Deck composite slab

Abstract

This invention provides a deck composite slab that uses a deck plate in which reinforcing bars cannot be placed within grooves or embossed areas, thereby reducing the amount of concrete and reinforcing bars compared to conventional flat deck slabs. [Solution] The deck plate 3 is either a flat deck 3A or a corrugated deck plate 3B. The reinforcing bars 13 are positioned higher than the top surface 10 of the deck plate. The deck composite slab 100 has a safety factor of actual load-bearing capacity greater than 2.0 for the long-term allowable load, a safety factor of actual load-bearing capacity greater than 1.5 for the short-term allowable load, a safety factor of actual load-bearing capacity greater than 0.7 for the theoretical maximum load of the deck composite slab 100, and a safety factor of actual stiffness greater than 0.9 for the theoretical initial stiffness of the deck composite slab 100.

Description

[Technical Field]

[0001] This invention relates to a deck composite slab. [Background technology]

[0002] A deck composite slab is a structure in which a reinforced concrete slab is constructed using a deck plate with reinforcing bars placed in its grooves, and the load is shared between the two. After the concrete poured into the deck plate hardens, the reinforced concrete slab, consisting of the reinforcing bars placed in the grooves of the deck plate and the concrete, supports the entire self-weight. The completed deck composite slab will vary depending on the cross-sectional shape and dimensions of the slab, the aspect ratio of the plane, and the surrounding support conditions. Common applications include "unidirectional slabs" and "orthotropic slabs."

[0003] Conventional deck plates used in composite deck slabs are corrugated deck plates with multiple grooves (corrugated deck plates). Such deck plates have grooves deep and wide enough to accommodate reinforcing bars. The grooves of a corrugated deck plate are formed by a flat section (lower flange) formed on the side of the deck plate's uppermost surface where concrete does not exist, and two inclined surfaces (webs) connecting the uppermost surface of the deck plate to the flat section. The groove depth of a corrugated deck plate is the distance from the uppermost surface of the deck plate to the bottom surface of the lower flange of the groove. The groove width is the distance between the intersection points of the uppermost surface of the deck plate and the inner surface of the groove on the web. The uppermost surface of the deck plate refers to the surface closest to the top surface of the concrete among the surfaces that the deck plate and concrete are in contact with.

[0004] Here, a "unidirectional slab" is a deck composite slab designed as a collection of beams in which the load is transmitted only in the longitudinal direction of the reinforced concrete slab (the longitudinal direction of the deck plate), with reinforcing bars placed in the grooves of the deck plate. Reinforcing bars are placed primarily to prevent crack propagation between the reinforcing bars in the grooves and the top surface of the concrete.

[0005] An orthotropic slab is a design method used when the scope of application for unidirectional slabs is exceeded. When the concrete thickness on the peak of the deck plate increases, reinforcement can be placed in a direction parallel to the width direction of the reinforced concrete slab (deck plate width direction) at a position higher than the upper flange of the groove of the deck plate. Therefore, reinforcement is placed in two directions: reinforcement placed in the groove of the deck plate parallel to the longitudinal direction of the deck plate (reinforcement 13 in Figure 9) and reinforcement placed at a position higher than the upper flange of the groove of the deck plate parallel to the width direction of the deck plate (reinforcement 13a in Figure 9). The design method for orthotropic slabs is the same as the design method for unidirectional slabs, but with the addition of anisotropy.

[0006] "Floor formwork construction" is a method in which formwork is assembled on a floor or an already poured reinforced concrete slab, and concrete is poured into the formwork. Formwork is a general term for temporary structures that maintain the poured concrete in a predetermined shape and dimensions and support it until the concrete reaches the appropriate strength, and plywood is usually used. The "deck plate construction method" is a type of floor formwork construction method in which steel deck plates are laid across the beam side or between the wall formwork, eliminating the need for supporting columns in between. A "flat deck slab" is a type of reinforced concrete slab constructed using the deck plate method. It is a reinforced concrete slab that uses steel deck plates (flat decks) for floor formwork as a substitute for plywood formwork. As floor formwork construction methods, deck plate construction methods, and flat deck slabs, those described in Non-Patent Document 2 are known.

[0007] Steel deck plates for floor formwork (flat decks) are thin steel sheet formwork materials used when pouring concrete for floors and roof slabs in steel-frame, reinforced concrete, and steel-reinforced concrete buildings. Flat decks have a flat surface that contacts the concrete and leg ribs on the underside, and are formed from thin steel sheets. The leg ribs are protruding on the opposite side from the surface that contacts the concrete and are mainly provided for stiffening. The cross-sectional shape of the leg ribs can be hollow, with space in all or part of the cross-sectional shape, or closed, with no space in the cross-sectional shape. Flat decks are used as formwork for the construction of reinforced concrete slabs in buildings, and the ends of the deck plate in the longitudinal direction may be end-closed by crushing the leg ribs. Flat deck slabs are designed so that during concrete construction, the deck plate supports the fixed load (the sum of the weight of the flat deck and the reinforced concrete slab) and the working load (construction load) during construction, and after the concrete hardens, the reinforced concrete slab supports the live load and the fixed load. The flat surface of the flat deck where the deck plate and concrete meet may have grooves or embossing. Grooves in a flat deck refer to a continuous series of uneven shapes formed parallel to the longitudinal direction of the deck plate. The grooves are formed downwards, upwards, or both from the flat surface where the deck plate and concrete meet. Embossing is a structure in which a partially uneven shape is formed downwards or upwards on the flat surface where the deck plate and concrete meet, with multiple similar uneven shapes formed in the longitudinal and width directions of the deck plate. Flat decks are non-specified building materials (non-structural members) that are not required to conform to JIS G 3352. A conventional flat deck is known as the one described in Non-Patent Literature 3.

[0008] A conventional deck composite slab is known, as described in Non-Patent Document 1. The conventional deck composite slab comprises a deck plate having multiple grooves, concrete poured onto the deck plate, and reinforcing bars arranged within the grooves.

Prior Art Documents

Non-Patent Documents

[0009]

Non-Patent Document 1

Non-Patent Document 2

Non-Patent Document 3

Non-Patent Document 4

Patent Documents

[0010]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0011] Non-patent document 1 defines a deck composite slab as a structure in which a reinforced concrete slab is constructed using a deck plate with reinforcing bars placed in its grooves, and the load is shared between the two. Therefore, it is stated that if the grooves of the deck plate are relatively small, it is not possible to place reinforcing bars in the grooves, and thus the requirements for a deck composite slab cannot be met. However, even if the reinforcing bars are placed higher than the top surface of the deck plate (the surface closest to the top of the concrete among the surfaces in contact between the deck plate and the concrete), that is, even if the reinforcing bars are not placed in the grooves, there is a possibility of expecting a composite effect as a deck composite slab, but this composite effect cannot be utilized, which presents a problem.

[0012] Furthermore, Notification No. 1399 specifies the fire-resistant specifications for reinforced concrete slab thickness (70 mm or more for 1 hour, and 100 mm or more for 2 hours). Also, Article 79 of the Building Standards Act Enforcement Order states that for reinforced concrete slabs, the minimum concrete cover thickness required to ensure the necessary fire resistance is 20 mm. On the other hand, in the case of a deck composite slab as described in Non-Patent Literature 1, where reinforcement is placed in a groove, the reinforcement in the groove is heated from three directions (heating from the lower flange 11a and the pair of webs 11b, 11b shown in Figure 8). Therefore, when the 20 mm concrete cover thickness is converted to an equivalent, the minimum concrete cover thickness required to ensure the necessary fire resistance is 31 mm. In this case, the deck composite slab has the problem that the concrete cover thickness required to ensure the necessary fire resistance is larger compared to a reinforced concrete slab (a reinforced concrete slab with a constant slab thickness). The concrete cover thickness of the reinforcement refers to the minimum value among the distances from each outer edge of all the reinforcement bars arranged in the reinforced concrete slab and deck composite slab to the surface where the deck plate and concrete meet (distance 20 shown in Figure 11) (shortest distance 20a shown in Figure 11).

[0013] The deck plate described in Non-Patent Document 1, which allows for reinforcement within the grooves, has a problem in that, because the groove depth and width of the deck plate are relatively large, there is a difference in drying shrinkage due to the difference in concrete volume between the part where the deck plate and concrete are in contact with the concrete and the part where the thickness from the surface to the top surface of the concrete is greatest and the part where it is least greatest, making it prone to cracking.

[0014] In flat deck slabs using steel deck plates (flat decks) for floor formwork, as shown in Non-Patent Document 3 and Patent Document 1, the design assumes that during concrete construction, the deck plate supports the fixed load (the sum of the weight of the flat deck and the weight of the reinforced concrete slab) and the working load (construction load) during construction, and after the concrete hardens, the reinforced concrete slab supports the live load and the fixed load. Therefore, in conventional flat deck slabs, the deck plate, which cannot be reinforced with reinforcing bars in the grooves, is not designed to support loads after the concrete hardens, and thus the performance of the deck plate is not fully utilized. In other words, conventional flat decks have the problem that they are not treated as structural materials after the concrete hardens, and the amount of reinforcing bars in the reinforced concrete slab needs to be increased, which leads to increased costs. In addition, in conventional flat deck slabs, because the flat deck is not treated as a structural material, fireproofing of the flat deck is required, which increases construction time.

[0015] This invention was made to solve the above-mentioned problems, and aims to provide a deck composite slab that can reduce the amount of concrete and reinforcement compared to conventional flat deck slabs, by using a deck plate in which reinforcement cannot be placed in the grooves or embossed areas. [Means for solving the problem]

[0016] The deck composite slab according to the present invention is a deck composite slab having a deck plate, reinforcing bars, and concrete cast on the deck plate, wherein the deck plate is a flat deck or a corrugated deck plate, the reinforcing bars are positioned higher than the uppermost surface of the deck plate, and the deck composite slab has a safety factor of actual load-bearing capacity greater than 2.0 for the long-term allowable load, a safety factor of actual load-bearing capacity greater than 1.5 for the short-term allowable load, a safety factor of actual load-bearing capacity greater than 0.7 for the theoretical maximum load of the deck composite slab, and a safety factor of actual stiffness greater than 0.9 for the theoretical initial stiffness of the deck composite slab.

[0017] In the deck composite slab according to the present invention, the deck plate is either a flat deck or a corrugated deck plate. The reinforcing bars are positioned higher than the top surface of the deck plate. The deck composite slab has a safety factor of actual load-bearing capacity greater than 2.0 for the long-term allowable load, a safety factor of actual load-bearing capacity greater than 1.5 for the short-term allowable load, a safety factor of actual load-bearing capacity greater than 0.7 for the theoretical maximum load of the deck composite slab, and a safety factor of actual stiffness greater than 0.9 for the theoretical initial stiffness of the deck composite slab. Therefore, even if the deck plate does not allow the entire cross-section of the reinforcing bars to be placed inside the grooves or embossed areas, it can be designed in the same way as a conventional deck composite slab. Thus, even when using such a deck plate, the composite effect of the deck composite slab, i.e., the deck plate can support the fixed load of the deck composite slab (the load obtained by adding the weight of the flat deck to the weight of the reinforced concrete slab). Furthermore, when using such deck plates, the reinforcing steel is heated from below in one direction, allowing the minimum concrete cover thickness required to ensure the necessary fire resistance to be reduced to 20 mm. In addition, because the grooves or embossing are small, the difference in concrete volume between the point where the deck plate contacts the concrete and the top surface of the concrete is greatest and the point where it is least greatest can be reduced compared to conventional deck composite slabs, thereby suppressing concrete cracking due to differences in drying shrinkage. Moreover, the concrete weight and amount of reinforcing steel can be reduced compared to conventional flat deck slabs.In summary, by using deck plates in which reinforcing steel cannot be placed in the grooves or embossing, it is possible to improve performance compared to conventional flat deck slabs, or to reduce costs and improve constructability by reducing the concrete weight and amount of reinforcing steel compared to conventional flat deck slabs. Furthermore, by reducing the self-weight of the reinforced concrete slab due to the reduction in concrete weight and amount of reinforcing steel, the thickness of the deck plate can be reduced, further reducing the fixed load.

[0018] The deck composite slab according to the present invention is a deck composite slab having a deck plate, reinforcing bars, and concrete poured on the deck plate, wherein the deck plate is a flat deck, and the flat deck has a flat plate portion in contact with the concrete and a leg rib on the lower side, and refers to a deck plate formed from a thin steel plate, and the flat plate portion is either left flat or has an embossed or grooved surface.

[0019] In the deck composite slab according to the present invention, the deck plate is a flat deck, and the flat portion is either left flat or has an embossed or grooved surface. For such a flat deck, the reinforcing bars are positioned higher than the top surface of the deck plate, and even if the deck plate does not allow the entire cross-section of the reinforcing bars to be placed inside the grooves or embossing, it is possible to design it in the same way as a conventional deck composite slab. Therefore, even when using such a deck plate, the composite effect of the deck composite slab, that is, the deck plate can support the fixed load of the deck composite slab (the load obtained by adding the weight of the flat deck to the weight of the reinforced concrete slab). Furthermore, when using such a deck plate, the reinforcing bars are heated from below in one direction, so the minimum cover thickness for the reinforcing bars required to ensure the necessary fire resistance can be set to 20 mm. In addition, because the grooves or embossing are small, the difference in concrete volume between the part where the thickness from the surface in contact with the deck plate to the top surface of the concrete is largest and the part where it is smallest can be reduced compared to a conventional deck composite slab, and concrete cracking due to differences in drying shrinkage can be suppressed. Furthermore, the concrete weight and amount of reinforcing steel can be reduced compared to conventional flat deck slabs. In addition, in the deck composite slab according to the present invention, a flat deck is used as the structural material, but by ensuring the fire-resistant specifications for the reinforced concrete slab thickness (70 mm or more for 1 hour, 100 mm or more for 2 hours) as indicated in Notification No. 1399, and ensuring a concrete cover thickness of 20 mm or more for the reinforcing steel to ensure the necessary fire resistance, it is possible to achieve 1-hour or 2-hour fire resistance even without fire-resistant coating. As a result, by using a deck plate in which reinforcing steel cannot be placed in the grooves or embossed areas, it is possible to improve performance compared to conventional flat deck slabs, or to reduce costs and improve constructability by reducing the concrete weight and amount of reinforcing steel compared to conventional flat deck slabs. Furthermore, by reducing the self-weight of the reinforced concrete slab due to the reduction in concrete weight and amount of reinforcing steel, the thickness of the flat deck can be reduced, further reducing the fixed load.

[0020] The deck composite slab according to the present invention is a deck composite slab having a deck plate, reinforcing bars, and concrete cast on the deck plate, wherein the deck plate is a flat deck or a corrugated deck plate, the flat portion of the flat deck has grooves or embossing, the depth of the grooves or embossing is less than 10 mm, and the shape of the grooves of the corrugated deck plate satisfies formula (3).

[0021]

number

[0022] In the deck composite slab according to the present invention, the deck plate is either a flat deck or a corrugated deck plate. The flat portion of the flat deck has grooves or embossing, and the depth of the grooves or embossing is less than 10 mm. That is, in such a flat deck, the small size of the grooves or embossing makes it impossible to place the entire cross-section of the reinforcing bar inside the grooves or embossing. The shape of the grooves of the corrugated deck plate satisfies equation (3). That is, in such a corrugated deck plate, the small size of the grooves or embossing makes it impossible to place the entire cross-section of the reinforcing bar inside the grooves or embossing. Even with a deck plate in which the entire cross-section of the reinforcing bar cannot be placed inside such grooves or embossing, it is possible to design it in the same way as a conventional deck composite slab. Therefore, even when using such a deck plate, the composite effect of the deck composite slab, that is, the deck plate can support the fixed load of the deck composite slab (the load obtained by adding the weight of the flat deck to the weight of the reinforced concrete slab). Furthermore, when using such deck plates, the reinforcing steel is heated from below in one direction, allowing the minimum concrete cover thickness required to ensure the necessary fire resistance to be reduced to 20 mm. In addition, because the grooves or embossing are small, the difference in concrete volume between the point where the deck plate contacts the concrete and the top surface of the concrete is greatest and the point where it is least greatest can be reduced compared to conventional deck composite slabs, thereby suppressing concrete cracking due to differences in drying shrinkage. Moreover, the concrete weight and amount of reinforcing steel can be reduced compared to conventional flat deck slabs.In summary, by using deck plates in which reinforcing steel cannot be placed in the grooves or embossing, it is possible to improve performance compared to conventional flat deck slabs, or to reduce costs and improve constructability by reducing the concrete weight and amount of reinforcing steel compared to conventional flat deck slabs. Furthermore, by reducing the self-weight of the reinforced concrete slab due to the reduction in concrete weight and amount of reinforcing steel, the thickness of the deck plate can be reduced, further reducing the fixed load.

[0023] The tensile section modulus of the deck composite slab is 6.10 cm 3 / m or more, 686cm 3 The compression section modulus of the deck composite slab is set to less than or equal to / m, and the value of the compression section modulus of the deck composite slab is 116cm 3 / m or more, 13500cm 3 The second moment of area of ​​the deck composite slab is set to less than or equal to / m, and the second moment of area of ​​the deck composite slab is 128cm 4 / m or more, 158000cm 4 It may be set to less than / m. In this case, when using a deck plate in which it is not possible to place reinforcing bars in the grooves or embossed areas, appropriate performance can be obtained as a deck composite slab. Furthermore, by setting the numerical range as described above, costs and the amount of reinforcing bars can be reduced.

[0024] The concrete cover thickness for the reinforcing bars to ensure the required fire resistance of the deck composite slab may be 20 mm or more. This concrete cover thickness can be matched to the concrete cover thickness for reinforcing bars to ensure the required fire resistance as stipulated in Article 79 of the Building Standards Act Enforcement Order. Furthermore, the weight of the concrete can be reduced by using the above numerical range.

[0025] The thickness of the deck plate may be set to 0.8 mm or more and 1.6 mm or less. In this case, appropriate performance as a deck composite slab can be obtained when using a deck plate in which reinforcing bars cannot be placed in the grooves or embossed areas. Furthermore, by setting the numerical range described above, the composite effect of the deck composite slab, that is, the effect that the deck plate can support the fixed load of the reinforced concrete slab, can be obtained, thereby expanding the applicable span of the deck composite slab and reducing the concrete thickness.

[0026] The height of the deck plate may be set to 50 mm or more and 100 mm or less. In this case, when using a deck plate in which steel bars cannot be arranged in the groove or the emboss, appropriate performance as a deck composite slab can be obtained. Further, by setting the above numerical range, the applicable span of the deck composite slab can be expanded.

[0027] The second moment of area of the deck plate is 60.5 cm 4 / m or more and 550 cm 4 / m or less. In this case, when using a deck plate in which steel bars cannot be arranged in the groove or the emboss, appropriate performance as a deck composite slab can be obtained. Further, by setting the above numerical range, the applicable span of the deck composite slab can be expanded.

[0028] The section modulus of the deck plate is 16.0 cm 3 / m or more and 76.2 cm 3 / m or less. In this case, when using a deck plate in which steel bars cannot be arranged in the groove or the emboss, appropriate performance as a deck composite slab can be obtained. Further, by setting the above numerical range, the applicable span of the deck composite slab can be expanded.

[0029] The mountain thickness of the concrete on the deck plate may be set to 50 mm or more and 300 mm or less. The lower limit value of 50 mm is the lower limit value of the applicable range described in Non-Patent Document 1, and the upper limit value of 300 mm is the upper limit value of the applicable range described in Non-Patent Document 3. In this case, when using a deck plate in which steel bars cannot be arranged in the groove or the emboss, appropriate performance as a deck composite slab can be obtained. Further, by setting the above numerical range, the effect of increasing the loading capacity can be obtained.

[0030] The reinforcing bars extend along a first direction parallel to the longitudinal direction of the deck plate (direction D1 in Figure 2), with a diameter of 10 mm or more and 19 mm or less. The reinforcing bars may be arranged in a second direction parallel to the width direction of the deck plate (direction D2 in Figure 2), perpendicular to the first direction, with a spacing of 100 mm or more and 300 mm or less. In this case, appropriate performance as a deck composite slab can be obtained when using a deck plate in which it is not possible to place reinforcing bars in grooves or embossed areas. Furthermore, by using the above numerical range, it is possible to obtain the effect of increasing the load capacity.

[0031] The reinforcing bars may be arranged in a two-tiered configuration, with the bars in each tier being perpendicular to each other. In other words, reinforcing bars extending in a second direction, perpendicular to the first direction, may be placed between the reinforcing bars extending in a first direction and the concrete surface. In this case, the strength of the deck composite slab can be improved compared to conventional methods.

[0032] The deck plate may be a deck plate conforming to JIS G 3352. In this way, even when using a flat deck in which reinforcing bars cannot be placed in the grooves or embossed areas, the combined effect of the deck composite slab, namely the effect that the deck plate can support the fixed load of the reinforced concrete slab, can be obtained.

[0033] The deck plate according to the present invention may constitute the deck composite slab described above. In this case, the same effects as the deck composite slab described above can be obtained. [Effects of the Invention]

[0034] According to the present invention, as a deck composite slab using a deck plate in which reinforcing bars cannot be placed in grooves or embossed areas, it is possible to provide a deck composite slab that can reduce the amount of concrete and reinforcing bars compared to conventional flat deck slabs. [Brief explanation of the drawing]

[0035] [Figure 1] This is a plan view of a deck composite slab according to an embodiment of the present invention. [Figure 2] This is a cross-sectional view along line II-II in Figure 1. [Figure 3] This is a cross-sectional view along line III-III in Figure 2. [Figure 4] This is a cross-sectional view showing another cross-sectional shape of a deck composite slab according to an embodiment of the present invention. [Figure 5] This is a cross-sectional view showing another cross-sectional shape of a deck composite slab according to an embodiment of the present invention. [Figure 6] This is a cross-sectional view showing another cross-sectional shape of a deck composite slab according to an embodiment of the present invention. [Figure 7] This is a cross-sectional view of a deck composite slab according to an embodiment of the present invention, with two layers of reinforcement. [Figure 8] This is a cross-sectional view of a conventional deck composite slab. [Figure 9] This is a cross-sectional view of a conventional deck composite slab with two layers of reinforcement. [Figure 10] This is a table regarding the concrete cover thickness for reinforcing bars as shown in the "Standard Specifications for Building Construction and Commentary JASS5 Reinforced Concrete Construction". [Figure 11] This is a diagram to explain the definition of concrete cover thickness for reinforcing bars. [Figure 12] This is a diagram illustrating the detailed dimensional relationships of the deck plates. [Figure 13] This table shows examples of deck plates that meet the specified conditions. [Figure 14] This table shows examples of deck plates that meet the specified conditions. [Figure 15] This table shows examples of deck plates that meet the specified conditions. [Figure 16] This table shows the cross-sectional properties of a deck composite slab. [Figure 17] This table shows the cross-sectional properties of a deck composite slab. [Figure 18] (a) is a table showing the overview of the test specimen, and (b) is a table showing a list of material specifications. [Figure 19]This shows test specimens of deck composite slabs "No. 1-8". [Figure 20] This shows the reinforced concrete specimen "No. 9". [Figure 21] This table shows the test results for "No. 1-9," as well as a comparison of calculated and experimental values. [Figure 22] This table shows examples of cases using "Wavy Deck Plate 1," "Flat Deck 6," and "Flat Deck 3." [Figure 23] This table compares the reinforcing steel weight between a design using floor formwork construction and a design using a deck composite slab according to an embodiment of the present invention. [Figure 24] This table compares the reinforcing steel weight between a design using floor formwork construction and a design using a deck composite slab according to an embodiment of the present invention. [Modes for carrying out the invention]

[0036] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

[0037] Figure 1 is a plan view of a deck composite slab 100 according to an embodiment of the present invention. Figure 2 is a cross-sectional view along line II-II in Figure 1. Figure 3 is a cross-sectional view along line III-III in Figure 2. As shown in Figure 1, the deck composite slab 100 is provided as a structural floor for a building. The deck composite slab 100 is installed in the building so as to extend horizontally. Note that each figure has a "deck plate longitudinal direction (direction D1 in Figures 1, 2, and 3)" and a "deck plate width direction (direction D2 in Figures 1, 2, and 3)". In the case of a flat deck 3A, the D1 direction is the direction in which the leg ribs 12 extend, and in the case of a corrugated deck plate 3B, it is the direction in which the grooves 11 extend. In the case of a flat deck 3A, the D2 direction is the direction in which the leg ribs 12 are aligned, and in the case of a corrugated deck plate 3B, it is the direction in which the grooves 11 are aligned. Flat deck 3A is a deck plate having a flat surface where the deck plate 3 and concrete 4 are in contact, and having leg ribs 12 on the underside. Corrugated deck plate 3B is a deck plate 3 having multiple grooves 11.

[0038] As shown in Figure 2, the deck composite slab 100 comprises a deck plate 3 and concrete 4. The deck composite slab 100 is supported by a pair of beam members 2.

[0039] The deck plate 3 shown in Figure 3 is either a flat deck 3A or a corrugated deck plate 3B. The flat deck 3A has a flat surface where the deck plate 3 and concrete 4 meet, and has leg ribs 12 on its lower side. The flat surface of the flat deck 3A where the deck plate 3 and concrete 4 meet may have either grooves 11 or embossing 15. The leg ribs 12 are parts that protrude on the opposite side from the surface where the flat deck 3A and concrete 4 meet, and are mainly provided for stiffening. The cross-sectional shape of the leg ribs 12 can be a hollow type with space in the entire or partial cross-sectional shape, or a closed type where there is no space in the cross-sectional shape of the leg ribs 12. The dimension L12 between the leg ribs 12 is set to a predetermined dimension. The grooves 11 of the flat deck refer to an uneven shape formed continuously in a direction parallel to the longitudinal direction D1 of the deck plate, and refer to the part of the deck plate 3 formed downward, upward, or both directions from the flat surface where the deck plate 3 and concrete 4 meet. The embossing 15 is a structure in which a partially uneven shape is formed on the lower or upper side of the flat surface where the deck plate 3 and the concrete 4 are in contact, and refers to a portion of the deck plate in which multiple similar uneven shapes are formed in the longitudinal direction D1 and the width direction D2 of the deck plate.

[0040] Corrugated deck plate 3B refers to deck plate 3 having multiple grooves 11. As shown in Figure 5(a), the grooves 11 of corrugated deck plate 3B are formed by a flat plate portion (lower flange 11a) formed on the side of the uppermost surface 10 of the deck plate where concrete 4 does not exist, and two inclined surfaces (webs 11b) connecting the uppermost surface 10 of the deck plate and the flat plate portion. The grooves 11 are formed continuously parallel to the longitudinal direction D1 of the deck plate 3.

[0041] As shown in Figure 3, the concrete 4 is poured onto the deck plate 3. The concrete 4 is filled into the grooves 11 of the deck plate 3 and is filled to a position higher than the top surface 10 of the deck plate. As a result, the concrete 4 has an upper surface above the deck plate 3 that extends in the longitudinal direction D1 and the width direction D2 of the deck plate. This upper surface becomes the top surface 100a of the deck composite slab 100. The top surface 10 of the deck plate is the surface that is closest to the concrete top surface 100a among the surfaces in contact between the deck plate 3 and the concrete 4.

[0042] Reinforcing bars 13 are arranged inside the concrete 4. The reinforcing bars 13 extend parallel to the longitudinal direction D1 of the deck plate. Multiple reinforcing bars 13 are arranged spaced apart from each other in the width direction D2 of the deck plate. The reinforcing bars 13 are placed between the top surface 10 of the deck plate and the reinforcing bars 7 for crack propagation prevention, which will be described later. As a result, the reinforcing bars 13 are placed higher than the top surface 10 of the deck plate 3. The reinforcing bars 13 may be arranged in a two-tiered arrangement, with an upper reinforcing bar 13a perpendicular to the lower reinforcing bar 13. For example, as shown in Figure 7, another reinforcing bar 13a extending parallel to the width direction D2 of the deck plate may be placed between the reinforcing bar 13 extending parallel to the longitudinal direction D1 of the deck plate and the reinforcing bar 7 for crack propagation prevention.

[0043] Reinforcement bars 7 may be placed inside the concrete 4, primarily to prevent crack propagation. The reinforcement bars 7 for preventing crack propagation are bars that extend parallel to both the longitudinal direction D1 of the deck plate and the width direction D2 of the deck plate. Welded wire mesh or the like may be used as the reinforcement bars 7 for preventing crack propagation. The reinforcement bars 7 for preventing crack propagation are placed between the reinforcement bars 13 and the upper surface 100a of the concrete.

[0044] The cross-sectional shape of the deck plate 3 is not limited to that shown in Figure 3; for example, those shown in Figures 4 to 6 may be adopted. The flat deck 3A shown in Figure 4(a) differs from Figure 3 in the structure of the groove 11 provided on the uppermost surface 10 of the deck plate. In the deck plate 3 shown in Figure 4(a), the groove 11 is formed at the position of the leg ribs 12 and in the center between a pair of leg ribs 12. The flat deck 3A has a flat plate portion 11c between the uppermost surface (convex-shaped ribs) 10 of the deck plate and the groove 11.

[0045] The flat deck 3A shown in Figure 4(b) has embossing 15 instead of the grooves 11 in Figure 3. The embossing 15 has a structure in which a partially uneven shape is formed below or above the top surface 10 of the deck plate. The reinforcing bars 13 are positioned higher than the top surface 10 of the deck plate.

[0046] In the corrugated deck plate 3B shown in Figure 5(a), the flat deck 3A as shown in Figure 3 is not used. The corrugated deck plate 3B has multiple grooves 11. Each groove 11 has a lower flange 11a and a pair of webs 11b, 11b. The grooves 11 of the corrugated deck plate 3B have a cross-sectional shape that satisfies equation (3). Therefore, reinforcing bars 13 cannot be placed in the grooves 11. The flat deck 3A shown in Figure 5(b) has a different shape of grooves 11 compared to Figure 3. The grooves 11 shown in Figure 5(b) have a V-shape. Also, the leg ribs 12 shown in Figure 5(b) have a different shape from the leg ribs 12 shown in Figure 3. The flat deck 3A shown in Figure 6 uses leg ribs 12 of a different shape compared to the deck plate 3 which has embossing 15 as shown in Figure 4(b). The concrete cover thickness refers to the minimum distance from the outer edge of each reinforcing bar 13 in the deck composite slab 100 to the surface where the deck plate 3 and concrete 4 meet. In the example shown in Figure 11, of the multiple distances 20, distance 20a is the concrete cover thickness.

[0047] Figure 8 shows a conventional deck composite slab 200 in which reinforcing bars 13 are arranged in the groove 11. In the conventional deck composite slab 200, the reinforcing bars 13 are heated in three directions from the lower flange 11a and the webs 11b, 11b of the groove 11. Therefore, the minimum cover thickness of 20 mm for reinforcing bars to ensure the required fire resistance performance as stipulated in Article 79 of the Building Standards Act Enforcement Order must be converted to an equivalent value, and the minimum cover thickness for reinforcing bars to ensure the required fire resistance performance must be 31 mm. On the other hand, in the case of the deck composite slab 100 according to this embodiment, in which reinforcing bars 13 are not arranged in the groove 11, the reinforcing bars 13 are heated in one direction from below, so there is no need to convert to an equivalent value for the minimum cover thickness, and the minimum cover thickness for reinforcing bars to ensure the required fire resistance performance can be 20 mm. Therefore, in this embodiment, the cover thickness for reinforcing bars to ensure the required fire resistance performance of the deck plate 3 may be 20 mm or more. The table shown in Figure 10 is the table presented in the "Standard Specifications for Building Construction and Commentary JASS5 Reinforced Concrete Construction".

[0048] Referring to Figure 12, the details of the dimensional relationship of the deck plate 3 will be explained. As shown in Figure 12(a), the depth of the groove 11 is "H". That is, it is the distance from the top surface 10 of the deck plate to the bottom surface of the deck plate. The width of the groove above the groove 11 is "b1". The width of the groove below the groove 11 is "b2". Note that if the bent portion of the deck plate 3 has an R portion, the starting point of the dimensions "b1" and "b2" is set to the "dimension restraint position" shown in Figures 12(b) and (c). As shown in Figure 12(b), in bent portions less than 90°, the dimension restraint position is the intersection of the imaginary line VL1 corresponding to the outer circumference of one flat plate portion and the imaginary line VL2 corresponding to the outer circumference of the other flat plate portion. As shown in Figure 12(c), in bent portions of 90° or more, the dimension restraint position is the point on the outer circumference of the R portion that has the largest dimension. When a virtual reinforcing bar 13 is placed in the groove 11, let "h" be the height of the center of the virtual reinforcing bar 13 from the lower surface of the lower flange 11a. Let "l" be the distance from the center of the virtual reinforcing bar 13 to the outer surface of the web 11b. At this time, if the angle that the web 11b makes with a straight line perpendicular to the top surface 10 of the deck plate is "θ / 2", then "θ = (b1-b2) / H". Also, "l" is given by equation (1). From the condition for the required fire cover thickness in the case of three-way heating, "l ≥ 31 mm". Furthermore, the condition for when a reinforcing bar 13 cannot be placed in the groove 11 is "h ≥ H". Therefore, by rearranging equation (1) and applying the relationship "h ≥ H", we get equation (2). Further rearranging this gives equation (3).

[0049]

number

[0050] One condition for not placing the entire cross-section of the reinforcing bar 13 within the groove 11 is that the depth of the groove 11 or the depth H of the emboss 15 is less than 10 mm. This is a condition under which it is not possible to place the entire cross-section of a 10 mm diameter reinforcing bar 13 within the groove 11. Alternatively, another condition for not placing the entire cross-section of the reinforcing bar 13 within the groove 11 is that the shape of the groove 11 satisfies the above equation (3).

[0051] Furthermore, the thickness of the deck plate 3 may be set to 0.8 mm or more and 1.6 mm or less. The height of the deck plate 3 may be set to 50 mm or more and 100 mm or less. The height of the deck plate 3 is a standard manufacturing dimension and refers to the height from the lowest surface of the deck plate 3 to the highest surface of the deck plate 3. A manufacturing tolerance is allowed for the height of the deck plate 3. For example, even if the actual manufacturing dimension is 101 mm, it is included in the height range of the deck plate 3. In the case of a flat deck, the height of the deck plate 3 (deck plate depth) is the vertical distance from the top surface 10 of the deck plate to the lower end of the leg rib 12. In the case of Figure 5(a), the height of the deck plate 3 is the vertical distance from the top surface 10 of the deck plate to the lower end of the lower flange 11a of the groove 11. The second moment of area of ​​the deck plate 3 is 60.5 cm 4 / m or more, 550cm 4 It may be set to less than / m. The section modulus of deck plate 3 is 16.0cm 3 / m or more, 76.2cm 3 It may be set to / m or less. Examples of deck plates 3 that satisfy these conditions are shown in Figures 13 to 15.

[0052] For example, a steel deck plate for floor formwork (flat deck) according to prior art, such as that described in Japanese Utility Model Publication No. 63-10022, is a non-designated building material (non-structural member) that is not required to conform to JIS G 3352. In contrast, the deck plate 3 used in the deck composite slab 100 according to this embodiment must be a deck plate (designated building material) that conforms to JIS G 3352.

[0053] Next, the conditions for the deck composite slab 100 according to this embodiment will be described. The deck composite slab 100 may have a safety factor of actual load-bearing capacity greater than 2.0 for the long-term allowable load, a safety factor of actual load-bearing capacity greater than 1.5 for the short-term allowable load, a safety factor of actual load-bearing capacity greater than 0.7 for the theoretical maximum load of the deck composite slab 100, and a safety factor of actual stiffness greater than 0.9 for the theoretical initial stiffness of the deck composite slab 100. The long-term allowable load is calculated using the value obtained by dividing the standard strength of concrete specified in the Building Standards Act, its enforcement ordinance, and Ministry of Construction Notification No. 2464 of 2000 by 3.0, and the value obtained by dividing the standard strength of reinforcing bars and deck plates by 1.5. The short-term allowable load is calculated using the standard strength of concrete, reinforcing bars, and deck plates specified in the Building Standards Act, its enforcement ordinance, and Ministry of Construction Notification No. 2464 of 2000. The theoretical values ​​are the load and stiffness calculated using the actual strength of the deck plate, reinforcing bars, and concrete.

[0054] The tensile section modulus of deck composite slab 100 is 6.10 cm 3 / m or more, 686cm 3 It may be set to less than / m. The value of the compression section modulus of the deck composite slab 100 is 116cm 3 / m or more, 13500cm 3 It may be set to less than or equal to / m. The tension side is the side on which the deck plate 3 of the deck composite slab 100 is placed, and the compression side is the upper surface side of the concrete 4 of the deck composite slab 100. The value of the second moment of area of ​​the deck composite slab 100 is 128cm 4 / m or more, 158000cm 4 It may be set to less than / m. The peak thickness of the concrete 4 on the deck plate 3 may be set to 50mm or more and 300mm or less. The peak thickness of the concrete 4 is the vertical dimension from the top surface 10 of the deck plate 3 to the top surface 100a of the concrete 4.

[0055] The reinforcing bars 13 extend along the longitudinal direction D1 of the deck plate 3, and the diameter of the reinforcing bars 13 may be 10 mm or more and 19 mm or less. The diameter may also be 19 mm or more. The reinforcing bars 13 may be arranged in the width direction D2 of the deck plate 3, which is perpendicular to the longitudinal direction D1 of the deck plate 3, with a reinforcement interval of 100 mm or more and 300 mm or less.

[0056] The standard strength of deck plate 3 is 205 N / mm². 2 More than 325N / mm 2 The following is acceptable, and the standard strength of concrete 4 is 18 N / mm². 2 More than 24N / mm 2 The following is acceptable, and the standard strength of reinforcing bar 13 is 235 N / mm². 2 More than 390N / mm 2 The following may be considered:

[0057] The support span for deck plate 3 is 2.0m to 4.0m. below It is often said that the load supported by the deck composite slab 100 according to the embodiment of the present invention is 1800 N / mm². 2 More than 20000N / mm 2 below It can be considered as such.

[0058] For crack prevention, the reinforcing bars 7 may have a diameter of 4 mm or more and 16 mm or less, with a spacing of 50 mm or more and 300 mm or less. When using welded wire mesh and reinforcing bar grids, the reinforcing bars may have a diameter of 6 mm and a spacing of 150 mm. When using deformed reinforcing bars, the reinforcing bars may have a diameter of 10 mm and a spacing of 200 mm.

[0059] Figures 16 and 17 show the cross-sectional performance tables for the deck composite slab 100 corresponding to this embodiment. In Figures 16 and 17, the cross-sectional performance of the deck composite slab 100 was calculated for each combination of the following uses: three specifications for the thickness of the concrete 4 on the crest, two specifications for the amount of reinforcement, and three specifications for the deck plate 3. The specifications for the thickness of the concrete 4 on the crest were "Climb thickness: 50 mm (lower limit of applicable range)", "Climb thickness: 120 mm" (see Figure 16), and "Climb thickness: 300 mm (upper limit of applicable range)" (see Figure 17). The amount of reinforcement was set to "Reinforcement bar diameter 10 mm, reinforcement spacing 300 mm (minimum reinforcement amount within the applicable range)" and "Reinforcement bar diameter 19 mm, reinforcement spacing 100 mm (maximum reinforcement amount within the applicable range)".

[0060] Three specifications were prepared for the cross-sectional performance of deck plate 3. "Corrugated deck plate 1" satisfies equation (3), has a deck plate depth of 50 mm (lower limit of the applicable range), and a second moment of area of ​​60.5 cm. 4 / m (lower limit of applicable range), section modulus is 16.0cm 3 The value is / m (lower limit of the applicable range). "Flat Deck 6" has a groove or emboss depth of 1.5 mm (less than 10 mm), a plate thickness of 1.6 mm (upper limit of the applicable range), a deck plate height of 100 mm (upper limit of the applicable range), and a second moment of area of ​​550 cm². 4 / m (upper limit of applicable range), section modulus is 76.2cm 3 The limit is / m (upper limit of the applicable range). "Flat Deck 3" has a groove or emboss depth of 7.0 mm (less than 10 mm), a plate thickness of 1.6 mm (upper limit of the applicable range), a deck plate height of 90 mm, and a second moment of area of ​​403 cm². 4 / m, section modulus of 69.1 cm 3 It is / m.

[0061] Next, a test to confirm the structural performance of the deck composite slab 100 according to this embodiment will be described. A structural test was conducted on a deck composite slab 100 using a deck plate 3 (in this test, a steel deck plate for floor formwork (flat deck 3A)) in which reinforcement cannot be placed in the groove 11, and the structural performance of the deck composite slab 100 was evaluated. The test method was unidirectional monotonic loading, which is generally used when evaluating the structural performance of a slab. Unidirectional monotonic loading is a test method in which a load is applied downward from the top surface of the concrete to the bottom surface of the deck plate at loading points 25, 25. The outline of the test specimen is shown in Figure 18(a), and the list of material specifications is shown in Figure 18(b). The outline of the test specimen is also shown in Figures 19 and 20. Figure 19 shows test specimens 150 of deck composite slabs "No. 1", "No. 2", "No. 3", "No. 4", "No. 5", "No. 6", "No. 7", and "No. 8". Figure 20 shows specimen 151 of the reinforced concrete slab "No. 9". As shown in Figures 19 and 20, specimens 150 and 151 of specimens "No. 1", "No. 2", "No. 3", "No. 4", "No. 5", "No. 6", "No. 7", "No. 8", and "No. 9" are supported at both ends of the deck plate longitudinal direction D1 by support points 21. In addition, a pair of loading points 25, 25 are provided near the center of the deck plate longitudinal direction D1 of specimens 150 and 151. The distance L1 between the pair of loading points 25, 25 of specimen 150 is 500 mm for "No. 1", "No. 7", and "No. 8", 1200 mm for "No. 2", 1490 mm for "No. 3", 1220 mm for "No. 4", 1180 mm for "No. 5", and 840 mm for "No. 6". The top thickness T1 of concrete 4 in test specimen 150 was 180 mm for "No. 1", "No. 7", and "No. 8", 150 mm for "No. 2", 120 mm for "No. 3" and "No. 5", and 300 mm for "No. 4" and "No. 6".

[0062] Next, we will explain the test results. Figure 21 shows the test results for "No.1", "No.2", "No.3", "No.4", "No.5", "No.6", "No.7", "No.8", and "No.9", as well as a comparison of calculated and experimental values.

[0063] In accordance with the required performance of deck composite slabs described in Non-Patent Literature 4: Commentary on Technical Standards for Deck Plate Versions and Design / Calculation Examples, when the required performance of a deck composite slab is defined as "a maximum test load of 2.0 or more relative to the long-term allowable load," "a maximum test load of 1.5 or more relative to the short-term allowable load," "a maximum test load of 0.7 or more relative to the theoretical maximum load," and "a test initial stiffness of 0.9 or more relative to the theoretical initial stiffness," it was confirmed from Figure 21 that the deck composite slab satisfies the following requirements when comparing the calculated and experimental values: "a maximum test load of 2.0 or more relative to the long-term allowable load," "a maximum test load of 1.5 or more relative to the short-term allowable load," "a maximum test load of 0.7 or more relative to the theoretical maximum load," and "a test initial stiffness of 0.9 or more relative to the theoretical initial stiffness." The long-term allowable load is calculated using the value obtained by dividing the standard strength of concrete, as stipulated in the Building Standards Act, its enforcement ordinance, and Ministry of Construction Notification No. 2464 of 2000, by 3.0, and the value obtained by dividing the standard strength of reinforcing steel and deck plates by 1.5. The short-term allowable load is calculated using the standard strengths of concrete, reinforcing steel, and deck plates, as stipulated in the Building Standards Act, its enforcement ordinance, and Ministry of Construction Notification No. 2464 of 2000. The theoretical values ​​are the loads and stiffness calculated using the actual strengths of the deck plates, reinforcing steel, and concrete. Therefore, since the deck composite slab 100 using steel deck plates for floor formwork (flat deck) meets the required performance, it can be said that even when steel deck plates for floor formwork (flat deck) are used, it is possible to evaluate it as the deck composite slab. In addition, from the comparison of experimental values ​​between the deck composite slab "No. 1" and the reinforced concrete slab "No. 9" in Figure 21, it was confirmed that the structural performance is improved by adding deck plates. Therefore, it can be said that the structural performance of the deck plate can be taken into consideration even in the design after the concrete has hardened. Furthermore, since a deck plate having a groove that satisfies equation (3) is considered to be more likely to yield the combined effect of the deck composite slab compared to a steel deck plate for floor formwork (flat deck), it is considered that even when a deck plate having a groove that satisfies equation (3) is used, it can be evaluated as the deck composite slab.

[0064] Here, Figure 22 shows an example using the "corrugated deck plate 1," "flat deck 6," and "flat deck 3" described above in Figures 16 and 17. The design conditions here are the same as those for Specification 1 "No. 1" and Specification 2 "No. 2" shown in Figure 18(a). The deck composite slab can be designed when "the generated deflection relative to the allowable deflection is less than 1.0" and "the generated moment relative to the allowable deflection is less than 1.0." The allowable deflection refers to the value obtained by dividing the support span by 250. The support span refers to the distance between the support points 21. The allowable moment refers to the moment when the long-term allowable stress acts on the cross-sectional performance of the deck composite slab calculated by the cross-sectional calculation method described in Non-Patent Literature 1. Generated deflection and generated moment refer to the deflection and moment when a live load is applied to the deck composite slab. Figure 22 confirms that even when using deck plates of other shapes within the applicable range of the deck composite slab, it is still possible to design it as the deck composite slab.

[0065] Next, the operation and effects of the deck composite slab 100 according to this embodiment will be described.

[0066] The deck composite slab 100 according to this embodiment is a deck composite slab 100 having a deck plate 3, reinforcing bars 13, and concrete 4 poured on the deck plate 3, wherein the deck plate 3 is a flat deck 3A or a corrugated deck plate 3B, the reinforcing bars 13 are positioned higher than the uppermost surface 10 of the deck plate, and the deck composite slab 100 has a safety factor of actual load-bearing capacity greater than 2.0 for the long-term allowable load, a safety factor of actual load-bearing capacity greater than 1.5 for the short-term allowable load, a safety factor of actual load-bearing capacity greater than 0.7 for the theoretical maximum load of the deck composite slab 100, and a safety factor of actual stiffness greater than 0.9 for the theoretical initial stiffness of the deck composite slab 100.

[0067] In the deck composite slab 100 according to this embodiment, the deck plate 3 is either a flat deck 3A or a corrugated deck plate 3B. The reinforcing bars 13 are positioned higher than the uppermost surface 10 of the deck plate. The deck composite slab 100 has a safety factor of actual load-bearing capacity greater than 2.0 for the long-term allowable load, a safety factor of actual load-bearing capacity greater than 1.5 for the short-term allowable load, a safety factor of actual load-bearing capacity greater than 0.7 for the theoretical maximum load of the deck composite slab 100, and a safety factor of actual stiffness greater than 0.9 for the theoretical initial stiffness of the deck composite slab 100. Therefore, even if the deck plate 3 does not allow the entire cross-section of the reinforcing bars 13 to be placed inside the grooves 11 or embossed areas 15, it is possible to design it in the same way as a conventional deck composite slab. As a result, even when using such a deck plate 3, the deck plate 3 can support the composite effect of the deck composite slab 100, that is, the fixed load of the deck composite slab 100 (the load obtained by adding the weight of the flat deck to the weight of the reinforced concrete slab). Furthermore, when using such a deck plate 3, the reinforcing bars 13 are heated from below in one direction, so the minimum concrete cover thickness for the reinforcing bars required to ensure the necessary fire resistance can be reduced to 20 mm. In addition, because the grooves 11 or embossing 15 are small, the difference in concrete volume between the part where the thickness from the surface where the deck plate 3 contacts the concrete to the top surface of the concrete 4 is largest and the part where it is smallest can be reduced in the width direction of the deck plate 3 compared to a conventional deck composite slab 200, thereby suppressing cracking of the concrete 4 due to differences in drying shrinkage. In addition, the amount of concrete and reinforcing bars can be reduced compared to a conventional flat deck slab. As a result, by using a deck plate 3 in which reinforcing bars cannot be placed in the grooves 11 or embossing 15, it is possible to improve performance compared to a conventional flat deck slab, or to reduce costs and improve workability by reducing the amount of concrete and reinforcing bars compared to a conventional flat deck slab. Furthermore, by reducing the self-weight of the reinforced concrete slab due to the reduction in concrete weight and reinforcing bars, the thickness of the deck plate can be reduced, further reducing the fixed load.

[0068] The deck composite slab 100 according to this embodiment is a deck composite slab 100 having a deck plate 3, reinforcing bars 13, and concrete 4 poured on the deck plate 3, wherein the deck plate 3 is a flat deck 3A, and the flat deck 3A has a flat plate portion 11c that the concrete 4 contacts and has leg ribs 12 on the lower side, and refers to a deck plate 3 formed from thin steel plate, and the flat plate portion 11c is either left as a flat plate or has an embossed or grooved surface.

[0069] In the deck composite slab 100 according to this embodiment, the deck plate 3 is a flat deck 3A, and the flat plate portion 11c is either left flat or has an embossed or grooved surface. Even if the deck plate 3 is such that the reinforcing bars 13 are positioned higher than the top surface 10 of the deck plate and the entire cross-section of the reinforcing bars 13 cannot be placed inside the grooves 11 or embossed surface 15, the same design as a conventional deck composite slab can be achieved. Therefore, even when using such a deck plate 3, the deck plate 3 can support the composite effect of the deck composite slab 100, that is, the fixed load of the deck composite slab 100 (the load obtained by adding the weight of the flat deck to the weight of the reinforced concrete slab). Furthermore, when using such a deck plate 3, the reinforcing bars 13 are heated from below in one direction, so the minimum cover thickness for the reinforcing bars required to ensure the necessary fire resistance can be set to 20 mm. Furthermore, because the grooves 11 or embossing 15 are small, the difference in concrete volume between the part where the thickness from the surface where the deck plate 3 and concrete contacts the top surface of the concrete 4 is greatest and the part where it is least greatest can be reduced compared to a conventional deck composite slab 200, thereby suppressing cracking of the concrete 4 due to differences in drying shrinkage. In addition, the amount of concrete and reinforcement can be reduced compared to a conventional flat deck slab. Moreover, in the deck composite slab 100 according to the present invention, a flat deck is used as the structural material, but by ensuring the fire-resistant specifications for the thickness of the reinforced concrete slab (70 mm or more for 1 hour, 100 mm or more for 2 hours) as indicated in Notification No. 1399, and ensuring a concrete cover thickness of 20 mm or more for the reinforcement to ensure the necessary fire resistance, it is possible to achieve 1-hour or 2-hour fire resistance even without applying fire-resistant coating.Based on the above, by using the deck plate 3 in which reinforcing bars cannot be placed in the grooves 11 or embossed areas 15, it is possible to improve performance compared to conventional flat deck slabs, or to reduce costs and improve workability by reducing the amount of concrete and reinforcing bars compared to conventional flat deck slabs. Furthermore, by reducing the self-weight of the reinforced concrete slab due to the reduction in the amount of concrete and reinforcing bars, the thickness of the flat deck can be reduced, and the fixed load can be further reduced.

[0070] The deck composite slab 100 according to this embodiment is a deck composite slab 100 having a deck plate 3, reinforcing bars 13, and concrete 4 poured on the deck plate 3, wherein the deck plate 3 is a flat deck 3A or a corrugated deck plate 3B, the flat portion 11c of the flat deck 3A has a groove 11 or emboss 15, the depth of the groove 11 or emboss 15 is less than 10 mm, and the shape of the groove 11 of the corrugated deck plate 3B satisfies formula (3).

[0071]

number

[0072] In the deck composite slab 100 according to this embodiment, the deck plate 3 is either a flat deck 3A or a corrugated deck plate 3B. The flat plate portion 11c of the flat deck 3A has grooves 11 or embossing 15, and the depth of the grooves 11 or embossing 15 is less than 10 mm. That is, in the flat deck 3A, because the grooves 11 or embossing 15 are small, the entire cross-section of the reinforcing bar 13 cannot be placed inside the grooves 11 or embossing 15. The shape of the grooves 11 or embossing 15 of the corrugated deck plate 3B satisfies equation (3). That is, in the corrugated deck plate 3B, because the grooves 11 are small, the entire cross-section of the reinforcing bar 13 cannot be placed inside the grooves 11. Even with such deck plates in which the entire cross-section of the reinforcing bar cannot be placed inside the grooves 11 or embossing 15, the same design as a conventional deck composite slab can be achieved. Therefore, even when using such a deck plate 3, the deck plate 3 can support the combined effect of the deck composite slab 100, that is, the fixed load of the deck composite slab 100 (the load of the reinforced concrete slab plus the weight of the flat deck). Furthermore, when using such a deck plate 3, the reinforcing bars 13 are heated from below in one direction, so the minimum cover thickness of the reinforcing bars required to ensure the necessary fire resistance can be set to 20 mm. In addition, because the grooves 11 or embossing 15 are small, the difference in concrete volume between the part where the thickness from the surface where the deck plate 3 and concrete contacts the top surface of the concrete 4 is largest and the part where it is smallest in the width direction of the deck plate 3 can be reduced compared to a conventional deck composite slab 200, and cracking of the concrete 4 due to differences in drying shrinkage can be suppressed. Furthermore, the amount of concrete and reinforcing bars can be reduced compared to a conventional flat deck slab.Based on the above, by using the deck plate 3, in which reinforcing bars cannot be placed in the grooves 11 or embossed areas 15, it is possible to improve performance compared to conventional flat deck slabs, or to reduce costs and improve constructability by reducing the amount of concrete and reinforcing bars compared to conventional flat deck slabs. Furthermore, by reducing the self-weight of the reinforced concrete slab due to the reduction in the amount of concrete and reinforcing bars, the thickness of the deck plate can be reduced, further reducing the fixed load.

[0073] As described above, even when using deck plates 3 in which the entire cross-section of the reinforcing bars cannot be placed inside the grooves or embossed areas, the composite effect of the deck composite slab 100 can be utilized. In other words, the deck plates 3 can support the fixed load of the reinforced concrete slab. As a result of this action, as shown in Figures 23 and 24, the weight of the reinforcing bars can be reduced in the design using the deck composite slab compared to the design using the conventional floor formwork method.

[0074] The tensile section modulus of the deck composite slab 100 is 6.10 cm 3 / m or more, 686cm 3 The compression section modulus of the deck composite slab 100 is set to less than or equal to / m, and the compression section modulus of the deck composite slab 100 is 116cm 3 / m or more, 13500cm 3 The second moment of area of ​​the deck composite slab 100 is set to less than or equal to / m, and the second moment of area of ​​the deck composite slab 100 is 128cm 4 / m or more, 158000cm 4 It may be set to less than / m. In this case, when using a deck plate 3 in which it is not possible to place reinforcing bars 13 in the grooves 11 or embossed areas 15, appropriate performance can be obtained as a deck composite slab 100. Furthermore, by setting the numerical range as described above, costs and the amount of reinforcing bars can be reduced.

[0075] The concrete cover thickness of the reinforcing bars 13 to ensure the required fire resistance may be set to 20 mm or more. In this case, even when using a deck plate 3 in which it is not possible to place the reinforcing bars 13 within the grooves 11 or embossed areas 15, appropriate performance can be obtained as a deck composite slab 100. Furthermore, the weight of the concrete can be reduced by setting the values ​​within the above range.

[0076] The thickness of the deck plate may be set to 0.8 mm or more and 1.6 mm or less. In this case, even when using a deck plate 3 in which reinforcing bars 13 cannot be placed in the grooves 11 or embossed areas 15, appropriate performance can be obtained as a deck composite slab 100. Furthermore, by setting the numerical range described above, the composite effect of the deck composite slab, that is, the effect that the deck plate can support the fixed load of the reinforced concrete slab, can be obtained, thereby expanding the applicable span of the deck composite slab 100 and reducing the concrete thickness.

[0077] The height of the deck plate may be set to 50 mm or more and 100 mm or less. In this case, even when using a deck plate 3 in which reinforcing bars 13 cannot be placed within the grooves 11 or embossed areas 15, appropriate performance can be obtained as a deck composite slab 100. Furthermore, by setting the height within the above numerical range, the applicable span of the deck composite slab can be expanded.

[0078] The second moment of area of ​​the deck plate is 60.5 cm. 4 / m or more, 550cm 4 It may be set to less than or equal to / m. In this case, when using a deck plate 3 in which it is not possible to place reinforcing bars 13 within the grooves 11 or embossed areas 15, appropriate performance can be obtained as a deck composite slab 100. Furthermore, by setting the numerical range described above, the applicable span of the deck composite slab can be expanded.

[0079] The section modulus of the deck plate is 16.0 cm 3 / m or more, 76.2cm 3It may be set to less than or equal to / m. In this case, when using a deck plate 3 in which it is not possible to place reinforcing bars 13 within the grooves 11 or embossed areas 15, appropriate performance can be obtained as a deck composite slab 100. Furthermore, by setting the numerical range described above, the applicable span of the deck composite slab can be expanded.

[0080] The thickness of the concrete ridges on the deck plate may be set to 50 mm or more and 300 mm or less. In this case, even when using a deck plate 3 in which reinforcing bars 13 cannot be placed in the grooves 11 or embossed areas 15, appropriate performance can be obtained as a deck composite slab 100. Furthermore, by setting the values ​​within the above range, the effect of being able to increase the load capacity can be obtained.

[0081] The reinforcing bars 13 extend along the longitudinal direction D1 of the deck plate 3, and the diameter of the reinforcing bars 13 is 10 mm or more and 19 mm or less. The reinforcing bars may be arranged in the D2 direction perpendicular to the D1 direction with a spacing of 100 mm or more and 300 mm or less. In this case, even when using a deck plate 3 in which it is not possible to arrange the reinforcing bars 13 in the grooves 11 or embossed areas 15, appropriate performance can be obtained as a deck composite slab 100. Furthermore, by setting the values ​​within the above range, the effect of being able to increase the load capacity can be obtained.

[0082] The reinforcing bars 13a may be arranged as a two-tiered reinforcement and perpendicular to the reinforcing bars 13. That is, the reinforcing bars 13a may be arranged along the width direction D2 of the deck plate 3. The diameter of the reinforcing bars 13a is 10 mm or more and 19 mm or less, and they may be arranged with a spacing of 100 mm or more and 300 mm or less in the longitudinal direction D1 of the deck plate 3. In this case, the strength of the conventional deck composite slab and the said deck composite slab 100 can be improved.

[0083] The deck plate 3 may be a deck plate conforming to JIS G 3352, i.e., a flat deck 3A. In this way, even when using a flat deck 3A in which reinforcing bars 13 cannot be placed in the grooves 11 or embossed areas 15, the combined effect of the deck composite slab 100 can be obtained. That is, the deck plate 3 and the reinforced concrete slab (a component of the deck composite slab 100 in which the reinforcing bars 13 and concrete 4 behave as a single unit) can be considered to behave as a staggered beam.

[0084] The deck plate 3 according to this embodiment may constitute the deck composite slab 100 described above. In this case, the same effects as the deck composite slab 100 described above can be obtained.

[0085] The present invention is not limited to the embodiments described above.

[0086] For example, the shape of the deck plate 3 may be modified as appropriate without departing from the spirit of the present invention. Also, the reinforcing bars 13 placed inside the concrete 4 may be modified as appropriate.

[0087] [Form 1] A deck composite slab having a deck plate, reinforcing bars, and concrete poured on the deck plate, The deck plate is a flat deck or a corrugated deck plate. The aforementioned reinforcing bars are positioned higher than the uppermost surface of the deck plate. A deck composite slab having a safety factor of actual load-bearing capacity greater than 2.0 with respect to the long-term allowable load of the deck composite slab, a safety factor of actual load-bearing capacity greater than 1.5 with respect to the short-term allowable load of the deck composite slab, a safety factor of actual load-bearing capacity greater than 0.7 with respect to the theoretical maximum load of the deck composite slab, and a safety factor of actual stiffness greater than 0.9 with respect to the theoretical initial stiffness of the deck composite slab. [Form 2] A deck composite slab having a deck plate, reinforcing bars, and concrete poured on the deck plate, The aforementioned deck plate is a flat deck, The aforementioned flat deck has a flat plate portion that contacts the concrete and a leg rib on its lower side, and refers to a deck plate formed from thin steel sheet. The aforementioned flat plate portion is either left flat, or embossed or grooved, in a deck composite slab. [Form 3] A deck composite slab having a deck plate, reinforcing bars, and concrete poured on the deck plate, The deck plate is a flat deck or a corrugated deck plate. The flat portion of the flat deck has grooves or embossing, and the depth of the grooves or embossing is less than 10 mm. The shape of the groove portion of the corrugated deck plate satisfies equation (3), and the deck composite slab.

[0088]

number

[0089] 3... Deck plate, 3A... Flat deck, 3B... Corrugated deck plate, 4... Concrete, 7... Reinforcement bars to prevent crack expansion, 10... Top surface of deck plate, 11... Groove, 12... Leg ribs, 13... Reinforcement bars, 13a... Upper reinforcement bars, 15... Embossing, 100... Deck composite slab, D1... Longitudinal direction (first direction), D2... Width direction (second direction).

Claims

1. A deck composite slab having a deck plate, reinforcing bars, and concrete poured on the deck plate, The deck plate is a flat deck or a corrugated deck plate. The aforementioned reinforcing bars are positioned higher than the uppermost surface of the deck plate. A deck composite slab having a safety factor of actual load-bearing capacity greater than 2.0 with respect to the long-term allowable load of the deck composite slab, a safety factor of actual load-bearing capacity greater than 1.5 with respect to the short-term allowable load of the deck composite slab, a safety factor of actual load-bearing capacity greater than 0.7 with respect to the theoretical maximum load of the deck composite slab, and a safety factor of actual stiffness greater than 0.9 with respect to the theoretical initial stiffness of the deck composite slab.

2. A deck composite slab having a deck plate, reinforcing bars, and concrete poured on the deck plate, The aforementioned deck plate is a flat deck, The aforementioned flat deck has a flat plate portion that contacts the concrete and a leg rib on its lower side, and refers to a deck plate formed from thin steel sheet. The aforementioned flat plate portion is either left flat, or embossed or grooved, in a deck composite slab.

3. A deck composite slab having a deck plate, reinforcing bars, and concrete poured on the deck plate, The deck plate is a flat deck or a corrugated deck plate. The flat portion of the flat deck has grooves or embossing, and the depth of the grooves or embossing is less than 10 mm. The shape of the groove portion of the corrugated deck plate satisfies equation (3), and the deck composite slab. [Math 1] however, θ=(b) １ -A ２ ) / H H: Depth of the groove in the deck plate b １ : Width above the groove of the deck plate b ２ : Width below the groove of the deck plate

4. The tensile section modulus of the aforementioned deck composite slab is 6.10 cm ３ / m or more, 686cm ３ Set to / m or less, The compression section modulus of the aforementioned deck composite slab is 116 cm ３ / m or more, 13500cm ３ Set to / m or less, The value of the cross-sectional second moment of the deck composite slab is 128 cm ４ / m or more and 158,000 cm ４ / m or less, and the deck composite slab according to claim 1 is set.

5. The deck composite slab according to claim 1, wherein the concrete cover thickness of the reinforcing bars to ensure the required fire resistance performance is 20 mm or more.

6. The deck composite slab according to claim 1, wherein the thickness of the deck plate is set to 0.8 mm or more and 1.6 mm or less.

7. The deck composite slab according to claim 1, wherein the height of the deck plate is set to 50 mm or more and 100 mm or less.

8. The second moment of area of ​​the aforementioned deck plate is 60.5 cm ４ / m or more, 550cm ４ The deck composite slab according to claim 1, which is set to / m or less.

9. The section modulus of the aforementioned deck plate is 16.0 cm ３ / m or more, 76.2cm ３ The deck composite slab according to claim 1, which is set to / m or less.

10. The deck composite slab according to claim 1, wherein the thickness of the concrete on the deck plate is set to 50 mm or more and 300 mm or less.

11. The reinforcing bars extend along a first direction that is aligned with the longitudinal direction of the deck plate, The diameter of the aforementioned reinforcing bars is 10 mm or more and 19 mm or less. The deck composite slab according to claim 1, wherein the reinforcing bars are arranged in a second direction perpendicular to the first direction and along the width direction of the deck plate, with reinforcing bar spacing of 100 mm or more and 300 mm or less.

12. The deck composite slab according to claim 1, wherein the reinforcing bars are arranged in a two-tiered arrangement, and the reinforcing bars in each tier are arranged perpendicular to each other.

13. The deck composite slab according to claim 2, wherein the deck plate is a deck plate conforming to JIS G 3352.

14. A deck plate constituting a deck composite slab according to any one of claims 1 to 13.

Images