JP6423655B2 - Floor structure - Google Patents

Description

  The present invention relates to a floor structure having a floor slab formed using a deck plate and supported by a wooden beam.

  There is a floor structure in which a steel deck plate is installed on a beam as a bottom formwork, a reinforcing bar is placed on the deck plate, and then concrete is placed to form a floor slab. For example, Patent Document 1 discloses a floor slab formed by placing concrete on a deck plate having a plurality of webs.

  However, when the beam is made of wood, there is a concern that the deck plate becomes a thermal bridge in the event of a fire, heat is transferred from the deck plate to the beam core, and the beam core reaches the combustion temperature.

JP 2003-239439 A

  This invention considers the fact which concerns, and makes it a subject to suppress transmission of the heat | fever from the deck plate of a floor slab at the time of a fire to the core material of a wooden beam.

A first aspect of the invention is a floor structure comprising: a deck plate having an end placed only on an outer peripheral portion surrounding a core material of a wooden beam; and a floor slab formed by placing concrete on the deck plate. It is.

In the first aspect of the invention, since the end portion of the deck plate is placed only on the outer peripheral portion of the wooden beam, the transfer of heat from the deck plate to the core material during a fire can be suppressed. Thereby, the temperature rise of the core material can be suppressed and the core material can be prevented from reaching the combustion temperature and burning. Therefore, in the event of a fire, the wooden beam can function as a structural member, and the state in which the floor slab is supported by the wooden beam can be maintained.

  According to a second aspect of the invention, in the floor structure of the first aspect, there is a truss reinforcing bar that is joined to the upper surface of the deck plate, and an end portion that protrudes from the deck plate is supported by the core material.

  In the invention of the second aspect, the weight of the concrete, the deck plate, and the truss reinforcing bar when the concrete is placed on the deck plate is mainly transmitted to the core material through the truss reinforcing bar, and these weights are mainly transmitted by the core material. Can bear.

  Therefore, even when the supporting force sufficient to support the deck plate cannot be expected at the outer peripheral portion of the wooden beam when placing concrete on the deck plate, the deck plate can be supported by the core material of the wooden beam. As a result, there is no need to install a support for supporting the deck plate, so it is possible to secure a construction flow line on the lower floor of the floor slab and increase the degree of freedom of the construction process on the lower floor of the floor slab. .

  In addition, the heat transferred from the deck plate to the truss rebar during a fire is absorbed by the concrete placed on the deck plate.

  Therefore, the transmission of heat from the deck plate to the core material via the truss reinforcement can be suppressed. Thereby, the temperature rise of the core material at the time of a fire can be suppressed, and it can prevent that a core material reaches combustion temperature and burns.

  The invention of the third aspect is the floor structure of the first or second aspect, wherein a hanging margin of the end portion of the deck plate to the outer peripheral portion is 20 mm or more, and a distance from the end portion of the deck plate to the core material is set. 30 mm or more.

  In the invention of the third aspect, the end of the deck plate can be reliably placed on the outer peripheral portion by setting the allowance for the outer peripheral portion of the end of the deck plate to 20 mm or more.

In addition, by setting the distance from the end of the deck plate to the core material to be 30 mm or more, when the outer periphery is burned by the transfer of heat from the deck plate to the outer periphery during a fire, the combustion of the outer periphery is the fireproof time. It can prevent reaching the heartwood inside.
In the invention of the fourth aspect, the outer peripheral portion has a burning stop layer surrounding the outer periphery of the core material, and a wooden burning allowance layer surrounding the outer periphery of the burning stop layer, and the end of the deck plate is It is a floor structure that is mounted only on the burning allowance layer and fixed by screws.

  Since this invention was set as the said structure, the transmission of the heat | fever from the deck plate of a floor slab to the core material of a wooden beam at the time of a fire can be suppressed.

It is a front sectional view showing the floor structure concerning a 1st embodiment of the present invention. It is front sectional drawing which shows the floor structure concerning 2nd Embodiment of this invention. It is a perspective view which shows the deck plate to which the truss reinforcement which concerns on 2nd Embodiment of this invention was attached.

  Embodiments of the present invention will be described with reference to the drawings. First, the floor structure according to the first embodiment of the present invention will be described.

  As shown in the front sectional view of FIG. 1, the floor structure 10 of the first embodiment includes a steel deck plate 12 and a floor slab 14. The deck plate 12 is supported by a wooden beam 16 as a wooden beam.

  The beam 16 includes a wooden beam core 18 as a core material for supporting a load, and an outer peripheral portion 20 disposed on the lower surface and side surfaces of the beam core 18 so as to surround the beam core 18. The outer peripheral portion 20 is configured to include a burning stop layer 22 that surrounds the outer periphery of the beam core portion 18 and a wooden burning allowance layer 24 that surrounds the outer periphery of the burning stop layer 22. The deck plate 12 is supported by the beam 16 with an end portion 26 placed on the burnup layer 24 of the outer peripheral portion 20 constituting the beam 16. The end portion 26 of the deck plate 12 is fixed to the burning allowance layer 24 by screws 28. If the gap between the lower surface of the end portion 26 of the deck plate 12 and the upper surface of the burnup layer 24 is reduced (for example, 3 mm or less), the lower surface of the end portion 26 of the deck plate 12 and the burnup layer 24 It is preferable because heat can be prevented from entering between the upper surface. It is more preferable that the lower surface of the end portion 26 of the deck plate 12 and the upper surface of the burning allowance layer 24 are brought into close contact with each other.

  The floor slab 14 is formed by placing a reinforcing bar 30 on the deck plate 12, placing concrete U on the deck plate 12 in-situ, and embedding the reinforcing bar 30 in the concrete U. As the deck plate 12, a flat deck plate is used. The flat deck plate is an end-closed deck plate made of a thin steel plate having a flat upper surface and ribs provided on the lower surface, and plays a role as a bottom mold when casting concrete for forming a floor slab.

Further, in the floor structure 10, the allowance L ₁ to the outer peripheral portion 20 of the end portion 26 of the deck plate 12 is set to 20 mm or more, and the distance L ₂ from the end portion 26 of the deck plate 12 to the beam core portion 18 is set to 30 mm or more.

  The outer peripheral portion 20 of the beam 16 means a portion of a layer provided on the outer periphery of a core material (a portion that bears a load in structural design) that supports a load in the beam. In the case of being formed of wood, the outer peripheral portion of the beam is provided on the outer periphery of the core portion supporting the load and assumed to disappear in the event of a fire.

  The beam core part 18 and the burning allowance layer 24 should just be formed with the timber. For example, the beam core 18 and the burning margin layer 24 may be formed of wood used for general wooden construction such as Yonematsu, Karamatsu, firewood, cedar, and Asunaro (hereinafter referred to as “general wood”). It may be a so-called laminated material obtained by processing general wood into plate-shaped or prismatic-shaped lumber, and assembling a plurality of these lumbers and bonding the lumbers together with an adhesive. FIG. 1 shows an example in which a beam core portion 18 and a burning allowance layer 24 are formed by a laminated material obtained by assembling a plurality of lumbers made of general wood and bonding the lumbers together with an adhesive.

  Moreover, the flame stop layer 22 should just be a layer which can suppress a flame and heat approach and can exhibit the flame stop effect. For example, the flame stop layer 22 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. You may form in combination with general wood. In FIG. 1, an example in which the flame-stopping layer 22 is formed by alternately arranging plate members 32 made of mortar that is a material having a larger heat capacity than general wood and wood parts 34 made of general wood. It is shown. The plate member 32 is fixed to the beam core 18 by screws 36.

  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 floor structure according to the first embodiment of the present invention will be described.

  In the floor structure 10 of the first embodiment, as shown in FIG. 1, in the beam 16, when a fire occurs, a flame ignites the burning margin layer 24 and the burning margin layer 24 burns. The burned combustion allowance layer 24 is carbonized. Thereby, the burning allowance layer 24 which carbonized heat transfer from the outside of the beam 16 to the beam core portion 18 is suppressed, and the heat transmitted from the outside of the beam 16 to the beam core portion 18 is burned and the layer 22 absorbs. Or the temperature rise of the beam core part 18 at the time of a fire and after the end of a fire can be suppressed, the beam core part 18 can be suppressed to less than a combustion temperature (for example, 260 ° C.), and the beam core part 18 can be burned out without burning. Therefore, the floor slab 14 can be supported by the beam core 18 during a predetermined time at the time of fire, or at the time of fire and after the end of fire.

  Moreover, in the floor structure 10 of 1st Embodiment, as shown in FIG. 1, since the edge part 26 of the deck plate 12 is mounted in the outer peripheral part 20 of the beam 16, from the deck plate 12 to the beam center part 18 at the time of a fire. Heat transfer can be suppressed. Thereby, the temperature rise of the beam core 18 can be suppressed, and the beam core 18 can be prevented from reaching the combustion temperature (for example, 260 ° C.) and burning. Therefore, in the event of a fire, the wooden beam 16 can function as a structural member, and the state in which the floor slab 14 is supported by the beam 16 can be maintained.

Furthermore, the floor structure 10 of the first embodiment, as shown in FIG. 1, a take cash L ₁ of the outer peripheral portion 20 of the end 26 of the deck plate 12 by a more than 20 mm, the deck plate to the outer peripheral portion 20 Twelve end portions 26 can be securely mounted.

Moreover, the floor structure 10 of the first embodiment, as shown in FIG. 1, the distance L ₂ from the end portion 26 of the deck plate 12 to Ryokokoro portion 18 by the above 30 mm, the outer peripheral from the deck plate 12 at the time of a fire When the outer peripheral portion 20 is combusted by the transfer of heat to the portion 20, the combustion of the outer peripheral portion 20 can be prevented from reaching the beam core portion 18 within the fireproof time.

  The first embodiment of the present invention has been described above.

  In the first embodiment, as shown in FIG. 1, an example in which the deck plate 12 is a flat deck plate is shown. However, the deck plate 12 may serve as a steel bottom mold. Any other shape may be used. For example, the deck plate 12 may be a steel plate provided with an emboss or a groove.

  Next, the floor structure according to the second embodiment of the present invention will be described. In the description of the second embodiment of the present invention, the same components as those in the first embodiment are denoted by the same reference numerals, and are appropriately omitted.

  As shown in the front sectional view of FIG. 2, the floor structure 38 of the second embodiment includes a steel deck plate 40 and a floor slab 42. The deck plate 40 is supported by the beam 16 with an end 44 placed on the burning allowance layer 24 of the outer peripheral portion 20 constituting the beam 16. An end portion 44 of the deck plate 40 is fixed to the combustion allowance layer 24 by screws 28. If the gap between the lower surface of the end portion 44 of the deck plate 40 and the upper surface of the burning allowance layer 24 is reduced (for example, 3 mm or less), the lower surface of the end portion 44 of the deck plate 40 and the burning allowance layer 24 It is preferable because heat can be prevented from entering between the upper surface. More preferably, the lower surface of the end portion 44 of the deck plate 40 and the upper surface of the combustion allowance layer 24 are brought into close contact with each other.

  As shown in the perspective view of FIG. 3, a deck plate with a truss reinforcing bar is used for the deck plate 40. The deck plate with truss rebar is composed of a flat plate made of steel with the truss rebar 46 joined and attached to the upper surface, and plays a role as a bottom formwork when casting concrete to form a floor slab .

  As shown in FIG. 2, the floor slab 42 is formed by casting concrete U on the deck plate 40 and embedding truss reinforcing bars 46 in the concrete U.

Moreover, the floor structure 38, the take cash _{L 1} of the outer peripheral portion 20 of the end portion 44 of the deck plate 40 and above 20 mm, and the distance _{L 2} from the end portion 44 of the deck plate 40 to Ryokokoro portion 18 as the above 30 mm.

  As shown in FIGS. 2 and 3, the truss reinforcing bar 46 is provided so that the end of the truss reinforcing bar 46 protrudes from the deck plate 40, and a leg member 48 provided at the end of the truss reinforcing bar 46. It is supported by the beam core part 18 via. It is preferable that the lower end portion 50 of the leg member 48 is securely fixed to the beam core portion 18 using a spacer or the like. As shown in FIG. 2, the ends of the upper end bars 52 of the truss reinforcing bars 46 are connected by an upper end connecting bar 54.

  The deck plate 40 can be manufactured, for example, by using a ready-made deck plate with a truss reinforcing bar and cutting an end portion of the deck plate with the truss reinforcing bar. In this way, it is possible to reduce the time and effort for manufacturing the deck plate with truss reinforcement.

  Next, the operation and effect of the floor structure according to the second embodiment of the present invention will be described.

  In the floor structure 38 of the second embodiment, as shown in FIG. 2, in the beam 16, when a fire occurs, a flame ignites the burning margin layer 24 and the burning margin layer 24 burns. The burned combustion allowance layer 24 is carbonized. Thereby, the burning allowance layer 24 which carbonized heat transfer from the outside of the beam 16 to the beam core portion 18 is suppressed, and the heat transmitted from the outside of the beam 16 to the beam core portion 18 is burned and the layer 22 absorbs. Or the temperature rise of the beam core part 18 at the time of a fire and after the end of a fire can be suppressed, the beam core part 18 can be suppressed to less than a combustion temperature (for example, 260 ° C.), and the beam core part 18 can be burned out without burning. Therefore, the floor slab 42 can be supported by the beam core 18 during a predetermined time at the time of fire, or at the time of fire and after the end of fire.

  Moreover, in the floor structure 38 of 2nd Embodiment, since the edge part 44 of the deck plate 40 is mounted in the outer peripheral part 20 of the beam 16, as shown in FIG. 2, from the deck plate 40 to the beam center part 18 at the time of a fire. Heat transfer can be suppressed. Thereby, the temperature rise of the beam core 18 can be suppressed, and the beam core 18 can be prevented from reaching the combustion temperature (for example, 260 ° C.) and burning. Therefore, in the event of a fire, the wooden beam 16 can function as a structural member, and the state in which the floor slab 42 is supported by the beam 16 can be maintained.

Furthermore, the floor structure 38 of the second embodiment, as shown in FIG. 2, the take cash L ₁ of the outer peripheral portion 20 of the end portion 44 of the deck plate 40 by a more than 20 mm, the deck plate to the outer peripheral portion 20 Forty end portions 44 can be reliably mounted.

Moreover, the floor structure 38 of the second embodiment, as shown in FIG. 2, the distance L ₂ from the end portion 44 of the deck plate 40 to Ryokokoro portion 18 by the above 30 mm, the outer peripheral from the deck plate 40 in the case of a fire When the outer peripheral portion 20 is combusted by the transfer of heat to the portion 20, the combustion of the outer peripheral portion 20 can be prevented from reaching the beam core portion 18 within the fireproof time.

  Furthermore, in the floor structure 38 of the second embodiment, as shown in FIG. 2, at the time of placing concrete on the deck plate 40, that is, the placed concrete U is hardened and the floor slab 42 on the beam 16 is formed. The weight of the concrete U, the deck plate 40, and the truss rebar 46 is mainly the truss rebar 46 until the fixed strength of the floor slab 42 that exhibits the predetermined strength and can support the floor slab 42 on the beam 16 is obtained. The weight is transmitted to the beam core 18 through the beam center, and the weight of the beam can be mainly borne by the beam core 18.

  Therefore, even when the supporting force sufficient to support the deck plate 40 when the concrete is placed on the deck plate 40 cannot be expected from the outer peripheral portion 20 of the beam 16, the deck plate 40 can be supported by the beam core portion 18 of the beam 16. it can. As a result, there is no need to install a support for supporting the deck plate 40, so that it is possible to secure a construction flow line on the lower floor of the floor slab 42 and increase the degree of freedom of the construction process on the lower floor of the floor slab 42. be able to.

  Further, in the floor structure 38 of the second embodiment, as shown in FIG. 2, the heat transmitted from the deck plate 40 to the truss reinforcement 46 in the event of a fire is absorbed by the concrete U placed on the deck plate 40. The

  Therefore, heat transfer from the deck plate 40 to the beam core 18 via the truss reinforcing bars 46 can be suppressed. Thereby, the temperature rise of the beam core part 18 at the time of a fire can be suppressed, and it can prevent that the beam core part 18 reaches combustion temperature and burns.

  Furthermore, in the floor structure 38 of the second embodiment, as shown in FIGS. 2 and 3, the truss reinforcing bar 46 is attached to the upper surface of the deck plate 40, so that the deck plate 40 is placed in the beam length direction of the beam 16, for example. When the floor slab 42 is constructed while being inclined to the side, the truss reinforcing bar 46 can function as a concrete flow stop when the concrete is placed.

  The second embodiment of the present invention has been described above.

  In addition, in 2nd Embodiment, as shown in FIG.2 and FIG.3, although the deck plate 40 showed the example made into the flat plate made from steel, as for the deck plate 40, truss reinforcement is attached to the upper surface, and Any other shape may be used as long as it plays the role of a steel bottom formwork.

  The first and second embodiments of the present invention have been described above.

  In the first and second embodiments, as shown in FIGS. 1 and 2, the beam 16 is configured to include the beam core portion 18, the burning stop layer 22, and the burning allowance layer 24. The beam 16 may be a wooden member having a portion corresponding to the beam core portion 18 (a portion that bears a load in structural design).

  The first and second embodiments of the present invention have been described above. However, the present invention is not limited to these embodiments, and the first and second embodiments of the present invention may be used in combination. Needless to say, the present invention can be implemented in various ways within the scope of the present invention.

10, 38 Floor structure 12, 40 Deck plate 14, 42 Floor slab 16 Beam (wooden beam)
18 Beam core (heartwood)
20 Peripheral part 26, 44 End part 46 Truss rebar U Concrete L ₁ Hanging allowance L ₂ distance

Claims (4)

A deck plate with an end placed only on the outer periphery surrounding the wooden beam core;
A floor slab formed by placing concrete on the deck plate;
With floor structure.   2. The floor structure according to claim 1, wherein the floor structure has a truss reinforcing bar that is joined to the upper surface of the deck plate and that is protruded from the deck plate and supported by the core material.   The floor structure according to claim 1 or 2, wherein a hooking margin of the end portion of the deck plate to the outer peripheral portion is set to 20 mm or more, and a distance from the end portion of the deck plate to the core material is set to 30 mm or more.   The outer peripheral portion has a flame stop layer surrounding the outer periphery of the core material, and a wooden burn allowance layer surrounding the outer periphery of the flame stop layer,
  The end of the deck plate is placed only on the burning allowance layer and is fixed by screws.
  The floor structure according to any one of claims 1 to 3.

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