JP3502292B2 - 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 composition of a plastic injection material which can be used for cavity filling, lightweight embankment and landfill of civil engineering structures.

[0002]

2. Description of the Related Art If there is groundwater or running water in the cavity filling part,
To prevent the injection material from being diluted with groundwater or running water,
The injection material may be required to have a property as a gel-like aggregate. Further, in the case where the filling portion is limitedly injected into the section, there is a problem that the ordinary cement milk-based injection material causes a problem of deviation to the surroundings and the limited injection cannot be performed. In this way, the state of becoming a gelled agglomerate, which is not diluted with groundwater or running water, and whose shape-imparting property makes it difficult for deviation to the surroundings is referred to as "plasticity". To do.

[0003] The applicant of the present invention, when mixed with cement milk and bentonite milk, a strong aggregate can be formed by the action of agglomeration of bentonite by calcium ions, and it is transformed into an injection material in a plastic state in which the flow value is controlled. It has been found that the above problems can be solved by injecting this mixture as an injection material, and a patent application has been filed as Japanese Patent Application No. 10-130143.

[0004]

By the way, at the place where the injection is performed, it is sometimes required that the strength be generated in a short time, for example, several hours. However, in the case of the injection material for which the above-mentioned patent application has been made, when general-purpose cement is used, in order to achieve the desired strength of 1 kgf / cm ² or more, 3
A plastic injection material that requires a day or so and exhibits strength in a shorter period is desired. As a material selection that satisfies such required performance, cement used for cement milk or cement air milk is ultra early strength Portland cement,
Alternatively, it is conceivable to use ultra-rapid cement, but such quick-setting special cement is more difficult to obtain than general-purpose cement, and even if it is available, the price of the cement is high, which increases the cost of the material. It becomes a factor.

Therefore, according to the present invention, a general-purpose cement is used without using the special quick-hardening cement.
An object of the present invention is to provide a plastic injection material that exhibits a strength of 1 kgf / cm ² or more within a short period of time within a day. Another object of the present invention is to provide a plastic injecting material which can be rapidly strengthened to the same level as or higher than the case of using the quick-hardening special cement by using general-purpose cement.

[0006]

Means for Solving the Problems As a result of various studies to solve the above problems, the present inventors have found that bentonite is aggregated by the action of cations as in the previously filed invention, and Using calcium ion of cement as ion, and using general-purpose cement as cement milk to promote rapid aggregation, and water glass, which is a general-purpose agent for bentonite milk, at least selected from polyaluminum chloride and sulfuric acid bands It was found that by adding one kind, a plastic injection material having appropriate plasticity and exhibiting strength in a desired early time can be obtained, and the present invention has been completed.

That is, according to the present invention, cement milk or cement air milk in which air bubbles are mixed in cement milk and bentonite milk in which at least one drug selected from water glass, polyaluminum chloride and a sulfuric acid band is mixed are stirred. A plastic injection material formed by mixing, the amount of cement, and SiO ₂ and Al in the drug.
_The ratio with respect to the total amount of ₂ O ₃ is 100: 2 to 100: 10 by weight, and the mixing ratio of cement and water in cement milk or cement air milk is 1: 0.3 to 1: 1 by weight. The mixing ratio of bentonite and water in bentonite milk is 1
It is characterized by being 4 to 1 to 12.

It should be noted that, in a period of about one day of curing, calcium ions in the cement milk and SiO ₂ or Al ₂
The contribution rate of the hydration reaction product with O ₃ to the strength can be considered to be almost equivalent. The ratio of the amount of cement and the total amount of SiO ₂ and Al ₂ O _{3 in} the drug is 100 by weight.
If it is less than 2, the strength equal to or higher than that when using a special quick-setting cement cannot be achieved. Also, the ratio is 100 pairs
If it exceeds 10, the setting and hardening of the plastic injection material will be too fast to allow uniform mixing, and the strength of the injection material will be reduced.

[0009]

[0010]

Furthermore, in the present invention, it is preferable that the swelling power of bentonite is 15 (ml / 2 g) or more.

In the present invention, it is preferable that the amount of bubbles mixed with the volume of the plastic injection material is 60% or less.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The plastic injection material of the present embodiment is
Cement milk or cement air milk is used as solution A, and bentonite milk and water glass, polyaluminum chloride or sulfuric acid band is used as solution B.

First, cement milk (cement, water, if necessary, various admixtures are mixed) or cement air milk (cement, water, air bubbles, if necessary, various admixtures are mixed) is prepared as the liquid A, and separately B A liquid prepared by mixing bentonite milk (bentonite, water, if necessary, various admixtures) with water glass, polyaluminum chloride, or a sulfuric acid band is prepared. Then, the liquid A and the liquid B are mixed and instantly plasticized to develop strength early.

The general-purpose cements used for the liquid A are various portland cements such as normal, early strength and moderate heat, mixed cements obtained by mixing at least one of the above portland cements with at least one of blast furnace slag, fly ash and the like, and cement-based solidification. You can choose from wood.

The cement milk may be made into cement air milk by mixing air bubbles obtained by foaming a foaming agent, if necessary. The amount of bubbles mixed is preferably 60% by volume or less of the amount of the plastic injection material, and the density is 0.6 g / cm ³ to 1.2 depending on the amount of bubbles.
It is possible to set an arbitrary density of about g / cm ³ . Density 0.6
To keep g / cm ³ or less, mixing air bubbles in excess of 60% results in too much air inclusion, resulting in too little usage of cement and bentonite. It becomes difficult to develop the strength of the cured product.

An admixture such as a water reducing agent may be added to the liquid A cement milk or cement air milk, if necessary. 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 high strength mixture setting. Further, when there is a possibility of material separation into the liquid A cement milk or cement air milk, a small amount of bentonite can be added to the liquid A as necessary for the purpose of preventing material separation.

The quality of the bentonite used in the liquid B is not particularly limited, but bentonite having a swelling power of 15 or more is preferable. The swelling power referred to here is determined by the Japan Bentonite Industry Association Test Method (JBAS-104), and is expressed as the apparent volume occupied in water when bentonite is gradually dropped into distilled water. That is, 2 g of bentonite sample in 100 ml of distilled water
The sample is dropped and left for 24 hours after the drop to read the apparent volume of the accumulated sample in the container. Therefore, the unit of swelling power is ml (milliliter) / 2 g.

When the swelling power is less than 15, it is necessary to increase the amount of bentonite added, and material separation easily occurs, which is not preferable. Further, when it is necessary to reduce the weight of the plastic injection material, it is necessary to reduce the amount of bentonite used, and for that purpose, bentonite having a swelling power of 15 or more is optimal.

Bentonite having a swelling power of 15 or more is used.
In that case, the amount added is approximately 80-120 kg / m³Good degree
Better, 100-120kg / m³Is more preferable. 80 kg
/ m³ If it is less than the range, material separation may occur during underwater casting.
50 kg / m³Below, the plasticizing effect is low. Also, 12
0 kg / m³If it exceeds the limit, bentonite will be damaged when preparing B solution.
Tend to be difficult to prepare and evenly bentonite milk
Yes, requires the addition of common bentonite dispersants
It Also, 150kg / m³Even if the dispersant is added,
It is difficult and difficult to train.

The ratio of water in solution B to bentonite is preferably 4 or more. If the ratio of water to bentonite is less than this, bentonite is liable to become a lump when preparing solution B,
It is difficult to prepare a uniform bentonite milk, and it is necessary to add a general bentonite dispersant.

Then, at least one chemical selected from water glass, polyaluminum chloride and a sulfuric acid band is added to the solution B.

Further, in this example, the ratio of the amount of cement to the total amount of SiO ₂ and Al ₂ O _{3 in} the drug is 1 by weight.
It is set to 00: 2 to 100: 10.

If the ratio of the amount of this cement to the total amount of SiO ₂ and Al ₂ O _{3 in} the drug is 100: 2 or less in weight ratio, the strength is equal to or more than that in the case of using the special quick-hardening cement. Can not be achieved. The same ratio is 10
If it exceeds 0:10, the setting and hardening will be too fast to allow uniform mixing, and the strength of the injection material will be lowered.

In this example, the flow value of the prepared plastic injection material is 8 according to the cylinder method, which is a standard test method of Japan Highway Public Corporation.
0 (independent) to 150 mm is preferable, and 80 to 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 15
If it is 0 mm, it can be sufficiently used as a plastic injection material if it is not affected by running water, but if it is used for underwater casting, it may cause turbidity or cracks in the material. 150 mm
The above is close to the fluidity of ordinary air mortar and air milk and is not suitable for limited injection.

In the embodiment of the present invention, the liquids A and B prepared in advance as described above are mixed in a milk state. The liquid A cement milk or cement air milk is in a suspension state in which the aqueous solution is supersaturated with calcium ions released from cement, and is filled with positive calcium ions.

On the other hand, in the bentonite milk of the liquid B, the bentonite swells and is charged with negative ions. By mixing such milks with each other, calcium positive ions neutralize the negative charge on the bentonite particle surface, causing a rapid agglutination reaction due to the intermolecular attractive force of the bentonite particles, so that it can be instantly plasticized. is there.

As described above, it is essential to mix milks in order to instantaneously and uniformly plasticize, and when cement powder is mixed with bentonite milk, it takes time to dissolve calcium ions. Difficult to plasticize.

The mixing ratio of the solutions A and B in the present invention is appropriately determined according to the purpose of use. The kneading time is preferably about 15 seconds or less with a hand mixer, and kneading longer than that is not preferable because material separation easily occurs.

A of the total amount of water in the compounding material of the plastic injection material
There is no particular restriction on the change of the distribution amount between liquids B and B, but in order to increase the material separation resistance of the cement milk of liquid A, the range in which homogeneous cement milk can be prepared (when using a water reducing agent etc.) Including cement: water = 1: 0.3 to 1: 1
Solution A should have as little water as possible.

Further, it is necessary to disperse the bentonite milk of the liquid B more uniformly in order to improve the plasticizing performance, and for that purpose, it is necessary to increase the amount of water in the liquid B. That is, when the total amount of water is constant, it is optimal to mix the amount of water in the liquid A as much as possible and the amount of water in the liquid B as much as possible within the range where uniform mixing performance does not deteriorate. However Bentonite:
When the amount of water is larger than water = 1: 12, the total amount of water becomes large and the separation becomes easy, and the strength of the hardened body of the plastic injection material decreases, which is not preferable.

[0032]

EXAMPLES The method of the present invention will be further described with reference to examples.
In the following examples, a method for preparing an injection material, a test material,
And the test method is as follows. The present embodiment describes one embodiment of the present invention, and the present invention is not limited to this.

(Preparation Method) Liquid A was prepared by kneading cement 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.

Solution B was prepared by kneading bentonite and water with a reciprocating stirring mixer for 5 minutes. Mixing of liquid A and liquid B
It was prepared by kneading with a hand mixer for about 10 to 15 seconds.

(Test Material) The materials used for the test are as follows. Cement: Blast furnace cement Class B: JIS R 5211 product Sumitomo Osaka Cement ultra-fast cement: Product name DAY300 Sumitomo Osaka Cement ultra-quick cement: Product name Jet cement Chemical water glass: JIS 3 (SiO ₂ concentration 25% solution, specific gravity) 1.5) Polyaluminum chloride: Tank truck (Al ₂ O ₃ concentration 10% solution, specific gravity 1.3) Sulfuric acid band: Tank truck (Al ₂ O ₃ concentration 8% solution, specific gravity 1.2) Bentonite (swelling power 16 .0)

(Test method) "Flow value" as a test item
Was measured for 3 hours and 1 day, and "uniaxial compressive strength" was measured according to the following criteria.

Flow value Conforms to the cylinder method of the consistency test method of the Japan Highway Public Corporation standard "Test method for air mortar and air milk (JHSA313-1992)". Put the sample into a cylinder with an inner diameter of 8 cm and a height of 8 cm, and after pulling it out. Measure the bottom diameter of the sample

Strength The strength of the cured product of the plastic injection material was measured as follows. Geotechnical Society Standard “Uniaxial compression test (JIS A 121
6) ”Specimen size φ5 × 10 cm, each age 3 pieces, curing at room temperature for 1 day

Examples of the present invention will be described below based on test data. In this example, the test was conducted on 10 cases by changing the formulations of solutions A and B. Table 1 shows the formulation examples, and Table 2 shows the flow value and uniaxial compressive strength.

[0040]

[Table 1]

[0041]

[Table 2]

As shown in Table 1, in this example, the cement component of A was used as a blast furnace cement B as a general-purpose cement.
TYPE 300, DAY300 as a special cement and jet cement are used, liquid B is mixed with no chemicals (blending 1, blend 2, blend 3), blast furnace cement type B is used as the cement component of solution A, and B When water glass is mixed with the liquid (compound 4, compound 7 to compound 10), blast furnace cement type B is used as the cement component of liquid A, and when polyaluminum chloride is mixed with liquid B (compound 5), A Blast furnace cement type B was used as the cement component of the liquid, and a sample was prepared for the case where the sulfuric acid band was mixed with the liquid B (formulation 6), and the flow value and the strength were measured.
When blending with jet cement, a retarder (Sumitomo Osaka Cement, Jet Setter (registered trademark)) was added to solution A in an amount of 0.3% of the cement amount in order to adjust the time until the cement set and harden. Was added.

Then, the above-mentioned formulation 4, formulations 7 to 10 (water
Glass amount 10-120 liters / m³ ) In case of
Table 2 and Figure 1 show the changes in strength for each formulation.
You

The following can be seen from the results shown in Table 2 and FIG. By using blast furnace cement type B and mixing water glass with liquid B, the required flow value can be obtained,
Moreover, the desired strength is achieved. By using blast furnace cement type B and mixing polyaluminum chloride or sulfuric acid band with solution B, the required flow value can be obtained and the desired strength is achieved. When blast furnace cement type B is used and water glass is mixed with the liquid B, if 10 liter / m ³ or less, the early strength effect is small, and if it is 120 liter / m ³ or more, the strength rather decreases. Therefore, the amount of water glass is 10 to 12
0 liter / m ³ is suitable, and when it is 20 to 80 liter / m ³ , the uniaxial compressive strength of a material a day is DAY 30.
When 0 or jet cement is used, it exceeds the uniaxial compressive strength, and good fast hardening is exhibited, which is preferable. This mixture was used as the amount of cement, the amount of SiO _{2 in} water glass, and the amount of Al ₂
Converted to the weight ratio with the total amount of O ₃ 100: 2 to 10
It becomes 0 to 10.

[0045]

As described above, according to the present invention, cement milk, or cement air milk obtained by mixing bubbles in cement milk, and at least one drug selected from water glass, polyaluminum chloride and sulfuric acid band are mixed. Is a plastic injection material formed by stirring and mixing bentonite milk.
The weight ratio of the total amount of O ₂ and Al ₂ O ₃ is 100: 2
~ 100 to 10, the mixing ratio of cement and water in cement milk or cement air milk is 1: 0.3 to 1 by weight.
1.Because the mixing ratio of bentonite and water in bentonite milk is 1: 4 to 1:12, it is necessary to mix general-purpose cement and general-purpose chemicals to instantly plasticize and develop strength early. It is possible to obtain a plastic injection material having appropriate plasticity and a desired early curing property without hindering the availability of the material at the construction site and increasing the cost of the material. In addition to being reliable, it has the effect of being applicable to lightweight embankments and landfills. In addition, the amount of cement and SiO ₂ and Al ₂ O in the medicine
The ratio to the total amount of ₃ is 100: 2 to 100: 10 by weight, the mixing ratio of cement and water in cement milk or cement air milk is 1: 0.3 to 1: 1 by weight, and the ratio in the bentonite milk is 3: 1. Mixing ratio of bentonite and water is 1: 4 to 1: 1
With a specific material composition design of 12, it is possible to obtain a plastic injection material having excellent early strength equal to or higher than the use of a quick-hardening special cement.

[Brief description of drawings]

FIG. 1 shows the one-day compressive strength (Si) of an injection material prepared by mixing cement milk prepared with blast furnace cement type B according to an example and bentonite milk containing water glass.
O ₂ + Al ₂ O ₃₎ is a graph showing the relationship between the amount / cement weight.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI // C09K 103: 00 C09K 103: 00 (56) References JP-A-9-279141 (JP, A) JP-A-59-120681 (JP, A) JP 10-81879 (JP, A) JP 52-100727 (JP, A) JP 7-247543 (JP, A) JP 61-62589 (JP, A) Kai 56-78464 (JP, A) JP 55-35533 (JP, A) JP 7-69695 (JP, A) JP 57-34056 (JP, A) JP 11-35361 ( JP, A) JP 9-71930 (JP, A) JP 11-193382 (JP, A) JP 11-310779 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C09K 17/00-17/50 E02D 3/12 101

Claims (3)

(57) [Claims] 1. Formed by stirring and mixing cement milk or cement air milk containing bubbles in cement milk and bentonite milk containing at least one agent selected from water glass, polyaluminum chloride and a sulfuric acid band. Plastic injection material, cement
And the total amount of SiO ₂ and Al ₂ O _{3 in} the drug
The weight ratio is 100 : 2 to 100 : 10 , and the cement mixture
Or the distribution of cement and water in cement air milk
The weight ratio is 1 to 0.3 to 1 to 1 , bentonite milk
Mixing ratio of the bentonite and water in a one-to-fourth to one-to-12 der
A plastic injection material characterized in that 2. The swelling power of bentonite is 15 ( ml / 2
g ) or more, The plastic injection material according to claim 1. 3. Mixing of air bubbles with respect to the volume of the plastic injection material.
Iriryou is 60% or less claim 1 or claim 2 plastic injection material according.