JP2001098270A - Ground solidification material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a suspension-type ground solidification material which is based on water glass and slag, has a long allowable time for permeation and hence is excellent in permeation properties, has high solidification strengths, hardly exhibits alkali leaching, and hardly influences on the environment. SOLUTION: This ground solidification material contains water glass and slag in a molar ratio of 2.5 or lower as essential ingredients provided that the amount of water glass compounded into 1,000 ml of the resultant liquid composition is 3.5-46 g in terms of SiO2 and that the slag is a finely particulate slag having a specific surface area of 5,000 cm2/g or higher.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ground consolidation material comprising slag as a main component and water glass added to and mixed with the slag. Agglomerates of the suspension are less likely to occur during injection, the permeation time is long, the permeability is excellent, and the solidified product obtained by curing the liquid mixture has high strength, and the solidifying strength lasts for a long time And a suspension-type ground consolidation material to be used.

[0002]

2. Description of the Related Art A ground consolidation material obtained by adding water glass to slag is known. However, such a mixed solution has relatively poor permeability, and a sufficient penetration distance cannot be obtained even with fine sand. Conventionally, a suspension-type injection material generally has better permeability as the particle size of the powder used becomes smaller.
However, when water glass having a low molar ratio is used as an alkali stimulant for slag, since the water glass has an aggregating action, even if slag that has been finely refined is used, the slag suspension and the water may be used. After mixing the glass diluent, the ultra-fine particles of slag aggregate with the passage of time to form aggregates of 10 microns or more, and in some cases 20 microns or more. The reality is that the other half of the time hardly penetrates.
As a result of such coagulation, the specific surface area of the slag is reduced to 15,
Even if it is as large as about 2,000 cm ² / g (average particle size of several microns or less), when it is mixed with water glass diluent, aggregates having a large particle size of 20 μm or more are formed. On the contrary, the permeability of the blended liquid was worse than when slag of about 2,000 cm ² / g was used.

[0003]

SUMMARY OF THE INVENTION The present inventors have made intensive studies to improve the above-mentioned drawbacks. As a result, when a specific amount of water glass is used in a specific amount, when slag and water glass are mixed, We discovered that slag aggregates were not formed, and that the permeation time of the blended liquid could be extended, so that the permeability was good, and that the entire blended liquid was solidified homogeneously and a high-strength consolidated product was obtained. Thus, the present invention has been completed. An object of the present invention is to provide a water which has a long permeation time, is excellent in permeability, exhibits high compaction strength, has little alkali leaching, has little effect on the environment, and has improved the above-mentioned disadvantages of the known art. An object of the present invention is to provide a glass-slag-based suspension-type ground consolidation material.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention uses fine particles of slag and a specific ratio of water glass having a molar ratio of 2.5 or less. That is, the amount of the water glass used in the present invention is such that the viscosity gradually increases with the lapse of time after the preparation of the blended liquid, and during the injection time as long as the blended liquid is continuously stirred on the ground. Is the amount that maintains fluidity. As described above, by reducing the amount of water glass used compared to the amount used in the conventional ground consolidation material, the suspended solids in the mixed solution can be kept evenly suspended, and can be prevented from settling out. The amount of coarse agglomerates generated in the mixture can be reduced, and the permeability of the liquid mixture can be improved.

[0005]

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 (SiO ₂
/ Me ₂ O; where Me is an alkali metal of Na and K) is 2.5 or less, preferably 2.5 or less and 1.0 or more.

The slag is obtained by rapidly cooling a blast furnace slag with water from a molten state and pulverizing the slag.
00cm ² / g or more, preferably a specific surface area of 8,000cm ² /
g or more, or an average particle size of 5 microns or less. The amount of slag used is such that as the specific surface area is larger, the strength is exhibited even in a small amount,
g or more, more preferably 100 g or more. In other words, generally, the slag used should have a higher reactivity as the particle size becomes smaller, and the permeability should be good, but when water glass is used in combination, coarse aggregates are formed as described above. It will be lost. However, the present invention was able to suppress the generation of coarse aggregates with the lapse of time by reducing the amount of water glass having a molar ratio of 2.5 or less. By using a water glass with a molar ratio and ultrafine particles with a small particle diameter, viscosity increases, sedimentation in the injection ground due to suspension of suspended matter is prevented, and a reaction effect due to a large alkali contact area,
Even a small amount of alkali gives strength. Furthermore, when ultrafine slag is used, the gelation time is shortened. However, in the present invention, the permeation time is sufficiently long because the amount of the water glass used as the alkali stimulant is small.

The amount of water glass used increases the viscosity of the liquid mixture.
Amount, preferably SiO 2 per 1,000 ml of the blended liquid.
_TwoIs not less than 3.5 g in weight and
An amount that does not result in a clear gelation state, preferably
SiO per 1,000 ml of liquid _Two46g or less as the weight of
It is. This is SiO_TwoDisplay with 35% water glass
Then, 10 to 130 ml of water glass per 1000 ml of compounded liquid
Is the amount The blended liquid of the present invention uses the amount of water glass.
The thickening time can be adjusted by
Can delay the thickening time by adding
You.

For increasing the thickening time, slaked lime may be added, but the thickening time can be easily increased by increasing the amount of water glass used.

The compounded liquid of the present invention is measured with a B-type viscometer,
Approximately 400 cps (centipoise) or more, about 1,000
Although it is less than cps, it does not flow out of the cup even when measured by the cup inversion method.
The elapsed time until the value becomes “thickening time”. There are some problems in measuring the suspension with a B-type viscometer, but the conventional gel-forming type ground consolidating material has a viscosity of the compounded liquid measured with a B-type viscometer. When the viscosity starts to increase, the viscosity rapidly increases to 2,000 cps or more and gels, so the value measured with a B-type viscometer was used as one standard.

[0010] In the above description, gelation means that a liquid compound liquid has a shape-retaining property due to a reaction, and is measured by the cup inversion method as described above. It is a state where it has stopped flowing. Here, “the gelling state does not become clear” means that when the gelling time is measured by the cup inversion method, even if the gel becomes thicker and becomes uneven (partially gelled) visually, the fluidity is completely lost. It is a state that does not disappear, at least when this state continues for 10 seconds or more.

The viscosity of the liquid mixture of the present invention gradually increases, but at a certain point, the viscosity rapidly increases, resulting in a non-uniform gel or almost a whole gel. When this is measured by the inverted cup method, the ordinary water glass-based injection material does not flow out of the cup when the gelation time comes, whereas the weak gel of the present invention flows out in a ragged manner. However, when injected into the ground, it fills the gaps in the sand and behaves similarly to gelled ones. That is, when such a mixed liquid according to the present invention is injected into the ground, if the ground is dense, the mixed liquid does not penetrate and acts like a conventional gel at the thickening stage, and the ground is rough. In some cases, injection (penetration) is continued even in a slightly weak gel state (a gel state that does not result in a clear gel state). In addition, even if the composition is not gelled by the cup inversion method, it is gradually solidified (or solidified) after pouring it into the soil, where no external force is applied between the soil particles.
You do it.

Further, in the compounded liquid of the present invention, the sedimentation rate (the suspended particles in the liquid are sedimented, which means the ratio) is reduced due to the increase in the viscosity, and therefore, the suspension is precipitated during the injection. It continues to penetrate into the ground without doing so and eventually becomes a relatively uniform compact.

For the preparation and mixing of the blended liquid, a slag suspension is prepared by adding slag while stirring water, while a water glass diluent is prepared by diluting water glass with water. A method of mixing both solutions may be used. At that time, the slag is not sufficiently dispersed even when suspended in water and is agglomerated,
By mixing with a low concentration of water glass diluent, the loosely agglomerated slag is peptized and the average particle size of the suspension becomes smaller. In addition, when the water glass is used in a large amount, when the water glass diluent is mixed with the slag suspension, aggregates having a size of 20 μm or more can be formed immediately or over time, and in some cases, 20% or more can be obtained. On the other hand, in the method of the present invention, aggregates larger than 20 microns are hardly formed.

The viscosity of the entire mixture increases with time. However, in the present invention, since the amount of water glass used is smaller than that of the conventional ground consolidation material, the viscosity is low when the mixture is prepared. Moreover, since the state lasts for a long time, the permeation time can be increased. In addition, the alkali of the water glass stimulates the slag to develop the strength of the consolidated product, and the obtained consolidated product has a high strength, and the strength lasts for a long time.

Another alkali material can be used in combination with the above-mentioned system consisting of water glass and slag in order to adjust the permeation time. Examples of such an alkali material include caustic alkali, alkali carbonate, alkali aluminate and the like. The water glass used in the present invention may be a low-molar-ratio water glass having a molar ratio of 2.5 or less by adding a caustic alkali to water glass having a large molar ratio.

Further, in a place where sufficient strength is not exhibited due to leaching of the alkali, fine particles cement or slaked lime is used in combination with the slag, so that the mixture of the slag and the fine particles cement has a self-hardening property, or a small amount of alkali is used. Is also formulated so as to develop strength. As the fine particle cement used here, Portland cement, alumina cement, and blast furnace slag cement are preferable, and a cement having a specific surface area of 5,000 cm ² / g or more is preferable. In this case, the use amount of the fine particle cement is preferably 5 to 30 parts by weight based on 100 parts by weight of the slag. It is not preferable to use more than 30 parts by weight of the fine particle cement because the liquid mixture thickens at a high temperature and the strength of the consolidated product is slightly lowered.
In addition, slaked lime slightly lowers permeability, so that fine particle cement is more preferable. In addition, by reducing the amount of the fine particle cement, the viscosity of the liquid B (slag suspension when used as a two-part type) can be kept low for a long period of time. Even at a very high temperature, the pot life of the solution B is long.

Here, although the used water glass is a small amount, it becomes a gel on the surface of the slag or between the slag particles, and the mixed solution is solidified as a whole, and the water permeability coefficient of the solidified material is reduced. . Further, water glass is necessary as an alkali agent for hardening the slag, but when the amount is too large, the initial strength of the consolidated product is reduced.
On the other hand, in the consolidated material of the present invention, the initial strength can be increased by reducing the amount of water glass or by using fine particle cement in combination.

[0018]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited thereto. 1. Materials used (1) Slag A slag having a specific surface area shown in Table 1 was used.

[0019]

[Table 1]

(2) Water glass Water glass having the composition shown in Table 2 was used.

[0021]

[Table 2]

(3) Cement Ultra-fine particle cement with specific surface area of 9,700 cm ² / g <Permeation test> A 5φ × 100 cm acrylic pipe is filled with Toyoura standard sand to a relative density of about 60% and saturated with water. After that, the compounding solutions of the following representative examples and comparative examples were injected at an injection pressure of 1 kgf / cm ² , and the permeation distance was measured. The filling of Toyoura standard sand was performed by dividing a predetermined amount into several times, and each time the side of the pipe was hit with a hammer. Further, the preparation of the compounding liquid was carried out by putting both liquids A and B in a mixer and stirring for 10 seconds. The permeation distance was defined as a permeation distance by measuring a range where the color was clearly changed from outside the pipe by visual observation.

Examples 1 to 9 and Comparative Examples 1 to 6 The water glass shown in Table 2 was diluted with water to obtain a liquid A. In Table 1, slag and cement were suspended in water to obtain a liquid B. Materials were prepared. With respect to the obtained ground consolidated material, the uniaxial compressive strength was measured according to the thickening time (or gel time) and the uniaxial compressive test method of the soil engineering standard. Thickening time is B
The time at which the viscosity reached 400 cps was measured with a mold viscometer, and was taken as the thickening time. The gel time was measured by a cup inverted method. Table 3 shows the results.

[0024]

[Table 3]

* 1 After 3 hours, the viscosity hardly increased.・ Note 2 It did not reach 400 cps even after 3 hours. * The comparative example marked with * is the gelation time. -Thickening time was measured at a liquid temperature of 20 ° C.

Examples 10 to 13 and Comparative Examples 7 to 8 The particle size distribution of some of the above Examples and Comparative Examples was measured by using a particle size distribution measuring apparatus by a light transmission method.
The particle size distribution was measured 10 minutes after preparing the liquid. Further, a blended liquid was prepared, and the viscosity was measured at an interval of 10 minutes using a B-type viscometer. At first, the measurement was performed 2 minutes after the liquid preparation. Table 4 shows some of the results. The slag NO. 3 and NO. As a result of suspending No. 4 in water and measuring the results, no aggregate of 10 μm or more was contained.

[0027]

[Table 4]

Examples 14 to 17 and Comparative Example 9 Some of the above Examples and Comparative Examples were subjected to a penetration test. Table 5 shows the results.

[0029]

[Table 5]

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Shunsuke Shimada 2- 15-10 Hongo, Bunkyo-ku, Tokyo F-Term (in reference) 4H026 CA03 CB03 CB07

Claims (3)

[Claims] 1. A suspended ground consolidation material comprising water glass having a molar ratio of 2.5 or less and slag as essential components and satisfying the following requirements. (1) The amount of water glass mixed per 1,000 ml of the mixed liquid is 3.5 to 46 g as SiO ₂ (2) The slag is a fine particle slag having a specific surface area of 5,000 cm ² / g or more 2. The ground consolidation material according to claim 1, further comprising the following requirements. (3) The blended liquid thickens with time but does not gel. (4) The amount of slag used must be 50 g or more per 1,000 ml of the total blended liquid. 3. The soil consolidation material according to claim 1, wherein cement is further added.