Deck slab and deck slab construction method

Abstract

To provide a deck slab allowing an opening formed after concrete casting to be easily reinforced.SOLUTION: A deck slab 100 has a deck plate 3 and a concrete 4 casted on the deck plate 3. An opening 101 is formed in the deck slab 100, penetrating therethrough in a thickness direction. An inner surface 101a of the opening 101 is reinforced by a steel material. This structure can reinforce the opening 101 by disposition of the steel material in the opening 101 without requiring provision of additional bar arrangement in the concrete 4 even if the opening 101 is formed in the deck slab 100 after casting of the concrete 4. Thereby, the opening 101 formed after casting of the concrete 4 can be easily reinforced.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a deck slab and a method for constructing a deck slab. [Background technology]

[0002] A conventional deck slab is known from Patent Document 1. This deck slab includes a deck plate and concrete poured on the deck plate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-41348 Summary of the Invention [Problem to be solved by the invention]

[0004] In some cases, openings are formed in the deck slab. Additional reinforcement is required around these openings to prevent cracks and to reinforce the deck. However, if an opening is formed in the deck slab after the concrete has been poured, additional reinforcement cannot be applied. Therefore, it is necessary to limit the size of the opening or directly reinforce the deck slab by adding small beams or other means.

[0005] The present invention has been made to solve such problems, and aims to provide a deck slab and a construction method for a deck slab that can easily reinforce openings formed after concrete is poured. [Means for solving the problem]

[0006] The deck slab of the present invention is a deck slab having a deck plate and concrete poured on the deck plate, in which an opening is formed through the thickness, and the inner surface of the opening is reinforced with steel.

[0007] The deck slab according to the present invention comprises a deck plate and concrete poured on the deck plate. An opening is formed in the deck slab, penetrating the deck slab in the thickness direction. The inner surface of this opening is reinforced with steel. With this structure, even if an opening is formed in the deck slab after concrete is poured, the opening can be reinforced by placing steel inside the opening without providing additional reinforcement inside the concrete. As described above, the opening formed after concrete is poured can be easily reinforced.

[0008] The inner surface of the opening may be reinforced with a steel pipe inserted into the opening, thereby making it possible to easily reinforce the inner surface of the opening over the entire periphery simply by inserting the steel pipe into the opening.

[0009] The deck slab may, for example, serve as a structural floor.

[0010] The opening width of the steel pipe may be set to 300 mm or less, which can improve the cross-sectional performance of the reinforced opening.

[0011] The height of the deck plate may be set to 50 mm or more and 120 mm or less, which can improve the cross-sectional performance of the reinforced opening.

[0012] The thickness of the deck plate may be set to 1.0 mm or more and 1.6 mm or less, which can improve the cross-sectional performance of the reinforced opening.

[0013] The thickness of the steel plate may be set to 7 mm or more, which can improve the cross-sectional performance of the reinforced opening.

[0014] The yield point of steel is 235N / mm 2 In this case, the cross-sectional performance of the reinforced opening can be improved.

[0015] The section modulus of steel is 20cm 3Over 183cm 3 In this case, the cross-sectional performance of the reinforced opening can be improved.

[0016] The value of the moment of inertia of steel is 100cm 4 Over 2561cm 4 In this case, the cross-sectional performance of the reinforced opening can be improved.

[0017] The deck slab construction method of the present invention is a method for constructing a deck slab having a deck plate and concrete poured on the deck plate, in which an opening formed in the deck slab that penetrates through the thickness direction is reinforced with steel material on the inner surface of the opening.

[0018] According to the deck slab construction method of the present invention, it is possible to obtain the same functions and effects as those of the above-mentioned deck slab. [Effects of the Invention]

[0019] According to the present invention, it is possible to provide a deck slab and a method for constructing a deck slab that can easily reinforce an opening formed after concrete is poured. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 2 is a plan view of a deck slab according to an embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 2. [Figure 5] FIG. 10 is a plan view showing a modified example of a deck slab according to a modified example. [Figure 6] 10 is a table showing the performance of examples at minimum cross section. [Figure 7] 10 is a table showing the performance of the examples at maximum cross section. [Figure 8] FIG. 10 is a cross-sectional view showing a deck slab according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

[0022] FIG. 1 is a plan view of a deck slab 100 according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. 2. As shown in FIG. 1, the deck slab 100 is provided as a structural floor of a building. The deck slab 100 is installed in the building so as to extend horizontally. Note that each drawing shows a "span direction D1" and a "width direction D2." The span direction D1 is the direction in which the deck plate 3, which will be described later, extends, and the width direction D2 is the direction in which the peak portions 3a of the deck plate 3 are aligned.

[0023] 2, the deck slab 100 includes a deck plate 3, concrete 4, and steel pipes 6. The deck slab 100 is supported by a pair of beams 2.

[0024] As shown in Figure 3, the deck plate 3 has alternating peaks 3a and valleys 3b in the width direction D2. The peaks 3a are provided so as to protrude upward from the bottom surfaces of the valleys 3b. The peaks 3a extend parallel to each other in the span direction D1 while being spaced apart from each other in the width direction D2. The peaks 3a form both side walls of the valleys 3b.

[0025] The concrete 4 is poured onto the deck plate 3. The concrete 4 is filled into the valleys 3b of the deck plate 3 up to a position higher than the top surfaces of the peaks 3a. As a result, the concrete 4 has an upper surface above the deck plate 3 that extends in the span direction D1 and width direction D2. This upper surface becomes the upper surface 100a of the deck slab 100.

[0026] Crack expansion prevention bars 7 are arranged inside the concrete 4. The crack expansion prevention bars 7 are mesh members that extend parallel to the span direction D1 and width direction D2. The crack expansion prevention bars 7 are arranged between the ridges 3a and the upper surface 100a.

[0027] 2 and 4, an opening 101 is formed in the deck slab 100, penetrating it in the thickness direction. The opening 101 extends in the vertical direction from the upper surface 100a of the deck slab 100 to the lower surface 3c of the deck plate 3. In the opening 101, a through hole is formed that penetrates all of the components, namely the deck plate 3, the concrete 4, and the crack expansion prevention reinforcement 7, in the thickness direction.

[0028] In this embodiment, the opening 101 has a rectangular shape (including a square shape) when viewed from above and below. The size of the opening 101 is not particularly limited, but may be 110 mm or more (here, the dimension per side), 150 mm or more, or even 300 mm or more. The upper limit of the size of the opening 101 is not particularly limited, but may be 600 mm or less. The opening 101 has four inner surfaces 101a formed in the shape of a square pillar. Each inner surface 101a is configured so that the cut surface of the concrete 4, the cut surface of the deck plate 3, and the cut surface of the crack expansion prevention reinforcement 7 are exposed.

[0029] The steel pipe 6 is a member that reinforces the deck slab 100 at the location where the opening 101 is formed. The steel pipe 6 functions as a steel material that reinforces the inner surface 101a of the opening 101. In this embodiment, the steel pipe 6 has a hollow rectangular prism shape. The four side wall portions 11 of the steel pipe 6 reinforce the four inner surfaces 101a, respectively. The steel pipe 6 is fixed to the inner surface 101a of the opening 101 with an adhesive. Alternatively, a mechanism may be provided in which a protrusion made of a steel plate or the like is provided on the upper part of the steel pipe 6 as a stopper, and the weight of the steel pipe 6 is supported by the concrete 4 via the protrusion. Alternatively, mortar or the like may be filled to fill the clearance provided for inserting the steel pipe 6, and after the mortar hardens, the weight of the steel pipe 6 may be supported by frictional resistance. After the mortar is filled in the clearance, formwork may be used to support the steel pipe 6 from below until the mortar hardens.

[0030] Specifically, as shown in FIG. 4 , the outer peripheral surface 11a of each side wall portion 11 of the steel pipe 6 is arranged so as to contact the respective inner surfaces 101a of the opening 101. The upper end 6a and the lower end 6b of the steel pipe 6 are configured to have cut edges parallel to the horizontal direction. The upper end 6a of the steel pipe 6 is arranged at the same height as the upper surface 100a of the deck slab 100. The lower end 6b of the steel pipe 6 is arranged at the same height as the lower surface 3c of the valley portion 3b of the deck plate 3. This results in a configuration in which the entire inner surface 101a of each opening 101 is covered by the side wall portions 11 of the steel pipe 6. Furthermore, the steel pipe 6 can be configured so as not to protrude upward from the upper surface 100a of the deck slab 100. Furthermore, the steel pipe 6 can be configured so as not to protrude more than necessary beyond the lower surface 3c of the deck plate 3. The height positions of the upper end 6a and the lower end 6b of the steel pipe 6 are not particularly limited. The opening 101 may have an inner surface 101 a that is partly exposed from the side wall 11 of the steel pipe 6 .

[0031] The procedure for reinforcing the opening 101 with the steel pipe 6 will be described. First, the opening 101 is formed in the existing deck slab of a building after concrete is poured (i.e., after construction). In this case, a steel pipe 6 having a size corresponding to the dimensions of the opening 101 and the thickness of the deck slab 100 is prepared. Then, the steel pipe 6 is inserted into the opening 101 and fixed.

[0032] The design method for the deck slab 100 will be explained. As a design method, by setting the thickness of the steel pipe 6 so that the "sectional performance of the missing cross-section" is equal to or less than the "sectional performance of the steel pipe," the decrease in strength and rigidity can be compensated for by the steel pipe 6. Figures 6 and 7 show examples of the above study, with minimum and maximum cross-sections. When the opening width is 300 mm and the steel pipe 6 spans the entire slab (from the top surface of the concrete to the underside of the deck), it can be confirmed that by setting the thickness of the steel pipe 6 to 7.0 mm or more, the values ​​of the tensile allowable moment, compressive allowable moment, and bending rigidity will all be equal to or less than the "sectional performance of the missing cross-section" (cross-sectional performance of the steel pipe). Regarding the Young's modulus of the "a. Missing Cross-Section" (composite slab), the Young's modulus of the steel material is 205,000 N / mm in accordance with the "Deck Plate Floor Structural Design and Construction Standards 2018." 2 is divided by the ratio of Young's modulus of steel to concrete (n=15) (205,000 / 15=13,667).

[0033] As shown in Figures 6 and 7, the opening width of the steel pipe 6 is set to 300 mm or less. The height of the deck plate 3 is set to 50 mm or more and 120 mm or less. The plate thickness of the deck plate 3 is set to 1.0 mm or more and 1.6 mm or less. The plate thickness of the steel material is set to 7 mm or more. The yield point of the steel material is 235 N / mm 2 The section modulus of the steel material (tensile section modulus) is set at 20cm or more. 3 Over 183cm 3 The second moment of area is set to 100cm. 4 Over 2561cm 4 It is set as follows:

[0034] Next, the action and effect of the deck slab 100 according to this embodiment will be described.

[0035] First, an opening 101 may be formed in the deck slab 100. Additional reinforcement is required around such an opening 101 to prevent cracks and to reinforce the deck slab. However, if an opening is formed in the deck slab 100 after concrete has been poured, additional reinforcement cannot be provided. Therefore, it is necessary to limit the size of the opening 101 or directly reinforce the deck slab by adding a small beam or the like.

[0036] Recently, Japan has also adopted the "SDGs Action Plan 2021" in order to achieve the "SDGs (Sustainable Development Goals)," and the construction industry is being called upon to work toward "carbon neutrality," which means virtually zero greenhouse gas emissions. Therefore, it is expected that renovation work, which reduces CO2 emissions by making effective use of existing buildings, will become more common than new construction work. In the case of renovation work, there are cases where openings 101 need to be installed later in hardened concrete due to changes in the use of rooms, etc., and there is a demand for simplified reinforcement in such cases.

[0037] For example, if the opening 101 is not reinforced with the steel pipe 6, the impact range W caused by forming the opening 101 will be the range shown in Figure 4. The width of this impact range W1 (defect impact width) will be larger than the width (defect width) of the opening 101. Within the impact range W1, there is a possibility that the deck plate 3 may peel off from the underside of the concrete 4.

[0038] In contrast, the deck slab 100 of this embodiment is a deck slab 100 having a deck plate 3 and concrete 4 poured on the deck plate 3, in which an opening 101 is formed that penetrates through the thickness, and the inner surface of the opening 101 is reinforced with steel (steel pipe 6).

[0039] The deck slab 100 includes a deck plate 3 and concrete 4 poured on the deck plate 3. The deck slab 100 has an opening 101 formed therethrough in the thickness direction. The inner surface 101a of the opening 101 is reinforced with steel. With this structure, even if the opening 101 is formed in the deck slab 100 after the concrete 4 is poured, by placing steel within the opening 101, stress generated in the defect can be transmitted in the span direction via the steel. This allows the opening 101 to be reinforced without providing additional reinforcement within the concrete 4. As a result, the width of the affected area W1 (defect affected width) is approximately the same as the width of the opening 101 (defect width W2). This prevents the deck plate 3 from peeling off from the concrete 4 around the opening 101. In this way, minimizing the width of the affected area W1 reduces the reduction in the rigidity and strength of the deck slab 100. As a result, the opening 101 formed after the concrete 4 is poured can be easily reinforced.

[0040] The inner surface 101a of the opening 101 may be reinforced by a steel pipe 6 inserted into the opening 101. In this way, by simply inserting the steel pipe 6 into the opening 101, the inner surface 101a of the opening 101 can be easily reinforced over the entire periphery.

[0041] The deck slab 100 may serve, for example, as a structural floor.

[0042] The opening width of the steel pipe 6 may be set to 300 mm or less. In this case, the cross-sectional performance of the reinforced opening 101 can be improved.

[0043] The height of the deck plate 3 may be set to 50 mm or more and 120 mm or less. In this case, the cross-sectional performance of the reinforced opening 101 can be improved.

[0044] The thickness of the deck plate 3 may be set to 1.0 mm or more and 1.6 mm or less. In this case, the cross-sectional performance of the reinforced opening 101 can be improved.

[0045] The thickness of the steel material may be set to 7 mm or more, in which case the cross-sectional performance of the reinforced opening 101 can be improved.

[0046] The yield point of steel is 235N / mm 2 In this case, the cross-sectional performance of the reinforced opening 101 can be improved.

[0047] The section modulus of steel is 20cm 3 Over 183cm 3 In this case, the cross-sectional performance of the reinforced opening 101 can be improved.

[0048] The value of the moment of inertia of steel is 100cm 4 Over 2561cm 4 In this case, the cross-sectional performance of the reinforced opening 101 can be improved.

[0049] The construction method for the deck slab 100 according to this embodiment is a construction method for the deck slab 100 having a deck plate 3 and concrete 4 poured on the deck plate 3, in which an opening 101 formed in the deck slab 100 and penetrating through the thickness direction is reinforced with steel material on the inner surface of the opening 101.

[0050] According to the construction method of the deck slab 100 according to this embodiment, it is possible to obtain the same functions and effects as those of the deck slab 100 described above.

[0051] The present invention is not limited to the above-described embodiments.

[0052] For example, the shape of the deck plate may be changed as appropriate without departing from the spirit of the present invention. Furthermore, the reinforcing bars disposed inside the concrete may also be changed as appropriate.

[0053] Furthermore, the shapes of the openings and steel pipes are not particularly limited. For example, a deck slab 200 as shown in Fig. 5 may be used. This deck slab 200 has a circular opening 201 when viewed from the top and bottom. The inner surface of the opening 201 is reinforced by a cylindrical steel pipe 206. Alternatively, the openings and steel pipes may have other polygonal shapes.

[0054] In the above-described embodiment, a steel pipe is used as the reinforcing steel material, but the reinforcing steel material is not limited to a steel pipe. For example, the reinforcing steel material may be provided by fixing a plurality of steel plates to the inner surface.

[0055] Furthermore, in the above-described embodiment, hollow steel pipes are used, but materials with internal reinforcement may also be used. For example, if the steel pipe is thin and the steel pipe alone does not have sufficient stress transmission effect, the inner surface may be reinforced with diagonal members or the like to the extent that the role of the through hole is not impaired. The attachment method of the diagonal members is not limited.

[0056] Known conventional deck slabs include composite deck slabs and composite deck slabs. A known composite deck slab is described in Patent Document 1. This composite deck slab includes a deck plate and concrete poured on the deck plate, and is structured so that the concrete resists compressive forces generated in the slab, while the deck plate resists tensile forces. A composite deck slab includes a deck plate, concrete poured on the deck plate, and tension reinforcing bars, and is structured so that the concrete resists compressive forces generated in the slab, while the tension reinforcing bars resist tensile forces.

[0057] The type of deck plate is not limited to that described in the above embodiment. For example, a deck plate 3 as shown in Fig. 8 may be used. The deck plate 3 shown in Fig. 8 has a substantially flat bottom wall portion, and ridge portions 3a are formed at predetermined intervals from the bottom wall portion, protruding upward. [Explanation of symbols]

[0058] 3...deck plate, 4...concrete, 6,206...steel pipe, 100,200...deck slab, 101,201...opening.

Claims

1. A deck slab having a deck plate and concrete poured on the deck plate, An opening is formed through the thickness direction, and the inner surface of the opening is reinforced with steel material, the inner surface of the opening is reinforced by a steel pipe inserted into the opening; The thickness of the steel pipe is set so that the cross-sectional performance of the missing cross-sectional portion is equal to or less than the cross-sectional performance of the steel pipe. Deck slab.

2. The deck slab of claim 1 , which serves as a structural floor.

3. 3. The deck slab according to claim 1, wherein the opening width of the steel pipe is set to 300 mm or less.

4. The deck slab according to any one of claims 1 to 3, wherein the height of the deck plate is set to 50 mm or more and 120 mm or less.

5. The deck slab according to any one of claims 1 to 4, wherein the plate thickness of the deck plate is set to 1.0 mm or more and 1.6 mm or less.

6. The deck slab according to any one of claims 1 to 5, wherein the plate thickness of the steel material is set to 7 mm or more.

7. The yield point of the steel material is 235 N / mm ２ The deck slab according to any one of claims 1 to 6, wherein the above is set.

8. The section modulus of the steel material is 20 cm ３ Above, 183cm ３ A deck slab according to any one of claims 1 to 7, set out below.

9. The value of the second moment of area of ​​the steel material is 100 cm ４ Above, 2561cm ４ A deck slab according to any one of claims 1 to 8, set out below.

10. A method for constructing a deck slab having a deck plate and concrete poured on the deck plate, The inner surface of the opening formed in the deck slab and penetrating in the thickness direction is reinforced with steel material, the inner surface of the opening is reinforced by a steel pipe inserted into the opening; The thickness of the steel pipe is set so that the cross-sectional performance of the missing cross-sectional portion is equal to or less than the cross-sectional performance of the steel pipe. How to construct a deck slab.

11. A construction method for a deck slab as described in Claim 10, wherein the thickness of the steel plate is set to 7 mm or more.

12. A deck slab construction method as described in claim 10 or claim 11, wherein the yield point of the steel material is set to 235 N / mm 2 or more.

13. The deck slab construction method according to any one of claims 10 to 12, wherein the section modulus of the steel material is set to a value of 20 cm 3 or more and 183 cm 3 or less.

14. The value of the moment of inertia of the steel material is set to 100 cm 4 or more and 2561 cm 4 or less. The deck slab construction method according to any one of claims 10 to 13.

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