JPH02217346A - Lining material and production of lined pipe using same material - Google Patents

Abstract

PURPOSE:To provide a lining material providing lined pipes capable of suppressing pH of initial water flow to a low value without effecting seal coating, consisting of a binder comprising alumina cement and blast furnace granulated slag powder, sand and water as main components. CONSTITUTION:30-95 pts.wt. alumina cement is blended with 70-5 pts.wt. blast furnace granulated slag powder to produce a binder. Then a lining material consisting of the binder, sand and water as main components is produced. Further the lining material can be mixed with an inorganic expanding material (e.g. calcium sulfoaluminate or calcium fluoride), a water reducing agent (e.g. lignin sulfonate), etc. The prepared lining material is lined to the inner face of a pipe by centrifugal forming method, the lined layer is solidified by humidifying curing so that a lined pipe having a small amount of soluble Al and excellent surface finish can be produced.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a lining material and a method for manufacturing a lining pipe, and more specifically, a lining material for lining the inner surface of pipes such as steel pipes and cast iron pipes supplied for water supply and sewage. and the manufacturing method of lining pipes.

[Conventional technology and its issues]

BACKGROUND ART The inner surfaces of steel pipes and cast iron pipes used for water and sewage systems have traditionally been lined to prevent rust, improve durability, and stabilize the quality of tap water.

Portland cement mortar is usually used as this lining material, but when used for water pipes, the alkaline content in the mortar is eluted during the initial water flow, resulting in a significant increase in the -10 or more of the water. .

In order to prevent the mortar layer from being destroyed under acidic conditions, a seal coat material is usually applied to the surface of the lining layer in portland cement mortar lining.

However, in actual buried use, the p-seal coating material decomposes and peels off due to acidic water such as underground water or sewage containing a large amount of free carbonate, exposing the surface of the lining layer, causing a rise in -, and peeling. There was a problem in that the seal coat material clogged pipes, water pumps, etc., and floated in tap water (9), creating a bad odor in tap water. In addition, there is also the problem that Ca''◆ is eluted from the peeled surface of the seal coat material, destroying the lining layer and reducing durability. As a method, a method of lining the inner surface of a pipe using cement and sand with low R and O content has been proposed (Japanese Patent Application Laid-Open No. 66-2968).
Publication No. 74). However, when this lining method is used, although the rise can be suppressed, α in the alumina cement mortar is eluted and soluble Atfit increases significantly during the initial water flow, resulting in 1111M clouding of drinking water.

In addition, since centrifugal molding was performed, a large amount of cement was segregated on the inner surface, which caused problems such as insufficient durability against acidic water.

In particular, it has been reported that soluble KL in drinking water is unfavorable for health when ingested in large quantities (Metal, 1985.55 (7)
, P63-65. Toshihiko Sato, Nikkan Kogyo Shimbun 1988.1
(October 29th issue, Asahi Shimbun 1989 January 17th issue, etc.), and lining pipes with a large amount of soluble At were not put into general use even though they had the effect of suppressing the rise.

Lining pipes using conventional Portland cement mortar contain only a trace amount of 3CaO-At203, a hydraulic calcium aluminate that causes soluble At, and therefore the amount of soluble At remains at 0.0 even without coating.
The level was very low, less than 2 ppm. However, when alumina cement is used as in JP-A No. 63-296874, CaO・Az, 1o3, CaO' 2
Since it contains hydraulic calcium aluminates such as At103 and 12Ca0 .7Azgo3 as main minerals, it had the problem of a significant increase in the amount of soluble At, and could not be used in practice.

Additionally, since alumina cement generates more heat during the initial stage of water use than Portland cement, water on the surface of the lining layer evaporates when the mortar hardens, resulting in unhardened areas due to lack of water needed for irrigation, and the surface becomes powder. There was a lot of hard work. For this reason, it is necessary to polish the surface of the lining layer to make it uniform, and there are problems in that it takes a great deal of time and effort to dispose of the polishing particles and polishing powder.

The present inventors have conducted intensive studies to solve each of the above problems 1, and as a result, the water rises at the initial stage of water flow, soluble At1Ik
The present invention was completed based on the knowledge that it is effective to use a lining material with a specific composition to increase the amount of hardened mortar and prevent surface unhardening of the mortar hard workpiece.

「+St-Means for solving the problem〕

That is, the present invention provides a lining material mainly composed of a binder consisting of 30 to 95 parts by weight of alumina cement and 70 to 5 parts by weight of granulated blast furnace slag powder, sand and water, and further comprising an inorganic expansive material and a water-reducing material. To9 is a method for producing lined pipes using these lining materials.

The present invention will be explained in detail below.

The alumina cement (hereinafter referred to as AC) according to the present invention is a clinker synthesized by a melting method and/or a calcination method from an alumina source such as bauxite, Bayer alumina, and alumina residual ash, and a karunga source such as quicklime, limestone, and slaked lime. is pulverized using a pulverizer such as a ball mill, roller mill, or Ong mill.

Its mineral composition is Ca01kC, u205 f A, CA%CAs, C, A% Cl2A7, C3A
C/A (
AC mainly having molar ratio)≦1 is preferable, and Ca030-40 has good pot life, hardenability, and strength development.
Hydraulic calcium aluminates having a weight of s and an At of 10,340 to 30 degrees are particularly preferred.

The granulated blast furnace slag powder (hereinafter referred to as slag powder) according to the present invention has a vitrification rate of 5OLs or more and a basicity (CaO+
MgO+ At, o3) / 5ins 1.5(
A quantitative ratio of 11 is preferable, and a ratio of 1.8 or more is particularly preferable because of excellent latent hydraulic properties. The vitrification rate is a value calculated from the area of a diffraction line by powder X-ray diffraction.

Vitrification rate (*) - (1-diffraction line area/total area) X
The particle size of the slag powder is preferably 711 or more, more preferably 8.000 or more, and more preferably 8,000 or more, as measured by the plain method. s, o o
If it is less than oα2/I, it is not preferable because the reactivity is poor, the strength of the cured product is poor, and the amount of soluble particles increases. In particular, 8,000i/# or more is preferable because strength development is good and soluble ALt is reduced.

The blending ratio of AC and slag powder according to the present invention is AC3Q
The ratio is ~95 parts by weight and 70 to 5 parts by weight of slag powder.

If the slag powder is less than 5 parts by weight, the effect of reducing the amount of soluble a is poor, and if it exceeds 70 parts by weight, hardening will be delayed and strength development will be poor, which is not preferable.

Particularly, 50 to 80 parts by weight of KAC and 50 to 201 parts by weight of slag powder are preferable because of their good strength development and soluble agglutinin reduction effect.

As the inorganic expansion material (hereinafter referred to as expansion material) according to the present invention, an ettringite-forming material made of carunum sulfoaluminate, gypsum, etc., or a lime-based material made of calcium fluoride, calcium oxide, etc. can be used.

In particular, ettringite-forming materials are preferable because they have a long pot life.

The blending ratio of the binder made of AC and slag powder and the expanding material is 85-98% binder and 15-2% expanding material by weight.
The ratio is preferably 90 to 96 parts by weight of the binder and 10 to 4 parts by weight of the expanding material.

If the amount of inflatable material exceeds 15 parts by weight, after long-term use,
The lining layer tends to undergo expansion failure, which is undesirable, and if it is less than a double layer, it lacks the effect as an expansion material, and the lining layer tends to suffer from shrinkage cracks, which is undesirable.

The particle size of the expanding material is preferably similar to that of AC,
4.000 to 6,000 am"/1 is preferable in the plain method. If it is extremely coarse or fine compared to AC, it will segregate during centrifugal molding and cause rounding, which is undesirable. .Portland cement usually contains 2,
500~3.500CI? /9 is used, but
In the present invention, those within the above range are preferred.

The water reducing agent according to the present invention includes lignin sulfonate type, naphthalene sulfonate type, naphthalene sulfonate formalin condensate type, melamine sulfonate formalin condensate type, polycarboxylate type, phosphoric acid type, and boric acid type. Among the Me-based oxycarboxylate salts, cinic acid-based and boric acid-based ones are particularly preferred, which form salts that are poorly soluble with At and have both a water-reducing effect and a soluble Kl-inhibiting effect.Specifically, , hesametaphosphoric acid, picric acid, tripolyphosphoric acid, boric acid, or their Na, salts, etc.

Each water-reducing agent can be used alone or in combination, and the sound of its use is 2100 m
It is preferable that the proportion is 0.1 to 1 part by weight to Kurabe, and from the viewpoint of good strength development, the proportion is 0.1 to 2 parts by weight.
preferred.

The sand according to the present invention is preferably river sand or mountain sand, which is less susceptible to salt damage or sunburn, and sea sand is undesirable because it contains a lot of NaCA.

The amount of sand used is per 1001 parts of binder or powder.
100 to 300 parts by weight of sand is usually used, depending on the diameter of the gourd tube. For example, in a tube with tf and 100 to 700φn,
100-27 parts by weight of sand per 100 parts by weight of binder or powder
This is the percentage of 0 weight parts.

In the present invention, the above-mentioned material is mixed with water in a mixer such as a pan-type mixer or a paddle mixer, and the temperature after kneading the mortar is preferably 25°C or lower, particularly preferably around 20°C.

If the temperature exceeds 25°C, false condensation tends to occur and pot life becomes difficult to dissipate, which is not preferable. 91. If the kneaded soil has a high degree of #), it is not preferable because a large amount of Aj(OH)3 is produced due to the transfer reaction of AC hydrate and the soluble a content increases. If the kneading temperature is as low as, for example, 5° C. or less, curing may be delayed and strength development may be affected, so it is not preferable to be too low.

The flow value of the mortar is preferably 200 m or more, especially 240 m or more based on the 15-tap flow value using a flow table.
-2801II are preferred. If the flow value is less than 200H, a uniform lining layer will not be formed on the circular surface of the tube during centrifugal molding. If it exceeds 280w, the lining layer will not be tightly tightened during centrifugal molding, and the paste layer will separate, causing cracks and peeling. There is a tendency to do this easily, which is not desirable.

Centrifugal molding is usually performed at 20G or higher, but in the present invention,
Particularly, 50 to 70G is preferable because the lining layer can be tightened well. If it is less than 50G, the mortar layer after centrifugal molding will not tighten properly and the laitance will not float sufficiently, and if it exceeds 7001G, the paste layer will separate and cracks will tend to occur, which is not preferable.

The centrifugal molding time at the maximum G is preferably 6 minutes or more, which is preferable because the lining layer is uniform9 and the compactness is good. In addition, it is preferable that the centrifugal molding time is 5 minutes or more to ensure stable water removal from the lining layer.

It is preferable that tubes lined by centrifugal molding be primarily cured under humidified conditions with a relative humidity of 30°R, H or higher, and 9! , preferably 80 inches R,H or more. Further, the curing temperature is preferably 25°C or lower, and it is more preferable to perform low temperature and humidified curing at around 20°C.

The curing time is preferably 4 hours or more immediately after the completion of lining, and it is more preferable to continue curing until the cement is completely heated by water.

Humidified curing under conditions other than the above is not preferred because uncured portions occur on the surface of the lining layer and the powdered slightly soluble At powder does not decrease.

- After the second curing has been completed, the surface of the lined pipe is polished uniformly by a conventional method, and then the pipe is secondly cured at room temperature and air-dried for two or more days before being buried and used. The polishing thickness depends on the pipe diameter, but is usually about 0.5 to 3 mm from the surface.

The secondary curing period is preferably carried out for 4 days or more, and particularly preferably 30 days or more, so that the initial water flow and the amount of soluble Kl are sufficiently reduced.

Cast iron pipes are usually used for the pipes processed by the method of the present invention, but can pipes that have been layered with lining layers in advance by a conventional method be used and have two or more lining source layers? It is possible to use.

In addition, in order to improve the acid resistance and long-term stability of the lining pipe, it is also effective to use Nricafume 1 limestone powder, fly ash, general polymer cement polymers, etc. in combination. Examples of polymers for polymer cement include natural rubber, chloroprene gum (CR), styrene butadiene rubber (SBR), rubber latex such as vinyl alcohol, furfuryl alcohol, and vinyl arsenate, water-soluble polymers, and resin emulsions. Can be used.

〔Example〕

The present invention will be explained in detail below with reference to Examples.

Example 1 AC and slag powder were blended as shown in Table 1 and mixed for 55 minutes using a small omnimixer (Chiyoda Giken Kogyo K) to produce a binder.

This binder 100, mold part and river sand 200) telSt
After drying for 6 minutes in a bread mixer, 26° soil 20n+
Add tap water to the flow value and mix for 5 minutes.
A mortar with a kneading temperature of 2D±2°C was prepared. This mortar full centrifugal molding machine 9100φli+X500t
A lining layer with a thickness of 5 fl was formed on the circular surface of a cast iron pipe with a thickness of 5 fl under conditions of 50 G for 5 minutes.

After the lining was completed, it was placed in a 20'C100SR,n humidifier, and after curing for 12 hours, the surface was placed on a lathe.
The tube was subjected to tIB polishing, and then subjected to secondary curing under air-dry conditions at room temperature for 6 days to obtain a lined tube of the present invention.

Its physical properties are also listed in Table-1.

For comparison, P! i City name: "Denka Alumina Cement No. 2" made by Denki Kagaku Kogyo Co., Ltd. 100, the neck and river sand 20 [1 mfr] were dried for 6 minutes in a pan mixer, then tap water was added to a flow value of 230 ± 20 m. In addition, the mixture was stirred for 5 minutes to prepare a mortar with a kneading temperature of 20±2°C.

After centrifugally molding this mortar, it becomes 100φII X50
0'0 in a cast iron pipe with a thickness of 5f under the conditions of 40G for 2 minutes.
After completing the 0 lining, which formed the 0.61I11 lining, the 0.61I11 surface was cured for 24 hours at room temperature and air-dried.The lining layer surface was polished with sandpaper while being sprinkled with tap water. I researched it.

After that, it was further cured for 6 days at room temperature and air-dried, and a lined pipe was prepared.

Measuring method> (1) Flow value: Tap the flow table 915 times and measure the diameter of the spread of the groin after death.

(2) Strength: Compressive strength using a 4X4X16cR test piece.

+3)-; After the inner surface of the lining tube after secondary curing was washed with ion-exchanged water, ion-exchanged water T-3,000 was added and immersed at 20°C for 24 hours, and this immersion water was used as -.

(4) Soluble At1i; - ICP the immersion water after measurement
(5) Surface pulverization: - The presence or absence of pulverization on the lining surface after the next curing was determined by visual observation.

Materials used〉 AC-a: Product name “Denka Alumina Cement No. 1”, manufactured by Denki Kagaku Kogyo Co., Ltd., CaO36-51 lid, Az, o, 5
3.5 N: ii % b: @ Product name "Denka Alumina Cement 2", manufactured by Denki Kagaku Kogyo Co., Ltd., CaO33-0% by weight, kt20348.5 weight c: @ Product name "Denka High Alumina Cement" CaO25
, 5-layer 1#chi, A111os 73.5] 1i warehouse slag progress: manufactured by Sumitomo Kinkaede Sales Co., Ltd., granulated blast furnace slag, basicity 2.06, plain 4.000 an"/Ji'
Ca045-61, MgO6-6, A
AsOs 12-4X: Il fb, 8101
31.33kft Chi @: # Plain 5,000
cm”/I-f: # Plain 8.000 an
'/g -g: I plane 10,000a
m”/9 Note: Samples of slag powder with different specific surface areas were prepared by changing the grinding time using a small patch ball mill.

Sand: 2.5 fi river sand from Tamana, Kumamoto Prefecture - Lower Example 2 The binder and expansion material were combined as shown in Table 2 and mixed for 55 minutes using a small omni mixer to produce a composition.

After drying 100 parts of this composition and 2001 parts of river sand in a pan-type mixer for 6 minutes, add a predetermined amount of water reducing agent, add tap water to a flow value of 230 ± 20 fl, and mix for 5 minutes. A mortar with a kneading temperature of 20±2°C was prepared.

A lining tube was obtained using this mortar in the same manner as in Example 1. Its physical properties are also listed in Table-2.

The measurements of physical properties and materials were the same as in Example 1, and the rest were as follows.

<Measurement method> (1) Surface cracks: The presence or absence of cracks on the surface of the lining pipe that had been secondarily cured for 50 days under room temperature and air dry conditions was visually determined.

Materials used〉 Expanding material h: Product name “Denka C8Aφ20”; Made by Denki Kagaku Kogyo J: Product name “For Expan products”; For Onoda cement cracking: Qiao-111 type anhydrite; Water reducing agent made by Central Glass T: Simple Product name [Mighty 150 ni Kao Seki Risein rn: Product name ``Vinsenru 80 ni Yamamai Chemical Table n: Product name ``Bolisu/l65L''; Botosu p: Sodium hexametaphosphate; Kanto Kagaku Reagent-grade K; Triseririn C-Na; Boric acid
.

Hokusand.

Hexametaphosphoric acid; Example 3 Binder 1001 from Table 1, Experiment 41-15 and 200 parts by weight of river sand were heated in a pan-shaped mixer for 6 minutes, then tap water was added to give a flow value of 230±20 fl. The mixture was mixed for 5 minutes to prepare a mortar with a kneading surface of 9 degrees Celsius, 20 degrees Celsius, and 2 degrees Celsius.

This mortar is made using a centrifugal molding machine of 100φ×5001
A lining layer with a thickness of 5j11 was entirely formed on the circular surface of an mOn iron tube under the conditions shown in Table 3.

The treatment after completion of the lining was carried out in accordance with Example 1, the measurement of physical properties and the materials were carried out in accordance with Examples 1 and 2, and the other operations were carried out as described below. Its physical properties are also listed in Table-3.

Measuring method> 111? Water draining from the inning field; visually confirmed
Judgment: ◎ (2) Finish of lining layer ;ll Example 4 The mortar produced by the method of Example 3 was molded into 50G-5 on the inner surface of a 100φm%5001111 cast iron pipe using a centrifugal molding machine.
A lining layer with a thickness of 5n was formed under the conditions of 1 minute.
The surface was polished 1N using a lathe, and secondary curing was performed under predetermined conditions to obtain a lined pipe.

The curing conditions and physical properties of the lining pipe are shown in Figure 4. Measurement of physical properties and materials were in accordance with Example 2.

Example 5 The mortar produced by the method of Example 6 was applied to the inner surface of a 200φ wealth 1X5001II+ cast iron pipe using a centrifugal molding machine.
A lining layer with a thickness of 8 fl was formed for 5 minutes.

After lining was completed, it was placed in a 20°C 100SR, H, O humidifier and cured for 12 hours.The surface was polished to a specified thickness using a lathe, and then it was cured for 6 days under air-dry conditions at room temperature. A lined tube was obtained.

Its physical properties are shown in Table-5. The physical properties were measured in accordance with Example 1, and the ion father exchange water cap was 147 when measuring the amount of - and soluble kl.
And so.

Table-5 Example 6 Portland cement (manufactured by Andes Shichimento 2100
M Kurabe and 200 parts by weight of river sand were left blank for 6 minutes in a pan-type mixer, then added with tap water in an amount to give a flow value of 210±10111, kneaded for 5 minutes, and kneaded at a temperature of 20±.
A Portland cement mortar at 2°C was prepared. This mortar is made using a centrifugal molding machine with a diameter of 200φ
A lining layer with a thickness of 5H was formed on the inner surface of a cast iron pipe with a thickness of 5H under conditions of 50G for 5 minutes.

After the lining is completed, leave it at room temperature in the dark at 3 o'clock, and further, 70
After steam curing at 4°C, lathe.

The nail surface was polished 111m. The lining material of the present invention produced by the method of Example 6 was applied to this Portland cement lining pipe under conditions of t-50()-5 minutes to a thickness of 5.
am lining? The process after lining is completed is as follows:
A two-layer lined pipe was prepared according to Example 5.

As a comparative example, a portland cement mortar lined pipe with a thickness of 8 nm produced by the method described above was used, and the physical properties were measured in the same manner as in Example 5. The physical properties are shown in Table-6.

Table 6 Example 7 In Example 2, chloroprene latex (trade name “Denkakuro O
flen LK-50, 5 parts (manufactured by Denki Kagaku Kogyo Co., Ltd.), 0.3 parts of boric acid and 0.3 parts of boric acid were mixed for 55 minutes using a Kurabe-kai compact omni mixer, and this composition was mixed with 1001 Kurabe and 200 iktf of river sand.
- Flow value 230 after drying for 5 minutes in a pan mixer
Add tap water with a neck length of ±20m, mix for 10 minutes, and knead the mortar at a temperature of 20±2℃ using a centrifugal molding machine at 30G for 5 minutes to make a 100φ Dragon X500111.
1 cast iron pipe was lined with a thickness of 5I1111. The treatment after completion of lining and the measurement of physical properties were in accordance with Example 1.

The lined pipe produced by this method showed good values of pH 8.0 and soluble At1t 2.2 m) pm, and the material age was 5.
Even after 5 days had elapsed, no appearance of itchiness was observed.

〔Effect of the invention〕

As is clear from the above, the lining pipe manufactured by the uninvented method does not require coating, and the initial water flow is
1 can be kept low, and compared to conventional AC toilet lining pipes, the bath quality can be significantly reduced.

Further, powdering of the lining surface which occurs during the second curing can be prevented, and a lined pipe with a good surface finish can be obtained.

Axis needle applicant Ryukikaji Kogyo Co., Ltd.

Claims (4)

[Claims] (1) A lining material whose main components are a binder consisting of 30 to 95 parts by weight of alumina cement and 70 to 5 parts by weight of granulated blast furnace slag powder, and sand and water. (2) A method for manufacturing a lined pipe, which comprises lining the inner surface of the pipe with the lining material according to claim 1 by centrifugal molding, and hardening the lining layer by humidified curing. (3) A composition comprising 85 to 98 parts by weight of the binder according to claim 1, 15 to 2 parts by weight of an inorganic expansive material, and 0.1 to 5 parts by weight of a water reducing agent based on a total of 100 parts by weight of the binder and inorganic expansive material. and lining material whose main ingredients are sand and water. (4) A method for manufacturing a lined pipe, which comprises lining the inner surface of the pipe with the lining material according to claim 3 by centrifugal molding, and hardening the lining layer by humidified curing.