Fire-resistant covering structure of structure

Abstract

To improve the fire resistance performance of a construction by multilayered fire-resistive covering materials and to easily support the fire-resistive covering materials layered on the surface of the construction.SOLUTION: A construction formed in a square cylindrical shape and constituting columns 10 or beams 20 is provided with frame members 11 and 21 at four corners and intermediate members 12 and 22 of an inner hollow shape which is bridged between frame members 11 and 21 at four corners; the intermediate members 12 and 22 are provided with a substrate crosspiece material C provided in the inner hollow part, and innermost fire-resistive covering materials 13 and 23 out of the plurality of layers of fire-resistive covering materials 13, 14, 15 / 23 (230), 24 and 25 provided on each of the four side surfaces of the construction are fixed to the frame members 11 and 21 and the intermediate members 12 and 22 at the four corners by fixing materials 16 and 26; the fixing materials 16 and 26 fastened to the intermediate members 12 and 22 fix the innermost fire-resistive covering materials 13 and 23 using the substrate crosspiece material C as a fixing substrate.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a fire-resistant covering structure for a structure that constitutes the skeleton of a wooden building. [Background technology]

[0002] In recent years, there has been a demand for a carbon-neutral society, which aims to achieve virtually zero carbon dioxide emissions, and for the achievement of the Sustainable Development Goals (SDGs), and the construction industry is also moving forward with efforts to use wooden buildings, which have lower carbon dioxide emissions.As a result, even when building relatively large buildings, wooden construction is sometimes adopted rather than steel-frame, reinforced concrete, or steel reinforced concrete construction methods. For example, Patent Document 1 discloses a construction technique for a wooden building having a skeleton formed from rectangular cylindrical pillars and beams (see, for example, Patent Document 1). In this technology, columns and beams are joined using joint members such as rectangular beam-column connectors, beam connectors, and other metal joints. The rectangular columns and beams are constructed with wooden timbers placed at each of the four corners of the columns and beams, and four sets of two-ply wooden building panels placed between adjacent timbers to connect the timbers. By using these rectangular columns and beams and the respective metal joints, it is possible to construct relatively large wooden buildings. The building panels are hollow, which contributes to reducing the weight of the columns and beams. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-21287 Summary of the Invention [Problem to be solved by the invention]

[0004] However, structural members such as pillars and beams must be reliably covered with fire-resistant covering materials to prevent the spread of fire. To improve fire resistance, it is necessary to install multiple layers of fire-resistant covering materials on the structure. However, when a building is large, the cross-sections of the columns, beams, and other structural components become large, and each piece of fire-resistant covering material used also has a large surface area. Because each piece of such fire-resistant covering material is quite heavy, the weight of the outermost fire-resistant covering material in a multi-layered structure is placed on the innermost layer (closest to the structure), making it difficult to support.

[0005] The present invention was made in consideration of the above circumstances, and its objective is to improve the fire resistance performance of a structure by using fire-resistant coating material superimposed in multiple layers, and to make it easier to support fire-resistant coating material superimposed in multiple layers on the surface of the structure. [Means for solving the problem]

[0006] The invention described in claim 1 is a fire-resistant covering structure for a structure formed in a rectangular cylindrical shape and constituting a column 10 or a beam 20 in a skeleton 2 of a building 1, as shown in, for example, FIGS. 1 to 8, The structure is wooden frame members 11 and 21 arranged at the four corners of the structure and formed long along the length of the structure; and intermediate wooden members 12, 22 formed long along the length of the structure, which are fixed to each of the four side surfaces along the length of the structure and span the frame members 11, 21 at the four corners, The intermediate members 12 and 22 are hollow panel bodies having an internal hollow portion, and are provided with a base crosspiece C (auxiliary crosspiece C) that is elongated along the longitudinal direction of the structure and is provided in the internal hollow portion. Each of the four side surfaces along the length of the structure is provided with a plate-like fire-resistant covering material 13, 14, 15, 23 (230), 24, 25, which is stacked in multiple layers; Of the multiple layers of fire-resistant covering materials 13, 14, 15, 23 (230), 24, 25, the innermost layer of fire-resistant covering material 13, 23 is fixed to the frame materials 11, 21 at the four corners and the intermediate members 12, 22 with fixing materials 16, 26, and the fixing materials 16, 26 fastened to the intermediate members 12, 22 fix the innermost layer of fire-resistant covering material 13, 23 using the base crosspiece material C as a fixing base.

[0007] According to the invention described in claim 1, each of the four longitudinal sides of a structure having wooden frame members 11 and 21 and wooden intermediate members 12 and 22 is provided with plate-shaped fire-resistant covering materials 13, 14, 15, 23 (230), 24, 25 stacked in multiple layers, so that the fire resistance performance of the rectangular cylindrical structure constituting the column 10 or beam 20 can be improved by the fire-resistant covering materials 13, 14, 15, 23 (230), 24, 25 stacked in multiple layers. Furthermore, of the multiple layers of fire-resistant coating materials 13, 14, 15, 23 (230), 24, 25, the innermost layer of fire-resistant coating material 13, 23 is fixed to the framing members 11, 21 at the four corners and the intermediate members 12, 22 with fasteners 16, 26. The fasteners 16, 26 fastened to the intermediate members 12, 22 secure the innermost layer of fire-resistant coating material 13, 23 to the long base members C provided in the hollow interiors of the intermediate members 12, 22 and extending along the length of the structure. This enables the innermost layer of fire-resistant coating material 13, 23 to be fixed to the core of the structure (i.e., the framing members 11, 21 at the four corners and the base members C). This improves the attachment stability of the innermost layer of fire-resistant coating material 13, 23 to the surface of the structure, making it easier to support the outer layer of fire-resistant coating materials 14, 15, 24, 25 superimposed on the innermost layer of fire-resistant coating material 13, 23.

[0008] The invention described in claim 2 is, for example, as shown in Figs. 2 to 8, in the fire-resistant covering structure for the structure described in claim 1, Among the multiple layers of fire-resistant coating materials 13, 14, 15, 23 (230), 24, 25, the innermost layer of fire-resistant coating material 13, 23 is characterized by having a thickness dimension set to be larger than that of the fire-resistant coating materials 14, 15, 24, 25 located outer than the innermost layer of fire-resistant coating material 13, 23 (230).

[0009] According to the invention described in claim 2, the innermost layer of fire-resistant coating material 13 / 23 is set to have a thickness dimension larger than that of the fire-resistant coating materials 14, 15, 24, and 25 located outer than the innermost layer of fire-resistant coating material 13 / 23 (230), and therefore the increased thickness can improve fire resistance performance.

[0010] The invention described in claim 3 is, for example, as shown in Figs. 2 to 8, in the fire-resistant covering structure for the structure described in claim 1, Of the multiple layers of fire-resistant coating materials 13, 14, 15, 23 (230), 24, 25, the outer layer fire-resistant coating materials 14, 15, 230, 24, 25, excluding the innermost layer fire-resistant coating material 13, 23, are characterized in that they are fixed to the inner layer fire-resistant coating materials 13, 14, 23 (230), 24 on which they are superimposed.

[0011] According to the invention described in claim 3, the outer layer fire-resistant coating materials 14, 15, 230, 24, 25 are fixed to the fire-resistant coating materials 13, 14, 23 (230), 24 located immediately inside them. Therefore, when three or more layers of fire-resistant coating materials 13, 14, 15, 23 (230), 24, 25 are stacked, the load on the innermost layer fire-resistant coating material 13, 23 can be reduced, contributing to improved installation stability of multiple layers of fire-resistant coating materials 13, 14, 15, 23 (230), 24, 25.

[0012] The invention described in claim 4 is, for example, as shown in Figs. 2 to 7, in the fire-resistant covering structure for the structure described in claim 1, Each of the layers of the fire-resistant covering material 13, 14, 15, 23 (230), 24, 25 is formed by allocating a plurality of pieces of fire-resistant covering material, The joints of the multiple pieces of fire-resistant coating material in the fire-resistant coating material 13, 14·23 (230), 24 on the inner layer side and the joints of the multiple pieces of fire-resistant coating material in the fire-resistant coating material 14, 15·230, 24, 25 superimposed on the outer layer side are set so as not to overlap.

[0013] According to the invention described in claim 4, the joints formed by the multiple pieces of fire-resistant coating material in the fire-resistant coating material 13, 14·23 (230), 24 on the inner layer side and the joints formed by the multiple pieces of fire-resistant coating material in the fire-resistant coating material 14, 15·230, 24, 25 superimposed on the outer layer side are set so as not to overlap, thereby improving fire resistance performance compared to when the joints overlap, for example.

[0014] The invention described in claim 5 is, for example, as shown in Figs. 2 to 7, in the fire-resistant covering structure for the structure described in claim 1, Each layer of the fire-resistant covering material in the multiple layers of fire-resistant covering materials 13, 14, 15, 23 (230), 24, 25 provided on each of the four side surfaces is formed in a rectangular shape that is long in the longitudinal direction along the length direction of the structure and short in the lateral direction perpendicular to the length direction of the structure, The multiple layers of fire-resistant coating materials 13, 14, 15, 23 (230), 24, 25 are characterized in that the fire-resistant coating materials 14, 15, 24, 25 located on the outer layer side have longer short-side lengths, and both short-side end portions thereof protrude outward more than both short-side end portions of the fire-resistant coating materials 13, 14, 23 (230), 24 located on the inner layer side.

[0015] According to the invention of claim 5, both short-side edge portions of the multiple-layer fire-resistant covering materials 13, 14, 15, 23 (230), 24, 25 provided on each of the four side surfaces are formed in a stepped shape that protrudes outward toward the outer layer, so that both short-side edge portions of the multiple-layer fire-resistant covering materials 13, 14, 15, 23 (230), 24, 25 provided on mutually orthogonal sides of the four side surfaces of the structure can be fitted together. This allows the multiple-layer fire-resistant covering materials 13, 14, 15, 23 (230), 24, 25 provided on each of the four side surfaces to be closely attached to each other, thereby improving fire resistance performance.

[0016] The invention described in claim 6 is, for example, as shown in Figs. 2 to 7, in the fire-resistant covering structure for a structure described in claim 5, The outer layer fire-resistant covering materials 14, 15, 24, 25 of the multiple layers of fire-resistant covering materials 13, 14, 15, 23 (230), 24, 25, excluding the innermost layer fire-resistant covering material 13, 23 (230), are fixed to the fire-resistant covering materials 13, 14, 15, 23 (230), 24, 25 on other sides arranged in a perpendicular direction.

[0017] According to the invention described in claim 6, the outer layer fire-resistant coating materials 14, 15, 24, 25, excluding the innermost layer fire-resistant coating material 13, 23 (230), are fixed to the fire-resistant coating materials 13, 14, 15, 23 (230), 24, 25 on other sides arranged in perpendicular directions, thereby increasing the adhesion between the multiple layers of fire-resistant coating materials 13, 14, 15, 23 (230), 24, 25 arranged on each of the four sides, and improving fire resistance performance.

[0018] The invention described in claim 7 is, for example, as shown in Figs. 2 to 8, in the fire-resistant covering structure of the structure described in claim 5 or 6, The multiple layers of fire-resistant coating materials 13, 14, 15, 23 (230), 24, 25 are characterized in that the longitudinal lengths of the fire-resistant coating materials 13, 14, 23 (230), 24 located on the inner layer side are longer, and both longitudinal end portions thereof protrude outward more than both longitudinal end portions of the fire-resistant coating materials 14, 15, 24, 25 located on the outer layer side.

[0019] According to the invention described in claim 7, both longitudinal side ends of the multiple-layer fire-resistant covering materials 13, 14, 15, 23 (230), 24, 25 provided on each of the four side surfaces are formed in a stepped shape that protrudes outward toward the inner layer, so that at the joint between the column 10 and the beam 20, the longitudinal side ends of the multiple-layer fire-resistant covering materials 13, 14, 15 provided on the side surfaces of the column 10 can be fitted so as to match the longitudinal side ends of the multiple-layer fire-resistant covering materials 23 (230), 24, 25 provided on the upper or lower surface of the beam 20. As a result, the multiple-layer fire-resistant covering materials 13, 14, 15, 23 (230), 24, 25 can be closely attached to each other at the joint between the column 10 and the beam 20, thereby improving fire resistance performance. [Effects of the Invention]

[0020] According to the present invention, the fire resistance performance of a structure can be improved by using fire-resistant coating materials stacked in multiple layers, and the fire-resistant coating materials stacked in multiple layers can be easily supported on the surface of the structure. Moreover, since it is possible to construct relatively large buildings using wood, it can contribute to realizing a carbon-free society by promoting carbon neutrality and achieving the goals of the SDGs. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is a schematic diagram illustrating the structure of a wooden building. [Figure 2] FIG. 1 is a perspective view showing a fire-resistant covering structure for a wooden prefabricated column. [Figure 3] This is a cross-sectional view showing the fire-resistant coating structure of a wooden assembly column. [Figure 4]FIG. 2 is a front view showing each layer of fire-resistant covering material used in the fire-resistant covering structure of a wooden prefabricated column. [Figure 5] FIG. 1 is a perspective view showing a fire-resistant coating structure of a wooden prefabricated beam. [Figure 6] FIG. 2 is a cross-sectional view showing a fire-resistant coating structure of a wooden prefabricated beam. [Figure 7] FIG. 2 is a front view showing each layer of fire-resistant covering material used in the fire-resistant covering structure of the wooden prefabricated beam. [Figure 8] This is a vertical cross-sectional view showing the joint between the fire-resistant covering material of the assembled column and the fire-resistant covering material of the assembled beam. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the embodiments described below are subject to various limitations that are technically preferable for implementing the present invention, but the technical scope of the present invention is not limited to the following embodiments and illustrated examples. Note that the directions in the following embodiments and illustrated examples are set solely for the convenience of explanation.

[0023] In FIG. 1, reference numeral 1 denotes a building. This building 1 is a 10-story high-rise building, and its skeleton 2 is mainly made of wood. In other words, the building 1 of this embodiment is a relatively large wooden building. The skeleton 2 is supported by a foundation 3. Exterior walls 4 made of, for example, ALC (autoclaved lightweight aerated concrete) are attached to the sides of the skeleton 2. A roof 5 is attached to the top surface of the skeleton 2, thereby forming the outer surface of the building 1. The exterior walls 4 are attached to, for example, wall supports 4a provided on the skeleton (see FIG. 8). Furthermore, inside the exterior wall 4 and roof 5, a floor 6 and partition walls 7 are attached to the skeleton 2 to form rooms.

[0024] The skeleton 2 is constructed by joining columns 10 and beams 20 with joint members such as rectangular parallelepiped column-beam joint metal fittings 30, column joint metal fittings 40, and beam joint metal fittings 50. That is, multiple columns 10 are fixed to anchor bolts (not shown) protruding from the foundation 3, and beams 20 are erected between the upper ends of these multiple columns 10 via joint members to construct the first floor of the building 1. Then, columns 10 for the second floor are fixed onto the joint members provided at the upper ends of each of the first floor columns 10, and beams 20 are erected between the upper ends of these multiple columns 10 via joint members to construct the second floor of the building 1. The third and subsequent floors have a similar configuration, and the skeleton 2 is constructed in this manner. In other words, the main body 2 of the building 1 in this embodiment is constructed by a column-beam structure consisting of columns 10 and beams 20 connected via joint members, which are arranged continuously in the horizontal and vertical directions.

[0025] (Regarding wooden prefabricated columns) The pillar 10 is a rectangular cylindrical structure (square cross section) with a hollow interior (center side) as a whole, and as shown in Figures 2 and 3, it is equipped with four frame members 11 and a plurality of intermediate members 12. In other words, the pillar 10 is a wooden assembled pillar constructed by assembling these four frame members 11 and a plurality of intermediate members 12. The pillars 10 are formed in a rectangular cylindrical shape, which contributes to reducing the weight of the body 2.

[0026] The four frame members 11 are arranged at the four corners of the wooden prefabricated column 10. Each frame member 11 is a long member that is square in cross section perpendicular to the longitudinal direction (vertical direction). Although structural laminated timber is used for the frame material 11 in this embodiment, solid square timber (pillar material), LVL (Laminated Veneer Lumber), CLT (Cross Laminated Timber), etc. may also be used. In other words, the frame material 11 is a solid material.

[0027] Sixteen connecting bolts 11a are embedded and fixed in the lower end surface of each frame material 11 so that their lower ends protrude beyond the lower end surface of the frame material 11. Furthermore, four connecting bolts 11a are embedded and fixed in the upper end surface of each frame material 11 so that their upper ends protrude beyond the upper end surface of the frame material 11. A method called glued-in rod (GIR) is used to join the connecting bolts 11a to the frame members 11. This method involves filling the gaps between the connecting bolts 11a and the insertion holes formed in the upper and lower end faces of each frame member 11 with adhesive, and as the adhesive hardens, stress is transmitted via the adhesive force and the connecting bolts 11a, generating joint strength.

[0028] Furthermore, both longitudinal ends (top and bottom ends) of each frame member 11 are covered with metal reinforcing caps 11b and fixed with fasteners such as screws, wood screws, etc. Sixteen holes for the sixteen connecting bolts 11a are formed in the reinforcing caps 11b.

[0029] The intermediate members 12 are provided between the frame members 11 at the four corners that are adjacent in the left-right and front-rear directions (XX' direction and YY' direction). That is, they are bridged (intermediate) between one adjacent frame member 11 and the other adjacent frame member 11 and are fixed thereto. The intermediate members 12, together with the frame members 11, form the four side surfaces (X side, X' side, Y side, Y' side) of the prefabricated wooden column 10. Furthermore, four intermediate members 12 are arranged between adjacent frame members 11, and the surface of the intermediate member 12 located on the front side is flush with the surface of the adjacent frame member 11. In other words, the intermediate member 12 located closest to the front side forms the four side surfaces of the prefabricated wooden column 10 together with the frame members 11 at the four corners. The thickness of the four intermediate members 12 and the width of the side surface of the frame member 11 are set to be equal.

[0030] The intermediate member 12 of this embodiment is made of a so-called architectural wood panel. An architectural wood panel is made by assembling vertical and horizontal frame materials F into a rectangular shape, and then attaching a face material B (e.g., plywood) to one or both sides of this rectangular frame, resulting in a hollow structure. In this embodiment, face material B is attached to both sides. The hollow space is usually filled with a heat insulating material (not shown) such as glass wool or rock wool. Furthermore, an auxiliary crosspiece material C (base crosspiece material) may be attached inside the rectangular frame. In this embodiment, four intermediate members 12 are provided on each side of the wooden prefabricated column 10, and only the intermediate member 12 located on the most obverse side has an auxiliary crosspiece C attached to the inside of the rectangular frame. The auxiliary beam members C are provided at least along the vertical direction of the intermediate member 12 (the height direction of the wooden prefabricated column 10), but may also be provided crossing the horizontal direction of the intermediate member 12. The vertical auxiliary rail material C is disposed inside the rectangular frame of the intermediate member 12 located on the most obverse side, along the center of the intermediate member 12 in the width direction. The intermediate member 12 is hollow inside, which contributes to reducing the weight of the wooden prefabricated column 10.

[0031] Furthermore, when a wooden prefabricated column 10 is assembled using such intermediate members 12, the intermediate members 12 may have the same vertical dimensions and be arranged vertically side by side between adjacent frame members 11, or may have different vertical dimensions and be arranged vertically side by side between adjacent frame members 11.

[0032] The four overlapping intermediate members 12 are bonded together with an adhesive. Each intermediate member 12 is bonded to the frame member 11 with an adhesive, and may also be fastened with screws.

[0033] Column connection hardware 40, which is a joint member, is provided at the upper and lower ends of the wooden prefabricated column 10 described above. The column connection hardware 40 is a hardware that is joined and fixed to the column-beam connection hardware 30. The column connection hardware 40 is formed in a rectangular frame shape by four connecting box-shaped hardware 41 spaced apart in the left and right, front and back directions (XX' direction and YY' direction) and four connecting parts 42 that connect these connecting box-shaped hardware 41 together.

[0034] The connecting box-shaped metal fittings 41 are fixed to the end faces of the four corners of the frame material 11. More specifically, they are fixed in contact with reinforcing caps 11b fixed to both end faces of the frame material 11 in the longitudinal direction. The plate portion of the connecting box metal fitting 41 on the frame material 11 side has through holes through which 16 connecting bolts 11a are inserted. Nuts are fastened to the tips of the 16 connecting bolts 11a inserted into the through holes, allowing the column connecting metal fitting 40 to be fixed to the longitudinal side end faces of the wooden prefabricated column 10. One side of the connecting box-shaped metal fitting 41 is open, and nuts can be tightened through this open area.

[0035] Four through holes 41a are formed in the plate portion of the connecting box metal fitting 41 opposite the frame material 11, through which connecting bolts (not shown) used when connecting the column connecting metal fitting 40 to the column-beam connecting metal fitting 30 or anchor bolts protruding from the foundation 3 are inserted. The operation of tightening nuts onto the tips of the connecting bolts or anchor bolts used for connecting to the column-beam connecting metal fitting 30 is also performed from the above-mentioned open areas.

[0036] The connecting portion 42 is formed by joining the webs of an H-shaped steel beam or two channel steel beams together, and is provided by bridging between adjacent connecting box-shaped metal fittings 41. The flange of this connecting portion 42 on the intermediate member 12 side contacts the end face of the four overlapping intermediate members 12, and is fastened to one of the intermediate members 12 with a screw.

[0037] Of the column joint hardware 40, the one provided at the lower end of the prefabricated wooden column 10 may be referred to as a column base joint hardware, and the one provided at the upper end of the prefabricated wooden column 10 may be referred to as a column capital joint hardware. These column base joint hardware 40 and column capital joint hardware 40 are fixed to the prefabricated wooden column 10 in an upside-down state.

[0038] Fire-resistant covering materials 13, 14, and 15 are attached to the four sides of the wooden prefabricated column 10 with the column base joint metal 40 and column capital joint metal 40 fixed. In other words, not only the frame material 11 and intermediate member 12 but also the column base joint metal 40 and column capital joint metal 40 are covered with the fire-resistant covering materials 13, 14, and 15. In this embodiment, the fire-resistant covering materials 13, 14, 15 are plate-shaped materials such as gypsum boards and calcium silicate boards, and specifically, reinforced gypsum boards are used.

[0039] The fire-resistant coating materials 13, 14, and 15 are provided in multiple layers stacked one on top of the other. The number of layers varies depending on the fire resistance time, with two layers stacked for one-hour fire resistance and three layers stacked for two-hour fire resistance. In this embodiment, three layers are used. Therefore, the fire-resistant coating materials 13, 14, and 15 include a first fire-resistant coating material 13, which is the innermost layer attached directly to the surface of the wooden prefabricated column 10, a second fire-resistant coating material 14, which is the middle layer located outside of it, and a third fire-resistant coating material 15, which is the exposed outermost layer.

[0040] The first fire-resistant covering material 13 is set to have a greater thickness than the second fire-resistant covering material 14 and the third fire-resistant covering material 15. In this embodiment, the thickness is set to, for example, 25 mm. On the other hand, the second fire-resistant covering material 14 and the third fire-resistant covering material 15 have a thickness of, for example, 21 mm, which is thinner than the first fire-resistant covering material 13 .

[0041] Since each of the fire-resistant covering materials 13, 14, and 15 is quite heavy, they are fixed in a state of being divided into a plurality of pieces, as shown in FIGS. Furthermore, because the fire-resistant covering materials 13, 14 located in the outer layers cover the fire-resistant covering materials 13, 14 located in the inner layers, the width dimensions of the fire-resistant covering materials 13, 14 located in the inner layers are narrower. In other words, the left ends of the fire-resistant covering materials 13, 14 located in the inner layers protrude leftward more than the left ends of the fire-resistant covering materials 14, 15 located in the outer layers, and the right ends of the fire-resistant covering materials 13, 14 located in the inner layers protrude rightward more than the right ends of the fire-resistant covering materials 14, 15 located in the outer layers. As a result, at the left and right side ends of the wooden pre-assembled column 10, the multiple layers of fire-resistant covering materials 13, 14, 15 are overlapped to form a staircase pattern. Furthermore, the vertical dimensions of the fire-resistant covering materials 13, 14, 15 are set such that the fire-resistant covering materials 13, 14 located in the inner layers are longer. In other words, the upper ends of the fire-resistant covering materials 13, 14 located in the inner layers protrude upward than the upper ends of the fire-resistant covering materials 14, 15 located in the outer layers, and the lower ends of the fire-resistant covering materials 13, 14 located in the inner layers protrude downward than the lower ends of the fire-resistant covering materials 14, 15 located in the outer layers. As a result, at the upper and lower ends of the wooden pre-assembled column 10, the multiple layers of fire-resistant covering materials 13, 14, 15 are stacked to form a staircase shape.

[0042] As shown in Fig. 4(a), the first fire-resistant covering material 13 is configured by arranging multiple pieces of fire-resistant covering material. In this embodiment, a total of four pieces of the first fire-resistant covering material 13 are used per side, and these four first fire-resistant covering materials 13 have the same dimensions (width dimension) in the left-right direction. In other words, the first fire-resistant covering material 13 is arranged in two pieces vertically and two pieces horizontally. Furthermore, the vertical dimensions of the bottom two sheets are different from those of the top two sheets, but this is not limited to this, and the bottom two sheets may be the same as those of the top two sheets. As a result, the first fire-resistant covering material 13 of the innermost layer is arranged in a state where a cross-shaped joint is formed.

[0043] The first fire-resistant covering material 13 is provided on each of the four sides of the wooden prefabricated column 10, but the width dimensions of each of the two parallel sides are different. That is, as shown in FIG. 3, the width dimension of the first fire-resistant covering material 13 provided on the X side surface of the wooden prefabricated column 10 is set to be equal to the width dimension of the first fire-resistant covering material 13 provided on the X' side surface. On the other hand, the width dimension of the first fire-resistant covering material 13 provided on the Y-side surface of the wooden prefabricated column 10 is set equal to the width dimension of the first fire-resistant covering material 13 provided on the Y'-side surface. The width dimension of the first fire-resistant covering material 13 on the Y-side surface and the Y'-side surface is set longer than the width dimension of the first fire-resistant covering material 13 on the X-side surface and the X'-side surface. Specifically, the width dimension is set longer by the thickness of the first fire-resistant covering material 13 on the X-side surface and the X'-side surface.

[0044] Furthermore, the innermost first fire-resistant covering material 13 is fixed to the wooden parts (frame material 11 and intermediate member 12) of the wooden prefabricated column 10 with screws 16 (fixing material). The screws 16 are basically driven into both widthwise ends of each first fire-resistant covering material 13, but may also be driven into the widthwise center if necessary. As described above, the first fire-resistant covering materials 13 are arranged in two vertical pieces and two horizontal pieces, so that adjacent ends of the two horizontal first fire-resistant covering materials 13 are located in the widthwise center of each side surface of the wooden prefabricated column 10. As shown in Fig. 3, an auxiliary crosspiece C of the intermediate member 12 located closest to the surface is disposed in the widthwise center of each side surface of the wooden prefabricated column 10. Therefore, adjacent ends of the two horizontal first fire-resistant covering materials 13 can be fastened together with screws using the auxiliary crosspiece C as a fixing base. The outer ends of the width direction of the two horizontal first fire-resistant covering materials 13 are fastened to the frame material 11 with screws.

[0045] As shown in Fig. 4(b), the second fire-resistant covering material 14 is configured by allocating multiple pieces of fire-resistant covering material. In this embodiment, a total of three pieces of the second fire-resistant covering material 14 are used per side. Of the three pieces, the middle piece is set to be wide, and the two pieces on the left and right are set to be narrower than the middle piece. The left and right dimensions (width dimensions) of the two second fire-resistant covering materials 14 on the left and right are set to be equal. Furthermore, when three second fire-resistant covering materials 14 are arranged in contact with each other, the left-right dimension (width dimension) is set to be longer than the left-right dimension (width dimension) of the first fire-resistant covering material 13. When the first fire-resistant covering material 13 and the second fire-resistant covering material 14 are overlapped, the left and right side edges of the second fire-resistant covering material 14 protrude laterally beyond the left and right side edges of the first fire-resistant covering material 13. The second fire-resistant covering material 14 in the middle layer is arranged with two vertical joints formed on the left and right sides, so that they do not overlap with the joints in the first fire-resistant covering material 13 in the innermost layer.

[0046] The two narrower left and right second fire-resistant covering materials 14 have their widthwise ends fixed to the first fire-resistant covering material 13 (and the second fire-resistant covering material 14 in the perpendicular direction) by staples 17. To explain in more detail, of the second fire-resistant covering materials 14 provided on the X side and the X' side, the two narrower second fire-resistant covering materials 14 have their ends on the middle second fire-resistant covering material 14 side fixed to the first fire-resistant covering material 13 on the same surface with staples 17, but their outer ends are fixed to the side end face of the first fire-resistant covering material 13 in a perpendicular direction with staples 17. In addition, of the second fire-resistant covering materials 14 provided on the Y side and the Y' side, the two narrower second fire-resistant covering materials 14 have their ends on the middle second fire-resistant covering material 14 side fixed to the first fire-resistant covering material 13 on the same surface with staples 17, but their outer ends are fixed to the side end faces of the second fire-resistant covering material 14 in the perpendicular direction with staples 17. Furthermore, a single wide second fire-resistant covering material 14 provided in the middle has both widthwise ends and a widthwise center portion fixed to the first fire-resistant covering material 13 by staples 17 .

[0047] As shown in Fig. 4(c), the third fire-resistant covering material 15 is configured by allocating multiple pieces of fire-resistant covering material. In this embodiment, a total of two pieces of the third fire-resistant covering material 15 are used per side. These two pieces of the third fire-resistant covering material 15 are set to have the same dimension (width dimension) in the left-right direction. Furthermore, when two third fire-resistant covering materials 15 are arranged side by side in contact with each other, the left-right dimension (width dimension) is set to be longer than the left-right dimension (width dimension) of the second fire-resistant covering material 14. When the second fire-resistant covering material 14 and the third fire-resistant covering material 15 are overlapped, the left and right side edges of the third fire-resistant covering material 15 protrude laterally beyond the left and right side edges of the second fire-resistant covering material 14. The third fire-resistant covering material 15, the outermost layer, is arranged with one vertical joint formed in the middle, so that it does not overlap with the joints in the second fire-resistant covering material 14, the middle layer.

[0048] The third fire-resistant covering material 15 is arranged in two horizontal pieces. Each third fire-resistant covering material 15 is fixed to the second fire-resistant covering material 14 (and the third fire-resistant covering material 15 in the perpendicular direction) by staples 17 at both widthwise ends and the widthwise center. To explain in more detail, each third fire-resistant covering material 15 provided on the X side and the X' side has its central end fixed to the second fire-resistant covering material 14 on the same surface with staples 17, while its outer end is fixed to the side end face of the second fire-resistant covering material 14 in a perpendicular direction with staples 17. In addition, each third fire-resistant covering material 15 provided on the Y side and Y' side has its central end fixed to the second fire-resistant covering material 14 on the same surface with staples 17, while its outer end is fixed to the side end face of the third fire-resistant covering material 15 in a perpendicular direction with staples 17.

[0049] The positions at which the fire-resistant covering materials 13, 14, and 15 are fixed with the screws 16 and staples 17 are not limited to the above example and can be changed as appropriate without departing from the spirit of the present invention. However, it is essential to fix the four corners of the fire-resistant covering materials 13, 14, and 15 and parts that are prone to bending with the screws 16 and staples 17. Also, the screws 16 and staples 17 should not overlap with the screws 16 or staples 17 on the underlying surface. Although not shown, the screws 16 and staples 17 should also be provided at appropriate intervals in the longitudinal direction of the fire-resistant covering materials 13, 14, and 15.

[0050] (About prefabricated wooden beams) The beam 20 is a rectangular cylindrical structure (with a rectangular cross section) with a hollow interior (center side) as a whole, and as shown in Figures 5 and 6, it includes four frame members 21 and a plurality of intermediate members 22. In other words, the beam 20 is a wooden prefabricated beam constructed by assembling these four frame members 21 and a plurality of intermediate members 212. The beams 20 are formed in a rectangular cylindrical shape, which contributes to reducing the weight of the body 2.

[0051] The four frame members 21 are arranged at the four corners of the prefabricated wooden beam 20. Each frame member 21 is a long material that is square in cross section perpendicular to the length direction (horizontal direction). The frame material 21 of this embodiment is a solid material similar to the frame material 11 of the wooden prefabricated column 10 described above.

[0052] Sixteen connecting bolts 21 a are embedded and fixed to both end surfaces of each frame material 21 in the longitudinal direction, with their tips protruding from the end surfaces of the frame material 21 . Furthermore, a method called Glued-in Rod (GIR) is used to join the connecting bolts 21a and the frame material 21.

[0053] Furthermore, both longitudinal ends (top and bottom ends) of each frame member 21 are covered with metal reinforcing caps 21b and fixed with fasteners such as screws, wood screws, etc. Sixteen holes for the sixteen connecting bolts 21a are formed in the reinforcing caps 21b.

[0054] The intermediate members 22 are provided between the frame members 21 at the four corners that are adjacent in the vertical and horizontal directions (ZZ' and YY' directions). That is, they are bridged (intermediate) between one adjacent frame member 21 and the other adjacent frame member 21 and are fixed thereto. The intermediate members 22, together with each frame member 21, form the four side surfaces (Z side, Z' side, Y side, Y' side) of the prefabricated wooden beam 20. Furthermore, four intermediate members 22 are placed one on top of the other between adjacent frame members 21, and the surface of the intermediate member 22 located on the front side is flush with the surface of the adjacent frame member 21. That is, the intermediate member 22 located closest to the front side forms the four side surfaces of the prefabricated wooden beam 20 together with the frame members 21 at the four corners. Furthermore, the thickness of the four intermediate members 22 and the width of the side surface of the frame material 21 (the dimension in the short direction) are set to be equal.

[0055] The intermediate member 22 of this embodiment is made of a so-called architectural wood panel. An architectural wood panel is made by assembling vertical and horizontal frame materials F into a rectangular shape, and then attaching face material B to one or both sides of this rectangular frame, resulting in a hollow structure. In this embodiment, face material B is attached to both sides. The hollow space is usually filled with insulating material (not shown) such as glass wool or rock wool. Furthermore, an auxiliary crosspiece material C (base crosspiece material) may be attached inside the rectangular frame. In this embodiment, four intermediate members 22 are provided on each side of the wooden prefabricated beam 20, and only the intermediate member 22 located on the most obverse side has an auxiliary crosspiece C attached to the inside of the rectangular frame. The auxiliary beam members C are provided at least along the vertical direction of the intermediate member 22 (the length direction of the prefabricated wooden beam 20), but may also be provided crossing the horizontal direction of the intermediate member 22. The vertical auxiliary rail material C is disposed inside the rectangular frame of the intermediate member 22 located on the most obverse side, along the center of the intermediate member 22 in the width direction. The intermediate member 22 is hollow inside, which contributes to reducing the weight of the prefabricated wooden beam 20.

[0056] Furthermore, when the wooden prefabricated beam 20 is assembled using such intermediate members 22, the intermediate members 22 may have the same length dimensions and be arranged side by side in the longitudinal direction between adjacent frame members 21, or may have different length dimensions and be arranged side by side in the longitudinal direction between adjacent frame members 21.

[0057] The four overlapping intermediate members 22 are bonded together with an adhesive. Each intermediate member 22 is bonded to the frame member 21 with an adhesive, and may also be fastened with screws.

[0058] Beam connection hardware 50, which is a joint member, is provided at both longitudinal ends of the wooden prefabricated beam 20. The beam connection hardware 50 is a hardware that is joined and fixed to the column-beam connection hardware 30. The beam connecting hardware 40 is formed in a rectangular frame shape by four connecting box-shaped hardware 51 arranged at a distance in the vertical and horizontal directions (ZZ' direction and YY' direction) and four connecting parts 52 that connect these connecting box-shaped hardware 51 to each other.

[0059] The connecting box-shaped metal fittings 51 are fixed to the end faces of the frame material 21 at the four corners. More specifically, they are fixed in contact with the reinforcing caps 21b fixed to both longitudinal end faces of the frame material 21. The fixing method is the same as in the case of the wooden prefabricated column 10 described above, and nuts are tightened onto the 16 connecting bolts 21a of the frame material 21 from the open parts of the connecting box-shaped metal fittings 51.

[0060] The plate portion of the connecting box hardware 51 opposite the frame material 21 is formed with one through hole 51a through which a connecting bolt (not shown) is inserted when connecting the beam connecting hardware 50 to the column-beam connecting hardware 30. The operation of tightening a nut onto the tip of the connecting bolt used to connect to the column-beam connecting hardware 30 is also performed from the above-mentioned open area.

[0061] The connecting portion 52 is formed by joining the webs of an H-shaped steel beam or two channel steel beams together, and is provided by bridging between adjacent connecting box-shaped metal fittings 51. The flange of this connecting portion 52 on the intermediate member 22 side contacts the end face of the four overlapping intermediate members 22, and is fastened to one of the intermediate members 22 with a screw.

[0062] Fire-resistant covering materials 23, 24, and 25 are attached to the four sides of the wooden prefabricated beam 20 with the beam connectors 50 fixed to both ends. In other words, not only the frame members 21 and intermediate members 22 but also the beam connectors 50 are covered with the fire-resistant covering materials 23, 24, and 25. In this embodiment, the fire-resistant covering materials 23, 24, and 25 are reinforced gypsum boards.

[0063] The fire-resistant covering materials 23, 24, and 25 are provided in multiple layers. However, in the case of the prefabricated wooden beam 20, since the underside is most susceptible to the effects of fire, one more layer of fire-resistant covering material 23 is attached to the underside than to the top and side surfaces. The number of layers of fire-resistant covering material 23, 24, 25 provided on the top and side surfaces of the prefabricated wooden beam 20 varies depending on the fire resistance time, with two layers for one-hour fire resistance and three layers for two-hour fire resistance. One layer is added for the bottom surface. In this embodiment, three layers are used for the top surface and side surfaces, and four layers are used for the bottom surface. In this embodiment, the fire-resistant coating materials 23, 24, 25 include a first fire-resistant coating material 23 which is the innermost layer attached directly to the surface (top and bottom surfaces, side surfaces) of the wooden prefabricated beam 20, an additional fire-resistant coating material 230 which is added to the underside to improve fire resistance performance, a second fire-resistant coating material 24 which is an intermediate layer located outside the first fire-resistant coating material 23 and the additional fire-resistant coating material 230, and a third fire-resistant coating material 25 which is the exposed outermost layer.

[0064] The first fire-resistant covering material 23 and the additional fire-resistant covering material 230 are set to have a greater thickness than the second fire-resistant covering material 24 and the third fire-resistant covering material 25. In this embodiment, the thickness is set to, for example, 25 mm. On the other hand, the second fire-resistant covering material 24 and the third fire-resistant covering material 25 are, for example, 21 mm thick, which is thinner than the first fire-resistant covering material 23 and the additional fire-resistant covering material 230.

[0065] Since each of the fire-resistant covering materials 23 (230), 24, and 25 is quite heavy, they are fixed in a state of being divided into a plurality of pieces, as shown in FIGS. Furthermore, the width of the fire-resistant covering materials 23 (230), 24, 25 located in the inner layer is narrower than that of the fire-resistant covering materials 23 (230), 24 located in the outer layer, because the fire-resistant covering materials 23 (230), 24 located in the inner layer are covered by the fire-resistant covering materials 24, 25 located in the outer layer. In other words, the left ends of the fire-resistant covering materials 23, 24 located in the inner layer protrude leftward more than the left ends of the fire-resistant covering materials 24, 25 located in the outer layer, and the right ends of the fire-resistant covering materials 23 (230), 24 located in the inner layer protrude rightward more than the right ends of the fire-resistant covering materials 24, 25 located in the outer layer. As a result, at the left and right side ends of the prefabricated wooden beam 20, the multiple layers of fire-resistant covering materials 23 (230), 24, 25 are overlapped to form a staircase pattern. Furthermore, the length of the fire-resistant covering materials 23 (230), 24, 25 is set so that the fire-resistant covering materials 23 (230), 24 located in the inner layers are longer. In other words, both longitudinal ends of the fire-resistant covering materials 23 (230), 24 located in the inner layers protrude outward more than both longitudinal ends of the fire-resistant covering materials 24, 25 located in the outer layers. As a result, at both longitudinal ends of the wooden pre-assembled beam 20, the multiple layers of fire-resistant covering materials 23 (230), 24, 25 are overlapped to form a staircase pattern. In Fig. 7, the diagrams (a), (d), and (f) in the left column show the layout of the fire-resistant covering materials 23, 24, and 25 provided on the side surfaces of the prefabricated wooden beam 20, and the diagrams (b), (c), (e), and (g) in the right column show the layout of the fire-resistant covering materials 23, 24, and 25 provided on the bottom and top surfaces of the prefabricated wooden beam 20. However, the additional fire-resistant covering material 230 shown in Fig. 7(c) is provided only on the bottom surface of the prefabricated wooden beam 20.

[0066] As shown in Figures 7(a) and 7(b), the first fire-resistant covering material 23 is configured by allocating multiple pieces of fire-resistant covering material. In this embodiment, a total of four pieces of the first fire-resistant covering material 23 are used per side, and these four first fire-resistant covering materials 23 have the same length and width dimensions. In other words, each side has two first fire-resistant covering materials 23 allocated in the lengthwise direction and two in the widthwise direction. Furthermore, the length and width dimensions of all four pieces are the same. As a result, the first fire-resistant covering material 23 of the innermost layer is arranged in a state where a cross-shaped joint is formed.

[0067] The first fire-resistant covering material 23 is provided on the top, bottom and side surfaces of the prefabricated wooden beam 20, but the width dimensions of each of the two parallel surfaces are different. In other words, the width dimension (dimension in the ZZ' direction) of the first fire-resistant covering material 23 provided on the Y side (one side) of the wooden assembled beam 20 is set to be equal to the width dimension (dimension in the ZZ' direction) of the first fire-resistant covering material 23 provided on the Y' side (other side). On the other hand, the width dimension (dimension in the YY' direction) of the first fire-resistant covering material 23 provided on the Z-side surface (lower surface) of the wooden prefabricated beam 20 is set equal to the width dimension (dimension in the YY' direction) of the first fire-resistant covering material 23 provided on the Z'-side surface (upper surface). The width dimensions of the first fire-resistant covering material 23 on the Z-side surface and Z'-side surface are set shorter than the width dimensions of the first fire-resistant covering material 23 on the Y-side surface and Y'-side surface.

[0068] Furthermore, the innermost first fire-resistant covering material 23 is fixed to the wooden parts (frame material 21 and intermediate member 22) of the wooden prefabricated beam 20 with screws 26 (fixing material). The screws 26 are basically driven into both widthwise ends of each first fire-resistant covering material 23, but may be driven into the widthwise center if necessary. As described above, the first fire-resistant covering materials 23 on each side are arranged two in the longitudinal direction and two in the lateral direction, so that adjacent ends of two first fire-resistant covering materials 23 aligned in the lateral direction are located in the widthwise center of each side of the wooden prefabricated beam 20. As shown in Fig. 6, an auxiliary crosspiece C of the intermediate member 22 positioned closest to the surface is located in the widthwise center of each side of the wooden prefabricated beam 20. Therefore, adjacent ends of two first fire-resistant covering materials 23 aligned in the lateral direction can be fastened together with screws using the auxiliary crosspiece C as a fixing base. The outer ends in the width direction of the two first fire-resistant covering materials 23 arranged side by side in the short direction are fastened to the frame material 21 with screws.

[0069] As shown in Fig. 7(c), the additional fire-resistant covering material 230 is configured by allocating multiple pieces of fire-resistant covering material. In this embodiment, a total of nine pieces of additional fire-resistant covering material 230 are used. In other words, the additional fire-resistant covering material 230 is allocated in three pieces in the longitudinal direction and three pieces in the lateral direction. In the longitudinal direction, the additional fire-resistant covering material 230 at the center in the longitudinal direction is the longest, and the additional fire-resistant covering materials 230 at both ends in the longitudinal direction are set to the same longitudinal dimension. In the short side direction, the additional fire-resistant covering material 230 at the center in the short side direction is the shortest and narrowest. On the other hand, the additional fire-resistant covering materials 230 at both ends in the short side direction are set to the same short side dimension and are set to be wider than the additional fire-resistant covering material 230 at the center. The additional fire-resistant covering material 230 added to the underside of the wooden prefabricated beam 20 (the underside of the first fire-resistant covering material 23 located on the underside side) is arranged with two joints formed in the longitudinal direction and two in the lateral direction, so that it does not overlap with the joints in the first fire-resistant covering material 13 of the innermost layer. Each of the additional fire-resistant covering materials 230 has both short-side ends and a short-side center portion fixed to the first fire-resistant covering material 23 located on the underside by staples 27.

[0070] As shown in Figs. 7(d) and (e), the second fire-resistant covering material 24 has different layouts on the Y side and Y' side and on the Z side and Z' side. As shown in Fig. 7(d), the second fire-resistant covering material 24 on the Y side and Y' side is configured by allocating multiple pieces of fire-resistant covering material. In this embodiment, a total of five pieces are used for the second fire-resistant covering material 24 on the Y side and Y' side. In other words, two pieces that are longer in the short direction are provided at both longitudinal ends, and three second fire-resistant covering materials 24 lined up in the short direction are allocated between these two second fire-resistant covering materials 24 in the long direction. Of the three second fire-resistant covering materials 24 in the short direction, the central second fire-resistant covering material 24 is set wider than the two outer second fire-resistant covering materials in the short direction. As shown in Figure 7(e), the second fire-resistant covering material 24 on the Z-side and Z'-side is configured by allocating multiple pieces of fire-resistant covering material. In this embodiment, a total of six pieces of second fire-resistant covering material 24 are used on the Z-side and Z'-side. In other words, two pieces of second fire-resistant covering material 24 are allocated in the longitudinal direction and three pieces in the lateral direction. Of the three pieces in the lateral direction, the middle second fire-resistant covering material 24 is set wider than the two pieces on the outside in the lateral direction.

[0071] When three second fire-resistant covering materials 24 are arranged in contact with each other in the short-side direction, the short-side dimension (width dimension) is set to be longer than the short-side dimension (width dimension) of the first fire-resistant covering material 23 and the additional fire-resistant covering material 230. When the first fire-resistant covering material 23 and the additional fire-resistant covering material 230 are overlapped with the second fire-resistant covering material 24, the short-side side end portions of the second fire-resistant covering material 24 protrude outward beyond the short-side side end portions of the first fire-resistant covering material 23 and the additional fire-resistant covering material 230.

[0072] The second fire-resistant covering material 24 on the Y-side and Y'-side is arranged with two joints along the short side at both longitudinal ends and two joints along the longitudinal direction between these two joints, so that they do not overlap with the joints in the first fire-resistant covering material 23, the innermost layer. The second fire-resistant covering material 24 on the Z-side and Z'-side is arranged with two longitudinal joints and one lateral joint, so that the joints in the innermost first fire-resistant covering material 23 and additional fire-resistant covering material 230 do not overlap.

[0073] The second fire-resistant coating material 24 is fixed to the first fire-resistant coating material 23 or the additional fire-resistant coating material 230 by staples 27. More specifically, of the second fire-resistant covering materials 24 provided on the Y side and the Y' side, the two narrower second fire-resistant covering materials 24 are fixed to the first fire-resistant covering material 23 on the same surface at the center portion in the short direction and at the end portion on the side of the middle second fire-resistant covering material 24 with staples 27. The outer end portion (outside in the ZZ' direction) is fixed to the side end face of the first fire-resistant covering material 23 in the perpendicular direction with staples 27. In addition, of the second fire-resistant covering materials 24 provided on the Z side (bottom surface), the two narrower second fire-resistant covering materials 24 have their ends on the middle second fire-resistant covering material 24 side fixed to the additional fire-resistant covering material 230 with staples 27, but their outer ends (outside in the YY' direction) are fixed with staples 27 to the side end face of the second fire-resistant covering material 24 in the perpendicular direction. On the other hand, of the second fire-resistant covering materials 24 provided on the Z' side (top surface), the two narrower second fire-resistant covering materials 24 have their ends on the middle second fire-resistant covering material 24 side fixed to the first fire-resistant covering material 23 on the same surface with staples 27, but their outer ends (outside in the YY' direction) are fixed with staples 27 to the side end surface of the second fire-resistant covering material 24 in the perpendicular direction.

[0074] Furthermore, a wide second fire-resistant covering material 24 is provided at the center of the short side of each face, and both widthwise ends and the widthwise center are fixed to the first fire-resistant covering material 23 or the additional fire-resistant covering material 230 by staples 27. In addition, two second fire-resistant covering materials 24 are formed longitudinally on the Y side and Y' side along the short side of the wooden assembled beam 20, and at least four corners are fixed to the first fire-resistant covering material 23 by staples 27.

[0075] As shown in Figs. 7(f) and (g), the third fire-resistant covering material 25 has different layouts on the Y side and Y' side and on the Z side and Z' side. As shown in Figure 7(f), the third fire-resistant covering material 25 on the Y side and the Y' side is configured by allocating multiple pieces of fire-resistant covering material. In this embodiment, a total of five pieces are used for the third fire-resistant covering material 25 on the Y side and the Y' side. In other words, two pieces that are long in the short direction are provided at both longitudinal ends, and three second fire-resistant covering materials 25 lined up in the short direction are allocated between these two second fire-resistant covering materials 25 in the long direction. Note that of the three second fire-resistant covering materials 25 in the short direction, the central second fire-resistant covering material 25 is set to be narrower than the two outer second fire-resistant covering materials in the short direction. As shown in Figure 7(g), the third fire-resistant covering material 15 on the Z-side and Z'-side is configured by allocating multiple pieces of fire-resistant covering material. In this embodiment, a total of four pieces of third fire-resistant covering material 25 are used on the Z-side and Z'-side. In other words, two pieces that are long in the short direction are provided at both longitudinal ends, and two second fire-resistant covering materials 25 lined up in the short direction are allocated between these two second fire-resistant covering materials 25 in the long direction. The two third fire-resistant covering materials 15 lined up in the short direction have the same width.

[0076] When three third fire-resistant covering materials 25 on the Y side and Y' side are arranged in contact with each other in the short direction, the short-side dimension (dimension in the ZZ' direction) of each third fire-resistant covering material 25 is set to be longer than the short-side dimension (dimension in the ZZ' direction) of the second fire-resistant covering material 24 on the Y side and Y' side. When the second fire-resistant covering material 24 on the Y side and Y' side and the third fire-resistant covering material 25 on the Y side and Y' side are overlapped, the short-side side end of each third fire-resistant covering material 25 protrudes outward beyond the short-side side end of the second fire-resistant covering material 24 on the Y side and Y' side. When two third fire-resistant covering materials 25 on the Z side and the Z' side are arranged in contact with each other in the short direction, the short-side dimension (dimension in the YY' direction) of the third fire-resistant covering material 25 is set to be longer than the short-side dimension (dimension in the YY' direction) of the second fire-resistant covering material 24 on the Z side and the Z' side. When the second fire-resistant covering material 24 on the Z side and the Z' side and the third fire-resistant covering material 25 on the Z side and the Z' side are overlapped, the short-side side end of the third fire-resistant covering material 25 protrudes outward more than the short-side side end of the second fire-resistant covering material 24 on the Z side and the Z' side.

[0077] The third fire-resistant covering materials 25 on the Y-side and Y'-side are arranged with two joints along the short side at both longitudinal ends and two joints along the longitudinal direction between these two joints. The middle third fire-resistant covering material 25 is set narrower than the middle second fire-resistant covering material 24. This prevents overlap with the joints in the second fire-resistant covering material 24 in the middle layer. The third fire-resistant covering material 25 on the Z-side and Z'-side is arranged with two joints along the short side at both longitudinal ends and one joint in the middle along the longitudinal direction between these two joints, so that it does not overlap with the joints in the second fire-resistant covering material 24 in the middle layer.

[0078] The third fire-resistant covering material 25 is fixed to the second fire-resistant covering material 24 or the third fire-resistant covering material 25 by staples 27 . More specifically, of the third fire-resistant covering materials 25 provided on the Y side and the Y' side, the two wider second fire-resistant covering materials 24 are fixed to the second fire-resistant covering material 24 on the same surface at the center of the short side and at the end on the middle third fire-resistant covering material 25 side with staples 27. The outer end (outside in the ZZ' direction) is fixed to the side end face of the second fire-resistant covering material 24 in the perpendicular direction with staples 27. Furthermore, the third fire-resistant covering material 25 on the Z side and Z' side is fixed to the second fire-resistant covering material 24 with staples 27 at the center portion in the short direction and at the end portion on the side of the adjacent third fire-resistant covering material 15. The outer end portion (outside in the YY' direction) is fixed with staples 27 to the side end face of the third fire-resistant covering material 25 in the perpendicular direction.

[0079] The positions at which the fire-resistant covering materials 23, 24, and 25 are fixed with the screws 26 and staples 27 are not limited to the above example and can be changed as appropriate without departing from the spirit of the present invention. However, it is essential that the four corners of the fire-resistant covering materials 23, 24, and 25 and parts that are prone to bending are fixed with the screws 26 and staples 27. In addition, the screws 26 and staples 27 should not overlap with the screws 26 or staples 27 on the underlying surface. Although not shown, the screws 26 and staples 27 should also be provided at appropriate intervals in the longitudinal direction of the fire-resistant covering materials 23, 24, and 25.

[0080] (Regarding the joint between the wooden prefabricated column and the wooden prefabricated beam) The column-beam connection hardware 30, which is a joint member, is formed in a rectangular parallelepiped shape, and as shown in Figure 8, column connection hardware 40 is connected to the bottom and top surfaces, and beam connection hardware 50 is connected to the side surfaces. The wooden assembled column 10 is joined to the column-beam connection hardware 30 by connecting the column-beam connection hardware 30 to the column connection hardware 40 (column base connection hardware 40, column capital connection hardware 40) with connecting bolts (not shown). In addition, the wooden prefabricated beam 20 is joined to the column-beam joint hardware 30 by connecting the column-beam joint hardware 30 and the beam joint hardware 50 with connecting bolts (not shown).

[0081] The side of the connecting box-shaped metal fitting 41 in the column connecting hardware 40 is flush with the side of the column-beam connecting hardware 30. In addition, the top and bottom surfaces of the connecting box-shaped metal fitting 51 in the beam connecting hardware 50 are flush with the top and bottom surfaces of the column-beam connecting hardware 30. Furthermore, the surface (bottom or top surface) of the column connecting hardware 40 facing the column-beam connecting hardware 30 and the top or bottom surface of the prefabricated wooden beam 20 (beam connecting hardware 50) are positioned in the same horizontal plane.

[0082] As described above, the column joint hardware 40 and the beam joint hardware 50 are positioned perpendicular to each other via the column-beam joint hardware 30. The fire-resistant covering materials 13, 14, and 15 provided on the surface of the prefabricated wooden column 10 and the fire-resistant covering materials 23, 24, and 25 provided on the surface of the prefabricated wooden beam 20 must fit together without any gaps to ensure fire resistance. 8, the multiple layers of fire-resistant covering materials 13, 14, 15 are overlapped to form a staircase at the upper and lower ends of the prefabricated wooden column 10. Furthermore, the multiple layers of fire-resistant covering materials 23 (230), 24, 25 are overlapped to form a staircase at both longitudinal ends of the prefabricated wooden beam 20. As a result, the multiple layers of fire-resistant covering materials 13, 14, 15 in the prefabricated wooden column 10 and the multiple layers of fire-resistant covering materials 23, 24, 25 in the prefabricated wooden beam 20 are in contact with each other in an interlocking state.

[0083] More specifically, the inner layers of the fire-resistant covering materials 13, 14, and 15 attached to each side of the wooden prefabricated column 10 are set to be longer in vertical dimension. In addition, the fire-resistant covering materials 13 and 14 on the inner layer side protrude upward or downward relative to the fire-resistant covering materials 14 and 15 on the outer layer side, so that the upper and lower ends of the fire-resistant covering materials 13, 14, and 15 on the inner layer side are formed in a stepped shape. On the other hand, the multiple layers of fire-resistant covering materials 23 (230), 24, 25 attached to the top, bottom, and both side surfaces of the prefabricated wooden beam 20 are set so that the length dimension is longer toward the inner layer. Also, the fire-resistant covering materials 23 (230), 24 on the inner layer side protrude in the longitudinal direction relative to the fire-resistant covering materials 24, 25 on the outer layer side, so that both longitudinal ends of the multiple layers of fire-resistant covering materials 23 (230), 24, 25 are formed in a stepped shape.

[0084] 8, in this embodiment, the first fire-resistant covering material 13 attached to the prefabricated wooden column 10 is set to a length that does not reach the end face of the column connection hardware 40 (the surface that contacts the column-beam connection hardware 30). On the other hand, the first fire-resistant covering material 23 attached to the prefabricated wooden beam 20 is set to a length that reaches the end face of the beam connection hardware 50 (the surface that contacts the column-beam connection hardware 30). As a result, the multiple layers of fire-resistant covering materials 13, 14, 15 on the prefabricated wooden column 10 and the multiple layers of fire-resistant covering materials 23, 24, 25 on the prefabricated wooden beam 20 are interlocked with each other without any gaps.

[0085] According to this embodiment, the following excellent effects are achieved. In other words, each of the four longitudinal sides of the structure comprising wooden frame members 11 and 21 and wooden intermediate members 12 and 22 is provided with plate-like fire-resistant covering materials 13, 14, 15, 23 (230), 24, 25 superimposed in multiple layers, and therefore the fire resistance performance of the rectangular cylindrical structure constituting the column 10 or beam 20 can be improved by the fire-resistant covering materials 13, 14, 15, 23 (230), 24, 25 superimposed in multiple layers. Furthermore, of the multiple layers of fire-resistant coating materials 13, 14, 15, 23 (230), 24, 25, the innermost layer of fire-resistant coating material 13, 23 is fixed to the framing members 11, 21 at the four corners and the intermediate members 12, 22 with fasteners 16, 26. The fasteners 16, 26 fastened to the intermediate members 12, 22 secure the innermost layer of fire-resistant coating material 13, 23 to the long base members C provided in the hollow interiors of the intermediate members 12, 22 and extending along the length of the structure. This enables the innermost layer of fire-resistant coating material 13, 23 to be fixed to the core of the structure (i.e., the framing members 11, 21 at the four corners and the base members C). This improves the attachment stability of the innermost layer of fire-resistant coating material 13, 23 to the surface of the structure, making it easier to support the outer layer of fire-resistant coating materials 14, 15, 24, 25 superimposed on the innermost layer of fire-resistant coating material 13, 23.

[0086] In addition, the innermost layer of fire-resistant coating material 13 / 23 is set to have a thickness dimension larger than that of the fire-resistant coating materials 14, 15 / 24, and 25 located on the outer layer side of the innermost layer of fire-resistant coating material 13 / 23 (230), so that the fire resistance performance can be improved by the amount of the increased thickness.

[0087] Furthermore, the outer layer fire-resistant coating materials 14, 15, 230, 24, 25 are fixed to the fire-resistant coating materials 13, 14, 23 (230), 24 located immediately inside them. Therefore, when three or more layers of fire-resistant coating materials 13, 14, 15, 23 (230), 24, 25 are stacked, the load on the innermost fire-resistant coating material 13, 23 can be reduced, which contributes to improving the installation stability of multiple layers of fire-resistant coating materials 13, 14, 15, 23 (230), 24, 25.

[0088] In addition, the joints formed by the multiple pieces of fire-resistant coating material in the fire-resistant coating material 13, 14·23 (230), 24 on the inner layer side and the joints formed by the multiple pieces of fire-resistant coating material in the fire-resistant coating material 14, 15·230, 24, 25 superimposed on the outer layer side are set so as not to overlap, thereby improving fire resistance performance compared to, for example, when the joints overlap.

[0089] Furthermore, since both short-side edge portions of the multiple-layer fire-resistant covering materials 13, 14, 15, 23 (230), 24, 25 provided on each of the four side surfaces are formed in a stepped shape that protrudes outward toward the outer layer, both short-side edge portions of the multiple-layer fire-resistant covering materials 13, 14, 15, 23 (230), 24, 25 provided on mutually orthogonal sides of the four side surfaces of the structure can be fitted together so that they match. This allows the multiple-layer fire-resistant covering materials 13, 14, 15, 23 (230), 24, 25 provided on each of the four side surfaces to be closely attached to each other, thereby improving fire resistance performance.

[0090] Furthermore, the outer layer fire-resistant coating materials 14, 15, 24, 25, excluding the innermost layer fire-resistant coating material 13, 23 (230), are fixed to the fire-resistant coating materials 13, 14, 15, 23 (230), 24, 25 on the other sides arranged in perpendicular directions, thereby increasing the adhesion between the multiple layers of fire-resistant coating materials 13, 14, 15, 23 (230), 24, 25 arranged on each of the four sides, and improving the fire resistance performance.

[0091] Furthermore, since both longitudinal side edges of the multiple-layered fire-resistant covering materials 13, 14, 15, 23 (230), 24, 25 provided on each of the four side surfaces are formed in a stepped shape that protrudes outward toward the inner layer, at the joint between the column 10 and the beam 20, the longitudinal side edges of the multiple-layered fire-resistant covering materials 13, 14, 15 provided on the side surfaces of the column 10 can be fitted so as to match the longitudinal side edges of the multiple-layered fire-resistant covering materials 23 (230), 24, 25 provided on the upper or lower surface of the beam 20. This allows the multiple-layered fire-resistant covering materials 13, 14, 15, 23 (230), 24, 25 to be closely attached to each other at the joint between the column 10 and the beam 20, thereby improving fire resistance performance. [Explanation of symbols]

[0092] 1. Building 2 skeleton 10 Wooden assembly pillar 11 Frame material 12 Intermediate parts 13 First fireproof covering material 14 Second fireproof covering material 15 Third fireproof covering material 20 Wooden assembly beam 21 Frame material 22 Intermediate parts 23 First fireproof covering material 230 Additional fireproof cladding 24 Second fireproof covering material 25 Third fireproof covering material 30 Column and beam joint hardware 40 Column joint hardware 50 Beam joint hardware F Frame material B-side material C Auxiliary beam

Claims

1. A fire-resistant covering structure for a structure formed in a rectangular cylindrical shape and constituting a column or beam in the skeleton of a building, The structure is Wooden frame members arranged at the four corners of the structure and formed long along the length direction of the structure; and an intermediate wooden member formed long along the length of the structure, the intermediate wooden member being fixed to the frame members at the four corners of each of the four sides along the length of the structure, the intermediate wooden member being formed long along the length of the structure. the intermediate member is a panel body formed in a hollow shape and having an internal hollow portion, and is provided with a base bar member that is long and extends along the longitudinal direction of the structure, A plate-shaped fire-resistant covering material is provided on each of the four side surfaces along the length direction of the structure, the plate-shaped fire-resistant covering material being stacked in multiple layers, A fire-resistant coating structure for a structure, characterized in that the innermost layer of fire-resistant coating material among the multiple layers is fixed to the frame materials at the four corners and the intermediate member with fixing materials, and the fixing materials fastened to the intermediate member fix the innermost layer of fire-resistant coating material using the base crosspiece material as a fixing base.

2. The fire-resistant covering structure for a structure according to claim 1, A fire-resistant coating structure for a structure, characterized in that the innermost layer of the multiple layers of fire-resistant coating materials is set to have a thickness dimension larger than that of the fire-resistant coating materials located outer than the innermost layer of fire-resistant coating material.

3. The fire-resistant covering structure for a structure according to claim 1, A fire-resistant coating structure for a structure, characterized in that the outer layer fire-resistant coating materials, excluding the innermost layer fire-resistant coating material, among the multiple layers of fire-resistant coating materials, are fixed to the inner layer fire-resistant coating material on which they are superimposed.

4. The fire-resistant covering structure for a structure according to claim 1, Each layer of the fire-resistant coating material in the multiple-layer fire-resistant coating material is configured by allocating multiple pieces of fire-resistant coating material, A fire-resistant coating structure for a structure, characterized in that the joints of the multiple pieces of fire-resistant coating material in the inner layer side and the joints of the multiple pieces of fire-resistant coating material in the fire-resistant coating material superimposed on the outer layer side are set so as not to overlap.

5. The fire-resistant covering structure for a structure according to claim 1, Each layer of the fire-resistant coating material in the plurality of layers provided on each of the four side surfaces is formed in a rectangular shape that is long in a longitudinal direction along the length direction of the structure and short in a lateral direction perpendicular to the length direction of the structure, A fire-resistant coating structure for a structure, characterized in that the multiple layers of fire-resistant coating material are set so that the fire-resistant coating material located on the outer layer has a longer short-side length, and both side ends in the short-side direction protrude outward beyond both side ends in the short-side direction of the fire-resistant coating material located on the inner layer.

6. The fire-resistant covering structure for a structure according to claim 5, A fire-resistant coating structure for a structure, characterized in that the fire-resistant coating material on the outer layer side, excluding the innermost fire-resistant coating material, of the multiple layers of fire-resistant coating material is fixed to the fire-resistant coating material on the other side surface provided in a perpendicular direction.

7. The fire-resistant coating structure for a structure according to claim 5 or 6, A fire-resistant coating structure for a structure, characterized in that the longitudinal length of the multiple layers of fire-resistant coating material is set longer for the fire-resistant coating material located on the inner layer side, and both longitudinal side ends of the fire-resistant coating material located on the outer layer side protrude outward beyond both longitudinal side ends of the fire-resistant coating material located on the outer layer side.

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