Slabs and slab construction methods

Abstract

To provide a slab and a slab construction method which can reduce construction time and can exhibit fire resistant performance.SOLUTION: A slab 1 including concrete 5 and a deck plate 2, comprises: the deck plate 2 having a flat plate part 3 formed in a flat shape and a rise part 4 rising upward from the flat plate part 3; the concrete 5 placed above the deck plate 2; and a fire resistant covering material 6 installed between an upper surface of the flat plate part 3 and the concrete 5, wherein the rise part 4 is brought into contact with the concrete 5.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] Slabs, such as composite slabs and reinforced concrete slabs, are used as components for floors, roofs, etc. For example, composite slabs, which consist of a deck plate with composite features such as embossing and concrete, are poured from the top of the deck plate with crack prevention reinforcement installed, and demonstrate the required structural performance after the concrete hardens. However, composite slabs have an exposed deck plate on the underside, and if the deck plate surface is heated by flames during a fire, the temperature of the deck plate and concrete will rise, gradually reducing their load-bearing capacity.

[0003] For these reasons, when used in structures requiring fire resistance, load-bearing heating tests are conducted on the actual cross-section and span to confirm whether the material can withstand the load for the specified fire resistance time (usually one or two hours for floors), and official approval (certified by the Minister of Land, Infrastructure, Transport and Tourism) is obtained before use. For specifications that do not meet the specified fire resistance time, a fire-resistant coating is applied to the underside of the deck plate to suppress temperature increases in the floor slab. As shown in Non-Patent Document 1, sprayed rock wool is used as a fire-resistant coating material, but health management issues arise, such as the labor required to manage the thickness of the fire-resistant coating and clean the floor surface after application, as well as the risk of inhaling dust during application. Furthermore, when sprayed rock wool is used on the underside of the deck plate, the worker must spray it while facing upwards, making application difficult.

[0004] In recent years, the use of fire resistance verification methods has become increasingly common in order to ensure rational fire resistance design. This design method involves calculating the predicted fire duration for each room and providing each component with fire resistance appropriate for that duration. However, rooms with many heated objects may require fire resistance of more than two hours. The fire resistance requirements for floors include heat insulation (surface temperature), non-damage resistance (deflection, deflection rate), and flame resistance (flame eruptions). The fire resistance verification method requires that all three of the above requirements be met during the required fire resistance period. In cases where the fire resistance period is extended, the temperature within the floor slab rises significantly, making it difficult to achieve both heat insulation and non-damage resistance.

[0005] For this reason, measures such as increasing the heat capacity by increasing the thickness of the concrete and then providing structural reinforcement such as rebar reinforcement, or, as mentioned above, applying fire-resistant coating to prevent the temperature rise of the floor slab, are necessary. However, if no coating is used, the floor thickness must be increased, which will have an impact on the floor height. In addition, the floor's own weight will also increase, which may have an impact on the cross-section of the frame. If fire-resistant coating is used, there are no such concerns, but the fire-resistant coating must be installed after the floor slab is constructed, which will affect the construction period.

[0006] In floor structures used in residential spaces such as condominiums, insulation is sometimes installed on the underside (underside) of the concrete floor slab. Insulation improves indoor livability and energy efficiency. It also plays a role in preventing condensation. However, with conventional slabs, the deck plate and concrete must be integrated, so insulation cannot be installed on the top surface of the deck plate; it must always be installed on the underside of the deck plate.

[0007] For example, the composite slab in Patent Document 1 is a composite slab comprising a deck plate having peaks and valleys, and a concrete slab that has been poured onto the deck plate and hardened. The deck plate has a flat upper flange located at the peaks, a flat lower flange located at the valleys, and a flat web connecting the upper and lower flanges, and only the underside of the lower flange, or only the underside of the lower flange and part or all of the outer surface of the web, is covered with a fire-resistant coating material. [Prior art documents] [Non-patent literature]

[0008] [Non-Patent Document 1] Rockwool Industry Association Product Introduction Fireproof Coating Materials<https: / / www.rwa.gr.jp / product / investment.html#01> [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-37717 Summary of the Invention [Problem to be solved by the invention]

[0010] Therefore, the present invention was devised in consideration of the above-mentioned circumstances, and its object is to provide a slab and a slab construction method that can shorten construction time and enable fire resistance performance to be exhibited. [Means for solving the problem]

[0011] The slab according to the present invention is a slab comprising concrete and a deck plate, and is provided with the deck plate having a flat portion formed in a flat plate shape and a rising portion rising upward from the flat portion, concrete poured above the deck plate, and a fire-resistant covering material installed between the upper surface of the flat portion and the concrete. The rising portion has an engaging rib that rises upward from the end of the flat plate portion and engages with another adjacent deck plate, and a reinforcing rib that rises upward from the flat plate portion, and the engaging rib and the reinforcing rib are in contact with the concrete.It is characterized by the following. The slab of the present invention is a slab comprising concrete and a deck plate, the deck plate having a plurality of flat plate portions spaced apart from each other and rising portions that rise upward from the flat plate portions and connect to the two spaced apart flat plate portions, concrete poured above the deck plate, and fire-resistant covering material installed between the upper surface of the flat plate portions and the concrete, wherein the rising portions are in contact with the concrete, and the deck plate has the flat plate portions and the rising portions exposed on the underside. The slab of the present invention is a slab comprising concrete and a deck plate, and comprises a deck plate having a flat portion formed in a flat plate shape and a rising portion rising upward from the flat portion, concrete poured above the deck plate, and a fire-resistant covering material installed between the upper surface of the flat portion and the concrete, wherein the rising portion has an engaging rib rising upward from the end of the flat portion and for engaging with another adjacent deck plate, and a reinforcing rib rising upward from the flat portion, and the reinforcing rib is a truss reinforcing bar fixed to the flat portion and formed by combining reinforcing bars in a truss shape, the engaging rib is covered with the fire-resistant covering material, and the truss reinforcing bar is in contact with the concrete.

[0012] The slab construction method according to the present invention is a method for constructing a slab comprising concrete and a deck plate, and includes an installation step of installing a fire-resistant covering material on an upper surface of the flat portion of the deck plate, the flat portion having a flat shape and a rising portion rising upward from the flat portion; and a step of pouring concrete from above the deck plate. hand, and a casting step of hardening the concrete. The rising portion has an engaging rib that rises upward from the end of the flat plate portion and engages with another adjacent deck plate, and a reinforcing rib that rises upward from the flat plate portion, and in the casting step, the engaging rib and the reinforcing rib are brought into contact with the concrete. It is characterized by the following. The slab construction method of the present invention is a method for constructing a slab comprising concrete and a deck plate, and comprises: an installation step of installing a fire-resistant covering material on the upper surface of the flat portion of the deck plate, which has a flat portion formed in a flat plate shape and a rising portion rising upward from the flat portion; and a pouring step of pouring concrete from above the deck plate to bring the rising portion into contact with the concrete and harden the concrete, wherein the deck plate has a plurality of flat portions spaced apart from each other and the rising portion connected to the two spaced apart flat portions, and the flat portion and the rising portion of the deck plate are exposed on the underside. The slab construction method of the present invention is a method for constructing a slab comprising concrete and a deck plate, and comprises: an installation step of installing a fire-resistant covering material on the upper surface of the flat portion of the deck plate, the flat portion having a flat shape and a rising portion rising upward from the flat portion; and a pouring step of pouring concrete from above the deck plate and allowing the concrete to harden, wherein the rising portion has an engaging rib that rises upward from the end of the flat portion and engages with another adjacent deck plate, and a reinforcing rib that rises upward from the flat portion, and the reinforcing rib is a truss reinforcing bar that is fixed to the flat portion and combined in a truss shape, and the installation step covers the engaging rib with the fire-resistant covering material, and the pouring step brings the truss reinforcing bar into contact with the concrete. [Effects of the Invention]

[0013] According to the present invention, it is possible to provide a slab and a slab construction method that can reduce construction time and enable fire resistance to be exhibited. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a perspective view showing an example of a structure in which a slab according to the first embodiment is used. [Figure 2] FIG. 2 is a perspective view showing an example of a slab according to the first embodiment. [Figure 3] FIG. 3 is a cross-sectional view showing an example of a slab according to the first embodiment. [Figure 4] FIG. 4 is a diagram showing an example of a slab construction method according to the first embodiment, in which FIG. 4(a) is a diagram showing an installation process, and FIG. 4(b) is a diagram showing a casting process. [Figure 5] FIG. 5 is a cross-sectional view showing an example of a slab according to the second embodiment. [Figure 6] FIG. 6 is a cross-sectional view showing an example of a slab according to the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, slabs according to several embodiments will be described in detail with reference to the drawings.

[0016] (First embodiment: slab) The slab 1 is used as a floor slab or roof slab of a structure. The slab 1 is made up of multiple deck plates 2 connected together and erected on a support member 8 such as an H-shaped steel beam. As shown in FIG. 1, the slab 1 includes the deck plates 2, concrete 5, and a fire-resistant covering material 6. The slab 1 includes, for example, a composite slab as shown in FIG. 1.

[0017] (Deck plate) The deck plate 2 is a deck plate formed into a rectangular shape in a plan view of a predetermined length by bending a steel plate of approximately 0.8 mm to 1.6 mm that has been subjected to rust prevention treatment, such as hot-dip galvanized steel plate. The length of the deck plate 2 varies depending on the length of the concrete slab to be constructed, the thickness of the steel plate, and the application, but is generally in the range of approximately 0.8 m to 3.7 m. For example, a Cynos Deck manufactured by Nippon Steel Construction Materials Co., Ltd. is used as the deck plate 2.

[0018] The deck plate 2 has a flat portion 3 and a rising portion 4. In this embodiment, only the flat portion 3 of the deck plate 2 is exposed on the lower side.

[0019] (flat plate part) The flat plate portion 3 functions as a structural member for supporting loads and is formed in a flat plate shape. The flat plate portion 3 has protrusions 31 for improving the rigidity of the flat plate portion 3. The protrusions 31 are convex strips with a trapezoidal cross section that are bent along the longitudinal direction of the deck plate 2. The protrusions 31 are formed by embossing or the like. While the protrusions 31 that are convex strips with a trapezoidal cross section are shown as an example, they may also be convex strips with a triangular or polygonal cross section. In other words, the protrusions 31 provided on the flat plate portion 3 may be convex strips or concave strips of other shapes as long as they are uneven and can be bent along the longitudinal direction to increase the rigidity of the flat plate portion. The protrusions 31 may be omitted.

[0020] (Rising part) The rising portion 4 is bent and rises upward from the flat plate portion 3. The upper end of the rising portion 4 is located higher than the upper end of the convex portion 31 of the flat plate portion 3. The rising portion 4 has a pair of engagement ribs (a first engagement rib 41 and a second engagement rib 42) rising from the end of the flat plate portion 3, and a reinforcing rib 43 provided between the first engagement rib 41 and the second engagement rib 42.

[0021] (Engagement rib) Of the pair of engagement ribs, the first engagement rib 41, which is the engagement rib on the right side shown in Figure 2, rises perpendicular to the flat plate portion 3. The first engagement rib 41 has the function of engaging with the second engagement rib 42 of another adjacent deck plate 2 to connect the deck plates 2 together.

[0022] The first engagement rib 41 is composed of a flat first web portion 41a that rises vertically to the surface of the flat portion 3, a rising inclined portion 41b that rises from the tip of the first web portion 41a and slopes upward inward (towards the reinforcing rib 43, the same applies below), a first flange portion 41c that continues horizontally from the tip of the rising inclined portion 41b, an engagement inclined portion 41d that slopes downward from the tip of the first flange portion 41c, and a guide inclined portion 41e that slopes from the tip of the engagement inclined portion 41d in the opposite direction to the engagement inclined portion 41d.

[0023] The first web portion 41a has multiple embossments 41f that protrude inward from the flat plate surface and are aligned parallel to each other at predetermined intervals. These embossments 41f are elongated ridges that slope up and down when viewed horizontally, and serve to prevent misalignment at the interface between the deck plate 2 and the concrete 5 poured inside it. Because the ridges of the embossments 41f slope up and down in this way, a single type of embossment can prevent misalignment in both the vertical and horizontal directions.

[0024] The corners at the joints of the first web portion 41a, the rising inclined portion 41b, the first flange portion 41c, the engaging inclined portion 41d, and the guide inclined portion 41e are all curved and bent to form rounded corners.

[0025] Of the pair of engaging ribs, the second engaging rib 42, which is the left engaging rib shown in FIG.

[0026] The second engagement rib 42 is composed of a flat second web portion 42a that rises perpendicular to the surface of the flat portion 3, an overhanging inclined portion 42b that rises in an inward and upward direction from the tip of the second web portion 42a, and a pressing inclined portion 42c that slopes downward from the tip of the overhanging inclined portion 42b.

[0027] Furthermore, the inclination height of the overhanging inclined portion 42b is higher than the inclination heights of the engaging inclined portion 41d and the guide inclined portion 41e, and the inclination angle of the overhanging inclined portion 42b is different from and gentler than the inclination angles of the engaging inclined portion 41d and the guide inclined portion 41e. Therefore, when the deck plate 2 is slid horizontally over a steel material or the like placed on it, the overhanging inclined portion 42b easily climbs over the engaging inclined portion 41d and the guide inclined portion 41e, making it easier for the second engagement rib 42 to engage with the first engagement rib of the other deck plate.

[0028] Furthermore, the inclination of the pressing inclined portion 42c is inclined in the same direction and at approximately the same angle as the engagement inclined portion 41d. Therefore, when the second engagement rib 42 engages with the first engagement rib of the other deck plate, a load is applied in a direction in which the inclination of the engagement inclined portion 41d and the pressing inclined portion 42c due to the weight of the deck plate 2 presses the second engagement rib 42 against the first engagement rib of the other deck plate 2, allowing the deck plates 2 to tightly engage with each other. This prevents cement components from hardening due to slag leaking when concrete is poured, and causing dirt that is difficult to remove to adhere to the underside of the deck plate.

[0029] As shown in FIG. 2, the second web portion 42a is formed with a plurality of embossments 42d that protrude inward from the flat surface and are arranged in parallel at predetermined intervals, similar to the embossments 41f.

[0030] As shown in each figure, similar to the first engagement rib 41, the corners at the joints of the second web portion 42a, the overhanging inclined portion 42b, and the pressing inclined portion 42c of the second engagement rib 42 are all curved and bent to form rounded corners.

[0031] As shown in Figure 3, the reinforcing rib 43 is installed vertically upward in the center of the deck plate 2 and is composed of an overlapping portion 44 where two flat steel plates overlap, and a reinforcing portion 45 with a triangular cross section formed at the tip of this overlapping portion 44, and has the function of improving the bending rigidity of the flat portion 3 in the longitudinal direction.

[0032] (concrete) As shown in Fig. 3, concrete 5 is made by mixing cement, fine aggregate, coarse aggregate, water, and admixtures, and mortar may also be used as needed. The concrete 5 is poured onto the upper surface of the deck plate 2 and hardened on the upper surface of the deck plate 2 after a predetermined time has passed.

[0033] The concrete 5 has a thickness of, for example, about 150 mm. If necessary, a welded wire mesh 51 is provided inside the concrete 5 above the rising portion 4 of the deck plate 2, ensuring a covering thickness of, for example, 30 mm or more. The welded wire mesh 51 bears tensile forces and prevents cracks in the concrete 5.

[0034] The welded wire mesh 51 is a well-known type used for concrete slabs. The welded wire mesh 51 is a wire mesh made by welding round steel bars and deformed steel wires of a predetermined diameter or larger into a grid shape at a predetermined pitch. The welded wire mesh can be replaced with a combination of deformed steel bars that are bound together.

[0035] The rising portion 4 comes into contact with the concrete 5. This allows a composite effect between the deck plate 2 and the concrete 5 to be exerted. In this embodiment, the first engaging rib 41, the second engaging rib 42, and the reinforcing rib 43 come into contact with the concrete 5.

[0036] (Fireproof covering material) The fire-resistant covering material 6 has fire resistance. The fire-resistant covering material 6 may also have heat insulation properties. The fire-resistant covering material 6 is formed in a sheet shape, and for example, a ceramic fiber blanket is used. The fire-resistant covering material 6 is installed between the upper surface of the flat plate portion 3 and the concrete 5. The fire-resistant covering material 6 is formed in a roll shape and unfolded, and installed so as to cover almost the entire upper surface of the flat plate portion 3. The fire-resistant covering material 6 is installed along the convex portion 31 of the flat plate portion 3. Note that the fire-resistant covering material 6 may be sprayed rock wool, which is a mixture of rock wool and cement.

[0037] (First embodiment: slab construction method) Next, a slab construction method according to this embodiment will be described. The slab construction method includes a setting step and a pouring step.

[0038] In the installation process, as shown in Figure 4(a), a fire-resistant covering material 6 is installed on the upper surface of the flat plate portion 3 of a deck plate 2, which has a flat plate portion 3 and a rising portion 4 rising upward from the flat plate portion 3. In the installation process, a roll-shaped fire-resistant covering material 6 is unfolded and installed on the upper surface of the flat plate portion 3. In detail, the fire-resistant covering material 6 is installed on the flat plate portion 3 between the first engaging rib 41 and the reinforcing rib 43, and on the flat plate portion 3 between the second engaging rib 42 and the reinforcing rib 43. In this way, the fire-resistant covering material 6 is installed over the entire upper surface of the flat plate portion 3 of the deck plate 2, with only the flat plate portion 3 exposed on the underside.

[0039] Next, in the pouring process, as shown in FIG. 4(b), welded wire mesh 51 is installed above rising portion 4. Then, in the pouring process, concrete 5 is poured from above deck plate 2, bringing rising portion 4 into contact with concrete 5, and the concrete 5 is hardened. Welded wire mesh 51 is embedded in concrete 5.

[0040] This completes the slab construction method.

[0041] In this embodiment, a fire-resistant covering material 6 is provided, which is placed between the upper surface of the flat plate portion 3 and the concrete 5. This allows the fire-resistant covering material 6 to be installed from the upper surface side of the flat plate portion 3, eliminating the need for upward work such as spraying rock wool from below onto the underside of the deck plate as in the past. This makes it easier to install the fire-resistant covering material 6, and shortens the construction time.

[0042] Furthermore, in this embodiment, a fire-resistant covering material 6 is provided between the upper surface of the flat plate portion 3 and the concrete 5, and the rising portion 4 is in contact with the concrete 5. This allows the deck plate 2 and the concrete 5 to have a composite effect. In addition, even if the underside of the deck plate 2 is scorched by fire, the fire-resistant covering material 6 can suppress the heat transferred from the flat plate portion 3 to the concrete 5, thereby suppressing the temperature rise of the concrete 5. This makes it possible to achieve fire resistance performance.

[0043] In this embodiment, only the flat portion 3 of the deck plate 2 is exposed on the underside, and the fire-resistant covering material 6 is installed to cover almost the entire upper surface of the flat portion 3. This makes it possible to suppress the temperature rise of the rising portion 4 even if the underside of the deck plate 2 is scorched by fire. This further suppresses the temperature rise of the concrete 5 in contact with the rising portion 4. As a result, it is possible to demonstrate fire resistance performance.

[0044] In this embodiment, the rising portion 4 has a first engagement rib 41 and a second engagement rib 42 for connecting to another adjacent deck plate 2, and a reinforcing rib 43 arranged between the first engagement rib 41 and the second engagement rib 42, and the first engagement rib 41, the second engagement rib 42, and the reinforcing rib 43 come into contact with the concrete 5. This further enhances the composite effect of the deck plate 2 and the concrete 5.

[0045] (Second embodiment: slab) 5, the slab 1 includes a deck plate 2, concrete 5, and a fire-resistant covering material 6. In this embodiment, the deck plate 2 has a flat portion 3 and a rising portion 4 exposed on the underside.

[0046] The fire-resistant covering material 6 is placed between the upper surface of the flat plate portion 3 and the concrete 5. The fire-resistant covering material 6 is placed so as to cover almost the entire upper surface of the flat plate portion 3.

[0047] In this embodiment, a fire-resistant covering material 6 is provided, which is placed between the upper surface of the flat plate portion 3 and the concrete 5. This allows the fire-resistant covering material 6 to be installed from the upper surface side of the flat plate portion 3, eliminating the need for upward work such as spraying rock wool from below onto the underside of the deck plate as in the past. This makes it easier to install the fire-resistant covering material 6, and shortens the construction time.

[0048] Furthermore, in this embodiment, a fire-resistant covering material 6 is provided between the upper surface of the flat plate portion 3 and the concrete 5, and the rising portion 4 is in contact with the concrete 5. This allows the deck plate 2 and the concrete 5 to have a composite effect. In addition, even if the underside of the deck plate 2 is scorched by fire, the fire-resistant covering material 6 can suppress the heat transferred from the flat plate portion 3 to the concrete 5, thereby suppressing the temperature rise of the concrete 5. This makes it possible to achieve fire resistance performance.

[0049] (Third embodiment: slab) As shown in Fig. 6, the slab 1 includes a deck plate 2, concrete 5, and a fire-resistant covering material 6. In this embodiment, only the flat plate portion 3 of the deck plate 2 is exposed on the underside. In this manner, the slab 1 includes, for example, a so-called reinforced concrete slab as shown in Fig. 6.

[0050] The first engagement rib 41 is formed by bending one side end of the flat plate portion 3 toward the concrete 5. The second engagement rib 42 is formed into a U-shape by bending the other side end of the flat plate portion 3 toward the concrete 5. The reinforcing rib 43 rises from the upper surface of the flat plate portion 3. The reinforcing rib 43 is a truss reinforcing bar formed by combining reinforcing bars in a truss shape and welded to the upper surface of the flat plate portion 3. The reinforcing rib 43 comes into contact with the concrete 5.

[0051] The fire-resistant covering material 6 is placed between the upper surface of the flat plate portion 3 and the concrete 5. The fire-resistant covering material 6 is placed so as to cover almost the entire upper surface of the flat plate portion 3, the first engaging rib 41, and the second engaging rib 42.

[0052] In this embodiment, a fire-resistant covering material 6 is provided, which is placed between the upper surface of the flat plate portion 3 and the concrete 5. This allows the fire-resistant covering material 6 to be installed from the upper surface side of the flat plate portion 3, eliminating the need for upward work such as spraying rock wool from below onto the underside of the deck plate as in the past. This makes it easier to install the fire-resistant covering material 6, and shortens the construction time.

[0053] Furthermore, in this embodiment, a fire-resistant covering material 6 is provided between the upper surface of the flat plate portion 3 and the concrete 5, and the rising portion 4 is in contact with the concrete 5. This allows the deck plate 2 and the concrete 5 to have a composite effect. In addition, even if the underside of the deck plate 2 is scorched by fire, the fire-resistant covering material 6 can suppress the heat transferred from the flat plate portion 3 to the concrete 5, thereby suppressing the temperature rise of the concrete 5. This makes it possible to achieve fire resistance performance.

[0054] In this embodiment, only the flat portion 3 of the deck plate 2 is exposed on the underside, and the fire-resistant covering material 6 is installed to cover almost the entire upper surface of the flat portion 3. This makes it possible to suppress the temperature rise of the rising portion 4 even if the underside of the deck plate 2 is scorched by fire. This further suppresses the temperature rise of the concrete 5 in contact with the rising portion 4. As a result, it is possible to demonstrate fire resistance performance.

[0055] In this embodiment, the rising portion 4 has a first engaging rib 41 and a second engaging rib 42 for connecting to an adjacent deck plate 2, and a reinforcing rib 43 disposed between the first engaging rib 41 and the second engaging rib 42. The reinforcing rib 43 contacts the concrete 5, and the fire-resistant covering material 6 is installed so as to cover substantially the entire upper surface of the flat portion 3 and the first engaging rib 41 and the second engaging rib 42. As a result, even if the underside of the deck plate 2 is engulfed in fire, the fire-resistant covering material 6 can also suppress heat transfer from the first engaging rib 41 and the second engaging rib 42 to the concrete 5. This further suppresses temperature rise in the concrete 5. As a result, fire resistance can be achieved.

[0056] Although the embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. Furthermore, the present invention can be embodied in various novel forms in addition to the above-described embodiments. Therefore, various omissions, substitutions, and modifications are possible in the above-described embodiments without departing from the spirit and scope of the present invention. Such novel forms and modifications are included within the scope and spirit of the present invention, as well as within the scope of the inventions set forth in the claims and equivalents of the inventions set forth in the claims. [Explanation of symbols]

[0057] 1: Slab 2: Deck plate 3: Flat plate part 31: Convex part 4: Rising section 41: First engagement rib 42: Second engagement rib 43: Reinforcement rib 44: Overlapped area 45: Reinforcement 5: Concrete 51: Welded wire mesh 6: Fireproof covering material 8: Support member

Claims

1. A slab comprising concrete and a deck plate, a deck plate having a flat portion formed in a flat plate shape and a rising portion rising upward from the flat portion; Concrete poured above the deck plate; a fire-resistant covering material installed between the upper surface of the flat plate portion and the concrete, The rising portion has an engagement rib that rises upward from an end of the flat plate portion and engages with another adjacent deck plate, and a reinforcing rib that rises upward from the flat plate portion, The engaging rib and the reinforcing rib are in contact with the concrete. Slab characterized by.

2. The deck plate has only the flat plate portion exposed on the lower side, The fire-resistant covering material is installed so as to cover substantially the entire upper surface of the flat plate portion.

2. The slab of claim 1, wherein:

3. A slab comprising concrete and a deck plate, a deck plate having a plurality of flat plate portions spaced apart from each other and rising portions rising upward from the flat plate portions and continuing to the two spaced apart flat plate portions; Concrete poured above the deck plate; a fire-resistant covering material installed between the upper surface of the flat plate portion and the concrete, The rising portion is in contact with the concrete, The deck plate has the flat portion and the rising portion exposed on the underside. Slab characterized by.

4. A slab comprising concrete and a deck plate, a deck plate having a flat portion formed in a flat plate shape and a rising portion rising upward from the flat portion; Concrete poured above the deck plate; a fire-resistant covering material installed between the upper surface of the flat plate portion and the concrete, The rising portion has an engagement rib that rises upward from an end of the flat plate portion and engages with another adjacent deck plate, and a reinforcing rib that rises upward from the flat plate portion, The reinforcing rib is a truss reinforcing bar fixed to the flat plate portion and formed by combining reinforcing bars in a truss shape, the engagement rib is covered with the fire-resistant covering material, The truss reinforcing bars are in contact with the concrete. Slab characterized by.

5. A construction method for a slab comprising concrete and a deck plate, an installation step of installing a fire-resistant covering material on an upper surface of the flat plate portion of a deck plate having a flat plate portion and a rising portion rising upward from the flat plate portion; and a pouring step of pouring concrete from above the deck plate and hardening the concrete. The rising portion has an engagement rib that rises upward from an end of the flat plate portion and engages with another adjacent deck plate, and a reinforcing rib that rises upward from the flat plate portion, In the casting step, the engaging rib and the reinforcing rib are brought into contact with the concrete. A slab construction method characterized by:

6. A method for constructing a slab comprising concrete and a deck plate, comprising: an installation step of installing a fire-resistant covering material on an upper surface of the flat plate portion of a deck plate having a flat plate portion and a rising portion rising upward from the flat plate portion; a pouring step of pouring concrete from above the deck plate to bring the rising portion into contact with the concrete and hardening the concrete, The deck plate has a plurality of the flat plate portions spaced apart from each other and the rising portion connected to the two spaced apart flat plate portions, The deck plate has the flat portion and the rising portion exposed on the lower side. A slab construction method characterized by:

7. A method for constructing a slab comprising concrete and a deck plate, comprising: an installation step of installing a fire-resistant covering material on an upper surface of the flat plate portion of a deck plate having a flat plate portion and a rising portion rising upward from the flat plate portion; and a pouring step of pouring concrete from above the deck plate and hardening the concrete. The rising portion has an engagement rib that rises upward from an end of the flat plate portion and engages with another adjacent deck plate, and a reinforcing rib that rises upward from the flat plate portion, The reinforcing rib is a truss reinforcing bar fixed to the flat plate portion and formed by combining reinforcing bars in a truss shape, In the installation step, the engaging rib is covered with the fire-resistant covering material, In the casting step, the truss reinforcing bar is brought into contact with the concrete. A slab construction method characterized by:

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