JP2001219417A - Form system for u-shaped pc member, method for manufacturing u-shaped pc member and u-shaped pc member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a form system for a U-shaped PC member for forming the U-shaped PC member in which a convertible U-shaped inner form is disposed upside down, a concrete is placed from its bottom side to improve its chargeability and having a high strength, a method for manufacturing the U-shaped PC member and the U-shaped PC member. SOLUTION: A pair of inside plates 14, 14a are opposed at an interval. A bottom plate 16 is disposed at an interval between upper ends of these plates. Reinforcing bars 49 are arranged between the plates. A holding plate 56 for holding the bard and blocking between the inside plates and the bottom plate is disposed to form a sectionally inverted U-shaped inner form 18. An interval between lower parts of the inside plates is held constant by an interval varying means 26. A pair of outside plates 20, 20a are disposed at a gap δ at the side of the inside plates. The gap δ is blocked from below by a blocking part 24. The concrete is placed from above the bottom plate over the gaps between the inside plates and the outside plates between the outside plates.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a formwork apparatus for forming a U-shaped PC member by placing concrete between inner and outer forms, a method of manufacturing the U-shaped PC member, and a U-shaped PC member. In particular, the inner mold having a U-shaped cross section is allowed to be diverted by allowing the dimensional change, and the inner mold is formed in a high strength by being set in an inverted U-shape. The present invention relates to a U-shaped PC member forming apparatus, a U-shaped PC member manufacturing method, and a U-shaped PC member.

[0002]

2. Description of the Related Art In a recent RC building, structural members such as columns, beams and walls are constructed using a PC (precast concrete) formwork. The PC beam formwork for constructing the RC beam is formed as a PC member having a U-shaped cross section, and after being built at the site, concrete is poured into the U shape. A general method of forming such a U-shaped PC member is to dispose a U-shaped inner mold frame in a U-shaped outer mold frame with an appropriate space between both side surfaces and a bottom surface thereof. The concrete is poured into a U-shaped space provided between the outer mold frames, and the product is obtained by removing the mold after curing the concrete.

Incidentally, in such a mold apparatus for molding a U-shaped PC member, an inner mold which is integrally formed so as to have a U-shaped cross section is generally used. When forming a plurality of types of U-shaped PC members having different sizes, it is necessary to prepare as many inner forms as the number corresponding to the types. That is, since the inner mold cannot be diverted, the cost of the mold increases and the cost of the product increases.

[0004] Therefore, one inner mold is made of a plurality of U-shaped P
A mold device capable of providing an inexpensive product by being convertible to a C member is disclosed in Utility Model Registration No. 25284.
Known as No. 36. That is, in this formwork apparatus, an L-shaped form is arranged on both sides, and a flat form is arranged between the bottom sides of these L-form forms, and the width of the flat form is changed to thereby form an inner form. Can be easily changed.

When the RC beam is constructed using the U-shaped PC formwork, the PC formwork is installed between the column members so that the U-shaped concave space faces upward at the construction site. After arranging reinforcing steel in the space, concrete is poured.

[0006]

However, in such a conventional U-shaped PC member formwork apparatus, the U-shaped inner formwork is erected in the outer formwork, that is, the base is arranged so that the bottom side is downward. To form a space having a U-shaped cross section between the inner and outer molds,
Concrete is poured into the U-shaped space from the narrow upper opening of the inner and outer frames. At this time, the upper end opening is to be provided at two places on the left and right separated by the thickness of the U-shaped PC member to be molded. In this case, for example, concrete poured into the U-shaped space from one opening is Only after this has passed through the bottom of the U-shaped space and wrapped around to the other opening, the inside of the form will be filled with concrete.

That is, the cast concrete has a narrow U
It is necessary to reach the mold space from one opening side to the other opening side through the bottom part, and one opening side which is the concrete casting side and the other opening side where concrete reaches Finally, the concrete level becomes the same level.Therefore, due to the large passage resistance and the lack of pressure difference between the casting start point and the end point, the concrete filling property is extremely poor, and nests are formed inside the concrete. It will be easier.

In consideration of this, it is conceivable to cast concrete from one opening to some extent and then to cast concrete from the other opening in order to improve the filling property of the concrete as much as possible. In this case, the necessity of placing concrete in a plurality of times complicates the concrete placing operation, forms a boundary surface between the primary concrete and the secondary concrete, and removes air. PC may be involved
The integration of the entire member may be impaired.

Further, by using a concrete having a high fluidity, even if the concrete is poured from one opening, the filling property into the formwork can be improved. However, the use of highly fluid concrete increases the cost of the product.

[0010] In addition, since large buoyancy acts on the inner formwork during concrete casting, the inner formwork must be heavy in weight so as not to rise due to the buoyancy, resulting in an increase in size. Furthermore, the joining mechanism between the mold frames is complicated, and the manufacturing cost is increased.

On the other hand, when the conventional U-shaped PC member is used as a PC beam formwork for RC beams, reinforcing bars and auxiliary bars are provided inside the U-shaped PC members in order to secure the strength of the formed RC beams. In order to arrange reinforcement using the supporting members that support them,
There was a problem that the work of arranging the bars on the site became complicated and time-consuming.

In view of the above, the present invention has been made in view of the above-mentioned conventional problems, and a U-shaped inner form which can be diverted is arranged upside down, and concrete is poured from the bottom side thereof. U-shaped PC that improves the filling property of concrete and forms a high-strength U-shaped PC member
Member formwork device, method for manufacturing U-shaped PC member, and U-shaped P
It is intended to provide a C member.

[0013]

SUMMARY OF THE INVENTION In order to achieve the above object, a mold apparatus for a U-shaped PC member according to the present invention comprises a pair of inner plates which are opposed to each other with a space therebetween, and a pair of inner plates which are located between upper ends of the inner plates. A bottom plate arranged at an interval, and an inner mold having an inverted U-shaped cross section including a holding plate that closes between the inner plate and the bottom plate and holds a reinforcing bar arranged between the inner plates, An outer mold frame comprising a pair of outer plates arranged side by side with a gap between the inner plate and a closing portion for closing the gap from below, and an interval variable means for expanding and contracting the interval between the lower portion of the inner plate Wherein a U-shaped PC member is produced from concrete cast between the outer plates over the gap between the inner plate and the outer plate from above the bottom plate.

Therefore, in this U-shaped PC member form device, the outer plate of the outer form is arranged beside the inner plate of the inner form with the inner and outer forms set. A gap is formed between the outer plates, and the gap between the inner and outer plates is closed by a closing portion from below. On the other hand, the upper end of the outer plate is largely open, and the open portion faces the bottom plate and the two holding plates disposed between the upper ends of the inner plate. At this time, the holding plate holds the reinforcing bars arranged between the inner plates while closing the gap between the upper end portion and the bottom portion of the inner plate. Can be prepared. Then, by casting concrete from the open portion, the concrete fills the gap between the inner and outer plates, and then fills the bottom plate and the holding plate. And
After curing in this state and concrete hardening, the mold is released. At the time of removing the mold, the outer mold frame can be easily removed because the outer plate is disposed outwardly, while the inner mold frame reduces the distance between the lower portions of the inner plate by means of variable spacing, thereby reducing the inner plate. While peeling off from the concrete, the inner plate is separated from the holding plate, and the bottom plate and the holding plate are peeled off from the concrete and removed. In this state, the U-shaped PC member is turned upside down.

In forming the U-shaped PC member, concrete can be poured from a large open portion between the outer plates, and a narrow gap formed between the inner and outer plates is bent. Since there is no part and the concrete faces only vertically and concrete is filled from above, the filling is performed easily and reliably. Next, after the narrow gap between the inner and outer plates is filled with concrete, concrete is poured over the bottom plate of the inner formwork to form the bottom of the U-shaped PC member. At this time, the concrete placement amount is adjusted so that the depth of the concrete covering the upper side of the bottom plate becomes the thickness of the bottom of the U-shaped PC member.
As described above, since the portion where the flow resistance increases when the concrete is filled can be eliminated, the filling property of the concrete is improved, and the necessity of using high-flow concrete is eliminated. Also, the PC member to be formed has a cross section inverted U
Because it is shaped like a letter, buoyancy does not work on the inner formwork even when concrete is cast. Therefore, it is not necessary to make the inner mold frame heavy in consideration of buoyancy, and it is possible to reduce the weight and size. Further, since the inner mold is composed of a pair of inner plates, a bottom plate forming a bottom portion, and two holding plates closing between them, it is necessary to replace the bottom plates or holding plates with different widths. Thus, the width of the inner frame can be made variable and can be applied to the manufacture of various U-shaped PC members having different sizes.

In the method of manufacturing a U-shaped PC member according to the present invention, a pair of inner plates are opposed to each other at an interval, and a bottom plate is disposed between upper ends of the inner plates at an interval therefrom. At the same time, a reinforcing bar interposed between the inner plates is arranged at the interval between the bottom plate and the inner plate, and the holding plate holding the reinforcing bars closes the space between the inner plate and the bottom plate to form an inverted U-shaped cross section. Forming an inner mold, forming an inner mold with a gap between the lower part of the inner plate being kept constant by a variable distance means, and disposing a pair of outer plates with a gap on the side of each inner plate An outer formwork setting step of closing the gap from below with a closing portion, a concrete casting step of casting concrete between the outer plates from the bottom plate over the gap between the inner plate and the outer plate, After curing, the lower part of the inner plate is After narrowing the distance, characterized in that a demolding step of demolding from the inner mold and the outer mold.

Therefore, in the method of manufacturing a U-shaped PC member using the above-described formwork apparatus, the inner formwork is formed in the inverted U-shape by the pair of the inner plate, the bottom plate and the two holding plates in the inner formwork setting step. And the reinforcing bars can be held by the holding plate and provided between the inner plates.

Further, a gap is formed between the outer plate and the inner mold by the outer mold setting step. Then, in the concrete casting step, concrete can be easily poured from the open portion between the largely opened outer plates into the gap. Next, it moves to the demolding process by hardening of the poured concrete, and in particular, after forcibly narrowing the distance between the lower portions of the inner plates by the interval variable means, by demolding from the inner and outer molds, The U-shaped PC member that has been turned upside down can be easily taken out.

Also, in the U-shaped PC board of the present invention, a U-shaped PC having a pair of side portions and a bottom portion connecting the side portions is provided.
A member, provided between an upper end portion of a pair of inner plates facing each other at a distance and a bottom plate arranged at an interval from these upper end portions, closing between the bottom plate and the inner plate; An inner mold having a holding plate for supporting a reinforcing bar projecting from a bottom portion of the U-shaped PC member between a pair of side portions, and a concrete casting space having an inverted U-shaped cross section between the inner mold and the inner mold. It is formed by casting concrete between the outer formwork to be sectioned.

Therefore, since the reinforcing bar is projected from the bottom between the side portions of the formed U-shaped PC member, concrete is cast when the RC beam is constructed using the U-shaped PC member. Without the need to arrange reinforcement between the sides before
Work on site can be greatly reduced. Further, the reinforcing bars prearranged on the PC member are held by the holding plate at the time of manufacturing, so that they can be reliably provided at a desired position without being moved even at the time of placing concrete.

[0021]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. 1 to 6 show U of the present invention.
FIG. 1 shows an embodiment of a mold apparatus for a mold PC member, FIG. 1 is a perspective view showing an end of the mold apparatus, FIG. 2 is an enlarged view of a portion A in FIG.
3 is an enlarged sectional view of a part B in FIG. 3, FIG. 5 is an enlarged sectional view of a part C in FIG. 3, and FIG. 6 is an enlarged sectional view showing a modification of the closing plate. is there.

Forming device 12 for U-shaped PC member 10 of the present invention
The basic structure of this is that a pair of inner plates 14, 14a opposed to each other with a predetermined interval S1, and these inner plates 14, 1
A bottom plate 16 disposed between the upper ends of the bottom plates 4a and spaced apart therefrom, and a reinforcing bar 49 for closing between the inner plates 14, 14a and the bottom plate 16 and arranging reinforcing bars between the inner plates 14, 14a. An inner frame 18 having an inverted U-shaped cross section formed of a holding plate 56 to be held, and an inner mold 14, which is arranged at an appropriate distance beside the inner plates 14, 14a, is formed higher than the inner plates 14, 14a, and An outer frame 22 including a pair of outer plates 20 and 20a whose upper ends are opened, and a closing portion 24 for closing between the inner plates 14 and 14a and lower ends of the outer plates 20 and 20a; A cut edge plate 21 for closing between the molded ends of the outer plates 14a and the outer plates 20 and 20a and a lower end of the inner plates 14 and 14a are provided. Under the mold A space variable means 26 for forcibly narrowing the distance between the parts, and concrete is poured between the inner and outer forms 18 and 22 from the upper end open portion 28 of the outer plates 20 and 20a, and the concrete is used to form the bottom plate 16 with the concrete. Cover the top of the.

Further, a U-shaped PC using the above-mentioned formwork device 12
The method of manufacturing the member 10 is such that a pair of inner plates 14 and 14a are opposed to each other with a predetermined interval S1,
The bottom plate 16 is arranged between the upper end portions of the inner plates 14 with a space therebetween, reinforcing bars 49 are arranged between the inner plates 14, 14a, and the inner plates 14, 14a are held by holding plates 56 holding the reinforcing bars 49.
The inner frame 18 having an inverted U-shaped cross section formed by closing the space between the inner plate 14 and the bottom plate 16 is supported by the support member 30, and the interval between the lower ends of the inner plates 14 and 14 a is made constant by the interval variable means 26. The step of setting the inner form to be held,
At the molding end of 4a, a wooden edge plate 21 is attached, and a pair of outer plates 20, 20a are arranged at appropriate intervals beside the inner plates 14, 14a.
An outer frame setting step of closing the lower end portion of the outer plates 20 and 20a with the closing portions 24;
A concrete casting step of casting concrete from the upper end open portion 28 of the bottom plate 16 so as to cover above the bottom plate 16 between the inner formwork 14, 14a and the outer formwork 20, 20a.
After the concrete is hardened, the wood edge plate 21 and the outer plates 20 and 20a are removed from the mold, and the U-shaped PC member 10 is lifted up. The distance between the inner plates 14 and 14a is removed by forcibly reducing the distance, and the inner plates 1 and 14a are removed.
And a releasing step of releasing the bottom plate 16 and the holding plate 56 between the 4, 14a.

That is, the U-shaped PC member forming apparatus 12 according to the present embodiment will be described by taking as an example a case where a PC beam formwork 10 is formed as a U-shaped PC member, and as shown in FIGS. The mold includes a mold 18 and an outer mold 22 disposed outside the mold 18. The inner frame 18 includes a pair of left and right inner plates 14, 14a.
And a bottom plate 16 for closing between the upper ends of the inner plates 14, 14a, and two holding plates 56 disposed between the inner plates 14, 14a and the bottom plate 16, respectively, to form an inverted U-shaped cross section. Be composed. The outer frame 22 is mainly composed of a pair of left and right outer plates 20 and 20a, and the inner plates 14 and 14a.
a and the lower end portions of the outer plates 20 and 20a are closed by the surface plate 34. The inner plates 14, 14a and the bottom plate 1
For 6, a concavo-convex plate such as a checker plate is used, and the concavo-convex portion 17 is arranged on the surface (concrete casting side).

The surface plate 34 is provided in a pair corresponding to the outer plates 20 and 20a, is arranged in parallel with a predetermined width S2 on the work floor 32, and the upper surface of the surface plate 34
It is 4. That is, the surface plate 34 includes upper and lower flanges 34.
a, 34b and a web 34c, and the upper surface of the upper flange 34a is
Becomes The outer plates 20, 20a are connected to the inner plates 14, 1 respectively.
4a, the outer plates 20, 20
a are connected by a connecting member 36, and the distance between the outer plates 20 and 20a is changed by the connecting member 36.
Is held by

A bent margin 38 is formed inward at the upper ends of the inner plates 14, 14a, and an extension member 40 is fixed to the lower surface of the distal end of the bent margin 38. This extension member 4
Numeral 0 is formed of an angled material having an L-shaped cross section, one outer surface 40a of which forms a horizontal plane, is superimposed on the lower surface of the distal end of the bent margin 38 and extends from the distal end, and the other outer surface 40b is bent. It is formed so as to form a vertical plane parallel to the tip portion of the. Further, extension members 40 are similarly fixed to the lower surfaces of both end portions of the bottom plate 16.

Then, as shown in FIG.
The vertical outer surfaces 40b of the extension members 40 fixed to the base plate 4a and the bottom plate 16 are arranged so as to face each other, and the holding plate 56 is bridged over the horizontal outer surfaces 40a of the extension members 40 to close the outer surfaces 40b. are doing. The two holding plates 56 and the bottom plate 16 close the space between the upper ends of the inner plates 14, 14a.
The upper surfaces of the two holding plates 56 and the bending margin 38 are flush with each other.

As shown in FIG. 2, the holding plate 56 has a recess 56a for holding the inner stirrup 49 arranged between the inner plates 14, 14a in the longitudinal direction of the formwork device 12. A plurality is provided at appropriate intervals along the direction.
The concave portion 56a is cut out from the end of the holding plate 56 on the bottom plate 16 side and has a width substantially equal to the outer diameter of the inner stirrup 49. Further, the concave portion 56a is
Are closed between the inner plates 14, 14a and the bottom plate 16 with substantially no gap by the inner stirrup 49. Further, an elastic member such as a rigid rubber having alkali resistance and oil resistance is provided on the inner peripheral surface of the concave portion 56a as necessary.
The gap between the recess 56a and the inner stirrup 49 may be closed.

On the back (opposing surface) of the inner plates 14, 14a, a rib 42 extending in the vertical direction is provided.
The ribs 43 are formed at predetermined intervals in the longitudinal direction of the inner plate 14a, and the lower ends of the inner plates 14, 14a are also provided with ribs 43. These ribs 42, 43 prevent the inner plates 14, 14a from bending under the pressure of concrete. To prevent. Furthermore,
On the lower surface of the bottom plate 16, between the extension members 40, the bottom plate 1
6, a plurality of reinforcing ribs 44 using an angle material are fixed at predetermined intervals in the length direction, thereby preventing the bottom plate 16 from being bent. If it can withstand sufficiently, it can be omitted.

The inner plates 14, 14a are arranged such that their lower ends are located inside the platen 34, and
The inner frame 18 is supported at a predetermined height by the support member 30 such that the lower ends of the inner plates 14 and 14a project slightly below the closing portion 24. The support member 30 is configured by providing a mounting member 30b at the upper end of the leg 30a.
Is mounted, the load of the inner mold 18 is supported by the support member 30.

A jack 26 is mounted between the lower ends of the inner plates 14 and 14a as a variable distance means. Extendable rods 26a protrude from both ends of the jack 26, and the distal ends of the extendable rods 26a are rotatably pin-connected to the ribs 42 on the back surfaces of the inner plates 14, 14a. The length of the jack 26 is set such that the upper and lower ends of the inner plates 14, 14a have the same distance when the inner frame 18 is set. Instead of the jack 26, a means for varying the distance between the lower end portions of the inner plates 14, 14a may be employed by a method in which a reaction force is applied to the surface plate 34 by a pressing member or the like.

When the PC beam formwork 10 is formed using the inner and outer formworks 18 and 22, the jack 26 is first used.
In the state where the interval between the lower ends of the inner plates 14, 14a is maintained,
The inner plates 14, 14a are supported by the support member 30. At this time, the support member 30 is attached to the inner plates 14, 14a.
3 units are installed at both ends in the length direction and at the center. Then, the bottom plate 16 is placed between the inner plates 14 and 14a with a space therebetween. Thereby, the inner plate 1
A slit 18a is formed between each of the base plates 4 and 14a and the bottom plate 16. In this state, a plurality of auxiliary streaks 46 are arranged in parallel along the length direction of the formwork device 12 on the upper surface of the bent margin 38 of the inner plates 14 and 14a and the bottom plate 16. At this time,
Instead of the auxiliary muscle 46, a lower main muscle may be used. In this embodiment, the auxiliary reinforcement 46 and the lower main reinforcement are the PC beam form 1
Although the length is set so as not to protrude from the beam end of 0, the lower main bar may protrude from the beam end in order to join with an external reinforcing bar.

Next, the support member 30 disposed at one end in the longitudinal direction of the inner plates 14, 14a is once removed, and
Half of all the inner stirrups 49 arranged in the C-beam form 10 are fed from the ends along the slits 18a, and the support member 30 is set again at the original position. Similarly, half of all the inner stirrups 49 are arranged from the other end side. The inner stirrup 49 is formed in an annular quadrilateral, one side of which is arranged on the auxiliary muscle 46 on the bottom plate 16, and two sides adjacent to the side are slits 1.
The inner plates 14, 14 a are arranged at predetermined intervals in the length direction of the inner plates 14, respectively, and are suspended from the auxiliary muscles 46. Then, the slit 18a is
And the inner stirrup 49 is
The inner frame 18 is formed while being held by the concave portion 56a provided in the inner mold 6.

The method of arranging the inner stirrup 49 and forming the inner frame 18 using three support members 30 has been described above. However, four or more support members 30 may be used. , The inner stirrup 49 is fed along the slit 18a, and the support members 30 are sequentially moved and arranged in accordance with the feed.

Then, a large number of outer stirrups 48 bent in an inverted U-shape are sequentially fed in from the end of the inner mold 18 and arranged at predetermined intervals in the length direction of the inner mold 18. At this time, feeding the outer stirrup 48 becomes easier by slightly shrinking the telescopic rod 26a of the jack 26 to narrow the interval between the inner plates 14, 14a. Further, the auxiliary muscle 47 is provided on the side of the outer stirrup 48.
And the auxiliary stirrups 46 and 47 and the outer stirrup 48 are connected by a binding line.

After the reinforcing arrangement is completed, as shown in FIG. 1, a wooden edge plate 21 is attached to the molding end of the inner mold frame 18 so as to cover the outer periphery of the inner mold frame 18. , 20a with a gap δ between the inner plates 14, 14a.
While being placed and fixed on the surface plate 34,
The upper ends of 0 and 20a are fixed with the connecting member 36.

The outer stirrup 48 has a lower end portion on both sides projecting downward from the closing portion 24 through a space between the inner plates 14, 14a and the platen 34. In this embodiment, this is shown in FIG. Thus, the corresponding portion is hermetically closed using the elastic foam 50. That is, an angle member 52 that forms a surface facing the inner plates 14 and 14a is vertically provided from the surface plate 34, while the facing surface 52 is formed on the surface of the inner plates 14 and 14a.
The contact plate 54 is spot-welded at a position opposed to. Therefore, the outer stirrup 48 is located between the angle member 52 and the backing plate 54, and the elastic foam 50 is provided between the facing surface 52 and the backing plate 54, and the outer stirrup 48 is provided. Is designed to seal the insertion part. As the elastic foam 50, a rigid rubber material having alkali resistance and oil resistance is used. In addition, the closing portion 24
Alternatively, the outer stirrup 48 may be held with the concave portion 24a as shown in FIG. 6 as if the inner stirrup 49 was held by the holding plate 56.

Then, in this manner, the inner and outer mold frames 18,
In the state where the installation of the concrete 22 is completed, a concrete placing space S is formed between the two, and concrete is poured from the upper end open portion 28 of the outer plates 20 and 20a. The filling space S is filled while the outer stirrup 48 and the inner stirrup 49 are buried. At this time, the amount of casting is adjusted so that the poured concrete covers the upper part of the bottom plate 16 of the inner formwork 18 with a depth equal to the bottom thickness of the PC beam formwork 10. Then, after the upper surface of the poured concrete is leveled, the concrete is cured and waits for the concrete to harden.

When the concrete is hardened by this curing, first, the outer plates 20, 20a and the wooden edge plate 21 are released from the mold while giving an impact by impact or the like, and then the PC beam form 10 is lifted by a few cm by an overhead crane or the like. . In this suspended state, the PC beam form 10 is lifted from the closing portion 24, and the lower ends of the inner plates 14, 14a are freely movable. The jack 26 is operated while hitting the inner plates 14, 14a. The telescopic rod 26a is shortened. Then, the distance between the lower ends of the inner plates 14, 14a is forcibly narrowed, so that the separation between the inner plates 14, 14a and the concrete proceeds from the lower portion, reaches the bending margin 38, and is released. Then, the detached inner plates 14, 14
a is moved inward so as not to hinder the lifting of the PC beam formwork 10. Finally, the bottom plate 16 and the holding plate 56 are removed while being hit. In this state, the PC beam formwork 10 is completely removed, and is lifted upside down and transported to the stock yard. The method of lifting the PC beam form 10 by several cm to disassemble the inner form 18 has been described above. However, the leg 30a of the support member 30 may be shrunk by several cm and dismantled. The PC beam form 10 with the attached 18 may be lifted upside down, temporarily inverted, and then the inner form 18 may be dismantled according to the above procedure.

Then, the P formed by the above method is
As shown in FIGS. 7 and 8, the C beam formwork 10
a and a bottom portion 10b connecting the side portions 10a form a U-shaped cross section, and an outer stirrup 4 is formed from the upper end of the side portion 10a.
8 project upward, and the bottom 10 between the side portions 10a
The inner stirrup 49 projects upward from b and is provided between the side parts 10a to form an integral part.

Therefore, in the formwork device 12 of the PC beam formwork 10 of this embodiment, the inner formwork 18 is turned upside down to
When the PC beam formwork 10 is formed, concrete can be poured from the large open portion 28 formed at the upper end portion between the outer plates 20 and 20a. , 14a and outer plates 20, 20
The narrow gap δ formed between the gap and the space a has no bent portion and faces vertically, and is only filled with concrete from above, and the filling is easily and reliably performed.

Therefore, since the portion where the flow resistance increases when the concrete is filled can be eliminated, the filling property of the concrete is improved, and it is not necessary to use a high-flow concrete.

Also, since the PC beam form 10 to be formed is formed in an inverted U-shaped cross section, no buoyancy acts on the inner form 18 even when concrete is cast. Therefore, the inner frame 18 does not need to be heavy in consideration of buoyancy, and can be reduced in weight and size. Furthermore, since the load applied to the bottom plate 16 and the holding plate 56 is only the weight of the concrete forming the bottom 10b of the PC beam form 10, the joining mechanism of the inner plates 14, 14a, the bottom plate 16 and the holding plate 56 can be simplified.

The inner frame 18 is formed of a pair of inner plates 1.
4, 14a, a bottom plate 16 arranged at an interval between the upper ends of the inner plates 14, 14a, and two holding plates 56 for closing between them, the bottom plates having different widths. By changing to the 16 or the holding plate 56, the width of the inner mold 18 can be made variable and can be diverted to the manufacture of various PC beam molds 10 having different sizes. If members having extra height and length are used as the inner plates 14 and 14a, not only the beam width but also the beam height (beam height) and the length of the PC beam differ. The production of the mold 10 becomes possible.

Also, the inner frame 18 has inner plates 14, 14.
a and the bottom plate 16 are spaced apart from each other and a slit 18a
Are formed, so that the inner plates 14, 14a
An inner stirrup 49 connected between them is provided in advance on the PC beam formwork 10, so that a high-strength PC beam formwork can be formed. Also, the holding plate 5 for closing the slit 18a
6 includes a plurality of recesses 5 for holding the inner stirrup 49.
Since the inner stirrups 49 are provided at intervals, the inner stirrup 49 can be easily arranged. Further, since the inner stirrup 49 is held, the inner stirrup 49 does not move even when the concrete is cast, and can be provided at a desired position. A high-strength PC beam formwork 10 can be formed in a well-balanced manner. In addition, since neither the inner stirrup 49 nor the outer stirrup 48 requires a separate jig or the like for supporting the reinforcing bars, it is easy to perform the reinforcing work and greatly reduce the manufacturing cost. Can be.

The inner frame 18 is composed of the bottom plate 16 and the inner plate 1.
4, 14a and the holding plate 56, and the bottom plate 16 and the holding plate 56 are simply placed on the support member 30, so that the assembly and disassembly of the inner mold 18 can be performed with one touch. The installation work of the inner formwork 18 can be performed quickly. Furthermore, since the upper ends of the outer plates 20 and 20a are largely open, the reinforcing bars such as the auxiliary bars 46 and 47, the inner and outer stirrups 48 and 49 can be easily assembled in the formwork device 12, The step of assembling in another place can be omitted. As described above, since the formwork operation and the rebar assembling are simplified and performed quickly, the productivity can be improved and the cost of the product can be reduced.

The PC beam formwork 10 is used when constructing an RC beam, is carried into the site, is arranged in a U-shaped cross-section such that the bottom 10b faces downward, and is installed between the column members. After the floor is laid, concrete is poured into the inside of the concave portion of the U-shaped PC beam formwork 10 to be integrated with the upper floor slab.
At this time, the inner stirrup 49 is embedded in the bottom portion 10b and is provided in a concave portion of the PC beam formwork 10. Further, the upper end of the inner stirrup 49 and the upper end of the outer stirrup 48 are buried and integrated in the concrete on the upper floor surface. At this time, the inside of the concave portion is the uneven portion 1 of the inner plates 14 and 14a and the bottom plate 16.
7, it has good adhesion to concrete cast on site during beam construction,
It becomes a structure having high strength integrated with post-cast concrete.

Also, a PC used for this RC beam construction work
Since the beam formwork 10 is already provided with the inner stirrup 49 at the manufacturing stage so as to protrude into the concave portion, it is possible to reduce the work of arranging reinforcing bars on site and to greatly reduce the construction time.

In the present embodiment, the inner stirrup 49 has an annular quadrilateral shape, and the outer stirrup 48 has an inverted U-shaped bent shape.
9. Both the outer stirrup 48 and the outer stirrup 48 may be in any shape, and any of them may be combined.

In this embodiment, the holding plate 56 is formed as a member different from the inner plates 14, 14a and the bottom plate 16. However, the present invention is not limited to this, and the holding plate 56 opens and closes the slit 18a. If possible, the end opposite to the concave portion 56a in which the inner stirrup 49 disposed in the slit 18a is held is connected to any of the inner plates 14, 14a or the bottom plate 16 via a hinge or the like. It does not matter.

In the present embodiment, the PC beam formwork 10 has been described as an example of the U-shaped PC member, but the present invention is not limited to this and can be preferably applied to PC products having a U-shaped cross section. .

Further, in the present embodiment, the form as a simple U-shaped PC member has been described. As a modified example, a U-shaped PC member having a slit at the bottom 10b for providing an RC wall under the beam is provided. It is also possible to form an L-shaped PC member with reinforcing bars to provide RC members on the side surfaces of the members. In this case, a partition plate is provided on the bottom plate 16 or the holding plate 56 of the inner mold frame 18 and concrete is cast, whereby a PC member having a slit or a predetermined shape other than a U-shaped can be extremely easily manufactured. be able to.

[0053]

As described above, the formwork apparatus for the U-shaped PC member, the method for manufacturing the U-shaped PC member, and the U-shaped PC according to the present invention.
As for the member, the inner plate and the bottom plate are provided at a distance and the holding plate is arranged between them, so that it can be diverted to manufacture PC products of various sizes, and the inner mold is installed upside down By doing so, it is possible to provide a large open part at the upper end of the outer plate of the outer formwork, making it easier to cast concrete, and to improve the fluidity of concrete throughout the inner and outer forms. Can be secured. For this reason,
The productivity can be improved without using high-fluidity concrete, and the cost of the product can be reduced. In addition, since the interval between the inner plates can be enlarged or reduced at the time of demolding by the interval variable means provided between the lower portions of the inner plates, the demolding operation of the inner mold can be easily performed.

Further, since a reinforcing plate interposed between the inner plates is held by a holding plate for closing between the inner plate and the bottom plate,
Reinforcing bars serving as the core of the mold PC member can be provided in advance in the manufacturing stage, and the working time can be reduced by easy bar arrangement work, and the manufacturing cost can be reduced.

Further, since the U-shaped PC member is provided with reinforcing bars between its side portions, when used as an RC form, the labor for arranging reinforcing bars on site can be greatly reduced, and the post-cast concrete can be used. An excellent effect of being able to form a high-strength structure integrated with the above is exhibited.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an end of a formwork apparatus according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a portion A in FIG.

FIG. 3 is a cross-sectional view of a formwork device showing one embodiment of the present invention.

FIG. 4 is an enlarged sectional view of a portion B in FIG.

FIG. 5 is an enlarged sectional view of a portion C in FIG. 3;

FIG. 6 is an enlarged sectional view showing a modification of FIG. 5;

FIG. 7 is a front view of a U-shaped PC member showing one embodiment of the present invention.

8 is a perspective view showing a state in which the U-shaped PC member of FIG. 7 is erected.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 PC beam formwork (U-shaped PC member) 10a Side part 10b Bottom part 12 Formwork device 14, 14a Inner plate 16 Bottom plate 18 Inner formwork 20, 20a Outer plate 22 Outer formwork 24 Closing part 26 Jack (interval variable means) 28 Open part 49 Inner stirrup (reinforcing bar) 56 Holding plate

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Noriyuki Furuya 4-640 Shimoseito, Kiyose-shi, Tokyo Co., Ltd. Inside the Obayashi Gumi Technical Research Institute Co., Ltd. (72) Inventor Yasuhiko Masuda 4-640 Shimoseito, Kiyose-shi, Tokyo Co., Ltd. F term in the laboratory (reference) 2E163 FA12 FD02 FD23 FD43 FD44 FD46 FF12 4G053 AA03 AA13 BB03 BC03 BC08 BD07 BE04 BE08 EA13 EB06 4G058 GA01 GB02 GC03 GD16 GF06

Claims (3)

[Claims] A pair of inner plates facing each other at an interval;
Cross-section reverse of a bottom plate disposed between the upper ends of the inner plates with a space therebetween, and a holding plate for closing the space between the inner plates and the bottom plate and holding reinforcing bars arranged between the inner plates. An outer mold comprising a U-shaped inner mold, a pair of outer plates arranged on a side of the inner plate with a gap therebetween, and a closing portion for closing the gap from below; a lower portion of the inner plate; And a variable interval means for expanding and contracting the interval between the outer plates, wherein the U-shaped PC member is manufactured from concrete cast over the gap between the inner plate and the outer plate from above the bottom plate. Forming device for U-shaped PC members. 2. A pair of inner plates are opposed to each other at an interval, and a bottom plate is arranged between the upper ends of the inner plates at an interval therefrom. Reinforcing bars are arranged on the inner plate, and the inner plate and the bottom plate are closed with a holding plate for holding the reinforcing bars to form an inner mold having an inverted U-shaped cross section. An inner mold frame setting step of keeping the distance of the inner mold constant by means of a variable distance means, and disposing a pair of outer boards with a gap beside each inner board, and closing the gap with a closing portion from below with an outer mold. A frame placing step; a concrete placing step of placing concrete between the outer plates over the gap between the inner plate and the outer plate from above the bottom plate; After reducing the distance, remove the mold from the inner mold and outer mold. A method of manufacturing a U-shaped PC member using a formwork device, comprising: 3. A U-shaped PC member having a pair of side portions and a bottom portion connecting the side portions, wherein the upper end portions of a pair of inner plates opposed to each other with a space therebetween are spaced apart from the upper end portions. Between the bottom plate and the inner plate, and the U-shaped P
An inner mold having a holding plate for supporting a reinforcing bar projecting from a bottom portion of the C member to between the pair of side portions, and an outer space defining an inverted U-shaped concrete casting space between the inner mold and the inner mold. A U-shaped PC member formed by casting concrete between the mold and a mold.