Construction method for laminated structure

Abstract

To obtain sufficient fire resistance while ensuring sound insulation performance in a laminated structure using wooden layers.SOLUTION: A laminated structure 10 comprises: a wooden layer 11; a first fire-resistant layer 12 provided on an upper surface 11a of the wooden layer 11; and a cement composition layer 13 provided on an upper surface 12a of the first fire-resistant layer 12. This configuration enables sufficient fire resistance against fires above the laminated structure 10 through the first fire-resistant layer 12 and the cement composition layer 13, while ensuring sound insulation performance via the cement composition layer 13.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for constructing a laminated structure that constitutes a floor structure. [Background technology]

[0002] As an example of a laminated floor structure using a wooden layer, Patent Document 1 discloses a laminated structure having wooden floorboards as the wooden layer and a reinforced concrete layer laminated on the wooden floorboards. With this laminated structure, the floor can be made lighter than when it is composed of only a reinforced concrete layer, and the fire resistance and sound insulation performance of the floor can be improved compared to when it is composed of only wooden floorboards. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2020-105697 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the laminated structure of Patent Document 1, when the concrete layer is heated by a fire, the heat is transferred directly to the wooden floorboards, leaving room for improvement in fire resistance. [Means for solving the problem]

[0005] A construction method for a laminated structure that solves the above problems is a construction method for a laminated structure having a wood layer, a first fire-resistant layer provided on the upper surface of the wood layer, and a cement composition layer provided on the upper surface of the first fire-resistant layer, and includes the following steps: a wood layer installation step of installing the wood layer at an installation location, a first fire-resistant layer formation step of providing the first fire-resistant layer on the upper surface of the wood layer after the wood layer installation step, and a pouring step of pouring a cement composition on the upper surface of the first fire-resistant layer after the first fire-resistant layer formation step.With this configuration, sufficient fire resistance can be obtained while ensuring sound insulation performance with the cement composition layer.

[0006] In the above-described construction method for a laminated structure, the casting step preferably includes supporting a reinforcing member on the upper surface of the first fire-resistant layer via a spacer, and then casting the cement composition so that the spacer and the reinforcing member are embedded. The reinforcing member is preferably one of wire mesh, reinforcing bars, and steel fibers. This configuration can suppress cracking of the cement composition layer.

[0007] In the method for constructing a laminated structure, the first fire-resistant layer may be a single layer member of a fire-resistant board. According to the above configuration, the fire resistance performance of the upper part of the laminated structure can be easily improved.

[0008] In the method for constructing a laminated structure, the first fire-resistant layer may be a laminated member of a plurality of fire-resistant boards. According to the above configuration, the fire resistance of the upper part of the laminated structure can be easily improved.

[0009] In the above-mentioned configuration, the fire-resistant board preferably has a thickness of 21 mm or more and 25 mm or less. With the above-mentioned configuration, it is possible to obtain the specified fire resistance required by, for example, Ministry of Construction Notification No. 1399 of 2000.

[0010] In the above-described construction method for a laminated structure, the first fire-resistant layer is preferably water-resistant. With this configuration, even if rainwater or the like penetrates the first fire-resistant layer, corrosion of the fire-resistant board is suppressed and the rainwater is less likely to reach the wood layer. As a result, the durability of the laminated structure can be improved.

[0011] In the above-mentioned configuration, the cement composition layer preferably has a thickness of at least 40 mm. According to the above-mentioned configuration, sufficient sound insulation performance can be obtained. The method for constructing a laminated structure preferably further includes a second fire-resistant layer forming step of providing a second fire-resistant layer on the underside of the wood layer. This configuration improves the fire resistance of the laminated structure against fires below the laminated structure. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a cross-sectional view showing a schematic configuration of an embodiment of a laminated structure. [Figure 2] FIG. 2 is a cross-sectional view showing a schematic configuration of an example of a laminated structure in which a first fire-resistant layer is formed of a single-layer member of a fire-resistant board. [Figure 3] FIG. 2 is a cross-sectional view showing a schematic configuration of an example of a laminated structure in which a first fire-resistant layer is formed of laminated members of fire-resistant boards. [Figure 4] 1 is a flowchart showing a method for constructing a laminated structure. DETAILED DESCRIPTION OF THE INVENTION

[0013] An embodiment of the laminated structure will be described with reference to FIGS. (Basic structure of laminated structure) As shown in Figure 1, the laminated structure 10 constitutes a floor supported by beams (not shown). The laminated structure 10 satisfies the fire resistance requirements specified in Ministry of Construction Notification No. 1399 of 2000.

[0014] The laminated structure 10 has a wood layer 11, a first fire-resistant layer 12, a cement composition layer 13, and a second fire-resistant layer 14. The laminated structure 10 also has a reinforcing member 15 in the cement composition layer 13.

[0015] The wooden layer 11 is made up of wooden floorboards connected to beam members (not shown). The wooden layer 11 functions as a structural element that makes up the floor. The wooden layer 11 is formed, for example, from CLT (Cross Laminated Timber) boards. When the wooden layer 11 is made up of CLT boards, the thickness of the wooden layer 11 is set to 60 mm to 270 mm depending on the requirements at the time.

[0016] The first fire-resistant layer 12 is provided on the upper surface 11a of the wooden layer 11. The first fire-resistant layer 12 covers the upper surface 11a of the wooden layer 11. The first fire-resistant layer 12 is made of a fire-resistant board with excellent fire resistance. The fire-resistant board is attached to the wooden layer 11 using a stapler or the like. The first fire-resistant layer 12 may be configured such that a single fire-resistant board covers the upper surface 11a, or such that multiple fire-resistant boards are arranged to cover the upper surface 11a. When the first fire-resistant layer 12 is made of multiple fire-resistant boards, it is preferable to provide a covering member that covers the joints of the fire-resistant boards. Furthermore, for example, when the first fire-resistant layer 12 is made of multiple wooden floorboards arranged along the floor surface direction of the wooden layer 11, it is preferable to prevent the joints of the fire-resistant boards from overlapping with the joints of the wooden floorboards. The fire-resistant board is preferably a waterproof reinforced gypsum board with a thickness of 21 mm to 25 mm and excellent water resistance.

[0017] The first fire-resistant layer 12 may be constructed of a laminated member in which multiple fire-resistant boards as described above are stacked together, depending on the fire resistance performance required by the above-mentioned notification at any given time (hereinafter referred to as fire resistance requirements). In such a configuration, the fire-resistant board in the upper layer is attached to the fire-resistant board in the lower layer using a tacker or the like. Furthermore, when each layer is constructed of multiple fire-resistant boards, it is preferable that the joints of the fire-resistant boards in the lower layer do not overlap with the joints of the fire-resistant boards in the upper layer.

[0018] The cement composition layer 13 is provided on the upper surface 12a of the first fire-resistant layer 12. The cement composition layer 13 is formed by hardening a cement composition poured onto the upper surface 12a of the first fire-resistant layer 12. The cement composition is, for example, mortar or concrete. The cement composition is also a cement-based material (fiber-reinforced concrete material) mixed with fibers, such as Slimcrete (registered trademark).

[0019] A reinforcing member 15 is disposed in the cement composition layer 13. The reinforcing member 15 improves the strength of the cement composition layer 13, thereby suppressing cracking of the cement composition layer 13. The reinforcing member 15 is made of, for example, a wire mesh or reinforcing bars. The reinforcing member 15 is installed before the cement composition is poured. The reinforcing member 15 is supported on the upper surface 12a of the first fire-resistant layer 12 via a spacer (not shown) or the like. The reinforcing member 15 is preferably installed at a position where the cover of the cement composition is about 25 mm. The reinforcing member 15 suppresses cracking of the cement composition layer 13. The cement composition layer 13 may also be reinforced with steel fibers mixed into the cement composition, as in the above-mentioned Slimcrete (registered trademark).

[0020] The thickness of the cement composition layer 13 is set according to the requirements at the time. The thickness of the cement composition layer 13 is preferably set to 40 mm or more. When the thickness of the cement composition layer 13 is 40 mm or more, sufficient sound insulation performance can be imparted to the laminate structure 10 using the wood layer 11. Furthermore, the thickness of the cement composition layer 13 is preferably set to 80 mm or less. When the thickness of the cement composition layer 13 is 80 mm or less, sufficient sound insulation performance can be imparted to the laminate structure 10 while the weight of the cement composition layer 13 can be reduced.

[0021] When pouring the cement composition, it is preferable to place a waterproof sheet so as to cover the upper surface 12a of the first fire-resistant layer 12. This makes it possible to prevent the moisture contained in the cement composition from penetrating into the first fire-resistant layer 12.

[0022] The second fire-resistant layer 14 is provided on the lower surface 11b of the wooden layer 11. The second fire-resistant layer 14 covers the lower surface 11b of the wooden layer 11. The second fire-resistant layer 14 forms the ceiling of the lower floor. The second fire-resistant layer 14 is composed of a laminated member in which fire-resistant boards are stacked. The fire-resistant board of the top layer is attached to the wooden layer 11 using a tacker or the like. The other fire-resistant boards are attached to the fire-resistant boards of the upper layers using a tacker or the like. Each layer may be composed of a single fire-resistant board, or may be composed of multiple fire-resistant boards arranged along the floor surface direction of the wooden layer 11. In this case, it is preferable to provide a covering member to cover the joints of the fire-resistant boards. The fire-resistant boards are preferably waterproof reinforced gypsum boards with a thickness of 21 mm to 25 mm and excellent water resistance.

[0023] (Example of laminated structure) Figure 2 shows a laminated structure for a one-hour fire resistance requirement. In the laminated structure 10 shown in Figure 2, the first fire-resistant layer 12 is composed of a single layer of fire-resistant board 16 having a thickness of 21 mm. The cement composition layer 13 is formed to a thickness of 40 mm. The second fire-resistant layer 14 is composed of a laminated member of fire-resistant boards 17 and 18 having a thickness of 21 mm.

[0024] Figure 3 shows a laminated structure for a two-hour fire resistance requirement. In the laminated structure 10 shown in Figure 3, the first fire-resistant layer 12 is composed of a laminated member of fire-resistant boards 19 and 20, each having a thickness of 21 mm. The cement composition layer 13 is formed to a thickness of 80 mm. The second fire-resistant layer 14 is composed of a laminated member of fire-resistant board 21, each having a thickness of 21 mm, and fire-resistant board 22, each having a thickness of 25 mm.

[0025] (Layered structure construction method) An example of a method for constructing the laminated structure 10 will be described below. Note that the description here will be made for a case where the fire resistance requirement is one hour.

[0026] As shown in FIG. 4, the construction method for a laminated structure includes a wood layer installation step (step S101), a first fireproof layer formation step (step S102), a pouring step (step S103), and a second fireproof layer formation step (step S104).

[0027] In the wood layer installation step (step S101), the wood layer 11 is installed at an installation location. Specifically, after the wood layer 11 is transported to the installation location, the wood layer 11 is supported by beam members (not shown). Then, the wood layer 11 is connected to the beam members.

[0028] In the first fireproof layer forming step (step S102), the first fireproof layer 12 is provided on the upper surface 11a of the wooden layer 11. Specifically, a fireproof board is attached so as to cover the upper surface 11a of the wooden layer 11.

[0029] In the casting step (step S103), the cement composition layer 13 is formed. Specifically, after a reinforcing member 15 is placed on the upper surface 12a of the first fire-resistant layer 12, the cement composition is cast. Then, when the cast cement composition hardens, the cement composition layer 13 is formed.

[0030] In the second fire-resistant layer forming step (step S104), the second fire-resistant layer 14 is provided on the lower surface 11b of the wooden layer 11. Specifically, a first layer of fire-resistant board is attached to cover the lower surface 11b of the wooden layer 11, and then a second layer of fire-resistant board is attached to cover the first layer of fire-resistant board. This completes the construction of the laminated structure 10.

[0031] In another example of the construction method for a laminated structure, the second fireproof layer forming step (step S104) may be performed before the wood layer installing step (step S101). In this case, in the second fire-resistant layer forming step, the second fire-resistant layer 14 is attached to the underside 11b of the wooden layer 11 at a location different from the installation location of the laminated structure 10, such as a manufacturing plant or stockyard for the wooden layer 11. Then, in the wooden layer installation step, the wooden layer 11 with the attached second fire-resistant layer 14 is installed at the installation location.

[0032] The effects of this embodiment will be described. (1) The laminated structure 10 has a first fire-resistant layer 12 between the wood layer 11 and the cement composition layer 13. Therefore, even if the cement composition layer 13 is heated, the heat is not directly transmitted to the wood layer 11. As a result, the cement composition layer 13 ensures sound insulation performance, while providing sufficient fire resistance against fires on the upper side of the laminated structure 10.

[0033] (2) Because the cement composition layer 13 is primarily responsible for the sound insulation performance of the laminated structure 10, sound-deadening materials such as glass wool and hollow spaces for arranging the sound-deadening materials are not required. This improves the construction speed, thereby enabling the construction period of the laminated structure 10 to be shortened.

[0034] (3) Furthermore, in rainy weather, the cement composition layer 13 functions as a roof, preventing rainwater from penetrating into the fireproof boards that make up the first fireproof layer 12. Furthermore, work can be carried out on the floor below the laminated structure 10 regardless of the weather.

[0035] (4) Since the first fire-resistant layer 12 is made up of a laminated member of a plurality of fire-resistant boards, the fire resistance of the upper part of the laminated structure 10 can be easily improved. (5) In this case, by preventing the joints of the fire-resistant boards from overlapping, it becomes difficult for the heat generated by a fire and the moisture that has penetrated into the first fire-resistant layer 12 to reach the wood layer 11 through the joints.

[0036] (6) Because the fireproof boards constituting the first fireproof layer 12 are water-resistant, even if moisture penetrates the first fireproof layer 12, corrosion of the fireproof boards is suppressed and the moisture is less likely to reach the wood layer 11. As a result, the durability of the laminated structure 10 can be improved. In addition, since it is possible to pour the cement composition into the first fireproof layer 12 without laying a waterproof sheet thereon, the construction period for the laminated structure 10 can be further shortened.

[0037] (7) The second fire-resistant layer 14 is provided on the lower surface 11b of the wood layer 11, so that the fire resistance of the layered structure 10 against fire below the layered structure 10 can be improved. (8) Since the second fire-resistant layer 14 is made up of a laminated member of a plurality of fire-resistant boards, the fire resistance performance of the lower side of the laminated structure 10 against fire can be easily improved.

[0038] (9) Because the fireproof board constituting the second fireproof layer 14 is water-resistant, even if moisture penetrates the second fireproof layer 14, corrosion of the fireproof board constituting the second fireproof layer 14 is suppressed.

[0039] This embodiment can be modified as follows: This embodiment and the following modifications can be combined and implemented within the scope of technical compatibility. The second fire-resistant layer 14 may be installed according to the requirements of the time. The second fire-resistant layer 14 does not have to be waterproof, and does not have to be a laminated member of multiple fire-resistant boards.

[0040] The cement composition layer 13 need only have a strength that satisfies the design requirements, and does not need to be reinforced by a reinforcing member 15 or the like. The cement composition layer 13 may have a thickness of less than 40 mm or more than 80 mm, as long as it satisfies the fire resistance requirements in combination with the fireproof board, for example, based on experiments or simulations.

[0041] The first fire-resistant layer 12 may be installed according to the requirements of the time. Therefore, the first fire-resistant layer 12 does not need to be water-resistant. The fire-resistant board constituting the first fire-resistant layer 12 may have a thickness of less than 21 mm or more than 25 mm, as long as it satisfies the fire-resistant requirements in combination with the cement composition layer 13 based on, for example, experiments or simulations.

[0042] The laminated structure 10 can also be applied to beams made of wooden materials. [Explanation of symbols]

[0043] 10...laminated structure, 11...wood layer, 11a...upper surface of wood layer, 11b...lower surface of wood layer, 12...first fire-resistant layer, 12a...upper surface of first fire-resistant layer, 13...cement composition layer, 14...second fire-resistant layer, 15...reinforcing member, 16, 17, 18, 19, 20, 21, 22...fire-resistant board.

Claims

1. A construction method for a laminated structure having a wood layer, a first fire-resistant layer provided on an upper surface of the wood layer, and a cement composition layer provided on an upper surface of the first fire-resistant layer, comprising: a wood layer installation step of installing the wood layer at an installation location; a first fire-resistant layer forming step of providing the first fire-resistant layer on an upper surface of the wood layer after the wood layer installing step; and a pouring step of pouring a cement composition onto an upper surface of the first fireproof layer after the first fireproof layer forming step. Construction method for laminated structures.

2. In the casting step, a reinforcing member is supported on the upper surface of the first fire-resistant layer via a spacer, and then the cement composition is cast so that the spacer and the reinforcing member are embedded. A method for applying the laminated structure of claim 1.

3. The reinforcing member is one of wire mesh, reinforcing bars, and steel fibers. A method for constructing the laminated structure of claim 2.

4. The first fire-resistant layer is a single layer of fire-resistant board. A method for constructing the laminated structure according to any one of claims 1 to 3.

5. The first fire-resistant layer is a laminated member of a plurality of fire-resistant boards. A method for constructing the laminated structure according to any one of claims 1 to 3.

6. The fireproof board has a thickness of 21 mm or more and 25 mm or less. A method for constructing the laminated structure according to claim 4 or 5.

7. The first fire-resistant layer is water-resistant. A method for applying the laminated structure according to any one of claims 1 to 6.

8. The cement composition layer has a thickness of at least 40 mm. A method for applying the laminated structure according to any one of claims 1 to 7.

9. The method further includes a second fire-resistant layer forming step of providing a second fire-resistant layer on the lower surface of the wood layer. A method for applying the laminated structure according to any one of claims 1 to 8.

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