JP6072529B2 - Cement quick setting agent, cement composition, spraying material, spraying method - Google Patents

Description

  The present invention relates to a cement quick setting agent, a cement composition, a spraying material, and a spraying method.

  In order to prevent collapse of exposed ground such as tunnel excavation or the like, a spraying method of quick setting concrete in which a quick setting agent is mixed with concrete is performed (see Patent Document 1). This method usually involves preparing shotcrete at a cement, aggregate, and water metering plant installed at the excavation site, transporting it with an agitator car, pumping it with a concrete pump, and using a confluence pipe installed in the middle. It is a method of mixing with a rapid setting agent fed from the other side and spraying it as a quick setting sprayed concrete on a natural ground surface to a predetermined thickness.

Accelerating agents include calcium aluminate, a mixture of alkali metal aluminate and alkali metal carbonate, etc., a mixture of calcium aluminate, alkali metal aluminate, and alkali metal carbonate, calcium aluminate and 3CaO · A mixture with SiO ₂ is known (see Patent Documents 2 to 5).

Japanese Patent Publication No. 60-4149 Japanese Patent Laid-Open No. 64-051351 Japanese Examined Patent Publication No. 56-27457 JP-A-61-026538 JP 63-2105050 A JP 2006-182617 A International Publication WO05 / 123620 Pamphlet JP-A-10-101389

  These quick setting agents have a function of promoting the setting of cement, and all of them are mixed with cement concrete and sprayed on the ground surface.

  However, these quick setting agents have a problem that concrete may be peeled off or the ground may be collapsed in a natural ground where there is a lot of spring water or a small amount of rock. Furthermore, in recent years, in order to reduce costs, there is a demand for a spray material that shortens the construction cycle and ensures safety even when the spray thickness is thin.

From the above, improvement in quick setting property and strength development property of shotcrete has been demanded, and new cement quick setting agents have been developed (see Patent Documents 6 to 7). Patent Document 6 is a rapid setting agent added to base concrete in which the total amount of gypsum contained in an admixture excluding cement and rapid setting agent exceeds 5 parts by weight in terms of SO ₃ with respect to 100 parts by weight of cement. A rapid setting agent containing aluminates and sodium aluminate having a Na ₂ O / Al ₂ O ₃ molar ratio of 0.65 or more and less than 1.00. Patent Document 7 is a quick setting agent for spraying containing calcium aluminate, gypsum, and alkali metal aluminate, and the calcium aluminate has a vitrification rate of 80% or more, and is CaO / Al _2. The O ₃ molar ratio is 1.9 to 3.0, and the content of the alkali metal aluminate is 1.5 to 10 parts in 100 parts of the rapid setting agent for spraying. It is a quick setting agent for spraying. These cement quick-setting agents and cement compositions are mainly the result of studying the ratio and particle size of calcium aluminate, gypsum and other subcomponents in the quick-setting agent, and the ratio of these crystals and non-crystals. Vitrification rate and particle size distribution have not been studied.

The particle size is an index of reaction activity, and the evaluation method includes specific surface area, particle size distribution, pore distribution and the like. For example, Patent Document 8 uses a rapid setting agent and gypsum having a specific surface area of brain (hereinafter referred to as “brain value”) of 6000 cm ² / g. However, since the brain value is the surface area of the entire powder, the reaction activity varies. May occur. This is because particles having individual particle sizes are distributed with a bias in frequency. In other words, the Blaine value cannot strictly evaluate individual particle sizes, that is, particles having individual reaction activities. The present invention limits the distribution width by classification operation. The present invention is different from Patent Document 8 in that variation in reaction activity is suppressed and particles having high activity are limited and used. In addition, the smaller the particle size, the higher the reaction activity, but the amount of dust increases, which may adversely affect the human body and may react with moisture in the air, resulting in poor storage stability.

The following formula is generally established for the specific surface area and the average particle diameter.
S = 6 / ρd (S: specific surface area, ρ: density, d: average particle diameter)
When the average particle diameter of calcium aluminate and gypsum (brane specific surface area of 6000 cm ² / g, density 3 g / cm ³ ) of Patent Document 8 is calculated by the above formula, it is 3.3 μm, and the particle diameter from the present invention Is small.

  As a result of various studies on the above problems and requirements, the present inventor used calcium aluminate and other raw materials having a specific vitrification rate and particle size distribution in an appropriate ratio, and further used a specific metal salt as a rapid setting agent. By containing, the knowledge which solves the above-mentioned subject was acquired, and it came to complete this invention.

That is, the present invention contains 1 to 5 parts of silicon in 100 parts of calcium aluminate in terms of oxide in 100 parts of calcium aluminate, alkali metal carbonate, alkali metal aluminate and gypsum, and vitrified. When the rate is 90% or more and 99% or less, the molar ratio of CaO to Al ₂ O ₃ (CaO / Al ₂ O ₃ ) is 1.5 to 2.5, and the particle diameter integrated value of 5 to 30 μm is 75% or more. A certain amount of calcium aluminate 20 parts or more and 50 parts or less, an alkali metal carbonate 1 part or more and 20 parts or less, an alkali metal aluminate 0.1 part or more and 20 parts or less, and a gypsum whose particle diameter integrated value of 5 to 30 μm is 50% or more. 21 parts or more and 45 parts or less of a cement quick setting agent, and further, hydroxide, bicarbonate, nitrate, nitrite, silicate, phosphate, sulfate, sulfite, bisulfite, Thiosulfate, thio A The cement quick-setting admixture containing an alkali metal salt is one or more selected from the en salt, alkali metal salt, an the cement quick-setting agent is sodium sulfate, and further, a hydroxide , A cement rapid hardening agent containing one or more alkaline earth metal salts selected from carbonate, nitrate, nitrite, phosphate and sulfite, wherein the alkaline earth metal salt is nitric acid The cement quick setting agent which is calcium, and further, the cement quick setting agent containing one or more aluminum salts selected from nitrates, phosphates and sulfates, wherein the aluminum salt is sulfuric acid A cement setting agent that is aluminum, a cement composition containing the cement setting agent and cement, a spray material containing the cement composition, the cement setting agent, and a cement composition. This is a spraying method that mixes with a mentament.

  By using the cement quick setting agent of the present invention, there is an effect of improving the quick setting property and strength development property of the quick setting shot concrete as compared with the conventional quick setting agent.

  Hereinafter, the present invention will be described in detail. In addition, the cement concrete as used in this invention is a general term for cement paste, mortar, and concrete. The part as used in the field of this invention means a mass part unless otherwise specified.

The calcium aluminate used in the present invention is a mixture of a raw material containing calcia and a raw material containing aluminum, and obtained by heat treatment such as firing in a kiln or melting in an electric furnace. It is a substance having hydration activity with ₂ O ₃ as a main component.

Calcium aluminate can contain silicon by mixing raw materials containing silica at the time of synthesis. The silicon content in 100 parts of calcium aluminate is preferably 1 to 5 parts, more preferably 1.5 to 3 parts in terms of oxide (SiO ₂ ). If it is less than 1 part, excellent initial strength development may not be obtained, and if it exceeds 5 parts, long-term strength development may be impaired.

Calcium aluminate is preferably quenched and vitrified after melting in an electric furnace, and the vitrification rate is preferably 90% or more and 99% or less, and more preferably 93% or more and 99% or less. If it is less than 90%, an excellent quick setting property may not be obtained. The vitrification rate is determined by measuring the main peak area S of the crystalline mineral in advance by powder X-ray diffraction of the sample before heating, heating at 1000 ° C. for 2 hours, and then slowly cooling at a cooling rate of 1-10 ° C./min. The main peak area S ₀ of the crystal mineral after heating by the powder X-ray diffraction method is obtained, and further, the vitrification rate χ is calculated by using the following equation using the values of S ₀ and S. Vitrification rate χ (%) = 100 × (1−S / S ₀ )

The calcium aluminate CaO to Al ₂ O ₃ molar ratio (CaO / Al ₂ O ₃ ) is preferably 1.5 to 2.5, and more preferably 1.7 to 2.3. If the molar ratio is outside this range, excellent quick setting may not be obtained.

  Calcium aluminate is preferably sieved to various particle sizes with a classifier. From the viewpoint of rapid setting and initial strength development, a particle size integrated value of 5-30 μm (hereinafter referred to as 5-30 μm integrated value) is 75% or more is preferable, and 90% or more is more preferable. If it is less than 75%, an excellent quick setting property or strength development property may not be obtained. The particle size distribution is measured using a particle size distribution measuring device (for example, HORIBA LA-920) by a laser diffraction / scattering method using ethanol as a sample dispersion medium. % Of the particle diameter integrated value is volume%.

  The amount of calcium aluminate used as a cement setting agent is preferably 20 parts or more and 50 parts or less, and preferably 30 parts or more and 45 parts or less, out of a total of 100 parts of calcium aluminate, alkali metal carbonate, alkali metal aluminate, and gypsum. Is more preferable. If it is less than 20 parts, excellent quick setting may not be obtained, and if it exceeds 50 parts, long-term strength development may be impaired.

  The alkali metal carbonate used in the present invention promotes the setting of cement concrete, and examples thereof include sodium carbonate, potassium carbonate, sodium hydrogen carbonate, and potassium hydrogen carbonate. Among these, sodium carbonate is preferable in terms of accelerating the setting.

  The amount of alkali metal carbonate used as the cement setting agent is preferably 1 part or more and 20 parts or less, preferably 5 parts or more and 15 parts, out of a total of 100 parts of calcium aluminate, alkali metal carbonate, alkali metal aluminate and gypsum. The following is more preferable. If it is less than 1 part, excellent quick setting may not be obtained, and if it exceeds 20 parts, long-term strength development may be impaired.

  The alkali metal aluminate used in the present invention promotes the setting of cement concrete, and is obtained by mixing and dissolving aluminum hydroxide and alkali metal hydroxide, and drying to obtain a powder.

  Examples of the alkali metal aluminate include lithium aluminate, sodium aluminate, and potassium aluminate, and one or two of these can be used. Among these, sodium aluminate is preferable in terms of rapid setting and initial strength development.

  The amount of the alkali metal aluminate used as the cement setting agent is preferably 0.1 part or more and 20 parts or less in 100 parts in total of calcium aluminate, alkali metal carbonate, alkali metal aluminate and gypsum, and 3 parts. More preferred is 13 parts or less. If it is less than 0.1 part, there may be cases where excellent quick setting properties cannot be obtained, and if it exceeds 20 parts, workability and long-term strength development may be reduced.

  The gypsum used in the present invention is mixed in order to improve the quick setting property and strength development property of cement concrete.

  As the gypsum, anhydrous gypsum, hemihydrate gypsum, dihydrate gypsum and the like can be used. Among these, anhydrous gypsum is preferable in terms of rapid setting and strength development.

  The gypsum is preferably 50% or more, and more preferably 70% or more, in terms of quick setting and initial strength development. If it is less than 50%, an excellent quick setting property or strength development property may not be obtained.

  The amount of gypsum used for the cement setting agent is preferably 21 parts or more and 45 parts or less, more preferably 30 parts or more and 40 parts or less, out of a total of 100 parts of calcium aluminate, alkali metal carbonate, alkali metal aluminate and gypsum. preferable. If it is less than 21 parts, the workability of concrete may be reduced, and it may be difficult to promote long-term strength development. If it exceeds 45 parts, rapid setting may be reduced, and initial strength development may be impaired.

  The cement quick setting agent of the present invention preferably uses an alkali metal salt in order to improve the initial strength development. Alkali metal salts include hydroxides, bicarbonates, nitrates, nitrites, silicates, phosphates, sulfates, sulfites, bisulfites, thiosulfates, thiocyanates, etc. (hereinafter alkali metals) 1 type or 2 or more types may be contained. Among these, sodium sulfate is preferable in terms of strength development. As the alkali metal salt, both an anhydride and a hydrate (hydrate) can be used, but a hydrate is preferable from the viewpoint of long-term strength development.

  The amount of the alkali metal salt used is 100 parts of a cement quick setting agent (hereinafter, 100 parts of the cement quick setting agent means 100 parts in total of calcium aluminate, alkali metal carbonate, alkali metal aluminate and gypsum. 0.5 to 8 parts is preferable, and 1 to 5 parts is more preferable. If the amount is less than 0.5 part, the excellent initial strength developability may not be obtained. If the amount exceeds 8 parts, the long-term strength developability may be impaired.

  The cement quick setting agent of the present invention preferably uses an alkaline earth metal salt in order to improve the initial strength development. As alkaline earth metal salts, one or more of hydroxides, carbonates, nitrates, nitrites, phosphates, sulfites, etc. (hereinafter sometimes collectively referred to as alkaline earth metal salts) are contained. It is possible to make it. Among these, calcium nitrate is preferable in terms of strength development. As the alkaline earth metal salt, both an anhydride and a hydrate (hydrate) can be used, but a hydrate is preferable from the viewpoint of long-term strength development.

  The amount of the alkaline earth metal salt used is preferably 0.5 to 5 parts, more preferably 1 to 3 parts, per 100 parts of the cement quick setting agent. If it is less than 0.5 part, excellent initial strength development may not be obtained, and if it exceeds 5 parts, long-term strength development may be impaired.

  The cement quick setting agent of the present invention preferably uses an aluminum salt in order to promote setting. As an aluminum salt, it is possible to contain 1 type, or 2 or more types of nitrates, phosphates, sulfates (hereinafter sometimes collectively referred to as aluminum salts). Among these, aluminum sulfate is preferable in terms of quick setting. As the aluminum salt, both an anhydride and a hydrate (hydrate) can be used, but a hydrate is preferable in terms of long-term strength development.

  The amount of aluminum salt used is preferably 1 to 8 parts, more preferably 2 to 5 parts, per 100 parts of the cement quick setting agent. If it is less than 1 part, excellent quick setting may not be obtained, and if it exceeds 8 parts, long-term strength development may be impaired.

  The amount of the cement quick setting agent of the present invention is preferably 3 to 20 parts, more preferably 5 to 15 parts, and most preferably 7 to 10 parts with respect to 100 parts of cement. If it is less than 3 parts, it may be difficult to promote the quick setting property of the quick setting shot concrete, and if it exceeds 20 parts, long-term strength development may be impaired.

  Here, the cement includes various portland cements such as normal, early strength, moderate heat, and super early strength, and various mixed cements obtained by mixing fly ash, blast furnace slag, and the like with these various portland cements. These can be used in the form of fine powder.

  The cement concrete used in the present invention contains cement and aggregate. Here, as the aggregate, those having low water absorption and high aggregate strength are preferable. The maximum dimension of the aggregate is not particularly limited as long as it can be sprayed.

  River sand, mountain sand, lime sand, quartz sand, and the like can be used as the fine aggregate, and river gravel, mountain gravel, lime gravel, and the like can be used as the coarse aggregate.

  The amount of water used for the cement concrete is preferably 35 parts or more and more preferably 40 to 55 parts with respect to 100 parts of cement in the cement concrete in terms of strength development. If it is less than 35 parts, cement concrete may not be sufficiently mixed.

  As a wet spraying method, for example, cement, fine aggregate, coarse aggregate, and water are added and mixed, pneumatically fed, a Y-shaped tube is provided in the middle, and pumped from one of them by a quick setting agent supply device. There is a method in which a cement quick setting agent is mixed and mixed to form a quick setting wet spray cement concrete.

  Moreover, the pressure of the pumping air for pumping the rapid setting agent is 0.01 to 0.3 MPa higher than the pumping pressure of the cement concrete so that the inside of the pumping tube is not blocked when the cement concrete is mixed in the pumping tube of the rapid setting agent. It is preferable.

  Hereinafter, the present invention will be described in detail based on experimental examples.

Experimental example 1
In 100 parts of calcium aluminate, calcium aluminate having the SiO ₂ amount, vitrification rate, and molar ratio (CaO / Al ₂ O ₃ ) shown in Table 1 was prepared. A cement quick-setting agent containing 40 parts of calcium aluminate, 10 parts of alkali metal carbonate, 10 parts of alkali metal aluminate and 40 parts of gypsum shown in Table 1 in 100 parts of cement quick-setting agent was prepared. Also, a mortar having a sand / cement ratio = 3 and a water / cement ratio = 52% by mass was prepared, and 8 parts of a cement quick setting agent was added to 100 parts of the cement to form a quick setting mortar. Compressive strength was measured. The results are also shown in Table 1.

<Materials used>
Cement: Ordinary Portland cement, commercially available, brain value 4000 cm ² / g, specific gravity 3.16
Fine Aggregate: River sand from Himekawa, Itoigawa City, Niigata Prefecture, surface dry condition, specific gravity 2.62
Calcium aluminate: calcia raw material, alumina raw material, and various proportions of silica raw material are mixed, melted at 1600 ° C. in an electric furnace, adjusted for cooling rate, various silicon contents (as oxides), various Calcium aluminate having a vitrification rate and various CaO / Al ₂ O ₃ (molar ratios) was synthesized, pulverized with a pulverizer such as a ball mill, and the particle size was adjusted by classification, 5-30 μm integrated value 90%
Alkali metal carbonate: sodium carbonate, commercial product alkali metal aluminate: sodium aluminate, commercial product gypsum: anhydrous gypsum, commercial product, 5-30 μm integrated value 70%

<Measurement method>
Setting time: Quick setting mortar measured according to the Japan Society of Civil Engineers standard "Quality standard for sprayed concrete quality (JSCED-102)" Compressive strength: Quick setting mortar measured according to JIS R 5201 Environmental test temperature: Set to 20 ° C

From Table 1, 1 to 5 parts of SiO ₂ is contained in 100 parts of calcium aluminate, and a calcium aluminate having a vitrification ratio of 90 to 99% and CaO / Al ₂ O ₃ of 1.5 to 2.5 is used. This is desirable as a property of the quick setting agent.

Experimental example 2
Using calcium aluminate and gypsum whose 5-30 μm integrated values are shown in Table 2, 40 parts of calcium aluminate, 10 parts of alkali metal carbonate, 10 parts of alkali metal aluminate, gypsum in 100 parts of cement quick setting agent A cement setting agent containing 40 parts was prepared. Except for the above, the same procedure as in “Experimental Example 1” was performed. Further, a mortar similar to “Experimental Example 1” was prepared, and 8 parts of a cement quick setting agent was added to 100 parts of the cement to form a quick setting mortar, and the setting time and compressive strength were measured. The results are also shown in Table 2.
Experiment No. In 2-1 (Comparative Example), a conventional quick setting agent (commercial product) was used.

<Materials used>
Calcium aluminate: SiO ₂ 3 parts, vitrification rate 95%, CaO / Al ₂ O ₃ (molar ratio) = 2.0, 5-30 μm integrated value adjusted to various values by classification Gypsum: anhydrous gypsum, Commercial products, various 5-30μm integrated values

  From Table 2, it is desirable as a property of the quick setting agent to use a cement quick setting agent in which the 5-30 μm integrated value of calcium aluminate is 75% or more and the 5-30 μm integrated value of gypsum is 50% or more. In the conventional product, the 5-30 μm integrated value of calcium aluminate is less than 75%, and the 5-30 μm integrated value of gypsum is less than 50%, so the properties of the quick setting agent were not better than those of the present invention.

Experimental example 3
A cement quick-setting agent containing calcium aluminate, alkali metal carbonate, alkali metal aluminate and gypsum in the amounts shown in Table 3 in 100 parts of cement quick-setting agent was prepared. Except for the above, the same procedure as in “Experimental Example 1” was performed. Further, a mortar similar to “Experimental Example 1” was prepared, and 8 parts of a cement quick setting agent was added to 100 parts of the cement to form a quick setting mortar, and the setting time and compressive strength were measured. The results are also shown in Table 3.

<Materials used>
Calcium aluminate: SiO ₂ 3 parts, vitrification rate 95%, CaO / Al ₂ O ₃ (molar ratio) = 2.0, 5-30 μm integrated value 90%

  From Table 3, the composition of the quick setting agent is 20 to 50 parts of calcium aluminate, 1 to 20 parts of alkali metal carbonate, 0.1 to 20 parts of alkali metal aluminate, and gypsum 21 in 100 parts of cement quick setting agent. ˜45 parts is desirable as a property of the quick setting agent.

Experimental Example 4
A quick setting agent containing 40 parts of calcium aluminate, 10 parts of alkali metal carbonate, 10 parts of alkali metal aluminate, and 40 parts of gypsum in 100 parts of the cement quick setting agent was prepared. A cement quick setting agent containing 100 parts of this quick setting agent and 2 parts of metal salts (alkali metal salt, alkaline earth metal salt, aluminum salt) shown in Table 4 was prepared. Except for the above, the same procedure as in “Experimental Example 1” was performed. Further, a mortar similar to “Experimental Example 1” was prepared, and 8 parts of a cement quick setting agent was added to 100 parts of the cement to form a quick setting mortar, and the setting time and compressive strength were measured. The results are also shown in Table 4.

<Materials used>
Calcium aluminate: SiO ₂ 3 parts, vitrification rate 95%, CaO / Al ₂ O ₃ (molar ratio) = 2.0, 5-30 μm Integrated value 90% Metal salt A: Alkali metal salt, hydroxylation Sodium, hydrate, commercially available metal salt B: alkali metal salt, sodium bicarbonate, hydrate, commercially available metal salt C: alkali metal salt, sodium nitrate, hydrate, commercially available metal salt D: alkali metal salt , Sodium nitrite, hydrate, commercially available metal salt E: alkali metal salt, sodium metasilicate, hydrate, commercially available metal salt F: alkali metal salt, sodium triphosphate, hydrate, commercially available metal Salt G: alkali metal salt, sodium sulfate, hydrate, commercially available metal salt H: alkali metal salt, sodium sulfite, hydrate, commercially available metal salt I: alkali metal salt, sodium bisulfite, hydrate, commercially available Metal salt Alkali metal salt, sodium thiosulfate, hydrate, commercially available metal salt K; alkali metal salt, sodium thiocyanate, hydrate, commercially available metal salt L: alkali metal salt, sodium sulfate, anhydride, commercially available metal Salt M: Alkali metal salt, potassium sulfate, hydrate, commercially available metal salt N: Alkaline earth metal salt, calcium hydroxide, hydrate, commercially available metal salt O: Alkaline earth metal salt, calcium carbonate, water Japanese product, commercially available metal salt P: alkaline earth metal salt, calcium nitrate, hydrate, commercially available metal salt Q: alkaline earth metal salt, calcium nitrite, hydrate, commercially available metal salt R: alkaline earth Metal salt, tribasic calcium phosphate, hydrate, commercially available metal salt S: alkaline earth metal salt, calcium sulfite, hydrate, commercially available metal salt T: alkaline earth metal salt, calcium nitrate, anhydride, commercially available Metal salt U : Alkaline earth metal salt, magnesium nitrate, hydrate, commercially available metal salt V: Aluminum salt, aluminum nitrate, hydrate, commercially available metal salt W: Aluminum salt, aluminum phosphate, hydrate, commercially available metal Salt X: Aluminum salt, aluminum sulfate, hydrate, commercial product Metal salt Y: Aluminum salt, aluminum sulfate, anhydride, commercial product

  From Table 4, it is suggested that sodium sulfate hydrate is used as the alkali metal salt, calcium nitrate hydrate is used as the alkaline earth metal salt, and aluminum sulfate hydrate is used as the aluminum salt. Desirable as a property.

Experimental Example 5
A quick setting agent containing 40 parts of calcium aluminate, 10 parts of alkali metal carbonate, 10 parts of alkali metal aluminate, and 40 parts of gypsum in 100 parts of the cement quick setting agent was prepared. 100 parts of this quick setting agent, and metal salts shown in Table 5 (sodium sulfate hydrate (metal salt G) as alkali metal salt, calcium nitrate hydrate (metal salt P) as alkaline earth metal salt, aluminum A cement setting agent containing aluminum sulfate hydrate (metal salt X) as a salt was prepared. Except for the above, the same procedure as in “Experimental Example 4” was performed. Further, a mortar similar to “Experimental Example 4” was prepared, and 8 parts of a cement quick setting agent was added to 100 parts of the cement to obtain a quick setting mortar, and the setting time and compressive strength were measured. The results are also shown in Table 5.

<Materials used>
Calcium aluminate: SiO ₂ 3 parts, vitrification rate 95%, CaO / Al ₂ O ₃ (molar ratio) = 2.0, 5-30 μm integrated value 90%

  From Table 5, the amount added to the quick setting agent is 0.5-8 parts for the alkali metal salt, 0.5-5 parts for the alkaline earth metal salt, and 1-8 parts for the aluminum salt. This is desirable as a binder property.

Experimental Example 6
A cement quick-setting agent (A) containing 40 parts of calcium aluminate, 10 parts of alkali metal carbonate, 10 parts of alkali metal aluminate, and 40 parts of gypsum in 100 parts of cement quick-setting agent was prepared. Further, a cement quick set comprising 100 parts of cement quickener (a) containing 2 parts of sodium sulfate as an alkali metal salt, 2 parts of magnesium nitrate as an alkaline earth metal salt, or 2 parts of aluminum sulfate as an aluminum salt Agents (i) to (d) were prepared. Except for the above, the same procedure as in “Experimental Example 4” was performed. Also, a mortar similar to “Experimental Example 4” was prepared, and with respect to 100 parts of the cement, a cement quick setting agent was added in the amount shown in Table 6 to obtain a quick setting mortar, and its setting time and compressive strength were measured. did. The results are also shown in Table 6.

<Materials used>
Calcium aluminate: SiO ₂ 3 parts, vitrification rate 95%, CaO / Al ₂ O ₃ (molar ratio) = 2.0, 5-30 μm integrated value 90% cement rapid setting agent (A): calcium aluminum Containing 40 parts of acidate, 10 parts of alkali metal carbonate, 10 parts of alkali metal aluminate, 40 parts of gypsum Cement quick setting agent (b): 100 parts of cement quick setting agent (a) and water of sodium sulfate Containing 2 parts of Japanese (metal salt G) Cement quick setting agent (c): Containing 100 parts of cement quick setting agent (a) and 2 parts of calcium nitrate hydrate (metal salt P) Cement quick setting agent (d): Cement quick setting agent (a) 100 parts and aluminum sulfate hydrate (metal salt X) 2 parts

  From Table 6, the amount of the cement quick-setting agent used is preferably 3 to 20 parts as a property of the quick-setting agent with respect to 100 parts of cement.

  By using the present invention, it is possible to increase the setting property and strength development compared to conventional quick setting agents, and therefore, it can be widely used in the fields of civil engineering and construction.

Claims (10)

In 100 parts of calcium aluminate, alkali metal carbonate, alkali metal aluminate and gypsum in total, 1 to 5 parts of silicon is contained in 100 parts of calcium aluminate in terms of oxides, and the vitrification rate is 90% or more and 99. 20 parts by weight of calcium aluminate with a molar ratio of CaO to Al ₂ O ₃ (CaO / Al ₂ O ₃ ) of 1.5 to 2.5 and an integrated particle diameter of 5 to 30 μm is 75% or more. 50 parts or less, alkali metal carbonate 1 part or more and 20 parts or less, alkali metal aluminate 0.1 part or more and 20 parts or less, gypsum 21 parts or more and 45 parts or less with an integrated particle diameter of 5 to 30 μm of 50% or more , Containing cement quickener. In addition, one or more selected from hydroxide, bicarbonate, nitrate, nitrite, silicate, phosphate, sulfate, sulfite, bisulfite, thiosulfate, and thiocyanate The cement quick-setting agent according to claim 1, comprising a certain alkali metal salt. The cement quick-setting agent according to claim 2, wherein the alkali metal salt is sodium sulfate . Furthermore, the alkaline earth metal salt which is 1 type (s) or 2 or more types chosen from a hydroxide, carbonate, nitrate, nitrite, phosphate, and sulfite is contained. Cement quick-setting agent. The cement quick setting agent according to claim 4, wherein the alkaline earth metal salt is calcium nitrate . Furthermore, the cement quick setting agent of one of Claims 1-5 containing the aluminum salt which is 1 type, or 2 or more types chosen from nitrate, a phosphate, and a sulfate . The cement quick-setting agent according to claim 6, wherein the aluminum salt is aluminum sulfate . A cement composition containing the cement quick setting agent according to claim 1 and cement. The spraying material containing the cement composition of Claim 8. A spraying method comprising mixing the cement quick setting agent according to claim 1 and cement.