Gypsum-based shearing panels, shear wall structures, and shear wall construction methods for wooden structures.

Abstract

The wall strength of a wooden structural shear wall can be increased without installing additional reinforcement or stiffening materials and without increasing the specific gravity and / or thickness of the gypsum-based surface material. [Solution] The gypsum-based shear face material for wooden structural shear walls is composed of a main or core material made of a plate-shaped gypsum hardened body blended with inorganic fiber and organic strength-improving materials to provide nail lateral resistance of 500 N or more, and a paper member covering at least the front and back surfaces of the main or core material. This shear face material has a nail lateral resistance of 6.5 to 8.9 kg / m 2 and in the in-plane shear test, -3 The ultimate displacement (δu2) is greater than rad, and the ultimate strength (corrected value) (Pu') is greater than 7.6 kN. The wooden shear wall using this shear face material has a load of 9.0 kg / m 2 The short-term standard shear strength (P0) is greater than that of a wooden structural shear wall using the same type of shear panel with an area density of 1000 or more.

Description

[Technical Field]

[0001] This invention relates to gypsum-based load-bearing panels for wooden structures, load-bearing wall structures, and load-bearing wall construction methods. to This relates to gypsum-based load-bearing panels, load-bearing wall structures, and load-bearing wall construction methods configured to increase the wall strength ratio without relying on increasing the maximum load-bearing capacity of the panel itself or on the placement of additional reinforcing or stiffening materials. [Background technology]

[0002] In Japan, several construction methods are known for building relatively small-scale structures such as residential buildings: the long-established timber frame construction method, the timber frame wall construction method which became popular after the 1970s, the steel frame construction method which became popular after the 1960s, and the steel house construction method which is becoming increasingly popular in recent years. The timber frame construction method is a method of constructing a timber frame structure by assembling timber with a rectangular cross-section as columns and beams, and is the most widespread traditional construction method in Japan. The timber frame wall construction method is also called the two-by-four method and is "a method of constructing walls and floor slabs by attaching structural plywood or similar materials to a frame made of wood" (Ministry of Land, Infrastructure, Transport and Tourism Notification No. 1540 and 1541 of 2002). The steel frame construction method is a method of constructing a steel frame structure by assembling steel materials that make up columns, beams, braces, etc. The steel house construction method is conceptually a structure in which the wooden frame members of the wooden frame wall construction method are replaced with lightweight steel sections, and is a steel frame wall construction method as defined in "Thin-Plate Lightweight Steel Section Construction" (Ministry of Land, Infrastructure, Transport and Tourism Notification No. 1641, 2001). In addition, other structural methods for small-scale buildings include reinforced concrete structures in the form of rigid frame structures or wall structures.

[0003] While a wide variety of structural types are known for small-scale buildings in Japan, the seismic performance of wooden structures will be described below as a technology related to the present invention.

[0004] Generally, construction methods for wooden structures are broadly classified into wooden post-and-beam construction and wooden frame wall construction. Due to the impact of recent large-scale earthquakes, research on the seismic resistance of wooden structures has attracted particular attention in Japan in recent years. In the practical application of architectural design in Japan, the frame length of structurally effective shear walls (the length of the wall in the building plan) is generally used as an indicator of the strength of wooden structures against short-term horizontal loads (seismic forces, wind pressure, etc.) (Patent Document 1: Japanese Patent Publication No. 2001-227086). A wall strength ratio corresponding to the structure of the shear wall is used to calculate the frame length. The wall strength ratio is an indicator of the seismic performance or strength performance of the shear wall, and the larger the value, the greater the seismic strength. When a specific number of shear walls should be adopted in the design, adopting a shear wall structure with a relatively high wall strength ratio can improve the overall seismic resistance of the building. In other words, in Japan, wooden structures require a certain amount of wall material under the Building Standards Act to achieve the necessary seismic resistance. The strength of a wooden structure against short-term horizontal loads is proportional to the wall strength multiplier of the load-bearing wall multiplier multiplied by the wall length. In normal building design, it is necessary to ensure a quantity of existing wall material (frame length of load-bearing wall × wall strength multiplier) greater than the required amount in both the beam direction and the girder direction. Generally, adopting a load-bearing wall structure with a relatively large wall strength multiplier reduces the number of load-bearing walls (number of installation locations) and improves the overall design freedom of the building. Conversely, adopting a load-bearing wall structure with a relatively small wall strength multiplier increases the number of load-bearing walls (number of installation locations) and decreases the overall design freedom of the building. Therefore, wall structures with a large wall strength multiplier are advantageous in improving the overall design freedom and seismic resistance of a building.

[0005] The wall strength ratios for general-purpose wooden load-bearing walls that have been used in Japan for many years are stipulated in Article 46 of the Building Standards Act Enforcement Order and Ministry of Construction Notification No. 1100 (June 1, 1981). On the other hand, for many load-bearing walls constructed in recent years that do not belong to such general-purpose wall structures, it is necessary to determine the wall strength ratio based on the certification of the Minister of Land, Infrastructure, Transport and Tourism as stipulated in Table 1 (viii) of Paragraph 4 of the same Article. For this reason, the wall strength ratios for many wooden load-bearing walls constructed in recent years must be set based on performance tests conducted by designated performance evaluation organizations, and the test methods for these performance tests are described in detail in the "Performance Test and Evaluation Procedures for Wooden Load-Bearing Walls and Their Strength Ratios" etc., published by each testing and inspection organization.

[0006] As described in numerous documents such as "Manual for Performance Testing and Evaluation of Shear Walls and Their Ratios in Wooden Structures," the performance test for determining the wall ratio of wooden shear walls is an in-plane shear test of the shear wall. In this test, a predetermined horizontal load is repeatedly applied to the shear wall specimen, and the relationship between the horizontal load (P) and the shear deformation angle (δ) is determined. The wall ratio is calculated by determining the short-term allowable shear strength (Pa) based on the horizontal load and shear deformation angle, as described in numerous technical documents such as "Allowable Stress Design for Wooden Frame Houses [1] (2017 Edition)," pages 63 and 300 (Non-Patent Literature 1), and dividing this by a predetermined strength (wall length L (m) × 1.96 (kN / m)) (shown as a formula in Figure 5). Therefore, the wall ratio is an indexed value obtained by dividing the short-term allowable shear strength (Pa) by this standard value (1.96L). Here, the short-term allowable shear strength (Pa), which is the basis for calculating the wall strength ratio, is, in principle, the value obtained by multiplying the smallest value among the following four indicators (values ​​obtained by multiplying each measured value obtained in the in-plane shear test by its respective variability coefficient) (i.e., the short-term standard shear strength (P0)) by a predetermined reduction coefficient (α) (a coefficient that evaluates the factors that reduce the strength). (1) Yield strength (Py) (2) The value of the ultimate yield strength (Pu) corrected based on the plasticity ratio (μ) (hereinafter referred to as "ultimate yield strength (corrected value) (Pu')"). (3) A value that is 2 / 3 of the maximum load-bearing capacity (Pmax) (4) Yield strength when shear deformation angle = 1 / 120 rad (in the case of no load or load)

[0007] On the other hand, "structural gypsum board" is known as a gypsum-based sheathing material that can be suitably used as a load-bearing sheathing material for wooden structural shear walls. "Structural gypsum board" is a gypsum board in which the nail lateral resistance of "reinforced gypsum board" has been strengthened, based on the applicant's technology described in Patent Publication No. 5642948 (Patent Document 3). Nail lateral resistance is the shear strength or shear yield of the nailed portion of the sheathing material measured by the measurement method specified in JIS A 6901. Figure 6 is a perspective view illustrating the outline of the nail lateral resistance test. The nail lateral resistance test used to determine the nail lateral resistance is specified in JIS A As specified in 6901, a 150 mm x 75 mm test specimen 100 is taken from the surface material under test, and a through hole 102 with a diameter of 2.6 mm is drilled at a position on the center line of the test specimen 100, 12 mm in the longitudinal direction from the edge 103 of one longitudinal end (upper end) of the test specimen 100, and a steel round bar 101 (2.6 mm in diameter, approximately 40 mm in length) is inserted through this through hole 102. This test involves holding the structural plane (center plane) of the test piece 100 in a generally vertical position, holding the round bar 101 in a horizontal position, fixing the other end (lower end) of the test piece in the longitudinal direction, applying a load FV to the round bar 101 to raise it at a speed of approximately 6 mm / min, and causing the test piece 100 to break due to the local load acting from the round bar 101 to the through hole 102 of the test piece 100 as the round bar 101 is displaced upward. The value of the nail lateral resistance is the strength (load) at which the test piece 100 breaks. Although similar tests concerning nail lateral resistance are also specified in ASTM, in this application, the invention is specified based on the value of the nail lateral resistance obtained by the test method of the nail lateral resistance test specified in JIS A 6901.

[0008] Structural gypsum board is currently defined in JIS A 6901 as a gypsum-based sheathing material having a nail lateral resistance of 750N or more (Type A) or 500N or more (Type B). Generally, structural gypsum board requires a thickness of 12.5 mm or more and a specific gravity of 0.75 or more. Therefore, a load-bearing wooden wall with structural gypsum board fixed to it must have a specific gravity of at least approximately 9.4 kg / m 2The surface density or surface weight (mass of load-bearing sheathing per unit area of ​​wall surface) is required. A wooden load-bearing wall using structural gypsum board as load-bearing sheathing exhibits a relatively higher wall strength ratio compared to a wooden load-bearing wall using (ordinary) gypsum board or reinforced gypsum board as load-bearing sheathing.

[0009] Generally, the short-term standard shear strength (P0) of structural gypsum board is determined by the yield strength (Py) among the four indicators mentioned above. As previously stated, the wall strength ratio is the value obtained by multiplying the short-term standard shear strength (P0) by the reduction factor (α) and dividing by the predetermined strength; therefore, the wall strength ratio of structural gypsum board is proportional to the yield strength (Py).

[0010] Structural gypsum board is a load-bearing panel limited to installation on interior walls, and its use as a load-bearing panel on the exterior walls of wooden exterior walls is not permitted. In contrast, Patent Publication No. 6412431 (Patent Document 2) discloses a gypsum board developed by the applicant as a gypsum-based load-bearing panel that can be installed on the exterior walls of wooden exterior walls, and which contains an organopolysiloxane compound as a load-bearing deterioration inhibitor in the gypsum core portion. A gypsum board developed by combining the technology described in Patent Document 2 with the technology described in Patent Publication No. 5642948 (Patent Document 3), which increases the shear strength or shear resistance of the nailed portion of the panel, has already been put into practical use in Japan under the product name "Tiger EX Board" (registered trademark, product of Yoshino Gypsum Co., Ltd.). This gypsum board (hereinafter referred to as "EX board") has dimensions and weight of 9.5 mm in thickness, 910 mm in width, 3030 mm in height, and approximately 26 kg in weight. EX board requires a specific gravity of approximately 1.0 to obtain the desired maximum load (maximum load-bearing capacity (Pmax)) in an in-plane shear test. Therefore, a wooden load-bearing wall to which EX board is fixed also requires a specific gravity of at least approximately 9.4 kg / m 2 The surface density or surface weight is required.

[0011] The short-term reference shear strength (P0) of the EX board is specified by the ultimate strength (corrected value) (Pu') among the above four indicators. This is due to the fact that as the value of the yield strength (Py) increased, the value of the ultimate strength (corrected value) (Pu') became the indicator showing the smallest value among the above four indicators.

[0012] Specifically, the ultimate strength (corrected value) (Pu') is a value obtained from the following formula based on the ultimate strength (Pu) measured by an in-plane shear test and the plastic strain rate (μ), and the short-term reference shear strength (P0) is a value obtained from the following formula based on the ultimate strength (corrected value) (Pu') and the coefficient of variation (β) of the measured values. Pu' = Pu × 0.2 × (2μ - 1) 1 / 2 P0 = β × Pu'

[0013] Therefore, the increase in the ultimate strength (Pu) is beneficial for increasing the wall magnification of the strength wall. However, the ultimate strength (Pu) generally has the property of increasing as the value of the maximum load (Pmax) that the surface material can withstand in the in-plane shear test, that is, the maximum strength, increases. For this reason, according to the findings and technical recognition of the present inventors, past research and development to increase the short-term reference shear strength (P0) of the gypsum-based strength surface material mainly aimed to increase the value of the maximum load (Pmax) measured in the in-plane shear test and indirectly increase the ultimate strength (Pu) accordingly, and did not intend to increase the ultimate strength (Pu) in relation to the ultimate displacement (δu) and the plastic strain rate (μ).

[0014] In addition, in this specification, for gypsum-based surface materials not specified in JIS A 6901 (gypsum board products), regardless of whether it is a gypsum-based surface material in which the gypsum core part (core material part) mainly made of gypsum is exposed on the outer surface or outer layer, or a gypsum-based surface material in which the outer surface or outer layer of the gypsum core part is covered with the base paper for gypsum board, it is referred to as "gypsum board" in this specification.

[0015] In the above-described performance test for determining the wall magnification of the wooden structural shear wall, the EX board exhibits a maximum load-bearing capacity that can withstand a relatively high maximum load. However, after obtaining the maximum load (maximum load-bearing capacity) at a specific shear deformation angle, when the shear deformation angle is slightly increased, punching out, edge breakage, cracking, etc. of the facing material occur, and the load rapidly decreases or there is a tendency to shear failure prematurely (for example, the comparative examples shown in FIGS. 4(A) and 5). As a result, in the above EX board, there has been a problem that the ultimate load-bearing capacity (corrected value) (Pu') is significantly reduced and the wall magnification is decreased. To solve such problems, as a countermeasure to increase the ultimate load-bearing capacity (corrected value) (Pu') and improve the wall magnification, a facing material reinforcement method is known in which a reinforcing material or a stiffening material such as a metal plate is disposed at the nailing portion to prevent destruction or breakage of the nailing portion (International Publication WO2019 / 203148A1 (Patent Document 4)). According to the wooden structural shear wall using such a reinforcing material or a stiffening material, it is considered possible to construct a wooden structural shear wall that improves the toughness and deformation followability of the load-bearing facing material and increases the above-described ultimate load-bearing capacity (corrected value) (Pu') without depending on an increase in the maximum load that the facing material can withstand in the above performance test, and exhibits a relatively high wall magnification.

Prior Art Documents

Patent Documents

[0016]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Non-Patent Documents

[0017]

Non-Patent Document 1

Summary of the Invention

[0018] However, according to the shear wall structure (Patent Document 4) which uses the above-mentioned reinforcing or stiffening material to increase the ultimate load-bearing capacity (corrected value) (Pu'), a step of additionally attaching the reinforcing or stiffening material to the surface of the shear wall material must be added to the material manufacturing process, or such a step must be additionally performed during the construction of the wooden shear wall. This type of step can complicate the manufacturing process of gypsum-based shear walls or worsen the workability of construction work.

[0019] In contrast, to improve the wall strength ratio of a wooden structural shear wall using gypsum-based sheathing without relying on such reinforcing or stiffening materials, it is considered necessary to increase the specific gravity and / or thickness of the gypsum-based sheathing to increase its maximum load-bearing capacity. However, as mentioned above, the EX board has a weight of approximately 26 kg in its standard dimensions (width approximately 910 mm, height approximately 3030 mm). Therefore, considering the actual work involved in construction workers manually fixing the sheathing sheathing to the wall substrate of a wooden structural shear wall, further increasing the specific gravity and / or thickness of the EX board or structural gypsum board is practically extremely difficult from the standpoint of constructability of wooden structural shear walls.

[0020] The present invention has been made in view of these problems, and its objective is to provide a gypsum-based load-bearing panel for wooden structural load-bearing walls that can increase the wall strength without additionally attaching reinforcing or stiffening materials, and without increasing the specific gravity and / or thickness of the gypsum-based panel.

[0021] The present invention also aims to provide a load-bearing wall structure and a load-bearing wall construction method for wooden structures using such gypsum-based facing materials as load-bearing facing materials.

[0022] The present invention further aims to provide a method for increasing the wall strength ratio of a wooden structural load-bearing wall, which can increase the wall strength ratio without relying on the reinforcement or stiffening effect of reinforcing or stiffening materials additionally provided to the gypsum-based facing material, and without relying on an increase in the specific gravity and / or thickness of the gypsum-based facing material. [Means for solving the problem]

[0023] To achieve the above objective, the present invention provides a gypsum-based load-bearing panel for wooden structural walls that is fastened to the wooden structural wall substrate of a wooden frame construction method or a wooden frame wall construction method by fasteners, The load-bearing sheathing material consists of a main material or core material made of a plate-shaped gypsum hardened body compounded with inorganic fibers and organic strength-enhancing materials, and a paper member covering at least the front and back surfaces of the main material or core material. It has a nail side resistance of 500 N or more, and the thickness of the sheathing material is set to a value of 10 mm or less, and the specific gravity of the sheathing material is set to a value of 0.96 or less. The surface density or surface weight, specified as the mass per unit area of ​​the wall surface, is 6.5 to 8.9 kg / m². 2 The surface density or surface weight is reduced to within the range. The ultimate displacement (δu2) of a shear wall, measured by an in-plane shear test using a shear wall specimen with a wall length of 1.82m, is 20 × 10⁻¹⁰. -3 This creates an ultimate displacement (δu2) greater than rad in the shear wall, A gypsum-based shear wall material characterized in that a correction value (Pu') greater than 7.6 kN is generated in the shear wall as a correction value (Pu') of the ultimate strength (Pu) determined based on the ultimate strength (Pu) and plasticity ratio (μ) of the shear wall measured by the in-plane shear test (Claim) 10 ) provides. In addition As stated above, in this application, the invention is defined based on the value of the nail lateral resistance obtained by the nail lateral resistance test method specified in JIS A 6901. Accordingly, in the above description relating to the present invention, the following description relating to the present invention, and the claims of this application, the value of "nail lateral resistance" is the value of "nail lateral resistance" measured by the "nail lateral resistance test" specified in JIS A 6901.

[0024] According to the gypsum-based load-bearing panel of the present invention, plaster While ensuring the minimum physical properties required for a load-bearing sheathing material (nail lateral resistance: 500N or more), the surface density of the sheathing material is actually reduced, resulting in a relatively low value (6.5~8.9 kg / m²). 2 ) is set to ). In the following description of this specification, "minimum physical properties" means a nail side resistance of 500N or more.

[0025] The above surface density values ​​(6.5~8.9 kg / m²) 2 ) is the surface density of structural gypsum board and EX board (approximately 9.4 kg / m²). 2This is smaller than the specified density, and therefore contradicts conventional methods for increasing the short-term standard shear strength (P0) (i.e., conventional methods that increase the maximum strength (maximum load (Pmax)) by increasing the specific gravity and / or plate thickness, thereby increasing the short-term standard shear strength (P0)). Under the conventional concept of increasing wall strength, this configuration was assumed to result in a decrease in wall strength. However, experiments by the inventors revealed that by reducing the surface density while ensuring the minimum physical properties of a gypsum-based shearing panel (nail lateral resistance: 500N or more), the ductility and deformation-following ability that the gypsum-based shearing panel potentially possesses become apparent, resulting in an increase in ultimate displacement (δu) and plasticity ratio (μ). This increases the ultimate strength (corrected value) (Pu'), and thus the short-term standard shear strength (P0) can be increased without necessarily increasing the maximum strength (maximum load (Pmax)). As mentioned above, the value of the short-term standard shear strength (P0) is proportional to the value of the wall strength ratio. Therefore, an increase in the ultimate displacement (δu) and plasticity ratio (μ), which result in an increase in the short-term standard shear strength (P0), is an effective factor in increasing the wall strength ratio. Thus, according to the gypsum-based shearing panel of the present invention, while ensuring the minimum physical properties of a gypsum-based shearing panel, the toughness and deformation-following ability of the gypsum-based panel are improved to increase the ultimate strength (corrected value) (Pu'), thereby increasing the wall strength ratio without adding reinforcing or stiffening materials, and without increasing the specific gravity and / or thickness of the gypsum-based shearing panel. Furthermore, since the above-mentioned shearing panel, like structural gypsum board and EX board, has at least the front and back surfaces of the main material or core material covered with a paper material, it can be easily manufactured on a conventional gypsum board manufacturing line. Furthermore, "front and back surfaces" refers to the front and back surfaces of the facing material, excluding the end faces or sides of the edges and side edges (i.e., the outer edges on all four sides) of the facing material.

[0026] Preferably, the thickness of the gypsum-based load-bearing panel is A value of 10mm or less and 8.5mm or more. For example, it is set to 9.5 mm or 9.0 mm. Gypsum-based load-bearing panels of this thickness are even more advantageous than structural gypsum boards that require a thickness of 12 mm or more, in that they can significantly reduce the wall thickness of load-bearing walls in wooden structures.Optionally, the hardened gypsum body has a nail side resistance of 980 N or less. do. Preferably, the above As the inorganic fiber, glass fiber or carbon fiber is blended into the gypsum hardened body, and as the organic strength improver, starch is blended into the gypsum hardened body. Preferably, the measured value (Py) of the yield strength measured by the in-plane shear test is a value greater than 7.6 kN, or the paper member is the base paper for gypsum board, or the measured value (Py) of the yield strength is a value greater than 7.6 kN and the paper member is the base paper for gypsum board.

[0027] Preferably, the specific gravity of the gypsum-based strength facing material is set to 0.96 or less (0.65 or more), preferably 0.9 or less (more preferably 0.8 or less). According to the gypsum-based strength facing material having such a specific gravity, compared with the EX board having a specific gravity of 1.0 or more, the facing material can be lightened, so that the weight of the wooden structural shear wall can be reduced, or the workability of the wooden structural shear wall or the construction work thereof is improved. It is advantageous in improving the workability and the like.

[0028] In a preferred embodiment of the present invention, the core material (gypsum core portion) of the gypsum-based strength facing material contains an organopolysiloxane compound as a strength deterioration preventing agent for preventing strength deterioration. According to such a strength facing material, it is possible to provide the strength facing material that can be constructed on the outer wall surface of the wooden exterior wall, similar to the EX board.

[0029] The present invention also has a structural shear wall for a wooden structure (claim 1 ) having a structure in which the above-mentioned gypsum-based strength facing material is attached to the wooden structure wall base of the wooden frame construction method or the wooden frame wall construction method by fasteners such as nails and screw bis. According to such a wooden structural shear wall, the toughness and deformation followability of the gypsum-based facing material are improved to increase the short-term standard shear strength (P0), and the specific gravity and / or plate thickness of the gypsum-based strength facing material are reduced, thereby reducing the self-weight of the shear wall or reducing the wall thickness. It becomes possible. The ultimate displacement (δu) obtained by the in-plane shear test of such a shear wall structure is at least 20 × 10 [[ID=I8]] -3 rad is greater than the value, preferably 22 × 10 -3The value is greater than or equal to rad, and this provides the ductility and deformation-following ability required for such displacements. Furthermore, according to the "Manual for Performance Testing and Evaluation of Shear Walls and Their Magnification in Wooden Structures," if the load does not decrease even when exceeding 1 / 15 rad in an in-plane shear test, and the ultimate displacement value cannot be obtained, the ultimate displacement (δu) is set to 1 / 15 rad. Therefore, the maximum value of the ultimate displacement (δu) is 1 / 15 rad (66.7 × 10⁻¹⁰ rad). -3 It is rad.

[0030] The present invention further provides a method for constructing a wooden structural load-bearing wall, characterized in that the above-mentioned gypsum-based load-bearing surface material is fastened to the wooden structural wall substrate of a wooden frame construction method or a wooden frame wall construction method using the above-mentioned fasteners (Claim) 4 This construction method for load-bearing walls improves the toughness and deformation-following properties of the gypsum-based shearing material, thereby increasing the short-term standard shear strength (P0), and also reduces the specific gravity and / or thickness of the gypsum-based shearing material. This makes it possible to lighten the load-bearing wall, improve the constructability of the load-bearing wall, or reduce the wall thickness. In an in-plane shear test of a load-bearing wall structure constructed by this method, the load-bearing wall has a load of at least 20 × 10 -3 A final displacement (δu) greater than the value of rad, preferably 22 × 10 -3 The ultimate displacement (δu) is greater than or equal to rad, and therefore, the shear wall possesses ductility and deformation-following ability corresponding to such an ultimate displacement (δu).

[0031] From another perspective, the present invention relates to a method for increasing the wall strength of a wooden structural load-bearing wall constructed by fastening a gypsum-based load-bearing panel to a wooden structural wall substrate of a wooden frame construction method or a wooden frame wall construction method using fasteners, It consists of a main material or core material made of plate-shaped gypsum hardened material blended with inorganic fibers and organic strength-enhancing materials, and a paper member covering at least the front and back surfaces of the main material or core material, has a nail side resistance of 500N or more, has a plate thickness of 10 mm or less, has a specific gravity of 0.96 or less, and has a surface density or surface weight specified as the mass per unit area of ​​the wall surface of 6.5 to 8.9 kg / m 2A gypsum-based load-bearing sheathing material, whose surface density or surface weight has been reduced to within a certain range, is fastened to the wooden wall substrate using fasteners. The ultimate displacement (δu2) of a load-bearing wall, measured by an in-plane shear test using a test specimen with a wall length of 1.82 m, is 20 × 10⁻¹⁰. -3 A method for increasing wall strength (Claim) characterized by ensuring an ultimate displacement (δu2) greater than rad, and ensuring a correction value (Pu') greater than 7.6kN for the ultimate strength (Pu) determined based on the ultimate strength (Pu) and plasticity ratio (μ) of the shear wall measured by the in-plane shear test (Claim) 7 ) provides do .

[0032] Preferably, the thickness of the gypsum-based load-bearing panel is A value of 10mm or less and 8.5mm or more. For example, set to 9.5 mm or 9.0 mm, and the specific gravity of the gypsum-based surface material is 0.96 or less. (Preferably a value of 0.8 or less) and 0.65 or more The above The value is set. More preferably, the measured yield strength (Py) measured by the in-plane shear test is greater than 7.6 kN, or the paper member is gypsum board base paper, or the measured yield strength (Py) is greater than 7.6 kN and the paper member is gypsum board base paper. [Effects of the Invention]

[0033] The gypsum-based load-bearing panel of the present invention improves the toughness and deformation-following properties of the gypsum-based panel by reducing the surface density, thereby increasing the ultimate load-bearing capacity (corrected value) (Pu') and the short-term standard shear strength (P0). This allows for an increase in wall strength without the need to add reinforcing or stiffening materials, and without increasing the specific gravity and / or thickness of the gypsum-based panel. Furthermore, since at least the front and back surfaces of the main material or core material of the gypsum-based load-bearing panel of the present invention are covered with a paper material, it can be easily manufactured using a conventional gypsum board manufacturing line.

[0034] Furthermore, according to the load-bearing wall structure for wooden structures of the present invention, the wall strength ratio can be increased, and the self-weight of the load-bearing wall can be reduced or the wall thickness can be reduced by reducing the specific gravity and / or thickness of the gypsum-based load-bearing surface material.

[0035] Furthermore, according to the shear wall construction method for wooden structures of the present invention, not only is the wall strength ratio increased, but the self-weight of the shear wall material is reduced by lowering the specific gravity and / or thickness of the gypsum-based shear wall material, thereby improving the constructability of the shear wall.

[0036] Furthermore, according to the method for increasing wall strength according to the present invention, while ensuring the minimum physical properties of a gypsum-based load-bearing panel (nail side resistance = 500N or more), the surface density is reduced, thereby ensuring a certain level of maximum load-bearing capacity (maximum load) while improving the toughness and deformation-following ability of the gypsum-based panel. As a result, the ultimate load-bearing capacity (corrected value) (Pu') can be increased. Therefore, the wall strength can be increased without relying on reinforcement or stiffening by additional reinforcing or stiffening materials provided to the gypsum-based panel, and without relying on an increase in the specific gravity and / or thickness of the gypsum-based panel. [Brief explanation of the drawing]

[0037] [Figure 1] Figure 1 is a schematic front view showing the configuration of load-bearing walls in a wooden structure. [Figure 2] Figure 2 shows a front view, cross view, and side view of the configuration of the shear wall test specimen used in the in-plane shear test for the shear wall structure shown in Figure 1. [Figure 3] Figure 3 is a diagram showing the physical properties and composition of gypsum boards according to the examples and comparative examples of the present invention. [Figure 4] Figure 4 is a diagram showing the load-deformation angle curve obtained by an in-plane shear test. Figure 4(A) shows the in-plane shear test results for a gypsum board according to a comparative example, and Figure 4(B) shows the in-plane shear test results for a gypsum board according to an embodiment of the present invention. [Figure 5] Figure 5 is a diagram showing the envelope created based on the load-deformation angle curve shown in Figure 4. [Figure 6]This is a perspective view showing an overview of the nail side resistance test specified in JIS A 6901. [Modes for carrying out the invention]

[0038] The configuration of a load-bearing wall according to a preferred embodiment of the present invention will be described in detail below with reference to the attached drawings.

[0039] Figure 1 is a schematic front view showing the configuration of load-bearing walls in a wooden structure.

[0040] The load-bearing wall 1 shown in Figure 1 is a wooden frame load-bearing wall constructed by fixing load-bearing panels 10 to a wooden frame on a reinforced concrete (RC) strip foundation F. The load-bearing panels 10 have dimensions of 9.5 mm in thickness, 910 mm in width, and approximately 2800 to 3030 mm in height (for example, 2900 mm), and weigh 6.5 to 8.9 kg / m 2 Surface density within the range (for example, surface density of 7.1 kg / m³) 2 ) has. Surface density (also called surface weight) is the mass (weight) per unit area of ​​the wall surface when viewed from the front. The load-bearing surface material 10 is a gypsum-based surface material composed of a flat gypsum core (gypsum core material) mixed with a predetermined amount of inorganic fibers (glass fibers) and organic strength-enhancing material (starch), and a gypsum board base paper (paper member) that covers both sides of the gypsum core.

[0041] The load-bearing wall 1 has a base 2 fixed to the upper surface of the strip foundation F by anchor bolts B. The load-bearing wall 1 is generally composed of this base 2, columns 3, intermediate columns 4, and joint columns 4' arranged vertically on the base 2 at predetermined intervals, horizontal members (beams, girders, eaves girders, gable girders) 5 supported at the upper end (or middle part) of the columns 3, and the load-bearing panel 10. The base 2, columns 3, intermediate columns 4, joint columns 4', and beams 5 that constitute the frame are timber (square timbers) with member cross-sections used in ordinary wooden buildings.

[0042] The load-bearing panel 10 is fixed to the base 2, column 3, intermediate column 4, joint column 4', and horizontal member 5 by nails 20. The nails 20 are, for example, galvanized iron round nails (NZ nails: JIS A 5508). In this example, for example, NZ50 nails (length 50 mm, head diameter approximately 6.6 mm, shaft diameter approximately 2.75 mm) are used as nails 20. The nails 20 are arranged at intervals S1 in the outer periphery of the load-bearing panel 10 and at intervals S2 in the central band of the load-bearing panel 10 that extends vertically. Preferably, the interval S1 is set to a dimension in the range of 50 mm to 200 mm (for example, 75 mm), and the interval S2 is set to a dimension in the range of 50 mm to 300 mm (for example, 150 mm).

[0043] The gypsum core (core material) of the load-bearing panel 10 contains a predetermined amount of inorganic fibers and an organic strength-enhancing agent, and has a nail lateral resistance of 500 N or more. The amount of inorganic fibers 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 inorganic fibers to be blended include glass fibers and carbon fibers. When glass fibers are used, glass fibers with a diameter of 5 to 25 μm and a length of 2 to 25 mm can be suitably used. The amount of organic strength-enhancing agent to be blended 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-enhancing agents to be blended include starch, polyvinyl acetate, polyvinyl alcohol, and polyacrylic. Both unprocessed starch and processed starch can be used as starch. Examples of processed starch include starch that has undergone physical treatment, chemical treatment, or enzymatic treatment. As a physically treated starch, pregelatinized starch can be suitably used. As a chemically treated starch, oxidized starch, phosphate-esterified starch, urea-phosphate-esterified starch, hydroxyethylated starch, hydroxypropylated starch, and acetylated starch can be suitably used.

[0044] The composition and structure of the load-bearing panel 10 are similar to those of "structural gypsum board" specified in JIS A 6901. However, the surface density of the load-bearing panel 10 is 6.5 to 8.9 kg / m³. 2 A value within the range (for example, 7.1 kg / m³)2 Therefore, the load-bearing panel 10 is 9.4 kg / m² as described above. 2 This is fundamentally different from the "structural gypsum board" specified in JIS A 6901, which requires a surface density of 9.4 kg / m². Furthermore, while "reinforced gypsum board" as defined in JIS A 6901 is known, "reinforced gypsum board" also has a surface density of 9.4 kg / m². 2 Because it requires the surface density described above, the load-bearing panel 10 is fundamentally different from "reinforced gypsum board." Furthermore, the load-bearing panel 10 differs from other "gypsum boards" in that it has a main material or core material that is compounded with inorganic fibers and organic strength-enhancing materials to exhibit nail lateral resistance of 500 N or more. In other words, the load-bearing panel 10 does not fall under any of the "gypsum boards" specified in the current JIS A 6901. In this specification, the load-bearing panel 10 will be identified or expressed as "gypsum-based panel" or "gypsum board" in this sense.

[0045] Generally, gypsum-based facing materials (including "gypsum board") are manufactured using general-purpose gypsum board manufacturing equipment. This equipment includes a mixer that prepares a gypsum slurry by mixing raw materials such as calcined gypsum, adhesive aids, hardening accelerators, and foam (or foaming agents) with the water required to slurry the calcined gypsum, as described in, for example, International Publication WO2019 / 058936. The gypsum slurry is spread onto the gypsum board base paper (bottom paper) on the conveyor belt of the gypsum board manufacturing equipment, and the gypsum board base paper (top paper) is then laminated on top of the gypsum slurry. The resulting strip-shaped, three-layer continuous laminate is then processed by various devices constituting the gypsum board manufacturing equipment, such as a rough cutting device, a forced drying device, and a cutting device, to form a gypsum product of predetermined dimensions, i.e., a gypsum-based facing material in which both sides of a hardened gypsum slurry (i.e., a gypsum core) are covered with gypsum board base paper. The specific gravity of gypsum-based surface materials is primarily adjusted by the amount of foam incorporated into the gypsum slurry.

[0046] With regard to load-bearing walls in wooden structures using structural gypsum board, reinforced gypsum board, and (ordinary) gypsum board as load-bearing panels as specified in JIS A 6901, the wall strength ratios for load-bearing panels in large-wall construction of wooden frame structures as specified in the aforementioned Ministry of Construction Notification No. 1100 are as follows: Structural gypsum board (Type A) 1.7 Structural gypsum board (Type B) 1.2 Reinforced gypsum board 0.9 (Standard) Gypsum board 0.9

[0047] Furthermore, the wall strength ratios for framed wall construction load-bearing walls (load-bearing walls with vertical frame spacing exceeding 50 cm) as stipulated in the aforementioned Ministry of Land, Infrastructure, Transport and Tourism Notification No. 1541 are as follows: Structural gypsum board (Type A) 1.7 Structural gypsum board (Type B) 1.5 Reinforced gypsum board 1.3 (Standard) Gypsum board 1.0

[0048] As described above, the wall strength ratio values ​​stipulated in the notifications 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, when using new materials or adopting a different wall strength ratio, it is necessary to conduct the aforementioned performance tests to determine the wall strength ratio values.

[0049] As mentioned above, the structural gypsum board and reinforced gypsum board specified in JIS A 6901 have a surface density of 9.4 kg / m². 2 The material must have the above properties and a specific gravity of 0.75 or higher. This is considered an important condition for increasing the maximum load that the panel can withstand and ensuring high short-term allowable shear strength (and therefore high wall strength) of wooden structural shear walls. In particular, for structural gypsum boards that are required to exhibit higher nail lateral resistance than reinforced gypsum boards, it has been thought that such surface density and specific gravity cannot be reduced. That is, surface density of 9.4 kg / m³ 2As described above, ensuring a specific gravity of 0.75 or higher was considered an essential condition for further increasing the wall strength ratio of the shear wall specimens (wooden shear walls) obtained in the aforementioned in-plane shear test. However, recent experiments by the inventors have shown that in gypsum-based panel materials given properties (nail lateral resistance) comparable to structural gypsum board by adding inorganic fibers or organic strength-enhancing materials, reducing the thickness of the panel or adjusting the amount of foam to reduce the specific gravity of the gypsum core, thereby reducing the surface density, allows the inherent toughness or deformation-following ability of the panel material itself to become apparent. As a result, the ultimate strength of the panel material can be effectively utilized and the plasticity ratio of the panel material can be increased, thus further improving the short-term allowable shear strength of wooden shear walls. The inventors conceived the present invention based on the findings obtained from such experiments. The experiments (in-plane shear tests) conducted by the inventors will be described in detail below.

[0050] Figure 2 is a front view showing the configuration of the shear wall test specimen used in the in-plane shear test for the shear wall structure shown in Figure 1. Cross-sectional view and side view Figures 3 to 5 are diagrams and charts showing the test results of the in-plane shear test. In Figure 2, the same reference numerals are used for components or members of the shear wall test specimen that correspond to or are equivalent to the components or members shown in Figure 1.

[0051] The inventors, in accordance with the specifications for the test specimen described in the "Manual for Performance Testing and Evaluation of Wooden Shear Walls and Their Magnification Factors," fabricated a shear wall test specimen (hereinafter simply referred to as "test specimen") with a wall width of 1820 mm and a height of 2730 mm, having the shear wall structure shown in Figure 2, as a test specimen of the shear wall structure shown in Figure 1, and conducted an in-plane shear test using a load-free testing device.

[0052] The test specimen shown in Figure 2 has a main structural component of a wooden frame consisting of a base 2 and columns 3 made of cedar lumber with a cross section of 105 × 105 mm, and horizontal members 5 made of Douglas fir lumber with a cross section of 180 × 105 mm supported by the columns 3. In the center between the columns 3, a joint column 4' made of cedar lumber with a cross section of 45 × 105 mm is erected, and between the columns 3 and the joint column 4', a stud 4 made of cedar lumber with a cross section of 27 × 105 mm is erected. A girder brace 5' made of cedar or Douglas fir lumber is installed between the columns 3 and the stud 4, and also between the stud 4 and the joint column 4'. As a test jig, a tensioning device 40 is placed at the joint between the base 2 and the columns 3, and at the joint between the horizontal member 5 and the columns 3. The base 2, column 3, joint column 4', intermediate column 4, horizontal member 5, and girder 5' constitute the axial members of the shear wall structure, and these members (axial members) form a rectangular frame.

[0053] In the test specimen shown in Figure 2, the vertical separation distance h1 between the base 2 and beam 3, the height h2 of the bracing 5', and the relative height h3 of beam 3 with respect to the bracing 5' were set to h1=2625mm, h2=1790mm, and h3=835mm, respectively. The spacing w1 between column 3 and joint column 4' (column center spacing) was set to w1=910mm, and the wall length L was set to 1.82m. The facing material 10 was divided vertically by the bracing 5', with the lower facing material 10a having dimensions of width 910mm and height 1820mm, and the upper facing material 10b having dimensions of width 910mm and height 865mm. The overlap dimensions h4 and h5 of facing materials 10a and 10b were set to 30mm.

[0054] In the test specimen shown in Figure 2, the nails 20 for fastening the facing materials 10a and 10b to the base 2, column 3, joint column 4', horizontal member 5, and girder 5' were arranged at equal intervals (interval S1 = 75 mm) around the entire circumference of the edge band of the facing materials 10a and 10b. The nails 20 for fastening the facing materials 10a and 10b to the intermediate column 4 were arranged at equal intervals (interval S2 = 150 mm) in the vertical central band of the facing materials 10a and 10b. NZ50 nails (length 50 mm, head diameter approximately 6.6 mm, shaft diameter approximately 2.75 mm) were used as the nails 20.

[0055] The inventors prepared gypsum boards according to Examples 1 to 5 and the Comparative Example shown in the diagram in Figure 3 as test specimens and conducted in-plane shear tests using a load-free testing apparatus. As described above, the gypsum boards of Examples 1 to 5 are gypsum-based surface materials consisting of a flat gypsum core (gypsum core material) mixed with a predetermined amount of inorganic fibers (glass fibers) and an organic strength enhancer (starch), and a gypsum board base paper (paper member) covering both sides of the gypsum core. The surface material of the Comparative Example is a gypsum board equivalent to the EX board (thickness 9.5 mm) described above, and is a gypsum-based surface material consisting of a flat gypsum core (gypsum core material) mixed with the same or smaller amounts of inorganic fibers (glass fibers) and organic strength enhancer (starch) as the gypsum boards of Examples 1 to 5, and a gypsum board base paper (paper member) covering both sides of the gypsum core. As shown in Figure 3, the gypsum boards of Examples 1-5 had a weight of 7.3-8.7 kg / m². 2 The surface density is within the range, and the comparative example gypsum board has a density of 9.8 kg / m². 2 It has a surface density.

[0056] The ultimate displacement δu2 of the gypsum boards in Examples 1-5, obtained by in-plane shear testing, was 26.8 × 10⁻⁶. -3 rad~36.0×10 -3 The ultimate displacement δu1 of the comparative gypsum board obtained by in-plane shear testing was 20.0 × 10⁻⁶ rad, and the ultimate displacement δu1 of the comparative gypsum board obtained by in-plane shear testing was 20.0 × 10⁻⁶. -3The value was rad. As shown in Figure 3, in the gypsum boards of Examples 1 to 5 and the Comparative Example, the yield strength Py was greater than the ultimate strength (corrected value) Pu', so the short-term standard shear strength P0 and wall strength ratio were determined by the ultimate strength (corrected value) Pu'. In the case of the gypsum boards of Examples 1 to 5, the value of the ultimate strength (corrected value) Pu' was larger than that of the gypsum board of the Comparative Example, and moreover, the difference between the yield strength Py and the ultimate strength (corrected value) Pu' was less than 2.0 kN (1.6 or less), and a tendency was observed for the difference between the yield strength Py and the ultimate strength (corrected value) Pu' to appear relatively small. In other words, as far as the test results shown in Figure 3 are concerned, in all of the Comparative Example and Examples 1 to 5, the ultimate strength (corrected value) Pu' is relatively smaller than the yield strength Py. However, in Examples 1 to 5, the difference between the yield strength Py and the ultimate strength (corrected value) Pu' decreases, and there is a tendency for the two to become numerically equal. The strength (load) and displacement (shear deformation angle) of each gypsum board in Examples 1 to 5 obtained by in-plane shear tests have substantially the same trend or characteristics, so the ultimate displacement (33.1 × 10) is generally intermediate. -3 Based on the test results of the gypsum board of Example 1, which showed a rad (radian), the properties of the gypsum board of the present invention are described below.

[0057] Figure 4 is a diagram showing the load-deformation angle curves obtained by in-plane shear tests. Figure 4(A) shows the in-plane shear test results for a gypsum board relating to a comparative example, and Figure 4(B) shows the in-plane shear test results for a gypsum board of Example 1. Figure 5 is a diagram showing the envelope created based on the load-deformation angle curves shown in Figure 4. The envelope is a characteristic curve of load (yield strength) and displacement (shear deformation angle) based on the load-deformation angle curve of the side that ultimately failed.

[0058] As shown in Figure 4(A), the comparative example gypsum board has a deformation angle of approximately 20 × 10 -3At rad, the maximum load (maximum yield strength) Pmax was reached, but subsequent horizontal loading acting immediately afterward substantially caused failure, resulting in a rapid decrease in the load (yield strength) of the gypsum-based panel to a value below 0.8Pmax. In Figure 4(A), the load level at the maximum load Pmax is shown by a dashed line, and the load level in the 0.8Pmax load reduction region is shown by a double-dash line. In Figure 4(A), the load-deformation angle curve during repeated loading immediately after the maximum load Pmax is shown below the 0.8Pmax load level indicated by the double-dash line. This curve is identified by the load difference ΔP from the 0.8Pmax load level.

[0059] As shown in Figures 4(A) and 5, in the case of the comparative example gypsum board, the deformation angle when the maximum load Pmax is applied is approximately 20 × 10 -3 Since failure occurs abruptly at rad, the ultimate displacement δu1 substantially coincides with the deformation angle at the maximum load Pmax. For this reason, it is not possible to increase the short-term allowable shear strength of the gypsum board by relying on the toughness or deformation-following ability of the gypsum board. To increase the short-term allowable shear strength of the gypsum board, it is necessary to increase the surface density and thus the maximum load, and this was recognized as substantially the only method for increasing the wall shear strength. However, as is clear from the load-deformation angle curves of Example 1 shown in Figures 4(B) and 5, by reducing the surface density while ensuring the minimum physical properties of a gypsum-based shearing panel (nail lateral resistance: 500N or more), the toughness or deformation-following ability that the gypsum board itself potentially possesses becomes apparent. As a result, it becomes possible to determine the short-term standard shear strength P0 based on the ultimate strength Pu and plasticity ratio μ. This point will be explained further below.

[0060] As shown in Figure 4(B), the gypsum board of Example 1 has a deformation angle of approximately 20 × 10 -3 After reaching the maximum load (maximum yield strength) Pmax in rad, the deformation angle in the 0.8Pmax load reduction region, i.e., the ultimate displacement δu2, becomes: Ultimate displacement δu2 = 33.1 × 10 -3 It was obtained as rad. As mentioned above, the ultimate displacement δu2 of each gypsum board in Examples 1 to 5 is 26.8 × 10, as shown in Figure 3. -3 rad~36.0×10 -3The values ​​were within the range of rad, and in Examples 2 to 5, the ultimate displacement δu2 was obtained that was roughly the same as in Example 1. That is, the gypsum boards in Examples 1 to 5 had a deformation angle of approximately 20 × 10 -3 After reaching the maximum load (maximum yield strength) Pmax in rad, subsequent repeated loading sustained plastic deformation until a deformation angle approximately 1.3 to 1.8 times the deformation angle at the maximum load Pmax was achieved. Consequently, the plasticity ratio μ increased relatively significantly.

[0061] As explained at the beginning of this book, the wall strength ratio is the value obtained by dividing the short-term allowable shear strength Pa by a predetermined strength standard value (L × 1.96). The short-term allowable shear strength Pa is the value obtained by multiplying the short-term standard shear strength P0 by a predetermined reduction coefficient α, as can be understood from the formula shown in Figure 5. Similar to in-plane shear tests of many gypsum-based facing materials in the past, the short-term standard shear strength P0 of each example and comparative example is determined by multiplying the correction value Pu' of the ultimate strength Pu obtained by correction based on the plasticity ratio μ (i.e., ultimate strength (corrected value) Pu') by the variation coefficient β. Therefore, as can be easily understood from the formula in Figure 5, the short-term standard shear strength P0 is proportional to the value of the ultimate strength Pu and increases with increasing plasticity ratio μ. Assuming that the plasticity ratio μ is proportional to the ultimate displacement δu and the yield displacement δv is approximately the same value, the short-term standard shear strength P0 increases with increasing ultimate displacement δu. That is, the short-term standard shear strength P0 can be increased by increasing the ultimate displacement δu. For the sake of simplicity, the variation coefficient β = 1.0 is assumed.

[0062] As shown in the table in Figure 5, the short-term standard shear strength P0 obtained with the gypsum board of Example 1 is significantly larger than the value of the short-term standard shear strength P0 obtained with the gypsum board of the Comparative Example. This means that the decrease in surface density increases the ultimate displacement δu2, thereby increasing the short-term standard shear strength P0, and as a result, the wall strength ratio can be increased. The reduction coefficient α is an artificially set value, and by multiplying the short-term standard shear strength P0 by the reduction coefficient α, the short-term allowable shear strength (Pa) is obtained, and this gives the final wall strength ratio value. For example, if the reduction coefficient is set to 0.75, the wall strength ratio of the wooden structural load-bearing wall using the gypsum board of Example 1 is 2.25, which is about 1.4 times the wall strength ratio of the Comparative Example (1.60). This value of wall strength ratio is significantly larger than the wall strength ratio of wooden structural load-bearing walls made of structural gypsum board etc. as specified in Ministry of Construction Notification No. 1100, etc. (the aforementioned wall strength ratio of 0.9 to 1.7).

[0063] As explained above, in the load-bearing wall 1 with the above configuration, the load-bearing surface material 10 consists of a main material or core material made of a plate-shaped gypsum hardened body blended with inorganic fibers and organic strength-enhancing materials to exhibit a nail lateral resistance of 500 N or more, and a paper member covering at least the front and back surfaces of the main material or core material. The surface density or surface weight of the load-bearing surface material 10, which is specified as the mass per unit area of ​​the wall surface, is 6.5 to 8.9 kg / m 2 The ultimate displacement δu2 of the shear wall 1, obtained by an in-plane shear test using a shear wall specimen with a wall length of 1.82m, is set to a value within the range of 33.1 × 10⁻¹⁰. -3 rad (Example 1), 20 × 10 -3The ultimate strength (corrected value) Pu' obtained by this in-plane shear test is greater than rad (comparative example), for example, 10.7kN (Example 1), which is greater than 7.6kN (comparative example). Assuming a variation coefficient β=1, the short-term allowable shear strength Pa is greater than 10.7kN (Example 1), which is greater than 7.6kN (comparative example). The wall strength ratio is greater than 2.25 (Example 1), which is greater than 1.60 (comparative example). Thus, with a load-bearing wall 1 having a structure in which load-bearing panels 10 are fastened to the wooden structural wall substrate of a wooden frame construction method with nails 20, while ensuring the minimum physical properties of a gypsum-based load-bearing panel (nail lateral resistance = 500N or more), the toughness and deformation-following ability of the gypsum-based panel are improved and the ultimate load-bearing capacity (corrected value) Pu' is increased. This makes it possible to increase the short-term standard shear strength P0 and the wall strength ratio without additionally attaching reinforcing or stiffening materials and without increasing the specific gravity and / or thickness of the load-bearing panel 10.

[0064] Although preferred embodiments and examples of the present invention have been described in detail above, it goes without saying that the present invention is not limited to the above embodiments and examples, and various modifications or changes are possible within the scope of the present invention as described in the claims.

[0065] For example, although the above embodiments and examples relate to load-bearing walls at the first-floor level of a wooden structure, the present invention can be similarly applied to load-bearing walls at the second or third-floor level. In the case of load-bearing walls at the second or third-floor level, the lower end of the load-bearing panel is fastened to a horizontal member or the like at the second or third-floor level.

[0066] Furthermore, although the above embodiments and examples relate to load-bearing wall structures using the timber frame construction method and large wall construction, the present invention may also be applied to load-bearing wall structures using the timber frame construction method with true wall construction or floor-first (floor-first) and large wall construction. As a modified example, the present invention may also be applied to load-bearing wall structures using the timber frame construction method, in which case the load-bearing panels are fastened to vertical frames, bottom frames, top frames, etc., instead of the sill plates, columns, and horizontal members.

[0067] Furthermore, although the test specimen shown in Figure 4 is a structure in which a gypsum board is divided vertically and a bracing piece is placed at the midpoint in the height direction, an in-plane shear test may also be conducted using a gypsum board with a height dimension that is substantially the same as the total height of the wooden frame. In the latter case, it is thought that the short-term standard shear strength can be further increased.

[0068] Furthermore, in the above embodiments and examples, the load-bearing panels are fastened to the wooden frame such as columns and horizontal members with nails, but the load-bearing panels may also be fastened to the wooden frame with other types of fasteners such as screw screws. [Industrial applicability]

[0069] This invention applies to gypsum-based shearing panels for wooden structures. In particular, this invention applies to gypsum-based shearing panels having a main or core material of a plate-shaped gypsum hardened body mixed with inorganic fibers and organic strength-enhancing materials to exhibit a nail lateral resistance of 500 N or more. This invention also applies to a method for increasing the wall strength ratio of wooden shear walls using such gypsum-based shearing panels. Furthermore, this invention applies to a shear wall structure and shear wall construction method for wooden structures, configured such as fastening such gypsum-based shearing panels to a wooden wall substrate of a wooden frame construction method or a wooden frame wall construction method, and structurally holding the shearing panels integrally with the wooden wall substrate. According to this invention, the wall strength ratio of wooden shear walls can be increased without additionally attaching reinforcing or stiffening materials, and without increasing the specific gravity and / or thickness of the gypsum-based shearing panels, so its practical value or effect is remarkable. [Explanation of Symbols]

[0070] 1 Load-bearing wall 2. Base 3 pillars 4 bay pillars 4' Joint post 5. Horizontal structural members (beams, girders, eaves purlins, gable purlins) 5' Bodysuit 10, 10a, 10b Gypsum-based load-bearing sheathing 20 Nails (fasteners)

Claims

1. In a wooden structural load-bearing wall having a structure in which a gypsum-based load-bearing panel is fastened to the wooden structural wall substrate of a wooden frame construction or wooden frame wall construction using fasteners, The aforementioned load-bearing panel is composed of a main material or core material made of a plate-shaped gypsum hardened body containing inorganic fibers and organic strength-enhancing materials, and a paper member covering at least the front and back surfaces of the main material or core material, and has a nail side resistance of 500 N or more, and the thickness of the panel is set to a value of 10 mm or less, and the specific gravity of the panel is set to a value of 0.96 or less, and the surface density or surface weight of the load-bearing panel, which is specified as the mass per unit area of ​​the wall surface, is 6.5 to 8.9 kg / m 2 The surface density or surface weight is reduced to within the range. The ultimate displacement (δu2) of the shear wall, measured by an in-plane shear test using a shear wall specimen with a wall length of 1.82 m, is 20 × 10 -3 The ultimate displacement (δu2) has a value greater than rad, A wooden shear wall characterized in that it has a correction value (Pu') greater than 7.6 kN as the correction value (Pu') of the ultimate strength (Pu) determined based on the ultimate strength (Pu) and plasticity ratio (μ) of the shear wall measured by the in-plane shear test.

2. The wooden shear wall according to claim 1, characterized in that the corrected value (Pu') of the ultimate strength (Pu) is 8.0 kN or greater, or the measured value (Py) of the yield strength of the shear wall measured by the in-plane shear test is 8.0 kN or greater, or both the corrected value (Pu') and the measured value (Py) are 8.0 kN or greater.

3. The wooden structural load-bearing wall according to claim 1 or 2, characterized in that the thickness of the gypsum-based load-bearing panel is set to a value of 8.5 mm or more.

4. In a construction method for wooden structural load-bearing walls in which gypsum-based load-bearing panels are fixed to the wooden structural wall substrate of a wooden frame construction method or a wooden frame wall construction method, It consists of a main material or core material made of plate-shaped gypsum hardened material compounded with inorganic fibers and organic strength-enhancing materials, and a paper member covering at least the front and back surfaces of the main material or core material, has a nail side resistance of 500 N or more, has a plate thickness of 10 mm or less, has a specific gravity of 0.96 or less, and has a surface density or surface weight specified as the mass per unit area of ​​the wall surface of 6.5 to 8.9 kg / m 2 A gypsum-based load-bearing sheathing material, whose surface density or surface weight has been reduced to within a certain range, is fastened to the wooden wall substrate using fasteners. The ultimate displacement (δu2) of the shear wall, measured by an in-plane shear test using a shear wall specimen with a wall length of 1.82 m, is 20 × 10 -3 A method for constructing a wooden shear wall, characterized by obtaining an ultimate displacement (δu2) larger than rad, and obtaining a correction value (Pu') of the ultimate strength (Pu) determined based on the ultimate strength (Pu) and plasticity ratio (μ) of the shear wall measured by the in-plane shear test, which is larger than 7.6 kN.

5. The construction method according to claim 4, characterized in that the correction value (Pu') of the ultimate strength (Pu) is increased to a value of 8.0 kN or more, or the measured value (Py) of the yield strength measured by the in-plane shear test is a value of 8.0 kN or more, or the correction value (Pu') is increased to a value of 8.0 kN or more and the measured value (Py) is a value of 8.0 kN or more.

6. The construction method according to claim 4 or 5, characterized in that the thickness of the gypsum-based load-bearing panel is set to a value of 8.5 mm or more.

7. In a method for increasing the wall strength of a wooden structural load-bearing wall constructed by fastening a gypsum-based load-bearing panel to the wooden structural wall substrate of a wooden frame construction or wooden frame wall construction using fasteners, It consists of a main material or core material made of plate-shaped gypsum hardened material compounded with inorganic fibers and organic strength-enhancing materials, and a paper member covering at least the front and back surfaces of the main material or core material, has a nail side resistance of 500 N or more, has a plate thickness of 10 mm or less, has a specific gravity of 0.96 or less, and has a surface density or surface weight specified as the mass per unit area of ​​the wall surface of 6.5 to 8.9 kg / m 2 A gypsum-based load-bearing sheathing material, whose surface density or surface weight has been reduced to within a certain range, is fastened to the wooden wall substrate using fasteners. The ultimate displacement (δu2) of a load-bearing wall, measured by an in-plane shear test using a test specimen with a wall length of 1.82 m, is 20 × 10⁻¹⁰. -3 A method for increasing the strength of a wall, characterized by ensuring an ultimate displacement (δu2) greater than rad, and ensuring a correction value (Pu') greater than 7.6 kN for the ultimate strength (Pu) determined based on the ultimate strength (Pu) and plasticity ratio (μ) of the shear wall measured by the in-plane shear test.

8. The method for increasing the wall strength according to claim 7, characterized in that the thickness of the gypsum-based load-bearing panel is set to a value of 8.5 mm or more.

9. The method for increasing wall strength according to claim 7, characterized in that the measured yield strength (Py) obtained by the in-plane shear test is greater than 7.6 kN, or the paper member is gypsum board base paper, or the measured yield strength (Py) is greater than 7.6 kN and the paper member is gypsum board base paper.

10. In a gypsum-based load-bearing panel for wooden structural walls, which is fastened to the wooden structural wall substrate of a wooden frame construction method or a wooden frame wall construction method using fasteners, The load-bearing panel is composed of a main material or core material made of a plate-shaped gypsum hardened body containing inorganic fibers and organic strength-enhancing materials, and a paper member covering at least the front and back surfaces of the main material or core material, and has a nail side resistance of 500 N or more, and the thickness of the panel is set to a value of 10 mm or less, and the specific gravity of the panel is set to a value of 0.96 or less, and the mass per unit area of ​​the wall surface is The surface density or surface weight specified is 6.5 to 8.9 kg / m². 2 The surface density or surface weight is reduced to within the range. The ultimate displacement (δu2) of a shear wall, measured by an in-plane shear test using a shear wall specimen with a wall length of 1.82 m, is 20 × 10⁻¹⁰. -3 This creates an ultimate displacement (δu2) greater than rad in the shear wall, A gypsum-based shear wall material characterized by generating a correction value (Pu') greater than 7.6 kN in the shear wall, which is determined based on the ultimate strength (Pu) and plasticity ratio (μ) of the shear wall measured by the in-plane shear test.

11. The gypsum-based load-bearing panel according to claim 10, characterized in that the thickness of the load-bearing panel is set to a value of 8.5 mm or more.

12. The gypsum-based load-bearing panel according to claim 10 or 11, characterized in that it has a laminated structure in which the surface or surface layer of the core material is covered with gypsum board base paper.

13. The gypsum-based load-bearing panel according to any one of claims 10 to 12, characterized in that the main material or core material of the gypsum-based load-bearing panel contains an organopolysiloxane compound as a load-bearing deterioration inhibitor to prevent load-bearing deterioration.

14. The gypsum-based load-bearing panel is characterized in that it has a nail side resistance of 980 N or less, as described in any one of claims 10 to 13.

15. The gypsum-based shearing panel according to claim 10, characterized in that the correction value (Pu') of the ultimate strength (Pu) is increased to a value of 8.0 kN or more, or the measured value (Py) of the yield strength measured by the in-plane shear test is a value of 8.0 kN or more, or the correction value (Pu') is increased to a value of 8.0 kN or more and the measured value (Py) is a value of 8.0 kN or more.

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