JPH0543286A - Production of cement-based slurry composition - Google Patents

Abstract

PURPOSE:To provide a method for producing cement-based slurry composition for grout which is excellent in stability and strength of the hardened material. CONSTITUTION:In a method for producing cement-based slurry composition for grout, the foam of a surfactant aqueous solution is mixed i.nto cement-based slurry at 5-30vol.%. The cement-based slurry composition is widely utilized as a binder of ground because bleeding of the slurry and separation of material are solved by using the obtained composition and both clogging of slurry at a time of force-feeding by a pump and uniformity thereof into ground are improved.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a cement-based slurry composition for grout.

[0002]

2. Description of the Related Art Conventionally, the problems to be solved by the invention
Cement-based slurries for grouting such as cement milk are widely used as a binder for ground by injecting into soft ground or cracked rock. These cement slurries for grout have a high water / cement ratio to improve fluidity in order to impart permeability into the ground and pipe transportability. However, the high fluidity impairs the stability of the slurry, causes breathing, and separates water, resulting in blockage in the injection pump and inability to send a uniform cement slurry into the ground, resulting in excess water. The desired strength cannot be obtained.

As a means for stabilizing the cement-based slurry for grout having a water / cement ratio of about 100%, there is a method of adding bentonite or a water-soluble polymer (Japanese Patent Laid-Open No. 62-17059). However, a sufficient effect cannot be obtained, and as a drawback, the viscosity of the slurry is increased and the strength of the cured product is decreased.

In view of the above-mentioned problems, the present invention is a method for producing a cement-based slurry composition which suppresses breathing and separation, and is extremely excellent in stability, and moreover the cement-based slurry for grout which satisfies the strength of the obtained cured product. A composition is provided.

[0005]

Means for Solving the Problems The present inventors have found that breathing and separation can be suppressed by mixing foam (aggregate of bubbles) of an aqueous solution of a surfactant in cement-based slurry, and completed the present invention. It came to do. That is, the present invention is to mix a specific amount of a foam of a surfactant aqueous solution into a cement-based slurry, to prevent breathing by increasing the contact points between the cement particles and water by the foam particles, and a spherical foam. By mixing the particles, the fluidity is improved and the permeability into the ground is significantly improved.

[0006] In the general foaming agent mixing method, fine and stable foams cannot be obtained, and the effect of suppressing breathing is insufficient, but according to the present invention, fine and stable foams can be mixed. Become. The present invention relates to a method for producing a cementitious slurry composition for grout, which comprises mixing 5 to 30% by volume of a foam of an aqueous surfactant solution into the cementitious slurry. If the amount of foam to be mixed is less than 5% by volume, a sufficient effect of suppressing breathing cannot be obtained, while if the amount of mixed foam exceeds 30% by volume, the viscosity and strength are greatly reduced, which is not practical.

To mix the foam of the aqueous surfactant solution into the cement-based slurry, the aqueous solution of the surfactant may be added to the cement-based slurry by using a foaming machine. According to this method, the bubbles to be added are fine, and it is possible to obtain stable bubbles with little fluctuation in the bubble distribution.
It has a remarkable effect on breathing suppression and fluidity. The surfactant used in the present invention does not limit the ionicity or the structure, and the surface tension in the range of 14 to 40 dyne / cm does not depend on the concentration of the surfactant aqueous solution. When the surface tension of this aqueous solution is 40 dyne / cm or more, the foamability is reduced. Further, since there is currently no surfactant having a surface tension of the aqueous solution of 14 dyne / cm or less, the surface tension of the aqueous solution of the surfactant is preferably 14 to 40 dyne / cm. Examples of surfactants include alkyl fatty acid salts, abietic acid salts, alkyl sulfuric acid ester salts, alkylbenzene sulfonic acid salts, polyoxyethylene alkyl sulfuric acid ester salts, polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, alkyl trimethyls. Ammonium chloride, alkyl betaine, etc. can be used alone or in combination of two or more.

The average particle size of the foam used in the present invention is 10 to 5
00 μm shows remarkable suppression of breathing. It is extremely difficult to industrially produce foams having an average particle size of less than 10 μm, whereas foams having an average particle size of more than 500 μm have a small surface area and thus the effect of suppressing breathing is reduced. The particle size of the foam can be adjusted by adjusting the compressed air of the foaming machine. The foaming machine that generates foam is not particularly limited, and a foaming machine for gypsum board, a foaming machine used for lightweight concrete, or the like can be used.

The cement-based slurry composition which is the subject of the present invention is mainly composed of cements such as ordinary Portland cement, early strength Portland cement, blast furnace cement and fly ash cement, but various admixtures ( Agents), for example, those containing blast furnace slag, fly ash, silica fume, water reducing agent, high performance water reducing agent, early strengthening agent, retarding agent, thickening agent, etc., are not limited.

[0010]

The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. Examples 1-9 and Comparative Examples 1-4 The physical properties of the ordinary Portland cement slurries were mixed with the foam of the aqueous surfactant solution. Table 1 shows the surfactant used, the concentration of the aqueous surfactant solution, the surface tension of the aqueous solution at the same concentration, and the average particle size of bubbles. The surface tension was measured using a Wilhelmy surface tensiometer (manufactured by Shimadzu Corporation). The average particle size of the bubbles is
The measurement was performed by analyzing the image of the foam with an image analyzer (manufactured by Nireco Co., Ltd.) using a micrograph of the foam.
The particle size of the foam was controlled by adjusting the pressure of the foaming machine. FIG. 1 shows a schematic view of the foaming machine. In FIG. 1, compressed air 1 and surfactant aqueous solution 2 are injected into a foaming machine body 5 made of glass beads having a diameter of 3 mm, and surfactant aqueous solution 2 is injected by a pump (not shown), and compressed air 1 is 1 to 4 kg. / c
Foam 4 can be obtained by sending the solution through a separate inlet pipe at a pressure of m ² to foam aqueous solution of surfactant 2 in foaming machine main body 5. In addition, the management of the amount of foaming is carried out by preliminarily determining the relationship between the amount of foaming solution 2 and the amount of foaming water to be charged into the foaming machine body 5 (the linear relationship between the amount of surfactant solution and the amount of foaming product). The amount of foam input is controlled according to the amount of the aqueous surfactant solution.

[0011]

[Table 1]

From the results shown in Table 1, when the surface tension is 40 dyne / cm or more like the 0.07% by weight sodium lauryl sulfate aqueous solution of surfactant (Experiment No. 11), it is difficult to form bubbles having a small particle size. I understand.

Table 2 shows the composition of the cement slurry carried out, the amount of foam mixed in Table 1, the breathing rate and the compressive strength.

[0014]

[Table 2]

The contents of Table 2 are shown below. W: Water C: Cement * 1: There is a lot of breathing, and the specified dimensions cannot be obtained, so measurement is not possible. * 2: Methyl Cellulose [High Metroses-10000,
Shin-Etsu Chemical Co., Ltd.] From the results in Table 2, the product of the present invention shows remarkable results in breathing suppression and strength as compared with the comparative product, and is suitable as a method for producing a cement-based slurry composition for grout. I understand.

[0016]

EFFECTS OF THE INVENTION By using the composition obtained by the present invention, bleeding of cement-based slurry for grout and material separation are eliminated, and clogging of the slurry during pumping and non-uniformity in the ground are improved. Therefore, it can be widely used as a ground binder.

[Brief description of drawings]

FIG. 1 is a schematic view of a foaming machine.

[Explanation of symbols]

 1 Compressed air 2 Surfactant aqueous solution 3 Glass beads 4 Foam 5 Main body of foaming machine

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location C04B 24:04) 2102-4G (C04B 28/04 24:20) 2102-4G (C04B 28/04) 24:12) 2102-4G (C04B 28/04 24:02) 2102-4G (C04B 28/04 24:16) 2102-4G

Claims (3)

[Claims] 1. A method for producing a cement-based slurry composition for grout, which comprises mixing 5 to 30% by volume of a foam of an aqueous surfactant solution into the cement-based slurry. 2. The surface tension of the aqueous surfactant solution is 14 to 40 dy.
The method for producing a cement-based slurry composition for grout according to claim 1, wherein the method is ne / cm. 3. The method for producing a cementitious slurry composition for grout according to claim 1, wherein the average particle size of the foam is in the range of 10 to 500 μm.