JPS6168364A - Manufacture of fiber reinforced pipe - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method of manufacturing a fiber-reinforced pipe, and more particularly to a method of manufacturing a pipe having a relatively small diameter and high bending strength.

(Prior Art) In recent years, sewerage systems have been developed not only in urban areas but also in rural areas, and as a result, the demand for sewerage pipes is expected to increase.

These types of pipes can be broadly divided into large diameter and small diameter.The former is used for the main purpose of collecting and discharging wastewater from each household, and the latter is used for 25mm each. It is used as a branch line to drain wastewater from gardens, factories, etc. Set*
*The amount is overwhelmingly small diameter.

Conventionally, most of these pipes have been made of reinforced concrete as rigid pipes, but during long-term use, drainage may seep into the ment, or some parts may become clogged or acidic. Concrete parts may be infiltrated by drainage water, corroding the reinforcing bars, losing their reinforcing effect, and even reducing the weight of the vehicle.
There was a phenomenon where the villages were crushed and destroyed.

This is mainly due to the corrosion of the reinforcing steel bars, and has been considered impossible to avoid.

However, in recent years, cement materials reinforced with alkali-resistant glass fibers (GRC) have appeared, and pipes made of such materials have been proposed. (Refer to % Kaimei No. 49-93411) (Problems to be solved by the invention) Due to the manufacturing method, this pipe can only be made with a medium diameter or larger, and pipes with a medium diameter or larger are made of fibers, etc. Reinforcing materials can be easily used in various forms, and therefore products with considerably high strength can be obtained, but the mechanism for supplying raw materials from inside the pipe is quite complex and large, so in the case of small diameters, the above proposal is not suitable. Not only is this method difficult to use, but also the manner and amount of reinforcing materials used are quite limited compared to those with large diameters. In fact, the centrifugal molding method is still preferable as a means of efficiently producing small-diameter fibers, but the form of the fibers used in this case is chopped
It is no exaggeration to say that only the In other words, in the case of pipes, fiber reinforcement is said to have the highest strength when concentrated near the outer surface of the pipe, so in order to concentrate fibers in that area by centrifugal forming, chopping This is because there is only a form.

However, as a form of reinforcing fiber, chopped strands cannot necessarily be expected to have a sufficient reinforcing effect when it comes to pipes.

(Means to solve the problem) In view of these points, the philosophy of non-invention is to conduct a research project to find a means to obtain a pipe with as much strength as possible, taking into account these constraints. As a result of investigation, it has been found that the above object can be achieved by selecting the materials used, such as cement, within a specific range, and by controlling the dehydration prior to hardening.

Thus, the present invention can be applied using 20 to 90 parts of slurry and 2 to 90 parts of gypsum.
20 parts by weight, cement mill 50 parts by weight, aggregate 0-500
Parts by weight, ff1M0.2~81i parts, water in a proportion of 20~120x parts based on the total amount of slag, gypsum, and cement; To provide a method for producing a fiber-reinforced pipe, which comprises centrifugally dehydrating and molding the product until it becomes 35 parts by weight, and then curing it.

If the amount of slag used in the present invention deviates from the above range, the strength will decrease, if the amount of gypsum is less than the above range, drying shrinkage will increase, and conversely if it exceeds the above range, the strength will decrease. If the amount of cement is less than the above range, the strength will be insufficient; if it exceeds the above range, the fibers will be immersed by the alkali in the cement, and if the amount of cement is less than the above range, the strength will be insufficient. If it is less than this range, the strength will be insufficient, and if it exceeds the range, the cured product will become rough and there is a risk of water passing through, so both are inappropriate. Although it is not necessary to use aggregate, it is preferable to use it because the strength can be maintained for a long period of time. In addition, if the amount of water during raw material preparation does not fall within the above range, fluidity will not be obtained, and on the other hand, if it exceeds the above range, the solid content will separate violently, making it difficult to mix uniformly. Both are inappropriate because they interfere.

The raw material thus made into UII is then passed through a centrifugal dehydration molding machine for forming pipes. As such a molding machine, one having an appropriate configuration can be adopted. For example, two pairs of wheels that support a rotating wheel frame, such as those used for molding general Hiem tubes, are supported on the base, and one pair of wheels are mutually aligned with the axis. A molding machine having a structure in which the driving wheels are spaced apart in the axial direction, and the other pair of wheel bodies are also spaced apart in the axial direction, but is in the form of an idle wheel, is preferably used.

A plurality of raw material supply nozzles are arranged at positions substantially along the longitudinal center line of the molding section of the molding machine, and the raw material is supplied to the molding section where it is centrifugally molded and dehydrated.

What is important at this time is the amount of water remaining after dehydration, and it is necessary that the remaining amount of water is 15 to 35 parts by weight based on the total amount of slag, gypsum, and cement.

If the water content deviates from the above range, it will be difficult to obtain maximum strength no matter how the subsequent treatment is carried out, making it unsuitable.

In fact, pipe forming and dewatering are performed simultaneously using a centrifugal forming machine, but the conditions are that the centrifugal force acceleration is 20 to 60 G at the center of the pipe wall thickness, and that the process is carried out for about 2 to 30 minutes. will be achieved.

In such an operation, after the molding is complete, centrifugal force must be continued to be applied for dehydration.

Further, the wall thickness of the molded pipe is 10 to 100W8 degrees, and if it deviates from this range, the strength will be insufficient and the weight will simply increase, which is not preferable.

Further, the inner diameter of the pipe is about 100 to 800 mm, and in the case of such a pipe, the highest strength can be found in consideration of the above-mentioned meat hood.

Examples of the aggregate used in the present invention include sand, lightweight aggregate sand, limestone powder sand, per2ite, and the like.

In addition, various types of fibers can be used as the fibers, but
In particular, it is particularly preferable to employ alkali-resistant fibers because a stable reinforcing effect can be expected over a long period of time.

These fibers are also commonly used as chopped stock.

Next, the present invention will be explained by examples.

l! Construction 1 rug 60 parts by weight 1 plaster 10! 30 parts by weight, 50 parts by weight of No. 5 silica sand as aggregate, 0.6 parts by weight of water reducing agent (0.6 parts by weight of Mighty N, 35 parts by weight of water, and these 1)
00 parts by weight were mixed with 3 parts by weight of alkali-resistant glass fibers cut to a length of 37 gourds to produce a nine-gold 2x tv4.

Then, using a centrifugal molding machine that manufactures normal Huum tubes,
While rotating this with a centrifugal acceleration of 3G, the length is 21
21. The above gI41 so that the wall thickness is 12fi and the pipe inner diameter is 250M! The Shitabrezu Tsukusu was put into the molding machine.

After the addition of Prezx, the acceleration was set to 50G and held for 15 minutes to allow water to leached into the inner surface of the pipe until the amount of water after molding and dehydration reached 24±3 parts by weight in accordance with the indication of the present invention, and this was removed.

Next, the inner surface was finished according to a conventional method, and the tube was cured and demolded in almost the same manner as a normal Hume tube. The results are shown in the table below.

Example 2 Using the same Bremix as in Example 1, a pipe with a length of 2 m, a wall thickness of 17 cm, and an inner diameter of 250 m was produced in the same manner.
t, and the results are shown in the table below.

Although the actual pipe 1 is similar to Comparative Example 1, and the pipe of Example 2 is similar to Comparative Example 2, it is understood that the product of the present invention has the advantages of being lightweight, easy to collapse, and high in strength. Ru・

Claims (1)

[Claims] 1. 20 to 90 parts by weight of slag, 2 to 20 parts by weight of gypsum, 5 to 50 parts by weight of cement, 0 to 500 parts by weight of aggregate, 0 parts by weight of fiber.
．． 2 to 8 parts by weight, water is 20 to 120 parts by weight based on the total amount of slag, gypsum, and cement, and water is 15 to 35 parts by weight based on the total amount of slag, gypsum, and cement. A method for manufacturing a fiber-reinforced pipe, characterized by centrifugal dehydration molding and then hardening. 2. Claims that the fibers are alkali-resistant glass fibers (1)
)the method of. 3. The method according to claim (1), wherein the centrifugal dehydration molding is carried out at the center of the wall thickness of the pipe at an acceleration of 20 to 60 G for 2 to 30 minutes. 4. The method according to claim (1), wherein the fiber-reinforced pipe has a wall thickness of 10 to 100 mm. 5. The method according to claim (1) or (4), wherein the fiber-reinforced pipe has an inner diameter of 100 to 800 mm.