JPH0436383A - Grout for ground - Google Patents

Abstract

PURPOSE:To prepare a grout for ground excellent in permeability and solidification strength by adding a specified curing agent to a solution of water glass. CONSTITUTION:A grout for ground comprising water glass and curing agent, wherein a reaction product formed between a hardly soluble polyvalent metal compd. (e.g. CaCO3) and a caustic alkali (e.g. NaOH) is used as the curing agent.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention uses a water glass liquid as a curing agent (reactant) in the form of fine particle suspension.
The present invention relates to the development of a chemical solution for ground injection that takes a long time to harden and exhibits excellent permeability and consolidation strength.

[Conventional technology]

As an inorganic suspended water glass grout that does not use cement, there has been a grout that uses water glass and limes such as poorly soluble slaked lime, quicklime, calcium carbonate, and dolomite as a reactant for a long time. Among these, slaked lime has extremely high reactivity, but since the particle size of slaked lime is about 10 to 40μ, it has the disadvantage of poor permeability, there is a limit to how much it can be crushed into fine particles, and it is economically expensive. becomes. Calcium carbonate generally has finer particles than slaked lime, but it still has its limits and is less reactive with water glass. Slightly soluble polyvalent metal compounds other than lime (including magnesium) generally do not react with water glass liquid, and are rarely found to be used as hardening agents for water glass.

[Problem that the invention seeks to solve]

The purpose of the present invention is to use extremely fine particles of polyvalent metal hydroxide as a hardening agent for water glass.
by reacting to form a colloid of hydroxide with small particle size, it gels a wide range of water glass liquids regardless of the molar ratio of water glass, creating a ground with excellent permeability and consolidation properties. The purpose of the present invention is to provide medical solutions for injection.

[Means for solving problems]

In order to achieve the above object, according to the present invention, a colloidal suspension of hydroxide consisting of a reaction product of a caustic agent and a poorly soluble polyvalent metal compound is reacted with a water glass liquid, thereby increasing Regardless of the ratio, we were able to gel a wide range of water glass solutions over a long period of time to obtain grout with excellent permeability and solidification properties.

Examples of the caustic alkali include caustic soda and caustic potash, and water glass having various molar ratios can be used.

Hardly soluble polyvalent metal compounds include heavy calcium carbonate, ferric oxide, aluminum oxide slaked lime, fine-grained light calcium carbonate, homologous magnesium carbonate, and other gypsum, quicklime, magnesia, magnesium hydroxide, and triiron tetroxide. etc.

[Effect]

A poorly soluble polyvalent metal compound and a caustic alkali gradually react to produce a polyvalent metal hydroxide in an aqueous solution, and this hydroxide is in the form of fine particles and a colloid.

When a polyvalent metal hydroxide is used as a poorly soluble polyvalent metal compound, the polyvalent metal hydroxide changes from a precipitate state to a colloid state due to caustic alkali, and appears to behave in the same way as fine particles. You will begin to take .

For this reason, all of the above hydroxides are thought to have better permeability than conventional suspension grouts.

Furthermore, these hydroxides produced can gel a wide range of water glasses regardless of their molar ratio.

〔Example〕

The present invention will be explained in detail below with reference to Examples.

[1] Materials used (1) Use water glasses with different water glass molar ratios as shown in Table 1 Table 1 (2) Use a caustic alkaline agent sodium hydroxide (caustic soda) reagent grade (3) Use poorly soluble polycarbonate The following four types of valent metal compounds are used as poorly soluble polyvalent metal compounds: 1) Calcium carbonate: Heavy calcium carbonate for industrial use 1i) 1I-converted red iron for the pig iron industry 1ii)! ! Aluminum chloride industrial alumina iv) Slaked lime calcium hydroxide (reagent grade) [2] Water glass and poorly soluble polyvalent metal compounds - Caustic soda system Water glass aqueous solution as liquid A, calcium carbonate and ferric oxide as liquid B Using a mixed suspension of aluminum oxide, slaked lime, and caustic soda, Table 2 shows the gelation time of the AB mixture and the unconfined compressive strength of the solidified body when cured in water.

As a control, an example is given in which a suspension of calcium carbonate, ferric oxide, aluminum oxide, and slaked lime alone is used as liquid B.

[3] Injection test into standard sand A mold with an inner diameter of 5 mm and a height of 10 cm was filled with Toyotori standard sand, and a small injection pump was used to inject it from the bottom of the mold.
A typical blended solution of No. 2 was injected, and the permeation state at the time of injection was observed.After 24 hours, the solids were taken out and cured in water, and the changes in -axial compressive strength over time were observed.

The results are shown in Table-3.

The following can be seen from Tables 2 and 3.

1. Gelation time In a system consisting of calcium carbonate and water glass, gelation takes a long time only when the molar ratio of water glass is low (approximately 2 or less).
When the molar ratio is about 2 or more), gelation does not occur. (Refer to Practice NcL1.6 in Table 2) A system consisting of ferric oxide, aluminum oxide and water glass (Refer to Practice N1117.19 in Table 2)
．． 22.24) does not cause gelation regardless of the molar ratio of water glass. Also, in a system consisting of slaked lime and water glass, if the molar ratio of water glass is large (Implementation NCL 27)
It gels in a short time (within 1 minute). However, in the system according to the present invention, any molar ratio of water glass can be gelled in an appropriate time, making it possible to use inexpensive No. 3 water glass.

(See Table 2) 2. System consisting of homogel strength calcium carbonate and low molar ratio water glass (Table 2
In 10.14), gelation occurs as described above, but
System using calcium carbonate and caustic soda according to the present invention for curing water glass (Practice PkL2.3.4 in Table-2)
．． 5.7.8.9.11.12.13.15.16,)
The homogel strength is much lower than that of In a system consisting of calcium carbonate and low molar ratio water glass, suspended matter gradually settles during gelation, and the lower layer is solidly consolidated, but the upper layer becomes softer and less uniform as a whole. It shows only low strength. In the system using calcium carbonate and caustic alkali according to the present invention, such a tendency is extremely small and the whole solidifies almost uniformly, so that the system as a whole is superior in strength. In the system that uses ferric oxide and aluminum oxide instead of calcium carbonate and does not use caustic soda (Execution Nα17.19.22.24 in Table 2), gelation does not occur at all as described above, but when caustic soda is used The system of the present invention (Table 2 implementation Nα18.20.
21, 23, 25, and 26), gelation occurred, and the strength of the homogel was somewhat inferior to that of the system of the present invention using calcium carbonate, but showed considerable strength.

The system of the present invention using slaked lime and caustic soda for hardening water glass (Table 2 implementation Na2B, 29.30.32.
33) is clearly superior in strength to the system consisting of slaked lime and water glass without using caustic soda (Example 27.31 in Table 2), despite the longer gelation time.

3. Permeability and sand gel strength A system consisting of calcium carbonate and water glass based on the observation results in the injection test into standard sand (Table 3 Implementation Nα 10.14)
and a system consisting of slaked lime and water glass (Table 3 Implementation N11
In case 31), the time required for penetration is long, and the obtained sand gel is strongly consolidated in the lower layer, but becomes softer as it goes to the upper layer, and the strength of the sand gel as a whole is weakened. This seems to be because the suspended matter does not sufficiently permeate to the upper layer in a uniform state, and the suspended matter permeates in a filtered form toward the upper layer.

In comparison, the system according to the present invention (Table 3)
．． 8.12.15.18.20.23.26.32), this tendency is very small, and therefore the sand gel is uniform and has superior strength. The effect is particularly remarkable in the calcium carbonate-caustic alkali system.

4. Molar ratio of water glass and equivalent molar ratio When caustic soda is added to liquid B and the equivalent molar ratio is adjusted to be the same molar ratio as low molar ratio water glass, the ratio in the case of slaked lime is higher than in the case of no addition of caustic soda. Except for this, it promotes gelation and is also excellent in consolidation strength. In the case of slaked lime, although it takes longer to gel, it has excellent consolidation strength. Table 4 summarizes the gelation time and consolidation strength for the cases where the equivalent molar ratio is the same from Table 2.
become that way.

From Table 4, compared to the implementation Na6.10S14 in Table 2 with calcium carbonate and no caustic soda added, caustic soda was added and adjusted to the same molar ratio (equivalent molar ratio) as 6, N[Llo, and Na14, respectively. NcL2 and company 3.7
In the cases of 4.8.11 and 4.8.11, the gelation time was shortened and the strength was significantly enhanced.

Arashi 19.24 is in an unconsolidated state, but when caustic soda is added (Table 2 implementation & 1B,
20.23.25) Gelation occurs and shows considerable strength.

Implementation of Table 2 using slaked lime and no addition of caustic soda N[L
In the case of 27, the gelation time is within 1 minute, and in the case of implementation storm 31, it is 1 minute.
5 minutes, but the addition of caustic soda (Table 2 Practice & 2B, 29.30.32.33) delays the gelation, yet the strength is excellent.

〔Effect of the invention〕

Based on the above facts, the present invention, in which a mixed suspension of a caustic alkali and a poorly soluble polyvalent metal compound is applied to a water glass solution, requires a long gelation time and provides a grout with excellent consolidation strength and permeability. I can do it.

In particular, the effect of calcium carbonate as a poorly soluble polyvalent metal compound is remarkable.

Claims (2)

[Claims] (1) A chemical solution for ground injection consisting of a water glass liquid and a hardening agent, characterized in that a reaction product of a poorly soluble polyvalent metal compound and an aqueous caustic alkali solution is used as the hardening agent. (2) The chemical liquid for ground injection according to claim 1, wherein the reaction product is in the form of fine particle suspension.