JPH01150504A - Concrete form for manufacture of concrete pile - Google Patents

Abstract

PURPOSE:To enable easily loading of concrete and taking out a pile out after molding, by dividing a cylindrical concrete form into three parts in a circumferential direction. CONSTITUTION:A concrete form 1 is generally cylindrical and formed of concrete forms 1a, 1b, and 1c obtained by dividing the concrete form 1 into three parts in a circumferential direction. At the time of molding of a pile 15, the two divided concrete forms 1b, 1c are set up on an assembling stand 16 under while the remaining concrete form 1a is removed, an iron rod cage 7 for reinforcement is set up within the divided concrete forms 1b, 1c and concrete 2 is loaded through an upper opening by dropping the concrete 2 from a loading machine 17 under this state. At this time, as the divided concrete forms 1b, 1c are raised upward than a semi-circular state, the concrete 2 is filled sufficiently in the divided concrete forms 1b, 1c and hard to overflow. At the time of taking out the pile 15, as the concrete form is disassembled into the concrete forms 1a, 1b, 1c, the pile 15 can be taking out easily.

Description

[Detailed Description of the Invention] [Technical Field] The present invention provides a concrete pile in which a cylindrical formwork is filled with concrete, and the formwork is rotated to form the concrete centrifugally! li! It concerns the formwork used.

[Background technology] Formwork 1 for conventional centrifugal forming of concrete piles
' is formed by semi-cylindrical divided formworks 1a' and lb' which are divided into upper and lower halves as shown in Fig. 8(a). As shown in (b), a core reinforcing bar cage is placed inside the other split formwork 1b' and filled with concrete 2.
a' over the split formwork 1b', and both split formworks 1a'
, lb' are fastened with 7 lances 3, both ends of the mold 1' are closed with end plates, and the mold 1' is rotated at high speed for centrifugal molding. However, such a conventional example has the following problem.

(1) When filling concrete 2 inside formwork 1',
Generally, with one split formwork 1g' removed, concrete 2 is poured into the other semi-cylindrical split formwork 1b' as shown in Figure 8(b). Since the volume cannot fit into the divided formwork 1b', it has to be packed in a mountain shape (and there is a problem that this filling work is done manually, which is difficult and time consuming.Also, even if it can be poured in a mountain shape, Split formwork 1a'
Before closing, the mounds of concrete 2 may collapse due to vibrations from surrounding processes (particularly due to vibrations from centrifugal forming), or the collapsed concrete 2 may rest on the 7-lunge 3, causing the split formwork 1a'
There was a problem that the door could not be closed.

(2) After the concrete pile has been centrifugally formed and cured, when removing the pile from the formwork 1'', remove the divided formwork 1a' and then lift the pile out from the divided formwork 1b', or split the pile. The formwork 1b' is turned over and the pile is rolled out, but since the divided formworks 1a' and lb' are semi-cylindrical, the contact area between the pile surface and the inner surface of the formwork 1' is large, and the concrete 2 is rolled out. There is a problem that it adheres closely to the inner surface and is difficult to remove from the mold.In particular, in the case of formwork for manufacturing knot piles etc. that have protrusions on the pile body, the formwork itself has an uneven shape, so the contact area increases. There is a problem that the piles are thick (and difficult to demold).
When manufacturing piles (prestressed concrete piles), there is a problem in that there are parts that adhere tightly between the nodes of the formwork and the nodes of the pile, which makes it difficult to remove the mold.Generally, PC piles are When manufacturing, a predetermined tension force is applied to the PC bars of the core reinforcing bar cage with concrete filled in the formwork (the reaction force of the tension is transmitted to the formwork via the end plates), and the pile is consolidated. After forming, that is, at the time of demolding, the tension applied to the formwork is released and tension is applied to the pile, but at this time the pile tends to shrink, while the formwork tries to stretch, so it sticks strongly at the joints.

[Object of the Invention] The present invention has been made in view of the above points, and the purpose of the present invention is to manufacture concrete piles that allow easy pouring of concrete and easy removal of piles after forming. To provide formwork for use.

[Disclosure of the Invention] The formwork for manufacturing concrete piles of the present invention is a cylindrical formwork divided into three parts in the circumferential direction, and the drawbacks of the conventional example are solved by having the structure as described above. In other words, by dividing the form into three parts, when pouring concrete, you can remove one divided formwork and put the two assembled formworks together, allowing you to pour concrete into the divided formwork, which has a shape closer to a cylinder than a semi-cylindrical one. As a result, there is no need to pile up concrete in a pile, making it easier to pour concrete, and when demolding, the three divided formwork can be disassembled and the formed pile can be pulled out. It has become easier to remove the pile.

The present invention will be explained in detail below with reference to Examples.

In this embodiment, an example of a concrete pile manufacturing formwork for manufacturing PC piles will be described.

As shown in FIGS. 1(a) and 1(b), a concrete pile manufacturing formwork (hereinafter referred to as formwork) 1 has a substantially cylindrical shape, and is divided into three divided formworks 1 at i b in the circumferential direction.
1 c. Split formwork 1 at 1 b
, 1 c are provided with 7 runs 3 extending in the longitudinal direction on both sides in the circumferential direction, and are assembled by fastening the 7 ranks 3 together with bolts and nuts. The formwork 1 is formed with knot forming portions 4 extending circumferentially at regular intervals in the longitudinal direction and projecting outward, and these knot forming portions 4 form the knots of the pile. ing. This joint forming part 4 is also divided into the formwork 1.
It is divided into three parts in the circumferential direction together with at 1 b and 1 c. Further, tires 5 are mounted on the formwork 1 at equal intervals in the longitudinal direction and extending in the circumferential direction, and the tires 5 are also divided into three parts together with the divided formworks 1 at 1 b and 1 c.

End plates 6 at 6 b are arranged at both ends of the formwork 1 in the longitudinal direction, and core reinforcing bars @7 are arranged inside the formwork 1 as shown in FIG. This core reinforcing steel I! 7 is a main reinforcing bar 7a that extends in the longitudinal direction and is arranged at intervals in the circumferential direction, and a main reinforcing bar 7a that is wound in a coil shape around the main reinforcing bar 7a.
It is made up of reinforcing bars 7b. End plates 8 are arranged at both ends of the formwork 1, and both ends of the main reinforcing bars 7a of the core reinforcing bar cage 7 are inserted through the end plates 8. One end of the main reinforcing bar 7a is one t! 1] It is connected to the part plate 6a by a screw connection, and the other end of the main reinforcing bar 7a is connected to a sliding plate 9 arranged at the other end in the formwork 2 by a screw connection. A screw pongee 10 is provided protruding from the sliding plate 9, and the screw sleeve 10 is inserted through the end plate 6b, and the nut 1 is screwed onto the screw pongee 10. A device for rotationally driving the formwork 1 is formed by providing a drive loaf 14 on a drive shaft 13 driven by a motor 12. The driving rows 214 are provided at the same intervals as the tires 5 of the formwork.

The pile 15 is formed in the following manner. As shown in FIG. 3, with one divided formwork 1a removed, the remaining two divided formworks 1b.

1c is assembled and set on the stand 16, and the divided formwork 1b is created.

Set the core reinforcing bar n7 in 1c, and in this state insert 8!
Concrete 2 is dropped from (hopper) 17 and poured into the divided formworks 1b and lc from the upper opening. At this time, since the disassembled formworks 1b and 1c stand up above the semi-cylindrical shape, the concrete 2 is sufficiently filled and does not easily spill.

Next, the divided formwork 1a is placed on the molded formwork 1a and the seven ramps 3 are connected to each other to assemble the formwork 1, and the formwork 1 is set on the drive roller 14, and the nuts 1 are tightened to apply tension to the core reinforcing bar n7. Next, the drive shaft 13 is driven to rotate the mold 1 to perform centrifugal molding. Pile 15 after centrifugal molding and curing
When the set 1 is formed, the tension is released by loosening the set 1, the divided formworks 1a, 1b, and lc are disassembled, and the pile 15 is taken out by lifting it or making it M-tight. When lifting, use a vacuum lifter 18 as shown in FIG. When removing the pile 15, the three divided formworks 1 a
Since the pile 15 is divided into t 16.1 c, the pile 15 can be easily taken out, and even if it is a PC pile with knots t 71 or < ile, it can be taken out easily. In other words, when the tension is released by loosening the nut 1, the pile 15 tends to shrink in the longitudinal direction, while the formwork 1 tries to expand in the longitudinal direction, causing the joints of the pile 15 and the joint forming part of the formwork 1 to 4
1t 1 b, It can be divided into 1 c and the pile 15 can be easily taken out.

In the above embodiment, the formwork 1 was divided into three parts in the circumferential direction to form the three divided formworks 1 at 1 b and 1 c. .

It may be smaller than 1c. Further, in the above embodiment, the seven flange 3 protrudes in the radial direction, but it may be one that protrudes horizontally as shown in FIG. 5, or one that protrudes vertically as shown in FIG. fJIJ6.

Furthermore, in the above embodiments, it has been described that a non-attached PC pile is manufactured, but a knotless pile or an RC pile may be used.

FIGS. 7(a) and 7(b) show other embodiments. In this embodiment, one side of the divided formworks 1b and 1c are rotatably connected to each other by a hinge 19. When the seven lamps 3 are connected to each other by the hinge 19, they are connected at a position closer to the outer periphery of the joint molded portion 4. In this case, centrifugal molding can be performed in the same manner as above, and pile 1
5 is taken out, the divided formworks 1b and 1c are opened in the direction of arrow A in FIG.

[Effect of the invention 1 As described above, the cylindrical formwork of the present invention is divided into three parts in the circumferential direction, so when pouring concrete, one divided formwork is removed and two divided formworks are assembled. Concrete can be poured into a split formwork that is more cylindrical than semi-cylindrical, and there is no need to pile up concrete, making it easy to pour concrete. It has a large amount of concrete (but does not spill), and when demolding, the three divided formwork can be disassembled and the formed pile can be pulled out, making it easy to remove the pile. This makes it easy to take out the pile even when a pile or a PC pile is formed.

[Brief explanation of the drawing]

Figure 1 6) (b) is a front view and partially cutaway side view of one embodiment of the present invention, Figure 2 is a partially cutaway front view of the same as the above, and Figure 3 is the side of the same as the above when concrete is being poured. 4 is a side sectional view of the same pile taken out, FIGS. 5 and 6 are side sectional views showing other shapes of the same formwork, tlIJ
7(,)(b) is a side sectional view and partially cutaway front view of another embodiment same as above, FIGS. 8(a) and 8(b) are sectional views of a conventional example, 1 is a formwork, 1 at 1 b. 1cJ! It is a split formwork. Agent Patent Attorney Ishi 1) Ai Shichi

Claims (1)

[Claims] [1] A formwork for manufacturing concrete piles, characterized by comprising a cylindrical formwork divided into three parts in the circumferential direction.