Floor structure

Abstract

To secure fire resistance of a building having a steel beam and a cross-laminated plate floor.SOLUTION: A reinforced concrete slab 14 is disposed on a steel beam 82 and supported by the steel beam 82. A cross-laminated plate floor 15 is disposed laterally to the reinforced concrete slab 14 and supported by the reinforced concrete slab 14. The reinforced concrete slab 14 projects laterally from above the steel beam 82 and has an end part (precast concrete member 42) for supporting the cross-laminated plate floor 15.SELECTED DRAWING: Figure 10

Description

Technical Field

[0001] This invention relates to a floor structure using a cross-laminated timber (CLT).

Background Art

[0002] Patent Document 1 discloses a column-beam steel frame floor CLT structure.

Prior Art Documents

Non-Patent Documents

[0003]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Since steel beams have a high thermal conductivity, they become hot during a fire, and the heat is transmitted to the cross-laminated floor, posing a risk of the cross-laminated floor catching fire. This invention aims to solve such problems, for example.

Means for Solving the Problems

[0005] The floor structure has a reinforced concrete slab and a cross-laminated timber floor. The reinforced concrete slab is disposed on the steel beam and supported by the steel beam. The cross-laminated timber floor is disposed laterally with respect to the reinforced concrete slab and supported by the reinforced concrete slab. The reinforced concrete slab projects laterally from above the steel beam and has an end portion for supporting the cross-laminated timber floor.

Effects of the Invention

[0006] According to the above floor structure, the distance between the steel beams and the orthogonal laminated timber floor can be increased, thereby preventing the orthogonal laminated timber floor from becoming too hot and catching fire due to heat transmitted through the steel beams, which have high thermal conductivity, in the event of a fire, thereby ensuring fire resistance. [Brief description of the drawings]

[0007] [Figure 1] FIG. [Diagram 2] FIG. [Diagram 3] FIG. 1 is a plan view showing an example of an orthogonal laminated board floor. [Figure 4] A side view showing an example of an orthogonal laminated board floor. [Diagram 5] A bottom view showing an example of an orthogonal laminated board floor. [Figure 6] FIG. 1 is a plan view showing an example of a precast concrete member. [Figure 7] FIG. 2 is a side view showing an example of a precast concrete member. [Figure 8] FIG. 2 is a bottom view showing an example of a precast concrete member. [Figure 9] FIG. 2 is a side cross-sectional view showing an example of a precast concrete member. [Figure 10] FIG. 4 is a partially enlarged cross-sectional side view showing an example of a floor structure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] A floor structure 10 will be described with reference to Figures 1 and 2. The floor structure 10 is a structure constituting the floor of a building having multiple columns 81 and multiple steel beams 82 and 83. The columns 81 are made of, for example, steel (S) or reinforced concrete (RC) and extend in the ±Z directions. The steel beam 82 is, for example, a large beam suspended between the two columns 81. The steel beam 83 is, for example, a small beam suspended between the two steel beams 82. The steel beams 82 and 83 are, for example, steel beams extending in the ±X directions or ±Y directions and are arranged in a lattice pattern.

[0009] The floor structure 10 includes, for example, a reinforced concrete slab 14 and a plurality of cross-laminated timber floors 15 .

[0010] The reinforced concrete slab 14 is, for example, substantially plate-shaped and made of reinforced concrete, and is placed on and supported by the steel beams 82 or 83. The reinforced concrete slab 14 has, for example, a cast-in-place concrete member 41 and a precast concrete member 42. The precast concrete member 42 protrudes laterally (in a direction perpendicular to the ±Z directions) from above the steel beams 82 or 83 (in the +Z direction), and is an end portion that supports the orthogonal laminated timber floor 15. The reinforced concrete slab 14 may be entirely made of precast concrete or entirely made of cast-in-place concrete.

[0011] The cross-laminated timber floor 15 is, for example, a rectangular plate formed by cross-laminated timber, and is disposed transversely to the reinforced concrete slab 14 and supported by the reinforced concrete slab 14. The orthogonal laminated timber floors 15 are arranged in a staggered pattern. That is, the orthogonal laminated timber floors 15 are arranged in diagonally adjacent areas, not in areas adjacent in the ±X direction or ±Y direction, among the multiple rectangular areas partitioned by the multiple steel beams 82 and 83 arranged in a lattice pattern. However, the rectangular areas in which the orthogonal laminated timber floors 15 are arranged do not need to be adjacent diagonally, and may be separated. In other words, the rectangular areas in which the orthogonal laminated timber floors 15 are arranged do not share a side formed by the steel beams 82 or 83. The floor of the rectangular area in which the orthogonal laminated timber floors 15 are arranged and the rectangular area in which the orthogonal laminated timber floors 15 are arranged and share a side formed by the steel beams 82 or 83 are always made of the reinforced concrete slab 14. In addition, the orthogonal laminated timber floors 15 are not arranged in a rectangular area that is in contact with the outer periphery of the floor structure 10. That is, all four sides of the orthogonal laminated timber floors 15 are always supported by the precast concrete members 42 of the reinforced concrete slab 14. This allows the building to assume a rigid floor, ensuring the integrity of the building.

[0012] The cross-laminated timber floor 15 will be described with reference to Figs. The orthogonal laminated timber floor 15 has, for example, an upper part 51 and a lower part 52 arranged below the upper part 51 (in the -Z direction). The upper part 51 and the lower part 52 are, for example, in the shape of a substantially rectangular plate. The upper part 51 is slightly larger than the lower part 52, and its outer edge is located outside the lower part 52 on all four sides (in the ±X and ±Y directions). By placing this part on the precast concrete member 42, the orthogonal laminated timber floor 15 is supported by the reinforced concrete slab 14.

[0013] The precast concrete member 42 will now be described with reference to FIGS. The precast concrete member 42 is a reinforced concrete member manufactured in a factory or the like, and has, for example, a frame portion 43, a support portion 44, and a plurality of reinforcing bars 46. The frame 43 is made of concrete and has, for example, a substantially rectangular frame shape perpendicular to the ±Z directions, with its inner periphery engaging with the outer periphery of the upper part 51 of the orthogonal laminated timber floor 15. A groove 45 extending laterally (perpendicular to the ±Z directions) is provided on the outer periphery of the frame 43. This enhances the integrity of the cast-in-place concrete member 41 and the precast concrete member 42. The support part 44 is made of concrete formed integrally with the frame part 43 and has a roughly rectangular frame shape that protrudes inward from the lower side (-Z side) of the inner periphery of the frame part 43. Its inner periphery engages with the outer periphery of the lower part 52 of the orthogonal laminated board floor 15 and supports the orthogonal laminated board floor 15 by placing the outer edge part of the upper part 51 of the orthogonal laminated board floor 15 on it. The reinforcing bars 46 are arranged inside the frame portion 43 and the support portion 44, and their ends are exposed to the outside from above and below the groove portion 45 on the outer periphery of the frame portion 43, and protrude outward. It should be noted that the precast concrete member 42 does not have to be frame-shaped, and may be, for example, an independent member for each side.

[0014] With reference to FIG. 10, the floor structure 10 will be described in detail. The cast-in-place concrete member 41 is a reinforced concrete member manufactured on-site. For example, after placing and installing a precast concrete member 42 on steel beams 82 or 83, reinforcing bars 47 are connected to reinforcing bars 46 of the precast concrete member 42, and the precast concrete member 42 is used as at least a part of a formwork to cast ready-mixed concrete, thereby manufacturing the cast-in-place concrete member 41 integrated with the precast concrete member 42, and thereby manufacturing the reinforced concrete slab 14.

[0015] As described above, the reinforced concrete slab 14 is placed on the steel beams 82 (or 83) and is supported by the steel beams 82 (or 83). The end of the reinforced concrete slab 14 made of the precast concrete members 42 overhangs laterally from the steel beam 82 (or 83) like a cantilever slab. The orthogonal laminated timber floor 15 is placed on this overhanging end and is supported by the reinforced concrete slab 14. When placing the orthogonal laminated board floor 15 on the reinforced concrete slab 14, the outer edge of the upper part 51 of the orthogonal laminated board floor 15 is placed on the support part 44 protruding from the underside of the reinforced concrete slab 14, so that the upper surface of the orthogonal laminated board floor 15 and the upper surface of the reinforced concrete slab 14 can be made flush with each other.

[0016] In this way, by placing the orthogonal laminated board floor 15 not directly on the steel beams 82 (or 83) but on the laterally protruding end of the reinforced concrete slab 14 placed on the steel beams 82 (or 83), the distance between the orthogonal laminated board floor 15 and the steel beams 82 (or 83) is increased, and it is possible to prevent the orthogonal laminated board floor 15 from becoming too hot and catching fire due to heat transmitted through the steel beams 82 (or 83), which have high thermal conductivity, in the event of a fire.

[0017] The floor structure 10 may further include a fire resistant board 16 and a fire resistant seal 17 . The fireproof board 16 is arranged to cover the upper and lower surfaces of the cross-laminated timber floor 15. A fire-resistant seal 17 seals between the edge of the reinforced concrete slab 14 and the fire-resistant board 16 . This further improves the fire resistance of the cross-laminated timber floor 15.

[0018] The above-described embodiment is an example for facilitating understanding of the present invention. The present invention is not limited thereto, and includes various modifications, changes, additions, or deletions without departing from the scope defined by the appended claims. This can be easily understood by those skilled in the art from the above description.

[0019] The need for wooden construction is increasing in order to reduce the environmental impact. In recent years, the use of CLT has also increased, with more and more examples of CLT earthquake-resistant walls and floors being used. While there are examples of CLT construction using it for walls and floors, there are also increasing examples of it being used for some floors in steel and reinforced concrete construction. This proposal concerns a method for connecting steel beams to CLT floors. In the case of medium to large-scale wooden structures, depending on the scale, fireproofing is required, with columns, beams and floors having fireproofing properties. Methods already exist for ensuring fireproofing for steel beams and CLT floors alone, but there are few examples of steel beams and CLT floors being fitted together for combined fireproofing. Fireproof boards are used as fireproofing covering for CLT floors, and rock wool is used as fireproofing covering for steel beams, but the issue is how to ensure fireproofing in the areas where the CLT and steel beams come into contact. This proposal is a construction method in which an RC slab is extended on top of the steel beams as a cantilever slab, and a CLT floor is placed on top of that. By placing an RC slab on top of the steel beams, the fireproof coating of the steel beams can be handled using normal construction methods. Furthermore, the fireproof boards installed on the CLT floor are fitted to the RC slab and filled with a fireproof seal, ensuring the fireproof performance of the CLT floor. By using PCa (precast concrete) for the cantilever slab, workability is improved. Furthermore, as both PCa and CLT are dry construction methods, the CLT floor can be easily removed. The integrity of the building (rigid floor) is ensured by arranging the CLT floor and RC slab in a staggered arrangement. This makes the concept of fireproofing clear. Also, by using PCa, CLT floors can be used as construction floors. And by using a staggered arrangement, a design based on the assumption of a rigid floor becomes possible. [Explanation of symbols]

[0020] 10 Floor structure, 14 Reinforced concrete slab, 15 Cross-laminated timber floor, 41 Cast-in-place concrete member, 42 Precast concrete member, 43 Frame, 44 Support, 45 Groove, 46, 47 Steel bar, 51 Top, 52 Bottom, 16 Fireproof board, 17 Fireproof seal, 81 Column, 82, 83 Steel beam.

Claims

1. a reinforced concrete slab placed on a steel beam and supported by the steel beam; An orthogonal laminated slab floor is arranged transversely to the reinforced concrete slab and supported by the reinforced concrete slab; Equipped with The reinforced concrete slab is The steel beam has an end portion that extends laterally from above and supports the orthogonal laminated board floor. floor structure.

2. A fireproof board covering the upper and lower surfaces of the orthogonal laminated board floor; a fireproof seal for sealing the gap between the edge of the reinforced concrete slab and the fireproof board; The floor structure of claim 1 further comprising:

3. The orthogonal laminated board floor is provided with a plurality of the orthogonal laminated board floors arranged in a staggered pattern.

3. The floor structure according to claim 1 or 2.

4. the end of the reinforced concrete slab is made of precast concrete; 3. The floor structure according to claim 1 or 2.

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