Composite fireproof coating structure for steel beams and construction method for composite fireproof coating structure for steel beams

Abstract

To block a space between a fire resistant board and a steel beam by a winding fire resistant coating material while suppressing breakage of the fire resistant board.SOLUTION: A construction method of a composite fire resistant coating structure of a steel beam comprises: a fire resistant board installing step of installing a fire resistant board 34 to whose surface 34B a metal plate 72 is attached at a lateral side of a steel beam 32 and making the surface 34B face the steel beam 32; a winding fire resistant coating material installing step of installing a winding fire resistant coating material 80 protruding to the fire resistant board 34 side from an opposite side to the fire resistant board 34 of the steel beam 32 through the bottom of the steel beam 32; and a weld-fixing pin construction step of sticking a weld-fixing pin 90 to a tip side of the winding fire resistant coating material 80 protruding to the fire resistant board 34 side and welding a tip of the weld-fixing pin 90 to the metal plate 72.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a composite fire-resistant covering structure for a steel beam and a construction method for the composite fire-resistant covering structure for a steel beam. [Background technology]

[0002] A composite fire-resistant coating structure for a steel beam is known, which comprises a steel beam, a fire-resistant board installed on the side of the steel beam, and a fire-resistant coating material that fire-coats the steel beam and extends from under the steel beam to seal the space between the steel beam and the fire-resistant board (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2011-190613 A [Patent Document 2] JP 2014-173379 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned composite fireproof covering structure of the steel beam, it is possible to use a wrap-around fireproof covering material as the fireproof covering material. In this case, a method of attaching the wrap-around fireproof covering material to the fireproof board can be to attach the tip side of the wrap-around fireproof covering material that protrudes from under the steel beam to the fireproof board installed on the side of the steel beam with a screw.

[0005] However, with the above mounting method, there is a possibility that the fireproof board may be damaged when the screws are screwed into the fireproof board.

[0006] In consideration of the above, the present invention aims to seal the space between a fireproof board and a steel beam with a wrapped fireproof covering material while suppressing damage to the fireproof board. [Means for solving the problem]

[0007] According to the first aspect The method for constructing a composite fire-resistant coating structure for a steel beam includes a fire-resistant board installation step of installing a fire-resistant board having a metal plate attached to its surface on the side of a steel beam with the surface facing the steel beam, a wrapped fire-resistant coating installation step of installing a wrapped fire-resistant coating material from the side of the steel beam opposite the fire-resistant board, passing under the steel beam and protruding toward the fire-resistant board, and a welding fixing pin installation step of inserting a welding fixing pin into the tip of the wrapped fire-resistant coating material protruding toward the fire-resistant board and welding the tip of the welding fixing pin to the metal plate.

[0008] According to the first aspect According to the construction method for a composite fire-resistant coating structure for a steel beam, first, in a fire-resistant board installation process, a fire-resistant board having a metal plate attached to its surface is installed on the side of the steel beam, with the surface of the fire-resistant board facing the steel beam.

[0009] Next, in the wrapping fireproof covering material installation process, the wrapping fireproof covering material is installed so as to pass under the steel beam from the side opposite the fireproof board and protrude toward the fireproof board.

[0010] Next, in the welding fixing pin installation process, a welding fixing pin is inserted into the tip of the wrapped fireproof covering material that protrudes from under the steel beam toward the fireproof board, and the tip of the welding fixing pin is welded to a metal plate.

[0011] In this way, in the present invention, the tip of the weld fixing pin is welded to the metal plate attached to the surface of the fireproof board, thereby attaching the tip side of the wrapped fireproof covering material to the fireproof board. Therefore, the space between the fireproof board and the steel beam can be blocked by the wrapped fireproof covering material while preventing damage to the fireproof board.

[0012] In addition, in the present invention, in the fireproof board installation step, the fireproof board to which the metal plate is attached in advance is installed on the side of the steel beam. Therefore, in the present invention, the metal plate can be attached to the fireproof board in an easier-to-operate state than in the case where the metal plate is attached to the fireproof board after the fireproof board is installed. Therefore, damage to the fireproof board is further suppressed.

[0013] In addition, if the fireproof board is damaged after installation, it takes time to replace the fireproof board. In contrast, in the present invention, a metal plate is attached to the fireproof board before installation, so that even if the fireproof board is damaged, it can be easily replaced. Therefore, workability is improved.

[0014] According to the second aspect The composite fire-resistant coating structure for a steel beam comprises a steel beam, a fire-resistant board installed on the side of the steel beam and having a metal plate attached to the surface facing the steel beam, a wrapped fire-resistant coating material that passes under the steel beam from the side of the steel beam opposite the fire-resistant board and extends toward the fire-resistant board with the protruding tip side overlapping the metal plate, and a welded fixing pin that penetrates the tip side of the wrapped fire-resistant coating material and has its tip welded to the metal plate.

[0015] Second aspect According to the composite fireproof covering structure for a steel beam, the fireproof board is installed on the side of the steel beam. A metal plate is attached to the surface of the fireproof board facing the steel beam. A tip of a wrapped fireproof covering material that passes under the steel beam and overhangs the fireproof board side from the opposite side of the steel beam to the fireproof board is overlapped on the metal plate. The tip of the wrapped fireproof covering material is attached to the fireproof board by a welded fixing pin that penetrates the tip and has a tip welded to the metal plate.

[0016] By attaching the metal plate to the fireproof board in this way, the tip side of the wrapped fireproof covering material can be easily attached to the fireproof board with a welding fixing pin, so that the space between the fireproof board and the steel beam can be blocked by the wrapped fireproof covering material while preventing damage to the fireproof board.

[0017] In addition, the metal plate can be attached to the fireproof board before the fireproof board is installed. Therefore, in the present invention, the metal plate can be attached to the fireproof board in a state that is easier to work with than when the metal plate is attached to the fireproof board after the fireproof board is installed. Therefore, damage to the fireproof board is further suppressed.

[0018] Furthermore, if the fireproof board is damaged after installation, it takes time to replace the fireproof board. In contrast, in the present invention, a metal plate is attached to the fireproof board before installation, so that even if the fireproof board is damaged, it can be easily replaced. Therefore, workability is improved.

[0019] According to the third aspect The composite fire-resistant coating structure for a steel beam comprises a steel beam, a fire-resistant board installed on the side of the steel beam with its surface facing the steel beam, a metal base material extending from the lower end of the steel beam toward the fire-resistant board, a wrapped fire-resistant coating material extending from the steel beam opposite the fire-resistant board toward the fire-resistant board, passing under the steel beam and the metal base material, with the protruding tip side being overlapped on the surface of the fire-resistant board, and a welded fixing pin that penetrates the tip side of the fire-resistant board and has its tip welded to the metal base material.

[0020] Third aspectAccording to the composite fireproof covering structure for a steel beam, the fireproof board is disposed on the side of the steel beam, with the front surface facing the steel beam. The front surface of the fireproof board is overlaid with the front end of the fireproof board, passing under the steel beam and the metal base material that protrudes from the lower end of the steel beam toward the fireproof board. The front end of the wrapped fireproof covering material is attached to the metal base material by a welded fixing pin that penetrates the front end and has its front end welded to the metal base material.

[0021] By providing the metal base material at the bottom end of the steel beam in this way, the wrapped fireproof covering material can be easily attached to the metal base material with a welding fixing pin, so that the space between the fireproof board and the steel beam can be blocked by the wrapped fireproof covering material while preventing damage to the fireproof board. Effect of the Invention

[0022] As described above, according to the present invention, the space between the fireproof board and the steel beam can be sealed with a wrap-around fireproof covering material while suppressing damage to the fireproof board. [Brief description of the drawings]

[0023] [Figure 1] 1 is a cross-sectional view showing a steel beam to which a composite fire-resistant coating structure for a steel beam according to a first embodiment is applied. FIG. [Diagram 2] FIG. 2 is an enlarged cross-sectional view showing the steel beam shown in FIG. [Diagram 3] FIG. 3 is a front view of the fireproof board shown in FIG. 2, seen from the steel beam side. [Figure 4] A cross-sectional view showing a steel beam to which a composite fire-resistant coating structure for a steel beam in accordance with a second embodiment is applied. [Diagram 5] 5 is a cross-sectional view corresponding to line 5-5 in FIG. 4. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] First embodiment First, the first embodiment will be described.

[0025] (Steel beam) 1 shows a steel beam 32 to which the composite fire-resistant coating structure for a steel beam according to this embodiment is applied. The steel beam 32 is formed of an H-shaped steel. The steel beam 32 has an upper flange 32B and a lower flange 32C that face each other in the vertical direction, and a web 32A that connects the upper flange 32B and the lower flange 32C.

[0026] The steel beams 32 are arranged along the ends of the slabs 20 to support the ends of the slabs 20. The slabs 20 are made of reinforced concrete and form the floors of a given floor of a multi-story structure. A curtain wall 12 is installed on the exterior side (the OUT side) of the steel beams 32 and the slabs 20.

[0027] (Curtain Wall) The curtain wall 12 constitutes the outer wall (exterior) of the structure. This curtain wall 12 has multiple mullions 14, upper and lower mullions 16 installed between adjacent mullions 14, and window glass 18 arranged within a frame surrounded by the multiple mullions 14 and the mullions 16. The mullions 14 are supported on a slab 20 via mullion brackets and fasteners (not shown).

[0028] (Fireproof board) The curtain wall 12 is arranged across the upper and lower floors of the structure, sandwiching the slab 20. A fireproof board 34 (fireproof board for curtain wall) is provided on the spandrel portion of this curtain wall 12. The fireproof board 34 is formed, for example, from a fiber-mixed calcium silicate board, a gypsum board, a rock wool board, a ceramic fiber board, or the like.

[0029] The fireproof board 34 is attached to the interior side of the curtain wall 12, facing the window glass 18. The outer periphery of the fireproof board 34 is held in place by a frame-shaped rail 36 that is provided along the mullions 14 and the latticework 16.

[0030] The fireproof board 34 is arranged with a space D left between it and the end of the slab 20. Also, the fireproof board 34 is arranged across the upper and lower floors of the structure with the slab 20 sandwiched therebetween. The upper part of this fireproof board 34 is supported by the slab 20 via a nut member 42 and a mounting member 44.

[0031] As shown in FIG. 2, the nut member 42 has a female screw portion 42A that is inserted into a through hole formed in the fireproof board 34, and a holding portion 42B that projects in a flange shape from the outdoor-side end of the female screw portion 42A and is in surface contact with the outdoor-side surface (outer surface) 34A of the fireproof board 34.

[0032] The mounting member 44 is formed of a steel plate or the like having an L-shaped cross section. This mounting member 44 has a mounting portion 44A that is attached to the upper surface of the slab 20, and a holding portion 44B that is in surface contact with the indoor-side surface (inner surface) 34B of the fireproof board 34.

[0033] A mounting hole 54 is formed in the mounting portion 44A. By screwing a bolt 56 inserted into this mounting hole 54 into an anchor nut 58 embedded in the upper surface of the slab 20, the mounting member 44 is fixed to the upper surface of the slab 20.

[0034] The holding portion 44B is overlapped with the surface 34B of the fireproof board 34. Also, a mounting hole 52 is formed in the holding portion 44B. By screwing a bolt 38 inserted into this mounting hole 52 into the female screw portion 42A of the nut member 42, the holding portion 44B is fixed to the surface 34B of the fireproof board 34.

[0035] Also, by screwing the bolt 38 into the female screw portion 42A of the nut member 42, the fireproof board 34 is held in a state of being sandwiched from both sides between the holding portion 42B of the nut member 42 and the holding portion 44B of the mounting member 44. Thereby, damage to the fireproof board 34 is suppressed.

[0036] A plurality of regulating members 60 are attached to the end of the slab 20. The plurality of regulating members 60 are arranged at intervals in the width direction of the fireproof board 34. Each regulating member 60 is bent in a crank shape. The regulating member 60 has an attachment portion 60A, an opposing portion 60B, and an overhanging portion 60C.

[0037] The mounting portion 60A is disposed between the upper surface of the slab 20 and the mounting portion 44A of the mounting member 44. Also, a mounting hole 62 is formed in the mounting portion 60A. The restricting member 60 and the mounting member 44 are fixed to the upper surface of the slab 20 by fastening the bolt 56 inserted into the mounting hole 62 and the mounting hole 54 of the mounting member 44 into the anchor nut 58.

[0038] The opposing portion 60B of the restricting member 60 extends downward from one end of the mounting portion 60A along the end face of the slab 20. A protruding portion 60C is provided at the lower end of this opposing portion 60B. The protruding portion 60C protrudes from the lower end of the opposing portion 60B toward the fireproof board 34, and its tip portion contacts the surface 34B of the fireproof board 34 below the nut member 42. This prevents the fireproof board 34 from tilting toward the slab 20 with the nut member 42 as a fulcrum.

[0039] A plate material 64 is placed across the overhanging portions 60C of adjacent restricting members 60. The plate material 64 is arranged along the space D between the fireproof board 34 and the slab 20. In addition, an interlayer sealing material 66 such as rock wool is placed on the plate material 64. By sealing the space D between the fireproof board 34 and the slab 20 with this interlayer sealing material 66, the inflow of hot air and flames from the space D to the floor above the slab 20 in the event of a fire is suppressed.

[0040] In this embodiment, the method of holding the fireproof board 34 using the nut members 42 has been described, but the method of holding the fireproof board 34 is not limited to this. The fireproof board 34 only needs to be supported by a framework such as the steel beams 32 and the floor (slab 20).

[0041] (Composite fireproof coating structure for steel beams) The steel beam 32 is fireproof covered by a composite fireproof structure of the fireproof board 34 and the wrapped fireproof covering material 80. Specifically, the fireproof board 34 is disposed on the side of the steel beam 32 on the outdoor side (the side indicated by the arrow OUT), with its surface 34B disposed opposite the outdoor side surface 32S1 of the steel beam 32. The fireproof board 34 provides fireproof coverage to the outdoor side surface 32S1 of the steel beam 32.

[0042] The exterior side surface 32S1 of the steel beam 32 conceptually includes the surface of the web 32A facing the exterior side (the side indicated by the arrow OUT), the end face of the upper flange 32B, and the end face of the lower flange 32C.

[0043] A backing material 70 and a metal plate 72 are attached to the surface 34B of the fireproof board 34 on the steel beam 32 side (the side indicated by the arrow IN). The backing material 70 and the metal plate 72 are attached to the fireproof board 34 in advance before the fireproof board 34 is installed.

[0044] The backing material 70 is formed into a rectangular column shape using rock wool, a calcium silicate board, or the like, and is joined to the surface of the fireproof board 34 with an adhesive or the like. The backing material 70 faces the lower end portion (lower flange 32C) of the steel beam 32.

[0045] 3, the backing material 70 is disposed along the width direction of the fireproof board 34, and extends from one end side to the other end side of the fireproof board 34. A metal plate 72 is attached below the backing material 70.

[0046] The metal plate 72 is made of a steel plate or the like. The metal plate 72 is disposed below the backing material 70 and adjacent to the backing material 70. The metal plate 72 is disposed along the width direction of the fireproof board 34, and extends from one end side to the other end side of the fireproof board 34. The metal plate 72 is formed with a plurality of through holes. The plurality of through holes are disposed at intervals in the longitudinal direction of the metal plate 72. The metal plate 72 is attached to the fireproof board 34 by screws 74 inserted into these through holes.

[0047] Note that the metal plate 72 is not limited to the screw 74. For example, it may be attached to the refractory board 34 by tightening a bolt inserted into the through hole of the metal plate 72 to a ghost eye nut embedded in the refractory board 34.

[0048] Also, the lining material 70 is not necessarily required to be installed and may be omitted. Here, the lining material 70 is installed to block the heat entering from the contact surface between the refractory board 34 and the tip side 84T of the lower surface covering portion 84 into the interior (side of the steel frame beam 32). Therefore, if the tip side 84T of the lower surface covering portion 84 is folded back downward along the refractory board 34 and a sufficient folding length is ensured, it is possible to prevent the intrusion of heat into the interior (side of the steel frame beam 32). In this case, the lining material 70 can be omitted.

[0049] (Wound refractory coating material) As shown in FIG. 2, the wound refractory coating material 80 is formed of rock wool or ceramic wool formed into a sheet shape. This wound refractory coating material 80 fireproofs the side surface 32S2 on the side opposite to the refractory board 34 (arrow IN side) of the steel frame beam 32 and the lower surface 32L of the steel frame beam 32, and projects toward the refractory board 34 side through the lower part of the steel frame beam 32.

[0050] Specifically, the wound refractory coating material 80 is bent in an L shape as a whole when viewed from the material axis direction of the steel frame beam 32. This wound refractory coating material 80 has a side surface covering portion 82 that fireproofs the indoor side surface 32S2 of the steel frame beam 32 and a lower surface covering portion 84 that fireproofs the lower surface 32L of the steel frame beam 32.

[0051] Note that the indoor side surface 32S2 of the steel frame beam 32 is a concept including the surface of the web 32A facing the indoor side (arrow IN side), the end surface of the upper flange 32B, and the end surface of the lower flange 32C.

[0052] The side covering part 82 is disposed along the beam direction of the steel beam 32 so as to cover the indoor-side side surface 32S2 of the steel beam 32. The side covering part 82 is disposed across the upper flange 32B and the lower flange 32C of the steel beam 32, and an upper end 82U of the side covering part 82 is attached to the end of the upper flange 32B by a welded fixing pin 90.

[0053] The lower surface covering portion 84 is disposed along the beam width direction of the steel beam 32 so as to cover the lower surface 32L of the lower flange 32C of the steel beam 32. The lower surface covering portion 84 also extends from the lower end of the side surface covering portion 82 along the lower surface of the lower flange 32C toward the fireproof board 34. The lower surface covering portion 84 is attached to the lower surface of the lower flange 32C by a welding fixing pin 90.

[0054] The tip side 84T of the lower surface covering part 84 is disposed along the lower surface of the backing material 70, and is overlapped on the surface 34B of the fireproof board 34 from above the metal plate 72. In addition, the tip side 84T of the lower surface covering part 84 is attached to the metal plate 72 by a plurality of welding fixing pins 90. The lower surface covering part 84 closes the space H between the fireproof board 34 and the steel beam 32.

[0055] The multiple welded fixing pins 90 are arranged at intervals in the width direction of the fireproof board 34. Each welded fixing pin 90 has a disk-shaped flange 90A and a pin 90B standing in the center of the flange 90A.

[0056] The pin 90B penetrates the tip side 84T of the lower surface covering portion 84 from below, and its tip is abutted against the metal plate 72. In this state, a current is passed from a welding machine (welding gun) (not shown) through the flange 90A to the pin 90B, thereby welding the tip of the pin 90B to the metal plate 72. The flange 90A is engaged with the lower surface of the lower surface covering portion 84. The tip side 84T of the lower surface covering portion 84 is attached to the surface 34B of the fireproof board 34 by this welding fixing pin 90.

[0057] This prevents hot air and flames from flowing into the steel beam 32 through the gap between the surface 34B of the fire-resistant board 34 and the tip side 84T of the underside covering portion 84 in the event of a fire. In addition, by arranging the tip side 84T of the underside covering portion 84 along the underside of the backing material 70, it is possible to further prevent hot air and flames from flowing into the steel beam 32 through the gap between the surface 34B of the fire-resistant board 34 and the tip side 84T of the underside covering portion 84 in the event of a fire.

[0058] (Construction method for composite fireproof coating structure of steel beams) Next, an example of a method for constructing a composite fire-resistant coating structure for a steel beam will be described.

[0059] (Fireproof board installation process) As shown in Fig. 1, first, in the fireproof board installation process, the curtain wall 12 is installed on the exterior side of the steel beam 32. Also, as shown in Fig. 2, the fireproof board 34, with the backing material 70 and metal plate 72 attached in advance to the surface 34B, is installed on the exterior side of the steel beam 32, so that the surface 34B of the fireproof board 34 faces the exterior side surface 32S2 of the steel beam 32.

[0060] Next, in the wrapping fireproof covering material installation process, the wrapping fireproof covering material 80 is installed so as to pass under the steel beam 32 from the side opposite the fireproof board 34 to the fireproof board 34 side.

[0061] More specifically, the side covering portion 82 of the wrapped fire-resistant covering material 80 is placed along the indoor side 32S2 of the steel beam 32, and its upper end 82U is attached to the end of the upper flange 32B of the steel beam 32 by a welded fixing pin 90.

[0062] Further, the lower surface covering portion 84 of the wrapped fire-resistant covering material 80 is placed along the lower surface of the lower flange 32C of the steel beam 32, and the lower surface covering portion 84 is attached to the lower surface of the lower flange 32C with a welding fixing pin 90. Furthermore, the tip side 84T of the lower surface covering portion 84 is placed along the lower surface of the backing material 70, and the tip side 84T is overlapped on the surface 34B of the fire-resistant board 34 from above the metal plate 72.

[0063] In this state, the pin 90B of the welding fixing pin 90 is inserted into the tip side 84T of the underside covering part 84, and the tip of the pin 90B is abutted against the metal plate 72 while the flange 90A is engaged with the underside of the underside covering part 84. In this state, a current is applied to the pin 90B from a welding machine (not shown) via the flange 90A to weld the tip of the pin 90B to the metal plate 72. As a result, the tip side 84T of the underside covering part 84 is attached to the fireproof board 34.

[0064] Through the above procedure, the steel beam 32 is fire-proofed by the fireproof board 34 and the wrap-around fireproof covering material 80.

[0065] The method for constructing the composite fireproof covering structure for the steel beam according to the present embodiment is not limited to the above-mentioned steps, and the above-mentioned steps may be replaced as appropriate. In addition to the above-mentioned steps, a new step may be added.

[0066] (Action and Effects) Next, the operation and effects of the first embodiment will be described.

[0067] 2, in this embodiment, the tip end portion of the pin 90B of the weld fixing pin 90 is welded to the metal plate 72, thereby attaching the tip end side 84T of the underside covering portion 84 of the wrapped fire-resistant covering material 80 to the fire-resistant board 34. Therefore, the space H between the fire-resistant board 34 and the steel beam 32 can be blocked by the underside covering portion 84 of the wrapped fire-resistant covering material 80, while preventing damage to the fire-resistant board 34.

[0068] Furthermore, in the fireproof board installation process, the fireproof board 34 to which the metal plate 72 has been attached in advance is installed on the side of the steel beam 32. Therefore, in this embodiment, the metal plate 72 can be attached to the fireproof board 34 with the screws 74 in an easier-to-construct state than in the case where the metal plate 72 is attached to the fireproof board 34 after the fireproof board 34 has been installed. Therefore, damage to the fireproof board 34 is further suppressed.

[0069] Furthermore, if the fireproof board 34 is damaged after installation, it takes time and effort to replace the fireproof board 34. In contrast, in this embodiment, the metal plate 72 is attached to the fireproof board 34 before installation, so that even if the fireproof board 34 is damaged, it can be easily replaced. Therefore, workability is improved.

[0070] Furthermore, the metal plate 72 is disposed below the backing material 70 and adjacent to the backing material 70. This allows the tip side 84T of the lower surface covering portion 84 to be easily overlapped on the metal plate 72 by disposing the tip side 84T of the lower surface covering portion 84 along the lower surface of the backing material 70. This further improves workability.

[0071] Second Embodiment Next, a second embodiment will be described. In the second embodiment, the same reference numerals will be used to designate the same members as in the first embodiment, and the description thereof will be omitted as appropriate.

[0072] As shown in Figure 4, in the composite fire-resistant coating structure for a steel beam in the second embodiment, the tip side 84T of the lower surface coating portion 84 of the wrapped fire-resistant coating material 80 is attached to a metal base material 100 attached to the lower end of the steel beam 32 by a welded fixing pin 90.

[0073] (Steel base material) 5, the metal base material 100 has a plurality of reinforcing bars 102 and a metal plate 104. The plurality of reinforcing bars 102 are formed of linear reinforcing bars or the like. The plurality of reinforcing bars 102 are also arranged at intervals in the material axial direction of the steel beam 32.

[0074] Each of the strength bones 102 is attached to the lower end of the steel beam 32 in a state in which it protrudes from the lower end of the steel beam 32 toward the fireproof board 34. More specifically, one end of each of the strength bones 102 is joined by welding or the like to the lower surface of the lower flange 32C of the steel beam 32. A metal plate 104 is attached to the tip side of the multiple strength bones 102 extending toward the fireproof board 34.

[0075] The metal plate 104 is formed of a strip-shaped steel plate or the like extending in the axial direction of the steel beam 32. This metal plate 104 is disposed below the tip ends of the multiple strength bones 102, and is joined to the tip ends of these strength bones 102 by welding or the like.

[0076] 4, the underside covering portion 84 of the wrapped fireproof covering material 80 extends along the underside of the metal base material 100 toward the fireproof board 34, with its tip side 84T overlapping the surface 34B of the fireproof board 34. The tip side 84T of this underside covering portion 84 is attached to the metal plate 104 of the metal base material 100 by a plurality of welding fixing pins 90. The underside covering portion 84 closes the space H between the fireproof board 34 and the steel beam 32.

[0077] More specifically, the pin 90B of the weld fixing pin 90 penetrates the tip side 84T of the lower surface covering portion 84 from below, and its tip is abutted against the metal plate 104. In this state, a current is passed from a welding machine (welding gun) (not shown) through the flange 90A to the pin 90B, thereby welding the tip of the pin 90B to the metal plate 104. The flange 90A is engaged with the lower surface of the lower surface covering portion 84. The weld fixing pin 90 attaches the tip side 84T of the lower surface covering portion 84 to the metal plate 104 of the metal base material 100.

[0078] This prevents hot air and flames from flowing into the steel beam 32 through the gap between the surface 34B of the fire-resistant board 34 and the tip side 84T of the underside covering portion 84 in the event of a fire. In addition, by arranging the tip side 84T of the underside covering portion 84 along the underside of the backing material 70, it is possible to further prevent hot air and flames from flowing into the steel beam 32 through the gap between the surface 34B of the fire-resistant board 34 and the tip side 84T of the underside covering portion 84 in the event of a fire.

[0079] (Action and Effects) Next, the operation and effects of the second embodiment will be described.

[0080] According to this embodiment, by providing the metal base material 100 at the lower end portion of the steel beam 32, the tip side 84T of the lower surface covering portion 84 of the wound fireproof covering material 80 can be attached to the metal plate 104 of the metal base material 100 by the welding fixing pin 90. Therefore, while suppressing the breakage of the fireproof board 34, the space H between the fireproof board 34 and the steel beam 32 can be closed by the lower surface covering portion 84 of the wound fireproof covering material 80.

[0081] Also, in this embodiment, like the first embodiment, since it is not necessary to attach the metal plate 104 to the fireproof board 34 with the screws 74 (see FIG. 2), breakage of the fireproof board 34 due to the screws 74 is suppressed.

[0082] Note that in the metal base material 100 of this embodiment, one metal plate 104 is attached to the tip sides of the plurality of web members 102. However, metal plates may be attached to the tip sides of the plurality of web members 102 respectively.

[0083] Also, the metal base material 100 of this embodiment includes a plurality of web members 102 and a metal plate 104. However, the metal plate 104 may be omitted from the metal base material 100, and the welding fixing pin 90 may be welded to the tip side of the web member 102.

[0084] Also, the metal base material 100 is not limited to the web member 102 or the like, and may be, for example, a shaped steel such as an L-shaped steel, a C-shaped steel, an H-shaped steel, or a steel pipe steel.

[0085] (Modification example) Next, modification examples of the above first embodiment and second embodiment will be described. In the following description, various modification examples will be described taking the first embodiment as an example, but these modification examples can also be appropriately applied to the second embodiment.

[0086] The fireproof board 34 according to the above embodiment is attached to the curtain wall 12. However, the fireproof board 34 is not limited to the curtain wall 12, and can also be attached to exterior materials such as precast concrete panels, ALC panels, and extruded cement panels (ECP).

[0087] Although one embodiment of the present invention has been described above, the present invention is not limited to such an embodiment, and one embodiment and various modified examples may be used in appropriate combination, and it is of course possible to implement the present invention in various forms without departing from the gist of the present invention. [Explanation of symbols]

[0088] 32 Steel beam 34 Fireproof board 34B Surface (fireproof board surface) 72 Metal plate 80 Wrapping fireproof coating material 84T Tip side (tip side of wrapped fireproof coating material) 90 Welded fixing pin 100 Metal base material

Claims

1. A fireproof board installation process for installing a fireproof board having a metal plate attached to a surface thereof that is not supported by a steel beam on the side of the steel beam, and facing the surface of the fireproof board to the steel beam; A winding fireproof covering material installation process in which a winding fireproof covering material is installed on the steel beam from the opposite side of the fireproof board, passing under the steel beam and protruding toward the fireproof board; a welding fixing pin installation process for inserting a welding fixing pin into a tip end of the wrapped fireproof covering material that protrudes toward the fireproof board side and welding a tip end of the welding fixing pin to the metal plate; A construction method for a composite fire-resistant coating structure for steel beams comprising:

2. Steel beams and A fireproof board is installed on the side of the steel beam and has a metal plate attached to a surface facing the steel beam that is not supported by the steel beam; A wound fireproof covering material that extends from the opposite side of the fireproof board in the steel beam to the fireproof board side through under the steel beam and has a protruding tip side overlapped with the metal plate; a weld fixing pin that penetrates the tip side of the wrapped fire-resistant covering material and has a tip portion welded to the metal plate; A composite fire-resistant coated steel beam structure.

3. The metal plate is attached to the surface of the fireproof board by a screw. The composite fire-resistant coating structure of steel beams according to claim 2.

4. A steel beam; a fireproof board installed on a side of the steel beam and having a surface facing the steel beam; A metal base material that protrudes from the lower end of the steel beam toward the fireproof board and does not support the fireproof board; A wrapped fireproof covering material that extends from the opposite side of the fireproof board in the steel beam to the fireproof board side through under the steel beam and the metal base material, and the protruding tip side is overlapped on the surface of the fireproof board; A weld fixing pin that penetrates the tip side of the fireproof board and has a tip portion welded to the metal base material; A composite fire-resistant coated steel beam structure.

5. The metal base material is arranged with a gap between it and the surface of the fireproof board. The composite fireproof coating structure for steel beams according to claim 4.

6. The metal base material protrudes from the lower end of the steel beam toward the fireproof board and has a plurality of strength ribs arranged at intervals in the material axis direction of the steel beam. A composite fire-resistant coating structure for a steel beam according to claim 4 or claim 5.

7. The metal base material extends in the material axis direction of the steel beam and has a metal plate attached to the tip side of the force beam. The composite fire-resistant coating structure for steel beams according to claim 6.

8. A curtain wall is provided on the side of the steel beam, The fireproof board is provided on the spandrel portion of the curtain wall. A composite fire-resistant coating structure for a steel beam according to any one of claims 2 to 7.

9. The fireproof board is formed of a calcium silicate board. The composite fireproof coating structure of a steel beam according to claim 8.

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