JPH0280205A - Frame device for centrifugal concrete molding machine - Google Patents

Abstract

PURPOSE:To remarkably increase working efficiency compared with bar arrangement of hoop joints by means of an ordinary reinforcing bars and bonding with other components more easily by supporting a bar with a side plate inside an outer frame constituted on a section rectangle, applying a spacer on the outside of the bar and winding in tension reinforcing fiber on the outside. CONSTITUTION:An outer frame 2 of section rectangular shape, a side plate 3 on a disk blocking both ends of said frame and a bar 4, a bar with a square triangle shaped section inserted into the outer frame 2 are provided. The end of the bar 4 is inserted into the side plate 3 and supported inside by the portion corresponding with the placed concrete thickness. Steel bars are placed just outside the bar 4 as spacers 5 of hoop joints, and reinforcing fiber such as carbon fiber or the like is wound through the outside of respective spacers 5, which are used as hoop bars 6. A frame device 1 is placed horizontally by placing a side plate 3 section between rotating rings 8-8a of a molding machine 7. Concrete is fed to the inside of the outer frame 2 to close both end surfaces. Concrete is made cohesive by centrifugal force, and surplus water is flowed out of a space between the side plate 3 and the outer frame 2 or the like.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a mold for a centrifugal concrete forming machine for obtaining a column having a hollow rectangular cross section and onto which main reinforcing bars can be placed later. It relates to a frame device.

(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.

In addition, precast concrete hollow columns are increasingly being used to connect the column/beam joints of precast concrete columns and the 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 has never been one in which a cubic column form is rotated using a centrifugal forming machine. .

The present invention has been made in view of the circumstances described above, and
The purpose of this is to form reinforcing bars of arbitrary length so that they can be placed at corners later, in order to facilitate connection with other members, and to create hoop reinforcements that are not affected by the concrete cover thickness or its neutralization. To provide a formwork device for a centrifugal concrete molding machine for obtaining a precast hollow column having a rectangular cross section.

(Means for Solving the Problem) In order to achieve the above object, a formwork device for a centrifugal concrete forming machine according to the present invention is provided for forming a hollow column having a rectangular cross section. As an inner formwork for use, rods are passed in parallel between a plurality of side boards set up at intervals to position and support the rods, and a circular locus connecting and surrounding each of the rods is formed between the rods. A spacer is interposed along the axial direction of the rod, and reinforcing fibers such as carbon fibers, aramid fibers, and glass fibers are wound around the spacer, and a column is placed between the side plates to surround them. The outer formwork was assembled integrally with the side plates so that the reinforcing fibers formed the hoop lines.

(Function) When the outer formwork is rotated, the side plates and rods also rotate together, exerting an even centrifugal force inside the formwork. When concrete is poured into the formwork while rotating, the centrifugal force forces the concrete tightly against the inner walls of the outer formwork and solidifies it.

At that time, the reinforcing fibers stored in the outer formwork in advance are
It is gradually buried in the concrete poured into the formwork, and adheres tightly to the poured concrete due to the centrifugal force of the molding machine.

If the rod is removed later, a notch is formed in the inner corner of the outer formwork that runs in the axial direction, and when the outer formwork is further removed from the mold, a hollow precast concrete column with a rectangular cross section is obtained. This concrete column will have hoop reinforcement made of reinforcing fibers installed in advance.

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

FIG. 1 shows an outline of the formwork device 1. This formwork device 1 includes an outer formwork 2 with a rectangular cross section, which is constructed by firmly assembling panels into a square cube shape, and side plates 3 shaped like discs that close both ends of the outer formwork 2.
and a rod 4 having a right triangular cross section and inserted into the outer formwork 2.

The ends of the rods 4 are inserted into and supported by through holes provided in the side plates 3 at corners of the outer formwork 2, located inward by an amount corresponding to the thickness of the poured concrete.

The outer formwork 2 needs to have sufficient strength to withstand the centrifugal force of the concrete thrown inside during rotation. The side plates 3 are screwed to both ends of the outer frame 2 so that the axial center of the outer frame 2 and the center of the side plates 3 are aligned.

By rotating the side plate 3, the outer formwork 2 is rotated.

The details are shown in FIG. 2 in the direction indicated by the arrows ■-■ in the figure.

Inside the outer formwork 2, in addition to the rod 4, there are steel rods attached to each outside side of the rod 4, which serve as spacers 5 for the hoop bars. That is, the rods 4 arranged near the four corners of the outer formwork 2
A reinforcing fiber such as carbon fiber is wound around the outside of each spacer 5 so as to pass through a position separated from the surface by the spacer 5, and this is used as a hoop muscle 6.

The hoop reinforcement 6 may be wound spirally around the outside of the spacer 5, and it is only necessary to wrap it tightly so as to press the spacer 5 inward, compared to the case where the hoop reinforcement is made of ordinary reinforcing steel. Its terminal end is fixed by tying it to a nearby spacer 5 or applying adhesive.

FIG. 3 shows the centrifugal concrete forming machine 7 and the above-mentioned formwork device 1 together. It is connected and driven by a drive wheel 10 attached to the output shaft of a motor 9 and a belt 11.

Therefore, when manufacturing a hollow prismatic column, the formwork device 1 is placed horizontally with the side plate 3 placed between the rotating wheels 8-8a of the molding machine 7.

That is, concrete is poured into the outer formwork 2 and both end surfaces of the outer formwork 2 are closed. To close it, the side plate 3 is screwed to the side of the outer formwork 2.

Concrete may be poured from the side of the outer formwork 2,
A part of the outer formwork 2 may be provided with an opening that can be opened and closed, and it may be possible to do so through this opening, but if the side end surface of the outer formwork 2 is to be completely closed, a concrete pressure hose should be placed in the center of the side plate 3. It is rotatably mounted, and the outer formwork 2 is rotated and concrete is poured in while increasing the rotational speed.

The centrifugal force causes the concrete to coagulate, and excess water flows out through the gap between the side panels 3 and the outer formwork 2. It is desirable to drain as much excess water as possible during rotation to obtain high quality concrete.

When the concrete is almost solidified, the centrifugal concrete molding machine 7 is stopped and the concrete is demolded. After demolding, a product as shown in FIG. 4 is obtained. This is a square prism 12 that has a cylindrical space inside due to centrifugal force.

Its four corners are provided with spline-shaped notches 13 with a rectangular cross section obtained by extracting the rod 4 from behind. The column main reinforcement 14 can be passed along this notch 13. Note that if the surface of the rod 4 is coated with a Teflon coating, or an edge cutting agent such as oil or fat is applied, it will be easier to remove it later.

(Effects) As explained in detail above, according to the formwork apparatus of the present invention, the rod housed inside the outer formwork having a rectangular cross section is supported by the side plates. Spacers can be placed on the outside, and reinforcing fibers can be wound under tension on the outside so as to communicate between the spacers. Therefore, compared to hoop reinforcement using ordinary reinforcing bars, the work efficiency is extremely high because the fibers are simply wrapped around each other, and since the reinforcing fibers are light and small in diameter, they have high tensile strength, so the reliability of the strength is high.
The burden of transportation and handling is also light.

In this way, the hollow precast concrete column obtained by the formwork apparatus of the present invention has a notch formed after the rod is removed, the column main reinforcement fits well, and it is considerably lighter than hoop reinforcement using ordinary reinforcing steel. This eliminates the need for column form work on site, which is extremely advantageous in saving labor and shortening the construction period.

[Brief explanation of the drawing]

The figures all relate to embodiments of the present invention; FIG. 1 is a perspective view showing a formwork device for a centrifugal concrete forming machine, and FIG.
An end view shown by the arrows ■-■ in the figure, FIG. 3 is a side view illustrating the state in which the formwork device is arranged in a centrifugal concrete molding machine, and FIG. 4 is an example of a hollow column obtained by the present invention. FIG. Fig. 1 1... Formwork device 3... Side plate 5... Spacer 7... Centrifugal concrete 8... Rotating wheel 10 ... Drive wheel 12 ... Square column 14 ... Column main reinforcement 2 ... Outer formwork 4 ... Rod body 6 ... Hoop reinforcement forming machine 9. ...Motor 11...Belt 13...Notch diagram Diagram

Claims (1)

[Claims] (1) In order to form a hollow column with a rectangular cross section, the rod is positioned and supported by passing it in parallel between multiple side plates set up at intervals as an inner formwork for forming the corners. A spacer along the axial direction of the rod is interposed between the rod and a circular locus connecting and surrounding each of the rods, and a carbon fiber, aramid fiber, or glass material is provided so as to circumscribe the spacer. Reinforcing fibers such as fibers are wound around them, and the outer form of the column is assembled integrally with the side plates between the side plates so that the reinforcing fibers form hoop lines. Formwork equipment for centrifugal concrete forming machines.