JP5165201B2 - Injection material, manufacturing method thereof, and injection method using the same - Google Patents

Description

  The present invention relates to an injecting material, a method for producing the same, and an injecting method using the injecting material, and more specifically, an injecting material to be used for improving the water shielding, solidity, and deformability of the foundation ground in the civil engineering and construction fields. , Its manufacturing method, and an injection method using the same.

  Conventionally, in underground structures such as dams and power plants, large structure foundations, tunnels, underground storage bases, and radioactive waste treatment facilities, and deep underground development in urban areas, In addition, in order to improve the deformability and stabilize the ground, injection work has been performed.

In such a socially important structure, in order to maintain the stability of the ground for a long period of time, the injection material used is a highly stable inorganic powder or a solidified inorganic powder dispersed in water. Many suspension-type injection materials are used (see Non-Patent Document 1).
However, when this suspension-type injection material is used, there are many construction problems such as the infiltration performance being hindered, and maintenance of the stability of the ground due to poor permeability is often insufficient. It was.

The cause is the influence of the geology that constitutes the ground. Typical examples of the ground are unconsolidated and low-consolidated sandy ground, or rocky ground where cracks occurring in the rock are developed with an opening width of micron order.
In these grounds, high penetration performance is required to fill the injection material in detail, so that the particles of the material that are not dissolved in water and dispersed like the suspension type injection material, The construction result depends on the size of the particle diameter and the viscosity of the injection solution.

  Regarding the particle size, it is generally said that the maximum particle size of the injected material penetrates at 1/3 of the crack width in the case of rocky material and 1/10 or less of the particle size of the sand that forms the formation in the case of sandy material. Yes.

  In addition, regarding the viscosity of the injection material, the higher the viscosity, the worse the resistance because the resistance becomes stronger, but on the other hand, in terms of obtaining improvement effects such as shortening the construction time and water permeability, It is preferable to increase the strength as much as possible. In this field, a material having a small particle diameter and a low viscosity even in a high concentration slurry is desired.

At present, as an injecting material that is often used as a suspension type injecting material, a finely divided cement having a small particle size of cement and a fine powder having pozzolanic activity, such as fly ash or blast furnace slag, are mixed. Have been developed and used (see Patent Document 1 and Patent Document 2).
However, although ultrafine cement has improved performance compared to conventional suspension-type injection materials, there is a limit to the production of ultrafine cement itself, particles with a maximum particle size of about 10 μm and an average particle size of several microns. In actual construction, if there are voids that cannot be penetrated even by ultrafine cement, the improvement of densification by filling may be insufficient. Therefore, there is a demand for the development of higher performance ground injection materials and ground injection methods for such construction.

Under such circumstances, an injecting material that improves performance by using fine particles having a small particle diameter in combination with ultrafine particle cement is currently being studied.
For example, a method of using kaolin with an average particle size of about 1 μm and ultrafine cement (Patent Document 3) and a method of mixing silica fume and fine particle cement and using it as an injection material (Patent Document 4) have been proposed.
However, when kaolin is used in combination, the particle size of kaolin is 5 μm at maximum and the average particle size is about 1 μm, which is not sufficient to obtain high permeability, and the viscosity of the slurry is high at high concentrations. It is used at a low concentration, and the durability due to reaction with cement is unclear. On the other hand, when silica fume is used in combination, the primary particle is about 0.5 μm and the particle diameter is small because of the use of fine particle silica mainly composed of silica fume, but it is usually a few μm simply by mixing with water or cement liquid. There is a problem that secondary particles that are aggregated to a certain extent are not dispersed and large particles remain.

In addition, when silica fine powder is used in combination with cement, the higher the concentration, the higher the viscosity and the lower the dispersibility.
Thus, when the fine particle powder is used, there is a problem that occurs because it is a fine particle, and there is a demand for how to solve the problem and obtain the maximum injection effect.

Proceedings of the 58th Annual Conference of the Japan Society of Civil Engineers, September 2003, pp. 341-342 JP 2003-336066 A Japanese Patent No. 3423913 Japanese Patent No. 3473810 Japanese Patent No. 3219276

  The problem to be solved by the present invention is that, in the ground constituted by fine voids, it is possible to penetrate into fine voids more than conventional suspension type injection material, and furthermore, injection of stability equal to or higher than that. It is to provide an injection material from which a material can be obtained, and which can be stably maintained over a long period of time, and also to provide an injection method for obtaining sufficient performance.

The present invention, SiO ₂ component comprises only fine particulate silica and water maximum particle size of particles below 1.0μm is 90% or more of primary particles of 85% or more, pH of 3 or more, less than 9, the concentration is 5 60% of an injection material that is a silica slurry having a viscosity of 20 to 50 mPa · S , and the concentration of the injection material is 30 to 60%, and consists of an ultrasonic device, a high-speed stirrer, and a wet pulverizer It is a method for producing an injection material using one or two or more types selected from the above, an injection method using the injection material, and an injection method using the injection material and a cement-based injection material in combination. .

  By using the injection material and the injection method of the present invention, it was impossible to improve the permeability with the conventional suspension type injection material, for example, it can penetrate into fine voids in the ground of several μm or less, After permeation, it reacts with the lime component eluted from the cement and solidifies, thereby improving the water barrier property and maintaining the effect for a long period of time, thereby obtaining an effect excellent in long-term durability.

  Unless otherwise specified, parts and% in the present invention are shown on a mass basis.

The fine particle silica used in the present invention is a method for collecting fumes (silica fume) generated from an electric furnace in the process of producing metallic silicon, ferrosilicon, or zirconia, for example, a slurry in which metallic silicon powder is dispersed in a high temperature field. Injected, burned, oxidized, and, for example, a method of sending a gasified silicon compound into a flame, such as a halide such as silicon tetrachloride, produced by a so-called dry method, Alternatively, for example, silica powder produced by any of wet methods of producing by precipitation from a silicate aqueous solution by a sol-gel method can be used, and there is no particular limitation. Of these, fine-particle silica produced by a dry method is particularly preferred because it has less agglomeration (structure).
The SiO ₂ component of the fine particle silica is preferably 85% or more, more preferably 90% or more.
Further, the particle diameter of the fine particle silica used is preferably 1.0 μm or less, more preferably 0.7 μm or less, as the maximum particle diameter of primary particles. If the maximum particle size of the primary particles exceeds 1.0 μm, if the viscosity of the slurry is lowered, the primary particles may settle without being dispersed.

  In the present invention, fine particle silica is dispersed in water to prepare a silica slurry.

The concentration of the silica slurry in the present invention is preferably 5 to 60%. Usually, when the silica slurry is actually used, the reactivity with the cement is lowered when the concentration is dilute, and from the economical viewpoint, the concentration is more preferably 30 to 60%. If the concentration of the silica slurry is less than 5%, it may cause sedimentation and impair the stability of the silica slurry. If it exceeds 60%, the density of the powder in the silica slurry will increase and it will be difficult to disperse uniformly. In some cases, the viscosity becomes high.
In the present invention, it is possible to dilute a silica slurry having a normal concentration of about 30 to 60% with water in the mixer according to the ground conditions, and the water / silica slurry ratio at that time is about 1 to 6. is there.

  The viscosity of the silica slurry is preferably 100 mPa · S or less, and more preferably 20 to 50 mPa · S. If it exceeds 100mPa · S, pressure will be applied when pumping, and workability may be deteriorated or permeability to the ground may be reduced.

In the present invention, it is preferable that the fine particle silica of 1.0 μm or less in the silica slurry is 90% or more. If it is less than 90%, that is, if the proportion of large particles exceeding 1.0 μm exceeds 10%, the permeability may be hindered, so that sufficient permeability may not be obtained.
If the particle diameter of the fine particle silica exceeds 1.0 μm, it may settle in the silica slurry and the dispersion stability may be lowered.

  In the present invention, fine particle silica is dispersed with water to prepare a silica slurry, but it is also possible to replace up to several percent of water with an organic compound having a hydroxyl group such as alcohols.

The fine particle slurry of the present invention can be dispersed only with water, but when the concentration is high, the pH is preferably 3 or more and less than 9 in order to maintain the stability of the slurry. If the pH is less than 3, there is a risk of corroding the equipment that is strongly acidic, and if the pH is 9 or more, the particles may aggregate and the viscosity of the slurry may increase or gel.
In order to make the pH 3 or more and less than 9, it is preferable to use an additive.

Examples of additives include inorganic acids such as sulfuric acid, hydrochloric acid, nitric acid, and phosphoric acid, and organic acids such as citric acid, malic acid, tartaric acid, and gluconic acid, and salts thereof, among which organic acids or their Salts are preferred.
The amount of the additive used is preferably 5 parts or less, more preferably 2 parts or less, based on 100 parts of fine-particle silica. If it exceeds 5 parts, dispersibility may be hindered, which is not preferable economically.

  The dispersion treatment method of the fine particle silica used in the present invention may be a method using any of an ultrasonic device, a high-speed stirrer, and a wet pulverizer. It is not limited. Among these, a method using a wet pulverizer is preferable from the viewpoint of high dispersibility in order that the pulverized ball directly contacts the particles and breaks up the aggregation.

  Although it does not specifically limit as an ultrasonic device, Generally the high output ultrasonic machine called a homogenizer has a favorable grinding | pulverization efficiency, and is preferable.

  As the high-speed stirrer, a structure in which not only the stirrer simply rotates at high speed but also a so-called turbulent state and a shearing force acts on the particles is preferable. For example, the product name “Sharp Flow Mill” manufactured by Taiheiyo Kiko Co., Ltd., the product names “Homomixer”, “Homomic Line Mill”, and “Homo Disper” manufactured by Tokushu Kika Kogyo Co., Ltd. are similar.

  In addition, as a device having a high processing capacity in a wet pulverizer, a medium stirring mill, a pulverizer using high-pressure water, or the like is preferable, and a medium stirring mill is more preferable from the viewpoint of pulverization capability. Furthermore, among the medium agitation mills, a flow tube type mill having excellent grinding performance is preferable.

  A pulverizer using high-pressure water means, for example, that a high pressure of 50 to 300 MPa is applied to a slurry in which silica fume and water are mixed, this slurry is branched into two flow paths, and collided against each other at the part where it merges again. It is to be crushed. Examples of such a pulverizer include a trade name “Ultimizer” manufactured by Sugino Machine, a product name “Nanomizer” manufactured by Nanomizer, and a product name “MicroFluitizer” manufactured by Microfluidic.

  As an injection method using the injection material of the present invention, a normal injection method can be used and is not particularly limited.

  Since the injection material of the present invention is cured by pozzolanic reaction with components eluted from cement, it is preferable to use it together with a cement-based injection material when it is necessary to consolidate the injection material for the purpose of construction.

  As cement-based injecting materials to be used in combination, cement such as ordinary cement, early-strength cement, and blast furnace cement, fine cement obtained by mixing slag and cement developed for pouring, ultra fine cement and ordinary cement are classified. Admixtures that promote hardening of cements that are generally classified as cement-based injections, such as injections that use special cements such as classified cements, and cement minerals such as sodium aluminate, water glass, or calcium aluminate. An injection material using an agent or an injection material using a clay mineral can be used, but in the present invention, it is preferable to use the injection material of the present invention in combination with a special cement having a small particle diameter.

The injection method when the injection material of the present invention is used in combination with a cement-type injection material can be used by mixing with a cement-type injection material, but it is not used by mixing with a cement-type injection material. It is preferable that each of the prepared injection materials is pumped and mixed in the ground, or is joined and injected immediately before injection.
In addition, a cement-based injection material is injected into the ground in advance, and a method of re-injecting the injection material of the present invention into a place where improvement cannot be sufficiently achieved, or after injecting slurry and filling fine voids in advance. A method of injecting a cement-based injection material is also possible.

  Hereinafter, although an example and a comparative example are given and the contents are explained in detail, the present invention is not limited to these.

Experimental example 1
Fine particles of 1.0μm or less are blended with fine silica and water, dispersed using a high-speed stirrer trade name “TK homodisper f-model” manufactured by Tokushu Kika Kogyo Co., Ltd. for 10 minutes at a rotational speed of 5,000 rpm. A silica slurry having a silica content of 95% and the concentrations and viscosities shown in Table 1 was prepared, and its permeability and bleeding rate were evaluated. The results are also shown in Table 1.

<Materials used>
Fine particle silica: manufactured by Denki Kagaku Kogyo, spherical silica, SiO ₂ component 98% or more, primary maximum particle size 0.7μm, primary particle average particle size 0.5μm
Water: Tap water

<Measurement method>
Viscosity: Measured using a B-type rotational viscometer Penetration: 1000 cc of injected material is poured from the top of a cylinder with a diameter of 5 cm and a length of 50 cm filled with Toyoura standard sand, and the penetration distance is measured. Bleeding rate: φ50 cm x 30 cm Fill the vinyl tube with the sample and measure the ratio of the height of the water separated from the slurry after standing for one day to the filling length.

Experimental example 2
Experimental Example 1 except that a silica slurry containing fine particle silica having a concentration of 50% and a viscosity of 50 mPa · S and containing 1.0 μm or less of fine particle silica as shown in Table 2 was prepared and the permeability was evaluated. As well as. The results are also shown in Table 2.

<Measurement method>
Fine particle silica of 1.0μm or less: particle size distribution, laser diffraction / scattering type particle size distribution analyzer, measured using the product name “LA-910W” manufactured by HORIBA

Experimental example 3
It was carried out in the same manner as in Experimental Example 2 except that a silica slurry containing a concentration shown in Table 3 and a fine particle silica of 1.0 μm or less with a viscosity of 50 mPa · S was prepared. The results are also shown in Table 3.

Experimental Example 4
The experiment was conducted in the same manner as in Experimental Example 2 except that a silica slurry containing a viscosity shown in Table 4 and a fine particle silica of 1.0 μm or less was prepared at a concentration of 50%. The results are also shown in Table 4.

Experimental Example 5
The experiment was performed in the same manner as in Experimental Example 2 except that a silica slurry containing the concentration, viscosity, and fine particle silica of 1.0 μm or less shown in Table 5 was prepared. The results are also shown in Table 5.

Experimental Example 6
The experiment was conducted in the same manner as in Experimental Example 2 except that the silica slurry was prepared by changing the concentration, viscosity, and pH of the silica slurry containing fine particle silica of 1.0 μm or less shown in Table 6 using an additive. The results are also shown in Table 6.

<Materials used>
Additive: 1st grade sulfuric acid, purity 97% or more, manufactured by Kishida Chemical Co., Ltd. 1st grade reagent, sodium hydroxide, purity 95% or more, manufactured by Kanto Chemical Co., Inc.

<Measurement method>
pH: measured using pH meter D-51 manufactured by HORIBA

Experimental Example 7
The same procedure as in Experimental Example 2 was performed except that the dispersion treatment was performed using the apparatus shown in Table 7. The results are also shown in Table 7.

<Measurement method>
Ultrasonic device: Product name “Ultrasonic US-300” manufactured by Nippon Seiki Co., Ltd.
Wet crusher: Product name "OB Mill" manufactured by Turbo Industry Co., Ltd.

  Improve the water-blocking, water-tightness, and deformability of the ground, such as dams and power plants, underground structures such as large structures, tunnels, underground storage bases, and radioactive waste treatment facilities, and deep underground development in urban areas. It can be applied to improved injection construction.

Claims (5)

SiO ₂ component comprises only fine particulate silica and water maximum particle size of particles below 1.0μm is 90% or more of primary particles of 85% or more, pH of 3 or more, less than 9, the concentration is 5 to 60% An injection material which is a silica slurry having a viscosity of 20 to 50 mPa · S.   The injection material according to claim 1, wherein the concentration is 30 to 60%.   The manufacturing method of the injection material of Claim 1 or 2 using 1 type, or 2 or more types selected from the group which consists of an ultrasonic device, a high-speed stirrer, and a wet crusher.   An injection method using the injection material according to claim 1.   An injection method comprising the injection material according to claim 1 and 2 in combination with a cement-based injection material.