JPH0480290A - Grout - Google Patents

Abstract

PURPOSE:To provide grout which suffers no instantaneous gelation and has good permeability by using aqueous colloidal silica as a main component and an aluminosilicate carrying ions of an alkaline earth metal as a gelling agent. CONSTITUTION:An aluminosilicate carrying ions of an alkaline earth metal (such as Mg or Ca ions) is prepared by supporting ions of the alkaline earth metal through ion exchange on noncrystalline aluminosilicate powder, a precursor of zeolite, in an amount of 5 - 30wt.% based on the oxides, or by the like processes. Then, using the aluminosilicate as a gelling agent, a grout is prepared by combining it with a main component of aqueous colloidal silica. The grout can be gelated without fail even in a long gelling time. Further, it can be grouted into a soil into which a cement-base material can be hardly grouted by virtue of the minute particle sizes of the aluminosilicate.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is a chemical solution for ground injection using water-based colloidal silica as a main ingredient, and is used for strengthening soft ground, stopping water flowing out from groundwater, etc. Regarding ground injection agents.

[Conventional technology]

Conventionally, ground injection agents that use water glass as the main ingredient are often used, and the hardening side (gelling agent) includes calcium salts such as portland cement, slaked lime, and steel slag, sodium hydrogen sulfate, magnesium sulfate, and phosphoric acid. Various acids, such as, organic acids such as glyoxal and ethylene carbonate, and esters have been used. In addition, an injection side using aqueous colloidal silica as the main ingredient has also been proposed because it dislikes the alkali of water glass.

For example, water-based colloidal silica, slaked lime, Portland cement (Japanese Unexamined Patent Publication No. 59-66482), alkaline earth metal salts such as magnesium sulfamate (Japanese Unexamined Patent Publication No. 63-168485), sodium chloride, sodium hydrogen sulfate, etc. Alkali metal salt of (JP-A-59-152
A method of curing by adding an electrolyte such as a trivalent metal salt such as an aluminum salt (Japanese Unexamined Patent Publication No. 152984/1984) has been proposed.

[Problem to be solved by the invention]

The method of using water glass has problems in durability due to the presence of a large amount of sodium salts contained in the injected material, as has already been introduced in many literatures, and furthermore, due to the salts leaching out. Contamination of groundwater and corrosion of underground objects are becoming problems.

These drawbacks are exactly the same when acid water glass is used. Therefore, the use of colloidal silica, which does not contain substantially or no alkali metal salts, has been attracting attention, but it is extremely difficult to gel colloidal silica effectively, and there are still many studies on this topic. It is being done for. In particular, it is extremely difficult to control the time from mixing colloidal silica and gelling agent until gelation occurs (referred to as gel time). For example, an alkali metal earth salt electrolyte instantaneously destroys the safety of the colloid and causes gelation, so the amount added must be carefully adjusted. Due to subsequent dilution of groundwater, it no longer forms a gel. Therefore, methods have been proposed that require double effort, such as injecting a gelling agent in advance and then injecting colloidal silica. This problem is exactly the same with alkali metal salts such as sodium carbonate and sodium sulfate, and trivalent metal salts such as aluminum salts and iron salts.

A solution to this problem is that the gelling agent injected at the same time as the colloidal silica contains more than enough gelling component to gel the colloidal silica, and that the gelling component is gradually released after injection, and Like colloidal silica, it must not be a material that can penetrate deep into the ground. After searching for a material that satisfies these conditions, we found that it supports alkaline earth metal ions through ion exchange. Aluminum non-licade showed favorable results.

The inventors of the present invention focused on the above facts and conducted intensive research into materials that satisfy these conditions. Surprisingly, the inventors found that alkaline earth metal ions were supported by ion exchange using aqueous colloidal silica as a king agent. The present inventors have discovered that a chemical agent using aluminosilicate as a gelling agent exhibits excellent ground injection performance, and has completed the present invention.

[Means for Solving the Problems] That is, the ground injection agent provided by the present invention is characterized in that it is composed of aqueous colloidal silica and aluminosilicate supporting alkaline earth metal ions. .

The present invention will be explained in detail below.

The aqueous colloidal silica used in the present invention is known, and is produced, for example, by an ion exchange method using water glass as a raw material, an acid neutralization method, an electrodialysis method, or a silica gel peptization method, and is disclosed in US Pat. No. 2,577,484. Specification, U.S. Patent No. 3
No. 711419, U.S. Patent No. 2,572,578, JP-A-52-33899, U.S. Patent No. 36
68088, JP-A-1-317115, etc. For example, US Patent No. 3650
977 specification and Japanese Patent Publication No. 46-7367, and U.S. Patent No. 29510.
Colloidal silica based on the method of dispersing fine silica powder in water described in No. 44 specification and Japanese Patent Application Laid-open No. 62-127216 can also be used.

Water-based colloidal silica with an average particle diameter of 3 to 1100 nm can be used, but those with large particle diameters have weak gel strength (an average diameter of 50 nm or less is practical in that sense. Commercially available standard Grade has an average diameter of 10-20n
m, this is practical. Small particle grades of 3 to IOnm are particularly preferred because of their high gel strength.

Furthermore, there is colloidal silica having an average particle size of 3 nm or less, but this grade has a high content of alkali stabilizer like water glass and is difficult to meet the purpose of the present invention.

Aqueous colloidal silica usually contains trace amounts of alkali ions (or hydrogen ions) as a colloid stabilizer, but the alkali content of the aqueous colloidal silica used in the present invention is SiO□/M20 (where M is an alkali 5 to 500 is preferable.

The ground injection agent of the present invention is characterized by using aqueous colloidal silica as a main ingredient and using aluminosilicate supported by ion exchange with alkaline earth metal ions as a gelling agent. As the silicate, amorphous aluminosilicate, which is a precursor of zeolite or synthetic zeolite, is preferably used. It is preferable that 90% or more of these aluminosilicates have an average particle diameter in the range of 0.1 to 10<->.

Various types of zeolites can be used as the zeolite, but for example, IM or two or more synthetic zeolites selected from A-type zeolite, It is advantageous. Other natural zeolites such as clinoptilolite, which can be produced in large quantities domestically, can also be used.

Furthermore, although amorphous aluminosilicate, which is a precursor of synthetic zeolite, is a gel-like substance, it has the same active and cation exchange ability as general natural or synthetic zeolite.
There is no particular limitation on the manufacturing history, and the method can be applied.

Since the aluminosilicate in the present invention is all in the sodium form, it must be ion-exchanged with an aqueous alkaline earth metal salt solution to support alkaline earth metal ions.

Examples of alkaline earth metals include Be, Mg, and Ca.

There are Sr, Ba, and Ra, but Mg and Ca are preferable because they can be used industrially at low cost. The amount of alkaline earth metal in the zeolite is 30 to 200 of the ion exchange equivalent of the zeolite.
%, and if it is less than 30%, the alkaline earth metal cannot be released or the gelation rate becomes extremely slow, so a large amount of zeolite must be used. Therefore, the viscosity on the injection side increases, making it difficult to inject.

The upper limit is 100% of the ion exchange equivalent, but
Even if an amount exceeding the ion exchange equivalent is attached or adsorbed due to the manufacturing method of the zeolite used, there is no substantial problem as long as the amount does not exceed 200%.

Moreover, if the alkaline earth metal ions supported on the aluminosilicate are expressed in weight%, the preferred range is 5 to 30% by weight based on the oxide in the aluminosilicate powder.

[For production]

Unlike the release of ionic components due to electrolyte dissolution or dissociation, the ground injection agent according to the present invention releases ions gradually through ion exchange, and therefore gels colloidal silica to form a hardened product with homogeneous and strong physical properties. to be generated. In addition, even if the alkaline earth metal ions contained in aluminosigate are in excess of what is necessary for the gelation of colloidal silica, the alkali ions and hydrogen ions that exist on the stable side of colloidal silica, or the ions and ions in the soil Only the alkaline earth gold I ions corresponding to the amount of exchange action are released, and the excess ions in the zeolite do not substantially exhibit any action, so the gel time can be set to be longer or shorter. For example, in order to quickly release alkaline earth metal ions contained in aluminosilicate, an extremely short gel time can be achieved by adjusting the alkali ions in colloidal silica (by adding NaOH, etc.). Therefore, a gelling agent component (alkaline earth metal ion) that is more than sufficient to gel colloidal silica can be introduced into the aluminosilicate into the ground, so that a reliable hardening effect can be obtained.

〔Example〕

Examples will be given below to explain. Gel time here refers to the time from when a gelling agent is added to colloidal silica until the mixture loses its fluidity, and even if the beaker containing the mixture is tilted 90 degrees. Measurements were taken up to the point where it stopped flowing. In addition, the strength of the gelled body is 50% of the contaminants before gelation.
The unconfined compressive strength was measured by placing the sample in an s-φX100-IIIH mold, gelling it, taking it out after a predetermined period of time, and using an Armsler type strength testing machine.

Examples 1 to 12 and Comparative Examples 1 to 3 Colloidal silica shown in A-1 and 2 of Table 1, A-type zeolite or X-type zeolite shown in B-1, 2, 3 and 4 of Table 2, A Using the substituted type zeolite precursor, various types of soil injection agents are prepared using liquid A and liquid B (slurry) having the composition shown in Table 3. Solution A and Solution B were mixed and continuously stirred using a mag-neutral cooler, and the gel time based on the gelation reaction of the ground injection agent was measured.

Table 3 shows the composition and gel time results of each injection.

Table Examples 13 to 16 Add the A-type zeolite in Table 2 as a powder to the colloidal silica 20 (ld) shown in A-1 in Table 1 to prepare a ground injection solution with the composition shown in Table 4. The gel time was measured by continuing stirring with a non-stick stirrer. Approximately 10 seconds before the gel time, the injection agent was poured into a 5.01Φ x 10 cmL mold to create a homogel for strength measurement.The composition of each injection agent and its use were Table 4 shows the results.

Example 17 The injection agent having the composition of Example 4 was injected under pressure into Toyoura standard sand in a 5.01Φ×100 cmL mold to create a sand gel for strength measurement. Three days later, test specimens of 5.0 cmΦXIO cmL were cut out from the injection part, middle part, and tip part of the sand gel, and a strength test was conducted. After the strength test, each specimen was pulverized and boiled in dilute hydrochloric acid to reduce the zeolite content to 1. The O component was eluted and the content was measured by ICP. Table 5 shows the results.
As shown in Figure 2, it can be seen that the zeolite penetrates well to the tip, creating a uniform hardened product.

As a comparison, the same test was conducted using the injection agent of Comparative Example 1, but the cement particles were filtered by the sand particles, and most of the cement penetrated only up to about 10 cm from the injection site, leaving the middle part. The gel was not formed because the part contained only colloidal silica.

Also, because the gelation time was short, it was not possible to inject all the way to the tip.

Table [Effects of the Invention] The ground injection agent according to the present invention can reliably gel even with a long gel time without instantaneously gelling colloids unlike electrolytes.

Furthermore, the particle size of aluminosilicate is 0゜1=l
Because it has a fine particle size, it can be injected even into the ground where it is difficult to inject conventional cement-based substances, and it can provide an injection agent with good penetration into the ground.

Claims (1)

[Scope of Claims] 1. A ground injection agent comprising aqueous colloidal silica and aluminosilicate supporting alkaline earth metal ions. 2. The ground injection agent according to claim 1, wherein the aluminosilicate supporting alkaline earth metal ions is a zeolite powder, and the alkaline earth metal ions are supported in the zeolite powder in an amount of 5 to 30% by weight based on oxides. 3. The aluminosilicate that supports alkaline earth metal ions is an amorphous aluminosilicate powder that is a precursor of zeolite, and the alkaline earth metal ions are contained in the amorphous aluminosilicate powder in an amount of 5 to 30% by weight on an oxide basis. % content of the ground injection agent according to claim 1.