JP2697745B2 - Lightweight cellular concrete composition and method for producing same using same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) The present invention relates to a steam-cured lightweight cellular concrete (hereinafter, referred to as "cellular concrete").
ALC) and a method for producing the same concrete structure using the same.

(Prior art) Conventionally, when manufacturing an ALC structure, a calcareous raw material composed of cement and lime or a calcareous raw material composed only of lime, and a siliceous raw material composed of silica stone or silica sand,
After a slurry is formed by adding an additive to a composition containing water as a main raw material, aluminum powder is further added, foamed and semi-plasticized, and then transferred to an autoclave, under high temperature and high pressure. The product has been steam cured.

(Problems to be Solved by the Invention) However, ALC, which is often used as a building material basically, is required to have the required characteristics and to be as low as possible in price. .

For the purpose of solving these problems, it has been proposed to raise the autoclave curing temperature in the ALC manufacturing process.However, this method requires a large amount of money to improve the equipment in order to raise the autoclave curing temperature. As a result, the cost of fuel consumed for the purpose of heating will also increase, and the industry has demanded the emergence of more efficient ALC production means.

The present invention solves the above-mentioned problems by reducing the time required for the autoclave curing treatment while using existing facilities,
Required characteristics of the structure (compressive strength specified in JIS A, 5416,
It is an object of the present invention to provide a composition which can sufficiently satisfy the absolute dryness specific gravity, flexural strength, rate of change in length, and heat insulating property, and a method for producing an ALC structure using the composition.

(Means for Solving the Problems) The present inventors have conducted various studies for the purpose of solving the above problems, and found that amorphous silica was previously adjusted so as to be dissolved at a ratio of 200 ppm or more and 3,000 ppm or less. Prepare the aqueous solution
It was found that the above-mentioned problem was solved by using the slaked lime obtained by digesting the aqueous solution after the aqueous solution was sufficiently stirred and then charged for a predetermined period of time to maintain it for a predetermined time as a calcareous raw material for ALC. Things. That is, the present invention relates to a lightweight cellular concrete composition comprising a calcareous raw material composed of cement and lime or a calcareous raw material composed only of lime, a siliceous raw material composed of silica stone or silica sand, and water as main raw materials. Part or all of the raw material is slaked lime containing amorphous silica, and the slaked lime is slaked lime obtained by digesting quicklime using an aqueous solution, and the aqueous solution is 200 ppm or more and 3,000 ppm or less of amorphous silica. In order to obtain a lightweight cellular concrete composition characterized in that it is an aqueous solution prepared so as to include at a ratio of Obtaining an aqueous solution containing 200 ppm or more and 3,000 ppm or less of silica, adding calcareous raw material to the obtained aqueous solution to obtain slaked lime through digestion treatment, and adding siliceous raw material to the obtained slaked lime Preparing a cement composition, adding Al powder and water to the composition to form a slurry, injecting the slurry into a desired mold, semi-plasticizing, and then performing a steam curing treatment, comprising: And a method for manufacturing the structure.

The amorphous silica powder in the present invention refers to silica gel,
There are silica sol, white carbon (fine powder silica) and the like, and as a commercial product, for example, "Nipsil (Nipsil) LP"
(Manufactured by Nippon Silica Kogyo KK)].

(Action) Slaked lime obtained by digesting quick lime using an aqueous solution containing amorphous silica within the above range, which is employed in the present invention, is used for shortening the ALC autoclave curing treatment time. On the other hand, although it is not clear why it works effectively, a fine CSH gel is formed on the surface of slaked lime, and this is formed by tobermorite (tobermorite, CaSiO ₃ .H ₂ O) or CSH.
It acts as a crystal nucleus of silicate, or silicate ions form a layered structure of slaked lime, so that silicate ions dissolve, thereby promoting crystal growth of tobermorite and consequently ALC
It is presumed that the production time was greatly reduced.

In the present invention, amorphous silica-containing slaked lime is used as a calcareous raw material for ALC production, and amorphous silica in an aqueous solution used when adjusting the amorphous silica-containing slaked lime is 200 ppm or more. The reason for defining 3,000 ppm is that the effect of shortening the autoclave curing treatment time cannot be sufficiently expected when the amount of amorphous silica in the aqueous solution used for adjusting the slaked lime containing the amorphous silica is less than 200 ppm. Yes,
Also, even if the amount of amorphous silica in the aqueous solution used to adjust the above-mentioned amorphous silica-containing slaked lime exceeds 3,000 ppm, the degree of improvement in the effect of improving its properties stagnates. Not only that, but also the viscosity of the solution when adjusting the above-mentioned amorphous silica-containing slaked lime becomes unnecessarily high, which hinders the processing of raw materials.

Example 1 Amorphous silica (purity 94%) "70 g of hot water (may be cold water) at a temperature of 50 ° C prepared in a container made of FRP and" Nipseal LP "manufactured by Nippon Silica Industry Co., Ltd." To
An aqueous solution containing amorphous silica having a silicate ion concentration of 1000 ppm was prepared by adding 74 gr, and after sufficiently stirring the aqueous solution containing amorphous silica, 47 kg of quicklime containing 96.9% by weight of CaO was added, and then 24 hours 55 parts by weight of slaked lime obtained by subjecting it to digestion, and 64.8% by weight of CaO and S
A raw material composition comprising 4 parts by weight of Portland cement containing 21.5% by weight of iO ₂ and 41 parts by weight of silica containing 94.5% by weight of SiO ₂ is obtained. To 100 parts by weight of this composition, 0.06 parts by weight of Al powder and 65 parts by weight of water were added to form a slurry, and the slurry was 150 mm in width, 400 mm in length and 1 in height.
When poured into a 50 mm mold, foamed and cured, and cured at 180 ° C for 5 hours, the obtained product has good crystallinity of tobermorite, and conventionally cured for about 12 hours. It was found that tobermorite, which was not sufficiently formed, was formed within a short time. In addition, except that the concentration of the amorphous silica-containing aqueous solution and the digestion time when producing the slaked lime used in Example 1 were variously changed, the light air bubbles obtained in the same manner as in Example 1 were all used. Table 1 shows the results of an investigation on the crystallinity of tobermorite in lightweight cellular concrete accompanying the fluctuations in slaked lime production conditions for concrete. The results show that the present invention is superior. I have. More specifically, according to the present invention, good results of tobermorite crystallinity are expressed from a silicate concentration of 1,000 ppm, a digestion time of 0.5 hr and a curing time of 7 hr, and the same concentration of 3,000 ppm is reduced to 5 hr per digestion time of 1 hr. ing. These results indicate that the conventional absence of amorphous silica is much more advantageous than the one that spent 12 hours of curing time under the same conditions.

Example 2 To 70 L of warm water at a temperature of 50 ° C. prepared in a container made of FRP, 74 gr of amorphous silica (purity 94%) “Nipsil LP“ manufactured by Nippon Silica Co., Ltd. ”” was added. An amorphous silica-containing aqueous solution having a silicate ion concentration of 1,000 ppm is prepared, and the amorphous silica-containing aqueous solution is sufficiently stirred. Then, 47 kg of quicklime containing 96.9% by weight of CaO is added, and then left for 24 hours. Slaked lime obtained by processing
A raw material composition comprising 41 parts by weight and 59 parts by weight of silica containing 94.5% by weight of SiO ₂ is obtained. To 100 parts by weight of this composition, 0.06 parts by weight of Al powder and 65 parts by weight of water were added to form a slurry, and the slurry was 150 mm in width, 400 mm in length,
After pouring into a 150 mm height mold, it is foamed and cured, 180 ° C
When the curing treatment was performed for 5 hours, the obtained product had good crystallinity of tobermorite, and tobermorite, which had not been sufficiently formed even in the conventional curing treatment of about 12 hours, was quickly cured. It was found to be formed.

Example 3 To 70 liters of hot water at a temperature of 50 ° C. prepared in a container made of FRP, 74 gr of amorphous silica (purity 94%) “trade name: NIPSEAL LP“ manufactured by Nippon Silica Co., Ltd. ”” was added. An amorphous silica-containing aqueous solution having a silicate ion concentration of 1000 ppm was prepared, and the amorphous silica-containing aqueous solution was sufficiently stirred. Then, 47 kg of quicklime containing 96.9% by weight of CaO was added, followed by 24 hours of digestion treatment. Slaked lime obtained by applying
And 22 parts by weight, obtain a CaO content of the quicklime 16 parts by weight of SiO ₂ minutes containing 96.9 wt% containing 94.5 wt% silica 62 parts by weight as a raw material composition composed of. To 100 parts by weight of this composition, 0.06 parts by weight of Al powder and 65 parts by weight of water were added to form a slurry, and this slurry was 150 mm wide, 400 mm long, and 150 mm high.
After pouring into a mold of mm, it is foamed and hardened.
When subjected to the curing treatment for a long time, the obtained product has good crystallinity of tobermorite, and tobermorite which was not sufficiently formed even in the conventional curing treatment for about 12 hours is formed in a short time The thing became clear.

As described above, when the present invention is practiced, it becomes clear that tobermorite crystals, which are said to greatly enhance the product characteristics, are formed in a lightweight cellular concrete product in a short time. In the manufacturing process of lightweight cellular concrete, it has been proved that the time required for manufacturing products, which is said to greatly contribute to cost reduction, can be easily reduced, and the effect thereof also increases.

(Effects of the Invention) As described above, according to the present invention, it is possible to shorten the autoclave curing time of a lightweight cellular concrete structure while using existing facilities, and to increase the suitability of lightweight cellular concrete. There is.

Claims (3)

(57) [Claims] 1. A lightweight cellular concrete composition comprising a calcareous raw material composed of cement and lime or a calcareous raw material composed only of lime, a siliceous raw material composed of silica stone or silica sand, and water as main raw materials. Part or all of the raw material is slaked lime containing amorphous silica, and the slaked lime is slaked lime obtained by digesting quicklime using an aqueous solution, and the aqueous solution is 200 ppm or more to 3,000 ppm or less of amorphous silica. A lightweight cellular concrete composition, characterized in that it is an aqueous solution prepared so as to be contained in the ratio of: 2. Obtaining an aqueous solution containing amorphous silica in an amount of 200 ppm to 3,000 ppm by adding amorphous silica powder to water, and adding slaked lime to the resulting aqueous solution by adding a calcareous raw material to digestion treatment. Then, a siliceous raw material is added to the obtained slaked lime to prepare a raw material composition.Al powder and water are added to the composition to form a slurry, and this slurry is semi-plasticized by injection molding into a desired mold. A method for producing a lightweight cellular concrete structure, comprising performing a steam curing treatment. 3. The method according to claim 2, wherein the step of preparing the raw material powder comprises replacing a part of the calcareous raw material with cement.