Fire-resistant structure for column-beam joint

Abstract

To provide a fire-resistant structure for column-beam joints that can ensure fire resistance equivalent to that of columns and beams.SOLUTION: In a fire-resistant structure 10 of a column-beam joint that connects a fire-resistant wood column 12 comprising a load-bearing wood core 20 and a fire-resistant cladding material 22 provided on the outside of the core 20 and a wood-steel hybrid beam 14 comprising a steel beam 26 and a wood cladding material 28 provided on the outside of the steel beam 26, via a T-shaped cross-sectional joint hardware 16 comprising a gusset plate 50 fixed to a side end of the steel beam 26 and a base plate 52 attached to the fire-resistant cladding material 22 on a side surface of the fire-resistant wood column 12, a cementitious solidifying material 18 filled in the area surrounding the joint hardware 16 is provided between the side end of the wood-steel hybrid beam 14 and the side face of the fire-resistant wood column 12.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a fire-resistant structure for a column-beam joint. [Background technology]

[0002] The applicant of the present patent has previously developed fire-resistant wooden columns and beams (Slim Fireproof Wood (registered trademark)) that ensure fire resistance for one or two hours by fire-proofing wood that supports a load with reinforced gypsum board and a fireproof sheet (see, for example, Patent Document 1). The applicant has also developed a wood-steel hybrid beam, which is a structural member in which a steel beam is fire-proof-covered with wood (hereinafter referred to as a wood covering material) (see, for example, Patent Document 2). On the other hand, although the specifications for column-beam joints are not stipulated, there is a risk that a building may collapse if the structural performance around the joints is reduced by fire heating, and therefore, the same fire resistance as that of the columns and beams is required for the column-beam joints.

[0003] Conventional fireproof structures for beam-column joints are known, for example, from Patent Documents 3 and 4. Patent Document 3 describes a joint between a fireproof wooden column with built-in steel and a fireproof wooden beam, in which wood is filled as a fireproof covering material. Patent Document 4 describes a joint between a wooden column and a steel beam, in which high-density wood or fire-retardant wood is used as a covering to burn. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6414670 [Patent Document 2] Patent Publication No. 2022-42750 [Patent Document 3] Patent No. 6019259 [Patent Document 4] JP 2018-3475 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the meantime, it is expected that metal joints such as gusset plates and splice plates will be used at the joints between fire-resistant wooden columns and wood-steel hybrid beams. In order to ensure the fire resistance of such joints, the following problems can be considered.

[0006] The temperature of the steel frame and metal joints in the wood-steel hybrid beams exceeds the allowable temperature (average 350°C, maximum 450°C), causing destruction. Heat conduction from metal joints can cause the wood core of fire-resistant wood columns to carbonize, and the wood covering of wood-steel hybrid beams to continue to burn, making it impossible to ensure the specified fire resistance. Gaps occur where materials meet around joints, allowing heat to enter and accelerating the combustion of wood, leading to carbonization of the wood core of fire-resistant wood columns and continued red-hot combustion of the wood covering of wood-steel hybrid beams.

[0007] For this reason, there was a need to develop a structure that could ensure fire resistance equivalent to that of fire-resistant wood columns and wood-steel hybrid beams, even at column-beam joints using metal joints.

[0008] The present invention has been made in consideration of the above, and aims to provide a fire-resistant structure for a column-beam joint that can ensure fire resistance performance equivalent to that of a column-beam joint. [Means for solving the problem]

[0009] In order to solve the above-mentioned problems and achieve the object, the fireproof structure of a column-beam joint of the present invention is a fireproof structure of a column-beam joint formed by joining a fireproof wood column composed of a wood core material that supports a load and a fireproof covering material provided on the outside of the core material, and a wood-steel hybrid beam composed of a steel beam and a wood covering material provided on the outside of the steel beam, via a T-shaped cross-section connecting metal fitting consisting of a gusset plate fixed to the side end of the steel beam and a base plate attached to the fireproof covering material on the side of the fireproof wood column, and characterized in that a cement-based solidification material is filled in the area around the connecting metal fitting between the side end of the wood-steel hybrid beam and the side of the fireproof wood column.

[0010] Furthermore, another fire-resistant structure of a column-beam joint according to the present invention is characterized in that, in the above-mentioned invention, a fire-resistant covering material or a wood covering material is provided on the outside of the cement-based solidification material.

[0011] In addition, another fire-resistant structure of a column-beam joint according to the present invention is characterized in that, in the above-mentioned invention, a non-wood-based fire-resistant coating material is provided on the end surface of the wood coating material at the side end of the wood-steel hybrid beam. Effect of the Invention

[0012] According to the fireproof structure for a column-beam joint of the present invention, a fireproof wood column comprising a wood core material that supports a load and a fireproof covering material provided on the outside of the core material, and a wood-steel hybrid beam comprising a steel beam and a wood covering material provided on the outside of the steel beam are joined via a T-shaped cross-section connecting metal fitting consisting of a gusset plate fixed to the side end of the steel beam and a base plate attached to the fireproof covering material on the side of the fireproof wood column, and a cement-based solidification material is filled in the area around the connecting metal fitting between the side end of the wood-steel hybrid beam and the side of the fireproof wood column, thereby achieving the effect of ensuring fire resistance performance equivalent to that of the column-beam at the column-beam joint between the fireproof wood column and the wood-steel hybrid beam.

[0013] In addition, according to another fire-resistant structure of a column-beam joint of the present invention, a fire-resistant coating material or wood coating material is provided on the outside of the cement-based solidification material, which has the effect of suppressing the temperature rise of the connecting metal fittings, preventing carbonization of the core material of the fire-resistant wooden column, and contributing to the stopping of fire of the wood coating material of the wood-steel hybrid beam.

[0014] In addition, according to another fireproof structure of the beam-column joint of the present invention, a non-wood-based fireproof coating material is provided on the end surface of the wood coating material at the side end of the wood-steel hybrid beam, which contributes to the extinguishing of the wood coating material. In addition, it has the effect of suppressing the continuation of the combustion of the wood coating material due to the inflow of heat from the gap caused by the shrinkage of the cement-based solidification material after filling. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 shows an embodiment of a fireproof structure for a beam-column joint according to the present invention, where (1) is a vertical cross-sectional view and (2) is a horizontal cross-sectional view. [Diagram 2] FIG. 2 is a diagram relating to the fire resistance test of Example 1 of the present invention, where (1) shows the test specimen and the temperature measurement positions, and (2) shows the internal temperature transition. [Diagram 3] FIG. 3 is a diagram relating to the fire resistance test of Example 2 of the present invention, where (1) shows the test specimen and the temperature measurement positions, and (2) shows the internal temperature transition. [Figure 4] FIG. 4 is a cross-sectional view showing the temperature measurement positions of the fire resistance test specimen, where (1) is measurement cross section A1, (2) is measurement cross section A2, (3) is measurement cross section A3, (4) is measurement cross section A4, and (5) is measurement cross section A5. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] The present invention has the following features (1) to (3). (1) Fill with concrete to prevent the temperature rise of the metal joints. (2) The concrete-filled areas are covered with reinforced gypsum boards or wooden panels to suppress the temperature rise of the connecting metal fittings, prevent the wood core material of fire-resistant wood columns from carbonizing, and help stop the wood covering material of wood-steel hybrid beams from burning. (3) By attaching reinforced gypsum boards to the ends of wood-steel hybrid beams, the reinforced gypsum boards absorb heat and stop the wood covering material from burning. In addition, the boards prevent the wood covering material from continuing to burn due to heat inflow through gaps caused by shrinkage of concrete after pouring.

[0017] In this specification, it is defined that the one-hour fire resistance performance has been achieved when the following two conditions are met after heating for one hour in accordance with the standard heating curve specified in ISO834, stopping heating and allowing to cool for 24 hours: (1) The fire should stop burning while it is being allowed to cool (it should go out on its own without the need for water or other extinguishing measures). (2) After cooling, all of the wood in the pillar core remains uncarbonized.

[0018] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of a fire-resistant structure for a column-beam joint according to the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to these preferred embodiments.

[0019] This embodiment is a structure that assumes one-hour fire resistance. As shown in Fig. 1, a fireproof structure 10 for a column-beam joint according to the embodiment of the present invention is a structure in which a fireproof wooden column 12 and a wood-steel hybrid beam 14 are joined via a joint metal 16, and concrete 18 (cement-based solidification material) is filled in the area around the joint metal 16.

[0020] (Fireproof wooden pillar) The fireproof wooden column 12 is a column with a square cross section, which includes a wooden core material 20 that supports a load, a fireproof covering material 22 provided on the entire outer circumference of the core material 20, and a finishing material 24. The core material 20 can be made of laminated wood such as larch. The fireproof covering material 22 is made of two reinforced gypsum boards 22A provided on the outer side of the core material 20 and a fireproof sheet 22B provided on the outer side. The fireproof sheet 22B is a thermally expandable fireproof sheet that expands when heated and the combustion residue forms a fireproof insulation layer, thereby exhibiting fireproof insulation performance. The finishing material 24 is made of a wooden board provided on the outer side of the fireproof sheet 22B. In this embodiment, it is assumed that one side of the cross section of the core material 20 is 540 mm, the thickness of the reinforced gypsum board 22A is 15 mm, the thickness of the fireproof sheet 22B is 2 mm, and the thickness of the wooden board of the finishing material 24 is 15 mm, but the present invention is not limited to this.

[0021] (Wood-steel hybrid beams) The wood-steel hybrid beam 14 includes a steel beam 26 made of a horizontally extending H-shaped steel, and wood covering material 28 provided on both the left and right outer sides and the underside of the steel beam 26. A floor material 30 is provided on the upper surface of the steel beam 26. The floor material 30 is formed of a floor slab using, for example, reinforced concrete or ALC (lightweight aerated concrete) boards. Note that, although the example shown in the figure shows a case where the wood-steel hybrid beam 14 is arranged only on the left side surface of the fire-resistant wood column 12, a similar wood-steel hybrid beam 14 may be arranged on the right side surface, front and rear surfaces, etc. of the fire-resistant wood column 12 to form a column-beam joint at each location.

[0022] The wooden covering material 28 is provided in the area on the side of the area defined by the upper flange 32, the lower flange 34, and the web 36 of the steel beam 26, and in the area below the lower surface of the lower flange 34, so as to cover both the left and right outer sides and the lower side of the steel beam 26. The wooden covering material 28 can be formed, for example, using a laminated timber with a vertically long rectangular cross section having a surface along the outer side of the web 36 and a groove for inserting one side of the lower flange 34. The two wooden covering materials 28 arranged on the left and right sides of the web 36 may be attached to each other below the lower flange 34 and bonded with an adhesive. For example, larch can be used as the material for the laminated timber. In order to absorb the construction error between the steel beam 26 and the wooden covering material 28, the steel beam 26 and the wooden covering material 28 may not be attached to each other, but a thin layer of air (for example, a layer thickness of about 3.5 mm) may be provided between them. Further, the wooden covering material 28 in this embodiment is assumed to have a thickness of 80 mm on the bottom side and 50 mm on the side sides, but the present invention is not limited to this.

[0023] The wooden covering material 28 and the steel beam 26 are fixed together via a lag screw 38. The lag screw 38 is a metal rod-shaped body having a plate-shaped head 38A and an axially shaped screw portion 38B. The screw portion 38B has a sharp tip and is provided with a screw thread on its outer periphery. The lag screw 38 is screwed into the wooden covering material 28 through through holes 40 provided on the upper and lower sides of the web 36 in the same vertical cross section. A plurality of the lag screws 38 are arranged at predetermined intervals in the beam axis direction (horizontal direction) of the steel beam 26, and are arranged so that the screwing directions of the lag screws 38 are staggered in the beam axis direction. In this manner, the steel beam 26 and the wooden covering materials 28 on both the left and right sides can be efficiently integrated together.

[0024] A washer 42 made of a plate is provided between one side of the web 36 and the wooden covering material 28, and a screw portion 38B is inserted into the washer 42. The web 36 and the wooden covering material 28 are connected via the washer 42, and any installation error between the web 36 and the wooden covering material 28 can be absorbed by cutting the wooden covering material 28 in the washer 42 area. This improves ease of installation.

[0025] The wooden covering material 28 is provided with a mounting hole 44 for mounting the lag screw 38 to the web 36. The mounting hole 44 is closed with a filler 46 after the lag screw 38 is tightened. The filler 46 is taken from the same laminated wood as the wooden covering material 28 and the grain is matched to ensure design. The length of the filler 46 is the length from the end face of the head 38A of the lag screw 38 to the surface of the wooden covering material 28, which is desirable to improve fire resistance. Note that mounting holes 44 may be provided in the center of the web 36 and in the left and right wooden covering materials 28 in the left and right directions, and the left and right wooden covering materials 28 may be connected to each other by passing a drift pin through the mounting hole 44. The opening of the mounting hole 44 may be closed with a filler 46.

[0026] A reinforced gypsum board 48 (non-wood-based fireproof coating material) is attached to the end surface 14A of the side end of the wood-steel hybrid beam 14. This reinforced gypsum board 48 absorbs heat during fire heating to stop the wood coating material 28 from burning. It also suppresses the continuation of burning of the wood coating material 28 due to the inflow of heat from gaps caused by the shrinkage of the concrete 18 after casting. The thicker the reinforced gypsum board 48, the better the heat insulation performance and heat absorption effect. For example, if the thickness of the reinforced gypsum board 48 is 15 mm or more, it is considered that a predetermined fire resistance performance (for example, 1 hour) is guaranteed. Note that the fireproof coating material provided on the end surface 14A of the side end of the wood-steel hybrid beam 14 is not limited to the reinforced gypsum board 48, and any non-wood-based fireproof coating material may be used. In addition, the thickness and number of this fireproof coating material can be appropriately set according to the required fire resistance performance, etc.

[0027] (Metal joints) The joint metal 16 has a T-shaped cross section when viewed from a horizontal plane, and is composed of a gusset plate 50 that is bolted to the side end of the steel beam 26, and a base plate 52 that is connected to the side end of the gusset plate 50 and attached to the surface of the fireproof sheet 22B on the side of the fireproof wooden column 12. To allow for thermal expansion and deformation of the fireproof sheet 22B when heated by a fire, the base plate 52 and the fireproof sheet 22B are not in close contact with each other, but a thin layer of air is provided between them.

[0028] The gusset plate 50 is butted against a web plate 54 that protrudes from the web 36 at the side end of the steel beam 26 toward the fire-resistant wooden column 12 in the left-right direction, and a plate 56 is disposed on the front and rear surfaces of this butting portion, straddling the gusset plate 50 and the web plate 54. The plates 50, 54, 56 are joined by a plurality of bolts 60 passed through through holes 58.

[0029] The base plate 52 is fixed to the fire-resistant wooden column 12 via steel rods 62 that are arranged to penetrate the fire-resistant wooden column 12 horizontally in the left-right direction. The steel rods 62 are arranged in three locations spaced apart in the vertical direction, two locations in front and behind the connection portion between the gusset plate 50 and the base plate 52, but the present invention is not limited to this, and other arrangement layouts and arrangement quantities may be used.

[0030] The end 62A of the steel bar 62 on the base plate 52 side passes through the insertion hole 52A provided in the base plate 52. This end 62A is threaded, and nuts 64A, 64B are screwed on both sides of the base plate 52. The end 62A is fixed to the base plate 52 by fastening the nut 64. The nut 64A arranged on the fireproof wooden column 12 side of the base plate 52 is arranged in the joint portion 22C of the fireproof covering material 22. A fireproof joint material 66 is filled around the nut 64A in the joint portion 22C. For example, a silicone-based sealant can be used as the fireproof joint material 66. A recess 68A is formed between the side portion of the core material 20 and the steel bar 62. This recess 68A is filled with a grout material 70 such as non-shrink mortar. The grout material 70 is provided to suppress heat conduction from the steel rod 62 to the core material 20 .

[0031] The opposite end 62B of the steel bar 62 is housed in a recess 68B formed in the back side of the core material 20, and passes through an anchor plate 72 that is disposed against the side of the recess 68B. This end 62B is threaded, and a nut 74 is screwed into the outside of the anchor plate 72. By fastening the nut 74, the end 62B is fixed to the side of the recess 68B via the anchor plate 72. The nut 74 also functions to adjust the construction accuracy.

[0032] The steel rod 62 may be, for example, a fully threaded bolt, a round bar with threads cut on both ends, an anchor bolt used in building foundations, a deformed reinforcing bar with threads cut on both ends, etc. It is preferable to insert the steel rod 62 into a tip hole provided in the core material 20 and to arrange the core material 20 and the steel rod 62 in a state of being attached to each other using an adhesive or the like.

[0033] (concrete) The concrete 18 is for suppressing the temperature rise of the metal joint 16, and is filled in the area around the metal joint 16 between the side end of the wood-steel hybrid beam 14 and the side of the fire-resistant wooden column 12. The thicker the concrete 18, the greater the heat capacity and the better the heat insulation performance. For this reason, if the thickness of the concrete 18 is set to be equal to or greater than the thickness of the test specimen described below, it is considered that a predetermined fire resistance performance (for example, for one hour) is guaranteed. It is desirable to pour the concrete 18 at the same time as pouring the concrete for the floor material 30, taking into consideration workability. Moreover, the present invention is not limited to the concrete 18, and other cement-based solidification materials such as mortar may be used instead of the concrete 18.

[0034] A fireproof covering material 76 and a finishing material 78 are provided on the side and bottom of the concrete 18. A floor material 30 is provided on the top of the concrete 18. The fireproof covering material 76 is made of reinforced gypsum board. The finishing material 78 is made of a wooden board provided on the outside of the fireproof covering material 76. Covering the filled part of the concrete 18 with the reinforced gypsum board or the wooden board contributes to suppressing the temperature rise of the joint metal 16, preventing carbonization of the core material 20 of the fireproof wooden column 12, and preventing the wood covering material 28 of the wood-steel hybrid beam 14 from burning. In this embodiment, it is assumed that the thickness of the reinforced gypsum board of the fireproof covering material 76 is 12.5 mm, and the thickness of the wooden board of the finishing material 78 is 10 mm, but this is not limited to this. Since the heat shielding performance improves as the thickness of the wooden board increases, it is considered that the predetermined fire resistance performance is guaranteed if the thickness of the wooden board is 10 mm or more.

[0035] The reinforced gypsum board of the fireproof covering material 76 is attached to the surface of the concrete 18 after the concrete 18 has been poured and cured. A gypsum-based adhesive can be used for attachment. However, it is preferable to use a combination of concrete screws and adhesive for the underside to prevent falling off. A vinyl acetate resin adhesive and staples can be used for attachment of the wooden board of the finishing material 78. Note that, as in the case of test specimen 2 described below, the reinforced gypsum board may be omitted and a wooden board may be attached to the wooden furring strip. Even in specifications without the reinforced gypsum board, a specified fire resistance performance can be ensured as shown in the fire resistance test described below.

[0036] According to this embodiment, it is possible to ensure fire resistance performance at the column-beam joint (concrete filled portion) equivalent to that of the fire-resistant wooden column 12 and the wood-steel hybrid beam 14. This ensures the fire safety of a building using the fire-resistant wooden column 12 and the wood-steel hybrid beam 14. In addition, concrete can be placed at the column-beam joint at the same time as concrete is poured for the floor material 30 to be constructed on the wood-steel hybrid beam 14. This reduces the effort required for pouring concrete.

[0037] (Verification of the Effects of the Invention) Next, tests carried out to verify the effects of the present invention and the results thereof will be described.

[0038] A simulated test specimen simulating the above fireproof structure 10 was prepared, and a fire resistance test was performed to examine the fire resistance performance. The fire resistance test was performed by placing the test specimen in a furnace, heating it for one hour according to the standard heating curve specified in ISO834, and then cooling it in the furnace for 24 hours. Two test specimens (test specimens 1 and 2) were prepared. Test specimen 1 is a specification (Example 1) in which the concrete-filled part is covered with a reinforced gypsum board (thickness 12.5 mm) and a wooden board (thickness 10 mm). Test specimen 2 is a specification (Example 2) in which the reinforced gypsum board is omitted and the concrete-filled part is covered with a wooden board (thickness 10 mm). A wooden board (thickness 10 mm) is attached to a wooden furring strip (thickness 20 mm).

[0039] The common specifications for specimens 1 and 2 are as follows. First, H-shaped steel for steel beam 26 was H-600×300×12×19. For wooden covering material 28, larch laminated lumber was used, with a thickness of 80 mm on the bottom side and 50 mm on the side. Reinforced gypsum board 48 (thickness 15 mm) was attached to the small end surface of wooden covering material 28. For core material 20 of fire-resistant wooden column 12, larch laminated lumber (same grade E95-F315, 540×540 mm) was used. For fire-resistant covering materials 22A and 22B, two sheets of reinforced gypsum board (thickness 15 mm×2) and a fire-resistant sheet (thickness 2 mm) were used. For finishing material 24, a wooden board (cedar decorative wood, thickness 15 mm) was used. For steel bar 62, a through bolt M30 (tip hole φ32) was used. The base plate 52 used was 25 x 300 x 600 mm. The surface of the concrete 18 was finished so that the sides and bottom were vertical and horizontal, respectively. The top surface of the concrete 18 was finished flush with the top surface of the upper flange 32 of the steel beam 26. The thickness of the concrete 18 was 91.5 mm when measured downward from the bottom end of the web plate 54 on the wood-steel hybrid beam 14 side, and 158.5 mm when measured laterally from the side of the web plate 54. In addition, the thickness was 23.5 mm when measured laterally from the side end of the base plate 52, and 53.5 mm when measured downward from the bottom end.

[0040] Figures 2 and 3 show schematic diagrams of the test specimens, the temperature measurement positions, and the temperature measurement results. Figure 2 corresponds to test specimen 1, and Figure 3 corresponds to test specimen 2. Temperature measurement positions P1 to P5 at temperature measurement cross sections A1 to A5 in Figures 2(1) and 3(1) are as shown in Figure 4. Figures 2(1) and 3(1) show the maximum temperature at each cross section. The temperature measurement results in Figures 2(2) and 3(2) use the maximum temperature value among the temperatures measured at each measurement position on temperature measurement cross sections A1 to A5.

[0041] As shown in Figure 2, in specimen 1, the maximum temperature of the wood core material around the joint was below 200°C, and no discoloration or carbonization was observed on the surface of the column core material around the joint. The maximum steel temperature of the wood-steel hybrid beam was 85°C, and the wood covering material also stopped burning. Furthermore, the maximum temperature of the joint metal was 81°C, which did not reach the temperature at which the wood would be carbonized.

[0042] On the other hand, as shown in Figure 3, for specimen 2, the maximum temperature of the wood core material around the joint was below 200°C, and no discoloration or carbonization was observed on the surface of the column core material around the joint. The maximum steel temperature of the wood-steel hybrid beam was 99°C, and the wood covering material also stopped burning. Furthermore, the maximum temperature of the joint metal was 149°C, which did not reach the temperature at which the wood would carbonize. Therefore, it was confirmed that the fire-resistant coating structure around the column-beam joint in this embodiment has a fire resistance performance of one hour.

[0043] As described above, the fireproof structure for a column-beam joint according to the present invention is a fireproof structure for a column-beam joint formed by joining a fireproof wood column comprising a wood core material that supports a load and a fireproof covering material provided on the outside of the core material, and a wood-steel hybrid beam comprising a steel beam and a wood covering material provided on the outside of the steel beam, via a T-shaped connecting metal member consisting of a gusset plate fixed to the side end of the steel beam and a base plate attached to the fireproof covering material on the side of the fireproof wood column. Since a cement-based solidification material is filled in the area around the connecting metal member between the side end of the wood-steel hybrid beam and the side of the fireproof wood column, the column-beam joint between the fireproof wood column and the wood-steel hybrid beam can ensure fire resistance equivalent to that of the column-beam.

[0044] In addition, according to another fire-resistant structure of a column-beam joint of the present invention, a fire-resistant coating material or wood coating material is provided on the outside of the cement-based solidification material, which contributes to suppressing the temperature rise of the connecting metal fittings, preventing carbonization of the core material of the fire-resistant wooden column, and stopping the fire of the wood coating material of the wood-steel hybrid beam.

[0045] In addition, according to another fireproof structure of the beam-column joint of the present invention, a non-wood-based fireproof coating material is provided on the end surface of the wood coating material at the side end of the wood-steel hybrid beam, which contributes to the extinguishing of the wood coating material. It also prevents the wood coating material from continuing to burn due to the inflow of heat from gaps caused by the shrinkage of the cement-based solidification material after filling. [Industrial Applicability]

[0046] As described above, the fire-resistant structure of the column-beam joint of the present invention is useful for the joint between a fire-resistant wooden column and a wood-steel hybrid beam, and is particularly suitable for ensuring fire resistance performance equivalent to that of a column-beam. [Explanation of symbols]

[0047] 10 Fireproofing of beam-column joints 12 Fireproof wooden pillar 14 Wood-steel hybrid beam 14A Small end 16 Joint metal fittings 18 Concrete (cement-based solidification material) 20 Core material 22 Fireproof cladding 22A Reinforced gypsum board 22B Fireproof sheet 22C Joint area 24 Finishing Materials 26 Steel Beam 28 Wood cladding 30 Flooring 32 Upper flange 34 Lower flange 36 Web 38 Lag screw 38A Head 38B Threaded section 40 through hole 42 Washer 44 Mounting holes 46 Filler 48 Reinforced gypsum board (non-wood based fireproof covering material) 50 Gusset Plate 52 Base plate 52A Insertion hole 54 Web Plate 56 Plate 58 Through hole 60 Volts 62 steel rod 62A,62B End 64A, 64B, 74 Nut 66 Fireproof joint material 68A, 68B Recess 70 Grout material 72 Fixing plate 76 Fireproof cladding 78 Finishing Materials

Claims

1. A fireproof structure of a column-beam joint is formed by joining a fireproof wooden column including a wooden core material that supports a load and a fireproof covering material provided on the outside of the core material, and a wood-steel hybrid beam including a steel beam and a wooden covering material provided on the outside of the steel beam, via a T-shaped cross-section connecting metal fitting consisting of a gusset plate fixed to the side end of the steel beam and a base plate attached to the fireproof covering material on the side of the fireproof wooden column, A fire-resistant structure of a beam-column joint, characterized in that a cement-based solidification material is filled in the area around the joint metal between the side end of the wood-steel hybrid beam and the side of the fire-resistant wood column.

2. 2. The fireproof structure of a column-beam joint according to claim 1, wherein a fireproof covering material or a wood covering material is provided on the outside of the cement-based solidification material.

3. A fireproof structure for a column-beam joint as described in claim 1 or 2, characterized in that a non-wood-based fire-resistant coating material is provided on the end surface of the wood coating material at the side end of the wood-steel hybrid beam.

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