JPH08319484A - Production of suspension - Google Patents

Abstract

PURPOSE: To obtain a suspension grout excellent in penetration and giving a high efficiency of injection. CONSTITUTION: A process for producing a suspension grout by dispersing a powder composed mainly of cement in water, wherein vibration is imparted by means of ultrasonic waves and/or a vibrator to disintegrate the agglomerated mass of the powder. The formation of coarse particles comprising the agglomerated mass can be prevented by the forced dispersion by means of ultrasonic waves and/or the vibrator. Because of an excellent penetration, the produced grout can be readily injected and effectively penetrated into the fine cracks and gaps of soft grounds, rock beds and concretes into which conventional suspension grouts could not be injected, so that it is possible to strengthen and improve these grounds, rock beds and concretes.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a suspension, and more particularly to a suspension used for filling cracks and voids for improving soft ground, preventing spring water, and strengthening rock and concrete. The present invention relates to a method for producing a suspension suitable for producing a turbid grout.

[0002]

2. Description of the Related Art Conventionally, in order to improve soft ground, prevent spring water, and strengthen rock and concrete, injection of grout to fill cracks and voids with suspension grout in which cement powder is dispersed in water The construction method is applied. The grout used in this grout pouring method is generally a suspension prepared by dispersing mixed powder of Portland cement, clay mineral, blast furnace slag, fly ash, etc. in water.

Conventionally, the mixed powder for grout is mixed and dispersed in a predetermined amount of water by a mixer to produce a suspension grout. The mixer used for producing the suspension grout includes a grout mixer and a pump integrated in one unit, or a mixer such as a jet mixer or a Kanifu mixer which also serves as a pressure feeder. In the grout mixer, a rotary shaft having a rotary blade is attached to a tank, and the grout is kneaded by a vortex generated by the rotary blade and convection in the tank. For bentonite and air mortar, a high-speed one having a maximum rotation speed of about 10,000 rpm is used.

[0004]

By the way, when pouring grout into cracks in concrete or voids in the ground, in order to easily inject grout, dispersed particles in the grout pass through pores of soil particles or cracks. It is necessary to have a particle size of a size that is easy to do.

However, in the suspension grout obtained by dispersing the mixed powder of Portland cement, clay mineral, etc., which has been conventionally used for grout, in water with the above mixer, in a state of being suspended in water, Actually, the powder particles are aggregated with each other to form a large particle mass. The particle size of each powder used in the grout is measured in a state close to complete dispersion, so the number of coarse particles is small, but in a suspension type grout in which this is dispersed in water, the powder aggregates. Then, a large amount of coarse particle aggregates are generated.

Therefore, in the conventional suspension type grout, the aggregates are collected in the flow passages such as cracks and voids near the injection port, and the flow passage width sudden change portion is clogged. As a result, grout often cannot penetrate into the inside. For this reason, conventionally, it was not possible to inject the suspension grout into the fine-grained sandstone layer, and it was not possible to improve the ground or strengthen the bedrock, so that it was often the case that the subsequent work could not be undertaken. By the way, in the conventional method for producing suspension-type grout, even if it is stirred with a high-speed rotating mixer, the particle aggregates formed by the agglomeration of the powder in the grout do not loosen, and agglomerated coarse particles remain, so that the fine sandstone It could not be injected into quality rock.

Generally, the maximum particle size of cement used for pouring grout is said to be 1/3 of the crack width and about 1/10 of the particle size of the formation. As described above, the width of the interval in which the grout permeates is set to be extremely larger than the maximum particle diameter of the cement, mainly because this aggregate particle aggregate is generated.

Therefore, it can be said that by loosening the agglomerates having a large diameter, the permeability of grout into a narrow space is improved.

The present invention has been made in view of the above-mentioned conventional circumstances, and it is possible to obtain a strong dispersion promoting action for loosening agglomerated agglomerates of powder, and therefore excellent permeability and injection efficiency. It is an object of the present invention to provide a method for producing a suspension capable of easily producing a highly suspended grout.

[0010]

According to a first aspect of the present invention, there is provided a method for producing a suspension in which a powder is dispersed in water to produce a suspension by applying an ultrasonic wave and / or a vibration by a vibrator. Characterized by loosening agglomerates of powder.

The method for producing a suspension according to claim 2 is the method according to claim 1.
In the above method, a powder containing cement as a main component is dispersed in water to produce a suspension grout.

The method for producing a suspension according to claim 3 is the method according to claim 1.
In the method of 2 or 2, the vibration is applied after or while adding the surfactant.

That is, the inventors of the present invention have conducted extensive studies to loosen the agglomerated particles of the grout powder to produce a suspension grout having excellent permeability and injection efficiency. It was found that when vibration is applied by ultrasonic waves or a vibrator at the time of production, aggregates of cement-based powder are loosened, coarse particles disappear, and the permeability of grout is dramatically improved. At that time, if a surfactant that promotes the dispersion of the powder in the grout is used, it becomes easier to loosen the agglomerated powder, and the injection amount is increased and the permeability is further improved. I found that I can do it.

The present invention has been completed based on the above findings.

The present invention will be described in detail below.

In the following, the case of producing a suspension grout by the method for producing a suspension of the present invention will be mainly described, but the present invention is not limited to the suspension grout.
It is also effective for the production of suspensions such as slurry, mortar and cement paste that constitutes concrete.

The gist of the present invention is to disperse a powder for grout in water to produce a suspension, and to loosen agglomerates of the powder particles, a conventional rotor blade is used to It is characterized by giving stronger vibration than the dispersion action. Specifically, ultrasonic waves and / or vibrators are used. It is desirable that these vibrations be applied during and / or after stirring by the rotary blades because the dispersion efficiency is high. Furthermore, by using a surfactant that promotes dispersion during this dispersion treatment, it becomes possible to more effectively loosen the agglomerated powder, and increase the injection amount and penetration of the resulting grout. The duration of can be improved. Further, it becomes possible to shorten the time for applying the ultrasonic wave and / or the vibrator.

In the present invention, when vibration is applied by ultrasonic waves, an ultrasonic transmitter with an output of about 10 to 2000 W may be used. Further, when the vibration is applied by the vibrator, it is preferable to use a vibrator having a frequency of about 5000 to 15000 vpm.

Generally, in the method of the present invention, water and cement or a powder for grout prepared by mixing cement or cement with clay mineral, blast furnace slag, fly ash, etc. at a predetermined ratio,
For example, after agitating with a mixer at a speed of about 200 to 800 rpm for about 0.5 to 2 minutes at a water powder ratio of about 2 to 10 according to a conventional method, the resulting kneaded product is ultrasonically and / or with a vibrator of about 0.5 to 2 minutes. It is carried out by performing a forced dispersion process that imparts vibration for about 5 minutes.

The particle size of the grout powder is preferably 50 μm or less in terms of its permeability.

When a surfactant is used, the surfactant may be added either during the stirring treatment or the forced dispersion treatment, or may be mixed with the grout powder in advance. .

As the surfactant to be used, lignin sulfonate and its derivative, oxycarboxylate, polyol derivative, polycarboxylate, naphthalene sulfonic acid formalin high condensate, melamine sulfonic acid formalin condensate, alkylallyl sulfone. Acid polymer,
Examples include chemical admixtures containing a highly condensed triazine compound, a methylol melamine condensate, a nitrogen-containing sulfonate, and an aminosulfonate as a main component.

The amount of the surfactant added is appropriately adjusted depending on the degree of loosening of the agglomerated powder and the injection property, but in the usual case, it is 1 to 3% by weight relative to the grout powder. preferable.

[0024]

By performing the forced dispersion treatment with ultrasonic waves or vibration of a vibrator, coarse particles of a large amount of agglomerates of powder generated in the dispersion system are effectively loosened and disappear. As a result, a large amount and smooth penetration of grout into suspension-type grouts using fine-grained cements and fine sandstone rocks and ground that could not be injected due to the presence of coarse particles in agglomerates. Like Furthermore, since the bubbles in the grout are reduced, the filling property of the grout after permeation becomes good.

The method of the present invention is particularly effective for producing cement milk-based grout, and is also effective for improving the separation resistance of grout.

Further, in the present invention, when a surfactant for improving the dispersibility is used in combination, the amount of the surfactant used can be reduced, and a more excellent improving effect can be obtained with a small amount of the surfactant used. be able to.

[0027]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples unless it exceeds the gist.

Example 1 Ultrafine particle cement "Finehard" (maximum particle diameter 12 µm) manufactured by Mitsubishi Materials Corp. was mixed at a water cement ratio of 6 with a hand mixer of 500 rpm for 30 seconds, and then kneaded into the mixture. Then, a bar-shaped vibrator having a frequency of 7000 vpm was inserted and forced dispersion treatment was performed for 60 seconds.

With respect to the obtained suspension grout, the particle size distribution of dispersed particles and the dispersibility and permeability were examined by the following method, and the results are shown in Table 1.

[Particle size distribution] The particle size distribution was measured with a laser diffraction type particle size meter in a state where forced dispersion treatment was not carried out with water as a medium such as ultrasonic waves.

[Dispersibility] The grout was put in a graduated cylinder and the change with time of the sedimentation volume was measured to evaluate the dispersibility.

[Permeability] 100 cc of grout was placed in a beaker and the thickness of 2 was put in a 200 ml cylindrical separatory funnel.
The penetration depth was measured by pouring from the top of a layer of standard sand (particle size 0.1 to 0.3 mm) for strength test of cement filled to 00 mm.

Second Embodiment In the first embodiment, the forced distribution process is performed and the output during operation is 1
Place a beaker containing the kneaded material in a 50 W ultrasonic cleaner 60
A grout was produced in the same manner except that it was immersed for 2 seconds, and the particle size distribution, dispersibility and permeability were examined in the same manner, and the results are shown in Table 1.

Comparative Example 1 A grout was prepared in the same manner as in Example 1 except that the forced dispersion treatment was not carried out, and the particle size distribution, dispersibility and permeability were examined in the same manner. The results are shown in Table 1.

As is clear from Table 1, by kneading with a mixer and then forcibly dispersing with a vibrator or ultrasonic waves, agglomerated coarse particles are reduced, and the dispersibility and the permeability to the sand layer are dramatically improved. To do. In particular, the tendency is remarkable in the forced dispersion treatment using ultrasonic waves.

[0036]

[Table 1]

Example 3 Ultrafine particle cement "Finehard" (maximum particle diameter 12 μm) and kaolin (maximum particle diameter 5 μm) manufactured by Mitsubishi Materials Co., Ltd. were mixed in equal weight to form a powder for injection, and a water powder ratio. After kneading at a ratio of 6 with a hand mixer of 500 rpm for 30 seconds, a forced dispersion treatment was carried out in the same manner as in Example 2 to obtain grout, and similarly the particle size distribution, dispersibility and permeability were examined, and the results are shown in Table 2. It was shown to.

Example 4 In Example 3, before kneading with a hand mixer,
The same procedure was performed except that 3% by weight of naphthalene sulfonic acid-based surfactant (Admixture "Mayty 100" manufactured by Kao Corporation) was added to the powder, and the particle size distribution, dispersibility and permeability were similarly obtained. Was examined and the results are shown in Table 2.

Comparative Example 2 The same procedure as in Example 3 was carried out except that the forced dispersion treatment was not carried out, and the particle size distribution, dispersibility and permeability were examined in the same manner. The results are shown in Table 2.

As is clear from Table 2, by performing forced dispersion treatment by ultrasonic waves after kneading with a mixer, agglomerated coarse particles are significantly reduced, and the dispersibility and the permeability to the sand layer are dramatically improved. However, if a surfactant that accelerates the dispersion of the powder is also used, the tendency becomes remarkable.

[0041]

[Table 2]

[0042]

As described in detail above, according to the method for producing a suspension of the present invention, when a powder is dispersed in water to produce a suspension, agglomerates of powder particles are effectively By disintegrating, it is possible to prevent the formation of coarse particles and form a suspension having extremely good uniform dispersibility.

In particular, the method for producing a suspension of the present invention is effective when a cement-based powder is dispersed in water to produce a suspension-type grout, and the formation of coarse particles in which powder particles are agglomerated. Therefore, it is possible to produce a suspension grout having excellent permeability and high injection efficiency. Suspension grout produced by the method of the present invention, because of its excellent permeability, soft ground that could not be injected by conventional suspension grout, fine cracks and voids in rock and concrete, easily injected It is possible to effectively infiltrate the ground, rock, and concrete, and strengthen and improve them.

Particularly, when a surfactant is used in combination, more excellent effects can be obtained.

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display area C09K 17/48 C09K 17/48 P // C09K 103: 00

Claims (3)

[Claims] 1. Dispersion of powder in water to produce a suspension, wherein vibration of ultrasonic waves and / or a vibrator is applied to loosen agglomerates of the powder. Production method. 2. The method for producing a suspension according to claim 1, wherein a powder containing cement as a main component is dispersed in water to produce a suspension grout. 3. The method for producing a suspension according to claim 1, wherein the vibration is applied after or while adding a surfactant.