JPH09316449A - Chemical for grouting - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a chemical for grouting which is the suspension type one comprising a ternary system of water glass, a slag and an alkali aluminate, capable of especially readily regulating the gelation time from the flash setting to several tens of min, homogeneously consodilated, excellent in permeability, further capable of preparing both a flash setting grouting material and a slow setting grouting material in the same blending system and enabling the composite grouting by the primary and secondary groutings. SOLUTION: This chemical for grouting is the suspension type chemical for grouting comprising water glass, a slag and an alkali aluminate and is composed so as to satisfy the following conditions (a), (b) and (c): (a) >=2.8 molar ratio of water glass, (b) >=5000cm<2> specific surface area of the slag and (c) 2-20 weight ratio SiO2 /Al2 O3 of the amount of the SiO2 in the water glass to the amount of Al2 O3 in the alkali aluminate. The chemical for grouting is composed by including an alkaline agent in the ternary system.

Description

Detailed Description of the Invention

The present invention relates to a suspension-type ground injection liquid chemical consisting of a ternary system of water glass, slag, and alkali aluminate, and in particular, the gelling time from instantaneous setting to several tens of minutes can be adjusted. It is easy and homogeneously solidified and has excellent permeability. Furthermore, both the quick-injection material and the slow-injection material can be prepared with the same compounding system. The present invention relates to a ground injection chemical solution that enables complex injection.

[0002]

2. Description of the Related Art It has long been known that water glass gels with alkali aluminate such as sodium aluminate. However, in this case, the gelation time was usually extremely short, within 1 minute, and the caking strength was relatively low, so that it was not practical.

As a method for improving it, conventionally, fine particles of slag, cement, or limes have been used in combination to increase the strength. However, even with this improvement, the adjustment of the gelation time, the uniform caking property, and the improvement of the permeability were not always satisfactory.

Further, a suspension type grout has been developed which comprises water glass, particularly water glass having a low molar ratio, slag, particularly fine particle slag, and sodium aluminate. This makes it possible to adjust the gelation time for a long time and to enhance the consolidation strength.

However, this grout is a few seconds to a few seconds.
The gelation time was adjusted over 10 minutes, the viscosity was low, it was difficult to improve the permeability, and it was not possible to obtain a homogeneous solidified body.

[0006]

DISCLOSURE OF THE INVENTION The inventors of the present invention have earnestly studied the physical properties and mixing conditions of water glass, slag, and alkali aluminate to be used, as well as a drug for stabilizing while maintaining a low viscosity, and as a result, the present invention was found. Has been completed.

The object of the present invention is to maintain a relatively low viscosity until gelation, to obtain a homogeneous solidified body, and to easily adjust the gelling time from a few seconds to several tens of minutes. In particular, the primary injection with the quick-injection injection material and the secondary injection with the slow-injection injection material can be easily prepared in the same compounding system to enable composite injection, and the above-mentioned drawbacks existing in the prior art are improved. The purpose is to provide a cloudy type ground injection chemical.

[0008]

In order to achieve the above-mentioned object, according to the present invention, in a ground injection chemical solution comprising water glass, slag, and alkali aluminate, the following (a), (b) ) And (c) are satisfied.

(A) The water glass has a molar ratio of 2.8 or more. (B) The specific surface area of the slag is 5000 cm ² / g or more, preferably 8000 cm ² / g or more. (C) The weight ratio of the amount of SiO _{2 in} water glass to the amount of Al ₂ O ₃ in the alkali aluminate SiO ₂ / Al ₂ O ₃ is ₂ to 20.

Further, in order to achieve the above-mentioned object, according to the present invention, in addition to the above-mentioned ground injection chemical solution, as a chemical agent for maintaining a low viscosity until stabilization and stabilizing, It is characterized in that the agent is used in combination.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

The water glass used in the present invention has a molar ratio of 2.
8 or more, and the slag is in the form of fine particles having a specific surface area of 5000 cm ² / g or more, preferably 8000 cm ² / g or more. The present invention comprises blending these two components with alkali aluminate. Examples of alkali aluminate include sodium aluminate and potassium aluminate. According to the present invention, when the alkali aluminate is added to the above two-component system, the amount of SiO ₂ in the water glass relative to the amount of Al ₂ O ₃ in the alkali aluminate, that is, SiO ₂ / Al ₂ O ₃ is ₂ by weight. Formulate to be within the range of -20.

The above-mentioned ground injection drug solution (grout) of the present invention further maintains the lower viscosity until gelation, without substantially changing various properties other than the viscosity of the grout. It is also possible to use an alkaline agent in combination as a drug for stabilizing the above-mentioned condition and further improving the permeability.

The above-mentioned grout of the present invention can increase the amount of water glass and decrease the amount of slag, as compared with the conventional low molar ratio water glass-particulate slag-alkali aluminate grout, and thus the gel can be used. It maintains a low viscosity until it is made into a polymer and improves its permeability.

Furthermore, the above-mentioned present invention can be activated as the amount of water glass and the amount of slag are both increased, and as the slag is finely pulverized, and the curing by alkali becomes remarkable. Therefore, the alkali content of water glass and the alkali content of alkali aluminate are small, ground water is less likely to be contaminated with alkali, and the reactivity with alumina is improved.

The amount of alkali aluminate is SiO ₂
It is desirable that the value of / Al ₂ O ₃ is in the range of 2 to 20, and the smaller the value in this range, the faster the gelation time. Therefore, in the present invention, these properties can be skillfully combined to adjust the required gelling time.

Examples of the alkali agent used in the present invention include alkali hydrogen carbonate, alkali carbonate, caustic alkali, and the like. Among them, sodium hydrogen carbonate is most excellent. By blending this alkaline agent, the present invention maintains a low viscosity and is stabilized, and is preferable as a permeable grout.

Any method can be used for blending the components of the present invention. In particular, a water glass aqueous solution is used as solution A, and a slag-aluminate alkaline solution or a solution in which an alkali agent is used in combination is used as solution B. As liquid, A-
A method of confluently mixing the liquid B can be adopted. In this blend, by reducing the amount of slag, it is possible to obtain a homogeneous solidified body having a low viscosity, and in terms of strength, the initial strength becomes high.

The above-mentioned suspension type ground injection chemicals according to the present invention is not only used as a general grout material, but especially in the same compounding system, using the double injection rod of the composite injection, the primary connection
Prepared as an infusion material for loose secondary infusion.

The operation of the present invention is as follows. That is, in the present invention, the alkali aluminate and the alkali of water glass further solubilize the silica content in the slag by combining the property of the aluminum ampholyte. This solubilization is more effective as the slag is made into fine particles, and the solubilized silica content reacts with the calcium content in the water glass and the alumina in the alkali aluminate together with the silica content in the water glass.・ Forms a colloid composed of calcium. It seems that the slag particles are entrapped in this colloid and solidify as a whole.

[Examples] The present invention will now be described in detail with reference to Examples, but the present invention is not limited thereto.

1. Materials used (1) Slag The blast furnace slag having the following composition was crushed to give 3 as shown in Table 1.
Slags having different specific surface areas were prepared.

Composition of blast furnace slag Specific gravity: 2.90, SiO ₂ : 34.0%, CaO: 41.1
%, MgO: 6.7%

[0024]

[Table 1]

(2) Water glass Three types of water glass shown in Table 2 having different molar ratios (molar concentration of SiO ₂ / molar concentration of Na ₂ O) were used.

[0026]

[Table 2]

(3) Alkali aluminate Three kinds of sodium aluminate solutions having different molar ratios (Na ₂ O molar concentration / Al ₂ O ₃ molar concentration) shown in Table 3 were used.

[0028]

[Table 3]

(4) Alkaline agent Sodium hydrogen carbonate (first-grade reagent: Na
HCO ₃ ) and caustic soda (sodium hydroxide, first-grade reagent: NaOH) were used.

2. Blending and Physical Properties (1) Water glass-fine particle slag-sodium aluminate system Blending examples of the system according to the present invention, the viscosity of the blending liquid, the gelling time, and the uniaxial compressive strength of the sand gel by curing in water are out of the range of the present invention. The results are shown in Table 4 in comparison with the comparative example.

Here, the viscosity was measured by the funnel viscosity, the gelation time was measured by the cup inversion method, and the uniaxial compressive strength of the sand gel was measured by the standard of soil engineering standard "Soil uniaxial compression test method".

[0032]

[Table 4]

Observing the examples in Table 4, it is easy to obtain a gelation time of several seconds to 30 minutes by appropriately blending each component within the scope of the present invention. It can be seen that since the amount of slag is generally small, the viscosity is low and the slag is homogeneously consolidated, so that the initial strength (after 2 days) is excellent.

Examples Nos. 1 to 4 are examples in which the amount of water glass and the amount of slag were fixed and the amount of sodium aluminate was changed. In these examples, if the value of SiO ₂ / Al ₂ O ₃ becomes smaller,
The gelation time is fast, and the larger it is, the slower it is. Further, as shown in Comparative Examples Nos. 1 and 2, when the value of SiO ₂ / Al ₂ O ₃ is increased or decreased to 2 or less, or 20 or more, the gelling time becomes instantaneous and partial gelation occurs. Or, it is extremely long, and in either case, the strength is lowered.

Further, as shown in Examples Nos. 5 and 6, when the amount of slag in Example No. 3 was decreased, the gelling time was long and the viscosity was decreased, but of course the strength was slightly decreased. To do. In addition, Example No. 7 has a specific surface area of 58 as slag.
In the example used was a 00cm ² / g, compared with Example No.3 of the above 9500cm ² / g, gel time prolonged slightly viscous slightly increased, the strength is slightly reduced, practically There is no problem on the top.

Comparative Example No. 3 has a slag specific surface area of 5000 cm ² /
This is an example of g or less (4200 cm ² / g), which is far worse than all physical properties. That is, as the slag, one having a specific surface area of 5000 cm ² / g or more, preferably 8000 cm ² / g or more is suitable.

Examples Nos. 8 to 11 are examples in which the amounts of water glass, slag and sodium aluminate were further changed within the range of the present invention, and even if the respective components were quantitatively changed within the range of the present invention. The same excellent effect as in the above experimental example is exhibited.

Comparative Examples Nos. 4 and 5 are examples in which the value of SiO ₂ / Al ₂ O ₃ is as large as 20 or more, and Comparative Examples Nos. 5 and 6 have a molar ratio of 2.8 or less (2.48). This is an example using water glass. These Comparative Examples Nos. 4 to 6 all have a large amount of slag, are relatively high in viscosity, and are excellent in 90-day strength, but their initial strength (after 2 days) is inferior to those of the examples of the present invention. To do.

In addition, Comparative Examples Nos. 2, 4, which have a long gelation time,
In the case of 5, the slag is slightly settled during gelation and the gel tends to be inhomogeneous.

(2) Addition of alkaline agent Sodium hydrogen carbonate and caustic soda were added as alkaline agents to the system of Example No. 3 in Table 4 and the results are shown in Table 5.
Here, the gelation time, the viscosity, and the uniaxial compressive strength of the sand gel were measured according to the previous time.

[0041]

[Table 5]

From Table 5, it can be seen that the addition of sodium hydrogen carbonate and sodium hydroxide reduces the viscosity. This effect is particularly remarkable in the case of using sodium hydrogen carbonate.

Almost no change was observed in the gelation time and the strength change due to the addition of the alkaline agent. Therefore,
The addition of an alkaline agent is effective when it is desired to further stabilize the grout by further lowering the viscosity in order to improve the permeability.

3. Chemical Solution for Composite Injection Among the examples of Tables 4 and 5 above, a compounding solution that gels in a few seconds was used as a primary injecting solution for consolidating a coarse soil layer, and then a compounding solution having a long gelation time was used as a secondary injecting solution. It was used for infiltration and consolidation in a fine-grained soil layer, and was able to consolidate all ground. The injectable drug solution according to the present invention is suitable as a so-called complex injectable drug solution.

Further, the present invention has low viscosity as a suspension type grout, excellent permeability, and exhibits strength not found in a solution type grout. As an example, Example No. 1 in Table 4 is the primary injection liquid, Example No. 3 in Table 4 or Example No. 13 in Table 5
Was used as the secondary injection. That is, A shown in Table 6
A liquid and a liquid B were prepared, and the liquids A and B were combined to make a primary injection liquid and a secondary injection liquid, respectively.

[0046]

[Table 6]

As shown in Table 6, the liquid A can be used as the primary injection liquid or the secondary injection liquid. Also,
As solution B, solution B _{1 is} used for the primary injection solution for short-time gelation,
The B ₂ or B ₃ solution was prepared as a secondary injection solution for slow gelation for a long time. Then, a primary injection solution for short-time gelation is prepared by confluence of A-B ₁ , and a secondary injection solution for slow-setting gelation for a long time is prepared by confluence of A-B ₂ or A-B _3. Each of them was compounded into the ground. As a result, the ground was entirely solidified.

[0048]

From the above results, the grout of the present invention comprising water glass-slag-alkali aluminate, or these and an alkali agent, can exhibit the following effects.

1. The gelation time can be appropriately selected within the range of several seconds to several tens of minutes. 2. Generally, since the amount of slag is small and the amount of water glass is large, the mixed solution has a relatively low viscosity. 3. It is easy to obtain a homogeneous solid. 4. Excellent strength, especially initial strength. 5. From the above, the present invention can be effectively used not only as a suspension-type ground injection chemical but also as a suspension-type composite injection chemical.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location // (C04B 28/26 22:08) 111: 70 C09K 103: 00

Claims (3)

[Claims] 1. A ground injection chemical solution comprising water glass, slag, and alkali aluminate, wherein the following (a):
A suspension-type ground injection chemical solution satisfying the conditions (b) and (c). (A) The water glass has a molar ratio of 2.8 or more. (B) The specific surface area of the slag is 5000 cm ² / g or more. (C) The weight ratio of the amount of SiO _{2 in} water glass to the amount of Al ₂ O ₃ in the alkali aluminate SiO ₂ / Al ₂ O ₃ is ₂ to 20. 2. The specific surface area of the slag according to claim 1 is 8000 cm ² /
The chemical liquid for ground injection according to claim 1, which is g or more. 3. The chemical liquid for ground injection according to claim 1, further comprising an alkaline agent.