WO2017171004A1

WO2017171004A1 - Setting regulation admixture

Info

Publication number: WO2017171004A1
Application number: PCT/JP2017/013595
Authority: WO
Inventors: 神谷　清志; 徳永　健二; 田原　英男
Original assignee: 三菱マテリアル株式会社
Priority date: 2016-03-31
Filing date: 2017-03-31
Publication date: 2017-10-05

Abstract

The present invention relates to a setting regulation admixture that is for adding to an ultra-rapid-hardening cement composition so as to regulate the setting start time of the ultra-rapid-hardening cement composition. This setting regulation admixture is characterized by being a compound that includes, in a mass ratio of 1:0.5-1:3: at least one setting regulator selected from the group that consists of inorganic carbonates, oxycarbonic acid, sodium aluminate, and sodium sulfate; and an inorganic powder.

Description

Setting adjustment admixture

The present invention relates to an agglomeration adjusting admixture that is added to an ultrafast cement composition to adjust the initial setting time of the ultrafast cement composition.
This application claims priority based on Japanese Patent Application No. 2016-073204 filed in Japan on March 31, 2016 and Japanese Patent Application No. 2017-060945 filed on March 27, 2017 in Japan. , The contents of which are incorporated herein.

Cement is usually used as a cement composition containing fine aggregates and coarse aggregates, and various admixtures depending on the application. As an admixture for accelerating the hardening of the cement composition, a quick-setting admixture combining calcium aluminate and an inorganic sulfate (gypsum) is known. This fast-setting admixture that combines calcium aluminate and inorganic sulfate has a strong effect of accelerating the hardening of the cement composition, and the cement composition containing this quick-setting admixture and cement is super-fast setting and contains water. The time (additional start time) from the addition to the start of condensation is short. For this reason, in order to ensure the pot life of this super-hard setting cement composition, it is necessary to control the setting time by adding a setting regulator. It becomes possible to secure the pot life by using a super-hard setting cement composition and a coagulant adjusting agent, and pavement work, grout work, repair and reinforcement work for concrete structures that require urgency and short construction time, It can also be used for concrete work. As the setting modifier, inorganic carbonates, oxycarboxylic acids, and sodium aluminates are known.

Patent Document 1 includes a quick-hardening cement containing 15-35% by weight of a quick-hardening component in which the weight ratio of calcium aluminate to inorganic sulfate is 1: 0.5 to 3, and includes an internal weight. A super-hard cement composition comprising sodium aluminate 0.2 to 3%, inorganic carbonate 0.2 to 5%, and oxycarboxylic acids 0.1 to 2% is disclosed.

Patent Document 2 discloses a calcium aluminate-based fast-hardening admixture containing calcium aluminate, an inorganic sulfate, and a setting regulator, and a super-hard-hardening cement composition containing the fast-hardening admixture and cement. In this Patent Document 2, sodium aluminate, inorganic carbonate and carboxylic acid are used as a setting modifier for a fast-curing admixture. At least one of these setting modifiers has a particle size configuration exceeding an average particle size of 45 μm. And 10 to 45% by mass of the first particles having a particle size of 90 μm or less, 30 to 70% by mass of the second particles having an average particle size of more than 90 μm and 150 μm or less, and 5 to 30 of the third particles having an average particle size of more than 150 μm and 500 μm or less. In addition, it is disclosed that the second particles are contained in a larger amount than the first particles and more than the third particles.

Japanese Patent Publication No. 3-41420 Japanese Patent No. 3912425

As described in Patent Document 1 and Patent Document 2, as a method for adjusting the initial setting time of a super-hard setting cement composition containing a quick-setting admixture in which calcium aluminate and inorganic sulfate are combined, a setting controller The method of adding is widely performed. However, the ultra-fast setting cement composition containing the quick-setting admixture and the setting modifier may delay the initial setting time when stored for a long period of time, compared to the ultra-fast setting cement composition immediately after manufacture. There was a problem. In addition, since the setting retarding agent alone is too sensitive, the amount of fluctuation of the setting start time is large by adding a small amount, and it is difficult to adjust the setting start time easily and accurately.

This invention has been made in view of the circumstances described above, and by adding to the ultrafast cement composition, the initial setting time of the ultrafast cement composition can be easily and accurately adjusted, It is another object of the present invention to provide an admixture for adjusting the initial setting time that can maintain the initial setting time stably even when the ultrafast cement composition is stored for a long period of time.

In order to solve the above-mentioned problems, the inventors of the present invention have intensively studied. As a result, the mass adjusting agent has a mass ratio of a coagulation regulator such as inorganic carbonate, oxycarboxylic acid, sodium aluminate and sodium sulfate, and inorganic powder. When added to the super-hard cement composition as a mixture containing 0.5 to 1: 3 (total amount of inorganic carbonate, oxycarboxylic acid, sodium aluminate and sodium sulfate: amount of inorganic powder) The finding that the initial setting time of a hard cement composition can be adjusted easily and accurately, and the initial setting time can be stably maintained even if the super fast hard cement composition is stored for a long period of time. Obtained.

The present invention has been made based on the above-mentioned findings, and the setting control admixture of the present invention is one or more selected from the group consisting of inorganic carbonate, oxycarboxylic acid, sodium aluminate and sodium sulfate. It is characterized by being a mixture containing a setting modifier and inorganic powder in a mass ratio of 1: 0.5 to 1: 3.

Since the setting modifier admixture of the present invention is a mixture of a setting modifier and an inorganic powder, the addition of the setting modifier admixture of the present invention to a super-hard setting cement composition has substantially two steps of setting agent. It will be mixed with the super-hard setting cement composition. For this reason, by using the setting control admixture of the present invention, the setting control agent can be uniformly dispersed in the super-hard setting cement composition. And, since the setting modifier diluted with the inorganic powder is uniformly dispersed in the super-hard setting cement composition to which the setting control admixture of the present invention is added, the setting control action of the cement by the setting control agent as a whole. The initial setting time of the super-hard setting cement composition can be adjusted reliably and accurately, and even if the super-fast setting cement composition is stored for a long period of time, the setting start time is stable. can do. That is, by using the setting adjusting admixture of the present invention, it becomes easy to adjust the addition amount of the setting adjusting agent for obtaining the required setting starting time, and it is possible to adjust the setting starting time with high accuracy. .

Here, in the setting control admixture of the present invention, the inorganic powder is Portland cement, limestone powder, silica powder, blast furnace slag powder, coal ash, fly ash, clay mineral, calcium aluminate powder, inorganic sulfate powder. It is preferable that it is one or more of them.
In this case, the above-mentioned inorganic powder does not adversely affect the performance related to the quick setting of the quick-setting admixture, and has low reactivity with the setting modifier, so the setting-adjusting admixture using these inorganic powders, By adding to the ultrafast cement composition, the initial setting time can be stably maintained even if the ultrafast cement composition is stored for a long period of time.

Moreover, in the setting control admixture of this invention, it is preferable that the average particle diameter of the said inorganic powder exists in the range of 10 micrometers or more and 200 micrometers or less.
In this case, since the inorganic powder is used as a fine inorganic powder having an average particle diameter in the above range, the setting modifier can be uniformly dispersed in the inorganic powder, and the composition of the setting modifier admixture becomes more uniform. At the same time, dispersibility in the ultrafast cement composition is improved. Therefore, by adding this setting adjusting admixture to the ultrafast cement composition, the initial setting time of the ultrafast cement composition can be adjusted more reliably and accurately, and the ultrafast cement composition can be used for a long time. Even when stored for a long time, the initial setting time can be stably maintained.

Furthermore, in the setting adjusting admixture of the present invention, when the setting adjusting agent contains an inorganic carbonate, the inorganic carbonate is one or more of potassium carbonate, lithium carbonate, sodium carbonate, sodium bicarbonate, ammonium carbonate. It is preferable that That is, one of these inorganic carbonates may be used alone, or two or more thereof may be used in combination.
In this case, since the inorganic carbonate is used as the setting adjuster, the setting adjusting action by the set adjusting agent can be surely exhibited. Therefore, by adding this setting adjusting admixture to the ultrafast cement composition, the initial setting time of the ultrafast cement composition can be adjusted more reliably and accurately.

Furthermore, in the setting modifier admixture of the present invention, when the setting modifier contains oxycarboxylic acid, the oxycarboxylic acid is one or more of tartaric acid, citric acid, malic acid, gluconic acid, and maleic acid. Preferably there is. That is, these oxycarboxylic acids may be used alone or in combination of two or more.
In this case, since the above oxycarboxylic acid is used as the setting modifier, the setting adjustment effect by the setting modifier can be reliably exhibited. Therefore, by adding this setting adjusting admixture to the ultrafast cement composition, the initial setting time of the ultrafast cement composition can be adjusted more reliably and accurately.

Furthermore, in the setting adjusting admixture of the present invention, it is preferable that the average particle diameter of the setting adjusting agent is in the range of 1 μm to 500 μm.
In this case, the setting modifier having an average particle diameter in the above range has high solubility in water and hardly changes in quality due to moisture in the atmosphere, so that the setting adjustment action can be maintained over a long period of time. . Furthermore, by adding this setting adjusting admixture to the ultrafast cement composition, the initial setting time of the ultrafast cement composition can be adjusted more reliably and accurately. Even when stored for a long period of time, the initial setting time can be stably maintained.

According to the present invention, it is possible to provide an admixture for adjusting the setting time that can stably maintain the setting start time even if the super-hard setting cement composition is stored for a long period of time.

Below, the setting adjustment admixture which is embodiment of this invention is demonstrated.
The setting control admixture of this embodiment is a mixture containing one or more setting control agents selected from the group consisting of inorganic carbonates, oxycarboxylic acids and sodium aluminates and inorganic powders.
In the present embodiment, the mixture includes a mixture obtained by simply mixing a setting modifier and an inorganic powder, and a mixed pulverized product obtained by mixing and pulverizing a setting modifier and an inorganic powder. In the setting control admixture of this embodiment, the setting control agent further contains sodium sulfate. The blending ratio of the setting modifier and the inorganic powder is in the range of 1: 0.5 to 1: 3 by mass ratio.
Hereinafter, the setting modifier and inorganic powder used in the setting modifier admixture of the present embodiment, and the blending amounts thereof will be described.

(Setting agent)
The setting modifier has the effect of adjusting the time from the addition of water to the ultrafast setting cement composition until the start of setting of the cement, that is, the action of delaying the setting time of the cement when using the ultrafast setting cement composition. Have. By delaying the setting time of the cement by the setting modifier, the fluidity of the ultrafast cement composition from when water is added to the ultrafast cement composition until the cement setting reaction proceeds is improved.
The delay of cement setting time due to the setting modifier is due to the fact that the setting modifier dissolves in water and chelate reacts with calcium ions and aluminum ions eluted from the quick setting admixture (calcium aluminate). By forming a film on the surface, it is considered that elution of calcium ions and aluminum ions from the quick-setting admixture is temporarily suppressed. However, since the film formed on the surface of the fast-curing admixture is extremely thin, it dissolves and disappears in a relatively short time. And after this film | membrane disappears, re-elution of the calcium ion and aluminum ion from a quick-hardening admixture begins, and the hardening reaction of cement advances.

The setting modifier used in the present embodiment includes one or more of inorganic carbonate, oxycarboxylic acid, sodium aluminate and sodium sulfate. The inorganic carbonate is preferably an alkali metal carbonate or bicarbonate. Examples of the inorganic carbonate include potassium carbonate, lithium carbonate, sodium carbonate, sodium bicarbonate, and ammonium carbonate. One of these inorganic carbonates may be used alone, or two or more thereof may be used in combination. Examples of oxycarboxylic acids include tartaric acid, citric acid, malic acid, gluconic acid, and maleic acid. One of these oxycarboxylic acids may be used alone, or two or more thereof may be used in combination.
The setting modifier is preferably used in combination of two or more of inorganic carbonate, oxycarboxylic acid, sodium aluminate and sodium sulfate. The combination of two or more is preferably three combinations of inorganic carbonate, oxycarboxylic acid and sodium aluminate, and more preferably four combinations of inorganic carbonate, oxycarboxylic acid, sodium aluminate and sodium sulfate.

Among the above-mentioned setting modifiers, sodium sulfate has a particularly fast dissolution rate in water. For this reason, sodium sulfate has a high effect of improving the fluidity of the ultrafast hardened cement composition after adding water. Moreover, since sodium sulfate is easy to melt | dissolve in water in a wide temperature range, it also has the effect of making the temperature dependence with respect to the initial setting time of the super-hard-hardening cement composition after adding water small.

The setting modifier preferably has an average particle size in the range of 1 μm to 500 μm. When the average particle size of the setting modifier is within this range, the solubility in water is high, and alteration due to moisture in the atmosphere hardly occurs, so that the setting adjusting action can be maintained for a long period of time. If the average particle size of the setting modifier is less than 1 μm, it will not be possible to maintain the action as a setting modifier by absorbing moisture in the atmosphere during storage with the setting agent alone, and maintaining the action as a setting modifier. As a result, the handling may be deteriorated. On the other hand, when the average particle diameter of the setting modifier exceeds 500 μm, the dissolution rate in water is slow, and there is a possibility that sufficient action as a setting regulator may not be exhibited.

(Inorganic powder)
The inorganic powder acts as a dispersion medium for diluting the setting modifier to uniformly disperse the setting modifier in the super-hard setting cement composition.
Examples of the inorganic powder include Portland cement, limestone powder, silica stone powder, blast furnace slag powder, coal ash, fly ash, clay mineral, calcium aluminate powder, and inorganic sulfate powder. One of these inorganic powders may be used alone, or two or more thereof may be used in combination. The inorganic sulfate powder is preferably gypsum, particularly preferably anhydrous gypsum.
The above-mentioned inorganic powder does not adversely affect the performance related to the quick setting of the quick setting admixture. Moreover, these inorganic powders have low reactivity with the setting modifier. For this reason, the above-mentioned setting control admixture using the inorganic powder is stable over a long period of time. In addition, the initial setting time can be stably maintained.

The inorganic powder preferably has an average particle size in the range of 10 μm to 200 μm. By using the inorganic powder as a fine inorganic powder having an average particle diameter in the above range, the setting modifier in the setting adjustment admixture can be dispersed in a more uniform state using the inorganic powder as a dispersion medium. The composition of the regulator becomes more uniform. Moreover, the fine inorganic powder whose average particle diameter is in the above range improves the dispersibility in the ultrafast cement composition. For this reason, by adding a setting control admixture containing this fine inorganic powder to the ultrafast hardening cement composition, it becomes possible to more uniformly disperse the setting control agent in the ultrafast setting cement composition. The initial setting time of the ultrafast cement composition can be adjusted more accurately and accurately, and the fluidity of the ultrafast cement composition after adding water is improved. Moreover, even if the super-hard setting cement composition is stored for a long period of time, the initial setting time can be stably maintained.

(Combination ratio of setting modifier and inorganic powder)
In the setting modifier admixture of the present embodiment, if the content of the setting modifier is too large, the effect of diluting the setting modifier is reduced, and the initial setting time, which is one of the objects of the present invention, is ensured and accurate. It becomes difficult to adjust well, and the dispersion effect of the coagulation adjusting agent is reduced, and the storage stability over a long period of time is also deteriorated. In addition, if the amount of inorganic powder is too large, the amount of setting control admixture added to the super-hard setting cement composition increases, resulting in a decrease in the ratio of the fast-setting admixture in the super-hard setting cement composition. , Early strength development is reduced.
For the above reasons, in the setting adjusting admixture of this embodiment, the mixing ratio of the setting adjusting agent and the inorganic powder is in the range of 1: 0.5 to 1: 3 by mass ratio.

The setting adjusting admixture of the present embodiment can be produced by mixing the setting adjusting agent and the inorganic powder at the above mixing ratio. Mixing is performed by dry mixing or dry mixing and grinding. The inorganic powder used as the raw material preferably has a Blaine specific surface area in the range of 2500 cm ² / g to 5000 cm ² / g. By mixing or mixing and pulverizing the inorganic powder and the coagulation modifier having a Blaine specific surface area in the above range so that the average particle size of the inorganic powder is in the range of 10 μm or more and 200 μm or less, the coagulation modifier is uniformly obtained. A dispersed setting control admixture can be obtained.
The specific surface area of the brane is measured by a specific surface area test using a brane air permeation apparatus described in JIS R 5201 “Cement physical test method”.

As the dry mixing device, a V-type mixer, a ribbon mixer, a pro-shear mixer or the like can be used. However, the present invention is not limited to this, and various types of commonly used cement material mixing devices can be used. Can be used. The mixing time can be appropriately adjusted according to the capacity of the mixing apparatus and the blending amount of each material. The mixing time can be appropriately adjusted according to the capacity of the mixing apparatus and the blending amount of each material.
As the dry mixing and pulverizing apparatus, a pulverizing apparatus such as a ball mill, a tube mill, a vertical mill, and an E mill can be used, but the present invention is not limited thereto, and various kinds of pulverizing apparatuses that are usually used as substances are used. A grinding device can be used. When mixed with a pulverizer, the inorganic powder and the setting modifier are mixed simultaneously while being pulverized (pulverization and mixing). The component of the setting modifier is softer and easier to pulverize than the inorganic powder, so the mixing and pulverizing time may be as short as about 5 to 15 minutes.

The setting-adjusting admixture of the present embodiment can be suitably used as an admixture for adjusting the setting start time of the super-hard setting cement composition. The super-hard setting cement composition is preferably a composition containing a quick-setting admixture in which calcium aluminate and inorganic sulfate are combined. Super hard cement composition is fine aggregate, coarse aggregate, water reducing agent, AE water reducing agent, high performance water reducing agent, high performance AE water reducing agent, fluidizing agent, waterproofing agent, foaming agent, antifoaming Agents, foaming agents, rust preventives for reinforced concrete, underwater non-separable admixtures, water retention agents, drying shrinkage reducing agents, separation reducing agents (thickening agents), antifreeze / cold resistant agents, re-emulsified powder polymers, silica fume, etc. It may contain material. The content of the setting modifier is 0.01% by mass with respect to the total amount of the setting-adjusting admixture and the ultrafast-hardening cement composition. The amount is preferably in the range of 5% by mass or less. If the content of the setting modifier is too large, the initial setting time may be delayed, and the initial strength development may be reduced. Further, if the content of the setting modifier is too small, the setting start time is shortened, and it may be difficult to secure a sufficient pot life.

The setting control admixture of the present embodiment configured as described above is a mixture of a setting control agent and an inorganic powder. By using this setting control admixture, the setting agent can be used in a super-hard setting cement composition. The setting adjuster can be uniformly dispersed. And, in the ultrafast hardening cement composition to which the setting adjusting admixture of the present embodiment is added, the setting adjusting component diluted with the inorganic powder is uniformly dispersed. The initial setting time of the ultrafast cement composition can be adjusted reliably and accurately, and the fluidity of the ultrafast cement composition after adding water is improved. Furthermore, even when the ultrafast hard cement composition is stored for a long period of time, the initial setting time can be stably maintained.

As mentioned above, although the setting adjustment admixture which is embodiment of this invention was demonstrated, this invention is not limited to this, It can change suitably in the range which does not deviate from the technical idea of the invention.
For example, the coagulation adjusting admixture of the present invention includes a water reducing agent, an AE water reducing agent, a high performance water reducing agent, a high performance AE water reducing agent, a fluidizing agent, a waterproofing agent, a foaming agent, a defoaming agent, a foaming agent, and a reinforced concrete prevention agent. Various admixtures such as a rusting agent, an inseparable admixture in water, a water retention agent, a drying shrinkage reducing agent, a separation reducing agent (thickening agent), a defrosting / cold resistant agent, a re-emulsified powder polymer, and silica fume may be included.

Next, examples of the present invention will be described in detail together with comparative examples.

[Materials used]
Table 1 below shows the types, compositions and abbreviations of the materials used in the examples and comparative examples.

[Example 1]
As setting regulators, sodium carbonate (Na-1), sodium carbonate (Na-2), sodium carbonate (Na-3), sodium aluminate (Al-1), sodium aluminate (Al-2), sodium aluminate (Al-3), tartaric acid (Ta-1), tartaric acid (Ta-2), tartaric acid (Ta-3), and limestone fine powder (LP) as an inorganic powder in a mass ratio of 3: 6: 3: 1: 2: 1: 1: 2: 1: 20 (= Na-1: Na-2: Na-3: Al-1: Al-2: Al-3: Ta-1: Ta-2: Ta-3: LP ) And then dry-mixed for 15 minutes to obtain a mixture (condensation adjusting admixture 1) containing the coagulation modifier and the inorganic powder in a mass ratio of 1: 1. The setting modifier before mixing, the inorganic powder (fine limestone powder), and the setting adjustment admixture 1 were each observed with an SEM (scanning electron microscope). As a result, the particle size of the setting modifier and limestone fine powder in the setting modifier admixture 1 was almost the same as before mixing. The average particle size of the fine limestone powder in the setting control admixture 1 was 85 μm, and the average particle size of sodium carbonate was 61 μm.
The average particle diameter of the fine limestone powder (inorganic powder) was measured by observing 100 particles using SEM, measuring the longest diameter of the particles, and taking the average of the measured longest diameter. Moreover, the average particle diameter of sodium carbonate (condensation adjusting agent) was also determined by observing 100 particles using SEM, measuring the longest diameter of the particles, and determining the average of the longest diameters measured. The limestone fine powder and sodium carbonate were identified by elemental analysis using EPMA (Electron Probe Microanalyzer).

[Example 2]
Sodium carbonate (Na-1), sodium carbonate (Na-2), sodium carbonate (Na-3), sodium aluminate (Al-1), sodium aluminate (Al-2), sodium aluminate (Al-3) , Tartaric acid (Ta-1), tartaric acid (Ta-2), tartaric acid (Ta-3), and ordinary Portland cement (N) as an inorganic powder in a mass ratio of 3: 6: 3: 1: 2: 1: 1 : 2: 1: 20 (= Na-1: Na-2: Na-3: Al-1: Al-2: Al-3: Ta-1: Ta-2: Ta-3: N) The mixture was put into a mixer and dry-mixed for 15 minutes to obtain a mixture (coagulation adjusting admixture 2) containing a setting modifier and an inorganic powder in a mass ratio of 1: 1. The setting modifier before mixing, inorganic powder (ordinary Portland cement), and setting modifier admixture 2 were each observed by SEM. As a result, the particle size of the setting modifier and ordinary Portland cement in the setting modifier admixture 2 were almost the same as before mixing. The average particle size of ordinary Portland cement in the setting control admixture 2 measured by SEM observation and elemental analysis by EPMA was 14 μm, and the average particle size of sodium carbonate was 58 μm.

[Example 3]
Sodium carbonate (Na-1), sodium carbonate (Na-2), sodium carbonate (Na-3), sodium aluminate (Al-1), sodium aluminate (Al-2), sodium aluminate (Al-3) , Tartaric acid (Ta-1), tartaric acid (Ta-2), tartaric acid (Ta-3), and ordinary Portland cement (N) as an inorganic powder in a mass ratio of 3: 6: 3: 1: 2: 1: 1 : 2: 1: 20 (= Na-1: Na-2: Na-3: Al-1: Al-2: Al-3: Ta-1: Ta-2: Ta-3: N) The mixture was put into a pulverizer and pulverized and mixed for 15 minutes to obtain a mixed pulverized product (condensation adjusting admixture 3) containing a setting modifier and an inorganic powder in a mass ratio of 1: 1. The setting modifier, the inorganic powder (ordinary Portland cement), and the setting modifier admixture 3 before mixing and pulverization were each observed with an SEM. As a result, the particle size of the setting modifier and ordinary Portland cement in the setting modifier admixture 3 became finer than before pulverization and mixing. The average particle size of ordinary Portland cement in the setting control admixture 3 measured by SEM observation and elemental analysis by EPMA was 12 μm, and the average particle size of sodium carbonate was 2.1 μm.

[Example 4]
As setting regulators, sodium carbonate (Na-1), sodium carbonate (Na-2), sodium carbonate (Na-3), sodium aluminate (Al-1), sodium aluminate (Al-2), sodium aluminate (Al-3), tartaric acid (Ta-1), tartaric acid (Ta-2), tartaric acid (Ta-3), sodium sulfate (NS-3) and limestone fine powder (LP) as an inorganic powder in a mass ratio of 3 : 6: 3: 1: 2: 1: 1: 2: 1: 12: 32 (= Na-1: Na-2: Na-3: Al-1: Al-2: Al-3: Ta-1: (Ta-2: Ta-3 :: NS-3: LP) in a mixer and dry-mixed for 15 minutes to set the coagulation modifier and the inorganic powder at a mass ratio of 1: 1. A mixture (condensation adjusting admixture 4) was obtained. The pre-mixing setting modifier, inorganic powder (limestone fine powder), and setting control admixture 4 were each observed with an SEM (scanning electron microscope). As a result, the particle size of the setting modifier and the limestone fine powder in the setting modifier admixture 4 was almost the same as before mixing. In addition, the average particle diameter of the limestone fine powder in the coagulation adjusting admixture 4 measured by SEM observation and elemental analysis by EPMA was 85 μm, and the average particle diameter of sodium carbonate was 61 μm.

[Comparative Example 1]
Sodium carbonate (Na-1), sodium carbonate (Na-2), sodium carbonate (Na-3), sodium aluminate (Al-1), sodium aluminate (Al-2), sodium aluminate (Al-3) , Tartaric acid (Ta-1), tartaric acid (Ta-2), and tartaric acid (Ta-3) in a mass ratio of 3: 6: 3: 1: 2: 1: 1: 2: 1 (= Na-1: Na-2: Na-3: Al-1: Al-2: Al-3: Ta-1: Ta-2: Ta-3) Same as Example 1 except that the mixture was charged into the mixer. Thus, a mixture of setting modifiers (setting agent) was obtained. In addition, the average particle diameter of sodium carbonate in the mixture measured by SEM observation and elemental analysis by EPMA was 75 μm.

Table 2 below shows the blending amount of each material used in Examples 1 to 4 and Comparative Example 1 and the mixing apparatus used for mixing the materials.

[Examples A-1 to A-3, Examples B-1 to B-3, Examples C-1 to C-3, Examples D-1 to D-3, Comparative Examples E-1 to E-3 ]
(1) Preparation of fast-curing admixture (SA-1) A mixer containing 120 parts by mass of anhydrous gypsum (CS) as an inorganic sulfate with respect to 100 parts by mass of calcium aluminate clinker powder (CA-S). And mixed. The obtained mixture was used as a fast-curing admixture (SA-1).
(2) Manufacture of super-fast-hardening cement composition The mixture prepared in Examples 1 to 4 and Comparative Example 1, the quick-hardening admixture (SA-1), ordinary Portland cement (N), and fine bone sand (S ) Was added to the mixer at the ratio (parts by mass) shown in Table 3 below to produce a super-hard setting cement composition. Table 3 shows the total content of setting modifiers (sodium carbonate, sodium aluminate, tartaric acid, sodium sulfate) with respect to the total amount of the ultrafast cement composition.

Cement mortar was prepared by adding water and kneading at a water amount ratio of 16 mass water with respect to 100 mass parts of the ultrafast cement composition immediately after production. The test temperature was 20 ° C. The resulting cement mortar was measured for 15 shots, setting time (starting and finishing), compressive strength at a material age of 2 hours and a material age of 3 hours. The results are shown in Table 4 together with the amount of setting adjusting admixture added to the super-hard setting cement composition and the total content of setting adjusters.
The 15 shot flow, setting time and compressive strength were measured according to the method described in JIS R 5201 “Physical Test Method for Cement”.

In addition, the ultra-fast hardened cement composition is packed in a plastic bag (capacity: 12L), pinholes (hole diameter: 0.5mm) are opened at four corners of the plastic bag, and the temperature is 30 ° C and the humidity is 80% RH. Each room was stored for 3 months and 6 months. Then, a cement mortar was prepared in the same manner as described above for the ultrafast cement composition after storage, and the setting time was measured. The results are shown in Table 4.

As shown in Table 4, Examples A-1 to A-3, Examples B-1 to B-3, Examples C-1 to C-3, Examples D-1 to D-3, In each of Comparative Examples 1 to 3, as the addition amount of the coagulation adjusting admixture was increased, the initial setting time was slow and the compressive strength was low. In Examples A-1 to A-3, Examples B-1 to B-3, and Examples D-1 to D-3, when the setting amount of the setting adjustment admixture increases by 0.08 parts by mass, the setting time of setting is 6 A delay of ˜8 minutes occurred and the compressive strength at the age of 3 hours decreased by 2-4%. In Examples C-1 to C-3, when the setting amount of the setting adjustment admixture increased by 0.08 parts by mass, the setting start time was delayed by 5 to 6 minutes, and the compression strength at the age of 3 hours was 2 to It decreased by 3%. On the other hand, in Comparative Examples E-1 to E-3, when the setting amount of the setting modifier is increased by 0.08 parts by mass, the setting start time is delayed by 22 to 24 minutes. The fluctuation of the initial setting time with respect to the quantity increased. The compressive strength at the age of 3 hours was 20% lower than the value when the content of the setting modifier was 0.116% by mass from the value when 0.100% by mass. Therefore, from the results shown in Table 4, it is easier and more accurate to adjust the initial setting time of the super-hard setting cement composition by using a setting control admixture prepared by mixing or grinding and mixing a setting control agent and inorganic powder. It was confirmed that it was possible. In addition, as shown in Examples D-1 to D-3, the coagulation adjusting admixture containing sodium sulfate (Example 4) has a large flow of 15 strokes at each addition amount, and the super-hardness after adding water. It was confirmed that the effect of improving the fluidity of the cement composition was particularly high.

Examples A-1 to A-3, Examples B-1 to B-3, Examples C-1 to C-3, and Comparative Examples E-1 to E-3 after storage all have storage periods. The longer the setting, the slower the initial setting time. The initial setting time of Examples A-1 to A-3 using limestone powder as the inorganic powder was 1.2 times longer after 3 months of storage and 1.3 to 1.5 times longer after 6 months of storage. In Examples B-1 to B-3 using ordinary Portland cement as the inorganic powder, the initial setting time was 1.1 times after 3 months of storage and 1.2 times longer after 6 months of storage. The storage delay was slow and the storage stability was good. In addition, Examples C-1 to C-3 prepared by pulverizing and mixing the coagulation adjusting admixture were substantially unchanged at 1.0 times in 3 months of storage and 1.1 times in 6 months of storage, and the storage stability was also improved. It was even better. In Comparative Examples E-1 to E-3, the initial setting time was 1.4 times or more after 3 months of storage and 1.8 times or more after 6 months of storage. In particular, Comparative Example E-3 having a setting modifier content of 0.116% by mass had an initial setting time of 120 minutes or more after 3 months of storage.
On the other hand, in Examples D-1 to D-3, there was almost no change in the initial setting time until 6 months of storage.

95 parts by mass of water with respect to 100 parts by mass of the ultra-fast hardened cement composition immediately after production (Example A-2, Example B-2, Example C-2, Example D-2, Comparative Example E-2) Cement mortar was prepared by adding water and kneading at a water amount ratio of The test temperature was 5 ° C, 20, 35 ° C. The cement mortar thus obtained was measured for setting time (initial and final), compressive strength at a material age of 2 hours and a material age of 3 hours. The results are shown in Table 5 together with the amount of setting adjusting admixture and the total content of setting adjusting agent added to the ultra-hard setting cement composition.
The setting time and compressive strength were measured according to the method described in JIS R 5201 “Cement physical test method”.

As shown in Table 5, Example A-2, Example B-2, Example C-2, Example D-2, and Comparative Example E-2 all had a condensation start time when the test temperature was high. It became early. The initial setting time of Example A-2 using limestone powder as the inorganic powder was 6 to 9 minutes earlier when the temperature increased by 15 ° C. The initial setting time of Example B-2 using ordinary Portland cement as the inorganic powder was 6 minutes earlier when the temperature increased by 15 ° C. In addition, the setting start time of Example C-2 and Example D-2 prepared by pulverizing and mixing the setting adjustment admixture was about 3 minutes earlier when the temperature was increased by 15 ° C. Compared to B-2, the temperature dependency was reduced. In contrast, the initial setting time of Comparative Example E-2 was 12 to 15 minutes earlier when the temperature was increased by 15 ° C., and Example A-2, Example B-2, Example C-2, and Example D Compared with -2, the temperature dependence became larger.

From the above results, the mixture containing the setting modifier and the inorganic powder in a predetermined ratio, that is, the setting adjustment admixture of the present invention has a slow accelerating action on the initial setting time compared with the setting agent alone, and It was confirmed that the storage stability was excellent. Moreover, it was confirmed that the temperature dependency on the initial setting time of the setting was reduced by preparing the setting adjusting admixture by pulverization and mixing. It was also confirmed that sodium sulfate was included in the setting adjustment admixture, and the fluidity was improved and the temperature dependence on the setting start time was reduced.

Claims

One or more setting modifiers selected from the group consisting of inorganic carbonate, oxycarboxylic acid, sodium aluminate and sodium sulfate, and inorganic powder are included in a mass ratio of 1: 0.5 to 1: 3. A setting control admixture characterized by being a mixture.
The inorganic powder is one or more of Portland cement, limestone powder, silica powder, blast furnace slag powder, coal ash, fly ash, clay mineral, calcium aluminate powder, and inorganic sulfate powder. Item 2. The setting adjusting admixture according to item 1.
3. The coagulation adjusting admixture according to claim 1 or 2, wherein the average particle size of the inorganic powder is in the range of 10 µm to 200 µm.
The said setting regulator contains inorganic carbonate, The said inorganic carbonate is one or more of potassium carbonate, lithium carbonate, sodium carbonate, sodium hydrogencarbonate, ammonium carbonate, The 1 thru | or 3 characterized by the above-mentioned. The setting adjustment admixture of any one of these.
The said setting regulator contains oxycarboxylic acid, The said oxycarboxylic acid is one or more of tartaric acid, a citric acid, malic acid, gluconic acid, and maleic acid, The any one of Claim 1 thru | or 4 characterized by the above-mentioned. The setting adjusting admixture according to claim 1.
6. The coagulation adjusting admixture according to claim 1, wherein an average particle diameter of the coagulation adjusting agent is in a range of 1 μm or more and 500 μm or less.