Fire-resistant coating structure and its construction method

Abstract

To provide a fire-resistant covering structure suitable as a dew condensation countermeasure for a composite fire-resistant structure of a column and a beam, and its construction method.SOLUTION: In a fire-resistant covering structure 10 comprising a fire-resistant covering material 16 continuously provided from the outside of a steel column or a steel beam 14 oppositely arranged in proximity to a wall body 12 to the surface of the wall body 12, a moisture-proof film 18 which is provided on the outside of the fire-resistant covering material 16 in order to suppress the transmission of steam W from the outside to the inside of the fire-resistant covering material 16 and whose moisture permeability resistance is higher than that of the fire-resistant covering material 16 is further provided.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] Conventionally, when installing steel beams and steel columns near the outer wall in a steel-frame building, the fire-resistant coating of the steel frame often adopts a composite fire-resistant structure with the outer wall. The reason for adopting the composite fire-resistant structure is that when the outer wall and the steel frame are close to each other, the workability of the fire-resistant coating on the surface of the steel frame on the outer wall side becomes extremely poor.

[0003] Since a heat insulating material for dew condensation prevention or the like is usually not installed on the outer wall surface of the composite fire-resistant structure, a large amount of dew condensation may occur on the outer wall surface in buildings such as cold regions, IDCs where the indoor humidity is high, hospitals, houses, hotels, etc., leading to actual damage.

[0004] The dew condensation in the composite fire-resistant structure occurs, for example, as shown in FIG. 6, when the indoor water vapor W generated by heating or the like penetrates through the fire-resistant coating material 2 covering the steel beam 1 and enters the inside 3 of the composite fire-resistant structure, and reaches the dew point on the inner surface of the outer wall 5 cooled by the outside air 4. Therefore, it is considered that if the moisture permeability resistance can be ensured by the fire-resistant coating material 2, this dew condensation can be suppressed. However, among the construction methods using commercially available fire-resistant coating materials currently, there is no material that can maintain sufficient moisture permeability resistance for dew condensation countermeasures. In FIG. 6, reference numeral 6 is a foamed plastic-based heat insulating material for preventing dew condensation. In the composite fire-resistant structure, it is not possible to construct such a heat insulating material on the inner surface of the outer wall 5 outside the fire resistance certification.

[0005] As a dew condensation countermeasure for the conventional composite fire-resistant structure, for example, there is a method of applying on-site foamed urethane to the surface of the fire-resistant coating material. However, in a severe environment such as a parapet part, the moisture permeability resistance may not be sufficient for dew condensation countermeasures. In addition, a boundary and a closing that can separate the part that requires moisture-proof measures from other parts while maintaining the fire resistance performance have not been established, and moisture-proof measures are required over a wide range.

[0006] Furthermore, other condensation prevention technologies for fire-resistant coating structures are known, for example, those described in Patent Documents 1 and 2. Patent Document 1 relates to a fire-resistant coating structure having a condensation prevention function that prevents condensation from forming on the surface of members such as steel frames, maintains fire resistance by improving water resistance, and allows for decorative finishing. This fire-resistant coating structure consists of a foamed fire-resistant coating layer formed from a foamed fire-resistant coating from the structure side on the surface of the structure, and a condensation-preventing coating layer formed from a condensation-preventing coating. Patent Document 2 relates to a fire-resistant coating structure for steel beams that can improve the heat insulation and airtightness around the steel beams while ensuring fire resistance for the steel beams. This fire-resistant coating structure comprises a thermally expandable fire-resistant coating sheet layer that covers the exposed portion of the outer circumference of the steel beam that does not face or abut against the outer wall or floor, an airtight layer of a metal film that covers the surface of the fire-resistant coating sheet layer, and a heat insulation layer mainly made of phenolic resin foam provided between the exposed portion and the fire-resistant coating sheet layer. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2001-200597 [Patent Document 2] Japanese Patent Publication No. 2010-43444 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] As mentioned above, there was a need for suitable condensation control measures in composite fire-resistant structures of columns and beams. Furthermore, there was a need to establish a technology that could accommodate the boundary between parts requiring moisture protection and other parts while maintaining continuous fire resistance.

[0009] The present invention has been made in view of the above, and aims to provide a fire-resistant coating structure and a method for constructing the same that is suitable as a condensation countermeasure for a composite fire-resistant structure of columns and beams. [Means for solving the problem]

[0010] To solve the above-mentioned problems and achieve the objective, the fire-resistant coating structure according to the present invention is a fire-resistant coating structure comprising a fire-resistant coating material continuously provided from the outside of a steel column or steel beam arranged opposite to a wall in close proximity to the wall, and further comprising a moisture-proof film provided on the outside of the fire-resistant coating material to suppress the transmission of water vapor from the outside to the inside of the fire-resistant coating material, and having a moisture resistance higher than the moisture resistance of the fire-resistant coating material.

[0011] Furthermore, another fire-resistant coating structure according to the present invention is characterized in that, in the above-described invention, the moisture-proof film is continuously provided spanning the end portion of the inorganic fire-resistant coating material that requires moisture-proofing measures and the portion adjacent to the end of the inorganic fire-resistant coating material that does not require moisture-proofing measures.

[0012] Furthermore, another fire-resistant coating structure according to the present invention is characterized in that, in the above-described invention, the moisture-proof film is composed of a film or sheet containing a polyester-based material or an aluminum-based material as the main material.

[0013] Furthermore, the method for constructing the fire-resistant coating structure according to the present invention is a method for constructing the fire-resistant coating structure described above, characterized in that a sheet-like fire-resistant coating material is manufactured by providing a moisture-proof film on the outside of a sheet-like inorganic fire-resistant coating material, and then this sheet-like fire-resistant coating material is attached from the outside of a steel column or steel beam to the surface of a wall. [Effects of the Invention]

[0014] The fire-resistant coating structure according to the present invention comprises a fire-resistant coating material continuously provided from the outside of a steel column or steel beam positioned opposite to a wall in close proximity to the wall surface, and further comprises a moisture-proof film provided on the outside of the fire-resistant coating material to suppress the transmission of water vapor from the outside to the inside of the fire-resistant coating material, and having a moisture resistance higher than the moisture resistance of the fire-resistant coating material, thereby having the effect of suppressing the occurrence of condensation in a composite fire-resistant structure of columns and beams.

[0015] Furthermore, according to another fire-resistant coating structure of the present invention, the moisture-proof film is continuously provided spanning the end portion of the inorganic fire-resistant coating material that requires moisture-proofing measures and the portion adjacent to the end of the inorganic fire-resistant coating material that does not require moisture-proofing measures. This provides the effect of separating the portion requiring moisture-proofing measures from the other portion while maintaining continuous fire resistance.

[0016] Furthermore, according to other fire-resistant coating structures of the present invention, the moisture-proof film is composed of a film or sheet containing polyester-based material or aluminum-based material as the main component, thereby ensuring moisture resistance while reducing construction costs.

[0017] Furthermore, according to the method for constructing the fire-resistant coating structure of the present invention, the above-described method for constructing the fire-resistant coating structure involves first manufacturing a sheet-like fire-resistant coating material by providing a moisture-proof film on the outside of a sheet-like inorganic fire-resistant coating material, and then attaching this sheet-like fire-resistant coating material from the outside of a steel column or steel beam to the surface of a wall. This method has the effect of easily constructing a structure that ensures fire resistance at the boundary between parts requiring moisture protection and other parts in a composite fire-resistant structure of columns and beams. [Brief explanation of the drawing]

[0018] [Figure 1] Figure 1 is a cross-sectional view showing an embodiment of the fire-resistant coating structure and its construction method according to the present invention, where (1) is an example of boundary detailing around a steel beam, and (2) is an example of boundary detailing between a moisture-proof specification and a general specification. [Figure 2] Figure 2 shows a comparison of the time changes of measured values, where (1) is the amount of water vapor, (2) is the temperature, and (3) is the humidity. [Figure 3] Figure 3 is a cross-sectional view showing an example of the arrangement of a composite fire-resistant structure for steel beams according to this embodiment. [Figure 4] Figure 4 is a cross-sectional view showing an example of the arrangement of a composite fire-resistant structure for a steel column according to this embodiment. [Figure 5]FIG. 5 is a cross-sectional view showing an example of the end moisture-proof treatment according to the present embodiment. [Figure 6] FIG. 6 is a cross-sectional view showing an example of a conventional synthetic refractory structure. MODE FOR CARRYING OUT THE INVENTION

[0019] Hereinafter, embodiments of the refractory coating structure and its construction method according to the present invention will be described in detail based on the drawings. Note that the present invention is not limited by this embodiment.

[0020] As shown in FIG. 1(1), the refractory coating structure 10 according to the embodiment of the present invention is applied to the steel beam 14 disposed close to the outer wall 12 (wall body) that partitions the interior A and the exterior B. This refractory coating structure 10 includes the surface on the interior side of the steel beam 14 and an inorganic refractory coating material 16 continuously provided from this surface to the inner surface of the outer wall 12. A moisture-proof film 18 is provided on the outer surface of the refractory coating material 16.

[0021] The outer wall 12 can be composed of, for example, an extruded cement plate (ECP). The steel beam 14 is made of an H-shaped steel having a web 20 and upper and lower flanges 22 and 24. A floor deck 26 is provided on the upper surface of the upper flange 22 of the steel beam 14. An interlayer filler 28 (interlayer partition material) is provided between the floor deck 26 and the outer wall 12. A heat insulating material 30 for preventing dew condensation is provided on the upper side of this interlayer filler 28 and the inner surface of the outer wall 12 on the lower side of the refractory coating structure 10. The heat insulating material 30 can be composed of, for example, a foamed plastic-based heat insulating material. The heat insulating material 30 is not essential and may be omitted. An interior material 32 is provided at a position on the interior side spaced apart from the heat insulating material 30. A ceiling base material 34 and a ceiling material 36 are provided below the lower flange 24 of the steel beam 14.

[0022] The fire-resistant coating material 16 can be constructed using, for example, an inorganic fire-resistant coating material such as sprayed rock wool. In this embodiment, it is assumed that the inorganic fire-resistant coating material 16 is formed into a sheet. The moisture-proof film 18 is for suppressing the transmission of water vapor W from the outside to the inside of the fire-resistant coating material 16, and can be constructed using, for example, a film or sheet containing polyester material as the main component, such as a polyester moisture-proof film or sheet. Using such a material ensures moisture resistance and reduces construction costs. However, the moisture-proof film 18 is not limited to this, and any film or sheet with moisture resistance that has a higher moisture permeability resistance than the fire-resistant coating material 16 may be used. Examples of such materials include films or sheets containing polyester material, rubber material, aluminum material such as aluminum foil, other film materials, foamed urethane, etc., as the main component. By providing the moisture-proof film 18 on the outer surface of the fire-resistant coating material 16, it is possible to prevent water vapor W in the room A from condensing on the inner surface of the outer wall 12.

[0023] When constructing this fire-resistant coating structure 10, first, a sheet-like inorganic fire-resistant coating material 16 is prepared. Next, a moisture-proof film 18 is provided on the outer surface of this fire-resistant coating material 16 to create a sheet-like fire-resistant coating material. After that, this sheet-like fire-resistant coating material is attached from the outside of the steel beam 14 to the surface of the exterior wall. In this way, the fire-resistant coating structure 10 can be easily constructed. As a method for providing the moisture-proof film to the fire-resistant coating material, for example, a method of attaching it via an adhesive can be used.

[0024] The operation and function of the above configuration will be explained. The inorganic fire-resistant coating material 16 has low water vapor resistance and allows water vapor W from the indoor side to pass through. However, by providing a moisture-proof film 18 with high water vapor resistance on the surface of the fire-resistant coating material 16, the transmission of water vapor W from the indoor side is suppressed. As the amount of water vapor W that penetrates into the interior 38 of the composite fire-resistant structure formed by the fire-resistant coating structure 10 decreases, the dew point temperature of the air inside the composite fire-resistant structure 38 is lowered, and the occurrence of condensation is reduced.

[0025] Therefore, according to this embodiment, it is possible to suppress the occurrence of condensation inside the composite fire-resistant structure 38 of the steel beam 14. Furthermore, since it is possible to apply the material only to the parts where moisture-proofing measures are necessary (e.g., only on the exterior wall side), parts where other moisture-proofing measures are not necessary can be covered with a sheet-like fire-resistant covering material 16 that does not have a moisture-proof film 18.

[0026] Furthermore, in rooms subject to interior finish restrictions under the Building Standards Act (rooms where surface materials must be non-combustible or semi-non-combustible), moisture-proof functionality can be ensured with exposed (no ceiling) fire-resistant coatings. For this reason, it has high applicability in room applications where ceilings are not typically installed, such as machine rooms and warehouses.

[0027] In the above embodiment, the case in which the steel beam is an H-shaped steel was used as an example, but the present invention is not limited to this, and any steel material that can be used for a steel beam may be used. For example, it may be made of steel material with other cross-sectional shapes. The same effects and advantages as described above can be achieved even in this case.

[0028] (Verification of the effects of the present invention) Next, we will describe the demonstration experiments conducted to verify the effects of the present invention.

[0029] This experiment involved constructing a fire-resistant coating structure according to the present invention under conditions close to those of actual construction, and confirming its constructability and moisture-proof properties. Specifically, a sheet-type fire-resistant coating material with a moisture-proof film was applied to the columns and beams inside an actual building. A wrap-around fire-resistant coating material made of heat-resistant rock wool felt was used. As a result, it was confirmed that it was possible to install the fire-resistant coating material without gaps at its edges. Subsequently, the outer perimeter of the composite fire-resistant structure of this example was covered with a vinyl sheet, and the temperature and humidity inside the vinyl sheet were measured while humidifying to confirm the moisture-proof effect. As a comparative example, a composite fire-resistant structure constructed with a sheet-type fire-resistant coating material without a moisture-proof film was also similarly covered with a vinyl sheet to confirm its moisture-proof effect.

[0030] The measurement results are shown in Figure 2. In the figure, the measurements for the Example (inside vinyl) and the Comparative Example (inside vinyl) are taken inside the vinyl sheet. As shown in this figure, it can be seen that by applying a sheet-like fire-resistant coating material with a moisture-proof film, the water vapor pressure inside the synthetic fire-resistant structure is lowered, suppressing and reducing the occurrence of condensation.

[0031] (Example of boundary detail between moisture-proof and standard specifications) Next, we will explain examples of boundary details for moisture-proof specifications and general specifications. As shown in Figure 1(2), this configuration involves dividing the inorganic fire-resistant coating material 16 on the interior surface of the steel beam 14 and exterior wall 12 into a moisture-proof specification requiring moisture protection and a general specification not requiring moisture protection. The moisture-proof film 18 is provided at the boundary between them. Specifically, the moisture-proof film 18 is provided continuously in a roughly Z-shape in cross-section, from the surface side of the moisture-proof fire-resistant coating material 16 through the end portion to the back side of the general specification fire-resistant coating material 16. In this way, it is possible to separate the part requiring moisture protection from the other part while maintaining continuous fire resistance performance.

[0032] (Example of a composite fire-resistant structure for steel beams) Next, we will explain an example of the construction of a composite fire-resistant structure for steel beam 14. As shown in Figure 3, this configuration involves continuously applying a sheet-like inorganic fire-resistant coating material 16 equipped with a moisture-proof film 18 to the inner surface of the outer wall 12, from the end of the upper flange 22 of the steel beam 14, through the end of the lower flange 24. The upper end 40 of the fire-resistant coating material 16 is folded outwards. This folded portion is fixed to the upper flange 22 by welding or other means using insulating fixing pins 42. The area around the end 40 of the fire-resistant coating material 16 is sealed with moisture-proof tape 48. Specifically, the moisture-proof tape 48 is continuously applied from the vicinity of the end 40 of the fire-resistant coating material 16 to the floor deck 26, straddling the heads of the fixing pins 42 and the end 40. The moisture-proof tape 48 can be made of the same material as the moisture-proof film 18.

[0033] The lower end 44 of the fire-resistant coating material 16 is bent and positioned to follow the lower and inner surfaces of the base material 46, which is made of L-shaped steel and fixed to the inner surface of the exterior wall 12. This end 44 extends to the lower side of the base material 14 and is fixed to the inner surface of the base material 46 by welding or other means using insulating fixing pins 42. In addition, the area around the end 44 of the fire-resistant coating material 16 is sealed with moisture-proof tape 48. Specifically, the moisture-proof tape 48 is continuously applied from the vicinity of the end 44 of the fire-resistant coating material 16 to the inner surface of the exterior wall 12, straddling the heads of the fixing pins 42 and the end 44.

[0034] Furthermore, the fire-resistant coating material 16 is fixed to the lower surface of the lower flange 24 by welding or other means using insulating fixing pins 42. The heads of these fixing pins 42 are sealed with moisture-proof tape 48 or the like. The upper corners of the interlayer seal 28 are also sealed with moisture-proof tape 48 or the like.

[0035] According to the above arrangement, the moisture-proof tape 48 seals the gaps that occur at the ends of the fire-resistant coating material 16 and around the fixing pins 42, and also suppresses the occurrence of condensation inside the composite fire-resistant structure.

[0036] (Example of a composite fire-resistant structure for steel columns) Next, we will explain an example of the construction of a composite fire-resistant structure for steel columns. As shown in Figure 4, this configuration is applied to steel columns 50 positioned opposite and in close proximity to the exterior wall 12. The steel columns 50 are made of H-shaped steel. A sheet-like inorganic fire-resistant coating material 16 with a moisture-proof film 18 is provided around the outer perimeter of the steel columns 50, except for the surface facing the exterior wall 12. This fire-resistant coating material 16 is provided continuously from the steel columns 50 to the inner surface of the exterior wall 12 in a roughly U-shape in plan view. The ends of the fire-resistant coating material 16 are bent outward along the inner surface of the exterior wall 12 and fixed to the inner surface of the exterior wall 12 with insulating fixing pins 42. The fire-resistant coating material 16 is also fixed to the outer flange of the steel columns 50 by welding or other means using insulating fixing pins 42. The heads of these fixing pins 42 are sealed with moisture-proof tape 48 or the like.

[0037] According to the above arrangement, the moisture-proof tape 48 seals the gaps around the fixing pins 42, and the occurrence of condensation inside the composite fire-resistant structure can be suppressed. In the above explanation, the case in which the steel column 50 is made of H-shaped steel was used as an example, but the steel column 50 may also be made of steel pipe columns such as square steel pipes. The same effects as above can be achieved even in this case.

[0038] (Example of edge moisture protection treatment) Next, we will explain a specific example of moisture-proofing treatment for the edges of the fire-resistant coating material 16. Figure 5A shows an example where the end is treated with moisture-proof tape 48 and foamed urethane 52, and Figure 5B shows an example where the end is treated with foamed urethane 52 only. A is a high-grade specification with high moisture-proof performance, B is a low-grade specification with low moisture-proof performance, and the specification in between is a medium-grade specification, with foamed urethane 52 omitted in A. In each figure, beam 1 shows the case where the steel beam 14 and floor deck 26 are perpendicular, beam 2 shows the case where the steel beam 14 and floor deck 26 are parallel, and beam 3 and column show the interface with the exterior wall 12.

[0039] As shown in Figure 5A, moisture-proof tape 48 is continuously applied across each end of the fire-resistant coating material 16, which has a moisture-proof film 18 on the outside, and then foamed urethane 52 is applied over it. The moisture-proof tape 48 can be made of the same material as the moisture-proof film 18. In this way, the moisture-proof tape 48 is continuously applied across the small end portions of the inorganic fire-resistant coating material 16 that require moisture protection and the portions close to the ends of the inorganic fire-resistant coating material 16 that do not require moisture protection, thereby ensuring fire resistance at the boundary between the portion requiring moisture protection and the other portions. In A, if the foamed urethane 52 is omitted, the moisture-proof performance can be reduced to a medium grade specification. Also, as shown in Figure 5B, if the application of the moisture-proof tape 48 is omitted and the ends are treated only with foamed urethane 52, the moisture-proof performance can be reduced to a low grade specification. Thus, it is possible to use different levels of moisture-proof performance (high, medium, low) depending on the required grade.

[0040] According to the above configuration, it is possible to achieve a finish that ensures fire resistance at the boundary between the parts requiring condensation prevention (moisture control) and other parts, thus allowing for construction that limits moisture control measures to the necessary areas.

[0041] As described above, the fire-resistant coating structure according to the present invention is a fire-resistant coating structure that includes a fire-resistant coating material continuously provided from the outside of a steel column or steel beam arranged opposite to a wall in close proximity to the wall, and further includes a moisture-proof film that is provided on the outside of the fire-resistant coating material to suppress the transmission of water vapor from the outside to the inside of the fire-resistant coating material and has a moisture resistance higher than the moisture resistance of the fire-resistant coating material, thereby suppressing the occurrence of condensation in a composite fire-resistant structure of columns and beams.

[0042] Furthermore, according to another fire-resistant coating structure of the present invention, the moisture-proof film is continuously provided spanning the end portion of the inorganic fire-resistant coating material that requires moisture-proofing measures and the portion adjacent to the end of the inorganic fire-resistant coating material that does not require moisture-proofing measures. This allows for the separation of the portion requiring moisture-proofing measures from the other portion while maintaining continuous fire resistance.

[0043] Furthermore, according to other fire-resistant coating structures of the present invention, the moisture-proof film is composed of a film or sheet containing a polyester-based material or an aluminum-based material as the main component, thereby ensuring moisture resistance and reducing construction costs.

[0044] Furthermore, according to the method for constructing the fire-resistant coating structure of the present invention, the above-described fire-resistant coating structure is constructed by first manufacturing a sheet-like fire-resistant coating material by providing a moisture-proof film on the outside of a sheet-like inorganic fire-resistant coating material, and then attaching this sheet-like fire-resistant coating material from the outside of the steel column or steel beam to the surface of the wall. This makes it possible to easily construct a structure that ensures fire resistance at the boundary between the part requiring moisture protection and other parts in a composite fire-resistant structure of columns and beams. [Industrial applicability]

[0045] As described above, the fire-resistant coating structure and its construction method according to the present invention are useful for fire-resistant coating in 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]

[0046] 10. Fire-resistant coating structure 12. Exterior wall (wall structure) 14 Steel beams 16 Fireproof cladding 18 Moisture-proof film 20 Web 22 Upper flange 24 Lower flange 26 Floor deck 28 Interlayer closure 30 Insulation 32 Interior materials 34 Ceiling underlayment 36 Ceiling materials 38 Internal 40,44 End 42 Fixing pins 46. ​​Underlayment 48 Moisture-proof tape 50 Steel columns 52 Polyurethane foam A Indoor B Outdoors

Claims

1. A fire-resistant covering structure comprising a fire-resistant covering material continuously provided from the outside of a steel column or steel beam positioned opposite to a wall in close proximity to the wall to the surface of the wall, further comprising a moisture-proof film or sheet provided on the outside of the fire-resistant covering material to suppress the transmission of water vapor from the outside to the inside of the fire-resistant covering material, the moisture resistance being higher than that of the fire-resistant covering material, The aforementioned film or sheet is made of a film or sheet mainly composed of an aluminum-based material or foamed urethane, and is characterized in that it is continuously provided from the surface side of the inorganic fire-resistant coating material that requires moisture protection measures, through the end portion of the edge, to the back side of the inorganic fire-resistant coating material that does not require moisture protection measures.

2. A method for constructing the fire-resistant coating structure described in claim 1, A method for constructing a fire-resistant coating structure, characterized by manufacturing a sheet-like fire-resistant coating material by providing the film or sheet on the outside of the sheet-like inorganic fire-resistant coating material, and then attaching the sheet-like fire-resistant coating material from the outside of the steel column or steel beam to the surface of the wall.

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