JP2001098661A - Fire resistive structure for h-shaped steel beam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form an H-shaped steel beam constituting a steel structure in a synthetic fire resistive covering structure which can be constructed easily and has a superior fire resistance and a thin under-beam section. SOLUTION: An H-shaped steel beam G is formed in a synthetic fire resistive covering structure by covering the beam G with a fire resistive coating material F2 composed of a fire resistive flooring material B placed on the upper flange g1 of the beam G, two fire resistive coating materials F1 and F1 composed of inorganic boards and arranged along the end faces of the upper and lower flanges g1 and g2 of the beams G, a metallic sheet F1 arranged along the lower flange G2 of the beam G, and a thermally expansible sheet f22 stuck to the internal surface of the metallic sheet f21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fire-resistant structure of an H-shaped steel beam constituting a steel structure of a building.

[0002]

2. Description of the Related Art In recent years, lightweight steel frames have been used for beams, columns, and the like that constitute main structural parts of buildings in apartment houses and detached houses. For steel beams and columns that constitute a main structural part of such a building, fire resistance performance standards are defined by the Ministry of Construction Notification No. 2999 and JIS A 1304. Is generally practiced with a material having excellent fire resistance (fire-resistant covering material).

[0003] For example, as described in JP-A-6-32664, a refractory coating material in which inorganic components such as vermiculite and rock wool are mixed with water glass or hydraulic cement is sprayed onto a steel beam or a steel column to form a steel frame. Known are those that ensure fire resistance of beams and steel columns.

[0004] A method of winding a flexible heat insulating material around a steel frame is also known.

[0005]

However, in the case of spraying a fire-resistant coating material to ensure fire-resistant performance, it is necessary to spray on-site at the time of construction, so that the working environment deteriorates and unevenness easily occurs. Since skilled skills are required, there is a problem that workability is reduced.

[0006] In the case of winding a flexible heat insulating material around a steel frame to secure fire resistance, construction of a part having a complicated shape is advantageous, but workability is poor in a general part and the thickness is large. there were. Furthermore, when the thickness of the refractory coating material is large, especially at the lower part of the beam, the height of the ceiling is reduced accordingly, and the room looks narrow or the volume is reduced. In this case, when trying to secure a certain ceiling height, there is a problem that the floor height becomes high, the structure works disadvantageously, and the cost increases.

[0007] In a building in which it is necessary to secure fire resistance to a steel column or a steel beam of a steel structure, the thickness is 1 unit.
Outer wall materials and floor materials with high fire resistance, such as a lightweight cellular concrete plate of 00 mm, are used. At least one surface of the steel beam G with which the outer wall material or the floor material contacts is protected by the highly fire-resistant outer wall material W or the floor material B (see FIG. 4). It is recognized that a composite fire-resistant coating structure with another fire-resistant coating material F is regarded as one fire-resistant coating material. When such a composite fire-resistant coating structure is employed, it is not necessary to coat one or three surfaces of the steel beam G, so that not only a great economic effect can be obtained, but also there is an advantage that workability is greatly improved.

The present invention has been made in view of the above problems, and provides an H-type steel frame fire-resistant structure that is excellent in workability and fire resistance and that can reduce the thickness of the lower part of the beam. It is.

[0009]

SUMMARY OF THE INVENTION The present invention relates to an H-shaped steel beam constituting a steel structure, a refractory floor material placed on an upper flange of the H-shaped steel beam, and an upper flange of the H-shaped steel beam. And a fireproof covering material covering the three sides except for the above, and the two ends of the fireproof covering material are arranged along the end faces of the upper and lower flanges of the H-shaped steel frame, while the kiguchi is abutted against the fireproof floor material. A thermal expansion material which is an inorganic board, and a refractory coating material disposed along the lower flange of the H-shaped steel beam is laminated on the inner surface of the metal plate and the metal plate to contact the lower flange of the H-shaped steel beam. It is characterized by being formed from a sheet.

Further, according to the present invention, both ends of the metal plate of the refractory coating material disposed along the lower flange of the H-shaped steel beam are bent along the outer edge of the inorganic board. It is characterized by the following.

Further, the present invention is characterized in that both ends of the metal plate of the refractory coating material disposed along the lower flange of the H-shaped steel beam are bent so as to wrap the thermally expandable sheet. Things.

Further, the present invention is characterized in that an inorganic heat-insulating layer is further laminated on the inner surface of the heat-expandable sheet of the refractory coating material disposed along the lower flange of the H-shaped steel beam. is there.

As fire-resistant flooring, lightweight cellular concrete board (ALC board), precast concrete board (PC
A conventionally used material such as a plate can be used.

The inorganic board is made of a nonflammable material and is not particularly limited as long as it is in the form of a board. For example, calcium silicate board, calcium silicate board mixed with fiber, calcium carbonate board, gypsum board, fiber Examples include a reinforced gypsum board, a perlite cement board, a fiber reinforced cement board, a wood chip cement board, a wood flour cement board, a slag gypsum board, a lightweight aerated concrete board (ALC board), and the like.

The thickness of the inorganic board depends on the desired fire resistance, but is preferably 20 to 50 mm. When the thickness of the inorganic board is less than 20 mm, the fire resistance is insufficient,
If it exceeds 50 mm, the weight increases and the workability deteriorates.

A plurality of inorganic boards may be laminated to have a predetermined thickness. The metal plate is not particularly limited as long as it is a metal having heat resistance, and examples thereof include a steel plate, a galvanized steel plate, a stainless steel plate, an aluminum / zinc alloy plate, and an aluminum plate.

The metal plate absorbs the expansion without being torn or cut by deforming or curving when the thermally expandable sheet expands.

The thickness of the metal plate is preferably 0.2 to 0.8 mm. If the thickness is less than 0.2 mm, it does not function as a flameproofing material or a shape-retaining material, and if it exceeds 0.8 mm, it becomes difficult to bend and deforms following the heat-insulating layer formed by expansion of the thermally expandable sheet. And the heat insulating layer may be damaged.

Materials constituting the heat-expandable sheet include:
Urethane resin, thermally expandable graphite, chloroprene, vermiculite, acrylic resin, phosphorus compound, nitrogen compound,
Materials such as polyhydric alcohols; compositions obtained by combining these with general-purpose coating compositions; and the like.

The heat-expandable sheet comprises a thermoplastic resin and / or
Or a resin selected from a rubber substance and / or an epoxy resin, a resin composition containing a phosphorus compound and an inorganic filler, exhibits sufficient heat insulating performance by expansion, can be formed into a sheet, and is excellent in handleability. .

The thermoplastic resin and / or rubber material is not particularly limited, and examples thereof include a polyolefin resin such as a polypropylene resin and a polyethylene resin;
Polypentene resin, polystyrene resin, acrylonitrile-butadiene-styrene resin, polycarbonate resin, polyphenylene ether resin, acrylic resin, polyamide resin, polyvinyl chloride resin, phenol resin, polyurethane resin, polybutene, poly Examples include chloroprene, butyl rubber, chlorinated butyl rubber, polybutadiene, polyisobutylene, and nitrile rubber.

Among them, halogenated resins such as polychloroprene and chlorinated butyl rubber have high flame retardancy by themselves, and cross-linking occurs due to dehalogenation reaction by heat, thereby improving the strength of the combustion residue after heating. Is preferred in that

The thermoplastic resins and / or rubber materials exemplified above are very flexible and have rubber-like properties, so that they can be filled with an inorganic filler at a high level, and the resulting resin sheet is flexible. It is flexible. In order to obtain a more flexible and flexible resin composition, a non-vulcanized rubber or a polyethylene resin is preferably used.

[0024] The thermoplastic resin and / or rubber material
They may be used alone or in combination of two or more. A blend of two or more resins may be used as the base resin in order to adjust the melt viscosity, flexibility, tackiness, etc. of the resin.

The thermoplastic resin and / or rubber substance may be cross-linked or modified as long as the fire resistance of the resin composition is not impaired. When such cross-linking or modification is performed, other components such as a phosphorus compound or an inorganic filler described below may be added to the thermoplastic resin and / or rubber substance which has been cross-linked and modified in advance. At the same time as compounding,
Alternatively, crosslinking and modification may be performed after the compounding. The crosslinking method is not particularly limited, and includes a crosslinking method generally performed for a thermoplastic resin or a rubber substance, such as a crosslinking method using various crosslinking agents, peroxides, and the like, a crosslinking method using electron beam irradiation, and the like. .

The epoxy resin is not particularly limited, but is basically obtained by reacting a monomer having an epoxy group with a curing agent.

Examples of the monomer having an epoxy group include bifunctional glycidyl ether types such as polyethylene glycol type, polypropylene glycol type, neopentyl glycol type, 1,6-hexanediol type, trimethylolpropane type, and propylene oxalate. Idobisphenol A type, hydrogenated bisphenol A type, and the like, as glycidyl ester types, hexahydrophthalic anhydride type, tetrahydrophthalic anhydride type, dimer acid type, P-
Examples of the polyfunctional glycidyl ether type such as the oxybenzoic acid type include phenol novolak type, orthocresol novolak type, DPP novolak type, and dicyclopentadiene phenol type.

These may be used alone or as a mixture of two or more. Examples of the curing agent include polyamines, acid anhydrides, polyphenols, and polymercaptans as polyaddition types, and tertiary amines and imidazoles as catalyst types.
Lewis acid complexes and the like.

The method for curing the epoxy resin is not particularly limited, and it can be performed by a known method.

The resin composition obtained from such a resin component can be freely selected depending on its design, from a very soft one to a hard one.

The phosphorus compound is not particularly restricted but includes, for example, red phosphorus; various phosphates such as triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, xylenyl diphenyl phosphate; Metal phosphates such as sodium phosphate, potassium phosphate, and magnesium phosphate; ammonium polyphosphates;
2) Compounds represented by PO (OR1) and the like.

In the formula, R1 and R3 represent hydrogen, carbon number 1
Represents a linear or branched alkyl group having from 16 to 16 or an aryl group having from 6 to 16 carbon atoms. R2 is a hydroxyl group, a linear or branched alkyl group having 1 to 16 carbon atoms, a linear or branched alkoxyl group having 1 to 16 carbon atoms,
Represents an aryl group having 6 to 16 carbon atoms or an aryloxy group having 6 to 16 carbon atoms.

Among these, from the viewpoint of fire resistance, red phosphorus, ammonium polyphosphates and the compounds represented by the above general formulas are preferable, and ammonium polyphosphates are more preferable in terms of performance, safety, cost and the like.

A small amount of red phosphorus improves the flame retardant effect. Commercially available red phosphorus can be used as the red phosphorus, but those obtained by coating the surface of red phosphorus particles with a resin are preferably used from the viewpoints of moisture resistance and safety such as not spontaneously igniting during kneading.

The ammonium polyphosphates are not particularly restricted but include, for example, ammonium polyphosphate and melamine-modified ammonium polyphosphate. Of these, ammonium polyphosphate is preferably used from the viewpoint of handleability. Commercially available products include, for example, "AP422" and "AP462" manufactured by Clariant; "Sumisafe P" manufactured by Sumitomo Chemical Industries; "Terage C60" manufactured by Chisso;
"Terage C70", "Terage C80" and the like.

The compound represented by the general formula R3 (R2) PO (OR1) is not particularly restricted but includes, for example, methylphosphonic acid, dimethyl methylphosphonate, diethyl methylphosphonate, ethylphosphonic acid, propylphosphonic acid, butylphosphonic acid 2-methylpropylphosphonic acid, t-butylphosphonic acid, 2,3-dimethyl-butylphosphonic acid, octylphosphonic acid, phenylphosphonic acid, dioctylphenylphosphonate, dimethylphosphinic acid, methylethylphosphinic acid, methylpropylphosphinic acid, Examples thereof include diethylphosphinic acid, dioctylphosphinic acid, phenylphosphinic acid, diethylphenylphosphinic acid, diphenylphosphinic acid, and bis (4-methoxyphenyl) phosphinic acid. Among them, t-butyl phosphonic acid is expensive, but is preferable in terms of high flame retardancy.

The phosphorus compounds may be used alone or in combination of two or more. The inorganic filler is not particularly limited, and includes, for example, metal oxides such as alumina, zinc oxide, titanium oxide, calcium oxide, magnesium oxide, iron oxide, tin oxide, antimony oxide, and ferrites; Hydrous inorganic substances such as magnesium, aluminum hydroxide and hydrotalcite; metal carbonates such as basic magnesium carbonate, calcium carbonate, magnesium carbonate, zinc carbonate, strontium carbonate and barium carbonate; calcium sulfate, gypsum fiber and calcium silicate Calcium salt; silica, diatomaceous earth, dawsonite, barium sulfate, talc, clay, mica, montmorillonite, bentonite, activated clay, sepiolite, imogolite, sericite, glass fiber, glass beads, silica-based balun, aluminum nitride, boron nitride , Silicon nitride, carbon black, graphite, carbon fiber, carbon balun, charcoal powder, various metal powders, potassium titanate, magnesium sulfate, lead zirconate titanate, aluminum borate, molybdenum sulfide, silicon carbide, stainless steel fiber, borane Examples include zinc acid, various magnetic powders, slag fibers, fly ash, and dewatered sludge. Among them, hydrous inorganic substances and metal carbonates are preferred.

Hydrous inorganic substances such as magnesium hydroxide and aluminum hydroxide endothermic due to the water generated by the dehydration reaction during heating, and the temperature rise is reduced to obtain high heat resistance. It is particularly preferable that the material remains and works as an aggregate, thereby improving the strength of the residue. Magnesium hydroxide and aluminum hydroxide have different temperature ranges where the dehydration effect is exhibited,
When used together, the temperature range in which the dehydration effect is exhibited is expanded, and a more effective temperature rise suppression effect is obtained.

Metal carbonates such as calcium carbonate and zinc carbonate are considered to promote swelling by reaction with a phosphorus compound. Particularly, when ammonium polyphosphate is used as the phosphorus compound, a high swelling effect is obtained. In addition, it acts as an effective aggregate and forms a combustion residue having high shape retention after burning.

Among the metal carbonates, further, alkali metal carbonates such as sodium carbonate; alkaline earth metal carbonates such as magnesium carbonate, calcium carbonate and strontium carbonate; carbonates of Group IIb metals such as zinc carbonate Is preferred.

In general, the inorganic filler acts as an aggregate, and is considered to contribute to an improvement in residue strength and an increase in heat capacity.

The inorganic filler may be used alone or in combination of two or more. As the particle size of the inorganic filler,
Those having a thickness of 0.5 to 100 μm can be used, and more preferably about 1 to 50 μm. Further, it is more preferable to use the inorganic filler having a large particle size and the inorganic filler having a small particle size in combination. By using the inorganic filler in combination, it is possible to increase the packing while maintaining the mechanical performance of the thermally expandable sheet. It becomes possible.

The resin composition may contain, in addition to the thermoplastic resin and / or the rubber substance, the phosphorus compound and the inorganic filler, neutralized heat-expandable graphite, polyhydric alcohol, and the like.

The neutralized heat-expandable graphite is obtained by neutralizing heat-expandable graphite which is a conventionally known substance. The heat-expandable graphite is made from powders such as natural scale graphite, pyrolytic graphite, quiche graphite, concentrated sulfuric acid, nitric acid, inorganic acids such as selenic acid and concentrated nitric acid, perchloric acid,
It is a graphite intercalation compound generated by treating with a strong oxidizing agent such as perchlorate, permanganate, dichromate, hydrogen peroxide, etc.It is a crystalline compound that maintains the layered structure of carbon .

The heat-expandable graphite obtained by the acid treatment is further neutralized with ammonia, an aliphatic lower amine, an alkali metal compound, an alkaline earth metal compound, etc. Expandable graphite.

The aliphatic lower amine is not particularly restricted but includes, for example, monomethylamine, dimethylamine, trimethylamine, ethylamine, propylamine, butylamine and the like.

The alkali metal compound and alkaline earth metal compound are not particularly restricted but include, for example, hydroxides, oxides, carbonates, sulfates, organic acid salts such as potassium, sodium, calcium, barium and magnesium. Is mentioned.

As a commercially available product of the heat-expandable graphite which has been subjected to the neutralization treatment, for example, "GREP-EG" manufactured by Tosoh Corporation is exemplified.

The particle size of the neutralized heat-expandable graphite is 2
0-200 mesh is preferred. When the particle size is smaller than 200 mesh, the degree of expansion of graphite is small, a predetermined refractory insulation layer cannot be obtained, and when the particle size is larger than 20 mesh, there is an advantage that the degree of expansion of graphite is large, but there is an advantage that the resin composition and When kneading, the dispersibility deteriorates, and a decrease in physical properties is inevitable.

The polyhydric alcohol is a hydrocarbon compound having two or more hydroxyl groups in the molecule, and has 1 to 5 carbon atoms.
0 is preferred. Examples of the polyhydric alcohol include ethylene glycol, diethylene glycol, propylene glycol, butylene glycol, 1,4-butanediol, 1,6-hexanediol, monopentaerythritol, dipentaerythritol, tripentaerythritol, neopentaerythritol, Sorbitol, inositol, mannitol, glucose, fructose,
Examples include starch and cellulose.

The polyhydric alcohols may be used alone or in combination of two or more. As the polyhydric alcohol, the ratio of the number of hydroxyl groups to the number of carbon atoms in the molecule [(number of hydroxyl groups)
/ (Number of carbon atoms)] is preferably 0.2 to 2.0, and more preferably [(number of hydroxyl groups) / (number of carbon atoms) such as pentaerythritol, sorbitol, mannitol and the like. ] Is 0.7 to 1.5. Above all, pentaerythritols are most preferred because of their high hydroxyl group content and high carbonization promoting effect.

Polyhydric alcohols having a ratio of the number of hydroxyl groups to the number of carbon atoms in the molecule [(the number of hydroxyl groups) / (the number of carbon atoms)] in the range of 0.2 to 2.0 are effectively dehydrated and condensed during combustion. To form a carbonized layer. When the above ratio [(number of hydroxyl groups) / (number of carbon atoms)] is less than 0.2, decomposition of carbon chains is more likely to occur during combustion than dehydration condensation, so that a sufficient carbonized layer cannot be formed, If it exceeds 2.0, the formation of a carbonized layer is not hindered, but the water resistance is significantly reduced. When the water resistance decreases, there are problems such as the polyhydric alcohol being eluted when the resin composition immediately after molding is cooled with water, and the above-mentioned polyhydric alcohol bleeding out due to humidity during storage of the molded article.

In order to impart tackiness to the heat-expandable sheet, for example, a tackifier may be added to a thermoplastic resin and / or a rubber substance.

The tackifier is not particularly restricted but includes, for example, tackifier resins, plasticizers, oils and fats, and low-polymerized polymers.

When an epoxy resin is used as the resin component of the resin composition, the epoxy resin composition may be directly cured on a metal plate in addition to the use as an adhesive heat-expandable sheet.

The resin composition constituting the heat-expandable sheet includes:
A flame retardant, an antioxidant, a metal harm inhibitor, an antistatic agent, a stabilizer, a crosslinking agent, a lubricant, a softener, a pigment, and the like may be added as long as the physical properties of the resin composition are not impaired.

The resin composition can be obtained by kneading the above-mentioned components using a conventionally known kneading apparatus such as a single-screw extruder, a twin-screw extruder, a Banbury mixer, a kneader mixer, and a two-roller. . The obtained resin composition can be formed into a heat-expandable sheet by a conventionally known method such as press molding, extrusion molding, or calendar molding.

The thickness of the heat-expandable sheet is 0.3 to 5.0.
mm is preferred. When the thickness is less than 0.3 mm, sufficient heat insulating properties are not exhibited even when expanded, and when the thickness exceeds 5.0 mm, not only the degree of freedom in construction is reduced, but also the weight becomes heavy and the handleability deteriorates. More preferably, it is 1.0 to 3.0 mm.

The heat-expandable sheet has an initial
Bulk density 0.8-2.0 g / cm ^ThreeWhat is preferred
And more preferably, 1.0 to 1.8 g / cm^ThreeIn
You. 0.8-2.0 g / c initial bulk density at 25 ° C
m^ThreeWithin the range, it is necessary for the heat-expandable sheet.
It does not impair the required physical properties such as heat insulation and fire resistance.
Can also be made excellent in workability.

The initial bulk density at 25 ° C. is 0.8
If it is less than g / cm ³ , a sufficient amount of a swelling agent, a carbonizing agent, a non-combustible filler, etc. cannot be added to the resin composition, and the expansion ratio after heating and the amount of residue become insufficient, Insufficient refractory and heat-insulating layer cannot be formed. If the initial bulk density at 25 ° C. exceeds 2.0 g / cm ³ , the weight of the heat-expandable sheet becomes too large, and the workability at the construction site decreases.

The heat-expandable sheet is heated at 500 ° C. for one hour.
Bulk density of 0.05 to 0.5 g / cm^ThreeIn
Are preferred, and more preferably 0.1 to 0.3 g
/ Cm^ThreeIt is. When heated at 500 ° C for 1 hour
The density is 0.05 g / cm ^ThreeIf it is less than
Because it is too much, the fireproof insulation layer is
0.5g / cm^ThreeBeyond
, The expansion ratio becomes insufficient and the fire resistance is fully demonstrated
Can not form a fire-resistant insulation layer
It becomes.

The heat-expandable sheet has a heat conductivity of 0.5 after being expanded in volume under heating conditions of 50 kW / m ² for 30 minutes.
It is preferably from 0.01 to 0.3 kcal / m / · h · ° C. When the thermal conductivity after volume expansion for 30 minutes under the heating condition of 50 kW / m ² exceeds 0.3 kcal / m · h · ° C., the heat insulation performance is insufficient, so that sufficient fire resistance is exhibited. Can not be performed, 0.01 kca1 / m
Anything below ℃ cannot be made with a mixture of organic and inorganic substances.

The heat-expandable sheet is a differential scanning calorimeter (DS)
60 at a heating rate of 10 ° C./min, measured according to C)
The total heat absorption when the temperature is raised to 0 ° C. is preferably 100 J / g or more. When the total heat absorption is 100 J / g or more, the temperature rise becomes slow, so that the heat insulating performance becomes better.

The inorganic heat-insulating layer is not particularly limited as long as it has heat-insulating properties, and general-purpose ones can be used. Examples thereof include a calcium silicate plate, a fiber-containing calcium silicate plate, a calcium carbonate plate, and a gypsum board. , Fiber reinforced gypsum board, perlite cement board, fiber reinforced cement board, wood chip cement board, wood powder cement board, inorganic board such as slag gypsum board; rock wool heat insulation board, ceramic wool blanket, alumina silica fiber felt, glass wool, heat resistant Known materials such as a sheet-like material such as glass wool may be used.

The thickness of the inorganic heat insulating layer is preferably 5 to 50 mm. If the thickness is less than 5 mm, the heat insulating effect is insufficient,
If it exceeds 50 mm, the weight becomes heavy and the workability deteriorates.

According to the present invention, since the H-shaped steel beam is formed in a composite fire-resistant coating structure covered with a fire-resistant floor material and a fire-resistant coating material, heat generated by fire is transmitted to the H-shaped steel beam. Can be reliably prevented.
It can be constructed with a simple work just to attach to the type steel beam. In addition, by disposing a thin refractory covering material made of a metal plate and a heat-expandable sheet on the lower flange of the H-shaped steel beam, the height of the floor can be increased at the lower part of the beam by the reduced thickness. The ceiling height can be secured, and the room does not look narrow and the volume does not decrease.

Further, if both ends of the metal plate of the refractory coating material arranged along the lower flange of the H-shaped steel beam are bent along the outer side edge of the inorganic board, the inorganic material can be used. The positioning of the refractory coating made of a metal plate and a heat-expandable sheet on the board is easy, and the options for fixing nails on the inorganic board are expanded. The joint formed at the joint with the covering material can be covered.

Further, when both ends of the metal plate of the refractory coating material arranged along the lower flange of the H-shaped steel beam are bent so as to wrap the thermally expandable sheet, the edge of the thermally expandable sheet is reduced. The portion can be prevented from being exposed.

Further, when an inorganic heat-insulating layer is further laminated on the inner surface of the heat-expandable sheet of the fire-resistant covering material disposed along the lower flange of the H-shaped steel beam, further excellent fire resistance can be obtained. It is possible, and the construction of the refractory coating material is improved.

[0070]

Embodiments of the present invention will be described below with reference to the drawings. (Embodiment 1) FIG. 1 shows Embodiment 1 of a fire-resistant structure for an H-shaped steel beam according to the present invention.

The fire-resistant structure according to the first embodiment has an H-shaped steel beam G
And the floor material B placed on the upper flange g1 of the H-shaped steel beam G
The two ends of the H-shaped steel beam G are provided with two refractory coating materials F1 disposed along the end faces of the upper and lower flanges g1 and g2 of the H-shaped steel beam G, while the wooden mouth is abutted against the floor material B. g2 disposed along the refractory coating material F2.

Here, the floor material B has a thickness of 100 mm.
ALC plate is used, and a 25-mm-thick calcium silicate plate is used as the refractory coating material F1. Further, the refractory coating material F2 is formed of a 0.3 mm-thick galvanized steel sheet f21 and a thermally expandable sheet f22 adhered to the inner surface of the galvanized steel sheet f21.

The heat-expandable sheet f22 had the composition shown in Table 1 below and the composition A (parts by weight) shown in Table 1 having a thickness of 5 m.
m.

[0074]

[Table 1] Then, the fire-resistant coating materials F1, F1 and F2 are made of a fire-resistant adhesive ("Kilbond" manufactured by Ask Corporation) and nails corresponding to the three surfaces except the one facing the fire-resistant floor material B of the steel beam G. It was formed in a U-shape and mounted over the steel beam G. (Embodiment 2) FIG. 2 shows Embodiment 2 of a fire-resistant structure for an H-shaped steel beam according to the present invention.

As in the first embodiment, the fire-resistant structure of the second embodiment includes an H-shaped steel beam G and an upper flange g1 of the H-shaped steel beam G.
And two refractory covering materials F1 arranged along the end faces of the upper and lower flanges g1 and g2 of the H-shaped steel frame beam G, while the butt end of the floor material B is placed against the floor material B. A refractory covering material F3 disposed along the lower flange g2 of the H-shaped steel beam G.

Here, the floor material B has a thickness of 100 mm.
ALC plate is used, and a 25-mm-thick calcium silicate plate is used as the refractory coating material F1. Further, the refractory coating material F3 is formed of a galvanized steel sheet f31 having a thickness of 0.3 mm and a thermally expandable sheet f32 adhered to the inner surface of the galvanized steel sheet f31. Also,
The edge of the galvanized steel sheet f31 has a refractory coating material F1.
Is bent at a right angle along the outer side edge.

Note that the heat-expandable sheet f32 is as shown in Table 1 above.
The composition shown in Table 5 was 5 mm
It is formed in.

As in the case of the first embodiment, the steel beams G correspond to the three surfaces except the one surface facing the refractory floor material B.
The fire-resistant coating materials F1, F1 and F3 were formed in a U-shape using a fire-resistant adhesive ("Kilbond" manufactured by Ask Corporation) and nails, and were attached to the steel beam G by mounting. (Embodiment 3) FIG. 3 shows Embodiment 3 of a fire-resistant structure for an H-shaped steel beam according to the present invention.

As in the first embodiment, the fire-resistant structure of the third embodiment includes an H-shaped steel beam G and an upper flange g1 of the H-shaped steel beam G.
And two refractory covering materials F1 arranged along the end faces of the upper and lower flanges g1 and g2 of the H-shaped steel frame beam G, while the butt end of the floor material B is placed against the floor material B. And a refractory coating F4 disposed along the lower flange g2 of the H-shaped steel beam G.

Here, the floor material B has a thickness of 100 mm.
ALC plate is used, and a 25-mm-thick calcium silicate plate is used as the refractory coating material F1. The refractory coating material F4 is made of a 0.3 mm thick galvanized steel sheet f41, a thermally expandable sheet f42 attached to the inner surface of the galvanized steel sheet f41, and a thickness 9 laminated on the inner surface of the thermally expandable sheet f42. 0.5 mm inorganic heat insulating layer (plaster board; manufactured by Yoshino Gypsum) f43. Further, the galvanized steel sheet f41 is bent in a U-shape so that the edge is along the front edge of the inorganic heat insulating layer f43.

Note that the heat-expandable sheet f42 is as shown in Table 1 above.
Of composition C (parts by weight) shown in Table 1 and a thickness of 1.5
mm.

Then, as in the case of the first embodiment, the steel beams G correspond to the three surfaces except the one surface facing the refractory floor material B.
The refractory covering materials F1, F1 and F4 were formed in a U-shape using a refractory adhesive ("Kilbond" manufactured by Ask Corporation) and nails, and were attached to the steel beam G by mounting. (Comparative Example) In the comparative example, as the fire-resistant covering material disposed along the lower flange g2 of the H-shaped steel beam G, a fire-resistant covering material F4 of Example 3 without the heat-expandable sheet f42 was used.
Other configurations are the same as those of the first to third embodiments.

For these Examples 1 to 3 and Comparative Example, a fire resistance heating test was performed in accordance with JIS A 1304, and the surface temperature of the steel beam H after one hour was measured by a thermocouple attached to the steel beam H. did. A sample having an average temperature of 350 ° C. or lower was evaluated as ○.

[0084]

As described above, according to the present invention, the H-shaped steel beam is formed in a composite fire-resistant coating structure covered with a fire-resistant floor material and a fire-resistant coating material. It can reliably prevent heat from being transmitted by fire,
It can be constructed by a simple operation of simply attaching the refractory coating to the H-shaped steel beam. In addition, by disposing a thin refractory covering material made of a metal plate and a heat-expandable sheet on the lower flange of the H-shaped steel beam, the height of the floor can be increased at the lower part of the beam by the reduced thickness. The ceiling height can be secured, and the room does not look narrow and the volume does not decrease.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing Example 1 of a fireproof structure of an H-shaped steel beam of the present invention.

FIG. 2 is a longitudinal sectional view showing Example 2 of a fire-resistant structure of an H-shaped steel beam of the present invention.

FIG. 3 is a longitudinal sectional view showing Example 3 of a fire-resistant structure of an H-shaped steel beam of the present invention.

FIG. 4 is a longitudinal sectional view showing an example of a composite fire-resistant coating structure of a steel beam.

[Explanation of symbols]

 GH type steel beam g1 Upper flange g2 Lower flange B Fireproof floor material F1 Fireproof coating material (calcium silicate plate) F2, F3, F4 Fireproof coating material f21, f31, f41 Metal plate (galvanized steel sheet) f22, f32, f42 Thermal expansion sheet f43 Inorganic heat insulating layer (gypsum board)

Continued on the front page F term (reference) 2E001 DE01 DE04 EA05 FA01 FA02 GA24 GA42 GA52 HA01 HA03 HA07 HA21 HB01 HB03 HB04 HD11 HE01 JA06

Claims (6)

[Claims] 1. An H-shaped steel beam constituting a steel structure;
A fire-resistant flooring material placed on the upper flange of the H-shaped steel beam and a fire-resistant coating material covering three surfaces except for the upper flange of the H-shaped steel beam, and the kiguchi is abutted against the fire-resistant flooring material. The two refractory coatings disposed along the end faces of the upper and lower flanges of the H-shaped steel beam are inorganic boards, and the refractory coatings disposed along the lower flange of the H-shaped steel beam are A refractory structure for an H-shaped steel beam, comprising a metal plate and a heat-expandable sheet laminated on an inner surface of the metal plate and in contact with a lower flange of the H-shaped steel beam. 2. Both ends of a metal plate of a fire-resistant coating material disposed along a lower flange of the H-shaped steel beam are bent along an outer edge of the inorganic board. The refractory structure for an H-shaped steel beam according to claim 1, wherein: 3. The refractory cladding metal plate disposed along the lower flange of the H-shaped steel beam, wherein both ends of the refractory metal plate are bent so as to surround the thermally expandable sheet. The fire-resistant structure of the H-shaped steel beam as described. 4. An inorganic heat-insulating layer is further laminated on an inner surface of a heat-expandable sheet of a refractory coating material disposed along a lower flange of the H-shaped steel beam.
The fire-resistant structure for an H-shaped steel beam according to claim 2 or 3. 5. The heat-expandable sheet is made of a resin composition in which a resin selected from a thermoplastic resin and / or a rubber substance and / or an epoxy resin contains a phosphorus compound and an inorganic filler. The fire-resistant structure for an H-shaped steel beam according to claim 1, 2, 3, or 4. 6. The method according to claim 1, wherein said inorganic board is selected from a calcium silicate board, a fiber reinforced gypsum board, a lightweight cellular concrete board and a wood chip cement board. The fire-resistant structure for an H-shaped steel beam according to claim 4 or 5.