JP4805721B2 - Quick setting spray method - Google Patents

Description

  The present invention relates to a spray material sprayed on a ground surface exposed in a tunnel such as a road, a railway, and a water conduit, and a method of spraying the material.

  In order to prevent collapse of exposed ground such as tunnel excavation, a spraying method using a quick setting sprayed concrete in which a quick setting agent is added to concrete as described in Japanese Patent Publication No. 60-4149 (Patent Document 1) Has been done.

  In recent years, a technique for increasing the strength of shotcrete has been developed in order to cope with the enlargement of the tunnel excavation section and the shortening of the construction time and excavation cycle. As shown, gypsum and calcium aluminate are blended in advance to increase the strength after spraying, or in advance to cement mortar as disclosed in JP-A-9-169557 (Patent Document 3). A method for increasing the strength of shotcrete from a short time by adding a quick setting agent mainly composed of calcium aluminate, as disclosed in JP-A-9-256791 (Patent Document 3), Cement mortar, quick-setting agent, and gypsum are pumped separately, and during the pumping of cement mortar, they are mixed, mixed, and sprayed. No lower spraying method (Patent Document 4) have been implemented.

Japanese Patent Publication No. 60-4149 Japanese Patent Laid-Open No. 50-16717 JP-A-9-169557 JP 9-256791 A

As mentioned above, in recent years, the strength of shotcrete has been increased due to advances in tunnel excavation technology, etc., but the water cement ratio of mortar concrete has been reduced to increase the strength, and fluidity has been increased. There is a problem that the holding time is reduced, workability is reduced, and if workability is prioritized, the water cement ratio increases and it becomes difficult to obtain a predetermined strength. Shotcrete was expected.

Furthermore, when the ground condition is bad, the tunnel shape may be greatly deformed due to the ground pressure, so that there is a problem that the shotcrete is cracked and possibly peeled off. Usually, natural pressure is often applied from a relatively early stage after excavation, and shotcrete has been required to have excellent fluidity retention.

That is, the problem to be solved by the present invention is a technique for obtaining excellent shotcrete with improved fluidity retention performance.

  As a result of intensive studies to solve the above problems, the present inventors confirmed that high fluidity retention can be obtained by using a base material using a specific material, concrete blending, and kneading method, The present invention has been completed.

That is, the present invention is, after kneading the cement concrete, gypsum, water reducing agent, an organic acid, and a base concrete obtained by adding an alkali metal carbonate, quick-setting property spraying method comprising the quick-setting admixture After kneading cement concrete, quick setting containing quick setting agent to base concrete to which admixture containing gypsum, water reducing agent, organic acid and alkali metal carbonate is added 10 to 60 seconds after mixing concrete with cement, containing rapid setting agent in base concrete to which gypsum, water reducing agent, organic acid, and alkali metal carbonate are added. It is a quick setting spraying method, and further, the quick setting spraying method comprising a fibrous substance, and the quick setting spraying method comprising a calcium aluminate as a quick setting agent. ,Sudden Agent calcium aluminate is a said acute sinterable spraying method which comprises an alkali metal aluminate and calcium hydroxide, cement weight of the base concrete, a 360~700kg / m ^3, use of water The quick-setting spraying method has an amount of 20 to 60 parts by mass with respect to a total of 100 parts by mass of cement and admixture, and the fine aggregate rate is 50% by volume or more. This is a quick setting spraying method in which the maximum dimension of fine aggregate is 5 mm or less, and the quick setting spraying method in which the maximum dimension of coarse aggregate is 15 mm or less .

  By using the present invention, quick setting shotcrete construction with improved fluidity retention time is possible.

Hereinafter, the present invention will be described in detail. In the present invention, a general term for cement paste, cement mortar, and cement concrete is referred to as cement concrete.

As the cement used in the present invention, various portland cements such as early strength and various mixed cements obtained by mixing blast furnace slag and fly ash with these portland cements can be used. Among these, ordinary Portland cement and / or early-strength Portland cement are preferable from the viewpoint of strength development.

The gypsum of the present invention is used, for example, for the purpose of increasing the strength of shotcrete. For example, gypsum other than gypsum in cement. Examples of the gypsum include anhydrous gypsum, hemihydrate gypsum, and dihydrate gypsum, and one or more of these can be used. Of these, anhydrous gypsum is preferred in terms of strength development. The particle size of the gypsum, the degree used for normal cement, for example, preferably 2500 cm ² / g or more in Blaine value, 3000 cm ² / g or more is more preferable.

The amount of gypsum used is preferably 5 to 20 parts by mass and more preferably 7 to 15 parts by mass with respect to 100 parts by mass of cement. If the amount is less than 5 parts by mass, it may be difficult to increase the strength development. If the amount exceeds 20 parts by mass, the concrete may expand for a long time and the concrete may be destroyed, thereby inhibiting the strength development.

  The water reducing agent of the present invention is used for the purpose of, for example, reducing the water / powder ratio of the base concrete and enhancing the strength development. Examples of water reducing agents include alkylallyl sulfonates, naphthalene sulfonates, and formalin condensates of melamine sulfonates, polycarboxylic acid polymer compounds, and the like, one or more of these. Can be used. As the water reducing agent, a powder water reducing agent is preferable.

0.1-2 mass parts is preferable with respect to 100 mass parts of cement as solid content, and, as for the usage-amount of a water reducing agent, 0.3-1 mass part is more preferable. If the amount is less than 0.1 parts by mass, it may be difficult to increase the strength development. If the amount exceeds 1 part by mass, the strength development may be inhibited.

  The organic acid of the present invention is used, for example, for the purpose of enhancing strength development. Examples of the organic acid include gluconic acid, tartaric acid, citric acid, and the like, or sodium salts and potassium salts thereof, and one or more kinds can be used.

0.05-1 mass part is preferable with respect to 100 mass parts of cement, and, as for the usage-amount of an organic acid, 0.1-0.5 mass part is more preferable. If it is less than 0.05 part by mass, it may be difficult to improve the strength development. If it exceeds 1 part by mass, the adhesion of concrete may be deteriorated.

  The alkali metal carbonate of the present invention is used, for example, for the purpose of improving the initial strength. Examples of the alkali metal carbonate include sodium carbonate, potassium carbonate, sodium bicarbonate and the like, and one or more of these can be used.

0.05-1 mass part is preferable with respect to 100 mass parts of cement, and, as for the usage-amount of alkali metal carbonate, 0.1-0.5 mass part is more preferable. If the amount is less than 0.05 parts by mass, it may be difficult to increase the initial strength development. If the amount exceeds 1 part by mass, the slump retention property of the base concrete may be lowered, and the workability may be deteriorated.

The quick setting agent of the present invention preferably contains calcium aluminate. Calcium aluminate refers to, for example, one obtained by heat-treating a mixture of a CaO raw material, an Al ₂ O ₃ raw material, etc., in a kiln or melting in an electric furnace. It is a quick-setting component that causes agglomeration. As a mineral component of calcium aluminate, when CaO is C and Al ₂ O ₃ is A, a calcium aluminate heat treated product represented by C ₃ A, C ₁₂ A ₇ , CA, CA ₂ or the like is pulverized. Can be mentioned. Furthermore, as other components, calcium aluminosilicate containing SiO ₂ , C ₁₁ A ₇ · CaX ₂ (X is a halogen such as fluorine) in which one CaO of C ₁₂ A ₇ is replaced with a halide such as CaF ₂ , C ₄ A ₃ · SO ₃ containing SO ₃ component and calcium aluminate in which alkali metals such as sodium, potassium and lithium are partly dissolved, and the like can be used. One or more of these can be used. is there.

Among these, amorphous calcium aluminate obtained by quenching the heat-treated product corresponding to the C ₁₂ A ₇ composition is preferable in terms of reaction activity. The particle size of the calcium aluminate, from the viewpoint of quick-setting property or development of strength, preferably 3000 cm ² / g or more in Blaine value, 4000 cm ² / g or more is more preferable.

  In the present invention, it is preferable to contain alkali metal aluminate and calcium hydroxide in calcium aluminate as a quick setting agent.

  The alkali metal aluminate of the present invention is used, for example, for the purpose of promoting initial setting. Examples of the alkali metal aluminate include lithium aluminate, sodium aluminate, and potassium aluminate, and one or more of these can be used.

1-50 mass parts is preferable with respect to 100 mass parts of calcium aluminates, and, as for the usage-amount of an alkali metal aluminate, 2-25 mass parts is more preferable. If it is less than 1 part by mass, it may be difficult to cause initial condensation, and if it exceeds 50 parts by mass, there is a possibility that deterioration of the coagulation property and long-term strength development may be inhibited.

  The calcium hydroxide of the present invention is used, for example, for the purpose of assisting rapid setting performance. Examples of calcium hydroxide include commercially available slaked lime and carbide soot produced as a by-product when acetylene is generated from calcium carbide.

1-20 mass parts is preferable with respect to 100 mass parts of calcium aluminate, and, as for the usage-amount of calcium hydroxide, 2-10 mass parts is more preferable. If it is less than 1 part by mass, it may be difficult to cause initial condensation, and if it exceeds 20 parts by mass, long-term strength development may be hindered.

Although the usage-amount of a quick setting agent is not restrict | limited in particular, 5-20 mass parts is preferable with respect to 100 mass parts of cement, and 7-15 mass parts is more preferable. When the amount is less than 5 parts by mass, it is difficult to cause initial condensation, and the piping is blocked more than 20 parts by mass, the rebound rate increases, and the workability may be deteriorated.

In the present invention, it is preferable to use a fibrous material. The fibrous material of the present invention can be either inorganic or organic, and has an effect of improving the impact resistance and toughness of shotcrete, for example. Examples of inorganic fibrous materials include glass fibers, carbon fibers, and metal fibers. Examples of organic fibers include vinylon fibers, recycled PET fibers, and polypropylene fibers, and one or more of these. Can be used. Among these, metal fibers and polypropylene fibers are preferable from the viewpoint of economy.

The length of the fibrous material is preferably 100 mm or less, and more preferably 0.5 to 60 mm in terms of concrete pumpability and mixing properties. If it exceeds 100 mm, the shotcrete may be clogged during the feeding.

The amount of the fibrous substance used is preferably 0.1 to 2% by volume, more preferably 0.5 to 1.5% by volume with respect to the base concrete volume. If the amount is less than 0.1% by volume, impact resistance may not be obtained. If the amount exceeds 2% by volume, the fluidity of the base concrete may be deteriorated or the piping may be blocked.

Cement weight of the base concrete used in the present invention is a ^{360~700kg / m 3, 400~500kg / m} 3 and more preferably. If it is less than 360 kg / m ³ , the concrete tends to be separated and the workability may be reduced, and if it exceeds 700 kg / m ³ , the viscosity of the concrete increases and the workability of the work may be reduced.

The present invention is used as an admixture containing, for example, gypsum, a water reducing agent, an organic acid, and an alkali metal carbonate. Gypsum, water reducing agent, organic acid, and alkali metal carbonate are preferably mixed in advance, but gypsum, water reducing agent, organic acid, and alkali metal carbonate are mixed into cement concrete for each material. May be.

The amount of water used is preferably 20 to 60 parts by mass and more preferably 25 to 50 parts by mass with respect to 100 parts by mass in total of cement and admixture. If the amount is less than 20 parts by mass, materials such as cement, gypsum, and quick setting agent increase, which is not economical, and there is a possibility that workability such as pumpability may be reduced. If it exceeds 60 parts by mass, strength development will be reduced and the effect may not be obtained.

  The fine aggregate ratio is preferably 50% by volume or more, and more preferably 60 to 80% by volume.

The aggregate such as fine aggregate and coarse aggregate used in the present invention preferably has a low water absorption rate and a high strength of the aggregate itself, but is not particularly limited.

The fine aggregate is preferably one having a maximum dimension of 5 mm or less, and examples thereof include river sand, mountain sand, and lime sand. As the coarse aggregate, those having a maximum dimension of 15 mm or less are preferable.

The slump of the base concrete used in the present invention is not strictly specified if it is adjusted so that spraying can be performed without hindrance, but when the water cement ratio is small, the slump becomes small and the pumping performance of the concrete pump is reduced. Since it falls, it is usually about 18 cm.

  In the method for kneading the base concrete in the present invention, the admixture is added after kneading the cement concrete containing water, cement, fine aggregate, and coarse aggregate to be added as necessary.

If the admixture is added before water, cement, fine aggregate, and coarse aggregate are mixed, the slump decreases with the passage of time after mixing.

The timing of adding the admixture varies depending on the performance of the kneading machine, but it is preferably 10 to 60 seconds and preferably 20 to 50 seconds after mixing water, cement, fine aggregate, and / or coarse aggregate. . If it is less than 10 seconds, fluidity retention may not be obtained, and if it exceeds 60 seconds, fluidity retention may not be obtained.

  Examples of the method of mixing the fibrous material include a method of adding to the base concrete side and the quick setting agent side, a method of adding only the fibrous material separately, and the like. When the fibrous substance is added to the base concrete side, it may be added before or after the admixture is added.

  The spraying method of the present invention can be applied by a generally applied wet spraying method or the like. An example of the spraying method will be described. Cement, water, and aggregate are mixed to prepare cement concrete. After that, an admixture is added, and further, base concrete containing fibrous substances is pumped through a transport pipe with a concrete pump. There is a method of adding a rapid setting agent with a mixing tube such as a Y-shaped tube and spraying it on a natural ground during the concrete pumping and before the spray nozzle. The spraying equipment used in the present invention is not particularly limited as long as the spraying is sufficiently performed, and a conventionally used spraying apparatus and other equipment can be used as they are.

  Hereinafter, the present invention will be described in detail by experimental examples. All the experimental examples were carried out at 20 ° C.

(Experimental example 1)
Using the materials shown below, cement / fine aggregate mass ratio = 1 / 2.5, water / powder ratio (powder is the sum of cement and admixture) = 40 mass%, and 100 mass parts of cement For the mortar kneaded by changing the addition timing of the admixture consisting of 9 parts by mass of gypsum, 0.6 parts by mass of water reducing agent, 0.3 parts by mass of organic acid, and 0.3 parts by mass of alkali metal carbonate. Changes over time in mortar flow, setting properties after addition of a quick setting agent, and strength development were measured.
The method of adding each material was as follows. After the mixing of water, cement, and fine aggregate was started, the admixture was added and mixed for 90 seconds at the time shown in Table 1, and then the quick setting agent was added.
Experiment No. 1-7 is the same as above except that an admixture made of gypsum was added 30 seconds after the start of mixing of water, cement, fine aggregate, water reducing agent, organic acid, and alkali metal carbonate. It was.
As the quick setting agent, a mixture of calcium aluminate: alkali metal aluminate: calcium hydroxide = 100: 10: 5 (mass ratio) was used.
10 parts by mass of the quick setting agent was added to 100 parts by mass of cement.
The results are shown in Table 1.

[Materials used]
Cement: Ordinary Portland cement, Blaine value 3200 cm ² / g, Specific gravity 3.15
Fine aggregate: Himekawa water sand from Itoigawa, Niigata Prefecture, surface dry density = 2.62, maximum dimension = 5mm
Gypsum: anhydrous gypsum, brain value 4000 cm ² / g, commercial water reducing agent: naphthalene sulfonate-based powder product, commercial product organic acid: citric acid, commercial product alkali metal carbonate: sodium bicarbonate, commercial product calcium aluminate: Amorphous obtained by quenching the heat-treated product corresponding to the C ₁₂ A ₇ composition, Blaine value 5900 cm ² / g
Alkali metal aluminate: sodium aluminate, commercial product calcium hydroxide: slaked lime, commercial product

[Evaluation methods]
(Flow value)
The flow value of the mortar flow test was measured. Measure mortar flow values immediately after kneading and 60 minutes after kneading. The test method conformed to JIS R 5201.
(Condensation time)
A setting test was conducted. The initial and final times of the mortar with the quick setting agent added were measured. The test method was carried out in accordance with the JSCE Standard JSCE-D 102-2001 Annex, a method for measuring the setting time of mortar by penetration resistance.
(Compressive strength)
The compressive strength of the mortar to which the quick setting agent was added was measured. The test method conformed to JIS R 5201.

The results in Table 1, the timing of addition of admixtures, cement, water, by setting after kneading fine aggregate, it was confirmed that Ru excellent retention of fluidity. Experiment No. conducted as a comparative example. In 1-1, since the fluidity | liquidity 60 minutes after kneading | mixing falls, construction property deteriorates. Experiment No. with late addition of admixture In 1-6, fluidity | liquidity and intensity | strength expression property 120 seconds after kneading fall.

(Experimental example 2)
Using concrete with the amount of cement shown in Table 2, the water / powder ratio shown in Table 2, and the fine aggregate ratio = 60% by volume, spraying with the addition of rapid setting agent, blocking the clogging in the piping Presence / absence, rebound rate and spray compression strength were measured. The admixture added to the concrete consists of 9 parts by weight of gypsum, 0.6 parts by weight of water reducing agent, 0.3 parts by weight of organic acid, and 0.3 parts by weight of alkali metal carbonate with respect to 100 parts by weight of cement. . The admixture was added 30 seconds after mixing water, cement, fine aggregate and coarse aggregate.
Concrete with admixture added is pumped using a concrete pump “Shintech MKW-25SMT”, and pneumatically transferred from one of the Y-shaped pipes provided in the middle of the pumping pipe by the “Denkanatom Cleat PAC250V” The quick setting agent was added and sprayed from a Y-tube through a 2 m pipe. The pumping speed of concrete was 10 m ³ / h.
As the quick setting agent, a mixture of calcium aluminate: alkali metal aluminate: calcium hydroxide = 100: 10: 5 (mass ratio) was used.
10 parts by mass of the quick setting agent was added to 100 parts by mass of cement.
The results are shown in Table 2.

[Materials used]
Coarse aggregate: No. 6 crushed stone from Itoigawa, Niigata Prefecture, maximum dimension = 15 mm, surface dry density = 2.64

[Evaluation methods]
(Possibility of blockage in piping)
During spraying, we checked for blockage in the concrete pumping path from the concrete pump to the nozzle tip.
(Rebound rate)
Concrete 1 m ³ spray poppy, after spraying ends, the amount of concrete that has fallen to the vinyl sheet lined on the floor without adhering to measure the rebound rate = (the concrete dropped without adhering during spray (Mass) / (total mass of concrete used for spraying) × 100 (%).
(Blowing compression strength)
The strength at the age of 10 minutes was measured by the initial strength test method of shotcrete by the JSCE-G 561-1999 drawing method. The compressive strength at the age of 28 days was measured with a 20-ton pressure machine on a specimen having a diameter of 5 cm and a length of 10 cm cored from a concrete block after spraying concrete onto a mold 50 cm wide x 50 cm long x 20 cm thick. The compressive strength was determined.

表２の結果から明らかなように、セメント量と水／粉体比を特定の範囲に設定することにより、配管の閉塞がない、リバウンド率が少ない、強度発現性が高い、吹付けコンクリートが得られた。

As is clear from the results in Table 2, by setting the cement amount and the water / powder ratio to specific ranges, there is no clogging of the pipe, the rebound rate is low, the strength expression is high, and the shotcrete is obtained. It was.

(Experimental example 3)
Spraying is performed using concrete having a composition of fiber amount, cement amount 450 kg / m ³ , water / powder ratio = 40 mass%, fine aggregate ratio = 60 volume% shown in Table 3 with respect to the base concrete volume. The test was performed in the same manner as in Experimental Example 2 except that the presence or absence of blockage in the piping and the impact resistance were measured.
The results are shown in Table 3.

[Materials used]
Fibrous material A: commercial vinylon fiber, fiber length 30 mm
Fibrous material B: Commercially available steel fiber, fiber length 30 mm
Fibrous material C: commercially available vinylon fiber, fiber length 0.5 mm
Fibrous material D: commercial vinylon fiber, fiber length 60 mm
Fibrous material E: Commercial vinylon fiber, fiber length 100 mm

[Evaluation methods]
(Impact resistance)
After 1 hour has passed since spraying, a piece of shot concrete cut to a width of 20 cm, length of 200 cm, and thickness of 1 cm is placed on a flattened sand, and a sphere weighing 100 g falls from a height of 50 cm. I let you. If the number of drops is 5 or less and cracked and destroyed, it is not allowed. If the number of drops is 5 or less and cracked a little, but it did not result in destruction, even if the number of drops exceeds 5 Those that did not crack and were not destroyed were considered good.

  From the results in Table 3, it was confirmed that the concrete obtained according to the present invention had no blockage of piping and was excellent in impact resistance.

(Experimental example 4)
About the base concrete of the mixing | blending which made fibrous substance A amount 1.0 volume% with respect to the base concrete volume, cement amount 450kg / m < ³ >, water / powder ratio = 40 mass%, fine aggregate rate = 60 volume%, The slump change of the base concrete kneaded by changing the addition time of the admixture was measured. The quick setting agent was added and sprayed, and the slump and spray compressive strength were measured. Other than that was carried out similarly to Experimental Example 2.
The results are shown in Table 4.

[Evaluation methods]
(slump)
The slump of the base concrete to which no quick setting agent was added was measured according to JIS A 1101.

From the results in Table 4, the setting time of the admixture was set after mixing the cement, water, fine aggregate, and coarse aggregate, so that the slump retention of the base concrete was improved, so the workability was excellent. It was confirmed that shotcrete was obtained and good strength development was obtained. Experiment No. conducted as a comparative example. In 4-1, since the fluidity | liquidity 60 minutes after kneading fell, workability deteriorated. Experiment No. with late addition of admixture In 4-5, the slump retention property 120 seconds after mixing decreased.

(Example 5)
Admixtures with mixing ratios shown in Table 5, fibrous substance A amount 1.0 volume%, cement amount 450 kg / m ³ , water / powder ratio = 40 mass%, fine aggregate ratio = 60 with respect to base concrete volume The slump change was measured for the base concrete blended in volume%. The quick setting agent was added and sprayed to measure the slump, rebound rate, impact resistance, and spray compressive strength. Other than that was carried out similarly to Experimental Example 2.
The results are shown in Table 5.

From the results of Table 3, it was confirmed that in the examples according to the present invention, the slump retainability was excellent, the quick setting property was excellent, and the good impact resistance and strength development were obtained. Experiment No. In No. 5-6, cracks occurred at the age of 28 days and the strength decreased. In 5-7, the slump was small. Experiment No. 5-12, material separation occurred. In 5-24, the slump retention was poor.

(Experimental example 6)
The amount of the quick setting material shown in Table 6 used, the composition of the quick setting material shown in Table 6, the amount of fibrous substance A 1.0% by volume, the amount of cement 450 kg / m ³ , water / Powder ratio = 40% by mass, fine aggregate ratio = 60% by volume, using concrete, spraying and measuring slump, rebound rate, impact resistance, spray compressive strength, It carried out similarly to Experimental example 2.
The results are shown in Table 6.

  From the results shown in Table 6, by using the quick setting agent according to the present invention, the rebound rate was reduced, and good impact resistance and strength development were obtained.

(Example 7)
Using concrete with a composition of 1.0% by volume of fibrous substance A with respect to the base concrete volume, cement amount shown in Table 7, water / powder ratio shown in Table 7, fine aggregate ratio = 60% by volume, The experiment was performed in the same manner as in Experimental Example 2, except that the presence or absence of piping blockage, the rebound rate, the impact resistance, and the spray compression strength were measured.
The results are shown in Table 7.

As is apparent from the results in Table 7, by adjusting to the cement amount and water / powder ratio according to the present invention, a shotcrete having excellent workability and impact resistance and having high strength development in a short time is obtained. It was.

In the spraying method, when the ground condition is bad, the tunnel shape may be greatly deformed due to the ground pressure, so that there is a problem that the sprayed concrete is cracked and possibly peeled off. Usually, natural ground pressure is often applied from a relatively early stage after excavation, and shotcrete has excellent fluidity retention, high strength in a short time, impact resistance and toughness. It was requested.
The present invention solves the above-described problems, and obtains shotcrete that improves fluidity retention performance, retains high strength in a short time, and is excellent in impact resistance.

Claims (10)

A rapid setting spraying method characterized by mixing a cement concrete and then mixing a quick setting agent with base concrete to which gypsum, water reducing agent, organic acid and alkali metal carbonate are added. After kneading the cement concrete, gypsum, water reducing agent, an organic acid, and a base concrete obtained by adding the admixture comprising an alkali metal carbonate, quick-setting property spray comprising a quick-setting admixture Construction method. 10-60 seconds after the kneading cement concrete, gypsum, water reducing agent, an organic acid, and a base concrete obtained by adding an alkali metal carbonate, quick-setting property spraying method comprising the quick-setting admixture. Moreover, quick-setting property spraying method according one of claims 1 to 3, comprising a fibrous material. The quick setting spraying method according to claim 1, wherein the quick setting agent contains calcium aluminate. The quick setting spraying method according to any one of claims 1 to 5 , wherein the quick setting agent contains calcium aluminate, alkali metal aluminate, and calcium hydroxide. Cement amount of base concrete is 360-700kg / m ³ The quick-setting spraying method according to claim 1, wherein the amount of water used is 20 to 60 parts by mass with respect to 100 parts by mass in total of cement and admixture. The quick setting spraying method according to claim 1, wherein the fine aggregate ratio is 50% by volume or more. 9. The quick setting spraying method according to claim 8, wherein the maximum size of the fine aggregate is 5 mm or less. The quick setting spraying method according to claim 8, wherein the coarse aggregate has a maximum dimension of 15 mm or less.