JP4461424B2 - Precast slab, installation method and disassembly method of precast slab - Google Patents

Description

  The present invention relates to a precast slab installed between steel beams, an installation method thereof, and a disassembly method thereof.

  In general, when building a steel structure building, the slab of the building is formed by a deck slab method in which a deck plate is laid between the assembled steel beams and concrete is placed on the deck plate. There are many cases. In the case of this construction method, a stud bolt or the like is welded to the upper surface of the flange of the steel beam, and the combined effect of the steel beam and the concrete portion of the slab is increased to integrate the steel beam and the slab.

In recent years, a precast slab method for forming a slab of a steel structure building using a precast slab member has been provided. This method is a method in which a precast slab member manufactured in advance in a factory or the like is bridged between steel beams, the precast slab member and the steel beam are rigidly joined, and a precast slab composed of the precast slab member is formed between the steel beams. Conventionally, as a structure for joining a precast slab member and a steel beam, a stud bolt welded to the upper surface of the flange of the steel beam is inserted into a hole formed at the end of the precast slab member, and a non-shrink mortar is inserted into the hole. There is a structure of filling and fixing (for example, see Patent Document 1).
JP-A-9-32171

  However, with the above-mentioned conventional deck slabs and precast slabs equipped with conventional joint structures, when demolishing a building, the slabs and steel beams are damaged using demolition heavy machinery, etc. There is a problem that occurs. Further, when dismantling, temporary equipment such as a soundproof / dustproof panel for preventing dust diffusion and noise is required in addition to a heavy machine for dismantling, which causes a problem that construction costs increase. Furthermore, since a large amount of industrial waste remains after dismantling, there is a problem that it has a large impact on the environment and a considerable cost for disposal of waste.

  The present invention takes the above-described conventional problems into consideration, and can reduce dust and noise at the time of dismantling as well as reduce the influence on the environment, and can further reduce costs. It aims at providing the installation method and dismantling method of a slab.

The invention according to claim 1 is a precast slab laid between steel beams, and is bridged between the steel beams and above a flange of the steel beams or an overhanging plate joined to the flanges. A precast plate member having a hole formed at a position thereof, a filler filled in the hole, an upper end fixed in the filler, and a lower end formed in the flange or the projecting plate A connecting member that is inserted through the hole and fastened by the fastening means is provided.
By such a feature, the precast plate member and the steel beam are separated by removing the fastening means and removing the filler and the connecting member from the hole.

According to a second aspect of the present invention, in the precast slab according to the first aspect, a pipe member is embedded in the precast plate member, and the hole is formed by the pipe member.
Due to such a feature, a hole is formed which has a smooth inner peripheral surface and can be easily extracted.

According to a third aspect of the present invention, in the precast slab according to the second aspect, a fixing member that is fixed in the precast plate member is joined to the pipe member.
With such a feature, the pull-out resistance of the pipe member embedded in the precast plate member to the precast plate member is improved.

The invention according to claim 4 is the precast slab according to any one of claims 1 to 3, wherein reinforcing bars for reinforcing the precast plate member around the hole are arranged in the precast plate member. Yes.
Due to these characteristics, the precast plate member around the hole where a large stress is generated by the difference in the inertial force of the floor and the shearing force between the frames during the earthquake acts as the shearing force in the floor surface is reinforced by the reinforcing bars. The

The invention according to claim 5 is the precast slab installation method according to any one of claims 1 to 4, wherein the fastening member is fastened to the flange or the projecting plate by the fastening means, and the connecting member. A step of bridging the precast plate member in which the pipe member is embedded between the steel beams, and a step of filling the pipe member with the filler so that an upper end portion of the pipe member is disposed in the pipe member. It is characterized by providing.
With such a feature, when the precast slab is assembled between the steel beams, the precast plate member and the steel beam are easily rigidly joined.

The invention according to claim 6 is a method of disassembling the precast slab according to any one of claims 1 to 4, wherein the step of removing the fastening means for fastening the connecting member to the flange or the projecting plate; And a step of extracting the filler formed integrally with the connecting member from the inside of the pipe member.
With such a feature, the precast plate member and the steel beam are separated from each other without damaging the precast plate member and the steel beam.

  According to the precast slab and the disassembling method thereof according to the present invention, the precast slab includes a precast plate member in which a hole is formed, a filler filled in the hole, and an upper end portion fixed in the filler and a lower end portion. And a connecting member to be fastened by the fastening means, and the precast slab is disassembled by the step of removing the fastening means and the step of extracting the filler and the connecting member from the hole, so that the precast plate member and the steel beam The precast plate member and the steel beam can be separated without damaging them, and can be disassembled without reducing the generation of dust and noise. As a result, it is not necessary to use a soundproof / dustproof panel or the like for the temporary facilities at the time of dismantling, and the cost can be reduced. In addition, precast plate members and steel beams after dismantling will not be damaged, so reusing them can significantly reduce the amount of industrial waste due to dismantling, reducing the environmental impact and waste disposal costs. Can do.

  Further, according to the precast slab installation method of the present invention, the step of fastening the connecting member to the steel beam by the fastening means, the step of bridging the precast plate member between the steel beams, and filling the tube member with the filler. Since the precast slab is formed between the steel beams by the process, the precast plate member and the steel beam are easily rigidly joined, and the work at the time of assembling the precast slab can be reduced.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a precast slab, a precast slab installation method, and a disassembly method according to the present invention will be described with reference to the drawings.

[First Embodiment]
First, the configuration of the precast slab 1 in the first embodiment will be described.
FIG. 1 is a cross-sectional view showing a precast slab 1. As shown in FIG. 1, the precast slab 1 is laid between steel beams 2 arranged in parallel at intervals, and is spanned between the steel beams 2 so that pipe members 4 are embedded at four corners. The precast plate member 3, the filler 5 filled in the tube member 4, and the connecting member 6 whose upper end is fixed in the filler 5 and whose lower end is fastened to the upper flange 2a of the steel beam 2 It consists of and.

  FIG. 2 is a plan view of the precast plate member 3, and FIG. 3 is a cross-sectional view taken along the line A-A shown in FIG. As shown in FIGS. 1, 2, and 3, the precast plate member 3 is made of reinforced concrete, and has a concrete portion 7 formed into a rectangular shape and a reinforcing material embedded entirely in the concrete portion 7. 8 and a pipe member 4 embedded in four corners. Reinforcing bar material 8 includes a slab bar 9 in which main bars and distribution bars are arranged in a grid in two upper and lower stages, a U-shaped end bar 10 that covers the end of the two-stage slab bar 9, and a precast plate member. 3 and peripheral muscles 11 arranged in two steps along the outer periphery. The bar arrangement pitch at the four corners of the slab bar 9 is shorter than the other intermediate sections.

  The pipe member 4 has a cylindrical shape with a square section extending in the vertical direction, and the upper and lower end surfaces of the pipe member 4 are formed flush with the upper surface 3a and the bottom surface 3b of the precast plate member 3, respectively. In the precast plate member 3, a hole 12 penetrating up and down of the precast plate member 3 is formed at a position located above the flange 2 a of the steel beam 2. The pipe member 4 is disposed outside the reinforcing bar 8, and two side faces 4 a of the four side faces of the pipe member 4 are joined to the concrete part 7, and the remaining side faces are formed flush with the end face of the concrete part 7. Has been exposed. The two side surfaces 4a in contact with the concrete portion 7 of the pipe member 4 are slightly inclined, and the pipe member 4 is formed in a wedge shape in which the inner diameter of the upper part is larger than the inner diameter of the lower part.

  Further, fixing members 13 made of steel bars or the like are welded to the side surfaces 4a of the two pipe members 4 in two upper and lower stages. The fixing member 13 is bent in a square shape so that one end thereof is shorter than the other end, and the one end is disposed horizontally along the side surface 4a of the tube member 4 and welded to both sides of the side surface 4a. The other end extends in a direction of 45 degrees obliquely to the slab bar 9 (one of the main bar and the distribution bar) and is fixed in the concrete portion 7.

  The filler 5 is filled up to the upper end surface of the pipe member 4 (hole 12), and is formed flush with the upper surface 3a of the precast plate member 3, respectively. The filler 5 is made of, for example, a non-shrink mortar, and is a liquid that is excellent in fluidity and is evenly filled in the holes 12 when filled, and has a predetermined strength after solidification. It is solid in shape. The solidified filler 5 and the inner peripheral surface of the pipe member 4 are joined by a predetermined frictional force.

  FIG. 4 is an enlarged cross-sectional view of a joint portion between the precast plate member 3 and the steel beam 2. As shown in FIG. 4, the connecting member 6 is composed of a long bolt with a head (nut) at the upper end, and the lower end of the connecting member 6 is a through hole 14 formed in the upper flange 2 a of the steel beam 2. The steel frame 2 is inserted into the upper flange 2 a of the steel beam 2 by fastening means 15. The fastening means 15 includes an upper nut 16 and an upper washer 17 that are arranged above the upper flange 2a and screwed to the connecting member 6, and a lower side that is arranged below the upper flange 2a and screwed to the connecting member 6. It consists of a nut 18 and a lower washer 19. The upper nut 16 and the upper washer 17 are embedded in the filler 5, and the filler 5, the connecting member 6, the upper nut 16 and the upper washer 17 are integrally formed. The lower nut 18 and the lower washer 19 can be removed by rotating the lower nut 18, and the lower nut 18 is fastened with a predetermined fastening force.

Next, the installation method of the precast slab 1 which consists of an above-described structure is demonstrated.
First, the process which manufactures the precast plate member 3 in a factory etc. is performed. Specifically, as shown in FIG. 5, a bottom mold 20 having a smooth surface is installed horizontally, and a side mold 21 is built on the bottom mold 20. The bottom mold 20 is made of a material that is not altered or deformed by concrete, and a material that can be easily separated from the concrete is used. Next, the reinforcing bars 8 shown in FIGS. 2 and 3 are arranged on the bottom mold 20, and the pipe members 4 are set at the four corners. At this time, the slab muscle 9 shown in FIGS. 2 and 3 arranges the upper and lower muscles upside down and the pipe member 4 is arranged with the large diameter side down, and the bottom mold 20 side is the precast plate. Assemble the upper surface 3a of the member 3. Further, when the concrete is placed, the pipe member 4 is fixed so as not to be washed away, and the end on the small diameter side is covered so that the concrete does not enter the pipe member 4. Further, the fixing member 13 is welded in advance to the side surface 4 a of the pipe member 4. Next, fresh concrete is placed in the molds 20 and 21, and the concrete part 7 is leveled to a predetermined thickness. At this time, it is not necessary to hold down the upper surface of the placed concrete. Thereafter, the bottom mold 20 and the side mold 21 are removed after a predetermined curing period. A smooth bed may be used instead of the bottom mold 20.

  On the other hand, at the site, as shown in FIG. 4, a process of fastening the connecting member 6 to the upper flange 2 a of the steel beam 2 by the fastening means 15 is performed before or after the steel frame is built. Specifically, the connecting member 6 in which the upper nut 16 is screwed to the intermediate portion and the upper washer 17 is fitted is inserted into the through hole 14 formed in the upper flange 2a from above the upper flange 2a. To do. Then, the lower nut 18 and the lower washer 19 are attached to the lower end portion of the connecting member 6 that is inserted through the through hole 14 and protrudes downward from the upper flange 2a, and the lower nut 18 is tightened so that the lower nut 16 and the lower nut 18 are tightened. The upper flange 2a is sandwiched between the side nuts 18 and the connecting member 6 is fixed.

  Next, as shown in FIG. 6, the manufactured precast plate member 3 is carried into the field, and the precast plate member 3 is bridged between the assembled steel beams 2. Specifically, after the molds 20 and 21 are removed, the precast plate member 3 is inverted so that the bottom mold 20 side is up by being lifted by a crane or the like. Since the lower surface at the time of placing the concrete becomes the upper surface of the precast plate member 3, the smooth upper surface 3a can be formed without performing the finishing operation. Next, the precast plate member 3 is lifted with a crane or the like and is bridged between the steel beams 2 on site. At this time, the precast plate member 3 is aligned so that the upper end portion of the connecting member 6 fastened to the upper flange 2a of the steel beam 2 is disposed in the pipe member 4 embedded in the precast plate member 3, When the connecting member 6 and the pipe member 4 face each other vertically, the precast plate member 3 is lowered straight down.

Next, as shown in FIG. 1, a process of filling the filler 5 into the pipe member 4 (hole 12) is performed. Specifically, the liquefied filler 5 is poured into the hole 12 until it is flush with the upper surface 3 a of the precast plate member 3. Then, the filler 5 is solidified after a curing period and the upper end portion of the connecting member 6 is fixed in the filler 5.
By solidifying the filler 5, the precast plate member 3 and the steel beam 2 are rigidly joined, and the assembly process of the precast slab 1 is completed.

Next, a method for disassembling the precast slab 1 having the above configuration will be described.
First, as shown in FIG. 4, the process of removing the fastening means 15 which fastens the connecting member 6 to the upper flange 2a of the steel beam 2 is performed. Specifically, the lower nut 18 tightened below the upper flange 2a is rotated and loosened using a tool (not shown). Then, the lower nut 18 and the lower washer 19 are respectively removed from the lower end portion of the connecting member 6.

Next, as shown in FIG. 1, a step of extracting the filler 5 formed integrally with the connecting member 6 from the pipe member 4 is performed. Specifically, the lower end portion of the connecting member 6 from which the lower nut 18 and the lower washer 19 are removed is hit vertically upward with a not-shown hammer. When the connecting member 6 is pushed upward, the connecting member 6 inserted into the through hole 14 comes out of the through hole 14, and the filler 5 in the tube member 4 solidified in a wedge shape is integrated with the connecting member 6. Jump out upward. At this time, the upper nut 16 and the upper washer 17 embedded in the filler 5 are removed together with the filler 5.
Finally, the precast plate member 3 from which the filler 5 and the connecting member 6 have been removed is lifted by a crane or the like, and the precast plate member 3 is removed from between the steel beams 2. This completes the dismantling of the precast slab 1.

  According to the precast slab 1 having the above-described configuration and the disassembling method thereof, the precast plate member 3 and the steel beam 2 are separated without damaging the precast plate member 3 and the steel beam 2. And noise generation can be reduced. As a result, it is not necessary to use a soundproof / dustproof panel or the like for temporary facilities at the time of dismantling, and the cost of dismantling work can be reduced. Further, since the disassembled precast plate member 3 and the steel beam 2 are not damaged, they can be reused. As a result, industrial waste generated at the time of dismantling can be remarkably reduced, the impact on the environment can be reduced, and waste disposal costs can be reduced to reduce costs.

  Further, when the inner peripheral surface of the hole 12 is rough, an unnecessary frictional force is generated between the inner peripheral surface of the hole 12 and the solidified filler 5, and the filler 5 solidified from the hole 12 during disassembly. However, in the precast slab 1 having the above-described configuration, the pipe member 4 is embedded in the precast plate member 3 and the hole 12 is formed by the pipe member 4. A smooth hole 12 is formed. Thereby, the solidified filler 5 in the hole 12 can be reliably extracted.

  Further, since the fixing member 13 that is fixed in the precast plate member 3 is joined to the pipe member 4, the pulling resistance of the tube member 4 embedded in the precast plate member 3 is improved. Thereby, the pipe member 4 and the precast plate member 3 are firmly integrated, and the pipe member 4 together with the filler 5 is precast when the solidified filler 5 is extracted from the pipe member 4 by hitting the connecting member 6. The escape from the plate member 3 can be prevented.

  Moreover, according to the installation method of the precast slab 1 which consists of an above-described structure, the precast plate member 3 and the steel beam 2 are easily rigidly joined, and the work at the time of the assembly of the precast slab 1 can be reduced. Thereby, the construction period of the construction work of the structure using the precast slab 1 can be shortened.

[Second Embodiment]
Next, the configuration of the precast slab 50 in the second embodiment will be described.
FIG. 7 is a plan view of the precast plate member 51, and FIG. 8 is a cross-sectional view taken along the line BB shown in FIG. As shown in FIGS. 7 and 8, a tube member 53 having a circular cross section for forming the hole 60 is embedded in the precast plate member 51. The pipe member 53 has a wedge shape whose diameter increases upward, and is disposed inside the reinforcing bar material 54 of the precast plate member 51, and the outer peripheral surface of the pipe member 53 is connected to the concrete portion 55 of the precast plate member 51. It is joined.

  A U-shaped reinforcing bar 56 that reinforces the periphery of the pipe member 53 is embedded in the precast plate member 51. The reinforcing bars 56 are bent along the outer peripheral surface of the pipe member 53, and both end parts extend toward the center position of the precast plate member 51, and are formed so as to surround the pipe member 53. Yes.

  FIG. 9 is a perspective view of a joint portion between the precast plate member 51 and the steel beam 52. As shown in FIG. 9, an overhanging plate 57 protruding from the side surface of the upper flange 52 a toward the inside of the steel beam 52 is joined to the upper flange 52 a of the steel beam 52. The upper flange 52a is firmly joined by welding. A through hole (not shown) is formed in the overhanging plate 57, and the lower end portion of the connecting member 58 is inserted into the through hole 14, and the connecting member 58 is fastened to the overhanging plate 57 by the fastening means 59. Yes. In addition, you may join the overhang | projection board 57 and the upper side flange 52a with a volt | bolt.

  According to the precast slab 50 having the above-described configuration, since the reinforcing bars 56 that reinforce the periphery of the pipe member 53 are arranged in the precast plate member 51, the inertial force and the frame of the precast slab 50 in the event of an earthquake are arranged. The precast plate member 51 around the pipe member 53 in which a large stress is generated by the difference in shearing force acting as an in-floor shearing force is reinforced by the reinforcing bars 56. Accordingly, the rigidity and strength of the joint portion (around the pipe member 53) of the precast plate member 51 joined to the steel beam 52 can be increased, and the rigidity of the entire structure including the precast slab 50 in the horizontal plane. And the strength can be increased.

  Further, since the overhanging plate 57 is joined to the upper flange 52a of the steel beam 52 and the connecting member 58 is attached to the overhanging plate 57, the connecting member is formed without forming a through hole in the upper flange 52a of the steel beam 52. 58 can be provided.

  The embodiments of the precast slab, the precast slab installation method and the disassembly method according to the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and may be appropriately selected within the scope of the present invention. It can be changed. For example, in the first embodiment described above, a non-shrink mortar is used for the filler 5, but the present invention uses a granular steel ball for the filler 100 as shown in FIG. Also good. When a steel ball is used for the filler 100, a bolt without a head (nut) is used for the connecting member 102, and the upper end portion of the connecting member 102 is placed in the pipe member 104 embedded in the precast plate member 103. After the precast plate member 103 is bridged between the steel beams 101 so as to be arranged, the filler 100 made of steel balls is packed into the pipe member 104. The filler 100 is kept for about the eighth minute without filling the pipe member 104 to the full. Then, a steel lid 105 is placed on the filler 100 packed in the pipe member 104, and then a nut 106 is screwed onto the upper end portion of the connecting member 102, and the lid 105 is tightened from above by the nut 106. . As a result, the lid 105 becomes a restraining material for the filler 100 made of steel balls, and the filler 100 is restrained so as not to come out and move, and the force can be transmitted to the connecting member 102 and the precast plate member 103. it can. Moreover, since the filler 100 and the connecting member 102 made of steel balls can be reused, no waste is generated after the precast slab dismantling.

  Further, in the first embodiment described above, a steel bar bent in a letter shape is used for the fixing member 13, and one end portion of the fixing member 13 is disposed horizontally along the side surface 4 a of the tube member 4. Although both sides are welded to the side surface 4a, as shown in FIG. 11, in the present invention, one end portion of the fixing member 200 is further bent and vertically arranged along the side surface 201a of the tube member 201 to the side surface 201a. Both sides may be welded. Further, in the present invention, as shown in FIG. 12, a fixing member 211 made of a stud bolt may be welded to the side surface 210 a of the tube member 210. Further, in the above-described embodiment, the fixing member 13 is provided in two upper and lower stages, but the present invention may have one or three stages.

  Further, in the above-described second embodiment, the reinforcing bar 56 is formed in a U-shape. However, in the present invention, an L-shaped reinforcing bar may be arranged around a pipe member or a hole, Peripheral bars arranged along the outer periphery of the precast plate member may be used as reinforcing bars.

  In the second embodiment described above, the hole 60 formed in the precast plate member 51 is formed by the pipe member 53. However, the present invention cuts the concrete portion of the precast plate member into a wedge shape. Holes may be formed, or surface treatment may be performed so that the inner peripheral surface of the hole is smooth, and processing may be performed so that the filler can be easily extracted.

It is sectional drawing of the precast slab for demonstrating 1st Embodiment of the precast slab which concerns on this invention, the installation method of a precast slab, and the dismantling method. It is a top view of the precast plate member for demonstrating 1st Embodiment of the precast slab which concerns on this invention, the installation method of a precast slab, and the dismantling method. It is sectional drawing of the precast plate member for demonstrating 1st Embodiment of the precast slab which concerns on this invention, the installation method of a precast slab, and the dismantling method. It is a fragmentary sectional view for explaining a 1st embodiment of a precast slab concerning the present invention, a setting method of a precast slab, and a dismantling method. It is a manufacture state figure of the precast plate member for explaining the 1st embodiment of the precast slab concerning the present invention, the installation method of a precast slab, and the dismantling method. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of a precast plate member for explaining a first embodiment of a precast slab, a precast slab installation method and a disassembly method according to the present invention. It is a top view of the precast plate member for demonstrating 2nd Embodiment of the precast slab which concerns on this invention, the installation method of a precast slab, and the dismantling method. It is sectional drawing of the precast plate member for demonstrating 2nd Embodiment of the precast slab which concerns on this invention, the installation method of a precast slab, and the dismantling method. It is a fragmentary perspective view for demonstrating 2nd Embodiment of the precast slab which concerns on this invention, the installation method of a precast slab, and the disassembly method. It is a fragmentary sectional view for demonstrating other embodiment of the precast slab which concerns on this invention, the installation method of a precast slab, and the disassembly method. It is a fragmentary perspective view for demonstrating other embodiment of the precast slab which concerns on this invention, the installation method of a precast slab, and the disassembly method. It is a fragmentary perspective view for demonstrating other embodiment of the precast slab which concerns on this invention, the installation method of a precast slab, and the disassembly method.

Explanation of symbols

2,52,101 Steel beam 1,50 Precast slabs 2a, 52a, 101a Upper flange (flange)
57 Overhang plate 12, 60 Hole 3, 51, 103 Precast plate member 5, 100 Filler 15, 59 Fastening means 6, 58, 102 Connection member 4, 53, 104, 201, 210 Pipe member 13 Fixing member 56 Reinforcing bar

Claims (6)

It is a precast slab erected between steel beams,
A precast plate member spanned between the steel beams and having a hole formed at a location located above the flange of the steel beam or an overhanging plate joined to the flange;
A filler filled in the hole;
An upper end portion is fixed in the filler, and a lower end portion is inserted into a through hole formed in the flange or the projecting plate, and a connecting member fastened by fastening means is provided. Precast slab to do. In the precast slab according to claim 1,
A pipe member is embedded in the precast plate member, and the hole is formed by the pipe member. In the precast slab according to claim 2,
A fixing member for fixing in the precast plate member is joined to the pipe member. In the precast slab according to any one of claims 1 to 3,
In the precast plate member, reinforcing bars for reinforcing the precast plate member around the hole are arranged. In the installation method of the precast slab in any one of Claim 1 to 4,
Fastening the connecting member to the flange or the projecting plate by the fastening means;
Bridging the precast plate member in which the pipe member is embedded between the steel beams so that the upper end portion of the connecting member is disposed in the pipe member;
A precast slab installation method comprising: filling the tube member with the filler. In the dismantling method of the precast slab according to any one of claims 1 to 4,
Removing the fastening means for fastening the connecting member to the flange or the projecting plate;
A method for disassembling a precast slab, comprising: a step of extracting the filler formed integrally with the connecting member from the inside of the pipe member.

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