WO2021024853A1

WO2021024853A1 - Cement admixture and hydraulic composition

Info

Publication number: WO2021024853A1
Application number: PCT/JP2020/028848
Authority: WO
Inventors: 貴光室川; 博貴水野; 孝記榊原; 岩崎　昌浩; 三島　俊一
Original assignee: デンカ株式会社
Priority date: 2019-08-02
Filing date: 2020-07-28
Publication date: 2021-02-11

Abstract

This cement admixture including aluminum sulfate satisfies the conditions that: (1) the aluminum sulfate is amorphous; (2) in a spectrum obtained by solid ²⁷Al-NMR of the aluminum sulfate, a peak is at a chemical shift of -0.20 ppm to -20.0 ppm, and the half-value width of the peak is 10.00 ppm to 35.00 ppm; (3) the aluminum sulfate has a pH of 1 to 6; and (4) the cement admixture has at most 70 mass% of particles having a particle diameter of 100 μm or more, and less than 30 mass% of particles having a particle diameter of 10 μm or less.

Description

Cement admixture and hydraulic composition

The present invention relates to a cement admixture and a hydraulic composition used in the fields of civil engineering, construction, etc.

In recent years, a wide variety of performances have been required for hydraulic compositions in the fields of civil engineering and construction. Among them, simplification of construction is a very important factor in considering the safety of workers. Here, simplification of construction means, for example, comprehensive rationalization such as improvement of construction speed, unification of materials, and improvement of handleability. In order to achieve simplification of construction, for example, it is important to improve the curing speed of the hydraulic composition, premix it, etc., and in fact, it is so-called ultrafast hardness, which has high condensation and high strength development. Various hydraulic compositions having the above have been proposed (for example, Patent Documents 1 to 3). In recent years, the performance required for hydraulic compositions has been increasing more and more with further improvement in simplification of construction and support for new applications.

Japanese Unexamined Patent Publication No. 3-12350 Japanese Unexamined Patent Publication No. 1-230455 Japanese Unexamined Patent Publication No. 11-139859

A cement admixture is blended in the hydraulic composition for the purpose of improving various properties such as curing speed. Conventionally, an alkaline admixture has been used as the cement admixture, but from the viewpoint of safety, it is desired to use an acidic admixture.
However, since a hydraulic substance such as cement is strongly alkaline, it is difficult to combine it with an acidic cement admixture, and there is a problem that a hydraulic composition having desired properties cannot be obtained. In fact, when a conventional acidic cement admixture suitable for improving the curing rate and premixing is added to the hydraulic composition, the storage stability of the hydraulic composition, the strength of the cured product, and the like are lowered. In addition, good cohesiveness and high strength from the very beginning may not be obtained.

The present invention has been made to solve the above-mentioned problems, and even if it is previously blended with an alkaline admixture in a hydraulic composition, the storage stability is unlikely to decrease, and the hydraulic composition has ultrafast hardness. A first object of the present invention is to provide a cement admixture capable of providing a hydraulic composition capable of obtaining a cured product having high strength.
Further, according to the present invention, even if the hydraulic composition is preliminarily blended with an alkaline admixture, the storage stability is unlikely to decrease, and the hydraulic composition exhibits good cohesiveness and high strength can be obtained from the very beginning. A second object is to provide a cement admixture capable of giving a substance.

As a result of diligent research to solve the above problems, the present inventors have conducted the above-mentioned problems, particularly the above-mentioned problems, in spite of the fact that the cement admixture containing aluminum sulfate having specific properties is acidic. We have found that the object of 1 can be solved, and have completed the first invention of the present invention.
That is, the first invention is as follows.

[1] A cement admixture containing aluminum sulfate that satisfies the following (1) to (4).
(1) The aluminum sulfate is amorphous.
(2) The solid aluminum sulfate ^{27 In the} spectrum obtained by Al-NMR, the chemical shift has a peak at -0.20 to -20.00 ppm, and the half width of the peak is 10.00 to 35.00 ppm. ..
(3) The pH of the aluminum sulfate is 1 to 6.
(4) Particles having a particle size of 100 μm or more are 70% by mass or less, and particles having a particle size of 10 μm or less are less than 30% by mass.
[2] The cement admixture according to [1], wherein an alkaline admixture having a pH of 8 or more is mixed.
[3] The cement admixture according to [1] or [2], which contains any of calcium aluminate, powdered sodium silicate, calcium sulfate, and by-product slaked lime.
[4] The cement admixture according to [3], which contains the calcium aluminate and has a pH of the calcium aluminate of 10 to 14.
[5] The cement admixture according to [4], wherein the calcium aluminate has an average particle size of 1 to 250 μm.
[6] The cement admixture according to [3], which contains the powdered sodium silicate and has an average particle size of 1 to 300 μm.
[7] The cement admixture according to [6], wherein the molar ratio (SiO ₂ / Na ₂ O) of SiO ₂ and Na ₂ O in the powdered sodium silicate is 0.5 to 5.
[8] The cement admixture according to [3], which contains the calcium sulfate and has an average particle size of the calcium sulfate of 1 to 150 μm.
[9] The cement admixture according to [8], wherein the calcium sulfate is anhydrous gypsum.
[10] The cement admixture according to [3], which contains the by-product slaked lime and has an average particle size of 1 to 300 μm.
[11] The cement admixture according to any one of [2] to [10], wherein the alkaline admixture contains an alkali metal carbonate.
[12] The cement admixture according to any one of [2] to [11], wherein the alkaline admixture contains an alkaline earth metal hydroxide.
[13] A hydraulic composition containing the cement admixture according to any one of [1] to [12] and a hydraulic substance.
The above [3] to [10] are also effective for the second purpose.

In addition, as a result of diligent research to solve the above problems, the present inventors have found that a cement admixture containing calcium aluminate and aluminum sulfate having specific properties is a problem, particularly the second problem. We have found that the object can be solved, and have completed the second invention of the present invention.
That is, the second invention is as follows.

[1] A cement admixture containing calcium aluminate and acidic aluminum sulfate satisfying the following (1) to (3).
(1) The aluminum sulfate is amorphous.
(2) The solid aluminum sulfate ^{27 In the} spectrum obtained by Al-NMR, the chemical shift has a peak at -0.20 to -20.00 ppm, and the half width of the peak is 10.00 to 35.00 ppm. ..
(3) Particles having a particle size of 100 μm or more are 70% by mass or less, and particles having a particle size of 10 μm or less are less than 30% by mass.
[2] The cement admixture according to [1], wherein the pH of the aluminum sulfate is 1 to 6.
[3] The cement admixture according to [1] or [2], wherein the calcium aluminate has a pH of 10 to 14.
[4] The cement admixture according to any one of [1] to [3], wherein the calcium aluminate has an average particle size of 1 to 250 μm.
[5] A hydraulic composition containing the cement admixture according to any one of [1] to [4] and a hydraulic substance.

As a result of diligent research to solve the above problems, the present inventors have solved the above problems, particularly the second purpose, with a cement admixture containing sodium silicate and aluminum sulfate having specific properties. He found out that he could do it, and completed the third invention, which is the present invention.
That is, the third invention is as follows.

[1] A cement admixture containing powdered sodium silicate and acidic aluminum sulfate satisfying the following (1) to (3).
(1) The aluminum sulfate is amorphous.
(2) The solid aluminum sulfate ^{27 In the} spectrum obtained by Al-NMR, the chemical shift has a peak at -0.20 to -20.00 ppm, and the half width of the peak is 10.00 to 35.00 ppm. ..
(3) Particles having a particle size of 100 μm or more are 70% by mass or less, and particles having a particle size of 10 μm or less are less than 30% by mass.
[2] The cement admixture according to [1], wherein the pH of the aluminum sulfate is 1 to 6.
[3] The cement admixture according to [1] or [2], wherein the powdered sodium silicate has an average particle size of 1 to 300 μm.
[4] The cement admixture according to any one of [1] to [3], wherein the molar ratio (SiO ₂ / Na ₂ O) of SiO ₂ to Na ₂ O in powdered sodium silicate is 0.5 to 5.
[5] A hydraulic composition containing the cement admixture according to any one of [1] to [4] and a hydraulic substance.

As a result of diligent research to solve the above problems, the present inventors have solved the above problems, particularly the second object, with a cement admixture containing calcium sulfate and aluminum sulfate having specific properties. He found out that he could do it, and completed the fourth invention, which is the present invention.
That is, the fourth invention is as follows.

[1] A cement admixture containing calcium sulfate and acidic aluminum sulfate satisfying the following (1) to (3).
(1) The aluminum sulfate is amorphous.
(2) The solid aluminum sulfate ^{27 In the} spectrum obtained by Al-NMR, the chemical shift has a peak at -0.20 to -20.00 ppm, and the half width of the peak is 10.00 to 35.00 ppm. ..
(3) Particles having a particle size of 100 μm or more are 70% by mass or less, and particles having a particle size of 10 μm or less are less than 30% by mass.
[2] The cement admixture according to [1], wherein the pH of the aluminum sulfate is 1 to 6.
[3] The cement admixture according to [1] or [2], wherein the calcium sulfate has an average particle size of 1 to 150 μm.
[4] The cement admixture according to any one of [1] to [3], wherein the calcium sulfate is anhydrous gypsum.
[5] A hydraulic composition containing the cement admixture according to any one of [1] to [4] and a hydraulic substance.

As a result of diligent research to solve the above problems, the present inventors have made a cement admixture containing by-product slaked lime and aluminum sulfate having specific properties the above-mentioned problems, particularly the second purpose. We have found that it can be solved, and have completed the fifth invention, which is the present invention.
That is, the fifth invention is as follows.

[1] A cement admixture containing by-product slaked lime and acidic aluminum sulfate satisfying the following (1) to (3).
(1) The aluminum sulfate is amorphous.
(2) The solid aluminum sulfate ^{27 In the} spectrum obtained by Al-NMR, the chemical shift has a peak at -0.20 to -20.00 ppm, and the half width of the peak is 10.00 to 35.00 ppm. ..
(3) Particles having a particle size of 100 μm or more are 70% by mass or less, and particles having a particle size of 10 μm or less are less than 30% by mass.
[2] The cement admixture according to [1], wherein the pH of the aluminum sulfate is 1 to 6.
[3] The cement admixture according to [1] or [2], wherein the by-product slaked lime has an average particle size of 1 to 300 μm.
[4] A hydraulic composition containing the cement admixture according to any one of [1] to [3] and a hydraulic substance.

According to the first invention, even if it is preliminarily blended with an alkaline admixture in a hydraulic composition, the storage stability is unlikely to decrease, and a hydraulically hardened body having ultrafast hardness and high strength can be obtained. A cement admixture that can provide the composition can be provided.
According to the second invention, even if the hydraulic composition is premixed with an alkaline admixture, the storage stability does not easily decrease, and the cement exhibits good cohesiveness and can obtain high strength from the very beginning. An admixture can be provided.
In particular, the hydraulic composition containing the cement admixture does not easily deteriorate in storage stability, and has high cohesive properties and high strength from the very beginning in a low temperature (5 ° C or lower) or high temperature (30 ° C or higher) environment. Since it can be obtained, in underground construction such as tunnels, stable rebound and adhesion can be achieved even in a spring water environment to some extent.
According to the third invention, even if the hydraulic composition is premixed with an alkaline admixture, the storage stability does not easily decrease, and the cement exhibits good cohesiveness and can obtain high strength from the very beginning. An admixture can be provided.
In particular, the hydraulic composition containing the cement admixture can have the above-mentioned effect and self-healing performance independent of the environmental temperature caused by sodium silicate.
According to the fourth invention, it is possible to provide a cement admixture that exhibits good cohesiveness and can obtain high strength from the very beginning.
In particular, it is possible to obtain a constant long-term strength without much dependence on the long-term strength in a high-temperature environment and the water-cement ratio of cement paste, cement mortar, and cement concrete.
According to the fifth invention, even if the hydraulic composition is premixed with an alkaline admixture, the storage stability does not easily decrease, and the cement exhibits good cohesiveness and can obtain high strength from the very beginning. An admixture can be provided.
In particular, condensation and initial strength development in a low temperature environment can be stably obtained, and it is possible to prevent the physical properties from being affected by the timing of addition to cement.

Hereinafter, embodiments of the present invention will be described in detail. The parts and% used in this specification are based on mass unless otherwise specified.
<First invention>
[Cement admixture]
The cement admixture of the first invention contains aluminum sulfate that satisfies the following (1) to (4).
(1) Aluminum sulfate is amorphous.
When aluminum sulfate is not amorphous, it is difficult to premix it with a hydraulic substance showing strong alkalinity such as cement, and even if it can be premixed, the storage stability of the hydraulic composition is lowered.
Here, whether or not aluminum sulfate is amorphous can be determined by X-ray diffraction analysis. Specifically, if the X-ray diffraction spectrum of aluminum sulfate is broad, it can be determined to be amorphous. For aluminum sulfate, a clear peak can be confirmed in the range of 2θ = 20 to 30 °, but those without a peak are considered amorphous.

(2) Solid aluminum sulfate ^{27 In the} spectrum obtained by Al-NMR, the chemical shift has a peak at -0.20 to -20.00 ppm, and the half width of the peak is 10.00 to 35.00 ppm. ..
If the peak chemical shift is greater than −0.20 ppm, it is difficult to premix with the hydraulic substance, and even if the premix can be achieved, the storage stability of the hydraulic composition may decrease. On the other hand, if the peak chemical shift is less than -20.00 ppm, a synergistic effect with an alkaline admixture having a pH of 8 or more may not be obtained.
The chemical shift of the peak is preferably −1.00 to -16.00 ppm, more preferably -2 to -15 ppm.

Further, if the half width of the peak is out of the above range, the curing rate of the hydraulic composition may not be sufficiently obtained. The half width of the peak is preferably 10 to 35 ppm, more preferably 25 to 32 ppm.

Here, the solid ²⁷ Al-NMR measurement of aluminum sulfate can be carried out under the following conditions using a commercially available measuring device, for example, a superconducting nuclear magnetic resonance device “ECX-400” manufactured by JEOL Ltd. ..
Observation nucleus: ²⁷ Al
Sample tube rotation speed: 10 KHz
Measurement temperature: Room temperature Pulse width: 3.3 μsec (90 ° pulse)
Waiting time: 5 seconds External standard: Aluminum nitrate

In order to obtain aluminum sulfate that satisfies the above requirements (1) and (2), for example, the heating temperature when heating a mixture of various raw materials may be adjusted.

(3) The pH of aluminum sulfate is 1 to 6.
If the pH of aluminum sulfate is out of the above range, the curing rate of the hydraulic composition will decrease. The pH is preferably 2 to 5, more preferably 2 to 4. Further, in order to set the pH of aluminum sulfate to 1 to 6, the above heating temperature may be adjusted.
In the present specification, the pH can be measured by adding 10 g to 100 ml of water at 20 ± 2 ° C. and stirring at 500 rpm using a pH meter.

(4) In aluminum sulfate, 70% or less of the particles have a particle size of 100 μm or more, and less than 30% of the particles have a particle size of 10 μm or less.
If the particle size of 100 μm or more exceeds 70%, the curing rate of the hydraulic substance cannot be sufficiently obtained, and if the particles having a particle size of 10 μm or less are 30% or more, an alkaline admixture having a pH of 8 or more. By coexisting with, storage deterioration becomes remarkable.
The particles having a particle size of 100 μm or more are preferably 50% or less, more preferably 30% or less. Further, the particles having a particle size of 10 μm or less are preferably 40% or more, more preferably 50% or more. The particle size can be adjusted by, for example, a sieve.
It should be noted that the admixture using aluminum sulfate in the range of (4) does not mean that a sufficient curing rate can be obtained from low temperature to high temperature, and it is expected that the curing rate will increase particularly at high temperature. Since it is thought that the curing rate can be controlled by the coexistence of alkaline substances with pH 8 or higher, it can be used in a wide temperature range from low temperature (10 ° C) to high temperature (30 ° C), so it can be applied stably in both summer and winter. is there.

Aluminum sulfate satisfying the above-mentioned (1) to (4) is prepared by mixing raw materials such as Al ₂ O ₃ source and SO ₃ source using an Al ₂ O ₃ source and an SO ₃ source to prepare a mixture. a method of heating treatment, a method of directly chemically reacting Al ₂ O ₃ source and SO ₃ source, a method is a chemical reaction after mixing was charged with Al ₂ O ₃ source and SO ₃ source in a solvent such as pure water or the like Can be used. In these methods, by controlling the production conditions, aluminum sulfate satisfying the above-mentioned (1) to (3) can be obtained.

The Al ₂ O ₃ source is not particularly limited, but aluminum sulfate, aluminate, and other inorganic aluminum compounds, organoaluminum compounds, and aluminum complexes can be used.

The sulfate of aluminum is not particularly limited, and examples thereof include ammonium alum, aluminum hydroxysulfate, and aluminum sulfate.
The alumate is not particularly limited, and examples thereof include lithium aluminate, sodium aluminate, potassium aluminate, calcium aluminate, and magnesium aluminate.
Other inorganic aluminum compounds are not particularly limited, but are, for example, bokisite, aluminum oxide, aluminum hydroxide, aluminum chloride, aluminum phosphate, aluminum nitrate, aluminum fluoride, polyaluminum chloride, aluminum carbonate, synthetic hydrotal. Sight, aluminum metasilicate and the like.

The organoaluminum compound is not particularly limited, and examples thereof include aluminum stearate, aluminum oxalate, aluminum isopropoxide, and aluminum formate.
The aluminum complex is not particularly limited, and examples thereof include tris (8-hydroxyquinolinato) aluminum.
As the Al ₂ O ₃ source, a single species can be used, but two or more species may be used in combination. Among the various Al ₂ O ₃ sources described above, aluminum sulfate is preferable because it has high solubility in water, low production cost, and excellent cohesiveness, but aluminum hydroxide is also preferable.

The SO ₃ source, but are not limited to, in addition to elemental sulfur, such as sulfur and sulfur oxide, sulfide, sulfate, sulfate, sulfite, sulfite, thiosulfate, sulfate, and organic sulfur compounds such as Can be used.
The sulfide is not particularly limited, and examples thereof include magnesium sulfide, calcium sulfide, iron sulfide, and phosphorus pentasulfide.
The sulfate is not particularly limited, and examples thereof include aniline sulfate, aluminum sulfate, ammonium sulfate, magnesium sulfate, manganese sulfate, barium sulfate, calcium sulfate, sodium sulphate, potassium sulphate, ammonium sulphate, and hydroxylamine sulfate.

The sulfite salt is not particularly limited, and examples thereof include ammonium hydrogen sulfite and calcium sulfite.
The thiosulfate is not particularly limited, and examples thereof include ammonium thiosulfate and barium thiosulfate.
The organic sulfur compound is not particularly limited, and examples thereof include resins such as a sulfonic acid derivative, a salt of a sulfonic acid derivative, mercaptan, thiophene, a thiophene derivative, polysulfone, polyether sulfone, and polyphenylene sulfide.
The SO ₃ source, can be used single type may be used in combination of two or more. Among the various SO ₃ source of the high solubility in water, from the viewpoint of excellent cheap and caking manufacturing cost, preferably sulfuric acid or sulfates, and most preferably sulfuric acid or ammonium alum.

Here, it is preferable that the obtained aluminum sulfate is pulverized by, for example, a known mill or the like so as to satisfy the requirement (4) by sieving or the like.

In the first invention, it is preferable to contain any one of calcium aluminate, powdered sodium silicate, calcium sulfate, and by-product slaked lime. The second invention described later when calcium aluminate is contained, the third invention described later when containing powdered sodium silicate, the fourth invention described later when calcium sulfate is contained, and the fourth invention described later when containing by-product slaked lime will be described later. The fourth invention is incorporated by reference.

<< Second Invention >>
[Cement admixture]
The cement admixture according to the present embodiment contains calcium aluminate and specific acidic aluminum sulfate.

(Calcium aluminumate)
Calcium aluminate (hereinafter, also referred to as CA) is a general term for compounds having CaO and Al ₂ O ₃ as main components and having hydration activity, and a part of Ca O and / or Al ₂ O ₃ is alkali metal oxidation. Substances, compounds substituted with alkaline earth metal oxides, silicon oxide, titanium oxide, iron oxide, alkali metal halides, alkaline earth metal halides, alkali metal sulfates, alkaline earth metal sulfates, etc., or It is a substance in which a small amount of these are solid-dissolved in a substance containing CaO and Al ₂ O ₃ as main components, and the CAs may be either crystalline or amorphous.

As a specific example of crystallinity, when CaO is C, Al ₂ O ₃ is A, and R ₂ O (Na ₂ O, K ₂ O, Li ₂ O) is R, C ₃ A and alkali metal are solidified therein. Melted C ₁₄ RA ₅ , CA and C ₁₂ A ₇ and C ₁₁ A ₇ · CaF ₂ , C ₄ A · Fe ₂ O ₃ and C ₃ A ₃ · CaSO ₄ etc. are mentioned, but the quick connection is good. Therefore, amorphous calcium aluminate is preferable. In the case of amorphous calcium aluminate, the vitrification rate is preferably 80% or more.

The calcium aluminate used in the present embodiment is mixed with a trace amount of alkali metal and / or alkaline earth metal from the industrial raw material, and some CAs containing the alkali metal and / or alkaline earth metal are generated. It is possible, but not limited by the presence of these few alkali metals and / or alkaline earth metals.

Calcium aluminate is preferably alkaline, and more preferably has a pH of 10-14. Being alkaline (particularly pH 10 to 14) makes it easier to exert the characteristics of calcium aluminate.

The CaO / Al ₂ O ₃ molar ratio of calcium aluminate is not particularly limited, but the molar ratio is preferably 2.0 to 3.0 in consideration of the strength development in the very early stage. When the molar ratio is 2.0 or more, the cohesive property at the very early stage can be improved, and when it is 3.0 or less, good long-term strength development can be easily obtained.

The specific surface area of the brain of calcium aluminate (hereinafter, may be simply referred to as "brain") is preferably 4000 to 8000 cm ² / g, and more preferably 5000 to 7000 cm ² / g. When it is 4000 to 8000 cm ² / g, the initial strength development can be easily obtained, and the handleability of the mortar and / or concrete at the time of spraying can be improved.
The brain specific surface area is measured based on the specific surface area test described in JIS R 5201 “Physical test method for cement”.

The average particle size of calcium aluminate is preferably 1 to 250 μm, and more preferably 1 to 150 μm, from the viewpoint of mixing with specific aluminum sulfate described later and exhibiting a good effect by mixing.
The average particle size can be measured and obtained by the laser diffraction / diffusion method.

(Specific acidic aluminum sulfate)
The aluminum sulfate according to the present embodiment is acidic aluminum sulfate that satisfies the following (1) to (3).
(1) Aluminum sulfate is amorphous.
The above (1) is the same as (1) according to the first invention.

(2) Solid aluminum sulfate ^{27 In the} spectrum obtained by Al-NMR, the chemical shift has a peak at -0.20 to -20.00 ppm, and the half width of the peak is 10.00 to 35.00 ppm. ..
The above (2) is the same as (2) according to the first invention.

(3) Particles having a particle size of 100 μm or more are 70% by mass or less, and particles having a particle size of 10 μm or less are less than 30% by mass.
The above (3) is the same as (2) according to the first invention.

The pH of aluminum sulfate is preferably 1 to 6. When the pH of aluminum sulfate is within the above range, the curing rate of the hydraulic composition can be improved. The pH is preferably 2 to 5, more preferably 2 to 4. Further, in order to set the pH of aluminum sulfate to 1 to 6, the heating temperature described above may be adjusted.
In the present specification, the pH can be measured by adding 10 g to 100 ml of water at 20 ± 2 ° C. and stirring at 500 rpm using a pH meter.

Acidic aluminum sulfate satisfying the above-mentioned (1) to (3) is mixed with raw materials such as Al ₂ O ₃ source and SO ₃ source using Al ₂ O ₃ source and SO ₃ source to form a mixture. how to Cooked after, a method of directly chemically reacting Al ₂ O ₃ source and SO ₃ source, react chemically after mixing was charged with Al ₂ O ₃ source and SO ₃ source in a solvent such as pure water A method or the like can be used. In these methods, by controlling the production conditions, aluminum sulfate satisfying the above-mentioned (1) to (3) can be obtained.

The Al ₂ O ₃ source and the SO ₃ source are the same as those according to the first invention.
Here, it is preferable that the obtained acidic aluminum sulfate is pulverized by, for example, a known mill or the like so as to satisfy the requirement (3) by sieving or the like.

The mixing ratio of calcium aluminate and acidic aluminum sulfate (calcium aluminate / acidic aluminum sulfate: mass ratio) according to the present embodiment may be 1 to 40 from the viewpoint of fully exerting mutual effects. It is preferably 2 to 30, and more preferably 2 to 30.

<< Third Invention >>
[Cement admixture]
The cement admixture according to the present embodiment contains sodium silicate and specific acidic aluminum sulfate.

(Soda silicate)
Soda silicate, a powdered quick-setting admixture, is a cement mortar for spraying mortar (hereinafter, may be simply referred to as "cement mortar") or cement concrete for spraying cement (hereinafter, may be simply referred to as "cement concrete"). On the other hand, it mainly exerts the effect of promoting the disappearance of fluidity in the very early stage. Further, for example, when the quick-setting material is cracked over a long period of time when sprayed using a powdered quick-setting agent, for example, 0.1 mm cracks can be repaired under running water conditions. can do. It is considered that this is because the sodium silicate gelled by water works to repair the crack itself and reduces its width.
From the viewpoint of efficiently exhibiting the above effects, the sodium silicate is preferably in the form of powder.

The molar ratio of SiO ₂ to Na ₂ O (SiO ₂ / Na ₂ O) in sodium silicate is preferably 0.5 to 5, as a powdered quick-setting admixture, for example, for promoting the loss of fluidity in the very early stage. 0.5 to 1.5 is more preferable, and 0.9 to 1.3 is even more preferable.
When the molar ratio is 0.5 or more, the powder is easy to handle, and when it is 1.5 or less, the fluidity disappears and the initial strength develops significantly immediately after the addition to cement mortar and cement concrete. It will be easier to obtain.

Examples of the sodium silicate include sodium orthosilicate, sodium metasilicate, and sodium sesquisilicate, and sodium metasilicate is preferable. Examples of sodium silicate include sodium silicate No. 1 [Na ₂ Si ₂ O ₅ (Na ₂ O · 2SiO ₂ : n = 2)] and sodium silicate No. 2 [Na ₄ Si ₅ O ₁₂ (Na ₂ O · 2. 5SiO ₂ : n = 2.5)], sodium silicate No. 3 [Na ₂ Si ₃ O ₇ (Na ₂ O · 3SiO ₂ : n = 3)], and sodium silicate No. 4 [Na ₂ Si ₄ O ₉ (Na) ₂ O · 4SiO ₂ : n = 4)] and the like.

The sodium silicate is not particularly limited whether it is a hydrate or an anhydride, but the number of hydrated water is preferably 9 or less, more preferably 5 or less, and further preferably the use of anhydrous.

Blaine specific surface area of the sodium silicate is preferably 300 ~ 1000cm ² / g, more preferably 500 ~ 800cm ² / g. When it is 300 to 1000 cm ² / g, the initial strength development can be easily obtained, and the handleability of the mortar and / or concrete at the time of spraying can be improved. The brain specific surface area is measured based on the specific surface area test described in JIS R 5201 “Physical test method for cement”.

The average particle size of sodium silicate is preferably 1 to 300 μm, and more preferably 1 to 250 μm, from the viewpoint of mixing with specific aluminum sulfate described later and exhibiting a good effect by mixing.
The average particle size can be determined by using, for example, a laser diffraction / scattering type particle size distribution measuring device manufactured by HORIBA.

The content of sodium silicate in the powdered quick-setting admixture of the present embodiment is preferably 0.5 to 20 parts, more preferably 1 to 10 parts out of 100 parts of the powdered quick-setting admixture. With 0.5 to 20 parts, the self-repairing function against cracks can be improved.

(Specific acidic aluminum sulfate)
The aluminum sulfate according to the present embodiment is the same as that of the "specific acidic aluminum sulfate" in the second invention.

The mixing ratio of sodium silicate and acidic aluminum sulfate (soda silicate / acidic aluminum sulfate: mass ratio) according to the present embodiment is 5/5 to 5/40 from the viewpoint of fully exerting mutual effects. Is preferable, and 5/5 to 5/20 is more preferable.

<< Fourth Invention >>
[Cement admixture]
The cement admixture according to the present embodiment contains calcium sulfate and specific acidic aluminum sulfate.

(Calcium sulfate)
Calcium sulfate imparts an effect of increasing the compressive strength to cement mortar and cement concrete mainly for a short period of time to a long period of time (for example, 28 days of age).

Calcium sulfate includes anhydrous, semi-aqueous, and binary depending on the presence or absence of water of crystallization, but both can be used.

The brain specific surface area of calcium sulfate is preferably 1000 cm ² / g or more, more preferably 2000 cm ² / g or more, and further preferably 3000 cm ² / g or more. When it is 1000 cm ² / g or more, it is easy to obtain strength development from a short time to a long period of time, and it is possible to improve the handleability of mortar and / or concrete at the time of spraying. Blaine specific surface area is preferably at 6000 cm ² / g or less, and more preferably less 5000 cm ² / g. The brain specific surface area is measured based on the specific surface area test described in JIS R 5201 “Physical test method for cement”.

Calcium sulfate is preferably contained in 10 to 60 parts, more preferably 15 to 60 parts, further preferably 15 to 50 parts, and particularly 20 to 50 parts in 100 parts of the powdered quick-setting admixture. Is more preferable. By including 10 to 60, the effect of increasing the long-term strength is more likely to be imparted.

The average particle size of calcium sulfate is preferably 1 to 150 μm, more preferably 10 to 100 μm, from the viewpoint of mixing with specific aluminum sulfate described later and exhibiting a good effect by mixing.
The average particle size can be measured and obtained by a laser diffraction / diffusion method.

The mixing ratio of calcium sulfate and acidic aluminum sulfate (calcium sulfate / acidic aluminum sulfate: mass ratio) according to the present embodiment is preferably 1 to 40 from the viewpoint of sufficiently exerting mutual effects. More preferably, it is 2 to 20.

<< Fifth Invention >>
[Cement admixture]
The cement admixture according to the present embodiment contains by-product slaked lime and specific acidic aluminum sulfate.

(By-product slaked lime)
By-product slaked lime is an effective material for ensuring the decrease in fluidity at the very beginning and the long-term strength development. By-product slaked lime refers to the carbide slag produced when the carbide is hydrated. Commercially available calcium hydroxide can be used in combination as appropriate. The content of by-product slaked lime is preferably 5 to 30 parts, more preferably 10 to 25 parts, out of 100 parts of the powdered quick-setting admixture. By having 5 or more parts, it is possible to ensure the quick-setting property and the long-term strength development. When the number of parts is 20 or less, good initial strength development can be easily obtained.

Blaine specific surface area of the by-product calcium hydroxide is preferably 1000 ~ 3000cm ² / g, and more preferably 1500 ~ 2500cm ² / g. When it is 1000 to 3000 cm ² / g, it is possible to secure the quick-setting property and the long-term strength development, and it is possible to easily obtain a good initial strength development. The brain specific surface area is measured based on the specific surface area test described in JIS R 5201 “Physical test method for cement”.

The average particle size of the by-product slaked lime is preferably 1 to 300 μm, more preferably 1 to 250 μm, from the viewpoint of mixing with specific aluminum sulfate described later and exhibiting a good effect by mixing.
The average particle size can be determined by using, for example, a laser diffraction / scattering type particle size distribution measuring device manufactured by HORIBA.

The mixing ratio of by-product slaked lime and acidic aluminum sulfate (by-product slaked lime / acidic aluminum sulfate: mass ratio) according to the present embodiment is 10/30 to 30/10 from the viewpoint of fully exerting mutual effects. It is preferably 10/30 to 20/10, and more preferably.

It is preferable that the cement admixture according to the first to fifth inventions is mixed with an alkaline admixture having a pH of 8 or more. Examples of the alkaline admixture include alkali metal aluminate, alkaline earth metal aluminate, alkaline earth metal carbonate, alkali metal hydroxide, alkali metal carbonate, alkaline earth metal hydroxide and the like. Of these, alkali metal carbonates and alkaline earth metal hydroxides are preferably contained.

Alkali metal carbonate can impart further cohesiveness and rapid hardness to cement. Examples of the alkali metal carbonate include sodium carbonate, sodium hydrogencarbonate, calcium carbonate, potassium carbonate, lithium carbonate, lithium hydrogencarbonate, beryllium carbonate, magnesium carbonate, etc. Among them, sodium carbonate, sodium hydrogencarbonate, calcium carbonate, and carbonate. Potassium is preferred. The content of the alkali metal carbonate in the alkaline admixture is preferably 50% or more, more preferably 80% or more.

Alkaline earth metal hydroxide can impart further cohesiveness, rapid hardness, and long-term strength development to cement. Examples of the alkaline earth metal hydroxide include calcium hydroxide, magnesium hydroxide, sodium hydroxide, potassium hydroxide, lithium hydroxide, beryllium hydroxide and the like, among which calcium hydroxide, magnesium hydroxide and hydroxide are used. Sodium and potassium hydroxide are preferable. The content of the alkaline earth metal hydroxide in the alkaline admixture is preferably 50% or more, more preferably 80% or more.

The alkaline admixture used in the cement admixture according to the first to fifth inventions preferably contains a combination of an alkali metal carbonate and an alkaline earth metal hydroxide. This combination makes it possible to impart significant cement coagulation, rapid hardening, and strength development. The combination of the alkali metal carbonate and the alkaline earth metal hydroxide in the alkaline admixture is preferably 50% or more, and more preferably 80% or more. The mass ratio of alkali metal carbonate to alkaline earth metal hydroxide in the combination is preferably 30/70 to 70/30 for alkali metal carbonate / alkaline earth metal hydroxide. , 40/60 to 60/40, more preferably.

The cement admixture and the alkaline admixture according to the first to fifth inventions are preferably mixed when added to a hydraulic substance, but the cement admixture according to the present invention has excellent storage stability with respect to alkali. , Preferably mixed 2-3 weeks before addition to the hydraulic material.

[Hydraulic composition]
The hydraulic composition according to the present invention contains the cement admixture and the hydraulic substance according to the first to fifth inventions, and preferably further contains the above-mentioned alkaline admixture.
The cement admixture according to the first to fifth inventions can be used together with various hydraulic substances to prepare a hydraulic composition. In particular, the cement admixtures according to the first to fifth inventions can be used together with an alkaline hydraulic substance even though they are acidic. Generally, when an acidic cement admixture is used together with an alkaline hydraulic substance to prepare a hydraulic composition, the storage stability tends to decrease, but the cement admixture according to the present invention is an alkaline hydraulic substance. Even if a hydraulic composition is prepared, the storage stability is unlikely to decrease. Therefore, the hydraulic composition prepared by using the cement admixture according to the present invention can be stored for a long period of time without any special storage method, construction method or handling method. Further, this hydraulic composition has ultrafast hardness and can form a cured product having high strength. Therefore, by using this hydraulic composition, it is possible to simplify the construction.

The water-hardening substance used in the water-hardening composition is not particularly limited, but for example, various Portland cements such as ordinary, fast-strength, moderate heat, low heat, and white; manufactured from city waste incineration ash and sewage sludge incineration ash as raw materials. Eco-cement to be used; examples include mixed cement containing blast furnace slag, silica fume, limestone, fly ash, gypsum and the like.
The pH of the hydraulic substance is not particularly limited, but is preferably more than 7, more preferably 8 or more, and further preferably 10 or more.

The hydraulic composition can contain known additives that can be generally blended as long as the effects of the present invention are not impaired. Additives are not particularly limited, but are rust preventives, colorants, polymers, fibers, fluidizers, neutralization inhibitors, waterproofing agents, thickeners, waterproofing agents, retarding agents, fast-strengthening agents, and accelerators. , Water reducing agent, high performance (AE) water reducing agent, foaming agent, foaming agent, AE agent, drying shrinkage reducing agent, quick-setting agent, leavening agent, cold resistance accelerator, efflorescence inhibitor, alkaline aggregate reaction inhibitor, Examples include black unevenness reducing agents and environmental purification admixtures. These additives can be used alone or in combination of two or more.

The cement admixture according to the first to fifth inventions in the hydraulic composition is preferably 1 to 30% by mass, more preferably 2 to 20% by mass, respectively. When the above-mentioned alkaline admixture is contained, the amount of the alkaline admixture is preferably 2 to 30 parts with respect to 100 parts of each cement admixture according to the first to fifth inventions, and 2 to 20 parts. Is more preferable.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples as long as it does not deviate from the gist thereof.

[Example according to the first invention]
<Preparation of aluminum sulfates A to E>
The following substances were used as raw materials.
Al ₂ O ₃ source: aluminum hydroxide, reagent, purity 99%
SO ₃ source: sulfuric acid, reagent, purity 99%
Solvent: pure water

Aluminum sulfates A to E were prepared by mixing an Al ₂ O ₃ source, an SO ₃ source, and a solvent at a molar ratio of 2: 3:10, and heating and reacting the mixture at each temperature shown in Table 1. .. Then, it was pulverized using a ball mill, and pulverized by a sieve so that particles having a particle size of 100 μm or more were 30% and particles having a particle size of 10 μm or less were 20%.
The aluminum sulfate prepared above was subjected to X-ray diffraction, solid ²⁷ Al-NMR, and pH evaluation.

X-ray diffraction was measured using Multi-Flex manufactured by Rigaku. The measurement was performed under the conditions of 2θ = 5 ° to 60 ° and 5 ° / min, with the tube voltage-tube current set to 40 KV-40 mA. In addition, PDXL was used as the analysis software. In the evaluation of X-ray diffraction, if the X-ray diffraction spectrum was broad, it was determined to be amorphous, and if it was not, it was determined to be crystalline. The results are shown in Table 1.

Solid ²⁷ Al-NMR was carried out under the above conditions using a superconducting nuclear magnetic resonance apparatus (ECX-400) manufactured by JEOL Ltd., and the chemical shift and full width at half maximum of the peak were measured. The results are shown in Table 1.

The pH of aluminum sulfate adjusted by the above method was measured by the method described above using a pH measuring meter (D-53S) manufactured by HORIBA. The results are shown in Table 1.

Next, 20 parts of the alkaline admixture A shown in Table 2 was mixed with 100 parts of aluminum sulfate of the type shown in Table 1 prepared above to prepare a cement admixture, and the number of days and the temperature 20 shown in Table 2 were 20. After storage at ° C. and humidity of 60%, a hydraulic composition composed of 100 parts of ordinary Portland cement (pH 14, industrial product) and 10 parts of cement admixture was obtained.
Then, 40 parts by mass of water (tap water) was further mixed with this hydraulic composition and mixed, and a coagulation test was conducted.
The setting test was carried out in accordance with JIS R5201 “Physical test method for cement”. The condensation test measured the onset time of condensation.
The results of each of the above evaluations are shown in Table 2.

Alkaline admixture a: Sodium carbonate, reagent, pH11
Alkaline admixture a: Sodium hydrogen carbonate, reagent, pH 8.3
Alkaline admixture c: Calcium carbonate, reagent, pH10
Alkaline admixture d: Potassium carbonate, reagent, pH12
Alkaline admixture e: Calcium hydroxide, reagent, pH11
Alkaline admixture F: Magnesium hydroxide, reagent, pH 10.5
Alkaline admixture: sodium hydroxide, reagent, pH14
Alkaline admixture: potassium hydroxide, reagent, pH13

As shown in Table 2, by using aluminum sulfate A, the setting time changed with the number of storage days. This is considered to be due to storage deterioration of the compound and the admixture. However, it was confirmed that the aluminum sulfates B to E did not show any storage deterioration, and that the aluminum sulfates B to D were particularly likely to have a promoting effect.

Next, 100 parts of aluminum sulfate C or aluminum sulfate C adjusted so that the proportion of particles having a particle size of 100 μm or more is shown in Table 3 and 20 parts of an alkaline admixture of the type shown in Table 3 are mixed and mixed. Then, the cement admixture was prepared and stored at the number of days shown in Table 3, the temperature at 20 ° C., and the humidity at 60%, and then a hydraulic composition consisting of 100 parts of ordinary Portland cement (pH 14, industrial product) and 10 parts of the cement admixture. I got something. Then, 40 parts by mass of water (tap water) was further mixed with this hydraulic composition, and a coagulation test and a measurement of compressive strength were performed.
The setting test and the measurement of the compressive strength were carried out in accordance with JIS R5201 “Physical test method for cement”. The condensation test measured the onset time of condensation.
The results of each of the above evaluations are shown in Table 3.

As shown in Table 3, it was confirmed that when the proportion of particles of aluminum sulfate having a particle size of 100 μm or more was 71% and 99%, the condensation initiation time was delayed. Further, when the proportion of particles having a particle size of 100 μm or more of aluminum sulfate was 70% or less, the cohesiveness and strength were good.

Next, 100 parts of aluminum sulfate C or aluminum sulfate C adjusted to have a particle size of 10 μm or less so as to be shown in Table 4 and 20 parts of an alkaline admixture of the type shown in Table 4 were blended. After mixing to prepare a cement admixture and storing it at the number of days shown in Table 4, temperature 20 ° C., and humidity 60%, hydraulic property consisting of 100 parts of ordinary Portland cement (pH 14, industrial product) and 10 parts of cement admixture The composition was obtained. Then, 40 parts by mass of water (tap water) was further mixed with this hydraulic composition, and a coagulation test and a measurement of compressive strength were performed.
The setting test and the measurement of the compressive strength were carried out in accordance with JIS R5201 “Physical test method for cement”. The condensation test measured the onset time of condensation.
The results of each of the above evaluations are shown in Table 4.

As shown in Table 4, it was found that when the proportion of particles having a particle size of 10 μm or less in aluminum sulfate C was 30% or more, storage deterioration was confirmed, and when it was less than 30%, no particular storage deterioration was confirmed. ..

Next, 100 parts of aluminum sulfate of the type shown in Table 5 and 20 parts of various alkaline admixtures are mixed and mixed to prepare a cement admixture, and the number of days shown in Table 5, temperature 20 ° C., and humidity 60% are adjusted. After storage, a hydraulic composition consisting of 100 parts of ordinary Portland cement (pH 14, industrial product) and 10 parts of cement admixture was obtained.
Then, 40 parts by mass of water (tap water) was further mixed with this hydraulic composition and mixed, and a strength test was conducted. The strength test was performed in accordance with JIS R5201 “Physical test method for cement”. In the strength test, the strength was measured 28 days after the addition of water to the hydraulic composition.
The results of each of the above evaluations are shown in Table 5.

As shown in Table 5, the strength of the material age 28 days changed with the number of storage days for each type of admixture, but the strength of the combination of aluminum sulfate A and various alkaline admixtures decreased with the number of storage days. On the other hand, it was confirmed that the combination of aluminum sulfate C and various alkaline admixtures had good storage stability and the strength did not decrease regardless of the number of storage days.

Next, 100 parts of aluminum sulfate of the type shown in Table 6 prepared above and 20 parts of various alkaline admixtures were mixed and mixed to prepare a cement admixture, and the number of days and temperature of 20 ° C. shown in Table 6 were adjusted. After storage at a humidity of 60%, a hydraulic composition consisting of 100 parts of ordinary Portland cement (pH 14, industrial product) and 10 parts of a cement admixture was obtained. When the alkaline admixtures A and O were mixed (Experiments No. 30 and 31), the ratio (A: O) of these was 50:50.
Then, 40 parts by mass of water (tap water) was further mixed with this hydraulic composition and mixed, and a strength test was conducted. The strength test was performed in accordance with JIS R5201 “Physical test method for cement”. In the strength test, the strength was measured 28 days after the addition of water to the hydraulic composition.
The results of each of the above evaluations are shown in Table 6.

As shown in Table 6, it was confirmed that the strength of aluminum sulfate A decreased depending on the number of storage days even when the admixture types were combined with a and o, but when aluminum sulfate C was combined with a and o, the strength was further increased. It was confirmed.

Next, the experimental numbers shown in Tables 3 and 4 are shown. 3, No. For 6 to 17, 100 parts of ordinary Portland cement (pH 14, industrial product), cement admixture, except that the temperature (test temperature) for obtaining the hydraulic composition was set to 20 ° C. to 10 ° C. or 30 ° C. A hydraulic composition consisting of 10 parts was obtained.
Then, 40 parts by mass of water (tap water) was further mixed with this hydraulic composition and mixed, and a coagulation test was conducted.
The setting test was carried out in accordance with JIS R5201 “Physical test method for cement”. The condensation test measured the onset time of condensation.
The results of each of the above evaluations are shown in Table 7.

As shown in Table 7, the admixture using aluminum sulfate in the range of the first invention can be used in a wide temperature range from low temperature (10 ° C.) to high temperature (30 ° C.), and is stable in both summer and winter. Is applicable.

As can be seen from the above results, according to the first invention, the hydraulic composition which has ultra-fast hardness and high strength of the cured product, as well as the storage stability is unlikely to decrease even if it is blended in the hydraulic composition in advance. A cement admixture capable of feeding can be provided. Further, according to the first invention, it is possible to provide a hydraulic composition having ultrafast hardness and high strength of a cured product, while the storage stability is unlikely to decrease.

[Example according to the second invention]
<Preparation of calcium aluminate A>
Raw materials (CaCO ₃ and Al ₂ O ₃ ) are pulverized and mixed so as to have a CaO / Al ₂ O ₃ molar ratio of 2.5, melted in an electric furnace, and rapidly cooled to have a vitrification rate of 90% and a brain of 5500 cm ² /. Calcium aluminate having g, pH 12 and an average particle size of 120 μm was prepared.

Next, 20 parts of the alkaline admixture A shown in Table 8 is mixed and mixed with a cement admixture containing 100 parts of aluminum sulfate and 1000 parts of calcium aluminate A of the types shown in Table 1 prepared above to make an alkali. A cement admixture containing the mixture was prepared and stored at the number of days shown in Table 8, a temperature of 20 ° C., and a humidity of 60%. Then, a hydraulic composition composed of 100 parts of ordinary Portland cement (pH 14, industrial product) and 10 parts of an alkali-containing cement admixture was obtained.
Then, 40 parts by mass of water (tap water) was further mixed with this hydraulic composition and mixed, and a coagulation test was conducted.
The setting test was carried out in accordance with JIS R5201 “Physical test method for cement”. The condensation test measured the onset time of condensation.
The results of each of the above evaluations are shown in Table 2.

The alkaline admixtures a, b, c, d, o, mosquito, ki, and ku in this example are the same as those used in the example according to the first invention.

As shown in Table 8, by using aluminum sulfate A, the setting time changed with the number of storage days. This is considered to be due to storage deterioration of the compound and the admixture. However, it was confirmed that the aluminum sulfates B to E did not show any storage deterioration, and that the aluminum sulfates B to D were particularly likely to have a promoting effect.

Next, 100 parts of aluminum sulfate C or aluminum sulfate C adjusted so that the proportion of particles having a particle size of 100 μm or more is shown in Table 9, 1000 parts of calcium aluminate A, and the types of alkaline mixture shown in Table 9 are mixed. 20 parts of the agent is mixed and mixed to prepare a cement admixture, and after storing at the number of days shown in Table 9, temperature 20 ° C. and humidity 60%, 100 parts of ordinary Portland cement (pH 14, industrial product) and cement admixture are mixed. A hydraulic composition consisting of 10 parts of the agent was obtained. Then, 40 parts by mass of water (tap water) was further mixed with this hydraulic composition, and a coagulation test and a measurement of compressive strength were performed.
The setting test and the measurement of the compressive strength were carried out in accordance with JIS R5201 “Physical test method for cement”. The condensation test measured the onset time of condensation.
The results of each of the above evaluations are shown in Table 9.

As shown in Table 9, it was confirmed that when the proportion of particles of aluminum sulfate having a particle size of 100 μm or more was 71% and 99%, the condensation initiation time was delayed. Further, when the proportion of particles having a particle size of 100 μm or more of aluminum sulfate was 70% or less, the cohesiveness and strength were good.

Next, 100 parts of aluminum sulfate C or aluminum sulfate C adjusted so that the proportion of particles having a particle size of 10 μm or less is shown in Table 10 and 1000 parts of calcium aluminate A are mixed with the types shown in Table 10. 20 parts of the agent is mixed and mixed to prepare a cement admixture, and after storing at the number of days shown in Table 10, temperature 20 ° C. and humidity 60%, 100 parts of ordinary Portland cement (pH 14, industrial product), cement A hydraulic composition consisting of 10 parts of an admixture was obtained. Then, 40 parts by mass of water (tap water) was further mixed with this hydraulic composition, and a coagulation test and a measurement of compressive strength were performed.
The setting test and the measurement of the compressive strength were carried out in accordance with JIS R5201 “Physical test method for cement”. The condensation test measured the onset time of condensation.
The results of each of the above evaluations are shown in Table 10.

As shown in Table 10, it was found that when the proportion of particles having a particle size of 10 μm or less in aluminum sulfate C was 30% or more, storage deterioration was confirmed, and when it was less than 30%, no particular storage deterioration was confirmed. ..

Next, 100 parts of aluminum sulfate of the type shown in Table 11, 1000 parts of calcium aluminate A, and 20 parts of various alkaline admixtures were mixed and mixed to prepare a cement admixture, and the number of days shown in Table 11 was determined. After storage at a temperature of 20 ° C. and a humidity of 60%, a hydraulic composition composed of 100 parts of ordinary Portland cement (pH 14, industrial product) and 10 parts of a cement admixture was obtained.
Then, 40 parts by mass of water (tap water) was further mixed with this hydraulic composition and mixed, and a strength test was conducted. The strength test was performed in accordance with JIS R5201 “Physical test method for cement”. In the strength test, the strength was measured 28 days after the addition of water to the hydraulic composition.
The results of each of the above evaluations are shown in Table 11.

As shown in Table 11, the strength of the material age 28 days changed with the number of storage days for each type of admixture, but the strength of the combination of aluminum sulfate A and various alkaline admixtures decreased with the number of storage days. On the other hand, it was confirmed that the combination of aluminum sulfate C and various alkaline admixtures had good storage stability and the strength did not decrease regardless of the number of storage days.

Next, 100 parts of aluminum sulfate of the type shown in Table 12 prepared above, 1000 parts of calcium aluminate A, and 20 parts of various alkaline admixtures were mixed and mixed to prepare a cement admixture, and Table 12 After storage at 20 ° C. and 60% humidity for the number of days shown in the above, a hydraulic composition consisting of 100 parts of ordinary Portland cement (pH 14, industrial product) and 10 parts of cement admixture was obtained. When the alkaline admixtures A and O were mixed (Experiments No. 30 and 31), the ratio (A: O) of these was 50:50.
Then, 40 parts by mass of water (tap water) was further mixed with this hydraulic composition and mixed, and a strength test was conducted. The strength test was performed in accordance with JIS R5201 “Physical test method for cement”. In the strength test, the strength was measured 28 days after the addition of water to the hydraulic composition.
The results of each of the above evaluations are shown in Table 12.

Next, the experimental numbers shown in Tables 9 and 10 are shown. 3, No. For 6 to 17, 100 parts of ordinary Portland cement (pH 14, industrial product), cement admixture, except that the temperature (test temperature) for obtaining the hydraulic composition was set to 20 ° C. to 10 ° C. or 30 ° C. A hydraulic composition consisting of 10 parts was obtained.
Then, 40 parts by mass of water (tap water) was further mixed with this hydraulic composition and mixed, and a coagulation test was conducted.
The setting test was carried out in accordance with JIS R5201 “Physical test method for cement”. The condensation test measured the onset time of condensation.
The results of each of the above evaluations are shown in Table 13.

As shown in Table 13, the admixture using aluminum sulfate within the range of the present invention can be used in a wide temperature range from low temperature (5 ° C) to high temperature (30 ° C), and therefore can be stably applied in both summer and winter. It is possible.

Experiment No. In the example of 3, the following calcium aluminates B to E were used instead of calcium aluminate A, and the temperature (test temperature) at the time of obtaining the hydraulic composition was set to 20 ° C. to 10 ° C. or 30 ° C. In the same manner except for the above, a hydraulic composition composed of 100 parts of ordinary Portland cement (pH 14, industrial product) and 10 parts of a cement admixture was obtained.
Then, 40 parts by mass of water (tap water) was further mixed with this hydraulic composition and mixed, and a coagulation test was conducted.
The setting test was carried out in accordance with JIS R5201 “Physical test method for cement”. The condensation test measured the onset time of condensation.
The results of each of the above evaluations are shown in Table 14.

Calcium aluminate B: Raw materials (CaCO ₃ and Al ₂ O ₃ ) are pulverized and mixed so as to have a CaO / Al ₂ O ₃ molar ratio of 2.5, melted in an electric furnace, rapidly cooled, and vitrified by 90%. , Brain 5500 cm ² / g, pH 12, and calcium aluminate having an average particle size of 0.4 μm were prepared.
Calcium aluminate C: Raw materials (CaCO ₃ and Al ₂ O ₃ ) are pulverized and mixed so as to have a CaO / Al ₂ O ₃ molar ratio of 2.5, melted in an electric furnace, rapidly cooled, and vitrified by 90%. , Brain 5500 cm ² / g, pH 12, and calcium aluminate having an average particle size of 2 μm were prepared.
Calcium aluminate D: Raw materials (CaCO ₃ and Al ₂ O ₃ ) are pulverized and mixed so as to have a CaO / Al ₂ O ₃ molar ratio of 2.5, melted in an electric furnace, rapidly cooled, and vitrified by 90%. , Brain 5500 cm ² / g, pH 12, and calcium aluminate having an average particle size of 230 μm were prepared.
Calcium aluminate E: Raw materials (CaCO ₃ and Al ₂ O ₃ ) are pulverized and mixed so as to have a CaO / Al ₂ O ₃ molar ratio of 2.5, melted in an electric furnace, rapidly cooled, and vitrified by 90%. , Brain 5500 cm ² / g, pH 11, and calcium aluminate having an average particle size of 300 μm were prepared.

As shown in Table 14, it was confirmed that by setting the average particle size of calcium aluminate to 1 to 250 μm, the condensation initiation time and the compressive strength were good even under the temperature conditions of 5 ° C. and 30 ° C.

As can be seen from the above results, according to the second invention, the hydraulic composition which has ultra-fast hardness and high strength of the cured product, as well as the storage stability is unlikely to decrease even if it is blended in the hydraulic composition in advance. A cement admixture capable of feeding can be provided. Further, according to the second invention, it is possible to provide a hydraulic composition which has ultra-fast hardness and high strength of a cured product while the storage stability is unlikely to decrease.

[Example according to the third invention]
<Powdered sodium silicate A>
As the powdered sodium silicate, an anhydrous salt having a SiO ₂ / Na ₂ O molar ratio of 1.0, a brain specific surface area of 600 cm ² / g, and an average particle size of 250 μm was used as a commercially available product.

"Experimental Example 1"
Next, 20 parts of the alkaline admixture A shown in Table 15 are mixed and mixed with the cement admixture containing 100 parts of aluminum sulfate of the type shown in Table 1 and 25 parts of powdered sodium silicate A prepared above to contain alkali. A cement admixture was prepared and stored at the number of days shown in Table 15, a temperature of 20 ° C., and a humidity of 60%. Then, a hydraulic composition composed of 100 parts of ordinary Portland cement (pH 14, industrial product) and 10 parts of an alkali-containing cement admixture was obtained.
Then, 40 parts by mass of water (tap water) was further mixed with this hydraulic composition and mixed, and a coagulation test was conducted.
The setting test was carried out in accordance with JIS R5201 “Physical test method for cement”. The condensation test measured the onset time of condensation.
The results of each of the above evaluations are shown in Table 15.

As shown in Table 15, by using aluminum sulfate A, the setting time changed with the number of storage days. This is considered to be due to storage deterioration of the compound and the admixture. However, it was confirmed that the aluminum sulfates B to E did not show any storage deterioration, and that the aluminum sulfates B to D were particularly likely to have a promoting effect.

Next, 100 parts of aluminum sulfate C or aluminum sulfate C adjusted so that the proportion of particles having a particle size of 100 μm or more is shown in Table 16, 25 parts of powdered sodium silicate A, and the types of alkaline admixtures shown in Table 16. 20 parts are mixed and mixed to prepare a cement admixture, and after storing at the number of days shown in Table 16, temperature 20 ° C. and humidity 60%, 100 parts of ordinary Portland cement (pH 14, industrial product), cement admixture A hydraulic composition consisting of 10 parts was obtained. Then, 40 parts by mass of water (tap water) was further mixed with this hydraulic composition, and a coagulation test and a measurement of compressive strength were performed.
The setting test and the measurement of the compressive strength were carried out in accordance with JIS R5201 “Physical test method for cement”. The condensation test measured the onset time of condensation.
The results of each of the above evaluations are shown in Table 16.

As shown in Table 16, it was confirmed that when the proportion of particles of aluminum sulfate having a particle size of 100 μm or more was 71% and 99%, the condensation initiation time was delayed. Further, when the proportion of particles having a particle size of 100 μm or more of aluminum sulfate was 70% or less, the cohesiveness and strength were good.

Next, 100 parts of aluminum sulfate C or aluminum sulfate C adjusted so that the proportion of particles having a particle size of 10 μm or less is shown in Table 17, 25 parts of powdered sodium silicate A, and the types of alkaline admixtures shown in Table 17 20 parts are mixed and mixed to prepare a cement admixture, and after storing at the number of days shown in Table 4, temperature 20 ° C. and humidity 60%, 100 parts of ordinary Portland cement (pH 14, industrial product) and cement admixture are mixed. A hydraulic composition consisting of 10 parts of the agent was obtained. Then, 40 parts by mass of water (tap water) was further mixed with this hydraulic composition, and a coagulation test and a measurement of compressive strength were performed.
The setting test and the measurement of the compressive strength were carried out in accordance with JIS R5201 “Physical test method for cement”. The condensation test measured the onset time of condensation.
The results of each of the above evaluations are shown in Table 17.

As shown in Table 17, it was found that when the proportion of particles having a particle size of 10 μm or less in aluminum sulfate C was 30% or more, storage deterioration was confirmed, and when it was less than 30%, no particular storage deterioration was confirmed. ..

Next, 100 parts of aluminum sulfate of the type shown in Table 18, 25 parts of powdered sodium silicate A, and 20 parts of various alkaline admixtures were mixed and mixed to prepare a cement admixture, and the number of days and temperature shown in Table 18 were obtained. After storage at 20 ° C. and 60% humidity, a hydraulic composition composed of 100 parts of ordinary Portland cement (pH 14, industrial product) and 10 parts of cement admixture was obtained.
Then, 40 parts by mass of water (tap water) was further mixed with this hydraulic composition and mixed, and a strength test was conducted. The strength test was performed in accordance with JIS R5201 “Physical test method for cement”. In the strength test, the strength was measured 28 days after the addition of water to the hydraulic composition.
The results of each of the above evaluations are shown in Table 18.

As shown in Table 18, the strength of the material age 28 days changed with the number of storage days for each type of admixture, but the strength of the combination of aluminum sulfate A and various alkaline admixtures decreased with the number of storage days. On the other hand, it was confirmed that the combination of aluminum sulfate C and various alkaline admixtures had good storage stability and the strength did not decrease regardless of the number of storage days.

Next, 100 parts of aluminum sulfate of the type shown in Table 19 prepared above, 25 parts of powdered sodium silicate A, and 20 parts of various alkaline admixtures were mixed and mixed to prepare a cement admixture, and Table 19 shows. After storage at the indicated number of days, temperature 20 ° C., and humidity 60%, a hydraulic composition composed of 100 parts of ordinary Portland cement (pH 14, industrial product) and 10 parts of cement admixture was obtained. When the alkaline admixtures A and O were mixed (Experiments No. 30 and 31), the ratio (A: O) of these was 50:50.
Then, 40 parts by mass of water (tap water) was further mixed with this hydraulic composition and mixed, and a strength test was conducted. The strength test was performed in accordance with JIS R5201 “Physical test method for cement”. In the strength test, the strength was measured 28 days after the addition of water to the hydraulic composition.
The results of each of the above evaluations are shown in Table 19.

As shown in Table 19, it was confirmed that the strength of aluminum sulfate A decreased depending on the number of storage days even when the admixture types were combined with a and o, but when aluminum sulfate C was combined with a and o, the strength was further increased. It was confirmed.

Next, the experimental numbers shown in Tables 16 and 17 are shown. 3, No. For 6 to 17, 100 parts of ordinary Portland cement (pH 14, industrial product), cement admixture, except that the temperature (test temperature) for obtaining the hydraulic composition was set to 20 ° C. to 10 ° C. or 30 ° C. A hydraulic composition consisting of 10 parts was obtained.
Then, 40 parts by mass of water (tap water) was further mixed with this hydraulic composition and mixed, and a coagulation test was conducted.
The setting test was carried out in accordance with JIS R5201 “Physical test method for cement”. The condensation test measured the onset time of condensation.
The results of each of the above evaluations are shown in Table 20.

As shown in Table 20, the admixture using aluminum sulfate within the range of the present invention can be used in a wide temperature range from low temperature (5 ° C) to high temperature (30 ° C), and therefore can be stably applied in both summer and winter. It is possible.

Experiment No. In the example of 3, instead of the powdered soda A, the powdered sodas B to E having the average particle size shown in Table 21 below are used, respectively, and the temperature (test temperature) for obtaining the hydraulic composition is 20. A hydraulic composition composed of 100 parts of ordinary Portland cement (pH 14, industrial product) and 10 parts of cement admixture was obtained in the same manner except that the temperature was changed from ° C. to 10 ° C. or 30 ° C.
Then, 40 parts by mass of water (tap water) was further mixed with this hydraulic composition and mixed, and a coagulation test was conducted.
The setting test was carried out in accordance with JIS R5201 “Physical test method for cement”. The condensation test measured the onset time of condensation.
The results of each of the above evaluations are shown in Table 21.

As shown in Table 21, it was confirmed that by setting the average particle size of the powdered sodium silicate to 1 to 300 μm, the setting time and the compressive strength were good in each storage day.

"Experimental Example 2"
As shown in Table 22, all tests were carried out in the same manner as in Experimental Example 1 except that sodium silicates having different SiO ₂ / Na ₂ O molar ratios were used. The composition of the powdered quick-setting admixture was described in Experiment No. It was prepared to have a composition of 1-5.
The fluidity decrease time, the setting time, and the compressive strength from the time when 80 g of the powdered quick-setting agent was added to the mortar to prepare the quick-setting mortar were measured. The results are also shown in Table 22 below.

From Table 22, it can be seen that there is a range of SiO ₂ / Na ₂ O molar ratio of sodium silicate showing preferable properties.

"Experimental Example 3"
The test was carried out in the same manner as in Experimental Example 1 except that the hydrates of sodium silicates shown in Table 23 were used. The composition of the powdered quick-setting admixture was described in Experiment No. It was prepared to have a composition of 1-5.
The fluidity decrease time, the setting time, and the compressive strength from the time when 80 g of the powdered quick-setting agent was added to the mortar to prepare the quick-setting mortar were measured. The results are also shown in Table 23.

From Table 23, it is considered that any type of sodium silicate hydrate is effective as a powdered quick-setting agent.

"Experimental Example 4"
Concrete (sprayed concrete) of 360 kg of cement, 216 kg of water, 1049 kg of fine aggregate, and 716 kg of coarse aggregate (Himekawa water system No. 6 crushed stone, Niigata prefecture, density 2.67 g / cm ³ ) was prepared. A concrete pump manufactured by MAYCO (Suprema) pumped concrete at a setting of 5 m ³ / h, and mixed and merged with compressed air from another system on the way to carry air. Further, at 3 m before discharge, the powdered quick-setting admixture shown in Table 24 below is applied by the transport device Werner Mader (WM-14 FU) so that the amount of the powdered quick-setting admixture is 10 parts per 100 parts of cement. It was mixed and merged with air-conveyed concrete to form a quick-bonding material, which was sprayed onto an iron plate from the tip of the nozzle. Table 24 shows the initial strength, long-term strength, rebound rate, and crack repair rate after spraying. It should be noted that the supply of the quick-setting admixture to the quick-setting admixture carrier uses a device of Spiroflow Co., Ltd. (FLEXIBLE SCREW CONVEYOR), and each device is controlled in conjunction with an electric signal.

"Test method"
Initial strength: The initial strength was measured by spraying on a mold according to JSCE-G561 and converting the pull-out strength at the age of 10 minutes, 3 hours, and 1 day into compression strength.

Long-term strength: Sprayed onto a mold according to JISCE-F561 and JIS A1107, cores were collected at 7 and 28 days of age, and the compressive strength was measured.

Rebound: According to JSCE-F563, the rebound when sprayed into a simulated tunnel with an excavation cross section of 15 m ² for 3 minutes was measured, and the rebound rate from the used sprayed concrete was calculated from the following formula.

(Equation) Rebound rate = amount of dropped concrete sprayed (kg) / amount of concrete sprayed used for spraying (kg) x 100 (%).
The rebound rate is preferably 20% or less.

Crack repair rate: A test piece was prepared by spraying sprayed concrete onto each of two 10 cm × 10 cm × 40 cm molds. Immediately after production, the 40 cm surfaces of the two specimens were placed in parallel and fixed so that the gap was 0.1 mm, and underwater curing was carried out at 20 ° C. for 6 months, observed with a microscope, and 0.1 mm width. The repair rate for the gap was calculated.
The crack repair rate is preferably 50% or more.

From Table 24, in the examples, the initial strength, the long-term strength, and the crack repair rate were all good.

As can be seen from the above results, according to the third invention, the hydraulic composition which has ultra-fast hardness and high strength of the cured product, as well as the storage stability is unlikely to decrease even if it is blended in the hydraulic composition in advance. A cement admixture capable of feeding can be provided. Further, according to the third invention, it is possible to provide a hydraulic composition having ultrafast hardness and high strength of a cured product, while the storage stability is unlikely to decrease.

[Example according to the fourth invention]
<Calcium sulfate A>
A pulverized product of natural anhydrous gypsum having a brain of 4500 cm ² / g and an average particle size of 70 μm was used.

Next, 20 parts of the alkaline admixture A shown in Table 25 are mixed and mixed with the cement admixture containing 100 parts of aluminum sulfate and 1000 parts of calcium sulfate A prepared above and mixed with the alkali-containing cement. The preparation was prepared and stored at the number of days shown in Table 25, a temperature of 20 ° C., and a humidity of 60%. Then, a hydraulic composition composed of 100 parts of ordinary Portland cement (pH 14, industrial product) and 10 parts of an alkali-containing cement admixture was obtained.
Then, 40 parts by mass of water (tap water) was further mixed with this hydraulic composition and mixed, and a coagulation test was conducted.
The setting test was carried out in accordance with JIS R5201 “Physical test method for cement”. The condensation test measured the onset time of condensation.
The results of each of the above evaluations are shown in Table 25.

As shown in Table 25, by using aluminum sulfate A, the setting time changed with the number of storage days. This is considered to be due to storage deterioration of the compound and the admixture. However, it was confirmed that the aluminum sulfates B to E did not show any storage deterioration, and that the aluminum sulfates B to D were particularly likely to have a promoting effect.

Next, 100 parts of aluminum sulfate C or aluminum sulfate C adjusted so that the proportion of particles having a particle size of 100 μm or more is shown in Table 26, 1000 parts of calcium sulfate A, and 20 parts of the alkaline admixture of the type shown in Table 26. To prepare a cement admixture by blending and mixing with, and storing at the number of days shown in Table 26, temperature 20 ° C., and humidity 60%, then 100 parts of ordinary Portland cement (pH 14, industrial product) and 10 parts of cement admixture. A hydraulic composition comprising the above was obtained. Then, 40 parts by mass of water (tap water) was further mixed with this hydraulic composition, and a coagulation test and a measurement of compressive strength were performed.
The setting test and the measurement of the compressive strength were carried out in accordance with JIS R5201 “Physical test method for cement”. The condensation test measured the onset time of condensation.
The results of each of the above evaluations are shown in Table 26.

As shown in Table 26, it was confirmed that when the proportion of particles of aluminum sulfate having a particle size of 100 μm or more was 71% and 99%, the condensation initiation time was delayed. Further, when the proportion of particles having a particle size of 100 μm or more of aluminum sulfate was 70% or less, the cohesiveness and strength were good.

Next, 100 parts of aluminum sulfate C or aluminum sulfate C adjusted so that the proportion of particles having a particle size of 10 μm or less is shown in Table 27, 1000 parts of calcium sulfate A, and 20 parts of the alkaline admixture of the type shown in Table 27. To prepare a cement admixture by blending and mixing with, and storing at the number of days shown in Table 27, temperature 20 ° C., and humidity 60%, then 100 parts of ordinary Portland cement (pH 14, industrial product), cement admixture 10 A hydraulic composition consisting of parts was obtained. Then, 40 parts by mass of water (tap water) was further mixed with this hydraulic composition, and a coagulation test and a measurement of compressive strength were performed.
The setting test and the measurement of the compressive strength were carried out in accordance with JIS R5201 “Physical test method for cement”. The condensation test measured the onset time of condensation.
The results of each of the above evaluations are shown in Table 27.

As shown in Table 27, it was found that when the proportion of particles having a particle size of 10 μm or less in aluminum sulfate C was 30% or more, storage deterioration was confirmed, and when it was less than 30%, no particular storage deterioration was confirmed. ..

Next, 100 parts of aluminum sulfate, 1000 parts of calcium sulfate A, and 20 parts of various alkaline admixtures of the types shown in Table 28 are mixed and mixed to prepare a cement admixture, and the number of days and the temperature of 20 ° C. shown in Table 28 are shown. After storage at a humidity of 60%, a hydraulic composition composed of 100 parts of ordinary Portland cement (pH 14, industrial product) and 10 parts of a cement admixture was obtained.
Then, 40 parts by mass of water (tap water) was further mixed with this hydraulic composition and mixed, and a strength test was conducted. The strength test was performed in accordance with JIS R5201 “Physical test method for cement”. In the strength test, the strength was measured 28 days after the addition of water to the hydraulic composition.
The results of each of the above evaluations are shown in Table 28.

As shown in Table 28, the strength of 28 days of material age changed with the number of storage days for each type of admixture, but the strength of the combination of aluminum sulfate A and various alkaline admixtures decreased with the number of storage days. On the other hand, it was confirmed that the combination of aluminum sulfate C and various alkaline admixtures had good storage stability and the strength did not decrease regardless of the number of storage days.

Next, 100 parts of aluminum sulfate, 1000 parts of calcium sulfate A, and 20 parts of various alkaline admixtures prepared above are mixed and mixed to prepare a cement admixture, and the number of days shown in Table 29 is obtained. After storage at a temperature of 20 ° C. and a humidity of 60%, a hydraulic composition composed of 100 parts of ordinary Portland cement (pH 14, industrial product) and 10 parts of a cement admixture was obtained. When the alkaline admixtures A and O were mixed (Experiments No. 30 and 31), the ratio (A: O) of these was 50:50.
Then, 40 parts by mass of water (tap water) was further mixed with this hydraulic composition and mixed, and a strength test was conducted. The strength test was performed in accordance with JIS R5201 “Physical test method for cement”. In the strength test, the strength was measured 28 days after the addition of water to the hydraulic composition.
The results of each of the above evaluations are shown in Table 29.

As shown in Table 29, it was confirmed that the strength of aluminum sulfate A decreased depending on the number of storage days even when the admixture types were combined with a and o, but when aluminum sulfate C was combined with a and o, the strength was further increased. It was confirmed.

Next, the experimental numbers shown in Tables 26 and 27. 3, No. For 6 to 17, 100 parts of ordinary Portland cement (pH 14, industrial product), cement admixture, except that the temperature (test temperature) for obtaining the hydraulic composition was set to 20 ° C. to 10 ° C. or 30 ° C. A hydraulic composition consisting of 10 parts was obtained.
Then, 40 parts by mass of water (tap water) was further mixed with this hydraulic composition and mixed, and a coagulation test was conducted.
The setting test was carried out in accordance with JIS R5201 “Physical test method for cement”. The condensation test measured the onset time of condensation.
The results of each of the above evaluations are shown in Table 30.

As shown in Table 30, the admixture using aluminum sulfate within the range of the present invention can be used in a wide temperature range from low temperature (5 ° C) to high temperature (30 ° C), and therefore can be stably applied in both summer and winter. It is possible.

Experiment No. In the example of 3, the temperature (test temperature) for obtaining the hydraulic composition was set to 20 ° C. to 10 ° C. by using calcium sulfates B to E having the average particle diameter shown in Table 31 below instead of calcium sulfate A. Alternatively, a hydraulic composition composed of 100 parts of ordinary Portland cement (pH 14, industrial product) and 10 parts of a cement admixture was obtained in the same manner except that the temperature was set to 30 ° C.
Then, 40 parts by mass of water (tap water) was further mixed with this hydraulic composition and mixed, and a coagulation test was conducted.
The setting test was carried out in accordance with JIS R5201 “Physical test method for cement”. The condensation test measured the onset time of condensation.
The results of each of the above evaluations are shown in Table 31.

As shown in Table 31, it was confirmed that by setting the average particle size of calcium aluminate to 1 to 150 μm, the initial firing and the compressive strength at each storage day were good.

As can be seen from the above results, according to the fourth invention, it is possible to provide a cement admixture capable of providing a hydraulic composition having ultrafast hardness and high strength of a cured product. Further, according to the fourth invention, it is possible to provide a hydraulic composition having ultrafast hardness and high strength of a cured product.

[Example according to the fifth invention]
<By-product slaked lime A>
As by-product slaked lime, carbide slag (brain 2000 cm ² / g, average particle size 250 μm) was used.

Next, 20 parts of the alkaline admixture A shown in Table 32 is mixed and mixed with the cement admixture containing 100 parts of aluminum sulfate and 20 parts of by-product slaked lime A of the types shown in Table 1 prepared above, and the cement containing alkali is mixed. The admixture was prepared and stored at the number of days shown in Table 32, a temperature of 20 ° C., and a humidity of 60%. Then, a hydraulic composition composed of 100 parts of ordinary Portland cement (pH 14, industrial product) and 10 parts of an alkali-containing cement admixture was obtained.
Then, 40 parts by mass of water (tap water) was further mixed with this hydraulic composition and mixed, and a coagulation test was conducted.
The setting test was carried out in accordance with JIS R5201 “Physical test method for cement”. The condensation test measured the onset time of condensation.
The results of each of the above evaluations are shown in Table 32.

As shown in Table 32, by using aluminum sulfate A, the setting time changed with the number of storage days. This is considered to be due to storage deterioration of the compound and the admixture. However, it was confirmed that the aluminum sulfates B to E did not show any storage deterioration, and that the aluminum sulfates B to D were particularly likely to have a promoting effect.

Next, 100 parts of aluminum sulfate C or aluminum sulfate C adjusted so that the proportion of particles having a particle size of 100 μm or more is shown in Table 3, 20 parts of by-product slaked lime A, and the alkaline admixture 20 of the type shown in Table 33. A cement admixture is prepared by mixing and mixing with parts, and after storing at the number of days shown in Table 33, temperature 20 ° C., and humidity 60%, 100 parts of ordinary Portland cement (pH 14, industrial product), cement admixture 10 A hydraulic composition consisting of parts was obtained. Then, 40 parts by mass of water (tap water) was further mixed with this hydraulic composition, and a coagulation test and a measurement of compressive strength were performed.
The setting test and the measurement of the compressive strength were carried out in accordance with JIS R5201 “Physical test method for cement”. The condensation test measured the onset time of condensation.
The results of each of the above evaluations are shown in Table 33.

As shown in Table 33, it was confirmed that when the proportion of particles of aluminum sulfate having a particle size of 100 μm or more was 71% and 99%, the condensation initiation time was delayed. Further, when the proportion of particles having a particle size of 100 μm or more of aluminum sulfate was 70% or less, the cohesiveness and strength were good.

Next, 100 parts of aluminum sulfate C or aluminum sulfate C adjusted so that the proportion of particles having a particle size of 10 μm or less is shown in Table 34, 20 parts of by-product slaked lime A, and the type of alkaline admixture 20 shown in Table 34. A cement admixture is prepared by blending and mixing with parts, and after storing at the number of days shown in Table 34, temperature 20 ° C., and humidity 60%, 100 parts of ordinary Portland cement (pH 14, industrial product), cement admixture A hydraulic composition consisting of 10 parts was obtained. Then, 40 parts by mass of water (tap water) was further mixed with this hydraulic composition, and a coagulation test and a measurement of compressive strength were performed.
The setting test and the measurement of the compressive strength were carried out in accordance with JIS R5201 “Physical test method for cement”. The condensation test measured the onset time of condensation.
The results of each of the above evaluations are shown in Table 34.

As shown in Table 34, it was found that when the proportion of particles having a particle size of 10 μm or less in aluminum sulfate C was 30% or more, storage deterioration was confirmed, and when it was less than 30%, no particular storage deterioration was confirmed. ..

Next, 100 parts of aluminum sulfate of the type shown in Table 35, 20 parts of by-product slaked lime A, and 20 parts of various alkaline admixtures are mixed and mixed to prepare a cement admixture, and the number of days and temperature 20 shown in Table 35 are 20. After storage at ° C. and humidity of 60%, a hydraulic composition composed of 100 parts of ordinary Portland cement (pH 14, industrial product) and 10 parts of cement admixture was obtained.
Then, 40 parts by mass of water (tap water) was further mixed with this hydraulic composition and mixed, and a strength test was conducted. The strength test was performed in accordance with JIS R5201 “Physical test method for cement”. In the strength test, the strength was measured 28 days after the addition of water to the hydraulic composition.
The results of each of the above evaluations are shown in Table 35.

As shown in Table 35, the strength of the material age 28 days changed with the number of storage days for each type of admixture, but the strength of the combination of aluminum sulfate A and various alkaline admixtures decreased with the number of storage days. On the other hand, it was confirmed that the combination of aluminum sulfate C and various alkaline admixtures had good storage stability and the strength did not decrease regardless of the number of storage days.

Next, 100 parts of aluminum sulfate of the type shown in Table 36 prepared above, 20 parts of by-product slaked lime A, and 20 parts of various alkaline admixtures are mixed and mixed to prepare a cement admixture, which is shown in Table 36. After storage at 20 ° C. and 60% humidity for the number of days, a hydraulic composition consisting of 100 parts of ordinary Portland cement (pH 14, industrial product) and 10 parts of cement admixture was obtained. When the alkaline admixtures A and O were mixed (Experiments No. 30 and 31), the ratio (A: O) of these was 50:50.
Then, 40 parts by mass of water (tap water) was further mixed with this hydraulic composition and mixed, and a strength test was conducted. The strength test was performed in accordance with JIS R5201 “Physical test method for cement”. In the strength test, the strength was measured 28 days after the addition of water to the hydraulic composition.
The results of each of the above evaluations are shown in Table 36.

As shown in Table 36, it was confirmed that the strength of aluminum sulfate A decreased depending on the number of storage days even when the admixture types were combined with a and o, but when aluminum sulfate C was combined with a and o, the strength was further increased. It was confirmed.

Next, the experimental numbers shown in Tables 33 and 34. 3, No. For 6 to 17, 100 parts of ordinary Portland cement (pH 14, industrial product), cement admixture, except that the temperature (test temperature) for obtaining the hydraulic composition was set to 20 ° C. to 5 ° C. or 30 ° C. A hydraulic composition consisting of 10 parts was obtained.
Then, 40 parts by mass of water (tap water) was further mixed with this hydraulic composition and mixed, and a coagulation test was conducted.
The setting test was carried out in accordance with JIS R5201 “Physical test method for cement”. The condensation test measured the onset time of condensation.
The results of each of the above evaluations are shown in Table 37.

As shown in Table 37, the admixture using aluminum sulfate within the range of the present invention can be used in a wide temperature range from low temperature (5 ° C) to high temperature (30 ° C), and therefore can be stably applied in both summer and winter. It is possible.

Experiment No. In the example of 3, the temperature (test temperature) at the time of obtaining the hydraulic composition by using the following by-product slaked limes B to E having different particle sizes instead of the by-product slaked lime A is set to 20 ° C. to 5 ° C. or 30 ° C. A hydraulic composition composed of 100 parts of ordinary Portland cement (pH 14, industrial product) and 10 parts of cement admixture was obtained in the same manner except that the temperature was set to ° C.
Then, 40 parts by mass of water (tap water) was further mixed with this hydraulic composition and mixed, and a coagulation test was conducted.
The setting test was carried out in accordance with JIS R5201 “Physical test method for cement”. The condensation test measured the onset time of condensation.
The results of each of the above evaluations are shown in Table 38.

As shown in Table 38, it was confirmed that by setting the average particle size of calcium aluminate to 1 to 250 μm, the setting time and the compressive strength were good in each storage day.

As can be seen from the above results, according to the fifth invention, the hydraulic composition which has ultra-fast hardness and high strength of the cured product, as well as the storage stability is unlikely to decrease even if it is blended in the hydraulic composition in advance. A cement admixture capable of feeding can be provided. Further, according to the fifth invention, it is possible to provide a hydraulic composition having ultra-fast hardness and high strength of a cured product, while the storage stability is unlikely to decrease.

The present invention can be suitably applied to cement admixtures used in the fields of civil engineering, construction and the like.

Claims

A cement admixture containing aluminum sulfate that satisfies the following (1) to (4).
(1) The aluminum sulfate is amorphous.
(2) The solid aluminum sulfate 27 In the spectrum obtained by Al-NMR, the chemical shift has a peak at -0.20 to -20.00 ppm, and the half width of the peak is 10.00 to 35.00 ppm. ..
(3) The pH of the aluminum sulfate is 1 to 6.
(4) Particles having a particle size of 100 μm or more are 70% by mass or less, and particles having a particle size of 10 μm or less are less than 30% by mass.
The cement admixture according to claim 1, wherein an alkaline admixture having a pH of 8 or more is mixed.
The cement admixture according to claim 1 or 2, which comprises any of calcium aluminate, powdered sodium silicate, calcium sulfate, and by-product slaked lime.
The cement admixture according to claim 3, which contains the calcium aluminate and has a pH of the calcium aluminate of 10 to 14.
The cement admixture according to claim 4, wherein the calcium aluminate has an average particle size of 1 to 250 μm.
The cement admixture according to claim 3, which contains the powdered soda silicate and has an average particle size of 1 to 300 μm.
The cement admixture according to claim 6, wherein the molar ratio (SiO 2 / Na 2 O) of SiO 2 and Na 2 O in the powdered sodium silicate is 0.5 to 5.
The cement admixture according to claim 3, which contains the calcium sulfate and has an average particle size of the calcium sulfate of 1 to 150 μm.
The cement admixture according to claim 8, wherein the calcium sulfate is anhydrous gypsum.
The cement admixture according to claim 3, which contains the by-product slaked lime and has an average particle size of the by-product slaked lime of 1 to 300 μm.
The cement admixture according to any one of claims 2 to 10, wherein the alkaline admixture contains an alkali metal carbonate.
The cement admixture according to any one of claims 2 to 11, wherein the alkaline admixture contains an alkaline earth metal hydroxide.
A hydraulic composition containing the cement admixture according to any one of claims 1 to 12 and a hydraulic substance.