JPH02163586A - Multilayered pipe having impregnated mortar layer - Google Patents

Abstract

PURPOSE:To obtain a multilayered pipe which can be easily constructed at a low cost by constituting a hume pipe, tile pipe, steel pipe, plastic pipe, etc., for transporting fluid, from a multilayered pipe in two or three layers consisting of an outer pipe layer, middle pipe layer made of the impregnated hardened cement mortar, and an inner pipe layer consisting of plastic sheet or plastic film. CONSTITUTION:A multilayered pipe having an impregnated mortar layer which consists of an outer pipe layer 1, middle pipe layer 2 made of the hardened material of the hardening cement mortar impregnated into a supporting body which is integrally joined with the inner wall of thin outer pipe layer 1, and an inner pipe layer 3 consisting of plastic sheet or plastic film which is integrally joined with the inside of the middle pipe layer 2. The hardening cement mortar is hardened at the normal temperature, and in case of an already constructed pipe made of concrete, the adhesiveness with the inner surface of the pipe is superior, even if the inner surface is wet, and since the middle pipe layer 2 is fiber-reinforced by the supporting body, the repaired multilayered pipe can be obtained easily at a low cost, and when a plastic sheet or plastic film is used for the inner pipe layer 3, corrosion resistance can be improved further.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to pipe bodies such as hume pipes, ceramic pipes, steel pipes, and plastic pipes used for transporting fluids, and in particular to existing pipe bodies. This invention relates to multilayer pipes that have been reinforced or repaired by lining treatment.

[Prior art] For example, existing pipes, such as sewer pipes, are often made of concrete, and they are usually corroded due to long-term use, and pipes that have not necessarily been used for many years. However, due to earthquakes and other tectonic movements, some cracks have formed, causing water leaks. In such a case, if the damage is severe, it will be necessary to replace it, but if the damage is not necessarily the same, it may be possible to repair it and use it.

In reality, repair work is certainly being carried out on existing pipes such as sewer pipes, and the repair methods that are currently in the spotlight are those disclosed in Japanese Patent Publications No. 58-33098 and No. 58-39646. As shown in the figure, while the damaged pipe is still installed, a hardening synthetic resin is introduced into the pipe and hardened by rubbing it tightly against the inner wall of the pipe. This is a multilayer pipe (two-layer pipe) having a synthetic resin layer. This multilayer pipe can be easily made with corrosion resistance and is strong because corrosion-resistant synthetic resin can be obtained relatively easily and the curing time and ratio of the resin can be freely selected. Therefore, it is useful, but synthetic resins are expensive, and curable synthetic resins are even more expensive, which is a very big drawback. Furthermore, although it is easy to obtain corrosion-resistant synthetic resins, hardening synthetic resins are more susceptible to hydrolysis, and especially when used in acidic or alkaline water streams, they are not necessarily the best. There are some drawbacks to those that have corrosion resistance. In addition, when curing curable synthetic resins, the formulation of this type of resin requires precision, so it cannot be easily done on site and must be done in a specific location of the equipment, so from the time of compounding, A certain amount of time is required before construction, and during this time it is usually necessary to keep it cool at around 0°C in order to prevent the curing reaction from proceeding any longer than necessary. After construction, it has to be heated to promote curing, which has drawbacks such as the need for hot water.

Furthermore, in many cases, the existing pipes are made of concrete I, pipes made of concrete, or ceramic pipes, so they also have the disadvantage that the compatibility between these materials and the hardening synthetic resin is inherently poor.

[Problems to be Solved by the Invention] In the case of an outer pipe layer or an existing pipe, the present invention eliminates the above-mentioned drawbacks and solves the problem of the state in which the pipe body is installed, starting from a pipe body that has suffered a loss of 1 g. The aim is to provide repaired multi-layer pipes that can be obtained inexpensively and easily by performing repair work on the outer pipe layer. SUMMARY OF THE INVENTION The present invention is directed to providing an inexpensive multi-layered pipe.Means for Solving the Problems The present invention consists of an outer pipe layer, a support body integrally bonded to the inner wall of this outer pipe layer, and a hardening cement mortar impregnated therein. Impregnated mortar consisting of 3 layers, 2 or 3 basic layers: a middle tube layer which is a hardened product, and an inner tube which is a plastic sheet or plastic film that is further integrally bonded to the inside of this middle tube layer if necessary. It is a multilayer pipe having layers. In particular, in the case of repairing an existing pipe as mentioned above, the outer pipe layer is the existing pipe, and the middle pipe layer and inner pipe layer are multilayer pipes with impregnated mortar layers formed by subsequent repair work. be.

[Function] In the present invention, the middle pipe layer has the role of reinforcing, strengthening, and protecting the outer pipe layer, and when the outer pipe layer is an existing pipe, the middle pipe layer is It has the role of facilitating one's own formation. Specifically, the support, which is one of the constituent materials of the middle tube layer, may include non-woven fabrics, coarse woven fabrics or laminates thereof, nets made by extrusion molding of twisted threads, single fibers or synthetic resins, and laminates thereof. A wire mesh can be used for the support, and the other constituent material, hardening cement mortar, is corrosion-resistant (especially acid-resistant) and can be easily obtained, so this support is impregnated with hardening cement mortar and hardened. L'↓ Alternatively, it has the role of strongly protecting the outer tube layer whose strength has weakened due to corrosion or the like.

In addition, from the point of view of forming the middle pipe layer, i.e., during construction when repairing an existing pipe, it is necessary to form a support in the form of a pipe with a diameter that matches the inner diameter of the outer pipe layer. A material impregnated with uncured hardening cement mortar is introduced into the existing pipe, the end of the pipe is closed, and pressure is applied by injecting fluid such as air or water into the pipe. This allows the middle pipe layer to be easily adhered to the inner wall of the existing pipe (outer pipe layer), and if the hardening cement mortar is cured in this state, it is possible to easily attach the middle pipe layer to the inner wall of the existing pipe (outer pipe layer). A tube layer can be formed.

Incidentally, as one method suitable for imparting the above-mentioned preferable properties to hardening cement mortar, Japanese Patent Application Laid-Open Nos. 60-42262 and 61. -20994
There is a method of blending using "cemen l-admixture = 6 agent" disclosed in each publication of No. 1.

In addition, the thickness of the support used here can be 3.0 to 20 mm in the case of non-woven fabric, and 4.0 to 6 mm in the case of using a support with an inner diameter of around 20 cm as the outer tube layer.
．． 0mm is suitable. In addition, a typical formulation example of hardening cement mortar of surface 11fi is as follows.

Compound Amount (parts by weight) Semen I-100 Silica sand 30~io.

Water 40-65 Cement admixture 1 4-8 (1) Mixture of curing accelerator, corrosion resistance agent, affinity improver, etc. as appropriate) Lastly, the role of the inner tube layer provided if necessary is as follows. Its two main functions are a protective effect on the intermediate canal layer and an auxiliary effect during the formation of the intermediate canal layer.

Plastin-ink sheet or Plastin-ink film J-
Nowadays, it is possible to select plastic materials with desired properties as appropriate for the plastic materials used in the construction. . Furthermore, since the plastic sheet or plastic film used does not need to be curable, the range of selection of plastic IA materials becomes wider. Examples of usable materials include polyethylene, polypropylene, polyvinyl chloride, polymethyl methacrylate, polystyrene, polyethylene terephthalate, etc. In particular, when repairing a sewer pipe to make it into a multilayer pipe, polyethylene, polypropylene, or polyvinyl chloride is preferable from the viewpoint of corrosion resistance. This property is the best among all synthetic resins. Furthermore, since this type of plastic sheet or plastic film can easily have a smooth surface, it is possible to reduce fluid resistance. In addition, especially when making an existing pipe into a multilayer pipe, when forming the middle pipe layer, the support formed in the shape of a pipe is impregnated with uncured hardening cement mortar (cement milk), and this is poured into the outer pipe layer. After introducing the impregnated tube into the tube, both ends of the impregnated tube are closed and a fluid such as air or water is introduced inside and pressurized, making it hollow and being pressed against the inner wall of the outer tube layer to harden it. To maintain the internal pressure, place a plastic sheet along the inside of the middle tube layer when it is not cured, and introduce air etc. into the inside of it, so that the plastic sheet will not allow fluids such as air to pass through. Therefore, pressurization work can be made easier. This plastic sheet or plastic film will form the inner tube layer.

The formation of multilayer pipes above has mainly been described in the case of converting existing pipes into multilayer pipes, but it can basically be done in the same way in the case of newly installed pipes or when producing multilayer pipes themselves in a factory. It should be easy to understand that this is the case.

[Example] Here, an example will be described. Numbers within 0 represent symbols in the drawings.

a) Pipe formation 1, outer pipe layer (1) A concrete pipe with an inner diameter of 20 cm, a wall thickness of 27 mm, and a length of 2 m was prepared.

2. Middle pipe layer (2) and inner pipe N (3) 2.1 Preparation of cement milk Amount (parts by weight) Ordinary cement 100 Silica sand No. 8 30 Water 40 Seishi Cyclim S-8000”
4 (*Corrosion-resistant cement admixture manufactured by Hiki Nanaon 01)2.
2 Support length 2.5m, width 65cm, thickness 5. A nonwoven fabric made of polyethylene fibers was prepared, and a polyethylene sheet I with a thickness of 0.3 mm was bonded to one side of the nonwoven fabric by heat fusion. Join both long sides of this with a plastic sheet on the inside to make it into a cylindrical shape, and attach it to this nonwoven fabric.
- It was uniformly impregnated with the cement milk prepared above.

2.3 Formation of Multilayer Pipe The nonwoven fabric laminate impregnated with the above cement milk was passed inside the outer pipe layer, and both ends of the nonwoven fabric were sealed with caps. Air is introduced by a compressor through the air introduction hole provided on one of the caps, and the amount of air is approximately 0.2 kg/c...
When pressurized to 2, the tubular material was able to be completely brought into close contact with the inner wall of the outer tubular layer. The cement milk left in this state for 3 hours had hardened sufficiently to retain its shape, so pressurization was discontinued. This was left for another 6 hours to allow the hardening cement mortar to completely harden, and then the next test was conducted.

b) Performance test 1, water resistance test Both ends of the obtained multilayer tube were sealed with pressure-resistant caps, the inside was filled with water, and the condition was observed while pressurized and the pressure was measured.

Pressurization was stopped when the pressure reached 3.0 kg, but
No abnormality was observed in this multilayer tube.

2. Corrosion resistance test When this multilayer tube was filled with an aqueous sulfuric acid solution with a pH of 1.0 and left for one week, no abnormalities were found inside.

[Effect of the invention] As described above, if the existing pipe is made into a multilayer pipe according to the present invention, the middle pipe layer is made of a hardened cement mortar impregnated with a support, so that this hardening cement mortar can be kept cool. It cures at room temperature and does not require heating, and has good adhesion to existing pipes made of concrete even if the inner surface is wet with pond water.
Since this middle tube layer is fiber-reinforced by the support, a repaired multilayer tube with sufficient strength can be easily and inexpensively obtained, and moreover, the inner tube layer has bra = 12
= If you use a stick sheet or plastic film,
This method is not only advantageous for forming multilayer pipes, but also allows corrosion resistance to be further improved at low cost, as well as reducing fluid flow resistance, thereby increasing the flow rate of the pipe. Moreover, if the multilayer pipe of the present invention is obtained by newly constructing a pipe or by factory production from the beginning, a corrosion-resistant and strong pipe body can be obtained from the beginning, and in any case, the present invention has useful effects. It has the following.

[Brief explanation of the drawing]

The figure is a cross-sectional view of a multilayer pipe obtained in an example of the present invention.

Claims (1)

[Scope of Claims] 1. An outer tube layer, a middle tube layer which is a hardened product of hardening cement mortar impregnated into a support integrally bonded to the inner wall of the outer tube layer, and if necessary, this middle tube layer. A multilayer tube having an impregnated mortar layer consisting of an inner tube layer which is a plastic sheet or film integrally bonded to the inside of the tube. 2. The multilayer pipe having an impregnated mortar layer according to claim 1, wherein the outer pipe layer is an existing pipe layer, and the middle pipe layer and the inner pipe layer are formed by subsequent construction.