JPH11100246A - Activated inorganic powder and cement composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composition high in setting rate and hardening rate by containing an Al compound and a Ca compound, which are specified in dissolving quantity and S exudation ratio to water, specific surface area and the pH of the Al compound, in a specific molar ratio of Al to Ca to control the solubility of Al and Ca ion to water. SOLUTION: The molar ratio is 0.1-10 and at least the following condition is satisfied. The Al dissolving quantity of the Al compound to 10 wt.% NaOH aq. solution is >=1000 ppm, the Ca dissolving quantity of the Ca compound to a distilled water at an ordinary temp. is ∞300 pm, the S dissolution of both compounds to distilled water at an ordinary temp. is <=50 ppm, the solubility of the Al compound to an alkaline aq. solution having pH 12.5 is ∞150 ppm/g, the specific surface area of the Al compound and the Ca compound are respectively 10-50 m<2> and 10-62 m<2> , the Al compound is aluminum hydroxide having pH 10-13 in an saturated aq. solution at an ordinary temp. and has 1-40 μm average particle diamete.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an active inorganic powder in which the solubility of calcium ions and aluminum ions in water is optimally controlled, and to a hardened cement body having a high setting speed and a high hardening speed. The present invention relates to a cement composition having excellent durability and dimensional stability.

[0002]

2. Description of the Related Art In the case of performing work using cement, in order to shorten the construction period, a cement which has a high setting speed and a high setting speed and is excellent in quick setting properties is required. In particular, it is important to shorten the construction period in emergency construction such as road construction, repair of railway and aviation-related facilities in urban areas. In a factory that manufactures industrial products made of cement, a cement excellent in quick-setting properties is desired in order to shorten the time required for shipment and simplify the curing equipment.

[0003] Japanese Patent Application Laid-Open No. 47-34519 discloses an ultra-rapid hardening cement which exhibits excellent fast-curing properties by forming ettringite at an early stage. Such an ultra-fast setting cement is commercially available from Chichibu Onoda Corporation under the trade name of jet cement, for example.

[0004] However, ettringite has a swelling property at the time of formation, water of crystallization in ettringite is easily desorbed at a lower temperature than water of crystallization in ordinary cement hydrate, and ettringite has an unhydrated calcium aluminate. It has properties such as changing to monosulfate hydrate having low strength development upon reaction. For this reason, the hardened cement containing ettringite has problems in durability and dimensional stability.

JP-A-8-91831 discloses a method for synthesizing calcium aluminum hydroxide obtained by mixing a clay mineral containing aluminum with slaked lime and applying mechanical energy to the mixture. ing. Further, it is described that the powder obtained by this method has hydraulic property and can be expected to be used for immobilization of various industrial materials and wastes.

In a solid-liquid reaction utilizing calcium ions or aluminum ions in a liquid phase such as a cement hardening reaction, the solubility of both ions in the liquid phase is improved and the amount of these ions is reduced. Optimum control, 3CaO
・ Al ₂ O ₃ .6H ₂ O (C3A.6H) and CaO.A
It is necessary to form calcium aluminate hydrate such as l ₂ O ₃ .10H ₂ O (CA.10H) in as short a time as possible. As a result, both the setting speed and the setting speed are increased, the dissolution of sulfate ions is suppressed, and ettringite hydrate is not formed, thereby improving the durability and dimensional stability of the cement. Therefore, in order to provide the cement with quick setting (setting speed and setting speed), durability and dimensional stability, the solubility of aluminum ions and calcium ions is controlled and the solubility of sulfate ions is suppressed. It is effective to add the obtained active inorganic powder to the cement.

However, Japanese Patent Application Laid-Open No. Hei 8-91831 discloses
In the case of considering the use of a powder obtained by the method described in Japanese Patent Publication No. JP-A-2006-15095 as a setting accelerator by adding it to cement, the curing speed is considerably slower than that of an ettringite type (jet cement). It is.

[0008]

SUMMARY OF THE INVENTION In view of the above, it is an object of the present invention to provide an inorganic powder in which the solubility of calcium ions and aluminum ions in water is controlled, and a cement having a high setting speed and a high hardening speed. An object of the present invention is to provide a cement composition excellent in durability and dimensional stability of a cured product.

[0009]

The active inorganic powder according to the first aspect of the present invention (hereinafter referred to as the first invention) satisfies at least one of the following conditions (a) to (e). It is characterized by comprising an aluminum compound and a calcium compound, wherein the molar ratio of aluminum / calcium is 0.1 to 10.

(A) When the aluminum compound is immersed in a 10% by weight aqueous sodium hydroxide solution at room temperature, the amount of aluminum dissolved is 1000 ppm or more, and when the calcium compound is immersed in distilled water at room temperature, The dissolved amount of calcium is 300 ppm or more, and the dissolved amount of sulfur is 50 ppm or less when the inorganic powder composed of both compounds is immersed in water at normal temperature. (B) When the aluminum compound is immersed in an aqueous alkaline solution having a pH of 12.5, the amount of aluminum dissolved is 150
ppm / g or more, and when the calcium compound is immersed in distilled water at room temperature, the dissolved amount of calcium is 30
0 ppm or more, and when the inorganic powder comprising both compounds is immersed in water at room temperature, the dissolved amount of sulfur is 50 ppm or less. (C) The aluminum compound has a specific surface area of 10 to 50 m ² / g, and the calcium compound has a specific surface area of 10 to 62 m ² / g. (D) The aluminum compound is aluminum hydroxide, and the pH value of a saturated aqueous solution of the aluminum hydroxide at room temperature is 10 to 13. (E) The aluminum compound has an average particle size of 1 to 40 μm.

The invention described in claim 2 of the present application (hereinafter referred to as “second
In the first invention, the active inorganic powder of the invention)
The aluminum compound is aluminum hydroxide, and the calcium compound is calcium hydroxide or calcium oxide.

[0012] The invention according to claim 3 of the present application (hereinafter referred to as "third")
The present invention provides a cement composition characterized in that the active inorganic powder described in the first or second invention is added to cement.

The first and second inventions relate to specific active inorganic powders. These inventions are collectively referred to as the active inorganic powder of the present invention, and the third invention is directed to the active inorganic powder of the present invention. Since it relates to the composition added to the cement, it will be referred to as the cement composition of the present invention. Hereinafter, the active inorganic powder of the present invention will be described in detail sequentially.

The active inorganic powder of the first invention comprises an aluminum (hereinafter, referred to as Al) compound and calcium (hereinafter, referred to as Al).
A composition comprising a compound (hereinafter referred to as Ca), wherein the molar ratio of Al / Ca in the composition is from 0.1 to 10;
It is necessary to satisfy at least one condition of (e).

Under the condition (a), the Al compound is
When immersed in a 10% by weight aqueous solution of sodium hydroxide at room temperature, the amount of Al dissolved must be 1000 ppm or more. More preferably, it is 3000 ppm or more. When the dissolved amount of Al is less than 1000 ppm,
When added to cement, the quick-curing properties (particularly the curing speed) become insufficient. In addition, since the curing rate increases as the amount of Al dissolved increases, there is no upper limit to the amount of Al dissolved.
It is.

The amount of Al dissolved under the condition (a) is as follows.
At room temperature, 1 g of the Al compound is immersed in 50 g of a 10% by weight aqueous sodium hydroxide solution, and
Is defined as the dissolved amount quantitatively analyzed by ICP (inductively coupled high frequency plasma spectroscopy).

In the condition (b), when the Al compound is immersed in an alkaline aqueous solution having a pH of 12.5,
It is necessary that the amount of Al dissolved is 150 ppm / g or more. More preferably, it is 300 ppm / g or more.
If the amount of Al dissolved is less than this value, when added to cement, the quick-curing properties will be insufficient. The higher the amount of Al dissolved, the faster the curing rate. Therefore, there is no upper limit for the amount of Al dissolved, but if it dares to show an effective range, 150 to 30
00 ppm.

The amount of Al dissolved under the condition (b) is as follows.
At room temperature, 50 g of an aqueous alkaline solution having a pH of 12.5 was immersed in a proportion of 1 g of an Al compound powder, stirred for 5 minutes, then separated into a residue and a filtrate, and the concentration of aluminum present in the filtrate was determined by IPC. This value is defined as the amount of Al dissolved. The alkaline aqueous solution used in this case is not particularly limited as long as the pH is 12.5, and specifically, NaOH, KOH
An aqueous solution prepared by dissolving an alkali metal salt such as in water and adjusting the pH to 12.5 is preferably used.

In both of the above conditions (a) and (b), when the Ca compound is immersed in distilled water at room temperature, the amount of dissolved Ca must be 300 ppm or more, and preferably 600 ppm or more. . Dissolution of Ca is 300p
When it is less than pm, when it is added to cement, the quick-curing property (particularly the curing speed) becomes insufficient. The higher the amount of Ca dissolved, the faster the curing speed. Therefore, there is no upper limit on the amount of Ca dissolved, but if the amount is intentionally in an effective range, it is 300 to 100.
00 ppm.

Further, in both of the conditions (a) and (b), A
When the inorganic powder composed of the l-compound and the Ca compound is immersed in water at room temperature, the dissolved amount of sulfur needs to be 50 ppm or less, and preferably 10 ppm or less. When the dissolved amount of sulfur exceeds 50 ppm, when added to cement, it reacts with dissolved Al and Ca to form ettringite hydrate, and the resulting cured cement has poor durability and dimensional stability. Become.

The dissolved amount of Ca is defined as a dissolved amount obtained by immersing 1 g of a Ca compound in 50 g of distilled water at room temperature and quantitatively analyzing Ca eluted in the compound by ICP.

Regarding the amount of sulfur dissolved, the inorganic powder 1 composed of an Al compound and a Ca compound
g is immersed in 50 g of distilled water, and the amount of sulfur eluted therein is defined as the amount dissolved by quantitative analysis by ICP.

Therefore, both of the above conditions (a) and (b)
It is not appropriate that the inorganic powder composed of the Al compound and the Ca compound contains a soluble sulfate compound such as aluminum sulfate (sulfate sulfate) and calcium sulfate [gypsum (CaSO4.2H2O)]. When sulfate compounds are included,
Sulfate ions dissolve in water to form ettringite hydrate, which reduces the durability and dimensional stability of the inorganic cured product.

Under the condition (c), the Al compound is 10
Having a specific surface area of ５０50 m ² / g and a Ca compound of 10
It is necessary to have a specific surface area of 62 m ² / g. A
When the specific surface area of the compound (1) is less than 10 m ² / g, the solubility of Al ions in the obtained active inorganic powder in water becomes insufficient, and when added to cement, the rapid curing property of the cement is poor. Will be enough. On the other hand, if it exceeds 50 m ² / g, the cohesive action of the Al compound is too large, and the workability of the cement composition obtained by using the compound is significantly deteriorated.

When the specific surface area of the Ca compound is less than 10 m ² / g, the solubility of Ca ions in water of the obtained active inorganic powder becomes insufficient, and when added to cement,
The quick-setting properties of the cement become insufficient. 62m ² / g
If the ratio exceeds the above, the cohesive action of the Al compound powder itself becomes too large, and it becomes difficult to prepare the powder itself.

The specific surface area of the Al compound and the Ca compound was determined by vacuum drying at 60 ° C. for 24 hours to degas, and then, using an automatic specific surface area measuring device, the relative pressure was 0.05 to 0.1.
At 25, it is determined by BET 5-point measurement.

Under the condition (d), the aluminum compound must be aluminum hydroxide, and the pH value of a saturated aqueous solution of the aluminum hydroxide at room temperature must be 10 to 13. The pH value of a general saturated aqueous solution of aluminum hydroxide is less than 10, and an active inorganic powder obtained using such an aluminum hydroxide powder is:
The solubility of aluminum ions in water becomes insufficient, and when added to cement, the rapid curing properties of the cement composition become insufficient. On the other hand, when the pH value exceeds 13, the curing speed of the cement composition is too fast, and the room temperature operation curing time (pot life) is shortened.

The pH value was measured by mixing 100 g of distilled water and 20 g of Al compound powder, stirring the mixture for 30 minutes, and putting an electrode of a pH meter into the resulting suspension (saturated aqueous solution). Value.

Under the condition (e), the average particle size is a numerical value obtained by measuring the particle size distribution using ethanol as a dispersant, and the average particle size of the Al compound is 1 to 40 μm. is necessary. When the average particle size is less than 1 μm, a strong cohesive force acts between the powder particles, so that it is difficult to produce the powder itself. On the other hand, if it exceeds 40 μm, the solubility of Al ions in the obtained active inorganic powder in water becomes insufficient, and when added to cement, the quick-setting properties of the cement become insufficient.

In the active inorganic powder of the present invention, a high A
A specific method for obtaining an Al compound having a solubility of 1 is not particularly limited, and includes, for example, a method of applying mechanical energy to the Al compound. When mechanical energy is applied, the crystal structure of the Al compound is disturbed and finely pulverized, and the particle diameter is reduced and the specific surface area is increased, so that the dissolving power and dissolution rate of Al ions in water are increased, The pH value of the saturated aqueous solution of the Al compound also increases.

Examples of the Al compound include aluminum hydroxide [Al (OH) ₃ ] and aluminum oxide (Al
Clay minerals containing aluminum, such as ₂ O ₃ ), kaolinite, montmorillonite, halothite, gypsite, and pyrophyllite. Among Al compounds,
Aluminum hydroxide and kaolin are particularly suitable for controlling the solubility of Al ions.

In the active inorganic powder of the present invention, the high C
A specific method for obtaining a Ca compound exhibiting the solubility of a is not particularly limited. For example, a soluble Ca compound may be used.
A method of applying mechanical energy to the compound can be used. When mechanical energy is applied, the crystal structure of the Ca compound is disturbed, and the Ca compound is finely ground to increase the specific surface area, so that the dissolving power and dissolution rate of Ca ions in water increase.

The Ca compound is not particularly limited as long as it is a compound having excellent solubility of Ca ions in water. For example, calcium hydroxide [slaked lime (Ca (OH) ₂ )] which is common as an industrial raw material is used. , Calcium oxide [quick lime (CaO)], cement, calcium nitrate [Ca (NO
3) ₂ · 4H ₂ O], calcium silicate hydrate (CaS
iO ₃ .nH ₂ O), calcium chloride hydrate (CaCl 2
₂ · 6H ₂ O), etc. However, among these, calcium hydroxide (slaked lime [Ca (OH) _2)] and calcium oxide (CaO) is particularly preferred.

The mechanical energy includes a compressive force,
Examples of the method include applying energy such as shearing force, impact force, and frictional force, and the method for applying these is not particularly limited. The method can be performed by using a crushing apparatus generally used for crushing. Examples of the pulverizer include a ball mill, a vibration mill, a planetary mill, and a medium agitation type mill. A ball media mill combining forces such as impact, friction, compression, and shearing; a roller mill; a mortar; Although a jet pulverizer in which force mainly acts is exemplified, among these, a ball medium mill is preferable because mechanical energy can be effectively applied to the inorganic powder mechanically.

When applying mechanical energy, it is preferable to use a grinding aid usually used for grinding cement clinker, silica sand, limestone and the like. The grinding aid is not particularly limited and includes, for example, alcohols such as methyl alcohol; liquids such as ethanolamines such as triethanolamine; solids such as sodium stearate and calcium stearate; Examples include gaseous substances such as acetone vapor.

The active inorganic powder according to the present invention comprises the above-mentioned A
and a composition comprising a Ca compound and a Ca compound, and the molar ratio of Al to Ca contained in the composition (Al / C
a) needs to be 0.1 to 10. Al /
The molar ratio of Ca is a numerical value indicating the ratio of (the number of Al atoms / the number of Ca atoms) contained in the composition constituting the active inorganic powder. Specifically, assuming that the weight of the Al compound used is WAl, the molecular weight MAl, and the weight of the Ca compound used is WCa, molecular weight MCa, the molar ratio (Al / Ca)
Is represented by (WAl / MAl) ÷ (WCa / MCa).

If the molar ratio deviates from the above range, the dissolution composition of Al ions and Ca ions in the active inorganic powder becomes inappropriate, making it difficult to form a stable calcium aluminate hydrate such as C ₃ A · 6H. Therefore, even if the active inorganic powder of the present invention is added to cement, the quick-curing property of the cement becomes insufficient.

Further, the active inorganic powder of the present invention comprises
In addition to the compound and the Ca compound, silicon,
It does not matter even if it contains a divalent or higher valent metal compound such as magnesium, iron or zinc.

The third invention is a cement composition obtained by adding the active inorganic powder of the present invention to cement. The cement is not particularly limited, and includes, for example, Portland cement such as ordinary Portland cement, early-strength Portland cement, ultra-high-strength Portland cement, moderate heat Portland cement, sulfate-resistant Portland cement, etc .; blast furnace cement, silica cement, fly ash cement And other special cements such as white Portland cement, cement-based solidifying material, and alumina cement. Of these, ordinary Portland cement is preferably used because it is inexpensive and has stable quality.

In the cement composition of the third invention, the addition amount of the active inorganic powder is not particularly limited, but is preferably 1 to 100 parts by weight with respect to 100 parts by weight of cement.
More preferably, it is 3 to 50 parts by weight. If it is less than 1 part by weight, there is no effect of addition, a sufficient setting rate and curing rate cannot be obtained, and if it exceeds 100 parts by weight, curing starts without sufficient workability. Pot life is too short.

The method of adding the active inorganic powder to the cement is not particularly limited as long as the active inorganic powder can be uniformly dispersed in the cement, and examples thereof include an Erich mixer and an omni mixer. And the like using a mixer.

Since the cement composition of the present invention does not form a large amount of ettringite in the obtained hardened cement body, the obtained hardened cement body is excellent in dimensional stability and durability.

[0043]

The active inorganic powder of the present invention is a composition comprising an Al compound and a Ca compound having a specified Al / Ca molar ratio, does not contain sulfate ions, and dissolves Al and Ca ions in water. Since the properties are specified to be optimal for the reaction, the formation of calcium aluminate hydrate is prioritized, the setting speed and the setting speed are both high, and ettringite hydrate is formed in the reaction in cement. It is designed to rapidly form a stable calcium aluminate hydrate such as C ₃ A.6H without the need.

Therefore, since the cement composition of the present invention is a composition in which the active inorganic powder of the present invention is added to cement, both the setting speed and the setting speed are increased, and a large amount of ettringite is generated in the hardened cement. Without this, the durability and dimensional stability are excellent.

[0045]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

(Examples 1 to 8, Comparative Examples 3 and 4) As an Al compound, aluminum hydroxide (manufactured by Sumitomo Chemical Co., Ltd., C
-31) and kaolin (Georgia, USA, average particle size 2.42 μm) were prepared as slaked lime (Kawai Lime Industry Co., Ltd.) and quick lime (Kawai Lime Industry Co., Ltd.) as Ca compounds.

Each of the inorganic compounds prepared above was individually added to 20 k
g each, Ultra Fine Mill (Mitsubishi Heavy Industries, AT
-20), 520 kg of zirconia balls having a diameter of 10 mm as a grinding medium and 100 g of ethanol as a grinding aid were added, and as shown in Table 1, mechanical energy was applied to activate the inorganic compound. The dissolution amounts of Al and Ca were measured by the evaluation methods under a) and the condition (b), and the results are shown in Table 1.

The mechanical energy applied to the inorganic compound is an average energy density (an average energy per hour, which is a value obtained by dividing the mechanical energy applied to the inorganic compound obtained by the following formula by the processing time) However, the mechanical energy shown in Table 1 was obtained by changing the treatment time under operating conditions of about 0.5 kwh / kg. Applied mechanical energy (kwh / kg) = {Amount of power consumed during operation during inorganic compound treatment (kwh)-Amount of power consumed during idle operation before input of inorganic compound (kwh)}
Amount of inorganic compound treated (kg)

The above-obtained Al compound and Ca compound were weighed so that the molar ratio of Al / Ca became the value shown in Table 1, and mixed with an omni mixer to prepare various active inorganic powders. did. At the same time, the amount of sulfur dissolved in each of the various active inorganic powders was measured by the evaluation method described later, and the results are shown in Table 1.

The above-mentioned various active inorganic powders were added in an amount of 15 parts by weight with respect to 100 parts by weight of ordinary Portland cement (manufactured by Chichibu Onoda), and mixed with an omni mixer to prepare a cement composition. The rapid curing property of the cement composition and the dimensional stability of the cured cement body were evaluated by the evaluation methods described below, and the results are summarized in Table 1.

FIG. 1 shows the relationship between the amount of energy applied and the amount of aluminum dissolved when the mechanical energy was applied to aluminum hydroxide. FIG. 2
The relationship between the amount of energy applied and the amount of aluminum dissolved when mechanical energy was applied to aluminum hydroxide was shown in FIG. In each case, the conditions for evaluating the amount of aluminum dissolution described later are used. FIG. 3 shows the relationship between the amount of Al dissolved and the compressive strength when added to cement. Figure 1,
From FIG. 2, by applying mechanical energy,
(A), (b) As the amount of aluminum hydroxide dissolved in each increases, the compressive strength of the cement composition increases, and FIG. 3 shows that the composition ratio of Al and Ca affects the strength developability. It can be understood.

COMPARATIVE EXAMPLE 1 A cement containing no active inorganic powder as a cement composition using jet cement (manufactured by Chichibu Onoda Co., Ltd.) as a cement. The properties were evaluated in the same manner as in Example 1. The dissolution amount is 1 g of jet cement and 50 g of water at room temperature.
, And the amounts of aluminum, calcium, and sulfur dissolved were measured at one time by ICP. The results are shown in Table 1.

Comparative Example 2 Aluminum hydroxide (manufactured by Sumitomo Chemical Co., Ltd., C-31) and slaked lime (manufactured by Kawai Lime Industry Co., Ltd.) were measured and mixed so that the Al / Ca molar ratio was 2/3. Using an ultrafine mill (AT-20, manufactured by Mitsubishi Heavy Industries, Ltd.), a mechanical energy of 4 kwh / kg was applied to the mixture in the same manner as in Example 1 to obtain an active inorganic powder. At the same time, the amounts of aluminum, calcium and sulfur dissolved in the active inorganic powder were measured and are shown in Table 1.

The obtained active inorganic powder was added to 100 parts by weight of ordinary Portland cement (manufactured by Chichibu Onoda Co.) for 1 part.
5 parts by weight, and mixed with an omni-mixer to prepare a cement composition. The cement composition was rapidly cured and the dimensional stability of the cured cement body was evaluated in the same manner as in Example 1. Are shown in Table 1.

[0055]

[Table 1]

Examples 9 to 21 and Comparative Examples 5 and 6 As shown in Table 2, aluminum hydroxide (manufactured by Sumitomo Chemical Co., Ltd., C-31) and slaked lime (manufactured by Kawai Lime Industry Co., Ltd.) were prepared. Individually, an active inorganic compound is produced by applying mechanical energy using an Ultra Fine Mill (AT-20, manufactured by Mitsubishi Heavy Industries, Ltd.), and its specific surface area and average particle size are measured by the evaluation method described later. The results are shown in Table 2.

The mechanical energy was applied by individually charging 1.5 kg of each of the inorganic compounds prepared above into an ultrafine mill (AT-20, manufactured by Mitsubishi Heavy Industries, Ltd.), and further adding 10 mmφ as a pulverizing medium. 45 kg of zirconia balls and 20 g of ethanol as a grinding aid were charged and pulverized.

The above-obtained Al compound and Ca compound were weighed so that the molar ratio of Al / Ca became the value shown in Table 2, and mixed with an omni mixer to prepare various active inorganic powders. Then, the mixture was added in an amount of 15 parts by weight with respect to 100 parts by weight of ordinary Portland cement (manufactured by Chichibu Onoda), and then mixed by an omni mixer to prepare a cement composition. The quick-curing property of the obtained cement composition and the dimensional stability of the cured cement body were measured by an evaluation method described later, and the results are shown in Table 2.

[0059]

[Table 2]

(Examples 22 to 26, Comparative Examples 7 and 8) Al
Aluminum hydroxide (manufactured by Sumitomo Chemical Co., Ltd.)
C-31), slaked lime (manufactured by Kawai Lime Industry Co., Ltd.) and quick lime (manufactured by Kawai Lime Industry Co., Ltd.) were prepared as Ca compounds, and these were individually separated into Ultra Fine Mill (manufactured by Mitsubishi Heavy Industries, AT
Using -20), the mechanical energy shown in Table 3 was applied to produce an active inorganic powder, and the pH of the activated aluminum hydroxide was measured by the evaluation method described later. The results are shown in Table 3. Was. In addition, mechanical energy was applied by individually charging 20 kg of the inorganic compound prepared above into an ultrafine mill (AT-20, manufactured by Mitsubishi Heavy Industries, Ltd.), and further grinding 520 kg of 10 mmφ zirconia balls as a grinding medium. 100 g of ethanol as auxiliary agent
And pulverized.

The above-obtained Al compound and Ca compound are weighed so that the molar ratio of Al / Ca is as shown in Table 3, and mixed by an omni mixer to produce various active inorganic powders. Then, the mixture was added in an amount of 15 parts by weight with respect to 100 parts by weight of ordinary Portland cement (manufactured by Chichibu Onoda), and then mixed by an omni mixer to prepare a cement composition. The quick-curing property of the obtained cement composition and the dimensional stability of the cured cement body were measured by an evaluation method described later, and the results are shown in Table 3.

[0062]

[Table 3]

<Evaluation Method> (1) Amount of Al Dissolution— (a) 1 g of each Al compound shown in Table 1 was immersed in 50 g of a 10% by weight aqueous sodium hydroxide solution at room temperature and stirred for 5 minutes. And then centrifuge (H108NA, manufactured by Domestic Centrifuge Co.)
To separate the filtrate and residue. The obtained filtrate is further filtered with filter paper (4A110m, manufactured by Advantech Toyo).
Filter again using m). The finally obtained filtrate was quantitatively analyzed for the aluminum concentration by ICP (inductively coupled high frequency plasma spectroscopy) to determine the amount of Al dissolved.

(2) Amount of Al Dissolution- (b) 1 g of each Al compound shown in Table 1 was added at room temperature to pH 1
Aqueous solution of sodium hydroxide adjusted to 2.5 (specifically, 0.17% by weight of NaOH aqueous solution) 50
g, stirred for 5 minutes, and then centrifuged (H108NA, manufactured by Kokusai Centrifuge Co., Ltd.) to separate the filtrate and the residue. The obtained filtrate is filtered again using a filter paper (4A110 mm, manufactured by Advantech Toyo). The finally obtained filtrate was quantitatively analyzed for the aluminum concentration by ICP (inductively coupled high frequency plasma spectroscopy) to determine the amount of Al dissolved.

(3) Dissolution amount of Ca 1 g of a Ca compound was immersed in 50 g of distilled water
After stirring for minutes, centrifuge (H10 manufactured by Domestic Centrifuge Co., Ltd.)
8NA) to separate the filtrate and residue. The obtained filtrate is further filtered with filter paper (4A1 manufactured by Advantech Toyo).
10 mm) and filter again. The finally obtained filtrate was quantitatively analyzed for the Ca concentration by ICP (inductively coupled high frequency plasma spectroscopy) to determine the amount of Ca dissolved.

(4) Amount of Sulfur Dissolved 1 g of inorganic powder composed of an Al compound and a Ca compound was immersed in 50 g of distilled water at room temperature and stirred for 5 minutes, and then centrifuged by a centrifuge (manufactured by Domestic Centrifuge Co., Ltd.). H108NA) to separate the filtrate and residue. The obtained filtrate is filtered again using a filter paper (4A110 mm, manufactured by Advantech Toyo). The finally obtained filtrate is subjected to IC
The sulfur concentration was quantitatively analyzed by P (Inductively Coupled High Frequency Plasma Spectroscopy) to determine the amount of sulfur dissolved.

(5) Specific Surface Area After the Al compound and the Ca compound were vacuum-dried at 60 ° C. for 24 hours and degassed, the relative pressure was measured using an automatic specific surface area measuring device (ASAP2000, manufactured by Shimadzu Corporation). 0.0
5 to 0.25, BET under conditions using nitrogen gas
Five-point measurement was carried out.

(6) pH value of Al compound At room temperature, 100 g of distilled water (pH; 6.8) and Al
After 20 g of the compound powder was mixed and stirred for 30 minutes, the resulting suspension (saturated aqueous solution) was measured by inserting an electrode of a pH meter. The measurement was waited at a constant value until it stopped, and the fixed value was used as a measured value.

(7) Average Particle Size An inorganic powder obtained by applying mechanical energy to an Al compound was measured using a laser diffraction type particle size distribution analyzer using ethanol as a dispersion medium.

(8) Fast-curing property / setting speed With respect to 100 parts by weight of the obtained cement composition, water 35
A part by weight was injected and kneaded to prepare a cement paste.
Regarding the obtained cement paste, JIS R 52
A setting test was performed according to the method described in No. 01 (Physical Testing Method for Cement 7. Setting Test), the start and end of setting were measured, and the difference was used as an index of setting speed. As the setting tester, an automatic setting tester (MIC-308-1, manufactured by Enai Seisakusho) was used. However, when the setting speed is extremely high and measurement is impossible, a setting retarder (Jet Setter, manufactured by Chichibu Onoda) is added to 100 parts by weight of the obtained cement composition. Similar measurements were made.

Curing speed The above-mentioned cement paste was cast into a cylindrical shape having a diameter of 5 cm and a height of 5 cm, and after 3 hours from the water injection, the compressive strength of the obtained cured cement was measured. Was used as an index of the curing speed. In addition, the measurement of the compressive strength
The test was performed according to IS R5201 (physical test method of cement 9. Strength test).

(9) Dimensional stability 100 parts by weight of the obtained cement composition, 50 parts by weight of No. 8 silica sand (manufactured by Rokuro Mining Co., Ltd.) and 40 parts by weight of water are kneaded, and the obtained kneaded material is mixed. 50mm × 150mm × 10mm
Was cast into a dumbbell shape. Thereafter, steam curing was performed in steam at 60 ° C. for 2 days to obtain a hardened cement.
The obtained cement hardened body was subjected to a test of three cycles in a cycle of “drying at 60 ° C. for one day and immersing in water for one day”, and measuring longitudinal dimensions before and after the test with a micrometer. The dimensional change rate was determined by the equation. Dimensional change rate (%) = [(saturated size after test-initial size) /
Initial dimensions] × 100 In the evaluation of dimensional stability, those having a dimensional change rate of 0.1 or less were marked with a circle, and those exceeding 0.1 were marked with a cross.

[0073]

Since the active inorganic powder of the present invention is constituted as described above, the solubility of aluminum ions and calcium ions in water is controlled so as to be optimal for the curing reaction. Therefore, it can be effectively used for a solid-liquid reaction utilizing aluminum or calcium in a liquid phase, and can sufficiently promote the setting and hardening of a hydraulic material such as cement. The cement composition to which the inorganic powder of the present invention is added has a high setting speed and a high setting speed, does not form a large amount of ettringite in the obtained hardened cement, and the obtained hardened cement has dimensional stability. And it becomes what was excellent in durability.

[Brief description of the drawings]

FIG. 1 is a graph showing the relationship between applied mechanical energy and the amount of Al dissolved (a).

FIG. 2 is a graph showing the relationship between applied mechanical energy and the amount of Al dissolved (b).

FIG. 3 shows the amount of Al dissolved in a 10% -NaOH aqueous solution (p
4 is a graph showing the relationship between the compression strength (pm) and the compressive strength.

FIG. 4 is a graph showing the relationship between the amount (ppm) of Al dissolved in an aqueous alkaline solution having a pH of 12.5 and compressive strength.

FIG. 5 is a graph showing the relationship between the molar ratio of Ca: Al and compressive strength.

Continued on the front page (72) Inventor Takashi Sahara 2-2 Kamikaba Kaminokocho, Minami-ku, Kyoto Sekisui Kagaku Kogyo Co., Ltd.

Claims (3)

[Claims] 1. An activity comprising an aluminum compound and a calcium compound satisfying at least one of the following conditions (a) to (e), wherein the molar ratio of aluminum / calcium is 0.1 to 10. Inorganic powder. (A) 10% by weight of aluminum compound at room temperature
When immersed in an aqueous sodium hydroxide solution, the dissolved amount of aluminum is 1000 ppm or more, and when the calcium compound is immersed in distilled water at room temperature, the dissolved amount of calcium is 300 ppm or more, and both compounds are dissolved. Is dissolved in water at room temperature, the dissolved amount of sulfur is 50 ppm or less. (B) When the aluminum compound is immersed in an aqueous alkaline solution having a pH of 12.5, the amount of aluminum dissolved is 150
ppm / g or more, and when the calcium compound is immersed in distilled water at room temperature, the dissolved amount of calcium is 30
0 ppm or more, and when the inorganic powder comprising both compounds is immersed in water at room temperature, the dissolved amount of sulfur is 50 ppm or less. (C) The aluminum compound has a specific surface area of 10 to 50 m ² / g, and the calcium compound has a specific surface area of 10 to 62 m ² / g. (D) The aluminum compound is aluminum hydroxide, and the pH value of the saturated aqueous solution of the aluminum hydroxide at room temperature is 10 to 13. (E) The aluminum compound has an average particle size of 1 to 40 μm. 2. The active inorganic powder according to claim 1, wherein the aluminum compound is aluminum hydroxide and the calcium compound is calcium hydroxide or calcium oxide. 3. A cement composition comprising the cement and the active inorganic powder according to claim 1 or 2 added thereto.