JP2527593B2 - Lightweight concrete panel and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION a. Field of Industrial Application The present invention relates to lightweight cellular concrete (hereinafter, “ALC”).
The present invention relates to a lightweight concrete panel using particles and a method for producing the same.

b. Conventional technology Conventionally, ALC panels have been widely used for weight reduction of buildings, heat insulation and fire resistance.

This ALC panel is generally manufactured by crushing raw coal and silica, which are the main raw materials, and mixing them at the required mixing ratio with water and a foaming agent (for example, aluminum powder) to form a slurry. Then, inject this into a mold with reinforcing reinforcing bars placed in it, and then cut the cake-solidified molded body into a predetermined size and shape with a cutting machine, and perform autoclave curing in the final step. It is hardened and manufactured by.

c. Problems to be Solved by the Invention However, the ALC panel manufactured by the above-mentioned manufacturing method has the following drawbacks.

ALC uses a foaming agent to generate bubbles, which is cured in an autoclave to cure, but the bubble generation state differs depending on the properties of the raw materials, the composition, temperature conditions, etc. in the bubble generation process. Therefore, it is difficult to obtain a uniform foamed product due to differences in specific gravity, compressive strength and the like.

Also, ALC is manufactured by increasing the volume by the foaming action of the foaming agent, but it is unavoidable that a cavity is created in the part on the back side of the reinforcing bar in the foaming direction. The rebar cannot be fully restrained inside it.

Furthermore, since the ALC panel is cut with a piano wire or the like in a semi-cured state before curing in an autoclave, the cut surface is not smooth, which is not preferable in terms of aesthetics.

On the other hand, in recent years, buildings have not been standardized due to effective use of land, sunlight, energy saving, and aesthetics, etc.
With the demand for panels, the current situation is to cut the ALC panel manufactured by the above-mentioned manufacturing method to the required dimensions by secondary processing to meet the demand. As a result, a large amount of cutting loss occurs, and how to treat this waste material is an important issue both economically and in terms of pollution.

The present invention has been made in view of the above-mentioned results of the ACL panel, and an object thereof is to provide a lightweight concrete panel capable of solving the problems of the ALC panel and a manufacturing method thereof without impairing the effective properties of the ALC. To do.

d. Means for Solving the Problems The present invention, in order to solve the above-mentioned problems, has a gist of bonding light-weight cellular concrete particles crushed to have a maximum particle diameter of 10 mm or less with Portland cement and styrene-acrylic resin. Lightweight concrete panel molded by, and lightweight cellular concrete particles crushed to a maximum particle size of 10 mm or less, water is mixed with Portland cement and styrene-acrylic resin as an adhesive, and the mixture is used as a formwork. It is a method of manufacturing a lightweight concrete panel that is manufactured by applying pressure and curing with high temperature and high pressure steam after casting.

e. Examples Hereinafter, the lightweight concrete panel of the present invention and the method for producing the same will be described in detail with reference to Examples.

Example (1) ALC material is ground with a jaw crusher or the like to prepare four types of samples having different maximum particle sizes.

Sample (A) has a maximum particle diameter of 15 mm, sample (B) has a diameter of 10 mm, sample (C) has a diameter of 5 mm, and sample (D) has a diameter of 1.2 mm, and the particle size distribution is shown in Table 1.

ALC particles with the above particle diameters were thoroughly mixed in the mixing ratio shown in Table 2, and after being placed in a mold, various pressures were applied with an Amsler universal testing machine, and after pressurization, high-temperature high-pressure steam curing was carried out by a conventional method. It carried out and compared various properties.

 The test results are shown in Table 3.

As shown in Table 3, in the mixture properties after kneading, the mixture using ALC particles (A) and (B) had coarse particles, and thus the mixture after kneading had stickiness, but ALC particles ( The one using D) has almost no stickiness and is "dry"
It was in the state of.

In addition, the mixture using ALC particles (D) had good workability in placing into a mold and did not adhere to a pressure plate after pressure molding, and had good workability, whereas ALC particles ( A), (B)
As described above, since the mixture of (1) and (2) was sticky, it was difficult to place it in the mixture, and a large amount of it adhered to the pressure plate, causing a problem in workability.

The smoothness of the panel surface after pressurization was the smallest with a small particle size, that is, ALC particles (D) were used, but even with ALC particles (C) and (B), It was found that flattening was achieved by increasing the pressure stress. However, with the ALC particles (A), it was difficult to obtain a sufficiently smooth panel product even if the pressure stress was increased.

From the above, it was found that in order to obtain at least a smooth lightweight concrete panel, it is necessary to use lightweight cellular concrete particles crushed to have a maximum particle size of 10 mm or less.

Example (2) Next, using ALC particles (D), the compounding amounts of ALC particles, Portland cement and styrene-acrylic resin were gradually changed, and otherwise the same as in Example (1) above. A panel was manufactured and its properties were examined.

 The test results are shown in Table 4.

When the amount of styrene-acrylic resin is large (20% by weight or more) and the amount of Portland cement is large, the tackiness of the mixture after kneading is increased, and the castability and demoldability on the mold are extremely poor,
It became impossible to mold.

On the other hand, in the condition that the resin was not added and the amount of Portland cement was small, the mixture was very good with excessive tackiness in the castability to the mold, but the mold release property of the mixture itself. Due to insufficient strength, there was a problem that demolding was difficult.

The amount of ALC particles blended was changed with respect to changes in Portland cement and styrene-acrylic resin, but when the amount of ALC particles is small, the effective properties of ALC particles are impaired, which is not preferable.

From the above results, the compounding amount of Portland cement and styrene-acrylic resin used as the adhesive for ALC particles is preferably about 20% by weight of the total solid amount of the former and about 5 to 10% by weight of the latter. It was also found that 60 to 75% by weight is suitable for ALC particles.

The test sample of Example (3) was prepared at the compounding ratio of Example (1) described above.
ALC particles (D) were used for pressure molding, and each was cured by two methods of high temperature and high pressure steam curing and indoor air curing. After that, using a diamond cutter, the specimen (3 cm x 3 cm x 15 cm)
Was prepared, and the water content of the specimen subjected to high temperature and high pressure steam curing was adjusted to a water content of 10 ± 2% by weight, and a strength test was conducted.

On the other hand, the sample that was cured by room air was subjected to a strength test without cutting the water content after cutting the specimen into the same size as above.

For the test, a bending test was performed using an autograph AG-A type manufactured by Shimadzu Corporation, and then a compression test was performed on the same specimen.

 The test results are shown in Table 5.

From the table, the one subjected to high temperature and high pressure steam curing was superior to the current ALC panel in both bending and compressive strength, and the bending strength was about 3 times and the compressive strength was about 2 times higher in some cases.

On the other hand, the indoor air-curing type had only about the same performance as the current ALC panel.

From this, it was found that high temperature and high pressure steam curing was required to obtain a panel with high strength.

Example (4) Two types of sample (D) and sample (B) as types of ALC particles
The effects of varying the ratio (w / s) of water to the total solid content were compared and compared mainly with the workability of pressure molding.

 The test results are shown in Table 6.

The results of the test are, as shown in Table 6, ALC particles (D)
When using, the workability such as the ability to cast the mixture into the specified mold, the smoothness of the product surface after pressurization, and the mold removability of the mold (w / s) is 35% by weight. Was the best case.

On the other hand, when ALC particles (B) were used, the case where (w / s) was 30% by weight was excellent.

Example (5) As the types of reinforcing bars used for the test body, 1.3 mmφ fine mesh (manufactured by Igeta Wire Mesh Co., Ltd.), welded wire mesh 2.6 mm
φ and ordinary iron wire 9mmφ were used. As for the type of ALC particles, the above-mentioned two types (D) and (B) of ALC particles were used, and a combination experiment was carried out with reference to the above-mentioned examples regarding the amount of placement on the mold and the pressing stress.

The test body should be 1/2 of the amount of one time the mixture is placed in the formwork.
, The sample was flattened, the reinforced anti-corrosion reinforcing bar was placed thereon, and the remaining half sample of the mixture was laminated and cast, followed by pressure molding.

The test body was compared with the commercially available ALC regarding the smoothness of the product surface and the presence or absence of cavities near the reinforcing bars.

 The test results are shown in Table 7.

As is clear from Table 7, in Test No. 1, a fine mesh of 1.3 mmφ was inserted as a reinforcing bar in the center of the member, and the pressure stress of the mixture was 9.2 kgf / cm ² from the above examples. It was As a result, the panel thickness after pressing was 23.5 mm, and the smoothness of the product surface was much flatter than that of ALC, and there were no cavities near the reinforcing bars.

Test No. 2 used a welded wire mesh of 2.6 mmφ as a reinforcing bar. The weight of the mixture is 1.4 kg and the stress is 18.4 kgf.
/ cm ^{2 was} added. As a result, the panel thickness after pressurization was 50 mm, and the smoothness of the product and the absence of cavities near the reinforcing bars were obtained compared to the ALC of the control example.

Next, tests No. 3 to No. 5 using ordinary rebar 9 mmφ were conducted by changing the amount of driving into the mold or changing the pressurizing stress based on test No. 1. The test result was good as in the above.

From the above test results, it was found that the manufacturing method according to the present invention can significantly improve the problem that cavities are formed in the vicinity of the reinforcing reinforcing bars of ALC and can provide a lightweight concrete panel having excellent performance.

Example (6) Constant pressure stress (2.3 kgf / cm ^{2 with} respect to the cross-sectional area of the test piece)
Then, the dimensional thickness of the product after pressurization, the smoothness of the product surface and the absolute dry specific gravity were compared and examined when the amount of casting on the mold was changed.

 The test results are shown in Table 8.

From the table, if the pressing stress is constant and the amount of placement on the form is changed,
It was found that products with different thicknesses can be manufactured, and in this case, the absolute dry specific gravity of the material is almost constant.

It was also found that the smoothness of the product surface was inferior as the amount of casting of the mixture increased when the pressure stress was constant.

Next, it was found that it is possible to manufacture a product having a member size of 100 mm or more by significantly increasing the amount of the mixture to be cast and increasing the pressure stress in consideration of the surface smoothness of the product. (See FIG. 9).

Example (7) The panel thickness of the product, the smoothness of the product surface, and the absolute dry specific gravity were examined when the amount of the mixture cast was kept constant and the pressure stress was changed.

 The test results are shown in Table 10.

When the pressure stress is changed within the range of 1.2 kgf / cm ^{2 to} 83 kgf / m ² ,
The greater the pressure stress, the thinner the panel thickness.

At this time, of course, the absolute dry specific gravity of the product also increases as the pressing stress increases. On the other hand, the smoothness of the product surface becomes flat when the pressure stress is 4.6 kgf / m ² and becomes 9.2 kgf / m ²
With the above, a completely flat panel could be manufactured.

As described above, according to the various examples described above, a lightweight concrete panel having a uniform product specific gravity and a smooth product surface without impairing the effective properties of ALC and the manufacturing method thereof have a maximum particle diameter of 10 mm or less. Milled lightweight cellular concrete particles with Portland cement and styrene-
Lightweight concrete panel molded by bonding with acrylic resin, and lightweight cellular concrete particles crushed to a maximum particle size of 10 mm or less, and Portland cement as an adhesive and styrene-mixing water with water, and mixing, It was found that the method is for producing a lightweight concrete panel produced by pouring the mixture into a mold and then applying pressure and curing it at high temperature and high pressure.

The lightweight cellular concrete particles crushed to have a maximum particle size of 10 mm or less may be a waste material of the ALC panel, but an ALC block is manufactured as a raw material for the lightweight concrete panel according to the present invention, and the block is It may be crushed and used as a raw material.

f. Effect of the invention The lightweight concrete panel according to the present invention is formed by adhering lightweight cellular concrete particles crushed to a maximum particle size of 10 mm or less with Portland cement and styrene-acrylic resin, and thus is lightweight. It is possible to obtain a lightweight concrete panel having a uniform product specific gravity and excellent strength, without impairing the effective properties of cellular concrete, that is, the lightness, the heat insulating property and the like.

Further, the method for producing a lightweight concrete panel according to the present invention is a lightweight cellular concrete particle crushed to a maximum particle size of 10 mm or less, and water is added to Portland cement and styrene-acrylic resin as an adhesive to mix the mixture. Since it is manufactured by placing it in a formwork, pressurizing it, and curing it at high temperature and high pressure steam, it has excellent smoothness on the surface of the product, and even when reinforcing bar is inserted inside, the material of the reinforcing bar is Is sufficiently adhered, and it is possible to manufacture panels with various product thicknesses (about 10 mm to 100 mm).

Claims (4)

(57) [Claims] 1. A lightweight concrete panel characterized by being formed by adhering lightweight cellular concrete particles crushed to a maximum particle size of 10 mm or less with Portland cement and styrene-acrylic resin. 2. The crushed lightweight cellular concrete particles account for 60% by weight or more of the total solid content, and Portland cement accounts for 20%.
The lightweight concrete panel according to claim 1, wherein the lightweight concrete panel contains at least 5% by weight of styrene-acrylic resin. 3. Light weight concrete concrete particles crushed to a maximum particle size of 10 mm or less, and Portland cement and styrene-acrylic resin as an adhesive are mixed with water, and the mixture is cast into a mold, A method for producing a lightweight concrete panel, which is characterized in that it is produced by pressurizing and curing at high temperature and high pressure steam. 4. The crushed lightweight cellular concrete particles account for 60% by weight or more of the total solid content, and Portland cement accounts for 20%.
The method for producing a lightweight concrete panel according to claim 3, wherein the mixture is at least 5% by weight and at least 5% by weight of styrene-acrylic resin.