JP3435122B2 - Plastic injection material - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic injection material obtained by mixing a hardening liquid, cement milk, and a plasticizing liquid, and more particularly to a plastic injection material capable of long-distance pumping.

[0002]

2. Description of the Related Art The inventors of the present application, as an injection material used for cavity filling of civil engineering structures, lightweight embankment, landfill, etc.
Cement milk (hardening liquid: liquid A), bentonite milk in which bentonite is turbid in water (plasticizing liquid: liquid B),
A plastic injection material obtained by mixing and stirring is proposed (see Japanese Patent Application Laid-Open No. 11-310779).

Further, the applicant of the present application has found and proposed that it is effective to use metakaolin or attapulgite in place of bentonite which is the plasticizing material of the present invention in adjusting the plasticizing liquid (Japanese Patent Application No. 2000-242242). Flat 11-226
754).

In any of the inventions, in order to improve the plasticity of the plastic injection material, a high-concentration plasticizing liquid (liquid B) is required. Taking attapulgite as an example, the plasticizing liquid has a flow value of about 200 mm and a viscosity of 9.0 dPaS.

[0005]

As described above, the plasticizing liquid in the prior art is inevitably high in viscosity and poor in fluidity. If this plasticizing liquid is used to carry out construction in normal equipment, the maximum length is 500 m. That is, there is a problem that it is not suitable for long-distance pressure feeding. It is conceivable to increase the pump capacity or provide a relay pump in response to this, but it is not realistic considering the installation conditions and cost of the pump.

Further, if the concentration of the plasticizing liquid is lowered to such an extent that it can be pumped to a predetermined distance, the plasticity of the plastic injection material is significantly deteriorated when it is kneaded with the hardening liquid (liquid A). There is a problem that bleeding occurs in the chemical liquid itself.

Therefore, an object of the present invention is to increase the fluidity (low viscosity) of the plasticizing liquid without lowering the plasticity of the plastic injection material.

[0008]

Means for Solving the Problems The inventor has conducted diligent studies, and if a small amount of phosphate is added as a dispersant, the plasticizing liquid (B
It has been found that the fluidity of the liquid) is dramatically improved.

According to the first aspect of the invention, at least one plasticizer selected from attapulgite and metakaolin, a phosphate dispersant, and a plasticizer containing water, and a hardening liquid containing cement milk are used. It is a plastic injection material formed by stirring and mixing.

According to a second aspect of the invention, in the plastic injection material according to the first aspect, the plasticizer is attapulgite, and the phosphate dispersant is 0.1% by weight based on 100 parts by weight of the plasticizer. It is 6 to 1.2 parts by weight of a plastic injection material.

According to a third aspect of the present invention, in the plastic injection material according to the second aspect, the mixing ratio of the hardening liquid and the plasticizing liquid is 1: 1 to 1: 8 by volume. It is a material.

According to a fourth aspect of the present invention, in the plastic injection material according to the first aspect, the plasticizer is metakaolin, and the phosphate dispersant is 0.1% by weight based on 100 parts by weight of the plasticizer. It is a plastic injection material of 005 to 0.03 parts by weight.

According to a fifth aspect of the present invention, in the plastic injection material according to the fourth aspect, the mixing ratio of the hardening liquid and the plasticizing liquid is 1: 1 to 1:11 by volume. It is a material.

According to the present invention, the fluidity of the plasticizing liquid becomes extremely good by adding the phosphate to the plasticizing liquid. Further, the plasticity of the injection material when it is kneaded with the curing liquid is almost the same as when the phosphate is added. These have been confirmed experimentally.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION In the plastic injecting material of the present invention, cement milk (cement, water, air bubbles, and various admixtures if necessary) is first prepared as a liquid A, and B is separately prepared.
As a liquid, a highly concentrated suspension (for example, attapulgite,
Adjust the water to a flow value of about 200 mm and a viscosity of 9.0 dPaS). Next, phosphates (sodium pyrophosphate, sodium tripolyphosphate, sodium tetrapolyphosphate, etc.) are added to this solution B in an amount of 1% (% by weight) with respect to the plasticizer. As a result, the fluidity of the liquid B is remarkably improved and the liquid is easily pumped (for example, 500 m or more). Further, the plasticity when the liquid A and the liquid B are mixed is no different from the conventional one.

The cement used in the liquid A is usually various types of portland cement such as early strength, ultrafast strength, white color, sulfate resistance, moderate heat and low heat, at least one of the above portland cement and at least blast furnace slag and fly ash. It can be selected from mixed cement mixed with one kind, jet cement, special cement such as alumina cement, and cement-based solidifying material. Further, the specific gravity may be adjusted by mixing sand, rubs, foam beads or the like with the cement milk.

Cement milk can be made into cement air milk by mixing air bubbles obtained by foaming a foaming agent, if necessary. In addition, the specific gravity may be adjusted by mixing sand, gravel, foam beads and the like into the cement milk.

If necessary, the liquid A cement milk contains
An admixture such as a water reducing agent, a retarder, or a dispersant may be added, and the addition of the admixture does not affect the plasticity after kneading. In addition, since it is possible to reduce the amount of unit water in the liquid A or increase the amount of unit cement in the liquid A by adding a water-reducing agent, it is possible to expand the range of formulation settings for high strength and light weight. By adding the retarder, it is possible to prevent the inside of the equipment such as the transportation pipe from being hardened and reduce the washing of the equipment.
By adding the dispersant, the fluidity of the liquid A is improved, and the transportation distance by piping or the like can be extended.

The present invention relates to A prepared in advance as described above.
Liquid and liquid B are made into a milk state and pressure-fed over a long distance with a pipe, and mixed instantaneously. At the mixing point, the liquid A cement milk is in a suspension state in which the aqueous solution is supersaturated with calcium ions released from the cement, and is filled with positive calcium ions.

On the other hand, the liquid B is charged with negative ions, and the calcium positive ions neutralize the negative charges on the surface of the plasticizing material particles by mixing such milks. A rapid agglutination reaction occurs due to the intermolecular attractive force, and it can be instantly plasticized.

The mixing ratio of the liquids A and B in the present invention is appropriately determined according to the purpose of use.
When using attapulgite as the plasticizer, A
Liquid: B liquid = 1: 1 to 1: 8 (volume ratio), when metakaolin is used as a plasticizer, A liquid: B liquid = 1: 1 to 1
The range of 1:11 (volume ratio) is preferable. When the proportion of the liquid B is less than the above range, the plasticizing performance is lowered, which is not preferable. Further, when the ratio of the liquid B is higher than the above range,
It is not preferable because it is difficult to uniformly mix the liquid A and the liquid B. Moreover, since the amount of the liquid A is relatively small, the amount of unit cement is small, which is not preferable.

The flow value of the prepared plastic injection material is 80 by the cylinder method, which is a standard test method of Japan Highway Public Corporation.
(Independent) -150 mm is preferable, and 80-120 mm is more preferable. When it is 80 to 120 mm, it is most suitable as a plastic injection material, and it can be used with very little material separation even in a place where water is poured or where running water is present. Also, 120 to 150
mm can be sufficiently used as a plastic injection material when it is not affected by running water, etc. However, when used for underwater casting, turbidity or material cracks may occur. Those with a diameter of 150 mm or more are close to the fluidity of ordinary air mortar and air milk and are not suitable for limited injection.

[0023]

EXAMPLES The plastic injection material according to the present invention will be further described with reference to examples. In the following examples, the method for preparing the injectable material, the test material, and the test method are as follows.

(Preparation Method) Liquid A was prepared by kneading the cement-based solidifying material and water with a hand mixer for 2 minutes. When bubbles were mixed, bubbles (a foaming agent was diluted 25-fold with water and then foamed 25-fold) were added to the mixture so that a predetermined amount was mixed, and the mixture was mixed for 30 seconds with a mixer.

The liquid B was prepared by kneading the plasticizing material and water with a reciprocating stirring mixer for 5 minutes. The liquid A and the liquid B were mixed by kneading with a hand mixer for about 10 to 15 seconds.

(Test Material) The materials used for the test are as follows. Hardening material: Sumitomo Osaka Cement Co., Ltd. cement-based solidifying material "Tough Rock" (trademark) Plasticizing material: attapulgite metakaolin (all plasticizing materials are adjusted to a 200 mesh sieve particle size) Dispersant: Sodium pyrophosphate (10 hydrate), etc.

(Test method) Flow value as a test item, 2
After 4 hours, the bleeding of the liquid B and the measurement of the viscosity were performed according to the following criteria. The flow values after the kneading of the liquids A and B and the comprehensive judgment (plasticity) based on these were performed.

The flow value is based on the standard of Japan Highway Public Corporation "Test method for air mortar and air milk (JHSA313-199).
2) ”by the cylinder method of the consistency test method. The sample was placed in a cylinder having an inner diameter of 8 cm and a height of 8 cm, and the diameter of the bottom surface of the sample after withdrawal was measured.

The bleeding was measured by the Japan Society of Civil Engineers, "Bleeding rate and expansion rate test method for injected mortar of prepacked concrete" (JSCE-F522-199).
According to 4). The viscosity was measured using a Visco Tester (VT-04) manufactured by Linen.

[Example 1] This example is performed assuming that attapulgite is used as a plasticizing material. The respective formulations and test results are shown in Tables 1 to 5.

Table 1 shows the flow values of attapulgite milk (liquid B) without adding a dispersant to the same liquid A (cement solidifying material amount 300 kg / m ³ , W / C = 0.5). The flow values of the injection material (solution A + solution B) after bleeding of solution B after 24 hours and mixing with solution A are shown after adjusting to about 200, 400, and 600 mm.

[0032]

[Table 1]

From Table 1, the bleeding increases as the concentration of solution B decreases, and the injection material (solution A + solution B) increases.
It can be seen that the plasticity of is decreased. In addition, the plasticity is judged as ◯ when the flow value of the liquid A and liquid B after kneading is 120 mm or less, and as x when the flow value exceeds 120 mm.

Table 2 shows that the dispersant (sodium pyrophosphate (10 hydrate)) was added to attapulgite milk (flow value 200 mm when the dispersant was not added). Then add the dispersant and knead. A dispersant is mixed in water in advance, and attapulgite is added to this water and kneaded. In this case, it is verified whether the flow value of the injection material changes.

[0035]

[Table 2]

From Table 2, it is judged that the addition of the dispersant to water is almost the same before and after the addition of the plasticizer (attapulgite). Therefore, the subsequent tests were carried out by adding a dispersant to water in advance.

Table 3 shows that when the amount of attapulgite, which is a plasticizer, is fixed, the amount of dispersant (sodium pyrophosphate (10 hydrate)) added is changed.
The viscosity of the liquid and the bleeding rate were evaluated.

[0038]

[Table 3]

From Table 3, when attapulgite is used as the plasticizer, the amount of sodium pyrophosphate (10 hydrate) added is 0.6 to 1.2 parts by weight per 100 parts by weight of the plasticizer. It turns out to be suitable. If it is 0.6 parts by weight or less, good fluidity cannot be obtained, and if it exceeds 1.2 parts by weight, sedimentation occurs.

Table 4 shows the determination of the plastic injection material when the mixing ratio of the liquid A and the liquid B was changed. In this example, the liquid A and the liquid B are changed in volume ratio from 1: 9 to 1: 0.5.

[0041]

[Table 4]

From Table 4, it is understood that the mixing ratio of the liquid A and the liquid B is appropriately in the range of 1: 1 to 1: 8 by volume ratio. B
If the ratio of the liquid is 0.5 or less, good plasticizing performance cannot be obtained, and if it is 9 or more, it is difficult to uniformly mix the liquid A and the liquid B.

Table 5 shows whether various organic acids function as dispersants. It is not effective except for phosphates.

[0044]

[Table 5]

[Example 2] This example is carried out on the assumption that metakaolin is used as a plasticizer.
The respective formulations and test results are shown in Tables 6 to 8.

In Table 6, the amount of metakaolin as a plasticizing agent was kept constant and the viscosity of solution B when the amount of dispersant (sodium pyrophosphate (10 hydrate)) was changed and The bleeding rate is determined.

[0047]

[Table 6]

From Table 6, when metakaolin is used as the plasticizer, the addition amount of sodium pyrophosphate (10 hydrate) is 0.005 to 0.
It turns out that 03 parts by weight are suitable. If it is 0.005 parts by weight or less, good fluidity cannot be obtained, and 0.0
If it exceeds 3 parts by weight, settling separation occurs.

Table 7 shows the determination of the plastic injection material when the mixing ratio of the liquid A and the liquid B was changed. In this example, the A liquid and the B liquid are changed in volume ratio from 1:12 to 1: 0.5.

[0050]

[Table 7]

From Table 7, it is understood that the mixing ratio of the liquid A and the liquid B is appropriately in the range of 1: 1 to 1:11 by volume. B
If the ratio of the liquid is 0.5 or less, good plasticizing performance cannot be obtained. When the ratio of liquid B is 12, the plasticity of the injection material is good, but the amount of cement-based solidifying material is 100 kg.
It becomes less than / m ³ and is not practical when the strength of the cured product is taken into consideration.

Table 8 examines whether various organic acids function as dispersants for metakaolin. It is not effective except for phosphates.

[0053]

[Table 8]

[0054]

As described above, according to the present invention, the fluidity of the plasticizing liquid can be made high (the viscosity is low) without deteriorating the plasticity of the plastic injection material,
This has the effect of being able to carry a long distance.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI E21D 11/00 E21D 11/00 A // (C04B 28/02 C04B 14:10 B 14:10 Z 22:16 Z 22:16 ) 111: 70 111: 70 C09K 103: 00 C09K 103: 00 (56) Reference JP-A-11-310779 (JP, A) JP-A-7-247543 (JP, A) JP-A 64-80620 (JP , A) JP-A-11-35361 (JP, A) JP-A-62-91453 (JP, A) JP-A-10-95976 (JP, A) JP-A-5-43875 (JP, A) International Publication 98 / 057905 (WO, A1) (58) Fields investigated (Int.Cl. ⁷ , DB name) C09K 17/00-17/52 B28C 1/00-9/04 E02D 3/12 E02D 5/00-5 / 20 E02D 17/00-17/20

Claims (5)

(57) [Claims] 1. A plasticizing liquid containing at least one plasticizer selected from attapulgite and metakaolin, a phosphate dispersant, and water, and a hardening liquid containing cement milk are mixed with stirring. Plastic injection material. 2. The plastic injection material according to claim 1, wherein the plasticizer is attapulgite, and the phosphate dispersant is 0.6 to 1.2 parts by weight with respect to 100 parts by weight of the plasticizer. . 3. The plastic injection material according to claim 2, wherein the mixing ratio of the hardening liquid and the plasticizing liquid is 1: 1 to 1: 8 by volume. 4. The plasticizer is metakaolin, and the phosphate dispersant is 0.0 with respect to 100 parts by weight of the plasticizer.
The plastic injection material according to claim 1, which is from 05 to 0.03 parts by weight. 5. The plastic injection material according to claim 4, wherein a mixing ratio of the hardening liquid and the plasticizing liquid is 1: 1 to 1:11 by volume ratio.