Fire-resistant structure of column-beam connection

Abstract

To provide a fire-resistant structure constituted of column-beam connection parts which can secure fire resistance efficiency equivalent to that of the column / beam itself.SOLUTION: A fire-resistant structure 100 is constituted of a column-beam connection part that is constructed by connecting: a fire-resistant ligneous column 12, which consists of a load-supporting ligneous column core material 26 and a fire-resistant covering material 28 arranged outside of the aforesaid column core material 26; and a fire-resistant ligneous beam 14, which consists of a load-supporting ligneous beam core material 34 and a fire-resistant covering material 36 arranged outside of the aforesaid beam core material 34; via a joint metal 16 with a T-shape section, which consists of a gusset plate 42 attached to the side end part of the aforesaid fire-resistant ligneous beam 14 and a base plate 44 attached to the side surface of the aforesaid fire-resistant ligneous column 12. The fire-resistant structure's fittings include a first fire-resistant covering material 20 arranged around the aforesaid joint metal 16 and a second fire-resistant covering material 22 arranged on the head surface 14A of the side end part of the aforesaid fire-resistant ligneous beam 14.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] Previously, the applicant of this patent has developed a fire-resistant wooden component (Slim Fire Wood (registered trademark)) that ensures fire resistance for one or two hours by fire-proofing wood that supports a load with reinforced gypsum board and a fire-resistant sheet (see, for example, Patent Document 1). Fire-resistant wooden components are required to ensure that the wood, which is the load-supporting part, does not carbonize during and after the fire heating, and fire resistance is ensured by covering it with a fire-resistant coating material according to the required fire resistance time so that the temperature is below the carbonization temperature of wood, about 200 to 260°C.

[0003] On the other hand, steel components are said to collapse when the temperature of the steel reaches about 550°C, so by covering them with fire-resistant coating materials such as sprayed rock wool, wrapped rock wool, calcium silicate boards, and fire-resistant paint, the rise in steel temperature can be suppressed and fire resistance can be ensured.

[0004] Conventional fireproof structures for beam-column joints are known from, for example, Patent Documents 2 and 3. In Patent Document 2, a covering material is applied to a steel beam at the joint between a wooden column and a steel beam to keep the temperature at which the wooden column will not burn. In Patent Document 3, a high-density wood or a fire-retardant wood is used as a cover to cover the joint between a wooden column and a steel beam as a burner. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6414670 [Patent Document 2] Patent No. 5990425 [Patent Document 3] JP 2018-3475 A Summary of the Invention [Problem to be solved by the invention]

[0006] The applicant of the present patent is currently developing a column-beam joint structure using the above-mentioned fire-resistant wooden members. In the structure in which a fire-resistant wooden column and a fire-resistant wooden beam are joined with a joint metal such as a gusset plate or a splice plate, there are the following problems in ensuring the fire resistance of the column-beam joint.

[0007] The temperature of the steel material in the joining metal exceeds the allowable temperature (average 350°C, maximum 450°C), causing destruction. Heat conduction from the metal joints causes the wood core material, which is the load-bearing member, to carbonize. Gaps occur where materials meet around joints, allowing heat to flow in and charring the wood that supports the load.

[0008] Furthermore, in structures in which steel columns and fire-resistant wooden beams are joined with metal joints such as gusset plates, there was the following problem: Because the allowable temperatures in fire heating of wood and steel members are different, even if the steel members are at or below their collapse temperature of 550°C, heat can be transferred from the fire-resistant covered steel columns and metal joints to the wooden core material of the fire-resistant wooden beams, causing the temperature of the wooden core material to reach 200-260°C and carbonizing it, which could cause it to lose its strength.

[0009] For this reason, there was a need to develop a structure that could ensure fire resistance at column-beam joints using metal joints equivalent to that of the columns and beams alone.

[0010] The present invention has been made in view of the above, and has an object to provide a fire-resistant structure for a column-beam joint that can ensure fire resistance performance equivalent to that of the column and beam alone. [Means for solving the problem]

[0011] 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 wooden column comprising a wooden column core material that supports a load and a fireproof covering material provided on the outside of the column core material, and a fireproof wooden beam comprising a wooden beam core material that supports a load and a fireproof covering material provided on the outside of the beam core material, joined together via a T-shaped cross-section connecting metal fitting consisting of a gusset plate connected to the side end of the fireproof wooden beam and a base plate attached to the side of the fireproof wooden column, characterized in that the fireproof structure comprises a first fireproof covering material provided around the connecting metal fitting between the side end of the fireproof wooden beam and the side of the fireproof wooden column, and a second fireproof covering material provided on the end surface of the side end of the fireproof wooden beam.

[0012] 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, the first fire-resistant covering material and the second fire-resistant covering material include reinforced gypsum board.

[0013] Another fireproof structure of a column-beam joint according to the present invention is a fireproof structure of a column-beam joint formed by joining a fireproof steel column comprising a steel column member and a fireproof covering material provided on the outside of the steel column member, and a fireproof wood beam comprising a wooden beam core material that supports a load and a fireproof covering material provided on the outside of the beam core material, via connecting metal fittings made of gusset plates attached to the side ends of the fireproof wood beam and the sides of the fireproof steel column, characterized in that it comprises a third fireproof covering material provided around the fireproof steel column and the connecting metal fittings in the portions where the connecting metal fittings are attached, and a fourth fireproof covering material provided on the end surface of the side end of the fireproof wood beam.

[0014] Furthermore, another fire-resistant structure of a column-beam joint according to the present invention is characterized in that, in the above-mentioned invention, the third fire-resistant coating material is composed of at least one of a wrap-around rock wool or a ceramic-based fire-resistant coating material, and the fourth fire-resistant coating material is composed of a reinforced gypsum board. Effect of the Invention

[0015] According to the fireproof structure for a column-beam joint of the present invention, a fireproof wooden column including a wooden column core material that supports a load and a fireproof covering material provided on the outside of the column core material, and a fireproof wooden beam including a wooden beam core material that supports a load and a fireproof covering material provided on the outside of the beam core material are joined via a T-shaped cross-section connecting metal fitting consisting of a gusset plate connected to the side end of the fireproof wooden beam and a base plate attached to the side of the fireproof wooden column, and a first fireproof covering material provided around the connecting metal fitting between the side end of the fireproof wooden beam and the side of the fireproof wooden column, and a second fireproof covering material provided on the end surface of the side end of the fireproof wooden beam, thereby achieving the effect of ensuring fire resistance performance equivalent to that of the column-beam alone at the column-beam joint between the fireproof wooden column and the fireproof wooden beam.

[0016] In addition, according to another fire-resistant structure of a column-beam joint of the present invention, the first fire-resistant covering material and the second fire-resistant covering material are composed of reinforced gypsum board, which has the effect of making them relatively easy to install.

[0017] According to another fireproof structure for a column-beam joint of the present invention, a fireproof steel column including a steel column member and a fireproof covering material provided on the outside of the steel column member, and a fireproof wood beam including a wooden beam core material that supports a load and a fireproof covering material provided on the outside of the beam core material are joined via connecting metal fittings made of gusset plates attached to the side ends of the fireproof wood beams and the sides of the fireproof steel column, and the fireproof structure further includes a third fireproof covering material provided around the fireproof steel column and the connecting metal fittings at the parts where the connecting metal fittings are attached, and a fourth fireproof covering material provided on the end surface of the side end of the fireproof wood beam. This has the effect of ensuring fire resistance equivalent to that of the column-beam alone at the column-beam joint between the fireproof steel column and the fireproof wood beam.

[0018] In addition, according to another fire-resistant structure of a column-beam joint of the present invention, the third fire-resistant coating material is composed of at least one of a wrap-around rock wool or a ceramic-based fire-resistant coating material, and the fourth fire-resistant coating material is composed of reinforced gypsum board, thereby achieving the effect of relatively easy installation. [Brief description of the drawings]

[0019] [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 of the first embodiment, and (2) is a vertical cross-sectional view of the second embodiment. [Diagram 2] FIG. 2 is a schematic diagram of the test specimen 1, where (1) is a vertical cross-sectional view and (2) is a horizontal cross-sectional view. [Diagram 3] FIG. 3 is a schematic diagram of the test specimen 2, where (1) is a vertical cross-sectional view and (2) is a horizontal cross-sectional view. [Figure 4] FIG. 4 shows the results of the fire resistance test of the test specimen 1, where (1) is a diagram showing the temperature measurement positions and (2) is a diagram showing the internal temperature transition. [Diagram 5] FIG. 5 shows the results of the fire resistance test of specimen 2, where (1) is a diagram showing the temperature measurement positions and (2) is a diagram showing the internal temperature transition. [Figure 6] FIG. 6 is a vertical sectional view showing a third embodiment of a fireproof structure for a column-beam joint according to the present invention. [Figure 7] FIG. 7 is a vertical sectional view showing a fireproof structure for a column-beam joint according to a fourth embodiment of the present invention. [Figure 8] FIG. 8 shows the results of the fire resistance test of specimen 3, where (1) is a diagram showing the temperature measurement positions and (2) is a diagram showing the internal temperature transition. [Figure 9] FIG. 9 shows the results of the fire resistance test of specimen 4, where (1) is a temperature measurement position diagram and (2) is a diagram showing the internal temperature transition. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] 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.

[0021] In this specification, it is defined that 2-hour fire resistance has been achieved when the following two conditions are met after heating for 2 hours in accordance with the standard heating curve specified in ISO834, stopping the heating, and allowing the material to cool for 24 hours: (1) The fire should stop burning while it is cooling (it should go out on its own without the need for water or other extinguishing measures). (2) After cooling, all of the wooden core material of the pillars or beams remains uncarbonized.

[0022] <Fireproof structure of column-beam joints using fireproof wooden columns and fireproof wooden beams> First, we will explain the first and second embodiments of the present invention that are applied to a column-beam joint between a fire-resistant wooden column and a fire-resistant wooden beam. Both of the first and second embodiments are intended for a structure that ensures a two-hour fire resistance.

[0023] (Embodiment 1) As shown in Fig. 1 (1), a fireproof structure 100 for a column-beam joint according to the first embodiment of the present invention is a structure in which a fireproof wooden column 12 and a fireproof wooden beam 14 are joined via a joint metal 16, and includes a first fireproof covering material 20 provided around the joint metal 16 via a base material 18, and a second fireproof covering material 22 provided on the end surface 14A of the side end of the fireproof wooden beam 14. The first fireproof covering material 20 in the first embodiment is composed only of a reinforced gypsum board 21A.

[0024] (Embodiment 2) As shown in Fig. 1 (2), a fireproof structure 200 for a column-beam joint according to the second embodiment of the present invention uses a fireproof covering material 21 which is a modified version of the first fireproof covering material 20 in the first embodiment, and simplifies the installation specifications. Specifically, the fireproof covering material 21 is fixed to the fireproof wooden beam 14 with screws 24 and adhesive without using a base material 18. The first fireproof covering material 21 in the second embodiment is composed of a reinforced gypsum board 21A and a fireproof sheet 21B. Hereinafter, the members common to the first and second embodiments will be described in detail.

[0025] (Fireproof wooden pillar) The fireproof wooden column 12 is a column with a rectangular cross section, which includes a wooden column core material 26 that supports a load, a fireproof covering material 28 provided on the entire outer circumference of the column core material 26, and a finishing material 30. The column core material 26 can be made of laminated wood such as larch. The fireproof covering material 28 is made of two reinforced gypsum boards 28A provided on the outer side of the column core material 26 and a fireproof sheet 28B provided on the outer side. The fireproof sheet 28B is a thermally expandable fireproof sheet that expands when heated to form a heat insulating layer and exhibits heat insulating performance. The finishing material 30 is made of a wooden board provided on the outer side of the fireproof sheet 28B. In this embodiment, it is assumed that one side of the cross section of the column core material 26 is several hundred mm, the thickness of the fireproof covering material 28 is about 50 mm, and the thickness of the wooden board of the finishing material 30 is 15 mm, but the present invention is not limited to this.

[0026] (Fireproof wooden beam) The fire-resistant wooden beam 14 is a rectangular cross-sectional beam including a wooden beam core material 34 that supports a load, a fire-resistant covering material 36 provided on the entire outer circumference of the beam core material 34 except for the upper surface, and a finishing material 38. The beam core material 34 can be made of laminated wood such as larch. The fire-resistant covering material 36 is made of two reinforced gypsum boards 36A provided on the outer side of the beam core material 34 and a fire-resistant sheet 36B provided on the outer side. The fire-resistant sheet 36B is a thermally expandable fire-resistant sheet that expands when heated to form a heat-insulating layer and exhibits heat-insulating performance. The finishing material 38 is made of a wooden board provided on the outer side of the fire-resistant sheet 36B. In this embodiment, it is assumed that one side of the cross section of the beam core material 34 is several hundred mm, the thickness of the fire-resistant covering material 36 is about 50 mm, and the thickness of the wooden board of the finishing 38 is 15 mm, but the present invention is not limited to this. A floor material 40 is provided on the upper surfaces of the fire-resistant wooden beams 14 and the fire-resistant wooden columns 12. The floor material 40 is made of a floor slab using, for example, reinforced concrete or ALC (lightweight aerated concrete) boards.

[0027] (Metal joints) The joint metal 16 has a T-shaped cross section when viewed from the horizontal plane, and is composed of a gusset plate 42 inserted and fixed into the side end of the beam core material 34, and a base plate 44 connected to the side end of this gusset plate 42 and attached to the surface of the fire-resistant sheet 28B on the side of the fire-resistant wooden column 12. To allow for thermal expansion and deformation of the fire-resistant sheet 28B when heated by a fire, the base plate 44 and the fire-resistant sheet 28B are not in close contact with each other, but a thin layer of air is provided between them.

[0028] The gusset plate 42 is a rectangular steel plate extending in the vertical and horizontal directions, with its upper end positioned lower than the upper end of the base plate 44 and its lower end positioned higher than the lower end of the base plate 44. One side end of the gusset plate 42 is joined to the base plate 44, and the other side end is inserted into the side end of the beam core material 34 and fixed inside the beam core material 34 with bolts or the like (not shown).

[0029] The base plate 44 is a rectangular steel plate extending vertically and longitudinally, and is fixed to the fire-resistant wooden column 12 via a steel rod 46 that is embedded horizontally in the left-right direction in the fire-resistant wooden column 12. The upper end of the base plate 44 is approximately coincident with the upper end of the fire-resistant wooden column 12. The base plate 44 in this embodiment is made of a rectangular steel plate with a width of about 300 mm, a height of 600 mm, and a thickness of about 25 mm. The steel rods 46 are arranged in three locations spaced apart in the vertical direction, two locations at the front and rear of the connection between the gusset plate 42 and the base plate 44, but the present invention is not limited to this, and other layouts and quantities may be used.

[0030] The end 46A of the steel bar 46 on the base plate 44 side passes through an insertion hole provided in the base plate 44. The end 46A is threaded, and nuts 48A, 48B are screwed on both sides of the base plate 44. The end 46A is fixed to the base plate 44 by fastening the nut 48. The nut 48A arranged on the fireproof wooden column 12 side of the base plate 44 is arranged in the joint portion 28C of the fireproof covering material 28. A fireproof joint material 50 is filled around the nut 48A in the joint portion 28C. For example, a silicone-based sealant can be used as the fireproof joint material 50. A recess 52 is formed between the inside of the column core material 26 and the steel bar 46. The recess 52 is filled with a grout material 54 such as non-shrink mortar. The grout material 54 is provided to suppress heat conduction from the steel bar 46 to the column core material 26.

[0031] The other side 46B of the steel bar 46 passes through the anchor plate 56 arranged in the recess 52 and is screwed into a nut (not shown) on the opposite side of the fire-resistant wooden column 12. The steel bar 46 may be, for example, a fully threaded bolt, a round bar with threads cut on both ends, an anchor bolt used in the foundations of buildings, a deformed bar with threads cut on both ends, or the like.

[0032] (First fire-resistant coating material) The first fire-resistant covering material 20 applied to the present embodiment 1 is composed of two reinforced gypsum boards 20A provided so as to cover the periphery of the base plate 44 and the gusset plate 42. A finishing material 60 made of a wooden board is provided on the outside of the first fire-resistant covering material 20. The reinforced gypsum boards 20A act to insulate against heat generated by fire. By covering the joint metal 16 with the first fire-resistant covering material 20, a temperature rise of the joint metal 16 is suppressed, and thus a temperature rise of the column core material 26 and the beam core material 34 can be suppressed.

[0033] The first fire-resistant covering material 21 applied to the second embodiment is composed of two reinforced gypsum boards 21A provided so as to cover the periphery of the base plate 44 and the gusset plate 42, and a fire-resistant sheet 21B provided on the outside thereof. A finishing material 60 made of a wooden board is provided on the outside of the fire-resistant sheet 21B. The reinforced gypsum boards 21A act to insulate against heat generated by fire. The fire-resistant sheet 21B is a thermally expandable fire-resistant sheet that expands when heated to form an insulating layer and exhibits insulating performance. By covering the joint metal 16 with the first fire-resistant covering material 21, the temperature rise of the joint metal 16 can be suppressed, and thus the temperature rise of the column core material 26 and the beam core material 34 can be suppressed.

[0034] A fire-resistant material such as heat-resistant rock wool may be filled into the gap between the joint metal 16 and the first fire-resistant covering material 20 or the fire-resistant covering material 21. This suppresses the temperature rise of the joint metal 16, thereby improving the fire resistance. As the heat-resistant rock wool, for example, high heat-resistant rock wool (product name: Makibee (registered trademark)) manufactured by Nichias Corporation can be used.

[0035] It is desirable that the first fire-resistant covering materials 20, 21 and the finishing material 60 have approximately the same thickness as the fire-resistant covering material 36 and the finishing material 38 of the fire-resistant wooden beam 14, respectively, and are provided continuously thereto so as to prevent gaps. It is also desirable that the ends of the first fire-resistant covering materials 20, 21 and the finishing material 60 on the fire-resistant wooden column 12 side are connected to the fire-resistant covering material 28 of the fire-resistant wooden column 12, respectively, so as to prevent gaps.

[0036] In addition, the thickness of the reinforced gypsum board 20A may be 50 mm or more because the heat shielding performance and heat absorbing effect improve as the thickness of the reinforced gypsum board 20A increases. For example, the reinforced gypsum board 20A may be constructed by laminating three sheets of 21 mm thick reinforced gypsum boards 20A. In addition, the thickness of the finishing material 60 increases, and it is considered that the heat shielding performance improves as the thickness is sufficient for carbonization during heating, and a predetermined fire resistance performance can be ensured without affecting the burning out. The carbonization speed of wood is about 0.6 to 1.0 mm / min, and it is carbonized to about 72 to 120 mm in 2 hours of heating, so the thickness of the finishing material 60 is preferably 15 mm or more and 72 mm or less as the thickness for carbonization during heating. In addition, in this embodiment, it is assumed that the thickness of the reinforced gypsum board 20A is 25 mm (total thickness 50 mm), the thickness of the fireproof sheet 20B is 2 mm, and the thickness of the wooden board of the finishing material 60 is 15 mm, but the present invention is not limited to this.

[0037] (Installation specifications for embodiment 1) In the present embodiment 1, as shown in FIG. 1(1), the first fireproof covering material 20 is fixed to the fireproof wooden beam 14 via the light iron base, which is the base material 18. The light iron base is composed of L-shaped angles 18A that are screwed to the side edge side and the lower edge side of the small surface 14A of the fireproof wooden beam 14, and square studs 18B that are screwed to each L-shaped angle 18A. The reinforced gypsum board 20A that serves as the underlayment of the first fireproof covering material 20 is screwed to the square stud 18B, and the reinforced gypsum board 20A that serves as the overlayment is attached to the square stud 18B via an adhesive applied to the outside of the reinforced gypsum board 20A and screwed to the square stud 18B. The finishing material 60 is attached to the outside of the reinforced gypsum board 20A via an adhesive and screwed. These constructions can be performed on-site. In this embodiment 1, the L-shaped angle 18A is assumed to be L-80 x 40 x t0.8, and the square stud 18B is assumed to be □-90 x 45 x t0.5, but other sizes of light steel bases may be used depending on the dimensions around the joint.

[0038] (Mounting specifications for embodiment 2) In the second embodiment, as shown in Fig. 1 (2), the first fire-resistant covering material 21 is fixed to the beam core material 34 of the fire-resistant wooden beam 14 with screws 24. In this case, the reinforced gypsum board 21A serving as the underlayment of the first fire-resistant covering material 21 is fastened to the beam core material 34 with screws 24, and a board in which the reinforced gypsum board 21A and the fire-resistant sheet 21B serving as the overlayment are integrated is attached to the outside of the first fire-resistant covering material 21, and fixed to the beam core material 34 with the screws 24 and adhesive. The finishing material 60 is attached to the outside of the board via adhesive and fastened with the screws 24. These construction steps can be carried out on-site.

[0039] (Second fire-resistant coating material) The second fireproof covering material 22 is composed of two reinforced gypsum boards 22A provided on the end surface 14A of the beam core material 34 of the fireproof wooden beam 14 close to the joint, and a fireproof sheet 22B provided on the outside. The reinforced gypsum boards 22A act to insulate and absorb heat during fire heating to stop the beam core material from burning. The fireproof sheet 22B is a thermally expandable fireproof sheet that expands when heated to form an insulating layer and exhibits insulating performance. By providing a fireproof covering material with the same covering composition as the fireproof wooden beam 14 on the end surface 14A of the beam core material 34, it is possible to suppress the inflow of heat from the end surface 14A and prevent the beam core material 34, which is a load-supporting member, from carbonizing.

[0040] The reinforced gypsum board 22A and the fireproof sheet 22B are preferably of the same thickness as the reinforced gypsum board 36A and the fireproof sheet 36B of the fireproof wooden beam 14, and their ends are preferably connected to the reinforced gypsum board 36A and the fireproof sheet 36B of the fireproof wooden beam 14 via joints 64. In this case, in order to prevent carbonization of the beam core material 34 due to the inflow of heat from the joints 64 of the reinforced gypsum boards 36A and 22A, it is preferable to attach the reinforced gypsum board 22A so that the joints 64 are stepped as shown in Figure 1. It is preferable to apply a heat-resistant aluminum tape or the like to the joints 64 and corners.

[0041] Since the fire resistance performance improves as the thickness of the reinforced gypsum board 22A increases, the thickness of the reinforced gypsum board 22A may be 50 mm or more. For example, the reinforced gypsum board 22A may be constructed by stacking three reinforced gypsum boards 22A each having a thickness of 21 mm. In this embodiment, the reinforced gypsum board 22A is assumed to have a thickness of 25 mm (total thickness 50 mm) and the fireproof sheet 22B is assumed to have a thickness of 2 mm, but the present invention is not limited to this.

[0042] According to the above-mentioned first and second embodiments, the fire resistance performance of the fire-resistant wooden column 12 and the fire-resistant wooden beam 14 alone can be secured at the column-beam joint between the fire-resistant wooden column 12 and the fire-resistant wooden beam 14. This ensures the fire safety of the building using the fire-resistant wooden column 12 and the fire-resistant wooden beam 14. Furthermore, by using a dry fire-resistant coating material for the first fire-resistant coating material 20, 21 and the second fire-resistant coating material 22 around the column-beam joint, the time required for curing can be reduced compared to the case of a wet fire-resistant coating material, and the absence of drying time leads to a shortening of the construction period. In addition, since the construction is relatively easy, the construction time and cost can be reduced.

[0043] (Verification of Effects of the First and Second Embodiments) Next, a fire resistance test conducted to verify the effects of the above-mentioned first and second embodiments and the results will be described.

[0044] Test specimens simulating the above fire-resistant structures 100 and 200 were prepared, and a fire resistance test was conducted to confirm the fire resistance performance. The fire resistance test was conducted by placing the test specimen in a furnace, heating it for 2 hours according to the standard heating curve specified in ISO834, and then cooling it in the furnace for 24 hours. Test specimens were prepared as follows: Test specimen 1, which uses a light steel base, and Test specimen 2, which does not use a light steel base. Figure 2 shows an overview of Test specimen 1, and Figure 3 shows an overview of Test specimen 2. The fire-resistant wooden columns 12 and joint metals 16 of Test specimens 1 and 2 were the same as those used in the above fire-resistant structures 100 and 200. To simplify the production of the test specimens, the core material of the fire-resistant wooden beams 14 was composed of light steel base and calcium silicate boards instead of wood.

[0045] Test specimen 1 corresponds to fire-resistant structure 100, with the left side of Fig. 2 corresponding to Example 1-1 of the present invention, and the right side corresponding to Example 1-2. Example 1-1 is one in which heat-resistant rock wool is filled around joint metal 16, while Example 1-2 is one in which no filling is done. In the center of the interior of fire-resistant wooden column 12, board-shaped fire-resistant material 32 is layered to divide the core material into left and right, providing thermal insulation between Examples 1-1 and 1-2.

[0046] Test specimen 2 corresponds to fire-resistant structure 200, with the left side of Fig. 3 corresponding to Example 2-1 of the present invention and the right side corresponding to Example 2-2. Example 2-1 is filled with heat-resistant rock wool around joint metal 16, while Example 2-2 is not filled with heat. Board-shaped fire-resistant material 32 is layered in the center of the inside of fire-resistant wooden column 12 to divide the core material into left and right, providing thermal insulation between Examples 2-1 and 2-2.

[0047] Figure 4(1) shows the temperature measurement positions of specimen 1, and (2) shows the temperature measurement results. Figure 5(1) shows the temperature measurement positions of specimen 2, and (2) shows the temperature measurement results. Figures 4(1) and 5(1) show the maximum temperatures at each temperature measurement position. The temperature measurement results in Figures 4(2) and 5(2) use the maximum temperature values ​​measured at each temperature measurement position P1 to P6.

[0048] As shown in FIG. 4, in the test specimen 1, the maximum temperature of the column core material and the beam core material around the joint was 200°C or less. In addition, the maximum temperature of the joint metal in contact with the beam core material was 100°C or less, and neither of them reached the temperature at which wood would be carbonized. In addition, as shown in FIG. 5, in the test specimen 2, the maximum temperature of the column core material and the beam core material around the joint was 200°C or less. In addition, the maximum temperature of the joint metal in contact with the beam core material was 100°C or less, and neither of them reached the temperature at which wood would be carbonized. Furthermore, in both test specimens 1 and 2, no discoloration or carbonization was observed on the surface of the column core material around the joint. From the above, it was confirmed that the fire-resistant coating specifications around the joints of Examples 1-1, 1-2, 2-1, and 2-2 have a fire resistance performance of 2 hours.

[0049] <Fireproof structure of column-beam joints made of fireproof steel columns and fireproof wooden beams> Next, a description will be given of embodiments 3 and 4 of the present invention, which are applied to a column-beam joint between a fire-resistant steel column and a fire-resistant wood beam. Both embodiments 3 and 4 are intended for a structure that ensures a two-hour fire resistance.

[0050] (Embodiment 3) As shown in FIG. 6, the fire-resistant structure 300 of a column-beam joint according to the third embodiment of the present invention is a structure formed by joining a fire-resistant steel column 66 and a fire-resistant wooden beam 14 via a connecting metal member 68, and is provided with a third fire-resistant coating material 70 provided around the fire-resistant steel column 66 and the connecting metal member 68 at the portion where the connecting metal member 68 is attached, and a fourth fire-resistant coating material 72 provided on the end surface 14A of the side end of the fire-resistant wooden beam 14.

[0051] (Fire-resistant steel columns) The fire-resistant steel column 66 is configured to include a steel pipe column 74 (steel member) with a circular cross section, and fire-resistant paint 76 (fire-resistant coating material) applied to the outside of the steel pipe column 74. An upper diaphragm 78 and a lower diaphragm 80 are provided at the column head of the fire-resistant steel column 66. The fire-resistant paint 76 is applied to the lower area of ​​the steel pipe column 74 excluding the column head. In this embodiment, the steel pipe column 74 has a diameter of φ219.5 mm, a thickness of 25 mm (cross-sectional shape factor of 45.1 mm), and a cross-sectional shape coefficient of 45.1 mm. -1 ) is assumed, but the present invention is not limited to this. Also, the steel frame member of the present invention is not limited to a steel pipe column with a circular cross section, and may be of other cross-sectional shapes.

[0052] (Fireproof wooden beam) The fire-resistant wooden beam 14 is a rectangular beam that includes a wooden beam core material 34 that supports the load, a fire-resistant covering material 36 that is provided on the entire outer periphery except for the top surface of the beam core material 34, and a finishing material 38. The fire-resistant wooden beam 14 can be constructed in the same manner as in the first and second embodiments.

[0053] (Metal joints) The connecting metal fittings 68 are made of gusset plates 82 attached to the side surfaces of the column heads of the fire-resistant steel columns 66. The gusset plate 82 is a generally rectangular steel plate extending in the up-down and left-right directions between the upper diaphragm 78 and the lower diaphragm 80, and its upper end is positioned away from the underside of the floor material 40. The side ends of the gusset plate 82 are inserted into the side ends of the beam core material 34 and fixed to the inside of the beam core material 34 with bolts or the like (not shown). In this embodiment, the gusset plate 82 has a height of 440 mm and a thickness of 12 mm (cross-sectional shape coefficient 171.2 mm). -1 ) is assumed, but the present invention is not limited to this.

[0054] (Third fire-resistant coating material) The third fire-resistant covering material 70 is made of wrapped rock wool (wrapped rock wool) and is fastened to the steel pipe pole 74 by a number of welding pins 84. The covering thickness of the wrapped rock wool on the steel pipe pole 74 is 105 mm. It is preferable to arrange the wrapped rock wool in a stack of multiple sheets. For example, if the thickness of the underlay is 65 mm and the thickness of the toplay is 40 mm, and they are wrapped around the steel pipe pole 74, a total thickness of 105 mm can be achieved. Note that the larger the cross-sectional shape coefficient of the steel pipe pole 74, the easier it is for the steel temperature to rise. Therefore, when the cross-sectional shape coefficient is 45.1 mm, the steel temperature is increased. -1 The specified fire resistance is guaranteed if the steel material has the following dimensions. As the wrapped rock wool, for example, high heat resistant rock wool (product name: Makibee (registered trademark)) manufactured by Nichias Corporation can be used.

[0055] The thickness of the rock wool wrapped around the gusset plate 82 is also set to 105 mm. As in the case of the steel pipe column 74, this can be achieved by a lower layer of 65 mm and an upper layer of 40 mm. Note that the larger the cross-sectional shape factor of the gusset plate 82, the easier it is for the steel temperature to rise. -1 The specified fire resistance is guaranteed if the steel dimensions are as follows. The thicker the wrapped rock wool is, the better the insulation performance will be, so the covering thickness may be 105 mm or more.

[0056] The coverage area of ​​the wrapped rock wool covering the column head of the steel pipe column 74 is desirably 900 mm or more from the underside of the floor. In addition, it is desirable that the fireproof paint 76 covering the steel pipe column 74 and the wrapped rock wool overlap by 10 mm or more in the vertical direction.

[0057] (Fourth fire-resistant coating material) The fourth fireproof covering material 72 is composed of two reinforced gypsum boards 72A provided on the end surface 14A of the beam core material 34 of the fireproof wooden beam 14 close to the joint, and a fireproof sheet 72B provided on the outside. The reinforced gypsum boards 72A act to insulate the beam core material 34 during fire heating and stop it from burning. The fireproof sheet 72B is a thermally expandable fireproof sheet that expands when heated to form an insulating layer and exhibits insulating performance. By providing a fireproof covering material with the same covering composition as the fireproof wooden beam 14 on the end surface 14A of the beam core material 34, it is possible to suppress the inflow of heat from the end surface 14A and prevent the beam core material 34, which is a load-supporting member, from carbonizing.

[0058] The reinforced gypsum board 72A and the fireproof sheet 72B are preferably of the same thickness as the reinforced gypsum board 36A and the fireproof sheet 36B of the fireproof wooden beam 14, and their ends are preferably connected to the reinforced gypsum board 36A and the fireproof sheet 36B of the fireproof wooden beam 14 via joints 64. In this case, in order to prevent carbonization of the beam core material 34 due to the inflow of heat from the joints 64 of the reinforced gypsum boards 72A and 36A, it is preferable to attach the reinforced gypsum board 72A so that the joints 64 are stepped. It is preferable to apply a heat-resistant aluminum tape or the like to the joints 64 and corners.

[0059] Since the fire resistance performance improves as the thickness of the reinforced gypsum board 72A increases, the thickness of the reinforced gypsum board 72A may be 50 mm or more. For example, the reinforced gypsum board 72A may be constructed by stacking three reinforced gypsum boards 72A each having a thickness of 21 mm. In this embodiment, the reinforced gypsum board 72A is assumed to have a thickness of 25 mm (total thickness 50 mm) and the fireproof sheet 72B is assumed to have a thickness of 2 mm, but the present invention is not limited to this.

[0060] According to the above-mentioned third embodiment, the fire resistance performance of the fire-resistant steel column 66 and the fire-resistant wooden beam 14 alone can be secured at the column-beam joint between the fire-resistant steel column 66 and the fire-resistant wooden beam 14. This ensures the fire safety of the building using the fire-resistant steel column 66 and the fire-resistant wooden beam 14. Furthermore, by using a dry fire-resistant coating material for the third and fourth fire-resistant coating materials 70, 72 around the column-beam joint, the time required for curing can be reduced compared to the case of a wet fire-resistant coating material, and the absence of drying time leads to a reduction in the construction period. In addition, since the workability is excellent, the work and cost of construction can be reduced. In addition, by using the fire-resistant paint 76 on the fire-resistant steel column 66, the appearance can be improved and the design can be improved.

[0061] (Embodiment 4) As shown in FIG. 7, the fire-resistant structure 400 of a beam-column joint according to the fourth embodiment of the present invention has a structure in which, in the third fire-resistant coating material 70 in the above-mentioned third embodiment, a wet ceramic-based fire-resistant coating material 70A is applied thickly instead of wrapped rock wool to increase the coating thickness.

[0062] The thickness of the ceramic fire-resistant coating material for the steel pipe pole 74 is 40 mm or more, which corresponds to a 3-hour fire resistance. The larger the cross-sectional shape factor of the steel pipe pole 74, the easier it is for the steel temperature to rise. -1 The specified fire resistance is guaranteed if the steel dimensions are as follows.

[0063] The thickness of the ceramic fire-resistant coating material for the gusset plate 82 is 40 mm or more, which corresponds to a 3-hour fire resistance. The larger the cross-sectional shape factor of the gusset plate 82, the easier it is for the steel temperature to rise. -1 The specified fire resistance is guaranteed if the steel dimensions are as follows. Note that the thicker the ceramic fireproof coating material, the better the insulation performance, so the coating thickness may be 40 mm or more.

[0064] The coverage area of ​​the ceramic fire-resistant coating material applied to the column head of the steel pipe column 74 is desirably 900 mm or more from the underside of the floor. In addition, it is desirable that the fire-resistant paint 76 that coats the steel pipe column 74 and the ceramic fire-resistant coating material overlap by 10 mm or more in the vertical direction.

[0065] According to the above-mentioned fourth embodiment, at the column-beam joint between the fireproof steel column 66 and the fireproof wooden beam 14, it is possible to ensure the same fire resistance as that of the fireproof steel column 66 and the fireproof wooden beam 14 alone. This makes it possible to guarantee the fire safety of a building using the fireproof steel column 66 and the fireproof wooden beam 14. In addition, by using fireproof paint or a ceramic-based fireproof coating material for the fireproof steel column 66, the appearance can be improved and the design can be enhanced.

[0066] (Verification of Effects of the Third and Fourth Embodiments) Next, a fire resistance test conducted to verify the effects of the above-mentioned third and fourth embodiments and the results thereof will be described.

[0067] Test specimens simulating the above fireproof structures 300 and 400 were prepared, and a fireproof test was conducted to confirm the fireproof performance. The fireproof test was conducted by placing the test specimen in a furnace, heating it for 2 hours according to the standard heating curve specified in ISO834, and then cooling it in the furnace for 24 hours. Test specimens were prepared as test specimen 3 using wrapped rock wool and test specimen 4 using a ceramic fireproof coating material. Test specimens 3 and 4 correspond to Examples 3 and 4 of the present invention, respectively. The fireproof steel columns 66 and joint metals 68 of test specimens 3 and 4 were the same as those used in the above fireproof structures 300 and 400. In order to simplify the production of the test specimens, the core material of the fireproof wooden beams 14 was composed of light iron substrate and calcium silicate board instead of wood.

[0068] Figure 8(1) shows the temperature measurement positions of test piece 3, and (2) shows the temperature measurement results. Figure 9(1) shows the temperature measurement positions of test piece 4, and (2) shows the temperature measurement results. Figures 8(1) and 9(1) show the maximum temperature at each temperature measurement position. The temperature measurement results in Figures 8(2) and 9(2) use the maximum temperature values ​​measured at each temperature measurement position P1 to P5.

[0069] As shown in Figures 8 and 9, in both specimens 3 and 4, the maximum temperature of the beam core material around the joint was below 260°C, and did not reach the temperature at which wood would be carbonized. In addition, the temperature of the gusset plate in contact with the beam core material was also below 260°C, confirming the effectiveness of the fire-resistant coating material. From the above, it was confirmed that the fire-resistant coating specifications around the joints in Examples 3 and 4 have a fire resistance performance of 2 hours.

[0070] 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 wooden column comprising a wooden column core material that supports a load and a fireproof covering material provided on the outside of the column core material, and a fireproof wooden beam comprising a wooden beam core material that supports a load and a fireproof covering material provided on the outside of the beam core material, via a T-shaped connecting metal member consisting of a gusset plate connected to the side end of the fireproof wooden beam and a base plate attached to the side of the fireproof wooden column, and further comprising a first fireproof covering material provided around the connecting metal member between the side end of the fireproof wooden beam and the side of the fireproof wooden column, and a second fireproof covering material provided on the end surface of the side end of the fireproof wooden beam, so that the fireproof structure can ensure fire resistance equivalent to that of the column-beam alone at the column-beam joint between the fireproof wooden column and the fireproof wooden beam.

[0071] In addition, according to another fire-resistant structure of a column-beam joint of the present invention, the first fire-resistant covering material and the second fire-resistant covering material are composed of reinforced gypsum board, and therefore can be installed relatively easily.

[0072] According to another fireproof structure for a column-beam joint of the present invention, a fireproof steel column including a steel column member and a fireproof covering material provided on the outside of the steel column member, and a fireproof wood beam including a wooden beam core material that supports a load and a fireproof covering material provided on the outside of the beam core material are joined via connecting metal fittings made of gusset plates attached to the side ends of the fireproof wood beams and the sides of the fireproof steel column, and the fireproof structure further includes a third fireproof covering material provided around the fireproof steel column and the connecting metal fittings at the parts where the connecting metal fittings are attached, and a fourth fireproof covering material provided on the end surface of the side end of the fireproof wood beam. Therefore, the fireproof structure can ensure fire resistance equivalent to that of the column-beam alone at the column-beam joint between the fireproof steel column and the fireproof wood beam.

[0073] In addition, according to another fire-resistant structure of a column-beam joint of the present invention, the third fire-resistant coating material is composed of at least one of a wrap-around rock wool or a ceramic-based fire-resistant coating material, and the fourth fire-resistant coating material is composed of reinforced gypsum board, so that it can be installed relatively easily.

[0074] The "Sustainable Development Goals (SDGs)" are 17 international goals that were adopted at the United Nations Summit in September 2015. The fireproof structure of the column-beam joint according to this embodiment can contribute to the achievement of, for example, "11. Sustainable urban and human settlements" among the 17 SDGs. [Industrial Applicability]

[0075] As described above, the fireproof structure of the column-beam joint according to the present invention is useful for the joint between a fireproof wooden column or a fireproof steel column and a fireproof wooden beam, and is particularly suitable for ensuring fireproof performance equivalent to that of the column-beam alone. [Explanation of symbols]

[0076] 12 Fireproof wooden pillar 14 Fireproof wooden beams 14A Small end 16,68 Metal joints 18 Base material 20,21 First fire-resistant coating material 20A, 21A, 22A, 28A, 36A Reinforced gypsum board 21B, 22B, 28B, 36B Fireproof sheet 22 Secondary fire-resistant coating material 24 Bis 26 Pillar core material 28,36 Fireproof cladding 28C Joint area 30,38,60 Finishing materials 32 Fireproof materials 34 Beam core material 40 Flooring 42,82 Gusset plate 44 Base Plate 46 steel rod 64 Joint 66 Fireproof Steel Column 70 Third fireproof coating material 72 Fourth Fire Resistant Coating Material 74 Steel pipe column (steel member) 76 Fire-resistant paint (fire-resistant coating material) 84 Welding pin 100,200,300,400 Fireproof structure of column-beam joints

Claims

1. A fireproof structure of a column-beam joint formed by joining a fireproof wooden column comprising a wooden column core material supporting a load and a fireproof covering material provided on the outside of the column core material, and a fireproof wooden beam comprising a wooden beam core material supporting a load and a fireproof covering material provided on the outside of the beam core material, via a T-shaped cross-section joint metal fitting consisting of a gusset plate connected to a side end of the fireproof wooden beam and a base plate attached to a side of the fireproof wooden column, A fire-resistant structure of a column-beam joint, characterized in that it comprises a first fire-resistant coating material provided around the joint metal between the side end of the fire-resistant wooden beam and the side of the fire-resistant wooden column, and a second fire-resistant coating material provided on the end face of the side end of the fire-resistant wooden beam.

2. 2. The fireproof structure for a column-beam joint according to claim 1, wherein the first fireproof covering material and the second fireproof covering material include reinforced gypsum boards.

3. A fireproof structure of a column-beam joint formed by joining a fireproof steel column including a steel column member and a fireproof covering material provided on the outside of the steel column member, and a fireproof wood beam including a wooden beam core material supporting a load and a fireproof covering material provided on the outside of the beam core material, via a connecting metal fitting made of a gusset plate attached to the side end of the fireproof wood beam and the side of the fireproof steel column, A fireproof structure of a column-beam joint, characterized in that it comprises a third fireproof coating material provided around the fireproof steel column and the connecting metal at the portion where the connecting metal is attached, and a fourth fireproof coating material provided on the end surface of the side end of the fireproof wood beam.

4. The fireproof structure of a column-beam joint as described in claim 3, characterized in that the third fireproof coating material is composed of at least one of a wrap-around rock wool or a ceramic-based fireproof coating material, and the fourth fireproof coating material is composed of a reinforced gypsum board.

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