearing facing material according to the present disclosure secures the minimum physical properties as a gypsum-based load-bearing facing material, while improving the toughness and deformation followability of the gypsum-based load-bearing facing material in the plastic region due to the reduction in areal density. In addition to increasing the ultimate yield strength (corrected value) (Pu'), the ultimate strength (corrected value) (Pu') is further increased by increasing the initial stiffness (K) and decreasing the yield point displacement (δv). As a result, the short-term standard shear capacity (P0 ) and wall magnification can be increased relatively significantly. Further, according to the present disclosure, as a fastener for fastening such a gypsum-based load-bearing surface material to a wooden structure wall foundation, a metal whose area ratio of head area/body cross-sectional area is set to a value within the range of 6 to 13 is used. This makes it possible to effectively suppress punch-out failure or reduce its effect without additionally attaching or arranging reinforcing or stiffening materials such as metal plates. Therefore, in combination with the above-mentioned effect of the gypsum-based load-bearing wall material, the short-term standard shear strength (P0) and wall magnification of the wooden structure load-bearing wall can be increased more effectively or efficiently. Furthermore, the above-mentioned load-bearing surface material, like the structural gypsum board and the aforementioned low-density gypsum-based load-bearing surface material (Patent Document 3), has at least the front and back surfaces of the main material or core material covered with paper members. , can be easily manufactured on a conventional gypsum board manufacturing line. Preferably, the gypsum-based load-bearing surface material of the present disclosure has a laminated structure in which the surface or surface layer of a core material is covered with base paper for gypsum board. In addition, "front and back surfaces" mean the front and back surfaces of the panel material excluding the edges and side edges (i.e., the four outer edges) of the panel material.

Preferably, the plate thickness of the gypsum-based load-bearing surface material is set to a value of 7.5 mm or more and less than 12 mm (more preferably a value of 8.5 mm or more and 10 mm or less), for example, 9.5 mm or 9.0 mm. Ru. A gypsum-based load-bearing surface material having such a board thickness is advantageous in reducing the wall thickness of a wooden structural load-bearing wall, etc., compared to a structural gypsum board that requires a board thickness of 12 mm or more. Optionally, the gypsum cured body has a nail side resistance of 980N or less.

Preferably, the gypsum-based load-bearing surface material has an ultimate displacement (δu) of the load-bearing wall of 24×10 ⁻³ measured by an in-plane shear test using a load-bearing wall test piece with a wall length of 1.82 m. An ultimate displacement (δu) of rad or more (preferably 26×10 ^-3 rad or more) is caused in the load-bearing wall. The value of the ultimate displacement (δu) set to a relatively high value, together with the increase in the initial stiffness (K) of the load-bearing wall and the decrease in the yield point displacement (δv), causes the value of the plasticity modulus (μ) to decrease. Since the increase is relatively large, it is extremely advantageous in increasing the short-term standard shear strength (P0) and wall magnification. Note that the ultimate displacement (δu) of the load-bearing wall is an index indicating the toughness and deformation followability of the load-bearing wall in the plastic region. According to the "Wooden Load-bearing Walls and Their Magnification Performance Testing and Evaluation Procedures", if the load does not decrease even after exceeding 1/15 rad in an in-plane shear test and the ultimate displacement value cannot be obtained, The final displacement (δu) is set to 1/15 rad. Therefore, the maximum value of the final displacement (δu) is 1/15 rad (66.7×10 ⁻³ rad).

Preferably, the specific gravity of the gypsum-based load-bearing surface material is within the range of 0.65 to 0.96, preferably within the range of 0.7 to 0.9 (more preferably, within the range of 0.7 to 0.9). 0.8). According to the gypsum-based load-bearing facing material having such a specific gravity, for example, the gypsum-based facing material of Patent Document 4 has a plate thickness of less than 12 mm but has a specific gravity of 1.0 or more, and therefore has a relatively large self-weight. Since the face material can be made lighter compared to products implemented in This is advantageous in improving the workability of construction work or the workability of construction work.

Furthermore, in a preferred embodiment of the present disclosure, the core material (gypsum core portion) of the gypsum-based load-bearing surface material contains an organopolysiloxane compound as a strength deterioration inhibitor that mainly prevents strength deterioration. According to such a load-bearing surface material, similarly to the gypsum-based load-bearing surface material described in Patent Document 4, it is possible to provide the above-mentioned load-bearing surface material that can be constructed on the outdoor wall surface of a wooden exterior wall.

From another perspective, the present disclosure provides a wall magnification of a wooden structure load-bearing wall constructed by fastening a gypsum-based load-bearing surface material to a wooden structure wall base using a wooden frame construction method or a wooden frame wall construction method using fasteners. In the augmentation method,
The load-bearing surface material is composed of a main material or core material made of a plate-shaped hardened gypsum body, and a paper member that covers at least the front and back surfaces of the main material or core material,
The areal density or areal weight of the load-bearing facing material, specified as the mass per unit area of the wall surface, is reduced to 6.5 to 8.9 kg/ ^m2 , and the load-bearing facing material has a nail side resistance of 500N or more and 6.5 kg/m2. The composition of the hardened gypsum of the main material or the core material is set so as to exhibit a compressive strength of .5 N/mm ² or more,
As the fastener, a metal nail whose area ratio of the area of the head/the cross-sectional area of the body is set to a value within the range of 6 to 13 is used to suppress the punching shear phenomenon or to prevent punching-out failure. reduce the effect,
Obtaining an ultimate displacement of a value larger than 20×10 ^-3 rad as the ultimate displacement (δu) of the load-bearing wall measured by an in-plane shear test using a load-bearing wall test piece with a wall length of 1.82 m. Provided is a method for increasing the wall magnification of a wooden structural load-bearing wall, which is characterized by the following.

According to such a wall magnification increasing method, the areal density of the gypsum-based load-bearing wall material is reduced by reducing the specific gravity and/or the plate thickness, thereby reducing the self-weight of the load-bearing wall or reducing the wall thickness. It becomes possible. Moreover, according to such a method of increasing wall magnification, as mentioned above, the toughness and deformation followability of the gypsum-based facing material (in the plastic region) are improved by lowering the density of the gypsum-based facing material, and the ultimate displacement (δu) In addition to increasing the value of , the initial stiffness (K) of the load-bearing wall increases due to the increase in the compressive strength of the gypsum-based facing material, which reduces the value of the yield point displacement (δv). As a result, due to the synergistic effect of the relatively small value of yield point displacement (δv) and the relatively large value of ultimate displacement (δu), the value of plasticity modulus (μ = δu / δv) increases relatively greatly, In this way, it is possible to relatively easily secure a value of 7.7 kN or more as the ultimate strength (corrected value) (Pu') of the wooden structural load-bearing wall.

The present disclosure further provides a wooden structure that is used in the above-mentioned construction method or used in the above-mentioned wall magnification increasing method and is fastened by the fastener to a wooden structure wall base of a wooden frame construction method or a wooden frame wall construction method. A gypsum-based load-bearing surface material for load-bearing walls,
exhibits a nail side resistance of 500 N or more, has a compressive strength of at least 6.5 N/mm ² or more, and has an areal density or areal weight within the range of 6.5 to 8.9 kg/m ² ,
In cooperation with the fasteners, the ultimate displacement (δu) of the load-bearing wall, measured by an in-plane shear test using a load-bearing wall specimen with a wall length of 1.82 m, is lower than 20×10 ⁻³ rad. To provide a gypsum-based load-bearing surface material characterized by increasing the load-bearing value to a large value.

According to the gypsum-based load-bearing facing material according to the present disclosure, the toughness and deformation followability of a load-bearing wall are improved by using a low-density gypsum-based load-bearing facing material with a reduced areal density, and this load-bearing facing material is used for a wooden structure wall. Regarding a load-bearing wall that is fastened to the base with fasteners, its initial stiffness (K) is increased to lower the yield point displacement (δv), thereby increasing the plasticity modulus (μ = δu / δv). , it becomes possible to increase the short-term standard shear strength (P0) and wall magnification. The gypsum-based load-bearing surface material according to the present disclosure is particularly applicable to load-bearing walls whose ultimate displacement (δu) value is difficult to increase easily, and load-bearing walls that have already exerted an ultimate displacement (δu) close to its upper limit. It can be effectively used as a load-bearing surface material to further increase short-term standard shear strength (P0) and wall magnification without increasing wall thickness or wall weight. Furthermore, the gypsum-based load-bearing facing material of the present disclosure can be easily manufactured using a conventional gypsum board manufacturing line, since at least the front and back surfaces of the main material or core material are covered with paper members.

The wooden structure load-bearing wall of the present disclosure equipped with such a gypsum-based load-bearing surface material and its construction method; On the other hand, according to a method for increasing the wall magnification of a wooden structural load-bearing wall, which consists of fastening it with fasteners, it is possible to obtain specific dimensions and shapes (head diameter D, body diameter d, and the ratio η of head area/body cross-sectional area). ) by using metal nails with can be improved relatively significantly. That is, according to the present disclosure, in a wooden structure load-bearing wall and its construction method, as well as a method for increasing the wall magnification of a wooden structure load-bearing wall, plaster can be installed without additionally attaching reinforcing materials or stiffening materials such as metal plates. It does not increase the areal density (specific gravity and/or plate thickness) of the system facing material (therefore, it does not increase the self-weight and/or wall thickness of the load-bearing wall), and the value of the ultimate displacement (δu) The short-term standard shear strength (P0) of the load-bearing wall and the wall magnification can be further increased without further increase.

Further, according to the load-bearing wall structure of a wooden structure building, its construction method, or load-bearing wall construction method according to the present disclosure, such a gypsum-based load-bearing wall material can be used as a load-bearing wall material in a wooden structure load-bearing wall. As a result, the areal density of the gypsum-based load-bearing surface material can be reduced without reducing (or effectively increasing) the short-term standard shear strength (P0) and wall magnification, thereby reducing the self-weight of the load-bearing wall. Alternatively, the wall thickness can be reduced, or the workability of the load-bearing wall can be improved.

Furthermore, according to the load-bearing wall structure of a wooden structure building, its construction method, or wall magnification increasing method according to the present disclosure, the initial stiffness (K) is increased to lower the yield point displacement (δv), and thereby , the ultimate strength (corrected value) (Pu') can be increased, and the short-term standard shear strength (P0) and wall magnification can be increased. It does not depend on reinforcement or stiffening by stiffeners, does not depend on an increase in the specific gravity and/or plate thickness of the gypsum-based facing material, and is largely dependent on an increase in the value of the ultimate displacement (δu). This makes it possible to increase the wall magnification.

FIG. 1 is a front view schematically showing an embodiment of a load-bearing wall of a wooden structure building according to the present disclosure. FIG. 2 is a partially enlarged partial cross-sectional view and a partially cutaway perspective view of a load-bearing wall showing a portion in which a gypsum-based load-bearing surface material is fixed to a wooden structural framework with nails. 2 is a front view, a cross-sectional view, and a side view showing the configuration of a load-bearing wall test piece used in an in-plane shear test of the load-bearing wall structure shown in FIG. 1. FIG. This is a diagram showing for reference the envelope of the load-deformation angle curve (indicated by a solid line) obtained by an in-plane shear test of an arbitrary wooden structure load-bearing wall. FIG. 3 is a diagram showing a linear graph converted into a load-deformation angle characteristic using a dashed-dotted line. Regarding the nails constituting the load-bearing wall according to the embodiment of the present disclosure and the two types of nails conventionally used for fastening gypsum-based load-bearing surface materials to the frame or framework of a wooden structure, the head diameter, body It is a chart showing the diameter and the area ratio of head area/torso cross-sectional area. FIG. 6 is a chart and a diagram showing a comparison of test results of an in-plane shear test regarding the wooden structural load-bearing wall using two conventional types of nails (Comparative Examples 1 and 2) shown in FIG. 5. The test results of the in-plane shear test were compared for the wooden structure load-bearing wall using the conventional nails (Comparative Example 3) shown in Figure 5 and the wooden structure load-bearing wall using the nails of the present example shown in Figure 5. FIG. The physical properties, composition, and proof test results of the gypsum-based load-bearing facing material constituting the present disclosure are shown as Reference Examples 1 to 4, and the chart shows the physical properties, composition, and proof-strength test results of the gypsum-based load-bearing facing material according to Comparative Example 4. be. 3 is a diagram showing test results of in-plane shear tests of load-bearing wall structures as load-deformation angle characteristics of a perfect elastic-plastic model for Reference Examples 1 to 4 and Comparative Example 4. FIG. FIG. 2 is a partial front view of a compressive strength testing device conceptually showing a compressive strength measuring method for measuring the compressive strength of a gypsum-based load-bearing surface material.

Hereinafter, the configuration of a wooden structure load-bearing wall according to a preferred embodiment of the present disclosure will be described in detail with reference to the accompanying drawings.

[About the overall structure of wooden structural load-bearing walls]
FIG. 1 is a front view schematically showing the configuration of a load-bearing wall of a wooden structure building according to a preferred embodiment of the present disclosure. In addition, (A) and (B) in FIG. 2 respectively relate to the load-bearing wall shown in FIG. 1, and show partially enlarged portions of the load-bearing wall in which the gypsum-based load-bearing surface material is fixed to the wooden framework with nails. FIG. 2 is a partial cross-sectional view and a partially cutaway perspective view.

The wooden structure load-bearing wall 1 shown in Fig. 1 is a wooden structure load-bearing wall of the wooden frame structure constructed by fixing a gypsum-based load-bearing face material 10 to a wooden frame on a cloth foundation F of a reinforced concrete (RC) structure. be. The load-bearing surface material 10 has dimensions of 9.5 mm in thickness, 910 mm in width, and about 2800 to 3030 mm (for example, about 2900 mm) in height, and has an areal density (in the range of 6.5 to 8.9 kg/m ² ). For example, it has an areal density of 7.5 kg/m ² ). The areal density (also called areal weight) is the mass (weight) per unit area (apparent area) of the wall when viewed from the front. As shown in FIG. 2, the load-bearing surface material 10 includes a flat gypsum core (gypsum core material) 11 mixed with a predetermined amount of inorganic fiber (glass fiber) and an organic strength improving material (starch), and both sides of the gypsum core. This is a gypsum-based load-bearing surface material composed of a covering gypsum board base paper (paper member) 12.

The load-bearing wall 1 has a base 2 fixed to the upper surface of a cloth foundation F by anchor bolts B. The load-bearing wall 1 consists of this foundation 2, columns 3, studs 4, and joint studs 4' arranged vertically on the foundation 2 at predetermined intervals, and horizontal columns supported by the upper end (or middle part) of the columns 3. It is generally composed of horizontal members (beams, girders, eave girders, girders) 5 and the load-bearing surface material 10 described above. The foundation 2, pillars 3, studs 4, joint studs 4', and horizontal members 5 that make up the frame are timbers (square timbers) with cross-sections that are used in ordinary wooden buildings.

The load-bearing surface material 10 is fixed to the foundation 2, columns 3, studs 4, joint studs 4', and horizontal members 5 with nails 20 made of iron or stainless steel (iron in this example). The nails 20 are arranged at intervals S1 in the four outer circumferential zones of the load-bearing panel 10, and are arranged at intervals S2 in the central zone of the load-bearing panel 10 extending in the vertical direction. Preferably, the spacing S1 is set to a dimension within the range of 50 mm to 200 mm (eg, 75 mm), and the spacing S2 is set to a dimension within the range of 50 mm to 300 mm (eg, 150 mm).

As shown in FIG. 2, the nail 20 has a flat or meshed head 21 with a circular profile in top view, a straight and smooth body 22 with a uniform circular cross section, and a body 22 with a straight and smooth shape having a uniform circular cross section. This iron nail is composed of a neck part 23 located at the base end of the body part 22 and integrally connecting the body part 22 and the head part 21, and a steeple-shaped tip part 24 located at the tip of the body part 22. The lower surface of the head 21 constitutes an annular seating surface 21b that is seated on the outer surface of the load-bearing surface material 10. The outer circumferential portion of the neck portion 23 is locally tapered or conically expanded in diameter and continues to the head portion 21, so the radial dimension of the seating surface 21b is equal to the diameter difference between the head portion 21 and the body portion 22. Although they do not necessarily match and are slightly smaller than the diameter difference, they are approximately the same value as the diameter difference.

Generally, in addition to the material and shape of the head 21 and body 22, the nail 20 has a diameter of the head 21 (head diameter D), a diameter of the body 22 (body diameter d), and a total length of the nail 20 (length L). ) etc. In this embodiment, the head diameter D, the trunk diameter d, and the length L are 7.07 mm, 2.45 mm, and about 50 mm, respectively, and the apparent area of the top surface 21a of the head 21 and the cross section of the trunk 22 are The ratio η (ie, head area/torso cross-sectional area) to the area of is 8.32 (see FIG. 5). In the present disclosure, the head diameter D is preferably set to a value within the range of 6.0 to 10.0 mm, more preferably within the range of 6.8 to 9.0 mm, and the trunk diameter d is preferably set to a value within the range of 6.8 to 9.0 mm. , is set within the range of 2.0 to 5.0 mm, more preferably within the range of 2.2 to 4.2 mm. Further, the ratio η of head area/body cross-sectional area is preferably set to a value within the range of 6 to 13, more preferably within the range of 7 to 11.

The gypsum core 11 of the load-bearing surface material 10 contains a predetermined amount of inorganic fibers and an organic strength improving material, and has a nail side resistance of 500N or more. The amount of inorganic fiber blended is 0.3 to 5 parts by weight, preferably 2 to 4 parts by weight, per 100 parts by weight of calcined gypsum. Examples of the inorganic fibers to be blended include glass fibers and carbon fibers. When using glass fibers, glass fibers having a diameter of 5 to 25 μm and a length of 2 to 25 mm can be suitably used. The amount of the organic strength improving material is 0.3 to 15 parts by weight, preferably 1 to 13 parts by weight, per 100 parts by weight of calcined gypsum. Examples of organic strength-improving materials to be blended include starch, polyvinyl acetate, polyvinyl alcohol, and polyacrylic. Note that as the starch, both unprocessed starch and processed starch can be used. The modified starch includes starch that has been subjected to physical treatment, chemical treatment, or enzymatic treatment. As the starch subjected to physical treatment, pregelatinized starch can be suitably used. Chemically treated starches include oxidized starch, phosphate starch, urea phosphate starch, hydroxypropylated phosphate cross-linked starch, hydroxyethylated starch, hydroxypropylated starch, cationized starch, and acetylated starch. Starch may be suitably used. The blending of the organic strength improving material ensures a relatively low areal density (area density within the range of 6.5 to 8.9 kg/m ² ) while achieving the desired compressive strength (6.5 N/mm ² or more). It is an effective means for imparting compressive strength) to the load-bearing facing material 10 and achieving or ensuring the desired nail side resistance (nail side resistance of 500 N or more) of the load-bearing facing material 10 in cooperation with the inorganic fibers, In addition, considering the fact that the blending of organic strength-improving materials does not greatly affect the overall quality of the gypsum-based load-bearing facing material, it is possible to improve the nail side resistance of the load-bearing facing material 10 by using simple and practical methods. It is a practical and effective means.

The composition and structure of the load-bearing surface material 10 are similar to those of "structural gypsum board" specified in JIS A 6901. However, the surface density of the load-bearing surface material 10 is a value within the range of 6.5 to 8.9 kg/m ² (for example, 7.5 kg/m ² ). Therefore, the load-bearing surface material 10 is fundamentally different from the "structural gypsum board" of JIS A 6901, which requires an areal density of 9.4 kg/m ² or more as described above. In addition, "reinforced gypsum board" specified in JIS A 6901 is known, but "reinforced gypsum board" also requires an areal density of 9.4 kg/m ² or more, so the load-bearing surface material 10 is It is fundamentally different from "reinforced gypsum board." Furthermore, the load-bearing surface material 10 is different from other "gypsum" in that it has a main material or core material (gypsum core 11) containing inorganic fibers and an organic strength improving material so as to exhibit a nail side resistance of 500N or more. It is also different from "Board". That is, the load-bearing surface material 10 does not correspond to any "gypsum board" specified in the current JIS A 6901. In this specification, the load-bearing surface material 10 shall be specified or expressed as a "gypsum-based load-bearing surface material" in this sense.

In general, gypsum-based load-bearing surface materials (including "gypsum board," "reinforced gypsum board," and "structural gypsum board") are made by covering the front and back sides of a plate-shaped main material or core material made of hardened gypsum with paper members ) is manufactured using general-purpose gypsum board manufacturing equipment. For example, as described in International Publication No. WO2019/058936, a gypsum board manufacturing device uses raw materials such as calcined gypsum, an adhesion aid, a hardening accelerator, and foam (or foaming agent), and the kneading required to slurry the calcined gypsum. It has a mixer that mixes with water to prepare gypsum slurry. The gypsum slurry is poured onto a gypsum board base paper (bottom paper) on a conveyor belt of a gypsum board manufacturing apparatus, and the gypsum board base paper (top paper) is laminated on top of the gypsum slurry. The strip-shaped continuous laminate having a three-layer structure thus formed is processed by each device, such as a rough cutting device, a forced drying device, and a cutting device, which constitute the gypsum board manufacturing device, and is processed into a gypsum product of a predetermined size, that is, a gypsum slurry. The hardened body (i.e., gypsum core) is coated on both sides with base paper for gypsum board to form a gypsum-based facing material. The specific gravity of the gypsum-based facing material is mainly adjusted by the amount of foam mixed in the gypsum slurry.

Concerning wooden structural load-bearing walls using structural gypsum board, reinforced gypsum board, and (ordinary) gypsum board as load-bearing facing materials specified in JIS A 6901, wooden frame structures specified in the Ministry of Construction Notification No. 1100 mentioned above. An example of the wall magnification of a load-bearing wall in a large wall construction is as follows.

Structural gypsum board (class A) 1.7
Structural gypsum board (class B) 1.2
Reinforced gypsum board 0.9
(Normal) Gypsum board 0.9

In addition, examples of the wall magnification of load-bearing walls using the frame wall construction method (load-bearing walls in which the interval between vertical frames exceeds 50 cm) specified in the above-mentioned Ministry of Land, Infrastructure, Transport and Tourism Notification No. 1541 are as follows.

Structural gypsum board (class A) 1.7
Structural gypsum board (class B) 1.5
Reinforced gypsum board 1.3
(Normal) Gypsum board 1.0

In this way, the wall magnification values specified in the public notices of the Ministry of Construction or the Ministry of Land, Infrastructure, Transport and Tourism are values that can be generally adopted without conducting individual performance tests. However, structural gypsum boards, reinforced gypsum boards, and (ordinary) gypsum boards that are recognized to be effective as load-bearing surface materials are limited to those with a thickness of 12 mm or more. Therefore, when effectively using a facing material made of a new material/composition or a gypsum-based facing material with a thickness of less than 12 mm as a load-bearing facing material, or when adopting a wall magnification different from the above values, the above-mentioned It is necessary to conduct a performance test to determine the wall magnification value.

As mentioned above, the above-mentioned structural gypsum board and reinforced gypsum board specified in JIS A 6901 require physical properties of an areal density of 9.4 kg/m ² or more and a specific gravity of 0.75 or more. This has been considered to be an important condition in increasing the maximum load that the facing material can withstand and ensuring a high short-term permissible shear capacity (and therefore a high wall magnification) of timber structural load-bearing walls. In particular, it has been thought that such areal density and specific gravity cannot be reduced in structural gypsum boards that are required to exhibit higher nail side resistance than reinforced gypsum boards. In other words, ensuring the physical properties of an areal density of 9.4 kg/m ² or more and a specific gravity of 0.75 or more will further increase the wall magnification of the load-bearing wall test specimen (wooden structure load-bearing wall) obtained in the above-mentioned in-plane shear test. It was considered to be an essential condition for achieving this. However, recent experiments by the present inventors have shown that a gypsum-based facing material with physical properties comparable to structural gypsum board (nail side resistance) by adding inorganic fibers and organic strength-improving materials By reducing the thickness of the material or adjusting the amount of foam to reduce the specific gravity of the gypsum core, thereby reducing the areal density, the latent toughness or deformability of the facing material itself will become apparent. As a result, it has been found that the ultimate strength of the load-bearing wall can be effectively utilized and the plasticity ratio of the load-bearing wall can be increased, thus further improving the short-term allowable shear strength of the load-bearing wall. This point is described in detail in Patent Document 3, but below we will explain the outline of the in-plane shear test for wooden structural load-bearing walls, and also explain the plasticity rate of the load-bearing wall due to the increase in the ultimate load-bearing strength of the load-bearing wall. The following describes general matters regarding the increase in the load-bearing wall and the associated improvement in the short-term allowable shear strength of the load-bearing wall and the wall magnification.

[About test specimens for in-plane shear tests of wooden structural load-bearing walls]
FIG. 3 is a front view, a cross-sectional view, and a side view showing the configuration of a load-bearing wall test piece used in the in-plane shear test regarding the load-bearing wall structure shown in FIG. 1.

In FIG. 3, components or components of the load-bearing wall test specimen that correspond to or correspond to the components or components shown in FIGS. 1 and 2 are given the same reference numerals.

The present inventors constructed the load-bearing wall structure shown in FIG. 3 as a test specimen of the load-bearing wall structure shown in FIG. A load-bearing wall test specimen (hereinafter simply referred to as the "test specimen") with a wall width of 1820 mm and a height of 2730 mm was manufactured, and an in-plane shear test was conducted using a non-loading test device.

The main structure of the test specimen shown in Fig. 3 is a wooden frame consisting of a base 2 and pillars 3 made of sawn cedar with a cross section of 105 x 105 mm, and a horizontal member 5 made of sawn Douglas fir with a cross section of 180 x 105 mm supported by the pillars 3. has a department. A joint stud 4' made of sawn cedar with a cross section of 45 x 105 mm is erected in the center between the columns 3, and a sawn cedar stud 4 with a cross section of 27 x 105 mm is installed between the column 3 and the joint stud 4'. It will be erected. A trunk link 5' made of sawn cedar or Douglas fir is installed between the pillar 3 and the stud 4, and also between the stud 4 and the joint stud 4'. As a test jig, a pulling hardware 40 is disposed at the joint between the base 2 and the column 3, and at the joint between the horizontal member 5 and the column 3. The foundation 2, columns 3, joint pillars 4', studs 4, horizontal members 5, and body joints 5' constitute the shaft members of the load-bearing wall structure, and these members (shaft members) form a rectangular frame. is formed.

In the test specimen shown in FIG. 3, the vertical distance h1 between the foundation 2 and the horizontal member 5, the height h2 of the body joint 5', and the relative height h3 of the horizontal member 5 with respect to the body joint 5' are h1 = 2625 mm. , h2 = 1790 mm, h3 = 835 mm, the distance w1 between the pillar 3 and the joint pillar 4' (column core spacing) was set w1 = 910 mm, and the length L of the wall was set to 1.82 m. The panel 10 is divided into upper and lower parts by a body joint 5', the lower panel 10a has dimensions of 910 mm in width and 1820 mm in height, and the panel 10b disposed on the upper side has dimensions of 910 mm in width and 1820 mm in height. It has dimensions of 865 mm. The cover dimensions h4 and h5 of the

face materials

10a and 10b were set to 30 mm.

In the test specimen shown in FIG. 3, nails 20 for fastening the

panels

10a, 10b to the base 2, pillars 3, joint pillars 4', horizontal members 5, and body joints 5' were attached to the edges of the

panels

10a, 10b. They were arranged at equal intervals (spacing S1 = 75 mm) over the entire circumference of the zone. Nails 20 for fastening the facing

materials

10a, 10b to the studs 4 were arranged at equal intervals (spacing S2 = 150 mm) in the vertical central zone of the facing

materials

10a, 10b.

[Explanation regarding short-term allowable shear strength and wall magnification of wooden structural load-bearing walls (premises of this disclosure)]
Figure 4 is an explanatory chart and line diagram showing for reference the test results of an in-plane shear test using any gypsum-based load-bearing surface material. The deformation angle curve is displayed as an envelope (shown as a solid line). With reference to FIG. 4, an in-plane shear test of a wood structure load-bearing wall will be described, and a method for determining the short-term allowable shear strength and wall magnification of the wood structure load-bearing wall will be described.

In FIG. 4, a linear graph obtained by converting the envelope of the load-deformation angle curve into the load-deformation angle characteristic of a perfect elastic-plastic model is shown by a dashed-dotted line. The perfect elastic-plastic model consists of a linear function straight line (Y = KX) in the linear elastic region indicating the initial stiffness K, and a straight line (Y = Pu) in the plastic deformation region (plastic region) extending parallel to the X-axis from the yield point σs. It consists of The yield point σs indicates the elastic limit. The initial stiffness K is a coefficient indicating the slope of the linear function straight line (Y=KX) in the elastic region. The area on the diagram of the region surrounded by the envelope, the X axis, and each line segment of X = δu, and the area on the diagram of the region surrounded by the X axis, each line segment of Y = KX, Y = Pu, and X = δu Area is equivalent. The method of converting the envelope into a fully elastoplastic model is described in many documents such as ``Wooden load-bearing walls and their magnification performance test/evaluation business method'' and is a well-known matter in material mechanics. Therefore, further explanation thereof will be omitted.

FIG. 4 shows the maximum proof stress Pmax, 0.8Pmax load reduction area, ultimate proof stress Pu, yield proof strength Py, ultimate displacement δu, yield point displacement δv, and yield displacement δy. The ultimate displacement δu and the yield point displacement δv are the values of the deformation angle in the 0.8Pmax load reduction region and the yield point σs, respectively. The yield displacement δy is the value of the deformation angle when the yield strength Py is expressed. Moreover, the plasticity modulus μ is the value (ratio) of ultimate displacement δu/yield point displacement δv. When the load (proof strength) decreases to 0.8Pmax after the maximum proof stress Pmax has occurred, the wall is considered to have substantially lost its proof strength, and the in-plane shear test essentially ends in the 0.8Pmax load reduction region. do.

The wall magnification is as described in many technical documents such as “Allowable Stress Design for Wooden Frame Construction Method Houses [1] (2017 Edition)”, pages 63 and 300 (Non-Patent Document 1), The short-term allowable shear strength (Pa) is calculated based on the yield strength Pmax, Pu, Py and the displacements δu, δv, δy specified by the perfect elasto-plastic model shown in 4. x 1.96 (kN/m)). That is, the wall magnification is the value obtained by dividing the short-term allowable shear strength (Pa) by this reference value (1.96L) and converting it into an index.

To further explain this point, when calculating the wall magnification, as a general rule, the short-term standard shear capacity (P0) is specified as the short-term standard shear capacity (P0), and the short-term standard shear capacity (P0) is specified as the short-term standard shear capacity (P0). ) is multiplied by a predetermined reduction coefficient (α) (a coefficient for evaluating the cause of a decrease in proof strength). Generally, in the case of a gypsum-based load-bearing surface material, the yield strength (1) or (2) below, that is, the yield strength (Py) or the ultimate yield strength (corrected value) (Pu'), exhibits the smallest value. Note that the value of the short-term standard shear strength (P0) obtained from the values of each yield strength (Py, Pu, Pmax) below is the value obtained by multiplying the value below by the dispersion coefficient (β).

(1) Yield strength (Py)
(2) Value of ultimate proof stress (Pu) corrected based on plasticity ratio (μ) (hereinafter referred to as "ultimate proof stress (corrected value) (Pu')")
(3) Value of 2/3 of maximum proof stress (Pmax) (4) Proof strength when shear deformation angle = 1/120 rad (for unloaded type or loaded type)

In general, the short-term standard shear strength (P0) of a load-bearing wall made by fastening the above-mentioned structural gypsum board (Patent Document 2) to a wooden structure wall base using fasteners is It is specified by proof strength (Py) (P0 = β x Py). As mentioned above, the wall magnification is the value obtained by multiplying the short-term standard shear strength (P0) by the reduction coefficient (α) and dividing it by the predetermined strength (1.96L). The wall magnification of a load-bearing wall that is fastened to a load-bearing wall using fasteners is proportional to the yield strength (Py).

On the other hand, the short-term standard shear strength (P0) of a load-bearing wall formed by fastening the gypsum-based facing material described in Patent Document 3, that is, the aforementioned low-density gypsum-based load-bearing facing material to the wooden structure wall base using fasteners. Usually, the ultimate proof stress (corrected value) (Pu') is the smallest value among the above four types of proof stress values, and therefore, the short-term standard shear strength (P0) and wall multiplication factor are used to calculate the wall multiplication factor. Unlike structural gypsum board, is proportional to the ultimate strength (corrected value) (Pu'). In the case of low-density gypsum-based load-bearing facing materials, as an unexpected effect of the lower density, the latent toughness and deformation-following properties of the gypsum-based load-bearing facing materials become apparent due to the decrease in areal density. As a result, the ultimate displacement (δu) of the load-bearing wall increases and an ultimate displacement (δu) of a value larger than 20×10 ^-3 rad is obtained. A load-bearing wall fixed to the foundation exhibits an ultimate load-bearing force (corrected value) (Pu') greater than 7.6 kN. Thus, as described above, the low-density gypsum-based load-bearing surface material exhibits a load-bearing strength equivalent to that of structural gypsum board, despite having a reduced areal density compared to structural gypsum board.

The ultimate yield strength (corrected value) (Pu') is the value obtained from the formula below based on the ultimate yield strength (Pu) and the plasticity ratio (μ), and the short-term standard shear strength (P0) is the ultimate yield strength (corrected value) (Pu') and the variation coefficient (β) of the measured values, this value is obtained from the following formula.

Pu'＝Pu×0.2×(2μ－1)1/2
P0=β×Pu'

That is, in the gypsum-based load-bearing facing material (i.e., low-density gypsum-based load-bearing facing material) of Patent Document 3, which reduces the areal density and brings out the latent toughness or deformability of the facing material itself, The ultimate displacement (δu) of the load-bearing wall increases to a value larger than 20×10 ^-3 rad, and as a result, the plasticity ratio μ (=δu/δv) increases and the ultimate strength (corrected value) (Pu' ) increases, which increases the short-term allowable shear capacity (Pa) and increases the wall magnification. In order to further increase the short-term allowable shear strength (Pa) and wall magnification, the present inventors further investigated the fastening structure of the face material and the plasticity ratio μ, changed the dimensions and shape of the nail 20, and changed the initial rigidity. The present disclosure was based on the finding that the plasticity modulus μ can be increased by increasing the plasticity modulus μ. This point will be explained below.

[About the dimensions and shape of the nail 20]
In conventional wooden load-bearing walls in which gypsum-based load-bearing facing materials are fixed to the frame or frame of a wooden structure, the gypsum-based load-bearing facing materials are generally assembled with NZ50 nails (plated iron round nails: JIS A 5508). Or it has been fixed to a framework. The NZ50 nail has dimensions (JIS A 5508) of a head diameter of 6.6 mm, a body diameter of 2.75 mm, and a nail length of 50 mm, and the ratio η of head area/body cross-sectional area is 5.76. As described in Patent Document 3, in an in-plane shear test using a test specimen of a wooden load-bearing wall in which a low-density gypsum-based load-bearing wall material is fixed to a framework or frame of a wooden structure with such nails, the final The displacement (δu) increases, and as a result, the ultimate strength (corrected value) (Pu'), the short-term standard shear strength (P0), and the wall magnification increase. However, in this in-plane shear test, the nail holes break due to repeated loads acting on the test specimen, causing a punching shear phenomenon, and the accompanying punch-out failure of the gypsum-based load-bearing surface material reduces the proof strength of the test specimen. A characteristic or feature was observed in which Pu suddenly decreased to 0.8Pmax, and the in-plane shear test was terminated. Therefore, it is considered difficult to further increase the short-term allowable shear strength (Pa) and wall magnification unless the failure or breakage of the nailed portion is suppressed and the punch-out failure of the gypsum-based load-bearing surface material is suppressed. Incidentally, as in the face material reinforcement method described in Patent Document 1, it may be possible to suppress or reduce punch-out failure by arranging a reinforcing material such as a metal plate or a stiffening material in the nailed part. However, as mentioned above, the attachment or arrangement of such reinforcing materials or stiffening materials becomes a factor that complicates the manufacturing process of the gypsum-based facing material and deteriorates the workability of construction work.

FIG. 5 shows the head diameter D, body diameter d, length L, and head area of nails 20 that constitute a load-bearing wall according to an example of the present disclosure, and nails N1 and N2 that constitute a load-bearing wall according to a comparative example. It is a chart showing the area ratio η of /body cross-sectional area as a comparison table. The values of the head diameter D, body diameter d, length L, and area ratio η of head area/body cross-sectional area of the nail 20 are as described above. Nail N1 is an iron nail distributed on the market as a NZ50 nail (JIS A 5508), and has the values shown in Figure 5 (head diameter D = 6.62 mm, body diameter d = 2.83 mm, head area/body cross section). The area ratio η = 5.48) is the value obtained by measuring the dimensions of each part of any 10 NZ50 nails obtained on the market and averaging the measured values, and is the value specified in JIS A 5508. Slightly different. Nail N2 is an iron nail distributed on the market as a CN50 nail (JIS A 5508), and has the values shown in Figure 5 (head diameter D = 6.67 mm, body diameter d = 2.92 mm, head area/body cross section). The area ratio η = 5.2) is also the value obtained by measuring the dimensions of each part of 10 arbitrary CN50 nails obtained on the market and averaging each measurement value, and is the value specified in JIS A 5508. are slightly different. Note that the lengths L of the nails 20, N1, and N2 are all approximately 50 mm.

FIG. 6 is a diagram and diagram for comparing the test results of an in-plane shear test regarding a load-bearing wall using nail N1 (Comparative Example 1) and a load-bearing wall using nail N2 (Comparative Example 2). be. FIG. 7 shows a diagram and lines for comparing test results of an in-plane shear test regarding a load-bearing wall using nail 20 (embodiment of the present disclosure) and a load-bearing wall using nail N1 (comparative example 3). It is a diagram. The gypsum-based load-bearing surface materials 10 of the embodiment and comparative examples 1 to 3 are all made of a flat gypsum core (gypsum core material) mixed with a predetermined amount of inorganic fiber (glass fiber) and organic strength improving material (starch). 11 and gypsum board base paper (paper member) 12 that covers both sides of the gypsum core. density, compressive strength of 6.5N/mm2 or more, and nail side resistance of 500N or more.

As is clear from the test results shown in Figure 6, the present inventors have found that in the case of gypsum-based load-bearing surface materials, thicker nails (Comparative Example 2 with a larger body diameter d than Comparative Example 1) do not necessarily suppress punch-out failure. It was confirmed that this method is not necessarily effective in improving the short-term allowable shear strength (Pa) and wall magnification. Furthermore, as is clear from the test results shown in FIG. 7, the inventors appropriately set the head diameter D, body diameter d, and ratio η of head area/body cross-sectional area in the case of a gypsum-based load-bearing surface material. It was confirmed that this could suppress or reduce punch-out failure of gypsum-based load-bearing facing materials, and relatively significantly improve short-term allowable shear strength (Pa) and wall magnification. This point will be explained below with reference to FIGS. 6 and 7.

Generally, the head diameter D and body diameter d of the nail N2 (Comparative Example 2) are larger than the head diameter D and body diameter d of the nail N1 (Comparative Example 1), thus suppressing or reducing punch-out fracture. It is generally recognized that the shear strength is superior to the nail N1 (thin nail), which has a relatively small body diameter d. However, in the case of low-density gypsum-based load-bearing facing material with increased compressive strength and nail side resistance, nail N2 actually reduces the short-term allowable shear strength (Pa) (therefore, reduces the wall magnification), as shown in Figure 6. )It has been found. This is because the punching shear phenomenon occurs relatively early in the in-plane shear test, and the proof stress (load) quickly decreases to Pu = 0.8Pmax (final displacement δuB <δuA), due to the wall having substantially lost its bearing strength.

On the other hand, when comparing the load-bearing wall of this example using the nail 20 and the load-bearing wall of Comparative Example 3 using the nail N1, as shown in FIG. 3) A low-density gypsum-based load-bearing surface material with increased compressive strength and nail side resistance, although it is a thin nail that is generally recognized to be smaller than the body diameter d and has inferior shear strength compared to Nail N1. In this case, such conventional recognition or knowledge is not necessarily applicable; as shown in FIG. 7, nail 20 increases the short-term allowable shear strength (Pa) compared to nail N1 (therefore, the wall ). This is because the diameter difference between the body diameter d and the head diameter D of the nail 20 increases due to the difference in the area ratio η of head area/body cross-sectional area, and as a result, the occurrence of the punching shear phenomenon is delayed, resulting in punching-out failure. This is thought to be the result of a delay in the timing of the decline in proof strength (load) (Pu = 0.8Pmax) due to failure or breakage of the nailed part, and an increase in the ultimate displacement (δuE > δuC).

Therefore, the head diameter D and trunk diameter d are set to 7.07 mm and 2.45 mm, respectively, and the head area/torso cross-sectional area is set to 8.32. A low-density gypsum-based bearing surface material with increased compressive strength and nail side resistance by enlarging the area and ensuring a sufficient annular and flat seating surface 21b (see Figure 2) that seats on the surface of the low-density gypsum-based bearing surface material. The short-term allowable shear strength (Pa) of the load-bearing wall 1 using the facing material can be effectively increased (therefore, the wall magnification can be effectively increased). However, it is considered necessary to consider not only the increase in the diameter difference between the head 21 and the body 22, but also the following conditions.

(1) In order to suppress the phenomenon that the face material 10 cracks due to the penetrating action of the nail during nailing, and in consideration of the nail head diameter D suitable for use with a nail gun, the head diameter D should be 10 mm or less, preferably 9 mm. Set as below.
(2) In order to suppress the punching shear phenomenon and reduce the effect of punching-out fracture, the head diameter D is set to 6 mm or more, preferably 6.8 mm or more.
(3) In order to suppress the phenomenon that the panel 10 cracks due to the penetrating action of the nail during nailing, and also to suppress the phenomenon of edge breakage of the panel during the in-plane shear test, the body diameter d is preferably 5 mm or less. is set to 4.2 mm or less.
(4) In order to prevent excessive bending deformation of the nail from occurring during the in-plane shear test, the body diameter d is set to 2 mm or more, preferably 2.2 mm or more.
(5) In order to prevent the strength of the neck portion 23 from decreasing excessively, the ratio η of head area/body cross-sectional area is set to 13 or less, preferably 11 or less.
(6) In order to ensure the effect of suppressing the punching shear phenomenon, the ratio η of head area/body cross-sectional area is set to 6 or more, preferably 7 or more.

Thus, in the load-bearing wall 1 using a low-density gypsum-based load-bearing surface material with increased compressive strength and nail side resistance, the head diameter D, body diameter d, and ratio η of head area/body cross-sectional area are set within appropriate numerical ranges. This suppresses the head 21 (nail head) from sinking into the face material 10, suppresses or reduces the punching shear phenomenon, and prevents cracks in the face material 10 that may occur during nailing. By suppressing it, the short-term allowable shear strength (Pa) of the load-bearing wall 1 can be effectively increased (therefore, the wall magnification can be effectively increased). In particular, in the case of a gypsum-based load-bearing facing material 10, nailing is done so that the head 21 is flush with the surface of the facing material and the covering material (base paper for gypsum board) 12 of the facing material 10 is not damaged or damaged. However, in particular, when the head 21 has an excessively large head diameter D, the phenomenon that the face material 10 cracks when the top surface 21a of the head 21 and the surface of the face material 10 are made flush with each other. is likely to occur ((1) above), therefore, the above settings regarding the head diameter D, trunk diameter d, and ratio η of head area/torso cross-sectional area are important in order to avoid such a phenomenon.

[Increase in initial stiffness due to increase in compressive strength, increase in short-term allowable shear strength Pa and wall magnification]
The present inventor uses nails 20 having specific dimensions and shapes as described above to secure low density load-bearing facings 10 with increased compressive strength and nail side resistance to the frame or framework of a wood structure. Although the inventor recognized that the short-term allowable shear strength Pa and wall magnification of the load-bearing wall 1 can be increased by It has been recognized that the short-term permissible shear strength Pa of the wall 1 and the wall magnification can be further increased. That is, by using the nail 20 having a specific size and shape and the low-density load-bearing facing material 10 with increased compressive strength and nail side resistance, it is possible not only to suppress or reduce the punching shear phenomenon, but also to improve the surface resistance. By increasing the initial stiffness of the material, the plasticity modulus μ can be increased, and as a synergistic effect of both, it becomes possible to effectively or efficiently increase the short-term allowable shear strength Pa and the wall magnification. Hereinafter, the effect of increasing the initial rigidity of the load-bearing surface material 10 due to the increase in compressive strength, and the increase in short-term allowable shear strength Pa and wall magnification caused by this will be explained.

As mentioned above, the compressive strength and nail side resistance of the gypsum-based load-bearing facing material 10 are determined by feeding organic strength-improving materials such as starch, polyvinyl acetate, polyvinyl alcohol, and polyacrylic together with inorganic fibers to a mixer for mixing gypsum slurry. It is increased by incorporating appropriate amounts of organic strength enhancers and inorganic fibers into the gypsum slurry. The blending of the above-mentioned organic strength improving material into the gypsum slurry ensures a relatively low areal density (area density within the range of 6.5 to 8.9 kg/m ² ) while achieving the desired compressive strength (6.5 N/m 2 ). mm ² or more) to the gypsum-based load-bearing facing material 10, and in cooperation with the inorganic fibers to give the gypsum-based load-bearing facing material 10 the desired nail side resistance (nail side resistance of 500 N or more). In addition, considering the fact that the combination of organic strength-improving materials does not significantly affect the overall quality of the gypsum-based load-bearing surface material, it is a simple and realistically or practically effective method. be.

Moreover, the increase in the compressive strength of the load-bearing wall 10 contributes to an increase in the initial stiffness K of the load-bearing wall 1, thereby reducing the yield point displacement δv without significantly reducing the ultimate displacement δu of the load-bearing wall. As a result, the plastic modulus μ of the load-bearing wall 1 increases relatively significantly, and thus the short-term allowable shear strength Pa and the wall magnification can increase, as explained in the following recent experiments by the present inventors. It was revealed by

The present inventors manufactured gypsum-based load-bearing surface materials according to Reference Examples 1 to 4 and Comparative Example 4 shown in the diagram of FIG. 8 as specimens, and conducted an in-plane shear test using a non-loading test device. . The blending amounts of the inorganic fibers and organic strength improving material shown in FIG. 8 are shown in parts by weight per 100 parts by weight of calcined gypsum. As mentioned above, the gypsum-based load-bearing surface material of Comparative Example 4 consists of a flat gypsum core (gypsum core material) mixed with a predetermined amount of inorganic fiber (glass fiber) and an organic strength improving material (starch), and a gypsum core material. It is a facing material composed of base paper for plasterboard (paper member) that covers both sides, and has an areal density within the range of about 7.4 to about 8.7 kg/m ² , and is similar to conventional plasterboard. Compared to the system load-bearing surface material (Patent Document 4), it has the performance of increasing the final displacement δu and plasticity modulus μ of the wooden structure load-bearing wall, and increasing the short-term allowable shear strength Pa and wall magnification. However, the gypsum-based load-bearing surface materials of Reference Examples 1 to 4 and Comparative Example 4 were used not with the nails 20 according to the present disclosure, but with conventional nails N1 (NZ50 nails) to attach the foundations 2, columns 3, studs 4, and joint studs 4'. , were fastened to the horizontal members 5 and the trunk link 5' (wooden framework shown in FIG. 3). This eliminates the effect or influence of the use of the nails 20, and increases the initial stiffness K of the load-bearing wall 1 due to the increase in the compressive strength of the load-bearing wall 10 (and therefore increases the plasticity modulus μ of the load-bearing wall 1). This is to evaluate only the increase in short-term allowable shear strength Pa and wall magnification. Note that the load-bearing walls whose performance is shown in FIGS. 8 and 9 do not have a structure in which the load-bearing wall 10 is fastened to the wooden frame using the nails 20 according to the present disclosure, so the figures are shown as Reference Examples 1 to 4. 8 and 9.

Referring to the test results shown in FIGS. 8 and 9, the test results for each test piece of Reference Examples 1 to 4 and Comparative Example ⁴ show that the maximum load ( After reaching the maximum yield strength) Pmax (Fig. 3), the deformation angle in the 0.8Pmax load reduction region, that is, the final displacement δu1 to δu5 (Fig. 9), is reached by repeated application of force without immediately breaking. , the final displacements δu1 to δu5 are deformation angles of approximately 30×10 ⁻³ rad. This is until after each test specimen of Reference Examples 1 to 4 and Comparative Example 4 reaches the maximum load (maximum proof stress) Pmax, a deformation angle approximately 1.5 times the deformation angle at the maximum load Pmax occurs. , means that plastic deformation is maintained by repeated application of force. As mentioned above, the sustainability of such plastic deformation reduces the areal density and reduces the potential of the gypsum board itself while ensuring the minimum physical properties (nail side resistance: 500N or more) as a gypsum-based load-bearing surface material. This is thought to be due to the fact that the toughness or deformation-following properties possessed by the steel have become apparent.

On the other hand, when comparing the compressive strength etc. of Reference Examples 1 to 4 and Comparative Example 4, the compressive strength of the gypsum-based load-bearing surface material of Comparative Example 4 is 6.0 N/mm ² , and the compressive strength of the gypsum-based load-bearing surface material of Comparative Example 4 is 6.0 N/mm 2 The compressive strength of the gypsum-based load-bearing facing material of Comparative Example 4 is relatively low compared to the compressive strength of the gypsum-based load-bearing facing material (6.5 N/mm ² or more), and the short-term The allowable shear strength Pa and wall magnification are relatively reduced.

[About measuring the compressive strength of load-bearing surface materials]
FIG. 10 schematically shows a method for measuring the compressive strength of a gypsum-based load-bearing surface material.

When measuring the compressive strength of gypsum-based load-bearing facing materials conducted by the present inventors, the gypsum-based load-bearing facing materials of Examples, Reference Examples, and Comparative Examples were cut into flat plates with dimensions of 4 cm x 4 cm, as shown in Figure 10. For Examples, Reference Examples, and Comparative Examples, a plurality of test pieces 101 were manufactured, and a test piece laminate 100 formed by laminating four of the same test pieces 101 without bonding them was placed on the top and bottom of the measuring device. It was inserted between the

loading plates

102 and 103 of. Then, a vertical compressive load Fv (and reaction force Rv) is applied to the test piece laminate 100 by the upper and lower loading rods 104, and the main material or core material made of hardened gypsum, that is, the gypsum core portion of the test piece 101. was destroyed, and the compressive load Fv at the time of destruction was measured. As a measuring device, a precision universal testing machine ("Autograph" manufactured by Shimadzu Corporation, model: AG-10NKI) was used. The present inventors measured the compressive load Fv at the time when any of the test pieces 101 constituting the test piece laminate 100 underwent compression failure, and calculated the value obtained by dividing this measured value by the area (16 cm ² ) of the test piece 100. was specified as the compressive strength of each gypsum-based load-bearing surface material.

The compressive strengths of the gypsum-based load-bearing facing materials of Reference Examples 1 to 4 and Comparative Example 4 thus identified are shown in FIG. As shown in Figure 8, the initial stiffness K of the gypsum-based load-bearing surface materials of Reference Examples 1 to 4 and Comparative Example 4 changes roughly corresponding to the increase or decrease in compressive strength. The value can be increased. Further, as shown in FIG. 8, by increasing or decreasing the initial stiffness K, the plasticity modulus μ can be changed, and the values of the ultimate proof stress (corrected value) Pu′ and the short-term allowable shear proof stress Pa can be changed. According to the physical properties of Reference Examples 1 to 4, as the compressive strength of the gypsum-based load-bearing surface material increases to a value of 6.5 N/mm ² or more, the final value of 7.8 kN or more is achieved as shown in Figure 8. Proof strength (corrected value) Pu' (short-term allowable shear strength Pa of 5.85 kN or more) is obtained.

That is, the gypsum-based load-bearing face materials of Reference Examples 1 to 4 have a compressive strength of 6.5 N/mm ² or more, and due to the associated increase in initial stiffness K and decrease in yield point displacement δv, relatively high plasticity. As a result, the ultimate strength (corrected value) Pu' and short-term allowable shear strength Pa of the test specimens of Reference Examples 1 to 4 are as follows: Pu' = 7.8 to 11.9 kN, Pa = 5. 85 to 8.92, and this value was significantly increased compared to the ultimate yield strength (corrected value) (=7.62 kN) and short-term allowable shear strength Pa (=5.72 kN) of the test specimen of Comparative Example 4. It is a value. Further, assuming that the reduction coefficient α = 0.75 and the variation coefficient β = 1.0, the wall magnification of the test specimens of Reference Examples 1 to 4 is 1.64 to 2.50, and the wall magnification of the test specimen of Comparative Example 4 is 1.64 to 2.50. The wall magnification (1.60) is significantly increased. In other words, due to the increase in the compressive strength of the load-bearing wall 10, the initial stiffness K of the load-bearing wall 1 increases, and as a result, the yield point displacement δv decreases without significantly reducing the ultimate displacement δu of the load-bearing wall. As a result, the plastic modulus μ (=δu/δv) of the load-bearing wall 1 increased relatively significantly, and thus the short-term allowable shear strength Pa and the wall magnification increased.

[About the increase in the plasticity modulus μ due to the increase in the initial stiffness K]
As mentioned above, the ultimate yield strength (corrected value) Pu' is the value obtained by correcting the ultimate yield strength Pu based on the plasticity ratio μ, and the short-term allowable shear strength Pa is a predetermined value for the ultimate yield strength (corrected value) Pu'. It is a value multiplied by a reduction coefficient α and a dispersion coefficient β, and the wall magnification is a value obtained by dividing the short-term allowable shear strength Pa by a predetermined strength reference value (L×1.96). Therefore, the wall magnification and the short-term allowable shear strength Pa are proportional to the value of the ultimate strength Pu and increase as the plasticity ratio μ increases. The plasticity modulus μ is a value that is proportional to the ultimate displacement δu and inversely proportional to the yield point displacement δv. Therefore, by increasing the ultimate displacement δu or decreasing the yield point displacement δv, the wall magnification and short-term allowable shear Yield strength Pa can be increased.

In FIG. 9, the test results of each of the test specimens of Reference Examples 1 to 4 and Comparative Example 4 are shown as a linear graph of the load-deformation angle characteristic of a perfect elastic-plastic model. Further, in FIG. 9, a linear function straight line Y=KX in the linear elastic region set to the initial stiffness K=2.0 kN/10 ^-3 rad is shown by a chain double-dashed line as a reference line for the initial stiffness K in the present disclosure. ing. Furthermore, FIG. 9 shows the linear elastic range linear function straight line Y=K1X to Y=K5X, the ultimate yield strength Pu1 to Pu5, and the yield point σs1 to σs5 for each of the test specimens of Reference Examples 1 to 4 and Comparative Example 4. has been done. As shown in Figure 8, the initial stiffness of each test specimen of Reference Examples 1 to 4 is K4 = 2.04 kN/10 ^-3 rad at the minimum value, and K3 = 2.91 kN/10 ^-3 rad at the maximum value. be. On the other hand, the initial stiffness of the test specimen of Comparative Example 4 is K5=1.94 kN/10 ^-3 rad. The initial stiffness K appears in FIG. 9 as the gradient of the linear function line of Y=KX, and in the test specimens of Reference Examples 1 to 4 in which the initial stiffness K is 2.0 kN/10 ^-3 rad or more, Each linear function line of Y=K1-4X is represented in FIG. 9 as a straight line with a steeper slope than the reference line of initial stiffness K=2.0 kN/10 ^-3 rad, and the initial stiffness K5 is 2.0 kN/10 ^- In Comparative Example 4, which shows a value of less than ³ rad, the linear function line of Y=K5X is represented in FIG. 9 as a straight line with a gentler slope than the reference line of initial stiffness K=2.0 kN/10 ^-3 rad. . That is, in each of the test specimens of Reference Examples 1 to 4 with increased compressive strength, the initial stiffness K1-4 showed a value of 2.0 kN/10 ^-3 rad or more, and as a result, the yield point displacement was relatively small. δv1 to δv4 are obtained, and together with relatively large ultimate displacements δu1 to δu4 and ultimate proof strengths Pu1 to Pu4, a relatively large ultimate proof stress (corrected value) Pu' and short-term allowable shear strength compared to Comparative Example 4 are obtained. Pa and wall magnification are obtained as shown in FIG.

As shown in FIGS. 8 and 9, the initial stiffness K of each test piece of Reference Examples 1 to 4 is greater than 2.0 kN/10 ^-3 rad, and the initial stiffness K of the test piece of Comparative Example 4 is 2.0 kN/10 -3 rad. The yield point displacements δv1 ^to δv4 of the test specimens of Reference Examples 1 to 4 are significantly smaller than the yield point displacement δv5 of the test specimen of Comparative Example 4. As shown in Figure 8, the wall magnification and short-term allowable shear strength Pa obtained by the test specimens of Reference Examples 1 to 4 are significantly larger than the values of the wall magnification and short-term permissible shear strength Pa obtained by the test specimen of Comparative Example 4. . This is considered to be the result of the increase in the plasticity modulus μ accompanying the decrease in the yield point displacement δv, which contributed relatively significantly to the increase in the wall magnification and the short-term allowable shear strength Pa.

As explained above, the load-bearing wall 1 according to this embodiment has the following features.
(1) The load-bearing surface material 10 is a plate-shaped plaster hardened material containing inorganic fibers and organic strength-improving materials so as to exhibit a nail side resistance of 500 N or more and a compressive strength of 6.5 N/mm ² or more. It is composed of a main material or core material consisting of a body, and a paper member covering at least the front and back surfaces of the main material or core material. The surface density of the load-bearing surface material 10, which is specified as the mass per unit area of the wall surface, is set to a value within the range of 6.5 to 8.9 kg/m ² . In the load-bearing wall 1 using the low-density gypsum-based load-bearing facing material 10 with increased compressive strength and nail side resistance, the head diameter D is within the range of 6.0 to 10.0 mm, and the body diameter d is 2. By setting the head area/body cross-sectional area ratio η within the range of .0 to 5.0 mm, the head 21 is prevented from sinking into the face material 10, and the punching shear is reduced. In addition to suppressing or reducing the phenomenon, cracking of the face material 10 that may occur during nailing is suppressed, and moreover, the short-term allowable shear strength Pa of the load-bearing wall 1 is effectively increased (therefore, the wall magnification is effectively increased). )be able to.
(2) In the load-bearing wall 1 using the low-density gypsum-based load-bearing facing material 10 with increased compressive strength and nail side resistance as described above, the ultimate displacement δu is, for example, 28.09×10 ^-3 to 34 Therefore, the ultimate displacement δu of a load-bearing wall using a conventional gypsum-based load-bearing facing material (for example, the gypsum-based load-bearing facing material described in Patent Document 4) increases to 20×10 ^-3 rad ^. Compared to the value of about ³ rad, the ultimate displacement δu of the load-bearing wall 1 increases significantly.
(3) In the load-bearing wall 1 using the low-density gypsum-based load-bearing facing material 10 with increased compressive strength and nail side resistance as described above, the load-bearing wall 1 according to Reference Examples 1 to 4 (FIGS. 8 and 9) As explained above, the yield point displacement δv1 to δv4 decreases to 6.04×10 ^-3 to 6.80×10 ^-3 rad as the initial stiffness K increases, and this value This value is significantly lower than the yield point displacement δv5=7.26×10 ⁻³ rad of the load-bearing wall. That is, the load-bearing face material 10 described as Reference Examples 1 to 4 above not only increases the ultimate displacement δu1 to δu4 of the load-bearing wall 1 and increases the plasticity modulus μ, but also increases the yield point displacement δv1 to δv4 of the load-bearing wall 1. Since the plasticity modulus μ is also increased by a decrease in , the wall magnification and the short-term allowable shear strength Pa can be relatively greatly increased.

Although the preferred embodiments and examples of the present disclosure have been described in detail above, the present disclosure is not limited to the above embodiments and examples, and within the scope of the present disclosure described in the claims. It goes without saying that various modifications or changes are possible.

For example, although the above embodiments and examples relate to a load-bearing wall at the first floor level of a wooden structure building, the present disclosure can be similarly applied to a load-bearing wall at the second or third floor level. . In the case of a load-bearing wall at the second or third floor level, the lower end of the load-bearing face member is fastened to a horizontal member or the like at the second or third floor level.

In addition, the above embodiments and examples relate to load-bearing wall structures using wooden frame construction methods and large walls; The present disclosure may be applied to. As a modified example, the present disclosure may be applied to the load-bearing wall structure of the wooden frame wall construction method, and in this case, the load-bearing surface materials are vertical frames, lower frames, upper frames, etc. instead of the foundations, columns, and horizontal members. It is fastened to.

Furthermore, the test specimen shown in Figure 3 has a structure in which the gypsum board is divided into upper and lower parts and a trunk joint is placed in the middle position in the height direction, but the height dimension is substantially the same as the total height of the wooden framework. An in-plane shear test may be performed using a gypsum board. In the latter case, it is considered that the short-term standard shear strength can be further increased.

The present disclosure is applied to a wooden structural load-bearing wall of a wooden structural building and a construction method thereof. In particular, the present disclosure provides a board having an areal density in the range of 6.5 to 8.9 kg/m ² and mixed with inorganic fibers and an organic strength-enhancing material so as to exhibit a nail side resistance of 500 N or more. A low-density gypsum-based load-bearing surface material with hardened gypsum as the main material or core material is fastened with metal nails to the wooden structure wall base of the wooden frame construction method or wooden frame wall construction method, and the load-bearing surface material is attached to the wooden structure. It is applied to a load-bearing wooden structure wall constructed to be structurally integrally held by a structural wall base and its construction method. The present disclosure also applies to a method for increasing the wall magnification of a wooden structure load-bearing wall using such a gypsum-based load-bearing wall material. The present disclosure further applies to such a wooden structure load-bearing wall, a method for increasing the wall magnification thereof, and a gypsum-based load-bearing surface material used in the construction method thereof. According to the present disclosure, by fastening a load-bearing fascia to a wooden structural wall base using metal nails having a specific shape and dimensions, gypsum-based It is possible to increase the wall magnification of a wooden structural load-bearing wall without increasing the specific gravity and/or thickness of the facing material, and without further increasing the value of the ultimate displacement (δu). The value or effect is significant.

This international application claims priority based on Japanese Patent Application No. 2022-122390 filed on July 30, 2022, and the entire contents of that application are incorporated into this international application.

1 Load-bearing wall 2 Foundation 3 Column 4 Stud 4' Joint stud 5 Horizontal members (beam, girder, eave girder, girder)
5' Trunk joints 10, 10a, 10b Gypsum-based load-bearing surface material 11 Flat gypsum core (gypsum core material)
12 Base paper for gypsum board (paper component)
20 Nails (fasteners)
21 Head

21a Top surface

21b Seating surface 22 Trunk 23 Neck 24 Tip D Head diameter d Trunk diameter L Length η Area ratio of head area/torso cross-sectional area

Claims

In a wooden structure load-bearing wall that has a structure in which a gypsum-based load-bearing surface material is fastened to the wooden structure wall base using fasteners using the wooden frame construction method or the wooden frame wall construction method,
The load-bearing surface material is composed of a main material or core material made of a plate-shaped gypsum hardened body, and a paper member that covers at least the front and back surfaces of the main material or core material,
The load-bearing facing material has an areal density or areal weight within the range of 6.5 to 8.9 kg/m 2 as the areal density or areal weight of the load-bearing facing material specified as the mass per unit area of the wall surface. At the same time, it exhibits a nail side resistance of 500N or more, and has a compressive strength of at least 6.5N/mm 2 or more,
The fastener is made of a metal nail having a head and a body, and the area ratio of the area of the head/the cross-sectional area of the body is set to a value within the range of 6 to 13,
As the ultimate displacement of the load-bearing wall measured by an in-plane shear test using a load-bearing wall test piece with a wall length of 1.82 m, the load-bearing wall has an ultimate displacement (δu) of a value larger than 20 × 10 -3 rad. A wooden structural load-bearing wall featuring:
The wooden structure load-bearing wall according to claim 1,
The body of the nail is a straight smooth body with a uniform circular cross-section and a spire-shaped tip, and the head of the nail is a flat-headed body with a circular profile in top view. Wood structure load-bearing wall characterized by a head in the form of a shaped or flat-headed mesh.
The wooden structure load-bearing wall according to claim 1,
After nailing, the nail is located in substantially the same plane as an annular and flat seating surface that seats on the outer surface of the load-bearing surface material and a wall surface constituted by the outer surface of the load-bearing surface material. A wooden structural load-bearing wall, characterized in that it has a constructed flat top surface.
The wooden structure load-bearing wall according to any one of claims 1 to 3,
The load-bearing surface material has a stiffness of 7.5 N/mm 2 or more in order to ensure an initial stiffness (K) of the load-bearing wall measured by the in-plane shear test of 2.2 kN/10 -3 rad or more. A wooden structural load-bearing wall that is characterized by its compressive strength.
The wooden structure load-bearing wall according to any one of claims 1 to 3,
The physical properties of the load-bearing wall measured by the in-plane shear test include:
(1) Yield point displacement (δv) of 7.2×10 -3 rad or less,
(2) Plasticity modulus (μ) of 4.2 or more,
(3) A correction value (Pu') of the ultimate strength (Pu) of 7.7 kN or more, and (4) A value of 7.7 kN or more, which is lower than the correction value (Pu') of the ultimate strength (Pu). Large yield strength (Py),
At least one of the physical properties consisting of the above-mentioned areal density or areal weight and the above-mentioned nail side resistance setting, and the above-mentioned property set to suppress the punching shear phenomenon or reduce the effect of punching-out fracture. A wooden structural load-bearing wall, which is secured by setting the nail head diameter, body diameter, and area ratio of head area/body cross-sectional area.
The wooden structure load-bearing wall according to any one of claims 1 to 3,
A wooden structural load-bearing wall, characterized in that the load-bearing face material has a thickness of less than 12 mm and/or a specific gravity of 0.96 or less.
The wooden structure load-bearing wall according to claim 1,
A wooden structure load-bearing wall, characterized in that the main material or the core material of the load-bearing surface material contains an inorganic fiber and/or an organic strength improving material.
The wooden structure load-bearing wall according to claim 1 or 7,
A wooden structural load-bearing wall, characterized in that the main material or core material of the gypsum-based load-bearing surface material contains an organopolysiloxane compound.
In the construction method of a wooden structure load-bearing wall, in which a gypsum-based load-bearing surface material is fixed to the wooden structure wall base of the wooden frame construction method or the wooden frame wall construction method,
A gypsum-based load-bearing surface material consisting of a main material or core material made of a plate-shaped hardened gypsum material and a paper member covering at least the front and back surfaces of the main material or core material, The areal density or areal weight specified as mass is within the range of 6.5 to 8.9 kg/ m2 , and the nail side resistance is 500 N or more and is at least 6.5 N/m2. A gypsum-based load-bearing surface material having a compressive strength of mm 2 or more is fastened to the wooden structure wall base using fasteners, and the fasteners have an area ratio of 6 to 13 of the area of the head/cross-sectional area of the body. using a metal nail set to a value within the range of
The ultimate displacement (δu) of the load-bearing wall measured by an in-plane shear test using a load-bearing wall test piece with a wall length of 1.82 m is greater than 20 × 10 -3 rad. A method for constructing a wooden structure load-bearing wall, which is characterized by constructing a wooden structure load-bearing wall.
The method for constructing a wooden structure load-bearing wall according to claim 9,
The body of the nail is a straight smooth body with a uniform circular cross-section and a spire-shaped tip, and the head of the nail is a flat-headed body with a circular profile in top view. A method of constructing a load-bearing wall made of wood, characterized by a head having a shape or a flat-head mesh shape.
The method for constructing a wooden structure load-bearing wall according to claim 9,
After nailing, the nail is located in substantially the same plane as an annular and flat seating surface that seats on the outer surface of the load-bearing surface material and a wall surface constituted by the outer surface of the load-bearing surface material. A method for constructing a wooden structural load-bearing wall, characterized by having a flat top surface.
The method for constructing a wooden structure load-bearing wall according to any one of claims 9 to 11,
The load-bearing surface material has a stiffness of 7.5 N/mm 2 or more in order to ensure an initial stiffness (K) of the load-bearing wall measured by the in-plane shear test of 2.2 kN/10 -3 rad or more. A method of constructing a wooden structural load-bearing wall that is characterized by its compressive strength.
The method for constructing a wooden structure load-bearing wall according to any one of claims 9 to 11,
The physical properties of the load-bearing wall measured by the in-plane shear test include:
(1) Yield point displacement (δv) of 7.2×10 -3 rad or less,
(2) Plasticity modulus (μ) of 4.2 or more,
(3) A correction value (Pu') of the ultimate strength (Pu) of 7.7 kN or more, and (4) A value of 7.7 kN or more, which is lower than the correction value (Pu') of the ultimate strength (Pu). Large yield strength (Py),
At least one of the physical properties consisting of the above-mentioned areal density or areal weight and the above-mentioned nail side resistance setting, and the above-mentioned property set to suppress the punching shear phenomenon or reduce the effect of punching-out fracture. A method for constructing a wooden structural load-bearing wall, which is secured by setting the nail head diameter, body diameter, and area ratio of head area/body cross-sectional area.
The method for constructing a wooden structure load-bearing wall according to any one of claims 9 to 11,
A method for constructing a wooden structure load-bearing wall, characterized in that the load-bearing face material has a thickness of less than 12 mm and/or a specific gravity of 0.96 or less.
The method for constructing a wooden structure load-bearing wall according to claim 9,
A method for constructing a wooden structure load-bearing wall, characterized in that the main material or the core material of the load-bearing surface material contains an inorganic fiber and/or an organic strength improving material.
In the method for constructing a wooden structural load-bearing wall according to claim 9 or 15,
A method for constructing a wooden structural load-bearing wall, characterized in that the main material or core material of the gypsum-based load-bearing surface material contains an organopolysiloxane compound.
In a method for increasing the wall magnification of a wooden structure load-bearing wall, which is constructed by fastening a gypsum-based load-bearing surface material to the wooden structure wall base of the wooden frame construction method or the wooden frame wall construction method using fasteners,
The load-bearing surface material is composed of a main material or core material made of a plate-shaped hardened gypsum body, and a paper member that covers at least the front and back surfaces of the main material or core material,
The areal density or areal weight of the load-bearing facing material, specified as the mass per unit area of the wall surface, is reduced to 6.5 to 8.9 kg/ m2 , and the load-bearing facing material has a nail side resistance of 500N or more and 6.5 kg/m2. The composition of the hardened gypsum of the main material or the core material is set so as to exhibit a compressive strength of .5 N/mm 2 or more,
As the fastener, a metal nail whose area ratio of the area of the head/the cross-sectional area of the body is set to a value within the range of 6 to 13 is used to suppress the punching shear phenomenon or to prevent punching-out failure. reduce the effect,
Obtaining an ultimate displacement of a value larger than 20×10 -3 rad as the ultimate displacement (δu) of the load-bearing wall measured by an in-plane shear test using a load-bearing wall test piece with a wall length of 1.82 m. A method for increasing the wall magnification of a wooden structural load-bearing wall.
The method for increasing the wall magnification of a wooden structure load-bearing wall according to claim 17,
The body of the nail is a straight smooth body with a uniform circular cross-section and a spire-shaped tip, and the head of the nail is a flat-headed body with a circular profile in top view. A method for increasing the wall magnification of a load-bearing wall made of wood, characterized in that the head is shaped or flat-headed.
The method for increasing the wall magnification of a wooden structure load-bearing wall according to claim 17,
After nailing, the nail is located in substantially the same plane as an annular and flat seating surface that seats on the outer surface of the load-bearing surface material and a wall surface constituted by the outer surface of the load-bearing surface material. A method for increasing the wall magnification of a wooden structural load-bearing wall, characterized by having a flat top surface constructed.
In the method for increasing the wall magnification of a wooden structural load-bearing wall according to any one of claims 17 to 19,
In order to ensure that the initial stiffness (K) of the load-bearing wall measured by the in-plane shear test is 2.2 kN/10 -3 rad or more, the compressive strength of 7.5 N/mm 2 or more is set to the load-bearing surface. A method for increasing the wall magnification of a load-bearing wall made of wood, characterized by retaining it in the timber.
In the method for increasing the wall magnification of a wooden structural load-bearing wall according to any one of claims 17 to 19,
The physical properties of the pre-bearing wall measured by the in-plane shear test are as follows:
(1) Yield point displacement (δv) of 7.2×10 -3 rad or less,
(2) Plasticity modulus (μ) of 4.2 or more,
(3) A correction value (Pu') of the ultimate strength (Pu) of 7.7 kN or more, and (4) A value of 7.7 kN or more, which is lower than the correction value (Pu') of the ultimate strength (Pu). Large yield strength (Py),
At least one of the physical properties consisting of the areal density or areal weight and the setting of the nail side resistance, and the nail set to suppress the punching shear phenomenon or reduce the effect of punching-out fracture. A method for increasing the wall magnification of a wooden structural load-bearing wall, characterized by setting the head diameter, body diameter, and area ratio of head area/body cross-sectional area.
In the method for increasing the wall magnification of a wooden structural load-bearing wall according to any one of claims 17 to 19,
A method for increasing wall magnification of a wooden structure load-bearing wall, characterized in that the load-bearing surface material has a thickness of less than 12 mm and/or a specific gravity of 0.96 or less.
The method for increasing the wall magnification of a wooden structure load-bearing wall according to claim 17,
A method for increasing wall magnification of a wooden structural load-bearing wall, characterized in that the main material or the core material of the load-bearing surface material contains inorganic fibers and/or organic strength improving materials.
In the method for increasing the wall magnification of a wooden structural load-bearing wall according to claim 17 or 23,
A method for increasing the wall magnification of a wooden structural load-bearing wall, characterized in that the main material or core material of the gypsum-based load-bearing surface material contains an organopolysiloxane compound.
Used in the construction method of a wooden structure load-bearing wall according to claim 9, or used in the method for increasing the wall magnification of a wooden structure load-bearing wall according to claim 17, and used in the wooden frame construction method or the wooden frame wall construction method. A gypsum-based load-bearing surface material for a wooden structure load-bearing wall, which is fastened to a wooden structure wall base by the fasteners,
exhibits a nail side resistance of 500 N or more, has a compressive strength of at least 6.5 N/mm 2 or more, and has an areal density or areal weight within the range of 6.5 to 8.9 kg/m 2 ,
In cooperation with the fasteners, the ultimate displacement (δu) of the load-bearing wall, measured by an in-plane shear test using a load-bearing wall specimen with a wall length of 1.82 m, is lower than 20×10 −3 rad. A gypsum-based load-bearing surface material that is characterized by its ability to increase to a large value.
In the gypsum-based load-bearing surface material according to claim 25,
A gypsum-based load-bearing surface material, wherein the load-bearing surface material has a thickness of less than 12 mm and/or a specific gravity of 0.96 or less.
In the gypsum-based load-bearing surface material according to claim 25 or 26,
In order to ensure that the initial stiffness (K) of the load-bearing wall measured by the in-plane shear test is 2.2 kN/10 -3 rad or more, the compressive strength is 7.5 N/mm 2 or more. A gypsum-based load-bearing surface material characterized by:
In the gypsum-based load-bearing surface material according to claim 25 or 26,
The physical properties of the load-bearing wall measured by the in-plane shear test include:
(1) Yield point displacement (δv) of 7.2×10-3 rad or less,
(2) Plasticity modulus (μ) of 4.2 or more,
(3) A correction value (Pu') of the ultimate strength (Pu) of 7.7 kN or more, and (4) A value of 7.7 kN or more, which is lower than the correction value (Pu') of the ultimate strength (Pu). Large yield strength (Py),
At least one of the physical properties consisting of the areal density or areal weight and the setting of the nail side resistance, and the head of the nail set to suppress the punching shear phenomenon or reduce punch-out fracture. A gypsum-based load-bearing surface material that is secured by setting a diameter, a body diameter, and an area ratio of the area of the head/the cross-sectional area of the body.
In the gypsum-based load-bearing surface material according to claim 25 or 26,
The gypsum-based load-bearing facing material is characterized in that the gypsum-based load-bearing facing material has a nail side resistance of 980N or less.
In the gypsum-based load-bearing surface material according to claim 25,
A gypsum-based load-bearing surface material, characterized in that the main material or the core material of the load-bearing surface material contains an inorganic fiber and/or an organic strength improving material.
In the gypsum-based load-bearing surface material according to claim 25 or 30,
A gypsum-based load-bearing surface material, characterized in that the main material or core material of the gypsum-based load-bearing surface material contains an organopolysiloxane compound.