JPH0464845B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a method for manufacturing a corrosion-resistant concrete pipe as an alternative to cement concrete pipes and steel pipes.

``Prior Art'' Conventionally, concrete pipes and steel pipes have been excellent as structural materials, but it is a well-known fact that they are vulnerable to corrosion caused by chemical action. Furthermore, since ceramic pipes, which are stable against chemical effects, undergo a high-temperature firing process, it is impossible to place reinforcing bars, so there are concerns about their breaking strength. Steel pipes are extremely susceptible to chemical attack, and not only do they have a short lifespan, but they also become clogged due to rust and lose their functionality as pipes. Although PVC pipes are resistant to chemical effects, they each have their own drawbacks, such as the lack of expensive top reinforcing bars, which make them easily deformed by earth pressure, and the fact that they are subject to severe deterioration from sunlight.

For example, in sewage systems, chemicals such as acids and salts flow in, as well as miscellaneous corrosive gases such as hydrogen sulfide generated from sewage, which decomposes calcium in cement and destroys concrete, which has become a social problem. The same applies to steel pipes. In addition, resin concrete, which is a mixture of concrete aggregate and resin, already exists, but in both cases, the resin and aggregate are mixed and then molded into the desired shape, so the early solidification and adhesiveness of the resin are important. is too large, etc.
Currently, it is extremely difficult to work with, making it impossible to manufacture high-quality products.

``Problems to be Solved by the Invention'' The present invention aims to easily obtain a concrete pipe that is strong, chemically stable, highly corrosion resistant, and has a smooth inner surface.

"Means for Solving the Problems" In order to achieve the above object, the present invention arranges reinforcing bars along the inner peripheral surface of a cylindrical form, rotates the form around its center line, and rotates the form around its inner circumference. A corrosion-resistant self-hardening liquid layer is maintained on the surface by centrifugal force, and then a mixed aggregate consisting of coarse aggregate and fine aggregate is poured into the same mold, and the coarse aggregate is brought into close contact with each other by the centrifugal force. Then, the surfaces of the coarse aggregate and fine aggregate are wetted with the autogenous hard liquid to form a mixed aggregate layer, and the fine aggregate is poured into the autogenous hard liquid that appears on the inner periphery of the mixed aggregate layer to form a mixed aggregate layer. It is constructed using a corrosion-resistant pipe manufacturing method characterized by forming and solidifying a mortar layer.

"Function" Therefore, mixed aggregate with fine aggregate 3 and coarse aggregate 2 is formed by centrifugal force inside the corrosion-resistant self-hardening liquid layer 7 held along the inner circumferential surface of the rotating cylindrical form 6. to form a mixed aggregate layer 12. The self-hardening liquid 1 wets the surfaces of the aggregates 2 and 3, and due to the volume occupied by the aggregates 2 and 3, the liquid 1 advances toward the center line of the formwork 6 between the aggregates. The aggregate layer 12 is submerged in the liquid layer 7, and a thin layer 13 of the autogenous hard liquid 1 is formed on the inner periphery of the aggregate layer 12. In this state, when fine aggregate 3 is further introduced into the formwork 6, the fine aggregate enters into the thin layer 13 due to its centrifugal force and forms a mortar layer 5 of fine aggregate. 1 hardens to form the aggregate layer 12 and the fine aggregate mortar layer 5.
The fine aggregate mortar layer 5 and the fine aggregate 3 in the aggregate layer 12 are integrally continuous, and both layers are formed integrally, and are removed from the mold after the hardening liquid 1 hardens, and are used to prevent corrosion of sewer pipes, etc. It is used in a sexual atmosphere.

``Example'' Rolling wheels 9, 9 are pivotally supported on a machine base 8, a steel cylindrical form 6 is supported on the same rolling wheels 9, 9, and one rolling wheel 9 is driven by a continuously variable speed motor 10. By rotating, the same mold frame 6 can be rotated around the center line a of the cylinder. A mold release agent is applied to the inner peripheral surface of the mold 6, or a mold release material 11 made of paper or the like is stretched. Then, cage-shaped reinforcing bars 4 are arranged inside the molded material or material 11 along the inner peripheral surface. Then the motor 10
is started to rotate the same mold frame 6 around the center line a, and in this state, a corrosion-resistant resin liquid (unsaturated polyester resin), a heated coal tar liquid, a heated asphalt liquid, a coal tar liquid diluted with a solvent (thinner, etc.), When a corrosion-resistant self-hardening liquid 1 such as a bituminous agent such as a diluted asphalt liquid is injected into the rotating form 6, the liquid 1 rotates along the inner peripheral surface due to its viscosity and is kept constant due to centrifugal force. A thick corrosion-resistant self-hardening liquid layer 7 is formed and maintained in that state (the state is shown in FIG. 2C). In this state, when a mixed aggregate consisting of fine aggregate 3 and coarse aggregate is poured into the same mold 6, a mixed aggregate layer 1 is formed to a uniform thickness by centrifugal force as shown in Fig. 2D. These aggregates 2, 3 enter the self-hardening liquid layer 7 due to the centrifugal force, reach the inner circumferential surface, come into close contact with each other, and The self-hardening liquid 1 wets the aggregates 2 and 3 and the reinforcing bars 4 and advances between the aggregates 2 and 3 and between the aggregates 2 and 3 and the reinforcing bars 4. And this advance self-hardening liquid 1
appears on the inner periphery of the mixed aggregate layer 12, and the layer 12 is submerged in the liquid 1 to form a thin self-hardening liquid layer 13 on the inner periphery (FIG. 2D). In this state, when only the fine aggregate 3 is introduced into the formwork 6, the fine aggregate 3 enters the thin layer 13 due to centrifugal force and is integrated with the fine aggregate portion in the mixed layer 12, forming fine aggregates. A mortar layer 5 is formed (FIG. 2). According to experiments, both layers 5 and 12 were maintained without collapsing even if the rotation of the formwork 6 was stopped at this point. Thereafter, the self-hardening liquid 1 hardens relatively quickly, and the aggregates 2 and 3 as well as the aggregates 2 and 3 and the reinforcing bars 4 are bonded and solidified, so that the formwork 6 is demolded and the corrosion-resistant concrete is made. Tube 14 can be removed. It is preferable that the self-hardening liquid 1 has as low a viscosity as possible within a range that maintains its adhesive properties after curing.
This is because the aggregates 2 and 3 easily enter the liquid. In addition, the surfaces of the aggregates 2 and 3 are kept dry,
Also, it is preferable that no silty fine powder adheres to the surface. When adding aggregates 2 and 3, add a mixture of coarse aggregate 2 and fine aggregate 3 to 8/10 to 9/10 of the thickness of the tube 14 so that the voids are as small as possible.
After this becomes a uniform mixed aggregate layer 12 and is submerged in the own hard liquid 1, the fine aggregate 3 is introduced into the remaining 1/10 to 2/10 thin layer 13 using centrifugal force as described above. . This is to form a smooth inner surface without causing the coarse aggregate 2 of the mixed aggregate layer 12 to protrude to the inner surface. The volume ratio of the above-mentioned hard liquid 1 and aggregates 2 and 3 is appropriately adjusted depending on the use of the pipe 14. In addition, the proportion of aggregates 2 and 3 contained in the self-hardening liquid 1 depends on the concentration of the same liquid 1, so the concentration should be adjusted using the above-mentioned solvent, heating temperature, etc. according to the external pressure strength and water tightness required by the product. I can do it. In addition, what is shown by 15 in the figure is both end flanges of the formwork 6, and 16
17 is a wheel bearing tire provided on the outer periphery of the formwork 6, 17 is a pulley provided on the rotating shaft of one of the wheels 9, 18 is a pulley provided on the output shaft of the motor 10, and 19 is both pulleys. This is the adjustment string that is tied to 17 and 18.

"Effects of the Invention" Since the present invention is based on the above-mentioned method, the external force is dispersed by the coarse aggregates 2 that are in close contact with each other, and the amount of self-hardening liquid required is small, so it is extremely economical.
It is possible to obtain a corrosion-resistant pipe that is strong enough to prevent the surfaces of both aggregates 2 and 3 from being wetted by corrosive substances, has high corrosion resistance such as weather resistance and acid resistance, and can be safely used in a corrosion-resistant atmosphere such as a sewage pipe. There is no need to mix materials outside the mold, and the corrosion-resistant tube 14 can be manufactured quickly and easily, making it suitable for mass production.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional front view showing the corrosion-resistant pipe of the present invention;
Figure 2 A, B, C, D, and E are manufacturing process diagrams, and Figure 3
The figure is a longitudinal sectional front view of the cylindrical formwork and reinforcing bars, FIG. 4 is a longitudinal sectional side view of FIG. 3, and FIG. 5 is a longitudinal sectional view immediately before demolding. DESCRIPTION OF SYMBOLS 1... Corrosion-resistant self-hardening liquid, 2... Coarse aggregate, 3... Fine aggregate, 4... Rebar, 5... Mortar layer, 6... Cylindrical formwork, 7... Corrosion-resistant self-hardening liquid layer, 12 ...Mixed aggregate layer.

Claims (1)

[Claims] 1 Reinforcing bars are arranged along the inner circumferential surface of a cylindrical formwork, the formwork is rotated around the center line to maintain a corrosion-resistant self-hardening liquid layer on the inner circumferential surface by centrifugal force, and then rough A mixed aggregate consisting of aggregate and fine aggregate is put into the same mold, the coarse aggregate is brought into close contact with each other by the centrifugal force, and the surface of the coarse aggregate and fine aggregate is brought into close contact with each other by the above-mentioned self-hardening liquid. A corrosion-resistant pipe manufacturing method characterized in that a mixed aggregate layer is formed by wetting, fine aggregate is added to the autogenous hard liquid that appears on the inner periphery, and a mortar layer is formed and solidified by the autogenous hard liquid. .