JP6362531B2 - Hydraulic composition - Google Patents

Description

  The present invention relates to a hydraulic composition, an early strengthening agent for a hydraulic composition, and a method for producing a cured body of the hydraulic composition.

  Concrete may be required to exhibit a certain degree of strength within about one day after being kneaded with hydraulic powder such as cement and water. For example, a concrete secondary product is kneaded with materials such as cement, aggregate, water, and a dispersant, placed in various molds, and commercialized through a curing (hardening) process. Since the same formwork is used many times, it is important to develop a high strength in the initial age from the viewpoint of improving the productivity, that is, the rotation rate of the formwork. Therefore, (1) Use early-strength cement as cement, (2) Use various polycarboxylic acid compounds as admixtures to reduce the amount of water in the cement composition, (3) Steam curing as a curing method Measures such as performing are taken.

  Today, there is a case where further shortening of the curing process is desired due to a demand for higher productivity. For example, in order to shorten the time until demolding in the production of concrete products, it is desired to develop a high strength within 24 hours after mixing with the hydraulic powder and water.

  In addition, although the curing time is shortened by heat curing such as steam curing, heat curing is not performed from the viewpoint of reducing energy costs associated with heat curing, that is, shortening the heating curing time and reducing the curing temperature. The method is anxious.

  In Patent Document 1, a hydraulic binder, water, and 0.1-5% by mass of finely divided titanium dioxide based on the hydraulic binder are mixed with stirring and in any desired order. A method for producing a high initial strength product containing an agent is disclosed.

Patent document 2 discloses the use of pyrogenic metal oxides for the production of self-filling compositions comprising a hydraulic binder and having a high initial strength, said composition comprising at least one hydraulic binder And water as a further component, and the product of the BET specific surface area [m ² / g] of the pyrogenic metal oxide and the mass ratio of the pyrogenic metal oxide to the hydraulic binder is hydraulic The use of ²⁰ to 200 m ² per 100 g of binder is disclosed.

  Patent Document 3 discloses a grout material composition that can be applied to a building such as a rebar of a concrete structure that has good heat resistance and fire resistance.

Special table 2009-536142 Special table 2009-536140 JP 2005-162551 A

  The present invention relates to a hydraulic composition in which the strength of the cured body is improved for about 8 hours and 16 hours, which serves as an index for demolding the cured body of the hydraulic composition from the mold after preparation, and such curing. The manufacturing method of the hardening body of the hydraulic composition from which a body is obtained, and the early strengthening agent for hydraulic compositions are provided. Hereinafter, the strength after 8 hours (including compressive strength after 8 hours) is described as 8 hour strength and the strength after 16 hours (including compressive strength after 16 hours) is described as 16 hour strength.

The present invention is a hydraulic composition comprising hydraulic powder, water, aggregate, dispersant and inorganic fine particles,
The inorganic fine particles are inorganic fine particles of a compound selected from iron oxide, magnesium hydroxide, strontium ferrite, silicon nitride, aluminum hydroxide oxide, cerium oxide, and yttrium oxide, and the specific surface area measured by the BET method is 20 m ^2. 1 type or more of inorganic fine particles of / g or more,
The content of the inorganic fine particles is 0.4 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the hydraulic powder.
It relates to a hydraulic composition.

The present invention also relates to an early strengthening agent for a hydraulic composition comprising one or more inorganic fine particles of a compound selected from iron oxide, magnesium hydroxide, strontium ferrite, silicon nitride, aluminum hydroxide oxide, cerium oxide, and yttrium oxide. In this regard, the present invention relates to an early strengthening agent for a hydraulic composition, wherein the inorganic fine particles are inorganic fine particles having a specific surface area measured by the BET method of 20 m ² / g or more.

Moreover, this invention relates to the manufacturing method of the hardening body of the hydraulic composition including the following process 1-process 5.
Step 1: Mixing water, a dispersant and inorganic fine particles to obtain a mixture, wherein the inorganic fine particles are iron oxide, magnesium hydroxide, strontium ferrite, silicon nitride, aluminum hydroxide oxide, cerium oxide, and oxidation A process comprising inorganic fine particles of a compound selected from yttrium, which is one or more inorganic fine particles having a specific surface area measured by a BET method of 20 m ² / g or more.
Step 2: A step of kneading the mixture obtained in Step 1, the hydraulic powder and the aggregate to obtain a hydraulic composition, wherein the inorganic fine particles in the mixture are contained in 100 parts by mass of the hydraulic powder. The process of using the said mixture so that it may become 0.4 to 10 mass parts.
Step 3: A step of filling the formwork with the hydraulic composition obtained in Step 2.
Step 4: A step of steam curing and curing the hydraulic composition filled in the mold obtained in Step 3 under the condition that the time for holding at 50 ° C. or higher is 1 hour or shorter.
Process 5: The process of demolding the hardening body obtained at the process 4 from a formwork.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the hardening composition which can improve intensity | strength for 8 hours and 16 hours, the hardening body of a hydraulic composition, and the early strengthening agent for hydraulic compositions are provided.

The mechanism for producing the effect of the present invention is unknown, but is estimated as follows.
The inorganic fine particles used in the present invention promote hydration of C ₃ S (3CaO.SiO ₂ , alite), which is one of the minerals contained in the cement, when kneading the cement and water, and the hydration reaction rate It is estimated that the strength is increased and the strength is improved early.
Hydration of C ₃ S is supposed to proceed in the following process.
(1) A large amount of Ca is eluted from C ₃ S to Si.
(2) From the surface of C ₃ S, a Si-rich gel layer (C—S—H I) in which Ca is released and water enters is formed.
(3) _{C 3} near the surface of S, _Ca ^{2 +} crystal nuclei generated on the surface becomes supersaturated Ca _{(OH) 2} and C-S-H II.
(4) The consumption of Si is promoted by the growth of C—S—H II, and C—S—H I is dissolved, and Ca and Si are further eluted from the dissolved surface.
In the process of (3), the inorganic fine particles according to the present invention increase the number of crystal nuclei, thereby promoting the crystal growth of Ca (OH) ₂ and C—S—H II, so that the strength is developed at an early stage. Presumed to be.

<Inorganic fine particles>
The inorganic fine particles according to the present invention are particles selected from iron oxide, magnesium hydroxide, strontium ferrite, silicon nitride, aluminum hydroxide oxide, cerium oxide, and yttrium oxide. One or more inorganic fine particles can be used.

From the viewpoint of 8 hour strength,
Inorganic fine particles of a compound selected from silicon nitride, aluminum hydroxide oxide, magnesium hydroxide, iron oxide, cerium oxide, strontium ferrite, and yttrium oxide are preferable,
More preferred are inorganic fine particles of a compound selected from silicon nitride, aluminum hydroxide oxide, magnesium hydroxide, iron oxide, cerium oxide, and strontium ferrite,
More preferably, inorganic fine particles of a compound selected from silicon nitride, aluminum hydroxide oxide, magnesium hydroxide, iron oxide, and cerium oxide,
More preferably, inorganic fine particles of a compound selected from silicon nitride, aluminum hydroxide oxide, magnesium hydroxide, and cerium oxide,
More preferably inorganic fine particles of a compound selected from silicon nitride and magnesium hydroxide,
Silicon nitride fine particles are even more preferable.

From the point of view of 16 hour strength,
Inorganic fine particles of a compound selected from silicon nitride, cerium oxide, aluminum hydroxide oxide, magnesium hydroxide, strontium ferrite, yttrium oxide, and iron oxide,
Inorganic fine particles of a compound selected from silicon nitride, cerium oxide, aluminum hydroxide oxide, magnesium hydroxide, strontium ferrite, and yttrium oxide are preferable,
More preferred are inorganic fine particles of a compound selected from silicon nitride, cerium oxide, aluminum hydroxide oxide, magnesium hydroxide, strontium ferrite,
More preferably, inorganic fine particles of a compound selected from silicon nitride, cerium oxide, aluminum hydroxide oxide, and magnesium hydroxide,
More preferably, inorganic fine particles of a compound selected from silicon nitride, cerium oxide, and aluminum hydroxide oxide,
More preferably, inorganic fine particles of a compound selected from silicon nitride and cerium oxide,
Silicon nitride fine particles are even more preferable.

The BET specific surface area of the inorganic fine particles according to the present invention is 20 m ² / g or more, and is preferably 25 m ² / g or more, more preferably 27 m ² / g or more, from the viewpoint of 8 hour strength and 16 hour strength, 30 m ^2. / G or more is more preferable. Moreover, 600 m < ² > / g or less is preferable from a viewpoint of initial dispersibility and intensity | strength improvement, 200 m < ² > / g or less is more preferable, 150 m < ² > / g or less is further more preferable, and 100 m < ² > / g or less is still more preferable.
In the present invention, the BET specific surface area is measured under the following conditions using a fully automatic specific surface area measuring device “Macsorb HM-model 1201” (manufactured by Mountec Co., Ltd.).
Degassing: 100 ° C. × 30 minutes, cooling × 4 minutes Measurement gas: using helium as a carrier gas and nitrogen as a coolant and adsorbate.
Further, the mixed gas concentration was 30.4%, and the flow rate was 25 ml / min. And

From the viewpoint of 8 hour strength and 16 hour strength, the average particle size of the inorganic fine particles according to the present invention is preferably 100 nm or less, more preferably 90 nm or less, still more preferably 70 nm or less, still more preferably 65 nm or less, and even more preferably 60 nm or less. Even more preferred. Further, from the viewpoint of improving initial dispersibility and strength, the average particle size of the inorganic fine particles according to the present invention is preferably 3 nm or more, more preferably 8 nm or more, further preferably 10 nm or more, and further preferably 15 nm or more.
The average particle diameter is defined as the diameter of the particle based on the BET specific surface area assuming that the non-porous particle is a true sphere.
That is, the average particle diameter is calculated from the BET specific surface area according to the following formula on the assumption that the particle is not a sphere by an electron microscope and assuming a true sphere.
Formula D = 6000 / ρS _m
The specific surface area per unit mass is S _m (m ² / g), the particle density is ρ (g / cm ³ ), and the particle diameter is D (nm).

  The inorganic fine particles according to the present invention can be used in the form of powder or dispersion. For example, cerium oxide can be used as a cerium oxide powder or a cerium oxide dispersion.

<Hydraulic composition>
The hydraulic composition of the present invention contains hydraulic powder, water, aggregate, a dispersant, and a predetermined amount of the inorganic fine particles.

  In the hydraulic composition of the present invention, the content of the inorganic fine particles according to the present invention is 0.4 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the hydraulic powder. This content is preferably 0.5 parts by mass or more, more preferably 0.7 parts by mass or more, still more preferably 0.9 parts by mass or more, and 1.0 parts by mass or more from the viewpoint of 8 hour strength and 16 hour strength. Is more preferable, 3 mass parts or more is further more preferable, and 4.5 mass parts or more is still more preferable. Moreover, this content is preferably 10 parts by mass or less, more preferably 7 parts by mass or less, and still more preferably 6 parts by mass or less from the viewpoint of economy.

  The hydraulic powder includes cement. Examples of the cement include ordinary Portland cement, early-strength Portland cement, ultra-early-strength Portland cement, sulfate-resistant Portland cement, low heat Portland cement, white Portland cement, and eco-cement (for example, JIS R5214). Among these, a cement selected from ordinary Portland cement and early-strength Portland cement is preferable, and ordinary Portland cement is more preferable from the viewpoints of improvement in strength for 8 hours, improvement in strength for 16 hours, and economic efficiency.

  The cement may include blast furnace slag, fly ash, silica fume, and the like, and may include non-hydraulic limestone fine powder and the like. Silica fume cement or blast furnace cement mixed with cement may be used.

  The hydraulic composition of the present invention contains a dispersant from the viewpoint of improving fluidity. Dispersants such as phosphate ester polymers, polycarboxylic acid copolymers, sulfonic acid copolymers, naphthalene polymers, melamine polymers, phenol polymers, lignin polymers, etc. Is mentioned. The dispersant may be an admixture containing other components.

  The hydraulic composition of the present invention is a hydraulic powder in which the content of the dispersant is from the viewpoint of improving the fluidity of the hydraulic composition and suppressing the delay in curing, and improving the strength for 8 hours and 16 hours. Preferably, 0.005 parts by mass or more, further 0.01 parts by mass or more, 0.05 parts by mass or more, and 2.5 parts by mass or less, and further 2.0 parts by mass with respect to 100 parts by mass of cement. Hereinafter, it is further preferably 1.5 parts by mass or less.

The dispersant is preferably a naphthalene polymer from the viewpoint of strength for 8 hours. The naphthalene polymer is preferably a naphthalenesulfonic acid formaldehyde condensate.
When a naphthalene polymer is used as a dispersant, the content of the naphthalene polymer in the hydraulic composition of the present invention is 100 parts by mass of hydraulic powder from the viewpoint of improving fluidity and suppressing strength reduction. On the other hand, 0.2 mass part is preferable, 0.5 mass part or more is more preferable, and 2.0 mass part or less is preferable, and 1.5 mass part or less is more preferable.

  The weight average molecular weight of the naphthalene polymer is preferably 1000 or more, more preferably 3000 or more, still more preferably 4000 or more, still more preferably 5000, and preferably 200000 or less, more preferably 100000 or less, still more preferably 80000. Hereinafter, it is more preferably 50000 or less. This weight average molecular weight is measured by gel permeation chromatography (GPC) shown below.

GPC conditions Column: G4000SWXL + G200SWXL (manufactured by Tosoh Corporation)
Eluent: 30 mM-CH ₃ COONa / CH ₃ CN = 6/4 (pH = 6.9)
Flow rate: 1.0 mL / min
Column temperature: 40 ° C
Detection: UV (280 nm)
Sample size: 2 mg / mL, 0.01 mL
Standard substance: Polystyrene sulfonic acid equivalent

  Naphthalene polymers can be used in liquid and powder form. Moreover, a commercial item can be used for a naphthalene type polymer, for example, Kao Co., Ltd. Mighty 150 is mentioned.

  Examples of the method for producing a naphthalene polymer include a method of obtaining a condensate by a condensation reaction of naphthalenesulfonic acid and formaldehyde. You may neutralize the said condensate. Moreover, you may remove the water insoluble matter byproduced by neutralization. For example, in order to obtain naphthalenesulfonic acid, 1.2 to 1.4 mol of sulfuric acid is used with respect to 1 mol of naphthalene and reacted at 150 to 165 ° C. for 2 to 5 hours to obtain a sulfonated product. Next, formalin is added dropwise at 85 to 95 ° C. over 3 to 6 hours to form 0.95 to 0.99 mol as formaldehyde with respect to 1 mol of the sulfonated product, and condensed at 95 to 105 ° C. after the addition. Perform the reaction. If necessary, water and a neutralizing agent are added to the condensate, and a neutralization step is performed at 80 to 95 ° C. The neutralizing agent is preferably added in an amount of 1.0 to 1.1 moles per each of naphthalenesulfonic acid and unreacted sulfuric acid. Further, water-insoluble matter generated by neutralization may be removed, preferably separated by filtration. By these steps, an aqueous solution of a naphthalenesulfonic acid formaldehyde condensate water-soluble salt is obtained. This aqueous solution can be used as it is as a naphthalene dispersant. Further, if necessary, the aqueous solution can be dried and pulverized to obtain a powdery naphthalenesulfonic acid formaldehyde condensate water-soluble salt, which may be used as a powdery naphthalene dispersant. Drying and powdering can be performed by spray drying, drum drying, freeze drying, or the like. Although the naphthalenesulfonic acid formaldehyde condensate can be obtained by the above method, the desired product can be obtained under other conditions and methods.

  The dispersant is preferably a polycarboxylic acid polymer from the viewpoint of strength for 16 hours.

  As the polycarboxylic acid copolymer, a copolymer of a monoester of polyalkylene glycol and (meth) acrylic acid and a carboxylic acid such as (meth) acrylic acid (compound described in JP-A-8-12397) Etc.), a copolymer of an unsaturated alcohol having a polyalkylene glycol and a carboxylic acid such as (meth) acrylic acid, a copolymer of an unsaturated alcohol having a polyalkylene glycol and a dicarboxylic acid such as maleic acid, etc. be able to. Here, (meth) acrylic acid is acrylic acid and / or methacrylic acid.

  The polycarboxylic acid copolymer is a polymerization of a monomer including a monomer (A1) represented by the following general formula (A1) and a monomer (A2) represented by the following general formula (A2). The copolymer obtained in this manner [hereinafter referred to as copolymer (A)] is preferred.

[Where,
R ¹ and R ² : each independently a hydrogen atom or a methyl group m1: an integer of 0 or more and 2 or less AO: an alkyleneoxy group having 2 or 3 carbon atoms n1: an average added mole number of AO, 4 or more and 300 or less X: A hydrogen atom or an alkyl group having 1 to 3 carbon atoms. ]

[Where,
R ³ , R ⁴ , R ⁵ : each independently a hydrogen atom, a methyl group, or (CH ₂ ) _m2 COOM ²
M1, M2: each independently represents a counter ion, hydrogen ion, alkali metal ion, alkaline earth metal ion (1/2 ion), organic ammonium ion, or ammonium ion,
m2: An integer of 0 or more and 2 or less. ]

  The copolymer (A) polymerizes a monomer containing the monomer (A1) represented by the general formula (A1) and the monomer (A2) represented by the general formula (A2). It is a copolymer obtained.

In general formula (A1), R ¹ and R ² are each a hydrogen atom or a methyl group. R ¹ is preferably a hydrogen atom. R ² is preferably a methyl group from the viewpoint of improving the strength for 8 hours and the strength for 16 hours.
m1 is an integer of 0 or more and 2 or less, and 0 is preferable from the viewpoint of improvement of 8 hour strength and 16 hour strength.
AO is an alkyleneoxy group selected from an alkyleneoxy group having 2 carbon atoms and an alkyleneoxy group having 3 carbon atoms, and is preferably an alkyleneoxy group having 2 carbon atoms, from the viewpoint of improving the strength for 8 hours and 16 hours.
n is an average added mole number of AO, and is a number of 4 or more and 300 or less. n is preferably 100 or more, more preferably 105 or more, further preferably 110 or more, and 8 hours from the viewpoint of ease of copolymerization, from the viewpoint of suppressing the setting delay and improving the strength of 8 hours and 16 hours. From the viewpoint of improving strength and strength for 16 hours, 200 or less is preferable, and 150 or less is more preferable. n is preferably 4 or more, more preferably 8 or more, and preferably 50 or less, more preferably 30 or less, from the viewpoint of reducing the viscosity of the hydraulic composition and from the viewpoint of improving the 8-hour strength and 16-hour strength. .
X is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and a hydrogen atom or a methyl group is preferable from the viewpoint of fluidity retention of the hydraulic composition and from the viewpoint of improvement of 8 hour strength and 16 hour strength, A methyl group is more preferred.

  As the monomer (A1), (1) one-end alkyl-blocked polyalkylene glycol such as methoxypolyethylene glycol, methoxypolypropylene glycol, methoxypolybutylene glycol, methoxypolystyrene glycol, ethoxypolyethylenepolypropyleneglycol, acrylic acid, methacrylic acid, And (2) ethylene oxide (hereinafter sometimes referred to as EO) and / or propylene oxide to a carboxylic acid selected from acrylic acid, methacrylic acid, and maleic acid Additives (hereinafter also referred to as PO) may be mentioned. The monomer (A1) is preferably an esterified product of methoxypolyethylene glycol and acrylic acid or methacrylic acid, more preferably an esterified product of methoxypolyethylene glycol and methacrylic acid, from the viewpoint of improving the strength for 8 hours and 16 hours.

In General Formula (A2), R ³ , R ⁴ , and R ⁵ are each independently a hydrogen atom, a methyl group, or (CH ₂ ) _m2 COOM ² . R ³ and R ⁵ are each preferably a hydrogen atom from the viewpoint of improving the 8-hour intensity and the 16-hour intensity. R ⁴ is preferably a methyl group from the viewpoint of improving the strength for 8 hours and the strength for 16 hours. M ¹ and M ² each represent a counter ion, which is a hydrogen ion, an alkali metal ion, an alkaline earth metal ion (1/2 ion), an ammonium ion, or an organic ammonium ion, and has an intensity of 8 hours and an intensity of 16 hours. From the viewpoint of improvement, sodium ion is preferred.

  As the monomer (A2), monocarboxylic acid monomers such as acrylic acid, methacrylic acid and crotonic acid, dicarboxylic acid monomers such as maleic acid, itaconic acid and fumaric acid, and their anhydrides or Examples of the salt include alkali metal salts, alkaline earth metal salts, ammonium salts, and mono, di, and trialkyl (2 to 8 carbon atoms) ammonium salts in which a hydroxyl group may be substituted. From the viewpoint of improving the strength for 8 hours and 16 hours, it is preferably a monomer selected from acrylic acid, methacrylic acid, maleic acid, and alkali metal salts thereof, and maleic anhydride, more preferably acrylic acid, It is a monomer selected from methacrylic acid and alkali metal salts thereof. More preferred are monomers selected from methacrylic acid and alkali metal salts of methacrylic acid.

  The copolymer (A) has a molar ratio (A1) / (A2) of the monomer (A1) to the monomer (A2) of 8 hours strength and 16 hours from the viewpoint of fluidity retention of the hydraulic composition. From the viewpoint of improving strength, 5/95 or more is preferable, 8/92 or more is more preferable, 50/50 or less is preferable, 40/60 or less is more preferable, and 38/62 or less is still more preferable.

  Of all the constituent monomers of the copolymer (A), the total amount of the monomer (A1) and the monomer (A2) is 90% by mass or more from the viewpoint of improving the strength for 8 hours and the strength for 16 hours. Preferably, 95 mass% or more is more preferable, 98 mass% or more is further preferable, 100 mass parts or less are preferable, substantially 100 mass% is further more preferable, and 100 mass% is still more preferable.

  The ratio of the mass of the monomer (A2) to the total mass of the monomer (A1) and the monomer (A2) is preferably 4% by mass or more from the viewpoint of improving the 8-hour strength and the 16-hour strength. More preferably, it is more preferably 25% by mass or less, and more preferably 16% by mass or less.

The weight average molecular weight of the copolymer (A) is preferably 20000 or more, more preferably 30000 or more, and more preferably 40000 or more from the viewpoint of fluidity retention of the hydraulic composition and the improvement of 8 hour strength and 16 hour strength. Furthermore, 150,000 or less is preferable and 100,000 or less is more preferable. In addition, the weight average molecular weight of a copolymer (A) is based on the gel permeation chromatography method (polyethylene glycol conversion), and specific conditions are as follows.
* Gel permeation chromatography conditions Apparatus: GPC (HLC-8320GPC) manufactured by Tosoh Corporation Column: G4000PWXL + G2500PWXL (made by Tosoh Corporation)
Eluent: 0.2M phosphate buffer / CH ₃ CN = 9/1
Flow rate: 1.0 mL / min
Column temperature: 40 ° C
Detection: RI
Sample size: 0.2 mg / mL
Standard substance: Polyethylene glycol equivalent (monodispersed polyethylene glycol with molecular weights 87500, 250,000, 145000, 46000, 24000)

  For example, the copolymer (A) is charged with water in a reaction vessel and heated, and the monomer (A1) and the monomer (A2) are mixed in a predetermined molar ratio ( It can be produced by reacting with A1) / (A2) and neutralizing after aging.

  When the polycarboxylic acid polymer and the copolymer (A) are used as a dispersant, the content of the polycarboxylic acid polymer and the copolymer (A) in the hydraulic composition of the present invention is water. From the viewpoint of improving the fluidity of the hard composition and suppressing the curing delay and from the viewpoint of improving the strength for 8 hours and the strength for 16 hours, 0.005 parts by mass or more with respect to hydraulic powder, preferably 100 parts by mass of cement. Further, it is preferably 0.01 parts by mass or more, further 0.05 parts by mass or more, and 2.5 parts by mass or less, further 1.5 parts by mass or less, and further 1.0 parts by mass or less.

  From the viewpoint of improving the 8-hour strength and 16-hour strength of the obtained cured product, the hydraulic composition has a water / cement ratio [the mass ratio of water and cement in the slurry (the mass of water / the mass of cement × 100), Usually abbreviated as W / C. ] Is preferably 50% or less, more preferably 45% or less, and further preferably 40% or less. Further, from the viewpoint of improving workability such as ease of kneading of the hydraulic composition, improvement of filling property to the mold at the time of casting, and improvement of 8 hour strength and 16 hour strength, 20% or more Further, 30% or more is preferable.

  The hydraulic composition of the present invention contains an aggregate. Examples of the aggregate include fine aggregate and coarse aggregate. The fine aggregate is preferably mountain sand, land sand, river sand and crushed sand, and the coarse aggregate is preferably mountain gravel, land gravel, river gravel and crushed stone. Depending on the application, lightweight aggregates may be used. The term “aggregate” is based on “Concrete Overview” (published on June 10, 1998, published by Technical Shoin).

Aggregates can be used in the usual ranges used for the preparation of concrete, mortar and the like. When the hydraulic composition is concrete, the amount of coarse aggregate used reduces the expression of the strength of the hydraulic composition and the amount of hydraulic powder such as cement, and improves the filling properties of the formwork and the like. From the viewpoint, the bulk volume is preferably 50% or more, more preferably 55% or more, further preferably 60% or more, more preferably 100% or less, more preferably 90% or less, and still more preferably 80% or less.
Further, when the hydraulic composition is concrete, the amount of fine aggregate used is preferably 500 kg / m ³ or more, more preferably 600 kg / m ³ or more, and 700 kg from the viewpoint of improving the filling property to the formwork or the like. / M ³ or more is more preferable, 1000 kg / m ³ or less is preferable, and 900 kg / m ³ or less is more preferable.
Also, if the hydraulic composition is mortar, the amount of fine aggregate is preferably from 800 kg / ^{m 3} or more, more preferably 900 kg / ^{m 3} or more, more preferably 1000 kg / ^{m 3} or more, and, 2000 kg / m ³ or less is preferable, 1800 kg / m ³ or less is more preferable, and 1700 kg / m ³ or less is more preferable.

  The hydraulic composition of the present invention can further contain other components. For example, AE agent, retarder, foaming agent, thickener, foaming agent, waterproofing agent, fluidizing agent, antifoaming agent and the like can be mentioned.

  The hydraulic composition of the present invention may be concrete or mortar. The hydraulic composition of the present invention can be used for self-leveling, for refractories, for plaster, for lightweight or mass concrete, for AE, for repair, for prepacked, for tramy, for ground improvement, for grout, for cold, etc. It is also useful in the field. From the viewpoint of developing strength by 24 hours after the preparation of the hydraulic composition and enabling early demolding from the mold, it is preferably used for concrete products such as concrete vibration products and centrifugal molded products.

<Early strength agent for hydraulic composition>
The early strengthening agent for hydraulic composition of the present invention contains the inorganic fine particles. A preferred embodiment of the inorganic fine particles is the same as the hydraulic composition of the present invention described above.

  The early strengthening agent for a hydraulic composition of the present invention is preferably 0.01% by mass or more, more preferably 1% by mass or more, and still more preferably from the viewpoint of improving the strength of 8 hours and 16 hours of the inorganic fine particles. Is 5% by mass or more, preferably 60% by mass or less, more preferably 50% by mass or less. Moreover, the early strengthening agent for hydraulic composition of the present invention may be composed of the inorganic fine particles.

  The early strengthening agent for a hydraulic composition of the present invention can be added and used at the time of preparing a hydraulic composition in which hydraulic powder such as cement and water are mixed. The early strengthening agent for hydraulic composition of the present invention is preferably mixed with water in advance when mixing the hydraulic powder and water from the viewpoint of improving the mixing property with the hydraulic powder. Moreover, the early strengthening agent for hydraulic compositions of the present invention can be mixed with water in advance and used as an aqueous solution from the viewpoint of workability such as addition of the early strengthening agent. That is, it is preferable to mix the mixture containing water and the early strengthening agent for hydraulic composition of the present invention with the hydraulic powder.

  In addition, the early strengthening agent for a hydraulic composition of the present invention is a hydraulic powder, preferably cement 100, at the time of preparing the hydraulic composition from the viewpoint of improving the strength of the obtained cured product for 8 hours and 16 hours. It is preferable that the inorganic fine particles in the early strengthening agent are added in an amount of 0.1 parts by mass or more and 10.0 parts by mass or less with respect to parts by mass. The added amount is preferably 0.2 parts by mass or more, more preferably 0.5 parts by mass or more, still more preferably 0.8 parts by mass or more, still more preferably 1 part by mass or more, and even more preferably 2 parts by mass or more. Preferably, 3 parts by mass or more is more preferable, and 3.5 parts by mass or more is more preferable. Moreover, 8.0 mass parts or less are more preferable from a viewpoint of suppressing an initial fluid fall, and 5.0 mass parts or less are still more preferable.

  Using the early strengthening agent for a hydraulic composition of the present invention, a cured product of the hydraulic composition can be obtained by air curing at room temperature (for example, 10 to 30 ° C.). In this invention, the intensity | strength of the hardening body to 24 hours can be improved even if it does not perform the curing under the heating of 40 degreeC or more, ie, what is called heat curing.

According to the present invention, there is provided an additive composition for hydraulic composition containing the early strengthening agent for hydraulic composition of the present invention and a dispersant.
The dispersant is a phosphate ester polymer, polycarboxylic acid copolymer, sulfonic acid copolymer, naphthalene polymer, melamine polymer, phenol from the viewpoint of improving the strength for 8 hours and 16 hours. One or more dispersants selected from a base polymer and a lignin polymer are preferable, and one or more dispersants selected from a naphthalene polymer and a polycarboxylic acid copolymer are more preferable.
The preferable aspect of the early strengthening agent for a hydraulic composition in this additive composition for a hydraulic composition is the same as the early strengthening agent for a hydraulic composition of the present invention described above. Moreover, the preferable aspect of the dispersing agent in this additive composition for hydraulic compositions is the same as the hydraulic composition of the above-mentioned this invention.

Further, according to the present invention, there is provided an additive composition for a hydraulic composition containing the inorganic fine particles and a dispersant,
The dispersant is a phosphate ester polymer, polycarboxylic acid copolymer, sulfonic acid copolymer, naphthalene polymer, melamine polymer, phenol from the viewpoint of improving the strength for 8 hours and 16 hours. One or more dispersants selected from a base polymer and a lignin polymer are preferred, and an additive composition for a hydraulic composition, more preferably a naphthalene polymer and a polycarboxylic acid copolymer, is provided.
The preferable aspect of the inorganic fine particles and the dispersant in the additive composition for hydraulic composition is the same as that of the hydraulic composition of the present invention described above.

The additive composition for hydraulic composition of the present invention is preferably 10% by mass or more, more preferably 30% by mass or more, preferably from the viewpoint of improving the strength of 8 hours and 16 hours of the inorganic fine particles. Is contained in an amount of 90% by mass or less, more preferably 70% by mass or less.
In the additive composition for hydraulic composition of the present invention, the dispersant is preferably 10% by mass or more, more preferably 30% by mass or more, and preferably from the viewpoint of improving the strength for 8 hours and 16 hours. 90 mass% or less, More preferably, it contains 70 mass% or less.
In addition, the additive composition for hydraulic compositions of the present invention can contain water as a component other than the inorganic fine particles and the dispersant. Moreover, the additive composition for hard compositions of the present invention may further contain other components. For example, AE agent, retarder, foaming agent, thickener, foaming agent, waterproofing agent, fluidizing agent, antifoaming agent and the like can be mentioned.

  From the viewpoint of improving the fluidity of the hydraulic composition and suppressing the delay in curing, and the viewpoint of improving the strength for 8 hours and 16 hours, the dispersant is 0% relative to hydraulic powder, preferably 100 parts by weight of cement. 0.005 parts by mass or more, 0.01 parts by mass or more, 0.05 parts by mass or more, 2.5 parts by mass or less, 2.0 parts by mass or less, and 1.5 parts by mass or less. It is preferable to be added to.

<Method for producing cured body>
The manufacturing method of the hardening body of this invention has the process of filling the hydraulic composition of this invention in a mold, curing and hardening, and the process of demolding the hardened said hydraulic composition.
More specifically, the manufacturing method of the hardening body of the hydraulic composition containing the following process 1-process 5 is mentioned.
Step 1: Mixing water, a dispersant and inorganic fine particles to obtain a mixture, wherein the inorganic fine particles are iron oxide, magnesium hydroxide, strontium ferrite, silicon nitride, aluminum hydroxide oxide, cerium oxide, yttrium oxide A process comprising: inorganic fine particles of a compound selected from the group consisting of inorganic fine particles having a specific surface area measured by a BET method of 20 m ² / g or more.
Step 2: A step of kneading the mixture obtained in Step 1, the hydraulic powder and the aggregate to obtain a hydraulic composition, wherein the inorganic fine particles in the mixture are contained in 100 parts by mass of the hydraulic powder. The process of using the said mixture so that it may become 0.4 to 10 mass parts.
Step 3: A step of filling the formwork with the hydraulic composition obtained in Step 2.
Process 4: The process of hardening the hydraulic composition with which the formwork obtained at the process 3 was filled.
Process 5: The process of demolding the hardening body obtained at the process 4 from a formwork.

  The inorganic fine particles, the dispersant, the hydraulic powder, and the aggregate used in the method for producing a cured product of the present invention are the same as those mentioned in the hydraulic composition and the early strengthening agent for the hydraulic composition of the present invention, respectively. There are also preferred embodiments. Moreover, it can replace and apply the content in a hydraulic composition to a compounding quantity.

  In step 1, water, a dispersant, and a compound represented by the inorganic fine particles are mixed. The mixing ratio is adjusted according to the composition of the hydraulic composition finally obtained.

  In step 2, the mixture obtained in step 1, the hydraulic powder and the aggregate are kneaded to obtain a hydraulic composition. The mixture is used so that the inorganic fine particles in the mixture are 0.4 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of hydraulic powder, preferably cement. This amount is preferably 0.5 parts by mass or more, more preferably 0.7 parts by mass or more, further preferably 0.9 parts by mass or more, and more preferably 1 part by mass or more from the viewpoint of improving the strength for 8 hours and 16 hours. Even more preferred is 3 parts by weight or more, still more preferred is 4.5 parts by weight or more. Moreover, 8 mass parts or less are more preferable, 6 mass parts or less are still more preferable, and 5 mass parts or less are still more preferable.

  Mixing of the mixture obtained in step 1, the hydraulic powder, and the aggregate can be performed using a mixer such as a mortar mixer or a forced biaxial mixer. Further, from the viewpoint of improving the strength for 8 hours and 16 hours, the mixing is preferably performed for 1 minute or more, more preferably 2 minutes or more, and preferably 5 minutes or less, more preferably 3 minutes or less.

  In step 3, the hydraulic composition obtained in step 2 is filled into a mold. As a formwork, a formwork for a building, a formwork for a concrete product, and the like can be given. Examples of the method of filling the mold include a method of directly feeding from a mixer, a method of pumping the hydraulic composition with a pump and introducing it into the mold.

In step 4, the hydraulic composition filled in the mold obtained in step 3 is cured. Step 4 is preferably a step in which the hydraulic composition filled in the mold obtained in Step 3 is cured under the condition that the time for holding at 50 ° C. or higher is 1 hour or shorter. In the method for producing a cured body of the hydraulic composition of the present invention, when curing the hydraulic composition, no additional energy such as steam heating is required to accelerate curing, and the concrete product is not cured by heating. It is also possible to produce a cured body of a hydraulic composition such as. In step 4, for example, the time during which the hydraulic composition is maintained at a curing temperature of 50 ° C. or higher as curing conditions is 1 hour or less, preferably 0.5 hours or less, more preferably 0 hours or more. Also, it may be 0 hours. In step 4, the hydraulic composition can be cured without steam curing. The time from contact of water with cement in the preparation of a hydraulic composition when producing concrete products without steam curing until the time of demolding improves the viewpoint of obtaining the strength necessary for demolding and the production cycle. From a viewpoint, 4 hours or more and 48 hours or less are preferable. In this case, the temperature is preferably 0 ° C. or higher, more preferably 10 ° C. or higher, and 40 ° C. or lower, more preferably 30 ° C. or lower. Heating and / or cooling in this temperature range can be appropriately performed.
When the hydraulic composition filled in the mold is cured at a temperature of 50 ° C. or higher, autoclaving and heat curing such as steam can be performed.

  In step 5, the cured body obtained in step 4 is removed from the mold. Steps 4 and 5 can be performed continuously under a series of temperature controls. Demolding of the cured body can be performed according to a known method.

  The method for producing a cured body of the hydraulic composition of the present invention can improve the strength of the cured body up to 24 hours without performing heat curing, and therefore can be suitably used for the production of concrete products. In the method for producing a cured product of the hydraulic composition of the present invention, such as the production of a concrete product, the hydraulic composition to which the additive for the hydraulic composition of the present invention is added is filled in a mold and cured and cured. And a step of removing the cured hydraulic composition from the mold. In the method for producing a cured body of the hydraulic composition of the present invention, since the curing of the hydraulic composition is accelerated, the time from preparation of the hydraulic composition to demolding can be shortened. The manufacturing method of the hardening body of the hydraulic composition of this invention has the process 2 which prepares the said hydraulic composition by making water contact a hydraulic composition, such as cement. In the present invention, the time from the start of the preparation of the hydraulic composition to the demolding, that is, the time from the contact of water with the cement to the start of demolding, obtains the strength necessary for demolding. From a viewpoint and a viewpoint which improves a manufacturing cycle, 4 hours or more, 6 hours or more are preferable, and 48 hours or less, and also 30 hours or less are preferable.

  The method for producing a cured body of the hydraulic composition of the present invention can improve the productivity of a cured body of a hydraulic composition such as a concrete product without performing heat curing, and thus is excellent in terms of reducing the burden on the environment. Is. As a hardened body of a hydraulic composition using a formwork that is a concrete product, as a civil engineering product, there are various block products for revetment, box culvert products, segment products used for tunnel construction, pier girder products, etc. Examples of building products include curtain wall products, pillars, beams, building member products used for floor boards, and the like.

  The mortar formulation is shown in Table 1, and the evaluation results are shown in Tables 2-4. The inorganic fine particles and the dispersant are as follows.

[Inorganic fine particles: product of the present invention]
・ Silicon nitride: Sigma Aldrich Japan GK ・ Iron oxide: Sigma Aldrich Japan GK ・ Magnesium hydroxide: Sigma Aldrich Japan GK ・ Strontium ferrite: Sigma Aldrich Japan GK ・ Cerium oxide powder: Sigma Aldrich Japan GK Company-made cerium oxide dispersion: Sigma Aldrich Japan G.K. Aluminum hydroxide: Wako Pure Chemical Industries, Ltd. Yttrium oxide: Sigma Aldrich Japan G.K.

[Inorganic fine particles: Comparative product]
・ Copper tetroxide: Sigma Aldrich Japan GK ・ Zinc oxide: Sigma Aldrich Japan GK ・ Zirconium oxide dispersion: Sigma Aldrich Japan GK ・ Magnesium hydroxide: Sigma Aldrich Japan GK, BET specific surface area 8.00 m ² / g
Nickel-zinc-iron-oxide: Sigma Aldrich Japan GK, “Nickelzinc iron oxide” (NiZnFe ₄ O ₄ )
Iron oxide: Sigma Aldrich Japan GK, BET specific surface area 3.72 m ² / g
・ Silicon nitride: Sigma Aldrich Japan GK, BET specific surface area 10.74 m ² / g

[Dispersant]
Polycarboxylic acid dispersant: A copolymer produced by the following method was used. In Tables 2-4, it described as PCE.
(Method for producing copolymer)
Into a glass reaction vessel (four-necked flask) equipped with a stirrer, 114 g of water was charged, purged with nitrogen while stirring, and heated to 80 ° C. in a nitrogen atmosphere. 60% by mass of ω-methoxypolyethylene glycol monomethacrylate (average addition mole number of ethylene oxide 120: ester purity 100%) aqueous solution 300 g, methacrylic acid (reagent: Wako Pure Chemical Industries, Ltd.) 11.5 g, and mercaptopropionic acid 0 Two solutions, a solution in which .98 g was mixed and dissolved, and a solution in which 1.9 g of ammonium persulfate was dissolved in 45 g of water were dropped into the reaction vessel over 1.5 hours. Thereafter, aging was performed for 1 hour, and a solution obtained by dissolving 0.8 g of ammonium persulfate in 15 g of water was added dropwise over 30 minutes, followed by aging for 1.5 hours. The temperature of the reaction system during this series was kept at 80 ° C. After completion of the aging, the mixture was cooled to 40 ° C. or lower and then neutralized with 9.6 g of a 48 mass% sodium hydroxide solution to obtain a copolymer having a weight average molecular weight of 53,000.

  Naphthalene polymer: Naphthalenesulfonic acid formaldehyde condensate (weight average molecular weight 20,000, manufactured by Kao Corporation, Mighty 150) was used. In Table 4, it was described as NSF. The weight average molecular weight was measured by GPC under the above conditions.

<Method for measuring BET specific surface area of inorganic fine particles>
Using a fully automatic specific surface area measuring device “Macsorb HM-model 1201” (manufactured by Mountec Co., Ltd.), the BET specific surface area of the inorganic fine particles was measured under the above conditions. In addition, it was confirmed by an electron microscope that the inorganic fine particles were not porous. The average particle diameter of the inorganic fine particles calculated by the above method from the BET specific surface area is shown in the table.

<Preparation and evaluation of mortar>
(1) Mortar preparation process The kneading water (W) which mixed the cement dispersant and the early strengthening agent as shown in Tables 2-4 and mixed these with water was prepared. Since the amounts of the cement dispersant and the early strengthening agent in the kneading water are very small, the total amount of the cement dispersing agent, the early strengthening agent and the water was set to the amount of the kneading water (W) in Table 1.
The polycarboxylic acid-based dispersant was added in an amount of 0.14 parts by mass as an effective component with respect to 100 parts by mass of cement. Further, 0.56 parts by mass of naphthalene-based dispersant was added as an effective component with respect to 100 parts by mass of cement.
In Tables 2 to 4, inorganic fine particles were used as early strengthening agents.

  Under the blending conditions shown in Table 1, cement (C) and fine aggregate (S) were added using a mortar mixer (universal mixing stirrer model: 5DM-03-γ) manufactured by Dalton Co. The kneading water (W) containing the cement dispersant and the early strengthening agent was added. At this time, an antifoaming agent was added so that the air entrainment amount was 2% or less. Then, mortar was prepared by main kneading for 60 seconds at a low speed rotation (63 rpm) of the mortar mixer and 120 seconds at a high speed rotation (128 rpm).

The mass ratio (W / C) of water and cement is 0.375 (37.5 parts by mass with respect to 100 parts by mass of cement). The fine aggregate is 175 parts by mass with respect to 100 parts by mass of cement. The components used are as follows.
・ W: Kneaded water (tap water containing cement dispersant and early strengthening agent)
C: Normal Portland cement (manufactured by Taiheiyo Cement Co., Ltd.), density 3.16 g / cm ³
S: Fine aggregate, from Joyo, mountain sand, FM = 2.67, density 2.56 g / cm ³

(2) Formwork filling and curing process Based on JIS A 1132, mortar is filled in a plurality of molds of cylindrical plastic molds (bottom diameter: 5 cm, height 10 cm) by a two-layer filling method, and 20 ° C. Curing was performed in the air (20 ° C.) and cured. Three specimens cured after 8 hours from the preparation of the mortar were removed from the mold to obtain specimens. The three specimens were used for measurement of compressive strength after 8 hours. Further, three specimens cured after 16 hours from the preparation of the mortar were removed from the mold to obtain specimens. The three specimens were used for measurement of compressive strength after 16 hours.

(3) Evaluation of Curing Strength The 8-hour strength and 16-hour strength of the specimens were measured based on JIS A1108, and the average value of three specimens was obtained. The results are shown in Tables 2-4.

In Tables 2 to 4, “addition amount” is a mass part in terms of pure content of inorganic fine particles with respect to 100 parts by mass of cement.
Moreover, in Tables 2-4, "strength improvement rate" is a ratio on the basis of the intensity | strength of the comparative example which does not add an early strengthening agent to cement (100%).

Claims (5)

A hydraulic composition comprising hydraulic powder, water, aggregate, dispersant and inorganic fine particles,
The inorganic fine particles are inorganic fine particles of a compound selected from iron oxide, magnesium hydroxide, strontium ferrite, silicon nitride, aluminum hydroxide oxide, cerium oxide, and yttrium oxide, and the specific surface area measured by the BET method is 20 m ^2. 1 type or more of inorganic fine particles of / g or more,
The content of the inorganic fine particles is 0.4 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the hydraulic powder.
Hydraulic composition. An early strengthening agent for a hydraulic composition comprising one or more inorganic fine particles of a compound selected from iron oxide, magnesium hydroxide, strontium ferrite, silicon nitride, aluminum hydroxide oxide, cerium oxide, and yttrium oxide, the inorganic fine particles Is an early strengthening agent for a hydraulic composition, which is inorganic fine particles having a specific surface area of 20 m ² / g or more measured by the BET method. The manufacturing method of the hardening body of the hydraulic composition containing the following process 1-process 5.
Step 1: Mixing water, a dispersant and inorganic fine particles to obtain a mixture, wherein the inorganic fine particles are iron oxide, magnesium hydroxide, strontium ferrite, silicon nitride, aluminum hydroxide oxide, cerium oxide, and oxidation A process comprising inorganic fine particles of a compound selected from yttrium, which is one or more inorganic fine particles having a specific surface area measured by a BET method of 20 m ² / g or more.
Step 2: A step of kneading the mixture obtained in Step 1, the hydraulic powder and the aggregate to obtain a hydraulic composition, wherein the inorganic fine particles in the mixture are contained in 100 parts by mass of the hydraulic powder. The process of using the said mixture so that it may become 0.4 to 10 mass parts.
Step 3: A step of filling the formwork with the hydraulic composition obtained in Step 2.
Process 4: The process of hardening the hydraulic composition with which the formwork obtained at the process 3 was filled.
Process 5: The process of demolding the hardening body obtained at the process 4 from a formwork.   The step 4 is a step of curing and curing the hydraulic composition filled in the mold obtained in the step 3 under a condition that the time for maintaining the hydraulic composition at 50 ° C or higher is 1 hour or shorter. The manufacturing method of the hardening body as described in any one of.   The manufacturing method of the hardening body of Claim 3 or 4 which hardens a hydraulic composition, without implementing steam curing in process 4.