JP2020041348A - Composite deck slab - Google Patents

Abstract

To provide a composite deck slab capable of preventing generation of a crack extending from a slab upper face toward a stud and a crack extending from a slab end portion.SOLUTION: In a composite deck slab, a steel beam 14 including a flange 14F with a stud is used. In at least a range of the flange, reinforcement means 15, 41 and 42 are used.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a composite deck slab.

In recent years, in the design of the joint between a steel beam and a floor slab, it has been designed as a composite beam integrating the steel beam and the concrete of the floor slab using the shear resistance function of the stud provided on the flange of the steel beam. In addition, designs have been made in which the horizontal force applied to the floor slab during an earthquake is transmitted to the steel beam using the shear resistance function of the stud, and the stud is often provided on the flange of the steel beam.
FIG. 12 shows a general example of a composite deck slab. A composite deck slab is formed by arranging a wire mesh 13 on the upper surface of a deck plate (bent steel plate) placed on left and right beams such as a steel frame and placing concrete 12 therein. Further, as proposed in Patent Document 1, it has been proposed to provide a stud 15 on a flange of a steel frame to reinforce the flange.
Conventionally, when joining a steel beam and a floor slab, a technique has been proposed in which a stud is provided on a flange of the steel beam and the steel beam and the concrete of the floor slab are integrated (for example, Patent Document 1 (Japanese Patent Laid-Open Publication No. 2002-131131)). 2012-012788)).
Japanese Patent Application Laid-Open No. 2006-023440 discloses a technique in which a plurality of studs are arranged and a reinforcing member is provided above the upper flange of a steel beam and fixed to the concrete of the floor slab. Publication).

JP 2012-012788 A JP-A-2006-023440

  As a result of studying the composite deck slab strength performance, the present inventors have found that cracks extending from the upper surface of the slab in the stud direction and cracks extending from the end of the slab are generated. An object of the present invention is to take measures to prevent this crack.

The present invention has realized a composite deck slab in which an end portion is reinforced by providing a restraining member above a flange of a steel beam or on a slab concrete end face.
In particular, members that are fastened to the studs provided above the flanges of the steel beams, or placed near the studs, disperse the shearing force and bearing pressure applied to the surrounding concrete. Suppress concrete breakage due to shearing force and bearing pressure. And the floor slab can make it possible to support a larger vertical load.
The main configuration of the present invention is as follows.

1. A composite deck slab in which a steel beam having a flange with studs is used, wherein reinforcing means is provided at least in a range of the flange. Studs include headed studs.
2. The stiffening means is characterized in that stiffeners are arranged along the rows of studs. The described synthetic deck slab.
Examples of the reinforcing material include a reinforcing bar and a plate body, and the reinforcing material may be provided on the end side of the composite deck slab with respect to the stud, or inside, or on both sides of the stud. The reinforcing member can be fixed to the free or stud by means such as binding or welding.
As the reinforcing material, an elongated plate can be arranged on the end side or inside the stud. This plate body can be fixed to the stud by means such as free or welding.
The reinforcement is provided in the longitudinal direction of the steel beam. The reinforcing material may be one or divided.
3. The reinforcing means is a stud having a tip whose height is equal to or higher than the reinforcing bar position of the wire mesh. Or 2. The described synthetic deck slab. The wire mesh can be joined to the stud by means such as welding. Alternatively, apart from the wire mesh, a reinforcing bar arrangement or a welding wire mesh in which a long reinforcing bar and a short reinforcing bar are assembled in a ladder shape can be used in combination.
4. The reinforcing means has a U-shape and is arranged on the upper surface of a flange of a steel beam. ~ 3. The synthetic deck slab according to any one of the above. The reinforcing means includes a reinforcing bar formed by bending in a U-shape. Although not limited in size, stiffeners having a width less than the spacing between adjacent studs and a length greater than the studs can be used. For example, the reinforcing members can be arranged so as to straddle the studs or provided between the studs. The number of reinforcements is not limited, but may be the same as the number of studs.
5. The reinforcing means is characterized in that a reinforcing bar is bent at the end of the slab from the upper portion of the wire mesh downward and disposed. ~ 4. The synthetic deck slab according to any one of the above.
For example, the reinforcing bar is placed at the end of the composite deck slab by bending once (90 degrees), and the tip of the reinforcing bar extends toward the deck plate by bending twice (180 degrees).
6. The reinforcing means is provided by extending a reinforcing reinforcing bar disposed in the groove of the deck plate toward the end of the slab and bending it upward. ~ 5. The synthetic deck slab according to any one of the above.
Examples of bending are once (90 degrees) and twice (180 degrees). It is also possible to fold it twice and place the tip of the folded reinforcing bar above the wire mesh.
Further, the reinforcing steel can be arranged inside the folded portion in the axial direction of the steel beam.
7. The reinforcing means comprises a reinforcing bar disposed on the lower surface of the wire mesh toward an end of the slab and an iron plate joined to an end of the reinforcing bar. ~ 6. The synthetic deck slab according to any one of the above.
8. The reinforcing means is composed of a reinforcing bar disposed from the inside of the groove of the deck plate toward the end of the slab and an iron plate joined to the end of the reinforcing bar. ~ 7. The synthetic deck slab according to any one of the above.
9. The reinforcing means is configured such that adjacent studs are alternately sewn and reinforcing materials such as reinforcing bars are arranged. ~ 8. The synthetic deck slab according to any one of the above.
10. The reinforcing means has a configuration in which reinforcing reinforcement or a welded wire mesh with a pitch smaller than the mesh of the wire mesh is placed over the headed stud and arranged. ~ 9. The synthetic deck slab according to any one of the above. An example of the reinforcing wire mesh is a ladder. Reinforcing reinforcement or welded mesh may be tied to the stud. The reinforcing means can be arranged above the wire mesh, but may be below.
11. The reinforcing means is arranged such that a plurality of reinforcing materials such as reinforcing bars are alternately sewn on adjacent studs in different directions. -10. The synthetic deck slab according to any one of the above.

1. ADVANTAGE OF THE INVENTION This invention can prevent the crack by heat exposure etc. by reinforcing the edge part of a composite deck slab in the joint part of a beam and a deck slab. Cracks can particularly prevent cracks that occur toward the studs on the upper side of the steel beam and cracks that occur at the ends of the slab.
2. A member tied to a stud provided on the upper part of the flange of the steel beam, or a member arranged in the vicinity of the stud suppresses the destruction of the concrete due to the shearing force or bearing force applied to the surrounding concrete. Also, the floor slab can support a larger vertical load.
3. Since the slab end, which is the upper region of the flange of the steel beam, is reinforced, the degree of fixing of the slab end of the composite deck slab to the steel beam can be improved.
4. The pull-out resistance of the slab end of the composite deck slab is improved, the degree of fixation to the steel beam is improved, the expansion of cracks at the composite deck slab end can be suppressed, and the allowable performance such as loading load and span can be increased. it can.

5. The present invention is mainly applied to a steel structure, and is applied to a composite deck slab composed of slab concrete and a deck plate such as a QL deck laid on a steel beam. The composite deck slab collapses at the fulcrum, which is the joint between the beam and the composite deck slab, in a fire or the like. Therefore, by reinforcing the fulcrum position (joining position) of the composite deck slab, it is possible to improve the permissible performance such as the loading load and the span and to improve the fire resistance performance.
According to the present invention, as means for reinforcing the end portion, (a) a reinforcing bar is attached to both sides of the end stud, (b) the end stud is lengthened, (c) a U-shaped reinforcing bar is inserted into the end portion, d) Arrangement of reinforcing bar turned up from above wire mesh, (e) Arrangement of reinforcing bar turned up from inside of groove of deck plate, (f) Arrangement of reinforcing bar with iron plate joined to end at lower surface of wire mesh (G) Reinforcing rebar with an iron plate joined to the end is arranged in the groove of the deck plate, (h) Reinforcing rebar with studs sewn, (i) Reinforcing welded wire mesh placed over studs, (j ) Reinforcing reinforcing bars are used in which a plurality of reinforcing bars are alternately sewn and arranged so as to sandwich the studs.
6. In the composite deck slab, the collapse of the fulcrum position (joint position) is one of the factors that determine the fire resistance time. FIG. 1 schematically shows an end collapse state of the composite deck slab in the event of a fire. As shown in this figure, the generated stress concentrates around the stud and causes cracking of the concrete. In addition, when the duration of heating is prolonged, the width of the generated crack is increased instead of increasing the number of cracks, which leads to collapse of the end. The composite deck slab collapses when it reaches the 3-hinge state. In composite deck slabs that do not take reinforcement means such as fireproof reinforcement, the collapse of the end results in the collapse of the composite deck slab, but in the present invention, the end of the composite deck slab is reinforced, improving the fire resistance performance Can be done. Further, when the beams supporting the ends of the composite deck slab are provided with a fire-resistant coating, the reinforcement of the present invention is also protected from the heat of fire, and the performance can be further improved. In the present invention, a reinforcing means for dispersing the stress generated around the stud is provided.

The figure which shows the end collapse situation of the synthetic deck slab at the time of fire. (A) Schematic diagram The figure which shows the synthetic deck slab which took the reinforcement means by 1st Embodiment. (A) and (b) diagrams in which reinforcing bars are provided on both sides of the stud, and (c) and (d) diagrams in which a steel plate wider than the reinforcing bar is provided along the stud surface. The figure which shows the synthetic deck slab which took the reinforcement means by 2nd Embodiment. (A) perspective view (b) sectional view The figure which shows the synthetic deck slab which took the reinforcement means by 3rd Embodiment. (A) perspective view (b) sectional view The figure which shows the synthetic deck slab which took the reinforcement means by 4th Embodiment. (A) Perspective view (b) Cross-sectional view (c) Perspective view of an example in which reinforcing bars are added (d) Cross-sectional view of an example in which reinforcing bars are added The figure which shows the cross section of the synthetic deck slab which took the reinforcement means by 5th Embodiment. The figure which shows the cross section of the synthetic deck slab which took the reinforcement means by 6th Embodiment. The figure which shows the cross section of the synthetic deck slab which took the reinforcement means by 7th Embodiment. The figure which shows the synthetic deck slab which took the reinforcement means by 8th Embodiment. (A) Steel beam top view plan view (b) Steel beam perspective view The figure which shows the synthetic deck slab which took the reinforcement means by 9th Embodiment. (A) Plan view (b) Perspective view The figure which shows the synthetic deck slab which took the reinforcement means by 10th Embodiment. (A) Steel beam top view plan view (b) Steel beam perspective view The figure which shows the structure of the general synthetic deck slab.

The present invention is a composite deck slab with reinforcing means at the ends.
The present invention is mainly applied to a steel structure, and is applied to a composite deck slab composed of slab concrete and a deck plate such as a QL deck laid on a steel beam. The basic structure of the composite deck slab is as shown in FIG. The QL deck is a deck plate that works integrally with concrete and is a synthetic slab conforming to the Ministry of Land, Infrastructure, Transport and Tourism Notification No. 326 of 2002. When concrete is cast, it plays the role of a deck plate formwork, and after hardening concrete, the deck plate mainly resists tensile force, concrete resists compressive force, withstands large loads, and can span long spans . The composite slab of the QL deck can be designed as a composite slab for vertical and in-plane horizontal loads acting on the floor.
Further, by joining the steel beam and the composite slab with a stud with a head, the steel beam can be designed as a composite beam.

The composite deck slab collapses at the fulcrum, which is the joint between the beam and the composite deck slab, in a fire or the like. Therefore, the present invention reinforces the fulcrum position (joining position) of the composite deck slab to improve the permissible performance such as the loading load and span, and the fire resistance.
The main end reinforcing means of the present invention includes: (a) attaching a reinforcing bar to both sides of the end stud; (b) lengthening the end stud; (c) inserting a U-shaped reinforcing bar at the end; (D) Arrange the reinforcing bar turned up from above the wire mesh, (e) Arrange the reinforcing bar turned up from inside the groove of the deck plate, (f) Place the reinforcing bar joined to the end of the iron plate on the lower surface of the wire mesh. Arrangement, (g) Reinforcing rebar with an iron plate joined to the end is disposed in the groove of the deck plate, (h) Reinforcing rebar with studs sewn, (i) Reinforcing welded wire mesh placed over studs, ( j) A reinforcing reinforcing bar in which a plurality of reinforcing bars are alternately sewn and arranged so as to sandwich the stud.
By taking these reinforcement means, the pull-out resistance of the slab end of the composite deck slab is improved, the degree of fixing to the steel beam is improved, the expansion of cracks at the composite deck slab end can be suppressed, and the loading load and Allowable performance such as span can be improved.
The present invention improves the degree of fixation of the end of the composite deck slab and disperses the stress acting on the stud, thereby preventing cracks that are likely to be generated on the end surface side or the upper surface of the end of the composite deck slab.
Strain caused by the load applied to the composite deck slab is easy to concentrate on the stud installed on the flange of the steel beam, so it is easy to induce cracks starting from the stud, but it improves the degree of fixing of the slab around the stud In addition, by adding adjacent studs, reinforcing bars, and dispersing stress to existing members such as wire mesh, it is possible to suppress cracking or pulling out at the end of the composite deck slab, thereby improving the proof stress.

Further, from the viewpoint of fire resistance, improvement in fire resistance performance can be expected.
The fire resistance time of the composite deck slab is determined by the collapse of the fulcrum position (joint position). The collapse situation of the composite deck slab at the end of a fire is schematically shown in FIG. 1, and the generated stress concentrates around the stud and causes cracking of the concrete. Further, when the heating time of the thermal exposure is prolonged, the width of the generated crack increases, which leads to collapse of the end portion.
The composite deck slab collapses when it reaches the 3-hinge state. In deck slabs that do not take reinforcement means such as refractory reinforcement, collapse of the ends results in collapse of the composite deck slab, but in the present invention, reinforcement means for dispersing the stress generated around the studs is performed, and the composite deck slab is Since the end portions are reinforced, fire resistance performance can be improved.

The present inventors have found that when the synthetic deck slab is exposed to a high temperature such as a fire, cracks as shown in FIG. 1 are generated, the edges become weaker, and the proof strength is reduced. Further analysis of the state of the cracks revealed that there were many cracks starting from the tips of the studs provided in the rows on the upper surface of the flange of the steel beam.
FIG. 1 is a schematic view of a composite deck slab in which QL deck slabs are installed on left and right steel beams using H-section steel. The cracks are simply shown from the upper end of a stud protruding from the upper surface of the flange of the steel beam (in this figure, an example of a stud with a head), the upper surface crack A1 on the upper surface of the slab and the end surface crack B1 on the end surface. It is.
Furthermore, as a result of examining the measures against cracking, it was determined that the main factor was that the stress caused by the strain generated in the composite deck slab concentrated on the stud, which is the connection point between the steel beam and the composite slab. Causes of the distortion include, for example, tension and compression due to its own weight or load, reduction in proof stress due to high temperature, and tension and compression due to elongation of a member.
In the present invention, as a measure to improve the dispersion of stress concentrated around the stud and the degree of fixation of the end of the composite slab, the end is reinforced to suppress the generation of cracks and the growth of cracks. Therefore, the composite deck slab realized by the present invention can increase the load capacity and improve the fire resistance performance.

(1st Embodiment)
Hereinafter, the composite deck slab according to the first embodiment of the present invention will be described with reference to FIG.
The composite deck slab 1 has an H-shaped steel beam 14 having a stud 15 with a head on a flange 14F, a QL deck plate 11 passed between the steel beams 14, 14, and a wire mesh 13 on the QL deck plate. It is composed of concrete 12 which is arranged and cast. As shown in FIG. 2, in the first embodiment, a steel bar and an elongated steel plate (flat bar) are arranged along a row of studs arranged in the axial direction of a steel beam.
2 (a) and 2 (b), an outer reinforcing bar 21a and an inner reinforcing bar 21b are attached to both sides of the stud 15 as stud double-sided reinforcing bars 21.
FIGS. 2C and 2D are examples in which the flat bar 22 extends along the outside of the stud 15.
The reinforcing bars 21 or the flat bars 22 on both sides of the stud are prevented from slipping upward because the stud has a head, but can be fixed to the stud 15 by welding or other means.

In the present embodiment, the reinforcement bars 21 or the flat bars 22 on both sides of the studs are arranged along the studs 15, so that the deformation of the studs is suppressed and the stress generated in the studs is distributed to the reinforcement bars 21 on both sides of the studs and the flat bars 22. Can be done. As a result, the generated stress is prevented from being concentrated around the individual studs, and the occurrence of cracks in the concrete can be prevented. By this reinforcing means, the pull-out resistance of the end of the slab of the composite deck slab is improved, the degree of fixing to the steel beam is improved, and the end of the composite deck slab can be prevented from cracking and the expansion of the crack can be suppressed. And other permissible performances can be enhanced.
And since the reinforcement which disperses the stress which arises around a stud is performed and the edge part of a synthetic deck slab is reinforced, fire resistance performance can be improved.

(2nd Embodiment)
A composite deck slab according to a second embodiment of the present invention will be described with reference to FIG.
As shown in FIG. 3A, the basic structure of the composite deck slab 1 is the same as that of FIG. In the second embodiment, a long stud 151 having a long stud length is used. The length of the long stud 15l is equal to or greater than the reinforcing bar height of the wire mesh 13.
By binding and welding the wire mesh to the long studs, the degree of fixing can be increased, the stress generated in each stud can be transmitted to the wire mesh, and the stress distribution to the wire mesh and other studs can be increased. . The length of the long stud is preferably “a stud whose stud tip is at a height equal to or higher than the bar arrangement position of the wire mesh”.

FIG. 3B shows an example using a stud having a long wire mesh height, FIG. 3C shows an example in which a wire mesh is fixed immediately below the head of the long stud, and FIG. FIG. 3 (e) shows an example of the intermediate beam, in which left and right wire meshes are arranged under a head in an overlapping manner, and FIG. 3 (e) shows a perspective view of FIG. 3 (c).
Raising the studs allows the wire mesh to be laid at the same height or below the studs, reducing stress on the studs, increasing the integrity of the studs and the wire mesh, and reducing the stress on individual studs. Concentration around the stud is prevented, and the stress generated around the stud can be dispersed.
Therefore, the same operation and effect as those of the first embodiment can be obtained.

(Third embodiment)
The basic structure of the composite deck slab 1 is the same as in FIG. The third embodiment is a composite deck slab in which a U-shaped reinforcing bar 31 formed into a U-shape is inserted around the stud 15 at the end of the composite deck slab 1 and reinforced.
A composite deck slab according to a third embodiment of the present invention will be described with reference to FIG. FIG. 4A schematically shows a state where the U-shaped reinforcing bar 31 is inserted into the stud 15 provided on the beam flange 14F. FIG. 4B schematically shows a state where the U-shaped reinforcing bar 31 is inserted into the end (outside) of the stud 15 provided in the beam axis direction. A U-shaped reinforcing bar 31 is provided so as to straddle the upper part of the stud 15.
The U-shaped reinforcing bar 31 is arranged so that a horizontal member is formed outside the flange of the steel beam and above the height of the head of the stud. The number of U-shaped rebars is basically to be equal to the number of studs.

  By dropping the U-shaped reinforcing bar 31 outside the stud 15 provided on the flange 14F of the steel beam 14, the degree of fixing of the end can be increased. The generation and growth of cracks generated near the end of the deck slab and near the upper surface of the slab generated from the vicinity of the stud 15 are suppressed by the U-shaped reinforcing bar 31.

(Fourth embodiment)
A composite deck slab according to a fourth embodiment of the present invention will be described with reference to FIG.
The basic structure of the composite deck slab 1 is the same as in FIG. In the fourth embodiment, the reinforcing reinforcing bar disposed above the wire mesh 13 is bent downward at the end of the composite deck slab from the stud. The bending of the reinforcing bars can be further bent below the slab and extend through the base end of the stud and into the groove of a deck plate such as a QL deck. The illustration shows a composite deck slab reinforced by arranging a lower hook reinforcing bar 41 folded at the slab end from the upper side of the wire mesh 13 to the base end side of the stud 15. By providing the lower folding hook reinforcement 41, the pull-out resistance of the slab is improved, the fixing degree is improved, and it is possible to suppress the expansion of cracks generated on the upper surface of the slab, and the cracks generated at the end of the slab. Can also be suppressed from expanding. The lower folding hook reinforcement 41 is bent twice at 90 degrees to form a 180-degree hook. It may be a 90-degree hook that is bent once at 90 degrees.
In the illustrated example, a reinforcing upper streak 41a that has passed on the upper surface side of the wire mesh 13 and above the tip of the stud passes between the left and right steel beams 14,14. The reinforcing steel bar is bent at the upper end of the flange 14F of the steel beam 14 on the end side from the wire mesh to become the end bar 41b. It is preferable that the bent distal end of the lower streak 41c pass through the base end side of the stud 15 and fit in the groove of the QL deck 11 above the right flange 14F of the steel beam 14.
The installation number of the lower folding hook reinforcements 41 is basically based on the number of studs, but can be adjusted according to the necessity of design and the like.

In the present embodiment, furthermore, the bent portion reinforcement 42 composed of the upper bent portion reinforcement 42a and the lower bent portion reinforcement 42b can be arranged inside the upper and lower folded portions in the axial direction of the steel frame. The bent portion reinforcing bars 42 are arranged in the axial direction of the steel beam 14 and need not be one over the entire length of the beam, but may be divided. It is desirable that the shorter one be longer than the interval between adjacent studs.
In addition, the wire mesh 13 can be extended to the end side as it is, and then folded back to form a lower hook reinforcement. Also, only the reinforcing bar in the direction between the steel beams 14 and 14 of the wire mesh 13 may be extended to the end side and folded back to form a lower hook reinforcing bar.
In the present embodiment, the reinforcing bars are arranged from above to below the ends, so that the degree of fixation of the ends is improved, and cracks generated at the ends and cracks generated at the upper part of the slab are prevented and suppressed.

(Fifth embodiment)
A composite deck slab according to a fifth embodiment of the present invention will be described with reference to FIG. The basic structure of the composite deck slab 1 is the same as in FIG. In the reinforcing means, the reinforcing reinforcing bar is bent upward from the inside of the groove of the deck plate to the upper portion of the wire mesh at the end of the slab. This is an embodiment relating to a composite deck slab in which a reinforcing bar can be folded back at the upper end.
In the fifth embodiment, the reinforcing steel reinforcing bar is reinforced by arranging the upper hook reinforcing bar 51 which passes through the groove of the QL deck 11, passes through the base end side of the stud 15, and is folded at the slab end. It is a synthetic deck slab. By providing the upper folding hook reinforcement 51, the pull-out resistance of the slab is improved, the degree of fixation is improved, and the cracks generated on the upper surface of the slab can be suppressed from expanding. Can also be suppressed from expanding.
The upper folding hook reinforcing bar 51 is bent twice at 90 degrees to form a 180-degree hook. It may be a 90-degree hook that is bent once at 90 degrees.
In the illustrated example, a reinforcing lower streak 51 a extending from inside the groove of the QL deck 11 and passing through the base end side of the stud passes between the steel beams 14. The upper folding hook reinforcement 51 for reinforcement is bent at the end side of the stud 15 above the flange 14F of the steel beam 14, and becomes an end reinforcement 51b. It is preferable that the end streaks 51b bend over the studs 15 to form the upper streaks 51c and extend above the wire mesh 13, and the tip thereof be equal to or more than the right flange 14F of the steel beam 14.
The number of the upper folding hook reinforcements 51 is basically the number of studs, but can be adjusted according to the necessity of design or the like.

In the present embodiment, if a refractory reinforcing bar is previously charged in the groove of the QL deck 11 of the composite deck slab 1, the refractory reinforcing bar is extended and used as the upper folding hook reinforcement 51. Can also.
In the present embodiment, the bent portion reinforcement 52 composed of the upper bent portion reinforcement 52a and the lower bent portion reinforcement 52b can be further arranged inside the upper and lower folded portions in the axial direction of the steel frame. The bent portion reinforcing bars 52 are arranged in the axial direction of the steel beam 14 and need not be one over the entire length of the beam, and may be divided. It is desirable that the shorter one be longer than the interval between adjacent studs.
In the present embodiment, the reinforcing bars are arranged upward from below the end, so that the degree of fixation of the end is improved, cracks occurring at the end can be prevented and suppressed, and furthermore, by turning back to the upper side of the stud. Cracks generated in the upper part of the slab can be prevented and suppressed.

(Sixth embodiment)
A composite deck slab according to a sixth embodiment of the present invention will be described with reference to FIG.
The basic structure of the composite deck slab 1 is the same as in FIG. This is an embodiment of the composite deck slab in which the reinforcing means includes a reinforcing bar disposed on the lower surface of the wire mesh toward the end of the slab and an iron plate joined to the end of the reinforcing bar.
A lower reinforcing bar 61 passing through the lower surface of the wire mesh 13 and an end face reinforcing plate 62 joined to the lower reinforcing bar 61 at an end surface of the composite deck slab are provided. With this configuration, the degree of fixation of the end surface of the composite deck slab is particularly improved, and the expansion of cracks generated at the end of the slab can be suppressed. In particular, since the end face portion reinforcing plate 62 is provided, the resistance to the extension of the lower surface reinforcing bar 61 is improved.
In the illustrated example, the lower reinforcement 61 for reinforcement passes below the wire mesh 13 and the height of the head of the stud 15 and is higher than the QL deck 11, and the end of the composite deck slab ends. Extending to Then, the end face reinforcing plate 62 and the lower face reinforcing bar 61 arranged on the end face of the slab are fixed by welding or the like. Although the end face reinforcing plate 62 is provided on the surface of the slab concrete in FIG. 7, it can be embedded in the slab concrete.
The number of the lower reinforcing bars 61 to be installed is basically equal to the number of the studs, but can be adjusted according to the necessity of design or the like.
The end face reinforcing plate 62 may be provided continuously in the axial direction of the steel beam 14. Alternatively, it may be divided and provided in plural. In the case of division, it is appropriate that the length is equal to or longer than the interval between adjacent studs.

  The lower surface reinforcement 61 provided on the flange 14F of the steel beam 14 and the end face reinforcing plate 62 provided at the end improve the degree of fixation of the end of the slab. Cracks generated in the upper part of the slab can be prevented and suppressed.

(Seventh embodiment)
A composite deck slab according to a seventh embodiment of the present invention will be described with reference to FIG.
The basic structure of the composite deck slab 1 is the same as in FIG. This is an embodiment relating to a composite deck slab in which a reinforcing bar as a reinforcing means is disposed from the inside of the groove of the deck plate toward the end of the slab, and an iron plate joined to the end of the reinforcing bar is provided.
A lower reinforcing bar 71 extending from the groove of the QL deck 11 and an end face reinforcing plate 72 joined to the lower reinforcing bar 71 at the end of the composite deck slab are provided. With this configuration, the degree of fixation of the end surface of the composite deck slab is particularly improved, and the expansion of cracks generated at the end of the slab can be suppressed. In particular, since the end face reinforcing plate 72 is provided, the resistance to the elongation of the lower reinforcing bar 71 is improved.
In the illustrated example, a lower reinforcing bar 71 for reinforcement passes through the inside of the groove of the QL deck 11 and extends to the end of the composite deck slab. The end face reinforcing plate 72 and the lower reinforcing bar 71 disposed in the concrete at the end of the slab are fixed by welding or the like. Although the end face reinforcing plate 72 is embedded in the slab concrete in FIG. 8, it can be provided on the end surface of the slab concrete.
The number of the lower reinforcing bars 71 to be installed is basically based on the number of the studs, but can be adjusted according to the necessity of design or the like.
The end face reinforcing plate 62 may be provided continuously in the axial direction of the steel beam 14. Alternatively, it may be divided and provided in plural. In the case of division, it is appropriate that the length is equal to or longer than the interval between adjacent studs.

In the present embodiment, if a refractory reinforcing bar is previously charged in the groove of the QL deck 11 of the composite deck slab 1, the refractory reinforcing bar is extended and used as the upper folding hook reinforcement 51. Can also.
The lower reinforcing bar 71 provided on the flange 14F of the steel beam 14 and the end face reinforcing plate 72 provided at the end improve the degree of fixation of the end of the slab, and prevent cracks generated at the end. Prevention and suppression.

(Eighth embodiment)
A composite deck slab according to an eighth embodiment of the present invention will be described with reference to FIG.
The basic structure of the composite deck slab 1 is the same as in FIG. This is an embodiment relating to a composite deck slab in which reinforcing bars as reinforcing means are arranged by alternately sewing adjacent studs.
Alternating refraction reinforcing bars 81 are provided such that one or a plurality of reinforcing bars alternately sew a plurality of studs 15 provided in a row on the flange 14F of the steel beam 14.
Since the staggered streaks 81 are provided, the studs are prevented from independently deforming, and the stress acting on the studs is dispersed and the studs are also loaded. When the stud 15 and the alternating refraction arrangement streaks 81 are connected by bundling or welding, the degree of fixation is further increased, and deformation can be suppressed. In addition, the stud 15 is a stud with a head, whereby the function of preventing the alternately bent arrangement streaks 81 from being removed is improved.
Since the alternating refraction arrangement streaks 81 are arranged below the wire mesh, the stress can be transmitted to the wire mesh and the stress can be dispersed.
It is preferable that the alternating refraction arrangement streaks 81 are continuous in the axial direction of the steel beam, but the function and function can be exhibited even if the length is between several studs.
FIG. 9 (a) shows an example in which one reinforcing bar is used as the alternating refraction arrangement bar 81, and FIG. 9 (b) shows two rebars of the upper alternating refraction arrangement bar 81a and the lower alternating refraction arrangement bar 81b vertically. The example of arrangement is shown. Both (a) and (b) use studs with heads. The number of alternating refraction arrangement lines may be three or more.

  End cracks and upper cracks leading from the end face or top face of the composite deck slab to the vicinity of the stud head strengthen the studs, disperse the stress applied to the studs, suppress deformation of the studs, and alternate refraction arrangement Since the streaks 81 also bear the stress, the cracks generated by the concentrated strain do not grow, and the cracks generated on the end face and the upper face can be prevented and suppressed.

(Ninth embodiment)
A composite deck slab according to a ninth embodiment of the present invention will be described with reference to FIG.
The basic structure of the composite deck slab 1 is the same as in FIG. It is an embodiment related to a composite deck slab in which a reinforcing welding wire mesh for reinforcement, which is a reinforcing means, is placed over a stud.
By arranging or fixing the reinforcing wire mesh around the stud, the stress acting on the stud can be dispersed also to the reinforcing wire mesh.
The reinforcement welding wire mesh preferably has a smaller pitch than the wire mesh, and is preferably connected to the stud by welding or binding. In addition, by arranging the reinforcing wire mesh above or below the wire mesh, it is possible to transmit stress to the wire mesh, and it is possible to further disperse the stress based on the strain generated at the end. .
The reinforcing wire mesh is preferably continuous in the axial direction of the steel beam, and it is sufficient that the width of the steel frame in the flange direction is within the width of the flange. The reinforcing wire mesh does not need to be one, and may be divided.
FIG. 10 shows an example of a composite deck slab in which the reinforcing welding wire mesh 91 is placed over the stud 15. (A) schematically shows a plan view, and (b) schematically shows a perspective view.
In the illustrated example, a reinforcing welding wire mesh 91 having a pitch smaller than that of the wire mesh 13 is covered by the headed stud 15 below the wire mesh 13. The reinforcing welding wire mesh 91 used is a ladder-like structure composed of two reinforcing bars extending in the axial direction of the steel beam 14 and a horizontal bar-shaped reinforcing bar orthogonal to the reinforcing bars. The reinforcing welding wire mesh 91 is connected to the stud 15 by means such as binding. By fixing the reinforcing wire mesh 91 having a small pitch to the stud 15, stress concentrated on the stud 15 caused by distortion can be dispersed. By using the stud with the head, the function of preventing the reinforcement welding wire mesh 91 from coming off is improved, and the pull-out resistance is improved. The reinforcing welding mesh may be configured by binding reinforcing bars or the like.

  End cracks and upper cracks connected from the end face or top face of the composite deck slab to the vicinity of the head of the stud are dispersed by the reinforcing welding wire mesh, and the cracks generated due to concentrated strain do not grow and are generated on the end face and the top face. Cracks can be prevented and suppressed.

(Tenth embodiment)
A composite deck slab according to a tenth embodiment of the present invention will be described with reference to FIG.
The reinforcing means is an embodiment relating to a composite deck slab in which a plurality of reinforcing bars are alternately sewn and arranged with adjacent studs in different directions.
Mutually refracting opposing arrangement bars 86 are provided in which two reinforcing bars are arranged so as to alternately sew a plurality of studs 15 provided in a row on the flange 14F of the steel beam 14.
Since there are the mutually alternating refraction opposed arrangement stripes 86, the studs are pressed from both sides, and the stress acting on the studs is transmitted to the mutually alternately refraction opposed arrangement arrangement stripes 86 and is burdened. When the studs 15 and the reciprocally alternating refraction arrangement bars 86 are connected by binding or welding, the degree of fixation is increased and the stress is dispersed. In addition, the stud 15 is a stud with a head, whereby the function of preventing the alternately bent arrangement streaks 81 from being removed is improved.
The mutually alternating refraction opposed arrangement stripes 86 are arranged below the wire mesh, so that stress can be transmitted to the wire mesh and the stress can be dispersed.
The mutually refracting opposed arrangement stripes 86 are preferably continuous in the axial direction of the steel beam, but the function and function can be exhibited even if the length is between several studs.
FIG. 11 (a) is a plan view schematically showing a mutual alternating refraction opposed arrangement bar 86 in which two rebars provided vertically are alternately refracted on adjacent studs in different directions. A perspective view is shown in FIG.

  End cracks and upper cracks from the end face or top face of the composite deck slab to the vicinity of the stud head strengthen the studs, disperse the stress applied to the studs, suppress deformation of the studs, and reciprocal refraction Since the opposed arrangement stripes 86 also bear the stress, the cracks generated by the concentrated strain do not grow, and the cracks generated on the end face and the upper face can be prevented and suppressed.

A1, A2 Top surface crack B1, B2 End surface crack

1 composite deck slab 11 deck plate (QL deck)
12 Concrete 13 Wire mesh 14 Steel beam 14b Intermediate steel beam 14F Flange 15 Stud 15l Long stud

21 Reinforcing bars on both sides of stud 21a Outer reinforcing bars 21b Inner reinforcing bars 22 Steel plate (flat bar)
31 U-shaped Reinforcement 41 Lower Hook Reinforcement 41a Upper Reinforcement 41b End Reinforcement 41c Lower Reinforcement 42 Bend Reinforcement 42a Upper Fold Reinforcement 42b Lower Bend Reinforcement 51 Upper Fold Hook Reinforcement 51a Lower Reinforcement 51b End streaks 51c Upper streaks 52 Bending portion reinforcing bars 52a Upper bending portion reinforcing bars 52b Lower bending portion reinforcing bars

Reference Signs List 61 lower reinforcing bar 62 end reinforcing plate 71 lower reinforcing bar 72 end reinforcing plate 81 (adjacent stud) alternating refracting arrangement 81a upper alternating refracting arrangement 81b lower alternating refracting arrangement 86 mutual alternating refracting opposing arrangement 91 91 welding for reinforcement Wire mesh

Claims (11)

  A composite deck slab in which a steel beam having a flange with studs is used, wherein reinforcing means is provided at least in a range of the flange.   2. The composite deck slab according to claim 1, wherein the reinforcement means comprises reinforcements arranged along rows of studs.   The composite deck slab according to claim 1 or 2, wherein the reinforcing means is a stud having a tip whose height is equal to or higher than a reinforcing bar position of the wire mesh.   The composite deck slab according to any one of claims 1 to 3, wherein the reinforcing means has a U shape and is disposed on an upper surface of the flange of the steel beam.   The composite deck slab according to any one of claims 1 to 4, wherein the reinforcing means is arranged by bending a reinforcing bar at an end of the slab downward from above the wire mesh.   6. The reinforcing means according to any one of claims 1 to 5, wherein the reinforcing means extends the reinforcing reinforcing bar arranged in the groove of the deck plate toward the end of the slab and is bent upward to be arranged. Synthetic deck slab.   The reinforcing means comprises a reinforcing bar disposed on the lower surface of the wire mesh toward an end of the slab and an iron plate joined to an end of the reinforcing bar. The synthetic deck slab according to 1.   The reinforcing means is composed of a reinforcing bar disposed from the inside of the groove of the deck plate toward the end of the slab and an iron plate joined to the end of the reinforcing bar. The synthetic deck slab according to 1.   The composite deck slab according to any one of claims 1 to 8, wherein the reinforcing means is arranged by reinforcing bars by alternately sewing adjacent studs.   The synthetic deck slab according to any one of claims 1 to 9, wherein the reinforcing means is a reinforcing wire mesh having a pitch narrower than that of the wire mesh, which is placed over the stud with head.   The composite deck slab according to any one of claims 1 to 10, wherein the reinforcing means is arranged by alternately sewing studs in which a plurality of reinforcing bars are adjacent in different directions.

Images