JP3675276B2 - Forming apparatus for U-shaped PC member and method for manufacturing U-shaped PC member - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a mold apparatus for molding a U-shaped PC member by placing concrete between inner and outer molds, and a U-shaped PC member.Regarding manufacturing methodIn particular, the inner mold frame having a U-shaped cross section is allowed to be diverted by allowing dimensional change, and the inner mold frame is formed with high strength by being set in an inverted U-shape. U-shaped PC member formwork apparatus, U-shaped PC memberIt relates to a manufacturing method.
[0002]
[Prior art]
In recent RC buildings, structural members such as columns, beams and walls are constructed using 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 this is built in the field, concrete is placed inside the U shape. A general molding method for such a U-shaped PC member is to arrange a U-shaped inner mold frame in a U-shaped outer mold frame with appropriate spaces between both side surfaces and the bottom surface thereof, Concrete is placed in a U-shaped space provided between the outer molds, and the product is obtained by demolding after curing the concrete.
[0003]
By the way, in such a mold apparatus for molding a U-shaped PC member, an inner mold that is integrally formed so as to have a U-shaped cross section is generally used. In the case of forming a plurality of types of U-shaped PC members having different sizes, it is necessary to prepare as many inner mold frames as the number corresponding to the types. In other words, since the inner mold cannot be diverted, the mold cost increases and the cost of the product is inevitably increased.
[0004]
Therefore, a formwork apparatus that can provide an inexpensive product by making one inner formwork divertable to a plurality of types of U-shaped PC members is known as Utility Model Registration No. 2528436. That is, in this mold apparatus, an L-shaped formwork is arranged on both sides, a flat formwork is arranged between the bases of these L-shaped forms, and the width of the flat formwork is changed, whereby the inner formwork The width of can be easily changed.
[0005]
Moreover, when constructing RC beams using this U-shaped PC formwork, the PC formwork is installed between the column members so that the recessed space formed in a U shape at the construction site faces upward. After placing reinforcing bars in the space, place concrete.
[0006]
[Problems to be solved by the invention]
However, such a conventional U-shaped PC member formwork apparatus has a U-shaped inner mold frame standing upright in the outer mold frame, that is, with its bottom side facing downward, between these inner and outer mold frames. A space having a U-shaped cross section is formed in the U-shaped space, and concrete is placed in the U-shaped space from the narrow upper end opening of the inner and outer molds. At this time, the upper end opening will be provided separately on the right and left by the wall thickness of the U-shaped PC member to be molded. In this case, for example, the concrete placed from one opening into the U-shaped space is The mold is filled with concrete only after it passes through the bottom of the U-shaped space and wraps around the other opening.
[0007]
That is, the placed concrete needs to reach a narrow U-shaped space from one opening side through the bottom to the other opening side, and the one opening side serving as the concrete placing side The other opening side where the concrete reaches finally becomes the same level, and therefore the filling property of the concrete is remarkably poor due to the fact that the passage resistance is large and there is no pressure difference between the starting point and the ending point. As a result, a nest is likely to occur inside.
[0008]
In consideration of this, in order to improve the filling property of the concrete as much as possible, it is conceivable that the concrete is cast from one opening to some extent, and then the concrete is driven from the other opening. In this case, the concrete placement work becomes complicated due to the necessity of placing the concrete in multiple times, a boundary surface is formed between the primary placement concrete and the secondary placement concrete, air There is a risk that the PC member may be involved, and the integration of the entire PC member may be impaired.
[0009]
Furthermore, by using a high fluidity concrete, it is possible to improve the filling property into the mold even when placing concrete from one opening, but in this case the high fluidity The cost of the product will increase due to the use of porous concrete.
[0010]
In addition, since large buoyancy acts on the inner mold when casting concrete, it is necessary to increase the weight of the inner mold so that the inner mold does not lift up due to the buoyancy. Furthermore, the joining mechanism between the molds becomes complicated, and the manufacturing cost increases.
[0011]
On the other hand, when the conventional U-shaped PC member is used as a PC beam form for an RC beam, in order to secure the strength of the RC beam to be formed, a reinforcing bar and an auxiliary bar are supported therein. Since the support member is used to arrange the bars, there is a problem that the arrangement work on the site becomes complicated and takes time and effort.
[0012]
Therefore, the present invention has been made in view of such a conventional problem, and by placing a U-shaped inner mold frame that can be diverted upside down and placing concrete from the bottom side thereof, An object of the present invention is to provide a U-shaped PC member formwork apparatus, a U-shaped PC member manufacturing method, and a U-shaped PC member, which improve the filling property of concrete and form a high-strength U-shaped PC member. .
[0013]
[Means for Solving the Problems]
In order to achieve such an object, the U-shaped PC member formwork apparatus of the present invention has a pair of inner plates opposed to each other with a gap therebetween, a bottom plate arranged with a gap between the upper ends of the inner plates, In addition, an inner mold frame having an inverted U-shaped cross section composed of a holding plate that closes the inner plate and the bottom plate and holds reinforcing bars arranged between the inner plates, and a gap on the side of the inner plate are provided. An outer mold frame comprising a pair of outer plates arranged apart from each other and a closing portion that closes the gap from below; and an interval variable means for expanding and reducing the interval between the lower portions of the inner plates. The U-shaped PC member is manufactured from concrete which is placed over the gap between the inner plate and the outer plate from the bottom plate.
[0014]
Therefore, in this U-shaped PC member formwork apparatus, the outer plate of the outer mold is disposed on the side of the inner plate of the inner mold in a state where the inner and outer molds are set. A gap is formed between the inner and outer plates, and the gap is closed from below by a closing portion. On the other hand, the upper end portion of the outer plate is largely opened, and the bottom plate and the two holding plates disposed between the upper end portions of the inner plate face the open portion. At this time, the holding plate holds the reinforcing bars arranged between the inner plates while closing the space between the upper end portion and the bottom portion of the inner plate. Can be provided. Then, by placing concrete from the open portion, the concrete is filled in the gap between the inner and outer plates and then filled on the bottom plate and the holding plate. Then, it is cured in this state and demolded when the concrete is hardened. At the time of demolding, the outer mold can be easily removed because the outer plate is arranged outward, while the inner mold can be removed by reducing the distance between the lower portions of the inner plates by means of the interval variable means. 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.
[0015]
In forming the U-shaped PC member, concrete can be placed from a large open portion between the outer plates, and the narrow gap formed between the inner and outer plates has no bent portion. It is only vertically filled with concrete from above, and the filling is performed easily and reliably. Next, after the narrow gap between the inner and outer plates is filled with concrete, the concrete is placed over the bottom plate of the inner mold frame, whereby the bottom of the U-shaped PC member is formed. At this time, the concrete placement amount is adjusted so that the concrete covering the upper side of the bottom plate has the thickness of the bottom of the U-shaped PC member. Thus, when filling concrete, it is possible to eliminate the portion where the flow resistance increases, so that the filling property of the concrete is improved and the necessity of using high-fluidity concrete is eliminated. Further, since the formed PC member has an inverted U-shaped cross section, buoyancy does not act on the inner mold even when concrete is placed. Therefore, the inner mold does not need to be heavy considering buoyancy, and can be reduced in weight and size. Furthermore, the inner mold frame is composed of a pair of inner plates, a bottom plate that forms the bottom, and two holding plates that close between them, so that they can be replaced with bottom plates or holding plates having different widths. Thus, it is possible to divert the width of the inner mold frame to manufacture various U-shaped PC members having different sizes.
[0016]
Moreover, in the manufacturing method of the U-shaped PC member of the present invention, the pair of inner plates are opposed to each other with a gap therebetween, and the bottom plate is disposed between the upper ends of these inner plates with a gap therebetween. Reinforcing bars interposed between the inner plates are arranged in the space between the inner plate and the inner plate, and the inner plate and the bottom plate are closed with a holding plate that holds the reinforcing bars, so that the inner section has an inverted U-shaped cross section. Forming the mold, and placing the pair of outer plates with a gap on the side of each inner plate, and the inner mold installation step of holding the interval between the lower portions of the inner plate constant by the interval variable means, An outer mold installation step for closing the gap from below at the closing portion, a concrete placing step for placing concrete between the outer plate and the inner plate and the outer plate between the outer plate, and after hardening of the concrete The distance between the lower portions of the inner plates is narrowed by the distance varying means. After, characterized in that a demolding step of demolding from the inner mold and the outer mold.
[0017]
Therefore, in the method of manufacturing a U-shaped PC member using the above-mentioned formwork device, the inner formwork is formed in an inverted U shape by the inner plate, the bottom plate and the two holding plates that form a pair in the inner formwork installation process. In addition, the reinforcing bars can be held between the inner plates by being held by the holding plates.
[0018]
Further, a gap is formed between the outer plate and the inner mold by the outer mold installation process. In the concrete placing step, the concrete can be easily placed from the open portion between the widely opened outer plates into the gap. Next, when the placed concrete hardens, it moves to the demolding process, in particular, after forcibly narrowing the distance between the lower parts of the inner plate by the interval variable means, by demolding from the inner and outer molds, The U-shaped PC member that is turned upside down can be easily taken out.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. 1 to 6 show an embodiment of a U-shaped PC member mold apparatus according to the present invention, FIG. 1 is a perspective view showing an end of the mold apparatus, and FIG. 2 is an enlarged view of portion A in FIG. 3 is a cross-sectional view of the mold apparatus, FIG. 4 is an enlarged cross-sectional view of a portion B in FIG. 3, FIG. 5 is an enlarged cross-sectional view of a portion C in FIG. is there.
[0022]
The basic structure of the formwork device 12 of the U-shaped PC member 10 according to the present invention includes a pair of inner plates 14 and 14a facing each other with a predetermined interval S1 and between the upper ends of these inner plates 14 and 14a. And a holding plate 56 that closes the inner plates 14, 14a and the bottom plate 16 and holds reinforcing bars 49 arranged between the inner plates 14, 14a. A pair of inner mold 18 having an inverted U-shaped cross section and a side of the inner plates 14, 14 a are provided with an appropriate interval and are formed higher than the inner plates 14, 14 a so that the upper ends thereof are opened. The outer plates 20, 20a, the inner plates 14, 14a and the outer mold frame 22 comprising a closing portion 24 for closing the lower ends of the outer plates 20, 20a, and the inner plates 14, 14a and the outer plates 20, 20a. Close between the molding ends The gap between the bottom plate 21 and the lower side of the inner plates 14 and 14a is maintained, and the interval between these lower ends is maintained during concrete pouring and the distance between the lower ends is forcibly narrowed during demolding. Means 26, and concrete is placed between the inner and outer molds 18 and 22 from the upper end open portions 28 of the outer plates 20 and 20a, and the concrete is covered with the concrete.
[0023]
Moreover, the manufacturing method of the U-shaped PC member 10 using the above-mentioned formwork apparatus 12 is provided with a predetermined interval S1 so as to confront the pair of inner plates 14 and 14a and between the upper ends of these inner plates 14 and 14a. The bottom plate 16 is arranged with a space therebetween, and reinforcing bars 49 are arranged between the inner plates 14 and 14a. The holding plate 56 that holds the reinforcing bars 49 closes the space between the inner plates 14 and 14a and the bottom plate 16. An inner mold frame installation step of supporting the inner mold frame 18 having an inverted U-shaped cross section constituted by the support member 30 and holding the distance between the lower ends of the inner plates 14 and 14a constant by the distance varying means 26; The end plate 21 is attached to the position of the molding end of the inner plates 14 and 14a, and a pair of outer plates 20 and 20a are arranged at appropriate intervals on the sides of the inner plates 14 and 14a. , 14a and outside plate 20, 20a The outer mold is installed between the inner molds 14 and 14a and the outer molds 20 and 20a through the outer mold installation process for closing the parts with the closing part 24 and the upper end opening portions 28 of the outer plates 20 and 20a. In the concrete placing step of placing concrete so as to cover the upper part, and after hardening of the concrete, the above-mentioned end plate 21 and the above-mentioned outside plates 20 and 20a are demolded, and then the U-type PC member 10 is lifted, The distance variable means 26 forcibly narrows the distance between the lower ends of the inner plates 14 and 14a to remove the inner plates 14 and 14a, and the bottom plate 16 and the holding plate 56 between the inner plates 14 and 14a. And a demolding step for demolding.
[0024]
That is, the mold apparatus 12 for the U-shaped PC member according to the present embodiment will be described by taking as an example the case where the PC beam mold 10 is formed as the U-shaped PC member. As shown in FIGS. And an outer mold frame 22 disposed outside the outer frame 22. The inner mold 18 is disposed between the pair of left and right inner plates 14 and 14a, the bottom plate 16 that closes the upper ends of the inner plates 14 and 14a, and the inner plates 14 and 14a and the bottom plate 16, respectively. The two holding plates 56 form an inverted U-shaped cross section. The outer mold frame 22 is mainly constituted by a pair of left and right outer plates 20 and 20a, and the inner plates 14 and 14a and the lower ends of the outer plates 20 and 20a are closed by a surface plate 34. The inner plates 14 and 14a and the bottom plate 16 are concavo-convex plates such as checker plates, and the concavo-convex portions 17 thereof are arranged on the surface (concrete placement side).
[0025]
A pair of surface plates 34 are provided corresponding to the outer plates 20, 20 a, arranged in parallel on the work floor 32 with a predetermined width S 2, and the upper surface of the surface plate 34 is a closing portion 24. That is, the surface plate 34 is formed of H-shaped steel made up of upper and lower flanges 34 a and 34 b and a web 34 c, and the upper surface of the upper flange 34 a becomes the closing portion 24. The outer plates 20 and 20a are formed sufficiently higher than the inner plates 14 and 14a, and the upper ends of the outer plates 20 and 20a are connected by a connecting member 36, and the interval between the outer plates 20 and 20a is It is held by the connecting member 36.
[0026]
A bending margin 38 is formed at the upper end of the inner plates 14, 14 a inward, and an extension member 40 is fixed to the lower surface of the distal end portion of the bending margin 38. The extending member 40 is formed of an angle member having an L-shaped cross section, and one outer surface 40a forms a horizontal surface and is superimposed on the lower surface of the distal end portion of the bending margin 38 and extends from the distal end portion, and the other outer surface 40b is formed. It is formed so as to form a vertical plane parallel to the tip of the bending allowance 38. Similarly, the extension members 40 are fixed to the lower surfaces of both side end portions of the bottom plate 16.
[0027]
And as shown in FIG. 4, it arrange | positions so that the perpendicular | vertical outer surfaces 40b of the extension member 40 fixed to the inner side plates 14 and 14a and the baseplate 16 may oppose, and a holding plate is attached to the horizontal outer surface 40a of these extension members 40 56 is spanned to close the space between the outer surfaces 40b. The two holding plates 56 and the bottom plate 16 close the upper end portions of the inner plates 14 and 14a. In this closed state, the upper surfaces of the bottom plate 16 and the two holding plates 56 and the upper surfaces of the bending margins 38 are used. And become the same.
[0028]
Further, as shown in FIG. 2, the holding plate 56 has a recess 56 a for holding the inner stirrup 49 arranged between the inner plates 14 and 14 a as appropriate along the length direction of the mold apparatus 12. A plurality are provided at intervals. The recess 56 a is notched from the end of the holding plate 56 on the bottom plate 16 side and is formed to have a width substantially the same as the outer diameter of the inner stirrup 49. Further, the concave portion 56a is closed by the inner stirrup 49 with almost no gap when the holding plate 56 is mounted between the inner plates 14 and 14a and the bottom plate 16. Further, an elastic member such as an alkali oil-resistant rubber or the like may be provided on the inner peripheral surface of the concave portion 56a as necessary, and the gap between the concave portion 56a and the inner stirrup 49 may be closed.
[0029]
In addition, ribs 42 extending in the vertical direction are formed on the back surfaces (opposing surfaces) of the inner plates 14 and 14a at predetermined intervals in the length direction of the inner plates 14 and 14a, and the lower ends of the inner plates 14 and 14a. Ribs 43 are also formed, and the ribs 42 and 43 prevent the inner plates 14 and 14a from being bent by the pressure of the concrete. Further, a plurality of reinforcing ribs 44 using an angle member are fixed between the extending members 40 on the lower surface of the bottom plate 16 with a predetermined interval in the length direction of the bottom plate 16, thereby preventing the bending of the bottom plate 16. The reinforcing rib 44 can be omitted when the bottom plate 16 has a small width and can sufficiently withstand the load of the concrete.
[0030]
The inner plates 14, 14 a are arranged so that the lower ends thereof are located inside the surface plate 34, and the lower ends of the inner plates 14, 14 a are projected slightly below the closing portion 24. Thus, the inner mold 18 is supported at a predetermined height by the support member 30. The support member 30 is configured by providing a mounting member 30b on the upper end portion of the leg portion 30a. When the extension member 40 is mounted on the mounting member 30b, the load of the inner mold 18 is applied to the support member 30b. 30.
[0031]
Further, a jack 26 is attached as a distance varying means between the lower ends of the inner plates 14 and 14a. The jack 26 has telescopic rods 26a projecting from both ends, and the distal ends of the telescopic rods 26a are pivotally coupled to the ribs 42 on the back surfaces of the inner plates 14 and 14a. The jack 26 is set to such a length that the distance between the upper and lower ends of the inner plates 14 and 14a becomes equal in the set state of the inner mold 18. Instead of the jack 26, a method of taking a reaction force on the surface plate 34 with a pressing member or the like can be used as a variable interval means for the lower end portions of the inner plates 14, 14a.
[0032]
When the PC beam mold 10 is formed using the inner and outer molds 18 and 22, the inner plate 14, 14 a is supported by the support member 30. At this time, three support members 30 are installed at both ends in the length direction of the inner plates 14 and 14a and at the center thereof. Then, the bottom plate 16 is placed between the inner plates 14 and 14a with a space therebetween. As a result, slits 18a are formed between the inner plates 14 and 14a and the bottom plate 16, respectively. In this state, a plurality of auxiliary bars 46 are arranged in parallel along the length direction of the mold apparatus 12 on the upper surfaces of the bending margin 38 of the inner plates 14 and 14 a and the bottom plate 16. At this time, the lower principal bar may be used instead of the auxiliary muscle 46. In the present embodiment, the auxiliary bars 46 and the bottom main bars are set to have a length that does not protrude from the beam end of the PC beam formwork 10, but the bottom main bars protrude from the beam end for joining with an external reinforcing bar. There is also.
[0033]
Next, the support member 30 arranged at one end in the length direction of the inner plates 14 and 14a is once removed, and half of all the inner stirrups 49 arranged in the PC beam formwork 10 are arranged at the end thereof. Then, the support member 30 is placed in the original position again. Similarly, half of all the inner stirrups 49 are also arranged from the other end side. The inner stirrup 49 is formed in an annular quadrilateral shape, one side of which is disposed on the auxiliary bar 46 on the bottom plate 16, and two sides adjacent to the side are passed through the slit 18 a, respectively. , 14a are arranged at predetermined intervals in the length direction and are suspended from the auxiliary muscle 46. The slit 18 a is closed by the holding plate 56, and the inner stirrup 49 is held by the recess 56 a provided in the holding plate 56 to form the inner mold 18.
[0034]
As described above, the method of arranging the inner stirrup 49 using the three support members 30 and forming the inner mold 18 has been shown. However, four or more support members 30 may be used. The inner stirrup 49 is fed along the slit 18a, and the support member 30 is also sequentially moved to arrange the bars.
[0035]
Then, a large number of outer stirrups 48 bent in an inverted U shape are sequentially fed from the end of the inner mold 18 and arranged in the length direction of the inner mold 18 with a predetermined interval. At this time, the outer stirrup 48 can be easily fed by slightly contracting the telescopic rod 26a of the jack 26 to narrow the distance between the inner plates 14, 14a. Further, auxiliary muscles 47 are arranged on the side surface of the outer stirrup 48, and these auxiliary muscles 46, 47 and the outer stirrup 48 are connected by a binding line.
[0036]
Then, after the bar arrangement is completed, as shown in FIG. 1, the end plate 21 is attached to the molding end portion of the inner mold frame 18 so as to cover the outer periphery of the inner mold frame 18, and the outer plates 20, 20a are attached. The upper plate of the opposed outer plates 20 and 20a is fixed by the connecting member 36 while being placed and fixed on the surface plate 34 while providing a gap δ between the inner plates 14 and 14a.
[0037]
By the way, the outer stirrup 48 protrudes downward from the closing portion 24 through the space between the inner plates 14 and 14a and the surface plate 34, but in this embodiment, it is elastic as shown in FIG. The part is sealed using the foam 50. That is, an angle member 52 that forms a facing surface with the inner plates 14, 14 a is suspended from the surface plate 34, while a contact plate 54 is spot-welded to the surface of the inner plates 14, 14 a at a position facing the facing surface 52. To do. Accordingly, the outer star wrap 48 is positioned between the angle member 52 and the contact plate 54, and the elastic foam 50 is provided between the facing surface 52 and the contact plate 54, so that the outer star wrap 48 is provided. The insertion part is sealed. As the elastic foam 50, an alkali oil-resistant rigid rubber-based material is used. Further, the closing portion 24 may be provided with a recess 24a as shown in FIG. 6 so as to hold the outer stirrup 48 as if the inner stirrup 49 was held by the holding plate 56.
[0038]
In a state where the installation of the inner and outer molds 18 and 22 is completed in this way, a concrete placement space S is formed between them, and the concrete is cast from the upper end open portion 28 of the outer plates 20 and 20a. By providing the concrete, the concrete fills the placement space S while the auxiliary bars 46 and 47, the outer star wrap 48 and the inner star wrap 49 are embedded. At this time, the placement amount is adjusted so that the placed concrete covers the upper portion of the inner plate 18 above the bottom plate 16 with a depth equal to the bottom thickness of the PC beam formwork 10. Then, after smoothing the top surface of the placed concrete, it is cured and waits for the concrete to harden.
[0039]
When the concrete is hardened by this curing, first, the outer plates 20, 20a and the end plate 21 are demolded while applying an impact by hitting or the like, and then the PC beam form 10 is lifted by several centimeters by an overhead crane or the like. In this lifted state, the PC beam formwork 10 is lifted from the closing portion 24 and the lower ends of the inner plates 14 and 14a are freely movable. The jack 26 is operated while striking the inner plates 14 and 14a. The telescopic rod 26a is shortened. Then, the distance between the lower end portions of the inner plates 14 and 14a is forcibly narrowed, so that the peeling between the inner plates 14 and 14a and the concrete proceeds from the lower portion, reaches the bending allowance 38, and is demolded. The removed inner plates 14 and 14a are moved inward so as not to disturb the lifting of the PC beam formwork 10. Finally, the bottom plate 16 and the holding plate 56 are removed while striking. In this state, the PC beam formwork 10 is completely removed from the mold, and is suspended and turned upside down and transported to the stock yard. The method for lifting the PC beam mold 10 by several centimeters and disassembling the inner mold 18 has been described above. However, the leg 30a of the support member 30 may be shrunk by several centimeters, or the inner mold 18 may be disassembled. The PC beam formwork 10 with the 18 attached thereto may be hung, turned upside down and temporarily placed, and then the inner formwork 18 may be disassembled according to the above procedure.
[0040]
The PC beam form 10 formed by the above method has a U-shaped cross section with a pair of side portions 10a and a bottom portion 10b connecting the side portions 10a as shown in FIGS. The outer star wrap 48 protrudes upward from the upper end of 10a, and the inner star wrap 49 protrudes upward from the bottom 10b between the side portions 10a to be integrated between the side portions 10a. .
[0041]
Therefore, in the formwork device 12 of the PC beam formwork 10 of the present embodiment, when forming the PC beam formwork 10 by turning the inner formwork 18 upside down and installing it in an inverted U shape, Concrete can be placed from a large open portion 28 formed at the upper end between the outer plates 20 and 20a, and a narrow gap δ formed between the inner plates 14 and 14a and the outer plates 20 and 20a. Is not bent and is oriented vertically and is only filled with concrete from above, and the filling is performed easily and reliably.
[0042]
Therefore, since the portion where the flow resistance increases when filling concrete in this way can be eliminated, the filling property of the concrete is improved, and it is not necessary to use high fluidity concrete.
[0043]
Further, since the formed PC beam form 10 is formed in an inverted U-shaped cross section, buoyancy does not act on the inner form 18 even when concrete is placed. Therefore, the inner mold 18 does not need to be heavy considering buoyancy, and can be reduced in weight and size. Further, since the load applied to the bottom plate 16 and the holding plate 56 is only the weight of the concrete forming the bottom portion 10b of the PC beam formwork 10, the joining mechanism of the inner plates 14, 14a, the bottom plate 16 and the holding plate 56 can be simplified.
[0044]
The inner mold 18 includes a pair of inner plates 14 and 14a, a bottom plate 16 disposed with a gap between the upper ends of the inner plates 14 and 14a, and two holding plates that close the gap between them. 56, it can be diverted to manufacture various PC beam molds 10 having different sizes by changing the width dimension of the inner mold 18 by replacing the bottom plate 16 or the holding plate 56 with different widths. it can. In addition, if a member having a margin in the height direction or the length direction is used as the inner plates 14 and 14a, PC beams having different sizes not only in the beam width but also in the height (the length of the beam) and the length of the beam. The mold 10 can be manufactured.
[0045]
In addition, since the inner plates 14 and 14a and the bottom plate 16 are arranged with a space therebetween and the slits 18a are formed in the inner mold 18, an inner stirrup 49 connected from the top of the bottom plate 16 to the inner plates 14 and 14a. Can be provided in advance in the PC beam formwork 10 to form a high-strength PC beam formwork. In addition, since the holding plate 56 that closes the slit 18a is provided with a plurality of recessed portions 56a that hold the inner stirrup 49 at intervals, the inner stirrup 49 can be easily arranged. . Furthermore, since the inner star wrap 49 is held, the inner star wrap 49 does not move even when placing concrete, and can be provided at a desired position, and the PC beam formwork 10 as a whole. In addition, a high-strength PC beam formwork 10 can be formed in a well-balanced manner. In addition, neither the inner star wrap 49 nor the outer star wrap 48 requires a separate jig or the like for supporting them during the bar arrangement, so that the bar arrangement work is easy and the manufacturing cost is greatly reduced. Can do.
[0046]
The inner mold 18 is composed of the bottom plate 16, the inner plates 14, 14 a and the holding plate 56, and the bottom plate 16 and the holding plate 56 are merely placed on the support member 30. 18 can be assembled and disassembled with one touch, and the installation work of the inner mold 18 can be performed quickly. Furthermore, since the upper ends of the outer plates 20 and 20a are largely open, the reinforcing bars 46 and 47, the inner reinforcing bars such as the outer stirrups 48 and 49 can be easily assembled in the mold apparatus 12, The process of assembling at another location can be omitted. Thus, the formwork and rebar assembly are simplified and performed quickly, so that productivity can be improved and the cost of the product can be reduced.
[0047]
The above-mentioned PC beam formwork 10 is used when constructing an RC beam, and is carried into the site and arranged in a U-shaped cross-section so that the bottom portion 10b faces downward. After the streak is made, concrete is placed inside the U-shaped concave portion of the PC beam formwork 10 so as to be integrated with the upper floor slab. At this time, the inner stirrup 49 is embedded in the bottom 10 b and is provided in the recess of the PC beam formwork 10. Further, the upper end portion of the inner stirrup 49 is embedded and integrated in the concrete on the upper floor surface together with the upper end portion of the outer stirrup 48. At this time, since the inside of the concave portion is formed in an uneven shape by the uneven portions 17 of the inner plates 14 and 14a and the bottom plate 16, the adhesion with the concrete placed on site at the time of beam construction becomes good, and the post-cast concrete It becomes a structure having high strength integrated with.
[0048]
Further, the PC beam formwork 10 used for the construction work of the RC beam is already provided with the inner star wrap 49 so as to protrude into the concave portion at the manufacturing stage, so that it is possible to reduce the on-site bar arrangement work. The construction time can be greatly reduced.
[0049]
In the present embodiment, the inner star wrap 49 has an annular quadrilateral shape and the outer star wrap 48 is bent in an inverted U shape, but both the inner star wrap 49 and the outer star wrap 48 have any shape. However, any of them may be combined.
[0050]
In the present embodiment, the holding plate 56 is shown as a separate member from the inner plates 14 and 14a and the bottom plate 16, but the holding plate 56 can open and close the slit 18a. If so, the end opposite to the recess 56a in which the inner stirrup 49 disposed in the slit 18a is held is connected to either the inner plate 14, 14a or the bottom plate 16 via a hinge or the like. I do not care.
[0051]
By the way, although this embodiment explained taking the example of the PC beam formwork 10 as the U-shaped PC member, the present invention is not limited to this and can be preferably applied to a PC product having a U-shaped cross section.
[0052]
Furthermore, in this embodiment, although the form as a simple-shaped U-shaped PC member was shown, in order to provide a RC wall under the beam as a modification, a U-shaped PC member provided with a slit in the bottom 10b, It is also possible to form an L-shaped PC member with reinforcing bars in order to provide an RC wall on the beam side surface. In this case, by providing a partition plate on the bottom plate 16 or holding plate 56 of the inner mold 18 and placing concrete, a PC member having a slit or a predetermined shape other than the U shape can be manufactured very easily. be able to.
[0053]
【The invention's effect】
  As described above, the U-shaped PC member formwork apparatus of the present invention, the U-shaped PC memberIn the manufacturing method,Since the inner plate and the bottom plate are spaced apart and the holding plate is placed between them, it can be used for the manufacture of PC products of various sizes, and the inner mold can be turned upside down to install the outer mold. It becomes possible to provide a large open part at the upper end of the outer plate of the frame, making it easy to place concrete and ensuring the fluidity of the concrete from corner to corner between the inner and outer molds. . For this reason, productivity can be improved and the cost of a product can be reduced without using highly fluid concrete. In addition, since the interval variable means provided between the lower portions of the inner plates allows the interval between the inner plates to be enlarged or reduced at the time of demolding, the demolding operation of the inner mold can be easily performed.
[0054]
Furthermore, since the reinforcing bar interposed between the inner plates is held by the holding plate that closes the space between the inner plate and the bottom plate, the reinforcing bar that becomes the core of the U-shaped PC member can be provided in advance in the manufacturing stage. Therefore, the work time can be shortened by the easy bar arrangement work, and the manufacturing cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an end portion of a mold apparatus showing 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 mold apparatus showing an embodiment of the present invention.
4 is an enlarged cross-sectional view of a portion B in FIG.
5 is an enlarged cross-sectional view of a portion C in FIG.
6 is an enlarged cross-sectional view showing a modification of FIG.
FIG. 7 is a front view of a U-shaped PC member showing an embodiment of the present invention.
8 is a perspective view showing a state in which the U-shaped PC member of FIG. 7 is upright. FIG.
[Explanation of symbols]
10 PC beam formwork (U-shaped PC member)
10a side
10b Bottom
12 Formwork device
14, 14a Inner plate
16 Bottom plate
18 Inside formwork
20, 20a outer plate
22 Outer formwork
24 Closure
26 Jack (variable interval means)
28 Open part
49 Inner stirrup (reinforcing bar)
56 Holding plate

Claims (2)

A pair of inner plates opposed to each other with a gap between them, a bottom plate arranged with a gap between them at the upper end of the inner plate, and the inner plate and the bottom plate are closed and arranged between the inner plates. An inner mold frame having an inverted U-shaped cross section composed of a holding plate for holding a reinforcing bar,
An outer mold frame composed of a pair of outer plates disposed on the side of the inner plate with a gap therebetween and a closing portion for closing the gap from below;
An interval variable means for expanding and reducing the interval between the lower portions of the inner plate,
A U-shaped PC member form apparatus, wherein a U-shaped PC member is manufactured from concrete placed between the outer plates from above the bottom plate over the gap between the inner plate and the outer plate. A pair of inner plates are opposed to each other, and a bottom plate is disposed between the upper ends of these inner plates and spaced from each other, and a gap between the bottom plate and the inner plate is interposed between the inner plates. Reinforcing bars are placed, and the inner plate and bottom plate are closed with a holding plate that holds the reinforcing bars to form an inner mold frame with an inverted U-shaped cross section, and the interval between the lower portions of the inner plate can be varied. An inner mold installation process that is held constant by means;
While arranging a pair of outer plates with a gap on the side of each inner plate, and closing the gap from below with a closing portion,
Between these outer plates, a concrete placing step of placing concrete over the gap between the inner plate and the outer plate from the bottom plate,
A demolding step of demolding from the inner mold frame and the outer mold frame after narrowing the distance between the lower portions of the inner plate by the interval variable means after hardening of the concrete;
The manufacturing method of the U-shaped PC member using the formwork apparatus characterized by the above-mentioned.

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