JP3249100B2 - Method of manufacturing PCa beam member with U-shaped cross section and formwork device therefor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a U-shaped PCa (precast concrete) beam member having a core bar inside a shear reinforcing bar, and a formwork apparatus therefor.

[0002]

2. Description of the Related Art In a hollow PCa member of this type, an outer mold is provided with a gap corresponding to a thickness outside an inner mold provided for forming a hollow portion. It is manufactured by pouring or pressing concrete in the space between the frame and the space. The problems in this case are the work of assembling the inner formwork, which requires the work in a very narrow space, and the work of removing the inner formwork after the poured concrete has hardened.

In order to solve the above-mentioned problems, in recent years, as disclosed in JP-A-5-16131, JP-A-62-233206, JP-A-5-278022, etc. A method for manufacturing a precast concrete member using a tube has been proposed. Taking the former Japanese Patent Application Laid-Open No. 5-16131 as an example, the manufacturing method is as follows. As shown in FIG. 7, the rigid flat plates 51A to 51D each having projections 52, 52.
Are arranged at predetermined intervals in the longitudinal direction inside the outer mold frame 53, and the main reinforcements 55, 55 are arranged inside thereof. , And the contracted air tube 50 is inserted into the inside of the shear reinforcing bars 54, 54, and then the air tube 50 is inflated by air supply to form an inner mold. By filling concrete in between, PC with U-shaped cross section shown in FIG.
A method for manufacturing the a-beam member 55 has been proposed. At the time of demolding, the air tube is degassed and shrunk so as to be separated from the concrete surface.

[0004]

However, in the case of manufacturing a PCa beam member shown in FIG. 1 having a core reinforcing bar 4B in addition to the shear reinforcing bar 4A, the air tube 5 is required.
An inner mold with 0 cannot be used. Further, in the case of the air tube 50, each side surface of each air tube 50 does not shrink evenly when the mold is removed, and one or two of the four side surfaces shrink in a state where the concrete surface is stuck. Therefore, there is a problem that it takes time and effort to completely separate the air tube 50 from the concrete surface.

[0005] Further, in the case of trying to separate from the concrete surface by degassing, a considerable amount of air must be degassed due to the large volume of the tube. The same amount of air had to be supplied, and there was a problem that the demolding and assembling took a long time and the work efficiency was poor.

Further, in the case of the air tube 50, the position fixing method is difficult, and the air tube 50 may move or float at the time of placing concrete. Therefore, there has been a problem that it is difficult to always stably secure product accuracy.

Accordingly, a main object of the present invention is to improve the efficiency and facilitation of installation and removal of an inner mold from a U-shaped PCa beam member having a core bar inside a shear reinforcing bar. It is another object of the present invention to provide a manufacturing method and a formwork apparatus capable of easily and reliably fixing the position of an inner formwork, preventing movement and floating during concrete casting and ensuring product accuracy.

[0008]

According to the manufacturing method of the present invention for solving the above-mentioned problems, there is provided a first step of installing an outer mold including at least a bottom mold and a side mold; A second step of installing a braided reinforcing bar including a shear reinforcing bar as a circumferential bar and a core bar arranged inside the shear reinforcing bar at a predetermined position inside the frame, and expanding and contracting by air intake or deaeration. It is possible to bring in two mat-shaped side inner formwork air panels and one bottom inner formwork air panel, and surround the side inner formwork air panel with the shear reinforcement and the core. It is inserted into the side space having a vertically long cross section, and is fixed immovably by pressing the front and back surfaces of the air panel for the side inner formwork with the shear reinforcing bars and the core bars by supplying air, respectively, and fixing the bottom inner mold. Inside the air panel for the frame A space surrounded by the muscle located at the bottom position between air panel for the side in formwork,
A third step of fixing both sides of the bottom inner formwork air panel immovably by pressurizing the both sides of the bottom inner formwork air panel with the replenishing muscles, and an upper muscle of the refilling muscles and the bottom inner formwork air panel;
Insert a spacer to prevent lifting between the upper surface
Fourth step and the air panel for the side in formwork for air panel, and a bottom portion formwork, a fifth step of filling concrete in a space defined by said outer frame, the inner side by degassing of the air to be the mold for pneumatic panel and a bottom portion formwork for air panel is deflated and performs demolding of inner mold, in which the sixth step of performing demolding of outer molds, characterized in that it consists to.

In this case, it is desirable to fix the side inner formwork air panel inseparably to the core muscle side. As the fixing means, for example, an adhesive tape or a hook-and-loop fastener tape can be used. Further, it is preferable that after the side inner form air panel and the bottom inner form air panel are installed, the side inner form air panel and the bottom inner form air panel are connected to each other by a bonding tape at an inner position thereof. . The air panel for the side inner formwork is fixed to the core muscle side, so that it shrinks from the concrete surface side during demolding (during degassing), and the demolding is surely performed by degassing. On the other hand, the bottom inner form air panel is connected to the side inner form air panel at the inner surface side position, so that the mold is contracted from the concrete surface side and demolding is surely performed by deaeration. Become.

On the other hand, the formwork device includes an outer formwork including at least a bottom formwork and a side formwork, and a shear reinforcement as a circumferential reinforcement installed inside the outer formwork. With respect to the braided rebar including the rebar arranged inside the shear reinforcement, air is taken in or deaerated to be inserted into a side space having a vertically long cross section surrounded by the shear reinforcement and the rebar. Two mat-shaped side inner formwork air panels that can be expanded and contracted by the air, and air inserted into a bottom position between the side inner formwork air panels in a space surrounded by the core streaks. A mat-shaped bottom inner formwork air panel that can be expanded and contracted by air intake or deaeration,
The upper muscle of the core muscle and the upper surface of the bottom inner formwork air panel
Lifting prevention spacer member inserted between
And characterized by the following.

[0011] In this case, is installed in an upper position of the side mold, it is desirable to a jig hanging set rebar Jisuru hanging the set rebar <br/> set Keru like.

In the present specification, the "core muscle"
The concept includes not only the reinforcing bars arranged as shear reinforcing bars, but also the disintegrating bars installed for the purpose of supporting the assembly panel and the air panel.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a sectional view of a formwork apparatus 1 for manufacturing a U-shaped PCa beam member according to the present invention, and FIG. 2 is a unitized view of the inner formwork air panels 5A to 5C. FIG. 5 is an enlarged perspective view of a main part showing a state in which the side panel inner form air panels 5A and 5B are inserted and installed.

The formwork apparatus 1 shown in this embodiment has a bottom formwork 3 provided with a bottom weir 3a on the upper surface side, and a side weir board 2a on the inner surface, which is supported upright on both sides of the upper surface of the bottom formwork 3. , 2b, and a pre-assembled rebar 4 having a core reinforcing bar 4B in addition to the shear reinforcement 4A inserted and installed inside the side molds 2A, 2B. And three air panels 5A to 5C for the inner formwork which are installed as supporting members.

More specifically, a plurality of, in this example, three H-shaped steels 10, 10 arranged in parallel to a floor surface F along a predetermined direction are laid on the upper side of the floor surface F. A bottom formwork 3 provided with a bottom weir 3a on the upper surface side, and a side formwork 2 comprising side weirs 2a, 2b on the inner surface, which are supported upright on both upper surfaces of the bottom form 3, respectively.
A and 2B are arranged to form an outer formwork.

At the upper part of the side molds 2A and 2B, a hanging jig 6 for a pre-assembled rebar is provided. The hanging jig 6 for the pre-assembled rebar is fixed to the side formwork 2A, 2
B, legs 11, 11 fixed respectively to the top of B, a beam portion 12 laid across the legs 11, 11, and a pair of right and left rebar locking hooks 13 suspended from the beam portion 12. ,
13 is a hanging jig, and the side formwork 2A,
It is provided at a total of two places, one at each of both ends in the longitudinal direction of 2B, or preferably, a plurality of them are provided at predetermined intervals along the longitudinal direction of the pre-assembled rebar 4 to suspend the pre-assembled rebar 4 without bending. Can be

Inside the outer die frame, the pre-assembled reinforcing bar 4 is suspended at a predetermined position by being suspended by the pre-assembled reinforcing bar suspending jig 5. The pre-assembled reinforcing bar 4 shown in the drawing includes a shear reinforcing bar 4A mainly provided on the outer peripheral portion, and main reinforcing bars 4C, 4C,... Disposed axially at each corner and lower side of the shear reinforcing bar 4A. A core bar 4B provided inside the reinforcing bar 4A,
It is composed of two assembling bars 4d and 4d arranged in the upper side along the axial direction to assemble the core bar 4B. The assembling bars are assembled at a location adjacent to the PCa member manufacturing yard, such as a crane. It is suspended inside the outer mold frame by the lifting equipment, and is suspended at a predetermined position by the pre-assembled reinforcing bar suspending jig 6. Air panels 5A to 5C for inner formwork to be described later
Is fixed to the pre-assembled reinforcing bar 4. Therefore, in order to secure the positioning accuracy of the inner formwork air panels 5A to 5C, it is necessary to accurately position the pre-assembled rebar 4, and the above-described hanging jig 6 for pre-assembled rebar is preferably used. You. Note that a pipe may be used instead of the main bars 4C.

The air panels 5A to 5C used as inner molds in the present mold apparatus are mat-shaped air structures having two substantially flat and parallel surfaces which can be expanded and contracted by air supply and deaeration. Body, for example,
No. 151604 can be used.

Two side air panels 5 serving as side inner molds
A, 5B and a bottom inner formwork air panel 5C serving as a bottom inner formwork make up an inner formwork in total of three sheets,
Pneumatic Panel 5A~5C for those in formwork, as shown in FIG. 2, cotter sheet 14 together covering the outer surface is provided as an air panel unit P _U, which is affixed by a surface fastener or adhesive. The cotter sheet 1
4 is a tarpaulin sheet 14 which is a kind of canvas for waterproof cloth.
A is a sheet material having a structure in which cotter forming dies 14B are arranged at a predetermined interval in A, and a cotter sheet 14C covering each cotter forming dies 14B is provided, and protects the inner formwork air panels 5A to 5C. It is used to increase the number of diversions. Therefore, if the air panel 5 for the inner
When the cotter forming protrusions are formed directly on A to 5C, the cotter sheet 14 can be omitted.

As the air panels 5A and 5B for the side inner formwork, the thickness is equivalent to or slightly larger than the side space width of the longitudinal cross section between the shear reinforcing bar 4A and the core bar 4B. (About several mm to several tens of mm), an air panel is used. As shown in FIG. 1, the air panel is contracted by deaeration and is provided in a side space between the shear reinforcement 4A and the core 4B. It is inserted and is fixed so as not to move by pressing the front and back surfaces of the side inner form air panels 5A and 5B against the shear reinforcing bars 4A and the core bars 4B by air supply. In addition, the air panels 5A, 5B for the side inner formwork
Are disposed with the cotter forming protrusions facing outward, respectively, and the cotter forming protrusions are previously arranged at positions not overlapping the shear reinforcing bars 4A.

When the installation of the side inner form air panels 5A, 5B is completed, as shown in FIG. 3, the outer side of the side inner form air panels 5A, 5B is stretched over the core 4B. The fixation tape 15 is used to fix to the core muscle 4B side. Air panel 5A for side inner formwork,
By fixing 5B to the core muscle 4B side, the air panels 5A and 5B for the side inner mold are contracted from the outer surface side (concrete surface side) at the time of degassing, and the peeling from the concrete surface is reliably performed. Become like In addition, as the fixing tape 15, an adhesive tape can be used instead,
It is desirable to use a hook-and-loop fastener tape which can be easily used repeatedly. As the fixing tape 15, a long tape continuous in the longitudinal direction of the air panels 5A and 5B for the side inner formwork may be used as shown by a broken line in FIG. Regarding the fixing position, it is desirable to dispose it in a plurality of stages in the vertical direction.

On the other hand, the bottom inner formwork air panel 5C disposed at the bottom has a dimension width slightly larger than the inner width of the core streaks 4B, specifically, the inner width of the core streaks 4B (the middle width). An air panel having a size width approximately larger than (strevel diameter × 2) + α is used, and the air panel 5A, 5B for the side inner formwork is in a space surrounded by the core streaks 4B.
It is located in the bottom position between. The air panel 5C for the bottom inner form is also similar to the air panels 5A and 5B for the side inner form,
By supplying air, both sides of the bottom inner formwork air panel are pressed against the core muscles 4B so as to be fixed so as not to move.

When the installation of the bottom inner formwork air panel 5C is completed, as shown in FIG. 1, the side inner formwork air panels 5A and 5B and the bottom inner formwork air panel 5C are provided.
At the inner surface side of C, the side inner form air panels 5A and 5B and the bottom inner form air panel 5C are connected by connecting tapes 20 and 20. By being connected to each other by the bonding tape 20, the air panel 5C for the bottom inner formwork contracts from the outer surface side (concrete surface side) at the time of degassing, so that peeling from the concrete surface is reliably performed.

The bottom inner mold frame air panel 5C is shown in FIG.
As shown in the figure, the core muscle 4B bites into the side of the bottom inner form air panel 5C due to the expansion, and the core muscle 4B
Side panels other than the part are air panels 5A, 5B for the side inner formwork
By pressing against the air gap, the gap at the joint portion of the air panel is closed, so that the concrete slag is prevented from leaking out when the concrete is poured. As shown in FIG. 1, the air panel 5 </ b> C for the bottom inner formwork is inserted and installed between the upper streak of the core bar 4 </ b> B and the upper surface of the bottom inner formwork air panel 5 </ b> C in order to prevent floating. to provided the migration prevention spacer member 16. In particular, when high-fluidity concrete is filled by press-fitting, it is necessary to provide the floating prevention spacer member 16 in order to resist pressure.
This ensures that the bottom inner formwork air panel 5C is lifted up.
You can really prevent it. In addition, the air supply and deaeration to the side and bottom inner formwork air panels 5A to 5C are performed by using a pressure reducing pump and a compressor while monitoring a pressure gauge provided in the middle of the air supply path. I do.

On the other hand, as shown in FIG. 5, for concrete casting, a funnel-shaped concrete inlet 17 is provided at an upper position of the outer formwork, and concrete is filled in a space between the outer formwork and the inner formwork. Make sure to cast it. The funnel-shaped concrete inlet 17 is provided with a simple vibrator 18 to promote the inflow of concrete, and a table vibrator 19 is provided to the formwork base in order to make the concrete dense and equalize the flow gradient. It is better to do so.

When the concrete placement is completed, the concrete is hardened and the mold is removed. Demolding is performed by degassing and shrinking from the side inner form air panels 5A and 5B and the bottom inner form air panel 5C and then removing them, while removing the base bolts for the side form 2A and 2B. .

[0028]

As described above in detail, according to the present invention, the installation and demolding of the inner formwork can be performed efficiently with the U-shaped PCa beam member having a core inside the shear reinforcing bars. The inner mold can be easily and reliably fixed in position and prevented from moving or floating at the time of placing concrete, thereby ensuring product accuracy.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a formwork device 1 for manufacturing a U-shaped PCa beam member according to the present invention.

FIG. 2 is a view showing how to unitize the inner formwork air panels 5A to 5C.

FIG. 3 is an enlarged perspective view of a main part showing an inserted state of the side panel inner frame air panels 5A and 5B.

FIG. 4 is a view taken along the line IV-IV in FIG. 1;

5 (A) is a sectional view, and FIG. 5 (B) is an end side view showing a formwork device for manufacturing a U-shaped PCa beam member in cross section.

FIG. 6 is a cross-sectional U-shaped PC manufactured by the formwork apparatus.
(A) is a front view and (B) is a side view showing a beam member.

FIG. 7 shows a U-shaped section P using a conventional air tube 50;
It is a figure which shows the manufacturing point of a Ca beam member.

FIG. 8 is a perspective view showing a manufactured PCa beam member 55 having a U-shaped cross section.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Form device for manufacturing PCa beam member with U-shaped cross section, 2A.2
B: Side formwork, 3: Bottom formwork, 4: Pre-assembled reinforcement, 4A: Shear reinforcement, 4B: Core reinforcement, 4C: Main reinforcement, 5A, 5B: Air panel for side inner formwork, 5C: Bottom inner form Air panel for frame,
6 ... Pre-assembled hanging bar jig, 15 ... Fixing tape, 16 ...
Floating prevention spacer member, 20 ... bonding tape

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Yuji Wakabayashi 47-3 Mita, Atsugi-shi, Kanagawa Sato Industrial Co., Ltd. (72) Inventor Atsumasa Nishio 47-3 Mita, Atsugi-shi, Kanagawa Sato Industrial Co., Ltd. (72) Inventor Kazuya Urakawa 47-3 Mita, Atsugi-shi, Kanagawa Prefecture, Sato Kogyo Co., Ltd. Inside the Central Technology Research Laboratory (72) Satoru Kondo 47-3 Mita, Atsugi-shi, Kanagawa Sato Kogyo Co., Ltd. (72) Inventor: Nobuo Tada, 336-1, Utsuzuka, Yashio-shi, Saitama Toyo Sangyo Co., Ltd. (72) Inventor: Kazuyasu Tamura 1536-3, Ojihara-shi, Ageo, Saitama (56) References JP-A-4-64665 (JP, A) JP-A-9-267323 (JP, A) JP-A-8-323725 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B 28B 7/00-7/46 B28B 23/00-23/22

Claims (5)

(57) [Claims] 1. A first step of installing an outer formwork including at least a bottom formwork and a side formwork; and a shear reinforcement as a circumferential reinforcement inside the outer formwork and the shear reinforcement. A second step of installing a braided rebar including a core bar arranged inside of a predetermined position, and two mat-shaped side inner formwork air panels which can be expanded and contracted by air intake or deaeration. One air panel for the bottom inner form is brought in, and the air panel for the side inner form is inserted into a side space having a vertically long cross section surrounded by the shear reinforcement and the core, and air is supplied to the side inner form. The front and back surfaces of the frame air panel are immovably fixed by being pressed against the shear reinforcing bars and the core bars, respectively, and the bottom inner form air panel is in a space surrounded by the core bars. Air pad for the side inner formwork Placed in the bottom position between Le, the third step of fixing immovably, the upper muscle of the core muscles by pressing the both sides of the air panel for the bottom portion formwork respectively core muscles by supply air Air panel top for bottom inner formwork
Insert a spacer member for preventing floating between
A fourth step, a fifth step of filling a space formed by the air panel for the side inner formwork and the air panel for the bottom inner formwork, and the outer formwork with the concrete, and the side inner formwork by deaeration of air. the use air panel and bottom portion formwork for air panel is deflated and performs demolding of inner mold, and a sixth step for demolding the outer molds, U-shaped cross section PCa beams characterized by comprising the Manufacturing method. 2. The method for manufacturing a U-shaped cross-section PCa beam member according to claim 1, wherein the side inner formwork air panel is fixed to the core line side so as to be inseparable. 3. After the side inner form air panel and the bottom inner form air panel are installed, the side inner form air panel and the bottom inner form air panel are connected to each other with a bonding tape at the inner surface side. The method for manufacturing a PCa beam member having a U-shaped cross section according to claim 1. 4. An outer formwork including at least a bottom formwork and a side formwork; a shear reinforcement as a circumferential reinforcement installed inside the outer formwork; and an inside of the shear reinforcement. For the braided rebar including the core to be arranged, inserted into the side space of the elongated cross section surrounded by the shear reinforcement and the core,
Two mat-shaped side inner formwork air panels that can be expanded and contracted by air intake or deaeration, and a bottom position between the side inner formwork air panels in a space surrounded by the core muscle A mat-shaped bottom inner formwork air panel inserted into the airbag and configured to be inflatable by inhalation or deaeration of air, an upper streak of the core muscle, and an upper surface of the bottom inner formwork air panel
Lifting prevention spacer member inserted between
And a formwork device for manufacturing a PCa beam member having a U-shaped cross section. 5. The formwork apparatus for manufacturing a PCa beam member having a U-shaped cross section as set forth in claim 4, further comprising a suspending jig for the braided reinforcement installed at an upper position of the side formwork and suspending the braided reinforcement.