JP2847337B2 - Ground injection liquid - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention provides a high-strength solidified product, and it is easy to adjust the gelling time over a wide range, in particular, a relatively long gelling time. The present invention relates to a ground injection liquid which has excellent properties and is therefore particularly suitable for injection into a permeable ground such as sandy soil.

[0002]

2. Description of the Related Art Suspended grout containing slaked lime and granulated slag has long been known as an inorganic soil injection liquid. It is very difficult to adjust this type of inorganic soil injection liquid to maintain low viscosity in order to permeate into sandy soil and the like and to have a long gelation time. However, although this adjustment is possible under strict control, deterioration of the consolidation strength is inevitable. That is, it is almost impossible to expect improvement of both the permeability and the strength of the inorganic ground injection liquid.

[0003] On the other hand, organic chemicals for injection can be expected to improve both permeability and strength. However, in general, this is not only very expensive, but also requires COD during the work management.
There is a problem that inspection is required.

[0004]

SUMMARY OF THE INVENTION The present inventor uses ordinary cement in place of the above-mentioned known technique, and uses the compounding conditions,
By examining the compounding ratio etc., the viscosity of the suspension grout relatively slowly rises and penetrates over a long time,
A slag-cement suspension grout that firmly solidifies was found, and water glass was mixed with this grout as a base.
Thus, the present invention has been completed.

[0005] That is, based on the slag-cement suspension grout, and mixed with water glass, the suspension is lower in concentration than the above-mentioned slag-cement suspension grout while maintaining high viscosity while maintaining low viscosity. Was found to be obtained, and the present invention was completed.

[0006] By adding an alkaline material to this system, it is possible to more easily adjust the gelation time mainly suitable for injection .

[0007] Therefore, the object of the present invention is to have a wide gelling time, especially a long gelling time, in spite of being an inorganic injection solution, and to have excellent permeability as a suspension type grout, It is another object of the present invention to provide a ground injection liquid in which the compaction strength is improved and the disadvantages of the above-mentioned known technique are improved.

[0008]

In order to achieve the above-mentioned object, according to the present invention, there are provided fine slag and fine cement.
And a suspended grout containing water glass , wherein the average particle size of the slag and the cement is 10 μm or less, the specific surface area is 5000 cm ² / g or more, and the mixing ratio of the cement is the fine particles. Slag and
50% to 1% of the total amount of the fine particle cement,
The glass is characterized in that the molar ratio is 2.8 or less .

[0009]

DETAILED DESCRIPTION OF THE INVENTION Hereinafter, the present invention will be described in detail.

The slag and cement used in the present invention are both fine particles, and each has an average particle diameter of:
The injection liquid obtained has a viscosity of 10 μm or less and a specific surface area of 5000 cm ² / g or more, and exhibits good viscosity, permeability, and consolidation strength.

Further, in the present invention, the mixing ratio of the slag and the cement is important. That is, in the present invention, the mixing ratio of the cement in the mixture is 50% to 1%, preferably 30% to 1%. If it is 50% or more, the viscosity rises remarkably, and within the range of 50% to 1% , low viscosity is maintained and high consolidation strength is reliably exhibited.

In the present invention, the mixing of the slag and the cement may be carried out after adjusting each of them under the conditions of an average particle diameter of 10 μm or less and a specific surface area of 5000 cm ² / g.
Alternatively, the coarse-grained slag and the cement may be mixed at a predetermined ratio and then finely pulverized to adjust to the above conditions.

[0013] As described above, the present invention ground infusate are those suspension type grout containing fine slag and particulate cement mixture conditions described above is based, made by further adding mixing water glass to the above suspension type grout . Thus, the infusion liquid of the present invention is intended to maintain the viscosity relatively low by reducing the blending amount of the slag-cement mixture, and to obtain a high-strength compact by speeding up the gelation time.

In particular, the above water glass has a molar ratio of 2.8 mol.
Or less, preferably in the range of about 2.8 to 1.5
It is. In such water glass, thixotropic
Good results with few phenomena
You.

Furthermore, in the present invention, an alkali material may be added to and mixed with the slag-cement-water glass suspension grout described above. Also in this case, the gel time of the slag-cement-water glass grout can be shortened without affecting the viscosity and strength of the obtained injection solution, which is useful for adjusting the gel time as described above.

The slag used in the present invention includes various types of slag such as granulated slag and blast furnace slag, and the cement includes various types of cement such as Portland cement, alumina cement and blast furnace cement.

Further, as the water glass used in the present invention, those having a wide range of molar ratios can be used. As described above, the water glass having a molar ratio of 2.8 or less, preferably 1.5 to 2.8 is preferred. Things.

Examples of the alkaline material include phosphates, aluminates, including bicarbonates, carbonates, and condensed phosphoric acids.
Examples of the agent exhibit a wide range of alkalinity such as caustic alkali.

Further, according to the present invention, various reactants for adjusting the gelation time, such as esters, aldehydes, amides, alcohols, acids, other inorganic and organic reactants, gelation accelerators, For example, an acidic silicic acid aqueous solution can be used in combination, and furthermore, fly ash, sinter,
Pozzolans such as diatomaceous earth and terra alba may be used in combination to form a composition that takes advantage of these characteristics, and a small amount of a dispersant may be used in combination.

The injection liquid of the present invention, which is constituted as described above, may be injected in a one-part system by using the fact that the gelation time can be easily adjusted. It is also possible to inject a short-time injection material into the ground, and then inject the compound of the present invention into the ground to form a composite injection, which is applied to various other injections.

[0021]

Generally, it is known that a conventional system in which slaked lime is mixed with slag exerts the inherent hydraulic property inherent to slag. It hardens by the stimulating action of slaked lime alkali.

On the other hand, in a mixed system of slag and cement, when the cement is as large as 50% or more, the cement is naturally hardened due to the self-hardening property of the cement itself, but the cement amount is 50% or less, particularly 30% or less. When the amount is small, the amount of slag increases and the alkali content of the cement decreases, and the slag itself hardly hardens. Therefore, when both the slag and the cement are finely divided into particles having an average particle size of 10 μm or less and a specific surface area of 500 cm ² / g as in the present invention, the reaction contact surface between them becomes large, whereby the hardening action between the two particles is achieved. Seems to progress.

Further, when water glass is added to the slag-cement system of the present invention, the alkali content of the water glass stimulates the latent hydraulic property of the slag to promote the release of calcium ions from the slag, and this calcium ion forms the water glass. SiO ²
Together with the cement itself to form a compact having high compaction strength.

As the water glass, any one having a molar ratio can be used.
A molar ratio of 2.8 or less, preferably about 2.8 to 1.5, is considered to be more suitable for increasing the affinity between cement and slag to induce the above reaction.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to examples, but the present invention is not limited thereto.

1. Materials used (1) Slag SiO ² : 33.0 2%, CaO: 41.9 4%, Al ₂ O
_{3: 12.8 3%, MgO:} 8.6 1%, Fe 2 O 3: 0.3
Granulated slag having a component composition of 7% was pulverized, and four types of granulated slag having different specific surface areas and average particle sizes shown in Table 1 were used.

[0027]

[Table 1]

(2) Cement SiO ² : 22.2%, CaO: 64.6%, Al ₂ O ₃ :
Portland cement having a component composition of 5.4% and Fe ₂ O ₃ : 3.1% was pulverized, and three kinds of Portland cements having different specific surface areas and average particle diameters shown in Table 2 were used.

[0029]

[Table 2]

(3) Water Glass Five kinds of water glass having different molar ratios shown in Table 3 were used.

[0031]

[Table 3]

(4) Alkaline material General-purpose industrial sodium hydrogen carbonate (NaHCO ₃ ) was used.

2. Unconfined compressive strength Unconfined compressive strength shows the results of a specimen of a sand gel obtained by filling a standard sand and a compounding solution while mixing them in a mold.
The day strength indicates the strength of a product cured in a mold for 7 days, and the 49-day strength indicates the strength of a product cured in a mold for 7 days and then cured in water for 42 days.

3. Slag-cement system Table 4 shows the formulation, gel time, viscosity, and unconfined compressive strength of the system consisting of the slag in Table 1 and the cement in Table 2.

[0035]

[Table 4]

In Table 4, in Examples 1 to 3, both or one of the slag and the cement was coarse particles outside the scope of the present invention, and the strength was further inferior to those of other systems. Implementation NO.7 ~ 11
Is a case where both slag and cement are in the form of fine particles within the scope of the present invention and the mixing ratio of slag and cement is variously changed. Although the viscosity and strength tend to increase as the ratio of the cement amount increases, the viscosity is low but the strength is possible but low in the practical NO. 7 (0.7% cement amount) where the ratio of the cement amount is very small. Viscosity rises remarkably when the cement content is around 50%. At NO.10 (50% cement content), the viscosity rise is slightly large. In Run No. 11 (50% cement), the viscosity increased rapidly.

From the above results, it is understood that the average particle system of slag and cement, the specific surface area, and the mixing ratio of cement are all preferably within the range of the present invention.

4. Slag-Cement-Water Glass System Since the preferred ranges of the particle size and mixing ratio of slag and cement have been found as described above, within the range, a system in which water glass having a different molar ratio is further mixed is used. Table 5 shows the gel time, viscosity, and uniaxial compressive strength.
Shown in

[0039]

[Table 5]

The amount of water glass in Table 5 was all SiO ₂
It was added so as to be 8% in conversion. In each case, the gelation time was significantly shortened as compared with the slag-cement system shown in Table 4, showing low viscosity and high strength. Among them, NO.12 with a molar ratio of 2.8 or more exhibited a slightly thixotropic phenomenon,
Despite its relatively high viscosity, the gelation time was instead long and the strength was weaker than the others. 2.8 molar ratio
In the following Examples Nos. 13 to 16, the gelation time was appropriate, the viscosity was low, and the strength was enhanced. Among these, in the case of working No. 16 having a molar ratio of 1.5 or less, the gelation time was relatively long, but the viscosity was higher than that of the other systems and the strength was not strengthened even though it was relatively long. In other words, if slag and cement having a particle size and a mixing ratio within the range of the present invention are mixed with water glass having a molar ratio of 2.8 or less, preferably about 1.5 to 2.8 as water glass (implemented) NO.13 to 15) Effectively increases the gelation time by maintaining a relatively low viscosity to enhance the strength.

5. System to which alkali material was added Table 6 shows the formulation, gel time, viscosity, and uniaxial compressive strength when sodium hydrogen carbonate was further added to the slag-cement system and slag-cement-water glass system.

[0042]

[Table 6]

In Table 6, the implementation Nos. 17 and 18 are the implementations in Table 4.
This is a system in which sodium hydrogen carbonate is added to the slag-cement system of NO.5, and the viscosity of the practically NO.5 is slightly reduced, and the extremely long gelation time is shortened. Run Nos. 19 and 20 are the slag-cement-water glass system of Table No. 14 with the addition of sodium bicarbonate in Table 5. Viscosity and strength hardly change compared to Run No. 14, but gel This has the effect of delaying the gelation time and adjusting it to a gelation time suitable for injection.

6. Penetration test A penetration test of the injection solution according to the present invention was performed using the injection device of FIG. In FIG. 1, 1 is a compressor, 2,
3 is a pressure gauge. A water tank 5 provided with a stirrer 4 connected to the compressor 1 is filled with the injection liquid 6 according to the present invention.

Reference numeral 7 denotes an acrylic mode in which sand 8 is filled. The injection liquid 6 filled in the water tank 5 is turned into the sand 8 in the acrylic mode 7 by the operation of the compressor 1.
Will be introduced. Here, the infusate 6 penetrates into the sand 8, and the infiltrate 6 that has permeated is collected by the measuring cylinder 11 and the permeation state is measured. 9 and 10 are wire nets. Table 7 shows the sand 8 filled in the acrylic mode 7, and Table 8 shows the measurement results of the penetration test.

[0046]

[Table 7]

[0047]

[Table 8]

Δ: The injection liquid discharged from the mold was normally gelled, and the internal solidification state was uniformly solidified. Δ: The injection liquid discharged from the mold gelled normally, but the internal solidification was uneven at the upper part, and generally the lower part was hard but the upper part was weak. X: Discharge of the injection liquid from the mold was uneven and inadequate due to clogging, and internal solidification was uneven and weak.

In Table 8, Experiments Nos. 1 to 8 are concentrated suspensions of slag-cement, which generally cannot be said to have good permeability. However, among them, fine slag-cement (cement) within the scope of the present invention is preferred. Experiments Nos. 5 to 8) clearly show improved permeability compared to particulate slag and cement outside the scope of the present invention (Experiments Nos. 1 to 4). Experiment Nos. 9 to 16 are slag
Experiment No. 13 using water glass within the scope of the present invention having a molar ratio of 2.01 from Experiment Nos. 9 to 12 having a water glass molar ratio of 2.8 or more in a cement-water glass system. ~ 16 clearly shows an improvement in permeability.

[0050]

Advantages of the Invention In the ground injection solution consisting of slag, cement and water glass , slag and cement
Each having an average particle size of 10 μm or less and a specific surface area of 5000 cm
And ^{2 /} g or more particulate, wherein the mixing ratio of cement
50% of the total amount of particulate slag and particulate cement ~
When the concentration is 1%, preferably 30% to 1%, the viscosity tends to decrease even in a thick suspension, and the permeability can be improved in combination with the long gelation time, and the solid suspension can be surely obtained. To obtain a high-strength consolidated body for a long period of time.

2. Furthermore, in the system of the present invention, the gel time while maintaining a relatively low viscosity by mixing water glass earlier, it is possible to enhance the strength. In particular, water glass having a molar ratio of 2.8 or less, more preferably 1.5 to 2.8, is more effective.

3. The addition of an alkali material to the above system helps to adjust the gel time suitable for injection.

[Brief description of the drawings]

 FIG. 1 is an explanatory view of an apparatus for injecting an injection solution into sand.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 4 Stirrer 5 Water tank 6 Injection liquid 7 Acrylic mold 8 Sand

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ identification symbol FI // (C04B 28/26 7:19) 111: 70 C09K 103: 00 (58) Fields surveyed (Int.Cl. ⁶ , DB Name) C09K 17/02 C04B 28/26 C09K 17/10 C09K 17/12 E02D 3/12 101

Claims (1)

(57) [Claims] 1. Fine particle slag, fine particle cement and water
Consists suspension type grout containing glass, the average particle size of the slag and cement are less 10μm respectively, a specific surface area of each 5000 cm 2 / ^g or more, the mixing ratio of the cement is said particulate slag and particulate cement
50 % to 1% of the total amount of water glass,
A ground injection liquid having a ratio of 2.8 or less .