JPH04149047A - Self-filling cement admixture - Google Patents

Abstract

PURPOSE:To improve the consistency, fluidity and segregation resistance of a cement composition by incorporating a specified copolycondensation product of aminobenzenesulfonic acid, phenol and formaldehyde and a nonionic water-soluble cellulose ether into the admixture. CONSTITUTION:From 0.8 to 1.2mols of a compd. shown by formula I (X is H or alkali metals), 0.8-2.0mols of a compd. shown by formula II and 1-3mols of formaldehyde are polymerized in the presence of an alkali catalyst to obtain the copolycondensation product (A) of aminobenzenesulfonic acid, phenol and formaldehyde. Subsequently, 100 pts.wt. of the component A and 5-50 pts.wt. of (B) a nonionic water-soluble cellulose ether (e.g. methylcellulose) are mixed to obtain a self-filling cement admixture. The admixture contg. 0.1-5 pts.wt. of the component A and 0.01-3 pts.wt. of the component B is added to 100 pts.wt. of cement.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a self-filling cement admixture that does not require compaction. More specifically, it increases the viscosity and fluidity of cement compositions such as cement paste, mortar, and concrete used as construction materials and secondary product materials, and gives them excellent separation resistance, eliminating the need for compaction. This invention relates to self-filling cement admixtures.

[Prior art and problems to be solved by the invention] Conventionally, the conventional method for constructing concrete compositions is to pour concrete into a formwork with reinforcing bars and compact it using vibrators. It is. However, in recent years, noise pollution caused by vibrators during pouring and labor shortages in the concrete industry have become serious problems.

In response to these problems, research has begun on self-compacting concrete that does not require vibration compaction, but the technology has not yet been put into practical use.

In general, when the fluidity of concrete is increased, aggregate separation occurs, and coarse aggregate becomes entangled, resulting in poor filling properties, as well as an inability to obtain uniform concrete, resulting in a decrease in strength. In addition, although aggregate separation is suppressed in concrete formulations with added thickeners, such as underwater concrete, there is a significant delay in curing time and slow development of initial strength, so this is a problem that can be used in construction, civil engineering, secondary products, etc. It is difficult to apply this to concrete.

[Means to solve the problem]

The present inventors have conducted intensive research to obtain a self-filling admixture that has high fluidity, high separation resistance, self-filling properties, little curing delay, and has no effect on strength, and has developed the product of the present invention. I have reached the point where I have completed the .

The present invention is characterized by using a specific dispersant and a water-soluble polymer in combination, and has discovered characteristics that cannot be obtained with conventional dispersants and water-soluble polymers. In other words, high-performance water reducing agents such as naphthalene sulfonate formalin condensates and melamine sulfonate formalin condensates, which are conventionally added as cement dispersants, have poor fluidity and viscosity when used in combination with water-soluble polymers. As a result, the contradictory performances of the two cannot be fully demonstrated individually, resulting in a decrease in the performance of each other.

The present inventors speculate that the cause of these problems is that the functional groups and hydrophilic/lipophilic balance due to the structure of the dispersant affect the water-soluble polymer. As a result of our studies, we have obtained a self-filling admixture that does not impair the separation resistance of water-soluble polymers and the high fluidity of dispersants.

That is, the present invention provides compounds of the following formula (A) 0.8 to 1.2
amine benzenesulfonic acid/phenol/formaldehyde cocondensate obtained by polymerizing 0.8 to 2.0 moles of the compound of formula (B) with 1 to 3 moles of formaldehyde and nonionic water-soluble cellulose ether. The present invention relates to a self-filling cement admixture characterized in that the present invention is a self-filling cement admixture.

Formula (A) Formula (B) As for the ratio of both components of aminobenzenesulfonic acid/phenol/formaldehyde cocondensate and nonionic water-soluble cellulose ether, in cocondensate/cellulose ether-10015-50, It satisfies high fluidity and separation resistance without degrading the performance of the components.

The amount of the self-filling cement admixture of the present invention added to the cement composition is 0 parts of aminebenzenesulfonic acid/phenol/formaldehyde condensate per 100 parts by weight of cement.
．． 1 to 5 parts by weight, preferably 0.5 to 2 parts by weight, and 0.01 to 3 parts by weight, preferably 0.05 to 1 part by weight of nonionic cellulose ether.

The aminobenzenesulfonic acid/phenol/formaldehyde cocondensate used in the present invention is
It is part of the concrete admixture described in No. 3419, and its synthesis method is described in that publication.

On the other hand, as the nonionic cellulose ether, methylcellulose, hydroxypropylmethylcellulose, hydroxyethylmethylcellulose, hydroxydiethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, etc. are used.

The cement admixture of the present invention can be used for concrete, mortar,
It is used as a self-filling admixture with high fluidity and low separability for cement compositions such as cement paste, and it can be added at the same time as water injection, or immediately after water injection until the end of kneading. be. It is also possible to add it to a cement mixture that has already been kneaded, or to tri-blend it with a cement composition.

Furthermore, the cement admixture of the present invention may be combined with other known cement admixtures (materials), such as AE agents, early strengthening agents, accelerators, foaming agents, antifoaming agents, retarders, crack reducers, and swelling agents. It is also possible to use it in combination with additives, fly ash, blast furnace slag, granulated slag, silica hume, inorganic fibers, and organic fibers.

〔Example〕

EXAMPLES The present invention will be explained below with reference to Examples, but the present invention is not limited to these Examples.

Example of manufacturing a co-condensate (1) An aminobenzenesulfonic acid/phenol/formaldehyde co-condensate was synthesized according to the method for synthesizing an aminoarylsulfonic acid/phenol/formaldehyde condensate described in Japanese Patent Publication No. 1-113419. .

An aqueous sodium hydroxide solution is added to a water mixture of 0.8 to 1.0 mol of 4-aminobenzenesulfonic acid and 0.8 to 2.0 mol of phenol to adjust the pt (pt) to 8.1.

The prepared solution is placed in a flask equipped with a stirrer, 37% formalin is added at 80°C, and the mixture is stirred under reflux for 5 to 20 hours (first step). This solution is cooled to 30° C. and hydroxylated.) The pH is adjusted to 11 with an aqueous solution of aluminum and stirred again under reflux for 3 hours (second step) to obtain a condensate.

Hereinafter, the contents of the co-condensate of the present invention produced according to Production Example (1) are shown in Table 1, 1 to 1O.

Table: Nagel Vermeation Chromatography Method (Polystyrene Average Molecular Weight Conversion) Water-Soluble Cellulose Ethers Used in Examples Table 2 shows the contents of the water-soluble cellulose ethers used in the Examples.

table The mix of concrete was as follows.

・Water/cement ratio = 47% ・Cement - 370 kg/m3 (ordinary Portland cement, manufactured by TO) ・Water - 167 kg/m' ・Plyassi x = 209 kg/m3 (manufactured by Kansai Electric Power Company) ・Fine aggregate = 627 kg/ m'' (Yodo river sand) - Coarse aggregate = 879 kg/m' (crushed stone from Takarazuka) Central cement admixture: Dissolved in kneading water.

The mixer used was a forced kneading mixer, and the kneading time was 2 minutes after all ingredients were added.

Evaluation method Evaluation was performed using the following method.

- Fluidity: The flow (spreading, cm) was measured after measuring the concrete slump value according to JIS-A-1101.

・Material separability; Visual judgment ○...No separation of aggregate and cement paste ×...Separation of aggregate and cement paste ・Amount of breathing;
The amount of breathing was measured according to JIS-8-11231.

Compressive strength: According to JIS-A-1132 how to prepare concrete test specimens, a self-filling method was used without using a push rod or pie break. Strength measurement is JIS
-A-1108 method was used for steam curing and measurement after 24 hours.

・Steam curing: preheat (25°C) for 2 hours, heat up at 20t/hour, hold (65°C) for 4 hours, then let it cool.

The obtained evaluation results are shown in Table-3.

Table 1 Melamine-based dispersant; Melmen F-10 (manufactured by Showa Denko) Toge Naphthalene-based dispersant; Mighty 150 (manufactured by Kao Corporation) ■ Admixture A: Melamine-phenol co-condensate Kimoto Admixture B: Water-soluble 9 bottles of cellulose ale Amount of admixture (solid content) added to this cement, wt% It can be seen that this material satisfies the required performance as a self-filling cement admixture because it has a large effect of suppressing material separation and breathing, and also does not cause a decrease in strength.

〔Effect of the invention〕

A cement mixture containing a small amount of the cement admixture of the present invention has high fluidity and high separation resistance, is self-filling, has little hardness retardation, and has little influence on strength.

In addition, since the curing time and time for initial strength development are improved, it will be easier to apply it to concrete in architecture, civil engineering, secondary products, etc.

Claims (1)

[Scope of Claims] 1 0.8 to 1.2 mol of a compound of the following formula (A) and a compound of the formula (
The aminobenzenesulfonic acid/phenol/formaldehyde cocondensate obtained by polymerizing 0.8 to 2.0 moles of the compound of B) with 1 to 3 moles of formaldehyde and nonionic water-soluble cellulose ether are essential components. A self-filling cement admixture featuring: Formula (A) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ Here, X means hydrogen or alkali metal. Formula (B) ▲There are mathematical formulas, chemical formulas, tables, etc.▼