JP7702365B2 - Deck plates for composite deck slabs and composite deck slabs - Google Patents

Description

The present invention relates to deck plates for composite deck slabs and composite deck slabs.

The floors of large buildings such as high-rise buildings are constructed with composite deck slabs formed from concrete (concrete parts) and deck plates. As deck plates used in composite deck slabs, for example, corrugated deck plates are known, which are formed by alternating inclined sections that are inclined in different directions and multiple peaks and valleys that are connected to each other through the inclined sections. In such deck plates, a key section (engagement section) that can engage with the concrete is formed as a structure to promote synthesis (engagement) with the concrete (see, for example, Patent Document 1).

A composite deck slab is formed by integrating the deck plate and concrete through the engagement parts on the deck plate. This creates a rational composite structure in which the deck plate bears tensile forces and the concrete bears compressive forces, supporting the constant load acting on the floor.

On the other hand, it is known that the strength of the deck plate, which bears the tensile force in a composite deck slab during a fire, is lost due to heat in the early stages of a fire, and the deck plate no longer functions as a structural component of the composite deck slab. In addition, composite deck slabs can collapse at the support points, which are the joints between the beams and the composite deck slab, during a fire, so composite deck slabs are known that reinforce the support points (joint points) to improve the allowable performance of loads and spans, and to improve fire resistance (see, for example, Patent Document 2).

JP 2021-156142 A JP 2020-41348 A

In the event of a fire, heat is transferred to the concrete through the deck plate, but concrete is constructed by solidifying through the hydration reaction between cement and water, and a large amount of water used in the hydration reaction remains inside the concrete. As a result, concrete has the characteristic of being less susceptible to temperature rise due to the moisture inside, even when heated by a fire, and it is known that the rate at which the temperature of concrete rises is slower than that of the deck plate.

Figure 9 is a conceptual diagram explaining the forces acting on a conventional composite deck slab 100 in the event of a fire. For example, the composite deck slab 100 based on Patent Document 2 is fixed to a support beam B, and the deck plate 200 is indirectly restrained by the support beam B. When heated during a fire, the deck plate 200 is subjected to an expansive force P1 that causes it to expand and stretch rapidly. However, the deck plate 200 is restrained by the support beam B at both ends, and a restraining force P2 acts on the deck plate 200, restraining the horizontal extension of the deck plate 200. Therefore, opposing forces, the expansive force and the restraining force, are generated in the heated deck plate 200, and a force P3 that tries to deform the composite deck slab vertically downward is applied.

In the deck composite slab 100, the deck plate 200 is enhanced in terms of its composition with the concrete 300 through the engagement portion. In the event of a fire, the deck composite slab 100 loses its structural function early on. Nevertheless, in the event of a fire, the deck plate 200 is subjected to a force P3 that pulls the concrete 300 vertically downward as it deforms. In other words, in addition to supporting the vertical load that the deck composite slab is designed to support, the vertically downward force P3 due to the thermal expansion of the deck plate 200 can have an unnecessary effect on the deck composite slab 100. This is considered to be one of the causes of the deterioration of the fire resistance of the deck composite slab 100, and measures are needed.

The present invention was made in consideration of the above problems, and aims to provide a technology that improves the fire resistance of composite deck slabs by promoting the separation of the deck plate from the concrete portion during a fire while ensuring the combination of the deck plate and the concrete portion.

In order to solve the above problems, the deck plate for a composite deck slab according to the present invention is a deck plate for a composite deck slab that is corrugated and has multiple peaks and valleys that are connected to each other via alternating inclined sections, and is equipped with an engagement section that is used to engage with the concrete section of the composite deck slab, and a deformation promotion section that promotes peeling from the concrete section during thermal expansion, and is characterized in that the deformation promotion section deforms so as to form a gap between the concrete section and the deformation promotion section during thermal expansion.

In addition, in a deck plate for a composite deck slab according to one aspect of the present invention, the engagement portion includes a groove formed at the transition between the inclined portion and the valley bottom, and the deformation promotion portion may be a protrusion portion provided at a predetermined interval along the extension direction of the groove and protruding from the groove side toward the valley bottom side so as to partially interrupt the extension of the groove.

In addition, in a deck plate for a composite deck slab according to one aspect of the present invention, the protrusion may have a pair of inclined surfaces extending in a direction in which the surfaces facing the extension direction of the groove intersect with each other, and an intervening surface extending along the extension direction of the groove between the pair of inclined surfaces.

In addition, in a deck plate for a composite deck slab according to one aspect of the present invention, the engagement portion includes a groove formed at the transition between the inclined portion and the valley bottom portion, and the deformation promoting portion may be a thermoplastic filler member provided in the groove so as to partially interrupt the extension of the groove, and provided at a predetermined interval along the extension direction of the groove.

In addition, in a deck plate for a composite deck slab according to one aspect of the present invention, the filling member may have a tip portion that protrudes from the groove toward the bottom of the valley and engages with the concrete portion.

In addition, in a deck plate for a composite deck slab according to one aspect of the present invention, the filling member may be formed so as to taper from the groove side toward the tip side.

In addition, in a deck plate for a composite deck slab according to one aspect of the present invention, the engagement portion includes a convex portion that protrudes toward the bottom of the valley at the inclined portion, and the convex portions are provided at a predetermined interval along the extension direction of the inclined portion, and the filling member may be provided between at least some of the convex portions.

Furthermore, in order to solve the above problems, the composite deck slab of the present invention is a composite deck slab comprising a concrete section and a corrugated deck plate that is formed by connecting multiple peaks and valleys that are continuous with each other via alternatingly inclined slopes and engages with the concrete section, the deck plate having an engagement section that is used for engaging with the concrete section in the composite deck slab, and a deformation promoting section that promotes peeling from the concrete section upon thermal expansion, and the deformation promoting section deforms so as to form a gap between the concrete section and the deck plate upon thermal expansion.

According to the present invention, the fire resistance of the composite deck slab is improved by ensuring the composite deck plate and concrete while promoting the separation of the deck plate from the concrete in the event of a fire.

FIG. 2 is a perspective view for explaining the configuration of the deck composite slab according to the first embodiment. FIG. 2 is a perspective view of a deck plate used in the deck composite slab according to the first embodiment. 3 is an enlarged view showing an engagement groove portion of the deck plate shown in FIG. 2. FIG. 3B is a cross-sectional view of the deck plate taken along line BB in FIG. 3A. 4 is a cross-sectional view of the deck plate taken along the longitudinal direction L at the engagement groove. FIG. 13 is a diagram showing a schematic state after the deck plate and the concrete portion are disengaged from each other. FIG. FIG. 11 is a partially enlarged perspective view of a deck plate for explaining a deformation promoting portion according to a modified example. FIG. 6B is a cross-sectional view of the deck plate taken along line BB in FIG. 6A. FIG. 11 is an enlarged view showing a portion of the deck plate in the second embodiment. 13A to 13C are diagrams for explaining modified examples of the deformation promoting portion in the second embodiment. FIG. 8B is a plan view for roughly explaining a modification of the deformation promoting portion in the second embodiment. FIG. 1 is a conceptual diagram illustrating the forces acting on a conventional deck composite slab in the event of a fire.

Below, an embodiment of the present invention will be described with reference to the drawings. Note that in the following description, the drawings are schematic, and it should be noted that the dimensional relationships and ratios of each element may differ from reality. There may also be parts in which the dimensional relationships and ratios differ between the drawings.

First Embodiment
[Deck composite slab]
FIG. 1 is a perspective view for explaining the configuration of a deck composite slab 1 according to the first embodiment. The deck composite slab 1 according to the first embodiment is a composite structure composed of, for example, a steel deck plate 10 and a concrete portion 60, and is used for the ceiling or floor of a building such as a steel frame structure. In the deck composite slab 1, the deck plate 10 resists tensile force, and the concrete portion 60 resists compressive force. This allows the deck composite slab 1 to withstand a large load and span between the support beams B of H-shaped steel over a long span. In this embodiment, a plurality of headed studs Sd are provided on the flange of the support beam B along the extension direction of the flange, but the headed studs Sd are not limited to the headed studs Sd, and burn-out plug welding or the like may be performed.

In the following, the direction in which the deck plate 10 is spanned between the support beams B of the building is referred to as the longitudinal direction (length direction) L of the deck plate 10, the direction in which the deck plate 10 extends intersecting the longitudinal direction L is referred to as the transverse direction (width direction) W, and the direction in which the deck plate 10 is placed on the support beams B is referred to as the height direction H of the deck plate 10.

(Deck plate)
2 is a perspective view of a deck plate 10 used in the deck composite slab 1 according to the first embodiment. The deck plate 10 in the first embodiment is a deck plate 10 for a corrugated deck composite slab 1 formed by connecting a plurality of crests 11 and valley bottoms 13 that are continuous with each other via inclined portions 15 that are alternately inclined in different directions, and is provided with engagement portions 20, 30 that are used for engagement with the concrete portion 60 in the deck composite slab 1, and a deformation promoting portion 40 that promotes peeling from the concrete portion 60 during thermal expansion, and is characterized in that the deformation promoting portion 40 deforms (including deformation, transformation, dissolution, etc.) so that a gap S is formed between the concrete portion 60 and the deformation promoting portion 40 during thermal expansion. The configuration of the deck plate 10 in the first embodiment will be specifically described below.

The deck plate 10 is a corrugated steel plate formed by roll forming or the like of a thin steel plate that has been subjected to a surface treatment such as zinc plating. The deck plate 10 does not have to be subjected to a surface treatment such as plating. The deck plate 10 has a peak portion 11, a valley bottom portion 13, a sloping portion 15, engagement portions 20, 30, and a deformation promoting portion 40. The deck plate 10 has a wave shape in which the peak portion 11 and the valley bottom portion 13, each extending in the longitudinal direction L, are connected to each other in the lateral direction W via the sloping portion 15.

The deck plate 10 itself is made up of two peaks 11, one valley bottom 13, and two pairs of inclined sections 15, and is formed in a wave shape in cross section along the short side direction W. Depending on the dimensions of the deck plate 120 in the short side direction W, only one peak 121 may be provided on one deck plate 120. When one deck plate 10 is connected to another deck plate 10 in the short side direction W, the connection between the deck plates 10 functions as the valley bottom 13. The deck plate 10 may also be end-closed at both ends in the longitudinal direction L.

The summit portion 11 is a flat portion located above the support beam B when the deck plate 10 is spanned between the support beams B (hereinafter also referred to as the "spanning state"), and is a plate-like portion extending in the longitudinal direction L. The summit portion 11 has a groove 12. The groove 12 is formed so as to be recessed toward the valley bottom portion 13. The groove 12 extends in the longitudinal direction L, and when there is only one groove 12, it is provided near the center in the lateral direction W.

The groove 12 in the peak portion 11 improves the strength of the peak portion 11. There is no need to form a single groove 12 in the peak portion 11, and multiple grooves 12 may be formed. Note that no groove 12 may be formed.

The valley bottom 13 is parallel or approximately parallel to the peak 11, and is a flat portion that is placed on the support beam B in the spanning state. The valley bottom 13 is a plate-like portion that extends in the longitudinal direction L. The valley bottom 13 does not overlap with the peak 11 in the lateral direction W. The groove 12 formed in the peak 11 may also be formed in the valley bottom 13.

The inclined portion 15 is a portion that connects the peak portion 11 and the valley bottom portion 13, and is a plate-shaped portion that extends in the longitudinal direction L. The inclined portion 15 extends obliquely from both ends of one peak portion 11 toward the valley bottom portion 13 in the lateral direction W. The inclined portion 15 is inclined to form a predetermined angle, for example an obtuse angle, with respect to the peak portion 11 and the valley bottom portion 13. The groove 12 formed in the peak portion 11 may be formed in the inclined portion 15.

The engaging portion 20 is provided on the inclined portion 15. The engaging portion 20 includes an engaging protrusion 21 and an engaging recess 22. The engaging protrusion 21 is a protrusion formed by, for example, embossing so as to protrude from the surface of the adjacent inclined portion 15 via one crest portion 11 to the opposite side (the valley bottom portion 13 side). A plurality of engaging protrusions 21 are provided at predetermined intervals along the extension direction (longitudinal direction L) of the inclined portion 15. The engaging recess 22 is located between the engaging protrusions 21 along the longitudinal direction L. The engaging protrusions 21 and the engaging recess 22 increase the strength of the inclined portion 150 and promote the engagement between the concrete portion 60 and the deck plate 10 described later, thereby enhancing the composite effect.

A bulge 14 is formed at the transition between the valley bottom 13 and the inclined portion 15. The bulge 14 is a portion that protrudes on opposite sides of a pair of inclined portions 15 at one peak portion 11. In other words, the bulge 14 on a pair of inclined portions 15 facing each other across the valley bottom 13 are formed to face each other and bulge in directions approaching each other. The bulge 14 is located on the valley bottom 13 side of the engagement protrusion 20.

The engagement portion 30 is formed as an engagement groove (ant groove) extending along the longitudinal direction L between the bulge portion 14 and the valley bottom portion 13 (hereinafter, also referred to as "engagement groove 30"). The cross section of the engagement groove 30 along the short side direction W is formed to be curved. The engagement groove 30 is formed in a direction approaching each other in a pair of inclined portions 15 in one peak portion 11. That is, in a pair of inclined portions 15 continuing to the valley bottom portion 13 of the deck plate 10, the engagement grooves 30 are formed to face each other and are curved in a direction away from each other. The engagement groove 30 promotes engagement between the concrete portion 60 and the deck plate 10 described later, enhancing the composite effect.

The deformation promoting portions 40 are provided at predetermined intervals along the extension direction (longitudinal direction L) of the engagement groove 30 so as to partially interrupt the extension of the engagement groove 30. The deformation promoting portions 40 are protrusions (hereinafter also referred to as "deformation protrusions 40") formed by protruding from the engagement groove 30 side toward the valley bottom 13 side. The deformation protrusions 40 are portions where deformation is actively promoted, for example, when the deck composite slab 1 is heated in the event of a fire and the deck plate 10 deforms due to thermal expansion.

Figure 3A is an enlarged view showing the engagement groove 30 of the deck plate 10 shown in Figure 2. Figure 3B is a cross-sectional view of the deck plate 10 taken along line B-B in Figure 3A. The deformed protrusion 40 is formed on the side facing the valley bottom 13, for example by embossing, so as to push out the deck plate 10 at each engagement groove 30. In other words, the deformed protrusion 40 is formed by protruding in the short direction W from each engagement groove 30 formed in the inclined portion 15 continuing from one crest 11 toward the continuing valley bottom 13. The extension of each engagement groove 30 in the longitudinal direction L is interrupted by the deformed protrusion 40, and the engagement groove 30 is divided so that multiple projections and recesses are continuously formed in the short direction W. This ensures that the engagement between the deck plate 10 and the concrete portion 60 is normally maintained in the divided engagement groove 30, while ensuring a portion that promotes disengagement between the deck plate 10 and the concrete portion 60 when the deck plate 10 is heated.

The deformed protrusion 40 has a pair of inclined surfaces 41 and a protrusion surface (intervening surface) 42. The pair of inclined surfaces 41 are surfaces facing the extension direction (longitudinal direction L) of the engagement groove 30, and extend in directions intersecting each other toward the adjacent valley bottom 13. The pair of inclined surfaces 41 extend from a surface or portion that defines the engagement groove 30 facing the lateral direction W along the longitudinal direction L toward the valley bottom 13 adjacent to the engagement groove 30, that is, so as to approach each other in the lateral direction W.

The protruding surface 42 is continuous with the inclined surface 41 on the side opposite to the portion of the inclined surface 41 that is continuous with the surface or portion that defines the engagement groove 30 facing the short direction W. The protruding surface 42 extends along the extension direction of the engagement groove 30 (longitudinal direction L) between the pair of inclined surfaces 41. The protruding surface 42 may be formed at the same position in the longitudinal direction L as the protruding surface 42 in the engagement groove 30 that faces it across the valley bottom 13, or may be formed at a position offset therefrom.

(Concrete section)
The concrete portion 60 is formed by solidifying concrete poured on the deck plate 10. Reinforcement bars (not shown) for preventing cracks, welded wire mesh 61 (see FIG. 1 ), and the like may be embedded inside the concrete portion 60.

[Characteristics of composite deck slabs]
According to the above-mentioned composite deck slab 1, it is possible to improve the fire resistance. The composite deck slab 1 is assumed to collapse at the fulcrum position, which is the joint with the support beam B, in the event of a fire, and the fulcrum position (joint position) is reinforced to improve the allowable performance such as the load and span, and to improve the fire resistance. A plurality of studs Sd provided on the flange of the support beam B are provided as a reinforcing means. The studs Sd are arranged in the short direction W on the support beam B. In addition, the performance of the composite deck slab 1 is further improved by further arranging reinforcing bars (not shown) and elongated steel plates (not shown) along the row of studs Sd.

This type of reinforcing means improves the pull-out resistance of the ends of the deck composite slab 1, improves the degree of fixation to the support beam B, and prevents cracks from forming at the ends of the deck composite slab 1 and inhibits their expansion, thereby enhancing the allowable performance of the live load and span. This distributes the stress generated around the studs Sd and reinforces the ends of the deck composite slab 1, improving the fire resistance.

In the event of a fire, the deck composite slab 1 will first heat up the deck plate 10 due to the flames scorching the ceiling from the floor below, and then the concrete section 60. The concrete section 60 has the characteristic that its temperature does not rise easily even when heated during a fire, because it contains a large amount of moisture inside. Therefore, there is a large difference between the rate at which the temperature rises in the deck plate 10 and the concrete section 60.

For example, the thermal expansion coefficients of the deck plate 10, which is the steel material in the composite deck slab 1, and the concrete portion 60 are the same at approximately 11.0×10 ^-6 °C (0.1 mm expansion/contraction per meter of unit length with a temperature change of 10 K). However, the deck plate 10 and the concrete portion 60 have significantly different rates of temperature rise depending on the fire conditions, etc., and in the deck plate 10 of the composite deck slab 1, expansion due to thermal expansion is significant compared to the thermal expansion of the concrete portion 60 in the early stages of a fire.

Here, we will explain the deformation of the deck plate 10 using Figure 4. Figure 4 is a cross-sectional view of the deck composite slab taken along the longitudinal direction L at the engagement groove 30. When the deck plate 10 is heated by flames caused by a fire, the deck plate 10 tries to deform by expanding due to thermal expansion. However, because the deck plate 10 is fixed to the support beam B at the end in the longitudinal direction L, a contracting force acts on the deck plate 10 in the longitudinal direction L.

The deck plate 10 is easily deformed by the deformation overhanging portion 40. The force acting on the pair of inclined surfaces 41 collides with the overhanging surface 42. The force generated inside the deck plate 10 has nowhere to escape, and at each deformation overhanging portion 40, the deck plate 10 deforms or buckles so that it bulges on the side opposite the concrete portion 60 (arrow P4). As a result, the mutual engagement (restraint) between the deck plate 10 and the concrete portion 60 is partially released, and a gap S is formed. By releasing the engagement between the deck plate 10 and the concrete portion 60, the deck plate 10 is prevented from pulling the concrete portion 60, and the adverse effect of the deck plate 10 on the entire deck composite slab 1 can be eliminated.

Figure 5 is a diagram showing the state after the disengagement between the deck plate 10 and the concrete part 60. The deck plate 10 in the first embodiment is provided with a deformation protrusion 40 for the purpose of intentionally promoting its deformation, so that a gap S is formed between the deck plate 10 and the concrete part 60 when heated by fire. In particular, a gap (air layer) S is formed between the deck plate 10 and the concrete part 60 along the longitudinal direction L, and an air layer S is provided between the deck plate 10 and the concrete part 60. In other words, since the deck plate 10 actively deforms during a fire, an air layer S with an additional insulating effect is formed between the deck plate 10 and the concrete part 60, and the fire resistance of the deck composite slab 1 can be further improved.

<Modification>
Fig. 6A is a partially enlarged perspective view of the deck plate 10A to explain the deformation promoting portion 50 according to a modified example. Fig. 6B is a cross-sectional view of the deck plate 10A taken along line B-B in Fig. 6A. Note that the same components as those in the above-described deck plate 10 are given the same reference numerals and will not be described. The deck plate 10A differs in the deformation protruding portion 40 of the deck plate 10.

In the first embodiment, the deformation promoting portion 40 is formed so as to protrude from the engagement groove 30 in the short direction W. In contrast, the deformation promoting portion 50 in the modified example is formed so that the surface facing the peak portion 11 of the engagement groove 30 protrudes in the height direction H toward the peak portion 11 (hereinafter, also referred to as the "deformation protrusion portion 50").

The deformed raised portion 50 is formed on the side facing the peak portion 11, for example by embossing, so as to push out the deck plate 10 at each engagement groove 30. In other words, the deformed raised portion 50 is formed by protruding in the height direction H at each engagement groove 30 formed in the inclined portion 15 continuing to one peak portion 11. The extension of each engagement groove 30 in the longitudinal direction L is interrupted by the deformed raised portion 50, and the engagement groove 30 is divided so that the unevenness is continuous, concave in the short direction W and convex in the height direction H.

The deformed protuberance 50 has a pair of inclined surfaces 51 and a top surface (intervening surface) 52. The pair of inclined surfaces 51 are surfaces facing the extension direction (longitudinal direction L) of the engagement groove 30, and extend in directions that intersect with each other. The pair of inclined surfaces 51 extend from a surface or portion of the engagement groove 30 facing the top surface 52 along the longitudinal direction L toward the top surface 52 so as to approach each other.

The top surface 52 is continuous with the inclined surface 51 on the side opposite to the portion of the inclined surface 51 that is continuous with the surface or portion of the engagement groove 30 facing the top surface 52. The top surface 52 extends between the pair of inclined surfaces 51 along the extension direction of the engagement groove 30 (longitudinal direction L). The top surface 52 is preferably in contact with the bulge portion 14, but does not need to be in contact if there is only a small gap between the top surface 52 and the bulge portion 14. The deformed protuberances 50 may be formed at the same position in the longitudinal direction L in the engagement grooves 30 that face each other across the valley bottom 13, or may be formed at offset positions.

The deck plate 10A is easily deformed due to the deformation ridges 50. The force acting on the pair of inclined surfaces 51 collides with the top surface 52. The force generated inside the deck plate 10A has nowhere to escape, and at each deformation ridge 50, the deck plate 10A deforms or buckles so that it bulges on the side opposite the peak 11. This partially releases the mutual engagement (restraint) between the deck plate 10A and the concrete portion 60. By releasing the engagement between the deck plate 10A and the concrete portion 60, the deck plate 10A is prevented from pulling the concrete portion 60 vertically downward, and the adverse effect of the deck plate 10A on the entire deck composite slab 1 can be eliminated.

Second Embodiment
Next, the deck composite slab 8 according to the second embodiment will be described with reference to FIG. 7. FIG. 7 is an enlarged view showing a part of the deck plate 10B according to the second embodiment. The same components as those of the deck composite slab 1 according to the first embodiment are denoted by the same reference numerals and will not be described. The deck composite slab 8 according to the second embodiment is a composite structure composed of, for example, a steel deck plate 10B and a concrete portion 60, and is used for the ceiling or floor of a reinforced concrete building. The deck plate 10B has a peak portion 11, a valley bottom portion 13, an inclined portion 15, engagement portions 20, 30, and deformation promoting portions 71, 72.

The deformation promoting portions 71 are provided at predetermined intervals along the extension direction (longitudinal direction L) of the engagement groove 30 so as to partially interrupt the extension of the engagement groove 30. In this embodiment, the deformation promoting portions 71 are filling members (hereinafter also referred to as "deformation filling members 71") formed from a thermoplastic resin or the like, but there are no particular limitations on the material, as long as they are filling members formed from a metal or alloy with a lower melting point than the deck plate 10B. The deformation filling members 71 are portions in which melting (deformation) is actively promoted before the deck composite slab 8 is heated in the event of a fire and the deck plate 10B is deformed due to thermal expansion.

The deformation facilitating portion 72 is provided in the engagement recess 22 of the engagement portion 20. In this embodiment, the deformation facilitating portion 72 is a filling member (hereinafter also referred to as "deformation filling member 72") formed from a thermoplastic resin or the like, but the material is not particularly limited as long as it is a filling member formed from a metal or alloy with a lower melting point than the deck plate 10B. Specifically, the deformation filling member 72 is provided in the engagement recess 22 between the two engagement protrusions 21 so as not to be continuous in the longitudinal direction L. This makes it possible to partially ensure the engagement between the deck plate 10B and the concrete portion 60 in normal times in the engagement portion 20, while ensuring a portion that promotes disengagement when the deck plate 10B is heated.

Furthermore, the deformable filling member 71 is provided so as to partially fill the engagement groove 30 along the longitudinal direction L. The deformable filling members 71 are provided at a predetermined interval from each other in the longitudinal direction L, and the engagement groove 30 is divided so that multiple concave and convex irregularities are continuously formed in the short direction W. In other words, the engagement groove 30 is the concave portion, and the deformable filling member 71 is the convex portion. This ensures that the engagement between the deck plate 10B and the concrete portion 60 is normally maintained in the divided engagement groove 30, while ensuring a portion that promotes disengagement when the deck plate 10B is heated. The deformable filling member 71 is contained within the engagement groove 30 so as not to exceed the bulge portion 14 in the short direction W.

According to the deck composite slab 8 of the second embodiment, the deformable filling members 71, 72 melt first in the early stages of a fire. As a result, the volume of the deformable filling members 71, 72 increases after melting, and they tend to move away from the concrete portion 60 to promote thermal expansion of the heated deck plate 10B. As a result, at the locations where the deformable filling members 71, 72 are provided, the deck plate 10B and the melted deformable filling members 71, 72 can move relative to each other at their interfaces, allowing the deck plate 10B to deform.

When the deck plate 10B deforms in a direction away from the concrete section 60, the melted deformed filling members 71, 72 also move in a direction away from the concrete section 60. This causes a gap S to form between the deck plate 10B and the concrete section 60 in the deformed filling section 71. As the deformed filling members 71, 72 melt, the elongation of the deck plate 10B due to thermal expansion is promoted, and the deformed filling members 71, 72 become the starting point that induces separation between the deck plate 10B and the concrete section 60 in the event of a fire.

The deformable filling member 72 in this embodiment may be provided in the engagement recess 22 of the deck plate 10 in the first embodiment.

<Modification>
Fig. 8A is a diagram for explaining a modified example of the deformation promoting portion 80 in the second embodiment. Fig. 8B is a plan view for generally explaining the modified example of the deformation promoting portion 80 in the second embodiment. The deformable filling member 71 in the second embodiment is formed to be contained within the engagement groove 30. In contrast, the deformable filling member 81 according to the modified example is formed to protrude in the short direction W from the engagement groove 30.

The deformable filling member 81 is a filling member formed from a thermoplastic resin or the like, but may also be a filling member formed from, for example, a metal or alloy that has a lower melting point than the deck plate 10B.

The deformed filling member 81 protrudes obliquely from the engagement groove 30 at the tip 81 in the short direction W toward the valley bottom 13 and toward the adjacent peak 11. The deformed filling member 81 is formed so as to taper from the engagement groove 30 side toward the tip 81 side. In other words, the width of the deformed filling member 81 in the longitudinal direction L is formed so as to continuously decrease from the engagement groove 30 side toward the tip 82 side. The cross-sectional shape of the deformed filling member 81 in the longitudinal direction L is trapezoidal or approximately trapezoidal in this embodiment, but may also be triangular.

The deformable filling member 81 is provided so as to partially fill the engagement groove 30 along the longitudinal direction L. The deformable filling member 81 is provided continuously in the longitudinal direction L, and the engagement groove 30 is divided so as to have a series of multiple concave and convex irregularities in the lateral direction W. In other words, the engagement groove 30 is the concave portion, and the deformable filling member 71 is the convex portion. The deformable filling member 81 is formed so as to taper toward the tip portion 82, so that a gap is created between adjacent deformable filling members 81 that widens from the engagement groove 30 side toward the lateral direction W.

The deformation promoting portion 83 is provided in the engagement recess 22 of the engagement portion 20. In this embodiment, the deformation promoting portion 83 is a filling member (hereinafter also referred to as the "deformation filling member 72") formed from a thermoplastic resin, but there are no particular limitations on the material, as long as the filling member is formed from a metal or alloy with a lower melting point than the deck plate 10B. Specifically, the deformation filling member 83 is provided in the engagement recess 22 between the two engagement protrusions 21 so as not to be continuous in the longitudinal direction L.

When the modified deformable filling member 81 is used, the amount of engagement between the deck plate 10B and the concrete section 60 in the engagement groove 30 is reduced compared to when the deformable filling member 71 is used. However, the tip 82 of the deformable filling member 81 protrudes in the short direction W, and the tip 82 plays a role in increasing the adhesion with the concrete section 60.

In addition, the volume of the deformable filling member 81 within the engagement groove 30 is larger than that of the tip portion 82, so that a larger amount of it melts when heated by a fire. This creates a larger gap (air layer) S between the deck plate 10B and the concrete portion 60, facilitating separation between the deck plate 10B and the concrete portion 60.

The cross-sectional shape of the deformable filling member 81 in the longitudinal direction L is not particularly limited and may be rectangular. The deformable filling member 81 in this embodiment may be provided on the deck plate 10 in the first embodiment.

＜Other＞
Although the preferred embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and includes all aspects included in the concept of the present invention and the scope of the claims. In addition, each configuration may be appropriately selected and combined so as to achieve at least a part of the above-mentioned problems and effects. In addition, for example, the shape, material, arrangement, size, etc. of each component in the above embodiment may be appropriately changed depending on the specific use mode of the present invention. The deck composite slab 1, 8 according to the present invention is intended to not inhibit, that is, to promote, the deformation of the deck plates 10, 10A, 10B due to heating during a fire, for example, and the shapes of the deck plates 10, 10A, 10B and the shapes of the engaging protrusions 20 and the engaging grooves 30 are not limited to the above embodiment, etc.

1, 8... Deck composite slab 10, 10A, 10B... Deck plate 11... Peak portion, 13... Valley bottom portion, 15... Inclined portion 20... Engagement portion 21... Engagement protrusion 22... Engagement recess 30... Engagement groove (engagement portion)
40... Deformation protrusion portion (deformation promotion portion)
41... Inclined surface, 42... Overhanging surface (intervening surface),
50... Deformation protuberance (deformation promotion portion)
51...Slope surface, 52...Top surface (intervening surface)
60: Concrete portion 71, 72, 81, 82: Deformation filling member (deformation promoting portion)

Claims (8)

A deck plate for a corrugated deck composite slab formed by connecting a plurality of crests and valley bottoms that are continuous with each other through alternating inclined slopes,
An engagement portion that promotes engagement between the concrete portion of the deck composite slab and the deck plate via a groove formed at the transition portion between the inclined portion and the valley bottom and/or a protrusion protruding toward the valley bottom side at the inclined portion ;
a deformation promoting portion that promotes separation of the deck plate from the concrete portion upon thermal expansion;
Equipped with
The deformation promoting portions are provided in the groove at predetermined intervals along the extension direction of the groove so as to partially interrupt the extension of the groove, and deform so as to form a gap between the concrete portion and the deformation promoting portions during thermal expansion. 2. The deck plate for a composite deck slab according to claim 1, wherein the deformation promoting portion is a protruding portion formed by protruding from the groove side toward the valley bottom side. The protruding portion is
A pair of inclined surfaces extending in directions intersecting each other, the surfaces facing the extension direction of the groove;
an intermediate surface extending between the pair of inclined surfaces along an extension direction of the groove;
The deck plate for a composite deck slab according to claim 2, further comprising: The deck plate for a composite deck slab according to claim 1, wherein the deformation promoting portion is a thermoplastic filler member. The deck plate for a composite deck slab according to claim 4, characterized in that the filling member has a tip portion that protrudes from the groove toward the bottom of the valley and engages with the concrete portion. The deck plate for a composite deck slab according to claim 5, characterized in that the filling member is tapered from the groove side toward the tip side. The protruding portion is provided at a plurality of predetermined intervals along an extension direction of the inclined portion,
The deformation promoting portion further includes a thermoplastic filling member provided between at least some of the protrusions.
A deck plate for a composite deck slab according to any one of claims 4 to 6. A deck plate for a deck composite slab according to any one of claims 1 to 7;
A concrete portion formed by concrete poured on the deck plate ;
A deck composite slab comprising :

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