JP2017179915A - Fire-resistant structure for connection part of fire-resistant beam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fire-resistant structure for a connection part of a fire-resistant beam that enables the fire-resistant beam to be installed readily without impairing a fire-resistant function of a beam with fire-resistant covering, by connecting an edge part of the fire-resistant beam to a support member using a connection metal fitting.SOLUTION: A fire-resistant structure 10 is for a connection between a fire-resistant beam 11 and a receiving beam 20, with connection metal fittings 32, 33 interposed in between. The fire-resistant beam 11 comprises a structural support beam 12 and a pair of beams 13 with fire-resistant covering. A support part covering member 21 is fitted to cover the receiving beam 20. The covering part connection metal fitting 33 is disposed in a central part in a width direction of the beam 13 with fire-resistant covering, and has a projecting plate part 33a projecting from the receiving beam 20 by a length not exceeding a length L and inserted into a slit part 13a formed on an edge surface of the beam 13 with fire-resistant covering, the length L being derived by subtracting a depth D of a design burning region of the beam 13 with fire-resistant covering from a width B of the beam 13 with fire-resistant covering.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a fireproof structure at a joint portion of a fireproof beam, and more particularly, to a fireproof structure at a joint portion of a fireproof beam used in a wooden building having a fire resistance performance equal to or higher than a 45-minute quasi-refractory structure to a support member via a joint hardware. .

  For example, in a Japanese residential building, a design in which the surface of a wooden beam, which is a structural material, is exposed indoors is preferred. In the wood space where such a beam is exposed, the exposed part of the beam, which is a structural material, is directly heated and burns in the event of a fire. However, it is necessary to secure the performance that does not collapse while withstanding the load that supports the building.

  For this reason, for example, when designing a beam with a quasi-refractory structure made of wood, it is common to perform a burnout design as shown in the Building Standards Act “Ministry of Construction No. 1358, No. 1358, Section 2 of the H12”. is there. The burn-in design adds a predetermined burn-in area (for example, 35 mm for the laminated wood in the quasi-refractory structure 45 minutes, for example 45 mm for the laminated material in the 1-hour fire-resistant structure) to the cross section required for the short-term structural strength during the earthquake. Although it is a design, this additional burn-in cannot be included in the structure calculation, so the structure calculation becomes inefficient.

  In addition, the cross-section of the beam after the burnout design tends to be a large cross-section, and generally exceeds the cross-sectional width of structural wood having a width of, for example, 105 mm or 120 mm. Is often treated as a special order, so it takes a lot of labor and time to produce structural wood including splicing.

  In response to these problems, for example, when designing an apparent beam in a wooden quasi-refractory structure, the refractory structure of the beam that can maintain the refractory performance of 45 minutes or more without using the burn-in design. Has been developed (see, for example, Patent Document 1). In addition, a fire-resistant structure of a beam has been developed that can be designed for burn-in without combining custom-made structural timber with a large cross-section of structural timber (for example, And Patent Document 2).

JP 2014-9499 A JP 2013-204261 A

  In the fireproof structure of a beam described in Patent Document 2, a structural support beam that bears structural strength and a side surface on both sides of the structural support beam are arranged by combining structural wood that is generally distributed. In addition, as a composite beam composed of a pair of fire-resistant covered beams that serve as a burn-in part, it is possible to form a fire-resistant beam considering the burn-in part, and these structural support beams and fire-resistant coated beams are By using a known beam receiver having a U-shaped cross-sectional shape, it is possible to easily support each of the ends by joining, for example, a receiving beam serving as a beam support member.

  However, when the end of the fireproof coated beam is joined to the support member using a beam receiver having a U-shaped cross-sectional shape, the metal beam receiver is a thermal bridge in the conventional joining method using the beam receiver. As a result, the burning of the fire-resistant coated beam is likely to spread, and the fire-resistant function of the fire-resistant coated beam may be impaired.

  In the present invention, the end of the fire-resistant beam is joined to the support member using a beam receiving metal fitting (joint metal fitting) without impairing the fire-resistant function of the fire-resistant coated beam arranged to cover both side surfaces of the structural support beam. An object of the present invention is to provide a fireproof structure at a joint of a fireproof beam that can easily install the fireproof beam in a wooden building having a fire resistance of 45 minutes or more.

  The present invention is a fire-resistant structure in a joint part of a fire-resistant beam used in a wooden building having a fire resistance of 45 minutes or more quasi-refractory structure to a support member via a joint hardware, and the fire-resistant beam is a structural support beam And a fireproof covering beam disposed on both sides of the structural support beam, and the structural support beam is joined to the support member via a structural part joint hardware fixed to the support member. In the fire-resistant coated beam, a pair of overhanging plate portions of a covering-joint metal fitting having a U-shaped cross section fixed to a support member is inserted into a slit portion formed on an end surface portion of the fire-resistant coated beam. The drift pin is driven from the side surface of the end portion of the fireproof coated beam, and is joined to the support member, and the support member covering member is attached to cover the support member. The coating The joint metal is disposed at the center in the width direction of the fireproof coated beam, and the projecting plate portion extends from the support member to the depth of the design burn-in area of the fireproof coated beam from the width of the fireproof coated beam. By providing a fireproof structure and fireproof structure at the joint of the fireproof beam that protrudes with a length not exceeding the length of pulling and inserted into the slit portion formed in the end face of the fireproof coated beam, Is achieved.

  And the fireproof structure in the joint part of the fireproof beam of the present invention is such that the structural part joint hardware has a U-shaped cross-sectional shape, and the structural support beam has a U-shaped cross-sectional shape of the structural part joint hardware. The drift pin is driven from the side surface of the end portion of the structural support beam in a state where the pair of overhanging plate portions are inserted into the slit portions formed in the end surface portion of the structural support beam. It is preferable that it is joined to the member.

  Further, in the fireproof structure in the joint portion of the fireproof beam according to the present invention, the overhanging plate portion of the structural joint metal fitting has a depth of the design burn-in area of the fireproof coated beam from the width of the fireproof coated beam from the support member. It is preferable that the protrusion protrudes with a length not exceeding the drawn length and is inserted into a slit portion formed in the end surface portion of the structural support beam.

  Furthermore, the fireproof structure in the joint portion of the fireproof beam according to the present invention is the drift pin engagement hole or the drift pin provided in the overhang plate portion of the structural portion joint metal fitting. In a state in which the position of the engagement notch and the position of the drift pin engagement hole or drift pin engagement notch provided in the overhang plate portion of the covering portion joint metal match when viewed from the width direction of the fireproof beam. A long drift pin attached to the support member and having a length capable of penetrating the support member at the same time is driven from the side surface of the end portion of the fire-resistant coated beam, so that the structural support beam and the fire-resistant coating are provided. It is preferable that the beam is integrally joined to the support member.

  Furthermore, in the fireproof structure in the joint portion of the fireproof beam of the present invention, it is preferable that the support member to which the fireproof beam is joined is a receiving beam or a receiving column.

  Moreover, in the fireproof structure in the joint portion of the fireproof beam of the present invention, it is preferable that the support member to which the fireproof beam is joined is a frame member of a wall.

  According to the fire-resistant structure in the joint of the fire-resistant beam of the present invention, the end of the fire-resistant beam is bonded to the end of the fire-resistant beam by using a joint hardware without impairing the fire-resistant function of the fire-resistant coated beam arranged on both sides of the structural support beam. A fire-resistant beam can be easily installed in a wooden building having a fire resistance performance equal to or higher than that of a 45-minute quasi-refractory structure by joining to a support member.

1 is a schematic perspective view illustrating an indoor space of a wooden building, illustrating a fireproof beam installed using a fireproof structure at a joint portion of a fireproof beam according to a preferred embodiment of the present invention. It is the A section expansion fracture perspective view of Drawing 1 explaining a fireproof beam installed using a fireproof structure in a joined part of a fireproof beam concerning one desirable embodiment of the present invention. It is a principal part plane sectional view which looked at FIG. 2 from upper direction explaining the fireproof structure in the junction part of the fireproof beam which concerns on preferable one Embodiment of this invention. It is a principal part disassembled perspective view explaining the fireproof structure in the junction part of the fireproof beam which concerns on preferable one Embodiment of this invention. (A) is a perspective view of a structure part joining metal fitting and a coating | coated part joining metal fitting, (b) is a rear view. (A), (b) is explanatory drawing of a design burn-in area. (A) is a schematic perspective view illustrating a fireproof structure when a support member to which a fireproof beam is joined is a receiving post, and (b) is a schematic cross-sectional view along BB in (a). .

  As shown in FIG. 1, the fire-resistant structure at the joint of the fire-resistant beams according to a preferred embodiment of the present invention is a wooden building having a fire resistance of 45 minutes or more, such as a residential building by a frame construction method. In addition, the end of the refractory beam 11 that constitutes the frame structure that supports the weight of the building itself, wind load, seismic load, etc. is connected to the receiving beam 20 as a support member via joint hardware 32 and 33 (see FIG. 4). It is adopted as a structure for joining. In the present embodiment, the refractory beam 11 is an exposed beam that is exposed from the ceiling surface of the room to the indoor space, and is an excellent tree due to the surface of the refractory beam 11 exposed as the exposed beam. The structural support beam 12 and a pair of fireproof coated beams arranged on both sides of the structural support beam 12 so that the fireproof performance of 45 minutes or more can be exhibited while maintaining the texture and design in the indoor space. 13 is a composite beam that can be designed to burn out (see FIGS. 2 and 3).

  In this embodiment, the structural support beam 12 and the pair of refractory coated beams 13 constituting the refractory beam 11 are joined to the receiving beam 20 via metal joints 32 and 33, respectively. The fireproof structure 10 in the joint portion of the fireproof beam according to the embodiment avoids that the burning of the fireproof covering beam 13 is easily spread by the joining metal piece 33 that joins the fireproof covering beam 13 being a thermal bridge at the time of fire heating. Thus, the fireproof function of the fireproof coated beam 13 can be effectively exhibited without being impaired.

  And the fire-resistant structure 10 in the junction part of the fire-resistant beam of this embodiment is a support member via the joint hardware 32 and 33 of the fire-resistant beam 11 used in the wooden building provided with the fire resistance performance more than 45 minutes quasi-fire resistant structure. As shown in FIGS. 2 to 4, the fireproof beam 11 includes a structural support beam 12 and a pair of fireproof coatings disposed on both sides of the structural support beam 12. The structural support beam 12 is fixed to the receiving beam 20, and a pair of overhanging plate portions 32a of a structural portion joint metal 32 having a preferably U-shaped cross section is formed by the structural support beam. The drift pin 30 is driven from the side surface of the end portion of the structural support beam 12 while being inserted into the slit portion 12a formed on the end surface portion 12, so that it is joined to the receiving beam 20 and fireproof. Coated beam 3 is a state in which a pair of overhanging plate portions 33 a of a covering portion joint metal 33 having a U-shaped cross section fixed to the receiving beam 20 is inserted into a slit portion 13 a formed at an end surface portion of the fireproof covering beam 13. Thus, the drift pin 30 is driven from the side surface of the end portion of the refractory coated beam 13 so that it is joined to the receiving beam 20.

  Covering the receiving beam 20 which is a support member, a support portion covering member 21 is attached in a state where the end surface is in contact with the side surface at the end portion of the fireproof covering beam 13 (see FIGS. 2 and 3). The joint metal part 33 is disposed at the center in the width direction of the fireproof covering beam 13, and the overhanging plate part 33 a is designed from the receiving beam 20 to the design burn-in area of the fireproof covering beam 13 from the width B of the fireproof covering beam 13. It protrudes with a length not exceeding a length L obtained by subtracting the depth D, and is inserted into a slit portion 13 a formed on the end surface portion of the fireproof covering beam 13.

  Further, in this embodiment, the overhang plate portion 32a of the structural joint metal fitting 32 is also designed from the receiving beam 20, the width B of the fireproof covering beam 13, and the design burn of the fireproof covering beam 13, as shown in FIGS. It protrudes with a length not exceeding the length L minus the depth D of the marginal region, and is inserted into a slit portion 12 a formed in the end surface portion of the structural support beam 12.

  Further, in the present embodiment, the structure joint metal fitting 32 and the covering part metal fitting 33 are arranged with the positions of the drift pin engagement holes 32d and the drift pin engagement notches 32e provided in the overhang plate portion 32a of the structure joint metal fitting 32. The position of the drift pin engaging hole 33d and the drift pin engaging notch 33e provided in the projecting plate portion 33a of the covering portion joint metal 33 matches the position of the receiving beam 20 in a state where they match with each other when viewed from the width direction of the refractory beam 11. The long drift pin 30 which is attached and has a length capable of penetrating them at the same time is driven from the side surface of the end portion of the fire-resistant coated beam 13 so that the structural support beam 12 and the fire-resistant coated beam 13 are connected. It is integrally joined to the receiving beam 20 (see FIG. 3).

  In this embodiment, the fire-resistant beam 11 is formed including the structural support beam 12 and the pair of fire-resistant coated beams 13 as described above. The structural support beam 12 is, for example, a wooden square timber made of Scots pine timber, which is a symmetric different grade composition timber. As shown in FIG. 2, for example, the structure support beam 12 has a length of about 105 mm in width and about 240 mm in height. It has a rectangular cross-sectional shape and a length of about 3600 mm. As shown in FIG. 4, a notch recess 12b having a substantially U-shaped cross section including a pair of parallel slits 12a cut in a direction perpendicular to the end face is formed on the end face of the structural support beam 12. Is formed. That is, the notch recess 12b is formed from an end surface notch portion 12c that is thinly cut along the end surface of the structural support beam 12 by an intermediate side portion having a substantially U-shaped cross section, and from both ends of the end surface notch portion 12c. It consists of a slit portion 12a formed by a pair of side portions having a substantially U-shaped cross section, which is cut perpendicularly in the axial direction of the structural support beam 12.

  In addition, the side surface of the end portion of the structural support beam 12 adjacent to the end surface portion where the notch recess 12b is formed is attached to the slit portion 12a so as to penetrate between both side surfaces. Of the plurality of drift pin engagement holes 32d and drift pin engagement notches 32e formed in the pair of overhang plate portions 32a of the joint metal fitting 32, some selected drift pin engagement holes 32d and drift pin engagements A drift pin driving hole 12d is formed at a position matching the notch 32e.

  As shown in FIGS. 4, 5 (a), and 5 (b), the structural part joint metal 32 for joining the structural support beam 12 to the receiving beam 20 as a support member is bent into a metal plate member or the like. Is a plate-like joint hardware formed so as to have a substantially U-shaped cross-sectional shape. The structure joint metal fitting 32 includes an abutting plate portion 32b having an intermediate side portion having a substantially U-shaped cross section and an overhanging plate portion 32a having a pair of side portions having a substantially U-shaped cross section. In the contact plate portion 32b, bolt fastening holes 32c are formed, for example, at three positions at positions corresponding to the bolt insertion holes 20a (see FIG. 3) formed in the receiving beam 20. By tightening the head portion of the bolt member 31 inserted into the bolt insertion hole 20a of the receiving beam 20 into these bolt fastening holes 32c, the structure joint metal fitting 32 can be fixed to the receiving beam 20. .

  In addition, the structural support beam 12 is joined to the receiving beam 20 via the structure joint metal 32 on each of the overhanging plate portions 32a of the pair of side portions having a substantially U-shaped cross section. A drift pin engaging hole 32d and a drift pin engaging notch 32e for locking the drift pin 30 are formed at a plurality of locations.

  When the structural support beam 12 is joined and fixed to the receiving beam 20 via the structural part joint metal 32, the pair of overhanging plate portions 32 a of the structural part joint metal 32 fixed to the receiving beam 20 are provided on the structural support beam 12. The pair of slit portions 12a of the notch recess portion 12b formed in the end surface portion are mounted so as to be fitted into each other. Further, the contact plate portion 32b of the structure joint metal fitting 32 is attached in a state of being housed in the end surface notch portion 12c of the notch recess portion 12b.

  Like the structural support beam 12, the fire-resistant coated beam 13 is a wooden square timber made of Scots pine laminated timber, for example, a symmetrically different-grade laminated timber, and has a width of 105 mm and a height as shown in FIG. It has a vertically long rectangular cross section with a size of about 240 mm and a length of about 3600 mm. As shown in FIG. 4, the end face portion of the fireproof covering beam 13 includes a notch recess 13b having a substantially U-shaped cross section including a pair of parallel slit portions 13a cut in a direction perpendicular to the end face. Is formed. That is, the notch recess 13b is formed from an end surface notch portion 13c formed by an intermediate side portion having a substantially U-shaped cross section, which is thinly cut along the end surface of the fireproof covering beam 13, and from both ends of the end surface notch portion 13c. It consists of a slit portion 13a formed by a pair of side portions having a substantially U-shaped cross-sectional shape cut perpendicularly in the axial direction of the fireproof covering beam 13.

  Further, the side surface of the end portion of the fireproof covering beam 13 adjacent to the end surface portion where the notched recess 13b is formed is covered with the slit portion 13a so as to penetrate between the side surfaces on both sides. Of the plurality of drift pin engagement holes 33d and drift pin engagement notches 33e formed in one overhang plate portion 33a, a part of selected drift pin engagement holes 33d and drift pins are formed. A drift pin driving hole 13d is formed at a position corresponding to the engagement notch 33e.

  As shown in FIGS. 4, 5 (a), and (b), the covering portion joint metal 33 for joining the fireproof covering beam 13 to the receiving beam 20 that is a support member is similar to the structure portion joint hardware 33. It is a plate-like joint metal that is formed by bending a metal plate member so as to have a substantially U-shaped cross-sectional shape. The covering portion joint metal 33 includes an abutting plate portion 33b having an intermediate side portion having a substantially U-shaped cross section and an overhanging plate portion 33a having a pair of side portions having a substantially U-shaped cross section. In the contact plate portion 33b, bolt fastening holes 33c are formed at, for example, three positions at positions corresponding to the bolt insertion holes 20a (see FIG. 3) formed in the receiving beam 20. By tightening the heads of the bolt members 31 inserted into the bolt insertion holes 20 a of the receiving beam 20 in these bolt fastening holes 33 c, the covering portion joint hardware 33 can be fixed to the receiving beam 20. .

  In addition, each of the overhanging plate portions 33a formed by a pair of side portions having a substantially U-shaped cross-sectional shape of the covering portion joint metal 33 is joined to the receiving beam 20 via the covering portion joint hardware 33. The drift pin engaging hole 33d and the drift pin engaging notch 33e for locking the drift pin 30 used at the time are formed at a plurality of locations.

  When the fire-resistant covering beam 13 is bonded and fixed to the receiving beam 20 via the covering portion joint metal 33, the pair of overhanging plate portions 33 a of the covering portion joint metal 33 fixed to the receiving beam 20 is formed of the fire-resistant covering beam 13. It is mounted so as to be fitted into the slit portion 13a of the notch recess 13b formed in the end surface portion. Further, the contact plate portion 33b of the covering portion joint metal piece 33 is attached in a state of being housed in the end surface notch portion 13c of the notch recess portion 13b.

  In this embodiment, as shown in FIG. 4, the end faces of the structural support beam 12 and the refractory coated beam 13 are formed on the extended plate portions 32 a and 33 a of the structural part joint metal 32 and the covering part joint metal 33 attached to the receiving beam 20. The structural support beam 12 and the fire-resistant coated beam 13 are received by a simple operation in which the drift pins 30 are driven through the drift pin engaging holes 12d and 13d after the slit portions 12a and 13a formed in each are fitted. It can be fixedly bonded to the beam 20.

  Here, the driving of the drift pin is performed in a state in which the end portions of the structural support beam 12 and the fireproof covering beam 13 are individually supported by the receiving beam 20 via the structural portion joint metal 32 and the covering portion joint metal 33. Similarly to the method, each of the beams 12 and 13 can be performed from the side surfaces of the end portions. However, in the present embodiment, as described above, the structural part joint metal 32 and the covering part joint metal 33 are structural part joints. The position of the drift pin engaging hole 32d and the drift pin engaging notch 32e provided in the overhanging plate portion 32a of the hardware 32, and the drift pin engaging hole 33d and drift provided in the overhanging plate portion 33a of the covering portion bonding hardware 33 are provided. The long drift pin 3 is attached to the receiving beam 20 in a state in which the position of the pin engagement notch 33e coincides with that of the refractory beam 11 when viewed from the width direction, and has a length capable of penetrating them simultaneously. There have been driven from the side of the end of one of the refractory coating beam 13 (see FIG. 3). As a result, the structural support beam 12 and the fireproof covering beams 13 on both sides can be integrally joined to the receiving beam 20.

  Further, in the present embodiment, the drift pin engaging hole 32 d and the drift pin engaging notch 32 e provided in the overhang plate portion 32 a of the structure joint metal fitting 32 and the overhang plate portion 33 a of the covering portion joint metal 33 are provided. The long drift pin 30 having a length capable of passing through the drift pin engaging hole 33d and the drift pin engaging notch 33e at the same time has a length shorter than the entire width of the refractory beam 11, as shown in FIG. doing. As a result, the long drift pin 30 is located in a region where both ends of the long drift pin 30 deviate from the design burn-in area of the fireproof coated beam 13 from the side surface opposite to the structural support beam 12 at the end of the fireproof coated beam 13. It is attached in the state embedded in the inside of the fireproof covering beam 13. Accordingly, the long drift pin 30 embedded in the fireproof coated beam 13 can be prevented from becoming a thermal bridge, and the fireproof function by the fireproof coated beam 13 can be improved. In the portion where the long drift pin 30 is not embedded in the drift pin driving hole 13d formed in the fireproof covering beam 13, a material having high heat insulation properties such as buried wood 34 or rock wool is embedded. The drift pin driving hole 13d is closed.

  In the present embodiment, a known floor member (not shown) having a predetermined fire resistance performance is attached to the upper surface portion of the fire resistant beam 11 so as to cover the upper surface of the fire resistant beam 11, so that the fire is prevented. The influence of the fire heating during heating does not reach the structural support beam 12 from the upper surface side. As a result, it is possible to effectively prevent the structural support beam 12 from being damaged or thermally deteriorated by combustion without providing a fireproof coating material on the upper surface portion of the fireproof beam 11. ing.

  In the present embodiment, as shown in FIGS. 2 and 3, a support portion covering member 21 is attached so as to cover the receiving beam 20 that is a support member. Similar to the structural support beam 12 and the fireproof covering beam 13, the support portion covering member 21 is a wooden square member made of, for example, Scots pine laminated wood, which is a symmetric different grade construction laminated wood, and has a width of 105 mm and a height of 240 mm, for example. It has a cross-sectional shape of a vertically long rectangle of about the size. The support portion covering member 21 is arranged so as to cover the surface of the receiving beam 20 made of the same square member, and in the state where the end surface is in contact with the side surface at the end portion of the fireproof covering beam 13, for example, a fixing screw is used. It is fixed to the receiving beam 20 by driving toward the receiving beam 20. The support portion covering member 21 functions together with the fireproof covering beam 13 as a burn-in area of the fireproof beam 11 and the receiving beam 20, so that the fireproof beam 11 and the receiving beam 20 have a fire resistance performance equal to or higher than the 45-minute quasi-refractory structure. Allows you to design to burn out.

  Further, in the present embodiment, as shown in FIG. 3, the covering portion joint metal 33 is disposed at the center in the width direction of the fireproof covering beam 13, and the pair of overhanging plate portions 33 a are formed of the fireproof covering beam 13. The depth of the design burn-in area of the fire-resistant coated beam 13 from the receiving beam 20 to the width B of the fire-resistant coated beam 13 so that the design burn-in area 40 (see FIGS. 7A and 7B) is included in the area outside. It protrudes with a length not exceeding the length L minus the length D, and is inserted into a slit portion 13 a formed on the end surface portion of the fireproof coated beam 13.

  Here, the design burn-in area can be appropriately set according to the material of the fireproof covering beam 13 and the required performance of the fireproof structure. For example, when the fire-resistant covering beam 13 is a wooden square member made of the above-mentioned Scots pine laminated timber and it is necessary to have a fire resistance performance of 45 minutes, the structural support at the end of the fire-resistant covering beam 13 A region within a depth of 35 mm from the side surface opposite to the beam 12 can be a design burn-in region 40. For example, when the fireproof covering beam 13 is a wooden square member made of the above-mentioned Scots pine laminated timber, and it is necessary to have the fireproof performance of a one hour fireproof structure, the structural support beam at the end of the fireproof covering beam 13 A region within a depth of 45 mm from the side surface opposite to 12 can be a design burn-in region.

  In particular, in the present embodiment, the support member covering member 21 is attached so as to cover the receiving beam 20 as the support member, with the end surface being in contact with the side surface of the end portion of the fireproof covering beam 13. Since it is thought that the covering member 21 can also contribute to the fireproof function by the fireproof covering beam 13, as shown in FIG. 6A, the design burn-in area 40 can be set as follows. .

That is, for example, the corner of the fire-resistant covering beam 13 and the supporting portion covering member 21 is the origin 0, the direction along the surface of the supporting portion covering member 21 is the x axis, and the direction along the fire resistant covering beam 13b is the Y axis. Assuming that the coordinates to be used are, for example, the design burn depth xc of the fireproof coated beam 13 is 45 mm, and the circle having the radius = 2 · xc ((x = −xc, y = xc)) (( x + xc) ² + (y−xc) ² = (2 · xc) ² ).

When y is greater than or equal to xc, an area within the depth xc (45 mm) from the side surface opposite to the structural support beam 12 at the end of the refractory coated beam 13 is defined as a design burnout area 40, and y is xc And (x + xc) ² + (y−xc) ² <(2 · xc) ² can be used as the design burn-in area 40.

  Here, the design burn-in depth xc of the refractory coated beam 13 can be obtained by the following formula (1).

  In the present embodiment, as shown in FIG. 6 (b), the fire-resistant beam 11 can be used as a support member joined to the frame member 20 'of the wall. In this case, the support covering member 21 'is preferably a gypsum board, a reinforced gypsum board, a calcium silicate board, a siding, a mortar, a concrete, a lightweight cellular concrete, a wood chip cement board, a flame retardant wood, a glass wool, a rock wool. A non-combustible material or a flame-retardant material made of, for example, can be arranged so as to cover the surface of the wall frame member 20 '. In the form shown in FIG. 6 (b), as the support portion covering member 21 ', for example, a reinforced plaster board having a thickness of 21 mm is attached in two layers. The support portion covering member 21 ′ is a frame member of the wall by, for example, receiving a fixing screw (not shown) toward the beam 20 in a state where the end face is in contact with the side surface at the end portion of the fireproof covering beam 13. It is fixed to 20 '.

In the form shown in FIG. 6B, the design burn-in area 40 can be set as follows. That is, for example, the corner of the fire-resistant covering beam 13 and the support portion covering member 21 ′ is the origin 0, the direction along the surface of the support covering member 21 ′ is the x axis, and the direction along the fire resistant covering beam 13b is the Y axis. Is assumed, for example, the design burn-in depth xc of the fireproof coated beam 13 is 45 mm, and the radius around the position of the coordinates (x = −xc, y = 2 · xc−z) = 2 · An xc circle ((x + xc) ² + (y− (2 · xc−z) ² = (2 · xc) ² ) is drawn.

  Here, z is a dimension at which the support portion covering member 21 ′ is carbonized in the negative direction of the y axis near the origin 0, and can be obtained by the following formula (2). For example, in the case of a fireproof structure for 1 hour (60 minutes), z becomes z = 21 × 60/60 = 21 mm, which is the same value as the thickness of one 21 mm thick gypsum board.

In the form shown in FIG. 6B, when y is 2 · xc-z or more, the end of the fireproof covering beam 13 is within a depth xc (45 mm) from the side surface opposite to the structural support beam 12. When the area is the design burn-in area 40, and y is smaller than 2 · xc−z and equal to or larger than −D (total thickness of the supporting portion covering member 21 ′), ((x + xc) ² + (y− ( 2 · xc−z)) ² <(2 · xc) ² may be the design burn-in area 40.

  And according to the fire-resistant structure 10 in the joint part of the fire-resistant beam of the present embodiment having the above-described configuration, without impairing the fire-resistant function by the fire-resistant covered beam 13 arranged to cover the side surfaces on both sides of the structural support beam 12, By joining the end of the refractory beam 11 to the support member 20 using the structural joint metal fitting 32 and the covering joint metal fitting 33 which are beam receivers, a wooden building having a fire resistance of 45 minutes or more quasi-refractory structure, The fire-resistant beam 11 can be easily installed.

  That is, according to the present embodiment, the fire-resistant beam 11 is formed to include the structural support beam 12 and the pair of fire-resistant coated beams 13, covers the receiving beam 20 that is a support member, and supports the support portion covering member 21. , 21 ′ are attached in a state where the end face is in contact with the side face at the end of the fireproof covering beam 13, and the covering joint metal fitting 33 is disposed at the center portion in the width direction of the fireproof covering beam 13, In addition, the depth of the design burn-in area of the fire-resistant coated beam 13 from the width B of the fire-resistant coated beam 13 from the receiving beam 20 so that the overhanging plate portion 33a fits in the area outside the design burn-in area of the fire-resistant coated beam 13. Since it protrudes with a length not exceeding the length L minus D and is inserted into the slit portion 13a formed on the end surface portion of the fireproof covering beam 13, the covering portion for joining the fireproof covering beam 13 at the time of fire heating Bonded hardware 33 becomes a thermal bridge It allows to avoid being easily burn crowded the spread of fire protection beam 13 effectively, refractory function of fireproofing beam 13, it is possible to ensure that the exerted without being impaired.

  The present invention is not limited to the above-described embodiment, and various modifications can be made. For example, the structure part bonding hardware is not necessarily required to have the same size and shape as the covering part bonding metal. It is also possible to use a structural part joint metal in which the overhang plate part projects longer than the overhang plate part of the covering part joint metal. Moreover, as shown in FIGS. 7 (a) and 7 (b), the refractory beam is a joint metal with a receiving column 50 or other wooden building frame member as a supporting member, as shown in FIGS. 7 (a) and 7 (b). It can also join via.

  Furthermore, the structural part joint hardware for fixing the structural support beam to the support member is not necessarily a joint hardware having a U-shaped cross section. It may be fixed to the supporting member using a member for fixing the beam.

10, 10 'Fire-resistant structure at joint of fire-resistant beam 11 Fire-resistant beam 12 Structure support beam 12a Slit 12d Drift pin driving hole 13 Fire-resistant covering beam 13a Slit 13d Drift pin driving hole 14 Lower surface fire-resistant covering 15 Wood board 20 receiving beam (supporting member)
20 'Wall frame member (support member)
20a Bolt insertion hole 21, 21 'Support part covering member 30 Long drift pin (drift pin)
31 Bolt member 32 Structure portion metal fitting 32a Overhang plate portion 32b Contact plate portion 32c Bolt fastening hole 32d Drift pin engagement hole 32e Drift pin engagement notch 33 Cover portion metal fitting 33a Overhang plate portion 33b Contact plate portion 33c Bolt Fastening hole 33d Drift pin engagement hole 33e Drift pin engagement notch 33f 'Reinforcement rib plate part 40 Design burn-off area 50 Receiving column (support member)

Claims (6)

A fireproof structure in a joint portion of a fireproof beam used in a wooden building having a fireproof performance equal to or greater than 45 minutes quasifireproof structure to a support member via a joint hardware,
The fire-resistant beam is formed to include a structural support beam and fire-resistant covered beams arranged on both sides of the structural support beam,
The structural support beam is joined to the support member via a structural part joint hardware fixed to the support member,
The fireproof covering beam is in a state where a pair of overhanging plate portions of a covering joint metal fixture having a U-shaped cross section fixed to a support member is inserted into a slit portion formed in an end surface portion of the fireproof covering beam. The drift pin is driven from the side surface of the end of the fireproof coated beam, and is joined to the support member,
Covering the support member, a support portion covering member is attached,
The covering joint metal fitting is disposed in the center portion in the width direction of the fireproof covering beam, and the projecting plate portion is designed to be designed from the support member and from the width of the fireproof covering beam. A fireproof structure at a joint portion of a fireproof beam that protrudes with a length not exceeding a length obtained by subtracting the depth of the fireproof beam and is inserted into a slit portion formed in an end surface portion of the fireproof coated beam.   The structural part joining hardware has a U-shaped cross-sectional shape, and the structural support beam has a pair of projecting plate parts having a U-shaped cross-sectional shape of the structural part joining hardware at the end surface part of the structural support beam. 2. The joining of the refractory beam according to claim 1, wherein the drift pin is driven from the side surface of the end portion of the structural support beam while being inserted into the formed slit portion, thereby joining the support member. 3. Fireproof structure in the part.   The overhang plate portion of the structural part joint metal protrudes from the support member with a length not exceeding the length of the fireproof coated beam minus the depth of the design burn-in area of the fireproof coated beam. The fireproof structure in the joint part of the fireproof beam of Claim 2 inserted in the slit part formed in the end surface part of a support beam.   The structure part metal fitting and the covering part metal fitting are arranged at positions of drift pin engagement holes and drift pin engagement notches provided in the overhanging plate part of the structure part metal fitting, and the overhang of the covering part metal fitting. The position of the drift pin engagement hole and the drift pin engagement notch provided in the plate portion is attached to the support member in a state of being matched when viewed from the width direction of the refractory beam, and can be penetrated simultaneously. Since the long drift pin having a length is driven from the side surface of the end portion of the fireproof coated beam, the structural support beam and the fireproof coated beam are integrally joined to the support member. The fireproof structure in the junction part of the fireproof beam of Claim 2 or 3.   The fireproof structure at the joint portion of the fireproof beam according to any one of claims 1 to 4, wherein the support member to which the fireproof beam is joined is a receiving beam or a receiving post.   The fireproof structure at the joint portion of the fireproof beam according to any one of claims 1 to 4, wherein the support member to which the fireproof beam is joined is a frame member of a wall.

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