JP6877299B2 - Spraying material and spraying method using it - Google Patents

Description

The present invention mainly relates to a slurry-like spraying material for sprayed concrete used in the civil engineering / construction industry and a spraying method using the slurry-like spraying material. The concrete of the present invention is a general term for cement paste, mortar, and concrete.

Conventionally, in order to prevent the collapse of exposed ground such as tunnel excavation, a spraying method using quick-setting concrete in which a quick-setting agent is mixed with concrete has been performed. In this method, sprayed concrete is usually prepared at a cement, aggregate, and water metering and mixing plant installed at the excavation site, pumped with a concrete pump, and pumped from the other with a confluence pipe provided in the middle. This is a construction method in which a binder is mixed and sprayed as quick-setting sprayed concrete onto the ground surface until it reaches a predetermined thickness. As the spraying method, (1) a method using a powdery quick-setting admixture based on calcium aluminate (Patent Documents 1 to 4), and (2) a liquid quick-setting admixture containing aluminum sulfate as a main component. Methods to be used (Patent Documents 5 to 7), (3) Method of slurrying the powdery quick-setting admixture with water (Patent Document 8), (4) Liquid quick-setting admixture A method of using an agent as a slurry (Patent Documents 9 to 11) is known.

However, although the method (1) can impart an excellent rapid binding force, a large amount of dust is generated, and improvement of the working environment may be required. Method (2) is a method in which only the liquid quick-setting admixture is merged and mixed with concrete, and the system is simple because it is only necessary to mount the liquid pump and the tank for storing the liquid quick-setting admixture on the spraying system. Be made. However, the liquid quick-setting agent containing aluminum sulfate as the main component has a weaker quick-setting force than the powder-like quick-setting agent, and when there is spring water from the ground, the adhesiveness deteriorates, and it peels off or rebounds. There is a problem that the occurrence of is increased. Further, in the methods (3) and (4), just before the powdery quick-setting admixture is merged and mixed with the concrete, water or a liquid quick-setting admixture is added to form a slurry and mixed, so that dust is generated. It is a technology that is effective in improving the work environment with a small amount. However, it is necessary to equip the sprayer with a pump for pumping liquid, a storage tank for liquid, and addition equipment for pumping powdered quick-setting admixture, which complicates the system and also during construction. Due to the self-hardening property of the powder quick-setting admixture, there are problems such as the nozzle for making a slurry easily solidifying, and improvement has been required. In addition, sprayed concrete using a liquid quick-setting admixture has improved initial strength, but its long-term strength tends to be lower than that of base concrete to which no quick-setting admixture is added. Then cracks were likely to occur.

Further, (5) a slurry-like spray material containing a slurry, cement and water containing an inorganic ^{fine powder having a BET specific surface area of 10 m 2} / g or more, which is inert to the divalent lower alcohol and the divalent lower alcohol. The construction method used is also known (Patent Document 12). However, since a fine powder having a BET specific surface area of 10 m ² / g or more is used, there is a problem that it is difficult to obtain a stable pumping property of the slurry. Further, (6) a technique of a liquid quick-setting admixture containing a liquid oil in calcium aluminate is known (Patent Document 13). However, when a liquid oil containing an unsaturated fatty acid is used, although the initial strength can be obtained, the subsequent strength does not increase, and there is a problem that the risk of concrete peeling increases.

Japanese Unexamined Patent Publication No. 64-051351 Special Publication No. 56-27457 Japanese Unexamined Patent Publication No. 61-026538 Japanese Unexamined Patent Publication No. 63-21050 Japanese Unexamined Patent Publication No. 2005-60201 Japanese Unexamined Patent Publication No. 2005-89276 Japanese Unexamined Patent Publication No. 2008-30999 Japanese Unexamined Patent Publication No. 2001-55597 Japanese Unexamined Patent Publication No. 05-139804 Japanese Unexamined Patent Publication No. 05-097491 Japanese Unexamined Patent Publication No. 2007-277051 Japanese Unexamined Patent Publication No. 2006-083005 Japanese Unexamined Patent Publication No. 2006-151760

Among the conventional spraying materials for sprayed concrete described above, those having excellent initial strength development have a large amount of dust generated, while those having a small amount of dust generation have inferior initial strength development, and the performance of both. There was no one that had both.
The present invention provides a spraying material for sprayed concrete, which has good initial strength development after spraying, a small amount of dust generated, and excellent safety and hygiene, and a spraying method using the same. With the goal.

As a result of studies to solve the above problems, the present inventors have made the calcium aluminate-based powder quick-setting material into a slurry in advance with a non-aqueous solvent, which simplifies the process in the same manner as the conventional liquid quick-setting agent. It is possible to use the above system, it is excellent in pumping performance, and it is possible to obtain the effect of suppressing dust generation and rebound, and to obtain the excellent quick-setting force that is a feature of calcium aluminate-based powder quick-setting material. I found.
That is, the present invention is as follows.

[1] sulfate CaO / _Al 2 _{O 3} molar ratio of 0.5 to 3.0, is Blaine specific surface area of the calcium aluminate is 3000 cm ² / g or more (A) is Blaine specific surface area of 2500 cm ² / g or more It is composed of the salt (B), and the content of the (A) is 20 to 80 parts by mass and the content of the (B) is 80 to 20 parts by mass in a total of 100 parts by mass of the (A) and the (B). inorganic and a powder quick-setting admixture comprising the composition at least 50 wt%, alcohols at, phenols, glycols, ethers, seen containing one or more amines and their addition compounds or derivatives, In addition, it is a slurry composed of a non-aqueous liquid having a water content of 5% or less, and the content of the powder quick-setting admixture is 40 to 80 parts by mass and the content of the non-aqueous liquid is 60 to 60 parts by mass in 100 parts by mass of the slurry. A slurry-like spray material for sprayed concrete, characterized in that the viscosity of the slurry at 20 ° C. is 10 Pa · s or less in 20 parts by mass.
[2] The slurry-like spray material for spray concrete according to [1], wherein the non-aqueous liquid is polyalkylene glycol or a derivative thereof.
[3] The slurry-like spray material for spray concrete according to [2], wherein the polyalkylene glycol or a derivative thereof has an average molecular weight of 100 to 1000.
[4] The slurry-like spray material for spray concrete according to any one of claims [1] to [3], which contains a dispersant.
[5] A spraying method characterized by mixing the slurry-like spraying material for sprayed concrete according to any one of [1] to [4] with concrete and spraying.

When the slurry-type spraying material for sprayed concrete of the present invention is used, a simplified system can be used as in the case of the conventional liquid quick-setting admixture, and the pumping property is excellent. Further, the effect of suppressing the generation of dust in the sprayed concrete and the effect of suppressing the rebound are good, and the excellent quick-setting force (short-time strength development), which is a characteristic of the calcium aluminate-based powder quick-setting material, can be obtained. ..

Hereinafter, the slurry-like spraying material for sprayed concrete of the present invention and the spraying method using the slurry-like spraying material will be described in detail. Unless otherwise specified, "parts" and "%" are based on mass.

The calcium aluminate present invention, a raw material containing calcia, by mixing raw materials containing alumina, calcined and in the kiln, obtained by heat treatment such as melting in an electric furnace, CaO and Al ₂ O ₃ is a general term for substances that have hydration activity as the main component, and some of them are alkali metal oxides, alkaline earth metal oxides, silicon oxide, titanium oxide, iron oxide, alkali metal halides, and alkalis. It is a substance in which earth metal halides, alkali metal sulfates, alkaline earth metal sulfates, etc. are replaced or solidly dissolved. Examples of the mineral form include CaO · Al ₂ O ₃ (CA), 12 CaO · 7 Al ₂ O ₃ (C ₁₂ A ₇ ), _{3 CaO · Al 2} O ₃ (C ₃ A) and the like. The particle size of the calcium aluminate, in terms of quick-setting property and the initial strength development, Blaine specific surface area (hereinafter, referred to as Blaine) 3,000 cm ² / g or more is preferable, 5,000 cm ² / g or more is more preferable. If it is less than 3,000 cm ² / g, the quick-setting property and the initial strength development may decrease. _{The CaO / Al 2} O ₃ molar ratio of calcium aluminate used in the present invention is in the range of 0.5 to 3.0, preferably 1.5 to 2.5. As long as it is within the molar ratio, it can be used regardless of the morphology such as crystalline and amorphous.

The sulfate salt of the present invention is used to improve the strength development. Examples of the sulfate include alkali metal sulfates such as sodium sulfate and potassium sulfate, alkaline earth metal sulfates such as magnesium sulfate and gypsum, aluminum sulfate and the like, and one or more of these can be used. Among these, gypsum is preferable in terms of slurry formation and strength development. Examples of gypsum used in the present invention include anhydrous gypsum, hemihydrate gypsum and dihydrate gypsum, and one or more of these can be used. Of these, anhydrous gypsum is preferable in terms of strength development. The specific surface area of the gypsum, in terms of strength development, preferably 2500 cm ² / g or more in Blaine value, 4000 cm ² / g or more is more preferable. If it is less than 2500 cm ² / g, the strength development may decrease.
As for the inorganic composition composed of calcium aluminate and sulfate, 20 to 80 parts of calcium aluminate is preferable, 30 to 70 parts is more preferable, and 40 to 60 parts is most preferable, out of 100 parts of the inorganic composition. If the amount of calcium aluminate is less than 20 parts, the initial setting may be delayed and the adhesion to the ground may be reduced, while if it exceeds 80 parts, the long-term strength development may be lowered.
The powder quick-setting admixture of the present invention preferably contains 50% by mass or more of the inorganic composition. If it is less than 50% by mass, the rapid binding force may decrease.

Examples of the non-aqueous liquid of the present invention include alcohols, phenols, glycols, ethers, amines, and one or more of these additional compounds and derivatives.
Examples of alcohols include aliphatic alcohols such as methyl alcohol, ethyl alcohol, propyl alcohol, butyl alcohol, amyl alcohol, hexyl alcohol, heptyl alcohol, octyl alcohol, capryl alcohol, nonyl alcohol, decyl alcohol, undecyl alcohol and lauryl alcohol. Aliper unsaturated alcohols such as saturated alcohols, allyl alcohols, crotyl alcohols and propagyl alcohols, alicyclic alcohols such as cyclopentanol and cyclohexanol, aromatic alcohols such as benzyl alcohol and cinnamyl alcohol, furfuryl alcohols and the like. Examples thereof include heterocyclic alcohols.

Examples of the phenols include monohydric phenols such as phenol, cresol, xylenol, carbachlor, timol and naphthol, divalent phenols such as catechol, resorcin and hydroquinone, and trivalent phenols such as pyrogallol and fluoroglusin.
Examples of glycols include ethylene glycol, propylene glycol, trimethylene glycol, 1,4-butanediol, 1,5-pentanediol and the like. Among them, the use of polyalkylene glycol or a derivative thereof is preferable, and the use of polyalkylene glycol having an average molecular weight of 100 to 1000 or a derivative thereof is more preferable.
Examples of ethers include aliphatic single ethers such as butyl ether, isobutyl ether, amyl ether and isoamyl ether, aliphatic mixed ethers such as methyl n-amyl ether, ethyl n-amyl ether and ethyl isoamyl ether, vinyl ether and the like. Examples thereof include aromatic ethers such as aliphatic unsaturated ethers, anisole, phenetol, phenyl ethers, benzyl ethers and naphthyl ethers, and cyclic ethers such as dioxane.

Examples of amines include aliphatic primary amines such as butylamine, amylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, tridecylamine, tetradecylamine and pentadecylamine, dipropylamine and dibutylamine. Aliphatic secondary amines such as diamilamine, triethylamine, tripropylamine, tributylamine, aliphatic tertiary amines such as triamylamine, alicyclic amines such as cyclopentylamine and cyclohexylamine, aniline, methylaniline, ethylaniline, and toluidine. , Aromatic amines such as benzylamine and the like.

If the water content of the non-aqueous liquid according to the present invention exceeds 5%, excellent quick-setting performance may not be obtained. This is because when the powder quick-setting admixture and the non-aqueous liquid are kneaded, the powder quick-setting admixture causes a hydration reaction due to the water contained in the non-aqueous liquid. The water content in the non-aqueous liquid is preferably 5% or less, more preferably 2% or less, still more preferably 1% or less.

The slurry in the present invention is composed of a powder quick-setting admixture and a non-aqueous liquid, and out of a total of 100 parts of the powder quick-setting admixture and the non-aqueous liquid, 40 to 80 parts of the powder quick-setting admixture is preferable, and 55 to 75 parts is preferable. More preferred. On the other hand, the amount of the non-aqueous liquid is preferably 20 to 60 parts, more preferably 25 to 45 parts. If the amount of non-aqueous liquid exceeds 60 parts, material separation may occur. On the other hand, if the amount of the non-aqueous liquid is less than 20 parts, the viscosity of the slurry becomes high and handling may become difficult.

If the viscosity of a slurry consisting of a powder quick-setting admixture and a non-aqueous liquid at 20 ° C exceeds 10 Pa · s, uniform pumping becomes difficult with a general liquid pump, and sprayed concrete of uniform quality cannot be obtained. There is. The viscosity of the slurry is more preferably 2 Pa · s or less for time-uniform pumping with a liquid pump.

The dispersant of the present invention can be appropriately used when it is necessary to impart separation resistance to the slurry-type sprayed material for sprayed concrete. Any known dispersant that can be applied to non-aqueous liquids can be used, but typical dispersants are polycarboxylic acid-based, polyphosphate-based, naphthalene sulfonic acid-based, nonionic surfactant-based, and cationic-based. Examples include surfactants.
Further, the sprayed concrete using the slurry-like spraying material of the present invention includes aggregates such as sand and gravel, as well as a water reducing agent, a high-performance water reducing agent, an AE water reducing agent, a high-performance AE water reducing agent, and a fluidizing agent. One of antifoaming agents, thickeners, rust preventives, antifreeze agents, shrinkage reducing agents, polymer emulsions and coagulation adjusters, clay minerals such as bentonite, and anion exchangers such as hydrotalcite, or It is possible to use two or more kinds within a range that does not substantially impair the object of the present invention.

In the present invention, the mixing method of each material is not particularly limited, and each material may be mixed at the time of construction, or a part or all of the materials may be mixed in advance. As the mixing device, any existing device can be used, and examples thereof include a tilting mixer, an omni mixer, a Henschel mixer, a V-type mixer, and a nauta mixer.

The amount of the slurry-type spray material for spray concrete of the present invention used is preferably 2 to 15 parts with respect to 100 parts of cement in terms of solid content. If the amount used is less than 2 parts, excellent coagulation properties may not be exhibited, while if it exceeds 15 parts, long-term strength development may deteriorate.
When producing the sprayed concrete of the present invention, the water content is preferably 30 to 75 parts with respect to 100 parts of cement. If it is less than 30 parts, the water content may be insufficient and kneading may not be sufficient, while if it exceeds 75 parts, the strength development may be impaired. In addition, when examining the composition, the amount of water contained in the aggregate, various additives, and the slurry-like spray material of the present invention is also taken into consideration.

The cement used in the sprayed concrete of the present invention is not particularly limited, and in addition to various Portland cements such as ordinary, early-strength, ultra-fast-strength, moderate heat, sulfate-resistant, and low heat, Portland cement and blast furnace Any of various mixed cements in which slag, fly ash, silica, fine powder of limestone, etc. are mixed can be used, and Portland cement is preferable from the viewpoint of easy availability, and ordinary Portland cement is most preferable.

The aggregate used in the sprayed concrete of the present invention is not particularly limited, but naturally produced aggregate or artificially produced aggregate whose particle size is adjusted can be used.

As the spraying method according to the present invention, a generally used wet spraying method and a dry spraying method can be used. Examples of the wet method include a method of mixing the slurry-like spray material for spray concrete of the present invention with concrete, and the dry method includes additives, water and the spray concrete of the present invention in cement and aggregate. Examples thereof include a method of mixing a slurry-like spray material.
As a method for producing the sprayed concrete by mixing the slurry-like spray material for spray concrete of the present invention with concrete, a shower ring pipe capable of adding the slurry-like spray material for spray concrete of the present invention in a shower shape or the like. It is preferable to mix immediately before spraying using a Y-shaped tube or the like. Specifically, it is preferable to add the slurry-type spraying material for sprayed concrete of the present invention to the pumped concrete so that the time until the sprayed concrete is discharged is preferably within 10 seconds and within 2 seconds. Is more preferable. When the slurry-like spray material for spray concrete of the present invention is added to concrete, it may be added in the form of mist with compressed air in advance.

The sprayed concrete to which the slurry-like spraying material for sprayed concrete of the present invention is added can be used as a support member at the time of construction of an underground structure typified by tunnel construction, and can be directly applied to the slope of the ground or a frame frame. It can also be used for slope stabilization method and repair of various concrete structures.

Hereinafter, the present invention will be described in more detail by showing the results of evaluation tests using Examples and Comparative Examples.

"Experimental Example 1"
Of 100 parts of the inorganic composition composed of calcium aluminate and sulfate, 50 parts of calcium aluminate and 50 parts of sulfate A were used as a powder quick-setting admixture. The powder quick-setting admixture and the non-aqueous liquid A were mixed at a mass ratio of 5/5 to form a slurry to prepare a slurry-like spraying material for sprayed concrete. The viscosities of all the slurries were 1 Pa · s or less.
Using the prepared slurry-like spraying material for sprayed concrete, the proctor penetration resistance value, the amount of dust, and the pumping property were evaluated. The evaluation was carried out at an environmental temperature of 20 ° C. The results are shown in Table 1.

<Material used>
Calcium aluminate: A _{mixture of CaO raw material and Al 2} O ₃ raw material, crushed, melted in an electric furnace, and rapidly cooled so that the _{CaO / Al 2} O ₃ molar ratio becomes a specific value.
Calcium aluminate A: CaO / Al ₂ O ₃ molar ratio 2.3, amorphous, brain value 6,500 cm ² / g
Calcium aluminate B: CaO / Al ₂ O ₃ molar ratio 1.7, amorphous, brain value 6,500 cm ² / g
Calcium aluminate C: CaO / Al ₂ O ₃ molar ratio 1.3, amorphous, brain value 6,500 cm ² / g
Calcium aluminate D: CaO / Al ₂ O ₃ molar ratio 0.5, amorphous, brain value 6,500 cm ² / g
Calcium aluminate E: CaO / Al ₂ O ₃ molar ratio 3.0, amorphous, brain value 6,500 cm ² / g
Calcium aluminate F: CaO / Al ₂ O ₃ molar ratio 0.3, amorphous, brain value 6,500 cm ² / g
Calcium aluminate G: CaO / Al ₂ O ₃ molar ratio 3.5, amorphous, brain value 6,500 cm ² / g
Sulfate A: crushed natural anhydrous gypsum, brain specific surface area 4,000 cm ² / g
Non-aqueous liquid A: Butyl alcohol, reagent first grade (manufactured by Wako Pure Chemical Industries, Ltd.), water content 1% or less Liquid quick-setting agent: manufactured by BASF Japan Co., Ltd., trade name "Master Lock SA161"
Powder quick-setting admixture: Denka Co., Ltd., trade name "Natomic TYPE-5"
Cement: Ordinary Portland cement, manufactured by Denka Co., Ltd., density 3.15 g / cm ³
Fine aggregate: River sand from Himekawa, Niigata Prefecture, density 2.62 g / cm ³
Coarse aggregate: crushed sand from Himekawa, Niigata Prefecture, maximum particle size 15 mm, density 2.65 g / cm ³
Water reducing agent: Polycarboxylic acid High-performance water reducing agent, commercial product Water: Tap water

<Evaluation method>
Procter penetration resistance (condensation property): Compliant with ASTMC 403 "Concrete setting time test method by penetration resistance". The mortar and the slurry spray material for spray concrete were mixed, and the cohesive property after 1 minute, 3 minutes and 10 minutes was evaluated.
C / S (cement / sand ratio) = 1 / 2.5, W / C (water / cement ratio) = 45% mortar is adjusted to SL (slump value) = 18 cm using a water reducing agent, and mortar 100 Five parts of slurry-like spraying material for sprayed concrete were added to the parts.
Amount of dust: Prepare concrete with a unit cement amount of 455 kg / m ³ , W / C = 45%, and s / a = 70%, ^{and air-push with a concrete pump at a pumping speed of 10 m 3} / h and a pumping pressure of 0.4 MPa. did. Slurry spray material for spray concrete was added to the mixing pipe provided in front of the spray nozzle so as to be 10 parts with respect to 100 parts of cement in the concrete, and 5 minutes after spraying into the simulated tunnel. The amount of dust was measured using a digital dust meter P-5L manufactured by Shibata Scientific Technology Co., Ltd. at a position 5 m from the spraying place.
Pumping property: After allowing the slurry-like spray material for spray concrete to stand at 20 ° C. for 72 hours, fill the hose with an inner diameter of 2 cm and a length of 5 m with the slurry-like spray material for spray concrete, and the pump pressure is 0. Those in which pumping was smoothly performed at 5 MPa were marked with ◯, those in which the pumping pressure increased to 0.8 MPa or more due to pumping were marked with Δ, and those in which the pumping pressure increased to 1.0 MPa or more due to pumping were marked with x.
Slurry viscosity: The slurry viscosity consisting of the powder quick-setting admixture and the non-aqueous liquid was measured with a Brookfield type (B type) viscometer.

CaO / Al ₂ O ₃ molar ratio of shotcrete for slurry spraying material using calcium aluminate 0.5 to 3.0 is 70% or more short strength development of the powder quick-setting admixture Shown, the amount of dust is equivalent to that of the liquid quick-setting admixture.

"Experimental Example 2"
The procedure was the same as in Experimental Example 1 except that calcium aluminates I to K were used. The results are shown in Table 2.
<Material used>
Calcium aluminate I: CaO / Al ₂ O ₃ molar ratio 1.7, amorphous, brain value 2,500 cm ² / g
Calcium aluminate J: CaO / Al ₂ O ₃ molar ratio 1.7, amorphous, brain value 3,000 cm ² / g
Calcium aluminate K: CaO / Al ₂ O ₃ molar ratio 1.7, amorphous, brain value 9,500 cm ² / g

Slurry spraying material for sprayed concrete using calcium aluminate with a brain value of 3000 cm ² / g or more shows short-term strength development of 70% or more of powder quick-setting admixture, which is equivalent to liquid quick-setting admixture. It is the amount of dust.

"Experimental Example 3"
The test was carried out in the same manner as in Experimental Example 1 except that calcium aluminate B and sulfates B to F were used. The results are shown in Table 3.
<Material used>
Sulfate B: crushed natural anhydrous gypsum, brain specific surface area 2,000 cm ² / g
Sulfate C: crushed natural anhydrous gypsum, brain specific surface area 2,500 cm ² / g
Sulfate D: crushed natural anhydrous gypsum, brain specific surface area 5,000 cm ² / g
Sulfate E: crushed hemihydrate gypsum, brain specific surface area 4,000 cm ² / g
Sulfate F: crushed dihydrate gypsum, brain specific surface area 4,000 cm ² / g

Slurry spraying materials for sprayed concrete using sulfates with a brain value of 2500 cm ² / g or more show short-term strength development of 70% or more of powder quick-setting admixtures, which is equivalent to liquid quick-setting admixtures. It is the amount of dust.

"Experimental Example 4"
The test was carried out in the same manner as in Experimental Example 1 except that the ratio of sulfate and calcium aluminate B was changed in 100 parts of the inorganic composition composed of sulfate A and calcium aluminate B. The results are shown in Table 4.

The slurry-like spray material for spray concrete having a calcium aluminate content of 20 to 80 parts in 100 parts of an inorganic composition composed of sulfate and calcium aluminate is shorter than 70% or more of the powder quick-setting admixture. It shows time-strength development and has the same amount of dust as a liquid quick-setting admixture.

"Experimental Example 5"
The content of calcium aluminate was 50 parts in 100 parts of the inorganic composition composed of sulfate and calcium aluminate. The test was carried out in the same manner as in Experimental Example 1 except that the inorganic composition and slaked lime were combined to form a powder quick-setting admixture, and the content of the inorganic composition in 100 parts of the powder quick-setting admixture was variously changed. The results are shown in Table 5.
<Material used>
Slaked lime: Special slaked lime, 600 μm sieve all

In 100 parts of an inorganic composition composed of sulfate and calcium aluminate, an inorganic composition having a calcium aluminate content of 50 parts, and a powder quick-setting admixture composed of slaked lime, the powder quick-setting admixture 100 The slurry-like spray material for sprayed concrete having an inorganic composition content of 50 parts or more in the part shows a short-term strength development of 70% or more of the powder quick-setting admixture, which is equivalent to that of the liquid quick-setting admixture. It is the amount of dust.

"Experimental Example 6"
The procedure was the same as in Experimental Example 1 except that the type of non-aqueous liquid was changed as shown in Table 6. The viscosities of the slurries were all 1 Pa · s or less. The results are shown in Table 6.
<Material used>
Non-aqueous liquid B: phenols, reagent first grade (manufactured by Wako Pure Chemical Industries, Ltd.) phenol, water content 1% or less Non-aqueous liquid C: glycols, reagent first grade (manufactured by Wako Pure Chemical Industries, Ltd.) ethylene glycol, Non-aqueous liquid D with a water content of 1% or less: ethers, reagent first grade (manufactured by Wako Pure Chemical Industries, Ltd.) Butyl ether, water content of 1% or less non-aqueous liquid E: amines, reagent first grade (manufactured by Wako Pure Chemical Industries, Ltd.) ) Aniline, non-aqueous liquid F: fatty acids, reagent first grade (manufactured by Wako Pure Chemical Industries, Ltd.), oleic acid, water content 1% or less Liquid G: distilled water

Slurry spraying materials for sprayed concrete using non-aqueous liquids A to E show a short-term strength development of 70% or more of the powder quick-setting admixture, and the amount of dust is equivalent to that of the liquid quick-setting admixture. There is.

"Experimental Example 7"
The same procedure as in Experimental Example 1 was carried out except that the non-aqueous liquid A was used and the viscosity was changed by changing the mixing ratio with the powder quick-setting admixture in various ways. The results are shown in Table 7.

The slurry-like spray material for sprayed concrete, which has a non-aqueous liquid content of 20 to 60 parts in 100 parts of the slurry, exhibits strength for a short time of 70% or more of that of the powder quick-setting admixture, and is a liquid quick-setting admixture. It has the same amount of dust and pumping performance as.

"Experimental Example 8"
The procedure was the same as in Experimental Example 1 except that the non-aqueous liquids HK were used. The results are shown in Table 8.
<Material used>
Non-aqueous liquid H: polyethylene glycol, average molecular weight 100, water content 1% or less Non-aqueous liquid I: polyethylene glycol, average molecular weight 200, water content 1% or less Non-aqueous liquid J: polyethylene glycol, average molecular weight 400, water content 1% Non-aqueous liquid K: Polyethylene glycol, average molecular weight 600, water content 1% or less Non-aqueous liquid L: Non-aqueous liquid H with polycarboxylic acid alkylamine salt-based dispersant "Product name: Nopcos Bath" (manufactured by Sannopco Co., Ltd.) ) Is mixed with 100 parts of slurry-like spray material for sprayed concrete by 0.5 part.

A slurry-like spray material for sprayed concrete, which uses a non-aqueous liquid as polyalkylene glycol and has an average molecular weight of 100 to 1000, exhibits a short-term strength of 70% or more of that of a powder quick-setting admixture, and is a liquid quick-setting admixture. It has the same amount of dust and pumping performance as.

Claims (5)

CaO / _Al 2 _{O 3} molar ratio of 0.5 to 3.0, sulphate Blaine specific surface area is the Blaine specific surface area of the calcium aluminate is 3000 cm ² / g or more (A) is 2500 cm ² / g or more (B ), The content of the (A) is 20 to 80 parts by mass, and the content of the (B) is 80 to 20 parts by mass in a total of 100 parts by mass of the above (A) and the above (B). and the powder quick-setting admixture comprising the composition at least 50 wt%, alcohols, phenols, glycols, ethers, seen containing one or more amines and their addition compounds or derivatives, and water A slurry consisting of a non-aqueous liquid having an amount of 5% or less , wherein the content of the powder quick-setting admixture is 40 to 80 parts by mass and the content of the non-aqueous liquid is 60 to 20 parts by mass in 100 parts by mass of the slurry. A slurry-like spray material for sprayed concrete, characterized in that the viscosity of the slurry at 20 ° C. is 10 Pa · s or less. The slurry-like spray material for spray concrete according to claim 1, wherein the non-aqueous liquid is polyalkylene glycol or a derivative thereof. The slurry-like spray material for spray concrete according to claim 2, wherein the polyalkylene glycol or a derivative thereof has an average molecular weight of 100 to 1000. The slurry-like spray material for spray concrete according to any one of claims 1 to 3, which contains a dispersant. A spraying method characterized by mixing the slurry-like spraying material for sprayed concrete according to any one of claims 1 to 4 with concrete and spraying.