JPH01150505A - Concrete form for manufacture of pc pile with node - Google Patents

Abstract

PURPOSE:To make demolding of a pile easy, by a method wherein semi- cylindrical half bodies of a concrete form are formed into a cylinder and node molding recessed parts provided at positions where nodes are formed comprise movable and elastic parts of rubbery plastic material in a longitudinal direction of the half bodies of the concrete form. CONSTITUTION:A manufacturing concrete form 1 is generally cylindrical, and comprises top and bottom two half bodies 1a, 1b which are obtained by dividing the concrete form into two parts in a circumferential direction. Rubbery elastic parts 10 are provided in the half bodies 1a, 1b of the concrete form extending over the circumferential direction and at equal intervals in the longitudinal direction. Node molding recessed parts 6 are provided in the elastic parts 10 and nodes of a PC pile 11 are formed by the knot molding recessed parts 6. The PC pile 11 is demolded by lifting the same in the inside of the half body 1b of the concrete form after removing the half body 1a of the concrete form. In this time, even if the PC pile 11 contracts, the node come off easily due to elastic deformation of the elastic parts 10 and demolding is performed smoothly.

Description

[Detailed Description of the Invention] [Technical Field 1] The present invention involves filling a cylindrical formwork with concrete, rotating the formwork and centrifugally forming it to produce a knotted PC pile (prestressed concrete pile). This invention relates to formwork for producing concrete piles.

[Background technology J Conventionally, when centrifugally forming PC piles, the formwork 1' is the eighth
As shown in Figures (a) and (b), it is made up of semi-cylindrical formwork halves 1a' and lb' which are divided into two vertically, and when one formwork half 1a' is removed, the other formwork half 1b'
A core reinforcing bar n2 is placed inside the interior, and concrete is filled, one half of the formwork 1a' is placed over the half of the formwork 1b', and both half of the formwork 1a' are closed.

lb' are fastened with 7 runs 4, both ends of the formwork 1' are closed with end plates 5a and 5b, tension is applied to the core reinforcing bar 2, and high-speed rotation is applied to the formwork 1'. This led to centrifugal molding. However, since the formwork 1' for producing knotted PC piles has knot forming recesses 6' on the inner surfaces of the formwork halves 1a and 1b, when the PC pile is formed, the knot forming recesses 6 of the formwork 1' There is a problem in that there is a part that tightly adheres between the PC pile and the nodes of the PC pile, making it difficult to demold. Generally, when manufacturing a PC pile, a predetermined tension force is applied to the core reinforcing bar IL2 with concrete filled in the formwork (the reaction force of the tension is applied to the formwork 1 through the end plates 5a and 5b).
After solidification of the PC pile (transmitted to Since the formwork 1' tries to stretch, it adheres 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 improve the knot forming recesses of the formwork after molding and the knots of the PC pile even in the case of forming PC piles. To provide a formwork for manufacturing knotted PC piles which can be easily demolded without having strong adhesion to the PC pile.

[Disclosure 1 of the Invention The formwork for producing knotted PC piles of the present invention is formed into a cylindrical shape by combining semi-cylindrical mold halves, and the knot-forming recesses provided at the positions where the knots are formed are made of a rubber-like elastic material. This is characterized by an elastic portion made of a material that is elastically movable in the longitudinal direction of the mold half, and by configuring as described above, the drawbacks of the conventional example are solved. In other words, the knot-forming recesses provided at the positions where the knots are formed are made of elastic parts made of rubber-like elastic material and can be elastically moved in the longitudinal direction of the mold half. Even if the knots of the PC pile move in the longitudinal direction of the PC pile even after the force is released, the knot-forming concave part moves due to the elasticity of the elastic part, and the knots do not stick tightly together, causing the PC pile to deteriorate after forming. Demoulding became easier.

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

As shown in FIGS. 1 and 2, a formwork for producing knotted PC piles (hereinafter referred to as formwork) 1 has a substantially cylindrical shape, and is divided into two halves in the circumferential direction, into upper and lower formwork halves 1a.

1b. This formwork half 1 at 1
b has a double-tube construction consisting of an outer tube 8 and an inner tube 9 made of metal. Seven runs 4 are provided in the longitudinal direction on both circumferential sides of the formwork halves 1 at 1 b, and can be assembled by fastening the seven runs 4 together with bolts and nuts. The seven runciers 4 are provided so as to extend between the outer tube 8 and the inner tube 9, and have windows 2 for fastening bolts and nuts to the outer tube 8, as shown in FIGS. 1(a) and (b).
0 is set. The 7 rungs 4 may be made to protrude outward from the outer tube 8 and can be fastened to each other with bolts and nuts. Formwork halves 1a, 1b
There are elastic parts 10 embedded in the circumferential direction at equal intervals in the longitudinal direction. This elastic ff1Sio is formed of a rubber-like elastic body, and is provided at intervals that form knots in the PC pile 11.

The outer periphery of the elastic portion 10 is supported by the outer tube 8 and is exposed on the inner side of the inner tube 9. Further, the rubber-like elastic body forming the elastic portion 10 is rubber, synthetic resin, thin metal plate, or the like. Inner tube 9
is supported by the outer tube 8 with ribs or the like. This elastic part 10
A knot forming recess 6 is formed in the hole, and the knot forming opening 6 forms the knot of the PC pile 11. Furthermore, tires 12 are mounted on the formwork halves 1 at 1 b at equal intervals in the longitudinal direction and in the circumferential direction. End plates 5a and 5b are arranged at both ends of the formwork 1 in the longitudinal direction,
Inside the formwork 1, core reinforcing bars n2 are arranged as shown in FIG. The core reinforcing bars i2 extend in the longitudinal direction and include a plurality of main reinforcing bars 2a and 2 arranged at intervals in the circumferential direction.
It is composed of a 7-branch reinforcing bar 2b wound in a coil around a. End plates 13 are disposed at both ends of the formwork 1, and both ends of the main reinforcing bars 2a of the core reinforcing bar cage 2 are inserted through the end plates 13. One end of the main reinforcing bar 7a is one end plate 5a
The other end of the main reinforcing bar 7a is connected to a sliding plate 14 disposed at the other end in the formwork 1 by a screw connection. A screw pongee 15 is provided protruding from the sliding plate 14, and a nut 16 is screwed onto the screw pongee 15 by inserting the screw shaft 15 through the end plate 5b. The device for rotationally driving the formwork 1 is formed by providing drive loaves 19 on a drive shaft 18 driven by a motor 17. These drive rollers 19 are provided at the same intervals as the tires 12 of the formwork 1. The PC bail 11 is formed in the following manner. As shown in Fig. 4, with the upper formwork half 1a removed, set the remaining formwork half 1b on the stand 2], set the core reinforcing bar n2 inside the formwork 1b, and in this state Feeding machine (hopper) 22
The concrete 3 is dropped from the top and poured into the formwork half 1b from the upper opening. Ids 23 are placed on both sides of the upper opening of the formwork half 1b to prevent the concrete 3 from spilling at this time. Next, the formwork half 1a is put on and the seven runs 74 are connected to assemble the formwork 1, the formwork 1 is set on the drive roller 19, and the nuts 15 are tightened to apply tension to the core reinforcing bar B2. Next, drive shaft 1
3 to rotate the formwork 1 and perform centrifugal molding. When the PC pile 11 is formed after centrifugal molding and curing, the nut 16 is loosened to release the tension. At this time, PC pile 1
1 contracts in the direction of arrow A in Figure 3, and formwork 1 extends in the direction of arrow f:lS3. Next, the formwork half 1a is removed, and the PC pile 11 inside the formwork half 1b is lifted upward by a vacuum lifter to remove the PC pile 11 from the mold. At this time, the PC
Even if the pile 11 shrinks, the knots are easily removed due to the elastic deformation of the elastic part 10, and demolding is performed smoothly. Such demolding may be performed by inverting the mold as shown in FIG.

Next, the embodiment shown in FIG. 7 will be explained. Formwork half 1 m,
Inside ib, separate metal plates 2] are arranged circumferentially at equal intervals in the longitudinal direction, and knot-forming recesses 6 are recessed in the metal plates 2] extending circumferentially.

An elastic part 10 made of a rubber-like elastic body is interposed between both sides of the metal plate 2 and the formwork half 1a, and the metal plate 2 is connected to the formwork half 1a through the elastic part 10. , 1b. In this embodiment as well, the knot-forming recess 6 can be moved in the longitudinal direction of the mold halves 1a, 1b by the elastic displacement of the elastic portion 10, and the PC pile 11 can be easily pulled out when demolding.

In the above embodiment, the seven runs 4 on both sides of the upper and lower formwork halves 1 at 1 b are connected with bolts and nuts, but the seven runs 4 on one side may be connected with a hinge so that they can be opened and closed.

[Effects of the Invention] As described above, the present invention is characterized by a joint molding (1 part is an elastic part made of a rubber-like elastic body, which is elastically movable in the longitudinal direction of the formwork half) provided at the position where the joints are formed. Therefore, after forming a PC pile by applying tension, even if the tension is released and the knots of the PC pile move in the longitudinal direction of the PC pile, the knot forming recesses will not be formed due to the elastic displacement of the elastic part. It can be moved, the knots do not stick tightly together as in the conventional method, and the PC pile can be easily demolded after molding.

[Brief explanation of the drawing]

1(a) and 2(b) are a front view and a side sectional view of one embodiment of the present invention, FIG. 1(c) is a side sectional view of another example of the above, and FIG.
The figure is a partially omitted plan view of the same item 2, Figure 3 is a plan cross-sectional view of the same item with the core reinforcing bars arranged, Figure 4 is a side sectional view of the same item with concrete being poured in, and Figure 5 is a partially omitted plan view of the same item. 6 is a side sectional view showing another example of taking out the PC pile of the same as above, FIG. 7 is a partially omitted plan view of another embodiment of the same as above, FIG. 8(,)(b) is a side sectional view and a plan view of a conventional example, in which 1 is a formwork;
a=1 b is a mold half, 6 is a joint forming recess, and 10 is an elastic part. Agent Patent Attorney Ishi 1) Choshichi

Claims (1)

[Scope of Claims] [1] The formwork is formed into a cylindrical shape by combining semi-cylindrical formwork halves, and the knot-forming recesses provided at the positions where the knots are formed are elastic parts made of a rubber-like elastic material. A formwork for manufacturing a knotted PC pile, characterized in that the half body is elastically movable in the longitudinal direction. [2] Claim 1, characterized in that an elastic part made of a rubber-like elastic body is provided on the inner surface of the mold half at a position where a knot is to be formed, and a knot forming recess is formed in this elastic part. Formwork for manufacturing knotted PC piles as described in Section 1. [3] A metal plate separate from the formwork half is placed on the inner surface of the formwork half at the position where the knots are to be formed, and a knot forming recess is provided in this metal plate, and both sides of this metal plate and the formwork A mold for manufacturing a knotted PC pile according to claim 1, characterized in that a metal plate is connected to the formwork half body with an elastic part made of a rubber-like elastic body interposed between the half body. frame.