JPH06305805A - Hydraulic composition and its production - Google Patents

Abstract

PURPOSE:To increase the resistance to aggregate separation by adding a molecular chain-branched glucan of a specific molecular weight and high-performance water-reducing agent to a hydraulic powder. CONSTITUTION:Cement such as Portland cement or a mixture thereof with fly ash of 3000m<2>/g fineness is used to prepare a hydraulic powder. Then, the hydraulic powder is combined with 0.05 to 5wt.% of beta-1,3-or beta-1,4-glucan having beta-1,6-linkage side chain of the formula of 3000,000 to 5,000,000 molecular weight and 0.3 to 3.0wt.% of high-performance water-reducing agent such as phenolsulfonic acid-formaldehyde condensate or polycarboxylic acid copolymer. Further, when needed, a slowly releasing dispersant, water-reducing AE agent, plasticizer, setting retarder and other cement additives are admixed and kneaded to give the objective hydraulic composition having 60-70cm slump flow value and high aggregate separation resistance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic composition having high fluidity and requiring no compaction, and a method for producing the same. More specifically, it enhances the viscosity and fluidity of concrete, mortar and paste used as building materials and secondary product materials, and imparts excellent properties to the separation resistance of aggregates, cement and water. The present invention relates to a hydraulic composition that does not require compaction.

[0002]

2. Description of the Related Art Generally, in the production of concrete products, it is general to put hard kneading concrete into a mold having reinforcing bars and to perform compaction by vibrating a vibrator. . However, in recent years, noise pollution caused by a vibrator during casting has become a serious problem. As a measure for reducing vibration noise, vibration compaction with soft concrete is conceivable, but if vibration is applied too much, aggregate separation occurs and blockage occurs between the reinforcing bars or between the reinforcing bars / forms due to the aggregate. As a result, the filling property is lowered and the concrete composition is made non-uniform, and the concrete strength is lowered.

[0003]

In view of the above problems, the present inventors have found that a concrete product excellent in filling property and material separation can be obtained by imparting thixotropic property to concrete, The invention has been completed.

That is, the present invention relates to a hydraulic composition containing a glucan having a branched structure with a molecular weight of 300,000 to 5,000,000, a high-performance water reducing agent and a hydraulic powder.

In the present invention, by using a glucan having a branched structure having a molecular weight of 300,000 to 5,000,000, the viscosity is high under the condition of low shear stress, and the performance is rapidly decreased with the application of shear stress. To do. As a result, it is possible to produce concrete having aggregate separation resistance after placing while maintaining high fluidity during placing. A straight-chain glucan having no branching such as curdlan, pakiman, and paramylon (for example, the hydraulic composition described in JP-A No. 4-367550) has a poor thixotropic property and thus does not exhibit sufficient separation resistance. Further, in a glucan having a branched structure with a long side chain, such as sclerotan or lentinan, the cohesiveness becomes too strong and the fluidity decreases.

As the glucan having a branched structure in the present invention, β-1,3-glucan having a branched structure and β-1,4-glucan having a branched structure are preferable. Among the β-1,3-glucans having a branched structure, β-1,
Β-1,3-glucan having a 6-linked side chain is particularly preferable, and as an example, a polysaccharide NG having the following chemical structural formula
L (manufactured by Nippon Synthetic Chemical Industry Co., Ltd.). Also,
Xanthan gum is suitable as the β-1,4-glucan having a branched structure.

[0007]

[Chemical 2]

The preferred addition amount of the glucan having a branched structure in the present invention is 0.05 to an effective amount with respect to cement.
It is 5% by weight, more preferably 0.1 to 2% by weight.

The branched glucan of the present invention preferably has a molecular weight of 300,000 to 5,000,000. If the molecular weight is less than 300,000, a sufficient thickening effect will not be exhibited. When it exceeds 5 million, the cohesiveness becomes remarkable and the thixotropy tends to be lost.

When the hydraulic composition of the present invention is used as compaction-free concrete, it requires a slump flow value of 50 cm or more in the slump test specified in JIS A 1101. A slump flow value of 60 cm or more is preferable to ensure sufficient filling properties. If the slump flow value is less than 50 cm, sufficient filling properties cannot be secured.

As the hydraulic powder in the present invention, cement or a mixture of fine powder having a fineness of 3,000 cm ² / g or more and cement is preferable. As the fine powder having a fineness of 3,000 cm ² / g or more, one or more fine powders selected from the group of blast furnace slag, fly ash, silica fume, stone powder, etc. are used, but the cost and supply side Considering the above, blast furnace slag, fly ash and stone powder are preferable. The fineness of fine powder is better as the specific surface area is higher from the viewpoint of separation resistance.For example, in the case of blast furnace slag, it is 5,000 to 10,000.
cm ² / g is preferred. Even if the fineness is less than this range, a predetermined separation resistance can be obtained by increasing the blending amount.

In order to obtain high fluidity (slump flow value: 50 cm or more) in the hydraulic composition of the present invention, it is preferable to add a high-performance water reducing agent in an effective amount of 0.3 to 3.0% by weight with respect to cement. Examples of the high-performance water reducing agent that can be used include naphthalene sulfonic acid metal salt formaldehyde condensate [for example, Mighty 150: manufactured by Kao Corporation] and melamine sulfonic acid metal salt formaldehyde condensate [for example, Mighty 150V-2: Kao Corporation. ) Made. Further, as the high-performance water reducing agent, a formaldehyde condensate of one or more compounds selected from the group of methylol compounds and sulfonate compounds of melamine, phenol, urea and aniline, for example, phenolsulfonic acid formaldehyde condensate (Patent No. .1097647, etc.),
Phenol / sulfanilic acid formaldehyde co-condensate (such as the compounds described in JP-A 1-113419), and one or two kinds selected from the group consisting of unsaturated monocarboxylic acids and their derivatives, unsaturated dicarboxylic acids and their derivatives Polymers or copolymers obtained by polymerizing the above monomers (such as the compounds described in JP-B No. 2-7901, JP-A No. 3-75252, and JP-B No. 2-8983) can be mentioned. The hydraulic composition of the present invention is used for concrete moldings. The concrete molded body is not particularly limited, and usually a molded body compacted by a vibrator is targeted.

The method of adding the superplasticizer in the present invention to the cement composition may be either an aqueous solution or a powder, and the addition timing is dry blending with cement, dissolution in kneading water, or It is possible to add the cement mixture at the start of kneading, that is, at the same time as or immediately after water injection to the cement until the end of kneading of the cement mixture, and it is also possible to add it to the cement mixture once kneaded. is there. In addition, it is possible to use either a method of adding the entire amount at a time or a method of adding the amount in several times.

When a known dispersant is used in combination, ligninsulfonic acid or a salt thereof, oxycarboxylic acid or a salt thereof, polycarboxylic acid or a salt thereof, and polyalkyl anhydride carboxylic acid or a salt thereof (for example, Japanese Patent Publication No. 63- 5346
No. 1, JP-A-62-83344, JP-A No. 1-270550) and the like, or one of them may be mixed with cement or a cement mixture, or one of them may be cement or a cement mixture. Alternatively, the other may be blended after kneading.

Further, other cement additives (materials) such as sustained-release dispersant, AE water-reducing agent, superplasticizer, high-performance water-reducing agent, retarder, early strengthening agent, accelerator, foaming agent, foaming agent. Agents, defoamers, water retention agents, thickeners, self-leveling agents, waterproofing agents, rust inhibitors, colorants, antifungal agents, crack reducing agents, polymer emulsions, other surfactants, water-soluble polymers, swelling agents Agents (materials), glass fibers, and combinations of a plurality of these are also possible.

[0016]

EFFECTS OF THE INVENTION According to the hydraulic composition of the present invention, since it is possible to secure high fluidity, aggregate separation resistance and strength, the method of using concrete and the method of constructing concrete are dramatically improved. In particular, in the production of concrete products, it has a great ripple effect on noise reduction and production rationalization.

[0017]

EXAMPLES The present invention will be described below with reference to production examples and examples, but the present invention is not limited to these examples.

<Material> Cement (C): ordinary Portland cement (specific gravity 3.1
7) Fine aggregate (S): Sand from Kinokawa (specific gravity 2.57) Coarse aggregate (G): Crushed stone from Takarazuka (specific gravity 2.62) Fine powder (F) Blast furnace slag: Specific surface area 8,000 cm ² / g, specific gravity 2.90 Fly ash : Specific surface area 3,600 cm ² / g, specific gravity 2.90 Stone powder: Specific surface area 3,500 cm ² / g, specific gravity 2.70 <Mixing method of concrete> Cement dispersant is previously mixed and dissolved in water. After mixing 50 liters of concrete for 3 minutes using a barrel mixer, slump flow and aggregate separation resistance were measured. The slump flow test was performed according to JIS A 1101. Tables 1 and 2 show the composition of the concrete composition prepared by using the above materials and the water reducing agent used.

[0019]

[Table 1]

[0020]

[Table 2]

Next, when the water reducing agent (high-performance water reducing agent or water reducing agent) shown in Table 2 and β-glucan (polysaccharide NGL, xanthan gum, etc. manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) were added under the compounding conditions shown in Table 1. Table 3 and Table 4 show the slump flow value (cm) of concrete and the separation resistance of concrete measured by the method of JIS A 1101.

[0022]

[Table 3]

[0023]

[Table 4]

From Tables 3 and 4, the hydraulic composition of the present invention shows high fluidity with a slump flow value of 60 cm or more and good separation resistance. On the other hand, in the case of the comparative product, when the water reducing agent is used, the separation resistance is satisfied, but even if 5% of the water reducing agent is added, the slump flow value is about 40 cm, which shows that the flow effect is not exhibited. In addition, it can be seen that in β-glucan having no branching, the separation resistance decreases when the slump flow value is 60 cm or more.

<Evaluation Results> The hydraulic composition of the present invention can have excellent aggregate separation resistance while maintaining excellent high fluidity as compared with conventional concrete.

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Claims (7)

[Claims] 1. A hydraulic composition comprising a glucan having a branched structure having a molecular weight of 300,000 to 5,000,000, a high-performance water reducing agent, and a hydraulic powder. 2. A glucan having a branched structure is β-1,6.
-The hydraulic composition according to claim 1, which is β-1,3-glucan having a side chain of binding. 3. β- having a side chain of β-1,6-bond
The hydraulic composition according to claim 2, wherein 1,3-glucan has the following chemical structural formula. [Chemical 1] 4. The hydraulic composition according to claim 1, wherein the glucan is β-1,4-glucan. 5. The high-performance water reducing agent is a formaldehyde condensate of one or more compounds selected from the group of methylol compounds and sulfonate compounds of any of naphthalene, melamine, phenol, urea and aniline. The hydraulic composition according to any one of 1 to 4. 6. A polymer obtained by polymerizing a high-performance water-reducing agent with one or more monomers selected from the group consisting of unsaturated monocarboxylic acids and their derivatives, unsaturated dicarboxylic acids and their derivatives. Or a copolymer.
The hydraulic composition according to any one of 1. 7. The method for producing the hydraulic composition according to claim 1, wherein the fluidity is such that the slump flow value is in the range of 60 to 70 cm in the slump test specified in JIS A 1101. .