JP2023008615A - Fire resistance structure of composite member - Google Patents

Abstract

To provide a fire resistance structure of a composite member capable of reassuring a fire resistance efficiency of a connection part of a wooden covering material and other non-wooden fire resistance covering material.SOLUTION: A fire resistance structure 10 of a connection part 20 between a first region R1 and a second region R2 at a composite member 18 comprises a steel frame member 12, a thick wooden covering material 14 covering the first region R1 of a surface of the steel frame member 12 and a thin non-wooden fire resistance covering material 16 covering the second region R2 of the surface of the steel frame member 12 adjacent to the first region R1 and has a non-wooden fire resistance covering material 22 covering the surface of the steel frame member 12 of the connection part 20 with a thickness equal to or greater than the thickness of the fire resistance covering material 16 of the second region R2 and an inorganic type fire resistance material 26 covering a header surface 24 of the wooden covering material 14 and the fire resistance covering material 22 of the connection part 20 continuously.SELECTED DRAWING: Figure 1

Description

The present invention relates to fire resistant structures of composite members, including wood-steel hybrid members of wood and steel.

Conventionally, the applicant of the present patent has proposed a wood-steel hybrid beam (hereinafter referred to as a wood-steel beam), which is a structural member having a fire resistance performance of one hour, in which a steel beam is coated with wood (hereinafter referred to as a wood coating material) for fire resistance. is being developed (see, for example, Patent Document 1). This wood covering material burns at a rate of 0.7 to 1.0 mm/min during a fire, but by stopping burning after the fire, it suppresses the temperature rise of the steel beams that support the load and plays a role in preventing collapse. there is

When a wooden steel beam is applied to a building, there may be places where the wooden cladding material and other fireproof cladding material come together. For example, in the outer periphery of a steel frame structure, through holes are provided in the steel frame beams for pipes to pass through. It is conceivable to coat the through-hole portion and its surroundings with fireproof coating with paint, sprayed rock wool, etc.).

When the types of fireproof coating materials are switched in the axial direction of the beam as described above, several techniques are known to ensure fireproof performance at the boundary between different types of fireproof coating materials. (See Patent Documents 2 and 3 for examples.)

Japanese Patent Application No. 2020-148315 (currently unpublished) Japanese Patent Application Laid-Open No. 2020-143528 Japanese Patent Application Laid-Open No. 2020-172808

By the way, when the wooden steel beam is applied to a building, there is a possibility that a predetermined fire resistance cannot be achieved at a place where a wooden covering material and another non-woody fireproof covering material meet. When a steel frame member is coated with a fire-resistant coating material such as fire-resistant paint or sprayed rock wool, the thickness and specifications of the fire-resistant coating material are determined so that the average temperature of the steel material is 350°C or less, and the maximum temperature is about 450°C or less. On the other hand, the ignition temperature of wood is about 200-260°C. Therefore, at the place where the wood coating material and another fireproof coating material meet, heat is transferred from the side of the steel frame member coated with the other non-woody fireproof coating material to the side of the steel frame member coated with the wood coating material. The steel material temperature of the steel frame member on the wooden covering material side may reach 200 to 260°C. As a result, the wood covering material burns from the inside and does not stop burning, and the steel material temperature of the steel frame member may reach 450° C. or higher. In addition, at the interface between the wooden covering material and the other non-woody fireproof covering material, the edge surface of the wooden covering material is exposed, and the gap between the wooden covering material and the other non-woody fireproof covering material There is a risk that the specified fire resistance cannot be ensured due to the occurrence of

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and provides a fire-resistant structure of synthetic members that can ensure the fire-resistant performance of the interface between the wooden covering material and the other non-woody fire-resistant covering material. With the goal.

In order to solve the above-described problems, the fire-resistant structure of synthetic members according to the present invention includes a steel frame member, a thick wood coating material covering a first region of the surface of the steel frame member, and a A fire-resistant structure of a joint between a first region and a second region in a composite member comprising a thin non-woody fire-resistant coating covering a second region of the surface of the steel member, the fire-resistant structure of the second region Non-woody fire-resistant coating material that covers the surface of steel frame members near the joint with a thickness greater than the thickness of the coating material, and an inorganic coating that continuously coats the edge of the wooden coating material and the fire-resistant coating material at the joint. It is characterized by having a system refractory material.

Another fire-resistant structure of synthetic members according to the present invention is characterized in that, in the above invention, the non-woody fire-resistant coating material is used as a fire-resistant paint and the thickness thereof is increased.

In the above-described invention, the inorganic fire-resistant material in the fire-resistant structure of other synthetic members according to the present invention is a reinforced gypsum board attached to the edge of the wooden covering material, and between the reinforced gypsum board and the steel frame member. characterized in that an inorganic filler is provided in the gap between the

According to the fireproof structure of the synthetic member according to the present invention, the steel frame member, the thick wood coating material covering the first region of the surface of the steel frame member, and the second surface of the steel frame member adjacent to the first region A fire resistant structure at the interface between a first zone and a second zone in a composite member comprising a thin non-woody fire resistant cladding covering the zone, the refractory structure being greater than or equal to the thickness of the fire resistant cladding in the second zone It has a non-woody fire-resistant coating material that covers the surface of the steel frame member near the joint with a thickness, and an inorganic fire-resistant material that continuously coats the end face of the wooden coating material and the fire-resistant coating material at the joint. Therefore, it is possible to ensure the fireproof performance of the interface between the wooden covering material and the other non-woody fireproof covering material.

In addition, according to the fire-resistant structure of another synthetic member according to the present invention, the non-woody fire-resistant coating material is used as a fire-resistant coating, and by increasing the thickness of the non-woody coating material, the fire-resistant performance of the interface between the wooden coating material and the fire-resistant coating There is an effect that can be ensured.

Further, according to another fire-resistant structure of synthetic members according to the present invention, the inorganic fire-resistant material is a reinforced gypsum board that is attached to the edge surface of the wooden covering material, and the gap between this reinforced gypsum board and the steel frame member Since the inorganic filler is provided in the inner wall, the inflow and combustion of heat from the edge can be suppressed, and the increase in the steel material temperature of the steel frame member on the wooden covering material side can be suppressed.

FIG. 1 is a side view showing an embodiment of a fire-resistant structure for synthetic members according to the present invention. FIG. 2 is a cross-sectional view along line AA of FIG. FIG. 3 is a cross-sectional view taken along line BB of FIG. FIG. 4 is a cross-sectional view taken along line CC of FIG. FIG. 5(1) is a graph showing the average temperature transition at each cross-sectional position, and FIG. 5(2) is a table showing the maximum temperature at each cross-sectional position.

EMBODIMENT OF THE INVENTION Below, embodiment of the fireproof structure of the synthetic member which concerns on this invention is described in detail based on drawing. In addition, this invention is not limited by this embodiment.

As shown in FIGS. 1 to 4, a composite fire-resistant structure 10 according to an embodiment of the present invention includes a steel beam 12 (steel frame member) and a thickness covering a first region R1 on the surface of the steel beam 12. A synthetic member 18 comprising a meat wood coating material 14 and a thin fire-resistant paint 16 (non-wood fire-resistant coating material) covering a second region R2 on the surface of the steel beam 12 adjacent to the first region R1. It is a fireproof structure of the interface part 20 between one area|region R1 and the 2nd area|region R2.

This fire-resistant structure 10 includes a fire-resistant paint 22 that coats the surface of the steel frame beam 12 of the joint portion 20 with a coating thickness equal to or greater than the coating thickness of the fire-resistant paint 16 in the second region R2, and the edge of the wood coating material 14. 24 and a reinforced gypsum board 26 (inorganic fireproof material) that continuously covers the fireproof paint 22 of the interface 20 . In the present embodiment, the fire-resistant paints 16 and 22 are required in the predetermined length range (the length range up to the fire-resistant coating material 42) within the second region R2 from the edge surface 24 of the wooden coating material 14. It is applied with the same thickness as the coating thickness. A finishing wood 28 and a plain gypsum board 30 are laminated in a manner adjacent to a reinforced gypsum board 26 on the lateral and downward outer portions of the edge face 24 of the wooden covering material 14 . Instead of providing the finishing wood 28 and the ordinary gypsum board 30, a reinforced gypsum board may be laid over the entire edge surface 24 of the wooden covering material 14. - 特許庁

The steel beams 12 are generally horizontally extending H-beams and have webs 32 , upper flanges 34 and lower flanges 36 . The steel frame beams 12 of the first region R1 and the steel frame beams 12 of the second region R2 are butted against each other at the joint portion 20 and joined to each other by the plate 38 provided on the web 32 and the bolt 40 . A beam formed by the steel frame beam 12 and the wooden covering material 14 in the first region R1 corresponds to the wooden steel beam. In the example shown in the figure, the steel frame beam 12 on the side of the second region R2 is provided with a fireproof covering material 42 made of a calcium silicate plate and a through hole 44 for passing a pipe through. It can be omitted. Note that the steel beams 12 in the first region R1 and the second region R2 may not be butted with the bolts 40 and the plates 38 . For example, the steel beams 12 of the first region R1 and the second region R2 may be continuous in the beam axis direction.

The wooden covering material 14 is made of laminated lumber provided in a manner to cover the top, bottom, left, and right of the steel frame beam 12, and is made of tree species such as hiba and Japanese larch having fire resistance of one hour, for example. The wood cladding 14 is fixed to the web 32 of the steel beam 12 with a fixing member 46 such as a lag screw. As shown in FIG. 4, the fixing member 46 is a metal rod-like body having a plate-like head portion 48 and a shaft-like screw portion 50 . The threaded portion 50 has a sharp tip and a threaded outer peripheral surface. The fixing member 46 is screwed into the wooden covering material 14 through through holes 52 provided on the upper and lower sides of the web 32 within the same cross section. The through hole 52 is closed with a filler wood 54 . As shown in FIG. 1, a plurality of fixing members 46 are arranged at predetermined intervals in the horizontal direction in which the steel beam 12 extends, and are arranged so that the screwing directions thereof alternate in the horizontal direction.

The fire-resistant paints 16 and 22 are made of a foamable fire-resistant material that foams in a predetermined temperature range when heated to suppress the temperature rise of the steel material. As such a fire-resistant paint, for example, there is a fire-resistant paint that starts foaming at around 250° C. when exposed to heat during a fire and expands 20 to 30 times to form a heat-insulating layer. In the present embodiment, both the coating thickness of the fire-resistant coating 16 in the second region R2 and the coating thickness of the fire-resistant coating 22 in the interface portion 20 are set to a coating thickness that satisfies the two-hour fire resistance performance. However, the present invention is not limited to this. Further, in this embodiment, the fire-resistant paints 16 and 22 having a coating thickness that satisfies the two-hour fire resistance performance are provided in the length range from the edge 24 of the wooden coating material 14 to the fire-resistant coating material 42 . However, the present invention is not limited to this. For example, for the length range exceeding the above range from the edge 24 of the wooden covering material 14, fire resistant paints 16 and 22 having a coating thickness that satisfies the fire resistance performance of 2 hours are provided, and the range beyond that is 1 hour long. A fire-resistant paint having a coating thickness that satisfies fire resistance performance may be provided.

The reinforced gypsum board 26 is in the form of a plate attached to the edge surface 24 of the wooden covering material 14 . Between the reinforced gypsum board 26 and the steel beam 12, a certain gap (clearance) is required for construction. In order to prevent heat from flowing through this gap, an inorganic filler 56 (for example, a calcium carbonate filler) is provided in the gap.

As described above, in the present embodiment, at the place where the wooden coating material 14 of the wooden steel beam and the fire-resistant paint 16 (non-woody fire-resistant coating material) meet, the fire-resistant paint , and a reinforced gypsum board 26 (inorganic fire-resistant material) is provided at the interface 20 between the wooden covering material 14 and the fire-resistant paint 22 . According to this embodiment, the following effects can be obtained.

(1) By changing the coating thickness of the fire-resistant paint from the 1-hour fire-resistant specification to the 2-hour fire-resistant specification, the temperature rise of the steel material on the fire-resistant paint 16 side (second region R2) is reduced, and the wood coating material 14 side ( The steel material temperature rise due to heat transfer to the steel frame beam 12 of the first region R1) is suppressed.
(2) By applying a reinforced gypsum board 26 to the edge surface 24 of the wooden covering material 14, the influx of heat from the edge surface 24 is suppressed. In addition, the edge surface 24 of the wooden covering material 14 is prevented from being directly exposed to the flame and burned.
(3) By providing the reinforced gypsum board 26 between the wood coating material 14 and the fire-resistant paint 16, the heat of the steel frame beam 12 on the fire-resistant paint 16 side is absorbed by the reinforced gypsum board 26, and the wood coating material 14 side heats up. Suppresses the rise in steel material temperature.

<Example>
Next, examples of the present invention will be described. In addition, the specification described below is the one-hour fire resistance test to verify the fire resistance performance. Figures 1 to 4 show the specifications of the interface with the fire-resistant paint in the wooden steel beam verified by the fire-resistant test. The dimensions and steel grade of the steel beams used for the test body are BH-900×150×16×19 and total length of 3450 mm (SS400). The wooden covering material is laminated cypress wood (symmetrical different grade E95-F270), the thickness of the covering material is 80 mm, and the cross-sectional dimensions of the wooden steel beam are 1067 mm×317 mm. In addition, in the fire resistance test, it was assumed that a through hole was provided in the steel frame beam.

(Paint thickness of fire-resistant paint)
In general, for a 1-hour fire-resistant structure, a fire-resistant paint having a coating thickness specified for 1-hour fire resistance should be applied. However, in the case of the fire-resistant paint that attaches to the wooden steel beams, we have achieved two-hour fire resistance in order to reduce the steel material temperature rise on the fire-resistant paint side and suppress the steel material temperature rise due to heat transfer to the steel beam on the wooden coating material side. Fire-resistant paint was applied with a coating thickness that was possible. This fire-resistant paint was applied over a length of 650 mm from the edge of the wooden covering material.

(Installation of reinforced gypsum board)
A plurality of reinforced gypsum boards were provided on the edge of the wooden covering material. In the fire resistance test, reinforced gypsum boards (thickness: 21 mm x 3 sheets) and reinforced gypsum boards (thickness: 12.5 mm) were overlapped to give a total thickness of 75.5 mm. By increasing the thickness of the reinforced gypsum board, the heat insulation performance is improved, and the amount of heat absorbed by the reinforced gypsum board is also increased, so it is thought that the fire resistance is improved. Therefore, if the total thickness of the reinforced gypsum boards provided on the edge of the wooden covering material is 75.5 mm or more, it is considered that the fire resistance performance can be secured even if the number and thickness of the reinforced gypsum boards are changed.

(Filling of gaps)
A clearance is required for construction work between the reinforced gypsum board attached to the edge of the wooden covering material and the steel beam. In order to prevent heat from flowing through this gap, an inorganic filler (for example, a calcium carbonate filler) was injected to fill the gap.

Also, in the fire resistance test, the specimen was manufactured so that the clearance between the reinforced gypsum board and the steel beam was 3 mm. However, by reducing the clearance between the reinforced gypsum board and the steel beam, the reinforced gypsum board can easily absorb the heat of the steel beam, and the influx of heat through the gap can be minimized. Therefore, if the clearance between the reinforced gypsum board and the steel frame beam is 3 mm or less, it is considered that the fire resistance performance will be secured.

(Installation of finish wood)
In order to improve the appearance, a finishing wood (laminated cedar wood, thickness 55 mm) and a plain gypsum board (thickness 12.5 mm) were layered on the periphery of the edge of the wooden covering material. In addition, when finishing wood is not attached, fireproof performance is considered to be secured by attaching reinforced gypsum board to the entire edge surface of the wooden covering material.

(Fire resistance test result)
Next, the results of a 1-hour fire resistance test at the interface using the above-mentioned test specimen will be described. In the fire resistance test, the test piece was heated for 1 hour and then allowed to cool in the furnace for 48 hours to complete the test. At the end of the test, red heat and smoke were not confirmed, and the wood coating material stopped burning. In addition, the finishing wood (55 mm thick) and ordinary gypsum board (12.5 mm thick) for finishing had fallen off, but the reinforced gypsum board (thickness 21 mm x 3 sheets + 12.5 mm thick) on the edge side had fallen off. remained.

FIG. 5(1) shows the time transition of the average temperature at each cross-sectional position measured by the thermocouples provided on the upper and lower flanges and the web. The legend in the figure indicates the horizontal distance from the position of the fore edge of the wooden covering material. FIG. 5(2) shows the maximum temperature at each cross-sectional position. As shown in FIG. 5 (2), the maximum steel material temperature of the steel beam coated with the fire-resistant paint is 341.5°C, and the steel material maximum temperature of the steel beam coated with the wood coating material is 202.0°C. It became 350 degrees C or less which is the allowable temperature of the steel material in the test. Therefore, it can be said that the specifications of this example have a fire resistance performance of one hour.

According to this embodiment, by using the reinforced gypsum board in the interface between the wooden covering material and the fire-resistant paint, it is possible to realize specifications that facilitate processing and construction on site. In addition, it is possible to consider the appearance at the time of finishing by using fire-resistant paint and designing the specifications assuming the installation of finishing wood.

In the above embodiment, the case where the fire-resistant paint is used for the non-woody fire-resistant covering material that is attached to the wood-based covering material has been described as an example, but the present invention is not limited to this. If it is a non-woody fire-resistant coating material that makes the steel temperature 340 ° C or less in a one-hour fire resistance test, non-woody fire-resistant coating materials other than fire-resistant paint (for example, sprayed rock wool or wet ceramic refractory coating material, etc.) may be used.

As described above, according to the fire-resistant structure of synthetic members according to the present invention, the steel frame member, the thick wooden coating material covering the first region of the surface of the steel frame member, and the steel frame adjacent to the first region A fire resistant structure of a joint between a first region and a second region of a composite member comprising a thin non-woody fire resistant coating covering a second region of the surface of the member, the fire resistant coating of the second region A non-woody fireproof coating material that covers the surface of the steel frame member near the joint with a thickness greater than the thickness of the wood, and an inorganic fireproof coating that continuously coats the edge of the wooden coating material and the joint part. , the fireproof performance of the interface between the wooden covering material and the other non-woody fireproof covering material can be ensured.

In addition, according to the fire-resistant structure of another synthetic member according to the present invention, the non-woody fire-resistant coating material is used as a fire-resistant coating, and by increasing the thickness of the non-woody coating material, the fire-resistant performance of the interface between the wooden coating material and the fire-resistant coating can be ensured.

Further, according to another fire-resistant structure of synthetic members according to the present invention, the inorganic fire-resistant material is a reinforced gypsum board that is attached to the edge surface of the wooden covering material, and the gap between this reinforced gypsum board and the steel frame member Since the inorganic filler is provided in the inner wall, it is possible to suppress the inflow and combustion of heat from the fore-end, and to suppress the temperature rise of the steel frame member on the wooden covering material side.

As described above, the fire-resistant structure of a synthetic member according to the present invention is useful for a synthetic member comprising a steel frame member and a wooden covering material, and in particular, the interface between the wooden covering material and another non-woody fire-resistant covering material. It is suitable for ensuring the fire resistance performance of

10 Fire-resistant structure of synthetic members 12 Steel beams (steel members)
14 wood coating material 16, 22 fire resistant paint (non-woody fire resistant coating material)
18 Synthetic member 20 Mating part 24 Edge face 26 Reinforced gypsum board (inorganic fireproof material)
28 finishing wood 30 ordinary gypsum board 32 web 34 upper flange 36 lower flange 38 plate 40 bolt 42 fireproof coating material 44 through hole 46 fixing member 48 head 50 threaded portion 52 through hole 54 filler 56 filler R1 first region R2 second region

Claims (3)

A steel frame member, a thick wooden coating material covering a first region of the surface of the steel frame member, and a thin non-woody fireproof coating material covering a second region of the surface of the steel frame member adjacent to the first region. A refractory structure of an interface between a first region and a second region in a composite member comprising:
a non-woody fire-resistant coating material that coats the surface of the steel frame member near the interface with a thickness equal to or greater than the thickness of the fire-resistant coating material in the second region;
1. A fire-resistant structure of a synthetic member, characterized by having an inorganic fire-resistant material continuously covering the end surface of a wooden covering material and the fire-resistant covering material of a joint portion. 2. The fire-resistant structure of synthetic members according to claim 1, wherein the non-woody fire-resistant coating material is made of a fire-resistant paint and its thickness is increased. The inorganic refractory material is a reinforced gypsum board that is attached to the edge of the wooden covering material, and an inorganic filler is provided in the gap between the reinforced gypsum board and the steel frame member. 3. Fire resistant structure of synthetic member according to 2.

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