JP2001098269A - Grout for hardly injectable ground and method for its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a grout which can be injected even into a gravel-clay layer ground into which the injection of a conventional grout is regarded to be difficult and which has a coefficient of permeability of 3.9×10-4 cm/s, thus enabling dam construction even at a site at which dam construction is considered to be impossible. SOLUTION: This grout comprises a fine blast furnace slag powder having the max. particle size of 12 μm or lower, a fine anhydrous gypsum powder having the max. particle size of 12 μm or lower or sodium hydroxide, a dispersant, and water.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injectable material (hereinafter referred to as a grout material) which can be injected into a ground made of fine-grained sand or a ground having fine cracks, into which a soil injectable material hardly penetrates, and a method for producing the same. .

[0002]

2. Description of the Related Art In recent years, dam construction often has poor ground at the construction site. In such a case, water blocking work is usually performed using a ground injection material. However, it is difficult to stop water and a predetermined capacity is not exhibited. Often. This is because ultrafine cement cement grout used as a grout is difficult to inject and cannot stop water. Accordingly, there has been a demand for the development of a high-performance grout material that can be easily injected even into a hardly injectable ground that cannot be injected with such an existing grout material.

A study was conducted to determine the cause of the above-mentioned difficult-to-inject ground. As a result, in the grout material mainly composed of the above-mentioned fine particles, ultra-fine particles aggregated during the production of the grout material to produce coarse particles. That led to the finding. Based on this fact, the applicant of the present invention
No. 4177, a method for producing an ultrafine cement grout material obtained by subjecting a kneaded product composed of an ultrafine powder mainly composed of ultrafine cement and a dispersant to ultrasonic treatment. Alternatively, a method for producing a kaolin-based grout material in which particles are dispersed in a kneaded product of water, kaolin and a dispersant adjusted to a predetermined pH value by the same ultrasonic treatment. Further, the present invention discloses a method for producing a grout material by mixing the ultrafine cement grout material and the kaolin grout material produced by the above production method.

[0004]

SUMMARY OF THE INVENTION The above-mentioned Japanese Patent Application Laid-Open No. 9-324 is disclosed.
Each of the above grout materials manufactured by the manufacturing method disclosed in Japanese Patent Publication No. 177 shows good permeability in the sand / clay layer ground, but the target water stopping effect in the debris / clay layer ground having a smaller permeability coefficient. Was not obtained.

[0005]

Means for Solving the Problems The present inventors have conducted various studies to develop a grout material that can be reliably injected even in the case of rubble or clay layer ground made of fine particles. The grout material shown and the manufacturing method thereof have been invented. The invention of claim 1 provides a hard-to-injectable ground grout comprising blast furnace slag fine powder having a maximum particle size of 12 μm or less, anhydrous gypsum fine powder or sodium hydroxide having a maximum particle size of 12 μm or less, a dispersant and water. Material.

According to a second aspect of the present invention, there is provided a grout material for hardly injectable ground, wherein the maximum particle size of the mixture of the blast furnace fine powder and the anhydrous gypsum fine powder according to the first aspect of the present invention is 12 μm or less.

A third aspect of the present invention relates to a blast furnace slag fine powder having a maximum particle size of 12 μm or less, a dispersant, water, and a maximum particle size of 12 μm.
This is a method for producing a grout material for hardly injectable ground, in which a kneaded material with the following anhydrous gypsum fine powder or sodium hydroxide is formed, and the kneaded material is subjected to ultrasonic treatment for 0.01 to 140 seconds.

A fourth aspect of the present invention is a method for producing a grout material for hardly injectable ground, wherein the water powder ratio of the kneaded material is 6 to 20.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention comprises a blast furnace slag fine powder having a particle size of 12 μm or less as a main component, and anhydrous gypsum or sodium hydroxide having a particle size of 12 μm or less, a dispersing agent, water as a stimulant. And a grouting material for hard-to-inject soil composed of The blast furnace slag fine powder and the anhydrous gypsum fine powder may be mixed in advance, and the maximum particle size of this mixture is 12 μm or less.

In the method for producing a grout material, a dispersant and water are added to a fine powder obtained by adding a predetermined amount of anhydrous gypsum fine powder to the above blast furnace slag fine powder so that a water powder ratio becomes 6 to 20. By subjecting the kneaded material to ultrasonic treatment for 0.01 to 140 seconds, aggregation of the particles of the blast furnace slag fine powder and the anhydrous gypsum fine powder (when using anhydrous gypsum) was prevented. This is a method for producing a grout material for hardly injectable ground injection. When forming the kneaded product mainly composed of the blast furnace slag fine powder, the order of adding the blast furnace slab fine powder, the anhydrous gypsum fine powder or sodium hydroxide, the dispersant and the water is not particularly limited, but it is necessary to consider the prevention of particle aggregation. For example, a predetermined amount of water and a dispersant are mixed, and while the mixture is being stirred, the blast furnace slag fine powder and the anhydrous gypsum fine powder or the mixture are gradually added and kneaded (stirred) to form a kneaded product. Is preferred.

The blast furnace slag fine powder used in the present invention is a quenched blast furnace slag fine powder having hydraulic properties due to the presence of a stimulating material. This is a product obtained by rapidly cooling a high-temperature slag (blast furnace slag) discharged from a blast furnace, and has a property of being hardened by a stimulant such as an alkaline substance. Fine granulated blast furnace slag powder having a maximum particle size of 12 μm or less is produced from the blast furnace slag by a pulverizer and a classifier. Maximum particle size is 12μm
If the ratio exceeds the above range, the permeability to the gravel / clay layer ground, which is the object of the present invention, becomes poor. Preferably 10 μm
The thickness is more preferably 8 μm or less.

The anhydrous gypsum used as the stimulant is a type II anhydrous gypsum, and the method and type of the anhydrous gypsum are not particularly limited. This anhydrous gypsum was treated with a pulverizer and a classifier in the same manner as the blast furnace slag fine powder to obtain a maximum particle size of 12%.
It was classified to μm or less. The maximum particle size is preferably 10 μm or less, more preferably 8 μm or less, similarly to the above blast furnace slag fine powder. The addition amount is 1.0 to 15.0% by weight based on the blast furnace slag fine powder. 1.
If it is less than 0%, the initial strength is poorly expressed. Also, 1
If it is added in excess of 5.0% by weight, the particles may aggregate, and the preferred range is 2.0 to 8.0% by weight. Also, sodium hydroxide can be used as a stimulant (agent). The amount of sodium hydroxide added is
The water used is added so as to have a concentration of 0.1 to 0.5N. If the addition amount is less than 0.1 normal, it takes too long to cure. If it exceeds 0.5, the curing time is too short to be unsuitable, and care must be taken in handling. A preferred range is 0.15 to 0.2
5 rules.

The dispersing agent is not particularly limited, and may be a commercially available high-performance dispersing agent such as a commercially available lignin sulfonate, polycyclic aroma sulfonate, melamine sulfonate, polyoxyethylene ether, or the like. Dispersants can be exemplified. As a guide of the amount of addition, a product name of Mighty 150 (naphthalene sulfonate) manufactured by Kao Corporation
In the case of the above, the content is 2 to 8% based on the blast furnace slag fine powder. However, since this value varies depending on the type of a commercially available dispersant, it is necessary to determine the value according to the dispersant used. .

In the present invention, the particles in the kneaded material mainly composed of the blast furnace slag fine powder are dispersed by the above dispersant and ultrasonic treatment. First, the fine powder particles are dispersed with the dispersant. However, since the particles to be used are fine powder, it is impossible to completely disperse the particles only with the dispersant. When the particle size in the kneaded material is measured, particles having a particle size larger than the maximum particle size of the used fine powder are detected, and the performance of the grout material is reduced. Therefore, the particles in the kneaded material are re-dispersed by the ultrasonic treatment, and the performance of the grout material is improved. The time for the ultrasonic treatment is 0.01 to 140 seconds. If the time is less than 0.01 second, the treatment time is too short and the dispersion of the particles is insufficient. 1
Even if the ultrasonic treatment is performed for more than 40 seconds, the effect does not change and it is uneconomical. Preferably it is 30 to 120 seconds.

The water powder ratio is an item that has a large effect on the performance of the grout material. In the grout material of the present invention, the water powder ratio is 6 to 20. If the water powder ratio is less than 6, the viscosity becomes too high, and a predetermined injection performance cannot be obtained. If it exceeds 20, the amount of the dispersant added increases, which is not economical. A preferable range of the water powder ratio is 8 to 16.

Further, it is preferable that the maximum particle size in the grout material produced by using the above-mentioned method for the blast furnace slag fine powder and the anhydrous gypsum fine powder does not exceed 12 μm. Further, as described above, the thickness is more preferably 10 μm or less and 8 μm or less. The particle size of the grout material of the present invention is a value measured using a laser diffraction type particle size distribution analyzer HR850 type manufactured by Cirrus Co., Ltd.

[0017]

EXAMPLES The present invention will be described in detail with reference to the following examples, but the present invention is not limited to these examples. Example 1 Granulated blast furnace slag and anhydrous gypsum fine powder at the level shown in Table 1 were produced using a crusher and a classifier for granulated blast furnace slag and commercially available anhydrous gypsum received at the Mitsubishi Materials Kurosaki Factory. The particle size distribution of the blast furnace slag fine powder and the anhydrous gypsum fine powder was measured using a laser diffraction type particle size distribution analyzer HR850 type manufactured by Cirrus Co., Ltd., using ethanol as a solvent. Further, the Blaine specific surface area was measured by a method specified in JIS R5201. Table 1 shows the results.

[0018]

[Table 1]

The grout material used in the present embodiment is prepared by adding water and a dispersant to a hand mixer (Makita type UT1301), stirring the mixture for 10 seconds, and subsequently stirring (mixing) a predetermined amount of fine powder ( And then mixing for 2 minutes to form a kneaded material (paste). Subsequently, a grout material is manufactured by performing a predetermined time treatment with a homogenizer (made by Nippon Seiki Co., Ltd .: US1200T, output 1200 W, frequency 15 kHz) as an ultrasonic disperser. However, when sodium hydroxide is used instead of anhydrous gypsum, it is added before charging the powder. )

The following items were tested to confirm the composition of the grout material of the present invention and its performance. (1) Dispersant addition amount In order to examine the dispersibility (addition amount of the dispersant) using Mighty 150 manufactured by Kao Corporation, the water powder ratio was set to 6 and the addition amount of the dispersant, the ultrasonic treatment time, Was changed to produce a grout material, and the particle size distribution of the grout material was measured using a laser diffraction type particle size distribution analyzer manufactured by Cirrus Co., Ltd. The results are as shown in Tables 2 and 3.

[0021]

[Table 2]

[0022]

[Table 3]

(2) Confirmation of permeability Of the above grout materials, those having the largest amount exceeding 8 μm in particle size, those having the largest Blaine specific surface area, and those having the smallest amount exceeding 8 μm in particle size are naturally determined. A penetration test was performed to compare the permeability. The results are as shown in Table 4.

[0024]

[Table 4]

(3) Water Powder Ratio The amount of the dispersant added was 5% by weight, and the injection pressure was 0.5 kgf / c.
Under the condition of m ^2, a penetration test was performed for a case where the water powder ratio was changed, and the relationship between the water powder ratio and the penetration length was examined. The result is as shown in FIG. The pressure permeation test was conducted by mixing a Kaho No. 7 silica sand and a Kaho silica sand filler at a weight ratio of 8: 1 in an acrylic mold tube of φ50 × 500 mm having a structure shown in FIG.
The bed was filled so as to have a density of × 10 ^{−4 to} 4.0 × 10 ⁻⁴ cm / s (a coefficient of permeability corresponding to the gravel / clay layer ground) to produce a bed for a penetration test. A penetration test was performed using this bed. (4) Determination of stimulant (agent) and its addition amount The selection of the stimulant and the examination of the addition amount are carried out by changing the addition amount of anhydrous gypsum, sodium hydroxide, calcium hydroxide and clinker powder to improve the natural permeability. It was measured. The results are as shown in Table 5, and it was found that except for anhydrous gypsum and sodium hydroxide, aggregation and gelation were caused and the permeability was inhibited.

[0026]

[Table 5]

Based on the results, the anhydrous gypsum and sodium hydroxide were obtained using blast furnace slag fine powder M-20.
A mortar specimen having a water-to-powder ratio of 0.6 and a sand-to-powder ratio of 3 was prepared in accordance with JIS R 5201 under a penetration test under the conditions of a water powder ratio of 10 and a pressure of 0.5 kgf / cm ^2. And
A strength test was carried out at the ages of 7 days and 28 days. The result is
It is as shown in FIG.

[0028]

[Table 6]

In the natural penetration test, 700 g of Toyoura sand was placed in an acrylic mold tube of φ50 × 500 mm at a height of 225 m.
bed filled with m (permeability k15 = 1.1 × 10
^-2 cm / s). In the test, the bed was saturated with water by infiltration into the bed before the grout was injected, 400 ml of the grout was injected, and the permeation length and the time until the grout came off from the bottom were measured. In addition, to confirm the curability of the grout material, 400 ml of the grout material was put into a polyethylene bag specified in JSCE-F522, and the cured state was confirmed. In addition, the amount of sediment was determined by grout material 5 shown in Table 5.
00 ml was taken in a measuring cylinder, and the amount of the precipitate after standing for 60 minutes was measured.

(5) Determination of Mixing From the above test results, regarding the physical properties of the blast furnace slag fine powder, which is a main component of the grout material of the present invention, the particle size of 8 μm or more which affects the permeability of the grout material is small. The result is M-20, followed by M-30. Based on these results and the results of the above tests (2) to (4), Table 7
The grout material having the composition shown in Table 2 was subjected to a penetration test to confirm the performance of the grout material. The results of these studies are as shown in FIG.

[0031]

[Table 7]

[Comparative Test] For comparison with the grout material of the present invention, an ultra fine cement grout material (trade name: Fine Hard) manufactured by Mitsubishi Materials Corporation (fineness: 1260)
0 cm ² / g), a kaolin-based fine powder grout material (trade name: Fine Hard K), a maximum particle diameter of 6 μm, and a particle diameter of d50 of 3.1 μm. First, the ultrafine cement grout material (F) was added to a mixture obtained by adding 3% by weight of water and mighty 150 measured so as to have a water powder ratio shown in FIG.
After kneading while supplying H) to form a kneaded material,
Ultrasonic treatment is applied for 120 seconds to produce an ultrafine cement grout material. At the same time, 4% of Mighty 150 was added to water adjusted to pH 11 and mixed, and the above-mentioned kaolin-based grout material (FK) was supplied to form a kneaded material. To produce a coated kaolin grout. The ultrafine cement grout material and the kaolin grout material were mixed at a volume ratio of 1: 1 to produce a grout material for comparison. Using this grout material, a mortar strength and penetration test were performed under the same conditions as in (4) of Example 1. The results are also shown in Tables 6 and 7
And as shown in FIG.

[0033]

[Effect of the Invention] grout of the present invention, conventional injection hydraulic conductivity 3.9 × 10 had been difficult - it was confirmed also be injected into ^{4 cm} / s degree of gravel-clay layers Ground . Therefore, it is considered that dam construction will be possible even at a site where it was previously impossible to construct a dam.

[Brief description of the drawings]

FIG. 1 is a process chart of a pressure penetration test.

FIG. 2 is a diagram showing a relationship between a water powder ratio and a permeation length in Examples.

FIG. 3 is a graph showing the relationship between the amount of stimulant added and the permeation length in an example.

FIG. 4 is a diagram showing the relationship between the water powder ratio and the permeation length in the grout material of the present invention.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09K 17/06 C09K 17/06 P E02D 3/12 101 E02D 3/12 101 // C04B 103: 40 C04B 103 : 40 111: 70 111: 70 C09K 103: 00 C09K 103: 00 (72) Inventor Koji Nagamizu 1 Fukuoka, Kitakyushu-shi, Yawata-nishi-ku, 1-Donami-cho F-term in the Mitsubishi Materials Corporation Cement Development Center (reference) 2D040 AA01 AB01 CA03 CA04 CA10 4G012 MA00 MB23 PA04 PB03 PB11 PB25 PC03 4H026 CA04 CA05 CB02 CB08 CC05 CC06

Claims (4)

[Claims] An injectable material for hard-to-inject ground comprising: a blast furnace slag fine powder having a maximum particle size of 12 μm or less; an anhydrous gypsum fine powder or sodium hydroxide having a maximum particle size of 12 μm or less; a dispersant; and water. . 2. The injection material for hardly injectable ground according to claim 1, wherein a maximum particle size of a mixture of the blast furnace slag fine powder and the anhydrous gypsum fine powder is 12 μm or less. 3. A kneaded product of a dispersant, water, blast furnace slag fine powder having a maximum particle size of 12 μm or less, and anhydrous gypsum fine powder having a maximum particle size of 12 μm or less or sodium hydroxide is formed. A method for producing a hard-to-injectable ground injection material to be subjected to ultrasonic treatment for up to 140 seconds. 4. The method according to claim 3, wherein the water powder ratio of the kneaded material is 6 to 20.