JP2021178751A - Rapid-hardening additive agent, and spray material - Google Patents

Abstract

To provide a rapid-hardening additive agent excellent in storage stability and rapid-hardening properties.SOLUTION: A rapid-hardening additive agent of the present invention is a powderly rapid-hardening additive agent containing calcium aluminate, aluminium sulfate, gypsum, and sodium sulfate, wherein in a volume frequency grain size distribution of the rapid-hardening additive agent measured by a laser diffraction scattering method, when a particle size whose cumulative value is 50% is D50 and when a particle size whose cumulative value is 10% is D10, D50 is 6 μm or more and 15 μm or less, D10 is 1 μm or more and 5 μm or less, and (D50-D10)/D50 is 0.1 or more and 1.0 or less.SELECTED DRAWING: None

Description

The present invention relates to a fast-setting admixture and a spraying material.

So far, various developments have been made on quick-setting admixtures. As this kind of technique, for example, the technique described in Patent Document 1 is known. Patent Document 1 describes a sprayed concrete composition containing a quick-setting material containing calcium aluminate, an aluminum sulfate salt, etc., cement, and an aggregate (claim 1).

JP-A-2017-109901

However, as a result of the study by the present inventor, it has been found that there is room for improvement in the storage stability and the quick-setting property in the quick-setting material described in Patent Document 1.

As a result of further studies, the present inventor has found that the storage stability and the quick-setting property can be controlled by appropriately selecting the particle size distribution using D10 and D50 in the powdery quick-setting admixture. Further diligent research based on such findings revealed that by using the three particle size distributions represented by D10, D50, and (D50-D10) / D50 as indicators, storage stability and rapid connection are stable. It is possible to evaluate, and by adjusting the three particle size distributions within an appropriate range, it is found that the storage stability and the quick-setting property in the powdery quick-setting admixture can be improved, and the present invention is completed. It came to.

According to the present invention
A powdery, fast-setting admixture containing calcium aluminate, aluminum sulphate, gypsum, and sodium sulphate.
In the volume frequency particle size distribution of the rapid admixture measured by the laser diffraction / scattering method, when the particle size having a cumulative value of 50% is D50 and the particle size having a cumulative value of 10% is D10.
D50 is 6 μm or more and 15 μm or less,
D10 is 1 μm or more and 5 μm or less, and (D50-D10) / D50 is 0.1 or more and 1.0 or less.
A fast-setting admixture is provided.

Further, according to the present invention.
Spraying materials are provided, including the fast-setting admixtures described above, and cement.

According to the present invention, a fast-setting admixture material having excellent storage stability and quick-setting property, and a spraying material using the fast-setting admixture material are provided.

The quick-setting admixture of the present embodiment will be outlined.

The fast-setting admixture is a powdery composition containing calcium aluminate, aluminum sulphate, gypsum, and sodium sulphate.
In this quick-setting admixture, when the particle size having a cumulative value of 50% is D50 and the particle size having a cumulative value of 10% is D10 in the volume frequency particle size distribution measured by the laser diffraction / scattering method,
D50 is 6 μm or more and 15 μm or less,
It is configured so that D10 satisfies 1 μm or more and 5 μm or less, and (D50-D10) / D50 satisfies 0.1 or more and 1.0 or less.

According to the findings of the present inventor, in a powdery quick-setting admixture, storage stability is obtained by using three particle size distributions represented by D10, D50, and (D50-D10) / D50 as indicators. It has been found that it is possible to stably evaluate the fast-setting property and the storage stability and the quick-setting property can be improved by adjusting the three particle size distributions within an appropriate range.

Although the detailed mechanism is not clear, in the powdery quick-setting admixture, by appropriately controlling the ratio of the fine powder fraction to the coarse powder fraction, the decrease in storage stability is suppressed, and the coagulation property is further improved. It is thought that this is because the decrease in the amount of powder can be suppressed.

According to this embodiment, it is possible to realize a fast-setting admixture having an excellent balance between storage stability and quick-setting.

Hereinafter, the quick-setting admixture of the present embodiment will be described in detail.

(Calcium aluminate)
Quick-setting property admixture comprises calcium aluminate (compound mainly composed of the CaO component and Al ₂ O ₃ component).
The calcium aluminate may contain either crystalline or amorphous, and these may be used alone or in combination of two or more.

The CaO / Al ₂ O ₃ in the calcium aluminate is, for example, 1.8 to 2.5, preferably 1.9 to 2.4 in molar ratio. By setting this molar ratio within this range, the amorphization rate can be increased and excellent initial condensation can be obtained.

Calcium aluminate may contain amorphous. The amorphization rate in the calcium aluminate is preferably 50% or more, more preferably 60% or more, further preferably 70% or more, still more preferably 80% or more in terms of mass. As a result, the initial cohesiveness can be enhanced.

The content of calcium aluminate is, for example, 60% by mass or more and 80% by mass or less, preferably 60% by mass or more and 75% by mass or less, and more preferably 60% by mass or more and 70% by mass in 100% by mass of the quick-setting admixture. It is as follows. By setting it to the above lower limit value or more, the quick connection can be improved. By setting the value to the upper limit or less, it is possible to achieve a balance between rapid connection and strength development.

The content of each mineral composition in the quick-setting admixture and the powder of calcium aluminate can be confirmed by a general analytical method. For example, the mineral composition of a powdery sample can be confirmed by the powder X-ray diffraction method and the data can be analyzed by the Rietveld method to quantify the mineral composition. It is also possible to calculate the mineral composition amount based on the identification results of the chemical composition and the powder X-ray diffraction.

Method for producing a calcium aluminate may, for example, CaO raw material, a raw material mixture containing Al ₂ O ₃ raw material, for example, may include a step of baking and melting the kiln or an electric furnace.

As the CaO raw material, those commercially available as an industrial raw material may be used, but may contain, for example, one or more selected from the group consisting of limestone, coal ash, quicklime, slaked lime, and acetylene-generating waste. Among these, slaked lime may be used.

As the Al ₂ O ₃ raw material, those commercially available as an industrial raw material may be used, but may contain, for example, one or more selected from the group consisting of bauxite, aluminum hydroxide, and aluminum residual ash. The aluminum residual ash may be mainly composed of aluminum hydroxide.

These raw materials are mixed and pulverized so as to have a predetermined mineral composition ratio to obtain a raw material mixture.

The method of mixed pulverization is not particularly limited, and a dry pulverization method or a wet pulverization method can be applied. In the case of the wet pulverization method, it is necessary to perform a dehydration treatment for subsequent granulation. When quicklime is used as a raw material, it is desirable to use a dry method.

Also by adjusting the feed rate of the raw material can be controlled the CaO / _Al 2 _{O 3} molar ratio of calcium aluminate.

The firing and melting temperatures may be, for example, 1,200 ° C to 1,800 ° C, or 1,300 ° C to 1,600 ° C. By setting it to the above lower limit value or more, the generation of impurities can be suppressed.
An electric furnace or a rotary kiln can be used for firing.

Clinker can be obtained by firing or melting. The clinker may be crushed by a known method to obtain a crushed product.
From the above, a powder of calcium aluminate can be obtained.

(Aluminum sulfate)
The fast-setting admixture contains aluminum sulphate. Aluminum sulphate can increase the rate of condensation.
The aluminum sulfate is not particularly limited, and may be an anhydrous salt or a hydrous salt (hydrate).
Aluminum sulphate hydrate has a higher dissolution rate and can improve the setting property as compared with its anhydride.
Aluminum sulphate hydrate contains, for example, 4 to 27 hydrates, preferably 10 to 18 hydrates, more preferably 14 to 18 hydrates. Among them, the setting property can be enhanced by containing 14 to 18 hydrates of aluminum sulfate, or at least 17 hydrates of aluminum sulfate.

The content of aluminum sulfate is, in _{terms of Al 2} (SO ₄ ) ₃ , in 100% by mass of the fast-setting admixture, for example, 1% by mass or more and 10% by mass or less, preferably 2% by mass or more and 9% by mass or less. It is preferably 3% by mass or more and 8% by mass or less. By setting it to the above lower limit value or more, the ability to promote condensation can be improved. By setting the value to the upper limit or less, it is possible to achieve a balance between the ability to promote condensation and the ability to develop strength.

(plaster)
Fast-setting admixtures include gypsum. Gypsum can improve the strength development.
Examples of gypsum include calcium sulfate, anhydrous gypsum, hemihydrate gypsum, and dihydrate gypsum.
In addition, naturally produced natural gypsum, gypsum excreted as an industrial by-product, gypsum by-product hydrofluoric acid, and the like may be used. One or more of these can be used. Above all, anhydrous gypsum may be used from the viewpoint of developing adhesive strength.

The content of gypsum is, in _{terms of CaSO 4} , 100% by mass of the fast-setting admixture, for example, 15% by mass or more and 30% by mass or less, preferably 15% by mass or more and 25% by mass or less, and more preferably 15% by mass or more. It is 20% by mass or less. By setting it to the above lower limit value or more, the strength development can be improved. By setting the value to the upper limit or less, it is possible to achieve a balance between rapid connection and strength development.

(Sodium sulfate)
The fast-setting admixture contains sodium sulfate. Sodium sulfate can improve the strength development.
Potassium sulfate, lithium sulfate and the like may be contained as the alkali metal sulfate other than sodium sulfate.
These may be used alone or in combination of two or more. Among these, neutral anhydrous bow glass may be used as the sodium sulfate.

The content of sodium sulfate is, for example, 3% by mass or more and 12% by mass or less, preferably 4% by mass or more and 10% by mass or less, more preferably 5 in 100% by mass of the quick-setting admixture in terms of _{Na 2} SO _4. It is by mass% or more and 10% by mass or less. By setting it to the above lower limit value or more, the strength development can be improved. By setting the value to the upper limit or less, it is possible to achieve a balance between rapid connection and strength development.

The quick-setting admixture does not contain alkali carbonate (alkali metal carbonate), or contains alkali carbonate in a content of 0.05% by mass or less with respect to 100% by mass of calcium aluminate.
Examples of the alkali carbonate include sodium carbonate, potassium carbonate, and sodium bicarbonate.

As described above, the storage stability of the quick-setting admixture can be improved by constructing the material so as to substantially contain no alkali carbonate. Further, with such a configuration, even when the acute admixture contains 14 to 18 hydrates of aluminum sulfate hydrate, it is possible to suppress a decrease in the storage stability thereof.

The fast-setting admixture may contain _{CaF 2.} That is, it may have a peak derived from _{CaF 2} in the powder X-ray diffraction pattern of the quick-setting admixture. Thereby, the storage stability can be further improved. Although the detailed mechanism is not clear, it is considered that _{the condensation delaying effect of CaF 2} can delay the progress of condensation due to the hydration of the fast-setting admixture, and as a result, the storage stability is improved.

_{The content of CaF 2} when quantitatively analyzed by the Reetbelt method is, for example, 0.3% by mass or more and 2% by mass or less, preferably 0.5% by mass or more and 1.9 in 100% by mass of the quick-setting admixture. It is mass% or less, more preferably 0.5 mass% or more and 1.7 mass% or less. Within such a range, storage stability can be further improved.

The quick-setting admixture may contain other components other than the above-mentioned components, that is, calcium aluminate, aluminum sulfate, gypsum, and sodium sulfate, as long as the effects of the invention are not impaired.
Examples of other components include _{one or more of SiO 2} , TiO ₂ , Fe ₂ O ₃ , MgO, K ₂ O and the like.

The content of other components in the quick-setting property admixture, relative to total 100 weight percent of CaO and _Al 2 _{O 3,} for example, 10 wt% or less, preferably 9 mass% or less, more preferably 8 wt% It may be as follows.

Hereinafter, the powder characteristics of the quick-setting admixture will be described.

For the quick-setting admixture, in the volume frequency particle size distribution measured by the laser diffraction scattering method, the particle size with a cumulative value of 50% is D50, the particle size with a cumulative value of 10% is D10, and the cumulative value is 90%. The particle size is D90.

D50 is 6 μm or more and 15 μm or less, preferably 7 μm or more and 13 μm or less, and more preferably 7 μm or more and 10 μm or less.
D10 is 1 μm or more and 5 μm or less, preferably 1 μm or more and 4 μm or less, and more preferably 1 μm or more and 3 μm or less.
(D50-D10) / D50 is 0.1 or more and 1.0 or less, preferably 0.2 or more and 0.8 or less, and more preferably 0.3 or more and 0.7 or less.
By setting D10, D50, and (D50-D10) / D50 within the above ranges, it is possible to balance the storage stability and the quick-setting property in the quick-setting miscible material.

The D90 is, for example, 50 μm or more and 300 μm or less, preferably 40 μm or more and 200 μm or less, and more preferably 30 μm or more and 150 μm or less. By setting D90 within the above range, it is possible to achieve a balance between storage stability and quick-setting property in the fast-setting miscible material.

(D90-D10) / D50 is, for example, 4.0 or more and 35.0 or less, preferably 5.0 or more and 35.0 or less, and more preferably 5.0 or more and 30.0 or less.
By setting (D90-D10) / D50 within the above range, it is possible to achieve a balance between storage stability and quick-setting property in the quick-setting miscible material.
(D90-D10) / D50 is a fast-setting admixture.

The fast-setting admixture was sieved using a sieve with a mesh opening of 75 μm, and the volume frequency particle size distribution of the remaining fraction (A) on the sieve was measured by the laser diffraction scattering method. The particle size having a value of 50% is D50, and the particle size having a cumulative value of 10% is D10.
The D50 is, for example, 130 μm or more and 400 μm or less, preferably 150 μm or more and 350 μm or less, and more preferably 200 μm or more and 300 μm or less.
D10 is, for example, 90 μm or more and 125 μm or less, preferably 100 μm or more and 125 μm or less, and more preferably 100 μm or more and 120 μm or less.
By setting D50 and D10 in the sieving fraction (A) within the above range, it is possible to achieve a balance between storage stability and quick-setting property in the fast-setting miscible material.

The fast-setting admixture was sieved using a sieve with a mesh opening of 75 μm, and the volume frequency particle size distribution of the subsieving fraction (B) that passed through this sieve was measured by the laser diffraction scattering method. The particle size at which is 50% is D50, and the particle size at which the cumulative value is 10% is D10.
The D50 is, for example, 7 μm or more and 12 μm or less, preferably 8 μm or more and 11 μm or less, and more preferably 8 μm or more and 10.
D10 is, for example, 0.5 μm or more and 6 μm or less, preferably 1 μm or more and 5 μm or less, and more preferably 1 μm or more and 4 μm or less.
By setting D50 and D10 in the sieving fraction (B) within the above range, it is possible to achieve a balance between storage stability and quick-setting property in the quick-setting miscible material.

In the present embodiment, for example, by appropriately selecting the type and blending amount of each component contained in the quick-setting admixture, the method for preparing the quick-setting admixture, and the like, the above D10, D50, D90, ((D50) -D10) / D50) and ((D90-D10) / D50) can be controlled. Among these, for example, the crushing of calcium aluminate and the classification treatment conditions are appropriately adjusted, and the particle size distribution and particle size in the mixture obtained after mixing the constituent materials of the quick-setting admixture are continuously measured. Then, using the result, the particle size is screened using an arbitrary sieve, and the screened particle size is mixed again so as to have the desired particle size distribution to adjust the particle size distribution and the particle size. The above D10, D50, D90, ((D50-D10) / D50), and ((D90-D10) / D50) can be mentioned as elements for setting a desired numerical range.

The cement composition of the present embodiment contains the above-mentioned quick-setting admixture and cement.
The cement composition can be used for various concrete applications, for example, spraying applications, ground improvement applications for injecting into the ground or stirring and solidifying with the ground, applications for filling gaps such as cavities, and the like.

As one embodiment of the cement composition, it can be used as a spraying material to be sprayed onto an exposed ground surface, for example, in tunnels such as roads, railroads and headraces.

The spraying material of the present embodiment contains the above-mentioned quick-setting admixture and cement.

The amount of the quick-setting admixture used varies depending on the purpose of use, but is usually 1 to 20 parts by mass, preferably 3 to 10 parts by mass in 100 parts by mass of cement.

As cement, various Portland cements such as ordinary, fast-strength, ultra-fast-strength, low heat, and moderate heat, various mixed cements in which blast furnace slag, fly ash, or silica are mixed with these Portland cements, urban waste incineration ash and sewage sludge. Waste utilization cement manufactured from incineration ash, so-called eco-cement (R), filler cement mixed with limestone powder, etc., alumina cement, sulfoaluminate cement, limestone calcined clay cement (LC3), etc. Can be mentioned. These may be used alone or in combination of two or more.

The amount of water used is not particularly limited, but usually, the water / cement composition ratio is, for example, about 25 to 70% by mass with respect to the cement composition composed of cement and the quick-setting admixture. Yes, it may be 30 to 60% by mass.

The kneading method is a generally used method and is not particularly limited. As the mixing device, any existing stirring device can be used, and for example, a tilting mixer, an omni mixer, a V-type mixer, a Henschel mixer, a Nauter mixer and the like can be used.

For mixing, each material may be mixed at the time of construction, or a part or all of them may be mixed in advance.

Spraying materials include aggregates such as sand and gravel, fibrous materials, swelling materials, hardeners, coagulation adjusters, water reducing agents, high-performance water reducing agents, AE agents, AE water reducing agents, high-performance AE water reducing agents, etc. Thickeners, rust preventives, antifreeze agents, heat hydration inhibitors, polymer emulsions, clay minerals such as bentonite and montmorillonite, ion exchangers such as zeolites, hydrotalcites, and hydrocarbimite, sulfates such as aluminum sulfate. It is possible to use a salt, a phosphate, and one or more other admixtures such as boric acid in combination as long as the object of the present invention is not substantially impaired.

The spraying material may also contain a liquid quick-setting admixture containing an aluminum salt.
Examples of the aluminum salt include aluminum sulfate and the like.

As the spraying method of the present embodiment, a dry spraying method can also be constructed, but from the viewpoint of reducing the amount of dust, a wet spraying method in which water is added to the cement concrete side in advance and kneaded before using the quick-setting admixture. It is preferable to use.

As a wet spraying method, cement, fine aggregate, coarse aggregate, and water are added and kneaded to form sprayed concrete, which is pneumatically fed, and a Y-shaped pipe is provided in the middle, and a quick-setting admixture supply device is provided from one of them. There is a method in which the quick-setting admixture is pneumatically fed and mixed to form a quick-setting wet-sprayed concrete.

Although the embodiments of the present invention have been described above, these are examples of the present invention, and various configurations other than the above can be adopted. Further, the present invention is not limited to the above-described embodiment, and modifications, improvements, and the like to the extent that the object of the present invention can be achieved are included in the present invention.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited to the description of these Examples.

[Experimental Example A]
(Preparation of quick-setting admixture)
As the quick-setting admixture, various materials were mixed so as to have the blending amounts shown in Table 1 to obtain a mixture. The materials used are shown below.
CA: calcium aluminate (amorphous, CaO / _Al 2 _{O 3} molar ratio: 2.4, vitrification ratio: 95%)
AS: Aluminum sulfate (17 hydrate, commercial product)
CS: Gypsum (anhydrous Japanese product, commercial product)
NS: Sodium sulfate (anhydrous product, commercial product)
CaF ₂ : Calcium fluoride (commercially available)

The obtained mixture was continuously measured for particle size distribution and particle size using a laser diffraction / scattering method, and based on the measurement results, it was screened using an arbitrary sieve. The screened particle sizes were mixed again so as to have the particle size distribution shown below to prepare the fast-setting admixtures A1 to A14.
D10: 5 μm
D50: 20 μm
D90: 200 μm
(D50-D10) / D50 = 0.8
(D90-D10) /D50=9.8

Next, 100 parts by mass of ordinary Portland cement (pH 14, industrial product), 10 parts by mass of the obtained quick-setting miscible material, and 40 parts by mass of water (tap water) were mixed to obtain a test sample. A condensation test was performed using the obtained test sample. The condensation test was carried out in accordance with JIS R5201 "Physical test method for cement", and the start time and the end time were measured.

From the results in Table 2, the material ratios constituting the quick-setting admixture are 60 to 80% by mass for calcium aluminate, 1 to 10% by mass for aluminum sulfate, 15 to 30% by mass for gypsum, and 3 to 12 by mass for sodium sulfate. It can be seen that% by mass is a suitable ratio. Further, _{it can be seen that if CaF 2} is 0.3 to 2% by mass, the quick-setting performance is not hindered.

[Experimental Example B]
In Example A, the particle size and particle size distribution were changed using the formulation confirmed to have quick-setting performance, and the storage stability of the quick-setting admixture was evaluated.
In the same manner as in Experimental Example A, the materials are mixed in a composition of 60% by mass of calcium aluminate, 10% by mass of aluminum sulfate, 20% by mass of gypsum, 9% by mass of sodium sulfate, and 1% by mass of calcium fluoride. Then, with respect to the obtained mixture, the particle size and the particle size distribution were changed, and the quick-setting admixtures B1 to B21 having the particle size and the particle size distribution in Table 3 were adjusted.
As for the quick-setting admixtures B3, B11, and B18, sodium carbonate (commercially available) was further added as an alkali carbonate in an amount of 0.05% by mass based on 100% by mass of calcium aluminate, and the quick-setting admixture B4 was further blended. For B12 and B19, sodium carbonate (commercially available) was further added as an alkali carbonate at 0.06% by mass with respect to 100% by mass of calcium aluminate, and alkali carbonate was added to the other quick-setting admixtures. I didn't.

Further, in any of the quick-setting admixtures B1 to B21, a sieve having a mesh size of 75 μm was used, and the particle sizes of the upper sieve fraction (A) and the lower sieve fraction (B) remaining on the sieve were within the following ranges. there were.
(A) D10: 90 to 125 μm, D50: 130 to 400 μm
(B) D10: 0.5 to 6 μm, D50: 7 to 12 μm

After packing the prepared quick-setting admixture in a bag and storing it in a room at a temperature of 20 ° C. and a humidity of 60% for a predetermined number of days, 100 parts by mass of ordinary Portland cement (pH 14, industrial product) and 10 parts by mass of the quick-setting admixture , 40 parts by mass of water (tap water) was mixed to obtain a test sample. Using the obtained test sample, a condensation test and a measurement of compressive strength were performed.
The condensation test and the measurement of compressive strength were carried out in accordance with JIS R5201 "Physical test method for cement". The condensation test measured the time of onset of condensation.

From the results in Table 4, it was shown that a fast-setting admixture with excellent quick-setting performance and storage stability can be realized by appropriately adjusting the particle size and particle size distribution.

[Experimental Example C]
In the compounding of the fast-setting admixture whose quick-setting performance was confirmed by Experimental Examples A and B, the particle size of the upper sieve fraction (A) and the lower sieve fraction (B) when a sieve having a mesh opening of 75 μm was used. The quick-setting admixtures C1 to C10 having an adjusted particle size distribution were prepared, and the storage stability performance was evaluated by the same method as in Experimental Example B.

In the same manner as in Experimental Example A, the materials are mixed in a composition of 60% by mass of calcium aluminate, 10% by mass of aluminum sulfate, 20% by mass of gypsum, 9% by mass of sodium sulfate, and 1% by mass of calcium fluoride. Then, for the obtained mixture, the particle size and particle size distribution were changed, and the particle size of the upper sieve fraction (A) and the lower sieve fraction (B) when using a sieve having an opening of 75 μm was adjusted, and Table 5 The fast-setting admixtures C1 to C10 having the particle size of (A) and the particle size of (B) were adjusted.

The particle size distribution of the prepared quick-setting admixtures C1 to C10 is within the following range.
D10: 1-5 μm, D50: 6-15 μm, D90: 50-300 μm

From the results in Table 6, by appropriately adjusting the particle size and particle size distribution of the upper sieve fraction (A) and the lower sieve fraction (B) when using a sieve with a mesh opening of 75 μm, quick-setting performance and storage It was shown that a fast-setting admixture with excellent stability can be realized.

[Experimental Example D]
A spraying test was carried out on the spraying materials prepared by using the quick-setting admixtures having the composition confirmed in Experimental Examples A to C for quick-setting performance and storage stability.

Concrete (sprayed concrete) of 360 kg of cement, 216 kg of water, 1049 kg of fine aggregate, and 716 kg of coarse aggregate (Himekawa water system No. 6 crushed stone, Niigata prefecture, density 2.67 g / cm ^{3) was prepared.} Concrete was pumped with a concrete pump of MAYCO (Suprema) at ^{a setting of 5 m 3} / h, and was mixed and merged with compressed air from another system on the way to carry air. Further, at a point 3 m before discharge, the powdery quick-setting admixture shown in Table 7 below is suddenly transferred to 10 parts with respect to 100 parts of cement by the transport device Werner Mader (WM-14 FU). The miscible admixture was mixed and merged with the air-conveyed concrete to form a quick-bonding material, which was sprayed onto the iron plate from the nozzle tip. The initial strength and long-term strength after spraying were examined. It should be noted that the supply of the quick-setting admixture to the quick-setting admixture carrier uses a device of Spiroflow Co., Ltd. (FLEXIBLE SCREW CONVEYOR), and each device is controlled in conjunction with an electric signal.

Initial strength: The initial strength was measured by spraying on a mold according to JSCE-G561 and converting the pull-out strength at a material age of 10 minutes, 3 hours, and 1 day into a compressive strength.

Long-term strength: The core was sampled at 7 and 28 days of age by spraying on a mold according to JISCE-F561 and JIS A1107, and the compressive strength was measured.

From Table 7, good results were obtained for both the initial strength and long-term strength of the sprayed concrete.

The quick-setting admixture of each example showed excellent storage stability and quick-setting results as compared with each comparative example. The quick-setting admixture of such an example can be suitably used as a spraying material.

According to the present invention
A powdery, fast-setting admixture containing calcium aluminate, aluminum sulphate, gypsum, and sodium sulphate.
In 100% by mass of the quick-setting admixture, the content of the calcium aluminate is 60% by mass or more and 80% by mass or less, the content of the aluminum sulfate is 1% by mass or more and 10% by mass or less, and the content of the plaster is 15% by mass or more and 30% by mass or less, the content of the sodium sulfate is 3% by mass or more and 12% by mass or less.
In the volume frequency particle size distribution of the rapid admixture measured by the laser diffraction / scattering method, when the particle size having a cumulative value of 50% is D50 and the particle size having a cumulative value of 10% is D10.
D50 is 6 μm or more and 15 μm or less,
D10 is 1 μm or more and 5 μm or less,
D90 is 50 μm or more and 300 μm or less, and (D50-D10) / D50 is 0.1 or more and 1.0 or less.
A fast-setting admixture is provided.

Although the embodiments of the present invention have been described above, these are examples of the present invention, and various configurations other than the above can be adopted. Further, the present invention is not limited to the above-described embodiment, and modifications, improvements, and the like to the extent that the object of the present invention can be achieved are included in the present invention.
Hereinafter, an example of the reference form will be added.
1. 1. A powdery, fast-setting admixture containing calcium aluminate, aluminum sulphate, gypsum, and sodium sulphate.
In the volume frequency particle size distribution of the rapid admixture measured by the laser diffraction / scattering method, when the particle size having a cumulative value of 50% is D50 and the particle size having a cumulative value of 10% is D10.
D50 is 6 μm or more and 15 μm or less,
D10 is 1 μm or more and 5 μm or less, and
(D50-D10) / D50 is 0.1 or more and 1.0 or less.
Fast-setting admixture.
2. 2. 1. 1. It is a quick-setting miscible material described in
In the volume frequency particle size distribution of the fast-setting admixture measured by the laser diffraction / scattering method, when the particle size at which the cumulative value is 90% is D90,
A fast-setting admixture having a D90 of 50 μm or more and 300 μm or less.
3. 3. 2. 2. It is a quick-setting miscible material described in
A fast-setting admixture having (D90-D10) / D50 of 4.0 or more and 35.0 or less.
4. 1. 1. ~ 3. The quick-setting miscible material described in any one of the above.
When the fast-setting admixture was sieved using a sieve with a mesh opening of 75 μm and the volume frequency particle size distribution of the sieve fraction (A) remaining on the sieve was measured by a laser diffraction scattering method, the particle size distribution was measured.
D50 is 130 μm or more and 400 μm or less, and
A fast-setting admixture having a D10 of 90 μm or more and 125 μm or less.
5. 1. 1. ~ 4. The quick-setting miscible material described in any one of the above.
When the fast-setting admixture was sieved using a sieve with an opening of 75 μm and the volume frequency particle size distribution of the subsieving fraction (B) passed through this sieve was measured by a laser diffraction scattering method.
D50 is 7 μm or more and 12 μm or less, and
A fast-setting admixture having a D10 of 0.5 μm or more and 6 μm or less.
6. 1. 1. ~ 5. The quick-setting miscible material described in any one of the above.
A fast-setting admixture which does not contain alkali carbonate or contains alkali carbonate in a content of 0.05% by mass or less with respect to 100% by mass of the calcium aluminate.
7. 1. 1. ~ 6. The quick-setting miscible material described in any one of the above.
A quick-setting admixture having a calcium aluminate content of 60% by mass or more and 80% by mass or less in 100% by mass of the quick-setting admixture.
8. 1. 1. ~ 7. The quick-setting miscible material described in any one of the above.
A quick-setting admixture having an aluminum sulfate content of 1% by mass or more and 10% by mass or less in 100% by mass of the quick-setting admixture.
9. 1. 1. ~ 8. The quick-setting miscible material described in any one of the above.
A quick-setting admixture having a gypsum content of 15% by mass or more and 30% by mass or less in 100% by mass of the quick-setting admixture.
10. 1. 1. ~ 9. The quick-setting miscible material described in any one of the above.
A quick-setting admixture having a sodium sulfate content of 3% by mass or more and 12% by mass or less in 100% by mass of the quick-setting admixture.
11. 1. 1. -10. The quick-setting miscible material described in any one of the above.
A fast-setting admixture containing _{CaF 2.}
12. 1. 1. ~ 11. The quick-setting miscible material described in any one of the above.
_{A fast-setting admixture whose CaF 2} content when quantitatively analyzed by the Rietveld method is 0.3% by mass or more and 2% by mass or less in 100% by mass of the quick-setting admixture.
13. 1. 1. ~ 12. A spraying material comprising the fast-setting admixture and cement described in any one of the above.
14. 13. It is a spraying material described in
A spraying material containing a liquid quick-setting agent containing an aluminum salt.

Claims (14)

A powdery, fast-setting admixture containing calcium aluminate, aluminum sulphate, gypsum, and sodium sulphate.
In the volume frequency particle size distribution of the rapid admixture measured by the laser diffraction / scattering method, when the particle size having a cumulative value of 50% is D50 and the particle size having a cumulative value of 10% is D10.
D50 is 6 μm or more and 15 μm or less,
D10 is 1 μm or more and 5 μm or less, and (D50-D10) / D50 is 0.1 or more and 1.0 or less.
Fast-setting admixture. The quick-setting miscible material according to claim 1.
In the volume frequency particle size distribution of the fast-setting admixture measured by the laser diffraction / scattering method, when the particle size at which the cumulative value is 90% is D90,
A fast-setting admixture having a D90 of 50 μm or more and 300 μm or less. The quick-setting miscible material according to claim 2.
A fast-setting admixture having (D90-D10) / D50 of 4.0 or more and 35.0 or less. The quick-setting miscible material according to any one of claims 1 to 3.
When the fast-setting admixture was sieved using a sieve with a mesh opening of 75 μm and the volume frequency particle size distribution of the sieve fraction (A) remaining on the sieve was measured by a laser diffraction scattering method, the particle size distribution was measured.
A fast-setting admixture having a D50 of 130 μm or more and 400 μm or less, and a D10 of 90 μm or more and 125 μm or less. The quick-setting miscible material according to any one of claims 1 to 4.
When the fast-setting admixture was sieved using a sieve with an opening of 75 μm and the volume frequency particle size distribution of the subsieving fraction (B) passed through this sieve was measured by a laser diffraction scattering method.
A fast-setting admixture having a D50 of 7 μm or more and 12 μm or less and a D10 of 0.5 μm or more and 6 μm or less. The quick-setting miscible material according to any one of claims 1 to 5.
A fast-setting admixture which does not contain alkali carbonate or contains alkali carbonate in a content of 0.05% by mass or less with respect to 100% by mass of the calcium aluminate. The quick-setting miscible material according to any one of claims 1 to 6.
A quick-setting admixture having a calcium aluminate content of 60% by mass or more and 80% by mass or less in 100% by mass of the quick-setting admixture. The quick-setting miscible material according to any one of claims 1 to 7.
A quick-setting admixture having an aluminum sulfate content of 1% by mass or more and 10% by mass or less in 100% by mass of the quick-setting admixture. The quick-setting miscible material according to any one of claims 1 to 8.
A quick-setting admixture having a gypsum content of 15% by mass or more and 30% by mass or less in 100% by mass of the quick-setting admixture. The quick-setting miscible material according to any one of claims 1 to 9.
A quick-setting admixture having a sodium sulfate content of 3% by mass or more and 12% by mass or less in 100% by mass of the quick-setting admixture. The quick-setting miscible material according to any one of claims 1 to 10.
A fast-setting admixture containing _{CaF 2.} The quick-setting miscible material according to any one of claims 1 to 11.
_{A fast-setting admixture whose CaF 2} content when quantitatively analyzed by the Rietveld method is 0.3% by mass or more and 2% by mass or less in 100% by mass of the quick-setting admixture. A spraying material comprising the fast-setting admixture according to any one of claims 1 to 12 and cement. The spraying material according to claim 13.
A spraying material containing a liquid quick-setting agent containing an aluminum salt.