JP2527700B2 - High strength hydraulic cement composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention provides a high-strength hydraulic cement composition, more specifically, the workability during construction is remarkably improved, and a cured product having higher strength can be obtained. It relates to a high-strength hydraulic cement composition.

<Conventional technology and its problems> Conventionally, when preparing a high-strength hydraulic cement composition,
It has been practiced to lower the water / cement ratio, to add ultrafine powder such as silica fume, if necessary, and to add a cement dispersant for further imparting fluidity.
Various types of such cement dispersants have been proposed.

However, the conventionally known cement dispersant has the following problems with respect to the highly-strength hydraulic cement composition with a highly water-reduced water / cement ratio of 30/100 (weight ratio) or less.

For example, with lignin sulfonate and polycarboxylate, etc., the water-reducing property is insufficient, the air entrainment is high, and the setting retardation is exhibited, so even if these are added, a substantially high-strength hydraulic cement composition is obtained. I can't get things. In addition, salts of naphthalene sulfonic acid formalin condensate, polycyclic aromatic sulfonic acid salts, melamine sulfonic acid formalin condensate salts, etc. do not have air entrainment and coagulation retardation properties as compared with lignin sulfonate. , It is difficult to give a desired high fluidity even if these are added to a highly reduced hydraulic cement composition having a water / cement ratio of 30/100 (weight ratio) or less. . Further, regarding a water-soluble vinyl copolymer having a sulfonic acid group or a carboxylic acid group in the molecule (JP-A-1-226757),
When the cement ratio is added to the highly water-reduced high-strength hydraulic cement composition of 30/100 (weight ratio) or less, a desired slump value can be imparted by appropriately selecting the addition amount, and It is known that the slump value changes little with time, and such a so-called fluidized high-strength hydraulic cement composition is originally excellent in fluidity according to the conventional knowledge that the slump value is used as an index of fluidity. Although it is said that the high-strength hydraulic cement composition has a high viscosity when it is actually used, its workability such as pumpability to a high place and mold filling property is poor. There are many difficulties in sex. The slump value, which has been an index of workability in the past, has a water / cement ratio of 30/100 (weight ratio).
In the following highly water-reduced high-strength hydraulic cement composition, it is not an index of workability.

<Problems to be Solved by the Invention and Means for Solving the Problems> The present invention provides an improved high-strength hydraulic cement composition that solves the above-mentioned conventional problems.

However, the inventors of the present invention have diligently studied from the above viewpoints on a high-strength hydraulic cement composition having a highly water-reduced water / cement ratio of 30/100 (weight ratio) or less. A (meth) allyl ether or an alkoxypolyethylene glycol mono (meth) allyl ether and a copolymer obtained by copolymerizing a maleic acid salt at a specific ratio are used together with cement or a binder made of cement and silica fume. The unit amount, water / binder ratio, cement dispersant content, etc., were adjusted to within the specified range, but showed a remarkable decrease in viscosity that could not be predicted from conventional knowledge, and therefore workability during actual construction was significantly improved. Moreover, it was found that high strength is exhibited after curing.

That is, the present invention is a hydraulic cement composition containing cement or a binder comprising cement and silica fume, an aggregate, water and the following cement dispersant, wherein the blending ratio of silica fume in the binder is 0 to 0. 30% by weight, unit amount of binder is 400 kg / m ³ or more, water / binder ratio is 10/100 to 30/1
00 (weight ratio), the content of the cement dispersant is 0.05 to 5 parts by weight per 100 parts by weight of the binder, and relates to a high-strength hydraulic cement composition.

Cement dispersant: A vinyl copolymer composed of a monomer unit represented by the following formula I and a monomer unit represented by the following formula II, wherein the ratio of each monomer unit is represented by the formula I. A vinyl copolymer having a monomer unit / monomer unit represented by the formula II = 1/2 to 2/1 (molar ratio) and a number average molecular weight of 500 to 6000.

Formula I; Formula II; [However, R ¹ is H or CH ₃ . R ² is H or an alkyl group having 1 to 3 carbon atoms. X and Y are the same or different at the same time, alkali metal, ammonium, or organic amine. n is an integer of 3 to 30. The cement dispersant used in the present invention is a monomer unit having polyethylene glycol mono (meth) allyl ether or alkoxy polyethylene glycol (meth) allyl ether as a monomer, and a monomer having maleate as a monomer. The unit is a vinyl copolymer containing units at a specific molar ratio. The vinyl copolymer composed of each of the monomer units can be obtained by radically copolymerizing the monomers that will form each of the monomer units in a specific ratio.

Examples of the monomer that will form the monomer unit represented by formula I include polyethylene glycol monoallyl ether, polyethylene glycol monomethallyl ether,
Alkoxy polyethylene glycol allyl ether and alkoxy polyethylene glycol methallyl ether are mentioned.

Polyethylene glycol mono (meth) allyl ether including polyethylene glycol monoallyl ether and polyethylene glycol monomethallyl ether is a desired mole addition of ethylene oxide to methallyl alcohol or allyl alcohol in the presence of an alkali catalyst such as sodium hydroxide or potassium hydroxide. Obtained by reacting. Alkoxy polyethylene glycol mono (meth) containing alkoxy polyethylene glycol allyl ether and alkoxy polyethylene glycol methallyl ether
The allyl ether can be obtained by reacting the above polyethylene glycol mono (meth) allyl ether with a known alkylating reagent such as methyl chloride, ethyl bromide or isopropyl chloride in the presence of an alkali. In either case, the number of moles of ethylene oxide added is 3 to 30, preferably 5 to 15.

As the monomer that will form the monomer unit represented by the formula I, one or more of the above may be used, among which alkoxypolyethylene glycol allyl ether is preferable, and methoxypolyethylene is particularly preferable. Glycol allyl ether is preferred.

Examples of the monomer forming the monomer unit represented by the formula II include an alkali metal salt, an ammonium salt and an organic amine salt of maleic acid. Of these, a dialkali metal maleate salt is preferable.

In the present invention, the vinyl copolymer used as the cement dispersant is obtained by radically copolymerizing the above-mentioned monomers in a predetermined molar ratio in the presence of a radical initiator. The copolymerization reaction may be either solution polymerization or bulk polymerization, but solution polymerization using an organic solvent or water is preferable. As a method for obtaining a vinyl copolymer, after copolymerizing an alkoxy polyethylene glycol mono (meth) allyl ether and maleic acid or maleic anhydride,
A method of neutralizing the obtained copolymer with alkali hydroxide, ammonia, an organic amine or the like may be used.

In the vinyl copolymer used as a cement dispersant, the ratio of each monomer unit is represented by the formula I:
The monomer unit represented by the formula II is 1/2 to 2/1 (molar ratio), preferably 2/3 to 3/2. Depending on the copolymerization molar ratio of each monomer in the radical copolymerization reaction, a vinyl copolymer having a corresponding molar ratio of each monomer unit can be obtained.

In the present invention, the vinyl copolymer used as the cement dispersant has a number average molecular weight of 500 to 6000 (GPC method, styrene-equivalent molecular weight), preferably 1000 to 4000. When the number average molecular weight is out of the range of 500 to 6000, the cement dispersibility is deteriorated.

In the high-strength hydraulic cement composition of the present invention, the content of the cement dispersant is 0.05 to 5 per 100 parts by weight of the binder.
Parts by weight, preferably 0.1 to 1.5 parts by weight. 0.05
If it is less than 5 parts by weight, a sufficient effect cannot be obtained, and conversely, if the amount is more than 5 parts by weight, the effect will reach a ceiling and it is not economical.

In the high-strength hydraulic cement composition of the present invention, the binder is cement alone or a mixture of cement and silica fume. As the cement, known hydraulic cement such as Portland cement, alumina cement or various mixed cements can be used. Silica fume is a finely divided silica as a main component SiO _2, SiO ₂
A content of 90% by weight or more is preferable. In order to express high strength in the obtained cured product, it is preferable to use a mixture of cement and silica fume as a binder, in which case the mixing ratio of silica fume is 30% by weight or less in the binder, preferably 10 to 25% by weight. In the high-strength hydraulic cement composition of the present invention, the unit amount of the binder is 400k.
g / m ³ or more, preferably 600 kg / m ³ or more. The water / binder ratio is 10/100 to 30/100 (weight ratio). 10/1
If it is less than 00 (weight ratio), the mixture cannot be substantially kneaded, and conversely, if it exceeds 30/100 (weight ratio), the desired high strength cannot be obtained. The water / binder ratio depends on the choice of cement dispersant and the amount added, but it is 10/100 to 30/100 (weight ratio)
Within the range, it is preferable to make it as low as possible so long as good workability can be obtained.

The high-strength hydraulic cement composition of the present invention is a binder,
It includes a cement mortar composition comprising water, a cement dispersant and fine aggregate, and a concrete composition further comprising coarse aggregate.

Examples of the present invention will be given below, but the present invention is not limited to the examples.

<Examples, etc.> Test Category 1 (Synthesis of vinyl copolymer) -Synthesis of vinyl copolymer A Polyethylene glycol monoallyl ether (oxyethylene unit average 5 mol) 139 g (0.5 mol), maleic acid 58 g (0.5 mol) Mol) and 155 g of water were charged into the reaction vessel, and the inside of the reaction vessel was replaced with nitrogen gas. While introducing nitrogen gas,
While keeping the inside of the reaction vessel at 90 ° C., a solution prepared by dissolving 6 g of ammonium persulfate in 100 g of water as a radical initiator was added over 2 hours. After the addition was completed, the reaction was continued at 95 ° C. for 2 hours to complete the polymerization reaction. 40% caustic soda solution in water 10
0 g was added for neutralization to obtain an aqueous solution containing 40% by weight of vinyl copolymer A. The number average molecular weight of the vinyl copolymer A contained in this aqueous solution was measured by GPC.
(Polysterene conversion value). (Measurement of number average molecular weight is the same below).

..Synthesis of vinyl copolymer F Methoxypolyethylene glycol monoallyl ether (oxyethylene unit average 7 mol) 366 g (1.0 mol),
116 g (1.0 mol) of maleic acid and 150 g of water were charged into a reaction vessel, and 100 g of a 14 wt% ammonium persulfate aqueous solution was used as a radical initiator, and the reaction was carried out in the same manner as in the synthesis of the vinyl copolymer A. The reaction product was neutralized by adding 200 g of 40% caustic soda aqueous solution to obtain an aqueous copolymer solution containing 56% by weight of vinyl copolymer F. Number average molecular weight is 2600
Met.

..Synthesis of vinyl copolymer R-1 Polyoxyethylene glycol monoallyl ether (oxyethylene unit average 5 mol) 139 g (0.5 mol) instead of polyoxyethylene glycol monoallyl ether (oxyethylene unit average 50 mol) 226 g (0.1 mol)
Was used, and the reaction was carried out in the same manner as in the synthesis of vinyl copolymer A except that the amount of maleic acid used was 11.6 g (0.1 mol). 40% caustic soda solution in the reaction product
Neutralize by adding 20 g, and 45% by weight of vinyl copolymer R-1
An aqueous solution containing it was obtained. The number average molecular weight was 4,300.

..Synthesis of vinyl copolymer R-3 Except that the amount of maleic acid used was 11.6 g (0.1 mol), the reaction was carried out in the same manner as in the synthesis of vinyl copolymer F. The reaction product was neutralized by adding 20 g of 40% caustic soda aqueous solution to obtain an aqueous solution containing 60% by weight of vinyl copolymer R-3. The number average molecular weight was 450.

..Synthesis of vinyl copolymer R-4 Polyethylene glycol monoallyl ether (oxyethylene unit average 10 mol) 30 g (0.06 mol) and water 475 g
Was charged into a reaction vessel, and the inside of the reaction vessel was replaced with nitrogen gas. While introducing nitrogen gas, keep the inside of the reaction vessel at 95 ° C,
447 g (1.81 mol) of 38% sodium acrylate aqueous solution and 40% 5% ammonium persulfate aqueous solution as a radical initiator
Parts over 120 minutes, and ammonium persulfate 5%
8 parts of aqueous solution were added over 20 minutes. After the addition was completed, the reaction was continued at 95 ° C. for 2 hours to complete the polymerization reaction. An aqueous solution containing 20.2% of a vinyl copolymer R-4 of polyethylene glycol monoallyl ether (oxyethylene unit average 10 mol) / sodium acrylate = 1/30 (molar ratio in terms of monomer) was obtained. Vinyl copolymer R-4 contained in this aqueous solution
Had a number average molecular weight of 5,200.

..Synthesis of vinyl copolymer R-5 Polyethylene glycol monoallyl ether (oxyethylene unit average 5 mol) 168 g (0.6 mol) and water 1015 g
Was charged into a reaction vessel, and the inside of the reaction vessel was replaced with nitrogen gas. While introducing nitrogen gas, keep the inside of the reaction vessel at 95 ° C,
514 g (1.81 mol) of 38% sodium methacrylate aqueous solution and 5% ammonium persulfate aqueous solution as a radical initiator
Add 120 parts over 120 minutes, and add ammonium persulfate 5
% Aqueous solution was added over 20 minutes. 95 ° C after addition
The reaction was continued for 2 hours to complete the polymerization reaction. An aqueous solution containing 20% of a vinyl copolymer R-5 of polyethylene glycol monoallyl ether (oxyethylene unit average 5 mol) / sodium methacrylate = 1/3 (molar ratio in terms of monomer) was obtained. Vinyl copolymer R- contained in this aqueous solution
The number average molecular weight of 5 was 510.

Similarly, vinyl copolymers B, C, D, E,
G, H and R-2 were synthesized.

Vinyl copolymers R-4 and R- having distinctly different structures
With the exception of 5, the contents of the other vinyl copolymers are summarized in Table 1.

-Test Category 2 (Mortar Test) Using the materials of (1) below, mortar was prepared by the method of (2) below, and the flow value and the like were measured. The results are shown in Table 3.

(1) Material Cement: Ordinary Portland cement (specific gravity = 3.16).

Fine aggregate: River sand from Oi River water system (specific gravity = 2.63, FM = 2.71).

Silica fume: Micro silica 940U (trade name, manufactured by Elchem, specific gravity = 2.20).

(2) Method Preparation of mortar: A mortar was prepared by adding the cement dispersant shown in Table 3 to the plain mortar composition shown in Table 2.

Flow value: Performed according to JIS-R5201.

Compressive strength: Conducted in accordance with the Japan Society of Civil Engineers standard “Test method for mixing water for concrete by compressive strength of mortar”.

-Test category 3 (concrete test) Using the materials of the following (1), fresh concrete having the composition shown in Table 4 was prepared, and slump and the like were measured by the method of the following (2). The results are shown in Table 5.

(1) Material Cement: Ordinary Portland cement (specific gravity = 3.16).

Silica fume: Micro silica 940U (trade name, manufactured by Elchem, specific gravity = 2.20).

Fine aggregate: River sand from Oi River water system (specific gravity = 2.63, FM = 2.71).

Coarse aggregate: Crushed stone from Danto (specific gravity = 2.61, FM = 6.65) (2) Method Slump: JIS-A1101 Air volume: JIS-A1128 L type flow rate: Yonezawa et al.・ Showa 63) Compressive strength: JIS-A1108 -Test Category 4 (Concrete Test) Using the materials of (1) below, fresh concrete having the composition shown in Table 6 was prepared, and slump and the like were measured by the method of (2) below. The results are shown in Table 7.

(1) Material Cement: Ordinary Portland cement (specific gravity = 3.16).

Silica fume: Micro silica 940U (trade name, manufactured by Elchem, specific gravity = 2.20).

Fine aggregate: River sand from Oi River water system (specific gravity = 2.63, FM = 2.71).

Coarse aggregate: Crushed stone from Danto (specific gravity = 2.61, FM = 6.65) (2) Method Slump: JIS-A1101 Air volume: JIS-A1128 L type flow rate: Yonezawa et al.・ Showa 63) Compressive strength: JIS-A1108 -Test Category 5 (concrete pumping test) Using the same materials as in Test Category 4, fresh concrete having the composition shown in Table 8 was prepared, and a pumping test was conducted by the method (1) below. The results are shown in Tables 9 and 10.

(1) Method The test apparatus shown in FIG. 1 was used. A pipe 21 was connected between two pump cars 11 and 12 each equipped with a hydraulic piston type pump. Pipe 21 is 6B between position P ₀ and position P _1.
→ The length is 1.5m using the Cheever tube narrowed to 5B, and after position P ₁ , each length is 5B using the straight or curved pipe, and the length between position P ₁ and position P ₂ is 10 m, 18.5 m between positions P ₂ and P ₃ , 39.5 m between positions P ₃ and P ₄ , 39.5 m between positions P ₄ and P ₅ , positions P ₅ and P between ₆ is 0.5R → rising 1m → 0.5R, actual length between the position P ₆ and the position P ₀ is a 113m, horizontal conversion by the "concrete pump method construction draft" of the architectural Institute of Japan The length is 150m. The discharge amount at position P ₆ of fresh concrete is 30 m ³ /
The pressure feeding test was performed by changing the pressure in three stages of h, 40 m ³ / h, and 50 m ³ / h. The quality of fresh concrete before and after pumping at a discharge rate of 40 m ³ / h was measured by the same method as in the case of test category 4, and the results are shown in Table 9. The discharge rate is 30 m ³
/ h, 40m ³ / h, and then measuring the pressure within the pipe 50 m ³ / pump main hydraulic and position of the pump wheel 11 in the h P ₁ ~P _5, the results shown in Table 10.

<Effects of the Invention> As is clear from the results of each table, in the present invention described above, in the highly water-reduced high-strength hydraulic cement composition having a water / binder ratio of 30100 (weight ratio) or less. ,
In actual construction, workability is remarkably improved, and high strength can be exhibited after curing.

[Brief description of drawings]

FIG. 1 is an overall view schematically showing a test apparatus used in the present invention. 11,12 …… Pump car, 21 …… Piping, P _{0 to} P ₆ …… Position

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Claims (2)

(57) [Claims] 1. A hydraulic cement composition comprising cement or a binder comprising cement and silica fume, aggregate, water and the following cement dispersant, wherein the blending ratio of silica fume in the binder is 0. 30% by weight, unit amount of binder is 400 kg / m ³ or more, water / binder ratio is 10/100 to 30/100 (weight ratio), cement dispersant content is 0.05 to 5 per 100 parts by weight of binder. A high-strength hydraulic cement composition, characterized in that it is parts by weight. Cement dispersant: A vinyl copolymer composed of a monomer unit represented by the following formula I and a monomer unit represented by the following formula II, wherein the ratio of each monomer unit is represented by the formula I. A vinyl copolymer having a monomer unit / monomer unit represented by the formula II = 1/2 to 2/1 (molar ratio) and a number average molecular weight of 500 to 6000. Formula I; Formula II; [However, R ¹ is H or CH ₃ . R ² is H or an alkyl group having 1 to 3 carbon atoms. X and Y are the same or different at the same time, alkali metal, ammonium, or organic amine. n is an integer of 3 to 30. ] 2. A monomer which forms a monomer unit represented by formula I is an alkoxypolyethylene glycol allyl ether, and a monomer which forms a monomer unit represented by formula II. The high-strength hydraulic cement composition according to claim 1, wherein the body is a dialkali metal maleate.