KR100433051B1 - Solidifing material for pouring into ground - Google Patents

Abstract

The present invention relates to a ground injecting solidifying material, and the ground injecting solidifying material of the present invention is mixed with water glass, colloidal silica or active silicic acid in a specific ratio, and has a self-hardening property in itself. By using a stabilized alkaline silica solution, and a de-alkali silica solution obtained by de-alkaliating the alkaline silica solution as a substrate, an acidic reactant, other reactants, cement, slug, and the like are added thereto. In spite of low silica concentration, high strength, high durability, long gelling time, and a technique for obtaining ground injection solidifying material which enables wide penetration as an injection material for preventing liquefaction of the ground are proposed.

Description

Solidifying material for pouring into ground

The present invention is based on a high molar ratio silica solution containing colloidal silica and water glass, and active silicic acid as a substrate, and is applied to the ground injection solid material which maintains a wide range of gelation time at low silica concentration. In particular, in the liquid liquefaction injection work of the ground, it is possible to improve the large-scale soil by continuous injection over a long time, and also high durability of the solidified body with high high-strength strength and further excellent ground injection quality It is about payment.

In general, the ground injection material formed by mixing colloidal silica with water glass is known to have excellent durability of solidified body. However, when the water glass No. 3 is mixed with colloidal silica in a large amount, it gels in an instant.

Conventionally, a method of avoiding gelation in such an instant and mixing a high molar ratio of water glass and colloidal silica to make a ground injection liquid having a magnetic property is known.

However, the injection liquid has a high silica concentration but does not have high grain strength. Moreover, when this is used as a unilateral liquid (A liquid) of 1.5 shots or 2.0 shots, the use thereof is limited because it gels itself.

The present inventors specify water glass and colloidal silica, or water glass, colloidal silica, and active silicic acid as a compounding component, and select a specific compounding ratio or SiO ₂ concentration which does not gelate itself before injecting into the ground during these blending. In addition, in the ground, it is possible to maintain a wide range of gelation time, especially long gelling time, and at the same time, to reduce the permeability due to the gelation deposition between the particles of the ground, which tends to occur during long-term continuous injection between the particles of the ground, and excellent ground liquefaction prevention ground injection It has been developed to complete the present invention by developing a high binder. Such a high aggregating material of the present invention also exhibits high high cohesive strength at a low SiO ₂ concentration, and is excellent in water quality preservation due to the low amount of unreacted water glass and reaction products.

Accordingly, an object of the present invention is based on a high molar ratio silica solution containing colloidal silica and water glass, and also active silicic acid, to maintain a wide range of gelation time at low silica concentration, and to prevent the liquefaction of the ground for a long time. It is to provide a high-density soil improvement by the continuous injection over, and furthermore, to provide a high-density land-based high-density material with excellent high-density strength and excellent water quality preservation, which improves the defects shown in the above-mentioned known technology.

In order to achieve the above object, according to the present invention, it comprises a colloidal silica and water glass, characterized in that it consists of an alkaline silica solution that does not gelate itself before injecting into the ground, and the concentration of SiO ₂ , Is 3 to 13% by weight, and the amount of SiO ₂ derived from colloidal silica is 1 to 50% by weight.

In addition, in order to achieve the above object, according to the present invention, an alkaline silica solution containing colloidal silica, water glass and active silicate, the concentration of SiO _{2 in} the solution is ₃ to 13% by weight, of which colloid The amount of SiO ₂ derived from silica and active silicic acid is 1 to 50% by weight.

Hereinafter, the present invention will be described in detail.

As described above, the solidifying material for ground injection according to the present invention is an alkaline silica solution containing colloidal silica and water glass, or these and active silicic acid as a compounding component.

The colloidal silica described above has a colloidal property and is a stable substance which is not semi-permanently gelled alone. An example of this preparation method is as follows.

First, the water-dilution liquid of water glass is dealkali-treated with an ion exchange resin or an ion exchange membrane, and the active silicic acid of pH 2-4 is obtained.

Subsequently, an alkali agent such as water glass or caustic soda is added to the obtained active silicic acid to adjust the pH value to about 8.5 to about 10 alkalinity, and at the same time to adjust the SiO ₂ concentration to about 3 to 5%, followed by a temperature of 70 to 95 ° C. The mixture is heated and granulated for 1 to 5 hours to obtain a colloidal silica mother liquid. Usually, the mother liquor is concentrated to a final colloidal silica until the SiO ₂ concentration is 20 to 30%. In the present invention, the mother liquor itself can also be used as colloidal silica.

The water glass used in the present invention is an aqueous solution of an alkali metal silicate, and preferably a relatively high molar ratio having a molar ratio of SiO ₂ / Na ₂ O of 3.4 or more, but is not gelled by mixing with colloidal silica or active silicate. Any molar ratio can be used.

The active silicic acid used in the present invention is obtained by removing the alkali component in the water glass by ion exchange resin treatment or ion exchange membrane treatment and adjusting the pH value to be lower than that of water glass.

In general, in the above-described mixed system of water glass and colloidal silica, or a mixture of these and active silicate, a high silica concentration (SiO ₂ concentration) tends to be an electrical unstable state, and thus the silica is electrically heterogeneous. It is difficult to form a gel with homogeneous strength because the weak parts are locally generated.

In the above-described mixed system, even if the gelation time during the mixing before the injection into the ground is adjusted to be long, in the ground after injection, the heterogeneously precipitated silica is deposited between the particles of the ground, so that the gap is clogged and the permeability is reduced. However, the injection pressure becomes excessive or cracks deviate, and a wide range can not be uniformly solidified as designed.

In particular, during the liquefaction prevention work of the ground, it is necessary to economically improve the large-capacity soil, and this requires a continuous injection of several hours to several tens of hours per injection stage by widening the interval of the injection holes.

The present invention corrects the above-mentioned irrationality, and in such a mixed system of water glass and colloidal silica, or a mixed system of these and active silicate, it is said that the stable liquid does not gel itself before the mixed liquid is injected into the ground, and at the same time, such a stable state It is a condition to maintain.

That is, the present invention, in the alkaline silica solution containing the colloidal silica and water glass described above, dilute the SiO ₂ concentration in the solution to ₃ to 13% by weight, and at the same time the amount of SiO ₂ derived from the colloidal silica It is set to 1 to 50% by weight, preferably 3 to 50% by weight, and thus it becomes a stable high-density material which itself hardly semi-permanently gels before being injected into the ground. In addition, there is a stabilized region even when the amount of colloidal silica is large relative to the amount of water glass. The region is thought because the right and left in accordance with the water glass, the type of colloidal silica, it is difficult to uniquely determined, the amount of SiO ₂ derived from colloidal silica to the total SiO ₂ uiyang would almost the order of 90% or more.

In addition, the present invention, in the alkaline silica solution containing the colloidal silica, water glass, and active silicic acid described above, dilute the SiO ₂ concentration in the solution to ₃ to 13% by weight, and at the same time colloidal silica and active silica The amount of SiO ₂ derived from is set to 1 to 50% by weight, preferably 3 to 50% by weight, thereby becoming a stable high-density material which itself hardly semi-permanently gels before being injected into the ground.

In the above-mentioned bar, the ratio of colloidal silica and the silicate is activated there is dependent on the kind thereof, it is desirable that the rate at which the amount of SiO ₂ derived from the active silicic acid to maintain a nearly 50% by weight or less.

In the above-described alkaline silica solution, a part of colloidal silica or active silicic acid is dissolved by alkali of water glass, and as a result, the particle diameter of the silica constituting the solution can be seen from the silica of the water glass from the particle diameter held by the colloidal silica. It is a high molar ratio silica solution distributed up to the particle size of silicic acid molecules. The molar ratio is higher than that of water glass and lower than that of colloidal silica or activated silica.

In a SiO ₂ concentration of the above alkaline silica solution, 3-13% by weight out of range, that is, the smaller the amount of SiO ₂ too low caking strength if smaller than 3% by weight, and the amount of SiO ₂ when greater than 13% by weight There are too many of these gellings themselves, so stability cannot be maintained.

In addition, the amount of SiO ₂ derived from colloidal silica, or the initial integrity of the water when the amount of SiO ₂ derived from colloidal silica and the active silica is gelled when smaller than the out-of-range of 1 to 50% by weight, that is, 1% by weight Although the strength is increased, the long-term strength is small, the durability is worsened, and the gelation time in the ground is gradually shortened. In addition, when it is larger than 50% by weight, the initial strength of the solidified product becomes small.

In addition, when stabilization is achieved by increasing the amount of colloidal silica with respect to the amount of water glass, the solids have a very low initial strength, which is not preferable as a normal grout, but the gelation time in the ground can be maintained for a long time. It can be used sufficiently as a liquefaction prevention binder.

In addition, the alkaline silica solution of the present invention has a relatively low sodium content. Therefore, dealkali treatment is relatively easy in the field using a small apparatus such as an ion exchange resin or a cartridge of an ion exchange membrane. It can also be set as a silica solution. As the de-alkali silica solution, one of a system which does not gelate itself, or one of a system that gels after a long time can be obtained. The gelling system after a long time is excellent in itself as an injection material for preventing liquefaction.

In the present invention, the reactant can be added and mixed with the alkaline silica solution or the de-alkali silica solution described above. Examples of the reactive agent include inorganic acids such as sulfuric acid, phosphoric acid, aluminum chloride, polyaluminum chloride, sulfuric acid band, organic acid (citric acid, succinic acid, acetic acid, etc.) and various acidic reagents, alkali metal salts, alkaline earth metal salts which are acidic in an aqueous solution. Salt, cement, slug, lime, gypsum and the like.

For example, an acidic reagent may be added to the alkaline silica solution to adjust the solution to an acidic to neutral region to obtain a grout having a predetermined gelation time. In this case, even if a strong acid such as sulfuric acid is not used as an acidic reagent, it is possible to shorten the gelation time in the ground by using phosphoric acid, aluminum chloride, polyaluminum chloride, band, organic acid, etc. It is possible to obtain a wide range of ground injection fasteners, particularly excellent as a liquefaction prevention hardener.

In addition, by adding a relatively small amount of various reactive agents to the alkaline silica solution or the de-alkali silica solution, it is possible to obtain a high-density material having a wide range of gelation time, in particular, a long gelling time and a shortening of gelation time in the ground. In this case, the obtained high-density binder is excellent in permeability, excellent in durability of the high-density binder, and high in strength and fast in strength, compared to a thinner silica concentration.

1 is a schematic diagram of a laboratory injection test apparatus.

<Description of Symbols for Main Parts of Drawings>

1: compressor 2, 3: pressure gauge

4 agitator 5 water tank

6: solidified material 7: acrylic pipe

8: Toyoura Standard Sand 9, 10: Switching Coke

11, 12: gold mesh 13: Mess cylinder

Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited by these Examples.

1. Material used

(1) active silicic acid

Water glass JIS No. 3 (Asahi Kogyo Co., Ltd. product, SiO ₂ 29.0%, Na ₂ O 9.0%) was diluted with water to obtain a dilution product of 5.8% of SiO ₂ and 1.8% of Na ₂ O, which was hydrogenated cation exchange. Activated silicic acid of SiO ₂ 5.8%, pH3.0 obtained by passing through a resin (Organo Co., Ltd. product, Amberlite IR-120B) column as de-alkali is used. PH is obtained).

(2) colloidal silica

The active silicic acid was introduced into alkaline water to 4% SiO ₂ , pH 9, and then heated to 90 ° C. and stirred for 2 hours to obtain a colloidal silica mother liquor. The content of SiO ₂ obtained by concentrating the mother liquor is 20% and 30.1% of colloidal silica. The average particle diameter of the colloidal silica is 4 millimeters and 15 millimeters. The properties are shown in Table 1.

TABLE 1

No. importance SiO ₂ (%) pH Average particle size (millimeters micron) 12 1.201.13 30.120.0 9.810.1 154

(3) water glass

As the ordinary water glass, JIS No. 3 glass shown in the following (a) is used, and No. 5 water glass shown in the following (b) is used as the high molar ratio water glass.

(a) No. 3 water glass (20 ° C.) 1.39, SiO ₂ 29.2%, Na ₂ O 9.5%, molar ratio 3.17 JIS 3 water glass.

(b) No. 5 water glass Specific gravity (20 ° C.) 1.32, SiO ₂ 25.5%, Na ₂ O 7.03%, molar ratio 3.75 water glass.

(4) Potassium chloride reagent class 1

Calcium chloride reagent class 1

Phosphoric Acid Reagent Level 1

Sodium bicarbonate reagent class 1

Poly Aluminum Chloride JIS Standard

(5) cement

Portland cement and blast furnace cement with different compositions and degrees of grinding shown in Table 2 are used.

TABLE 2

Cement type SiO ₂ (%) Al ₂ O ₃ (%) Fe ₂ O ₃ (%) CaO (%) MgO (%) basicity Hydroponics Brain Ratio Surface Area (㎠ / g) One Portland Cement 21.9 5.3 3.1 65.1 1.4 3.28 2.15 3,200 2 Blast furnace cement 25.8 9.4 2.0 54.9 3.4 2.61 1.47 9,700

In Table 2, the average particle diameter of blast furnace cement of type No. 2 of cement is about 3 microns.

(6) slug

Slugs of the compositions shown in Table 3 are used.

TABLE 3

SiO ₂ (%) Al ₂ O ₃ (%) Fe ₂ O ₃ (%) CaO (%) MgO (%) basicity Hydroponics Brain Ratio Surface Area (㎠ / g) 31.4 18.6 1.0 46.2 1.3 2.11 0.91 15,000

(7) sand

Toyura standard sand is used as fine sand, and sea sand from Chiba is used as silty sand.

2. Measurement

(1) Sandgel uniaxial compressive strength

Sand gel from Toyoura standard sand is cured by polyvinylidene chloride sealed curing (20 ℃) and measured by Soil Uniaxial Compression Test Method.

(2) gelation time

(a) Gelation time of homogel

It measures by the cup inverting method at 20 degreeC.

(b) gelation time in the ground

The grout liquor is mixed with the sand at 20 ° C. and stopped, and the material floating on the top is discarded, and bamboo skewers are pierced in the sand.

(3) pH

Measure with a glass electrode pH meter.

3. Alkaline Silica Solution

Colloidal silica and water glass or colloidal silica and activated silica and water glass are mixed to obtain alkaline silica solution. These mixing ratios and SiO ₂ concentrations of the mixed solution, the amount of SiO ₂ derived from colloidal silica or colloidal silica and activated silica, and stability are shown in Table 4.

TABLE 4

Alkaline Silica Solution Mixing ratio (per 1000g) Alkaline Silica Solution Colloidal silica (g) Water glass (g) Active silica (g) Water (g) SiO ₂ (%) stability Table 1 No. No. 3 No. 5 Total Colloidal silica origin Derived from colloidal silica and active silicate One 2 Comparative Example 1 - One - 99 - 900 2.5 0.8 - No gelation Comparative Example 2 - 2 - 198 - 800 5.1 0.8 - No gelation Example 1 10 - - 190 - 800 5.2 5.8 - No gelation Example 2 - 30 170 - - 800 5.6 10.8 - No gelation Example 3 - 150 - 150 - 700 6.8 43.9 - No gelation Example 4 50 - 200 - - 750 7.4 20.5 - No gelation Example 5 100 - - 300 - 600 10.7 28.2 - No gelation Example 6 - 250 250 - - 500 12.3 40.7 - No gelation Example 7 320 - - 30 - 650 10.4 92.6 - No gelation Example 8 50 - - 300 100 550 9.7 - 21.4 No gelation Comparative Example 3 250 - - 250 - 500 13.9 54.1 - Vangelization after 4-5 months

In Table 4, the concentration of SiO ₂ in the alkaline silica solution is about 13%, and below that, the gel is semi-permanently stable without gelation. Therefore, these alkaline silica solutions can be stored for a long time, can be handled like grout raw materials, and can be brought into the injection site at a factory. In Comparative Example 3 of 13% or more, the gelled state was obtained after 4 to 5 months.

In addition, in Comparative Example 3, the amount of SiO ₂ derived from colloidal silica is also beyond the scope of the present invention, and the drawback is that the strength expression is slow when gelled with a reactant.

Therefore, when the SiO ₂ concentration is about 13% or less, a stable alkaline silica solution can be obtained in most cases.

In Comparative Examples 1 and 2, the concentration of SiO ₂ derived from colloidal silica was 1% or less, and in Comparative Example 1, the amount of total SiO ₂ was also 3% or less, which is outside the scope of the present invention. These are of course not gelled and stable. However, as will be described later, the solids obtained by the addition of the reactant are very fragile, and the strength is significantly lowered below the SiO ₂ concentration around 3%.

In contrast to Example 6, Example 7 is an example in which colloidal silica is stabilized in a large amount. Example 8 is an example in which a small amount of active silica is mixed and stabilized. In this case, the amount of SiO ₂ derived from active silicic acid in the amount of SiO ₂ of colloidal silica and active silicic acid is 27.8%, which is 50% or less.

4. De-alkali silica solution

The alkaline silica solution is de-alkali treated by ion exchange resin treatment or ion exchange membrane treatment to obtain a de-alkali silica solution.

5,000 ml of the alkaline silica solution obtained in Example 4 of Table 4 was mixed with 900 ml of a cation exchange resin to obtain a de-alkali silica solution having a pH of 3.5. The de-alkali silica solution was gelled at a concentration of 7.1% of SiO ₂ for about 30 to 35 hours.

Also, instead of the cation exchange resin treatment, electrolysis dialysis was carried out using a negative / positive ion exchange membrane at a current density of 3 A / dm ² , and when the pH reached 3.5, the dialysis was stopped to remove almost the same cation exchange resin treatment. An alkali silica solution was obtained.

A simple water glass solution having almost the same SiO ₂ concentration is lowered to about pH3.5 by a direct cation exchange resin, and about several times the cation exchange resin described above is required. In the ion exchange membrane method, the number of ion exchange membranes is increased, and the dialysis time takes a long time.

When the pH of the alkaline silica solution of Example 6, which had a higher SiO ₂ concentration, was reduced to about 3.5 by the same treatment, the gelation time was accelerated to about 20 to 24 hours. These de-alkali silica solutions themselves can be used as ground injecting materials having excellent permeability. Moreover, since Na ion is removed, it is more preferable also from an environmental conservation point.

5. Alkaline silica solution-acid reactant

Table 5 shows the results of mixing the alkaline silica solution of Example 2 of Table 4 with phosphoric acid as the acidic reagent and adjusting the neutral to acidic regions.

TABLE 5

Example Comparative Example Combination (per 1000ml) Mixed solution Alkaline silica solution or water glass solution for control (ml) Phosphoric Acid (ml) Water (ml) pH Gelation time (20 ℃) (minutes) Sand gel uniaxial compressive strength (kgf / ㎠) 2 days 28 days Example 9 Example 10 Example 11 Example 12 Comparative Example 4 Alkaline silica solution of Example 2 of Table 4: No. 9003 Water glass: 135 1517202345 85838077795 6.85.54.03.13.4 10 ~ 1230 ~ 40180 ~ 200500 ~ 55070 2.72.42.11.82.3 3.53.23.02.62.6

In Table 5, it was found that the gelling time of the present invention can be adjusted, in particular, for a long time. Comparing Examples 11 and 12, in which the SiO ₂ concentration and pH were approximately the same using the same No. 3 water glass, and Comparative Example 4 (No. 3 water glass-phosphate system), the amount of phosphoric acid was very small in the Example, about half the amount. Suffice. In addition, although the gelling time is very long, it is possible to obtain a high-density material which is not inferior in strength.

6. Alkaline Silica Solution-Reactor System, De-Alkali Silica Solution-Reactor System

The alkaline silica solution of Table 4 is stable without gelation except for Comparative Example 3. It can be gelatinized by adding a reactive agent to this. The gelation can also be adjusted by adding a reactant to the de-alkali silica solution. The gelation time and the high grain strength of the alkaline silica solution-reactive system and the de-alkali silica solution-reactive system are shown collectively in Table 6.

TABLE 6

The first half of Table 6 was observed, and the gelation time ranged from a short time to a long time, and the long gelation time was particularly easy to adjust. In Examples 14 and 15, in which the amount of SiO ₂ derived from colloidal silica is relatively high, the two-day strength is low but the 28-day strength is very high.

In Comparative Example 5 in which the SiO ₂ concentration is less than or equal to the range of the present invention, the high grain strength is very low. In Comparative Example 6 beyond the scope of the present invention, although SiO ₂ is rich, there is a sign that the increase in high grain strength is not seen but rather decreases.

In the case of the dealkali silica solution of Example 21, compared with Example 17 having the same degree of SiO ₂ , the gelation time is significantly longer, but the strength is hardly different.

In the suspension type examples (Examples 16, 18, and 20) in which cement and slug are mixed, the initial strength is slightly lower than that of Comparative Example 8 of the conventional water glass-cement system, but is significantly strengthened at long-term strength.

Further, in the thick of Comparative Example 7 of the SiO ₂ it has a drawback is liable to gelation in a non-uniform and connective up in an instant.

7. Gelation time

As well as the gelation time of the homogel, furthermore, it is preferable that the gelation time in the ground can be kept long to prevent liquefaction. The gelation time (underground gelation time) in Toyoura standard sand and Chiba Prefecture sea sand was measured about a part of the compounding liquid with long gelation time of the said Tables 5 and 6. In addition, it was compared with the acidic silica sol showing a long gelation time as a target, and the results are shown in Table 7.

TABLE 7

Example Comparative Example sample Gelation time (20 ℃) (minutes) Homogel bowels of the earth TOYOURA STANDARD SAND Chiba Prefecture Sea Sand Example 24 Example 25 Example 26 Example 27 Example 28 Example 29 Example 30 Example 31 Comparative Example 9 Mixed Liquid Table 6 of Example 13 of Mixed Liquid Table 6 of Example 13 of Mixed Liquid Table 6 of Example 17 of Mixed Liquid Table 6 of Example 15 of Example 15 of Mixed Liquid Table 6 of Example 11 of Table 13 the exemplary mixture of example 22. Table 6 example 23 a mixture of SiO ₂ of about 5% of water-glass of pH2.8 - sulfate calculated integrity silica sol 700 ~ 800 180 ~ 200 550 ~ 600 700 ~ 800 450 ~ 500 1800 ~ 2000 1000 ~ 1100 150 ~ 2001 800 ~ 2000 600 ~ 700 150 ~ 180 250 ~ 300 500 ~ 600 300 ~ 400 1300 ~ 1500 800 ~ 90035 ~ 4050 ~ 60 250 ~ 30080 ~ 10050 ~ 60180 ~ 200 120 ~ 140800 ~ 1000 400 ~ 45010 ~ 155 ~ 6

In Table 7, homogels of conventional acidic silicaazoles (Comparative Example 9) exhibit very long gelling times, which are significantly shortened in the ground. In particular, it is very noticeable in Chiba Prefecture.

On the other hand, in Examples 24 to 31 of the present invention, it was found that the shortening of the gelation time in the ground was very small and still maintained a lot of gelation time. This enables wide penetration as an injection material for preventing liquefaction.

8. Penetration test

As can be clearly seen from the results of the above test, the ground injecting material of the present invention can be easily adjusted for a wide range of gelation time, in particular a long time gelation time, moreover, because the gelation time is shortened even in the ground can be expected excellent permeability. However, for the sake of clarity, the penetration test was conducted using the penetration injection test apparatus in the laboratory shown in FIG.

In FIG. 1, the injection material 6 is filled into a water tank 5 equipped with a stirrer 4 connected to the compressor 1 via pressure gauges 2, 3. 7 is an acrylic pipe having an internal diameter of 50 mm and a height of 1.5 m, and the standard sand 8 is divided into nine layers, and each layer is hardened to have a relative density of 60% by horizontal strike.

Subsequently, the injection material 6 filled in the water tank 5 is press-fitted into the standard sand 8 in the pipe 7 by the injection pressure of the compressor 1 at 0.5 kgf / cm <2>. The injection material penetrated into the standard sand (8) and the penetration distance was observed. In Fig. 1, 9 and 10 are switching cocks, 11 and 12 are gold meshes, and 13 are measuring cylinders.

Table 8 shows the test results and test results. In Table 8, penetration tests Nos. 1 to 7 are the high resolution materials according to the present invention, penetration tests Nos. 8 and 9 are the high resolution materials used as comparative examples, and No. 8 is a system outside the scope of the present invention. 9 is a conventional acidic silicasol.

TABLE 8

Penetration test Usage Penetration test result 123456 Formulation of Table 13 Formulation of Formula 11 Formula 11 of Example 11 Formulation of Example 17 of Table 6 Formulation of Example 19 of Table 6 Formulation of Formula 21 of Example 6 of Table 6 Formulation of Example 22 of Table 6 Evenly penetrates the entire length of standard sand 8 uniformly 7 Formulation of Example 23 in Table 6 Penetrated near the entire length of standard sand 8, somewhat uneven around 10 cm 8 Formulation solution of Comparative Example 6 in Table 6 It penetrated uniformly from the lower part of the standard sand 8 to the height of 1.0 ~ 1.1m, but the upper part was unevenly penetrated. 9 Water glass-sulfur acidic silicasol with pH 2.8 of about 5% SiO ₂ Penetrates only 40-50 cm from the bottom of standard sand 8.

In Table 8, in the system according to the present invention of the penetration tests Nos. 1 to 6, the whole of the standard sand 8 of the acrylic pipe 7 was well penetrated, and the whole was uniformly solidified. Penetration test No. 7 is a system related to the present invention, which has a very high content of water glass and is slightly inferior to the above penetration tests No. 1 to 6.

On the other hand, penetration test No. 8 of the comparative example showed considerable penetration, but did not penetrate up to the total length of 1.5 m. That is, comparing the penetration test No. 2 of the present invention with the penetration test No. 8 of the comparative example, the gelation time of the homogel is inferior to the permeability despite the latter.

In addition, the penetration test No. 9 of the comparative example shows that the gelation time of the homogel is remarkably long, but it is very poor in permeability.

As described above, it has been demonstrated that the high-density binder of the present invention has excellent permeability.

As described above, an alkaline silica solution in which colloidal silica and water glass or active silicic acid are mixed in a specific ratio, and a ground-injection-coating material based on a de-alkali silica solution in which the alkaline silica solution is de-alkali have the following results. It can be.

1. A wide range of gelling time can be adjusted, especially long gelling time, and at the same time, the gelation time is shortened even in the ground. Therefore, the permeability is good and is very excellent as a high injection material for preventing liquefaction of the ground.

2. It shows high grain strength compared to low silica concentration.

3. Alkali content is low and water integrity is excellent.

4. Since alkaline silica solution is not self-hardening, it can be preserved or brought into the injection site at the factory.

5. De-alkali silica solution can be easily obtained from small scale devices such as ion exchange resins and cartridges of ion exchange membranes.

6. Even when cement or slug is used, it can be gelled homogeneously and high strength can be obtained.

Claims (8)

Alkaline silica solution containing colloidal silica and water glass, the concentration of SiO _{2 in the} solution is 3-13% by weight, of which the amount of SiO ₂ derived from colloidal silica is 1-50% by weight, before the injection into the ground It is a gel which does not gel itself, has a wide range of gelation time in the ground, and consists of an alkaline silica solution having excellent permeability. delete Alkaline silica solution containing colloidal silica, water glass and active silicic acid, the concentration of SiO _{2 in the} solution is _{3 to 13} % by weight, of which the amount of SiO ₂ derived from colloidal silica and active silicic acid is 1 to 50% by weight The ground-injection-coating material, characterized in that it does not gel itself before being injected into the ground, and has an extensive gelling time in the ground, and is made of an alkaline silica solution having excellent permeability. The method according to claim 1 or 3, A grounding filler for ground injection, wherein the alkaline silica solution is subjected to de-alkali treatment to form a de-alkali silica solution. The method according to claim 1 or 3, A ground injection material comprising a mixture of a reactant further. The method of claim 4, wherein A ground injection material comprising a mixture of a reactant further. The method of claim 5, wherein And a reactant is selected from the group of acidic reactants, inorganic salts, cement, and slugs. The method of claim 6, And a reactant is selected from the group of acidic reactants, inorganic salts, cement, and slugs.