JPH06239651A - Cement admixture for self leveling and cement composition containing the same - Google Patents

Abstract

PURPOSE:To obtain a cement admixture or a cement composition for self leveling respectively useful as a self leveling floor material, etc., in the field of architecture. CONSTITUTION:This cement admixture for leveling is composed mainly of a casein, polyethylene oxide, a water retention agent and an anti-foaming agent and the cement composition for self leveling is composed mainly of cement, an aggregate and the cement admixture. If this invented cement composition for leveling is used, a subfloor excellent in fluidity, low in reduction of fluidity at the initial stage, free from generation of a troweling unevenness pattern on the cured surface and excellent in smoothness can be provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cement admixture for self-leveling and a cement composition for self-leveling, which are mainly used for self-leveling floor materials in the field of construction.

[0002]

2. Description of the Related Art In recent years, surface accuracy has been improved by pouring mortar, which is a hydraulic composition mainly composed of gypsum or cement, onto a floor surface such as concrete slab or foamed concrete and fluidizing it naturally. The self-leveling material that forms an excellent horizontal surface has been developed and put into practical use.

Generally, the self-leveling material has excellent fluidity when kneaded with water and poured into an uneven floor surface, and does not cause solid-liquid separation until it hardens to form a uniform horizontal surface. However, even after curing, it is required to be physically stable against repeated dry and wet conditions.

However, in order to meet these requirements, the gypsum-based self-leveling material had problems of poor water resistance and low physical strength (gypsum and lime No. 222 1
989p262-268).

On the other hand, in cement-based self-leveling materials, a technique based on a melamine sulfonate-based high-performance water reducing agent as a fluidizing component, a casein-based technique, and the like have been proposed (Japanese Patent Laid-Open No. 56-56). -84358, JP-A-59-92960).

However, the self-leveling material using a high-performance water reducing agent does not have a very high fluidity,
At the time of construction, it is necessary to extend the work with registration marks,
There is a problem in that the stretched portion such as a register mark remains as a "copper wave" after curing, and the smoothness is impaired.

Further, the self-leveling material using caseins has good initial fluidity and does not require a stretching operation, but the fluidity retention time is short and fluidity decreases in a short time. It wasn't resolved.

As a result of various studies to solve the above-mentioned problems, the inventor of the present invention has excellent fluidity and can secure a certain fluidity retention time by using a specific material. The knowledge that "the iron wave" did not remain was obtained, and the present invention was completed.

[0009]

Means for Solving the Problems That is, the present invention is a cement admixture for self-leveling, which comprises caseins, polyethylene oxide, a water retention agent, and an antifoaming agent as main components, and a cement, an aggregate, and the cement. A cement composition for self-leveling, which comprises an admixture.

The present invention will be described in detail below.

Examples of caseins according to the present invention include casein, gelatin, petroleum engineered proteins and the like.
The amount of caseins used is 100 parts by weight of cement,
0.2 to 6 parts by weight is preferable. If it is less than 0.2 part by weight, good fluidity cannot be obtained, and if it exceeds 6 parts by weight, retardation of setting occurs and the strength development is adversely affected.

Here, as the cement, normal, early strength,
And various portland cements such as super early strength, these portland cements, blast furnace slag, fly ash,
Alternatively, various mixed cements mixed with silica, moderate heat cements, white cements, colloidal cements and the like can be mentioned.

The polyethylene oxide according to the present invention is
When used in combination with the above caseins, they have a synergistic effect of giving good flowability to the cement and extending the fluidity retention time. The average molecular weight of polyethylene oxide is preferably 150,000 to 400,000. If the average molecular weight is less than 150,000, no effect can be expected in terms of fluidity retention time, and if it exceeds 400,000, the fluidity tends to decrease. The maximum particle size of polyethylene oxide is preferably 0.5 mm or less. If the maximum particle size exceeds 0.5 mm, the solubility in water will decrease and it will not be possible to obtain good fluidity, and insoluble particles will float on the construction surface and tend to adversely affect the smoothness of the floor surface. There is. The amount of polyethylene oxide used is 0.1 per 100 parts by weight of cement.
-3 parts by weight is preferred. If it is less than 0.1 part by weight, the fluidity retention time tends to be short, and if it exceeds 3 parts by weight, the fluidity tends to be impaired.

Examples of the water retention agent according to the present invention include cellulose-based, acrylic acid-based, polyvinyl alcohol-based, vinyl-based, and rubber latex-based water retention agents. In the present invention, the use of cellulose-based ones is particularly preferable. . The amount of water retention agent used is 100 parts by weight of cement,
It is preferably 0.1 to 0.5 parts by weight. If it is less than 0.1 part by weight, the water retention is insufficient, and the tendency that the floor surface becomes rough due to drying becomes noticeable, and if it exceeds 0.5 part by weight, the amount of water necessary for obtaining fluidity becomes excessive and the strength decreases. Tend to.

As the defoaming agent according to the present invention, generally used defoaming agents such as silicone type and nonionic type surfactants can be used. The amount of defoaming agent used is preferably 0.05 to 0.5 parts by weight with respect to 100 parts by weight of cement. If it is less than 0.05 parts by weight, the defoaming effect is small, and if it exceeds 0.5 parts by weight, the fluidity tends to be impaired.

The aggregate according to the present invention is not particularly limited, and natural sand such as mountain sand and river sand, silica sand, and lime sand can be used. The grain size of the aggregate is 1.0 to 1.0 in FM value.
The range of 2.0 is preferable, and the range of 1.2 to 1.4 is particularly preferable from the viewpoint of suppressing the development of good fluidity and material separation.
The amount of aggregate used is 40 to 200 for 100 parts by weight of cement.
It is preferably part by weight. If it is less than 40 parts by weight, cracking tends to occur, and if it exceeds 200 parts by weight, the fluidity tends to decrease.

Further, in the present invention, fly ash or the like is added to improve the fluidity of the cement composition, and
It is preferable to use slaked lime or the like together in order to suppress material separation. The use amount of fly ash is preferably 20 to 40 parts by weight with respect to 100 parts by weight of cement, and the use amount of slaked lime is preferably 1 to 5 parts by weight with respect to 100 parts by weight of cement.

The cement admixture and the cement composition of the present invention may be prepared by mixing the respective materials at the time of construction, or may be partially or wholly mixed in advance.

[0019]

EXAMPLES The present invention will be described in detail below with reference to examples.

Example 1 100 parts by weight of cement, 180 parts by weight of aggregate c, 0.3 parts by weight of water retention agent, and 0.1 parts by weight of defoaming agent were added to 100 parts by weight of a cement composition obtained by using the composition shown in Table 1. On the other hand, 26 parts by weight of water was added and kneaded to adjust the mortar, and the flow value, length change, compression strength were measured, and the surface state after curing was observed. The results are also shown in Table 1.

<Measurement method> Flow value: JIS was measured on a smooth acrylic plate supported horizontally.
Place the flow cone specified by R 5201, pour the mortar immediately after kneading into it to the upper end of the flow cone, then immediately pull up the flow cone in the vertical direction and measure the spread of the mortar in mm units and obtain the flow value. did. Change in length: Mortar is packed using a 4 x 4 x 16 cm mold frame specified in JIS R 5201, and the molded product obtained by curing for 1 day at 20 ° C and 80% humidity is JIS R 1125. It measured according to the comparator method of the length change measuring method shown. Compressive strength: Molded product obtained by filling mortar in a mold of 4 × 4 × 16 cm shown in JIS R 5201 and curing for 1 day at 20 ° C. and 80% humidity. The compression strength was measured according to the test method. Observation of surface state: A mortar plate of 1 × 2 m is poured with a kneading mortar so as to have a thickness of 10 mm, and is stretched with a trowel. Further, after 15 minutes, stretching with a trowel was carried out again, and the "iron wave" state after curing was observed.

<Materials used> Cement: Ordinary Portland cement manufactured by Denki Kagaku Kogyo Aggregate c: Quartz sand, FM value 1.3 Casein: Commercial milk casein Polyethylene oxide C: Commercial product, molecular weight 300,000, maximum particle size 0.5 mm Water retention agent : Shin-Etsu Chemical Co., Ltd. methyl cellulose defoamer: San Nopco defoamer, main component nonionic surfactant

[0023]

[Table 1]

Example 2 The procedure of Example 1 was repeated, except that the formulation shown in Table 2 was used. The results are also shown in Table 2.

<Materials used> Polyethylene oxide A: Commercial product, molecular weight 150,000, maximum particle size 0.5 mm Polyethylene oxide B: Commercial product, molecular weight 200,000, maximum particle size 0.5 mm Polyethylene oxide D: Commercial product, molecular weight 400,000 Maximum particle size 0.5 mm

[0026]

[Table 2]

Example 3 100 parts by weight of cement, 1.0 part by weight of caseins, 0.5 part by weight of polyethylene oxide C, 180 parts by weight of aggregate c,
The same procedure as in Example 1 was carried out except that the formulation shown in Table 3 was used. The results are also shown in Table 3. The materials used were the same as in Example 1.

[0028]

[Table 3]

Example 4 100 parts by weight of cement, 1.0 part by weight of caseins, 0.5 part by weight of polyethylene oxide C, 0.3 part by weight of a water retention agent, and 0.1 part by weight of a defoaming agent, except that the composition shown in Table 4 was used. Is
The same procedure as in Example 1 was performed. The results are also shown in Table 4. The materials used were as follows, and the other materials used were the same as in Example 1.

<Material used> Aggregate a: Quartz sand, FM value 1.0 Aggregate b: Quartz sand, FM value 1.2 Aggregate d: Quartz sand, FM value 1.4 Aggregate e: Quartz sand, FM value 2.0 Aggregate f: Mountain sand, FM value 1.3 Aggregate g: River sand, FM value 1.3 Aggregate h: Lime sand, FM value 1.3

[0031]

[Table 4]

Example 5 100 parts by weight of cement, 1.0 part by weight of caseins, 0.5 part by weight of polyethylene oxide C, 180 parts by weight of aggregate c, water retention agent
Example 1 was repeated except that 3 parts by weight and 0.1 part by weight of the defoaming agent were used and the formulations shown in Table 5 were used. The materials used were as follows, and the other materials used were the same as in Example 1. The results are also shown in Table 5.

<Materials used> Fly ash: Fly ash made by Joban Thermal Power Industry Slaked lime: Slaked lime made by Chichibu Lime Company

[0034]

[Table 5]

[0035]

EFFECTS OF THE INVENTION By using the self-leveling cement composition of the present invention, the fluidity is excellent, the fluidity is not deteriorated in the initial stage, and "the iron wave" remains on the construction surface after curing. It is possible to provide a floor base with excellent smoothness and the like.

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Claims (2)

[Claims] 1. Caseins, polyethylene oxide,
A cement admixture for self-leveling, which mainly contains a water retention agent and a defoaming agent. 2. A cement composition for self-leveling, which comprises a cement, an aggregate, and the cement admixture according to claim 1.