JPH07138057A - Complex cement admixture composition and packaged body - Google Patents

Abstract

PURPOSE:To obtain a complex cement admixture composition having good dispersibility when added in a cement slurry and excellent in solubility of the water soluble admixture by homogeneously mixing water soluble cement admixture powder with fine powder. CONSTITUTION:(a) One pt.wt. water soluble cement admixture powder and (b) <=1-99 pts.wt. fine powder are homogeneously mixed to obtain this complex cement admixture composition. Further, a packaged body of the complex cement admixture is obtained by filling the complex cement admixture composition in a packaging material which can be degraded in a cement compound. The water soluble cement admixture powder includes all cement admixture which are able to be powdered, e.g. a superplasticizer, a hardening accelerator, a setting retarder, a separation reducer, a preservative, an expanding agent, a coloring agent, a reinforcing material, etc. Here, silica based fine powder is specifically suitable as fine powder.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite cement admixture composition and a package which have good dispersibility when added to a cement slurry and excellent solubility of a water-soluble admixture.

[0002]

2. Description of the Related Art At present, cement admixtures include superplasticizers, AE agents, AE water reducing agents, high-performance AE water reducing agents, hardening accelerators, setting retarders, separation reducing agents, rust preventives, swelling agents, polymers. Admixtures, shrinkage-reducing agents, coloring agents, reinforcing agents, etc. are used, and in using them, cement admixtures are added in accordance with the standard formulation of cement formulations such as concrete and mortar. Of these additives to cement, it is rather more appropriate to call them "cement admixtures", and some are actually marketed as "cement admixtures", but in the present invention, these are also included. Called "cement admixture".

These admixtures are often added as liquid admixtures to cement mixes such as concrete and mortar. In particular, as an admixture for preventing slump reduction, a powder or granular admixture without water is proposed for the purpose of preventing the occurrence of cracking due to strength reduction and drying shrinkage (Japanese Patent Laid-Open No. 58-125652). Issue).

However, since the powdery or granular admixture is added as a solid to water / inorganic slurry such as concrete or mortar, it is difficult to completely dissolve the admixture, and the performance of these admixtures is insufficient. It was difficult to make it work.

In particular, polymer surfactants, which have recently been often used as an admixture, are powdered by water when dissolved in a cement mixture such as concrete, mortar and cement slurry by a conventional dissolution method. The surface becomes a sticky film, and the particles agglomerate to make the viscous film an impermeable layer, resulting in a so-called lump.
As a result, the dispersibility is deteriorated, and the dissolution rate is significantly reduced, so that the slump does not decrease when the dispersibility is extremely poor, and the lump remains in the concrete, mortar, and cement slurries. There was a problem that speckled lumps remained on the surface, impairing the surface aesthetics.

Further, a fluidizing agent, an AE agent, an AE water reducing agent, a high-performance AE water reducing agent, a curing accelerator, a setting retarder, a separation reducing agent, an anticorrosive agent, a swelling agent, a polymer admixture, a shrinkage reducing agent, and a coloring agent. When using additives, reinforcing agents, etc., it is necessary to calculate and add a predetermined amount of cement admixture in accordance with the standard formulation of cement mix such as concrete and mortar. There is a problem that spillage or leakage occurs, which deteriorates handleability and working environment.

[0007]

DISCLOSURE OF THE INVENTION As a result of intensive studies to solve the above-mentioned problems of the prior art, the inventors of the present invention blended a specific fine powder in a water-soluble cement admixture to obtain a uniform solid. It has been found that the problem of poor dispersibility / solubility in cement mixes such as concrete, mortar, and cement slurry can be solved if they are dispersed. further,
By uniformly dispersing the fine powder to the water-insoluble cement admixture powder, the above effect becomes more remarkable.

[0008] The inventors of the present invention have also obtained a powder cement admixture having poor handleability by filling these composite cement admixtures in a packaging material which is crushed in a cement mixture.
It has been found that it can be conveniently added into cement formulations.

[0009]

That is, the composite cement admixture composition of the present invention comprises (a) a water-soluble cement admixture powder and (a) 1 part by weight of the cement admixture powder. More than 99 parts by weight and more than 99 parts by weight of (b) fine powder is uniformly mixed in powder.

The composite cement admixture package of the present invention comprises a composite cement admixture composition obtained by uniformly mixing (a) a water-soluble cement admixture powder and (b) a fine powder. , A packing material that is crushed in a cement composition is filled.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The water-soluble cement admixture powder used in the present invention includes all cement admixtures capable of forming powders, for example, fluidizers, AE agents, AE water reducing agents, high-performance AE water reducing agents. Agents, curing accelerators, setting retarders, separation reducing agents, rust preventives, swelling agents, polymer admixtures, shrinkage reducing agents, coloring agents, reinforcing agents and the like.

[0012] The cement admixture using a water-soluble polymer powder having a relatively poor solubility in water has a particularly remarkable effect. Examples of the water-soluble polymer powder include polystyrene sulfonic acid which is a synthetic polymer or a salt thereof (sodium salt, calcium salt, etc.), naphthalene sulfonate formalin condensate (sodium salt, calcium salt, etc.),
Examples thereof include polyacrylic acid type polymers, polyacrylamide type polymers and partial hydrolysates thereof, polyvinyl alcohol type polymers and the like. Further, as semi-synthetic polymers, cellulosic polymers such as methyl cellulose and hydroxyethyl cellulose, starch, lignin-based polymers, natural polymer types, various sugars, plant mucilage typified by gums, mucus produced by microbial fermentation. , Animal proteins and the like.

The fine powder of the present invention includes, for example, general inorganic powder, that is, carbon black, carbon fiber powder, carbon-based fine powder such as diamond, metal oxide such as aluminum oxide and titanium oxide, Metal hydroxides such as aluminum hydroxide and magnesium hydroxide, carbonates such as calcium carbonate, sulfates such as barium sulfate, iron powder, aluminum powder, lead powder, zinc powder, titanium powder, alloy powder and the like, Alternatively, silica fume, silica flour, talc, white carbon, fly ash, bentonite, mica, zeolite, SiC, glass, clay, silica-based fine powder such as hydrous silicate, and the like, silica-based fine powder is particularly preferable. .

It is also possible to use general fine powders of organic substances such as resin powders of polyethylene, polypropylene, etc., resin emulsions or latex dry powders, and powders derived from natural organic substances. As the fine powder of the present invention, a water-insoluble or poorly water-soluble fine powder is suitable.

The amount of (a) cement admixture powder and (b) fine powder mixed in the admixture composition of the present invention is such that (a) :( b) exceeds 1: 1, and the weight ratio is 1:99. Up to the range of (1
/ 1 <(a) / (b) ≤1 / 99) is preferable, and more preferably more than 1: 1 and up to 1: 9 (1/1 <(a) /
(B) ≦ 1/9).

(A) The average particle size of the cement admixture powder is
1 μm to 5 mm is suitable, and preferably 1 μm to 3 m
m. As described above, the cement admixture powder of the present invention includes not only ordinary powdery materials but also powders close to granules and lumps.

The average particle size of the fine powder (b) of the present invention is 0.0
A particle size of 1 to 100 μm is preferable, and 0.0 is preferable.
It is 3 to 50 μm.

The ratio of (a) the average particle size of the cement admixture powder to (b) the average particle size of the fine powder is (b) / (a) =
The range of 0.0001 to 1 is suitable, further preferably 0.001 to 0.1, and more preferably 0.005.
It is in the range of 0.05. (B) By making the average particle size of the fine powder smaller than that of the (a) cement admixture powder, (b) the fine powder mixes in the gap of the (a) cement admixture powder, so that both are uniformly mixed. be able to.

The composite cement admixture composition of the present invention is a combination of water-soluble admixture powder and fine powder,
Even if a composition obtained by combining a plurality of these components is mixed, the effect is sufficiently exhibited if a uniform solid dispersion state is obtained by uniform mixing.

In order to produce the composite cement admixture composition of the present invention, it is sufficient to mix (a) the cement admixture powder and (b) the fine powder, and the usual dry blending method of powder is applied as it is. it can.

Further, the composite cement admixture composition of the present invention comprises (a) a small amount of cement admixture powder (b).
It can be produced by any of a method of mixing fine powder, (b) a method of gradually mixing fine powder with (a) a mixture of cement admixture powder, and a method of mixing both together.

The shape and material of the agitating vessel and the agitating blades of the mixer used for the production are not particularly problematic, and the horizontal cylinder type mixer, the inclined cylinder type mixer, the V type mixer, the cuboid type mixer are used. A machine, a double cone type mixer, a ribbon type mixer, a screw mixer or the like which has been conventionally used may be used, and they may be stirred and mixed for about 10 minutes.

The composite cement admixture composition of the present invention exhibits good dispersibility and dissolves in that the surface viscosity generated on the surface of the cement admixture powder upon contact with water is determined by the fine powder film of the present invention. It is considered that the solubility is remarkably improved as compared with the usual single system in which the fine powder is not added due to the action mechanism of suppressing the aggregation of particles and preventing the generation of lumps.

The packaging material used in the present invention is not particularly limited as long as it can be crushed in the cement mixture. For example, all packaging materials that can be filled with the composite cement admixture powder of the present invention, such as fibrous materials such as paper, film-like materials using water-soluble polymers, or capsule-like materials are included.

As the packaging material, one containing a fibrous substance is preferably used, and paper is typical. More preferably, a water-soluble or water-decomposable packaging material is used, and particularly preferably, a non-water-degradable or poorly water-degradable packaging material for neutral or acidic water and an alkaline water-degradable packaging material.

In the alkaline water-degradable packaging material, the binding of the fibrous material is weakened in the alkaline atmosphere in the cement composition, and the crushing of the packaging material and the dispersion of the fibrous material in the cement composition are facilitated.

The fibrous substance is not particularly limited as long as it is a fibrous material having a dispersibility in water. For example, wood pulp, non-wood pulp, rayon fiber,
Examples thereof include polyester fiber and hemp fiber. Specifically, kraft pulp or sulfite pulp for papermaking, dissolved pulp for chemical fiber is preferably used, but straw fiber, plant fiber such as hemp pulp, cotton pulp, polyamide, synthetic fibers such as polyether, Further, inorganic fibers such as glass fiber, asbestos, rock wool, slag wool, silica wool, silica alumina wool and the like can be used.

The packaging material of the present invention preferably contains a carboxyl group-containing polymer in addition to the fibrous substance. The carboxyl group-containing polymer is preferably one that dissolves or swells in a cement mixture, particularly does not substantially dissolve or swell in neutral or acidic ordinary water, and dissolves or swells in an alkaline cement mixture. Those that do are preferred. Specific examples of the carboxyl group-containing polymer include polysaccharide derivatives, synthetic polymers and natural products.

Examples of the polysaccharide derivative include carboxymethyl cellulose, carboxyethyl cellulose, carboxymethylated starch and salts thereof. Among these, carboxymethyl cellulose (CMC) is particularly preferable, and acid type CMC-H or CMC-Ca, CM
C-Al etc. are mentioned. The substitution degree (DS) of these CMCs is not particularly limited, but those of 0.2 to 1.0 are preferable.

As the synthetic polymer, a polymer of unsaturated carboxylic acid or a copolymer of two or more kinds of unsaturated carboxylic acid,
Alternatively, there may be mentioned a copolymer with another monomer copolymerizable with an unsaturated carboxylic acid or a salt thereof. Such unsaturated carboxylic acid, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic anhydride, maleic acid,
Examples include fumaric acid. Other monomers copolymerizable with these unsaturated carboxylic acids include esters of unsaturated carboxylic acids, vinyl acetate, olefins such as ethylene,
Examples thereof include acrylamide and vinyl ether.

As the natural products, alginic acid, xanthan gum, tarant gum, pectin and the like can be used. Among the above, a polysaccharide derivative is preferable, and fibrous carboxymethyl cellulose and carboxyethyl cellulose are particularly preferable.

The packaging material composed of the above fibrous substance and the polysaccharide derivative is usually made by wet or dry paper making into a sheet. The obtained sheet is NaOH, NaHCO
_It may be neutralized or unneutralized with an alkaline agent such as ₃ . When neutralized, it becomes soluble in neutral water.

The reason why the composite cement admixture package of the present invention exhibits good dispersibility and dissolves is considered to be due to the following action mechanism. When the above composite cement admixture composition is packed into a packaging material to be crushed in a cement mixture to form a package, when the package is added to the cement mixture, the carboxyl in the packaging material is immediately obtained. When the group-containing polymer dissolves or swells in the alkaline cement mixture and is further stirred in the cement mixture, the carboxyl group-containing polymer is rapidly solubilized and the binding of the fibrous substance is weakened. And disintegrate to release the composite cement admixture powder and the fibrous material is loosened and uniformly dispersed in the cement formulation. On the other hand, it has sufficient strength as a packaging material before being added to the cement mixture.

Further, in the composite cement admixture composition which is the content, the fine powder in which the solid is uniformly dispersed suppresses the aggregation due to the surface viscosity generated on the surface of the composite cement admixture upon contact with water, and the generation of lumps occurs. prevent.

Therefore, the solubility is remarkably improved as compared with the usual homogeneous dissolution without addition of the fine powder additive. In the case of the admixture package, 0.01 to 99 parts by weight of the fine powder (b) can be suitably uniformly mixed with 1 part by weight of the cement admixture powder (a).

[0036]

According to the present invention, the following effects can be obtained. (1) Since the cement admixture powder can be completely dissolved in the cement mixture, the fine powder and the simple production method can be used without the troublesome production process and costly modification. The problems of agglomeration of powder particles and lumps, which are problems, can be prevented, and the performance of the cement admixture can be fully exhibited. Furthermore, problems in surface aesthetics such as residual dissolution can be solved.

(2) without causing problems of solubility,
Since the water-soluble cement admixture can be added as a powder, the water content does not increase as in the case where it is added as an aqueous solution, and it is possible to prevent the strength of concrete from decreasing and cracking due to drying shrinkage.

(3) The composite cement admixture composition can be packaged in a predetermined amount in accordance with the standard formulation of cement mix such as concrete and mortar, and the labor of measurement at the time of use can be saved. In addition, there is no spillage or scattering of the admixture at the work site, there is no need for a measuring instrument, etc., and management is easy.

[0039]

【Example】

(1) Manufacture of composite cement admixture composition Shinto equipped with a ribbon-type stirring blade at a ratio shown in Table 3 so that the total amount of the cement admixture powder and the fine powder shown in Table 3 will be 100 g. Using a three-one motor manufactured by Kagaku Co., Ltd., the mixture was mixed for 5 minutes to produce the composite cement admixture composition of the present invention (Sample No. 1, 3, 5, 7, 9,
10, 11, 13, 14, 15). In addition, an admixture containing no additive fine powder was also evaluated (Sample No. 16,
17).

(2) Manufacturing of packaging material (a) Fibrous acid type carboxymethyl cellulose and NB
KP pulp was paper-made using a square sheet machine (Kumagaya Riki Kogyo Co., Ltd.), and the obtained sheet was dried by a roll rotary dryer to form a sheet, and a fibrous substance and fibrous carboxymethyl cellulose were mixed and produced. A water-decomposable sheet was produced. (B) The water-decomposable sheet produced in (a) above is treated with NaO.
A water-decomposable sheet was manufactured by neutralizing with a H aqueous solution.

(3) Production of Cement Admixture Package A sample No. of the composite cement admixture composition obtained in (1) above. A package (15 cm × 15 cm) made of the water-decomposable sheet obtained in (2) was filled with an amount such that 1,5,7,17 of the cement admixture powder component was 100 g, and the mixture was prepared as an admixture package. (Sample No. 2, 6, 8, 1
8).

Similarly, sample N of the composite cement admixture composition
o. 3 and 11 were filled in a package made of a water-decomposable sheet to prepare an admixture package (Sample No. 4, 12).
These sample No. The results of evaluating 1 to 18 according to the following evaluation method are shown in Table 3 (composition / packaging of composite cement admixture) and Table 4 (evaluation result).

(4) Solubility in Concrete Slurry (Amount of Undissolved Dama) A composite cement admixture composition or package produced in the above (1) to (3) is filled in a water-decomposable sheet. For each sheet, the net content of cement admixture is 100
g to 50 liters of concrete slurry (see Table 1) and stirred for 1 minute with a tilting mixer (Maruto Seisakusho). The resulting admixture-added concrete slurry was 1 m in length, 1 m in width, It was poured into a mold having a depth of 5 cm, and the number of undissolved (damaged) particles of the water-soluble cement admixture powder observed on the cured surface after one day and night was evaluated. At the same time, the residual dissolution of the sheet was evaluated. The formulation of the concrete slurry used is shown in Table 1 below.

[0044]

[Table 1] Table 1: Mixing water of concrete slurry : Tap water 167 kg / m ³ Cement: Normal Portland cement 320 kg / m ³ Manufactured by Onoda Cement Co., Ltd., specific gravity 3.16 Fine aggregate: Kawasago Fujikawa FM = 2.30, specific gravity 2.65 815 kg / m ³ Coarse aggregate: Crushed stone Kisarazu FM = 6.80, specific gravity 2.60 996.4 kg / m ³ Maximum size of coarse aggregate 20mm AE water reducing agent: Pozzolith No.70 0.35kg / m ³ AE agent: Vinsol 0.02kg / m ³ Slump: 15.0cm

(5) Fluidity The fluidity of the cement admixture in concrete slurry was measured. The base concrete slurry was manufactured in accordance with the Japanese Society of Architectural Construction Standard Specifications, and the slump was mixed to have a size of 8 cm. The formulation is shown in Table 2. To them, the amount of cement admixture in the composite cement admixture was added so that the slump increase amount was 10 cm, and the amount of 60% was added under the same conditions as the base concrete slurry production.
After stirring for 2 seconds, the slump at that time was measured.

[0046]

[Table 2] Table 2: Mixing water of base concrete slurry : Tap water 163 kg / m ³ Cement: Ordinary Portland Cement, manufactured by Nippon Cement Co., Ltd., specific gravity 3.16 320 kg / m ³ Fine aggregate: Kashima FM = 2.64, specific gravity 2.63 836 kg / m ³ Coarse aggregate: Ome FM = 6.68, specific gravity 2.64 930 kg / m ³ Maximum size of coarse aggregate 20mm AE agent: Vinsol 0.064kg / m ³

[0047]

[Table 3]Table 3: Composition and packaging of composite cement admixture composition Composite cement admixture composition Packaging Cement admixture powder (a) Fine powder (b) Average Average particle size Particle size Composition usedName (μm) Name (μm) (a: b)Sheet Example Sample No. 1 PSS / Na 90 Silica fume 1.4 40: 60-2 PSS / Na 90 Silica fume 1.4 40:60 3 PSS / Ca 90 fly ash 1.5 30: 70-4 PSS / Ca 90 fly ash 1.5 30:70 5 PSS / Na + GA / Na 90 Silica fume 1.4 40: 60-6 PSS / Na + GA / Na 90 Silica fume 1.4 40:60 7 NSF / Na 70 Bentonite 15.0 20: 80-8 NSF / Na 70 Bentonite 15.0 20:80 9 PA / Na 110 White carbon 0.2 45: 55-10 MS / Na 80 Fly ash 1.5 30: 70-11 LS / Na 60 Silica flower 0.3 30: 70-12 LS / Na 60 Silica flower 0.3 30:70 13 PSS / Na 90 Calcium carbonate 1.5 30: 70 − 14 PSS ・ Ca 90 Titanium oxide 0.2 40: 60 − 15 PSS ・ Na ＋ GA ・ Na 90 Calcium carbonate 1.5 30:70 − Comparative example 16 PSS / Na 90 non-added − 100: 0 − 17 PSS / Na + GA / Na 90 non-added − 100: 0 − 18 PSS / Na + GA / Na 90 No additive − 100: 0 PSS / Na: Sodium polystyrene sulfonate PSS / Ca: Calcium polystyrene sulfonate PSS / Na + GA / Na: Polystyrene sulfonate
Thorium: Sodium gluconate = 85:15 blended product NSF / Na: Naphthalenesulfonic acid formalin condensate
Sodium salt PA / Na: Sodium polycarboxylate MS / Na: Sodium melamine sulfonate LS / Na: Sodium lignin sulfonate

[0048]

[Table 4] Table 4: Evaluation results Fluidization of concrete surface Undissolved lump amount of sheet (pieces) (slump: cm) Undissolved Example Example No. 1 0 18.5 -20 18.0 None 3 0 18.5 -40 18.0 None 5 0 18.5 − 6 0 18.0 None 7 0 18.0 − 8 0 18.0 None 9 0 18.5 − 10 0 18.5 − 11 0 18.0 − 12 0 18.0 None 13 0 18.5 − 14 0 18.0 − 15 0 18.5 − Comparative Example 16 12 15.0-17 10 15.5-18 11 15.5 None From the results in the table, by using the admixture composition and the package of the present invention, there is no unmelted residue on the concrete surface,
It also had sufficient performance in terms of fluidity.

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[Procedure amendment]

[Submission date] December 22, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0011

[Correction method] Change

[Correction content]

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The water-soluble cement admixture powder used in the present invention includes all cement admixtures capable of forming powders, for example, fluidizers, AE agents, AE water reducing agents, high-performance AE water reducing agents. Agents, curing accelerators, setting retarders, separation reducing agents, thickening agents, rust preventives, swelling agents, polymer admixtures, shrinkage reducing agents, coloring agents, reinforcing agents and the like.

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Claims (4)

[Claims] 1. (a) a water-soluble cement admixture powder;
(A) Composite cement admixture composition characterized in that more than 1 part by weight and 99 parts by weight or less of (b) fine powder are uniformly mixed with 1 part by weight of cement admixture powder. object. 2. The composite cement admixture composition according to claim 1, wherein the fine powder (b) is a silica-based fine powder. 3. The average particle size of (a) cement admixture powder is 1 μm to 5 mm, and (b) the average particle size of fine powder is 0.01 μm.
The composite cement admixture composition according to any one of claims 1 to 3, wherein the composition is m to 100 µm. 4. (a) Water-soluble cement admixture powder,
(B) A cement admixture package, which is obtained by filling a composite cement admixture composition obtained by uniformly mixing fine powder with a fine powder into a packaging material to be crushed in a cement mixture. .