JP2014029093A - Junction structure of structural members - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a junction structure of structural members capable of inhibiting heat transferred from a steel structural member to a wooden structural member.SOLUTION: A junction structure of structural members 10 comprises: a first structural member 12 which is made of steel; a second structural member 14 which has a wooden core material 18 and a fire spread prevention layer 20; a junction member 24 which joins the first structural member 12 and the second structural member 14; and a covering layer 16 which covers the first structural member 12 to keep heat transferred from the same to the core material 18 at a temperature which does not cause the core material 18 to burn.

Description

  The present invention relates to a joining structure of a structural member obtained by joining a steel structural member and a wooden structural member.

  A technique for constructing a building by joining steel beams to wooden columns has been proposed. For example, in patent document 1, the steel beam is joined to the wooden pillar using the connection metal fitting.

  However, if the steel beam is heated in the event of a fire and this heat is transferred to the wooden column and exceeds the combustion start temperature of the wooden column, the wooden column will burn and it will not be possible to maintain the soundness of the structural member. End up. In general, the combustion start temperature of a wooden column is lower than the fireproof temperature of a steel beam (the temperature at which a steel beam can maintain its soundness as a structural member with almost no decrease in yield strength). Even if it is applied to the beam, there is a concern that the wooden pillar will burn due to the heat transferred from the steel beam.

JP 2009-174271 A

  This invention considers the fact which concerns, and makes it a subject to provide the joining structure of the structural member which can suppress the heat transmitted from the steel structural member to the wooden structural member.

  The invention according to claim 1 is a first structural member made of steel, a second structural member comprising a wooden core material that supports a load, and a flame stop layer surrounding the core material, and the first structural member. And the second structural member, a joining member for transmitting force from the first structural member to the core material and from the core material to the first structural member, and covering the first structural member, the first structural member And a covering layer that brings the heat transferred from the core to the core to a temperature at which the core does not burn.

  In the first aspect of the present invention, the heat transferred from the first structural member heated by the fire to the core material of the second structural member is set to a temperature at which the core material does not burn (temperature less than the combustion start temperature). Thus, the core material of the second structural member can be prevented from burning. Thereby, the fire resistance of a 2nd structural member is ensured at the time of a fire, and the soundness of the 2nd structural member as a structural member can be maintained.

  In addition, since the force is transmitted from the first structural member to the core material and from the core material to the first structural member by the bonding member, the bonding strength between the first structural member and the second structural member can be reliably ensured.

  Furthermore, since the fire resistance of the second structural member is obtained by a fireproof coating (coating layer) provided on the first structural member, the first structural member and the second structural member can be joined by a general joining method. .

  According to a second aspect of the present invention, in the joining structure of structural members according to the first aspect, the covering layer is a plate-like fireproof member surrounding the first structural member, and an end portion of the fireproof member And the flame stop layer are connected directly or through a fireproof seal.

  In the invention described in claim 2, by forming the coating layer as a plate-like fireproof member, the coating layer can be formed more easily than when the coating layer is formed by spraying.

  In addition, since the end of the refractory member and the flame stop layer are connected directly or via a fireproof seal, heat is transferred from the end of the refractory member and the flame stop layer to the core of the second structural member. Can be suppressed.

  According to a third aspect of the present invention, in the joint structure of the structural member according to the first or second aspect, the other than the joint end portion than the thickness of the covering layer covering the joint end portion of the first structural member. The thickness of the coating layer covering the portion of the first structural member is reduced.

  In invention of Claim 3, the coating amount of the fireproof coating with respect to the whole 1st structural member can be restrained, without reducing the fireproof performance of a 2nd structural member largely. Thereby, the weight reduction of the 1st structural member including a fireproof coating can be achieved.

  Since this invention was set as the said structure, the heat transmitted from the steel structural member to a wooden structural member can be suppressed.

It is a perspective view which shows the joining structure of the structural member which concerns on embodiment of this invention. It is a sectional side view which shows the joining structure of the structural member which concerns on embodiment of this invention. It is AA sectional drawing of FIG. It is a plane sectional view showing the modification of the joining structure of the structural member concerning the embodiment of the present invention. It is a perspective view which shows the modification of the joining structure of the structural member which concerns on embodiment of this invention. It is a perspective view which shows the modification of the joining structure of the structural member which concerns on embodiment of this invention. It is a cross-sectional view which shows the modification of the joining structure of the structural member which concerns on embodiment of this invention.

  Embodiments of the present invention will be described with reference to the drawings. First, a structure for joining structural members according to an embodiment of the present invention will be described.

  As shown in the perspective view of FIG. 1 and the side sectional view of FIG. 2, the structural member joining structure 10 (hereinafter referred to as “joining structure 10”) of the present embodiment includes a beam 12 as a first structural member, It has the pillar 14 as a 2nd structural member, the gusset plate 24 as a joining member, and the coating layer 16 as a fireproof coating.

  The beam 12 is made of H-shaped steel. The column 14 includes a column core material 18 as a wooden core material that supports a load, a flame stop layer 20 that surrounds the periphery of the column core material 18, and a wooden burn allowance layer 22 that surrounds the periphery of the flame stop layer 20. . The gusset plate 24 is made of a steel plate, and a plate-like base plate 26 is provided at the end.

  The end portion (base plate 26) of the gusset plate 24 is inserted into a notch portion 42 formed on the side surface (burning stop layer 20 and burning allowance layer 22) of the column 14 on the beam 12 side. The beam 12 is joined to the column 14 with the back surface 36 of the base plate 26 in contact with the side surface 18.

  The gusset plate 24 allows the anchor bolts 28 to pass through through holes 38 formed substantially horizontally in the column core material 18, and nuts 30 and 32 are screwed and tightened to both ends of the anchor bolt 28, whereby the column core material 18. The back surface 36 is brought into contact with the side surface and fixed to the column core material 18. Thereby, the gusset plate 24 is provided so as to protrude to the outside of the column 14. For example, as shown in FIG. 2, a plate 150 may be interposed between the column core material 18 (the bottom surface of a notch portion 34 described later) and the nut 30. In this way, when the nut 30 is tightened, the nut 30 can be prevented from sinking into the column core material 18.

  As shown in FIG. 2, a notch 34 in which the nut 30, the left end of the anchor bolt 28, and the plate 150 are accommodated is formed on the side surface opposite to the beam 12 of the column core 18. A flame stop layer 20 and a burn allowance layer 22 are provided so as to cover 34. The notch 34 is filled with a heat insulating material M such as rock wool or mortar and is subjected to a fireproofing treatment to prevent heat from entering the column core material 18 from the notch 34. In addition, without forming the notch portion 34, for example, the nut 30, the left end portion of the anchor bolt 28, and the notch portion that accommodates the plate 150 are disposed on the side surface opposite to the beam 12 of the column 14 (the flame stop layer 20 and It may be formed in the burning allowance layer 22) and the notch may be filled with the heat insulating material M.

  The beam 12 is pin-connected to the gusset plate 24 by being bolted to the gusset plate 24 by high strength bolts 44 and nuts 46. Thus, the gusset plate 24 pins the beam 12 to the column 14 and transmits a force from the beam 12 to the column core 18 and from the column core 18 to the beam 12.

  The covering layer 16 is formed by plate-like fire-resistant members 40A to 40C made of calcium silicate plates that are attached to the beam 12 by box attachment and cover the side and lower surfaces of the beam 12. The heat transferred from the beam 12 to the column core member 18 is set to a temperature at which the column core member 18 does not burn. The temperature at which the column core material 18 does not burn is the flame resistance temperature of the column 14 that can maintain the soundness as a structural member without burning down the column core material 18 that constitutes the column 14 at the time of fire, that is, the column. It means a temperature (for example, 260 ° C.) lower than the combustion start temperature of the core material 18.

  As shown in FIG. 3 which is an AA cross-sectional view of FIG. 2, the end portions (end surfaces) of the refractory members 40A and 40B constituting the side wall of the covering layer 16 and the side surface of the flame stop layer 20 are directly or refractory. It is connected through a seal. In FIG. 3, the end portions (end surfaces) of the refractory members 40 </ b> A and 40 </ b> B are brought into contact with the side surfaces of the flame stop layer 20, and the end portions (end surfaces) of the refractory members 40 </ b> A and 40 </ b> B and the side surfaces of the flame stop layer 20 are directly connected. An example is shown. Moreover, as shown in FIG. 2, the edge part (end surface) of the refractory member 40C which comprises the bottom wall of the coating layer 16, and the side surface of the column core material 18 are connected directly or through the refractory seal. FIG. 2 shows an example in which the end portion (end surface) of the refractory member 40C is brought into contact with the side surface of the column core member 18 and the end portion (end surface) of the refractory member 40C and the side surface of the column core member 18 are directly connected. Yes. The end portions (end surfaces) of the refractory members 40A and 40B may be connected to the side surfaces of the column core 18 directly or through a refractory seal, or the end portions (end surfaces) of the refractory members 40C may be connected to the side surfaces of the flame stop layer 20. Further, they may be connected directly or through a fireproof seal.

  As shown in FIG. 2, a floor slab 48 made of reinforced concrete is provided on the upper surface of the beam 12. Further, the notch portion 42 is formed between the upper surface of the base plate 26, the lower surfaces of the non-burning layer 20 and the burning allowance layer 22, and the lower surface of the base plate 26 with the gusset plate 24 fixed to the side surface of the column core material 18. And a gap of about 10 to 20 mm between the upper surface of the flame stop layer 20 and the burn allowance layer 22 (hereinafter, the gap formed on the upper surface of the base plate 26 is referred to as “upper joint”, The gap formed on the lower surface of the base plate 26 is referred to as “lower joint”). In this way, since the opening area of the notch 42 can be increased, the gusset plate 24 (base plate 26), the beam 12, and the refractory members 40A to 40C can be easily inserted.

  The upper joint and the lower joint are filled with a heat insulating material W such as rock wool and mortar, and are subjected to a fireproofing treatment, thereby preventing heat from entering from the upper joint and the lower joint. In addition, when the upper joint and the lower joint are filled with a heat-insulating flexible material, the upper joint and the lower joint can be obtained even when the flame-stopping layer 20 and the burning allowance layer 22 contract in the vertical direction due to drying or the like. Can be kept closed.

  In the construction method for constructing the joint structure 10, first, the through-hole 38 formed in the column core 18 of the column 14 in a state in which the back surface 36 of the gusset plate 24 is brought into contact with the side surface of the column core 18 and the gusset plate 24 is disposed. Then, the anchor bolt 28 is inserted into the fixing hole 54 formed in the base plate 26.

  Next, the gusset plate 24 is fixed to the side surface of the column core member 18 by screwing and tightening the nuts 30 and 32 to both ends of the anchor bolt 28.

  Next, the beam 12 is bolted to the gusset plate 24 by the high strength bolt 44 and the nut 46.

  Next, the notch 34 is filled with the heat insulating material M, and the upper joint and the lower joint are filled with the heat insulating material W, and then concrete is placed on the upper surface of the beam 12 to form the floor slab 48.

  In addition, the column core material 18 and the burning allowance layer 22 should just be formed with the timber. For example, the pillar core material 18 and the burning margin layer 22 may be formed of wood (hereinafter referred to as “general wood”) used in general wooden construction such as Yonematsu, Karamatsu, firewood, cedar, and Asunaro. The general wood may be processed into a single material such as a plate or a prism, and a plurality of such single materials may be assembled and bonded together with an adhesive to be integrated.

  Moreover, the flame stop layer 20 should just be a layer which can suppress a flame and the entrance | invasion of a heat | fever, and can exhibit a flame stop effect. For example, the flame stop layer 20 may be a layer having flame retardancy or a layer capable of absorbing heat.

  Examples of the flame retardant layer include a flame retardant chemical injection layer obtained by injecting a flame retardant chemical into wood and making it incombustible. The layer capable of absorbing heat may be formed of a material having a larger heat capacity than general wood, a material having higher thermal insulation than general wood, or a material having higher thermal inertia than general wood. It may be formed by combining with general wood (in FIG. 3, plate members 50 formed of mortar which is a material having a larger heat capacity than general wood and plate members 52 formed of general wood are alternately arranged. An example is shown in which it is arranged to form a flame stop layer 20). In addition, a flame-retardant layer is formed by combining a layer having flame retardancy and a layer capable of absorbing heat (for example, alternately arranging layers having flame retardancy and layers capable of absorbing heat). 20 may be formed.

  Examples of materials having a larger heat capacity than general wood include inorganic materials such as mortar, stone, glass, fiber reinforced cement, and plaster, and various metal materials. Examples of the material having higher heat insulation than general wood include calcium silicate board, rock wool, and glass wool. Examples of the material having higher thermal inertia than general wood include wood such as Selangan Batu, Jara, and Bongoshi.

  Next, the operation and effect of the joint structure for structural members according to the embodiment of the present invention will be described.

  In the joint structure 10 according to the embodiment of the present invention, the beam 12 is pin-joined to the gusset plate 24 by bolting the beam 12 to the gusset plate 24 with high-strength bolts 44 and nuts 46 as shown in FIGS. Is done. As a result, the beam 12 is pin-joined to the column 14. In addition, since the force is transmitted from the beam 12 to the column core member 18 and from the column core member 18 to the beam 12 by the gusset plate 24, the bonding strength between the beam 12 and the column 14 can be reliably ensured.

  Further, as shown in FIG. 3, in the pillar 14, when a fire occurs, a flame ignites the burning allowance layer 22 and the burning allowance layer 22 burns. The burned combustion allowance layer 22 is carbonized. As a result, the burning allowance layer 22 that carbonizes heat transfer from the outside of the pillar 14 to the pillar core material 18 and the oxygen supply is cut off, and the burning stop layer 20 absorbs heat, so at the time of fire (heating) and the end of fire (heating) The temperature rise of the column core material 18 afterwards can be suppressed.

  Therefore, during the fire (heating) and after the end of the fire (heating), the column core material 18 of the column 14 is kept below the combustion start temperature for a predetermined time (for example, 1 hour in the case of fire resistance for 1 hour). The core material 18 can be burned off without burning.

  Further, the covering layer 16 changes the heat transferred from the beam 12 heated by the fire to the column core material 18 of the column 14 to a temperature at which the column core material 18 does not burn (temperature lower than the combustion start temperature). It is possible to prevent the column core material 18 from burning. Thereby, the fire resistance of the pillar 14 is ensured at the time of a fire, and the soundness of the pillar 14 as a structural member can be maintained.

  Moreover, since the fire resistance of the column 14 is obtained by the fireproof coating (coating layer 16) provided on the beam 12, the beam 12 and the column 14 can be joined by a general joining method.

  As shown in FIGS. 2 and 3, the cover layer 16 can be formed into plate-like fireproof members 40 </ b> A to 40 </ b> C, so that the cover layer can be formed more easily than when the cover layer is formed by spraying.

  Furthermore, since the edge part (end surface) of the refractory members 40A and 40B and the side surface of the flame stop layer 20 are connected directly or via a fireproof seal, the end part of the fire resistant members 40A and 40B and the flame stop layer 20 are connected. It is possible to suppress the heat from being transmitted to the column core material 18 of the column 14.

  The embodiment of the present invention has been described above.

  In the present embodiment, as shown in FIG. 2, an example in which the gusset plate 24 is fixed to the side surface of the column core member 18 is shown, but force is applied from the beam 12 to the column core member 18 and from the column core member 18 to the beam 12. If it can be communicated, the gusset plate 24 may be fixed to the flame stop layer 20 or the burn allowance layer 22.

  Further, in the present embodiment, as shown in FIG. 2, the example in which the gusset plate 24 is fixed to the column core 18 of the column 14 using the anchor bolt 28 is shown, but the gusset plate 24 is securely fixed to the column core 18. If possible, other fixing methods may be used. For example, the gusset plate 24 may be fixed to the column core 18 with a lag screw.

  Furthermore, in this embodiment, although the example which connected the edge part (end surface) of the fireproof members 40A and 40B and the side surface of the flame stop layer 20 directly or through the fireproof seal was shown, for example, the plane of FIG. You may make it the structure of the joining structure 74 of the structural member shown in sectional drawing. In FIG. 4, the plate member 50 located at the beam 12 side corner portion of the flame stop layer 20 is provided so as to reach the side surface of the column 14 on the beam 12 side, and the side surface 56 of the plate member 50 located at this corner portion; The ends (end surfaces) of the fireproof members 40A and 40B are connected directly or via a fireproof seal.

  Moreover, in this embodiment, although the example which formed the coating layer 16 as fireproof coating by the plate-shaped fireproof members 40A-C comprised by the calcium silicate board was shown, this fireproof coating (coating layer 16) is shown. In the event of a fire, the beam 12 does not reach a temperature higher than the fireproof temperature (the temperature at which the H-shaped steel constituting the beam 12 can maintain its soundness as a structural member with almost no decrease in yield strength, eg, 350 ° C.) The temperature at which the column core 18 does not burn the heat transmitted from the beam 12 heated by the fire to the column core 18 of the column 14 (a temperature lower than the combustion start temperature of the column core 18; for example, 260 As long as it can be coated so as not to reach a temperature higher than ° C), it may be formed using a material other than the calcium silicate plate. For example, the fireproof coating may be formed of wet fireproof paint, sprayed rock wool, dry rock wool sheet, high heat resistant rock wool sheet, thermal expansion sheet, calcium silicate board, gypsum board, wooden board, concrete member.

  The dry fireproof coating material may be attached directly to the H-shaped steel constituting the beam 12 or may be attached by box attachment. Moreover, if the wooden board of a finishing material is used as a fireproof coating material, it can improve aesthetics and can improve design. By burning and carbonizing the wooden board in the event of a fire, heat transfer from the outside of the wooden board to the beam 12 and oxygen supply can be blocked, and the temperature rise of the beam 12 can be suppressed. In general, wood burns about 0.6 mm per minute. Therefore, when a wooden board is used as a fireproof coating material that is fireproof for 1 hour, the thickness may be 36 mm (= 0.6 mm × 60 minutes) or more.

  The perspective view of FIG. 5 shows an example of a joining structure 76 of structural members in which a coating layer 58 as a fireproof coating covering the beam 12 is formed by spraying rock wool 60, and the perspective view of FIG. The example of the joining structure 78 of the structural member which formed the covering layer 62 as a fireproof covering which covers the concrete 64 from the concrete is shown.

  Furthermore, a wood hybrid member in which steel material is embedded may be used as the beam 12. In the wood hybrid member, the wood covering the steel material serves as a fireproof coating.

  Moreover, you may make it provide the same kind or different kind of fireproof coating material in piles. In the cross-sectional view of FIG. 7, an example of a joining structure 80 of structural members in which a covering layer 66 covering the beam 12 is formed by spraying rock wool 60 and the covering layer 68 covering the covering layer 66 is formed by the refractory members 40A to 40C. It is shown. That is, in FIG. 7, a plurality of fireproof covering materials (covering layers 66 and 68) are provided in an overlapping manner.

  Moreover, in this embodiment, although the example which covers the beam 12 with the coating layer 16 was shown, joining edge part rather than the coating thickness of the coating layer 16 which covers the joining edge part 70 (refer FIG. 1) of the beam 12 is shown. The covering thickness of the covering layer 16 that covers a portion of the beam 12 other than 70 (for example, the central portion of the beam 12) may be reduced. For example, the coating thickness of the coating layer 16 that covers the joint end portion 70 of the beam 12 is set to a coating thickness that suppresses the temperature of the beam 12 to 260 ° C. or less, and the coating thickness of the coating layer 16 that covers the central portion of the beam 12. Is set to a coating thickness that suppresses the temperature of the beam 12 to 350 ° C. or less.

  If it does in this way, the covering amount of the fireproof covering with respect to the whole beam 12 can be suppressed, without reducing the fireproof performance of the pillar 14 significantly. Thereby, the weight reduction of the beam 12 including a fireproof coating can be achieved.

  Furthermore, in the present embodiment, the first structural member is a steel beam (beam 12) made of H-shaped steel, and the second structural member is made up of the column core material 18, the dead end layer 20, and the burning allowance layer 22. In this example, the first structural member is a steel column composed of H-shaped steel, and the second structural member is composed of a core material, a dead end layer, and a burning allowance layer. It may be a wooden beam. Moreover, you may use the joining structure 10 of this embodiment for joining of other structural members (joining of a steel structural member and a wooden structural member).

  Further, in the present embodiment, as shown in FIG. 2, an example in which the beam 12 is pin-bonded to the column 14 by bolting the beam 12 to the gusset plate 24 is shown, but the beam 12 is rigidly bonded to the column 14. May be.

  Furthermore, in this embodiment, as shown in FIG. 1, an example in which one beam 12 is joined to the column 14 is shown, but any number of beams 12 to be joined to the column 14 may be used. For example, only one beam 12 may be joined to the column 14, or two or three beams 12 may be joined to the column 14 so as to be arranged in a straight line, an L shape, or a T shape in plan view. Alternatively, the four beams 12 may be joined to the columns 14 so as to be radially arranged in a plan view.

  Further, in the present embodiment, as shown in FIG. 1, the column 14 as the second structural member includes a column core 18 as a wooden core that supports a load, and a flame stop layer 20 surrounding the column core 18. Although the example provided with the wood burning allowance layer 22 surrounding the periphery of the flame stop layer 20 is shown, the second structural member includes the wood core material supporting the load and the flame stop layer surrounding the periphery of the heart material. As long as it has. That is, the burn allowance layer 22 may be provided as appropriate, and the periphery of the flame stop layer 20 may be surrounded by a layer other than the burn allowance layer 22 (for example, a thin wooden finish).

  As mentioned above, although embodiment of this invention was described, this invention is not limited to such embodiment at all, Of course, in the range which does not deviate from the summary of this invention, it can implement in a various aspect.

10, 74, 76, 78, 80 Structural member joint structure 12 Beam (first structural member)
14 Pillar (second structural member)
16, 58, 62, 66, 68 Coating layer 18 Column core material (core material)
20 Flame stop layer 24 Gusset plate (joining member)
70 Joint end

Claims (3)

A first structural member made of steel;
A second structural member comprising a wooden core material supporting a load and a dead end layer surrounding the core material;
A joining member that joins the first structural member and the second structural member, and transmits a force from the first structural member to the core material and from the core material to the first structural member;
A coating layer that covers the first structural member and sets the heat transferred from the first structural member to the core material so that the core material does not burn;
Bonding structure of structural members having The covering layer is a plate-like fireproof member that surrounds the periphery of the first structural member,
The joining structure of the structural member according to claim 1, wherein an end portion of the refractory member and the flame stop layer are connected directly or through a refractory seal.   The thickness of the said coating layer which covers the site | parts of the said 1st structural member other than the said joining edge part is made thinner than the thickness of the said coating layer which covers the joining edge part of the said 1st structural member. Bonding structure of structural members.

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