JPH0466163B2 - - Google Patents

Description

[Detailed Description of the Invention] <<Industrial Application Field>> The present invention provides 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 installed 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 turning efficiency for reinforced concrete structures and its ability to produce high-quality concrete products.

Then, in order to connect the column/beam joints of the precast concrete columns and the columns together in the axial direction,
Hollow columns made of precast concrete are increasingly being used.

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. While continuing to cure, a hollow column is obtained.

The molds mentioned above were generally cylindrical in shape because they were rotated.

《Problem to be solved by the invention》 However, the pillars of buildings are usually formed with a rectangular cross section, and there has never been one in which a cubic-shaped pillar form is rotated by a centrifugal forming machine. .

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

<<Means for Solving the Problems>> In order to achieve the above object, the formwork device for a centrifugal concrete forming machine according to the present invention has a corner forming method for forming a hollow column having a rectangular cross section. As an inner formwork for use, rods are passed parallel to each other between multiple side boards set up at intervals to position and support them.
A spacer along the axial direction of the rod is interposed between the rod and a circular locus that connects and surrounds each of the rods,
Reinforcing fibers such as carbon fibers, aramid fibers, and glass fibers are wound around the spacer so as to circumscribe the spacer, and the outer form of the column is assembled integrally with the side plates between the side plates so as to surround them. The reinforcing fibers were made to form hoop lines.

《Operation》 When the outer formwork is rotated, the side plates and rods also rotate together, and an even centrifugal force acts 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 this time, the reinforcing fibers previously housed in the outer formwork are gradually buried in the concrete poured into the formwork, and are tightly adhered to the poured concrete by the centrifugal force of the forming machine.

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

<<Example>> 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 apparatus 1. This formwork device 1 consists of an outer formwork 2 with a rectangular cross section, which is constructed by firmly assembling panels into a square cube shape, side plates 3 shaped like discs that close both ends of the outer formwork 2, and The rod 4 is inserted therethrough and has a right triangular cross section.

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 of the arrow in the figure.

Inside the outer formwork 2, in addition to the rod 4, there are steel rods attached to each side of the outside of the rod 4, which serve as spacers 5 for the hoop bars. That is, reinforcing fibers such as carbon fibers are wound through the outside of each spacer 5 so as to pass through a position separated by the spacers 5 from the surface of the rod 4 arranged near the four corners of the outer formwork 2.
This is called 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 molding machine 7 and the formwork device 1 together, and the centrifugal concrete molding machine 7 has rotating wheels 8-8a arranged at left and right intervals.
One rotating wheel 8 is driven in communication with a driving wheel 10 attached to the output shaft of a motor 9 by a belt 11.

However, when manufacturing a hollow prism,
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, or from an opening that can be opened and closed in a part of the outer formwork 2. When closing, a concrete pressure feeding hose is rotatably attached to the center of the side plate 3, and concrete is poured in while rotating the outer formwork 2 and 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. When 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, so that the outside of the rod is supported by the side plates. A spacer can be applied to the spacer, and reinforcing fibers can be wound around the outer side of the spacer under tension so as to connect each spacer. Therefore, compared to hoop reinforcing bars made of ordinary reinforcing bars, the work efficiency is extremely high because the fibers are simply wrapped around them, and the reinforcing fibers are light and have a small diameter, but have high tensile strength, so they are highly reliable in terms of strength, and are easy to transport. The handling burden is also light.

In this way, in the hollow precast concrete column obtained by the formwork apparatus of the present invention, a notch is formed after the bar is removed, and the column main reinforcement fits well, and compared to hoop reinforcement using ordinary reinforcing bars. It is quite light and eliminates the need for pillar construction on site, which is extremely advantageous in saving labor and shortening the construction period.

[Brief explanation of the drawing]

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

Claims (1)

[Claims] 1. In order to form a hollow column with a rectangular cross section, as an inner mold for forming the corners, a rod is passed in parallel between a plurality of side plates set up at intervals, positioned and supported, A spacer along the axial direction of the rod is interposed between the rod and a circular locus that connects and surrounds each of the rods, and carbon fiber, aramid fiber, glass fiber, etc. is provided so as to circumscribe the spacer. A centrifugal device characterized in that reinforcing fibers are wound around the outer frame of the column between the side plates so as to surround them, and the outer form of the column is integrally assembled with the side plates so that the reinforcing fibers form a hoop line. Formwork equipment for concrete forming machines.