JP2627253B2 - Grout material for cable coating - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a grout material for covering a cable, which is mainly used for covering a suspension structure (cable) of a cable-stayed PC bridge.

[0002]

2. Description of the Related Art Conventionally, a cement (hydraulic composition) slurry is used as a grouting material (hereinafter, abbreviated as a grouting material for cable coating) to be injected into a gap between a cable of a cable-stayed PC cable and a cable cladding tube. Although it is used, the cured cement (hydraulic composition) slurry generally has a small tensile strength and a small tensile strain, and thus has a disadvantage that cracks occur when subjected to a post-load. In order to solve this drawback, a grout material based on polymer cement (hydraulic composition composite) has been proposed (JP-A-59-45552, JP-A-59-135281, Tsuyoshi Kobayashi et al .; "Cable grout"). Properties of Polymer Semeton as Materials ", Proceedings of the 38th Annual Meeting of the Japan Society of Civil Engineers, 5
P. 263-264, 1983).

[0003]

However, these grout materials for covering cables also have poor workability (workability) due to lack of fluidity (free flow value, flow down time) at the time of slurry preparation, and after curing. The tensile strength and tensile strain of the cured product are not yet sufficient. The present invention overcomes the above-mentioned problems of the prior art, and is excellent in fluidity at the time of slurry preparation and workability at the time of construction, and for easily obtaining a cured body having excellent tensile strength and tensile strain. Grout material is to be provided.

[0004]

According to the present invention, (P)
An average particle size of 30 to 50 obtained by emulsion polymerization of one or more unsaturated monomers having a carboxylic acid (salt) group and / or a sulfonic acid (salt) group with a (meth) acrylate ester.
The present invention provides a grout material for cable coating, which is a polymer hydraulic composition composite comprising a 200 nm acrylic micropolymer emulsion and (C) a hydraulic composition.

Since the grout material for a cable of the present invention comprises a polymer hydraulic composition composite comprising (P) an acrylic micropolymer emulsion and (C) a hydraulic composition, the (P) acrylic micropolymer emulsion and (C) )
Since the hydraulic composition is uniformly and finely dispersed, the fluidity at the time of slurry preparation is improved, so that the workability at the time of slurry application is improved, and further, such a polymer hydraulic composition composite is densely packed. Due to the hardening, the tensile strength, the tensile strain and the like of the hardened body are significantly increased.

Hereinafter, the grout material for covering a cable according to the present invention will be described in detail. The unsaturated monomer having a carboxylic acid (salt) group (hereinafter abbreviated as an unsaturated carboxylic acid (salt)) used in the preparation of the (P) acrylic micropolymer emulsion used in the present invention is acrylic acid. Methacrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid and their half esters, half amides and salts thereof, and the like. Particularly preferred. Specific examples of the unsaturated monomer having a sulfonic acid group (hereinafter, abbreviated as unsaturated sulfonic acid (salt)) include styrene sulfonic acid, α-methylstyrene sulfonic acid and salts thereof, -Acrylamide-2
-Methylpropanesulfonic acid, 2-methacrylamide-
Sulfonic acid monomers such as 2-methylpropanesulfonic acid, 2-acrylamidobutanesulfonic acid, 2-acrylamidobutane-2-sulfonic acid and salts thereof, and vinylsulfonic acids and salts thereof are exemplified. Preferably, styrene sulfonic acid, 2-acrylamide-2-
Methylpropanesulfonic acid or a salt thereof. The amount of these used is generally 0.1 to 10% by weight based on the total amount of monomers excluding the reactive monomer.

As the (meth) acrylate, acrylates having an ethylenic double bond (eg, methyl acrylate, ethyl acrylate, butyl acrylate, octyl acrylate, 2-ethylhexyl acrylate), Methacrylates (eg, methyl methacrylate, ethyl methacrylate, butyl methacrylate,
Octyl methacrylate) and the like. These (meth) acrylates may be used alone,
Two or more kinds may be used in combination. Further, in order to improve strength, water resistance, and chemical stability, it is preferable to copolymerize a crosslinking agent having a plurality of functional groups in one molecule.
Examples of these crosslinking agents include trimethylolpropane triacrylate, glycidyl acrylate, glycidyl methacrylate, bisphenol A polyoxyethylene adduct di (meth) acrylate, triallyl isocyanurate, and N-methylol (meth) acrylamide. It is preferable that trimethylolpropane triacrylate is used after being copolymerized at 0.1 to 5% by weight with respect to the unsaturated monomer of the core portion and / or shell portion described below. Furthermore, in the present invention, (P) monomers other than acrylic monomers, for example, styrenes such as styrene and α-methylstyrene, and dienes such as butadiene and isoprene, as long as the performance of the acrylic micropolymer emulsion is not impaired. And vinyl esters such as vinyl acetate and vinyl propionate, and nitriles such as acrylonitrile and α-methylacrylonitrile.

In the (P) acrylic micropolymer emulsion most preferably used in the present invention, the resin composition of the particles differs between the inner layer (core) and the outer layer (shell).
It is composed of polymer fine particles having a shell type heterostratified structure, wherein the weight ratio of the unsaturated monomer constituting the core portion and the shell portion is 4/6 to 9/1, and the unsaturated monomer in the core portion Wherein the weight composition of the alkyl group has 1 to 8 carbon atoms 55 to 100% by weight alkyl acrylate alkyl group has 1 to 4 carbon atoms 0 to 45% by weight alkyl methacrylate unsaturated carboxylic acid or / And 0 to 5% by weight of unsaturated sulfonic acid or a salt thereof as a crosslinking agent, and the weight composition of the unsaturated monomer in the shell portion is such that the alkyl group has 1 to 8 carbon atoms. 49.9% by weight Alkyl acrylate Alkyl group having 1 to 4 carbon atoms 45 to 90% by weight Alkyl methacrylate Ethylenically unsaturated carboxylic acid and / or ethylenic 0.1 to 10% by weight Unsaturated sulfonic acid or salt thereof Crosslinking agent 0-5% by weight It is obtained by an essential component.

As the emulsifier for emulsion polymerization used for preparing the (P) acrylic micropolymer emulsion used in the present invention, the following anionic and nonionic emulsifiers are used.

[Representative Examples of Anionic Emulsifier] (1) Polyoxyalkylene alkylaryl ether sulfonate sulfate salt

Embedded imageR₁: C₆~₂₀Alkyl group n: 0-100, preferably 5-40 M₁Monovalent or divalent cation (2) polyoxyalkylene alkyl ether sulfate
Salt

Embedded image R ₁ —O— (AO) n—SO ₃ M ₁ (wherein R ₁ , A, n and M ₁ are the same as described above) (3) Polyoxyethylene alkyl aryl ether sulfate salt

Embedded image (Wherein, R ₁ , A, n and M ₁ are the same as above)

Embedded image M₁, A, n: Same as above R_Two: Hydrogen atom or methyl group R_Three: C₁~ C₃₀Alkyl, alkenyl or alkyl
Phenyl group having a phenyl or alkenyl group, fatty acid
residue

Embedded image (In the formula, M ₁ , A, n, R ₂ and R ₃ are the same as described above.)

Embedded image (Where M₁, A, n, R_TwoAnd R_ThreeIs the same as above)

Embedded image (Where M₁, A, n, R_TwoAnd R_ThreeIs the same as above)

Embedded image (Where M₁, A, n, R_TwoAnd R_ThreeIs the same as above m: 0,1 R_Four: -CH_Two-, -CH_TwoCH_Two-Or phenylene group)

Embedded image (M ₁ , A, n, m, R ₂ , R ₃ and R ₄ are the same as above)

[Typical examples of nonionic emulsifiers]

Embedded image (10) Polyoxyalkylene alkyl aryl ether
(In the formula, p is 0 to 100, preferably 5 to 70, and R ₂ and A are the same as described above.)

(11) Polyoxyalkylene alkyl ether R ₁ -O- (AO) pH (wherein R ₁ , A and p are the same as above)

These anionic emulsifiers and nonionic emulsifiers can be used alone or in combination of two or more, but it is preferable to use one or more emulsifiers having ethylene oxide and propylene oxide groups in the molecule. More preferably, the compound of the above (1) as an anionic emulsifier and the above (1) as a nonionic emulsifier
It is desirable to use one or more compounds of 0) or (11). These emulsifiers are used in an amount of 0.5
It is good to use in the range of 15 to 15% by weight, preferably 1 to 10% by weight.

Examples of the polymerization initiator include, for example, hydrogen peroxide alone or a combination of hydrogen peroxide and a carboxylic acid such as tartaric acid, citric acid and ascorbic acid, or hydrogen peroxide and oxalic acid, sulfinic acid and salts or oxyacids thereof. Combinations with aldehydes, water-soluble iron salts, etc., as well as peroxides such as persulfates, percarbonates, perborates, and 2,2'-azobis (2-aminodipropane) and salts thereof, 2'-azobis (N, N'-dimethylene-isobutylamidine)
And its salts, and water-soluble azo initiators such as 4,4'-azobis (4-cyanovaleric acid) and its salts. For the preparation of the acrylic water-dispersible resin used in the present invention, it is preferable to use the above water-soluble azo initiator in an amount of 0.1 to 3% by weight of the unsaturated monomer mixture.

The (P) acrylic micropolymer emulsion used in the present invention can be prepared by the following general emulsion polymerization method using the above unsaturated monomer, emulsifier, and polymerization initiator. That is, after dissolving the emulsifier in the aqueous phase and emulsifying and solubilizing a part of the core unsaturated monomer, a polymerization initiator is added, and then the core unsaturated monomer and the shell unsaturated monomer are added. Emulsion polymerization can be prepared by any of the monomer dropping method in which the monomer is dropped in the order of the body, or the emulsifier, a method in which a part of water and an unsaturated monomer are previously mixed and emulsified by a pre-emulsification method in which the unsaturated monomer is dropped. The use of the pre-emulsification method is more preferable in order to reduce the amount of the polymer adhering to the polymerization vessel or the stirring blade, which is a disadvantage. In particular, when producing an acrylic water-dispersible resin having a core-shell type heterostratified structure, a point to be noted is that the polymerization of the core part and the polymerization of the shell part become block-type bonds, and therefore, the core After the completion of the polymerization, the aging is preferably performed for several minutes to several hours. The (P) acrylic micropolymer emulsion used in the present invention has a viscosity of 10 to 1000 cp at a solid content of 40% by weight.
(Brookfield viscometer), which has good workability and low viscosity can contain 50% or more of solids.

It is desirable that the (P) acrylic micropolymer emulsion used in the present invention has an average particle size of 30 to 200 nm, preferably 150 nm or less, more preferably 100 nm or less.
If it exceeds 200 nm, the effect of improving the strength and weather resistance of the cured product is often insufficient.

The acrylic micropolymer emulsion (A) used in the present invention can be easily obtained by emulsion polymerization as described above, but can be incorporated into the composition in the form of the obtained emulsion. In this case, the amount of the resin used is 10 to 40 parts by weight as a solid content based on 100 parts by weight of the hydraulic composition (C). If the amount is less than 10 parts by weight, the cured product obtained has poor bending strength, tensile strength and tensile strain. Conversely, if the amount exceeds 40 parts by weight, the compressive strength decreases.

The hydraulic composition (C) used in the present invention includes:
Cements such as portland cement, fly ash cement, silica cement, blast furnace cement and gypsum cement, and gypsums such as hemihydrate, dihydrate, and hexahydrate gypsum. Any of these may be used. Particularly preferred hydraulic compositions are cements. In the present invention, when a grout material for cable coating is prepared using (P) an acrylic micropolymer emulsion and (C) a hydraulic composition, the grout material depends on the fluidity (free flow value, falling time) of the slurry. And 25 to 4 parts by weight of water with respect to 100 parts by weight of the hydraulic composition cement.
0 parts by weight can be added. Further, in the present invention, in order to improve the performance of the grout material for cable coating, inorganic substances (cement admixture materials) such as silica fume, fly ash, blast furnace slag, fine sand, mica, stone powder, glass powder, aluminum powder and lignin are used. Sulfonic acid (salt), resin acid (salt), higher fatty acid (salt), naphthalene sulfonic acid (salt), formalin condensate, aromatic aminosulfonic acid (salt) compound, polystyrene sulfonic acid (salt), poly ( (Chemical) Acrylic acid (salt) compound, polyalkylene glycol, methylcellulose, hydroxyethylcellulose, nitrite, 1-hydroxyethane 1,1-diphosphonic acid (salt) and other known chemical admixtures for cement (AE agents, Water reducing agent, fluidizing agent, defoaming agent, humectant, rust inhibitor, etc.). In order to obtain the cable cladding material of the present invention, the (P) acrylic micropolymer emulsion and the (C) hydraulic composition may be appropriately mixed, but the (P) acrylic micropolymer emulsion can be easily and uniformly prepared. Since (C) the hydraulic composition is finely dispersed, the (P) acrylic micropolymer emulsion and (C) the hydraulic composition can be blended and prepared in the same manner. The composition (A) may be prepared by dividing and blending the acrylic micropolymer emulsion (A).

[0018]

The polymer hydraulic composition composite slurry prepared by mixing the (P) acrylic micropolymer emulsion and (C) hydraulic composition used in the present invention has a free flow value, a flow time and the like. In addition, since the cured product has excellent tensile strength and tensile strain, etc., the grout material for cable coating of the present invention using this material as a main component is superior to a conventional product when injected into a gap with a cable cladding tube. The work is easy and the injection time can be greatly reduced. In addition, since a cured product of the uniform and dense polymer hydraulic composition composite is obtained, a cable having excellent strength characteristics can be provided.

[0019]

The present invention will now be described more specifically with reference to examples and comparative examples. The parts and percentages shown below are based on weight.

[Preparation of polymer cement slurry] JI
The ordinary portland cement and the acrylic micropolymer emulsions shown in Tables 1 and 2 were kneaded using a kneader specified in SR5201 (physical test method for cement) to prepare a polymer cement slurry. At this time, the polymer cement ratio (%) was adjusted to 25.0 and the water cement ratio (%) was adjusted to 33.0. [Evaluation of Fluidity of Polymer Cement Slurry] The polymer cement slurry was evaluated for fluidity by measuring the following free flow value and flow time. -Free flow value The flow value (mm) was measured 30 minutes and 1 hour immediately after the preparation of the polymer cement slurry according to JIS R5201.・ Flowing time Standard of Japan Society of Civil Engineers [PC grout test method (JSCE-198
According to 6)] was measured efflux time of the polymer cement slurry (in seconds) using a J ₁₄ funnel. [Evaluation of performance of cured polymer cement] The following properties of the cured polymer cement were measured and evaluated. The cured product was cured under a humid air condition at 20 ° C. and a relative humidity of 80%, and was then air-dried at 20 ° C. and a relative humidity of 65% for 26 days. -Compressive strength, static modulus of elasticity Standard of Japan Society of Civil Engineers [PC grout test method (JSCE-198
6)], a compression strength test was performed. Further, a wire strain gauge having a gauge length of 20 mm was attached to the height, the center, and the symmetrical position of the side surface of the test specimen for compressive strength test, the compressive strain was measured, and the static elastic modulus was obtained. -Tensile strength and tensile strain A tensile strength test was performed according to ASTM C190. A gauge length of 20 mm at the center of the stress concentration part of the specimen for tensile test
And a tensile strain was measured. Table 3 shows the above results. The emulsion N
o. Nos. 1 to 3 are examples of the present invention. 4 and 5 are comparative examples. From Table 3, emulsion No. The fluidity and the performance of the cured product of the polymer cement slurry according to the present invention using Nos. 1 to 3 are remarkably good. It can be seen that the physical properties of the polymer cements using Nos. 4 to 5 are greatly improved. In addition, the emulsion No. 1 according to the present invention. A polymer cement slurry using No. 1 was applied to a PC cable-stayed bridge cable on site. As a result, the injection time can be greatly reduced, the workability (workability) is also greatly improved, and the cured product exhibits excellent compressive strength, static elastic modulus, tensile strength and tensile strain. It was confirmed that such a polymer cement was suitable as a grout material for cables.

Acrylic polymer emulsion

[Table 1]

Emulsifier for acrylic micropolymer emulsion

[Table 2]

Performance of polymer cement

[Table 3]

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location C23F 11/00 C23F 11/00 F D07B 1/00 D07B 1/00 E04G 21/12 104 E04G 21 / 12 104D (72) Inventor Kyoichi Notoya 7-21-1, Nishishinjuku, Shinjuku-ku, Tokyo Nihon Kasei Co., Ltd. (56) References JP-A-1-164747 (JP, A) JP-A-63-260846 ( JP, A)

Claims (2)

(57) [Claims] 1. Average particles obtained by emulsion polymerization of (P) one or more unsaturated monomers having a carboxylic acid (salt) group and / or a sulfonic acid (salt) group with a (meth) acrylic ester. A grout material for cable coating, which is a polymer hydraulic composition composite comprising an acrylic micropolymer emulsion having a diameter of 30 to 200 nm and a hydraulic composition (C). 2. The grout material for cable coating according to claim 1, wherein the acrylic micropolymer emulsion is a crosslinked acrylic micropolymer emulsion.