JPH0757704B2 - Concrete panel manufacturing method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a concrete panel. More specifically, the present invention relates to a method for manufacturing a concrete panel for manufacturing a concrete building material plate for construction and civil engineering, in which a filling process is used to eliminate the compaction step due to vibration of a vibrator or the like.

[0002]

2. Description of the Related Art Conventionally, as a method of constructing a concrete composition, it has been generally practiced to put concrete into a mold having reinforcing bars and to perform compaction by vibrating a vibrator. is there. However, in recent years, the noise pollution caused by a vibrator when placing concrete and the shortage of manpower in the concrete industry have become serious problems. In the field of secondary products, construction members are becoming thinner and bar reinforcement is becoming denser, making it difficult to perform construction that relies on vibrators. Moreover, in the production of concrete building material boards decorated with tiles and stones, there is a problem that the paste may leak from the joints to the tiles or stones due to vibration conditions, or the filling of the joint paste may be insufficient. ing.

With respect to these problems, research on concrete having self-filling property which does not require vibration compaction has been started, but it is the current situation that it has not yet been put into practical use technically. Generally, when the fluidity of concrete is increased, the aggregate is separated, and the aggregate is blocked between the reinforcements and between the reinforcements / forms. As a result, the filling property is deteriorated and the concrete composition is made non-uniform, resulting in a decrease in concrete strength.

Further, the change of the flow value becomes remarkable with respect to the change of the water amount on the surface of the aggregate, and there is a problem in the quality stability of the concrete. In the case of concrete mix with a large amount of thickening agent, such as underwater concrete, the aggregate separation and the stability of concrete quality are improved, but the viscosity becomes extremely high (for example, underwater disclosed in Japanese Patent Publication No. 62-35984). In the concrete composition for construction, the viscosity of the mixing water of concrete is 500 to 5000 cP), not only the filling work becomes difficult, but the initial strength is delayed due to the delay of the curing time which is the property of the thickener. Therefore, it is difficult to apply it to architecture and civil engineering, especially secondary products.

[0005]

Means for Solving the Problems The inventors of the present invention have made extensive studies in view of the above problems, and as a result, by using a lightweight aggregate and mixing cement and fine powder in a specific ratio, high fluidity and separation resistance can be obtained. The present invention has completed a method for producing a concrete panel using a concrete composition having high properties, self-filling properties, and little hardening delay.

That is, the present invention provides a concrete composition containing a high-performance water-reducing agent, cement (C), fine powder (P), lightweight aggregate and water-soluble polymer, in the following (1) to (2):
And a slump flow value according to JIS A 1101 of 55 cm or more is used to provide a method for producing a concrete panel. (1) (C + P) / (total concrete composition) × 100 = 16
~ 28% by volume (according to JIS R 5201 Le Chatelier specific gravity bottle method
Concrete composition used for the manufacture of concrete panels having a specific gravity of 2.0 or less present invention measurements) (2) concrete composition by using a small lightweight aggregate specific gravity than normal aggregate motion in the vertical direction of the aggregate As a result of the dramatic improvement in the property, it has excellent separation resistance as compared with the conventional high-filling concrete (for example, the concrete material described in JP-A-4-164849). The specific gravity of the aggregate that is normally used is about 2.5, but in the present invention,
Coarse aggregates with a specific gravity of 1.0 to 1.5 and fine aggregates with a specific gravity of 1.3 to 1.8 are used as lightweight aggregates. As the lightweight aggregate, those with trade names such as Asanolite (manufactured by Nippon Cement) and Ephenolite (manufactured by Kyushu Electric Power Co., Inc., Kobe Steel) can be used.

The total amount of cement and fine powder in the concrete composition used in the present invention is suitably 16 to 28% by volume, more preferably 18 to 28% by volume, based on the total concrete composition.
24% by volume is good. If the total amount of the cement and the fine powder exceeds the above range, the fluidity is lowered due to thickening, and if it is less than the above range, the separation resistance is lowered, which is not preferable. In addition,
The volume of ment and fine powder is JIS R 5201 (Cement physical
Test method) was measured by the Le Chatelier pycnometer method.

The fine powder used in the concrete composition used in the present invention can be used if the Blaine value (specific surface area) defined by JIS R 5201-64 is 2500 cm ² / g or more. For example, one or more fine powders selected from the group consisting of blast furnace slag, fly ash, silica fume and stone powder are used. The fineness of the 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
5,000 to 10,000 cm ² / g is preferable. Even if the fineness is less than this range, a predetermined separation resistance can be obtained by increasing the blending amount.

The specific gravity of the concrete composition used in the present invention is suitably 2.0 or less, more preferably 1.9 or less. If the specific gravity exceeds 2.0, separation resistance and quality stability will deteriorate.

In the production method of the present invention, high fluidity (JIS
In order to obtain a slump flow value specified by A 1101: 55 cm or more), it is preferable to add a superplasticizer as an active ingredient to cement in an amount of 0.3 to 3.0% by weight. As a high-performance water reducing agent that can be used, naphthalene sulfonic acid metal salt formaldehyde condensate (for example, trade name Mighty 150:
Kao Corp.] and melamine sulfonic acid metal salt formaldehyde condensate [for example, trade name Mighty 150V-2: Kao Corp.]. Furthermore, as a high performance water reducing agent,
One or more formaldehyde condensates selected from methylol compounds and sulphonated compounds of melamine, urea, phenol or aniline, for example, phenol sulphonate formaldehyde condensates (compounds of Patent No. 1097647, etc.), phenol / sulfanilic acid Salt-formaldehyde co-condensate (such as the compounds described in JP-A-1-113419), and one or more selected from the group consisting of unsaturated monocarboxylic acids and their derivatives, unsaturated dicarboxylic acids and their derivatives. Polymers or copolymers obtained by polymerizing monomers (Japanese Patent Publication No. 2-7901 and JP-A-3-75252).
Compounds described in JP-B No. 2-8983.

Examples of the water-soluble polymer used in the concrete composition used in the present invention include nonionic cellulose ether, polyethylene glycol, polyacrylic acid metal salt and polyacrylamide. The amount of water-soluble polymer added is such that the viscosity of the mixing water during concrete production is 10
A range of up to 300 cP is preferable. If it is less than 10 cP, the fluctuation range of the concrete flow value with respect to the change in the amount of water on the aggregate surface becomes large, and the quality stability deteriorates. Further, when the viscosity of the kneading water is higher than 300 cP, the filling property and the initial strength are lowered.

The production method of the present invention is generally suitable for the production of vibration-molded concrete products, for example, a member to which tiles, stones, etc. are attached in advance. Particularly, it is useful for manufacturing a member having a member thickness of about 20 to 150 mm or a member having a dense bar arrangement, which is difficult to compact with a vibrator. Of course, it can be applied to the production of secondary products other than vibration molded products.

The method of adding the superplasticizer used in the concrete composition used in the present invention to the cement composition is as follows:
It is possible in either state of aqueous solution or powder, its addition time, dry blending with cement, dissolution in kneading water, or kneading start time of cement compound, that is, from the same time or immediately after water injection to cement It is also possible to add it before the kneading of the cement mixture, or to add it to the cement mixture once kneaded. In addition, it is possible to use either a method of adding the entire amount at a time or a method of adding the total amount in several times.

When a known dispersant is used in combination, ligninsulfonic acid or its salt, oxycarboxylic acid or its salt,
Polyalkylcarboxylic acid anhydrides or salts thereof (for example, JP-B-63-5346, JP-A-62-83344, JP-A-1-270550)
No.) or the like, or after mixing one with the cement or the cement mixture, or by mixing one with the cement or the cement mixture and kneading the mixture with the other. good.

Further, other cement additives (materials) such as sustained-release dispersant, AE water-reducing agent, superplasticizer, other high-performance water-reducing agent, retarder, early-strengthening agent, accelerator, foaming agent. , Foaming agent, defoaming agent, water retention agent, thickener, self-leveling agent, waterproofing agent,
It is also possible to use a rust preventive agent, a colorant, a fungicide, a crack reducing agent, a polymer emulsion, a surfactant, another water-soluble polymer, a swelling agent (material), a glass fiber and a combination of a plurality of these.

[0016]

EFFECTS OF THE INVENTION According to the method for manufacturing a tile pre-attachment member of the present invention, since concrete can be filled without applying vibration, problems such as leakage of paste during construction and insufficient filling of joints are improved. It Further, it is also useful for manufacturing a thin-layer building material board for which it is difficult to use a vibrator or a concrete product having high-density reinforcement. In particular, in the production of concrete products, it is possible to produce concrete with a constant flow (55 to 70 cm) even under the current sand quality control conditions, and the ripple effect on noise reduction and production rationalization is great.

[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.

(1) Material Cement (C): ordinary Portland cement (specific gravity 3.1)
7) Fine aggregate (S): River sand from Kinokawa (specific gravity 2.57, FM 2.91) Coarse aggregate (G): Asanolite (specific gravity 1.38, FM 6.34) Fine powder (P): Blast furnace slag (SL), specific surface area 8,000 cm ²
/ g, specific gravity 2.90 and fly ash (FA), specific surface area 3,6
00 cm ² / g, specific gravity 2.90 (2) Mixing method of concrete Mixing cement dispersant in advance and dissolving in water, 1 at 20 ℃
Knead 50 liters of concrete for 3 minutes using a 00 liter twin-screw mixer. Table 1 shows the composition of the concrete composition prepared by using the material of (1) above.

[0019]

[Table 1]

(3) Evaluation of concrete composition / concrete product (A) Next, as a high-performance water reducing agent for the concrete composition of Table 1, A: sodium naphthalenesulfonate formaldehyde condensate [trade name: Mighty 150, Kao (stock) B): sodium melamine sulfonate formaldehyde condensate [trade name: Mighty 150V-2, manufactured by Kao Corporation] and concrete slump measured by the method of JIS A 1101 when the water-soluble polymer shown in Table 2 is added Flow value (cm),
The aggregate separation resistance of concrete and the quality stability of concrete were measured. In addition, the leak state of the paste and the filling property of the joint when the tile pre-applied plate were manufactured were also measured.
The measuring method is as follows.

-Aggregate separation resistance It was judged by the following criteria by visual observation (visual inspection). ○: Aggregate separation and water separation ×: Aggregate separation and water separation ・ Concrete quality stability The surface water ratio (%) of the fine aggregate that can maintain the flow value within the range of 55 to 70 cm with the specified mixture ). The surface water rate is a value corresponding to the flow value and is expressed by the following equation.
Therefore, the larger the range of surface water ratio that can be maintained in the range of 55 to 70 cm, the higher the quality stability, and the pass standard was 4% or more.

[0022]

[Equation 1]

Leakage state of paste The adherence of the cement paste to the tile was judged visually (visually) according to the following criteria. ○: Paste adhered to tiles of less than 5% △: Paste adhered to tiles of 5% or more and less than 20% ×; Paste adhered to tiles of 20% or more ・ Filling property of joints The following criteria were judged by visual inspection (the naked eye). ◯: No unfilled portion ×: Unfilled portion These results are shown in Table 3.

[0024]

[Table 2]

[0025]

[Table 3]

Note) * 1 Addition amount; weight% of cement (hereinafter the same) * 2 A water-soluble polymer was added so as to have the following viscosity of kneading water. The kneading water viscosity was measured with a B-type viscometer at room temperature.

From Table 3, in the production method of the present invention, in order to prevent the paste from leaking and to obtain a good joint filling property, a high fluidity with a slump flow value of 55 cm or more and a good separation resistance and quality were obtained. It turns out that stability is needed.
The composition of the comparative product having a low powder content cannot satisfy the flowability, the separation resistance and the quality stability. As a result, paste leakage and unfilled joints occurred. In addition, the composition with a high powder content decreases the fluidity and quality stability,
It can be seen that when the specific gravity is larger than 2.0, the separation resistance and the quality stability decrease.

(4) Evaluation of Concrete Composition / Concrete Product (B) Next, the concrete composition of mix No. 3 in Table 1 above and the water-soluble polymer were: A: sodium polyacrylate [MW 500,000, Kao Co., Ltd.] B: Polyethylene glycol [PEG # 20,000, manufactured by Nacalai Tesque Co., Ltd.] and the high-performance water reducing agent shown in Table 4 or a general water reducing agent for comparison and evaluated in the same manner as (3) above. I did. The results are shown in Table 5.
Shown in.

[0029]

[Table 4]

[0030]

[Table 5]

To obtain a slump flow value of about 60 cm,
From the results of Table 5, the high-performance water reducing agent was added to the cement weight.
It can be seen that it is necessary to add 0.3 to 3.0% by weight. On the other hand, in the case of the comparative product, although the leakage of the paste is satisfied, even if the water reducing agent is added in an amount of 5% by weight with respect to the weight of the cement, the slump flow value is about 40 cm, no flow effect is exhibited, and the quality stability is low. I understand.

(Evaluation Results) The concrete panel manufacturing method of the present invention has excellent joint filling properties and suppresses the leakage of paste as compared with the conventional concrete manufacturing method.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display location C04B 18:14 A 18:08 B 14:06 Z 24:22 C 24:30 D 24:38 D 24:26 D 24:32 A 24:26) E (72) Inventor Yoshihiko Horo 23-23, 385 Kajoji, Tajiri-cho, Sennan-gun, Osaka Prefecture

Claims (2)

[Claims] 1. A concrete composition containing a high-performance water reducing agent, cement (C), fine powder (P), lightweight aggregate and water-soluble polymer, which satisfies the following conditions (1) to (2): A method for producing a concrete panel, characterized by using a concrete composition having a slump flow value of 55 cm or more according to JIS A 1101. (1) (C + P) / (total concrete composition) × 100 = 16
~ 28% by volume (according to JIS R 5201 Le Chatelier specific gravity bottle method
( Measurement) (2) The specific gravity of the concrete composition is 2.0 or less 2. The production of a concrete panel according to claim 1, wherein the water-soluble polymer is one or more selected from the group consisting of nonionic cellulose ether, polyethylene glycol, polyacrylic acid metal salt and polyacrylamide. Method.