JPS59184283A - Curable composition - Google Patents

Abstract

PURPOSE:To provide a curable composition containing cement or lime and colloidal silicic acid, with the concentration of SiO2 derived from the colloidal silicic acid adjuted within a specified range, which retains fluidity for a long time in pouring operation and flows only in a predetermined region. CONSTITUTION:The composition contains cement or lime and colloidal silicic acid, with the concentration of SiO2 derived from the colloidal silicic acid being adjusted to 0.01-0.3mol/l. When the concentration of SiO2 excees 0.3mol/l, the liquid mixture instantly forms non-flowing gel while when it is lower than 0.01mol/l, no distinct gelation takes place. The colloidal silicic acid (silica gel) is obtained by removing or minimizing Na ion from water glass, e.g., by passing the glass through an ion exchange resin or neutralizing it with sulfuric acid, followed by removal of Na and sulfuric acid ions.

Description

[Detailed description of the invention] [Technical field to which the invention pertains] The present invention relates to a curable composition used as a ground injection material, and particularly to a curable composition suitable for self-hardening muddy water used in downfill press-fitting, muddy water construction methods, spraying, etc. The present invention relates to sexual compositions.

[Prior art and its problems]

Cement suspensions, cement-bentonite suspensions, hydraulic lath-cement mixtures, and the like have conventionally been used as this type of curable composition for ground injection. However, when a cement suspension or a cement-bentonite liquid is used for filling and injecting, the solidification time is long, so it is easy to deviate, and it is difficult to fill and solidify only the necessary areas.

For example, in the case of backfill injection, it is necessary to fill the voids 100%, but when cement-bentonite suspension or cement suspension is used, the solidification time is long, so
In order to fill 00% voids, it is necessary to send a large amount of injection liquid, which causes problems such as the injection liquid deviating to areas other than the required area and being injected into the water supply, causing alkaline pollution. After injection, the suspension settles and the solids shrink, leaving voids, which causes problems such as subsidence of the ground surface during tunnel construction.Also, the solids shrink and become alkaline. Strong syneresis water is generated, which causes the problem of contaminating the surrounding groundwater with alkalinity.

[Purpose of the invention]

An object of the present invention is to provide a curable composition that has fluidity over a long period of time during injection work, flows only in a predetermined area, causes pleasing after assimilation, and is less likely to contaminate groundwater with alkalinity. be.

[Key points of the invention]

In order to achieve the above object, the present invention includes cement or lime and a silicate colloid, and adjusts the concentration of SiO2 caused by the silicate colloid to a range of 0.01 to 0.3 mol/l. It is characterized by:

[Detailed description of the invention]

Generally, when a cement or lime suspension is mixed with an aqueous water glass solution, if the water glass concentration in the mixture is high, it will gel immediately, but the alkali caused by the water glass will elute from the solidified material over a long period of time. . If the amount of water glass is gradually reduced, the gelation time will become longer, but if left as is, the suspension will precipitate and separate into two layers by the time it reaches gelation, resulting in caking. If the water glass concentration decreases, the whole will not be able to maintain a constant strength.
Cement that did not gel completely and settled
Otherwise, only the lime solidifies.

In contrast, the present invention mixes the suspension and the silicic acid colloid, and sets the concentration of 5IO2 caused by the silicic acid colloid in the mixed liquid to 0.01 to 0.3 mol/l. This is an improved version of .

If the SiO2 concentration is as high as 0.3 mol/l, the mixture immediately forms a non-flowable gel and is unsuitable; No obvious gelation occurs.

The silicic acid colloid (silica sol) used in the present invention is obtained by removing or reducing Na ions from water glass, for example, by passing the water glass through an ion exchange resin to remove Na ions from the water glass, or It is obtained by neutralizing water glass with sulfuric acid and then removing Na ions and sulfate ions.

- For example, water glass is passed through an ion exchange resin such as a zeolite-based cation exchanger or an ammonium-based ion exchanger, and the generated silica sol is further added to the water glass at a temperature of 80°C to 90°C, and the ion exchanger is again added to the water glass. It is obtained by passing it through an exchange resin to perform ion exchange, and a comparatively thin (dilute) silica sol is obtained. Even more pure “
In order to obtain Suina 7 Likasol, the above-mentioned dilute silica sol is adjusted to slightly alkaline, and the above-mentioned silica sol is further added to it while evaporating to stabilize and concentrate at the same time, or the activated silica sol after ion exchange is A method in which the silicic acid colloidal solution in the present invention is stabilized by heating under a suitable alkali and further adding activated silica sol is also used.
Most of the a ions have been separated and removed, and the molar ratio is 10.
Preferably, the pH is usually adjusted to a weak alkalinity of 8 to 1O, and the content of 8i02 is 10 to 60.
% (weight) and molar ratio (8ioz/NazO) are adjusted to be higher than that of the blade. If the molar ratio is lower than 10, the silicic acid colloid will dissolve and become an aqueous solution of oxalate. Of course, use an acidic to neutral silicic acid colloid stabilized with acid, aluminum, ammonium, etc. Also, the particle size of silicic acid colloid is approximately 6 to 5.
The main particle size is 0 mμ, and when the particle size is 5Qmμ or more, precipitation tends to occur.

Usually, silicic acid colloid has a molar ratio (S io2/Na2O)
GAHA'; 100Q to 10, and a pH value of 8 to 10 is desirable for stability of the colloid.

In addition, if we show the relationship between the pleating phenomenon of the mixed liquid of cement or lime and silicate colloid and the amount of silicate colloid in the present invention, pleating occurs when the SiO2 concentration is 0.01.
It is large when the mol/l value is small, and decreases significantly as the SiO2 concentration increases.

The above-mentioned liquid mixture in the present invention becomes gel-like immediately after being blended, but within the above-mentioned concentration range, it becomes fluid when external force is applied. For this reason, it has fluidity while being press-fitted by a pump in backfill injection, and as soon as a predetermined amount has flowed in and the pump is stopped, it becomes gel-like and does not flow out of that area, and moreover, almost no pleating occurs.

For this reason, the injected material reduces the voids by approximately 100 in a given area.
It has the excellent properties of not causing any risk of deviation even when it is filled to nearly 20%, and does not cause precipitate until it solidifies.

In addition, the 7''!I composition is a mixture of a liquid mixture whose pH value is adjusted to neutral or acidic by mixing water glass and an acid such as sulfuric acid, and a suspension containing cement and lime as active ingredients. It is known that the reaction between water glass and the above-mentioned acids is sensitive, so a slight difference in the amount of mixture will cause the pH to fluctuate widely, making it difficult to adjust to neutrality and easily becoming acidic. When water glass and cement are mixed, the hydraulic properties of the cement are inhibited, making it difficult to obtain high strength.In particular, ions of mineral acids such as 504- are unfavorable for cement hardening.

In contrast, the pH of the silicic acid colloid used in the present invention is adjusted to be neutral, weakly alkaline, or weakly acidic, so it can achieve high consolidation strength without impairing the hydraulic properties of cement or its reactivity with lime. Obtainable.

In addition, silicic acid colloid is excellent in terms of water quality maintenance in the ground where it is poured.01' Figure 1 shows the relationship between silicic acid colloid OPH value and gelling time, and the PH value and gelling time of a mixed solution of silicate water glass and acid. In FIG. 1, which is a graph showing the relationship between the 0. In addition, a, d are curves related to a mixed solution of water glass and sulfuric acid, and the concentrations of 5i02 are 0.1 mol/l and 0.15 mol/l, respectively.
It is l.

Hereinafter, the present invention will be explained in more detail by showing various experimental data.

The silicic acid colloids used in the experiment are shown in Table-1.

Table-1 Consolidation rate, strength test, and fluidity when using silicic acid colloid, when using a silicic acid aqueous solution prepared by adding water glass to panic acid or sulfate aqueous solution, and when using water glass alone The test results are shown in Tables 2 to 6. The solidification rate shown in each table refers to the solidification rate when the mixture is left stationary after mixing.
The solidification rate of the solidified portion of the suspension after solidification is shown.

For example, a solidification rate of 100% means that the suspended matter has solidified without settling at all, and a solidification rate of 70% means that the suspended matter has settled and the area 30% above the surface has not yet settled. It indicates a state of solidification or a state of solidification without containing any suspended matter, and therefore means that voids are formed or weak gel portions remain after press-fitting.

Table 2 Table 3 Fluidity of the mixed liquid; a- When liquids A and B are mixed, they immediately become gel-like, but they flow easily by stirring. b- Once they become gel, they do not become fluid even if they are stirred.

Even if c-A and Bi are mixed, it does not clearly become gel-like.

Table 4 Fluidity of mixed liquid: a-When liquids A and B are mixed, they immediately become gel-like, but they flow easily by stirring.

b-Table 0 that does not become fluid even if stirred once it becomes a gel-
5 Therefore, it flows easily.

b - Once it becomes a gel, it does not become fluid even if it is stirred.

c- Even when liquids A and B were mixed, it was clearly gel-like (unsafe).

From Tables 2 to 6, the following can be clearly seen.

1) When the concentration of SiO2 caused by silicic acid colloid in the mixed solution is 0.01 to 0.3 mol/l, the solidification rate is 90% or more in all cases, and the fluidity can be improved by stirring while forming a gel-like state. sell.

2) When the concentration of 5i02 is less than 0.01 mol/min, no obvious gel-like body is formed.

3) When the concentration of SI02 is 0.3 mol/or more, it immediately gels and no fluidity can be obtained even with stirring.

4) If water glass is used as a substitute for silicic acid colloid, fluidity cannot be obtained even if stirred after mole formation. 5) Mix water glass with acid or acidic salt to create a neutral or acidic silicic acid aqueous solution. When used, the strength of the consolidated product is low and the consolidation rate is also low.

From the above, the effects of the present invention can be verified.

In addition, in the present invention, in addition to lime, it is effective to use one or more of slag, fly ash, and gypsum in combination to increase strength. Of course, a mixture of sand, stone powder, bentonite, etc., or a foaming agent may also be added.

Furthermore, when the composition of the present invention is used for back-filling, it is possible to mix cement or lime suspension and silicate colloid and then inject it, or to inject the silicate colloid from the middle while pumping the suspension. may be combined with the above suspension and injected. Furthermore, when using it for spraying, you can mix all the ingredients in a mortar mixer in advance and then spray it with a mortar can, or you can knead the suspension in a mortar mixer and send it. The silicic acid colloid solution may be combined with the silicic acid colloid solution, and the resulting mixed solution may be sprayed through a mortar gun, or the cement and aggregate may be fed to one side in a dry state.
The silicic acid colloid liquid may be sent to the other side, and when sprayed from a mortar gun, the two may be combined and sprayed.

The curable composition of the present invention can be used in the following applications in addition to the above-mentioned backfill press-fitting.

■ Filling the void on the back of the sheet pile.

■ A method of creating a water-stop wall by driving sheet piles equipped with press-fit pipes into the ground continuously and then pulling up the sheet piles while injecting the composition.

■ A method of making a pile by drilling a hole with an earth drill and then pulling it up while injecting this composition.

(2) A method of discharging the present composition using a hole drilling machine with stirring blades, mixing it with soil, stirring it, and creating a consolidated pile or a consolidated wall in the ground.

(2) A method in which the present composition is used as drilling mud to excavate the ground to dig a trench in the ground, and then the mud made from the present composition is solidified to 1 to form a water-stop wall.

■ Excavate the ground using bentonite mud, dig a trench underground, and then press this composition from the bottom to replace the bentonite mud, or mix this composition with bentonite mud and solidify to stop water. How to form walls.

■ In ■ and ■, a method in which concrete panels, concrete pipes, and other underground structures are left buried in the composition and allowed to solidify.

■ A method of mixing sludge and waste with this composition and solidifying it.

■　Method of injecting into the ground with large voids.

[Phase] Method of filling old guide piles with this composition.

0 A method of forming a solidified substance of a specific shape in the sea using the present composition to form an adhesion bed for fish cakes and seaweed.

@ A method of spraying on slopes to protect slopes, or spraying on tunnel excavations to create a consolidated layer. In normal mortar spraying or concrete spraying, when the slope of the sprayed surface is steep, there is a lot of aggregate splashing and a large amount of sprayed material is wasted, but the cured product of the present invention When sprayed, it immediately becomes gel-like and adheres to the excavated surface or slope, so there is no waste of spraying and a consolidated layer with extremely good watertightness can be formed. The composition according to the invention has the property that it gels while the suspension is dispersed in the entire solution without precipitating the gelled product, and maintains fluidity by applying force such as stirring while gelling, and furthermore, It is a composition that is extremely useful in practice, as it has high strength and excellent adhesion.

[Brief explanation of drawings]

FIG. 1 is a graph showing the relationship between the gelation time and the pH of a solution containing silicic acid colloid and water glass as an acid.

Claims (1)

[Claims] Contains cement or lime and silicate colloid, and the concentration of 8102 due to the silicate colloid is 0.01 to 0.
．． A curable composition adjusted to a range of 3 mol/l.