JP2018021407A - Fire-resistant woody member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fire-resistant woody member that can be made slim in its cross section.SOLUTION: A fire-resistant woody member 100 has a core material 10 made of woody material that supports load. The core material 10 has a polygonal cross-sectional shape. A corner part 14 of the polygonal shape is chamfered, and the dimensions of chamfering are in a range of 10-50 mm.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a fire-resistant wood member suitable for use as a building structural member such as a column or a beam, and more particularly to a fire-resistant wood member having improved fire resistance performance at corners in a member cross section.

  Conventionally, when constructing a structure with wooden pillars or beams made of wooden material, the wooden material is vulnerable to fire, so if necessary, cover the wooden material with a heat insulating material to suppress the temperature rise due to fire heating Measures are being taken. When fire-resistant wooden members such as wooden pillars and wooden beams having a rectangular cross section whose surface is covered with a heat insulating material such as gypsum board are subjected to fire heating, the internal wood portion becomes high due to heat conduction through the heat insulating material of the surface layer.

  In particular, as shown in FIG. 7, in a fire-resistant wood member in which a wood core material 1 serving as a load supporting portion is covered with a gypsum board 2, a wooden pillar (1) having a quadrangular section is obtained by heating F from the surroundings due to a fire. In this case, the amount of heat input to the two corners 3 at the lower end of the square-shaped wooden beam provided under the floor 4 in (2) is the side part. 5 (the amount of heat input per unit area) and higher than that of the side surface portion 5. Since these corner portions 3 are portions that are likely to rise in temperature when heated from two right angles in a cross-sectional view, thermal deterioration of the corner portions 3 becomes a weak point portion in fire resistance performance such as load support performance of the wooden member. . That is, when the corner portion 3 exceeds the ignition temperature of the wood earlier than the side surface portion 5 and starts to burn, it spreads to the inside and the side surface portion 5 where the ignition temperature has not yet reached, and the cross section of the member due to carbonization / ashing is lost. Inviting, there is a risk that the structural strength will be collapsed due to a decrease in the member yield strength.

  On the other hand, in order to ensure the fireproof performance of a corner part, the fireproof wooden member which gave various devices is known (for example, refer patent documents 1-4).

JP 2012-136939 A Japanese Patent No. 4871660 JP2015-129431A Japanese Patent Laying-Open No. 2015-061969

  However, in the conventional structure described above, in order to enhance the fire resistance performance of the corner portion, a material having high fire resistance performance is used for the portion, or the entire member is covered with the thickness of the fireproof coating necessary for the corner portion. As a result, the coating layer was thickened. For this reason, there has been a problem that the manufacturing method of the refractory wood member becomes complicated and the coating layer becomes thick, resulting in an increase in cost and an increase in member cross section.

  For this reason, there has been a demand for the development of a fire-resistant woody member that can achieve a slimmer member cross-section while having the same structural performance as that of the prior art.

  This invention is made | formed in view of the above, Comprising: It aims at providing the fire-resistant woody member which can aim at slimming of a member cross section.

  In order to solve the above-described problems and achieve the object, the fire-resistant wood member according to the present invention is a fire-resistant wood member provided with a core material made of a wood material that supports a load, and a cross-section of the core material The shape is a polygonal shape, and the corners of the polygonal shape are chamfered, and the chamfering dimension is in the range of 10 to 50 mm.

  Another fire-resistant wood member according to the present invention is characterized in that, in the above-described invention, a chamfer dimension is in a range of 20 to 50 mm.

  Another fire-resistant wood member according to the present invention is characterized in that, in the above-described invention, a reflector that reflects heat is provided in a chamfered portion of a corner portion of a core material.

  In addition, another fire-resistant wood member according to the present invention is characterized in that in the above-described invention, it further includes a flame stop layer or a finishing material provided outside the core material.

  In addition, in the above-described invention, another fire-resistant wood member according to the present invention further includes a flame stop layer provided outside the core material, and a finishing material provided outside the flame stop layer. .

  In addition, in another fireproof wood member according to the present invention, in the above-described invention, a hollow portion is formed between the chamfered portion of the corner portion of the core material and the flame stop layer or finish layer provided on the outside thereof. The hollow portion is provided with at least one of a heat insulating material and an endothermic material.

  The fire-resistant wood member according to the present invention is a fire-resistant wood member provided with a core material made of a wood material that supports a load, and the cross-sectional shape of the core material is a polygonal shape. Since the corner is chamfered and the chamfer dimension is in the range of 10 to 50 mm, the temperature rise of the corner which becomes a fire resistance weak point can be suppressed, and the fire resistance performance of the corner can be remarkably improved. Therefore, even if the member is thinned, the structural performance equivalent to or higher than that of the conventional structure can be ensured, and it is possible to reduce the cross section of the member and reduce the cost. Further, by using this fire-resistant woody member for indoor pillars, beams, etc., the openness of the indoor space is enhanced, and the room can be effectively utilized.

  Further, according to another fire-resistant wood member according to the present invention, since the chamfer dimension is in a range of 20 to 50 mm, it is possible to more reliably suppress the temperature rise of the corner portion which becomes a fire resistance weak point, and the fire resistance performance of the corner portion. There is an effect that can be further improved.

  Further, according to another fire-resistant wood member according to the present invention, since the reflector that reflects heat is provided in the chamfered portion of the corner portion of the core material, the core material through the chamfered portion. There is an effect that an increase in temperature can be effectively suppressed.

  Further, according to another fireproof wood member according to the present invention, since it further includes a flame stop layer or a finishing material provided on the outer side of the core material, the flame stop layer suppresses transfer of heat to the core material due to a fire. The core material can be prevented from being carbonized and burned. In addition, the finish material has an effect that wood texture can be imparted to the outside of the core material.

  Further, according to another fire-resistant wood member according to the present invention, it further includes a flame stop layer provided on the outer side of the core material and a finishing material provided on the outer side of the flame stop layer. The effect of suppressing heat transfer to the core material, preventing carbonization and combustion of the core material, and providing a wood texture to the outside of the core material by the finishing material is achieved.

  Further, according to the other fire-resistant wood member according to the present invention, a hollow portion is formed between the chamfered portion of the corner portion of the core material and the flame stop layer or finish layer provided on the outside thereof, Since this hollow portion is provided with at least one of a heat insulating material and an endothermic material, it is possible to effectively suppress an increase in the temperature of the core material due to radiation / convection heat transfer through the hollow portion. .

FIG. 1 (1) is a cross-sectional view showing an embodiment of a fire-resistant wood member according to the present invention, (2) is an enlarged view of a corner portion of (1), and (3) is a cross-sectional view showing a comparative example of the present invention. (4) is an enlarged view of a corner portion of (3). FIG. 2 is a schematic diagram of an analysis model performed for verifying the effects of the present invention. FIG. 3 is a diagram showing a change with time in the core corner temperature (without a chamfered hollow reflector). FIG. 4 is a diagram showing a change with time in the core corner temperature (with a chamfered hollow reflector). FIG. 5 is a view showing a temperature distribution (without a chamfered hollow part reflector) on the surface of the core (corner-side part line symmetrical position), (1) is 30 minutes after the start of heating, (2) Is 60 minutes. FIG. 6 is a diagram showing a temperature distribution (with a reflector of a chamfered hollow part) on the core surface (corner part to side part line symmetrical position), (1) is 30 minutes after the start of heating, (2) Is 60 minutes. FIG. 7 is an example of a conventional refractory wood member subjected to fire heating, in which (1) is a horizontal sectional view of a wooden pillar and (2) is a vertical sectional view of a wooden beam.

  Hereinafter, an embodiment of a fire-resistant wood member according to the present invention will be described in detail based on the drawings taking a wood pillar as an example. Note that the present invention is not limited to the embodiments.

  As shown in FIGS. 1 (1) and (2), a fire-resistant wood member 100 according to the present embodiment includes a core material 10 made of a wood material that supports a load, and a flame stop layer provided outside the core material 10. 12 is a wooden pillar. The cross-sectional shape of the core material 10 is a regular square shape (polygonal shape), and the corner portion 14 (corner portion) of the regular square shape is chamfered. In the following description, this chamfered portion is referred to as a chamfered portion 16.

  The chamfer dimension of the chamfered portion 16 is the length L shown in FIG. 2, and the chamfer angle is 45 °. That is, the cross-sectional shape of the chamfered portion 16 according to the present embodiment is a right-angled isosceles triangle having the same side length L, and the hypotenuse forms the surface of the core member 10. The chamfer dimension L is preferably set in a range of 10 to 50 mm in order to achieve the object of the present invention to suppress the temperature rise of the corner portion 14, from the viewpoint of more reliably suppressing the temperature rise. It is more preferable to set within a range of 20 to 50 mm. The chamfered portion 16 can be formed, for example, by cutting a corner of the cross section of the core material 10 to make a surface.

  The core material 10 is made of a laminated material (woody material) that supports a load. As the core material 10, it can comprise using the general laminated material which consists of a cedar, a larch etc., for example. Although the thickness (distance between opposite sides) of the core material 10 can be appropriately adjusted according to the application, it can be set to, for example, about 450 mm.

  The flame stop layer 12 is a coating layer having fire resistance, for example, an inorganic material having endothermic and / or heat insulation properties, a nonflammable material that does not easily burn, or foams when heated and increases its thickness significantly. It can comprise with materials, such as a fireproof sheet and a fireproof film which express property. This fire-stop layer 12 has a function of preventing heat from being transferred to the adjacent inner core material 10 in the event of a fire, preventing the core material 10 from being carbonized or burning, and suppressing heat conduction to the core material 10. Demonstrate the effect. When the flame stop layer 12 is made of an inorganic material, for example, a board-like material such as a reinforced gypsum board, a gypsum board, or a calcium board (calcium silicate board) can be used. Moreover, the thickness can be suitably adjusted according to a use. When the thickness is increased, the effect of suppressing heat conduction is improved. These boards may be stacked to a predetermined thickness. Here, materials such as reinforced gypsum board, gypsum board, and calcium silicate board (calcium silicate board) are suitable for the burn-out layer 12 because they are available at a very low price and have high heat insulation and heat absorption. . Further, when the flame-stopping layer 12 is made of a non-combustible material, for example, non-combustible wood obtained by impregnating wood with a chemical such as boric acid to be incombustible can be used. Although the thickness of the flame stop layer 12 can be suitably adjusted according to a use, it is preferable to set it as about 15 mm-45 mm, for example, and it is more preferable to set it as about 30 mm. Further, when the flame-stopping layer 12 is made of a material such as the above-mentioned fireproof sheet or fireproof film, the thickness can be appropriately adjusted according to the application, but it is preferably about 1 mm to 12 mm, for example. More preferably, it is about 1.5 mm to 6 mm.

The operation of the fireproof wood member 100 configured as described above will be described.
1 (1) and 1 (2) show this embodiment, and FIGS. 3 (3) and 4 (4) show comparative examples. The comparative example is a conventional structure in which the corner portion 14 of the core member 10 has no chamfered portion 16. As shown in FIGS. (4) and (2), the thicknesses of the flame stop layer 12 of the comparative example and the present embodiment are t ₀ and t _s , respectively, and the corner portions 14 ( Let E ₀ and E _{s be} the heat energy flowing into the hatched portion), and T ₀ and T _s be the temperatures of the corner portions 14 (hatched portions). When the thickness _t 0 = _{t s} of burning blind layer 12, the thermal energy _E 0> _{E s} flowing into the corner portion 14, the temperature _T 0> _{T s.} For this reason, according to this Embodiment, the temperature rise of the corner part 14 can be suppressed compared with a comparative example.

  As described above, according to the fire-resistant wood member 100, by providing the chamfered portion 16 at the corner portion 14 that becomes a fire resistant weak point due to concentration of heat energy, the temperature rise of the corner portion 14 is suppressed, and the fire resistance performance thereof. Can be remarkably improved. Therefore, even if the member is thinned, the structural performance equivalent to or higher than that of the conventional structure can be ensured, and the member cross section can be slimmed and the cost can be reduced. In addition, by using this refractory wood member 100 for an indoor pillar (or beam) or the like, the openness of the indoor space is enhanced and the room can be effectively utilized.

  Here, you may comprise the chamfering part 16 as a hollow part (henceforth a chamfering hollow part). That is, the chamfered hollow portion is a right-angled isosceles triangular shape formed between the surface of the core material 10 formed by chamfering the corner portion 14 of the core material 10 and the flame stop layer 12 provided on the outside thereof. You may form in the space of. Further, this chamfered hollow portion may be filled with at least one of a heat insulating material and an endothermic material. By carrying out like this, the temperature rise of the core material 10 by radiation | emission and convection heat transfer through a chamfering hollow part can be suppressed effectively. As a material for filling the chamfered hollow portion, for example, the same material as that of the flame stop layer 12 may be used.

  Moreover, as shown in FIG. 1 (2) or FIG. 2, you may provide the reflector 18 which reflects heat in the surface of the core material 10 which faces said chamfering hollow part. By carrying out like this, the temperature rise of the core material 10 through the chamfered part can be suppressed effectively. In addition to this, a similar reflector 18 may be provided on the surface of the flame stop layer 12 facing the chamfered hollow portion. In this way, the temperature rise can be more effectively suppressed.

  In the above embodiment, a finishing material for imparting a wood texture to the outer side of the flame stop layer 12 may be further provided. Alternatively, a finishing material for imparting a wood texture may be provided on the outer side of the core material 10 in place of the flame stop layer 12. By this finishing material, the outer surface of the refractory wood member 100 can have a wood texture or a grain-like appearance. As the finishing material, a woody material such as wood or a decorative laminated material is desirable for cost saving, but a building finishing material such as a cloth material may be used. The thickness of the finishing material is preferably about 3 mm to 30 mm, for example, but of course, it may be thinner than this.

  Moreover, in said embodiment, you may comprise the flame stop layer 12 by two or more flame stop layers from which an effect | action and a function differ. Even if it does in this way, it is possible to show the effect similar to the above.

(Verification of effects of the present invention)
Next, verification of the operational effects of the present invention will be described.
In order to quantitatively grasp the range of chamfering and its effect, a two-dimensional heat conduction analysis was conducted. As shown in FIG. 2, the analysis model is a wooden column in which a 20 cm square core material 10 is covered with a heat insulating material (burnt layer 12) made of gypsum board having a total thickness of 30 mm. The analysis parameters are the range of chamfering and the presence or absence of a thermal reflector on the inner surface of the chamfered hollow portion. Regarding the chamfering range, the chamfering angle is set to 45 °, and the isosceles length L of the chamfering range (the isosceles triangle surrounded by the two sides on the core member 10 and the cut surface) in which the planar shape is a right-angled isosceles triangle is The level was set to 0, 10, 20, 30, 40, 50 mm as a parameter. With respect to the chamfered hollow portion, the presence or absence of a thermal reflector (hereinafter referred to as a reflector) was used as a parameter. The heating was performed under the condition that the surface of the member was subjected to heating for 1 hour according to the standard heating temperature time curve defined in IOS834. The latent heat of vaporization at 100 ° C. was taken into account, assuming that the water content of the gypsum board was 6 wt% and the water content of the core material was 10 wt%. The emissivity of the reflector was 0.04 (equivalent to the emissivity of the aluminum foil). In addition, radiant heat transfer and convective heat transfer in the hollow portion were taken into account. In this analysis, it was assumed that the wood material did not burn even if the ignition temperature of the wood material was exceeded.

  FIGS. 3 and 4 show the time-dependent changes in the corner temperature caused by chamfering, and FIGS. 5 and 6 show the temperature distribution on the surface of the core material at 30 minutes and 60 minutes after the start of heating.

Effectiveness and effective range of chamfering As shown in FIGS. 3 to 6, the temperature rise at the corners is suppressed by chamfering a square cross section (chamfering 0 mm). It is also effective to install a reflector on the inner surface of the hollow portion. Regarding the chamfering range, in the plane of the isosceles triangle, the chamfering range becomes wider as the length L of the isosceles is increased. From FIGS. 5 and 6, the length L of the isosceles is 50 mm or more (chamfering 50 mm or more). However, it is estimated that the effect of chamfering does not change greatly. Further, it is easily estimated that this tendency does not greatly depend on the size of the member cross section. On the other hand, if the chamfering range of the core material is increased, it cannot be denied that the structural member cross-sectional performance (axial rigidity, bending rigidity) is lowered. Taking these into consideration, it is desirable that the length L of one side of the chamfer be 50 mm or less regardless of the size of the cross-section of the member.

-Thermal characteristics of the chamfered hollow part (the part surrounded by the heat insulating material and the core material) As shown in the temperature distribution diagram at 60 minutes in Fig. 5 (2), in this analysis, the temperature of the surface generated by chamfering is It became higher than a corner | angular part (part shown with the code | symbol G in the figure). Since this phenomenon is not recognized in the temperature distribution diagram at 60 minutes in FIG. 6 (2), the phenomenon that occurs because the supply of heat energy by radiant and convective heat transfer exceeds the supply through the heat insulating material. It can be said.

-Measures for suppressing temperature rise of core material through chamfered hollow portion From the comparison between FIG. 5 and FIG. 6, it can be confirmed that it is effective to install a reflector on the surface of the core material facing the chamfered hollow portion. In this analysis example, the reflector is installed only on the surface of the core material facing the hollow portion. However, if the reflector is also installed on the surface of the heat insulating material facing the hollow portion, the effectiveness is further increased.

  In addition to installing a reflector, it can be said that filling a chamfered hollow portion with a heat insulating material or a heat absorbing material is also effective as a means for suppressing a temperature rise due to radiation / convection heat transfer. As the heat insulating material to be filled in the chamfered hollow portion, for example, a bulk or felt of an inorganic fiber such as heat-resistant rock wool, a bulk or felt of a highly heat-resistant biosoluble fiber is effective. Examples of the endothermic material to be filled in the chamfered hollow part include free water (moisture that evaporates at 100 ° C.), mortar containing a large amount of chemically adsorbed water, hydrated gypsum, and the like. A water-based adhesive such as a pack material sealed with an impermeable sheet (for example, PET aluminum paper) or a vinyl acetate adhesive is effective.

  In the above description, a member having a quadrangular cross section is taken as an example. However, the chamfering of the corner portion 14 is effective even in a wooden member having a triangular cross section or a polygonal cross section having a pentagonal shape or more. An effect can be produced. That is, providing a space between the non-flammable layer 12 covering the surface of the core material 10 and the core material 10 or filling the space with a heat insulating material or an endothermic material suppresses the temperature rise of the core material corner 14. And effective in improving fire resistance.

  As described above, according to the fire-resistant wood member according to the present invention, it is a wood member having fire resistance provided with a core material made of a wood material that supports a load, and the cross-sectional shape of the core material is a polygonal shape. Yes, the corners of this polygonal shape are chamfered, and the chamfered dimensions are in the range of 10 to 50 mm, so the temperature rise of the corners, which is a weak point in fire resistance, is suppressed, and the fire resistance performance of the corners is remarkably improved. can do. Therefore, even if the member is thinned, the structural performance equivalent to or higher than that of the conventional structure can be ensured, and the member cross section can be slimmed and the cost can be reduced. Further, by using this fire-resistant woody member for indoor pillars, beams, etc., the openness of the indoor space is enhanced, and the room can be effectively utilized.

  Further, according to another fire-resistant wood member according to the present invention, since the chamfer dimension is in a range of 20 to 50 mm, it is possible to more reliably suppress the temperature rise of the corner portion which becomes a fire resistance weak point, and the fire resistance performance of the corner portion. Can be further improved.

  Further, according to another fire-resistant wood member according to the present invention, since the reflector that reflects heat is provided in the chamfered portion of the corner portion of the core material, the core material through the chamfered portion. The temperature rise can be effectively suppressed.

  Further, according to another fireproof wood member according to the present invention, since it further includes a flame stop layer or a finishing material provided on the outer side of the core material, the flame stop layer suppresses transfer of heat to the core material due to a fire. The core material can be prevented from being carbonized and burned. Moreover, a wood texture can be given to the outer side of a core material with a finishing material.

  Further, according to another fire-resistant wood member according to the present invention, it further includes a flame stop layer provided on the outer side of the core material and a finishing material provided on the outer side of the flame stop layer. Heat transmission to the core material can be suppressed, carbonization and combustion of the core material can be prevented, and a wood texture can be imparted to the outside of the core material by the finishing material.

  Further, according to the other fire-resistant wood member according to the present invention, a hollow portion is formed between the chamfered portion of the corner portion of the core material and the flame stop layer or finish layer provided on the outside thereof, Since at least one of the heat insulating material and the heat absorbing material is provided in the hollow portion, the temperature rise of the core material due to the radiation / convection heat transfer through the hollow portion can be effectively suppressed.

  As described above, the refractory wood member according to the present invention is useful for use as a building structural member, and is particularly suitable for slimming the member cross section and, hence, cost reduction.

10 Core material 12 Non-burning layer 14 Corner (corner)
16 Chamfered part 18 Reflector L Chamfer dimension 100 Fireproof wood member

Claims (6)

A wood member having fire resistance with a core made of a wood material that supports a load,
A fire-resistant wood member characterized in that the cross-sectional shape of the core material is a polygonal shape, the corners of the polygonal shape are chamfered, and the chamfered dimension is in the range of 10 to 50 mm.   The fire-resistant woody member according to claim 1, wherein the chamfer dimension is in a range of 20 to 50 mm.   The fire-resistant woody member according to claim 1 or 2, wherein a reflector that reflects heat is provided at a chamfered portion of a corner portion of the core material.   The refractory wood member according to any one of claims 1 to 3, further comprising a flame stop layer or a finishing material provided on the outer side of the core material.   The refractory wood member according to any one of claims 1 to 3, further comprising a flame stop layer provided outside the core material, and a finishing material provided outside the flame stop layer.   A hollow portion is formed between the chamfered portion of the corner portion of the core material and the flame stop layer or finish layer provided on the outside, and at least one of a heat insulating material and an endothermic material is provided in the hollow portion. The fire-resistant woody member according to claim 4 or 5, wherein

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