Fire resistive covering structure

Abstract

To provide a fire resistive covering structure which is suitable as a measure against dew condensation on synthetic fire resistive structure of pillars and beams, and a construction method therefor.SOLUTION: There is provided a fire resistive covering structure 10 that comprises an inorganic fire resistive covering material 16 provided continuously from outside a steel pillar or steel beam 14 arranged closely opposite a wall body 12 to a surface of the wall body 12. The fire resistive covering structure further comprises an organic fire resistive coating material 18 which is provided outside the inorganic fire resistive covering material 16, and has moisture resistance higher than the moisture resistance of the inorganic fire resistive covering material 16 so as to suppress steam W from being transmitted from outside to inside the inorganic fire resistive covering material 16. The organic coating material 18 may be formed of a material consisting principally of modified asphalt-based water resistive material.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a fire-resistant covering structure having a moisture-proof function and a construction method thereof. [Background technology]

[0002] Conventionally, when steel beams or columns are installed near the exterior walls of steel-framed buildings, the fireproof covering of the steel frame is often made into a composite fireproof structure with the exterior wall. The reason for adopting a composite fireproof structure is that the close proximity of the exterior wall to the steel frame makes it extremely difficult to apply the fireproof covering to the exterior side of the steel frame.

[0003] Due to fire-resistance certification, insulation materials to prevent condensation cannot be installed on the exterior walls of synthetic fire-resistant structures. Therefore, in cold regions or buildings with high indoor humidity, such as IDCs, hospitals, homes, and hotels, a large amount of condensation can occur on the exterior walls, leading to actual damage.

[0004] Condensation in a composite fireproof structure occurs when, for example, water vapor W generated on room A side by heating, etc., penetrates through the fireproof coating material 2 covering the steel beams 1, penetrates into the interior 3 of the composite fireproof structure, and reaches the dew point on the inner surface of the exterior wall 5 cooled by the outside air 4, as shown in Figure 3. For this reason, it is thought that this condensation can be suppressed if the fireproof coating material 2 can ensure moisture permeability resistance. However, there are no fireproof coating materials currently on the market that have sufficient moisture permeability resistance to prevent condensation. In Figure 3, reference numeral 6 denotes a foamed plastic insulation material for preventing condensation. In a composite fireproof structure, such insulation cannot be installed on the inner surface of the exterior wall 5 due to fireproof certification.

[0005] Conventional countermeasures against condensation in synthetic fireproof structures include, for example, a method of using wrapped rockwool felt with a moisture-proof layer, such as Makibee with a moisture-proof layer ("Makibee" is a registered trademark), and a method of applying in-situ foamed urethane to the surface of the fireproof coating material. However, because wrapped rockwool felt with a moisture-proof layer is a dry construction method, it is difficult to apply moisture-proofing treatment to the ends of the fireproof coating material and the joints with members that penetrate the fireproof coating, and in-situ foamed urethane does not have sufficient moisture permeability resistance in terms of condensation countermeasures, and both methods have problems in terms of practicality and quality assurance.

[0006] Another known condensation prevention technique for a fire-resistant coating structure is described in, for example, Patent Document 1. Patent Document 1 relates to a fire-resistant coating structure that can improve the heat insulation and airtightness around a steel column while ensuring the fire resistance of the steel column that faces a non-combustible exterior wall. This fire-resistant coating structure includes a heat-expandable fire-resistant coating sheet layer that covers the exposed portion of the outer periphery of the steel column that does not face the exterior wall, an airtight layer of metal film that covers the surface of the fire-resistant coating sheet layer, and a heat insulation layer made mainly of a phenolic resin foam that is provided between the exposed portion of the steel column and the fire-resistant coating sheet layer. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2010-43445 A Summary of the Invention [Problem to be solved by the invention]

[0008] As mentioned above, there was a demand for an appropriate measure against condensation in the composite fireproof structure of columns and beams. There was also a demand for a technology that can form a stable moisture barrier without gaps at the ends of fireproof coating materials and at the joints with members that penetrate the fireproof coating.

[0009] The present invention has been made in view of the above, and an object of the present invention is to provide a fire-resistant covering structure suitable as a measure against condensation in a composite fire-resistant structure of columns and beams, and a construction method thereof. [Means for solving the problem]

[0010] In order to solve the above-mentioned problems and achieve the object, the fire-resistant coated structure of the present invention is a fire-resistant coated structure comprising an inorganic fire-resistant coating material that is continuously provided from the outside of a steel column or steel beam that is arranged adjacent to and facing a wall to the surface of the wall, and is characterized in that it further comprises an organic coating material that is provided on the outside of the inorganic fire-resistant coating material to suppress water vapor transmission from the outside to the inside of the inorganic fire-resistant coating material and has a moisture permeation resistance higher than that of the inorganic fire-resistant coating material.

[0011] Furthermore, another fire-resistant covering structure according to the present invention is characterized in that in the above-mentioned invention, the organic coating material is composed of a material mainly made of any one of modified asphalt-based waterproofing material, asphalt-based emulsion moisture-proofing material, water-soluble acrylic-based waterproofing material, ultra-fast-curing urethane waterproofing material, highly elastic acrylic rubber-based wall waterproofing decorative material, ultra-low-pollution NAD elastic polyurethane resin paint, and ultra-low-pollution water-based elastic fluororesin paint.

[0012] Furthermore, the method for constructing a fire-resistant covering structure according to the present invention is a method for constructing the above-mentioned fire-resistant covering structure, characterized in that a sheet-like fire-resistant covering material is manufactured by providing an organic coating material on the outside of a sheet-like inorganic fire-resistant covering material, and then this sheet-like fire-resistant covering material is attached from the outside of a steel column or steel beam to the surface of a wall.

[0013] In addition, another method of construction of a fire-resistant coating structure according to the present invention is characterized in that, in the above-mentioned invention, a sheet-shaped fire-resistant coating material is produced by spraying an organic coating material onto the outside of a sheet-shaped inorganic fire-resistant coating material.

[0014] Another method for constructing a fire-resistant covering structure according to the present invention is a method for constructing the above-mentioned fire-resistant covering structure, characterized in that a sheet-like inorganic fire-resistant covering material is attached from the outside of a steel column or steel beam to the surface of a wall, and then an organic coating material is sprayed onto the outside of this sheet-like inorganic fire-resistant covering material. Effect of the Invention

[0015] The fire-resistant covering structure of the present invention is provided with an inorganic fire-resistant covering material that is continuously provided from the outside of a steel column or steel beam that is arranged adjacent to and facing a wall to the surface of the wall, and further includes an organic coating material that is provided on the outside of the inorganic fire-resistant covering material to suppress the transmission of water vapor from the outside to the inside of the inorganic fire-resistant covering material and has a moisture permeation resistance higher than that of the inorganic fire-resistant covering material, thereby achieving the effect of suppressing the occurrence of condensation in the composite fire-resistant structure of the columns and beams.

[0016] Furthermore, according to another fire-resistant covering structure of the present invention, the organic coating material is composed of a material whose main component is any of modified asphalt-based waterproofing material, asphalt-based emulsion moisture-proofing material, water-soluble acrylic-based waterproofing material, ultra-fast-curing urethane waterproofing material, highly elastic acrylic rubber-based wall waterproof decorative material, ultra-low-pollution NAD elastic polyurethane resin paint, and ultra-low-pollution water-based elastic fluororesin paint, thereby achieving the effect of ensuring moisture-proofing properties while reducing construction costs.

[0017] Furthermore, according to the method for constructing a fire-resistant covering structure of the present invention, which is a method for constructing the above-mentioned fire-resistant covering structure, a sheet-like fire-resistant covering material is manufactured by providing an organic coating material on the outside of a sheet-like inorganic fire-resistant covering material, and then this sheet-like fire-resistant covering material is attached from the outside of a steel column or steel beam to the surface of a wall, thereby achieving the effect of easily constructing a composite fire-resistant structure of columns and beams that suppresses the occurrence of condensation.

[0018] In addition, according to another construction method for a fire-resistant coating structure of the present invention, a sheet-shaped fire-resistant coating material is manufactured by spraying an organic coating material onto the outside of a sheet-shaped inorganic fire-resistant coating material, which has the effect of easily realizing the formation of a seamless moisture-proof layer even on a complex base shape.

[0019] Furthermore, according to another method for constructing a fire-resistant covering structure of the present invention, which is a method for constructing the above-mentioned fire-resistant covering structure, a sheet-like inorganic fire-resistant covering material is attached from the outside of a steel column or steel beam to the surface of a wall, and then an organic coating material is sprayed onto the outside of the sheet-like inorganic fire-resistant covering material, thereby achieving the effect of forming a stable moisture-proof layer without gaps even at the ends of the fire-resistant covering material. [Brief description of the drawings]

[0020] [Figure 1] FIG. 1 is a cross-sectional view showing an embodiment of a fire-resistant covering structure and a construction method thereof according to the present invention. [Diagram 2] Figure 2 is a table comparing the measured values ​​of each coating material with the moisture permeability resistivity of in-situ foamed urethane. [Diagram 3] FIG. 3 is a cross-sectional view showing an example of a conventional composite fire-resistant structure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of a fire-resistant covering structure and a method for constructing the same according to the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to these preferred embodiments.

[0022] As shown in Fig. 1, a fire-resistant coated structure 10 according to an embodiment of the present invention is applied to a steel beam 14 arranged adjacent to an exterior wall 12 (wall body) that separates an interior room A from an exterior room B. This fire-resistant coated structure 10 includes an inorganic fire-resistant coating material 16 provided continuously on the surface of the steel beam 14 on the interior room A side and from this surface to the inner surface of the exterior wall 12. On the outer surface of the fire-resistant coating material 16, a moisture-proof coat 18 (organic coating material) is provided.

[0023] The exterior wall 12 can be made of, for example, a precast reinforced concrete panel, an ALC plate, an extruded cement board (ECP), or the like. The steel beam 14 is made of an H-shaped steel having a web 20 and upper and lower flanges 22, 24. A floor 26 such as a reinforced concrete slab or an ALC plate is provided on the upper surface of the upper flange 22 of the steel beam 14. A layer seal 28 is provided between the floor 26 and the exterior wall 12. A heat insulating material 30 for preventing condensation is provided on the upper side of this layer seal 28 and on the inner surface of the exterior wall 12 below the fire-resistant covering structure 10. The heat insulating material 30 can be made of, for example, a foamed plastic heat insulating material. An interior material 32 is provided on the indoor side at a distance from the heat insulating material 30. A ceiling base material 34 and a ceiling material 36 are provided on the lower side of the lower flange 24 of the steel beam 14.

[0024] The fireproof coating material 16 can be made of an inorganic fireproof coating material such as sprayed rock wool, Makibee (registered trademark), wrapped rock wool felt, etc. In this embodiment, it is assumed that the inorganic fireproof coating material 16 is formed into a sheet shape.

[0025] The moisture-proof coat 18 is an organic coating material for suppressing the permeation of water vapor W from the outside to the inside of the fire-resistant coating material 16, and can be composed of, for example, modified asphalt-based waterproofing material, asphalt-based emulsion moisture-proofing material, water-soluble acrylic waterproofing material, ultra-fast curing urethane waterproofing material, highly elastic acrylic rubber-based wall waterproofing decorative material, ultra-low-pollution NAD elastic polyurethane resin paint, ultra-low-pollution water-based elastic fluororesin paint, or other materials mainly made of these materials. By using such a general-purpose waterproofing material, it is possible to ensure moisture resistance and reduce construction costs. However, the moisture-proof coat 18 is not limited to this, and any organic coating material having a moisture permeation resistance higher than that of the fire-resistant coating material 16 may be used. By providing the moisture-proof coat 18 on the outer surface of the fire-resistant coating material 16, it is possible to prevent the water vapor W in the room A from condensing on the inner surface of the exterior wall 12.

[0026] When constructing this fire-resistant covering structure 10, for example, a sheet-like inorganic fire-resistant covering material 16 is prepared, and a moisture-proof coating 18 is applied to the outer surface of this fire-resistant covering material 16 to manufacture a sheet-like fire-resistant covering material. This sheet-like fire-resistant covering material is then attached from the outside of the steel beams 14 to the surface of the exterior wall 12. In this manner, the fire-resistant covering structure 10 that suppresses the occurrence of condensation can be easily constructed. Here, the moisture-proof coating 18 may be applied by spraying onto the outer surface of the fire-resistant covering material 16. In this manner, a seamless moisture-proof layer can be easily formed even on a complex substrate shape.

[0027] Alternatively, instead of applying the material in this manner, a sheet-like inorganic fireproof coating material 16 may be attached from the outside of the steel beams 14 to the surface of the exterior wall 12, and then the moisture-proof coating 18 may be sprayed onto the surface of the attached fireproof coating material 16. In this way, a stable moisture-proof layer without gaps can be formed even at the ends of the fireproof coating material 16.

[0028] The operation and function of the above configuration will now be described. Although the inorganic fire-resistant coating material 16 has low moisture permeability resistance and allows water vapor W on the indoor side to pass through, providing a moisture-proof coating 18 with high moisture permeability resistance on the surface of the fire-resistant coating material 16 suppresses the permeation of water vapor W on the indoor side. By reducing the amount of water vapor W penetrating into the interior 38 of the composite fire-resistant structure formed by the fire-resistant coating structure 10, the dew point temperature of the air inside 38 of the composite fire-resistant structure is lowered and the occurrence of condensation is reduced.

[0029] Therefore, according to this embodiment, it is possible to suppress the occurrence of condensation inside 38 of the composite fireproof structure of steel beams 14. Also, by applying moisture-proof coating 18 by a spraying method, it is possible to easily form a seamless moisture-proof layer even on a complex base shape. Also, it is possible to improve workability.

[0030] In addition, in rooms subject to interior design restrictions under the Building Standards Act (rooms where the surface material must be non-combustible or semi-non-combustible), the moisture-proof function of the fireproof coating material can be guaranteed even in an exposed state (without a ceiling). This has the effect of making it highly applicable in rooms where ceilings are not normally installed, such as machine rooms and warehouses.

[0031] In the above embodiment, the present invention is described with reference to a composite fire-resistant structure of steel beams, but the present invention is not limited to this and can also be applied to a composite fire-resistant structure of steel columns. In this case, the same effects as those described above can be obtained.

[0032] (Example) Next, an embodiment of the present invention will be described. As moisture-proof coatings, two types of modified asphalt-based waterproofing materials (waterproofing materials A and B), an asphalt-based emulsion moisture-proofing material, a water-soluble acrylic fire-resistant joint spray (organic waterproofing material), a two-component ultra-fast-curing urethane waterproofing material, and an organic insulating material (on-site foamed urethane) were selected, and the moisture permeability resistance and moisture permeability specific resistance of each material were measured. The measured values ​​of each moisture-proof coating are shown in Figure 2. The modified asphalt-based waterproofing material corresponds to an embodiment of the present invention, and the other materials correspond to comparative examples. Note that no actual measurements were made for the on-site foamed urethane, and the values ​​given in Reference 1 were used.

[0033] [Reference 1] "Condensation in Buildings - Its Causes and Countermeasures", Masashi Yamada, Inoue Shoin Publishing, 1996, p.286

[0034] As shown in Figure 2, the moisture permeability resistance of the modified asphalt-based waterproofing material of this embodiment is significantly higher than that of moisture-proof coatings such as urethane foamed in place. Therefore, by applying the moisture-proof coating of this embodiment to the surface of the inorganic fire-resistant coating material that constitutes the composite fire-resistant structure, it is possible to suppress and reduce the occurrence of condensation inside the composite fire-resistant structure. In addition, with other waterproofing materials and highly waterproof paints, by increasing the thickness of the coating film, it is possible to ensure the same moisture-proofing effect as the modified asphalt-based waterproofing material of this embodiment.

[0035] As described above, the fire-resistant covering structure of the present invention is a fire-resistant covering structure comprising an inorganic fire-resistant covering material that is continuously provided from the outside of a steel column or steel beam that is arranged adjacent to and facing a wall to the surface of the wall, and further comprises an organic coating material that is provided on the outside of the inorganic fire-resistant covering material in order to suppress the transmission of water vapor from the outside to the inside of the inorganic fire-resistant covering material and has a moisture permeation resistance higher than that of the inorganic fire-resistant covering material, thereby making it possible to suppress the occurrence of condensation in the composite fire-resistant structure of the columns and beams.

[0036] Furthermore, according to another fire-resistant covering structure of the present invention, the organic coating material is composed of a material whose main component is any of modified asphalt-based waterproofing material, asphalt-based emulsion moisture-proofing material, water-soluble acrylic-based waterproofing material, ultra-fast-curing urethane waterproofing material, highly elastic acrylic rubber-based wall waterproof decorative material, ultra-low-polluting NAD elastic polyurethane resin paint, and ultra-low-polluting water-based elastic fluororesin paint, thereby ensuring moisture-proofing and reducing construction costs.

[0037] Furthermore, according to the method for constructing a fire-resistant covering structure of the present invention, which is a method for constructing the above-mentioned fire-resistant covering structure, a sheet-like fire-resistant covering material is manufactured by providing an organic coating material on the outside of a sheet-like inorganic fire-resistant covering material, and then this sheet-like fire-resistant covering material is attached from the outside of a steel column or steel beam to the surface of a wall, so that a composite fire-resistant structure of columns and beams that suppresses the occurrence of condensation can be easily constructed.

[0038] In addition, according to another construction method for a fire-resistant coating structure of the present invention, a sheet-shaped fire-resistant coating material is manufactured by spraying an organic coating material onto the outside of a sheet-shaped inorganic fire-resistant coating material, so that it is possible to easily form a seamless moisture barrier layer even on a complex base shape.

[0039] Furthermore, according to another method for constructing a fire-resistant covering structure of the present invention, which is a method for constructing the above-mentioned fire-resistant covering structure, a sheet-like inorganic fire-resistant covering material is attached from the outside of a steel column or steel beam to the surface of a wall, and then an organic coating material is sprayed onto the outside of this sheet-like inorganic fire-resistant covering material, so that a stable moisture-proof layer without gaps can be formed even at the ends of the fire-resistant covering material. [Industrial Applicability]

[0040] INDUSTRIAL APPLICABILITY As described above, the fire-resistant covering structure and its construction method according to the present invention are useful for fire-resistant covering of composite fire-resistant structures of columns and beams, and are particularly suitable for suppressing the occurrence of condensation inside the composite fire-resistant structure. [Explanation of symbols]

[0041] 10 Fire-resistant coating structure 12 Exterior wall (wall) 14 Steel beam 16 Fireproof cladding 18 Moisture-proof coating (coating material) 20 Web 22 Upper flange 24 Bottom flange 26 Beds 28 Layer Blocking 30 Insulation 32 Interior materials 34 Ceiling underlayment 36 Ceiling materials 38 Internal A Indoor B Outdoors

Claims

1. A fire-resistant coating structure comprising a sheet-like inorganic fire-resistant coating material that is continuously provided from the outside of a steel column or steel beam that is arranged adjacent to and facing a wall to the surface of the wall, wherein an organic coating material is sprayed onto the outside of the inorganic fire-resistant coating material.

2. The fire-resistant coating structure according to claim 1, characterized in that the organic coating material is composed mainly of any of the following materials: modified asphalt-based waterproofing material, asphalt-based emulsion moisture-proofing material, water-soluble acrylic-based waterproofing material, ultra-fast-curing urethane waterproofing material, highly elastic acrylic rubber-based wall waterproofing decorative material, ultra-low-pollution NAD elastic polyurethane resin paint, and ultra-low-pollution water-based elastic fluororesin paint.

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