Composite floor

Abstract

To provide a composite floor having excellent stress transmission properties between a wood face material and a concrete slab, without lowering of productivity of the wood face material and lowering of site workability of the concrete slab.SOLUTION: A composite floor 50 has a wood face material 10 and a concrete slab 20 disposed on a first wide face 15 of the wood face material 10. To a first wide face 15, a steel plate 30 with a second wide face 31 in a contact state is fixed through a fastener 40. The steel plate 30 is embedded in the concrete slab 20. The steel plate 30 has an opening 35. The opening 35 is filled with concrete 25 of the concrete slab 20 to form a shear key.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to synthetic flooring. [Background technology]

[0002] On October 1, 2010, the "Law for Promoting the Use of Wood in Public Buildings, etc." came into effect. One of the aims of this law is to contribute to the realization of carbon neutrality and the prevention of global warming. For example, efforts are being made to promote the use of wood in low-rise public buildings (converting to wooden structures) and woodification (using wood for interior decoration, etc.).

[0003] Furthermore, a 2000 amendment to the Building Standards Act eliminated the previous restriction that wooden buildings must be no more than three stories high. Now, even if the main structural members are made of wood, wooden buildings can be four stories or higher, provided that they are fire-resistant. This, combined with the above-mentioned Wood Utilization Promotion Act, is expected to lead to an increase in the construction of wooden buildings, including high-rise buildings.

[0004] Now, looking at the floors of buildings such as apartment buildings, when floors are constructed using only wood such as wood surface materials, in order to improve or enhance performance issues that are problematic for wood, such as sound insulation and fire resistance, a composite floor is sometimes constructed in which wood surface materials are laminated with a concrete floor slab. This is proposed, for example, in Patent Documents 1 and 2.

[0005] Patent Document 1 proposes a load-bearing board member, which comprises wood layers laminated so that the fiber direction of the wood fibers crosses in each layer, and a concrete layer or mortar layer joined to one surface of the wood layer, and the wood layer and the concrete layer or mortar layer are connected via stress transmission means. More specifically, a plurality of recesses are formed on the upper surface of the wood layer, and lag screws, which are stress transmission means, are screwed into the recesses, and concrete flows into the recesses to form protrusions that engage with the recesses.

[0006] On the other hand, Patent Document 2 proposes a composite floor structure, which comprises a wooden floor made of wood materials, a reinforced concrete slab placed on the upper surface of the wooden floor, and wood screw-like screws driven into the upper surface of the wooden floor to connect the wooden floor and the reinforced concrete slab, and no fire-resistant covering material is provided on the underside of the wooden floor. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2017-78307 A [Patent Document 2] Patent Publication No. 2021-173020 Summary of the Invention [Problem to be solved by the invention]

[0008] The load-bearing board member described in Patent Document 1 is said to be able to reduce the weight of the load-bearing board member and improve its strength. Meanwhile, the composite floor structure described in Patent Document 2 is said to be able to expose the wooden surface of the wooden floor structure by not providing a fire-resistant covering material on the underside of the wooden floor structure.

[0009] However, the load-bearing board member described in Patent Document 1 requires the machining of recesses into the wood layer, which requires time and effort to produce the wood layer, posing a problem in terms of productivity, and this problem becomes even more pronounced when the number of recesses is increased.

[0010] On the other hand, in the composite floor structure described in Patent Document 2, stress is transmitted between the wooden structural floor and the reinforced concrete slab using screws, so it is unavoidable that a large number of screws are required to achieve the specified stress transmission performance. This means that the reinforced concrete slab must be constructed under conditions in which a large number of screws protrude from the top surface of the wooden structural floor, posing an issue of reduced workability of the reinforced concrete slab.

[0011] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a composite floor that has excellent stress transmission properties between wood surface materials and concrete floor slabs, and does not pose a risk of reduced productivity of the wood surface materials or reduced on-site workability of the concrete floor slabs. [Means for solving the problem]

[0012] In order to achieve the above object, one aspect of the synthetic bed according to the present invention is: A composite floor having a wood surface material and a concrete floor slab disposed on one first wide surface of the wood surface material, A steel plate is fixed to the first wide surface via a fastener with the second wide surface abutting against the first wide surface, and the steel plate is embedded inside the concrete floor slab. The steel plate is provided with an opening, and the opening is filled with concrete from the concrete deck to form a shear key.

[0013] According to this embodiment, a steel plate with an opening that is fixed to the first wide surface of the wooden panel and embedded in the concrete slab is used as the stress transfer mechanism between the wooden panel and the concrete floor slab.The steel plate, whose opening is filled with the concrete of the concrete slab, acts as a shear key, forming a composite floor with excellent stress transfer properties.Therefore, there are no problems with reduced workability of the concrete slab when applying a large number of screws, or reduced manufacturability due to the need to machine recesses in the wooden panel.

[0014] Here, the openings in the steel plate where the second wide surface of the wooden panel abuts against the first wide surface are filled with concrete from the concrete slab, forming a shear resistance mechanism against the shear force that acts on the panel. Furthermore, the sides of the steel plate and the heads of the fasteners form a bearing resistance mechanism against the shear force that acts on the panel.

[0015] The shear resistance can be changed by adjusting the size of the opening in the steel plate. Also, the bearing resistance can be changed by adjusting the side area of ​​the steel plate (the thickness of the steel plate and the length of the edge) and the side area of ​​the head of the fastener.

[0016] Here, various types of reinforcing bars are arranged inside the concrete deck, such as double reinforcement, which has upper and lower end reinforcements, both of which are arranged in a grid pattern with multiple reinforcing bars in perpendicular directions, and single reinforcement, which has multiple reinforcing bars arranged in a grid pattern in perpendicular directions at the center of the deck thickness.

[0017] The fasteners include screws including wood screws, screws including wood screws, nails, lag screws, bolts, etc. The number of fasteners is set based on the required shear resistance and the cross-sectional area per fastener. For example, there are two fasteners provided at one diagonal position of a rectangular steel plate in plan view, and four fasteners provided near the four corners.

[0018] This embodiment includes a form in which the second wide surface of a steel plate having a large area (for example, an area of ​​approximately 1 / 5 to 1 / 3 of the total area of ​​the first wide surface of the wooden panel) is fixed to the first wide surface of the wooden panel, and a form in which the second wide surfaces of multiple steel plates with relatively small areas are fixed; however, from the viewpoint of stress transferability throughout the entire area of ​​the wooden panel and the concrete floor slab, a form in which the second wide surfaces of multiple steel plates are fixed to the wooden panel is preferred.

[0019] In either form, the application of steel plates with openings means that a large number of screws are not required to form a composite floor with the required stress transfer properties, eliminating the risk of reduced workability when constructing a concrete floor slab above a wooden surface material.

[0020] Another aspect of the synthetic floor according to the present invention is the fastener is a lag screw bolt with a head; The upper part of the lag screw bolt protrudes from the steel plate and is embedded inside the concrete deck, and the head forms a peeling resistance mechanism between the concrete deck and the wood surface material.

[0021] According to this aspect, the upper part of the lag screw bolt protrudes from the steel plate and is embedded inside the concrete floor slab, so that the head of the lag screw bolt forms a peeling resistance mechanism (or separation resistance mechanism) that resists peeling (separation) in the vertical direction between the concrete floor slab and the wooden surface material. Here, the peeling resistance performance can be changed by adjusting the overhang area of ​​the head that overhangs laterally from the shaft part of the lag screw bolt.

[0022] Another aspect of the synthetic floor according to the present invention is The wooden surface material is one of laminated lumber, solid wood, structural plywood, laminated veneer lumber, cross-laminated lumber, and nail-jointed laminated lumber.

[0023] According to this embodiment, the wood surface material is any one of laminated timber, solid wood, structural plywood, laminated veneer lumber (LVL), cross laminated timber (CLT), and nail laminated timber (NLT), so that various types of wood surface materials can be applied.

[0024] In particular, when the wooden surface material is a cross-laminated board, it is preferable because, for example, a wider range of wooden surface materials with different length and width dimensions can be applied compared to other forms, and therefore the number of connection points between wooden surface materials on site can be reduced as much as possible.

[0025] Another aspect of the synthetic floor according to the present invention is A plurality of the steel plates are fixed to the first wide surface at intervals.

[0026] According to this aspect, by fixing multiple steel plates at intervals to the first wide surface of the wooden panel, a composite floor with excellent stress transfer properties between the wooden panel and the concrete floor slab can be formed. Effect of the Invention

[0027] As can be understood from the above explanation, the composite floor of the present invention can provide a composite floor that has excellent stress transmission properties between the wood surface material and the concrete floor slab, and does not pose any risk of reduced productivity of the wood surface material or reduced on-site workability of the concrete floor slab. [Brief description of the drawings]

[0028] [Figure 1] FIG. 2 is a longitudinal cross-sectional view of an example of a synthetic floor according to an embodiment. [Diagram 2] FIG. 2 is a cross-sectional view taken along the line II-II of FIG. 1 and cut at an upper position of the steel plate. [Diagram 3] FIG. 2 is a plan view showing an example of a state in which a plurality of steel plates are attached to a first wide surface of a wooden panel material. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] Hereinafter, a synthetic floor according to an embodiment will be described with reference to the accompanying drawings. In this specification and the drawings, substantially the same components are designated by the same reference numerals to avoid redundant description.

[0030] [Synthetic floor according to the embodiment] An example of a composite floor according to an embodiment will be described with reference to Figures 1 to 3. Here, Figure 1 is a vertical cross-sectional view of an example of a composite floor according to an embodiment, and Figure 2 is a cross-sectional view taken along the line II-II in Figure 1 and cut at an upper position of a steel plate. Also, Figure 3 is a plan view of an example of a state in which a plurality of steel plates are attached to a first wide surface of a wood surface material, as viewed from above.

[0031] The composite floor 50 has a wooden surface material 10 and a concrete floor slab 20 disposed on one of the first wide surfaces 15 of the wooden surface material 10. Here, inside the concrete floor slab 20, there is double reinforcement or single reinforcement in which multiple reinforcing bars are arranged in a lattice pattern when viewed from above, but illustrations of these reinforcement bars are omitted.

[0032] The wooden surface material 10 in the illustrated example is made of cross-laminated timber (CLT). CLT 10 is made by laminating multiple veneers 11, each of which is made of multiple sawn boards 12 with the same wood grain direction bonded together with an adhesive, so that the grain directions are alternately crossed at right angles, and then bonding them together with an adhesive.

[0033] Here, the wooden surface material 10 may be made of nailed timber (NLT), laminated veneer lumber (LVL), structural plywood, etc., in addition to the CLT shown in the figure, but CLT can be used with a wide range of wooden surface materials with dimensions up to 12m x 2.6m, making it possible to reduce the number of connections between wooden surface materials on-site as much as possible. This improves the strength of the composite floor 50 and improves construction efficiency. In addition, CLT is preferable because it is resistant to deformation and can further improve the rigidity of the composite floor 50, as multiple veneers 11 are layered with their fibers perpendicular to each other.

[0034] A second wide surface 31 of a steel plate 30 having an opening 35 is abutted against the first wide surface 15 of the wooden surface material 10 and fixed to the wooden surface material 10 via a lag screw bolt 40 (an example of a fastener).

[0035] More specifically, a lag screw bolt 40 is inserted through bolt holes 33 located near two diagonally opposite corners of a steel plate 30 that has a square shape in plan view (an example of a rectangle) with each side having a length of t, and is driven into the wood panel 10 with its upper portion 45, including its head 42, protruding from the top surface of the steel plate 30 and tightened.

[0036] The entire steel plate 30 is embedded inside the concrete deck 20 constructed on site, and the opening 35 is filled with concrete constructed on site and hardens to form a filled concrete body 25, which forms a shear resistance mechanism.

[0037] Here, the length t of one side of the illustrated steel plate 30 can be set to, for example, about 100 mm to 300 mm, the opening 35 opened in the center is circular in plan view with a diameter φ, which can be set to about 50 mm to 200 mm, and the plate thickness can be set in the range of about 10 mm to 30 mm. The shape of the steel plate 30 in plan view may be a circle, an ellipse, or a polygon other than a rectangle other than a square, and the shape of the opening 35 in plan view may be a polygon, an ellipse, or the like other than a circle.

[0038] In the illustrated example, the number of lag screw bolts 40 that secure the steel plate 30 to the wooden surface material 10 is two, but the number of lag screw bolts 40 that secure the steel plate 30 to the wooden surface material 10 is set according to the cross-sectional area of ​​each bolt, which corresponds to the shear resistance force against the acting shear force Q. Therefore, for example, the steel plate 30 may be secured to the wooden surface material 10 by a total of four lag screw bolts 40 via bolt holes 33 located near the four corners.

[0039] As shown in Figure 1, when a horizontal shear force Q, for example, acts on a composite floor 50, the filled concrete body 25 filled in the opening 35 of the steel plate 30 joining the wood surface material 10 and the concrete floor slab 20 forms a shear resistance mechanism that resists the shear force Q with its shear resistance force S1.

[0040] Furthermore, the area of ​​the side surface 32 of the steel plate 30 and the side area of ​​the upper portions 45 of the two lag screw bolts 40 protruding upward from the steel plate 30 form a bearing resistance mechanism that resists the shear force Q with its bearing resistance force S2.

[0041] In other words, the steel plate 30 which is a shear key and the lag screw bolt 40 whose upper part 45 protrudes upward resist the shear force Q borne by one steel plate 30 with the shear resistance force S1 and the bearing resistance force S2 provided by the shear resistance mechanism and the bearing resistance mechanism.

[0042] Here, the shear resistance S1 can be changed by adjusting the size of the opening 35 in the steel plate 30. Therefore, it is preferable to set the plan area of ​​the opening 35 that corresponds to the required shear resistance S1 on the premise of the design standard strength of the concrete to be applied (the shear strength based on that), and to apply a steel plate 30 with a plan area that has a sufficient edge clearance from the opening 35 of the set plan area.

[0043] In addition, the bearing resistance force S2 can be changed by adjusting the area of ​​the side 32 of the steel plate 30 (the thickness of the steel plate and the length of the end edge) and further by adjusting the side area of ​​the upper part 45 including the head 42 of the lag screw bolt 40.

[0044] Therefore, for example, when adjusting the area of ​​the side surface 32 of the steel plate 30, the bearing pressure resistance force S2 can be increased by using a thick steel plate 30 or by welding together a plurality of steel plates 30 as necessary. Also, the bearing pressure resistance force S2 can be increased by making the lag screw bolt 40 protrude upward from the top surface of the steel plate 30 to increase the side area.

[0045] In addition, since the upper part 45 of the lag screw bolt 40 protrudes upward from the steel plate 30 and is embedded inside the concrete floor slab 20, the head 42 of the lag screw bolt 40 forms a peeling resistance mechanism that resists with a peeling resistance force S3 when the concrete floor slab 20 and the wooden surface material 10 try to peel up and down in the Z direction.

[0046] Here, by adjusting the protruding area of ​​the head 42 that protrudes laterally from the shaft 41 of the lag screw bolt 40, the peeling resistance performance can be changed.

[0047] The plurality of steel plates 30 having the openings 35 described above with reference to FIGS. 1 and 2 are disposed over the entire wide surface 15 of the wooden panel material 10, for example, in the manner shown in FIG.

[0048] Specifically, in the first wide surface 15 having a rectangular shape in plan view with each side extending in the XY direction, the plurality of steel plates 30 are arranged at predetermined intervals in the X and Y directions. Note that the arrangement of the plurality of steel plates 30 may be a randomly distributed arrangement other than that shown in the drawings.

[0049] According to the composite floor 50 shown in the figure, a steel plate 30 with an opening 35 that is fixed to the first wide surface 15 of the wooden surface material 10 and embedded in the concrete floor slab 20 is used as the stress transfer mechanism between the wooden surface material 10 and the concrete floor slab 20.This means that the steel plate 30, in which the opening 35 is filled with the concrete of the concrete floor slab 20 to form a filled concrete body 25, acts as a shear key to form a composite floor 50 with excellent stress transfer properties, and there are no problems with reduced workability of the concrete floor slab when applying a large number of screws or reduced manufacturability due to the need to machine recesses in the wooden surface material.

[0050] In addition, the present invention is not limited to the configuration shown here, and may be implemented in other embodiments in which other components are combined with the configurations and the like of the above-mentioned embodiment. In this regard, the present invention may be modified within the scope of the gist of the present invention, and may be appropriately determined according to the application form. [Explanation of symbols]

[0051] 10: Wood surface material (cross-laminated timber, CLT) 11: Single board 12: Saw board 15: First wide surface 20: Concrete floor slab 25: Filled concrete body (concrete, shear resistance mechanism) 30: Steel plate (Shear key) 31: Second wide surface 32: Side 33: Bolt hole 35:Aperture 40: Fastener (lag screw bolt) 41: Shaft 42:Head 45: Upper part 50:Synthetic floor Q: Shear force S1: Shear resistance S2: Bearing resistance S3: Peel resistance

Claims

1. A composite floor having a wood surface material and a concrete floor slab disposed on one first wide surface of the wood surface material, A steel plate is fixed to the first wide surface via a fastener with the second wide surface in contact therewith, and the steel plate is embedded inside the concrete floor slab; A composite floor, characterized in that an opening is provided in the steel plate, and the opening is filled with concrete of the concrete floor slab to form a shear key.

2. the fastener is a lag screw bolt with a head; The composite floor described in claim 1, characterized in that the upper part of the lag screw bolt protrudes from the steel plate and is embedded inside the concrete floor slab, and the head forms a peeling resistance mechanism between the concrete floor slab and the wood surface material.

3. 3. The synthetic floor according to claim 1 or 2, wherein the wooden surface material is any one of laminated wood, solid wood, structural plywood, laminated veneer lumber, cross-laminated lumber, and nail-jointed laminated lumber.

4. 3. The synthetic floor according to claim 1 or 2, wherein a plurality of the steel plates are fixed to the first wide surface at intervals.

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