JPS5924756B2 - Method for manufacturing concrete products with hollow parts - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a method for manufacturing concrete products having hollow parts, characterized in that plastic monomer is impregnated under pressure into minute voids in concrete using an inner frame material. .

The most common concrete products with hollow parts are humid pipes, reinforced concrete piles, prestressed concrete piles, hollow poles, etc., and conventional manufacturing methods use centrifugal force or non-deformable inner frame materials. Either concrete should be placed between it and the outer frame material to give it vibration.

However, concrete products with hollow parts that utilize centrifugal force require large-scale centrifugal force forming equipment during manufacturing, and concrete products that utilize vibration do not have a dense quality, so they have low compressive strength, tensile strength, and bending strength. In other cases, sufficient strength cannot be obtained.

In addition, the conventional production method of impregnating concrete with plastic to improve its physical properties has difficulty in sufficiently impregnating plastic monomers into microscopic voids, and requires complex equipment and machinery such as impregnating containers for plastic monomers. This process is troublesome, and has the disadvantage of significant loss and contamination of expensive plastic monomers.

The present invention has been proposed in view of the above, and is a method for manufacturing concrete products having hollow parts using an inner frame material in a simple manner, and in addition, it is possible to easily add sufficient plastic monomer to the microscopic voids of concrete. It is pressure impregnated.

Briefly, as shown in FIG. 1, the method for manufacturing concrete products of the present invention includes storing an inner frame member 2 inside an outer frame member 1, and placing concrete in an annular space 3 formed between both frame members 1 and 2. 4
to be poured.

Once the annular space 3 is filled with concrete 4, the outer frame material 1 is placed on the vibrating device 5 and vibrated to make the concrete 4 denser, and if there are gaps in the space 3, concrete is poured further. Fill.

After the annular space 3 is filled with concrete in this manner, fluid such as water, oil, air, etc. is supplied under pressure to the inside of the inner frame member 2 using a supply device 6 such as a compressor or a pump, and the concrete is expanded.
Concrete 4 is compacted under pressure from the inside.

As a result, the concrete 4 becomes compacted and becomes dense, and the water content is squeezed out from the upper end or the lower end.

Next, the inner frame material 2 is expanded and cured in normal pressure steam, or the upper and lower ends of the outer frame material 1 are covered with lid materials 7 and 7 to airtightly seal the inside and heated. Then, the mold is cured at high temperature and high pressure, and once it has sufficiently cured, it is removed from the mold.

In the manufacturing method described above, the outer frame material 1 is made of, for example, metal and has sufficient strength and rigidity to withstand the internal pressure applied from concrete.

However, as shown in FIG.
A fluid pipe 25 having an on-off valve 24 is connected to the end of the hollow frame 22.

Since this inner frame material 2 has the same length as the outer frame material 1, the annular space 3 formed when the inner frame material 2 is stored in the center of the outer frame material 2 has a length equal to 0. It becomes cylindrical.

After this space 3 is filled with concrete 4, when the fluid pipe 25 is connected to the supply device 6 and air, oil, etc. is supplied under pressure to the hollow frame 22, the bellows 21 expands in the outer circumferential direction, and the metal plate 23 to compact the concrete 4 under pressure.

In this case, since the higher the pressure of the fluid supplied to the inside of the hollow frame 22, the more it expands, it is preferable to increase the pressure applied to the concrete as much as possible to strengthen compaction.

Further, in order to prevent the hollow frame 22 from expanding in the length direction, it is preferable to fix both ends.

In this way, when concrete is compressed from the inside using an inner frame material and then cured, the density becomes extremely high, so that the strength of concrete products in compression, tension, bending, etc. becomes extremely high.

Therefore, according to the above manufacturing method, it is possible to easily manufacture a concrete product having a high-strength hollow part, and there is no need for a large-scale centrifugal force molding machine. No skilled work is required.

Further, according to the above manufacturing method, the outer frame material may or may not be sealed with a lid or the like, and the concrete can contain reinforcing materials such as reinforcing bars, PC steel bars, and steel fibers.

Furthermore, during the manufacturing process, it is most effective to cure while maintaining the expansion force of the inner frame material; The frame material may be removed and cured.

In order to manufacture a concrete product with further strength by impregnating the concrete product having a hollow part manufactured in the above manner with plastic, the outer frame material 1 is attached to the cured concrete product a as shown in Fig. 3. After S-drying and vacuum treatment to remove moisture contained in the concrete and air present inside minute voids, the inner frame material 2 is housed in the hollow interior of the concrete product, and the upper and lower ends of the outer frame material 1 are Covering materials 7, 7 are closely adhered to the container and filled with plastic monomer b.

In this case, the inner frame material may be housed in the hollow interior of the concrete product, sealed with a lid material, dried and vacuum treated, and then filled with a plastic monomer.

When the inner frame material 2 is expanded, the plastic monomer is pressurized and impregnated into the microscopic voids in the concrete. After the monomer has sufficiently impregnated into the microscopic voids, the plastic monomer inside the frame material is discharged, and hot water or steam is supplied. The plastic monomer impregnated into the microscopic voids is thermally polymerized into a polymer.

Therefore, according to the above method, there is no need for a container for impregnating plastic monomers as in the conventional method, and loss and contamination of plastic monomers are significantly reduced, resulting in high economical effects.

Moreover, not only the installation of various machines for monomer impregnation becomes extremely simple, but also the work becomes easy.

Note that the inner frame material used to impregnate the concrete product with plastic monomer should have a metal plate removed, and the hollow frame should be made of plastic to prevent monomer erosion.

In summary, according to the present invention, a concrete product having a hollow portion can be made very easily, and the minute voids of the concrete product can be sufficiently impregnated with plastic to produce a product with high physical properties.

In addition, manufacturing does not require large-scale equipment such as plastic monomer impregnation containers or special technology.
Furthermore, since the concrete product always has a predetermined strength, it is possible to provide products that meet various purposes.

Furthermore, the present invention is economical because loss and contamination of plastic monomers are significantly reduced.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing the manufacturing process before impregnating the plastic, Fig. 2 (I) is a longitudinal cross-sectional view of the inner frame material, Fig. 2 (n) is a cross-sectional view of the inner frame material, and Fig. 3 The figure is a schematic diagram showing the process of impregnating plastic.

Claims (1)

[Claims] 1. The inner frame material is housed inside the outer frame material to form an annular space between the two frame materials, and after pouring concrete into this annular space, the inner frame material is expanded. After drying and vacuum treating the cured concrete product while compressing the concrete under pressure, the inside of the sealed outer frame material is filled with plastic monomer, and the inner frame material is expanded to infuse the plastic monomer into the microscopic voids of the concrete. A method for manufacturing a concrete product having a hollow portion, characterized in that the concrete product is impregnated with pressure under pressure.