JP6590187B2 - Joint structure of wood and steel - Google Patents

Description

  The present invention relates to a structure of a joint portion between a wooden material and a steel frame material.

  Conventionally, as a construction method for directly joining the refractory wood pillar 1 and the steel beam 2, as shown in FIGS. 9 and 10, a base plate and a gusset are attached to a load supporting portion (hereinafter referred to as a core material 1 a) of the refractory wood pillar 1. A construction method for joining the steel beam 2 using the plate 3 or the like, and a construction method for joining the steel beam 2 through the core material 1a of the refractory wood column 1 as shown in FIGS. (For example, refer to Patent Document 1 and Patent Document 2).

  In general, the steel beam 2 is provided with a fireproof coating in order to ensure fire resistance (non-damage) against 1 hour fire heating (standard heating temperature time curve defined in ISO834).

  The refractory wood pillar 1 is provided with a burnup layer (a heat insulation layer is formed by self-burning and carbonization) and / or a stop layer (inhibition of combustion and carbonization of the burnup layer) 1b on the surface layer of the core material 1a. The burning allowance layer and the burning stop layer 1b are handled as a fireproof coating layer so as to ensure the load supporting ability of the core material 1a in the event of a fire.

JP 2013-053415 A JP 2006-022639 A

  Here, it is known that the steel material temperature rises to about 500-550 degreeC, when the steel beam which ensured fire resistance with respect to the fire heating for 1 hour receives the fire heating for 1 hour. For this reason, the site | part of the refractory wood pillar which contacts and joins the steel beam which gave fireproof coating also reaches about 500-550 degreeC.

  Therefore, in the above-mentioned conventional joint construction method, the part where the steel beam and the core of the refractory wood column contact and join exceeds the ignition temperature (260 ° C) of the wood in the event of a fire, and the refractory wood column has its load bearing capacity May be lost. Moreover, even if the temperature of the steel beam does not exceed the ignition temperature of wood, if the temperature is close to 200 ° C., the core material of the refractory wood column may be carbonized, and the mechanical properties of the core material may be lost. .

  In view of the above circumstances, the present invention contacts and joins the steel frame even when the joint between the wood material and the steel frame is subjected to a one-hour fire heating (standard heating temperature time curve defined in ISO834). An object of the present invention is to provide a joint structure between a wooden material and a steel frame that can suppress the temperature of the core material of the wooden material to 260 ° C. or lower, more preferably 200 ° C. or lower, and exhibits excellent fire resistance performance. And

  In order to achieve the above object, the present invention provides the following means.

The joint structure of the wood material and the steel frame according to the present invention is a structure of a joint portion of the wood material and the steel frame material, and is provided with a fireproof coating to form a fireproof coating layer around the steel frame material. wherein the wooden material side, the thickness of the than the general portion of the other portions of the steel material is configured to provide a increased thickness portion in which the thickness of the refractory coating layer on a large, fire protection layer in the general part of the 20 mm, the heating perimeter / cross-sectional area of the steel frame material is 0.169 or less, and the wood material core material when subjected to fire heating for 1 hour based on the standard heating temperature time curve defined in ISO834 When the temperature of the steel material is suppressed to 260 ° C. or less, the length range of the steel frame material of 0.75 m or more from the surface of the core material of the wooden material is the increased thickness portion, and the fireproof coating layer of the increased thickness portion The thickness of the wood is 60 mm or more, and the temperature of the wood core is 200 ° C. In the case of restraining downward, the length range of the steel frame material of 2.00 m or more from the surface of the core material of the wooden material is the increased thickness portion, and the thickness of the fireproof coating layer of the increased thickness portion is 80 mm. In the case where the temperature of the core material of the wooden material is suppressed to 200 ° C. or less, the length range of the steel frame material of 0.80 m or more from the surface of the core material of the wooden material is defined as the increased thickness portion. And the thickness of the said fireproof coating layer of the additional thickness part is comprised as 100 mm or more, It is characterized by the above-mentioned.

In order to ensure the fire resistance performance of the joint composed of refractory wooden columns and steel beams, the simplest method is to increase the thickness of the fire protection coating over the entire length of the steel beams. Fireproof coating is required, which increases the amount of material used and decreases the construction yield.
On the other hand, according to the joint structure of the wood material and the steel frame of the present invention, it is possible to minimize the increase in the amount of material used and the decrease in the yield, and to ensure the fire resistance performance of the joint portion. It becomes possible.

It is a figure which shows the junction part structure of the wood material and steel frame which concern on one Embodiment of this invention. It is the X1-X1 arrow view figure of FIG. FIG. 2 is an X2-X2 arrow view of FIG. 1. It is a figure which shows a simulation result, and is a figure which shows the steel material maximum temperature at the time of setting the thickness of an additional thick part to 40 mm. It is a figure which shows a simulation result, and is a figure which shows the steel material maximum temperature at the time of setting the thickness of an additional thick part to 60 mm. It is a figure which shows a simulation result, and is a figure which shows the steel materials highest temperature at the time of setting the thickness of an additional thick part to 80 mm. It is a figure which shows a simulation result, and is a figure which shows the steel material maximum temperature at the time of setting the thickness of an additional thick part to 100 mm. It is a figure which shows a simulation result, and is a figure which shows the relationship of the thickness of an additional thick part, the range of an additional thick part, and steel material highest temperature. It is a front view which shows the junction part structure of the conventional fireproof wooden pillar and steel beam. FIG. 10 is a cross-sectional view taken along line X1-X1 in FIG. 9 and illustrating a conventional joint structure between a refractory wood column and a steel beam. It is a front view which shows the junction part structure of the conventional fireproof wooden pillar and steel beam. It is a X1-X1 arrow directional view of FIG. 11, and is a plane sectional view which shows the junction part structure of the conventional refractory wood pillar and a steel beam.

  Hereinafter, with reference to FIG. 1 to FIG. 8, a description will be given of a joint structure of a wood material and a steel material according to an embodiment of the present invention.

  In the present embodiment, a joint formed by joining a refractory wood column (wood material) and a steel beam (steel material) is subjected to 1 hour fire heating (fire heating based on a standard heating temperature time curve defined in ISO834). Joint of wood material and steel frame that can suppress the temperature of the core material at the contact position (joining position) between the core material of the refractory wood column and the steel beam to 260 ° C. or lower or 200 ° C. or lower It relates to the structure (fireproof coating construction method).

As shown in FIGS. 1 to 3 (see FIGS. 9 to 11), in the joined portion structure A of the wood material and the steel frame of this embodiment, first, the refractory wood pillar 1 burns on the surface layer of the core material 1a. It is formed by providing a surrogate layer and / or a flame stop layer 1b. Further, the steel beam 2 is disposed by being appropriately connected to the refractory wood column 1 by means, and the surface (surrounding) is provided with a refractory coating 4.
In addition, the code | symbol 5 in a figure has shown RC floor. Moreover, you may make it give the fireproof wooden pillar 1 fireproof coating on the surface.

  Furthermore, in the joint structure A of the wood material and the steel frame of the present embodiment, the fireproof coating 4 is applied to form the fireproof coating layer (4) around the steel beam 2, and the fireproof wooden column 1 of the steel beam 2 is formed. On the side (joint portion side), an increased thickness portion 7 is provided in which the thickness of the fireproof coating layer (4) is made larger than the general portion 6 of the other portion of the steel beam 2.

  At this time, when the temperature of the refractory wood pillar 1 (core material 1a) is suppressed to 260 ° C. or less when subjected to fire heating for 1 hour based on the standard heating temperature time curve defined in ISO834, the thickened portion is increased. When the thickness t of the refractory coating layer (4) 7 is set to three times or more that of the refractory coating layer (4) of the general part 6 and the temperature of the refractory wood column 1 is suppressed to 200 ° C. or less, It is preferable that the thickness t of the fireproof coating layer (4) is set to be four times or more that of the fireproof coating layer (4) of the general part 6.

  Furthermore, when the temperature of the fire-resistant wood pillar 1 (core material 1a) is suppressed to 260 ° C. or lower when subjected to fire heating for 1 hour based on the standard heating temperature time curve defined in ISO834, the fire-resistant wood pillar It is more preferable that the length range of the steel beam 2 of 0.75 m or more from the surface of 1 is increased to be the thick portion 7 and the thickness t of the fireproof coating layer (4) of the increased thick portion 7 is 60 mm or more.

  When the temperature of the refractory wood column 1 is suppressed to 200 ° C. or lower, the length range of the steel beam 2 of 2.00 m or more from the surface of the refractory wood column 1 is increased to a thick portion 7 and the increased thickness portion 7 When the thickness t of the fireproof covering layer (4) is set to 80 mm or more, or the temperature of the fireproof wooden column 1 is suppressed to 200 ° C. or less, the steel beam 2 of 0.80 m or more from the surface of the fireproof wooden column 1 is formed. More preferably, the length range is increased to a thick part 7 and the thickness t of the fireproof coating layer (4) of the increased thickness part 7 is set to 100 mm or more.

  Here, a simulation (numerical analysis) result is shown, and the superiority of the joint structure A between the woody material and the steel frame of this embodiment will be described.

  In this simulation, a 1-hour fire-resistant steel beam covered with a fire-resistant rock wool of 20 mm thickness (fire-resistant coating 4: for example, Michibei manufactured by NICHIAS Corporation has obtained a fire resistance certification of 20 hours in thickness). 2 is contacted and joined to the core material 1a of the refractory wood pillar 1.

  A numerical analysis model of the joint structure A of the wood material and the steel frame structure of this embodiment configured as described above is as shown in FIG.

  As shown in FIG. 1, by making the portion that contacts and joins the refractory wood column 1 as the heat insulation boundary S, the outflow of thermal energy to the joint is eliminated. For this reason, a more conservative result can be obtained than when the core material 1a of the refractory wood column 1 is directly modeled.

  In FIG. 1, the 1-hour refractory steel beam 2 is divided into a general part 6 (heat-resistant rock wool (Makibei) 4 having a thickness of 20 mm) and a thickened part 7 near the joint.

In this simulation, the steel cross section is a standard steel material of H-400 × 200 × 8 × 13 mm (a steel material cross section used as a standard in the fire resistance certification test (performance evaluation test)), and the coating thickness t of the increased thickness portion 7 is 20, The length ranges from 40, 60, 80, and 100 mm to the joined portion of the increased thickness portion 7 were 0.2, 0.6, 1.0, and 2.0 m.
The steel beam has a total length L of 7.0 m.

The maximum steel temperature distribution in the beam axis direction of the numerical analysis model shown in FIG. 1 is shown in FIGS.
From this result, when the increased thickness range of the refractory coating 4, that is, the length range of the increased thickness portion 7 is expanded, the maximum steel temperature of the right heat insulation boundary layer (contact / joining position with the refractory wood column 1) decreases, but increases. It was confirmed that there was no significant difference when the thickness range was 1 m and 2 m.

  Next, with respect to the calculation results shown in FIGS. 4 to 7, FIG. 8 shows the results of summarizing the reduction effect of the maximum steel temperature due to the increased thickness and the increased thickness range of the fireproof coating 4.

  As shown in FIG. 8, when the fireproof coating thickness t of the increased thickness portion 7 is 40 mm, the maximum steel material temperature of the steel beam 2 that contacts and joins the core material 1a cannot be made 260 ° C. or less, which is the ignition temperature of wood. .

  Based on the result of FIG. 8, the core material 1a of the refractory wood column 1 is increased by increasing the fireproof coating thickness t in the vicinity of the joint in the joint composed of the refractory wood column 1 and the 1 hour refractory steel beam 2. Deriving the combination of the target performance of the construction method to ensure the fire resistance performance and the thickness and range of the fireproof coating is as follows.

  Fireproof coating 4 such as heat-resistant rock wool is applied to the steel beam 2, the coating thickness t of the general part 6 is 20 mm, the heating circumference / cross-sectional area is 0.169 or less, and the fireproof coating of the fire-resistant wooden pillar 1 at the joint is burned. It consists of a stop layer and / or a burning allowance layer 1b, or is covered with a fireproof coating having performance equivalent to these construction methods.

Then, from FIG. 8, if the range of 0.75 m or more from the surface of the joint (core material 1 a) is fireproof coated with a thickness t of 60 mm or more, the temperature of the core material 1 a is reduced to 260 ° C. or less, which is the ignition temperature of wood. Can be suppressed.
Moreover, if the range of 2.0 m or more from the joint surface is fireproof coated with a thickness t of 80 mm or more, the temperature of the core material 1 a can be suppressed to 200 ° C. or less, which is a standard for the carbonization temperature of wood. Furthermore, even if the range of 0.8 m or more from the surface of the joint is fireproof coated with a thickness t of 100 mm or more, the temperature of the core material 1 a can be suppressed to 200 ° C. or less, which is a standard for the carbonization temperature of wood.

  Therefore, in the joint structure A between the wood material and the steel frame of the present embodiment, even when the joint between the refractory wood column 1 and the steel beam 2 is subjected to fire heating for 1 hour, It is possible to suppress the temperature of the core material 1a of the fire-resistant wood pillar 1 at the joining portion to 260 ° C. or less, more preferably 200 ° C. or less, and a joint structure A between the wood material and the steel frame material that exhibits excellent fire resistance performance. It becomes possible to provide.

  Here, in order to ensure the fire resistance performance of the joint composed of the fire-resistant wooden column 1 and the steel beam 2, it is the simplest method to increase the fire-resistant coating thickness over the entire length L of the steel beam 2. However, this construction method requires an extra fireproof coating 4, which increases the amount of material used and reduces the construction yield.

  On the other hand, according to the joint structure A of the wood material and the steel frame of the present embodiment, an increase in the amount of material used and a decrease in yield can be kept to a minimum, and the fire resistance performance of the joint is ensured. It becomes possible.

  As mentioned above, although one Embodiment of the junction part structure of the wood material and steel frame material which concerns on this invention was described, this invention is not limited to said one Embodiment, It can change suitably in the range which does not deviate from the meaning. It is.

  For example, in the present embodiment, the wooden material and the steel frame according to the present invention have been described as being a fire-resistant wooden column and a steel beam, respectively, but it is particularly necessary to limit the type of member (column, beam). However, the present invention is applicable to any joint structure that joins a wood material and a steel frame material.

1 Fireproof wooden pillar (wooden material)
1a Core material 1b Burning allowance layer and / or burning stop layer 2 Steel beam (steel frame)
3 Gusset plate 4 Fireproof coating (Fireproof coating layer)
5 RC floor 6 General part 7 Increased thickness part A Joint structure of wood and steel

Claims (1)

It is the structure of the joint between wood and steel frame,
While applying a fireproof coating to form a fireproof coating layer around the steel frame,
On the wooden material side of the steel frame material, an increased thickness part is provided in which the thickness of the fireproof coating layer is made larger than the general part of the other part of the steel frame material,
The thickness of the fireproof coating layer of the general part is 20 mm,
The heating perimeter / cross-sectional area of the steel aggregate is 0.169 or less,
When subjected to fire heating for 1 hour based on the standard heating temperature time curve specified in ISO834,
When the temperature of the core material of the wooden material is suppressed to 260 ° C. or less, the length range of the steel frame material of 0.75 m or more from the surface of the core material of the wooden material is the increased thickness portion, and the increased The thickness of the thick fireproof coating layer is 60 mm or more,
When the temperature of the core material of the wood material is suppressed to 200 ° C. or less, the length range of the steel frame material of 2.00 m or more from the surface of the core material of the wood material is the increased thickness portion, and the increase The thickness of the thick fireproof coating layer is 80 mm or more,
Alternatively, when the temperature of the core material of the wooden material is suppressed to 200 ° C. or less, the length range of the steel frame material of 0.80 m or more from the surface of the core material of the wooden material is the increased thickness portion, and A joining structure of a wood material and a steel frame, characterized in that the thickness of the additional thick portion of the fireproof coating layer is 100 mm or more.

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