Fireproof coating structure and its construction method

Abstract

To provide a fireproof covering structure capable of reliably performing fireproof covering on an outer wall of a steel beam, and a construction method thereof.SOLUTION: A fireproof covering structure includes: a fire-resistant paint 26 provided to the side opposite to a wall 12 on the outer surface of a steel member 14 placed facing and close to the wall 12; and a fireproof covering material 28 sprayed from the side not facing wall 12 to an area where the fire-resistant paint 26 is provided. Also, in order to prevent a spray material 28 from falling off from the surface of the steel member 14, a fall prevention material 30 may be provided to the steel member 14.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a fireproof coating structure and a construction method thereof.

Background Art

[0002] Conventionally, in the construction of steel structure buildings, the fireproof coating work of the outer peripheral beam is generally carried out after the outer wall is attached. As shown in Fig. 5(1), there is a composite fireproof coating method in which the outer wall 1 is used as a part of the fireproof coating of the steel beam 2, but when the fireproof structure has not been certified by the country, the composite fireproof coating method cannot be applied. In that case, as shown in Fig. 5(2), the steel beam 2 must be covered with a fireproof coating material 3. In addition, the reference numeral 4 in Fig. 5 is the floor, and the reference numeral 5 is the floor slab.

[0003] On the other hand, as conventional techniques related to such fireproof coating structures, for example, those described in Patent Documents 1 to 3 are known. Patent Document 1 describes a method of constructing a steel column or a steel beam in which a fireproof paint is applied to the inner surface of a U-shaped portion formed by the web and flange of an H-shaped steel, and then a fireproof outer plate is attached to the outside thereof, and then a fireproof material is sprayed from the inside of the steel column or the steel beam. Further, Patent Document 2 describes a steel column constituting a steel structure covered with a fireproof outer wall material, a fireproof coating material, and a fireproof ventilation member disposed at the butting portion thereof. Further, Patent Document 3 describes that a fireproof coating material covering the lower flange of a steel beam extends to the side of a concrete outer wall plate, and a backing material of a non-combustible fibrous material is doubly disposed on the upper portion of the joint surface between the end surface of the fireproof coating material and the concrete outer wall plate.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

[0005] By the way, as shown in FIG. 5(2), when the gap L between the outer wall 1 and the lower flange 2A of the steel frame beam 2 is so small that a human hand cannot enter, it is impossible to apply the fireproof coating between the outer wall 1 and the steel frame beam 2. Even if the fireproof coating material 3 could be applied to this narrow space, it would be difficult to confirm whether the steel frame beam 2 is completely covered with the fireproof coating material 3. If there are gaps or holes in even a part of the fireproof coating material 3 and the steel frame beam 2 is exposed, the temperature of the steel frame beam 2 will rise during a fire and the strength of the steel material will decrease, and there is a risk that the member or the structure will collapse.

[0006] For this reason, when the space between the outer peripheral steel frame beam and the outer wall is narrow and the steel frame beam cannot be covered with a fireproof coating material, or when the certification of the fireproof structure has not been obtained from the country and the synthetic fireproof coating method cannot be applied, etc., there has been a demand for a construction method that can surely perform the fireproof coating on the outer wall side of the outer peripheral steel frame beam.

[0007] The present invention has been made in view of the above, and an object thereof is to provide a fireproof coating structure capable of surely performing the fireproof coating on the outer wall side of a steel frame beam and a construction method thereof. Means for Solving the Problems

[0008] In order to solve the above-described problems and achieve the object, the fireproof coating structure according to the present invention includes a fireproof paint provided on the side facing the wall body among the outer surface of the steel frame member disposed opposite to and close to the wall body, and a fireproof spraying material sprayed over the region where the fireproof paint is provided from the side not facing the wall body.

[0009] Further, another fireproof coating structure according to the present invention is characterized in that, in the above-described invention, the spraying material is rock wool.

[0010] Further, another fireproof coating structure according to the present invention is characterized in that, in the above-described invention, it further includes a detachment prevention material provided on the steel frame member in order to prevent the spraying material from detaching from the surface of the steel frame member.

[0011] Further, a fireproof coating method according to the present invention is a method of constructing the above-described fireproof coating structure, and includes the steps of transporting a steel frame member, on the outer surface of which a fireproof paint has been previously provided on the side facing the wall, to a construction site, and applying a spraying material in a region where the fireproof paint is to be provided from the side of the outer surface of the steel frame member that does not face the wall at the construction site.

Advantages of the Invention

[0012] According to the fireproof coating structure of the present invention, among the outer surfaces of the steel frame members arranged opposite to each other in proximity to the wall, a fireproof paint provided on the side facing the wall and a fireproof spraying material sprayed over a region where the fireproof paint is provided from the side not facing the wall are provided, so that the fireproof coating on the wall side of the steel frame member can be surely performed by the fireproof paint. Therefore, there is an effect that the fireproof coating on the outer wall side of the steel beam can be surely performed.

[0013] Further, according to another fireproof coating structure of the present invention, since the spraying material is rock wool, there is an effect that it can be easily applied to the outside of the steel frame member.

[0014] Further, according to another fireproof coating structure of the present invention, since it further includes a detachment prevention material provided on the steel frame member in order to prevent the spraying material from detaching from the surface of the steel frame member, there is an effect that the detachment of the spraying material can be prevented.

[0015] Moreover, according to the fireproof coating method of the present invention, which is a method for constructing the above-described fireproof coating structure, it includes a step of transporting to the construction site a steel frame member having a fireproof paint provided in advance on the side of the outer surface of the steel frame member facing the wall among the outer surfaces of the steel frame member, and a step of applying a spraying material to the area where the fireproof paint is to be provided from the side of the outer surface of the steel frame member that does not face the wall at the construction site. Therefore, the fireproof coating on the wall side of the steel frame member can be surely performed by the fireproof paint. Thus, it has the effect of surely performing the fireproof coating on the outer wall side of the steel beam.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying out the Invention

[0017] The present invention is for surely performing the fireproof coating on the outer wall side of the outer peripheral steel frame member and ensuring the fireproof performance when the space between the outer peripheral steel frame member and the outer wall is narrow and the steel frame member cannot be covered with a fireproof coating, or when the certification of the fireproof structure has not been obtained from the country and the synthetic fireproof coating method cannot be applied.

[0018] Hereinafter, embodiments of the fireproof coating structure and its construction method according to the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited by these embodiments.

[0019] (Embodiment 1) First, Embodiment 1 of the present invention will be described. As shown in Fig. 1(1), the fireproof coating structure 100 according to Embodiment 1 of the present invention is applied to a steel girder 14 (steel frame member) arranged close to an outer wall 12 (wall body) that partitions an indoor area A and an outdoor area B. The outer wall 12 can be composed of, for example, a precast concrete plate, a lightweight foamed concrete plate (ALC plate), an extruded cement plate (ECP), etc. The steel girder 14 is made of an H-shaped steel having a web 16 and upper and lower flanges 18, 20. A floor 22 such as concrete or ALC is provided on the upper surface of the upper flange 18 of the steel girder 14. An interlayer seal 24 (interlayer partitioning material) is provided between the floor 22 and the outer wall 12.

[0020] This fireproof coating structure 100 includes a fireproof paint 26 provided on the side of the outer surface of the steel girder 14 facing the outer wall 12, and a fireproof spraying material 28 provided over the area where the fireproof paint 26 is installed from the side not facing the outer wall 12. Specifically, the fireproof paint 26 is continuously provided from the edge of the upper flange 18 to the lower surface of the upper flange 18, the left side surface of the web 16, the upper surface of the lower flange 20, and the edge area. On the other hand, the spraying material 28 is continuously provided over the area from the lower surface of the floor 22 to the edge of the upper flange 18, the lower surface, the right side surface of the web 16, the upper surface of the lower flange 20, the edge, and the entire lower surface.

[0021] On the end side on the outer wall 12 side of the lower surface of the lower flange 20, a fall prevention fitting 30 (fall prevention material) is attached. When applying the spraying material 28 to the entire lower surface of the lower flange 20, since the spraying material 28 sprayed on the lower surface may fall off during normal times and during a fire, this fall prevention fitting 30 is used to prevent the fall. For this fall prevention fitting 30, for example, commercially available fittings, etc. (for example, "Drip Lock" (Refractory Coating Industry Cooperative), product name "Styro Lock" (Tilement Co., Ltd.), retaining pins used for fixing winding refractory coating materials (for example, Makibee (registered trademark)), etc.) can be used. When using a fall prevention fitting 30 having a base portion and a tip portion such as Drip Lock or Styro Lock, the base portion is adhered to the steel material surface for use. As the adhesive used for the adhesion, an inorganic adhesive (for example, Insulation Adhesive (Nichia Corporation)) or a synthetic rubber-based adhesive (for example, Seven Redin (registered trademark) (Seven Industries Co., Ltd.)) is suitable. Also, when using a retaining pin, the retaining pin is attached to the steel material surface by welding without using an adhesive. In addition, when using the above-mentioned fall prevention fitting 30, the installation interval of the fall prevention fitting in the material axis direction of the steel frame beam 14 is preferably 450 mm or less, more preferably 300 mm or less.

[0022] The fireproof paint 26 is a foaming type that foams and thickens upon heating. For example, a fireproof paint mainly composed of ammonium polyphosphate can be used. In such a fireproof paint, when heated during a fire, foaming starts at around 250 °C, foams 20 to 30 times to form a heat insulation layer, and suppresses the temperature rise of the steel material. The fireproof paint 26 is preferably pre-coated (pre-painted) at a factory such as a prefabricator on the steel material surface in a thickness unit of several millimeters to a dozen millimeters.

[0023] The spraying material 28 is provided by spraying it on the remaining range outside the pre-painting range of the fireproof paint 26. For this spraying material 28, for example, an inorganic refractory coating material such as sprayed rock wool can be used. The spraying material 28 is preferably applied to the steel frame beam 14 at the construction site.

[0024] When constructing the above-mentioned fire-resistant coating structure 100, first, at a factory such as a prefabricator in advance, a fire-resistant paint 26 is pre-coated on the surface of the steel girder 14 on the outer wall 12 side. Then, this steel girder 14 is transported to the building construction site and attached to the construction position near the outer wall 12. Next, after attaching the anti-drop hardware 30 to the lower flange 20 of the steel girder 14, the spraying material 28 is sprayed onto the remaining portion of the surface of the steel girder 14. By doing so, the fire-resistant coating structure 100 can be easily constructed. Also, the fire-resistant coating on the outer wall 12 side of the steel girder 14 can be surely performed by the pre-coated fire-resistant paint 26.

[0025] Therefore, according to the present embodiment, even if the space between the outer peripheral steel girder 14 and the outer wall 12 is narrow, the fire-resistant coating on the outer wall 12 side of the outer peripheral steel girder 14 can be surely performed to ensure the fire resistance performance. Also, even in a case where the certification of the fire-resistant structure has not been obtained from the state and the synthetic fire-resistant coating method cannot be applied, the fire-resistant coating on the outer wall 12 side of the outer peripheral steel girder 14 can be surely performed to ensure the fire resistance performance. Furthermore, by pre-coating the fire-resistant paint 26 on the steel girder 14 at the factory, the labor for the fire-resistant coating work at the construction site can be saved.

[0026] In the above embodiment, the case where the steel girder 14 is an H-shaped steel has been described as an example, but the present invention is not limited to this, and any steel member that can be used for the steel girder may be used. For example, it may be composed of steel materials with other cross-sectional shapes. Even in this case, the same operational effects as described above can be achieved. Also, in the above embodiment, the case where the steel member is the steel girder 14 has been described as an example, but the present invention is not limited to this, and it may be a steel column. The cross-sectional shape of the steel column may be any cross-sectional shape that can be used for the steel column. Even in this case, the same operational effects as described above can be achieved.

[0027] (Embodiment 2) Next, Embodiment 2 of the present invention will be described. As shown in Fig. 1(2), the fireproof coating structure 200 according to the second embodiment is obtained by applying a fireproof paint 26 and a spraying material 28 to the coating of the lower surface of the lower flange 20 in the above-described first embodiment. Specifically, the fireproof paint 26 is continuously provided from the mouth of the upper flange 18 to the lower surface of the upper flange 18, the left side surface of the web 16, the upper surface of the lower flange 20, the mouth, and a partial area of the lower surface. On the other hand, the spraying material 28 is continuously provided from the lower surface of the floor 22 to the mouth of the upper flange 18, the lower surface, the right side surface of the web 16, the upper surface of the lower flange 20, the mouth, and a partial area of the lower surface.

[0028] Also in this case, since there is a possibility of dropping in the construction part of the spraying material 28, a drop prevention metal fitting 30 is attached. The ends of the fireproof paint 26 and the spraying material 28 are overlapped with a predetermined overlapping margin d. It is desirable to ensure that the overlapping margin d is 10 mm or more, preferably 20 mm or more. With such a configuration, the same operational effects as those of the above-described first embodiment can be achieved.

[0029] (Embodiment 3) Next, the third embodiment of the present invention will be described. As shown in Fig. 1(3), the fireproof coating structure 300 according to the third embodiment is obtained by applying the fireproof paint 26 to the entire lower surface of the lower flange 20 in the above-described first embodiment. Specifically, the fireproof paint 26 is continuously provided from the mouth of the upper flange 18 to the lower surface of the upper flange 18, the left side surface of the web 16, the upper surface of the lower flange 20, the mouth, and the entire area of the lower surface. On the other hand, the spraying material 28 is continuously provided from the lower surface of the floor 22 to the mouth of the upper flange 18, the lower surface, the right side surface of the web 16, the upper surface of the lower flange 20, and the mouth area.

[0030] In this case, since there is a possibility that the spraying material 28 on the mouth surface of the lower flange 20 on the side opposite to the outer wall 12 may drop off, a drop prevention metal fitting 30 is attached to this mouth surface. With such a configuration, the same operational effects as those of the above-described first embodiment can be achieved.

[0031] (Embodiment 4) Next, Embodiment 4 of the present invention will be described. As shown in Fig. 1(4), the fireproof coating structure 400 according to Embodiment 4 of the present invention is obtained by applying a fireproof paint 26 from the entire lower surface of the lower flange 20 to the small end surface on the side opposite to the outer wall 12 in Embodiment 1 above. Specifically, the fireproof paint 26 is continuously provided over the regions of the small end of the upper flange 18, the lower surface of the upper flange 18, the left side surface of the web 16, the upper surface of the lower flange 20, the small end (left), the lower surface, and the small end (right). On the other hand, the sprayed material 28 is continuously provided over the regions of the small end of the upper flange 18, the lower surface, the right side surface of the web 16, and the upper surface of the lower flange 20 from the lower surface of the floor 22.

[0032] In this case, since there is no possibility of the sprayed material 28 falling off, the anti-falling hardware 30 is unnecessary. Even with such a configuration, the same operational effects as those in Embodiment 1 above can be achieved.

[0033] <Verification of the Effects of the Present Invention> Next, the fire resistance test conducted to confirm the effects of the present invention will be described. The test specimens used in the fire resistance test were of three types: a specification in which sprayed rock wool was applied to the entire lower surface of the lower flange (Example 1 of the present invention: Figs. 2(1) and (4)), a specification in which a fireproof paint and sprayed rock wool were applied to the coating of the lower surface of the lower flange (Example 2 of the present invention: Fig. 2(2)), and a normal spraying method (comparative example: Fig. 2(3)). The cross-section of the steel beam was H-400×200×8×13 mm, the thickness of the sprayed rock wool was 25 mm, and the thickness of the fireproof paint was 1.5 mm. A drip lock was used as the anti-falling hardware and attached with a synthetic rubber-based adhesive.

[0034] The fire resistance test was a heating test in which the test specimen was placed in a fire resistance test furnace and heated for 1 hour according to a predetermined heating temperature-time curve. As a result of this fire resistance test, no falling off of the sprayed rock wool applied to the lower surface of the lower flange occurred. The thermocouple attachment positions of the test specimen are shown in Fig. 3, and the temperature measurement results by the thermocouple are shown in Fig. 4. Fig. 4(1) shows the temperature measurement results of Example 1, (2) shows the temperature measurement results of Example 2, and (3) shows the temperature measurement results of the comparative example.

[0035] As shown in Fig. 4, the steel material temperatures of the test specimens of Example 1 and Example 2 satisfy 550°C or lower, preferably 510°C or lower, which is a standard of the allowable value of the steel material temperature for satisfying the fire resistance performance. It was confirmed that the boundary portion between the construction surface of the fireproof paint and the sprayed rock wool does not become a weak point and has the required fire resistance performance.

[0036] As described above, according to the fireproof coating structure according to the present invention, among the outer surfaces of the steel frame members arranged opposite to each other close to the wall body, a fireproof paint provided on the side facing the wall body and a fireproof sprayed material sprayed over the region where the fireproof paint is provided from the side not facing the wall body are provided. Therefore, the fireproof coating on the wall body side of the steel frame member can be surely performed by the fireproof paint. Therefore, the fireproof coating on the outer wall side of the steel beam can be surely performed.

[0037] Moreover, according to another fireproof coating structure according to the present invention, since the sprayed material is rock wool, it can be easily applied to the outside of the steel frame member.

[0038] Moreover, according to another fireproof coating structure according to the present invention, since a falling prevention material provided on the steel frame member is further provided to prevent the sprayed material from falling off the surface of the steel frame member, the falling of the sprayed material can be prevented.

[0039] Moreover, according to the fireproof coating method according to the present invention, it is a method of constructing the above-described fireproof coating structure, and includes a step of transporting a steel frame member in which a fireproof paint is previously provided on the side facing the wall body among the outer surfaces of the steel frame member to a construction site, and a step of applying a sprayed material over the region where the fireproof paint is provided from the side not facing the wall body among the outer surfaces of the steel frame member at the construction site. Therefore, the fireproof coating on the wall body side of the steel frame member can be surely performed by the fireproof paint. Therefore, the fireproof coating on the outer wall side of the steel beam can be surely performed.

Industrial Applicability

[0040] As described above, the fireproof coating structure and its construction method according to the present invention are useful when the space between the outer peripheral steel beam and the outer wall is narrow and the steel beam cannot be covered with a fireproof coating material, or when the fireproof structure has not been certified by the state and the synthetic fireproof coating method cannot be applied. In particular, it is suitable for reliably performing the fireproof coating on the outer wall side of the outer peripheral steel beam.

Explanation of reference numerals

[0041] 12 Outer wall (wall body) 14 Steel beam (steel member) 16 Web 18 Upper flange 20 Lower flange 22 Floor 24 Interlayer partition 26 Fireproof paint 28 Spraying material 30 Anti-dropping metalware (anti-dropping material) 100, 200, 300, 400 Fireproof coating structure A Indoor B Outdoor

Claims

1. Among the outer surfaces of the steel frame members arranged opposite to and close to the wall body, there are provided a fireproof paint provided on the side facing the wall body, and a fireproof spraying material sprayed over the region where the fireproof paint is provided from the side not facing the wall body, the steel frame member is made of an H-shaped steel having a web and upper and lower flanges, and a floor is provided on the upper surface of the upper flange, the fireproof paint is continuously provided over a region from the edge of the upper flange to the lower surface of the upper flange, the side surface of the web, the upper surface of the lower flange, the edge, and a part of the lower surface, the spraying material is continuously provided over a region from the lower surface of the floor to the edge of the upper flange, the lower surface, the side surface of the web, the upper surface of the lower flange, the edge, and a part of the lower surface, the end portions of the fireproof paint provided on the lower surface of the lower flange and the spraying material provided on the lower surface of the lower flange are overlapped with a predetermined overlapping margin, a falling prevention material for preventing the spraying material from falling off the lower surface of the lower flange is provided on the lower surface of the lower flange, the falling prevention material is characterized by being composed of a base portion adhered to the lower surface of the lower flange, a falling prevention metalware having a tip portion, or a retaining pin welded to the lower surface of the lower flange, and is a fireproof coating structure.

2. Among the outer surfaces of the steel frame members arranged opposite to and close to the wall body, there are provided a fireproof paint provided on the side facing the wall body, and a fireproof spraying material sprayed over the region where the fireproof paint is provided from the side not facing the wall body, the steel frame member is made of an H-shaped steel having a web and upper and lower flanges, and a floor is provided on the upper surface of the upper flange, the fireproof paint is continuously provided over a region from the edge of the upper flange to the lower surface of the upper flange, the side surface of the web, the upper surface of the lower flange, the edge, and the entire lower surface, the spraying material is continuously provided over a region from the lower surface of the floor to the edge of the upper flange, the lower surface, the side surface of the web, the upper surface of the lower flange, and the edge, a falling prevention material for preventing the spraying material from falling off the edge surface of the lower flange on the side not facing the wall body is provided on the edge surface of the lower flange on the side not facing the wall body, the falling prevention material is characterized by being composed of a base portion adhered to the edge surface of the lower flange, a falling prevention metalware having a tip portion, or a retaining pin welded to the edge surface of the lower flange, and is a fireproof coating structure. **Claim 3**: A fireproof coating provided on the side facing the wall body among the outer surfaces of the steel frame members arranged opposite to each other close to the wall body, and a fireproof spraying material sprayed over the area where the fireproof coating is provided from the side not facing the wall body. The steel frame member is made of an H-shaped steel having a web and upper and lower flanges, and a floor is provided on the upper surface of the upper flange. The fireproof coating is continuously provided from the edge of the upper flange to the lower surface of the upper flange, the side surface of the web, the upper surface of the lower flange, the edge and the lower surface on the side facing the wall body, and the edge area on the side not facing the wall body. The spraying material is continuously provided from the lower surface of the floor to the edge, the lower surface of the upper flange, the side surface of the web, and the upper surface of the lower flange. A fireproof covering structure characterized by this. **Claim 4** A method for constructing the fireproof covering structure according to any one of Claims 1 to 3, The step of transporting the steel frame member, on which the fireproof coating has been previously provided on the side facing the wall body among the outer surfaces of the steel frame member, to the construction site, and the step of constructing the spraying material over the area where the fireproof coating is provided from the side not facing the wall body among the outer surfaces of the steel frame member at the construction site. A method for constructing a fireproof covering structure characterized by this.

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