JPH08217508A - Cement admixture and cement composition - Google Patents

Abstract

PURPOSE: To obtain a cement admixture and cement composition used in flooring the warehouse, parking area, gas station, kitchen, food processing factory, etc. CONSTITUTION: The cement admixture contains a thickener contg. polyethylene oxide and protein, superplasticizer, quick hardening agent and setting retarder, and the cement composition contains cement, the admixture and aggregate. By use of this composition, excellent fluidity is obtained, and trowel-plastering is dispensed with. Further, a dense hardened body is obtained, and the wear resistance is improved.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a cement admixture and a cement composition, and in particular, it is excellent in abrasion resistance and at the time of construction, such as floors of warehouses, parking lots, gas stations, kitchens, food processing plants and the like. The present invention relates to a cement admixture and a cement composition that require fluidity.

[0002]

2. Description of the Related Art Conventionally, in order to obtain a hardened cement product requiring abrasion resistance, cement, ultrafine powder,
And a method of obtaining a wear-resistant cement hardened product by forming a dense hydrated hardened product using a dispersant, or a wear-resistant cement composition by using cement and wear-resistant aggregate together. Various techniques have been proposed such as the method of obtaining
(JP-B-60-59182, JP-A-3-174344).

However, when these techniques are applied to actual construction, since the fluidity of the cement mixture kneaded with water is poor, a method of applying with a plaster plaster must be taken, and the construction surface is smooth. There was a problem that a great deal of labor and advanced plastering technology were required to finish it.

Further, for example, in order to cope with early opening so that the construction site can be used on the next day of construction, ordinary cement has a low initial abrasion resistance. Therefore, it is necessary to use abrasion-resistant aggregate. However, this causes an increase in raw material cost, and as a result, there is a problem that this technology is difficult to spread widely.

The present inventor has conducted various studies to solve the above-mentioned problems, and as a result, by using a specific material,
It has been found that a cement composition having a high fluidity can be obtained by forming a dense hydrated cured product, and completed the present invention.

[0006]

That is, the present invention is a cement admixture containing a thickener containing polyethylene oxide and protein, a fluidizing agent, a quick hardening material, and a setting retarder, A cement admixture containing calcium fluoroaluminate as a main component as a rapid hardening material, and further a cement composition containing cement, the cement admixture, and an aggregate.

The present invention will be described in detail below.

The thickener used in the present invention has the effect of preventing material separation and breathing by increasing the viscosity of the cement kneaded product, and contains polyethylene oxide and protein in its components. It is a thing.

Polyethylene oxide is produced by ring-opening polymerization of ethylene oxide, and a stable viscosity of a cement kneaded product can be obtained at pH 4-12. The amount of polyethylene oxide used is 100
0.05 to 5 parts by weight, preferably 0.1 to 1 parts by weight
More preferably parts by weight. Outside this range, good fluidity may not be obtained.

Protein has an effect of preventing bleeding of cement at low viscosity, and in the present invention, proteins such as casein, gelatin, and petroleum engineered protein can be used. The amount of protein used is 10
0.1 to 5 parts by weight is preferable, and 0.5 to 2 parts by weight is 0 parts by weight.
More preferably parts by weight. If it is less than 0.1 part by weight, good fluidity may not be obtained, and if it exceeds 5 parts by weight, setting retardation may occur and the strength development may be adversely affected.

The method for mixing polyethylene oxide and protein is not particularly limited, and it is a method of mixing in advance with cement, a method of individually mixing them during cement kneading, or a method of mixing polyethylene oxide and protein. It is possible to do so.

The fluidizing agent used in the present invention means to give an electric potential to cement particles to utilize the electrostatic repulsion force thereof, or to adsorb on the surface of cement particles to form a steric hindrance of polymer. For example, the dispersibility of cement particles is enhanced. There are naphthalene-based superplasticizers, lignin-based superplasticizers, and melamine-based superplasticizers that give an electric potential to the cement particles and utilize the electrostatic repulsive force thereof. There are polycarboxylic acid-based superplasticizers that form steric hindrance of molecules. The amount of the fluidizing agent used is preferably 0.1 to 5 parts by weight, more preferably 0.5 to 2 parts by weight, based on 100 parts by weight of cement. If it is less than 0.1 part by weight, good fluidity may not be obtained, and if it exceeds 5 parts by weight, retardation of setting may occur to adversely affect strength development.

The quick-hardening material used in the present invention plays a role of accelerating the setting of cement. Calcium aluminate, calcium aluminate in which alkali such as sodium is dissolved, and calcium aluminate are used. It is a mixture of calcium sulfate containing CaF ₂ and a rapid hardening component such as inorganic sulfate.
It is preferable to use calcium fluoroaluminate and an inorganic sulfate together.

Here, calcium aluminate means CaO.
Al₂O₃, 12CaO / 7Al₂O₃, And 3CaO ・ Al ₂O₃Ore, etc.
It has a chemical composition and is mainly composed of calcareous and alumina-based materials.
The various raw materials to be used are the CaO and Al in the product after firing.₂O₃To
Adjusting to have the above mineral composition, 1,000 ° C or higher
Obtained by firing above. Calcium aluminum
The powder fineness is not particularly limited.
For example, the Blaine specific surface area is 1,000 to 8,000 cm.²/ g is preferred
Yes.

Calcium fluoroaluminate is represented by xCaO.yAl ₂ O ₃ .zCaF ₂ (x, y, and z are positive numbers) and contains calcareous, aluminous, and fluorides as main components. CaO, Al ₂ O _{3 in} the product after firing various raw materials and
It can be obtained by firing at 1,000 ° C. or higher while controlling the molar ratio of CaF ₂ . The molar ratio of CaO / Al ₂ O ₃ / CaF _{2 in} the product is 3/3/1, 11/7/1, 1/1 / 0.1
5 and 1 / 1.6 / 0.35. The firing method of calcium fluoroaluminate is not particularly limited except that it is fired at 1,000 ° C. or higher, but for example, an electric furnace or a rotary kiln can be used, and the firing time is also particularly limited. Not a thing. The method for cooling the fired product is also not particularly limited, and for example, any method such as a rapid cooling method with water or high-pressure air or a gradual cooling method with standing can be used.
Further, calcium fluoroaluminate can be used regardless of whether it is crystalline or amorphous, and the presence of other components or impurities is not particularly limited. Especially when considering industrial processes, from industrial raw materials, as other _{components, SiO 2, Fe 2 O 3} , TiO 2, and although contamination of SO ₃ and the like are expected, usually mixed amount of less than 20 wt% However, the physical properties of the present invention are not impaired. In the present invention, the calcined calcium fluoroaluminate is further pulverized and
It is preferable to classify to a suitable fineness. The fineness of calcium fluoroaluminate is not particularly limited, and for example, the Blaine specific surface area is 1,000 to 8,000.
cm ² / g is preferred.

The inorganic sulfate used in combination with the rapid hardening component in the present invention is for facilitating the control of the setting time of the rapid hardening component. Specifically, it refers to an alkali metal or alkaline earth metal sulfate, for example, anhydrous, half-water, and the use of dihydrated calcium sulfate is preferable, among them are slightly soluble or insoluble such as type II anhydrous gypsum. Those are particularly preferable. The fineness of the inorganic sulfate is the Blaine specific surface area of 2,000c.
m ² / g or more is preferable, and 3,000 to 8,000 cm ² / g is more preferable. The amount of the inorganic sulfate used is preferably 50 to 300 parts by weight, more preferably 100 to 200 parts by weight, based on 100 parts by weight of the rapid hardening component. If it is less than 50 parts by weight, rapid hardening and initial strength development may be insufficient, and if it exceeds 300 parts by weight, the long-term stability of the hardened cement product may be deteriorated.

In the present invention, the amount of the rapid hardening material used is preferably 5 to 35 parts by weight with respect to 100 parts by weight of cement.
-25 parts by weight is more preferred. If it is less than 5 parts by weight, rapid hardening and initial strength development may be insufficient, and if it exceeds 35 parts by weight, it may be difficult to adjust the pot life of the cement kneaded product.

The set retarder used in the present invention is one which delays or temporarily stops the hydration reaction by temporarily adsorbing it on cement or a quick-hardening material. One or more of oxycarboxylic acids or salts thereof such as citric acid, tartaric acid, gluconic acid and malic acid or inorganic salts such as calcium hydroxide, calcium oxide, sodium aluminate, sodium carbonate and potassium carbonate are used. it can. The amount of the setting retarder used may be appropriately determined according to the purpose and is not particularly limited,
Normally, 0.1 is added to 100 parts by weight of cement and quick-hardening material.
Is preferably 2 to 2 parts by weight, more preferably 0.2 to 1 part by weight. If the amount is less than 0.1 part by weight, the setting may be accelerated, and 2
If it exceeds the weight part, strength development may be deteriorated.

In the present invention, a thickener, a fluidizing agent, a quick hardening material,
And a set retarder is used as a cement admixture.

As the cement used in the present invention, various kinds of portland cements such as normal, early strength, ultrafast strength, white, and moderate heat, various mixed cements obtained by mixing portland cement with blast furnace slag, silica, etc., and colloids Examples include cement.

The aggregate used in the present invention is used for improving the fluidity of the cement kneaded product and for improving the durability of the hardened cement product, and it is used for river sand, sea sand, and silica sand. However, it is preferable to use an aggregate having a Mohs hardness of 6 or more. Aggregates with a Mohs hardness of 6 or higher include pyrite, hematite, magnetite, yellow jade, lawsonite, corundum, phenasite, spinel, beryl, gold vermiculite,
Tourmaline, granite, beryl, cruciate, zircon, calcined bauxite, calcined bauxite, fused alumina, boron carbide, tungsten carbide, ferrosilicon nitride,
Examples thereof include boron nitride, fused silica, electrofused magnesia, and silicon carbide. The amount of aggregate used is preferably 30 to 250 parts by weight, based on 100 parts by weight of cement and the rapid hardening material,
50 to 150 parts by weight is more preferable. If it is less than 30 parts by weight, it may not be possible to obtain sufficient durability of the hardened cement product, and if it exceeds 250 parts by weight, sufficient fluidity may not be obtained.

The amount of water used in the present invention is not particularly limited, but is 20 to 5 relative to 100 parts by weight of cement.
0 parts by weight is preferable, and 25 to 40 parts by weight is more preferable. 20
If it is less than part by weight, sufficient fluidity may not be obtained,
If it exceeds 50 parts by weight, sufficient abrasion resistance may not be obtained.

In the present invention, further, if necessary, celluloses such as methyl cellulose, hydroxymethyl cellulose, and carboxymethyl cellulose, polymer emulsions such as vinyl acetate emulsion and acrylic emulsion, rubber latex such as styrene butadiene rubber latex and chloroprene rubber latex, In addition, various admixtures or admixtures such as antifoaming agents such as silicone can be used in combination.

In the cement composition of the present invention, the respective materials may be mixed at the time of construction, or some or all of them may be mixed in advance.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below.

Example 1 10 parts by weight of a rapid-hardening component and 10 parts by weight of inorganic sulfate with respect to 100 parts by weight of cement, and the types and amounts of thickeners and superplasticizers were changed as shown in Table 1 to obtain cement. A cement composition was prepared by mixing 1 part by weight of a set retarder and 150 parts by weight of aggregate with 100 parts by weight of hardened hardwood, and 13 parts by weight of water for 100 parts by weight of the cement composition. A part was added and kneaded to prepare a mortar test body. The flow value, handling time (HT), change in length and wear loss of the produced mortar were measured. The results are also shown in Table 1.

<Materials used> Cement: Normal Portland cement manufactured by Denki Kagaku Kogyo Co., Ltd. Thickener A: Polyethylene oxide, commercially available product Thickener B: Milk casein, manufactured by Wako Chemical Co., Ltd. Fluidizer a: Lignin dispersant, commercially available Product fluidizing agent b: naphthalene-based dispersant, commercial product Fluidizing agent c: melamine-based dispersant, commercial product Rapid hardening component C: calcium fluoroaluminate, CaO / Al ₂
O ₃ / CaF ₂ molar ratio 3/3/1, Blaine 4,250 cm ² / g Inorganic sulfate: Type II anhydrous gypsum, Blaine 5,100 cm ² / g Coagulation retarder: Sodium gluconate, Wako Pure Chemical Reagent first grade

<Measurement method> Flow value: JI on a smooth acrylic plate supported horizontally
Place the flow cone specified in SR 5201, and pour the mortar just after kneading into it to the upper end of the flow cone. Immediately afterwards, pull up the flow cone vertically,
The spread of the mortar after 1 minute is measured in mm, and the acceptance criteria is
300-340 mm. If it is less than 300 mm, sufficient workability may not be obtained, and if it exceeds 340 mm, breathing may occur and a smooth finished surface may not be obtained. Handling time: 500c after mixing all ingredients with a mixer
c Move to a beaker and let it stand still. Measure the curing start time until it stops flowing even if the container is laid sideways. Pass criteria is 40 to 70 minutes.
If it is less than 40 minutes, the construction time may be too short, and it may not be possible to take time to clean the mixer and tools. If it exceeds 70 minutes, it may not be possible to open it the next day. Change in length: The molded product obtained by filling mortar with a 4 × 4 × 16 cm mold frame specified in JIS R 5201 and curing for 1 day at 20 ° C. and 80% humidity is JIS A 1125. Measured according to the comparator method of the indicated length change measurement method. The acceptance standard is -0.05% or less. If it exceeds −0.05%, the hardened cement may be cracked. Abrasion loss amount: A well-kneaded mortar was cast into a φ100 × 7mm mold according to JIS R 5201 and kept for 7 days at 20 ° C and a humidity of 8
The test piece was aged at 0%, and the wear loss weight was measured by the Taber wear tester under the conditions of a wear wheel H-22, a load of 250 g, and a rotation speed of 2,000, and the wear loss weight was measured and used as the wear loss amount. The acceptance standard is 2.5g or less. If it exceeds 2.5 g, sufficient abrasion resistance cannot be obtained, and wear or abrasion phenomenon may occur early.

[0029]

[Table 1]

Example 2 1 part by weight of each of a thickener A, a thickener B and a fluidizing agent c was added to 100 parts by weight of cement, and the amounts of the rapid hardening component and the inorganic sulfate were made equal. The same procedure as in Example 1 was carried out except that the type and amount of calcium fluoroaluminate as the rapid hardening component were changed as shown in Table 2. The results are also shown in Table 2.

<Materials used> Rapidly hardened component a: calcium fluoroaluminate, CaO / Al₂
O₃/ CaF₂Molar ratio 11/7/1, Blaine 4,100 cm²/ g Rapid hardening component B: Calcium fluoroaluminate, CaO / Al₂
O₃/ CaF₂Molar ratio 1/1 / 0.15, Blaine 4,200 cm²/ g Rapid hardening component d: Calcium fluoroaluminate, CaO / Al₂
O₃/ CaF₂Molar ratio 1 / 1.6 / 0.35, Blaine 4,300 cm²/ g Rapid hardening component E: Calcium aluminate, main mineral composition CaO
Al₂O₃, Brain 5,100 cm ²/ g Rapid hardening component F: Calcium aluminate, main mineral composition 12Ca
O ・ 7Al₂O₃, Brain 4,900 cm²/ g

[0032]

[Table 2]

Example 3 1 part by weight of each of thickener A, thickener B and fluidizing agent c was added to 100 parts by weight of cement. As in Example 1, except that the amount of inorganic sulfate was changed as shown in FIG. The results are also shown in Table 3.

[0034]

[Table 3]

[0035]

EFFECTS OF THE INVENTION By using the cement composition of the present invention, excellent fluidity is obtained, and as a result, a smooth finished surface can be easily obtained. Therefore, it is not necessary to finish with a plastering iron. There is. Further, a dense hydrated cured product can be formed, and wear resistance is improved. Furthermore, since it is hard, it can be used for emergency repair work.
It is possible to provide a flooring material having excellent wear resistance.

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Claims (3)

[Claims] 1. A cement admixture comprising a thickening agent containing polyethylene oxide and protein, a fluidizing agent, a quick hardening material, and a setting retarder. 2. The cement admixture according to claim 1, wherein the rapid hardening material is mainly composed of calcium fluoroaluminate. 3. A cement composition comprising cement, the cement admixture according to claim 1 or 2, and an aggregate.