JP2002053357A - Quick setting agent, spraying material and spraying method using the same quick setting agent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a quick setting agent which enables reduction in rebound ratio when spraying work with quick setting spraying cement concrete is executed, and also to obtain such a spraying material containing the quick setting agent. SOLUTION: This quick setting agent comprises aluminum sulfate, an alkali metal sulfate and at least one of calcium aluminates. This spraying material consists of cement concrete and the quick setting agent mixed to the cement concrete. This spraying method involves conveying the quick setting agent while pressurizing it with compressed air, and joining the flow of the agent to the flow of cement concrete and mixing them together to form the spraying material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spraying material to be sprayed on an exposed ground surface in a tunnel such as a road, a railway, and a headrace, and a spraying method using the same. In addition,
In the present invention, paste, mortar, and concrete are collectively referred to as cement concrete.

[0002]

2. Description of the Related Art Conventionally, a method of spraying quick-setting concrete in which a quick-setting agent is mixed with concrete has been performed in order to prevent collapse of an exposed ground such as a tunnel excavation (Japanese Patent Publication No. Sho 6).
0-4149).

[0003] In this method, a concrete is usually prepared by mixing a cement, an aggregate and water to prepare a shotcrete, transported by an agitator truck, and pumped by a concrete pump in a measuring and mixing plant installed at an excavation site. Is mixed with the quick-setting agent pumped from the other side and sprayed as quick-setting sprayable concrete to a predetermined thickness on the ground surface.

[0004] As the quick-setting agent used at this time, calcium aluminate and / or alkali aluminate and a mixture thereof with an alkali carbonate and the like are known (Japanese Patent Application Laid-Open No. 64-51351, Kosho 56-274
57, JP-A-61-26538, and JP-A-63-21050).

[0005] Recently, an alkali-aggregate-reaction-inhibiting quick-setting agent containing aluminum sulfate has been known as a permanent structure that can be used for a long period of time to enhance the long-term strength development. As an alkali-aggregate reaction-inhibiting quick-setting agent containing aluminum sulfate, a mixture of hydrous aluminum sulfate having crystal water and calcium aluminate has been proposed (JP-A-8-48553).

[0006]

However, when the conventional quick-setting admixture is used, there is a problem that the rebound rate at the time of spraying is large and the long-term strength development is low.

Further, when a mixture of hydrous aluminum sulfate and calcium aluminate is used, there is a problem that the initial strength development is low, especially at low temperatures, the initial strength development is remarkably reduced, and the water-cement ratio is affected. there were.

As a result of various studies on the above-mentioned problems, the present inventor has obtained the knowledge that can solve the above-mentioned problems by using a specific spraying material, and has completed the present invention.

That is, the present invention is a quick-setting agent containing calcium aluminates, aluminum sulfate, and an alkali metal sulfate, wherein the alkali metal sulfate is contained in an amount of 10 to 30 parts by mass in 100 parts by mass of the quick-setting agent. It is the quick-setting agent in parts by mass, wherein the calcium aluminate has a CaO / Al ₂ O ₃ (molar ratio) of 1.5 to 3.0, and further comprises an aromatic sulfonic acid and And / or the quick-setting agent containing an aromatic sulfonic acid formaldehyde condensate, wherein the quick-setting agent is a powder-form quick-setting agent, and further the water-containing quick-setting agent. A quick-setting agent having a pH of less than 7 and a vitrification ratio of calcium aluminates of 40% or more. And, it is a spray material obtained by mixing cement concrete containing cement and the quick setting agent, and further, the spray material is a cement material containing polyalkylene oxide, and further a fibrous material. The spray material comprises a substance. Also, there is provided a spraying method characterized in that the quick-setting agent is pressure-fed by pressurized air and mixed and mixed with cement concrete.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

The quick-setting agent used in the present invention contains calcium aluminates, aluminum sulfate, and alkali metal sulfate.

The calcium aluminates used in the present invention can be obtained by mixing a raw material containing calcia and a raw material containing alumina, and performing a heat treatment such as firing in a kiln or melting in an electric furnace. , CaO and Al ₂ O ₃ as main components and a general term for substances having hydration activity, and some of CaO and / or Al ₂ O ₃ are alkali metal oxides, alkaline earth metal oxides, Compounds substituted with silicon, titanium oxide, iron oxide, alkali metal halide, alkaline earth metal halide, alkali metal sulfate, alkaline earth metal sulfate, or CaO and Al ₂
It is a substance in which a small amount of these are dissolved in a substance containing O ₃ as a main component. The mineral form may be either crystalline or amorphous.

Of these, calcium aluminate is preferred in terms of reaction activity, and 12CaO · 7Al ₂ O ₃
A mixture containing amorphous calcium aluminate obtained by quenching a heat-treated product corresponding to a composition (hereinafter referred to as C ₁₂ A ₇ ) is more preferable.

The vitrification rate of calcium aluminates is preferably 40% or more in terms of accelerating initial setting, improving initial strength development, and reducing rebound rate.
% Or more, more preferably 80% or more,
100% is most preferred. If it is less than 40%, coagulation properties and strength development properties are impaired, and the rebound rate increases.

The vitrification rate was determined by heating the calcium aluminate of the present invention under the conditions of 1000 ° C. for 2 hours, then gradually cooling it at a cooling rate of 5 ° C./min. measuring the area S ₀ of the main peak of the main peak area S of the crystals of calcium aluminates in the sample of the present invention this S _0, in which to determine the vitrification ratio χ by equation (1). χ (%) = 100 × (1−S / S ₀ ) Equation (1)

CaO / Al of calcium aluminates
₂ O ₃ (molar ratio) promotes the initial setting, improves the initial strength development, and reduces the rebound rate.
3.0, preferably 1.7 to 2.5. If it is less than 1.5, the coagulability and the initial strength development are impaired, and the rebound rate becomes large. If it exceeds 3.0, the coagulation and the strength development are impaired, and the rebound rate becomes large, which is economically undesirable. .

The particle size of calcium aluminates is 4,000 cm in Blaine value in terms of quick setting and initial strength development.
² / g or more is preferable, and 5000 cm ² / g or more is more preferable. If it is less than 4000 cm ² / g, the quick setting property and the initial strength expression property may be reduced.

The aluminum sulfate used in the present invention is a component that promotes initial setting and reduces the rebound rate.
Aluminum ions are supplied during the hydration reaction of cement, react with calcium ions from cement and calcium aluminates to form calcium aluminate hydrate, and further react with sulfate ions to quickly react with calcium sulfate. It produces aluminate hydrate and contributes to improving the initial strength development.

Aluminum sulfate can be used both in the form of an anhydride and a hydrate, and the anhydride and the hydrate may be used in combination. Among these, hydrates are preferred because they have a large effect of promoting initial setting, reducing the rebound rate, and improving initial strength development.

The amount of aluminum sulfate used is calculated as anhydride and is based on 100 parts by mass of calcium aluminate.
The amount is preferably 5 to 100 parts by mass, more preferably 10 to 45 parts by mass, and most preferably 10 to 40 parts by mass. If the amount is less than 5 parts by mass, the rebound rate is large, and there is a possibility that initial setting is difficult. If the amount exceeds 100 parts by mass, the long-term strength development may be impaired.

The alkali metal sulfate used in the present invention is:
It is a component that improves initial strength development.

Examples of the alkali metal sulfate include sodium sulfate, potassium sulfate, sodium bisulfate, sodium sulfite, potash alum, chrome alum, iron alum and the like. Among these, one or two or more of the group consisting of sodium sulfate, potassium sulfate, and potassium alum are preferable in terms of good coagulation properties and initial strength development, and sodium sulfate and / or potassium sulfate are preferable. More preferred, sodium sulfate is most preferred.

As the alkali metal sulfate, both an anhydride and a hydrate can be used, and an anhydride and a hydrate may be used in combination. Of these, anhydrides are preferred from the viewpoint of stability.

The amount of the alkali metal sulfate used is 10 to 30 parts by mass in 100 parts by mass of the quick-setting agent containing calcium aluminates, aluminum sulfate and alkali metal sulfate.
A mass part is preferable and 15-20 mass parts is more preferable.
If the amount is less than 10 parts by mass, the rebound rate is large, impairing the initial strength development, and when the quick-setting agent is a slurry, the quick-setting cement concrete may have low pumpability,
If the amount exceeds the mass part, the coagulation property and the long-term strength development property may be impaired.

Gypsum or a setting accelerator may be used in combination with the quick setting agent in order to improve initial setting and strength development.

In the present invention, calcium aluminates, in order to reduce the rebound rate and improve the strength development,
Accelerators containing aluminum sulfate and alkali metal sulfates are preferred. In order to further reduce the rebound rate and dust, it is possible to further mix water (hereinafter referred to as slurry water) to form a quick-setting slurry.

When a quick-setting agent slurry is used, the pH of the quick-setting agent slurry is set to 7 in order to promote initial setting, improve the pumpability and initial strength development of the quick-setting agent slurry, and reduce the rebound rate. Less than 3, preferably 3 or more and less than 7, preferably 4
To 6 are more preferable. If it is less than 3, the coagulation property and the initial strength expression property may be inhibited, and the rebound rate may increase,
If it is 7 or more, the pumpability becomes small, the long-term strength development is impaired, and the rebound rate becomes large. The pH of the quick-setting agent slurry referred to in the present invention is such that the quick-setting agent slurry is further diluted with water for 1 hour.
It is the pH of the dilution diluted to 0 times.

The amount of the slurry water used is preferably 30 to 600 parts by mass, and 50 to 8 parts by mass with respect to 100 parts by mass of the quick setting agent.
0 parts by mass is more preferred. If the amount is less than 30 parts by mass, the amount of dust may not be reduced, and if it exceeds 600 parts by mass, the strength development may be reduced.

To improve the properties of cement concrete, a slurry retarder, a thickener, and an ultrafine powder may be used in combination with the slurry water. Further, aluminum sulfate or alkali metal sulfate may be dissolved in slurry water and used.

On the other hand, when a powder quick-setting agent is used as a quick-setting agent, there is no need for a step of wetting or slurrying the quick-setting agent, and there is an advantage that workability is easy.

The amount of the quick setting agent used is preferably 2 to 25 parts by mass, in terms of solid content, with respect to 100 parts by mass of cement.
-20 mass parts is more preferable, and 7-15 mass parts is most preferable. If the amount is less than 2 parts by mass, the initial setting may not be easily promoted. If the amount exceeds 25 parts by mass, the long-term strength development may be impaired.

As the cement used in the present invention, various kinds of portland cement which are usually commercially available, such as ordinary, fast strength, moderate heat and super fast strength, and a mixture of these portland cements with fly ash, blast furnace slag, etc. Various mixed cements and the like can be mentioned, and these may be used after being pulverized. Of these, ordinary Portland cement and / or early-strength Portland cement are preferred in terms of good pumpability of cement concrete.

Further, in the present invention, it is preferable to use a polyalkylene oxide on the cement concrete side from the viewpoint of reducing the rebound rate and the amount of dust.

The polyalkylene oxide (hereinafter referred to as PAO) used in the present invention imparts viscosity to cement concrete, prevents dripping of the cement concrete from the sprayed surface immediately after spraying, and reduces the rebound rate and the amount of dust. is there. Examples of the polyalkylene oxide include polyethylene oxide, polypropylene oxide, and polybutylene oxide. Among them, polyethylene oxide is preferred because it gives viscosity to cement concrete and has a great effect of reducing the rebound rate and the amount of dust at the time of spraying.

The molecular weight of PAO is preferably 1,000,000 to 5,000,000. If it is less than 1,000,000, the viscosity of the cement concrete is small, and it may not be possible to prevent the dripping of the cement concrete from the spraying surface immediately after spraying, and if it exceeds 5,000,000, the strength expression is impaired, and when the quick-setting agent is a slurry, There is a possibility that the pumpability of the quick setting cement concrete obtained by mixing the quick setting agent and the cement concrete may be reduced.

The amount of PAO used is preferably 0.001 to 0.2 part by mass, and more preferably 0.1 to 0.2 part by mass, based on 100 parts by mass of cement.
005 to 0.1 part by mass is more preferred. If it is less than 0.001 part by mass, the viscosity of the quick-setting cement concrete is small, the amount of dust is large, the rebound rate may be large, and if it exceeds 0.2 part by mass, the viscosity and rebound rate of the cement concrete are large, When the amount of dust is large and the quick setting agent is a slurry, there is a possibility that the pumpability of the quick setting cement concrete may be affected.

Further, in the present invention, it is preferable to use an aromatic sulfonic acid and / or an aromatic sulfonic acid formaldehyde condensate on the quick setting agent side in view of reduction of a rebound rate and a dust amount.

The aromatic sulfonic acid used in the present invention and / or
Or, an aromatic sulfonic acid formaldehyde condensate (hereinafter referred to as aromatic sulfonic acids) improves the fluidity of cement concrete and the dispersibility of a quick-setting agent, improves the adhesion of quick-setting cement concrete during spraying, and rebounds. It reduces the rate and the amount of dust, and any of liquid and powder can be used. Further, when the viscosity increases by reacting with the polyalkylene oxide in the cement concrete, the adhesiveness of the quick-setting cement concrete at the time of spraying is improved, and the effect of reducing the rebound rate and the amount of dust is further increased. Aromatic sulfonic acids include naphthalene sulfonic acid, alkyl naphthalene sulfonic acid, bisphenol A
Sulfonic acid, phenolsulfonic acid, trisphenolsulfonic acid, 4-phenoxybenzene-4'-sulfonic acid, methyldiphenylethersulfonic acid, and aromatic sulfonic acids of anthracenesulfonic acid, and formaldehyde condensates of these aromatic sulfonic acids and the like Is mentioned. Further, the aromatic ring may have an alkyl group. Among them, the fluidity of cement concrete and the dispersibility of the quick-setting agent are improved, the quick-setting property at the time of spraying The adhesion of cement concrete is improved, and the rebound rate and the effect of reducing the amount of dust are large, Aromatic sulfonic acid formaldehyde condensate is preferable, and one or more members selected from the group consisting of naphthalene sulfonic acid formaldehyde condensate, alkylnaphthalene sulfonic acid formaldehyde condensate, and bisphenol A sulfonic acid formaldehyde condensate are more preferable, and β-naphthalene sulfone An acid formaldehyde condensate (hereinafter referred to as β-NS) is most preferred.

The amount of the aromatic sulfonic acid to be used is 0.1 to 100 parts by mass of the quick-setting agent containing calcium aluminates, aluminum sulfate and alkali metal sulfate.
The amount is preferably from 5 to 5 parts by mass, more preferably from 0.1 to 3 parts by mass. If it is less than 0.05 parts by mass, the fluidity of the cement concrete and the dispersibility of the quick setting agent are improved, the quick setting property of the cement concrete when spraying is improved, and the effect of reducing the rebound rate and the amount of dust is small. If it exceeds 5 parts by mass, the rebound rate is large, the amount of dust is large, and the strength development may be impaired.

Further, in the present invention, it is preferable to use a fibrous substance in the quick-setting cement concrete from the viewpoint of improving the bending strength, impact resistance and toughness of the quick-setting cement concrete.

As the fibrous substance used in the present invention, both inorganic and organic substances can be used. Examples of the inorganic fibrous substance include glass fiber, rock wool, asbestos, ceramic fiber, and metal fiber, and examples of the organic fibrous substance include vinylon fiber, polyethylene fiber, polypropylene fiber, polyacryl fiber, and cellulose fiber. , Polyvinyl alcohol fiber, polyamide fiber, pulp,
Hemp, wood wool, wood chips and the like. Also, carbon fibers can be used. Among these, metal fibers and / or vinylon fibers are preferred in terms of economy.

The length of the fibrous substance is preferably 50 mm or less, more preferably 30 mm or less, in view of the pumpability and the mixing property. If it exceeds 50 mm, the pumping tube may be closed during the pumping.

The amount of the fibrous substance used is 0.1 to 100 parts by volume of cement concrete containing the fibrous substance.
1.5 parts by volume is preferable, and 0.3 to 1.2 parts by volume is more preferable. If it is less than 0.1 volume part, bending strength, impact resistance,
And the toughness may not be improved, and if it exceeds 1.5 parts by volume, the pumpability of the quick-setting cement concrete decreases,
There is a possibility that impact resistance and strength development properties may be impaired.

In the present invention, an AE agent or a foaming agent may be further added to mix air bubbles to reduce the amount of dust.

The amount of water in the cement concrete is preferably from 35 to 65 parts by mass, more preferably from 40 to 55 parts by mass, per 100 parts by mass of the cement. If the amount is less than 35 parts by mass, the cement concrete may not be sufficiently mixed. If the amount exceeds 65 parts by mass, the strength development may be low. The water here does not include slurry water.

The aggregate used in the present invention is not particularly limited as long as it can be sprayed, but a material having high aggregate strength is preferable. As fine aggregate, river sand, mountain sand, lime sand, silica sand, and the like can be used, and as coarse aggregate, river gravel, mountain gravel, lime gravel, and the like can be used.

In the spraying method used in the present invention, quick-setting cement concrete can be sprayed in terms of required physical properties, economy and workability.

As a spraying method in a case where the quick-setting agent is not converted into a slurry, the cement-setting concrete and the powdery quick-setting agent are separately fed under pressure, and the powdery quick-setting agent is mixed and mixed with the cement concrete to form a quick-setting cement. The spraying method of spraying as concrete is preferred.

As a spraying method when a quick-setting agent slurry is used, cement concrete and a quick-setting agent are separately fed under pressure, and water is added to the quick-setting agent immediately before the cement concrete and the quick-setting agent are mixed and rapidly set. It is preferable to use a spraying method in which the quick-setting agent slurry is mixed and mixed with cement concrete and sprayed as quick-setting cement concrete. A wet spraying method or a dry spraying method can be used. Among these, the wet spraying method is preferable because the amount of dust is small.

As a wet spraying method when a quick-setting agent slurry is used, cement, aggregate, and water are mixed and kneaded, and air-pressure fed. A method of adding and spraying a quick-setting agent slurry that has been slurried by adding water just before the addition.

In the case of using the quick-setting agent slurry, as a dry spraying method, cement and aggregate are mixed, air-pressure fed, and the quick-setting agent slurry obtained by the same method as the wet spraying method is used.
A method in which water is added and sprayed is used.

Thus, the amount of dust and the rebound rate can be reduced and the working environment can be improved by making the quick-setting agent into a slurry and mixing it with cement concrete.

The method of making the quick-setting agent into a slurry is not particularly limited. For example, a method of making the quick-setting agent into a slurry by adding water with high-pressure water from several places around one of the Y-tubes for air-pressure feeding. Preferred are mentioned. This high-pressure water also has the effect of injecting the quick-setting agent slurry into cement concrete, so that the mixing property is improved. As a result, the reactivity with cement concrete is increased, the amount of dust and the rebound rate are reduced, the setting property and the strength development are improved, and the quality of the quick-setting sprayed concrete is stabilized.

In the spraying method of the present invention, conventional spraying equipment can be used. The spraying equipment is not particularly limited as long as the spraying is sufficiently performed. For example, Aliver 280, a trade name of Aliver Co., Ltd., is used for pumping cement concrete, and a quick-setting agent pumping device is used for pumping quick-setting agent. "Natom Cleat" can be used. A common water pump may be used to add water to the quick-setting agent to form a quick-setting agent slurry, and a method of applying pressurized air during pressurization and pressurizing may be used.

The pressure at which cement concrete is pumped is 0.
It is preferably larger by 2 to 0.6 MPa. The pressure of the compressed air for pumping the quick-setting agent is preferably 0.01 to 0.3 MPa higher than that of cement concrete.

The speed of the quick-setting cement concrete is preferably 4 to 20 m ³ / h. Furthermore, the junction of the quick-setting agent and the cement concrete may have a pipe shape or a structure in which the inner wall of the pipe is easily turbulent or a helical structure in order to improve the mixing property.

[0057]

The present invention will be described below in detail based on experimental examples.

EXPERIMENTAL EXAMPLE 1 A unit amount of each material was set to 500 kg / m ^{3 of} cement and 20 parts of water.
0 kg / m ^3, the fine aggregate 1173kg / m ^3, and coarse aggregate 510kg / m ^3, furthermore, with respect to 100 parts by weight of cement, and the PAO of 0.02 parts by weight, spraying concrete containing the fibrous material In 100 parts by volume, a spray concrete was prepared by adding 1.0 part by volume of a fibrous substance,
Under a condition of a pumping speed of 4 m ³ / h and a pumping pressure of 0.4 MPa, the concrete was pumped by a concrete pump “Aliba-280”. On the other hand, 100 parts by mass of calcium aluminates, aluminum sulfate in parts by mass shown in Table 1 in terms of anhydride, and calcium aluminates, aluminum sulfate,
18 parts by weight of alkali metal sulfate and 100 parts by weight of quick-setting agent containing alkali metal sulfate and quick-setting agent 10
A powdery quick-setting admixture obtained by mixing 2 parts by mass of the aromatic sulfonic acid α with respect to 0 parts by mass was pneumatically fed so as to be 10 parts by mass with respect to 100 parts by mass of the cement. This quick-setting agent was pumped under the condition of a pumping pressure of 0.5 MPa, and was mixed with sprayed concrete to obtain a quick-setting sprayed concrete. This quick setting sprayed concrete was evaluated. Table 1 shows the results.

(Materials used) Cement: ordinary Portland cement, commercially available product, Blaine value 3200 cm ² / g, specific gravity 3.16 Fine aggregate: river sand from Himekawa, Niigata prefecture, surface water content 4.0%, specific gravity 2.62 coarse Aggregate: Gravel from Himekawa, Niigata Prefecture, surface dry, specific gravity 2.6
4. Maximum dimension 10mm PAO: polyethylene oxide, molecular weight 2,000,000, commercially available fibrous substance: steel fiber, length 30mm, specific gravity 7.8, commercially available calcium aluminates: calcium aluminate, mainly C ₁₂ A ₇ Corresponding to the composition containing, amorphous, Blaine value 6000 cm ² / g, calcia raw material and alumina raw material mixed at a predetermined ratio, melted in high frequency induction furnace, quenched,
100% vitrification, pulverized, CaO / Al
₂ O ₃ (molar ratio) = 2.0 Aluminum sulfate: hydrous aluminum sulfate, commercial product Alkali metal sulfate: sodium sulfate, anhydride, commercial product Aromatic sulfonic acids α: β-NS: powder, commercial product

(Measurement method) Setting time: Knead mortar with a material excluding coarse aggregate in shotcrete, and measure according to the Japan Society of Civil Engineers standard “Quick-setting agent quality standard for shotcrete (JSCED-102)”. did. Compressive strength: measured at 20 ° C. The prepared quick-setting spray concrete was sprayed on a pull-out formwork having a width of 25 cm × length of 25 cm and a formwork of width 50 cm × length 50 cm × thickness 20 cm. The initial strength at the age of 3 hours was measured using a pull-out form specimen. The pin was covered with quick-setting spray concrete from the surface of the pull-out form, and the pin was pulled out from the back side of the form, and the pull-out strength at that time was determined.
The compressive strength was calculated from (compressive strength) = (pull-out strength) × 4 / (specimen surface area). 50c width after 1 day
A specimen having a diameter of 5 cm and a length of 10 cm collected from a mold having a size of mx 50 cm in length x 20 cm in thickness was used.
It measured with the 0-ton pressure machine. Rebound rate: Quick-setting sprayed concrete was sprayed at a pumping speed of 4 m ³ / h for 10 minutes into a simulated tunnel 3.5 m high and 2.5 m wide made of an iron plate in an arch shape. Thereafter, (rebound rate) = (mass of quick-setting sprayed concrete dropped without adhering to the simulated tunnel) / (mass of quick-setting sprayed concrete sprayed on the simulated tunnel) × 100
(%).

[0061]

[Table 1]

Experimental Example 2 100 parts by mass of calcium aluminates shown in Table 2
25 parts by weight of aluminum oxide in terms of anhydride, and
Lucium aluminates, aluminum sulfate, and aluminum
18 substances in 100 parts by mass of quick setting agent containing potassium metal sulfate
Parts by weight of alkali metal sulfate and 100 parts by mass of quick setting agent
Parts by weight of 2 parts by weight of an aromatic sulfonic acid α
Same as Experimental Example 1 except that a powdered quick setting agent was used.
And evaluated. Table 2 shows the results. (Materials used) Calcium aluminates: Mainly C₁₂A
₇Corresponding to a composition containing^Two/
g, calcia raw material and alumina raw material mixed at a predetermined ratio
After being melted in a high frequency induction furnace, it is gradually cooled, and vitrification rate is 40%
And crushed, CaO / Al _TwoO_Three(Molar ratio) =
2.0 Calcium aluminates: mainly C₁₂A₇Composition containing
Correspondence, Brain value 6000cm^Two/ G, Calcia Hara
Material and alumina raw material are mixed at a predetermined ratio,
After being melted, the mixture was gradually cooled to a vitrification rate of 60% and pulverized.
Of CaO / Al _TwoO_Three(Molar ratio) = 2.0 Calcium aluminates: mainly C₁₂A₇Composition containing
Correspondence, Brain value 6000cm^Two/ G, Calcia Hara
Material and alumina raw material are mixed at a predetermined ratio,
After quenching, it was quenched to make the vitrification rate 80%,
Of CaO / Al _TwoO_Three(Molar ratio) = 2.0

[0063]

[Table 2]

Experimental Example 3 100 parts by mass of calcium aluminates shown in Table 3, 25 parts by mass of aluminum sulfate in terms of anhydride, and a quick setting agent containing calcium aluminates, aluminum sulfate and alkali metal sulfate Except that 18 parts by mass of the alkali metal sulfate in 100 parts by mass, and 100 parts by mass of the quick-setting admixture, a powdery quick-setting admixture obtained by mixing 2 parts by mass of the aromatic sulfonic acids α was used. Evaluation was performed in the same manner as in Experimental Example 1. Table 3 shows the results. (Materials used) Calcium aluminates: A calcia raw material and an alumina raw material are mixed at a predetermined ratio, melted in a high frequency induction furnace, quenched, made vitrified to 100%, pulverized, amorphous, Blaine value 6000 cm ² / g, CaO / Al ₂ O
₃ (molar ratio) = 1.5 Calcium aluminate: calcia raw material and alumina raw material are mixed at a predetermined ratio, melted in a high frequency induction furnace, quenched, made vitrified to 100%, pulverized, amorphous Quality, Brain value 6000 cm ² / g, CaO / Al ₂ O
₃ (Molar ratio) = 1.7 Calcium aluminate: calcia raw material and alumina raw material are mixed at a predetermined ratio, melted in a high frequency induction furnace, quenched, made vitrified to 100%, pulverized, amorphous Quality, Brain value 6000 cm ² / g, CaO / Al ₂ O
₃ (Molar ratio) = 2.5 Calcium aluminates: A mixture of calcia raw material and alumina raw material at a predetermined ratio, melted in a high frequency induction furnace, quenched, made vitrified to 100%, pulverized, amorphous Quality, Brain value 6000 cm ² / g, CaO / Al ₂ O
₃ (molar ratio) = 3.0

[0065]

[Table 3]

Experimental Example 4 100 parts by mass of calcium aluminates, 25 parts by mass of aluminum sulfate in terms of anhydride, and 100 parts by mass of a quick setting agent containing calcium aluminates, aluminum sulfate and alkali metal sulfate The experiment was conducted in the same manner as in Table 4 except that the powdered quick-setting admixture obtained by mixing 2 parts by mass of the aromatic sulfonic acids α with 100 parts by mass of the alkali metal sulfate and 100 parts by mass of the quick-setting admixture was used. Evaluation was performed in the same manner as in Example 1. Table 4 shows the results.

[0067]

[Table 4]

Experimental Example 5 18 parts by weight of alkali metal sulfate and 10 parts by weight of 100 parts by weight of a quick-setting agent containing aluminum sulfate and an alkali metal sulfate without using calcium aluminates were used.
Experimental Example 1 except that a powdery quick-setting admixture obtained by mixing 2 parts by mass of the aromatic sulfonic acids α with 0 parts by mass was used.
The evaluation was performed in the same manner as described above. Table 5 shows the results.

(Measurement method) Low-temperature compressive strength: Measured in the same manner as the compressive strength except that the measurement was performed at 10 ° C.

[0070]

[Table 5]

EXPERIMENTAL EXAMPLE 6 100 parts by mass of calcium aluminates, 25 parts by mass of aluminum sulfate in terms of anhydride, and 100 parts by mass of a quick setting agent containing calcium aluminates, aluminum sulfate and alkali metal sulfate The experiment was carried out except that a powdery quick-setting admixture obtained by mixing 18 parts by mass of the alkali metal sulfate and 100 parts by mass of the quick-setting admixture with the aromatic sulfonic acids α shown in Table 6 was used. Evaluation was performed in the same manner as in Example 1. Table 6 shows the results.

(Materials used) Aromatic sulfonic acids β: β-alkylnaphthalenesulfonic acid formaldehyde condensate, powdered, commercially available aromatic sulfonic acids γ: bisphenol A formaldehyde condensate, powdered, commercially available aromatic sulfonic acids δ : Phenolsulfonic acid, powdered, commercially available

(Measurement Method) Dust amount: Quick-setting shotcrete was formed in an arched form from an iron plate at a pumping speed of 4 m ³ / h for 10 minutes, at a height of 3.5.
m, a 2.5 m wide simulated tunnel. Thereafter, the amount of dust was measured at a fixed position of 3 m from the spray location, and the average value of the measured values was shown.

[0074]

[Table 6]

Experimental Example 7 The amount of PAO shown in Table 7 was measured with respect to 100 parts by mass of cement.
And 100 parts by volume of the shotcrete containing the fibrous substance, to prepare a sprayed concrete to which 1.0 part by volume of the fibrous substance was added and pumped the same, and on the other hand, 100 parts by mass of calcium aluminates and aluminum sulfate. 25 parts by weight in terms of anhydride, and 18 parts by weight of alkali metal sulfate in 100 parts by weight of a quick-setting agent containing calcium aluminates, aluminum sulfate, and alkali metal sulfate,
The same procedure as in Experimental Example 1 was carried out, except that a powdery quick-setting admixture obtained by mixing 2 parts by mass of the aromatic sulfonic acid α with respect to 100 parts by mass of the quick-setting admixture was used and evaluated. Table 7 shows the results.

[0076]

[Table 7]

Experimental Example 8 0.02 parts by mass of PA was added to 100 parts by mass of cement.
O and 100 parts by volume of the shotcrete containing the fibrous substance were prepared by adding and spraying the shotcrete containing the amount of the fibrous substance shown in Table 8, while 100 parts by mass of calcium aluminates and aluminum sulfate were added. 25 parts by mass in terms of anhydride, and calcium aluminates,
Aluminum sulfate and 18 parts by mass of alkali metal sulfate in 100 parts by mass of quick setting agent containing alkali metal sulfate, and 2 parts by mass of aromatic sulfonic acids α mixed with 100 parts by mass of quick setting agent Except for using the powdered quick setting agent, the same procedure as in Experimental Example 1 was performed and evaluated. Table 8 shows the results.

(Measurement method) Impact resistance: quick setting after one hour of age A piece of shot-cast concrete cut out to a width of 20 cm x a length of 20 cm x a thickness of 1 cm is placed on flattened standard sand. A 200 g sphere was dropped from a height of 50 cm. × if it was broken within 5 drops, 、 if it was cracked without breaking,
Those that did not crack without breaking were marked as ○.

[Table 8]

Experimental Example 9 100 parts by mass of calcium aluminates, 25 parts by mass of aluminum sulfate in terms of anhydride, and 100 parts by mass of a quick setting agent containing calcium aluminates, aluminum sulfate and alkali metal sulfate 18 parts by mass of alkali metal sulfate and 100 parts by mass of quick-setting admixture are mixed with 2 parts by mass of a sulphonic acid α to form a quick-setting admixture by air pressure. The water shown in Table 9 was added to 100 parts by mass of the quick setting agent through a hole formed in several places around the pipe to form a quick setting agent slurry. The same procedure as in Experimental Example 1 was carried out except that the shotcrete fed from the other end of the pipe was mixed with the sprayed concrete to form a quick-setting sprayed concrete. Table 9 shows the results.

[0080]

[Table 9]

Experimental Example 10 100 parts by mass of calcium aluminates, 25 parts by mass of aluminum sulfate in terms of anhydride, and 100 parts by mass of a quick-setting admixture containing calcium aluminates, aluminum sulfate and alkali metal sulfate 18 parts by mass of alkali metal sulfate and 100 parts by mass of quick-setting admixture are mixed with 2 parts by mass of a sulphonic acid α to form a quick-setting admixture by air pressure. From the holes drilled at several places around the tube of
0 parts by mass of the slurry water is added to form a quick setting slurry,
This quick-setting agent slurry was pressure-fed and mixed with the sprayed concrete fed from the other end of the Y-shaped pipe to obtain a quick-setting sprayed concrete. Table 10 shows the results.

(Measurement Method) pH: The pH of a diluted product prepared by diluting the quick-setting agent slurry 10-fold with water was shown. Pumpability: The sprayed concrete was pumped by a concrete pump by 20 m, then mixed with a quick-setting agent to form a quick-setting concrete, and the quick-setting concrete was sprayed for 5 minutes. The case where the Y-shaped pipe or the pipe was not clogged was evaluated as 、, the case where the Y-shaped pipe or the pipe was slightly clogged was evaluated as x, and the case where the Y-shaped pipe or the pipe was clogged and could not be sprayed was evaluated as x. Sauce: Rapid-setting shotcrete was pumped at a pumping speed of 4 m ³ / h for 10 minutes, 3.5 m high made of steel plate in an arch shape.
It was sprayed on a mock tunnel with a width of 2.5 m. Thereafter, the case where the rapid-setting concrete was not dripped from the side wall of the simulated tunnel was evaluated as ○, the case where it was slightly dripped was rated as Δ, and the case where it was drastically dripped was evaluated as ×.

[0083]

[Table 10]

[0084]

By using the spray material of the present invention,
The rebound rate when spraying quick setting cement concrete can be reduced. In addition, since high strength can be expected in the initial stage and long term, the sprayed thickness can be reduced, the construction cost can be reduced, and the safety can be improved because high strength can be obtained immediately after spraying.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) C04B 22:14 C04B 22:14 A 24:20 24:20 24:22 24:22 C 24:32 24: 32 A 16:06 16:06 B 14:48) 14:48) Z 103: 44 103: 44 (72) Inventor Masahiro Iwasaki 2209 Aomi, Aomi-cho, Nishikubiki-gun, Niigata Inside the Aomi Plant of Denki Kagaku Kogyo Co., Ltd. 72) Inventor Akira Watanabe 2209 Aomi, Aomi-cho, Nishikubiki-gun, Niigata Pref.

Claims (12)

[Claims] 1. A quick-setting agent containing calcium aluminates, aluminum sulfate, and an alkali metal sulfate. 2. The quick setting agent according to claim 1, wherein the alkali metal sulfate is 10 to 30 parts by mass based on 100 parts by mass of the quick setting agent. 3. CaO / A of calcium aluminates
l ₂ O ₃ (molar ratio) is quick-setting admixture according to claim 1 or 2, wherein 1.5 to 3.0. 4. The quick-setting agent according to claim 1, further comprising an aromatic sulfonic acid and / or an aromatic sulfonic acid formaldehyde condensate. 5. The setting agent according to claim 1, wherein the setting agent is in a powder form. 6. The method according to claim 1, further comprising water.
2. The quick-setting admixture according to claim 1. 7. The setting agent according to claim 6, wherein the pH of the setting agent is less than 7. 8. The quick-setting agent according to claim 1, wherein the calcium aluminate has a vitrification ratio of 40% or more. 9. A spray material obtained by mixing cement concrete containing cement and the quick-setting admixture according to claim 1. 10. The spray material according to claim 9, wherein the cement concrete further comprises a polyalkylene oxide. 11. The spray material according to claim 9, further comprising a fibrous substance. 12. A spraying method wherein the quick-setting agent according to any one of claims 1 to 8 is pressure-fed by pressurized air and mixed and mixed with cement concrete.