Fireproof covering structure for wooden foundation in mixed structure building

Abstract

To provide a fireproof covering structure for wooden foundation for fire prevention purpose in a mixed structure building formed by joining a wooden upper-floor structure to an RC lower-floor structure with a packing interposed between the wooden foundation and the top surface of the RC structure.SOLUTION: In a fireproof covering structure 10 to cover for fire resistance a wooden foundation 11 that is installed at a joint part with an upper surface 21c of an upper reinforced concrete part 21a on a lower floor structure 21 and forms the foundation part of a wooden upper floor structure 22, the wooden foundation 11 is placed on the upper surface 21c of the upper reinforced concrete part 21a of the lower floor structure 21 with a packing 12 interposed therebetween at the joint with the upper surface 21c, and an outer side surface 11a is covered by a fireproof covering wall material 14. A fireproof putty 13 is filled in a U-shaped recess 16 surrounded with a lower end surface 14a of the fireproof covering wall material 14, the upper end surface 21c of the upper reinforced concrete part 21a, and a side surface 12a of the packing 12.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a fire-resistant covering structure for a wooden foundation in a mixed-structure building, which is formed by joining a wooden upper floor structure to a lower floor structure having an upper reinforced concrete section at its upper end. [Background technology]

[0002] In wooden buildings, it is common to install a foundation (wooden foundation) made of wooden square timbers with foundation packing interposed on the reinforced concrete foundation that rises from the ground surface and supports the building, and then erect framework columns from the installed wooden foundation to build the first floor structure (see, for example, Patent Document 1). Also, in the heat-insulating structure of Patent Document 1, in order to improve the heat insulation of the foundation packing, for example, a heat insulating material is placed to cover the outdoor side of the foundation packing.

[0003] On the other hand, the fire resistance required for exterior walls with fireproof structure or semi-fireproof performance is that the exterior wall will not easily break down in the event of a fire in a neighboring building (non-damageability), and will not transmit heat that would cause the fire to spread to the back side of the exterior wall (heat insulation). In addition, the fire resistance (fireproof equipment, etc.) required for openings in exterior walls (parts that are at risk of fire spreading in semi-fireproof areas, etc.) is that the flames will not easily penetrate in the event of a fire in a neighboring building (flame insulation). These are intended to prevent the spread of fire in the neighboring building to the building in question for a certain period of time (30 minutes for fireproof structure, 20 minutes for semi-fireproof performance and fireproof equipment).

[0004] It is also important to ensure that gaps caused by foundation packing between the reinforced concrete foundation, which rises from the ground level, and the wooden base do not become a route for the spread of fire in the event of a fire in the adjacent building; however, taking into consideration the following: in the event of a fire in the adjacent building, the heating that would be received by the foundation, which is located at the bottom of the building, is smaller than the heating that would be received by the exterior walls above this (the shape factor is smaller); inside the foundation there are almost no stored combustible materials (furniture, interior decoration, etc.) that would cause the fire to spread rapidly if the fire spread inside the building; and in a full-scale fire experiment on a three-story wooden apartment building (conducted by the Building Research Institute of the Ministry of Construction in 1996), there was no fire spreading from openings in the foundation, it is said that the foundation part close to ground level is unlikely to become a weak point in the event of a fire in the adjacent building, even if there are no special fire prevention measures similar to those for exterior walls and openings in exterior walls (see, for example, non-patent document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2018-165448 A [Non-patent literature]

[0006] [Non-Patent Document 1] Architectural Institute of Japan, Fire Prevention Committee, April 2012, "Q&A on Fire Resistance of Housing Materials," page 9 Summary of the Invention [Problem to be solved by the invention]

[0007] In response to this, in recent years, from the viewpoint of wood utilization, various mixed-structure buildings have been planned for construction of mid- to high-rise buildings, preferably 3 to 9 stories high, by joining a wooden upper floor structure to a lower floor structure made of reinforced concrete (RC). When constructing a building by joining a wooden upper floor structure to a lower floor structure having, for example, a slab portion at the upper end portion of the RC upper reinforced concrete portion of the RC structure, the wooden foundation, which is preferably installed with a packing interposed between the upper end surface of the rising wall erected from the periphery of the RC slab portion at the upper end portion of the lower floor structure, is located in the middle portion of the building in the height direction, and is therefore considered to be highly likely to become a weak point in the event of a fire in the neighboring building.

[0008] In other words, in a mixed structure building formed by joining a wooden upper floor structure on top of a lower floor structure with an upper reinforced concrete section made of reinforced concrete at the top end, the fit of placing gasket between the wooden foundation and the upper reinforced concrete section of RC will be at a height above the second floor floor level and away from the ground level. Therefore, it is not the fit at the bottom of the building where no fire prevention measures are required, and while it is desirable to take fire prevention and resistance measures, the current situation is that specific measures regarding such fire prevention measures have not been fully considered.

[0009] In addition, when it comes to fitting a structure where a gasket is placed between the wooden foundation and the upper reinforced concrete part of the RC structure at a height above the second floor level, making a major change to the existing general fitting at the bottom, where a foundation gasket is placed between the RC foundation and the wooden foundation, will result in more design considerations, so it is wise to keep the design as it is as much as possible.

[0010] The present invention aims to provide a fire-resistant covering structure for a wooden foundation in a mixed-structure building formed by joining a wooden upper floor structure to a lower floor structure having an upper reinforced concrete section made of reinforced concrete at the top end, which has a simple configuration in which a gasket is interposed between the wooden foundation and the upper reinforced concrete section, and which can provide effective fire prevention measures at a height away from the ground surface. [Means for solving the problem]

[0011] The present invention provides a fire-resistant coating structure for a wooden foundation in a mixed structure building formed by joining a wooden upper floor structure to a lower floor structure having an upper end portion of an upper reinforced concrete section made of reinforced concrete (RC), the fire-resistant coating structure being installed at the joint with the upper surface of the upper reinforced concrete section of the lower floor structure to provide fire-resistant coating for the wooden foundation that constitutes the foundation of the upper floor structure, the wooden foundation being placed on the upper surface of the upper reinforced concrete section of the lower floor structure at the joint with the upper surface of the upper reinforced concrete section of the lower floor structure with a gasket interposed therebetween, the outer side being covered by a fire-resistant coating wall material, and the U-shaped recess surrounded by the lower end surface of the fire-resistant coating wall material, the upper surface of the upper reinforced concrete section of the lower floor structure, and the side of the gasket being filled with fire-resistant putty, thereby achieving the above-mentioned object.

[0012] Furthermore, it is preferable that the fire-resistant coating structure of the wooden base in the mixed structure building of the present invention is configured by attaching a bent metal plate extending in the longitudinal direction of the wooden base, the bent metal plate having a cross-sectional shape capable of continuously covering the lower edge portion of the outer surface of the fire-resistant coating wall material, the lower end surface of the fire-resistant coating wall material, and the side surface of the filled fire-resistant putty.

[0013] In addition, it is preferable that the fire-resistant coating structure of the wooden base in the mixed-structure building of the present invention is such that insulating wood covering the lower edge portion of the outer surface of the fire-resistant coating wall material is attached by extending it in the longitudinal direction of the wooden base.

[0014] Furthermore, in the fire-resistant coating structure of the wooden foundation in the mixed-structure building of the present invention, it is preferable that the upper surface of the lower floor structure to which the upper floor structure is joined via the wooden foundation is the upper end surface of a rising wall provided on the outer periphery of the upper reinforced concrete section.

[0015] Furthermore, in the fire-resistant coating structure of the wooden foundation in the mixed-structure building of the present invention, it is preferable that the lower floor structure is a 1- to 5-story structure and the upper floor structure is a 2- to 4-story structure. Effect of the Invention

[0016] According to the fire-resistant coating structure for the wooden foundation in a mixed structure building of the present invention, in a mixed structure building formed by joining a wooden upper floor structure to a lower floor structure having an upper reinforced concrete section made of reinforced concrete at the top end, a gasket is interposed between the wooden foundation and the upper reinforced concrete section, and the structure is fitted at a height away from the ground level, providing effective fire prevention measures with a simple configuration. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1 is a schematic cross-sectional view illustrating a mixed-structure building in which a fire-resistant covering structure for a wooden foundation according to a preferred embodiment of the present invention is adopted. [Diagram 2] FIG. 2 is an enlarged view of part A in FIG. 1, illustrating a fire-resistant covering structure for a wooden foundation in a mixed-structure building according to a preferred embodiment of the present invention. [Diagram 3] FIG. 3 is an enlarged view of part A in FIG. 1, illustrating a fire-resistant covering structure for a wooden foundation in a mixed-structure building according to another preferred embodiment of the present invention. [Figure 4] FIG. 4 is an enlarged view of part A in FIG. 1, illustrating a fire-resistant covering structure for a wooden foundation in a mixed-structure building according to still another preferred embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] A fire-resistant coating structure 10 for a wooden foundation according to a preferred embodiment of the present invention (see Figure 2) is used in a mixed-structure building 20, for example a three-story building as shown in Figure 1, in which the first floor is a lower floor structure 21 made of reinforced concrete and the second and third floors are made of wood and the upper floor structure 22 is made of wood. The fire-resistant coating structure 10 for a wooden foundation according to a preferred embodiment of the present invention (see Figure 2) is used in a mixed-structure building 20, for example a three-story building in which the first floor is a lower floor structure 21 made of reinforced concrete and the second and third floors are made of wood and the upper floor structure 22 is made of wood. The fire-resistant coating structure 10 for a wooden foundation 11 (see Figure 2) is used in a mixed-structure building 20, for example a three-story building as shown in Figure 1, ... and the lower floor structure 21 is made of wood and the upper floor structure 22 is made of wood and the lower floor structure 21 is made of wood and the upper floor structure 22 is made of wood and the lower floor structure 21 is made of wood and the upper floor structure 22 is made of wood and the upper floor structure 22 is made of wood and the upper floor structure 22 is made of wood and the upper floor structure 21 is made of wood and the lower floor structure 21 is made of wood and the upper floor structure 22 is made of wood and the upper floor structure 21 is made of

[0019] In other words, in the case of a conventional technology in which a wooden foundation is installed with a foundation gasket interposed between it and an RC foundation formed by rising from the ground surface, the wooden foundation is disposed at the foundation part located at the lowest part of the building, so it is thought that there is little possibility of it becoming a weak point in the event of a fire in an adjacent building even without special fire prevention measures. However, in the mixed structure building 20 of this embodiment, the fit of interposing gasket 12 between the wooden foundation 11 and the RC upper reinforced concrete part 21a at the upper end part of the lower floor structure 21 is at a height position away from the ground surface above the second floor floor level, so a technical problem arises in which it is desirable to consider the need for new fire prevention and resistance measures.

[0020] The fire-resistant covering structure 10 for a wooden foundation in this embodiment is intended to solve the technical problems specific to a mixed-structure building 20 formed by joining a wooden upper floor structure 22 to a lower floor structure 21 having an upper reinforced concrete section 21a made of reinforced concrete at its upper end. A gasket 12 is interposed between the wooden foundation 11 and the upper reinforced concrete section 21a, which is the RC structure of the skeleton, and the structure is fitted at a height away from the ground surface, allowing for effective fire prevention measures to be taken with a simple configuration.

[0021] The fire-resistant covering structure 10 for the wooden foundation in the mixed-structure building 20 of this embodiment is a fire-resistant covering structure for fire-resistant covering the wooden foundation 11, which is installed at the joint between the upper surface 21c of the upper reinforced concrete part 21a of the lower floor structure 21 and forms the foundation part of the upper floor structure 22 in the mixed-structure building 20 formed by joining a wooden upper floor structure 22 to the lower floor structure 21 having an upper end part of an upper reinforced concrete part 21a of RC construction, as shown in Figs. 1 and 2. Thus, the wooden foundation 11 is placed on the upper surface 21c of the upper reinforced concrete part 21a of the lower floor structure 21 at the joint with said upper surface 21c via a gasket 12, and the outer side surface 11a is covered with a fire-resistant covering wall material 14. A U-shaped recess 16 surrounded by the lower end surface 14a of the fire-resistant covering wall material 14, the upper surface 21c of the upper reinforced concrete part 21a of the lower floor structure, and the side surface 12a of the gasket 12 is filled with fire-resistant putty 13.

[0022] In addition, in this embodiment, the upper surface 21c of the lower floor structure 21 to which the upper floor structure 22 is joined via the wooden foundation 11 serves as the upper reinforced concrete portion 21a, and is preferably the upper end surface of a RC-constructed rising wall 21b erected on the outer periphery of the slab portion.

[0023] In this embodiment, the lower floor structure 21 constituting the first floor of the mixed-structure building 20 is preferably entirely made of RC, including the upper reinforced concrete part 21a at the upper end. That is, the lower floor structure 21 is preferably entirely made of RC by erecting it from, for example, a foundation base 21d (see FIG. 1) made of RC to form the outer wall part 21e made of RC, and supporting it on the upper end of the outer wall part 21e to form the upper reinforced concrete part 21a. Here, in the present invention, the lower floor structure 21 having the upper reinforced concrete part 21a made of RC at its upper end does not necessarily have to be entirely made of RC, and may be a structure having at least the upper end part made of RC upper reinforced concrete part 21a, such as a lower floor structure whose columns and beams are made of steel (S construction).

[0024] In this embodiment, the upper floor structure 22 constituting the second and third floors of the mixed structure building 20 is a wooden building, for example, by frame construction or frame wall construction. That is, the upper floor structure 22 is preferably a wooden building in its entirety, with the upper end surface of the RC-constructed rising wall 21b erected from the outer periphery of the slab as the upper reinforced concrete part 21a being supported by the wooden base 11 placed on the upper surface 21c of the upper reinforced concrete part 21a with a packing 12 interposed therebetween as described later, and the columns 15b are assembled in an erected state, and beams 22b and the like are assembled. Here, in the present invention, the upper floor structure 22 may include a non-wooden part, such as a RC or S-construction part, except for the wooden base 11. Furthermore, the wooden foundation 11 does not necessarily have to be placed on the upper end surface of a RC-constructed rising wall 21b erected from the outer periphery of the slab as the upper surface 21c of the upper reinforced concrete part 21a of the lower floor structure 21 to which the upper floor structure 22 is joined via the wooden foundation 11, but the surface of the slab part in the inner area surrounded by the rising wall 21b can be used as the upper surface 21c of the upper reinforced concrete part 21a of the lower floor structure 21 to which the upper floor structure 22 is joined, and the wooden foundation 11 can be placed on this in a predetermined position with a packing 12 interposed therebetween. A flat slab part without a rising wall 21b erected from the outer periphery can be used as the upper reinforced concrete part 21a, and the foundation 11 can be placed on a predetermined position on the upper surface 21c of this, with a packing 12 interposed therebetween.

[0025] In this embodiment, the wooden foundation 11, which is preferably installed at the joint with the upper surface 21c of the upper reinforced concrete part 21a of the lower floor structure 21 and forms the foundation part of the upper floor structure 22, is made of wooden square timber having a rectangular (square) cross section of about 105 to 120 mm x 105 to 120 mm, for example, like a conventional wooden foundation installed with a foundation packing interposed between the RC foundation formed by rising from the ground surface. The wooden foundation 11 is installed continuously in the center part of the upper end surface 21c of the rising wall 21b of the upper reinforced concrete part 21a, which is preferably formed with a width of about 160 to 200 mm, along the extension direction of the upper end surface 21c, preferably over the entire area of ​​the rising wall 21b. As described above, the wooden base 11 is preferably placed on top of the upper end surface 21c of the rising wall 21b of the upper reinforced concrete section 21a, with a gasket 12 interposed between the wooden base 11 and the upper end surface 21c.

[0026] In this embodiment, the packing 12 preferably interposed between the upper end surface 21c of the rising wall 21b of the upper reinforced concrete part 21a and the wooden foundation 11 can be the same as the conventional packing interposed between the foundation of the reinforced concrete structure formed by rising from the ground surface and the wooden foundation. More specifically, various types of KISO packings manufactured by JOTO TECHNO CO., LTD. described in "General Catalog 2023-2024, KISO Packing Series" can be used. The packing 12 has a thickness (height) of, for example, about 20 mm and is formed to have a width of, for example, about 105 mm, similar to the wooden foundation 11, and is provided continuously in the central part of the upper end surface 21c of the rising wall 21b of the upper reinforced concrete part 21a, which is preferably formed with a width of about 160 mm, along the extension direction of the upper end surface 21c, preferably over the entire area of ​​the rising wall 21b. As a result, exposed portions with a width of about 27.5 mm are left on both sides of the packing 12 at the inner and outer side edge portions of the upper end surface 21c of the rising wall 21b. The exposed portions are filled with fireproof putty 13, which will be described later, so as to cover them.

[0027] The fire-resistant covering wall material 14, which is placed on the upper end surface 21c of the rising wall 21b with the packing 12 interposed therebetween and covers the outer side surface 11a of the wooden base 11, forms a wall base material for the exterior wall portion of the wooden upper floor structure 22. The fire-resistant covering wall material 14 is installed in a state where it covers the outer side surface 11a of the wooden base 11 by extending downward to the lower end edge of the wooden base 11 and being attached. In this embodiment, the fire-resistant covering wall material 14 is made of, for example, gypsum board with a thickness of about 21 mm, which is known as a fire-resistant covering material, and is preferably attached in a state where two sheets are stacked, extending downward to the outer side surface 11a of the wooden base 11 as a wall base material for the exterior wall portion. In this embodiment, on the indoor side of the wooden base 11, a covering wall material 15a made of, for example, plywood which forms the wall base material of the inner wall portion is attached by extending downward to the lower edge of the wooden base 11, and the inner portion sandwiched between the outer fire-resistant covering wall material 14 and the covering wall material 15a is filled with known soundproofing material and heat insulating material.

[0028] In this embodiment, at the joint between the wooden foundation 11 and the upper end surface 21c of the rising wall 21b of the upper reinforced concrete portion 21a of the lower floor structure 21, the lower end surface 14a of the fireproof covering wall material 14, the upper surface 21c of the upper reinforced concrete portion 21a of the lower floor structure, and the U-shaped recess 16 surrounded by the side surface 12a of the packing 12 are filled with fireproof putty 13. As the fireproof putty 13, for example, known fireproof putty such as aluminum hydroxide-based, sodium silicate-based, acrylic-based, and epoxy-based putty can be used. More specifically, the product names "Fireproof putty hardening type non-combustible type" (manufactured by Inaba Denki Sangyo Co., Ltd.), "AS Bond" (manufactured by A&A Material Co., Ltd.), and "Tiger Gyptite" (manufactured by Yoshino Gypsum Co., Ltd.) can be preferably used as the fireproof putty 13. The fireproof putty 13 is clay-like and can change shape to fit the filled area until it dries and hardens, so it can be easily filled into the U-shaped recess 16. Once solidified, the fireproof putty does not shrink even when heated and maintains its shape. This makes it possible to effectively prevent high-temperature flames and heat from being transmitted to the wooden base 11 through gaps that form on the lower end surface 14a of the fireproof covering wall material 14 or the upper end surface 21c of the rising wall 21b in the event of a fire in an adjacent building, for example, and to prevent carbonization due to heating, especially at the lower corners of the wooden base 11.

[0029] As a result, according to the fire-resistant covering structure 10 for the wooden foundation in the mixed structure building of this embodiment, in the mixed structure building 20 formed by joining the wooden upper floor structure 22 to the lower floor structure 21 having the upper reinforced concrete section 21a of RC construction, a gasket 12 is interposed between the wooden foundation 11 and the upper end surface 21c of the rising wall 21b of the upper reinforced concrete section 21a, which is preferably the RC structure, at a height away from the ground, and a foundation gasket is interposed between the conventional RC foundation and the wooden foundation, making it possible to take more effective fire prevention measures, for example to prevent the wooden foundation 11 from being carbonized due to heating, without making major changes to the general fit at the bottom of a building, by using a simple configuration such as filling the U-shaped recess 16 with fire-resistant putty 13, without increasing the number of design considerations.

[0030] Furthermore, as a result, even if a fire breaks out in the mixed-structure building 20 due to the influence of a fire in the neighboring building, the wooden foundation 11, which is a weak point in the framework of the wooden upper floor structure 22, can be fire-resistant coated, effectively preventing the effects of the fire from spreading to the wooden foundation 11 and the wooden columns, beams, and walls supported by it. This allows the entire framework of the upper floor structure 22, including the wooden foundation 11, to be maintained even after the fire is extinguished, thereby imparting excellent fire resistance to the mixed-structure building 20.

[0031] Fig. 3 illustrates a fire-resistant covering structure 10' for a wooden foundation in a mixed-structure building 20 according to another preferred embodiment of the present invention. In the fire-resistant covering structure 10' shown in Fig. 3, in addition to the above-mentioned fire-resistant covering structure 10 shown in Fig. 2, a bent metal plate 17 is attached in the length direction of the wooden foundation 11, preferably having a cross-sectional shape capable of continuously covering the lower end edge of the outer surface 14b of the fire-resistant covering wall material 14, the lower end surface 14a of the fire-resistant covering wall material 14, and the side of the filled fireproof putty 13. The bent metal plate 17 can be easily obtained by bending a metal plate into a desired shape.

[0032] The fireproof covering structure 10' for a wooden base according to another embodiment shown in Fig. 3 also has the same effect as the fireproof covering structure 10 according to the above embodiment, and in particular, the bent metal plate 17 is attached to cover the lower end edge of the outer surface 14b of the fireproof covering wall material 14, the lower end surface 14a of the fireproof covering wall material 14, and the side of the filled fireproof putty 13. This makes it possible to more effectively fireproof cover the part of the wooden base 11 that is a weak point in the event of a fire by suppressing the transmission of high heat from the outside to the wooden base 11 through the lower end of the fireproof covering wall material 14 and the boundary between the lower end surface 14a of the fireproof covering wall material 14 and the fireproof putty 13. The bent metal plate 17 does not necessarily need to be attached continuously over the entire length of the wooden base 11, and can be attached in a spliced ​​state, intermittently, or partially only at the necessary places.

[0033] FIG. 4 illustrates a fire-resistant covering structure 10" for a wooden foundation in a mixed structure building according to another preferred embodiment of the present invention. In the fire-resistant covering structure 10" shown in FIG. 4, in addition to the above-mentioned fire-resistant covering structure 10 shown in FIG. 2, a piece of insulating wood 18, which preferably covers the lower edge of the outer surface 14b of the fire-resistant covering wall material 14, is attached extending in the length direction of the wooden foundation 11. The insulating wood 18 can be a rod-shaped piece of wood, preferably having a rectangular cross-sectional shape, made of lumber, laminated lumber, LVL, plywood, or the like.

[0034] The fire-resistant covering structure 10" for a wooden base according to another embodiment shown in FIG. 4 also has the same effects as the fire-resistant covering structure 10 according to the above embodiment. In particular, the insulating wood 18 is attached to cover the lower edge of the outer surface 14b of the fire-resistant covering wall material 14. This prevents high heat during a fire from being transmitted from the outside to the wooden base 11 via the lower end of the fire-resistant covering wall material 14 for, for example, 10 to 20 minutes until the insulating wood 18 is completely burned, and makes it possible to more effectively fire-proof the part of the wooden base 11 that is a weak point during a fire. The insulating wood 18 does not necessarily have to be attached continuously over the entire length of the wooden base 11, and can be attached in a spliced ​​state, intermittently, or partially only at necessary locations. The insulating wood 18 can also be attached in a state where it protrudes downward from the lower end of the outer surface 14b of the fire-resistant covering wall material 14.

[0035] The present invention is not limited to the above-mentioned embodiments, and various modifications are possible. For example, a mixed structure building formed by joining a wooden upper floor structure to a lower floor structure having an upper end portion of an RC upper reinforced concrete part is not necessarily a three-story building in which the first floor portion is an RC lower floor structure and the second and third floor portions are wooden upper floor structures. Preferably, for example, in a 2-9 story mixed structure building with a 1-hour to 2-hour fire-resistant structure in which the lower floor structure is a 1-6 story RC structure and the upper floor structure is a 1-4 story wooden structure, the fire-resistant coating structure of the wooden foundation of the present invention can be adopted at the joint between the RC lower floor structure and the wooden upper floor structure. The fire-resistant coating wall material does not necessarily have to be gypsum board, and may be any other known fire-resistant coating wall material known as a wall base material for fire-resistant coating. Soundproofing material and heat insulating material may be installed in the space surrounded by the fire-resistant covering wall material, the covering wall material, and the pillars. [Explanation of symbols]

[0036] 10,10',10” Fireproof coated wooden base 11 Wooden base 11a Outer side 12 Packing 12a side 13 Fireproof putty 14 Wall materials for fireproof coating 14a Lower end surface 14b External surface 15a Wall covering materials 15b pillar 16 U-shaped recess 17 Bent sheet metal 18. Wood for insulation 20 Mixed structure buildings 21 Lower floor structure 21a Upper reinforced concrete section 21b Rising wall 21c Top surface (top surface of upper reinforced concrete part, top surface of lower floor structure) 21d Foundation base 21e Exterior wall part 22 Upper Floor Structure 22b Beam

Claims

1. A fire-resistant covering structure for a wooden foundation in a mixed-structure building formed by joining a wooden upper-floor structure to a lower-floor structure having an upper end portion of an upper reinforced concrete section, the fire-resistant covering structure for a wooden foundation in a mixed-structure building is installed at the joint between the upper surface of the upper reinforced concrete section of the lower-floor structure and the upper surface of the upper reinforced concrete section to provide fire-resistant covering for the wooden foundation that constitutes the foundation portion of the upper-floor structure, The wooden foundation is placed on the upper surface of the upper reinforced concrete part of the lower floor structure at the joint with the upper surface of the upper reinforced concrete part of the lower floor structure, with a gasket interposed between the wooden foundation and the upper surface, and its outer side is covered with a fire-resistant covering wall material.The fire-resistant covering structure for a wooden foundation in a mixed structure building has a U-shaped recess surrounded by the lower end surface of the fire-resistant covering wall material, the upper surface of the upper reinforced concrete part of the lower floor structure, and the side of the gasket, and is filled with fire-resistant putty.

2. A fire-resistant coating structure for a wooden foundation in a mixed-structure building as described in claim 1, in which a bent metal plate having a cross-sectional shape that can continuously cover the lower edge portion of the outer surface of the fire-resistant coating wall material, the lower end surface of the fire-resistant coating wall material, and the side of the filled fire-resistant putty is attached by extending in the longitudinal direction of the wooden foundation.

3. 2. A fire-resistant coating structure for a wooden foundation in a mixed-structure building according to claim 1, wherein insulating wood covering the lower edge of the outer surface of the fire-resistant coating wall material is attached extending in the longitudinal direction of the wooden foundation.

4. A fire-resistant coating structure for a wooden foundation in a mixed-structure building as described in any one of claims 1 to 3, wherein the upper surface of the lower floor structure to which the upper floor structure is joined via the wooden foundation is the upper end surface of a rising wall provided on the outer periphery of the upper reinforced concrete section.

5. A fire-resistant coating structure for a wooden foundation in a mixed-structure building as described in any one of claims 1 to 3, wherein the upper floor structure is a 1 to 4 story structure and the mixed-structure building is 2 to 9 stories.

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