JPH1045457A - Nonshrinkage-hardening composition and its hardened body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress shrinkage by hardening and to improve flowability, handleability, compressive strength and durability by incorporating cement, a gel forming material, fine powder or acicular inorg. powder and a dispersant. SOLUTION: Cement is composed of a latent hydraulic material and a hardening stimulant and 100 pts.wt. of this cement is blended with 0.1-10 pts.wt. at least one kind of gel forming material or is further blended with 2-50 pts.wt. fine powder or acicular inorg. powder of <=10μm average particle diameter and 0.1-10 pts.wt. dispersant based on 100 pts.wt., in total, of the cement and fine powder. The gel forming material is selected from among agar-agar, agarose, amylopectin, carrageenan, xanthane gum, konjakmannan, sodium alginate, tannin and CMC.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a building and construction material,
The present invention relates to a curable composition useful as a solidifying material for civil engineering materials, landscape materials, and wastes. More specifically, as an application utilizing the ease of handling and durability of cement without shrinkage, for example, as a structural material for building, a road paving material, a building and construction material such as cement for dams, and as a solidifying material for various wastes. Regarding the composition that can be used, more specifically, building materials such as driving form materials, floor slabs, interior and exterior materials, etc., road paving materials, cement for dams, shielding materials for nuclear power plants, and civil engineering materials such as structures. The present invention relates to a composition which can be used as a solidifying material for waste such as incineration ash and various solids.

[0002]

2. Description of the Related Art Conventionally, cement, mortar, and concrete shrink when cured and dried to cause cracks, resulting in reduced strength and peeling off from reinforcing bars and the like, which have caused many problems. In such a case, an inorganic expander is often used, but a large amount of the expander is required, or there is alkali slag cement or the like in which the expander does not work.

Although various organic shrinkage reducing agents have been developed, they have an effect on the drying shrinkage of cement, but have no effect on shrinkage during hydration hardening, and have no effect unless used in large amounts. , Difficult to control. Therefore, even if they are used, it is very difficult to improve the quality of the concrete, and there is a problem that the quality of the concrete becomes poor.

[0004]

Accordingly, cracks due to shrinkage during hydration hardening of conventional cement and concrete,
Poor adhesion to reinforcing bars, etc., resulting in concrete deterioration,
Infiltration of rainwater is an unavoidable problem.

[0005]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have reached the present invention. That is, the present invention provides (1) a cement-free, curable composition containing at least one of cement, a gel-forming substance, and if necessary, fine powder, acicular inorganic powder, or a dispersant; The non-shrinkable curable composition according to the above (1), which is a combination of a latent hydraulic substance and a curing stimulant, (3) the gel-forming substance is carrageenan, sodium alginate, xanthan gum, konjac mannan,
(4) The non-shrinkable curable composition according to the above (1) or (2), containing at least one selected from agar, agarose, amylopectin, tannin, and carboxymethyl cellulose. And a cured product obtained by curing the non-shrinkable curable composition according to any one of the above.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
Specific examples of cements that can be used in the present invention include Portland cement, blast furnace cement, early-strength cement, moderate heat cement, high sulfate cement, alumina cement, fly ash cement, alkali slag cement, latent hydraulic material and hardening stimulus. And a combination of a latent hydraulic substance and a hardening stimulant.

Specific examples of the latent hydraulic substance that can be used in the above include granulated blast furnace slag, converter slag, coal ash,
Examples include volcanic ash and rice husk, and granulated blast furnace slag is preferred.

Various alkaline substances can be used as the curing stimulant. Specific examples of the curing stimulant that can be used include alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, and lithium hydroxide; alkali metal carbonates such as sodium carbonate, potassium carbonate, and lithium carbonate; and calcium hydroxide and water. Hydroxides of alkaline earth metals such as magnesium oxide, phosphates such as sodium pyrophosphate, potassium pyrophosphate, dipotassium phosphate, tripotassium phosphate, and trisodium phosphate; sodium (meth) silicate, potassium (meth) silicate And the like.

The amount of the curing stimulant used depends on its basicity (alkaline strength), the particle size of the latent hydraulic substance, the type and amount of various fine powders to be added as required, and the amount of water. However, the latent hydraulic substance and fine powder (optional component)
Is from 0.2 to 20 parts by weight, preferably from 2 to 10 parts by weight, based on 100 parts by weight of the total amount.

The gel-forming substance used in the present invention is a substance which forms a gel by reacting with Ca ⁺⁺ , Al ⁺⁺⁺ , Mg ⁺⁺ , Fe ^{+++ and the} like in cements, and melts and cools during warm weather. And a substance that forms a gel by using a crosslinking agent in combination.

Specific examples of the gel-forming substance that can be used include:
Carrageenan, sodium alginate, xanthan gum, konjac mannan, agar, agarose, amylopectin, tannin, carboxymethylcellulose, furcellane, pectin, starch, tamarind gum, curdlan,
Xansan, gellan, soy protein, gelatin, egg, fish meat protein and the like.

Among these gel-forming substances, agar, agarose, amylopectin, carrageenan, xanthan gum, konjac mannan, sodium alginate, tannin,
Carboxymethylcellulose is preferred, among which agar,
Agarose and amylopectin are particularly preferred.

The amount of these gel-forming substances used is usually 0.1 to 10 parts by weight, preferably 0.3 to 6 parts by weight, particularly preferably 0.5 to 3 parts by weight, based on 100 parts by weight of cements. is there. Here, when a latent hydraulic substance + hardening stimulant is used as cements, the term “cements” simply refers to latent hydraulic substances alone. The same applies to the following unless otherwise specified.

These gel-forming substances can be used in addition to reducing the curing shrinkage, and can also prevent the separation, bleeding or drying shrinkage of each component in the kneaded non-shrinkable curable composition of the present invention. Expansion can be expected.

The non-shrinkable curable composition of the present invention contains a fine powder if necessary. As the fine powder, those having an average particle size smaller than the average particle size of the cements, preferably smaller than the average particle size of the cements by 1 order or more, more preferably 2 orders or more are used. The preferred average particle size of the fine powder is 10 μm or less, more preferably 0.01 to 5 μm, and most preferably 0.05 to 5 μm.
1 μm.

Specific fine powders that can be used include, for example, silica fume, fly ash, silica sand, silica stone powder, clay, talc, kaolin, calcium carbonate, ground ceramic, ground cooled blast furnace slag, titania, zirconia, alumina, Aerosil, etc. are mentioned, but in addition to improving the moldability at the time of extrusion molding and the flowability at the time of cast molding, and the effect of improving the mechanical strength of the cured product after curing and curing is remarkable, It is particularly preferred to use silica fume. The amount of the fine powder to be used varies depending on the size (particle size) and type of cements and the type and amount of other various admixtures to be added as necessary, but usually 2 to 100 parts by weight of cements. 50 parts by weight, preferably 5 to 25 parts by weight.

The non-shrinkable curable composition of the present invention contains a dispersant as required. The dispersant is a polymer having a carboxylic acid group or a salt thereof in the molecule, for example, poly (meth) acrylate, acrylic acid / maleic acid copolymer, acrylic acid / maleic acid / vinyl ether copolymer, acrylic acid Itaconic acid / styrene copolymer, acrylic acid / itaconic acid / methacrylic acid / styrene copolymer, maleic anhydride / C5-C8 olefin copolymer, etc. can be used. In the above, as the C5 -C8 olefin, 2-methylbutene-1, pentene-1, hexene-
1, cyclopentene, cyclohexene and the like.
When the dispersant has a salt of a carboxylic acid group, examples of the salt include alkali metal salts such as lithium salt, sodium salt, and potassium salt, and further include ammonium salt.
Amine salts can also be used.

Further, the dispersant may be (meth) acrylic acid,
It may be a copolymer of maleic acid, itaconic acid, styrene, vinyl ethers and a copolymerizable monomer. Examples of the copolymerizable monomer include hydroxyethyl (meth) acrylate, N-vinylpyrrolidone, sodium styrene sulfonate, sodium allyl sulfonate, sodium methallyl sulfonate, vinyl acetate, methyl acrylate, ethyl acrylate, and acrylic acid. Examples thereof include butyl, acrylonitrile, methyl methacrylate, acrylamide, methacrylamide, ethylene, propylene, and isobutylene.

Specifically, sodium salt of acrylic acid / maleic acid copolymer, sodium salt of acrylic acid / itaconic acid / styrene copolymer, and sodium salt of acrylic acid / itaconic acid / methacrylic acid / styrene copolymer Sodium salt,
Sodium salt of acrylic acid / maleic anhydride / isobutyl vinyl ether copolymer, sodium salt of acrylic acid / maleic anhydride / styrene copolymer, sodium salt of maleic anhydride / 2-methylbutene-1 / pentene-1 copolymer And the like can also be used as a dispersant.

The dispersant used in the present invention is not limited to the (co) polymers mentioned here. That is, a formalin condensate of naphthalene sulfonic acid, a melamine sulfonic acid formalin condensate, a lignin sulfonic acid condensate, or the like, which is known as a water reducing agent for cement and concrete, can also be used in combination. These water reducing agents can be used alone or in combination of two or more.

The amount of the dispersant used depends on the required properties of the material (cured product of the present invention) obtained by curing the non-shrinkable curable composition of the present invention and the method of molding the composition for obtaining the cured product. Although it varies depending on the like, it is usually 0.1 to 10 parts by weight, preferably 0.3 to 6 parts by weight, particularly preferably 0.5 to 3 parts by weight based on 100 parts by weight of the total amount of cement and fine powder (optional component). It is. If the amount of the dispersant is less than 0.1 parts by weight, kneading becomes difficult or the fluidity is reduced, depending on the amount of water to be added.

The non-shrinkable curable composition of the present invention optionally contains an acicular inorganic powder. Specific examples of the acicular inorganic powder that can be used include wollastonite, sepiolite, chrysotile, amosite, and tremorite. The amount of the acicular inorganic powder used is 100 cements.
It is 2 to 50 parts by weight, preferably 5 to 25 parts by weight based on parts by weight.

In the non-shrinkable curable composition of the present invention, various admixtures can be further used, if necessary. As the admixture, for example, pulverized slowly cooled slag, ferrochrome slag, silica, alumina, talc, silica sand, silica powder,
Examples include clay, kaolin, calcium carbonate, ground ceramics, inorganic fillers such as titania, zirconia, and gravel; curing retarders such as sugar and glucose; surface treatment agents such as silane coupling agents; and pigments.

When these various admixtures are used, they are usually used in an amount of 10 to 300 parts by weight with respect to 100 parts by weight of cement in the case of an inorganic filler, a curing retarder, a surface treatment agent, a pigment and the like. Is usually 0.1 to 20 parts by weight with respect to 100 parts by weight of cements.

Further, fibers and the like can be added for the purpose of improving the toughness of the obtained cured product. Specific examples of fibers that can be used include glass fiber, carbon fiber, vinylon, nylon, aramid, polypropylene, acrylic,
Examples include fibers such as polyester, cellulose fibers, steel, and alumina fibers. The amount of fiber used is cement 1
It is usually 0.1 to 10 parts by weight based on 00 parts by weight.

The non-shrinkable curable composition of the present invention can be obtained by uniformly mixing the above components at a predetermined ratio. The non-shrinkable hydraulic composition of the present invention can be easily made into a cured product similarly to known mortar and concrete. For example, after kneading the above components together with water using a kneader such as a concrete mixer, a mortar mixer, a kneader ruder, a rotary kneader, or a roll kneader to obtain a kneaded product, a casting process, an extrusion process, a press process, etc. After curing into a molded body by a molding method, the cured body is cured. The amount of water used for kneading depends on the composition of the non-shrinkable curable composition and is not particularly limited, but is usually 10 to 100% by weight of the non-shrinkable hydraulic composition of the present invention.

Curing for curing is usually performed at room temperature to 100 ° C.
The reaction is performed at a temperature of 2 to 100 hours under a saturated vapor pressure, but the autoclave treatment may be performed at a temperature of 100 ° C. or higher for 1 to 20 hours. Alternatively, the molded body in the initial stage of wet curing can be immersed in water and cured in water. In the present invention, the higher the curing temperature is, the faster the curing tends to be. However, a temperature of room temperature to 100 ° C. is generally used.

[0028]

The present invention will be described in detail with reference to the following examples. Further, the present invention is not limited to these examples.
In the Reference Examples and Examples, parts and% are based on weight unless otherwise specified.

The flow values in the examples were measured for pastes or mortars after kneading according to JIS R5201. Further, for the fluidity of the kneaded material having a better fluidity of a flow value of 300 or more, a P funnel value (second) was measured. or,
The shrinkage was measured by a dial gauge method of JIS A1129 before and after curing. The compressive strength in the examples was determined by using a sample made of a 4 × 4 × 16 cm prismatic specimen for cement mortar made of a cured product using Tensilon (manufactured by Orientec) at a loading speed of 0.2 m.
Strength when broken by compressing at m / min (kgf / cm2)
It is.

Example 1 Ordinary Portland cement 10 in a concrete mixer
0 parts, Toyoura standard sand 100 parts, water 40 parts, naphthalenesulfonic acid formalin condensate (Mighty 150, manufactured by Kao)
1.5 parts and 1 part of carrageenan were added and kneaded to obtain a non-shrinkable curable composition of the present invention. Table 1 shows the results of measuring the flow value of the obtained composition. Next, the obtained kneaded material was placed in a 4 × 4 × 16 cm mold, allowed to stand at room temperature for 4 hours, and then steam-cured at 60 ° C. for 20 hours to obtain a cured product of the present invention.
Table 1 shows the results of measuring the shrinkage and the compressive strength of the obtained cured product. Table 1 also shows the results of measuring the flow value, shrinkage ratio and compressive strength of the kneaded product and the cured product obtained in the same manner as described above without adding carrageenan as a comparative example.

[0031]

Table 1 Flow value (mm) Shrinkage (× 10 ⁴ ) Compressive strength (kgf / cm ² ) Example 1 260 2.1 450 Comparative Example 250 18.6 430

Example 2 A mortar mixer was used to add a Blaine specific surface area of 4000 cm ² /
g blast furnace granulated slag (Nippon Steel Esment) 900 parts,
100 parts of silica fume (manufactured by Nippon Heavy Industries) and 10 parts of agarose were added and mixed with stirring for 90 seconds. Subsequently, 10 parts of an olefin-maleic anhydride copolymer (work 500, manufactured by Zeon Corporation), an aqueous solution composed of 400 parts of water and 2 parts of sugar, and 100 parts of 25% by weight caustic soda were added.
The mixture was further kneaded for 6 minutes to obtain a paste composition.

The flow value of the obtained paste composition (kneaded material) was 250 mm. Next, the obtained kneaded material was placed in a mold for compression test, allowed to stand at room temperature for 4 hours, allowed to solidify, and then subjected to steam curing in an atmosphere of a saturated vapor pressure of 60 ° C. for one day. Was measured for its physical properties. Table 2 shows the results. As a comparative example, Table 2 also shows the results of measuring the flow value, shrinkage, and compressive strength of the kneaded product and the cured product obtained in the same manner as described above without adding agarose.

[0034]

Table 2 Flow value (mm) Shrinkage rate (× 10 ⁴ ) Compressive strength (kgf / cm ² ) Example 2 250 3.4 670 Comparative example 2 270 23.8 750

Examples 3 to 5 The same operation as in Example 2 was repeated, except that the type and amount of the gel-forming substance were changed in the column of the composition of the kneaded material shown in Table 3, to obtain the kneaded material and the cured product. The results of measuring the flow value, shrinkage, and compressive strength of the kneaded and cured products are shown in Table 3 in Table 3.

[0036]

Table 3 Composition of kneaded product Physical properties of kneaded product and cured product Example Gel-forming substance Addition amount P funnel value Shrinkage ratio Compressive strength (parts) sec × 10 ⁴ kgf / cm ² 3 Xanthan gum 535 2.7 550 4 Agar 10 35 0.4 470 5 Sodium alginate 520 1.3 580

Examples 6 to 8 A planetary mixer was equipped with a Blaine specific surface area of 4000 cm.
² / g granulated blast furnace slag (Nippon Steel Esment) 900
Parts, 100 parts of silica fume (manufactured by Nippon Heavy Industries, Ltd.), 1000 parts of silica sand No. 6, and the type and amount of the gel-forming substance shown in the column of the composition of the kneaded material in Table 4, were stirred and mixed for 90 seconds.
Subsequently, an aqueous solution composed of 20 parts of the work 500, 1 part of sugar and 260 parts of water was added, and kneaded for another 10 minutes.
A mortar composition was obtained by adding 100 parts of 25% by weight of caustic soda. Subsequently, curing was carried out in the same manner as in Example 1 to obtain a cured product of the present invention. Table 4 shows the results of measuring the flow value, shrinkage ratio and compressive strength of the obtained kneaded material and cured product.
Are shown in the column of physical properties of the kneaded product and the cured product. Table 4 also shows, as a comparative example, physical properties measured for a kneaded product and a cured product obtained in the same manner without adding a gel-forming substance.

[0038]

Table 4 Composition of kneaded product Physical properties of kneaded product and cured product Example Gel-forming substance Addition amount P funnel value Shrinkage compressive strength (parts) sec × 10 ⁴ kgf / cm ² 6 Tannin 15 22 0.8 421 7 Konjac mannan 20 35 1.6 345 8 Amylopectin 5 43 3.7 480 Comparative example 25 17.5 435

Examples 9 to 11 A concrete mixer having a Blaine specific surface area of 4000 cm
² / g blast furnace granulated slag (Nippon Steel Esment) 950
Parts, 50 parts of silica fume (manufactured by Nippon Heavy Industries), 100 parts of wollastonite, and agar, 2 parts (Example 9), 5 parts (Example 10), and 40 parts (Example 11) were added and mixed. Next, 75 parts of work 500 and 300 parts of water
And 2 parts of sugar, and the mixture was further stirred and kneaded for 5 minutes to obtain a slurry having good fluidity. Next, 100 parts of 25% sodium hydroxide was mixed with the mixture to obtain a paste. These pastes were cured in the same manner as in Example 1 to obtain a cured product of the present invention. The results of measuring the flow value, shrinkage, and compressive strength of the obtained paste (kneaded product) and cured product are shown in Table 5 in the column of physical properties of the kneaded product and cured product. Table 5 also shows the physical properties of the kneaded and cured products obtained without addition of agar as comparative examples.

[0040]

Table 5 Composition of kneaded product Physical properties of kneaded product and cured product Example Gel-forming substance addition amount P funnel value shrinkage compressive strength (parts) sec × 10 ⁴ kgf / cm ² 9 agar 2 227.7 312 10 agar 520 0.9 431 11 agar 40 34 1.6 359 comparative example 25 32.5 395

[0041]

The composition of the present invention is an epoch-making curable composition which gives a cured product with less curing shrinkage than conventional cement compositions, and is excellent in fluidity and easy to handle. Material. Further, the cured product of the present invention is excellent in various strengths such as compressive strength, and has little exfoliation from reinforcing bars and the like due to small curing shrinkage, and is also excellent in durability, and is excellent in construction, construction, civil engineering, landscape materials. And a wide range of fields such as solidification materials for waste.

Claims (4)

[Claims] 1. A non-shrinkable curable composition comprising a cement, a gel-forming substance, and, if necessary, at least one of fine powder, acicular inorganic powder and a dispersant. 2. The non-shrinkable curable composition according to claim 1, wherein the cement is a combination of a latent hydraulic substance and a curing stimulant. 3. The gel-forming substance is carrageenan, sodium alginate, xanthan gum, konjac mannan, agar,
The non-shrink curable composition according to claim 1 or 2, comprising at least one selected from agarose, amylopectin, tannin, and carboxymethylcellulose. 4. A cured product obtained by curing the non-shrinkable curable composition according to claim 1.