JP2015068076A - Construction method of concrete hollow slab and embedding body used for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a construction method of a concrete hollow slab in which an embedding body can be fixed in a slab reliably and firmly, the tilt and lateral movement of the embedding body may not occur even by concrete pressure or buoyancy of the embedding body in the concrete placement, a covering thickness with the concrete of the embedding body is secured and a sufficient proof stress can be obtained, workability, stability and high quality are superior, and repair work is unnecessary while having superior workability and labor saving properties.SOLUTION: A construction method of a concrete hollow slab includes: a bottom rebar arrangement step of arranging a bottom rebar in a lattice pattern; a bottom fixing rebar arrangement step of arranging a bottom fixing rebar to support a bottom side of the embedding body between adjacent bottom rebars; a top fixing rebar temporal placement step of temporarily placing a top fixing rebar for securing a top side of the embedding body on the bottom rebar or the bottom fixing rebar; a top rebar arrangement step of arranging a top rebar in the lattice pattern; an embedding body installation step of installing the embedding body on the bottom fixing rebar in a space partitioned by the bottom rebar and the top rebar; and a top fixing rebar engagement step of engaging the top fixing rebar between the embedding body and the top rebar.

Description

  The present invention relates to a concrete hollow slab construction method in which a hollow concrete slab is formed by embedding a light-weighted embedded material in a reinforced concrete slab of a building, and an embedded material used therefor.

Conventionally, a hollow slab method is known in which an embedded body made of a lightweight material is embedded in concrete after completion of slab reinforcement work. In this method, upper and lower slab reinforcing bars are arranged on the upper surface of a slab form plate, an embedded body made of a lightweight material is arranged between the slab reinforcing bars, and then concrete is placed. Thereby, a long span concrete hollow slab can be constructed.
And in (patent document 1) and (patent document 2), the concrete hollow slab construction method which embeds the embedded body which has a fixed plane on the upper surface like the shape which cut off the rectangular parallelepiped shape and the upper and lower sides of the spherical body with the parallel surface. As a method, a method of disposing an embedded body in a space between upper and lower reinforcing bars after slab reinforcing work such as a lower reinforcing bar and an upper reinforcing bar is disclosed.
In these methods, after the slab reinforcement work is completed, the embedded body is arranged, so that the fixed bars that receive the lower embedded body are simultaneously arranged at the time of the lower-end reinforcement reinforcement in the slab reinforcement work. In addition, it is difficult to insert a long fixing bar into the lower surface of the upper end reinforcing bar or insert a certain length of holding fitting to fix the upper surface of the implant after arranging the upper end reinforcing bar. Since the workability is also poor, a fixing method is adopted in which fixing bars and holding metal fittings for fixing the embedded body are arranged from above the upper end reinforcing bar, and are bound to the upper surface of the upper end reinforcing bar to hold down the embedded body. ing.

JP 2006-9363 A JP 2006-70616 A

However, the above conventional technique has the following problems.
(1) As in (Patent Document 1) and (Patent Document 2), a fixed bar is placed on the upper surface of the upper end reinforcing bar, the embedded body is pressed by the fixing bar, and the fixed bar and the upper end reinforcing bar are bound by a binding wire. With the fixing method, it is difficult to prevent the embedded body from tilting or laterally moving with the force of the binding wire, and the binding wire breaks due to the concrete pressure and the buoyancy of the embedded body when casting concrete, and the embedded body tilts. Or lateral movement has occurred. Thereby, the cover thickness with the concrete of an embedding body was not securable, and it had the subject that the proof of a slab would become insufficient easily.
(2) Moreover, the embedded body of (Patent Literature 1) and (Patent Literature 2) having a certain flat surface on the upper surface, such as a rectangular parallelepiped shape or a shape obtained by cutting the top and bottom of a sphere with parallel surfaces, is a cover with concrete. Since the thickness cannot be ensured, there is a problem that the crack prevention bars and the structural reinforcing bars necessary for the structural design cannot be arranged on the upper surface.
(3) Furthermore, in the method in which the embedded body is held down by the fixed reinforcing bar or the holding metal fitting arranged on the upper surface side of the upper end reinforcing bar in (Patent Document 1) and (Patent Document 2), the binding wire is broken by the concrete placing pressure. As a result, insufficient pressing into the embedded body may occur, and the embedded body may tilt or move laterally and protrude from the top rebar. It was necessary at all times and had the problem of lack of workability and labor saving.
(4) In addition, since the shape of the conventional embedded body is a rectangular parallelepiped or a cube, the space saving during transportation and inventory in the factory or on-site has been required, and improvement in stack stability has been demanded. .

  The present invention solves the above-mentioned problems, and can securely and firmly fix the embedded body in the slab. The inclination of the embedded body and the buoyancy of the embedded body can also be increased depending on the concrete pressure and the buoyancy of the embedded body. There is no lateral movement, it is possible to obtain sufficient strength by securing the cover thickness of the embedded concrete and concrete, excellent workability, stability and high quality, and no repair work is required. The construction method of the concrete hollow slab with excellent workability and labor-saving and the simple structure can be securely fixed between the upper and lower ends of the reinforced concrete slab, and tilt and lateral movement may occur. The purpose of the present invention is to provide an embedded body that is excellent in workability and fixing stability, is excellent in space saving and stackability during transportation, and in stock in the factory or at the site.

Means for solving the problems, and actions and effects obtained thereby

In order to solve the above problems, a concrete hollow slab construction method of the present invention and an embedded body used therefor have the following configurations.
In the method for constructing a concrete hollow slab according to claim 1 of the present invention, an embedded body is disposed in a space partitioned in a lattice shape by a lower end reinforcing bar and an upper end reinforcing bar in a formwork, and concrete is placed. A method for constructing a concrete hollow slab, comprising a lower end reinforcing bar arranging step of arranging the lower end reinforcing bar in a lattice shape, and a lower fixing bar for supporting the lower surface side of the embedded body between the adjacent lower end reinforcing bars. A lower fixed reinforcing bar arranging step, an upper fixing bar temporary placing step for temporarily placing an upper fixing rod for fixing the upper surface side of the implant on the lower reinforcing bar or the lower fixing rod, and the upper end An upper end reinforcing bar arrangement step of arranging reinforcing bars in a lattice shape, an implant installation step of installing the implant on the lower fixing bar in the space, and the upper fixing bar with the implant An upper fixing bar engaging step for engaging between the upper end reinforcing bars; We have the example was constructed.
This configuration has the following operations and effects.
(1) A lower end reinforcing bar reinforcing step for arranging the lower end reinforcing bar in a lattice shape and a lower fixed reinforcing bar reinforcing step for arranging a lower fixing bar for supporting the lower surface side of the implant between adjacent lower end reinforcing bars. Therefore, the main part of the lower fixing bar can be supported by the lower end reinforcing bar, and when the implant is installed on the lower fixing bar in the space in the implant installation process in the later process, It can be reliably supported by the lower end reinforcing bars and the lower fixing bars, and the support stability of the implant is excellent.
(2) Upper fixing that temporarily places the upper fixing bar for fixing the upper surface of the implant on the lower or lower fixing bar before the upper bar reinforcing step to arrange the upper bar in a grid pattern Since it has a temporary stapling process, it is not necessary to insert an upper fixing bar to fix the upper surface of the embedded body below the upper reinforcing bar after the upper bar reinforcing process or the implant installation process. Excellent in properties.
(3) Since the upper fixing bar for fixing the upper surface side of the implant can be temporarily placed on the lower end reinforcing bar or the lower fixing bar in advance by the upper fixing bar temporary placing step, the upper fixing bar in the subsequent step In the engagement process, lift the upper fixing bar temporarily placed on the lower end reinforcing bar or lower fixing bar, and slide the upper fixing bar from the outside of the implant to easily slide between the implant and the upper end reinforcing bar. It can be inserted into and engaged with and is excellent in workability.
(4) In the upper fixing bar engaging step, the upper fixing bar can be engaged between the implant and the upper end reinforcing bar, so that the upper surface side of the upper fixing bar can be securely and firmly fixed by the upper end reinforcing bar. Yes, even if the binding wire that binds the upper fixing bar and the top reinforcing bar breaks, the embedded body will not rise, there will be no insufficient pressing of the embedded body, and the reliability and stability of fixing the embedded body Excellent.
(5) The implant is disposed between the lower fixing bar disposed above the lower end reinforcing bar and the upper fixing bar disposed below the upper end reinforcing bar, so that the embedded body is placed between the lower end reinforcing bar and the lower reinforcing bar. It can be firmly fixed by being sandwiched by the entire top rebar, and it can prevent the occurrence of inclination, lateral movement, lifting, etc. of the embedded body, so ensure the cover thickness with the concrete of the embedded body, Sufficient proof stress can be obtained, and a highly accurate and stable quality concrete hollow slab can be formed. Also, the work of repairing the embedded body at the time of placing the concrete is unnecessary, and it is excellent in workability and labor saving.

Here, the shape of the embedded body can be selected as appropriate, but a shape formed in a rectangular parallelepiped shape, a cubic shape, a cylindrical shape, or the like is preferably used.
Further, the embedded body has a specific gravity that is sufficiently smaller than the specific gravity of concrete. For example, a plastic foam, an inorganic foam, a plastic hollow molded body, or the like is preferably used.
Examples of the plastic foam include foams such as polystyrene, polyethylene, polypropylene (including a copolymer), polyethylene / polystyrene composite resin, polyvinyl chloride, polyvinylidene chloride, acrylonitrile / styrene copolymer, and polyurethane. it can.
As an inorganic foam, foam block bodies, such as ALC, glass, and pearlite, can be used, for example.
As a material for the plastic hollow molded body, for example, polyvinyl chloride, polyethylene terephthalate, polycarbonate and the like can be used in addition to olefin resins such as polystyrene, polyethylene, and polypropylene.
The size of the embedded body is determined based on the slab thickness, the amount of bar arrangement, the cover thickness of the main reinforcement concrete, etc., but in the case of forming a rectangular parallelepiped shape, the length is 100 mm × width 100 mm × height 100 mm to length A thing of about 500 mm × width 500 mm × height 250 mm is preferably used.

The arrangement of the embedded body can be selected as appropriate, and is not limited to the arrangement in all the spaces partitioned by the lower end reinforcing bar and the upper end reinforcing bar, and is arranged in a row or in a staggered manner. You can also.
In the lower fixed reinforcing bar arranging step, the number and arrangement of the lower fixed reinforcing bars arranged between adjacent lower reinforcing bars can be selected as appropriate. For example, the lower fixing bars may be arranged only in the vertical direction, or may be arranged only in the horizontal direction. At this time, when the two lower fixed muscles are arranged in parallel with respect to one space, the lower surface of the implant can be supported at two locations, front and rear, or left and right, and the support stability is excellent.
In the upper fixing bar engaging step, the number of the upper fixing bars to be engaged between the implant and the upper end reinforcing bar may be one or two, but when the two upper fixing bars are arranged in parallel, The upper surface of the embedded body can be pressed in two places, front and rear or left and right, and the tilt and lateral movement of the embedded body can be reliably prevented, and the fixing stability is excellent.
In addition, the lower end reinforcing bar arrangement process and the upper end reinforcing bar arrangement process are performed in the same manner as in the past. The lower end reinforcing bar and the upper end reinforcing bar are held at substantially constant intervals by a main bar support (rebar spacer) to form a space.

Invention of Claim 2 is the construction method of the concrete hollow slab of Claim 1, Comprising: In the said upper fixed reinforcement engagement process, the said upper fixed reinforcement is a notch shape on the upper surface of the said implant. It has the structure engaged with the upper fixed-muscle receiving level | step difference part formed in this.
With this configuration, in addition to the operations and effects of claim 1, the following operations and effects are provided.
(1) In the upper fixing bar engaging step, the upper fixing bar is engaged with the upper fixing bar receiving step portion formed in a cutout shape on the upper surface of the implant. The upper fixed muscles sandwiched between the fixed muscle receiving stepped portions can effectively prevent the lateral movement of the implant, and the fixation stability of the implant is excellent.
(2) Since the upper fixed muscle receiving stepped portion is formed in a cutout shape on the upper surface of the implant, when the upper fixed muscle is engaged by sliding from the outside of the implant, the upper fixed muscle Can be easily positioned by abutting against the side surface of the convex portion facing the upper fixed muscle receiving stepped portion, and is excellent in workability.
Here, when the upper fixed muscle receiving stepped portion is formed on both sides of the upper surface of the implant, the convex portion formed between the upper fixed muscle receiving stepped portion and the upper fixed muscle receiving stepped portion on both sides is formed. The two upper fixing bars can be fixed so as to be sandwiched from both sides, and the lateral movement of the implant can be surely prevented.

Invention of Claim 3 is the construction method of the concrete hollow slab of Claim 1 or 2, Comprising: In the said embedded body installation process, the said lower fixed reinforcement is formed in the lower surface of the said embedded body. It has the structure fitted to the lower fixed reinforcement receiving groove.
With this configuration, the following functions and effects are provided in addition to the functions and effects of the first or second aspect.
(1) In the implant installation step, the lower fixed muscle is fitted into the lower fixed muscle receiving groove formed on the lower surface of the implant, so that the implant is securely supported by the lower fixed muscle, The lateral movement of the implant can be prevented, and the support stability of the implant is excellent.

Invention of Claim 4 is a construction method of the concrete hollow slab of any one of Claim 1 thru | or 3, Comprising: The said lower fixed reinforcement and the said upper fixed reinforcement are arrange | positioned orthogonally. It has a configuration.
With this configuration, in addition to the operation and effect of any one of claims 1 to 3, the following operation and effect are provided.
(1) Since the lower fixing muscle and the upper fixing muscle are disposed orthogonally, the implant can be reliably prevented from moving in the front-rear direction and the left-right direction. Excellent stability.

An embedded body according to a fifth aspect of the present invention is an embedded body used in the method for constructing a concrete hollow slab according to any one of the first to fourth aspects, wherein the lower body is formed on a lower surface of the lower body. A lower fixed bar receiving groove into which the fixed bar is fitted, and an upper fixed bar receiving step portion formed in a cutout shape on the upper surface and engaged with the upper fixed bar has a configuration arranged. doing.
This configuration has the following operations and effects.
(1) Since the lower fixed muscle receiving groove is formed on the lower surface and the lower fixing muscle is fitted, the implant can be fixed at a predetermined position simply by fitting the lower fixing muscle into the lower fixing muscle receiving groove. Position prevention and excellent fixing stability.
(2) Since the lower fixed muscle receiving groove is formed on the lower surface, just place the implant on the lower fixed muscle and push it down to fit the lower fixed muscle into the lower fixed muscle receiving groove and fix it. It can be done and has excellent workability.
(3) Since the upper fixed muscle receiving stepped portion is formed in a cutout shape on the upper surface and engaged with the upper fixed muscle, the implant can be obtained by simply engaging the upper fixing muscle with the upper fixed muscle receiving stepped portion. It can be fixed at a predetermined position to prevent displacement, and the fixing stability is excellent.
(4) Since the upper fixing bar receiving step portion is formed on the upper surface, the upper fixing bar can be easily engaged between the upper reinforcing bar and the upper fixing bar receiving step portion by sliding the upper fixing bar from the outside of the implant. It can be made and has excellent workability.
(5) The embedded body can be fixed by sandwiching it from above and below by means of the lower fixing bar fitted into the lower fixing bar receiving groove and the upper fixing bar engaged with the upper fixing bar receiving stepped portion. Since the body can be prevented from tilting and moving horizontally and vertically, there is no need for repair work of the embedded body when placing concrete, and it is excellent in workability and labor saving.

Here, the lower fixing bar receiving groove only needs to be able to fit the lower fixing bar, and the shape and size thereof can be appropriately selected according to the shape and size of the lower fixing bar to be fitted.
The number and arrangement of the lower fixed muscle receiving grooves can be appropriately selected depending on the shape and size of the implant, but by forming at least two lower fixed muscle receiving grooves, The lower surface can be reliably supported, and the support stability is excellent.
The upper fixing bar receiving stepped portion is not limited as long as it can engage the upper fixing bar, and the depth (height) and width thereof can be appropriately selected according to the size of the upper fixing bar to be engaged. . When the depth (height) of the upper fixed reinforcement receiving step is formed to be approximately equal to the diameter (height dimension) of the upper fixed reinforcement, the bottom of the upper reinforcing bar and the bottom of the upper fixed reinforcement receiving step The gap formed between them is almost the same as the diameter (height dimension) of the upper fixed muscle, and the implant, the upper fixed reinforcement, and the upper end reinforcement can be brought into contact with each other, and the fixing reliability is excellent. .
The upper fixed muscle receiving stepped portion can be formed at one or two locations, but it is preferable that the two upper fixed muscle receiving stepped portions are arranged opposite to both sides of the upper surface of the embedded body. A convex portion can be formed between the two upper fixing bar receiving stepped portions, and the two upper fixing bars engaged with each upper fixing bar receiving stepped portion are fixed so as to sandwich the protruding portion from both sides. This is because the lateral displacement of the embedded body can be reliably prevented and the fixing stability is excellent.
If the volume of the embedded body needs to be adjusted due to the structural design of the concrete hollow slab, the depth of the lower fixed reinforcement receiving groove on the lower surface and the depth (height) of the upper fixed reinforcement receiving stepped portion are the diameter of the lower fixed reinforcement. By forming it larger than (height direction dimension) and the diameter of the upper fixing bar (height direction dimension), the embedded body can be lifted and fixed at the time of placing concrete, and the design flexibility is excellent.

The invention according to claim 6 is the implant according to claim 5, wherein the lower fixed muscle receiving groove and the upper fixed muscle receiving stepped portion are formed orthogonally.
With this configuration, in addition to the operation and effect of claim 5, the following operation and effect are provided.
(1) Since the lower fixed muscle receiving groove and the upper fixed muscle receiving step portion are formed orthogonally, the lower fixed muscle receiving groove and the upper fixed muscle receiving step portion are engaged with each other. The upper fixing muscle can reliably prevent the implant from moving in the front-rear direction and the left-right direction, and is excellent in fixing reliability and stability.

The invention according to claim 7 is the implant according to claim 5 or 6, and has a configuration including a recessed portion for bar arrangement formed on at least one of the upper surface and the lower surface.
With this configuration, in addition to the functions and effects of claim 5 or 6, the following functions and effects are provided.
(1) By having a concave portion for bar arrangement formed on at least one of the upper and lower surfaces, the cover thickness of concrete is secured on the upper and lower surfaces of the embedded body, and crack prevention bars and structural reinforcing bars are placed. It has excellent versatility and structural design flexibility.
(2) By having the reinforcing bar recess, the punching shear can be strengthened, the concrete hollow slab hardly resonates, and the sound insulation is excellent.
Here, the concave portion for bar arrangement can be appropriately formed according to the structural design of the concrete hollow slab. Although the shape and size of the concave portion for bar arrangement can be selected as appropriate, those formed in a semi-cylindrical shape are preferably used.

The invention according to claim 8 is the embedded body according to any one of claims 5 to 7, comprising: a convex portion formed on the top surface; and a fitting concave portion formed on the bottom surface. It has the composition provided.
With this configuration, in addition to the function and effect of any one of claims 5 to 7, the following function and effect are provided.
(1) Since the convex portion formed on the upper surface and the fitting concave portion formed on the lower surface, the convex portion of the other embedded body is fitted into the fitting concave portion of one of the embedded bodies, and a plurality of The embedded bodies can be stacked easily, preventing collapse and bulkiness, and excellent in space saving and stack stability during transportation and stocking in the factory or at the site.
Here, the convex portion can be appropriately formed on the upper surface of the embedded body, but by using the remaining portion formed with the upper fixed muscle receiving stepped portion as the convex portion, it is excellent in productivity and space saving. . Note that the fitting recess can be appropriately formed according to the shape and position of the protrusion.

The model perspective view which shows the state before concrete placement of the concrete hollow slab formed with the construction method of the concrete hollow slab of Embodiment 1 The lower surface side model perspective view of the implant used for the construction method of the concrete hollow slab of Embodiment 1 Upper surface side schematic perspective view of an embedded body used in the concrete hollow slab construction method of Embodiment 1 The model perspective view which shows the state after the upper-end reinforcing bar arrangement process in the construction method of the concrete hollow slab of Embodiment 1 The model perspective view which shows the implant installation process and the upper fixed reinforcement engagement process in the construction method of the concrete hollow slab of Embodiment 1 The principal part schematic front view which shows the arrangement | positioning state of the embedded body in the concrete hollow slab formed with the construction method of the concrete hollow slab of Embodiment 1 The principal part schematic side view which shows the arrangement | positioning state of the embedded body in the concrete hollow slab formed with the construction method of the concrete hollow slab of Embodiment 1

(Embodiment 1)
A concrete hollow slab construction method according to Embodiment 1 of the present invention and an embedded body used therefor will be described below with reference to the drawings. The present invention is not limited to the embodiments described below.
FIG. 1 is a schematic perspective view showing a state of a concrete hollow slab formed by the concrete hollow slab construction method of Embodiment 1 before placing concrete.
In FIG. 1, 1 is a concrete hollow slab before placing concrete, which is formed by the concrete hollow slab construction method in the first embodiment, 2 is a mold plate at the lower part of the slab, and 3 is an important part of the mold plate 2. The main reinforcing bar support 5a, 5b of the concrete hollow slab 1 provided is supported at the main point by the main reinforcing bar support 3, and the lower end reinforcing bars of the concrete hollow slab arranged in a lattice shape of about 45 cm in length and width, 6a, 6b are the key points The upper end of the concrete hollow slab supported by the main bar support 3 and arranged in a lattice shape of about 45 cm in length and width, 7a is arranged in parallel between the lower end reinforcing bars 5a between the adjacent lower end reinforcing bars 5a. The lower fixing bars 7b for supporting the lower surface side of the embedded body 8 to be described later are disposed in parallel between the upper end reinforcing bars 6b in two adjacent horizontal upper reinforcing bars 6b. Between the reinforcing bars 6a The upper fixing bars 8 and 8 are foams made of a synthetic resin such as polystyrene, and are formed in a substantially rectangular parallelepiped shape having a length and width of about 30 cm. 9a and 9b are auxiliary reinforcing bars such as crack prevention bars arranged on the lower surface and upper surface of the embedded body 10, and 10 is a lower end side by hooking a hook portion on the upper end side to the upper end reinforcing bars 6a and 6b. Is a floating metal fitting that prevents the lower end reinforcing bars 5a and 5b and the upper end reinforcing bars 6a and 6b from being lifted up with respect to the embedded body 8 by fixing them to the mold plate 2.
In the present embodiment, a direction parallel to the lower end reinforcing bar 5a is defined as a vertical direction (front-rear direction), and a direction parallel to the lower end reinforcing bar 5b is defined as a horizontal direction (left / right direction).

Next, the detail of the implant used for the construction method of the concrete hollow slab of Embodiment 1 is demonstrated.
FIG. 2 is a schematic perspective view of the lower surface side of the embedded body used in the concrete hollow slab construction method of the first embodiment, and FIG. 3 shows the structure of the embedded body used in the concrete hollow slab construction method of the first embodiment. It is an upper surface side model perspective view.
In FIG. 2, reference numeral 8 a denotes two lower fixed muscle receiving grooves formed on the lower surface of the embedded body 8 to which the lower fixed muscle 7 a is fitted, and 8 b denotes a fitting formed on the center portion of the lower surface of the embedded body 8. The concave portion 8c is a reinforcing bar concave portion formed in a semi-cylindrical shape deeper than the fitting concave portion 8b in the lower surface center portion of the embedded body 8.
In FIG. 3, 8 d is a notch formed on both sides of the upper surface of the implant 8 and the upper fixed muscle receiving stepped portion is engaged with the upper fixing muscle 7 b, and 8 e is on both sides of the upper surface of the implant 8. A convex portion 8f formed at the center of the upper surface of the embedded body 8 by forming the upper fixed muscle receiving stepped portion 8d is formed in a semi-cylindrical shape perpendicular to the convex portion 8e at the center of the lower surface of the embedded body 8. It is the recessed part for reinforcing bars formed.

The fitting recesses 8b are formed to have the same dimensions as the projections 8e, so that when the embedded body 8 is transported or stored, the fitting recesses 8b and the projections 8e are fitted and the plurality of embedded bodies 8 are stacked. Excellent stack stability and space saving.
In addition, the reinforcing bar recesses 8c and 8f can be appropriately formed according to the structural design of the concrete hollow slab. The shape and size of the reinforcing bar recesses 8c and 8f are not limited to the present embodiment, and can be appropriately selected.

The construction method of the concrete hollow slab of Embodiment 1 using the embedded body configured as described above will be described.
FIG. 4 is a schematic perspective view showing a state after the upper reinforcing bar arrangement process in the concrete hollow slab construction method of the first embodiment, and FIG. 5 is an embedded installation in the concrete hollow slab construction method of the first embodiment. FIG. 6 is a schematic perspective view showing a process and an upper fixing bar engaging step, and FIG. 6 is a schematic front view of a main part showing an arrangement state of embedded bodies in the concrete hollow slab formed by the concrete hollow slab construction method of the first embodiment. FIG. 7 is a schematic side view of an essential part showing an arrangement state of embedded bodies in a concrete hollow slab formed by the concrete hollow slab construction method of the first embodiment.

In FIG. 4, first, in the lower end reinforcing bar reinforcing step, the lower end reinforcing bars 5a and 5b are arranged in a lattice pattern using the main reinforcing bar support 3. At this time, it arrange | positions so that the vertical lower end reinforcement 5a may be orthogonally crossed on the horizontal direction lower reinforcement 5b, and a cross | intersection part is bound and fixed by a binding wire (not shown). In addition, auxiliary reinforcing bars 9a such as crack prevention bars are also arranged below the lower end reinforcing bars 5a in parallel with the lower end reinforcing bars 5b, and the intersections with the lower end reinforcing bars 5a are bound and fixed.
Next, in the lower fixed reinforcing bar arranging step, two lower fixed reinforcing bars 7a that support the lower surface side of the implant 8 are placed between adjacent lower reinforcing bars 5a, 5a. The lower fixing bar 7a is arranged on the lower end reinforcing bar 5b in parallel with the lower end reinforcing bar 5a, and binds and fixes the intersection.
Next, in the upper fixing bar temporary placing step, the upper fixing bar 7b for fixing the upper surface side of the implant 8 is temporarily placed on the lower end reinforcing bar 5a. At this time, two upper fixing bars 7b are arranged between the adjacent lower reinforcing bars 5b and 5b so as to be orthogonal to the lower fixing bars 7a. It is preferable to arrange it on the immediate side of the lower end reinforcing bar 5b so that it does not get in the way when installed on the reinforcing bar 7a.
Next, in the upper bar reinforcing bar arranging step, the upper reinforcing bars 6a and 6b are arranged in a lattice using the main bar support 3. At this time, it arrange | positions so that the upper end reinforcement 6a of the vertical direction may orthogonally cross on the upper end reinforcement 6b of a horizontal direction, and a cross | intersection part is bound and fixed.
As described above, the state after the upper bar reinforcing bar arranging step shown in FIG. 4 is obtained.

Next, in FIG. 5, in the embedded body installation process, on the two lower fixing bars 7 a on the lower end reinforcing bar 5 b in the space partitioned by the lower end reinforcing bars 5 a and 5 b and the upper end reinforcing bars 6 a and 6 b. The embedded body 8 is installed, and the lower fixed muscle 7 a is fitted into the lower fixed muscle receiving groove 8 a on the lower surface of the embedded body 8. Thereafter, in order to prevent the embedded body 8 from moving laterally, the intersection of the lower fixing bar 7a and the lower end reinforcing bar 5b is bound and fixed.
Next, in the upper fixed bar engaging step, the upper fixed bar 7b previously placed in the direction perpendicular to the lower fixed bar 7a in the upper fixed bar temporary placing step is moved upward as shown on the front side in the vertical direction of FIG. And is slid from the outer side of the embedded body 8 to the center side, and is fitted between the embedded body 8 and the upper end reinforcing bar 6a as shown in the vertical direction in FIG. Then, after the embedded body 8 is sandwiched between the lower fixed muscle 7a and the upper fixed muscle 7b, the intersection of the upper fixed muscle 7b and the upper end reinforcing bar 6a is bound to fix the embedded body 8.
Finally, auxiliary reinforcing bars 9b such as crack prevention bars are arranged from above the upper end reinforcing bars 6b to bind the intersections, and the concrete hollow slab 1 shown in FIG. 1 is obtained. In addition, as needed, you may arrange | position the height holding | maintenance bar | burr etc. which connect the middle of the longitudinal direction of the lower end reinforcement 5b and the upper end reinforcement 6b, and hold | maintain the space | interval of the lower end reinforcement 5b and the upper end reinforcement 6b.

As shown in FIG. 6, the embedded body 8 in the concrete hollow slab 1 formed as described above is formed by fitting the two lower fixing bars 7a into the lower fixing bar receiving groove 8a. 8 is supported by the whole lower end reinforcement 5a, 5b, and the horizontal movement of the left-right direction is prevented. The number and arrangement of the lower fixed muscle receiving grooves 8a can be appropriately selected according to the shape and size of the implant 8, but the two lower fixed muscle receiving grooves 8a are formed as in the present embodiment. By forming, the support of the embedded body 8 is excellent in stability.
Further, as shown in FIG. 7, the upper fixing bar 7b is fitted into and engaged with the gap surrounded by the upper fixing bar receiving step 8d on the lower surface of the upper end reinforcing bar 6a and the upper surface of the embedded body 8, thereby The embedded body 8 can be pressed down by the entire upper rebar 6a, 6b via the fixed reinforcement 7b, and lateral movement and lifting in the front-rear direction are prevented.

In particular, the bottom surface of the upper reinforcing bar 6a is formed by forming the depth (height) of the upper fixing bar receiving stepped portion 8d substantially equal to the diameter (height direction dimension) of the upper fixing bar 7b as in the present embodiment. The gap formed between the upper fixing bar receiving step 8d and the bottom part of the upper fixing bar receiving stepped part 8d is substantially equal to the diameter (height direction dimension) of the upper fixing bar 7b. The upper end rebar 6a can be reliably brought into contact with, and the fixing reliability is excellent. Further, by disposing the two upper fixed muscle receiving stepped portions 8d on both sides of the upper surface of the embedded body 8, a convex portion 8e can be formed between the two upper fixed muscle receiving stepped portions 8d, With the two upper fixing bars 7b engaged with the respective upper fixing bar receiving stepped parts 8d, the convex part 8e is fixed so as to be sandwiched from both sides, thereby reliably preventing the positional deviation of the embedded body 8 in the front-rear direction. It is excellent in fixing stability.
In the structural design, when the reinforcing bars 9a, 9b such as crack prevention bars are required on the upper and lower surfaces of the embedded body 8, as shown in FIGS. The bar can be placed at the position.

The construction method of the concrete hollow slab of the first embodiment configured as described above has the following operation.
(1) A lower end reinforcing bar reinforcing step for arranging the lower end reinforcing bar in a lattice shape and a lower fixed reinforcing bar reinforcing step for arranging a lower fixing bar for supporting the lower surface side of the implant between adjacent lower end reinforcing bars. Therefore, the main part of the lower fixing bar can be supported by the lower end reinforcing bar, and when the implant is installed on the lower fixing bar in the space in the implant installation process in the later process, It can be reliably supported by the lower end reinforcing bars and the lower fixing bars, and the support stability of the implant is excellent.
(2) Upper fixing that temporarily places the upper fixing bar for fixing the upper surface of the implant on the lower or lower fixing bar before the upper bar reinforcing step to arrange the upper bar in a grid pattern Since it has a temporary stapling process, it is not necessary to insert an upper fixing bar to fix the upper surface of the embedded body below the upper reinforcing bar after the upper bar reinforcing process or the implant installation process. Excellent in properties.
(3) Since the upper fixing bar for fixing the upper surface side of the implant can be temporarily placed on the lower end reinforcing bar or the lower fixing bar in advance by the upper fixing bar temporary placing step, the upper fixing bar in the subsequent step In the engagement process, lift the upper fixing bar temporarily placed on the lower end reinforcing bar or lower fixing bar, and slide the upper fixing bar from the outside of the implant to easily slide between the implant and the upper end reinforcing bar. It can be made to engage with, and it is excellent in workability.
(4) In the upper fixing bar engaging step, the upper fixing bar can be engaged between the implant and the upper end reinforcing bar, so that the upper surface side of the upper fixing bar can be securely and firmly fixed by the upper end reinforcing bar. Yes, even if the binding wire that binds the upper fixing bar and the top reinforcing bar breaks, the embedded body will not rise, there will be no insufficient pressing of the embedded body, and the reliability and stability of fixing the embedded body Excellent.
(5) The implant is disposed between the lower fixing bar disposed above the lower end reinforcing bar and the upper fixing bar disposed below the upper end reinforcing bar, so that the embedded body is placed between the lower end reinforcing bar and the lower reinforcing bar. It can be firmly fixed by being sandwiched by the entire top rebar, and it can prevent the occurrence of inclination, lateral movement, lifting, etc. of the embedded body, so ensure the cover thickness with the concrete of the embedded body, Sufficient proof stress can be obtained, and a highly accurate and stable quality concrete hollow slab can be formed. Also, the work of repairing the embedded body at the time of placing the concrete is unnecessary, and it is excellent in workability and labor saving.
(6) In the upper fixed bar engaging step, the upper fixed bar is engaged with the upper fixed bar receiving step portion formed in a cutout shape on the upper surface of the implant. The upper fixed muscles sandwiched between the fixed muscle receiving stepped portions can effectively prevent the lateral movement of the implant, and the fixation stability of the implant is excellent.
(7) Since the upper fixed muscle receiving stepped portion is formed in a cutout shape on the upper surface of the implant, when the upper fixed muscle is engaged by sliding from the outside of the implant, the upper fixed muscle Can be easily positioned by abutting against the side surface of the convex portion facing the upper fixed muscle receiving stepped portion, and is excellent in workability.
(8) In the implant installation step, the lower fixed muscle is fitted into the lower fixed muscle receiving groove formed on the lower surface of the implant, so that the implant is securely supported by the lower fixed muscle, The lateral movement of the implant can be prevented, and the support stability of the implant is excellent.
(9) Since the lower fixing muscle and the upper fixing muscle are disposed orthogonally, the implant can be reliably prevented from moving in the front-rear direction and the left-right direction. Excellent stability.
The construction method of the concrete hollow slab of Embodiment 1 configured as described above and the embedded body used therefor have the following actions.

The embedded body used in the method for constructing the concrete hollow slab of the first embodiment configured as described above has the following effects.
(1) Since the lower fixed muscle receiving groove is formed on the lower surface and the lower fixing muscle is fitted, the implant can be fixed at a predetermined position simply by fitting the lower fixing muscle into the lower fixing muscle receiving groove. Position prevention and excellent fixing stability.
(2) Since the lower fixed muscle receiving groove is formed on the lower surface, just place the implant on the lower fixed muscle and push it down to fit the lower fixed muscle into the lower fixed muscle receiving groove and fix it. It can be done and has excellent workability.
(3) Since the upper fixed muscle receiving stepped portion is formed in a cutout shape on the upper surface and engaged with the upper fixed muscle, the implant can be obtained by simply engaging the upper fixing muscle with the upper fixed muscle receiving stepped portion. It can be fixed at a predetermined position to prevent displacement, and the fixing stability is excellent.
(4) Since the upper fixing bar receiving step portion is formed on the upper surface, the upper fixing bar can be easily engaged between the upper reinforcing bar and the upper fixing bar receiving step portion by sliding the upper fixing bar from the outside of the implant. It can be made and has excellent workability.
(5) The embedded body can be fixed by sandwiching it from above and below by means of the lower fixing bar fitted into the lower fixing bar receiving groove and the upper fixing bar engaged with the upper fixing bar receiving stepped portion. Since the body can be prevented from tilting and moving horizontally and vertically, there is no need for repair work of the embedded body when placing concrete, and it is excellent in workability and labor saving.
(6) By forming the lower fixed muscle receiving groove and the upper fixed muscle receiving stepped portion orthogonally, the lower fixed muscle receiving groove and the upper fixed muscle receiving stepped portion are engaged with each other. The upper fixing muscle can reliably prevent the implant from moving in the front-rear direction and the left-right direction, and is excellent in fixing reliability and stability.
(7) By having a concave portion for bar arrangement formed on at least one of the upper and lower surfaces, the cover thickness of concrete is secured on the upper and lower surfaces of the embedded body, and crack prevention bars and structural reinforcing bars are placed. It has excellent versatility and structural design flexibility.
(8) By having the concave portion for bar arrangement, the punching shear can be strengthened, the concrete hollow slab hardly resonates, and the sound insulation is excellent.
(9) Since the convex portion formed on the upper surface and the fitting concave portion formed on the lower surface are provided, the convex portion of the other embedded body is fitted into the fitting concave portion of the one embedded body, The embedded bodies can be stacked easily, preventing collapse and bulkiness, and excellent in space saving and stack stability during transportation and stocking in the factory or at the site.

  The present invention can securely and firmly fix the embedded body, and the embedded body is not tilted or laterally moved by the concrete pressure or the buoyancy of the embedded body when placing concrete. A concrete with excellent workability, labor-saving, no need for repair work, etc. Providing a construction method for hollow slabs and a simple structure, it can be securely fixed between the upper and lower reinforcing bars in reinforced concrete slabs, without tilting or lateral movement, and excellent in workability and fixing stability It is possible to realize a high-quality and highly stable concrete hollow slab by providing an embedded body with excellent space saving and stackability during transportation, inventory in the factory or on-site. .

DESCRIPTION OF SYMBOLS 1 Concrete hollow slab 2 Formwork 3 Main bar support 5a, 5b Lower end reinforcement 6a, 6b Upper end reinforcement 7a Lower fixed reinforcement 7b Upper fixed reinforcement 8 Implant 8a Lower fixed reinforcement receiving groove 8b Fitting recessed part 8c Reinforcing part recessed part 8d Upper fixed reinforcement receiving step 8e Convex 8f Reinforcing bars 9a, 9b Auxiliary rebar 10 Floating bracket

Claims (8)

A method of constructing a concrete hollow slab in which an embedded body is disposed in a space partitioned in a lattice shape by a lower end reinforcing bar and an upper end reinforcing bar in a formwork, and concrete is placed thereon,
Lower end reinforcing bar reinforcing step of arranging the lower end reinforcing bar in a lattice shape, and lower fixed reinforcing bar reinforcing step of arranging a lower fixing bar supporting the lower surface side of the embedded body between the adjacent lower end reinforcing bars, An upper fixing bar temporary placing step of temporarily placing an upper fixing bar for fixing the upper surface side of the embedded body on the lower end reinforcing bar or the lower fixing bar, and an upper end reinforcing bar that arranges the upper end reinforcing bar in a lattice shape Arrangement step, an implant installation step of installing the implant on the lower fixing bar in the space, and an upper part for engaging the upper fixing bar between the implant and the upper end reinforcing bar A method for constructing a concrete hollow slab, comprising: a fixed reinforcement engaging step. 2. The upper fixed muscle engaging step, wherein the upper fixed muscle is engaged with an upper fixed muscle receiving stepped portion formed in a cutout shape on the upper surface of the implant. Construction method for concrete hollow slabs. 3. The concrete hollow slab according to claim 1, wherein in the embedded body installation step, the lower fixing bar is fitted into a lower fixing bar receiving groove formed on a lower surface of the embedded body. 4. Construction method. The construction method for a concrete hollow slab according to any one of claims 1 to 3, wherein the lower fixing bars and the upper fixing bars are arranged orthogonally. An embedded body used in the method for constructing a concrete hollow slab according to any one of claims 1 to 4,
A lower fixing bar receiving groove formed on the lower surface and fitted with the lower fixing bar; and an upper fixing bar receiving step portion formed on the upper surface and engaged with the upper fixing bar. A featured implant. 6. The implant according to claim 5, wherein the lower fixed muscle receiving groove and the upper fixed muscle receiving stepped portion are formed to be orthogonal to each other. The implant according to claim 5 or 6, further comprising a reinforcing bar recess formed on at least one of the upper surface and the lower surface. The implant according to any one of claims 5 to 7, further comprising a convex portion formed on the upper surface and a fitting concave portion formed on the lower surface.

Images