Fire-resistant covering structure for h-shaped steel beam

Abstract

To provide a fire-resistant covering structure for an H-shaped steel beam equipped with a wooden fire-resistant covering material that is easy to install on site.SOLUTION: A fire-resistant covering structure 1 for an H-shaped steel beam includes fire-resistant covering mounting members 9 arranged on both sides of a web 5 of an H-shaped steel beam 7, a first wooden side fire-resistant covering member 11 arranged on one side of the H-shaped steel beam 7 and covering the side of an upper flange 3a of the H-shaped steel beam 7 and a portion of the web 5, a second wooden side fire-resistant covering member 13 arranged on the other side of the H-shaped steel beam 7 and covering the side of the upper flange 3a of the H-shaped steel beam 7 and a portion of the web 5, and a lower fire-resistant covering member 15 covering portions of the lower flange 3b of the H-shaped steel beam 7 and both sides of the web 5 that are not covered by the first side fire-resistant covering member 11 and the second side fire-resistant covering member 13 on both sides of the web 5. The first side fire-resistant covering member 11, the second side fire-resistant covering member 13, and the lower fire-resistant covering member 15 are fastened to the fire-resistant covering mounting members 9.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This relates to a fire-resistant covering structure for an H-shaped steel beam, which is composed of two flanges and one web and is placed below a floor member. [Background technology]

[0002] In order to prevent the building from collapsing during a fire until people can evacuate, the main structural components must be fire-resistant. Because steel has the property of losing strength at high temperatures, steel-framed buildings are fitted with fire-resistant coatings to prevent the temperature of structural components from rising during a fire. In particular, columns and beams are the main components that support a building, so they require high fire resistance. To prevent the temperature of the coated steel frame from rising even under high temperatures during a fire, non-combustible and highly heat-insulating materials such as sprayed rock wool, rock wool felt, calcium silicate board, fire-resistant paint, and gypsum board are generally used for fire-resistant covering.

[0003] A conventional fire-resistant covering structure will be briefly described with reference to the drawings. Figure 11 shows a spray-type fire-resistant coating structure using sprayed rock wool 111 for an H-shaped steel beam 7 installed below a floor member 8, where the sprayed rock wool 111 is coated so as to come into contact with the flange 3 and web 5. The one shown in FIG. 12 is an H-shaped steel beam 7 surrounded by a felt-like fire-resistant covering material 113 . What is shown in Figure 13 is three board-shaped fire-resistant covering materials 115 such as calcium silicate boards, fixed to a steel base 117 fixed to an H-shaped steel beam 7 with fastening materials 119 such as screws 53.

[0004] In the case of general fire-resistant coatings such as sprayed rock wool and calcium silicate boards, they are all applied on-site, so the H-shaped steel beams 7 are processed by a steel frame fabricator and then transported to the site, and the fire-resistant coating is applied after the steel frame work is completed.

[0005] In recent years, fire-resistant coating structures using wood have been seen, with the hope that wood's heat-shielding properties will help reduce CO2 emissions. The background to the use of wood is the reduction of CO2 emissions, and it is believed that using wood as a building material will help fix the carbon stored in the wood, leading to a reduction in CO2 emissions.

[0006] As an example of a fire-resistant covering structure using wood, Patent Document 1 discloses a wood-steel hybrid member in which both outer sides of an H-shaped steel beam are covered with a wood covering material. The structure disclosed in Patent Document 1, as shown schematically in Figure 14, covers an H-shaped steel beam 7 with a pair of wooden covering materials 121, and the wooden covering materials 121 are provided with grooves 123 that match the shapes of the upper and lower flanges. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2023-25813 Summary of the Invention [Problem to be solved by the invention]

[0008] During a fire, wood carbonizes from the surface, so it is important for fire resistance performance to ensure that the coating thickness on the side of flange 3 and the underside of lower flange 3b is sufficient for the required fire resistance time. In the case of a conventional structure such as that shown in Figure 14, the size of the wooden covering material 121 depends on the size of the H-shaped steel beam 7. Therefore, when the H-shaped steel beam 7 has a large cross section with a beam depth of nearly 1000 mm, the cross section of the wooden covering material 121 becomes very large and too heavy for a person to carry. Since fireproof covering work for beams on site is generally done manually using aerial work vehicles or the like, workability becomes extremely poor when the size and weight of the wooden covering material 121 are large.

[0009] Therefore, it is considered to coat the material in advance at a factory and then transport it to the site, and the procedure is as follows. First, the steel frame and wood covering material are processed separately. That is, the H-shaped steel beams are processed by a steel frame fabricator, and the wood covering material is manufactured by a lumber manufacturer and then processed by the same manufacturer or a pre-cutting company.

[0010] The H-shaped steel beams, wooden fireproofing cladding, and other components are then transported to a steel frame fabricator, a wood cladding pre-cutting company, or a lumber manufacturer, etc., where they are assembled. After assembly is complete, they are transported to the site.

[0011] In the above construction process, the conventional example has the following problems. Because wood covering materials also serve as interior decoration, transporting them to the site requires careful care to prevent them from getting scratched, dirty, or exposed to the elements, and they cannot be transported in multiple layers, making the process of transporting them time-consuming.

[0012] Furthermore, around the areas where construction is carried out on site, such as the joints of H-shaped steel beams, bolted joints and welded joints must be constructed on site, and they cannot be covered in advance at the factory, so construction on site is inevitable. However, when assembling on-site, the large size and weight pose problems in terms of workability.

[0013] However, it is possible to use a different type of fire-resistant coating on-site, but in this case, the temperature of the steel beams must be kept below approximately 200°C to prevent the wood coating from igniting. However, in general fire-resistant coated structures, specifications such as coating thickness are determined from the perspective of preventing the collapse of steel beams, but these specifications can cause the temperature of the beams to rise to nearly 350°C, so in order to keep the temperature of the steel beams below approximately 200°C, it is necessary to select special fire-resistant coating specifications such as increasing the coating thickness (this is because general fire-resistance certification tests require an average steel temperature of 350°C or less and a maximum temperature of 450°C or less as temperature criteria). As described above, conventional fire-resistant covering structures using wood covering materials have various problems in terms of workability.

[0014] The present invention has been made to solve such problems, and aims to provide a fire-resistant covering structure for H-shaped steel beams equipped with wooden fire-resistant covering material that is easy to install on site. [Means for solving the problem]

[0015] (1) The fire-resistant covering structure for an H-shaped steel beam according to the present invention is a fire-resistant covering structure for an H-shaped steel beam that is composed of two flanges and one web and is placed below a floor member, and includes fire-resistant covering material mounting members placed on both sides of the web of the H-shaped steel beam; a first wooden side fire-resistant covering material disposed on one side of the H-shaped steel beam and covering a side of the upper flange of the H-shaped steel beam and a part of the web; a second wooden side fire-resistant covering material disposed on the other side of the H-shaped steel beam and covering a side surface of the upper flange of the H-shaped steel beam and a part of the web; a lower fire-resistant covering material that covers the lower flange of the H-shaped steel beam and both sides of the web, and the portions of the web on both sides that are not covered by the first side fire-resistant covering material and the second side fire-resistant covering material; The first side fire-resistant covering material, the second side fire-resistant covering material and the lower fire-resistant covering material are fastened to the fire-resistant covering material mounting member.

[0016] (2) Furthermore, in the above (1), the fire-resistant coating material mounting member is located inside both side surfaces of the flange of the H-shaped steel beam in the plate width direction, the first side fire-resistant coating material and the second side fire-resistant coating material have a step portion on which a part of the upper flange of the H-shaped steel beam is placed, and the lower fire-resistant coating material is divided into two in the width direction and has a groove into which the lower flange of the H-shaped steel beam can be inserted.

[0017] (3) Furthermore, in the above (1) or (2), the fire-resistant coating material mounting member is made of a wooden member placed on each side of the web of the H-shaped steel beam, and these two members are connected and fixed by a connecting part that passes through the web.

[0018] (4) Furthermore, in the above (3), the first side fire-resistant covering material, the second side fire-resistant covering material, the lower fire-resistant covering material and the fire-resistant covering material mounting member are fixed by screws arranged in the trench, and filler wood is arranged in the trench to hide the screws.

[0019] (5) In addition, in the above-mentioned (4), the depth of the counterbore provided in the first side fire-resistant covering material and the second side fire-resistant covering material is equal to or greater than the horizontal distance from the surface of the first side fire-resistant covering material and the surface of the second side fire-resistant covering material to the side of the upper flange, The depth of the counterbore provided in the lower fire-resistant covering material is equal to or greater than the horizontal distance from the surface of the lower fire-resistant covering material to the side surface of the lower flange, The filler placed in the countersink is characterized by having a distance from the surface of the first side fire-resistant covering material, the second side fire-resistant covering material or the lower fire-resistant covering material to the head of the screw.

[0020] (6) Furthermore, in any of the above (3) to (5), a non-combustible spacer is provided between the first side fire-resistant covering material, the second side fire-resistant covering material and the lower fire-resistant covering material and the H-shaped steel beam, and the first side fire-resistant covering material, the second side fire-resistant covering material and the lower fire-resistant covering material are not in contact with the H-shaped steel beam.

[0021] (7) Furthermore, in any of the above (3) to (5), a non-combustible member is arranged between the first side fire-resistant covering material, the second side fire-resistant covering material, and the lower fire-resistant covering material and the fire-resistant covering material mounting member.

[0022] (8) Furthermore, in the above (7), a non-combustible member is arranged between the lower flange of the H-shaped steel beam and the lower fire-resistant covering material.

[0023] (9) In addition, in the structure described in any one of (3) to (5) above, a through hole penetrating the web of the H-shaped steel beam, the fire-resistant covering material mounting member, the first side fire-resistant covering material, and the second side fire-resistant covering material, and a non-combustible cylindrical covering material covering at least the web of the H-shaped steel beam and the inner surface of the through hole of the fire-resistant covering material mounting member are provided, The inner diameter of the through holes provided in the first side fire-resistant covering material and the second side fire-resistant covering material is set to be equal to or smaller than the inner diameter of the tubular covering material. [Effects of the Invention]

[0024] In the present invention, fire-resistant covering material mounting members are attached to both sides of the web of an H-shaped steel beam, and first and second wooden side fire-resistant covering materials are attached to each side of the H-shaped steel beam to cover the sides of the upper flange of the H-shaped steel beam and part of the web, and a lower fire-resistant covering material is further provided to cover the lower flange of the H-shaped steel beam and the parts on both sides of the web that are not covered by the first side fire-resistant covering material and the second side fire-resistant covering material.This reduces the weight of the wooden fire-resistant covering material and makes on-site installation easier. In addition, since the fire-resistant covering material mounting members are hidden by the wooden fire-resistant covering material, there is no need to protect them during transportation to the site. In this way, the present invention solves the problems of on-site workability and transportation. [Brief explanation of the drawings]

[0025] [Figure 1] FIG. 2 is an explanatory diagram of the fire-resistant coating structure of the H-shaped steel beam according to the first embodiment, and is a cross-sectional view taken in a direction perpendicular to the material axis. [Figure 2] FIG. 10 is an explanatory diagram of a fire-resistant coating structure for an H-shaped steel beam according to embodiment 2, and is a cross-sectional view taken in a direction perpendicular to the material axis. [Figure 3] FIG. 10 is an explanatory diagram of a fire-resistant coating structure for an H-shaped steel beam according to embodiment 3, and is a cross-sectional view taken in a direction perpendicular to the material axis. [Figure 4] FIG. 10 is an explanatory diagram of a fire-resistant coating structure for an H-shaped steel beam according to embodiment 4, and is a cross-sectional view taken in a direction perpendicular to the material axis. [Figure 5]FIG. 10 is an explanatory diagram of a fire-resistant coating structure for an H-shaped steel beam according to embodiment 5, and is a cross-sectional view taken in a direction perpendicular to the material axis. [Figure 6] FIG. 10 is an explanatory diagram of a fire-resistant coating structure for an H-shaped steel beam according to embodiment 6, and is a cross-sectional view perpendicular to the material axis. [Figure 7] FIG. 10 is an explanatory diagram of a fire-resistant coating structure for an H-shaped steel beam according to embodiment 7, and is a cross-sectional view perpendicular to the material axis. [Figure 8] FIG. 13 is an explanatory diagram of a fire-resistant coating structure for an H-shaped steel beam according to embodiment 8, and is a cross-sectional view perpendicular to the material axis. [Figure 9] FIG. 13 is an explanatory diagram of a fire-resistant coating structure for an H-shaped steel beam according to embodiment 9, and is a cross-sectional view perpendicular to the material axis. [Figure 10] FIG. 20 is an explanatory diagram of a fire-resistant coating structure for an H-shaped steel beam according to embodiment 10, and is a cross-sectional view perpendicular to the material axis. [Figure 11] FIG. 1 is an explanatory diagram of a conventional fire-resistant coating structure, showing a cross section perpendicular to the material axis (part 1). [Figure 12] FIG. 2 is an explanatory diagram of a conventional fire-resistant coating structure, showing a cross section perpendicular to the material axis (part 2). [Figure 13] FIG. 3 is an explanatory diagram of a conventional fire-resistant coating structure, showing a cross section perpendicular to the material axis (part 3). [Figure 14] FIG. 4 is an explanatory diagram of a conventional fire-resistant coating structure, showing a cross section perpendicular to the material axis (part 4). DETAILED DESCRIPTION OF THE INVENTION

[0026] A fire-resistant covering structure according to each embodiment of the present invention will be described with reference to the drawings. [Embodiment 1] As shown in Figure 1, the fire-resistant coating structure 1 for an H-shaped steel beam in embodiment 1 is an H-shaped steel beam 7 consisting of two flanges 3 and one web 5, and is placed below a floor member 8.It is equipped with a fire-resistant coating mounting member 9, a wooden first side fire-resistant coating member 11, a wooden second side fire-resistant coating member 13, and a wooden lower fire-resistant coating member 15, and the first side fire-resistant coating member 11, the second side fire-resistant coating member 13, and the lower fire-resistant coating member 15 are fastened to the fire-resistant coating mounting member 9. In the following description, when the first side fire-resistant covering material 11, the second side fire-resistant covering material 13 and the lower fire-resistant covering material 15 are collectively referred to simply as "fire-resistant covering materials 11, 13, 15".

[0027] The H-shaped steel beam 7 includes a rolled H-shaped steel beam manufactured by rolling, and a welded H-shaped steel beam assembled by assembling plate members into an H shape by welding.

[0028] The fire-resistant covering material mounting members 9 are arranged on both side surfaces of the web 5 of the H-shaped steel beam 7. The fire-resistant covering material mounting member 9 is made of, for example, gypsum board, and is provided so as to fill the space surrounded by the flange 3 and the web 5. The fire-resistant covering material mounting member 9 is attached to the H-shaped steel beam 7 by, for example, a steel base 117 and fasteners 119 shown in Figure 13.

[0029] The first wooden side fire-resistant covering material 11 is arranged on one side of the H-shaped steel beam 7 and covers the side of the upper flange 3 a of the H-shaped steel beam 7 and part of the web 5 . The second wooden side fire-resistant covering material 13 is placed on the side of the H-shaped steel beam 7 where the first side fire-resistant covering material 11 is not provided, and covers the side of the upper flange 3a of the H-shaped steel beam 7 and part of the web 5. The wooden lower fire-resistant covering material 15 covers the lower flange 3b of the H-shaped steel beam 7 and the areas on both sides of the web 5 that are not covered by the first side fire-resistant covering material 11 and the second side fire-resistant covering material 13 on both sides of the web 5. The fire-resistant covering materials 11, 13, and 15 are made of wooden members, and examples of the wooden members include wood, laminated timber, cross-laminated timber (CLT), and laminated veneer lumber (LVL).

[0030] The thickness of the fire-resistant coating materials 11, 13, and 15 is determined from the viewpoint of preventing the collapse of the steel beams due to floor or live loads, etc., when the strength of the steel beams decreases due to high temperatures during a fire. The fire-resistant covering materials 11, 13, and 15 are intended to be installed manually on site using a high-altitude work vehicle or the like, so the length of the beam in the axial direction only needs to be determined so that the weight can be carried by a person, and the beam is divided into multiple parts in the axial direction.

[0031] The fire-resistant covering mounting member 9 covers the web 5 of the H-shaped steel beam 7. However, it is not expected to function as the fire-resistant covering members 11, 13, and 15. Instead, it serves the function of mounting the fire-resistant covering members 11, 13, and 15 and separating the inner surface of the fire-resistant covering members 11, 13, and 15 from the air space. When a large air space exists on the inner surface of the wooden fire-resistant covering members 11, 13, and 15 and the inner surface of the wooden fire-resistant covering members is in contact with the air space, flammable gases generated from the wooden fire-resistant covering members 11, 13, and 15 may react with oxygen in the air space on the inner surface and ignite. In other words, the wood may burn on the inner surface of the covering member, causing the H-shaped steel beam to become very hot. Therefore, the fire-resistant covering mounting member 9 serves to prevent the inner surface of the fire-resistant covering members 11, 13, and 15 from burning.

[0032] As described above, in this embodiment, the wooden fire-resistant covering materials 11, 13, and 15 that make up the fire-resistant covering structure 1 are constructed from three components, which makes it possible to reduce the weight of each component and improves on-site workability. Furthermore, the fire-resistant covering material mounting member 9 is covered by the fire-resistant covering materials 11, 13, and 15 and is in a hidden position, so scratches and dirt during transportation do not impair the design. Therefore, even if the fireproof covering materials are attached at a factory, there is no need to take the time to transport them, and only the wooden fireproof covering materials 11, 13, and 15 can be installed on-site.

[0033] Next, the construction flow of the fire-resistant covering structure 1 configured as above and the processing of each member will be described. The fire-resistant coating structure 1 of this embodiment is composed of fire-resistant coating materials 11, 13, and 15 and a fire-resistant coating material mounting member 9. Basically, it is assumed that the fire-resistant coating material mounting member 9 will be installed in a factory and the fire-resistant coating materials 11, 13, and 15 will be installed on-site, but the fire-resistant coating materials 11, 13, and 15 can also be installed in a factory depending on the situation. As with the conventional wood-based fireproof coatings mentioned above, the steel frame and wood processing is carried out by a steel frame fabricator, wood manufacturer, or pre-cutting company, respectively.

[0034] <H-shaped steel beam> In addition to the processing of the joint part, the H-shaped steel beam 7 is provided with through holes 103 for equipment piping (see Embodiment 10) in the web 5 and holes for passing through joint parts 33 such as coach screws (see Embodiment 3) as required.

[0035] <Fire-resistant coating material attachment member> Generally, since a secondary beam or a tertiary beam is provided in the H-shaped steel beam 7 to be fire-resistant coated in the orthogonal direction, a gusset plate is provided at the joint part. Therefore, the fire-resistant coating material attachment member 9 should have a length in the axial direction of the beam member less than the length between the gusset plates so as not to interfere with the gusset plate, and it is preferably provided by being divided into a plurality of parts in the axial direction of the beam member. When a stiffener for beam reinforcement is provided, it may be divided so as not to interfere with the gusset plate in the same manner.

[0036] <Fire-resistant coating material> It is desirable that the wooden fire-resistant coating materials 11, 13, and 15 be sent to the site after processing and installed on site. Note that the fire-resistant coating materials 11, 13, and 15 are composed of three members, but each member is transported without being attached to the steel frame beam, so the loading during transportation has a high degree of freedom, and there is no complexity such as curing in the case of transportation in the state of being attached to the steel frame beam as in the conventional example.

[0037] When a beam (secondary beam or tertiary beam) or other members in the orthogonal direction are attached to the H-shaped steel beam 7 to be fire-resistant coated, the fire-resistant coating materials 11, 13, and 15 need to be processed so as not to interfere with these members. In particular, when a secondary beam is attached in the orthogonal direction, it is necessary to ensure that there is no interference including the fire-resistant coating of the secondary beam. It is also necessary to ensure that there is no interference with the gusset plate of the brace and the intermediate column. Therefore, it is desirable that at least those of the fire-resistant coating materials 11, 13, and 15 located around the joint with other members be attached after the steel structure work is completed, that is, after the welding and bolt construction of the beam joint and the beam end joint are completed.

[0038] If gaps occur between the first side fire-resistant covering material 11 and the second side fire-resistant covering material 13 on the upper flange 3a side and the floor slab or deck plate, it is advisable to fill the gaps with a fire-resistant filler or the like. Similarly, if gaps occur between the fire-resistant covering materials 11, 13, and 15, they should be filled with fire-resistant filler or the like.

[0039] [Embodiment 2] A fire-resistant covering structure 21 for an H-shaped steel beam according to embodiment 2 will be described with reference to Fig. 2. In Fig. 2, parts that are the same as or common to those in Fig. 1 are given the same reference numerals and descriptions thereof will be omitted. This also applies to Fig. 3 and subsequent figures.

[0040] In the fire-resistant coating structure 21 for an H-shaped steel beam in this embodiment, the fire-resistant coating mounting member 9 is located inside both side surfaces in the plate width direction of the flange 3 of the H-shaped steel beam 7, a step portion 23 is formed in the first side fire-resistant coating material 11 and the second side fire-resistant coating material 13 on which a part of the upper flange 3a of the H-shaped steel beam 7 is placed, and a groove 25 is formed in the lower fire-resistant coating material 15 into which the lower flange 3b of the H-shaped steel beam 7 can be inserted. When forming a groove 25 in the lower fire-resistant covering material 15, the lower fire-resistant covering material 15 is divided into two parts in the width direction, i.e., in the direction perpendicular to the axis (left and right in the figure), as shown in Figure 2, to enable assembly. In addition, in embodiment 1, the lower fire-resistant covering material 15 is shown as not being divided, but even if grooves 25 are not formed, the lower fire-resistant covering material 15 may be divided in the width direction.

[0041] The reason why the fire-resistant covering material mounting members 9 are positioned inside both side surfaces in the width direction of the flanges 3 of the H-shaped steel beams 7 is as follows. As explained in the first embodiment, it is desirable from the viewpoint of workability that the fire-resistant covering material mounting members 9 be attached to the H-shaped steel beams 7 in advance in a factory and then transported to the site. Generally, when transporting an H-shaped steel beam 7 by truck, the H-shaped steel beam 7 is placed on top of sleepers or the like, so if the fire-resistant coating material mounting member 9 is located outside the side of the flange 3, it may come into contact with the sleepers or the like and be slightly deformed locally due to its own weight. Therefore, in this embodiment, the fire-resistant covering material mounting member 9 is positioned inside both side surfaces of the flange 3 of the H-shaped steel beam 7 in the plate width direction, thereby preventing deformation during transportation.

[0042] In addition, the joints at the boundary between the first side fire-resistant coating material 11 and the second side fire-resistant coating material 13, which cover the upper flange 3a and part of the side of the web 5, and the lower fire-resistant coating material 15, which covers the lower flange 3b and part of the side of the web 5, may open up slightly due to shrinkage, which may accelerate the progression of carbonization in the event of a fire. Therefore, it is desirable to ensure that the coating thickness in this area is sufficient to prevent excessive heat from flowing into the fire-resistant coating material mounting members 9 on the sides of the web 5 from the joint areas.

[0043] In this regard, in this embodiment, by positioning the surface of the fire-resistant coating material mounting member 9 inside the side of the flange 3, the thickness of the fire-resistant coating at the joint portion is increased, and therefore the fire resistance of the joint portion can be ensured without changing the external dimensions of the fire-resistant coating structure 21.

[0044] In this embodiment, grooves 25 are provided in the lower fire-resistant covering material 15 to prevent interference with the flange 3, but there is a risk that the H-shaped steel beam 7 may be deformed due to initial irregularities. For this reason, by making the grooves 25 several mm larger than the nominal dimensions of the flange 3, interference can be reliably prevented, and as a result, workability is ensured.

[0045] [Embodiment 3] A fire-resistant covering structure 31 for an H-shaped steel beam according to the third embodiment will be described with reference to FIG. The fire-resistant coating structure 31 for an H-shaped steel beam in this embodiment is composed of wooden members with fire-resistant coating material mounting members 9 placed on both sides of the web 5 of the H-shaped steel beam 7, and these two members are connected and fixed by connecting parts 33 such as coach screws that pass through the web 5.

[0046] The wooden members that make up the fire-resistant covering material mounting member 9, like the fire-resistant covering materials 11, 13, and 15, include wood, laminated timber, CLT, LVL, and the like. The fire-resistant coating material mounting member 9 must be at least as high as the internal clearance distance between the upper and lower flanges 3 so as not to interfere with the upper and lower flanges 3 of the beam. However, since beams have initial irregularities, it is advisable to make the mounting member 9 a few mm smaller than the internal clearance distance between the upper and lower flanges 3.

[0047] The reason why the fire-resistant covering material mounting member 9 is made of wood is as follows. As mentioned above, the use of wood leads to a reduction in CO2 emissions, so the use of wooden members for the fire-resistant covering material mounting members 9 further increases the effect of reducing CO2 emissions.

[0048] Furthermore, considering that many H-shaped steel beams 7 will be transported at once, it is desirable to suppress the increase in weight of the H-shaped steel beams 7 due to the attachment of the fire-resistant covering material mounting members 9. From this perspective, wooden members with low density are suitable for the fire-resistant covering material mounting members 9.

[0049] When the fire-resistant covering mounting members 9 are made of wood, it is necessary to devise a method for fixing them to the H-shaped steel beam 7. In this regard, in this embodiment, the fire-resistant covering mounting members 9 arranged on both sides of the web 5 of the H-shaped steel beam 7 are connected and fixed by connecting parts 33 such as coach screws that penetrate the web 5. This allows the two wooden fire-resistant covering mounting members 9 to be fixed simply and reliably.

[0050] Other possible methods of fixing the wooden fire-resistant covering material mounting member 9 to the H-shaped steel beam 7 include gluing or attaching metal fittings to the steel beam separately. However, in the former case, there is a risk that initial irregularities will cause gaps to form between the H-shaped steel beam 7 and the fire-resistant covering material mounting member 9, which may result in poor joining or separation during transportation. In addition, the latter has the problem that the metal fittings interfere with the first side fire-resistant covering material 11 and the second side fire-resistant covering material 13, requiring additional processing such as creating grooves 25 in the first side fire-resistant covering material 11 and the second side fire-resistant covering material 13. Therefore, in order to prevent interference with the fire-resistant covering materials 11, 13, 15 and to ensure secure fixation even if there is an initial defect, it is desirable to fix the material using a connecting part 33 such as a coach screw that penetrates the web 5.

[0051] The joining part 33 may be a coach screw or a bolt. By providing a countersink in the area where the joining part 33 is to be installed, it is possible to prevent interference with the fire-resistant covering materials 11, 13, and 15. After joining, it is desirable to provide a filler 35 in the countersink as shown in Figure 3.

[0052] Furthermore, it is desirable to have two or more fixing points per fire-resistant covering material mounting member 9, and providing two fixing points will ensure a secure position. Specifically, examples of joint positions include near the center of the beam depth and near both ends in the axial direction of the beam material.

[0053] As mentioned above, the fire-resistant coating material mounting member 9 is processed in advance at the factory, but if there are parts of the web 5 of the H-shaped steel beam 7 that cannot be fixed, such as when a through hole 103 is provided in the web 5 (see embodiment 10), the fixing points are positioned and processed to avoid the parts that cannot be fixed, such as the through hole 103. In the case of a rolled H-shaped steel beam 7, the fillet is located at the intersection of the beam flange 3 and the web 5, and in the case of a welded and assembled H-shaped steel beam 7, the weld is located at the intersection of the beam flange 3 and the web 5, so if there is a possibility of contact with these, it is a good idea to shave off the corners of the wooden fire-resistant coating mounting member 9.

[0054] [Embodiment 4] A fire-resistant covering structure 41 for an H-shaped steel beam according to a fourth embodiment will be described with reference to FIG. The fire-resistant coating structure 41 for an H-shaped steel beam in this embodiment is configured so that the wooden fire-resistant coating material mounting member 9 is positioned inside both widthwise sides of the flange 3 of the H-shaped steel beam 7, as described in embodiment 2.

[0055] [Embodiment 5] A fire-resistant covering structure 51 for an H-shaped steel beam according to the fifth embodiment will be described with reference to FIG. In the fire-resistant coating structure 51 for H-shaped steel beams in this embodiment, as in embodiment 3, the fire-resistant coating material mounting members 9 are made of wood, and the first side fire-resistant coating material 11, the second side fire-resistant coating material 13, and the lower fire-resistant coating material 15 are fixed to the wooden fire-resistant coating material mounting members 9 with screws 53 placed in the trench, and filler wood 35 is placed in the trench to hide the screws 53.

[0056] As a method for fixing the fire-resistant covering materials 11, 13, 15 to the fire-resistant covering material mounting member 9, in addition to the method of mechanically joining them with the screws 53 proposed in this embodiment, an adhesive method can also be used. However, the adhesive method is not preferable because it involves problems such as initial defects and the need to control the amount of adhesive, and the mechanical joining method using screws 53 is easier to work with. However, it is desirable to provide a filler 35 to prevent heat from being transferred to the fire-resistant covering material mounting member 9 through the screw 53 in the event of a fire. By providing the filler 35, the screw 53 can be hidden, which is also excellent in terms of design.

[0057] [Embodiment 6] A fire-resistant covering structure 61 for an H-shaped steel beam according to a sixth embodiment will be described with reference to FIG. The fire-resistant coating structure 61 for H-shaped steel beams in this embodiment corresponds to a modified example of embodiment 5, and differs from embodiment 5 in that the following three points are specified. The first is that the depth of the counterbore provided in the first side fire-resistant covering material 11 and the second side fire-resistant covering material 13 is greater than the horizontal distance from the surface of the first side fire-resistant covering material 11 and the second side fire-resistant covering material 13 to the side of the upper flange 3a. The second point is that the depth of the seat groove provided in the lower fire-resistant covering material 15 is equal to or greater than the horizontal distance from the surface of the lower fire-resistant covering material 15 to the side surface of the lower flange 3b. The third point is that the filler 35 placed in the trench has a distance from the surface of the fire-resistant covering materials 11, 13, and 15 to the head of the screw 53.

[0058] As a prerequisite for specifying the above three points, the surface of the fire-resistant covering material mounting member 9 is positioned inside the side surface of the flange 3, as in the second embodiment.

[0059] In the event of a fire, carbonization progresses from the surface of the wooden fire-resistant covering materials 11, 13, and 15, so if the seat groove is too shallow, there is a risk that heat will be transmitted through the screws 53 to the internal fire-resistant covering material mounting members 9, as mentioned above. To prevent this, it is desirable to specify that the head of the screw 53 is located at a deep position, and from this perspective, in this embodiment, the position of the head of the screw 53 is specified as described above. Another advantage is that the deeper the excavation, the shorter the screws 53 can be used for installation.

[0060] [Embodiment 7] A fire-resistant covering structure 71 for an H-shaped steel beam according to a seventh embodiment will be described with reference to FIG. The fire-resistant coating structure 71 for H-shaped steel beams in this embodiment, as in embodiment 3, is based on the premise that the fire-resistant coating material mounting member 9 is a wooden member, and non-combustible spacers 73 are provided between the first side fire-resistant coating material 11, the second side fire-resistant coating material 13 and the lower fire-resistant coating material 15 and the H-shaped steel beam 7, so that the first side fire-resistant coating material 11, the second side fire-resistant coating material 13 and the lower fire-resistant coating material 15 do not come into contact with the H-shaped steel beam 7.

[0061] On-site joints for H-shaped steel beams 7 are either friction joints using high-strength bolts or welded joints. However, in the case of welded joints, the H-shaped steel beams 7 become very hot, and if wooden fire-resistant covering materials 11, 13, 15 or fire-resistant covering material mounting members 9 come into contact with the H-shaped steel beams 7, there is a risk of fire at the contact points. Therefore, in this embodiment, to solve this problem, spacers 73 are provided to prevent the wooden fire-resistant covering materials 11, 13, 15 and the fire-resistant covering material mounting members 9 from coming into contact with the H-shaped steel beam 7, and by using non-flammable spacers 73, the spacers 73 themselves are also prevented from catching fire.

[0062] [Embodiment 8] A fire-resistant covering structure 81 for an H-shaped steel beam according to the eighth embodiment will be described with reference to FIG. The fire-resistant coating structure 81 for H-shaped steel beams in this embodiment, as in embodiment 3, is based on the premise that the fire-resistant coating material mounting member 9 is a wooden member, and a plate-shaped non-combustible member 83 is arranged between the first side fire-resistant coating material 11, the second side fire-resistant coating material 13, and the lower fire-resistant coating material 15 and the fire-resistant coating material mounting member 9.

[0063] Although the wooden fire-resistant covering materials 11, 13, and 15 burn in the event of a fire, the carbonized layer that is formed functions as an insulating material, thereby functioning as the fire-resistant covering materials 11, 13, and 15. However, the required fire resistance time differs depending on the floor height, and if the required fire resistance time is long, the required thickness of the fire-resistant covering material (covering thickness) becomes large if only the wooden fire-resistant covering materials 11, 13, and 15 are used, which increases the weight accordingly and impairs workability. In this case, it is conceivable to provide separate fire-resistant members on the outer surfaces of the wooden fire-resistant covering materials 11, 13, and 15, but this would impair the design.

[0064] Therefore, in this embodiment, a non-combustible member 83 is provided as a fire-resistant reinforcement material between the first side fire-resistant covering material 11, the second side fire-resistant covering material 13, and the lower fire-resistant covering material 15 and the fire-resistant covering material mounting member 9, thereby preventing an excessive increase in the thickness of the fire-resistant covering material (covering thickness) even if the required fire resistance time is extended, and preventing a decrease in workability.

[0065] The non-combustible member 83 is joined to the fire-resistant covering material mounting member 9 with screws 53 or adhesive. As explained in the fifth embodiment, when the first side fire-resistant covering material 11, the second side fire-resistant covering material 13, and the lower fire-resistant covering material 15 are joined with screws 53, a strong joining can be achieved by providing the screws 53 so that they penetrate the non-combustible member and reach the internal fire-resistant covering material mounting member 9.

[0066] A plurality of non-combustible members 83 may be provided in layers depending on the required fire resistance time. In addition, the side surface of the flange 3 may also be covered with a non-combustible member to further improve fire resistance.

[0067] [Embodiment 9] A fire-resistant covering structure 91 for an H-shaped steel beam according to a ninth embodiment will be described with reference to FIG. The fire-resistant coating structure 91 for H-shaped steel beams in this embodiment is based on the structure of embodiment 8, and a non-combustible member 83 is also arranged between the lower flange 3b of the H-shaped steel beam 7 and the lower fire-resistant coating material 15.

[0068] As in embodiment 8, by installing non-flammable components inside, it is possible to prevent excessive increases in the thickness of the fire-resistant coating material (coating thickness) even when the required fire resistance time is long without compromising the design, and as a result, it is possible to suppress a decrease in workability. It is desirable that the non-combustible member 83 be joined to the bottom flange 3b of the H-shaped steel beam 7 via metal fittings, or to the non-combustible member 83 on the side of the beam as explained in the eighth embodiment.

[0069] [Embodiment 10] A fire-resistant covering structure 101 for an H-shaped steel beam according to a tenth embodiment will be described with reference to FIG. The fire-resistant coating structure 101 for an H-shaped steel beam in this embodiment is based on the premise that the fire-resistant coating material mounting member 9 is a wooden member, as in embodiment 3, and assumes that a web through hole 107 for equipment piping, etc. is provided in the web 5 of the H-shaped steel beam 7. A through hole 103 is provided that penetrates the web 5 of the H-shaped steel beam 7, the fire-resistant covering material mounting member 9, the first side fire-resistant covering material 11, and the second side fire-resistant covering material 13, and a non-flammable, tubular covering material (hereinafter referred to as ``tubular covering material 105'') is provided that covers the inner surfaces of the web through hole 107 and the through hole 108 of the fire-resistant covering material mounting member 9 (hereinafter referred to as ``mounting member through hole 108''). The inner diameter of the covering material through holes 106 provided in the first side fire-resistant covering material 11 and the second side fire-resistant covering material 13 is set to be equal to or smaller than the inner diameter of the tubular covering material 105 .

[0070] When a web through hole 107 is provided, it is necessary to prevent heat from entering the H-shaped steel beam 7 through the web through hole 107, so the inner circumference of the web 5 and the fire-resistant covering material mounting member 9 is covered with a tubular covering material 105.

[0071] In this case, if the tubular covering material 105 is visible from the surrounding area, it will detract from the design, so to prevent this, the diameter of the covering material through hole 106 provided in the first side fire-resistant covering material 11 and the second side fire-resistant covering material 13 is made equal to or smaller than the inner diameter of the tubular covering material 105. Examples of the cylindrical covering material 105 include mortar, calcium silicate, and gypsum, and other non-combustible materials can also be used as long as they are cylindrical, but an appropriate thickness is set depending on the material in order to reduce heat input to the web 5.

[0072] The tubular covering material 105 is attached to the fire-resistant covering material attachment member 9, and is preferably installed in advance at the factory. The through hole (hereinafter referred to as "mounting member through hole 108") provided in the fire-resistant covering material mounting member 9 is provided at a position concentric with the web through hole 107 provided in the H-shaped steel beam 7, so that the inner diameter of the tubular covering material 105 is smaller than that of the web through hole 107. This is to prevent the tubular covering material 105 from interfering with the web 5 if the position is slightly misaligned. The tubular covering material 105 is provided so as to pass through the web through-hole 107 and the mounting member through-hole 108. The tubular covering material 105 is preferably fixed to the fire-resistant covering material mounting member 9 so as not to shift during transportation. The cylindrical covering material 105 may also be provided on the inner circumferential surface of the covering material through-hole 106 . [Explanation of symbols]

[0073] 1. Fire-resistant coating structure (embodiment 1) 3 flange 3a Upper flange 3b Lower flange 5. Web 7 H-shaped steel beam 8 Flooring 9. Fire-resistant covering material mounting components 11 1st side fireproof cladding 13 Second side fireproof cladding 15 Lower fireproof cladding 11, 13, 15 Fireproof cladding 21 Fire-resistant covering structure (embodiment 2) 23 Step section 25 groove 31 Fire-resistant covering structure (Embodiment 3) 33 Joint parts 35 Filler 41 Fire-resistant covering structure (Embodiment 4) 51 Fire-resistant covering structure (Embodiment 5) 53 Bis 61 Fire-resistant covering structure (Embodiment 6) 71 Fire-resistant covering structure (Embodiment 7) 73 Spacer 81 Fire-resistant covering structure (Embodiment 8) 83 Non-combustible materials 91 Fire-resistant covering structure (Embodiment 9) 101 Fire-resistant covering structure (embodiment 10) 103 Through hole 105 Cylindrical sheathing material 106 Covering material penetration hole 107 Web through hole 108 Mounting member through hole 111 Sprayed Rock Wool 113 Felt-like fire-resistant covering material 115 Board-shaped fire-resistant covering material 117 Steel base 119 Fasteners 121 Wood cladding 123 Groove

Claims

1. A fire-resistant covering structure for an H-shaped steel beam that is composed of two flanges and one web and is placed below a floor member, a fire-resistant covering material mounting member disposed on both sides of the web of the H-shaped steel beam; a first side fire-resistant covering material made of wood that is arranged on one side of the H-shaped steel beam and covers a side surface of the upper flange of the H-shaped steel beam and a part of the web; a second wooden side fire-resistant covering material disposed on the other side of the H-shaped steel beam and covering a side surface of the upper flange of the H-shaped steel beam and a part of the web; a lower fire-resistant covering material that covers the lower flange of the H-shaped steel beam and both sides of the web, and that covers portions of the web on both sides that are not covered by the first side fire-resistant covering material and the second side fire-resistant covering material; A fire-resistant coating structure for an H-shaped steel beam, characterized in that the first side fire-resistant coating material, the second side fire-resistant coating material and the lower fire-resistant coating material are fastened to the fire-resistant coating material mounting member.

2. The fire-resistant coating structure for an H-shaped steel beam as described in claim 1, characterized in that the fire-resistant coating material mounting members are located inside both side surfaces of the flange of the H-shaped steel beam in the plate width direction, the first side fire-resistant coating material and the second side fire-resistant coating material have stepped portions on which part of the upper flange of the H-shaped steel beam is placed, and the lower fire-resistant coating material is divided into two in the width direction and has a groove into which the lower flange of the H-shaped steel beam can be inserted.

3. The fire-resistant coating structure for an H-shaped steel beam as described in claim 1 or 2, characterized in that the fire-resistant coating material mounting members consist of wooden members placed on both sides of the web of the H-shaped steel beam, and these two members are connected and fixed by connecting parts that pass through the web.

4. The fire-resistant coating structure for an H-shaped steel beam as described in claim 3, characterized in that the first side fire-resistant coating material, the second side fire-resistant coating material, the lower fire-resistant coating material and the fire-resistant coating material mounting members are fixed by screws placed in a trench, and filler wood is placed in the trench to hide the screws.

5. the depth of the counterbore provided in the first side fire-resistant covering material and the second side fire-resistant covering material is equal to or greater than the horizontal distance from the surface of the first side fire-resistant covering material and the second side fire-resistant covering material to the side surface of the upper flange, The depth of the counterbore provided in the lower fire-resistant covering material is equal to or greater than the horizontal distance from the surface of the lower fire-resistant covering material to the side surface of the lower flange, A fire-resistant coating structure for an H-shaped steel beam as described in claim 4, characterized in that the filler placed in the countersink has a distance from the surface of the first side fire-resistant coating material, the second side fire-resistant coating material, or the lower fire-resistant coating material to the head of the screw.

6. 4. The fire-resistant covering structure for H-shaped steel beams according to claim 3, wherein non-combustible spacers are provided between the first side fire-resistant covering material, the second side fire-resistant covering material and the lower fire-resistant covering material and the H-shaped steel beams, so that the first side fire-resistant covering material, the second side fire-resistant covering material and the lower fire-resistant covering material are not in contact with the H-shaped steel beams.

7. A fire-resistant coating structure for an H-shaped steel beam as described in claim 3, characterized in that non-combustible members are arranged between the first side fire-resistant coating material, the second side fire-resistant coating material, and the lower fire-resistant coating material and the fire-resistant coating material mounting members.

8. 8. A fire-resistant coating structure for an H-shaped steel beam according to claim 7, characterized in that a non-combustible member is arranged between the lower flange of the H-shaped steel beam and the lower fire-resistant coating material.

9. a through hole penetrating the web of the H-shaped steel beam, the fire-resistant covering material mounting member, the first side fire-resistant covering material, and the second side fire-resistant covering material; and a non-combustible cylindrical covering material covering at least the web of the H-shaped steel beam and the inner surface of the through hole of the fire-resistant covering material mounting member, A fire-resistant coating structure for an H-shaped steel beam as described in claim 3, characterized in that the inner diameter of the through holes provided in the first side fire-resistant coating material and the second side fire-resistant coating material is set to be smaller than the inner diameter of the tubular coating material.

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