Wooden fire-resistant structure

Abstract

To provide a fire-resistant wooden structure that can ensure fire resistance and has excellent workability. [Solution] A fire-resistant wooden structure 1 used for building columns or beams comprises a wooden structural core material 10 that supports loads, a first covering material 11 that covers the outer surface of the wooden structural core material 10, and a second covering material 12 that covers the outer surface of the first covering material 11. The first covering material 11 contains organic fibers and has a moisture content of 6.0% or more derived from free water or crystal water, while the second covering material 12 has a moisture content of 3.0% or less derived from free water or crystal water. The first covering material 11 is made of either a slag gypsum board or a wood wool cement board, and the second covering material 12 is made of a calcium silicate board.

Description

[Technical Field]

[0001] The present invention relates to a fire-resistant wooden structure. [Background technology]

[0002] Conventionally, fire-resistant structures have been known that can maintain load capacity for a long period of time even if the surface is carbonized due to exposure to flames during a fire by preventing the core material from carbonizing. One example of a fire-resistant structure is a wooden fire-resistant structure in which a non-combustible material is attached to the outer surface of a wooden structural core material.

[0003] For example, Patent Document 1 discloses a wooden building component having a structural section with a long, rectangular cross section that receives a load, a covering section that covers all four sides of the cross section of the structural section along its entire length, and a gypsum board that is layered between the structural section and the covering section and prevents the load acting on the structural section from being transmitted to the covering section. Because the structural section is covered with gypsum board, it is not directly exposed to flames and carbonization proceeds very slowly, thereby improving fire resistance. Furthermore, because the surface of the wooden building component is covered with the covering section, the gypsum board is not exposed to the outside, ensuring its appearance. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 4359275 Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, the wooden building component described in Patent Document 1 uses gypsum board as a non-combustible material. However, gypsum board has the disadvantage of being heavy and difficult to install as a covering material. Therefore, it is not desirable to use gypsum board alone as a covering material to ensure fire resistance.

[0006] Therefore, an object of the present invention is to provide a fire-resistant wooden structure that can ensure fire resistance and is easy to install. [Means for solving the problem]

[0007] In response to the above-mentioned problems, the fire-resistant wooden structure of the present invention is a fire-resistant wooden structure used for the columns, beams, or walls of a building, and comprises a wooden structural core material that supports a load, a first covering material that covers the outer surface of the wooden structural core material, and a second covering material that covers the outer surface of the first covering material, wherein the first covering material contains organic fibers, free water, or crystal water, and has a moisture content of 6.0% or more derived from free water or crystal water, and the second covering material has a moisture content of 3.0% or less derived from free water or crystal water.

[0008] Here, the bulk density of the second coating material is 0.15 g / cm 3 More than 0.70g / cm 3 It is desirable that it be less than this.

[0009] Furthermore, the fire-resistant wooden structure of the present invention is a fire-resistant wooden structure used for the columns, beams, or walls of a building, and is characterized in that it comprises a wooden structural core material that supports a load, a first covering material that covers the outer surface of the wooden structural core material, and a second covering material that covers the outer surface of the first covering material, wherein the first covering material is made of a slag gypsum board, and the second covering material is made of a calcium silicate board.

[0010] It is desirable that the thickness of the first covering material be 10 mm or more and 30 mm or less, and the thickness of the second covering material be 10 mm or more and 30 mm or less.

[0011] Furthermore, the fire-resistant wooden structure of the present invention is a fire-resistant wooden structure used for the columns, beams or walls of a building, and comprises a core material for a wooden structure that supports a load, a first covering material that covers the outer surface of the core material for the wooden structure, and a second covering material that covers the outer surface of the first covering material, wherein the first covering material is made of a wood wool cement board and the second covering material is made of a calcium silicate board.

[0012] It is desirable that the thickness of the first covering material be 10 mm or more and 20 mm or less, and the thickness of the second covering material be 20 mm or more and 30 mm or less.

[0013] Here, it is desirable that the device further includes a surface material that covers the outer peripheral surface of the second coating material, the surface material being fixed to the first coating material and the second coating material by a fixing member, and the tip of the fixing member being positioned inside the first coating material so as not to penetrate the first coating material.

[0014] It is also desirable that the wooden structure further comprises a surface material that covers the outer surface of the second covering material, and that the surface material is fixed to the wooden structural core material by a fixing member that penetrates the first covering material and the second covering material.

[0015] Furthermore, it is desirable that the thickness of the first coating material be three times or less the thickness of the second coating material, or that the thickness of the second coating material be three times or less the thickness of the first coating material, or that the first coating material have the same thickness as the second coating material. [Effects of the Invention]

[0016] Thus, in the fire-resistant wooden structure of the present invention, the first coating material covering the outer surface of the wooden structural core contains organic fibers and has a moisture content of 6.0% or more derived from free water or crystal water, and the second coating material covering the outer surface of the first coating material has a moisture content of 3.0% or less derived from free water or crystal water. Furthermore, in the fire-resistant wooden structure of the present invention, the first coating material covering the outer surface of the wooden structural core is made of slag gypsum board or wood wool cement board, and the second coating material is made of calcium silicate board.

[0017] This allows the core material for a wooden structure to be covered with the highly fire-resistant first and second covering materials in a layered structure, thereby improving the fire resistance of the fire-resistant wooden structure and ensuring excellent workability.

[0018] Here, the bulk density of the second coating material is 0.15 g / cm 3 More than 0.70g / cm 3 This means that workability can be further improved by using a second covering material that has a lower bulk density and is lighter than reinforced gypsum board.

[0019] The fire-resistant wooden structure further includes a surface material that covers the outer surface of the second covering material. The surface material is fixed to the first and second covering materials by fixing members, and the tips of the fixing members are positioned inside the first covering material so as not to penetrate the first covering material. This prevents the fixing members from becoming a thermal bridge that carbonizes the wooden structural core material in the event of a fire. This further improves the fire resistance of the fire-resistant wooden structure.

[0020] The surface material is fixed to the core material for a wooden structure by fixing members that penetrate the first and second covering materials, thereby enabling the fixing members to more firmly integrate the surface material, first and second covering materials, and core material for a wooden structure.

[0021] The thickness of the first covering material is three times or less the thickness of the second covering material, or the thickness of the second covering material is three times or less the thickness of the first covering material, or the first covering material has the same thickness as the second covering material. In either case, this allows the periphery of the core material for a wooden structure to be covered with highly fire-resistant members to form a layered structure. Therefore, in either case, the fire resistance of the fire-resistant wooden structure can be further improved.

[0022] Furthermore, when the first covering material is a slag gypsum board and the second covering material is a calcium silicate board, the thickness of the first covering material is 10 mm to 30 mm, and the thickness of the second covering material is 10 mm to 30 mm. Also, when the first covering material is a wood wool cement board and the second covering material is a calcium silicate board, the thickness of the first covering material is 10 mm to 20 mm, and the thickness of the second covering material is 20 mm to 30 mm. In other words, by combining a non-combustible first covering material and a lightweight calcium silicate board within the above thickness ranges, both fire resistance and excellent workability can be ensured. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is a perspective view partially showing the inside of a fire-resistant wood structure according to an embodiment of the present invention. [Figure 2] 1 is a cross-sectional view of a wood fire-resistant structure according to an embodiment of the present invention. [Figure 3] 1(a) is a schematic enlarged cross-sectional view of a wood fireproof structure before heating, and FIG. 1(b) is a schematic enlarged cross-sectional view of the wood fireproof structure in the first stage during heating. [Figure 4] 1(a) is a schematic enlarged cross-sectional view of a wood fireproof structure in the second stage during heating, and FIG. 1(b) is a schematic enlarged cross-sectional view of a wood fireproof structure in the third stage during heating. [Figure 5] 10 is a graph showing the relationship between temperature change and thermal conductivity of each material. [Figure 6] 1 is a graph showing the relationship between temperature change and linear shrinkage rate of each material. [Figure 7]1 is a graph showing the relationship between temperature change and apparent volumetric specific heat of each material. [Figure 8] FIG. 1 is a diagram showing the relationship between the temperature rise of each material and the amount of heat required to raise the temperature. [Figure 9] FIG. 1 is a diagram for explaining an outline of a test specimen used in a fire resistance experiment. [Figure 10] 1 is a graph showing temperature changes in a heating furnace in a fire resistance experiment. [Figure 11] 1 is a graph showing temperature changes at each measurement point of a test specimen in a fire resistance experiment. DETAILED DESCRIPTION OF THE INVENTION

[0024] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a perspective view of a fire-resistant wooden structure according to an embodiment of the present invention, and Fig. 2 is a cross-sectional view thereof.

[0025] As shown in Figure 1, the fire-resistant wooden structure 1 is a structure used for the columns, beams, or walls of a building, and comprises a wooden structural core material 10 that supports a load, a first covering material 11 that covers the outer surface of the wooden structural core material 10, a second covering material 12 that covers the outer surface of the first covering material 11, and a surface material 13 that covers the outer surface of the second covering material 12.

[0026] <Wooden structural core material> The wooden structural core 10 is formed in the shape of a rectangular prism with four sides. There are no restrictions on the species of wood used for the wooden structural core 10, and it can be made of wood such as cedar, cypress, red pine, black pine, cypress, larch, Japanese cypress, Japanese cedar, Douglas fir, Japanese hemlock, zelkova, chestnut, oak, Japanese oak, or beech. The wooden structural core 10 can be solid wood, glued laminated lumber, laminated veneer lumber, cross-laminated lumber, or ungraded lumber. The wooden structural core 10 can be made of commonly available or custom-made lumber.

[0027] The wood structural core material 10 is not limited in density, but may have a density of, for example, 0.38±0.08 g / cm 3The core material 10 for a wooden structure contains moisture, and although there is no limit to the moisture content, the moisture content can be, for example, 15% or less. As shown in Figures 1 and 2, the core material 10 for a wooden structure can be a square timber with a rectangular cross section (for example, 600 mm x 600 mm).

[0028] <First covering material> The first covering material 11 is formed to have a cylindrical cross section so as to surround the four side surfaces of the wooden structural core material 10. As shown in Fig. 2, the first covering material 11 is composed of a plurality of plate-like members, each of which is fixed to each side surface of the wooden structural core material 10 by a first fastener 21 such as a screw. The first fastener 21 penetrates the first covering material 11 in the thickness direction, and its tip is inserted into the wooden structural core material 10. The first covering material 11 is formed, for example, from a slag gypsum board or a wood wool cement board.

[0029] <Slag gypsum board> Slag gypsum board is a material classified as a fiber-reinforced cement board under JIS A5430. It contains slag, gypsum, and organic fibers, primarily waste paper. Specifically, slag gypsum board is a non-combustible material containing 1-5 wt% or less of organic fiber (waste paper), and contains 30-50 wt% granulated blast furnace slag, 30-50 wt% gypsum dihydrate, and 5 wt% or less of waste paper. Slag gypsum board is a material with high hardness even before heating and maintains the same hardness during heating. Because slag gypsum board contains highly tenacious organic fibers, cracking due to heating is extremely minimal, preventing damage. It also reduces heat infiltration through cracks to the backside.

[0030] Slag gypsum board contains free water and crystal water, and its bulk density is 0.90 g / cm 3 More than 1.20g / cm 3 For example, the value of the moisture content of a sample stored at 23°C and 50% RH is 1.17 g / cm 3 The proportion of moisture derived from free water and crystallized water in the slag gypsum board was about 13.2%, and the amount of free water and crystallized water was 0.16 g / cm 3(An example of a specimen stored in an environment of 23°C and 50% RH). Slag gypsum boards contain the same amount of free water and crystalline water as reinforced gypsum boards in the same volume. In addition, in an example of a specimen using slag gypsum boards as the first covering material, the maximum temperature reached by the slag gypsum boards was approximately 300°C.

[0031] Here, crystallization water refers to water that is chemically bound to the material components in slag gypsum board, and is different from water that is not chemically bound (free water). The gypsum in slag gypsum board is gypsum dihydrate (CaSO4·2H20), just like the gypsum in reinforced gypsum board, and when heated, it releases moisture and becomes gypsum hemihydrate (CaSO4·1 / 2H2O). When hemihydrate is heated, it releases moisture and becomes gypsum anhydrite (CaSO4). The crystallization water contained in gypsum exhibits fire resistance, allowing it to be used as a fire-resistant material. The amount of moisture in slag gypsum board is determined by the mass loss from room temperature to 200°C.

[0032] The gypsum and blast furnace slag contained in slag gypsum boards are by-products, and disposing of them as is would be an environmental burden, but using them in slag gypsum boards reduces the environmental burden. The waste paper used in slag gypsum boards is also a recycled material. As 87% of the material in slag gypsum boards is made up of recycled materials, CO2 emissions can be reduced.

[0033] <Wood cement board> Wood wool cement board is a material classified as a wood-based cement board as defined in JIS A5404, and is a semi-non-combustible material that uses, for example, 100% domestically produced thinned cypress as organic fiber. Specifically, wood wool cement board is a semi-non-combustible material that contains 1 to 30 wt% organic fiber (wood wool), and contains 70 wt% or more cement and 30 wt% or less wood wool. Wood wool cement board is a material that has hardness even before heating, and maintains the same hardness during heating.

[0034] The wood wool cement board contains highly tenacious organic fibers, which minimizes cracking due to heating and improves impact resistance. Wood wool cement board contains free water and crystalline water, and has a bulk density of 1.0 g / cm. 3 For example, the density of a sample stored at 23°C and 50% RH is 1.13 g / cm 3 The proportion of moisture derived from free water and crystallized water in the wood wool cement board was about 7.0%, and the amount of free water and crystallized water was 0.08 g / cm 3 (An example of a board stored in an environment of 23°C and 50% RH). The moisture content of the wood wool cement board was determined by the mass loss from room temperature to 200°C. In addition, the maximum temperature reached by the wood wool cement board in this example was approximately 300°C.

[0035] In the case of wood wool cement boards, the decomposition of the crystalline water in the hardened cement paste occurs at around 450°C, but when wood wool cement boards are coated on the inside of calcium silicate boards, depending on the heating conditions, the wood wool cement board may not reach 450°C, and the crystalline water may not be decomposed.

[0036] The bulk density of reinforced gypsum board is 0.75 to 0.95 g / cm 3 For example, the density of a sample stored at 23°C and 50% RH is 0.79 g / cm 3 It was.

[0037] <Second covering material> The second covering material 12 is formed to have a cylindrical cross section so as to cover the outer peripheral surface of the first covering material 11. The second covering material 12 is formed of, for example, a calcium silicate plate.

[0038] As shown in FIG. 2 , the second covering material 12 is composed of multiple plate-like members, each of which is fixed to the first covering material 11 by a second fastener 22 such as a screw. To firmly fasten the first covering material 11 and the second covering material 12 to the wooden structural core material 10, the second fastener 22 penetrates the second covering material 12 in the thickness direction and has its tip inserted into the first covering material 11. It is preferable that the second fastener 22 penetrates the first covering material 11 and the second covering material 12 in the thickness direction and is inserted into the wooden structural core material 10. It is preferable that the second fastener 22 be located at a distance of 30 mm or more from the corners of the wooden structural core material 10. It is preferable that the second fastener 22 be made of stainless steel, which has a lower thermal conductivity than iron.

[0039] <Calcium silicate board> The calcium silicate board according to an embodiment of the present invention is a non-combustible material belonging to the xonotlite group, which has little structural change due to heat shrinkage and high fire resistance and heat insulation properties, and contains 65 to 80 wt% calcium silicate, less than 10 wt% calcium hydroxide, and less than 3 wt% crystalline silica (quartz). Calcium silicate boards can maintain low thermal conductivity over a wide range of temperatures, i.e., they are highly heat-insulating materials, with a fire resistance temperature of approximately 1000°C. Calcium silicate boards contain moisture and have a bulk density of 0.15 g / cm. 3 More than 0.70g / cm 3 For example, the value of the moisture content of a sample stored at 23°C and 50% RH is 0.30 g / cm 3 In addition, the calcium silicate board had a moisture content of about 2.2% (less than 3.0%) derived from free water and crystal water, and the moisture content was 0.007 g / cm 3 (An example of a sample stored in an environment of 23°C and 50% RH.) Since calcium silicate boards contain almost no water of crystallization, the amount of water lost by drying at 105°C was used as the amount of water.

[0040] <Surface material> The surface material 13 is formed to have a cylindrical cross section so as to surround the second covering material 12. The material of the surface material 13 is not particularly limited, as long as it is made of wood formed into a general board shape. The surface of the surface material 13 may be coated with a paint that improves weather resistance, durability, and aesthetics, as well as a boric acid or phosphoric acid agent. The boric acid or phosphoric acid agent releases moisture when heated, slowing the temperature rise of the present invention in the event of a fire and improving fire resistance.

[0041] The surface material 13 is fixed to the first covering material 11 and the second covering material 12 by third fasteners (fixing members) 23 such as screws. The tips of the third fasteners 23 are disposed inside the first covering material 11 so as not to penetrate the first covering material 11. In other words, the third fasteners 23 penetrate the surface material 13, the second covering material 12, and the first covering material 11 in that order in the thickness direction, and the tips do not reach the wooden structural core material 10.

[0042] Furthermore, when the first covering material 11 and the second covering material 12 are to be firmly fixed to the wooden structural core material 10, it is desirable that the third fixing device 23 penetrates the first covering material 11 and the second covering material 12 and is inserted into the wooden structural core material 10. It is desirable that the third fixing device 23 be located, for example, 30 mm or more away from the corners of the wooden structural core material 10. It is desirable that the material for the third fixing device 23 be stainless steel, which has a lower thermal conductivity than iron.

[0043] The third fixing member 23 may be fitted with a wooden plug 23a that hides the screw head, or non-combustible wood or a non-combustible material may be used instead of the wooden plug 23a. The wooden plug 23a, non-combustible wood or non-combustible material fitted to the screw head in this way can reduce the thermal bridge of the screw.

[0044] Here, changes that occur in a wooden fireproof structure 1 as heating progresses in the event of a fire or the like will be described with reference to Figures 3 and 4. Figure 3(a) is a schematic enlarged cross-sectional view of the wooden fireproof structure 1 before heating, Figure 3(b) is a schematic enlarged cross-sectional view of the wooden fireproof structure in the first stage of heating, Figure 4(a) is a schematic enlarged cross-sectional view of the wooden fireproof structure in the second stage of heating, and Figure 4(b) is a schematic enlarged cross-sectional view of the wooden fireproof structure in the third stage of heating.

[0045] As shown in Figure 3(a), before heating, the first coating material 11 and the surface material 13 contain a large amount of moisture W (see the circles in the figure). The second coating material 12, which is placed for the purpose of heat insulation, contains almost no moisture. In the first stage of heating shown in Figure 3(b), the surface material 13, which is heated from the outside by a flame or the like, is carbonized, and the moisture in the heated first coating material 11 decreases.

[0046] In the second stage of heating shown in FIG. 4(a), the carbonized surface material 13 is burned away, and the moisture content of the first coating material 11 heated through the second coating material 12 is further reduced. In the third stage of heating shown in FIG. 4(b), the moisture content of the first coating material 11 heated through the second coating material 12 is further reduced. As long as the first coating material 11 retains free water and crystallized water, the first coating material 11 is believed to suppress a temperature rise in the wooden structural core material 10 and maintain the temperature below the carbonization temperature (approximately 260°C) of the wood in the wooden structural core material 10. Therefore, a high moisture content in the first coating material 11 is desirable. Even if the moisture content of the first coating material 11 and the second coating material 12 decreases as shown in FIG. 4(b), they can still maintain their fire-resistant coating performance as insulating materials.

[0047] In order to improve the fire resistance of the fire-resistant wooden structure 1, it is important that at least one of the first covering material 11 and the second covering material 12 has a high moisture content, in other words, that the temperature does not easily rise. Below, the materials that make up the first covering material 11 and the second covering material 12 are compared and explained.

[0048] This section explains the thermal conductivity, linear shrinkage rate, apparent volumetric specific heat, and amount of heat required to raise the temperature of the slag gypsum board used in the first covering material 11 and the calcium silicate board used in the second covering material 12. Conventionally used reinforced gypsum board will also be explained for comparison.

[0049] Figure 5 is a graph showing the relationship between temperature and thermal conductivity for slag gypsum board, calcium silicate board, and reinforced gypsum board. The lower the thermal conductivity, the less heat is transferred, and calcium silicate board had the lowest thermal conductivity. For example, using calcium silicate board for the second covering material 12 is thought to have the effect of suppressing the inflow of heat into the interior.

[0050] Figure 6 is a graph showing the relationship between the temperature of slag gypsum board, calcium silicate board, and reinforced gypsum board and the linear shrinkage rate of the covering material due to heating. For each material, the linear shrinkage rate gradually increased with increasing temperature within the range from room temperature to about 600°C, and once the temperature exceeded 600°C, the linear shrinkage rate of the reinforced gypsum board and slag gypsum board increased sharply.

[0051] The linear shrinkage rate is thought to affect the ease with which joints open and cracks occur, and calcium silicate board had the smallest linear shrinkage rate. By using calcium silicate board for the outer fire-resistant coating layer (second coating material 12), which is prone to high temperatures, it is thought that there is an effect of suppressing the inflow of heat into the interior due to joints opening and cracks.

[0052] Figure 7 is a graph showing the relationship between the temperature of slag gypsum board, calcium silicate board, and reinforced gypsum board and the apparent volumetric specific heat, which indicates how difficult it is to raise the temperature. The apparent volumetric specific heat of reinforced gypsum board and slag gypsum board increased at approximately 100 to 200°C. This is thought to be due to the latent heat of vaporization of the crystalline water contained in the reinforced gypsum board and slag gypsum board.

[0053] The greater the amount of free water and crystalline water contained in a slag gypsum board, reinforced gypsum board, or calcium silicate board, the greater the apparent volumetric specific heat, and the greater the apparent volumetric specific heat, the less likely the temperature will rise. The target carbonization temperature for wood used as the wooden structural core material 10 is said to be approximately 260°C, but by using a slag gypsum board, which is less likely to rise in temperature in the range of approximately 100 to 200°C, as the inner first covering material 11, it is thought that this will have the effect of lengthening the time until the surface of the wooden structural core material 10 reaches the carbonization temperature.

[0054] 8 is a diagram showing the relationship between the temperature rise of a slag gypsum board, a calcium silicate board, and a reinforced gypsum board and the amount of heat required to achieve that temperature rise. The temperature rise was calculated from the apparent volumetric specific heat for four ranges: 20°C to 260°C, 20°C to 300°C, 20°C to 400°C, and 20°C to 500°C.

[0055] As shown in Figure 8, it was confirmed that in all ranges, the amount of heat required to raise the temperature was greatest for slag gypsum board, followed by reinforced gypsum board and calcium silicate board in that order. The greater the amount of heat required to raise the temperature, the more difficult it is to raise the temperature. In all of the temperature ranges shown in the graph, the amount of heat required to raise the temperature was greatest for slag gypsum board. This confirmed that slag gypsum board is less susceptible to temperature rise than reinforced gypsum board.

[0056] Thus, in the fire-resistant wooden structure 1 according to the embodiment, the first coating material 11 covering the outer surface of the wooden structural core material 10 contains organic fibers, free water, or crystal water, and has a moisture content of 6.0% or more derived from free water or crystal water, while the second coating material 12 covering the outer surface of the first coating material 11 has a moisture content of 3.0% or less derived from free water or crystal water. The first coating material 11 is made of either a slag gypsum board or a wood wool cement board, and the second coating material 12 is made of a calcium silicate board.

[0057] As a result, the highly fire-resistant first covering material 11 and second covering material 12 form a layered structure around the wooden structural core material 10. This makes it possible to obtain a fire-resistant wooden structure 1 that ensures fire resistance and excellent workability.

[0058] Here, the bulk density of the second coating material 12 is 0.15 g / cm 3 More than 0.70g / cm 3 This allows for improved workability by using the second covering material 12, which has a lower bulk density and is lighter than reinforced gypsum board.

[0059] The fire-resistant wooden structure 1 further includes a surface material 13 that covers the outer surface of the second covering material 12. The surface material 13 is fixed to the first covering material 11 and the second covering material 12 by a third fastener (fixing member) 23. The tip of the third fastener 23 is positioned inside the first covering material 11 so as not to penetrate the first covering material 11. This prevents the fixing member from becoming a thermal bridge that carbonizes the wooden structural core material in the event of a fire. This further improves the fire resistance of the fire-resistant wooden structure 1.

[0060] Additionally, the surface material 13 is fixed to the wooden structural core material by third fasteners 23 that penetrate the first covering material 11 and the second covering material 12. In this way, the third fasteners 23 integrate the surface material 13, the first covering material 11, the second covering material 12, and the wooden structural core material 10. This ensures the strength of the entire fire-resistant wooden structure.

[0061] Furthermore, the thickness of the first covering material 11 is no more than three times the thickness of the second covering material 12, or the thickness of the second covering material 12 is no more than three times the thickness of the first covering material 11, or the first covering material 11 has the same thickness as the second covering material 12. In either case, this allows the wooden structural core material 10 to be covered with highly fire-resistant members to form a layered structure. Therefore, in either case, the fire resistance of the fire-resistant wooden structure 1 can be further improved.

[0062] Furthermore, when the first covering material 11 is a slag gypsum board and the second covering material 12 is a calcium silicate board, the thickness of the first covering material 11 is 10 mm to 30 mm, and the thickness of the second covering material 12 is 10 mm to 30 mm. When the first covering material 11 is a wood wool cement board and the second covering material 12 is a calcium silicate board, the thickness of the first covering material 11 is 10 mm to 20 mm, and the thickness of the second covering material 12 is 20 mm to 30 mm. In other words, by using the non-combustible first covering material 11 and the lightweight calcium silicate board together within the above thickness ranges, fire resistance and excellent workability can be ensured.

[0063] Next, a fire resistance experiment to confirm the fire resistance performance of the fireproof wooden structure 1 according to the embodiment will be described. The fireproof wooden structure 1 as a test specimen was placed in a heating furnace and heated for 1 hour according to the standard heating temperature curve, after which the heating was stopped and the structure was allowed to cool for about 180 minutes (see FIG. 10).

[0064] As shown in Fig. 9, the measurement points in the wooden fireproof structure 1 were eight locations A1 to A8 inside the wooden fireproof structure 1. Specifically, the corner temperatures were measured at four locations A1, A3, A5, and A7, and the flat temperature was measured at four locations A2, A4, A6, and A8.

[0065] The results of the fire resistance experiment are shown in Figure 11. The experiment results show that the temperature of the fire-resistant wooden structure 1 was higher at the corners (A1, A3, A5, A7) than at the flat surfaces (A2, A4, A6, A8), and that at all measurement points, the temperature was below 260°C, the target carbonization temperature of the wooden structural core material 10. After the experiment, the covering material was removed and the condition of the wooden structural core material 10 was checked, but there was no carbonization of the wooden structural core material 10, confirming that the present invention has fire resistance. <Test specimen specifications> ·Wooden structural core material (laminated wood), 600mm x 600mm Slag gypsum board, 12mm thick Calcium silicate board, 30mm thick Surface material (laminated wood), thickness 18mm [Example]

[0066] Example 1 An element test specimen of a fire-resistant wooden structure 1 was prepared by arranging a wooden structural core material 10, a first covering material 11, and a second covering material 12 in this order from the inside. A slag gypsum board was used for the first covering material 11, and a calcium silicate board was used for the second covering material 12. <Test specimen specifications> Structural wood core (sawn lumber), 60mm thick Slag gypsum board, 30mm thick Calcium silicate board, 10mm thick

[0067] (Examples 2 and 3) Examples 2 and 3 are the same as Example 1 except for the difference in thickness of the first covering material 11 and the second covering material 12. Specifically, Example 2 used a 20 mm thick slag gypsum board for the first covering material 11, and a 20 mm thick calcium silicate board for the second covering material 12. Example 3 used a 10 mm thick slag gypsum board for the first covering material 11, and a 30 mm thick calcium silicate board for the second covering material 12.

[0068] (Comparative Examples 1 to 4) In Comparative Example 1, only a 40 mm thick slag gypsum board was used. In Comparative Example 2, only a 40 mm thick calcium silicate board was used. In Comparative Example 3, a 20 mm thick calcium silicate board was used for the first covering material 11, and a 20 mm thick slag gypsum board was used for the second covering material 12. In Comparative Example 4, only a 40 mm thick reinforced gypsum board was used.

[0069] (Examples 4 to 5) Next, examples and comparative examples of a fireproof wooden structure 1 in which the first covering material 11 is made of a cemented wood wool board and the second covering material 12 is made of a calcium silicate board will be described. In examples 4 and 5, elemental test specimens of the fireproof wooden structure 1 were prepared by arranging the wooden structural core material 10, the first covering material 11, and the second covering material 12 in this order from the inside to cover the structure. A cemented wood wool board was used for the first covering material 11, and a calcium silicate board was used for the second covering material 12. <Test specimen specifications> Structural wood core (sawn lumber), 60mm thick ·Wood cement board Calcium silicate board

[0070] In Example 4, a 20 mm thick wood wool cement board and a 20 mm thick calcium silicate board were used, and in Example 5, a 10 mm thick wood wool cement board and a 30 mm thick calcium silicate board were used.

[0071] (Comparative Example 5) Only a 40 mm thick wood wool cement board was used in Comparative Example 5. The experimental conditions for Examples 1 to 5 and Comparative Examples 1 to 5 are as shown in Table 1.

[0072] <Evaluation> In Examples 1 to 5 and Comparative Examples 1 to 5, the wood was heated in a small electric furnace, and the time elapsed until the surface temperature of the wood reached 260° C. was measured. In addition, the workability was evaluated based on the weight of the entire fireproof wooden structure 1. The evaluation results are shown in Table 1.

[0073] [Table 1]

[0074] The results showed that Examples 1 to 3 took a longer time for the surface temperature to reach 260°C than Comparative Examples 1 to 5. In particular, Examples 1 and 2 took a longer time for the surface temperature to reach 260°C than the other Examples and Comparative Examples 1 to 4. Furthermore, by combining calcium silicate boards, weight reduction can be achieved, thereby improving workability.

[0075] In this way, the overall evaluation of Examples 1 to 3, in which the fire-resistant covering material located on the inside of the wood fire-resistant structure 1 was slag gypsum board and the fire-resistant covering material located on the outside was calcium silicate board, was rated as good, and it was confirmed that both fire resistance performance and workability were met compared to Comparative Examples 1 to 5, which received an overall evaluation of bad.

[0076] The results showed that Examples 4 to 5 took a longer time for the surface temperature to reach 260°C than Comparative Examples 2 to 5. Furthermore, by combining calcium silicate boards, weight reduction can be achieved, thereby improving workability. Note that Comparative Example 1 took a longer time for the surface temperature to reach 260°C than Examples 4 to 5, but because it was composed only of slag gypsum boards, it was difficult to achieve weight reduction, and workability was poor.

[0077] In this way, the overall evaluation of Examples 4 to 5, in which the fire-resistant covering material located on the inside of the wood fire-resistant structure 1 was a wood wool cement board and the fire-resistant covering material located on the outside was a calcium silicate board, was rated as good, and it was confirmed that both fire resistance performance and workability were met compared to Comparative Examples 1 to 5, which received an overall evaluation of bad.

[0078] Although the embodiments of the present invention have been described in detail above with reference to the drawings, the specific configurations are not limited to these embodiments, and design changes that do not deviate from the gist of the present invention are included in the present invention.

[0079] For example, in the above embodiment, the fixing of the wooden structural core material 10 to the first covering material 11, the fixing of the first covering material 11 to the second covering material 12, and the fixing of the second covering material 12 to the surface material 13 may all be done using screws only, adhesive only, or a combination of screws and adhesive.

[0080] In the above embodiment, the first covering material 11, the second covering material 12, and the surface material 13 are each composed of a single layer of plate-like material, but each may be composed of multiple plate-like materials stacked in the thickness direction. The first covering material 11 and the second covering material 12 may each be composed of a single layer or multiple layers. Specifically, the second covering material 12, which is arranged to cover the periphery of the first covering material 11, may be further covered with the first covering material 11, or the first covering material 11 may be further covered with the second covering material 12. Furthermore, the wooden structural core material 10 may be coated with a paint to enhance durability. [Explanation of symbols]

[0081] 1: Wooden fireproof structure 10: Core material for wooden structures 11:First covering material 12:Second covering material 13: Surface material

Claims

1. A fire-resistant wooden structure used for the columns, beams or walls of a building, a wooden structural core material that supports a load; a first covering material that covers the outer peripheral surface of the core material for wooden structure; a second coating material that covers an outer peripheral surface of the first coating material, The first covering material is made of a slag gypsum board, The second coating material is made of calcium silicate board. A fire-resistant wooden structure characterized by:

2. A fire-resistant wooden structure used for the columns, beams or walls of a building, a wooden structural core material that supports a load; a first covering material that covers the outer peripheral surface of the core material for wooden structure; a second coating material that covers an outer peripheral surface of the first coating material, the first covering material is made of a wood wool cement board, The second coating material is made of calcium silicate board. A fire-resistant wooden structure characterized by:

3. Further provided is a surface material that covers an outer peripheral surface of the second coating material, the surface material is fixed to the first covering material and the second covering material by a fixing member; 3. A wood fire-resistant structure according to claim 1, wherein the tip of the fixing member is arranged inside the first covering material so as not to penetrate the first covering material.

4. Further provided is a surface material that covers an outer peripheral surface of the second coating material, 3. The fire-resistant wooden structure according to claim 1, wherein the surface material is fixed to the core material for the wooden structure by a fixing member that penetrates the first covering material and the second covering material.

5. 3. The wood fire-resistant structure according to claim 1, wherein the thickness of the first covering material is three times or less the thickness of the second covering material.

6. 3. The wood fire-resistant structure according to claim 1, wherein the thickness of the second covering material is three times or less the thickness of the first covering material.

7. 3. The fire-resistant wood structure according to claim 1, wherein the first covering material has the same thickness as the second covering material.

8. The bulk density of the second coating material is 0.15 g / cm ３ 0.70g / cm or more ３ 3. The fire-resistant wood structure according to claim 1, wherein the refractory wood structure has a thickness of less than 1 / 2 mm.

9. The thickness of the first coating material is 10 mm or more and 30 mm or less, 2. The fire-resistant wooden structure according to claim 1, wherein the thickness of the second covering material is 10 mm or more and 30 mm or less.

10. The thickness of the first coating material is 10 mm or more and 20 mm or less, 3. The fire-resistant wooden structure according to claim 2, wherein the thickness of the second covering material is 20 mm or more and 30 mm or less.

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