JP4619649B2 - Low hygroscopic lightweight cellular concrete and its manufacturing method - Google Patents

Description

  The present invention relates to a lightweight cellular concrete having low hygroscopicity and a method for producing the same.

In recent years, it has been industrially desired for building materials to have higher material life and safety. In general, cement-based building materials cause expansion and contraction in the process of adsorption and desorption of moisture in the air, and by repeating this, there is a possibility that the material strength is reduced. Therefore, it is desired to suppress the hygroscopic property of lightweight cellular concrete.
However, since the lightweight cellular concrete surface contains many hydroxyl groups (silanol groups) in the surface functional groups, it is highly hydrophilic and it is difficult to suppress moisture adsorption. Up to now, several methods have been proposed for the purpose of imparting water resistance to lightweight cellular concrete, and even those methods may reduce the water adsorption property to lightweight cellular concrete. Does not modify the surface of lightweight cellular concrete and does not reduce the hydroxyl groups of the surface functional groups, and does not essentially improve the hygroscopicity.

  For example, Patent Document 1 and Patent Document 2 below propose a method of adding polydimethylsiloxane to a raw slurry for producing lightweight cellular concrete. However, the polydimethylsiloxane used in these methods does not have a functional group that reacts with the hydroxyl group of lightweight cellular concrete and reduces the hydroxyl group in its constituent components. It cannot be reduced. In addition, it is possible to use a partly modified polydimethylsiloxane and a functional group that reacts with a hydroxyl group, but all these methods are added to the raw material to produce lightweight cellular concrete. It reacts with raw materials having hydroxyl groups in the process, so it is not an effective means for reducing hydroxyl groups on the surface of lightweight cellular concrete, and the formation of components of lightweight cellular concrete may be hindered if the hydroxyl groups of the material are reduced more than necessary. There is.

  Further, Patent Document 3, Patent Document 4 and Patent Document 5 below propose a method in which light-weight aerated concrete is brought into contact with vapor of alkylalkoxysilane. Alkyl alkoxylanes used in these methods react with hydroxyl groups present on the surface of lightweight cellular concrete, so that hydroxyl groups can be reduced. However, since these methods have been proposed for the purpose of improving the water absorption of lightweight cellular concrete, those described in the specification are all repellent such as methyltrimethoxysilane and methyltriethoxysilane. There are only one alkyl group that is a water group and three alkoxyl groups that can be hydrolyzed to react with the lightweight cellular concrete surface, that is, trifunctional alkylalkoxysilanes. In other words, the hydroxyl group on the surface of lightweight cellular concrete reacts with the hydroxyl group (silanol group) generated by hydrolysis of the alkoxyl group in the alkylalkoxylane, and the water-repellent group is placed on the lightweight cellular concrete surface to absorb water. Is reduced.

What should be noted here is that trifunctional alkylalkoxysilanes generate three hydroxyl groups upon hydrolysis. That is, even if one hydroxyl group in the alkylalkoxylane reacts with the hydroxyl group on the surface of the lightweight cellular concrete, two hydroxyl groups increase as a whole. That is, the number of hydroxyl groups does not decrease unless the three hydroxyl groups in the alkylalkoxysilane react with the hydroxyl groups on the lightweight cellular concrete surface. In general, the hydroxyl groups of all alkoxysilanes do not react ideally and remain unreacted.
That is, in the method using trifunctional alkylalkoxysilane, it is possible to reduce the water absorption of bulk water with respect to the lightweight cellular concrete, but it is not possible to greatly reduce the hydroxyl group on the surface of the lightweight cellular concrete.

JP 58-55359 A Japanese Patent Publication No. 01-58148 JP 59-116465 A Japanese Patent Laid-Open No. 06-271371 International Publication No. 01/47834

  The present invention relates to a lightweight cellular concrete with a reduced hydroxyl group on the lightweight cellular concrete surface and a method for producing the same, in order to suppress moisture adsorption of the lightweight cellular concrete without impairing the lightweight and excellent heat insulation performance of the lightweight cellular concrete. The purpose is to provide.

As a result of intensive studies to solve the above problems, the present inventors have found that the hydroxyl group on the surface of the lightweight cellular concrete is reduced by bringing a specific organosilicon compound into contact with the lightweight cellular concrete, thereby completing the present invention. It came to do.
That is, the present invention
[1] A lightweight cellular concrete in which a lightweight cellular concrete surface is reacted with an organosilicon compound represented by the following general formula (1) comprising one or more types,
R ₃ SiX (1)
(Wherein R represents an alkyl group, an aryl group, an allyl group, X represents an alkoxyl group, an acetoxy group, a ketoxime group, an amide group, an amino group, a vinyl ether group, and a halogen atom. May be different.)
In the infrared spectroscopy spectrum by the diffuse reflection method, when the maximum absorbance of the absorption peak at a wave number of 3000 to 3650 cm ⁻¹ is I (OH) and the maximum absorbance of the absorption peak at a wave number of 925 to 1025 cm ⁻¹ is I (CSH), Lightweight cellular concrete characterized in that I (OH) / I (CSH) satisfies the range of 0.3 or less,
[2] A method for producing lightweight cellular concrete, characterized in that the lightweight cellular concrete surface is treated by contacting an organosilicon compound represented by the following general formula (1) comprising one or more types of the surface :
It is.
R ₃ SiX (1)
(Wherein R represents an alkyl group, an aryl group, an allyl group, X represents an alkoxyl group, an acetoxy group, a ketoxime group, an amide group, an amino group, a vinyl ether group, and a halogen atom. May be different.)

  The lightweight cellular concrete of the present invention has the effect of reducing the hydroxyl groups on the surface of the lightweight cellular concrete and suppressing moisture adsorption on the surface of the lightweight cellular concrete without impairing the performance of the lightweight cellular concrete that is lightweight and excellent in heat insulation.

The present invention will be specifically described below.
The lightweight cellular concrete in the present invention is not particularly limited as long as it is lightweight cellular concrete. As a typical production method, for example, a siliceous raw material such as silica and a calcining material such as cement, gypsum and quick lime represented by ordinary Portland cement were mixed as a main component with a foaming agent such as aluminum. The raw material slurry is poured into a mold and cured to a hardness suitable for cutting, then removed from the mold to form a semi-cured mortar block, which is cut with a wire such as a piano wire that is tensioned Is a method of curing an autoclave. Here, the lightweight cellular concrete may be provided with reinforcing reinforcing bars or wire nets as necessary.

In the present invention, the infrared absorption spectrum of the lightweight cellular concrete is measured by a diffuse reflection method using an infrared spectrophotometer (FTS-6000, manufactured by Nippon Bio-Rad Laboratories). In the obtained infrared absorption spectrum, the absorption peak appearing in the range of wave numbers 925 to 1025 cm ⁻¹ is estimated to be derived from the vibration of Si—O constituting the lightweight cellular concrete, and the absorption peak appearing in the range of wave numbers 3000 to 3650 cm ^−1. The peak is presumed to originate from O-H vibration. Here, the maximum absorbance of the absorption peak at a wave number of 3000 to 3650 cm ⁻¹ is defined as I (OH), and the maximum absorbance of the absorption peak at a wave number of 925 to 1025 cm ⁻¹ is defined as I (CSH). That is, the lower the ratio of I (OH) to I (CSH), that is, I (OH) / I (CSH), the lower the hydroxyl groups on the lightweight cellular concrete surface.

In the present invention, I (OH) / I (CSH) is 0. 3 Ru following range der. If I (OH) / I (CSH) is in the range of 0.5 or less, the hydroxyl group on the lightweight cellular concrete surface may be reduced, and the hygroscopic property of the lightweight cellular concrete may be suppressed.
In the present invention, the extraction test with water is carried out by crushing lightweight aerated concrete previously dried in a hot air dryer at 60 ° C. for 24 hours in a mortar, and then water (distilled water) per 1 g of lightweight aerated concrete in a screw tube bottle with a lid. Mix at a rate of 100 g, shake strongly up and down with the lid closed, thoroughly blend lightweight lightweight concrete powder and water, and then stir for 24 hours with a Mick Rotor (MR5 manufactured by ASONE Corporation) The water repellent component contained in the lightweight cellular concrete was extracted, and then the lightweight cellular concrete powder obtained by filtration was air-dried. Here, lightweight foam concrete powder and water are placed in a screw tube bottle with a lid and shaken in advance. In the case of lightweight foam concrete with large water repellency, the lightweight foam concrete powder floats completely in the water. This is because, even if stirring is performed in this state, it does not come into physical contact with water and is not extracted.

  In the present invention, the measurement of the amount of water vapor adsorbed when the relative pressure of water vapor (water vapor pressure relative to the saturated water vapor pressure) obtained by the water vapor adsorption isotherm is 0.95 is obtained by measuring the lightweight cellular concrete subjected to the extraction test with water by the above method It vacuum-dried at the temperature of 80 degreeC for 5 hours, and measured with the water vapor | steam adsorption isotherm measuring apparatus (Nippon Bell Co., Ltd. BELSORP 18) at 25 degreeC. Here, in the case of the method of adding polydimethylsiloxane as a water repellent to the raw material, there is a possibility that the polydimethylsiloxane is dispersed so as to surround the hydroxyl group on the surface of the lightweight cellular concrete and temporarily suppress the adsorption of water vapor. However, since building materials that require long-term durability cannot be said to be an essential improvement, in the present invention, water vapor adsorption isotherms were measured after sufficient extraction with water in advance. Here, the extraction includes not only dissolution of the water repellent component in water but also physical leakage.

In the low hygroscopic lightweight cellular concrete of the present invention, the water vapor adsorption amount at a relative pressure of 0.95 obtained by water vapor adsorption isotherm measurement at 25 ° C. after the extraction test with water may be in the range of 100 ml / g or less. It is necessary, preferably in the range of 80 ml / g or less, more preferably in the range of 70 ml / g or less.
The organosilicon compound used in the present invention can be represented by the general formula R ₃ SiX. Here, R is not particularly limited as long as it has water repellency. For example, R is an alkyl group, an aryl group, an allyl group, etc., and the functional group X is hydrolyzed to form a hydroxyl group (silanol group). Although it will not specifically limit if it is a thing, For example, they are an alkoxyl group, an acetoxy group, a ketoxime group, an amide group, an amino group, a vinyl ether group, a halogen atom, etc. Further, the water repellent groups R may be the same or different, and two or more kinds of organosilicon compounds represented by the above general formula can be mixed and used.

  Moreover, as an organosilicon compound used for general purposes, there are trialkylalkoxysilane and trialkylchlorosilane. Here, the alkyl group is not particularly limited, but a methyl group, an ethyl group, and a propyl group are the most versatile, and an alkoxyl group is also not particularly limited, but a methoxy group and an ethoxy group are the most versatile. That is, as the most general-purpose organosilicon compounds, for example, trimethylmethoxysilane, trimethylethoxysilane, triethylmethoxysilane, triethylethoxysilane, tripropylmethoxysilane, tripropylethoxysilane, trimethylchlorosilane, triethylchlorosilane, tripropylchlorosilane, etc. Is mentioned.

  Since the organosilicon compound of the present invention has only one functional group that hydrolyzes to generate a hydroxyl group, when it reacts with the hydroxyl group on the lightweight cellular concrete surface, it can be surely blocked. Even when unreacted materials remain or when self-condensation occurs between the silicon compounds, the above-mentioned most general-purpose trialkylalkoxysilanes and trialkylchlorosilanes have high vapor pressures, and can be used as they are. In the case where a component that does not evaporate and remains but does not easily evaporate when left at room temperature, vacuuming at about 40 to 80 ° C. is also a preferable mode. Here, the hydroxyl group on the lightweight cellular concrete surface and the hydroxyl group of the organosilicon compound are dehydrated and condensed with each other to form a chemical bond and form a new siloxane bond. Has excellent durability. In the present invention, the lightweight cellular concrete surface also includes surfaces such as gel holes, capillary condensation holes, and bubbles introduced during foaming.

Further, the organosilicon compound having two or more on a functional group capable of generating a hydroxyl group by hydrolysis, ideally all of the functional groups react with lightweight concrete surface, or by self-condensation, never eliminated, one that Part remains unreacted, that is, remains as a hydroxyl group. In this case, the hydroxyl groups on the lightweight cellular concrete surface are not efficiently reduced. In particular, it is a well-known fact that organosilicon compounds having three functional groups that generate hydroxyl groups react three-dimensionally under alkaline conditions, and even three-dimensionally react even on the surface of lightweight lightweight concrete with alkalinity. It is speculated that a considerable amount of hydroxyl groups may remain.
In the present invention, the method of contacting the lightweight cellular concrete with the organosilicate compound is not particularly limited, but it can be suitably produced by, for example, the following method. That is, a method of immersing lightweight cellular concrete in an organic silicate compound solution to infiltrate the organosilicon compound inside the lightweight cellular concrete, a method of allowing vaporization of vaporized organic silicate compound to penetrate into the lightweight cellular concrete, etc. It is done.

  As a method of immersing lightweight aerated concrete in an organosilicate compound, it is possible to immerse it in an organosilicon compound solution, but not only bubbles inside the lightweight aerated concrete but also capillary condensation holes formed in the manufacturing process. It is essential to penetrate into the pores containing, for example, it is preferable to penetrate the solution into the lightweight cellular concrete to the inside of the lightweight cellular concrete by deaeration with a vacuum pump or the like to reduce the pressure. It is a mode. In general, organosilicon compounds are often insoluble in water, and if the pores inside lightweight cellular concrete contain a lot of water, the organosilicon compound will not penetrate into the pores, so it must be thoroughly dried. It is important. However, if for some reason the organosilicon compound must be infiltrated with water filled in the pores inside the lightweight cellular concrete, a compatible system is formed with the three components of water, organosilicon compound and solvent. By selecting a solvent, the organosilicon compound dissolves into the pores sealed with water, and the organosilicon compound penetrates into every corner of the lightweight cellular concrete, reducing the hydroxyl group on the lightweight cellular concrete surface. It becomes. Here, the solvent for diluting the organosilicon compound is not particularly limited as long as it forms a compatible system with three components of water, the organosilicon compound, and the solvent, and examples thereof include methanol, ethanol, and acetone.

  The vaporized organosilicon compound vapor penetrates into the lightweight cellular concrete. The organosilicon compound and lightweight cellular concrete are placed in the same sealed container, and the interior of the sealed container is evacuated and then heated and sealed. It is possible to generate an organosilicon compound vapor in the container. In this case, however, the organosilicon compound can only penetrate through diffusion inside the lightweight cellular concrete, so that the organosilicon compound reaches every corner inside the lightweight cellular concrete. It takes time to infiltrate the compound. Therefore, the inside of the sealed container containing lightweight aerated concrete is heated and depressurized (pressure P1), and the organosilicon compound is put into another sealed container connected to the next sealed container and a tube that can be opened and closed with a valve. After reducing the pressure in the container, the container is heated to generate vapor of the organosilicon compound in the sealed container, and the vapor pressure of the organosilicon compound is set to a pressure (pressure P2) higher than the pressure P1 in advance. When the valve is opened in this state, the organosilicon compound vapor flows into the sealed container containing the lightweight cellular concrete, and the organosilicon compound vapor penetrates into the lightweight cellular concrete. Here, since the penetration into the lightweight cellular concrete is not the diffusion but the pressure difference is the driving force, the organosilicon compound penetrates into the lightweight cellular concrete very quickly, and the hydroxyl group and the organosilicon compound on the lightweight cellular concrete surface It becomes possible to reduce the hydroxyl group on the lightweight cellular concrete surface by the reaction of the hydroxyl group. Here, when a lot of water is contained in the pores in the lightweight cellular concrete, the organosilicon compound does not permeate into the pores.

As described above, the penetration into the lightweight cellular concrete is the difference between the pressure P1 when the pressure is reduced and the pressure P2 after flowing the vapor of the organosilicon compound (P2-P1) because the pressure difference becomes a driving force. Determined by Accordingly, the required pressure difference is proportional to the thickness of the lightweight cellular concrete, but is usually preferably 1000 to 100000 Pa, more preferably 5000 to 90000 Pa, and further 8000 to 80000 Pa. It is particularly preferred. Since the required pressure difference (P2-P1) is proportional to the lightweight cellular concrete thickness, a preliminary test is performed in advance using a test specimen of lightweight cellular concrete to obtain the required pressure difference (P2-P1). The method is also a preferred embodiment.
In order to allow the organosilicon compound vapor to penetrate into the lightweight cellular concrete, not only the sealed container containing the lightweight cellular concrete and the pipe connecting the sealed container to a temperature at which the organosilicon compound vapor is cooled and does not condense. The lightweight cellular concrete itself should be heated sufficiently, and the inside of the sealed container containing the organosilicon compound in advance should be reduced in pressure as much as possible to remove the air. It is better to fill it with a vapor of an organosilicon compound.

In the present invention, the time for treating the lightweight cellular concrete with the organosilicon compound is usually 0.1 to 5 hours, but if the reaction between the organosilicon compound and the lightweight cellular concrete is not completely completed, the lightweight cellular concrete is further reduced. The concrete may be subjected to heat treatment at 60 to 180 ° C. for about 0.5 to 1 week, within a range where the lightweight cellular concrete is not thermally deteriorated, or left at room temperature for about several days to 2 months. Here, the heating method is not particularly limited, and general hot air heating, far-infrared heating, steam heating, or the like can be used.
The low hygroscopic lightweight cellular concrete of the present invention can be used as an outer wall material, a floor material, a partition material or a roof material as well as the conventional use.

Hereinafter, the present invention will be described in more detail with reference to examples.
Various measurement methods used in the present invention are as follows.

<Infrared absorption spectrum>
In the infrared spectroscopic measurement by the diffuse reflection method, an FTS-6000 type infrared spectrophotometer manufactured by Nippon Bio-Rad Laboratories was used as the measuring apparatus. Lightweight cellular concrete is pulverized in a mortar for 5 minutes or longer, then the ground sample is mixed with KBr powder pulverized in a mortar for 5 minutes or longer, and the mixed sample is further pulverized and stirred in a mortar for 5 minutes or longer. Was used as a measurement sample. When mixing the KBr powder, the amount of lightweight cellular concrete was set to 0.3 wt% with respect to the potassium bromide KBr powder, although it varies depending on the measurement. The measurement sample was attached to the sample stage of the measurement device in an amount of 300 mg or less, although it differs depending on the measurement.

The measurement sample was dried with dry air for 30 minutes or more while attached to the sample stage, and then spectroscopic measurement was performed without taking out from the dry air. The purity of the dry air was 99.99%. The integration conditions for the spectroscopic measurement were 256 scans with a resolution of 4 cm ⁻¹ . In the background correction, the spectrum of KBr powder was measured under the integration conditions, and then automatic correction was performed, and Kubelka-Munk conversion processing was performed for the purpose of further improving the quantitativeness. The KBr powder used for background correction was pulverized in a mortar for 5 minutes or more, dried in dry air for 30 minutes or more while attached to the sample table, and then spectroscopically measured without being taken out from the dry air. Went. From the maximum absorbance of the absorption peak at a wave number of 3000 to 3650 cm ^{−1 in} the spectrum thus measured, I (OH) which is the absorbance of vibration of the O—H group is obtained, and the maximum of the absorption peak at 925 to 1025 cm ⁻¹ is obtained. From the absorbance, I (CSH), which is the absorbance of vibration of Si—O constituting the lightweight cellular concrete, was determined.

<Extraction test with water>
After crushing lightweight aerated concrete previously dried in a hot air dryer at 60 ° C for 24 hours in a mortar, mix it in a screw tube bottle with a lid at a rate of 100 g of water (distilled water) per 1 g of lightweight aerated concrete, and close the lid. The mixture is shaken strongly up and down to fully blend the lightweight cellular concrete powder and water, and then stirred for 24 hours with a Mic Rotor (MR5 manufactured by ASONE Co., Ltd.). The water repellent contained in the lightweight cellular concrete The agent component was extracted, and then the lightweight cellular concrete powder obtained by filtration was air-dried.

<Water vapor adsorption isotherm measurement>
The measurement of the amount of water vapor adsorption at a relative pressure of water vapor of 0.95 was performed by drying the lightweight cellular concrete subjected to the extraction test with water by the above method at a temperature of 80 ° C. for 5 hours, and measuring the water vapor adsorption isotherm at 25 ° C. (Japan) It was measured by Bell Co., Ltd. BELSORP 18).

<Production example of lightweight cellular concrete substrate>
The lightweight cellular concrete used as the substrate was produced by the following method. 53 parts by weight of silica, 2.5 parts by weight of dry gypsum, 7.5 parts by weight of quicklime, and 37 parts by weight of ordinary Portland cement are put into a tank containing 68 parts by weight of water with respect to 100 parts by weight of these solids, After mixing for 2 minutes, 0.06 part by weight of aluminum powder was mixed and stirred for 30 seconds. Next, after pouring the obtained mortar slurry into the mold, it was kept at 60 ° C. for 90 minutes and pre-cured in a state where moisture evaporation was suppressed, and the resulting semi-cured lightweight cellular mortar block was played with a piano wire. Disconnected. The obtained semi-cured lightweight aerated concrete was placed in an autoclave, air in the autoclave was removed under reduced pressure, saturated steam was injected, and high temperature and high pressure curing was performed at 180 ° C. for 4 hours.

[Example 1]
The lightweight cellular concrete obtained by the above production method was cut into a length of 40 mm, a width of 40 mm, and a length of 160 mm, and then dried with a hot air dryer at 60 ° C. for 24 hours. A methanol solution containing 10 wt% trimethylmethoxysilane (Shin-Etsu Chemical Co., Ltd. LS-510) was poured until the lightweight cellular concrete was sufficiently immersed. Next, this stainless steel container is put in a vacuum container, reduced in pressure to 50 mmHg, held in that state for 1 hour, then brought to atmospheric pressure, and left for 24 hours in a state where the lightweight cellular concrete is immersed in the trimethylmethoxysilane-containing methanol solution. did. The lightweight cellular concrete taken out from the trimethylmethoxysilane-containing methanol solution was air-dried at room temperature and then heat-treated at 80 ° C. for 1 hour.
The I (OH) / I (CSH) of the infrared absorption spectrum obtained by the above method of the low-hygroscopic lightweight cellular concrete obtained in this example is 0.25, and the relative water vapor after the water extraction test water vapor adsorption amount of pressure 0.95 was 65 m l / g.

[Example 2]
The lightweight cellular concrete obtained by the above production method was cut into a length of 40 mm, a width of 40 mm, and a length of 160 mm, dried for 24 hours with a hot air drier at 60 ° C., and then put in a sealed container with a capacity of 10,000 cm ³ , The inside of the container and the attached piping were heated to 80 ° C., and then the pressure was reduced to 300 Pa. Next, 70 g of trimethylmethoxysilane was put in another sealed container having a capacity of 10,000 cm ³ connected by a tube that can be opened and closed by a valve, and the pressure was reduced to 300 Pa, followed by heating to 80 ° C. to obtain a vapor of trimethylmethoxysilane. Therefore, the valve was opened, and trimethylmethoxysilane vapor was injected into a sealed container containing lightweight aerated concrete for 1 minute, and the pressure in the sealed container was adjusted to 16500 Pa, and left as it was for 24 hours.
The I (OH) / I (CSH) of the infrared absorption spectrum obtained by the above method of the low hygroscopic lightweight cellular concrete obtained in this example is 0.23, and the relative water vapor after the water extraction test is 0.23. The water vapor adsorption amount at a pressure of 0.95 was 64 ml / g.

[Comparative Example 1]
A low hygroscopic lightweight cellular concrete was obtained in the same manner as in Example 1 except that the organosilicon compound used was propyltriethoxysilane.
The I (OH) / I (CSH) of the infrared absorption spectrum obtained by the above method of the low-hygroscopic lightweight cellular concrete obtained in this comparative example is 0.54, and the relative water vapor after the water extraction test The water vapor adsorption amount at a pressure of 0.95 was 81 ml / g.

[Comparative Example 2]
A low hygroscopic lightweight cellular concrete was obtained in the same manner as in Example 2 except that the organosilicon compound used was propyltriethoxysilane and the sealed container was heated to 180 ° C.
The I (OH) / I (CSH) of the infrared absorption spectrum obtained by the above method of the low-hygroscopic lightweight cellular concrete obtained in this Comparative Example is 0.57, and the relative water vapor after the water extraction test is 0.57. The water vapor adsorption amount at a pressure of 0.95 was 84 ml / g.

[Comparative Example 3]
In this comparative example, the lightweight cellular concrete is the same as the above production method except that 3 parts by weight of alkyl-modified silicone oil (KF-4003 Shin-Etsu Chemical Co., Ltd.) is added to 100 parts by weight of the solid content in the mortar slurry. I got it.
I (OH) / I (CSH) of the infrared absorption spectrum obtained by the above method of the lightweight cellular concrete obtained in this comparative example is 0.60, and the relative pressure of water vapor after the water extraction test is 0. The water vapor adsorption amount at 95 was 103 ml / g.

[Comparative Example 4]
In this comparative example, lightweight cellular concrete was obtained in the same manner as in the above production method except that 0.5 parts by weight of alkyl-modified silicone oil was added to 100 parts by weight of solid content in the mortar slurry.
The I (OH) / I (CSH) of the infrared absorption spectrum obtained by the above method of the lightweight cellular concrete obtained in this comparative example is 0.66, and the relative pressure of water vapor after the water extraction test is 0. The water vapor adsorption amount at 95 was 115 ml / g.

  The lightweight cellular concrete of the present invention is a lightweight cellular concrete with reduced hygroscopicity without impairing the lightweight and excellent heat insulation performance of the lightweight cellular concrete, and therefore can be suitably used in the field of building materials.

Claims (2)

A lightweight cellular concrete in which the lightweight cellular concrete surface is reacted with an organosilicon compound represented by the following general formula (1) comprising one or more types:
R ₃ SiX (1)
(Wherein R represents an alkyl group, an aryl group, an allyl group, X represents an alkoxyl group, an acetoxy group, a ketoxime group, an amide group, an amino group, a vinyl ether group, and a halogen atom. May be different.)
In the infrared spectroscopy spectrum by the diffuse reflection method, when the maximum absorbance of the absorption peak at a wave number of 3000 to 3650 cm ⁻¹ is I (OH) and the maximum absorbance of the absorption peak at a wave number of 925 to 1025 cm ⁻¹ is I (CSH), A lightweight cellular concrete characterized in that I (OH) / I (CSH) satisfies a range of 0.3 or less.   A method for producing a lightweight cellular concrete, characterized in that a lightweight cellular concrete surface is treated by contacting with an organosilicon compound represented by the following general formula (1) comprising one or more types.
R _Three SiX (1)
(Wherein R represents an alkyl group, an aryl group, an allyl group, X represents an alkoxyl group, an acetoxy group, a ketoxime group, an amide group, an amino group, a vinyl ether group, and a halogen atom. May be different.)