JPH02106304A - Semi-pc post and manufacture thereof - Google Patents

Abstract

PURPOSE:To form a hollow semi-PC post being a cross-sectional rectangular by arranging hoop reinforcement set with cores therebetween on the inner part of a post mold frame consisting of PC board arranged with iron reinforcement in its longitudinal and lateral directions in use of spacer such as a doughnut or the like, after that, centrifugally concrete-molding them. CONSTITUTION:A PC board 1 is fabricated in a manner such that fine steel wires are folded into equilateral triangles, and a three dimensional wire gauze 2 being continued with the equilateral triangles longitudinally and laterally is spread over on the same plain face, and mortal 3 is set on the lower half thereof. Next, the face to be exposed with the three dimensional wire gauze 2 of the PC board 1 is turned into the inside and fabricated firmly so as to be constituted into a cross-sectional rectangular. Cores 17 for restraining a post main reinforcement arranged in the intermediate part of the post are disposed in the hoop reinforcement. Concrete is inputted thereinto by rotating a mold frame device 5. Inasmuch as the hoop reinforcement and the cores are disposed therein. A semi-PC post having a large cross-sectional area can be manufactured.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention is directed to obtaining a semi-precast concrete column having a hollow cross-sectional shape and into which column main reinforcement can be installed later, and a column body thereof. Regarding the manufacturing method.

(Prior Art) In recent years, precast concrete has been used in high-rise buildings because of its high construction efficiency for reinforced concrete structures and its ability to produce high-quality concrete products.

Increasingly, precast concrete hollow columns are being used to connect the columns and beams of precast concrete columns and to connect columns together in the axial direction.

Such hollow columns are generally made using a centrifugal concrete forming machine, and when concrete is poured into the formwork while rotating, the concrete adheres tightly to the inner wall of the formwork due to centrifugal force. It is cured as it is to obtain a hollow column.

The above-mentioned formwork was generally of a cylindrical type because it was rotated.

(Problem to be solved by the invention) However, building columns are usually formed with a rectangular cross section, and there are not many cases in which a cubic column form is rotated using a centrifugal forming machine. This was due to the fact that it had the strength to withstand centrifugal force and the practical situation that demolding was difficult.

The present invention has been made in view of the circumstances described above, and
The purpose is to provide a semi-PC column that is a precast hollow column that facilitates connection with other members and allows for the installation of column main reinforcement later, and a manufacturing method for obtaining the same. It is in.

(Means for Solving the Problems) In order to achieve the above object, a semi-PC column and a method for manufacturing the same according to the present invention are provided with a core that is provided between the hoop bars and a midway portion of the hoop bars, and As a method, a PC plate with reinforcing bars arranged vertically and horizontally is assembled into a frame to form a column form, and hoop bars with cores placed inside are set apart from the inner surface of the form using spacers such as donuts. After placement, the form is rotated by a centrifugal concrete forming machine and concrete is poured into the form to the extent that a tube is obtained.

(Function) Since the weir plate is made of reinforced concrete, it can sufficiently withstand the centrifugal force of the centrifugal forming machine, and at the same time as the PC plate becomes a disposable formwork, it can also withstand shock during transportation.

In addition, the core improves the positioning and shear strength of the column main reinforcement.

(Embodiments) Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

Figure 1 shows the 26 plate 1 used for the formwork weir plate.
The plate 1 is made by bending a thin steel wire vertically into an equilateral triangle shape, developing a three-dimensional wire mesh 2 in which the triangles are continuous vertically and horizontally on the same plane, and placing mortar 3 in the lower half of the wire mesh 2.

The exposed tops of the three-dimensional wire mesh 2 are at the apex angles of the above-mentioned equilateral triangle, and the steel wires 4 are laid lengthwise and laterally between the exposed tops.

The lower half of the three-dimensional wire mesh 2 serves as reinforcing bars for the mortar 3.

FIG. 2 shows an outline of the formwork device 5. This formwork device 5 is firmly assembled into a square cube shape with the exposed surface of the three-dimensional wire mesh 2 of the 26-plate 1 facing inside, and is configured to have a rectangular cross section.

Further, in order to reduce the work process on site and increase the strength of the half-PC column 13 obtained, the formwork device 5 is configured as shown in FIG. 3.

In this case, hoop lines 16 into which doughnut-shaped spacers 15 are fitted are arranged intermittently in the axial direction inside the formwork device 5 of the previous embodiment.

A half-PC column 13 is obtained which is provided with hoop striations 16 in advance.

This hoop reinforcement 16 is provided with a core 17 for restraining the main column reinforcement placed in the middle of the column, thereby obtaining a half-PC column 13 with a core. The cores 17 may be provided vertically and horizontally in a square shape.

When manufacturing the half-PC column 13, square members 6 having a right triangular cross section are passed through the four corners of the hoop reinforcement 16, and these are temporarily fixed.

As a means of temporary fixing, it may be lightly fastened to the steel wire 4 with a wire. Further, the means for assembling the 26-plate 1 into a square shape may be to wrap a band plate around its outer periphery and tighten it.

However, the opening on the side is closed leaving an opening for pouring concrete. Furthermore, disks 7 are fitted on both sides of the formwork device 5, and a centrifugal concrete forming machine 8 is installed as shown in FIG.
The formwork device 5 is rotated by rotating the disk 7.

The centrifugal concrete forming machine 8 has rotary wheels 9-9a spaced apart from each other on the left and right, one of the rotary wheels 9 is connected to a motor 10.
It is rotated via a belt 12 by a drive wheel 11 attached to the output shaft of the motor.

A concrete pressure feed hose is rotatably connected to the center of the iron plate that closes the side opening of the formwork device 5, the formwork device 5 is rotated, and concrete is poured in while further increasing the rotational speed.

Centrifugal force causes the concrete to coagulate, and excess water flows out from the edges of the formwork. It is desirable to drain as much excess water as possible during rotation to obtain high quality concrete.

When the concrete has almost solidified, the centrifugal concrete molding machine 8 is stopped, and the iron plate and square timber 61 that close the side end face of the formwork device 5 are removed. A product as shown in FIG. 5 is obtained.

A half-PC column 13 with a rectangular space formed inside is completed by the centrifugal force and the square timbers 6.

The PC plate 1 of the formwork device 5 and the post-cast concrete 14 are strongly adhered and integrated together with the part of the three-dimensional wire mesh 2 protruding from the surface of the PC plate 1.

That is, the formwork device 5 serves as an outer formwork for the half-PC column 13, and serves as a constituent material of the half-PC column 13 as it is, and there is no need to remove it from the mold. Then, the half-PC columns 13 are assembled at the required locations on-site, and concrete is poured on-site by passing the column main reinforcement into the internal space.

(Effects) As explained in detail above, according to the present invention, by using a PC plate that can sufficiently withstand the centrifugal force of a centrifugal concrete molding machine, a hollow semi-PC plate with a solid and strong rectangular cross section can be produced. A column can be formed.

In addition, the PC plate also serves as a formwork weir plate, which does not involve demolding work, and since the hoop strips and cores are arranged, it has the effect of greatly improving work efficiency, and the hoop strips and cores are arranged. Because of the child placement, it is possible to provide a half-PC column with a fairly large cross-sectional area.

[Brief explanation of drawings]

The figures all relate to embodiments of the present invention, with Figure 1 being a perspective view of a PC plate, and Figure 2 showing a formwork device for a centrifugal concrete forming machine constructed by assembling the PC plates of Figure 1 into a rectangular shape. FIG. 3 is a cross-sectional view showing the formwork device according to the embodiment, and FIG.
This figure is a side view showing the state of a centrifugal concrete molding machine in which the formwork device of FIG. 3 is arranged, and FIG. 5 is a plan view illustrating a half-PC column obtained by the formwork device of the present invention. 1... PC version 3... Mortar 5... Formwork device 7... Disk 8... Centrifugal concrete 9... ... Rotating wheel 11 ... Drive wheel 13 ... Half PC column 2 ... Three-dimensional wire mesh 4 ... Steel wire 6 ... Square Material forming machine 10. ... Motor 12 ... Belt 14 ... Concrete 15 ... Spacer 16 ... Hoop line 17 ... Core

Claims (2)

[Claims] (1) A tubular precast concrete column with a core installed between two hoop bars. (2) A PC board with reinforcing bars arranged vertically and horizontally is assembled into a frame to form a column form, and hoop bars with cores are placed inside the frame while determining the distance from the inner surface of the form using spacers such as donuts. After that, the formwork is rotated by a centrifugal concrete forming machine and concrete is poured into the formwork to the extent that a pipe body is obtained.