JPS5919078B2 - Manufacturing method of lightweight cellular concrete - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing lightweight cellular concrete, which has a surface free of flakiness and brittleness, has medium hardness, and has extremely excellent water repellency and suitability for topcoating. It is something.

Lightweight aerated concrete that has been commercially available up to now has the disadvantage that it is inherently fragile due to a decrease in the bonding strength of the cement structure due to weight reduction, is powdery, and is easily chipped by nails or the like.

Also, because it is porous, it has extremely high water absorption, causing cracks and cracks due to frost damage.

When lightweight cellular concrete is used as a building material or for other purposes, a waterproof coating is usually applied to the surface of the base material, but even in such cases, due to the powdery nature of the base material, There were disadvantages such as poor adhesion and limited coating materials that could be used.

The present invention solves the disadvantages of lightweight cellular concrete by modifying it during the production process of lightweight cellular concrete, making the surface denser and harder, improving water repellency and topcoating without losing the characteristics unique to lightweight cellular concrete. The present invention aims to provide a method for producing high-strength, lightweight cellular concrete with excellent paintability.

In order to make use of the lightweight cement structure and improve its bonding strength, the present inventors preliminarily generated a cementitious gel structure, and then used a treatment agent consisting of a water-soluble silicate and an organic resin water dispersion. This objective was achieved by impregnating the steel with water followed by high temperature and high pressure steam curing.

The principle of the present invention can be considered as follows.

That is, by impregnating the cement slurry aggregates with the water-soluble silicate and organic resin aqueous dispersion, the silicate aqueous solution and the organic resin aqueous dispersion quickly permeate into the cement aggregates.

Water-soluble silicates are gelled by polyvalent metal ions such as Ca'' ions produced from cement, and tobermorite produced by high-temperature and high-pressure steam curing, as well as silica (such as quartz) and The silica gel precipitated by the valent metal ions is integrated to form a strong insoluble silicic acid surface layer.

Further, the organic resin aqueous dispersion fuses to the surface of the porous substrate under high temperature and high pressure conditions, forming a complex entangled with silicic acid.

Here, the reason for using a mixed solution of water-soluble silicate and organic resin aqueous dispersion is that the cement aggregates are treated with the pre-mixed solution as in the present invention, although the effects of each will be described later. This facilitates the permeability of the aqueous organic resin dispersion into the base material, and allows the water-soluble silicate and the aqueous organic resin dispersion to bond firmly and three-dimensionally to the surface layer of the aggregate under high temperature and high pressure curing. On the other hand, even if the water-soluble silicate and the organic resin aqueous dispersion are impregnated individually and separately to form a composite layer, they will not be entangled three-dimensionally as described above. This is because the desired effect cannot be expected because the desired surface layer cannot be obtained.

The reason why an aqueous organic resin dispersion is used in the present invention is that a water-soluble polymer reacts with an aqueous silicate solution, salts out and separates, and prevents the hardening of the base material in the autoclave, making it impossible to obtain the desired effect. It's for a reason.

This series of reactions progresses only during high-temperature, high-pressure steam curing, and through this reaction, a highly hard and hydrophobic organic resin creates a base material that has a dense surface, water repellency, and is suitable for topcoating. climb.

Lightweight aerated concrete is generally a water slurry of hydraulic powder made of a mixture of portland cement or calcareous raw materials and silicic acid raw materials, foamed with metal powder such as aluminum, or foamed with surfactants, protein decomposition products, etc. It is manufactured by foaming with a foaming agent or the like, then molding, and generally performing steam curing under high temperature and high pressure conditions of 160'C to 210C to impart strength.

The water-soluble silicate used in the present invention has the general formula M20
・A water-soluble silicate with n=1 to 10 represented by n5i02, an alkali metal silicate consisting of an alkali metal belonging to Group 1A of the periodic table and silicic acid, and a tertiary amine consisting of a tertiary amine and silicic acid. Examples include silicates, quaternary ammonium silicate consisting of quaternary ammonium and silicic acid, and guanidine silicate consisting of guanidine and silicic acid.

As alkali metal silicates, sodium silicate, potassium silicate, lithium silicate, cesium silicate, etc. can be used, and as tertiary amine silicates, triethanolamine silicate and quaternary ammonium silicates can be used. Tetraethanolammonium silicate and tetramethanolammonium silicate can be used.

These silicates may be used alone or in combination of two or more.

As the organic resin aqueous dispersion, known conventional emulsions such as styrene-butadiene emulsions, acrylic emulsions, and vinyl acetate emulsions, and microemulsions can be used.

In addition to these anionic surfactants, nonionic surfactants, cationic surfactants, and combination emulsions of these surfactants, water-soluble resins such as those with an acid value of 30 to
Acrylic emulsions, styrene-butadiene emulsions, vinyl acetate emulsions, with protective colloids containing water-soluble resins made water-soluble by neutralizing approximately 150 alkyd resins, acrylic resins, and maleated polybutadiene with ammonia and/or amines. Furthermore, self-emulsifying acrylic emulsions and alkyd emulsions into which hydrophilic groups such as carboxyl groups are introduced up to the water solubilization limit can also be used.

The processing agent of the present invention may contain auxiliary materials such as color pigments in addition to the above-mentioned components.

The treatment agent used in the present invention has a solid content weight ratio of water-soluble silicate and organic resin water dispersion of 100:0.5.
~5: Must consist of 100 items.

If the solid content weight ratio of water-soluble silicate and organic resin water dispersion is other than the above ratio, the silicate improves the hardness of the surface layer of the base material, or the organic resin improves both water repellency and suitability for overcoating. You cannot get a combined performance.

The concentration of the treatment agent is preferably in the range of about 3 to 45% by weight; if the concentration of the treatment agent is less than the lower limit concentration, the impregnation of the substrate surface is insufficient, and if it exceeds the upper limit, the treatment agent There are difficulties in keeping it stable.

The amount of the treatment agent impregnated into the lightweight aerated concrete aggregate is 10 to 1300 r per 1 d area of the concrete aggregate.
f? (processing agent solid content equivalent value) is desirable.

As the impregnation method in the present invention, it is possible to adopt any of the following methods: immersing the lightweight concrete aggregates in a treatment agent, or coating the surface of the aggregates with a brush, spray coating, roll coating, flow coating, or shower coating. .

In particular, when using the immersion method, the entire mold can be immersed in a treatment liquid before demolding, and the cement aggregate can be impregnated with the treatment liquid, and at the same time the mold can be demolded using the buoyancy of the treatment liquid.

According to this method, the treatment liquid can be uniformly impregnated over the entire surface of the aggregate, the treatment process is simplified, and the aggregate can be demolded even in a state of low strength, improving the rotation rate of mold use. Benefits include being able to

Incidentally, as a method of promoting the permeability of the treatment agent into the interior of the aggregate and the hydrothermal reaction, it is also possible to carry out the demolding in advance in water and then transfer it to the treatment liquid bath and immerse it.

After being impregnated with a processing agent by the method described above, a curing treatment is performed in high temperature and high pressure steam in an autoclave.

The present invention described above provides a method for producing high-strength lightweight cellular concrete. Next, in order to further embody the content of the present invention, the present invention will be described with reference to Examples.

In the examples, "parts" and "%" indicate parts by weight and % by weight, respectively.

Manufacturing Example of Cement Slurry Agglomerate Manufacturing Example 1 100 parts of a quick-setting cement raw material consisting of 40 parts of Portland cement, 30 parts of silica sand, 6.5 parts of alumina cement, and 1.3 parts of slaked lime was added to 0 parts of dodecylbenzenesulfonic acid sorter. .5 parts and 0.1 part of methyl cellulose (trade name: Hymetrose 90SH-4000, manufactured by Shin-Etsu Chemical Co., Ltd.) was poured into 60 parts of a foamed aqueous solution and mixed to obtain a specific gravity of 0.
．． Immediately after obtaining 86 cement slurry, 1010X
It was poured into a 10×40 mold, left to stand for 30 minutes, and then removed from the mold.

Production example 2 Lime mixture 35 consisting of 20 parts of slaked lime and 80 parts of quicklime
part, 65 parts of silica sand, and 0.06 parts of aluminum powder,
1 part of triethanolamine per 100 parts of lime mixture
, 5 parts and 50 parts of water were placed in a humid atmosphere adjusted to 40°C and 80% relative humidity in a 1010X10X
After pouring into a No. 40 formwork and leaving it for 4 hours, a coagulated body with a specific gravity of 0.75 was prepared. The cement body that protruded from the top of the formwork due to foaming was cut with a piano wire, and then the side frame was removed from the mold.

Example 1 The cement aggregate prepared in Production Example 1 was mixed with a 30% aqueous sodium silicate solution (M, R22, where M and R mean the molar ratio of the silicic acid component to the alkali component).

same as below. ), 4 parts of rubber latex emulsion (Cementex C: product of Obana Sangyo Co., Ltd.) (rubber latex component 35%) (processing agent solid content impregnated amount 1300 f/ff1), and then Take out the aggregate and heat it at 180°G, 1 ok/cr?
It was cured for 8 hours in a L autoclave.

The physical properties of this product in the air-dried state are shown in Table 1.

Example 2 20% tetraethanol ammonium silicate (M, R = 9.8) 1 was added to the cement aggregate prepared in Production Example 1.
0 Part o, 7 Krylic Emulsion (Freimar AC3
3: Impregnated with a treatment agent consisting of 4 parts (Rohm & Haas product) (solid content 45%) and 300 parts of tap water using a spray gun (treatment agent solid content impregnation amount 120 fi/rn:
), and then autoclaved for 8 hours at 180° C. in high-temperature, high-pressure steam at 10 kg/crtt.

The physical properties of this product in the air-dried state are shown in Table 1.

Example 3 To the cement aggregate prepared in Production Example 2, 80 parts of a 20% potassium silicate aqueous solution (M, R = 23.5) and 20 parts of a 20% lithium silicate aqueous solution (M, R = 7.5) were added. 100 parts of a mixture of
), 600 parts of tap water, and 5 parts of titanium oxide (Titanium White RK: Teikoku Kako Co., Ltd. product). minutes) Impregnation, then 180℃, 10kg/crI
The sample was autoclaved for 8 hours in high-temperature, high-pressure steam.

The physical properties of this product in the air-dried state are shown in Table 1.

Example 4 The cement aggregate prepared in Production Example 2 was mixed with 100 parts of a 20% lithium silicate aqueous solution (M, R = 7.5) and microemulsion (Honko) EC817: Inu Nippon Ink Co., Ltd. product) (solid The sample was impregnated in a treatment agent consisting of 5 parts (30%) and 110 parts of clean water (impregnated amount: 300 g/m2), and then autoclaved for 8 hours in high-temperature, high-pressure steam at 180°C and 10 Y/d.

The physical properties of this product in the air-dried state are shown in Table 1.

Comparative Example 1 The cement aggregate prepared in Production Example 1 was immersed in tap water, and then the aggregate was taken out and heated to 180°C and 10 kg.
The sample was autoclaved for 8 hours in high-temperature, high-pressure steam of /ffl.

The physical properties of this product in the air-dried state are shown in Table 1.

Comparative Example 2 To the cement aggregate prepared in Production Example 1, 1000 parts of 30% sodium silicate (M, R = 2) and acrylic emulsion (Freimar AC33: Rohm & Haas product) were added.
After impregnating with a treatment agent consisting of 3 parts (solid content: 45%) using a spray gun, the sample was cured in an autoclave for 8 hours in high-temperature, high-pressure steam at 180° C. and iokg/=.

The physical properties of this product in the air-dried state are shown in Table 1.

Comparative Example 3 The cement aggregate prepared in Production Example 1 was made into an acrylic emulsion (Freimar AC33: a product of Rohm & Barth)
The sample was impregnated in a treatment agent consisting of 100 parts of clean water and 100 parts of clean water, and then autoclaved for 8 hours in high-temperature, high-pressure steam at 1'80°C and 10 kg/cr/l.

The physical properties of this product in the air-dried state are shown in Table 1.

Claims (1)

[Claims] 1. In the manufacturing process of a lightweight cellular concrete base material made of a kneaded body of hydraulic cement material and water, a cementitious slurry of the base material is poured into a formwork and allowed to set, and then water-soluble silica is added to the aggregate. A method for producing lightweight cellular concrete having a surface layer with good water repellency and suitability for topcoating, which comprises impregnating the concrete with a treatment agent consisting of an acid salt and an aqueous dispersion of organic resin, and then curing with high temperature and high pressure steam.