JP6353591B1 - Synthetic floor slab - Google Patents

Abstract

A deck plate capable of forming a composite floor slab having excellent strength is provided. A deck plate includes a substrate, a plurality of first reinforcing bars arranged in parallel to each other at the same height position on the substrate, and a waveform shape that vibrates with the same amplitude and the same cycle on the same plane. The lattice bars 4A and 4B which are opposed to each other in a posture inclined in the opposite direction at both side positions sandwiching the first rebar 3 and a plurality of first rebars 3 provided on the plurality of first rebars 3 and perpendicular to the first rebar 3 2nd reinforcement 5 is provided. On the surface of the substrate 21, ridges 22A and 22B to which the lower bent portions 41 of the lattice muscles 4A and 4B are fixed are integrally formed with an inclination that matches the inclination of the lattice muscles 4A and 4B. The bent portions 41 below the lattice muscles 4A and 4B are overlapped with the inner surfaces of the protrusions 22A and 22B and are welded at positions above the bent ends. Each upper bent portion 40 is applied to the side surface of the first reinforcing bar 3 and welded at a position below the bent end. [Selection] Figure 2

Description

This invention relates to synthetic deck constructed are integrated and concrete that is Da設on the upper surface of the deck plate and the deck plate are, this invention is particularly, loosening is integrated by the heat from the underfloor FIRE The present invention relates to a composite slab excellent in fire resistance that can be suppressed.

  Conventionally, a method using a deck plate has been adopted to construct a floor of a steel structure or reinforced concrete building. One method of this type is to make the deck plate and concrete work together as a composite floor slab. Other construction methods consider the deck plate as a discarded formwork and do not consider it as a structural member of the floor slab. A composite floor slab using a deck plate is formed by forming a plurality of concave grooves and ridges on the surface of the steel plate constituting the deck plate by bending or pressing, and bending in the direction perpendicular to the concave grooves and ridges. In addition to increasing the strength against contact, the contact area between the concrete and the deck plate is increased to ensure the structural strength, thereby integrating the steel plate of the deck plate that is resistant to tensile force and the concrete that is resistant to compressive force into cooperation. .

  The above-mentioned synthetic floor slab is so-called “unequal-thickness cross section”, and the thickness is not uniform throughout, and the bottom surface of the floor is an uneven surface. There is a problem that the impact sound from the floor easily propagates, and a gap is formed at the top of the partition wall between the adjacent rooms, so that it is difficult to block the generated sound and vibration sound between the adjacent rooms. For this reason, it has been desired to develop a composite floor slab having an “equal thickness section” with a flat bottom surface and a uniform thickness throughout.

  A synthetic floor slab that meets the above requirements has recently been proposed with a structure shown in FIG. This composite floor slab 120 is a unit in which the deck plate 9 installed on the beam 110 and the concrete 100 placed on the steel plate 90 of the deck plate 9 are integrated and cooperated. 90 has a structure in which a plurality of webs 91 are integrally formed. In the deck plate 9 as well, the strength against bending in the direction perpendicular to the web 91 having the T-shaped cross section is increased as in the case of the deck plate. The web 91 is provided on the steel plate 90 at regular intervals, and the concrete 100 is cast and filled in each space S formed by being partitioned by the web 91. The web 91 has an overhanging portion 92 at the top, and the concrete 100 cast on the steel plate 90 is fixed to the deck plate 9 and integrated. The web 91 improves the strength of the concrete 100 by restraining the concrete 100 from being deformed by a load (see, for example, Patent Document 1).

JP 2003-239439 A

  In the composite floor slab 120 described in Patent Document 1, the strength of the concrete 100 is improved by integration with the deck plate 9, but when the concrete 100 is placed, as shown in FIG. Therefore, it is difficult to fill the concrete 100 to every corner on the steel plate 90. In particular, the concrete 100 does not reach the base end portion of each web 91, and there is a possibility that a gap is formed, which becomes a factor that hinders the integration of the concrete 100 and the deck plate 9.

  In addition, when the overhanging portion 92 of the web 91 is enlarged in order to increase the contact area with the concrete 100, a gap between the concrete 100 a in the space S and the concrete 100 b on the overhanging portion 92 of the web 91 can be reduced. There is a risk of cracking due to shrinkage. Furthermore, as a result of surplus water in the concrete 100 moving along the respective webs 91, a fragile layer due to moisture may be generated on the surfaces of the respective webs 91 and the steel plates 90. In addition, the concrete 100a in the space S between the webs 91 and 91 can be prevented from being deformed by a load due to the restraining effect of the web 91 in the width direction, but there is no such restraining effect in the length direction. The deformation due to the load cannot be suppressed, and the strength cannot be sufficiently increased.

  In general, the floor structure is bent when a concrete load is applied. However, when high heat is applied to the lower surface of the steel plate 90 in the event of a fire, both the steel plate 90 and the web 91 having a high thermal conductivity become high temperature, and the concrete is also concrete. 100 also heats up and the temperature rises. Since the steel plate 90 and the concrete 100 have the same coefficient of thermal expansion, they both expand in the same way. Since moisture is contained in the concrete 100, they are in close contact until the vaporization temperature of water (100 ° C.) is reached. However, after the concrete 100 reaches 100 ° C., the heat energy transferred from the steel plate 90 is consumed by the moisture vaporization phenomenon in the concrete, and the surface temperature of the concrete 100 stagnates at 100 ° C. Since the temperature continues to rise, a temperature difference occurs between the two, and the steel plate 90 having a large expansion amount moves in a direction of peeling from the surface of the concrete 100. At this point, the integrity of the steel plate 90 and the concrete 100 is loosened.

  When the temperature of the steel plate 90 reaches 200 ° C., a phenomenon called “blue heat embrittlement” occurs, and the steel plate 90 increases in tensile strength but deteriorates in deformation resistance such as elongation. For this reason, the steel plate 90 cannot follow the thermal expansion of the concrete 100, the integrity of the steel plate 90 and the concrete 100 is lost, and the bending caused by the temperature difference between the upper and lower sides of the concrete 100 can withstand only the performance of the cross-sectional shape of the concrete 100. It will be. However, since the concrete 100 has a large heat capacity, the temperature difference between the upper and lower surfaces is reduced, and the difference in expansion amount is eliminated, so that the deflection amount speed on the concrete upper surface is reduced.

This invention has been made in view of the above problems, to provide a formed synthetic floor slab and the concrete which is Da設on the upper surface of the deck plate and the deck plate are integrated, further, normal temperature and An object is to provide a composite floor slab excellent in load resistance during a fire.

A composite floor slab according to the present invention is a composite floor slab formed by integrating a deck plate installed in a row on a beam and concrete placed on an upper surface of the deck plate , the deck plate Is a substrate made of a hot-dip galvanized steel sheet and has a wave shape that vibrates with the same amplitude and the same period on the same plane, and has an upper bent portion, a lower bent portion, and an oblique straight portion between the upper and lower bent portions. A plurality of lattice trusses that form a pair of lattice stripes that form a series of pairs and a lattice stripe and a substrate that are arranged in parallel with each other along the length direction of the substrate at the same height position on the substrate. A first reinforcing bar, and a plurality of second reinforcing bars provided on the plurality of first reinforcing bars so as to be orthogonal to the first reinforcing bar and parallel to each other. The pair of lattice bars are arranged to face each other across the entire length of the first rebar in a posture inclined in opposite directions to both side positions sandwiching the first rebar, and the surface of the substrate is symmetrical with respect to the position of the first rebar. At the position, the protrusions that are paired by bending the substrate diagonally upward and turning back are formed integrally with the substrate over the entire length with an inclination that matches the inclination of the lattice muscle. The lower bent parts of each pair of lattice muscles are welded at the positions of the lower ends of the two linear parts above the bent ends, overlaid on the inner or outer surface of each pair of protrusions. The bent portion is applied to the side of the first reinforcing bar and welded at the position of the upper ends of the two linear portions below the bent end.

  When concrete is placed on the board of the deck plate having the above-described configuration, the solid truss formed by the lattice bars arranged on both sides of the first reinforcing bar is used for the concrete load on the board and the work of workers, etc. Suspend the load to form a strong floor formwork. In addition, there is no wall that obstructs the flow of concrete on the board, so the concrete spreads to every corner of the deck plate and fills the board, leaving no gaps in the placed concrete. Integration with the substrate is not hindered.

  The pair of lattice muscles have a wave shape that vibrates on the same plane with the same amplitude and the same period, and each lower bent portion is welded to the ridge at a position above the bent end, and each upper bent Since the portion is welded to the first reinforcing bar at a position below the bent end, each lattice bar, the first reinforcing bar and the protrusion are firmly connected. A three-dimensional truss is formed by a pair of lattice muscles in the width direction, and a truss having a corrugated shape of each lattice muscle is formed in the length direction. The paired lattice muscles are filled on the substrate. The concrete is restrained from being deformed in the width direction and the length direction by the load, and this restraint effect maintains the integration of the concrete and the deck plate, and increases the strength of the composite floor slab.

  In addition, when high heat is applied to the bottom surface of the board in the event of a fire, the first rebar is fixed deep in the concrete that is not easily affected by high heat from the bottom surface, and a pair of lattices is fixed to the first rebar. Since each lattice is also fixed to the protrusion provided on the substrate, thermal expansion in the length direction and width direction of the substrate is suppressed, and as a result, the integration between the substrate and the concrete is impaired. In other words, the total deformation caused by the deflection of the composite floor slab due to its own weight and loading load and the expansion difference between the upper and lower surfaces of the slab can be suppressed.

  Furthermore, since there is nothing on the substrate that becomes a wall like a conventional web or a width that has a web overhang, cracks may occur due to shrinkage during drying, or excess water in the concrete. There is no risk that a vulnerable layer will be generated.

  In a preferred embodiment of the present invention, each pair of protrusions is formed with an inclination of 60 degrees or more and 80 degrees or less with respect to the surface of the substrate, and more preferably, each pair of protrusions is The angles of inclination are the same.

  In a further preferred embodiment, each pair of protrusions is formed at a height of at least 15 mm from the surface of the substrate.

  In a more preferred embodiment, a protrusion is provided at a portion where the protrusion is welded to the lattice.

  According to this invention, it is possible to form a composite floor slab that is integrated with the concrete cast on the upper surface, and furthermore, it is possible to obtain a composite floor slab that is excellent in load resistance at room temperature and during a fire. .

It is sectional drawing of the synthetic floor slab of one Embodiment. It is a front view which shows one Example of a deck plate. FIG. 3 is a side view of the embodiment of FIG. 2. It is sectional drawing which expands and shows the welding part of a protrusion and a lattice muscle. It is a side view which expands and shows the position of the protrusion formed in a protrusion. It is sectional drawing which expands and shows the welding part of the protrusion and the lattice in another Example. It is a perspective view which shows the state by which the deformation | transformation of concrete is restrained. It is sectional drawing which shows the conventional synthetic floor slab. It is a perspective view which shows the state in which the deformation | transformation of concrete is restrained in the prior art example of FIG.

  FIG. 1 shows a composite floor slab 1 configured by connecting a plurality of deck plates 2 according to an embodiment. Each deck plate 2 is connected in the width direction w to form an assembly structure 20 of the deck plate 2. The assembled structure 20 is supported on the four beams 110 at the outer peripheral ends. Concrete 100 is cast on the upper surface of the assembly structure 20, and the concrete 100 and each deck plate 2 are integrated to form the composite floor slab 1. In the following description, the direction in which the deck plates 2 are connected is referred to as “width direction w”, and the direction orthogonal to the width direction w, that is, the longitudinal direction of the deck plate 2 is referred to as “length direction L”.

As shown in FIG. 2 and FIG. 3, the deck plate 2 is a plated steel plate excellent in corrosion resistance and rust prevention effect, specifically, a hot dip galvanized steel plate and steel strip (JIS G) defined in JIS standards.
3302), a plurality of first reinforcing bars 3 arranged parallel to each other along the length direction L at the same height position on the substrate 21, and the first reinforcing bars 3 for each first reinforcing bar 3. A pair of latticed muscles 4A and 4B that are opposed to each other across the entire length in a posture inclined in opposite directions at both sides of the sandwiched area, and a plurality of first reinforcing bars 3 that are provided in parallel with each other perpendicular to the first reinforcing bars 3 The second rebar 5 is provided.

  The first reinforcing bar 3 and the second reinforcing bar 5 are straight steel materials having a circular cross-sectional shape, and, for example, a deformed steel bar of JIS G3112 standard product is used. The first reinforcing bar 3 and the second reinforcing bar 5 work as a main material of the fixing mechanism for integrating the substrate 21 and the concrete 100, and at the same time, the first reinforcing bar 3 is formed by the lattice bars 4 A and 4 B on both sides and the substrate 21. A triangular three-dimensional truss is constituted, and it plays a role of supporting and suspending the beam as a slab form support until the cast concrete 100 has a predetermined strength. The second rebar 5 plays a role of dispersion and miniaturization of dry shrinkage cracks that are likely to occur when the concrete 100 is not placed so long. In addition, you may use the design lattice of the deformed reinforcement lattice defined in the "welding wire mesh and reinforcement lattice" of JISG3551 for the 2nd reinforcement.

  The lattice muscles 4A and 4B are made of, for example, JIS G3532 standard iron wires, and have a waveform shape that vibrates with the same amplitude and the same cycle along the same planes P1 and P2, respectively. The bent portion 41 on the side and the oblique straight portions 42 and 43 between the upper and lower bent portions 40 and 41 are continuous in series.

  On the surface of the substrate 21, for each position c of the first reinforcing bar 3, pairs of protrusions 22 </ b> A and 22 </ b> B are formed integrally with the substrate 21 over the entire length at positions symmetrical to the position c of the first reinforcing bar 3. ing. A bent portion 41 on the lower side of each pair of lattice muscles 4A and 4B is fixed to the inner surface of each protrusion 22A and 22B by welding. As shown in FIG. 4, each of the protrusions 22 </ b> A and 22 </ b> B is integrally formed with the substrate 21 by bending and folding the substrate 21 obliquely upward. The height h of each protrusion 22A, 22B from the surface of the substrate 21 is set to at least 15 mm (15 mm in this embodiment), but is appropriately determined according to the thickness and inclination of the lattice muscles 4A, 4B. .

  The bent portions 41 on the lower side of the paired lattice muscles 4A and 4B are overlapped with the inner surfaces of the protruding ridges 22A and 22B, respectively, and are positioned above the bent end 41p, that is, the straight portion 42. , 43 are spot welded to the ridges 22A, 22B. Each upper bent portion 40 is applied to the side surface of the first reinforcing bar 3, and the position below the bent end 40p, that is, the upper ends of the linear portions 42 and 43 (indicated by y in FIG. 3) are spot-welded. . Since the strength of the bent end 41p of the lower bent portion 41 of the lattice muscles 4A and 4B and the bent end 40p of the upper bent portion 40 are reduced by bending, the position above the bent end 41p and the bent end 40p Welding is performed at a lower position, thereby maintaining the joint strength at the welding point.

  The inclinations αa and αb of the respective lattice muscles 4A and 4B forming a pair with the inclinations βa and βb of the protrusions 22A and 22B with respect to the substrate 21 respectively coincide (αa = βa, αb = βb). Thus, the outer surface of the lower bent portion 41 of each lattice muscle 4A, 4B is opposed to the inner surface of each protrusion 22A, 22B, and both are surface-joined by welding. The slopes βa and βb of the protrusions 4A and 4B are preferably formed at an angle of 60 degrees or more and 80 degrees or less, more preferably 64 degrees or more and 77 degrees or less with respect to the surface of the substrate 21. In addition, it is desirable that the slopes βa and βb of the two coincide (βa = βb).

  On the inner surface of each protrusion 22A, 22B, as shown in FIG. 5, there is a mountain at the welding site (the position indicated by x in FIG. 4) with the lower bent portion 41 of each lattice 4A, 4B. Molds or hemispherical protrusions 23, 23 are integrally projected. Since the bending end 41p of the lower bent portion 41 of the lattice muscles 4A and 4B has a reduced strength due to bending, each projection 23 is a straight portion 42, 43 above the bent end 41p and has the same height. Formed in position. When the electrode terminal of the welding machine is applied to the lower bent portion 41 of the lattice muscles 4A, 4B and energized, the lower bent portion 41 of the lattice muscles 4A, 4B at the positions of the protrusions 23 becomes the protrusions 22A, 22B. To be welded.

  In the above embodiment, the outer surfaces of the bent portions 41 on the lower side of the respective lattice muscles 4A and 4B that are paired are joined to the inner sides of the pair of protruding ridges 22A and 22B, as shown in FIG. In addition, the inner surface of the lower bent portion 41 of the lattice muscle 4A, 4B may be joined to the outer surface of each protrusion 22A, 22B. In this case, on the outer surface of each protrusion 22A, 22B, The above-described chevron or hemispherical projections 23, 23 are integrally formed.

  When the concrete 100 is placed on the substrate 21 of the assembly structure 20 having the above-described configuration, the three-dimensional truss formed by the lattice bars 4A and 4B arranged on both sides of the first rebar 3 is placed on the substrate 21. Suspend concrete loads and work loads such as workers. Since there is no wall that obstructs the flow of the concrete 100 on the substrate 21, the concrete 100 is filled to the corner of each deck plate 2 and filled in the substrate 21. There is no gap between the substrate 21 and the integration of the concrete 100 and the substrate 21 is not hindered.

  The pair of lattice muscles 4A and 4B has a waveform shape that vibrates on the same plane with the same amplitude and the same period, and the lower bent portions 41 are projected ridges 22A and 22B at positions above the bent ends 41p. Since each upper bent portion 40 is welded to the first rebar 3 at a position below the bent end 40p, each lattice 4A, 4B, the first rebar 3 and the protrusions 22A, 22B are strong. Combined with In the width direction w, a solid truss is formed by the pair of lattice muscles 4A and 4B, and in the length direction L, a truss having a wave shape of each lattice muscle 4A and 4B is formed. The streaks 4A and 4B restrain the concrete 100 filled on the substrate 21 from being deformed in the width direction w and the length direction L by a load, and the concrete 100 and the deck plate 2 are integrated by this restraining effect. Is maintained, and the strength of the composite floor slab 1 is increased.

  FIG. 7 shows a state in which the deformation of the concrete 100 is constrained by the first rebar 3, the lattice bars 4 </ b> A and 4 </ b> B, and the second rebar 5 on the substrate 21. The concrete 100a in the space surrounded by the lattice bars 4A and 4B forming the shape is a shape in which the reinforcing bars are fastened by the reinforcing bars, and the lattice bars 4A and 4B and the second reinforcing bars on the substrate 21 The concrete 100b in the trapezoidal space surrounded by 5 has a shape in which a tag is tightened by these reinforcing bar members.

  Further, since there is no such thing as a conventional web-like wall or a web-like overhanging portion on the substrate 21, cracks may occur due to shrinkage during drying, There is no risk of a fragile layer due to excess water.

  Further, when high heat is applied to the lower surface of the substrate 21 in the event of a fire, the first rebar 3 is fixed deep in the concrete 100 that is not easily affected by the high heat from the lower surface, and a lattice that makes a pair with the first rebar 3. 4A and 4B are fixed, and the lattice muscles 4A and 4B are also fixed to the protrusions 22A and 22B provided on the substrate 21, so that the thermal expansion in the length direction L and the width direction w of the substrate 21 occurs. As a result, the integration between the substrate 21 and the concrete 100 is not impaired, and the total deformation caused by the weight of the composite floor slab 1 and the deflection due to the load and the expansion difference between the upper surface and the lower surface of the slab can be suppressed.

DESCRIPTION OF SYMBOLS 1 Composite floor slab 2 Deck plate 3 1st reinforcement 4A, 4B Lattice reinforcement 5 2nd reinforcement 20 Assembly structure 21 Board | substrate 22A, 22B Projection 23 Projection 41, 42 Bending part 40p, 41p Bending end

Claims (5)

A composite floor slab configured by integrating a deck plate installed in a row on a beam and a concrete placed on the top surface of the deck plate ,
The deck plate is formed of a hot dip galvanized steel plate and has a wave shape that vibrates on the same plane with the same amplitude and the same period, and an oblique straight line between the upper bent portion, the lower bent portion, and the upper and lower bent portions. A triangular three-dimensional truss is composed of lattice lattices that form a pair of consecutive portions, and lattice muscles and substrates that are arranged in parallel with each other along the length of the substrate at the same height on the substrate. A plurality of first reinforcing bars and a plurality of second reinforcing bars that are provided on the plurality of first reinforcing bars so as to be orthogonal to the first reinforcing bars and in parallel with each other, and a pair of lattice bars is provided for each first reinforcing bar. It is oppositely arranged over the entire length in a posture inclined in the opposite direction to both side positions sandwiching one reinforcing bar, and the substrate is bent and folded back obliquely upward at a position symmetrical to the position of the first reinforcing bar on the surface of the substrate. The pair of ridges that are Are formed on the substrate integrally over the entire length with a slope that matches,
The lower bent parts of each pair of lattice muscles are welded at the positions of the lower ends of the two linear parts above the bent ends, overlaid on the inner or outer surface of each pair of protrusions. The bent portion is a composite floor slab that is applied to the side of the first reinforcing bar and welded at the positions of the upper ends of the two linear portions below the bent end. 2. The composite floor slab according to claim 1, wherein each of the protrusions forming a pair is formed with an inclination of 60 degrees or more and 80 degrees or less with respect to the surface of the substrate. The composite floor slab according to claim 1 or 2, wherein each pair of ridges has a matching inclination angle. The composite slab according to any one of claims 1 to 3, wherein each pair of protrusions is formed at a height of at least 15 mm from the surface of the substrate. The composite floor slab according to claim 1, wherein a protrusion is provided at a portion of the protrusion that is welded to the lattice.