JP6697927B2 - Fireproof structure at the joint of fireproof beams - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a fire resistant structure in a joint portion of a fire resistant beam, and particularly relates to a fire resistant structure in a joint portion of a fire resistant beam used in a wooden building having a fire resistance performance of 45 minutes quasi fire resistant structure or more to a support member via a joint metal. .

  For example, in Japanese residential buildings, a design in which the surface of a wooden beam, which is a structural material, is exposed in the room is preferred. In a wooden space where such a beam is exposed, the exposed portion of the beam, which is the structural material, is directly heated and easily burned in the event of a fire. However, it is necessary to ensure the performance that does not collapse while withstanding the load supporting the building.

  For this reason, for example, when designing a beam with a quasi-fireproof structure made of wood, it is common to perform the burnout design as shown in the Building Standards Act, “H12, Ministry of Construction Notification No. 1358, Paragraph 2”. is there. For the burnout design, add a specified burnout amount (for example, 35 mm for laminated lumber in quasi-fireproof structure for 45 minutes, for example, 45 mm for laminated lumber in 1 hour fireproof structure) to the cross section required for short-term structural strength during an earthquake. Although it is a design, since the added burnout amount cannot be included in the structural calculation, the structural calculation becomes inefficient.

  In addition, the cross-section of the beam after the burnout design tends to have a large finished width, and the width exceeds the cross-sectional width of structural wood that is generally circulated, for example, 105 mm or 120 mm. Since it is often handled as a custom-made product, it takes a lot of time and effort to produce structural timber including joint processing.

  To solve these problems, for example, when designing an exposed beam in a wooden quasi-fireproof structure, the quasi-fireproof structure of the quasi-fireproof structure can maintain a fireproof performance of 45 minutes or more without designing a burn-out structure. Have been developed (see, for example, Patent Document 1). In addition, a fire-resistant structure of a beam has been developed that allows the design of a burning margin without the need to custom-build a large-section structural timber by combining commonly used structural lumber (for example, , Patent Document 2).

JP, 2014-9499, A JP, 2013-204261, A

  In the beam refractory structure described in Patent Document 2 above, a structural supporting beam that bears structural strength and a side surface on both sides of the structural supporting beam are arranged by combining structural wood that is generally in circulation. As a composite beam consisting of a pair of fireproof covered beams that become burnout parts, it is possible to form a fireproof beam considering the burnout part, and these structural support beams and fireproof covered beams are By using a known beam receiving member having a U-shaped cross section, for example, an end portion is joined to a receiving beam serving as a supporting member of the beam, and each beam can be easily supported.

  However, when the end of the fireproof coated beam is joined to the support member using the beam receiver having a U-shaped cross section, the metal beam receiver is a thermal bridge by the same method as the conventional beam receiver. Therefore, it is conceivable that burn-in of the fire-resistant coated beam is likely to spread and the fire-resistant function of the fire-resistant coated beam is impaired.

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

The present invention relates to a fireproof structure in a joint portion of a fireproof beam used in a wooden building having a fireproof performance of 45 minutes or more quasi-fireproof structure to a support member via a joint metal, wherein the fireproof beam is a structural support beam. And a refractory-covered 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 joining metal member fixed to the support member. The refractory covered beam has a pair of overhanging plate parts of a covering part joining metal having a U-shaped cross-section fixed to a supporting member and is inserted into a slit part formed in an end face part of the refractory covering beam. In the state where the drift pin is driven in from the side surface of the end portion of the fireproof coated beam, the drift pin is joined to the supporting member, the supporting member is covered, and the supporting portion covering member has the end surface It is attached in a state of abutting on the side surface at the end of the fireproof coated beam, the coating part joint metal is arranged in the widthwise central part of the fireproof coated beam, and the projecting plate part is From the support member, the slit portion formed in the end face portion of the fireproof covered beam, protruding from the width of the fireproof covered beam by a length less than the length of the design burnout region of the fireproof covered beam The object is achieved by providing a refractory structure at the joints of the refractory beams that are plugged in.

  And, in the fire resistant structure in the joint portion of the fire resistant beam of the present invention, the structural portion joining metal article has a U-shaped cross-sectional shape, and the structural support beam has a U-shaped cross sectional shape of the structural portion joining metal object. With the pair of overhanging plate portions being inserted into the slits formed in the end surface portions of the structural support beams, the drift pins are driven in from the side surfaces of the end portions of the structural support beams to support the structure. It is preferably bonded to the member.

  Further, in the refractory structure in the joint portion of the fireproof beam of the present invention, the overhanging plate portion of the structural part joint metal is from the support member, from the width of the fireproof covered beam to the depth of the design burnout region of the fireproof covered beam It is preferable that the protrusion is provided with a length that does not exceed the drawn length, and the protrusion is inserted into a slit portion formed in the end face portion of the structural support beam.

  Further, in the fire resistant structure in the joint portion of the fire resistant beam of the present invention, the structure portion joint metal and the covering portion joint metal are provided with a drift pin engagement hole or a drift pin provided in the projecting plate portion of the structure portion joint metal. In a state in which the position of the engagement notch and the position of the drift pin engagement hole or the drift pin engagement notch provided in the overhanging plate portion of the covering portion joint metal article match when viewed from the width direction of the refractory 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 in from a side surface of an end portion of the fire-resistant coated beam, whereby 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 fire resistant structure in the joint portion of the fire resistant beam of the present invention, it is preferable that the support member to which the fire resistant beam is joined is a receiving beam or a supporting column.

  Further, 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 frame member.

  According to the fire-resistant structure in the joint portion of the fire-resistant beam of the present invention, the end portion of the fire-resistant beam can be formed by using the joining metal object without impairing the fire-resistant function of the fire-resistant covered beam arranged to cover both side surfaces of the structural support beam. The fire-resistant beam can be easily installed in a wooden structure that is joined to the support member and has a fire resistance performance of 45 minutes or more quasi-fire resistant structure.

It is a schematic perspective view which illustrates the indoor space of a wooden structure explaining the fireproof beam installed using the fireproof structure in the junction part of the fireproof beam which concerns on one preferable embodiment of this invention. FIG. 2 is an enlarged cutaway perspective view of a portion A of FIG. 1 for explaining the fireproof beam installed by using the fireproof structure in the joint portion of the fireproof beam according to the preferred embodiment of the present invention. FIG. 3 is a plan sectional view of an essential part of FIG. 2 seen from above, illustrating a fire resistant structure in a joint portion of a fire resistant beam according to a preferred embodiment of the present invention. It is a principal part exploded perspective view explaining the fireproof structure in the joined part of the fireproof beam concerning one desirable embodiment of the present invention. (A) is a perspective view of a structural part joining metal object and a covering part joining metal object, and (b) is a rear view. (A), (b) is explanatory drawing of a design burn-off area|region. (A) is a schematic perspective view illustrating a fire resistant structure in the case where a support member to which a fire resistant beam is joined is a support column, and (b) is a schematic sectional view taken along line BB of (a). ..

  A fire resistant structure at a joint portion of a fire resistant beam according to a preferred embodiment of the present invention is a wooden building having a fire resistant performance of 45 minutes quasi fire resistant structure or more, for example, in a residential building by a frame construction method, as shown in FIG. In addition, the end of the refractory beam 11 constituting the frame structure supporting the weight of the building itself, wind load, seismic load, etc. is connected to the receiving beam 20 which is a supporting member through the metal joints 32, 33 (see FIG. 4). It was adopted as a structure for joining. In the present embodiment, the fire-resistant beam 11 is a revealing beam that is provided so as to be exposed from the ceiling surface of the room to the interior space, and the excellent wood by the surface of the fire-resistant beam 11 exposed as the revealing beam. The structure support beam 12 and a pair of fireproof coated beams arranged on both sides of the structure support beam 12 so that the quasi-fireproof structure can exhibit the fireproof performance for 45 minutes or more while maintaining the texture and design in the indoor space. It is a composite beam consisting of 13 and a burnable design (see FIGS. 2 and 3).

  In the present embodiment, the structural support beam 12 and the pair of fireproof coated beams 13 forming the fireproof beam 11 are joined to the receiving beam 20 via the metal joining hardware 32, 33, respectively. The refractory structure 10 at the joint portion of the refractory beam according to the embodiment avoids that the burn-in of the refractory-covered beam 13 is likely to spread due to the joint metal 33 that joins the refractory-covered beam 13 serving as a thermal bridge during heating by a fire. Thus, the fireproof function of the fireproof coated beam 13 can be effectively exerted without being impaired.

  The fireproof structure 10 at the joint portion of the fireproof beam of the present embodiment is a support member for the fireproof beam 11 used in a wooden structure having a fireproof performance of 45 minutes or more quasi-fireproof structure via the joint metal parts 32, 33. As shown in FIGS. 2 to 4, which is a structure at a joint to the receiving beam 20, the fireproof beam 11 includes a structural support beam 12 and a pair of fireproof coatings arranged on both sides of the structural support beam 12. The structural support beam 12 is formed by including the beam 13, and the structural support beam 12 includes a pair of projecting plate portions 32a of the structural part joint metal fitting 32 fixed to the receiving beam 20 and preferably having a U-shaped cross section. Since 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 in the end surface portion 12 of the structural support beam 12, it is bonded to the receiving beam 20 and is fire resistant. In the covered beam 13, a pair of overhanging plate parts 33 a of a covered part joint metal 33 having a U-shaped cross section fixed to the receiving beam 20 is inserted into a slit part 13 a formed in an end face part of the fireproof covered beam 13. The drift pin 30 is driven in from the side surface of the end portion of the refractory-covered beam 13 in the state where it is joined to the receiving beam 20.

  A supporting portion covering member 21 is attached so as to cover the receiving beam 20 which is a supporting member, with its end face abutting on the side face at the end of the fireproof covered beam 13 (see FIGS. 2 and 3). The joint metal part 33 is arranged in the central portion in the width direction of the refractory-covered beam 13, and the overhanging plate part 33a extends from the receiving beam 20, the width B of the refractory-covered beam 13 to the design burn-in region of the refractory-covered beam 13. The protrusion 13 has a length that does not exceed the length L obtained by subtracting the depth D, and is inserted into the slit portion 13a formed in the end face portion of the fireproof coated beam 13.

  Further, in the present embodiment, the projecting plate portion 32a of the structure-joint metal fitting 32 is also designed to burn from the receiving beam 20, the width B of the fireproof covered beam 13 to the design fireproof beam 13 of the fireproof covered beam 13, as shown in FIGS. 3 and 4. It protrudes with a length that does not exceed the length L obtained by subtracting the depth D of the margin region, and is inserted into the slit portion 12 a formed in the end face portion of the structural support beam 12.

  Further, in the present embodiment, the structure-part joint metal fitting 32 and the covering-part joint metal fitting 33 are located at the positions of the drift pin engagement hole 32d and the drift pin engagement cutout 32e provided in the overhanging plate part 32a of the structure part joint hardware 32. , The position of the drift pin engagement hole 33d and the drift pin engagement notch 33e provided in the overhanging plate portion 33a of the covering portion joint metal 33 are aligned with the receiving beam 20 when viewed from the width direction of the refractory beam 11. Since the long drift pins 30 which are attached and have a length capable of penetrating them at the same time are driven in from the side surface of the end portion of the fireproof covered beam 13, the structural support beam 12 and the fireproof covered beam 13 are separated from each other. It is integrally joined to the receiving beam 20 (see FIG. 3).

  In 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, as described above. The structural support beam 12 is a wooden timber made of, for example, a laminated wood of Scots pine, which is a symmetrically graded laminated lumber, and as shown in FIG. 2, for example, has a width of 105 mm and a height of 240 mm and is vertically long. It has a rectangular cross-sectional shape and a length of about 3600 mm. As shown in FIG. 4, the end face portion of the structural support beam 12 is provided with a notched concave portion 12b having a substantially U-shaped cross section, which includes a pair of parallel slit portions 12a cut in a direction perpendicular to the end face. Has been formed. That is, the cutout recess 12b is formed by thinly cutting out along the end face of the structural support beam 12 from the end face cutout 12c formed by the intermediate side portion of the substantially U-shaped cross-sectional shape, and both ends of the end face cutout 12c. It is composed of a slit portion 12a that is a vertical cut in the axial direction of the structural support beam 12 and that has a pair of side portions having a substantially U-shaped cross section.

  In addition, a structure in which a slit 12a is attached to a side surface of a portion of the end portion of the structural support beam 12 that is close to the end surface portion where the cutout recess 12b is formed so as to penetrate between the both side surfaces. Of the plurality of drift pin engagement holes 32d and the drift pin engagement notches 32e formed in the pair of overhang plate portions 32a of the partial joint hardware 32, a selected part of the drift pin engagement holes 32d and the drift pin engagement holes 32d. A drift pin driving hole 12d is formed at a position corresponding to the combined cutout 32e.

  As shown in FIGS. 4 and 5(a) and 5(b), the structure portion joining metal 32 for joining the structure supporting beam 12 to the receiving beam 20 which is a supporting member is bent into a metal plate member or the like. It is a plate-shaped joining metal object which is processed and formed so as to have a substantially U-shaped cross section. The structural portion joining hardware 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. Bolt fastening holes 32c are formed at, for example, three positions in the contact plate portion 32b 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 20a of the receiving beam 20 into these bolt fastening holes 32c, the structural part joint metal 32 can be fixed to the receiving beam 20. ..

  In addition, the structural support beam 12 is bonded to the receiving beam 20 via the structural part bonding metal 32, respectively, on the overhanging plate parts 32a of the structural part bonding metal part 32 formed by a pair of side portions having a substantially U-shaped cross section. The drift pin engaging hole 32d and the drift pin engaging notch 32e for locking the drift pin 30 used at the time of doing are formed in multiple places.

  When the structure supporting beam 12 is joined and fixed to the receiving beam 20 via the structure joining metal 32, the pair of overhanging plate portions 32 a of the structure joining metal 32 fixed to the receiving beam 20 are not The slits 12a of the cutout recess 12b formed in the end face portion are fitted so as to be fitted into each other. Further, the abutting plate portion 32b of the structural part joining metal fitting 32 is attached in a state of being housed in the end face cutout portion 12c of the cutout recessed portion 12b.

  Similar to the structural support beam 12, the fire-resistant coated beam 13 is a wooden lumber made of, for example, a Scots pine laminated wood which is a symmetrically graded laminated wood, and as shown in FIG. 2, for example, has a width of 105 mm and a height. It has a vertically long rectangular cross-sectional shape of about 240 mm and a length of about 3600 mm. As shown in FIG. 4, a cutout recess 13b having a substantially U-shaped cross section, which includes a pair of parallel slits 13a cut in a direction perpendicular to the end face, is provided on the end face portion of the fireproof coated beam 13. Has been formed. That is, the cutout recess 13b is formed by thinly cutting out along the end face of the fireproof coated beam 13 from the end face cutout 13c by the intermediate side portion of the substantially U-shaped cross section and both end portions of the end face cutout 13c. It is composed of a slit portion 13a formed by a pair of side portions having a substantially U-shaped cross section, which is vertically cut in the axial direction of the fireproof covered beam 13.

  In addition, on the side surface of the end portion of the fireproof coated beam 13 that is close to the end surface portion where the cutout recess 13b is formed, the coating attached to 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 the drift pin engagement cutouts 33e formed in the one overhang plate portion 33a of the partial joint metal 33, selected drift pin engagement holes 33d and drift pins A drift pin driving hole 13d is formed at a position matching the engagement notch 33e.

  As shown in FIGS. 4 and 5(a) and 5(b), the covering portion joining metal 33 for joining the fireproof coated beam 13 to the receiving beam 20 which is a supporting member is similar to the structure joining metal 33 as shown in FIGS. This is a plate-shaped joining metal object formed by bending a metal plate member so as to have a substantially U-shaped cross-sectional shape. The covering portion joining metal member 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. Bolt fastening holes 33c are formed in the contact plate portion 33b at, for example, three positions at positions corresponding to the bolt insertion holes 20a (see FIG. 3) formed in the receiving beam 20. By fastening the heads of the bolt members 31 inserted into the bolt insertion holes 20a of the receiving beam 20 into these bolt fastening holes 33c, the covering portion joint metal 33 can be fixed to the receiving beam 20. ..

  In addition, the refractory-covered beam 13 is joined to the receiving beam 20 via the covering part joining metal part 33, respectively, on the overhanging plate parts 33a formed by a pair of sides of the covering part joining metal part 33 having a substantially U-shaped cross section. The drift pin engaging hole 33d and the drift pin engaging notch 33e for locking the drift pin 30 used at the time of doing are formed in multiple places.

  When the fire-resistant coated beam 13 is bonded and fixed to the receiving beam 20 via the cover-bonding metal article 33, the pair of overhanging plate portions 33 a of the cover-bonding metal article 33 fixed to the receive beam 20 are The slit 13a of the cutout recess 13b formed in the end face portion is fitted so as to fit snugly. Further, the contact plate portion 33b of the covering portion joint metal 33 is attached in a state of being housed in the end face cutout portion 13c of the cutout recessed portion 13b.

  In the present embodiment, as shown in FIG. 4, the end faces of the structural support beam 12 and the fireproof coated beam 13 are attached to the overhanging plate portions 32a and 33a of the structural part joint metal 32 and the cover part metal joint 33 attached to the receiving beam 20. The structure supporting beam 12 and the fireproof coated beam 13 are received by a simple operation of driving the drift pin 30 through the drift pin engaging holes 12d and 13d after fitting the slit portions 12a and 13a formed in It can be bonded and fixed to the beam 20.

  Here, the driving of the drift pin is performed in the state where the end portions of the structural support beam 12 and the fireproof coated beam 13 are individually supported by the receiving beam 20 via the structural portion joint metal 32 and the coating portion metal joint 33. Similar to the method, it can be performed from the side surfaces of the ends of the individual beams 12 and 13, respectively. However, in the present embodiment, as described above, the structural part joint metal 32 and the cover part joint metal 33 are the structural part joints. The positions of the drift pin engagement hole 32d and the drift pin engagement notch 32e provided in the overhang plate portion 32a of the metal fitting 32, and the drift pin engagement hole 33d and the drift provided in the overhang plate portion 33a of the covering portion joining hardware 33. The pin engagement notch 33e is attached to the receiving beam 20 in a state where the position of the pin engagement notch 33e is matched when viewed from the width direction of the refractory beam 11, and the long drift pin 30 having a length capable of penetrating these at the same time is It is driven in from the side surface of the end portion of the refractory covered beam 13 (see FIG. 3). This allows the structural support beam 12 and the fireproof coated beams 13 on both sides to be integrally bonded to the receiving beam 20.

  Further, in the present embodiment, the drift pin engaging hole 32d and the drift pin engaging notch 32e provided in the overhanging plate portion 32a of the structural part joining metal fitting 32 and the overhanging plate portion 33a of the covering part joining metal fitting 33 are provided. As shown in FIG. 3, the long drift pin 30 having a length capable of simultaneously penetrating the drift pin engagement hole 33d and the drift pin engagement notch 33e has a length shorter than the entire width of the refractory beam 11. is doing. As a result, the long drift pin 30 has its both ends from the side surface of the end of the fireproof covered beam 13 opposite to the structural support beam 12, in a region outside the designed burnout region of the fireproof covered beam 13. It is attached in a state of being buried inside the fireproof coated beam 13. As a result, the long drift pin 30 embedded inside the fireproof covered beam 13 can be prevented from becoming a thermal bridge, and the fireproof function of the fireproof covered beam 13 can be improved. In the portion of the drift pin driving hole 13d formed in the fireproof coated beam 13 where the long drift pin 30 is not buried, a material having a high heat insulating property such as a buried tree 34 or rock wool is embedded. The drift pin driving hole 13d is closed.

  In addition, in the present embodiment, a publicly 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 to thereby prevent a fire. The effect of 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 which is a supporting member. Similar to the structural support beam 12 and the fireproof coated beam 13, the support portion covering member 21 is a wooden square bar made of, for example, a Scots pine laminated wood which is a symmetrical different grade composite laminated wood, and has a width of 105 mm and a height of 240 mm, for example. It has a vertically-long rectangular cross-sectional shape with a size of about the same. The support portion covering member 21 is arranged so as to overlap the surface of the receiving beam 20 made of the same square member, and, for example, with a fixing screw in a state where the end surface is in contact with the side surface of the end portion of the fireproof covered beam 13. It is fixed to the receiving beam 20 by driving it toward the receiving beam 20. The support portion covering member 21 functions as the burn-up region of the fire-resistant beam 11 and the receiving beam 20 together with the fire-resistant coated beam 13 so that the fire-resistant beam 11 and the receiving beam 20 have a fire resistance performance of a quasi-fireproof structure of 45 minutes or more. Allows you to design a burnout.

  Further, in the present embodiment, as shown in FIG. 3, the covering portion joining metal member 33 is arranged at the center portion in the width direction of the fireproof covered beam 13, and the pair of overhanging plate portions 33 a are arranged on the fireproof covered beam 13. The depth of the design burn-in region of the fire-resistant coated beam 13 to the width B of the fire-resistant coated beam 13 from the receiving beam 20 so that the design burn-in region 40 (see FIGS. 7A and 7B) is accommodated in a region outside. It protrudes by a length that does not exceed the length L obtained by subtracting the length D, and is inserted into the slit portion 13a formed in the end face portion of the fireproof coated beam 13.

  Here, the design burnout area can be appropriately set according to the material of the fireproof coated beam 13 and the required performance of the fireproof structure. For example, when the fire-resistant coated beam 13 is a wooden lumber made of the above-mentioned Scots pine laminated wood, and it is necessary to have a fire resistance performance of a semi-fire resistant structure for 45 minutes, structural support of the end portion of the fire-resistant coated beam 13 is required. A region within a depth of 35 mm from the side surface on the side opposite to the beam 12 can be set as the design burning margin region 40. For example, when the fireproof coated beam 13 is a wooden lumber made of the above-mentioned Scots pine laminated lumber, 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 coated beam 13 is used. An area within a depth of 45 mm from the side surface on the side opposite to 12 can be set as the design burn-off area.

  In particular, in the present embodiment, the supporting portion covering member 21 is attached so as to cover the receiving beam 20 which is a supporting member, with the end surface abutting on the side surface of the end portion of the fireproof covering beam 13. Since it is considered that the covering member 21 can also contribute to the fireproof function of the fireproof covered beam 13, as shown in FIG. 6A, it is possible to set the design burnout region 40 as follows. ..

That is, for example, the entry corner between the refractory-covered beam 13 and the support-portion covering member 21 is the origin 0, the direction along the surface of the support-portion covering member 21 is the x-axis, and the direction along the refractory-covered beam 13b is the Y-axis. When assuming the coordinate to be set, for example, the design burn-out depth xc of the fireproof covered beam 13 is set to 45 mm, and a circle having a radius of 2·xc (((==−xc, y=xc)) as the center. Draw x+xc) ² +(y−xc) ² =(2·xc) ² ).

Then, when y is greater than or equal to xc, a region within a depth xc (45 mm) from the side surface of the end portion of the refractory-covered beam 13 opposite to the structural support beam 12 is defined as a design burn-off region 40, and y is xc When it is smaller than and larger than -xc, the area of ((x+xc) ² +(y-xc) ² <(2·xc) ² can be set as the design burning margin area 40.

  Here, the designed burn-out depth xc of the fireproof coated beam 13 can be obtained by the following mathematical expression (1).

  Further, in the present embodiment, as shown in FIG. 6B, the refractory beam 11 can also be used by being joined to the wall frame member 20 ′ as a support member. In this case, the support portion covering member 21' is preferably gypsum board, reinforced gypsum board, calcium silicate board, siding, mortar, concrete, lightweight cellular concrete, wood chip cement board, flame-retardant wood, glass wool, rock wool. Non-combustible or flame-retardant materials, such as, can be placed over the surface of the wall frame member 20'. In the form shown in FIG. 6B, two reinforced gypsum boards having a thickness of 21 mm, for example, are attached as the support portion covering member 21 ′ in a stacked manner. The support portion covering member 21 ′ is, for example, by driving a fixing screw (not shown) toward the receiving beam 20 in a state where the end surface is in contact with the side surface of the end portion of the refractory-covered beam 13, so that a frame skeleton member of the wall. It is fixed at 20'.

In the form shown in FIG. 6B, the design burning margin area 40 can be set as follows. That is, for example, the entry corner between the refractory covered beam 13 and the supporting portion covering member 21' is set as the origin 0, the direction along the surface of the supporting portion covering member 21' is the x axis, and the direction along the refractory covering beam 13b is the Y axis. Assuming the coordinates to be, for example, the design flammable 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· Draw a circle of xc ((x+xc) ² +(y−(2·xc−z) ² =(2·xc) ² ).

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

In the configuration shown in FIG. 6(b), when y is 2·xc−z or more, the depth xc (45 mm) or less is reached from the side surface of the end portion of the fireproof covered beam 13 opposite to the structural support beam 12. When the region is the design burning margin region 40 and y is smaller than 2·xc−z and is −D (total thickness of the support portion covering member 21′) or more, ((x+xc) ² +(y−( The region of 2·xc−z)) ² <(2·xc) ² can be set as the design burning margin region 40.

  Then, according to the fireproof structure 10 at the joint portion of the fireproof beam of the present embodiment having the above-described configuration, without impairing the fireproof function of the fireproof covered beam 13 arranged to cover the side surfaces on both sides of the structure support beam 12, The end portion of the refractory beam 11 is joined to the support member 20 using the structure joint metal fitting 32 and the covering portion metal joint 33, which are beam receiving metal fittings, to a wooden building having a fire resistance performance of 45 minutes quasi fire resistant structure or more, The fireproof 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, and covers the receiving beam 20 which is a support member and the support portion covering member 21. , 21 ′ are attached with their end faces abutting against the side faces at the end of the fireproof coated beam 13, and the coating part joint metal 33 is arranged in the central portion in the width direction of the fireproof coated beam 13. In addition, from the receiving beam 20, the width B of the refractory covered beam 13 to the depth of the design burn-in region of the refractory covered beam 13 so that the overhanging plate portion 33a fits in a region outside the designed flammable region of the refractory covered beam 13. Since it is inserted into the slit portion 13a formed in the end face portion of the fireproof covered beam 13 so as to protrude by a length that does not exceed the length L minus D, the cover portion that joins the fireproof covered beam 13 at the time of fire heating. Since the joint metal 33 serves as a thermal bridge, it is possible to effectively prevent the burn-in of the refractory-covered beam 13 from easily spreading, and to ensure that the fire-resistant function of the refractory-covered beam 13 is exerted without being impaired. It becomes possible to

  It should be noted that the present invention is not limited to the above embodiment, and various modifications can be made. For example, the structure-bonding metal article does not necessarily have to have the same size and shape as the covering-section metal fitting. It is also possible to use a structure-bonding metal part in which the overhanging plate part projects longer than the overhanging plate part of the covering part-bonding metal part. In addition to the frame members of the receiving beam and the wall, the fire-resistant beam uses the supporting columns 50 and other frame members of the wooden structure as the supporting members, as shown in FIGS. 7(a) and 7(b). It can also be joined via.

  Furthermore, the structural part joint metal fixture for fixing the structural support beam to the support member does not necessarily have to be a joint metal fixture having a U-shaped cross-sectional shape, and the structural support beam may be used as a joint member such as a screw member or a bolt member. It may be fixed to the support member by using a member for fixing the beam.

10, 10' Fireproof structure at joint of fireproof beam 11 Fireproof beam 12 Structural support beam 12a Slit portion 12d Drift pin driving hole 13 Fireproof coated beam 13a Slit portion 13d Drift pin driving hole 14 Lower surface fireproof coating material 15 Makeup 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 part joint metal 32a overhang plate part 32b contact plate part 32c bolt tightening hole 32d drift pin engagement hole 32e drift pin engagement notch 33 covering part joint metal 33a overhang plate part 33b contact plate part 33c bolt Fastening hole 33d Drift pin engaging hole 33e Drift pin engaging notch 33f' Reinforcing rib plate portion 40 Design burnout area 50 Support post (supporting member)

Claims (6)

45 minutes quasi-fireproof structure, which is a fireproof structure in a joint portion of a refractory beam used in a wooden structure having a fireproof performance of a quasi-fireproof structure or more, to a supporting member via a joint metal,
The fire-resistant beam is formed to include a structural support beam and a fire-resistant coated beam arranged on both sides of the structural support beam,
The structural support beam is joined to the support member via a structural part joining metal fixture fixed to the support member,
The refractory covered beam is a state in which a pair of overhanging plate parts of a cover part joint metal having a U-shaped cross section fixed to a supporting member are inserted into a slit part formed in an end face part of the refractory covered beam. , By being driven into the drift pin from the side surface of the end of the fireproof coated beam, it is joined to the support member,
Covering the support member, the support portion covering member is attached in a state where the end surface is in contact with the side surface at the end portion of the fireproof covered beam ,
The covering part joint metal is arranged in a central portion in the width direction of the refractory covered beam, and the overhanging plate part extends from the supporting member to the width of the refractory covered beam to the design burn-out region of the refractory covered beam. The refractory structure in the joint portion of the refractory beam projecting with a length not exceeding the depth of the above and inserted into the slit portion formed in the end face portion of the refractory covered beam.   The structural part joint metal has a U-shaped cross section, and the structural support beam has a pair of projecting plate parts having a U-shaped cross section of the structural part joint metal on the end face part of the structural support beam. The joining of the refractory beam according to claim 1, wherein the structural support beam is joined to the support member by being driven in from a side surface of an end portion of the structural support beam while being inserted into the formed slit portion. Fireproof structure in the section.   The projecting plate portion of the structural part joining metal article protrudes from the support member by a length that does not exceed the length of the width of the refractory covered beam minus the depth of the design burnout region of the refractory covered beam, The fireproof structure at a joint portion of the fireproof beam according to claim 2, wherein the fireproof structure is inserted into a slit portion formed at an end surface portion of the support beam.   Positions of the drift pin engaging hole and the drift pin engaging notch provided in the overhanging plate portion of the structural part joint metal and the overhang of the cover part joint metal The positions of the drift pin engagement holes and the drift pin engagement cutouts provided in the plate portion are attached to the support member in a state of matching when viewed from the width direction of the refractory beam, and these can be penetrated simultaneously. A long drift pin having a length is driven in from a side surface of an end portion of the refractory-covered beam, so that the structural support beam and the refractory-covered beam are integrally joined to the support member. A fireproof structure at a joint portion of the fireproof beams according to claim 2 or 3.   The refractory structure in the joint part 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 column.   The refractory structure in the joint part 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 frame member.

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