JP2006002541A - Joint structure of precast concrete floor slabs - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reinforced concrete floor which is low in cost, reusable, and can be assembled/disassembled in a short construction period. <P>SOLUTION: According to the structure of the reinforced concrete floor, precast concrete floor slabs 2, 2 are arranged on a reinforced concrete beam 3 such that joint ends 2a, 2a thereof are opposed to each other, and a gap between joint end faces 2b, 2b from which dowel reinforcements (projection portions) 4 are projected, is filled with a filler 5. Further a partition plate 1 which is drawable after cure of the filler 5 is interposed between the joint end faces. The partition plate 1 is formed by welding a plurality of round bars serving as a shear key for transmitting a shearing force, to both surfaces of a rectangular plate in parallel with a direction that draws the partition plate 1. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a joint structure for precast concrete slabs.

In the conventional rebuilding of reinforced concrete buildings, all the concrete in existing buildings is finely crushed and discarded, or recycled as part of the material. However, the environment such as saving resources and energy or reducing carbon dioxide emissions. In order to reduce the load, it is preferable to reuse (reuse) the structure as a member rather than crush the structure and recycle it as a material.
However, in cast-in-place reinforced concrete structures, since the concrete is built in one piece, it is difficult to disassemble and reuse in units of members, and even in the case of precast reinforced concrete structures, they are divided into parts for assembly. Although the assembly is assembled, since the joint is integrated, it is still difficult to disassemble and reuse.
On the other hand, in Patent Document 1, in order to easily move the precast concrete plate, adjust the height during installation, connect the plate to the plate, and inject grout, a connecting jig is embedded in the end of the precast concrete plate and precast with bolts. An invention for joining concrete plates together is disclosed.
Japanese Patent Laid-Open No. 9-100503 (page 3-4, FIG. 2)

However, in the case of the invention described in Patent Document 1, there is a problem that the initial cost of the precast concrete plate becomes very high because it is necessary to embed a connecting jig in the end portion of the precast concrete plate.
The present invention has been made in view of the above-described problems, and an object thereof is to provide a reusable reinforced concrete floor that can be assembled and disassembled at a low cost and in a short construction period.

In order to achieve the above object, in the joint structure of precast concrete floor slabs according to the present invention, the precast concrete floor slabs having projecting portions on joint end surfaces are joined together on a beam, and the precast concrete facing each other A filler is filled between the joining end faces of the floor slab, and a partition plate that can be pulled out after the filler is cured is interposed.
In this invention, since the filler is filled between the joining end surfaces which have a protrusion part, the shear force and compressive force between precast concrete slabs can be transmitted. In addition, because a partition plate that can be pulled out after the filler is hardened is inserted between the joint end faces, if the partition plate is pulled out by using a drawing device such as a jack, the precast concrete slab can be easily disassembled and reused. be able to. This makes it possible to assemble and dismantle a reinforced concrete floor as a reusable member at a low cost and in a short construction period.
In addition, according to the present invention, no rolling work is involved when the floor is dismantled, so that noise and dust are not generated.

Further, in the joint structure of the precast concrete floor slab according to the present invention, the precast concrete floor slab having a protruding portion on the joint end face is joined to the side surface of the beam, and the joint end face of the precast concrete floor slab and the above A filler is filled between the side surfaces of the beam, and a partition plate that can be pulled out after the filler is cured is interposed.
In the present invention, the floor height can be kept low by joining a precast concrete floor slab having a protruding portion on the joining end face to the side face of the beam. In addition, the precast concrete slab can be easily disassembled by pulling out the partition plate by inserting a detachable partition plate between the joint end face of the precast concrete slab and the side of the beam and filling the filler. And can be reused.

Moreover, in the joining structure of the precast concrete floor slab which concerns on this invention, it is preferable that the said partition plate has the shear key arrange | positioned in parallel with the drawing-out direction of the said partition plate on the surface.
In the present invention, a shear force can be transmitted between precast concrete slabs by providing a shear key on the surface of the partition plate. Further, by arranging the shear key parallel to the drawing direction of the partition plate, the shear key does not become an obstacle when the partition plate is pulled out, and the partition plate can be easily pulled out.

Further, in the precast concrete slab joining structure according to the present invention, it is preferable that the partition plate has an extraction hole at an upper end portion or a lower end portion thereof.
Here, the upper end portion refers to an end portion that is on the upper side when the partition plate is interposed between the joining end surfaces, and the lower end portion is an end that is on the lower side when the partition plate is interposed between the joining end surfaces. Refers to the part.
In the present invention, a hole for extraction is provided in the upper end portion or the lower end portion of the partition plate, so that the hook can be hooked in the hole and pulled out using a pulling device such as a jack.
In addition, an internal thread part may be formed in the extraction hole, an eyebolt or the like may be attached to the internal thread part, and the eyebolt may be used for extraction.

Moreover, in the joining structure of the precast concrete slab according to the present invention, the partition plate may have a tapered shape in which the thickness gradually decreases from the upper end portion toward the lower end portion.
In the present invention, since the partition plate has a tapered shape in which the thickness gradually decreases from the upper end portion toward the lower end portion, the partition plate can be easily pulled out.

  Moreover, in the joining structure of the precast concrete floor slab which concerns on this invention, the said protrusion part may be a rod-shaped member which protrudes from the said joining end surface, and may be the shear cotter formed in the convex shape on the said joining end surface.

  According to the present invention, a reusable reinforced concrete structure that can be assembled and disassembled at a low cost and in a short period of time by filling a filler by inserting a detachable partition plate between joint end faces of a precast concrete slab. Floor can be realized.

DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment of a precast concrete slab joining structure according to the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view showing a first embodiment of a precast concrete slab joining structure according to the present invention.
As shown in FIG. 1, in this embodiment, joint ends 2 a and 2 a of precast concrete floor slabs 2 and 2 are arranged opposite to each other on a reinforced concrete beam 3, and dowel bars (projecting portions) 4 protrude. Between the joining end faces 2b and 2b to be filled, a filler 5 is filled, and a partition plate 1 that can be pulled out after the filler 5 is cured is inserted.

FIG. 2 shows the shape of the partition plate 1, (a) is a plan view, (b) is an elevation view, and (c) is a side view. FIG. 3 is a perspective view of the partition plate 1.
The partition plate 1 is formed by welding a plurality of round steels 1b... Serving as a shear key for transmitting a shearing force to both surfaces of a rectangular flat plate 1a. The plurality of round bars 1b are welded in parallel with the drawing direction P of the partition plate 1. When the partition plate 1 is pulled out, the round bar 1b does not become an obstacle, and the partition plate 1 can be easily pulled out. It can be done.
A hole 1c penetrating the flat plate 1a is provided at the upper end portion of the partition plate 1, and a hook can be hooked into the hole 1c to be pulled out using a pulling device (not shown) such as a jack.
The length of the partition plate 1 is set to such a length that the drawing operation can be performed without difficulty, and is arranged over the entire length of the joining end portion 2a of the precast concrete floor slab 2. This is because if the partition plate 1 is too long, the pulling force required for pulling out the partition plate 1 becomes too large, and if the partition plate 1 is too short, the number of times of drawing increases and the labor of construction increases.
If it is not necessary to transmit shearing force between the precast concrete slabs 2 and 2 depending on the design conditions, the partition plate 1 having a smooth surface without a shear key may be used.

The dowel bar 4 as the projecting portion only needs to be able to transmit a shearing force, and may be a deformed bar, a stud with a head, a reinforcing bar having an enlarged diameter part at the end, a bar made of FRP, a steel plate, or the like.
Moreover, it replaces with the dowel bar | burr 4, and you may form a convex shear cotter in the joining end surface 2b, or the steel plate which has a shear cotter may adhere to the joining end surface 2b.

  As the filler 5, concrete, fiber reinforced concrete, non-shrink mortar, expanded mortar, or the like can be used. The filler 5 has a strength capable of transmitting shearing force and compressive force between the precast concrete slabs 2 and 2, and a partition plate. Any material that does not become an obstacle when pulling out 1 can be used.

  When dismantling the floor, the partition plate 1 is pulled out of the floor using a drawing device (not shown). If it does so, the clearance gap for the thickness of the partition plate 1 will be made between the adjacent precast concrete floor slabs 2 and 2, and the precast concrete floor slabs 2 and 2 will be isolate | separated completely. Therefore, if the precast concrete floor slab 2 and the beam 3 are not joined, the precast concrete floor slab 2 can be removed simply by pulling out the partition plate 1. The removed precast concrete floor slab 2 is transported to a site yard or a factory, and the filler 5 adhering to the joining end surface 2b is removed and reused.

In the joint structure of the precast concrete floor slab according to the present embodiment, the filler 5 is filled between the joint end faces 2b and 2b having the dowel bars 4, so that the shear force and the compressive force between the precast concrete floor slabs 2 and 2 are increased. Can communicate. Moreover, since the partition plate 1 which can be pulled out after hardening of the filler 5 is inserted between the joining end surfaces 2b and 2b, if the partition plate 1 is pulled out using a pulling device such as a jack, the precast concrete floor slab 2 is removed. It can be easily disassembled and reused. This makes it possible to assemble and dismantle a reinforced concrete floor as a reusable member at a low cost and in a short construction period.
In addition, in the joint structure of the precast concrete slabs according to the present embodiment, no noise or dust is generated because no rolling work is involved when the floor is dismantled.

Next, another embodiment of the precast concrete slab joining structure according to the present invention will be described with reference to FIGS.
In the second embodiment shown in FIG. 4, the side face 13b of the reinforced concrete beam 13 is partially increased to form the increased hitting portion 13a, and the joint end of the precast concrete slab 12 is placed on the increased hitting portion 13a. The part 12a is placed. The filler 15 is filled between the joint end surface 12b of the precast concrete floor slab 12 and the side surface 13b of the beam 13 from which the dowel bar 14 protrudes, and the partition plate 11 that can be pulled out after the filler 15 is cured is interposed. Inserted. Thereby, the floor height can be kept low.

  The third embodiment shown in FIG. 5 is a form in which the first embodiment and the second embodiment are compromised, and a notch 23a is formed on the upper side surface of the reinforced concrete beam 23, and the precast concrete is formed. A notch 22 c is provided on the lower surface of the joint end 22 a of the floor slab 22, and the notch 22 c of the precast concrete slab 22 is fitted and placed on the notch 23 a of the beam 23. As a result, it is not necessary to increase the number of side faces of the beam 23, and the floor height can be suppressed to some extent.

  In the fourth embodiment shown in FIG. 6, a headed stud 36 is projected from the upper surface 33 a of the reinforced concrete beam 33 between the joint end faces 32 b of the precast concrete floor slabs 32, 32. The partition plates 31 and 31 are inserted on both sides. Thereby, the precast concrete floor slabs 32 and 32 and the beam 33 can be integrated.

  In the fifth embodiment shown in FIG. 7, the partition plate 41 is obliquely installed so as to have a predetermined angle with respect to a vertical plane parallel to the material axis of the reinforced concrete beam 43. Thereby, when the precast concrete slab 42 'is first lifted and decomposed, it can be dismantled more smoothly.

Next, another shape of the partition plate will be described with reference to FIGS.
The partition plate 10 shown in FIG. 8 (a) is obtained by welding a steel plate 10b as a shear key to both surfaces of a rectangular flat plate 10a having an extraction hole 10c at the upper end.
The partition plate 20 shown in FIG. 8B is obtained by integrally forming ribs 20b on the surface of a rectangular flat plate 20a.
Moreover, although not shown in figure, the partition plate in which steel plate itself became folded plate shape may be sufficient.

The partition plate 30 shown in FIG. 9A includes a hole 30 c in which an internal thread portion is formed in the upper end surface 30 d of the partition plate 30. Thereby, an eyebolt etc. can be attached to the hole 30c and the partition plate 30 can be pulled out using the eyebolt.
The partition plate 40 shown in FIG. 9B has a tapered shape in which the cross section gradually decreases from the upper end surface 40d of the partition plate 40 toward the lower end surface 40e, and the partition plate 40 can be easily pulled out.

  As mentioned above, although embodiment of the joining structure of the precast concrete floor slab which concerns on this invention was described, this invention is not limited to said embodiment, In the range which does not deviate from the meaning, it can change suitably. For example, the beam is not limited to a reinforced concrete beam, and may be a steel beam. It is also possible to combine the various embodiments described above.

It is sectional drawing which shows 1st embodiment of the joining structure of the precast concrete floor slab which concerns on this invention. The shape of a partition plate is shown, (a) is a top view, (b) is an elevation view, and (c) is a side view. It is a perspective view of a partition plate. It is sectional drawing which shows 2nd embodiment of the joining structure of the precast concrete floor slab which concerns on this invention. It is sectional drawing which shows 3rd embodiment of the joining structure of the precast concrete floor slab which concerns on this invention. It is sectional drawing which shows 4th embodiment of the joining structure of the precast concrete floor slab which concerns on this invention. It is sectional drawing which shows 5th embodiment of the joining structure of the precast concrete floor slab which concerns on this invention. It is a perspective view of the partition plate which has another shape. It is a perspective view of the partition plate which has another shape.

Explanation of symbols

1, 10, 11, 20, 21, 30, 31, 40, 41 Partition plate 2, 12, 22, 32, 42 Precast concrete floor slab 3, 13, 23, 33, 43 Beam 4, 14, 24, 34, 44 Dowels (projection)
5, 15, 25, 35, 45 Filler

Claims (7)

It is a structure in which precast concrete floor slabs having protruding portions on the joining end faces are joined on the beam,
A joining structure for precast concrete floor slabs, wherein a filler is filled between opposing joint end faces of the precast concrete floor slab, and a partition plate that can be pulled out after the filler is cured is inserted. A precast concrete floor slab having a protruding portion on the joining end face is joined to the side of the beam,
A precast concrete floor, wherein a filler is filled between a joint end surface of the precast concrete floor slab and a side surface of the beam, and a partition plate that can be pulled out after the filler is cured is inserted. Plate joint structure.   The joint structure for precast concrete slabs according to claim 1, wherein the partition plate has a shear key disposed on a surface thereof in parallel with a drawing direction of the partition plate.   The precast concrete floor slab joining structure according to any one of claims 1 to 3, wherein the partition plate is formed with a hole for extraction at an upper end portion or a lower end portion thereof.   5. The precast concrete slab joining structure according to claim 1, wherein the partition plate has a tapered shape in which a thickness gradually decreases from an upper end portion toward a lower end portion.   6. The precast concrete slab joining structure according to claim 1, wherein the projecting portion is a bar-like member projecting from the joining end face.   6. The precast concrete slab joining structure according to claim 1, wherein the projecting portion is a sheacotter formed in a convex shape on the joining end face.

Images