JPH032826B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a lightweight aerated concrete composition that exhibits rapid hardening, high strength, and excellent moldability and mold release properties. In the present invention, the cellular concrete composition includes not only ordinary concrete but also paste and mortar. Generally, ordinary aerated concrete is called autoclaved aerated concrete (ALC).
When comparing its performance with ALC, it has lower molding efficiency in industrial production than ALC, and
It has the disadvantage of being lower in strength than ALC. In order to improve the above-mentioned drawbacks, the inventors of the present invention have continued to conduct intensive research and study on rapid hardening high-strength concrete compositions. As a result, in a cellular concrete composition that is not particularly subjected to autoclave treatment, ordinary portland cement, jet cement, and halloysite are used. It has been discovered that by blending with a halloysite derivative or a halloysite derivative, a cellular concrete composition that exhibits rapid hardening, high strength, good moldability and mold releasability, and is excellent in industrial productivity can be obtained. It has been reached. That is, when ordinary Portland cement is foamed by the preform method or the premix method, setting is extremely slow and it takes a long time to release from the mold, resulting in extremely poor industrial productivity. However, adding jet cement to normal Portland cement to promote setting causes poor hardening. For example, according to a report by Onoda Cement Co., Ltd. Central Research Institute,
It has been announced that when jet cement is mixed, the balance of mineral composition values such as aluminate and gypsum, which were strictly controlled during the production of jet cement, is disrupted, resulting in abnormal setting and hardening. For this reason, it is prohibited to mix jet cement with ordinary Portland cement. Jet cement, which exhibits practical strength within 2 to 3 hours after water injection, develops its strength due to "ettringite" produced by the hydration reaction of C ₁₁ A ₇ CaF ₂ and gypsum, and the strength will not increase after the first day of age. It is said to occur due to the hydration reaction of the phase (C ₃ S),
When mixed with ordinary Portland cement, it is thought that the hydration reaction is inhibited, resulting in poor curing, but according to the findings of the present inventors, this tendency is even stronger in aerated concrete, and the hydration reaction is inhibited. This resulted in poor strength development.
The present inventors conducted various studies based on the above findings, and found that when halloysite or a halloysite derivative was added to a mixed cement of ordinary Portland cement and diet cement, the Mixed cement with 50-20 parts by weight of jet cement and 100 parts by weight
When 5 to 30 parts by weight of halloysite or halloysite derivatives are blended, the hydration reaction is unexpectedly promoted, strength is developed, moldability is improved, and mold releasability is significantly improved. This discovery led to the present invention. The present invention will be explained in more detail below. The cellular concrete composition according to the present invention is a cellular concrete composition produced by a preform method or a premix method, and contains ordinary Portland cement, jet cement, and halloysite or a halloysite derivative. In this case, the aerated concrete composition of the present invention includes 50 to 80 parts by weight of ordinary Portland cement, especially 60 to 80 parts by weight, and 50 to 20 parts by weight of jet cement.
Mixed cement 100 parts by weight, especially 40-20 parts by weight
It is preferable to mix 5 to 30 parts by weight, particularly 10 to 20 parts by weight of halloysite or a halloysite derivative. In addition, halloysite (AlO ₃・2SiO ₂・4H ₂ O)
Although both a 7 Å anhydride and a 10 Å hydrate can be used, it is more preferable to use a 7 Å anhydride. In addition, as a halloysite derivative, barium halloysite (BaO・Al ₂ O ₃・
3SiO ₂ .nH ₂ O (where n = 2 to 10) can be suitably used, but ordinary sodium A type zeolite or the like may also be used. The aerated concrete composition of the present invention is formed by mixing the above components and adding ordinary foaming agents such as proteins and surfactants.
In the present application, components such as a grouting agent, a rust preventive agent, a coloring agent, a waterproofing agent, an organic polymer material, and the like may be added as appropriate. In addition, in the present invention, fine powdered silica sand is mixed with cement as a fine aggregate for the purpose of imparting long-term strength.
It can be added in an amount of 5 to 15 parts per 100 parts by weight. That is, normally fine powdered silica sand has a tendency to deteriorate hardening and mold releasability, but when used in combination with halloysite in the present invention, it enhances the mold releasability of foamed concrete products, significantly improves productivity, and improves the long-term stability of concrete. It is extremely effective in developing hardness. As mentioned above, the aerated concrete composition of the present invention exhibits rapid hardening and high strength by blending halloysite or a halloysite derivative into a mixed cement of ordinary Portland cement and jet cement, and has excellent moldability and releasability. For example, when a mixed cement of 80 parts by weight of ordinary Portland cement and 20 parts by weight of jet cement is poured into aerated concrete, if it is removed from the mold after 50 to 90 minutes, it will not harden sufficiently and the concrete will be removed from the mold. Although it becomes defective,
If 10 to 20 parts by weight of halloysite is mixed with 100 parts by weight of the above mixed cement and poured into aerated concrete in the same way, it can be easily demolded after 50 to 90 minutes, and the mold release performance is remarkable. This improves factory productivity. Although the principle behind such remarkable effectiveness of halloysite is not clear, it is presumed that it is due to the reaction between the OH group of the halloysite component and lime. In any case, in the case of no addition of halloysite, concrete adheres to the mold during demolding, resulting in poor molding without a clean surface. The bubbles become significantly smaller and more uniform. In other words, when foamed concrete is made by putting a foaming agent into mortar, and when it is poured and removed from the mold, if halloysite is not added, the surface will be heavily scattered with foam molds, but if halloysite is added, foam concrete will be formed. The foam becomes small particles, and the appearance of the foamed concrete surface shows a small, uniform, round foamed surface. Therefore, it has excellent moldability and mold release properties, and this has a subtle effect on the development of concrete strength. It has a positive impact and also contributes significantly to industrial productivity. EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples. Example 1 Halloysite reaction product BaO Al ₂ O ₃ obtained by reacting 650 g of ordinary Portland cement, 350 g of jet cement, and halloysite with barium hydroxide at about 100°C for 15 minutes to 2 hours and then washing with water.
_3SiO2・_nH2O (however, n=2~10) (250mesh all
Place 100g of pass) in a dice mixer, mix thoroughly, and add water reducing agent (Mighty 150,
Pour 8g (manufactured by Kao Soap Co., Ltd.) into a solution prepared by dissolving 178ml of water and mix well. A foam material made by foaming a special protein and a 1% aqueous surfactant solution using a foaming machine is put into this mortar and kneaded, and this operation is continued until the bulk specific gravity becomes about 0.7. after that,
The mixture was poured into three molds each measuring 4 x 4 x 16 cm. When the mold was removed after 50 minutes, it was removed cleanly without any damage or adhesion (the mold release oil was Noxon).
C11 (the same applies hereafter). Weight immediately after demolding (3
The average value of books) was 179.6g. When this was soaked in water for 7 days and then air-dried, the compressive strength was measured.
The average weight was 38.1 Kg/cm ² , and the average bulk specific gravity was 0.68. The appearance of the foam showed uniform small bubbles with a round foam surface. Example 2 650g of ordinary Portland cement, 350g of jet cement, 100g of halloysite and fine silica sand A
(250mesh all pass) 100g was placed in a dice mixer, thoroughly mixed, and then processed and cast in the same manner as in Example 1. When the mold was removed after 50 minutes, it was removed cleanly without any damage or adhesion. The weight (average value of three pieces) immediately after demolding was 234.3 g. This was immersed in water for 5 days and then air-dried to measure the compressive strength, which showed an average of 51.6 kg/cm ² and an average bulk specific gravity of 0.88. The appearance of the foam was that it had very small bubbles and a round, uniform foam surface compared to a cellular concrete product without the addition of halloysite. Example 3 650 g of ordinary Portland cement, 350 g of jet cement, and 200 g of halloysite were placed in a dice mixer, thoroughly mixed, and then treated in the same manner as in Example 1 and cast. When the mold was removed after 50 minutes, it was removed cleanly without any damage or adhesion. The weight (average value of three pieces) immediately after demolding was 176.0 g. After curing for one week, the average compressive strength was 30.2 Kg/cm ² and the average bulk specific gravity was 0.69. In addition, the appearance of the foam showed that the foam was smaller and more homogeneous than that of the foam without the addition of halloysite. Example 4 800 g of ordinary Portland cement, 200 g of jet cement, 100 g of halloysite, and fine silica sand A
(250mesh all pass) 100g was placed in a dice mixer, thoroughly mixed, and then processed and cast in the same manner as in Example 1. When the mold was removed after 90 minutes, it was removed cleanly without any damage or adhesion. The weight (average value of three pieces) immediately after demolding was 178.0 g. When this was soaked in water for 6 days and air-dried, the average compressive strength was 24.7.
Kg/cm ² and bulk specific gravity was 0.68. Note that the bubbles on the appearance of the foam were small. Example 5 600 g of ordinary Portland cement, 400 g of jet cement, and 100 g of halloysite were placed in a dice mixer, thoroughly mixed, and then treated in the same manner as in Example 1 and cast. When the mold was removed after 50 minutes, it was removed cleanly without any damage or adhesion. The weight (average value of three pieces) immediately after demolding was 168.3 g. After curing for about one week, the average compressive strength was 37.5 Kg/cm ² and the bulk specific gravity was 0.68. Comparative Example 700 g of ordinary Portland cement and 300 g of jet cement were placed in a dice mixer, mixed thoroughly, and then treated in the same manner as in Example 1 and cast. When the molds were removed after 50 minutes, there was concrete adhesion around the top of the molds, and all three molds were defective. Weight immediately after demolding (average value of 3 pieces) is 168.3g
It was hot. The compressive strength after air-drying is the average
The weight was 28.4Kg/cm ² and the bulk specific gravity was 0.69. The appearance of the foam was that the bubbles on the surface were large and irregular in size. In addition, the weight of the aerated concrete of the above examples and comparative examples immediately after demolding, the weight after air drying for 7 to 10 days, the bulk specific gravity after air drying, the compressive strength after air drying, and the compressive strength after air drying. Shown in the table below.

【table】

[Table] From the above results, it was confirmed that the aerated concrete composition of the present invention has high strength and excellent moldability and mold release properties. On the other hand, the aerated concrete composition of the comparative example which did not contain halloysite had poor moldability and mold release properties.

Claims (1)

[Scope of Claims] 1. A cellular concrete composition produced by a preform method or a premix method, characterized in that it contains ordinary Portland cement, jet cement, and halloysite or a halloysite derivative. . 2 Mixed cement of 50 to 80 parts by weight of ordinary Portland cement and 50 to 20 parts by weight of jet cement
The aerated concrete composition according to claim 1, which contains 5 to 30 parts by weight of halloysite or a halloysite derivative per 100 parts by weight.