JP3318598B2 - Method for producing high-strength lightweight concrete molding - 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 producing a high-strength lightweight concrete molding, and more particularly, to a method of adding a melamine-based high-performance water reducing agent to a concrete raw material using an artificial lightweight aggregate, and The present invention relates to a method for producing a lightweight and high-strength concrete molded body by a method using only normal-pressure steam curing without using high-temperature and high-pressure steam curing in an autoclave or the like by mixing fine bubbles therein.

[0002]

2. Description of the Related Art Conventionally, concrete called light-weight concrete or cellular concrete includes natural lightweight aggregates (eg, Oshima volcanic rubble, Haruna volcanic rubble, etc.) and artificial lightweight aggregates (eg, mesalite, asanolite, etc.). Or perlite, etc., and as a means of weight reduction,
A large amount of air bubbles were mixed in concrete.

[0003]

However, when the weight is reduced by a method of mixing and mixing lightweight aggregates and air bubbles, the strength is reduced due to the influence of these materials, and the workability is also poor. Separation may cause defects in quality and appearance, such as occurrence of corner cracks and cracks in the molded product. For this reason, it has been said that it is difficult to form a lightweight and high-strength concrete molded body.

[0004] The present invention solves the above problems, there is no separation of materials, no corner breakage or cracking of the product, and
It is an object of the present invention to obtain a lightweight and high-strength concrete molded article by normal-pressure steam curing.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, the slump flow is large and the use of the vibrator is small, with the optimum combination of the raw materials. The present inventors have found that a high-strength lightweight concrete product having good properties and excellent physical properties can be obtained by normal-pressure steam curing without using high-temperature and high-pressure steam curing such as an autoclave, thereby forming the present invention.

That is, the production method according to claim 1 is characterized in that a binder consisting of cement and slag fine powder is mixed with a bone-dry specific gravity of 0.7.
人工 1.0 of artificial lightweight aggregate, and 0.50.51.2 wt% of melamine-based high-performance water reducing agent with respect to the binder, and adding and mixing this as an aqueous solution or with water. 20 to 100 per concrete 1m ³
High strength lightweight concrete with air-dry specific gravity of 1.0 to 1.5 compressive strength of 150 to 360 kgf / cm ² This is a method for producing a molded article.

[0007] Further, according to a second aspect of the present invention, a binder comprising cement and slag fine powder, and a bone-dry specific gravity of 1.2 to 1.8 are provided.
Mixed with the artificial lightweight aggregate from
A melamine-based high-performance water reducing agent of 5 to 1.2% by weight is used as an aqueous solution or added together with water, mixed with the mixture, mixed with 150 to 200 liters of fine air bubbles per m ³ of concrete, and molded. A method for producing a high-strength lightweight concrete molded product characterized by normal-pressure steam curing, wherein the molded product has an air-dry specific gravity of 1.4 to 1.5 and a compressive strength of 210 kgf / cm ² or more.

[0008] The production method of the present invention comprises three main steps: a kneading step of uniformly kneading the raw material and the air bubbles to obtain a lightweight concrete, a molding step of driving the mixture into a mold, and a step of performing normal-pressure steam curing. Consists of

First, in the first invention, as a first step, a binder composed of raw material cement and slag fine powder and an artificial lightweight aggregate having an absolute dry specific gravity of 0.7 to 1.0 are uniformly mixed. And, to this mixed material, the binder material weight of 0.
5 to 1.2 as an aqueous solution the weight percentage of melamine superplasticizers, or after the addition at the same time as the water, the bubbles were foamed by separately pre foaming machine, per concrete 1 m ³
20 to 100 l are mixed and evenly mixed to make lightweight concrete. The cells in the lightweight concrete are present as stable fine closed cells. The bubbles in this case are
The resin film-forming foaming liquid prepared using a foaming agent, a foam film stabilizer, a resin and water is supplied as foamed foam via a foaming machine. The artificial lightweight aggregate is a granulated artificial lightweight aggregate.

Table 1 shows an example of a preferable mixing ratio of the raw materials.
Shown in

[0011]

[Table 1] Water 212kgf / m ³ Cement 380 〃 (Binder) Slag fine powder 200 〃 () Lightweight aggregate 416 〃 Melamine-based high-performance water reducing agent 0.8% (% by weight based on binder) Bubbles 60 l / m ³

According to the mixing ratio shown in Table 1, the slump flow is large despite the small amount of water due to the fluidity of the slag fine powder and the addition of the melamine-based high-performance water reducing agent.
Also, the separation of materials is significantly reduced by the inclusion of air bubbles,
A high-strength lightweight concrete compact can be obtained.

The relationship between air-dry specific gravity and compressive strength using various existing aggregates is as shown in FIG. 1 (from “Lightweight Aggregate Concrete Handbook”). The intensity values obtained by experiment are shown by changing the values.

In the second step, the concrete uniformly mixed and mixed is gently poured into a mold by a method such as a tremy method or a pouring method. In this case, it is necessary to pay attention so that entrained air does not enter.

Finally, as a third step, after the concrete is poured into the formwork, normal pressure steam curing is performed. Curing time, concrete is poured into the formwork, pre-cured for 3-4 hours, then raised to 50-60 ° C over 3-4 hours,
Maintain the temperature of 50-60 ° C for 4-5 hours, then cool to room temperature over 4-5 hours. With this normal pressure steam curing,
Concrete strength can be quickly increased.

Next, in the second invention, as a first step, a binder composed of raw materials cement and slag fine powder and an artificial lightweight aggregate having a bone-dry specific gravity of 1.2 to 1.8 are uniformly mixed. Then, 0.5% of the weight of the binder is added to the binder.
As an aqueous solution of 1.2% by weight of melamine-based superplasticizers, or after the addition at the same time as the water, the bubbles were foamed by separately pre foaming machine, per concrete 1 m ³
150-200 liters mixed and evenly mixed, lightweight concrete
And As the artificial lightweight aggregate in this case, a non-granulated artificial lightweight aggregate obtained by crushing a rough stone, adjusting the particle size, and firing is used. In addition, as in the first aspect, the bubbles are bubbles formed by foaming a resin film-forming foaming liquid prepared using a foaming agent, a foam film stabilizer, a resin and water through a foaming machine. Supplied.

Table 2 shows an example of a preferable mixing ratio of the raw materials.
Shown in

[0018]

TABLE 2 Water 190kgf / m ³ Cement 370 〃 (binder) slag 225 〃 (〃) natural sand 65 〃 lightweight aggregate 643 〃 melamine superplasticizers 0.8% (wt% with respect to binder) bubble 170 l / m ³

According to the mixing ratio in Table 1, the slump flow is large despite the small amount of water due to the flowability of the slag fine powder and the addition of the melamine-based high-performance water reducing agent.
Also, the separation of materials is significantly reduced by the inclusion of air bubbles,
Since the air-drying specific gravity of the molded product is 1.4 to 1.5, a stable, high-strength, lightweight concrete molded product can be always obtained.

The relationship between the air-dry specific gravity and the compressive strength of a molded product using a non-granulated artificial lightweight aggregate is as shown in FIG. 2. In FIG. The intensity values obtained by the experiment are shown.

In the next second step, as in the first invention, the uniformly kneaded concrete is gently poured into a mold by a method such as a toremy method or an injection method. In this case, it is necessary to take care so that the entrained air does not enter.

Finally, as a third step, after the concrete is poured into a mold, normal pressure steam curing is performed. Curing time was 50-60 after the concrete was poured into a mold and pre-cultured for 3-4 hours, and then 3-4 hours ^. C to 50-60 ^. C temperature for 4-5 hours, then
Cool down to room temperature over 5 hours. By the normal pressure steam curing, the strength of the concrete can be quickly increased.

[0023]

The present invention will be described below in more detail with reference to Examples and Comparative Examples.

Example 1 380 parts by weight of cement (manufactured by Mitsubishi Mining) and 200 parts by weight of slag fine powder (manufactured by Nippon Steel Chemical) were simultaneously charged into a mixer and mixed for 30 seconds, and then 416 parts by weight of artificial lightweight aggregate (manufactured by Uchiyama Advance) After mixing for 20 seconds, 216.6 parts by weight of an aqueous solution containing 0.8% by weight of a melamine-based high-performance water reducing agent (manufactured by Dainippon Ink and Chemicals, Inc.) with respect to the binder is added and mixed for 1 minute and 30 seconds. After mixing this with 60 l of foamed bubbles,
After kneading for 30 minutes, pour it into the mold, and after molding,
Preliminary 4 hours, normal temperature steam curing, temperature rise 3 hours 55 ° C. 5 hours, temperature fall 4 hours curing, molding was performed to obtain a lightweight concrete molded body.

Comparative Examples 1 and 2 In Comparative Example 1, the amount of bubbles in Example 1 was increased, and in Comparative Example 2, the bubbles in Example 1 were omitted. The molding procedure and method were the same as in Example 1. It was implemented. The formulation is shown in Table 3.

[0026]

[Table 3]

Comparative Example 3 In Comparative Example 3, the bonding material of Example 1 was used as a cement alone and bubbles were omitted, and the molding procedure and method were performed according to Example 1. The formulation is shown in Table 4.

The results of the experiment are as shown in Table 4.

[0029]

[Table 4]

As described above, the lightweight concrete molded article obtained according to the first aspect of the invention is lightweight and excellent in strength, and is suitable for various uses as a material for buildings and structures.

Example 2 370 parts by weight of cement (manufactured by Mitsubishi Mining) and 225 parts by weight of slag fine powder (manufactured by Nippon Steel Chemical) were simultaneously charged into a mixer and mixed for 30 seconds. After that, 65 parts by weight of natural sand, artificial lightweight aggregate (Japan) After adding 643 parts by weight and mixing for 20 seconds, add about 194.8 parts by weight of an aqueous solution containing about 0.8% by weight of a melamine-based high-performance water reducing agent (manufactured by Dainippon Ink and Chemicals) based on the binder. And mix for 1 minute 30 seconds. Pre-foamed bubbles
After mixing 170 l, the mixture was kneaded for 2 minutes and 30 seconds and then poured into a mold. After completion of molding, curing was carried out for 4 hours in advance, 5 hours at 55 ° C. as a normal temperature steam curing, 55 hours at 55 ° C., and 4 hours of cooling. Into a lightweight concrete compact.

Comparative Example 1 In Comparative Example 1, a melamine-based high-performance water reducing agent (manufactured by Dainippon Ink and Chemicals) of Example 2 was used as a naphthalene-based high-performance water reducing agent (Mighty 150: manufactured by Kao Soap Co., Ltd.). The procedure and method were performed according to the second embodiment. The formulation is shown in Table 5.

[0033]

[Table 5]

Comparative Examples 2 and 3 Comparative Example 2 used the binder of Example 2 as a cement alone, and Comparative Example 3 used the melamine-based high-performance water reducing agent (manufactured by Dainippon Ink and Chemicals, Ltd.) of Comparative Example 2 as naphthalene. A high performance water reducing agent (Mighty 150: manufactured by Kao Soap Co., Ltd.) was used, and the molding procedure and method were carried out in accordance with Example 2. The formulation is shown in Table 5.

The results of the experiment are as shown in Table 6.

[0036]

[Table 6]

As described above, the lightweight concrete molded article obtained by the second invention is lightweight and excellent in strength, and is suitable for various uses as a material for buildings and structures.

[0038]

As described above, according to the present invention,
A stable, high-strength, lightweight concrete compact with the following advantages can be obtained.In addition to various properties that conventional lightweight and aerated concrete products do not have, in addition to large plates and lightweight concrete products with complex shapes. In addition to increasing the strength, it is possible not only to reduce the weight of the member but also to reduce the thickness of the member by increasing the strength.

1. The surface finish after casting can be easily ironed without separation of materials, and it is possible to use normal pressure steam curing without using high temperature and high pressure steam curing, thereby improving work efficiency. A product of uniform quality is obtained.

2. Even if it is lightweight, the strength is remarkably higher than that of conventional lightweight concrete, and a stable and high-quality product is always obtained, and the product has an aesthetic appearance without chipping or cracking of the product.

3. The high strength makes it possible to reduce the weight of the members, the structure of the building is reduced, and the overall weight is reduced, so that the foundation can be easily constructed and resources can be saved. It becomes possible.

4. Excellent freezing damage resistance due to the inclusion of fine closed cells.

[Brief description of the drawings]

FIG. 1 is a diagram showing a relationship between an air-dry specific gravity and a compressive strength of various aggregates.

FIG. 2 is a diagram showing a relationship between an air-dry specific gravity and a compressive strength of a molded body using a non-granulated artificial lightweight aggregate.

Continued on the front page (51) Int.Cl. ⁷ Identification code FI C04B 24:12) C04B 24:12) Z

Claims (2)

(57) [Claims] 1. A binder comprising cement and slag fine powder, and an artificial lightweight aggregate having an absolute dry specific gravity of 0.7 to 1.0,
Thereto, with 0.5 to 1.2% by weight of melamine-based superplasticizer with respect to binding material, which was added to and mixed with or water as an aqueous solution, to the mixture, the concrete 1 m ³
20 to 100 liters of fine air bubbles are mixed and molded.
A method for producing a high-strength lightweight concrete molded product having an air-drying specific gravity of 1.0 to 1.5 and a compressive strength of 150 to 360 kgf / cm ² , characterized by normal pressure steam curing. 2. A binder comprising cement and slag fine powder and an artificial lightweight aggregate having an absolute dry specific gravity of 1.2 to 1.8,
Thereto, with 0.5 to 1.2% by weight of melamine-based superplasticizer with respect to binding material, which was added to and mixed with or water as an aqueous solution, to the mixture, the concrete 1 m ³
The air-drying specific gravity of the molded body is 1.4 to 1.5, and the compressive strength is 210 kgf / cm ² or more. A method for manufacturing a high-strength lightweight concrete molding.