JP2001199754A - Mortar composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mortar composition free from material separation problem and having high fluidity and low heat-generation. SOLUTION: The objective mortar composition contains (A) 20-50 pts.wt. of an admixture containing (a1) fine powder of water granulated blast furnace slag and/or pozzolana fine powder and (a2) a substance producing ettringite, (B) 30-100 pts.wt. of aggregate fine powder having a specific gravity of >=2.7 and particle diameter of <=0.15 mm and (C) 180-390 pts.wt. of fine aggregate having a specific gravity of 2.7-4.8 and particle diameter of >0.15 mm and <=5 mm based on 100 pts.wt. of cement.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a weight mortar composition which does not separate materials and generates less heat despite a high ratio of fine aggregate to cement.

[0002]

2. Description of the Related Art Among mortars, heavy mortars using heavy aggregates having a large specific gravity are used for injecting radiation shielding walls, earthquake-resistant walls, sound insulation walls, basic structures of mechanical devices and the like. In such a weight mortar composition, there is a problem that material separation easily occurs due to a large specific gravity of the aggregate, and the fluidity of the mortar is poor. In order to improve these, 7 to 13 parts by weight of the grout admixture and 180 to 300 parts by weight of a weight aggregate having a specific gravity of 3.0 or more with respect to 100 parts by weight of the pozzolanic substance-containing Portland cement,
Then, a weight grout mortar composition to which water is added (Japanese Patent No. 2133650) has been proposed. However, with this mortar composition, the calorific value cannot be suppressed,
When used for a bulkhead of a nuclear facility having a wall thickness of 1 m or more, there is a problem that unless the number of times of driving is increased, thermal stress cracks are likely to occur. In addition, when the ratio of the weight aggregate to the cement was increased, there was a tendency that the material was separated or the fluidity was deteriorated.

[0003]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a weight mortar composition which has no material separation, has good fluidity, and generates less heat.

[0004]

Means for Solving the Problems Under such circumstances, the present inventors have conducted intensive studies and found that a specific admixture and
By using a specific fine powder aggregate, even if the ratio of the fine aggregate to the cement is high, material separation does not occur, the fluidity is good, the heat generation is small, and a mortar composition that suppresses cracking can be obtained. And completed the present invention.

That is, the present invention relates to a method of mixing (A) (a ₁ ) a granulated blast furnace slag fine powder and / or a pozzolan fine powder and (a ₂ ) a substance which forms ettringite with respect to 100 parts by weight of cement. 20 to 50 parts by weight, (B) 30 to 100 parts by weight of fine aggregate having a specific gravity of 2.7 or more and a particle size of 0.15 mm or less, and (C) a particle size of 0.15 mm with a specific gravity of 2.7 to 4.8 Over 5m
The present invention provides a mortar composition containing 180 to 390 parts by weight of fine aggregate of m or less.

Further, the present invention relates to (C) a specific gravity of 2.7 to 4.8.
Fine aggregate 180-39 with a particle size exceeding 0.15 mm and 5 mm or less
0 parts by weight is mixed with water, and 20 to 50 parts by weight of an admixture containing (A) (a ₁ ) granulated blast furnace slag fine powder and / or pozzolan fine powder and (a ₂ ) a substance generating ettringite. , (B)
Fine aggregate 30 with specific gravity of 2.7 or more and particle size of 0.15 mm or less
It is an object of the present invention to provide a method for producing mortar, which comprises mixing and mixing 100 parts by weight of cement and 100 parts by weight of cement.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The cement used in the present invention is not particularly limited as long as it is used for ordinary mortar.
For example, any one of ordinary, fast, ultra-high, moderate heat, low heat, etc. Portland cement can be used, and ordinary Portland cement, medium heat Portland cement and low heat Portland cement are particularly preferred.

The admixture of the component (A) used in the present invention comprises (a ₁ )
Granulated blast furnace slag powder and / or pozzolan powder (a ₂ )
And a substance that produces ettringite. As the fine powder of granulated blast furnace slag or fine pozzolan of the component (a ₁ ), ultrafine silica powder is preferable. Component (a ₁₎ is 40 to 80% by weight in admixture, preferably contained particularly 40 to 70 wt%. When the ratio of the granulated blast furnace slag fine powder and / or the pozzolan fine powder in the admixture is high, the non-separation characteristics particularly at low temperatures are favorable, which is preferable.

Examples of the substance that forms ettringite as the component (a ₂ ) include alumina cement and gypsum, ultra-hard cement, calcium aluminate, and Irwin, and Irwin clinker powder is particularly preferred. component
(a ₂ ) is 10 to 40% by weight, particularly 10 to 20% by weight in the admixture.
It is preferable that the content is contained by weight.

In the admixture, in addition to the components (a ₁ ) and (a ₂ ),
Further, a water reducing agent can be blended. Examples of the water reducing agent include those containing a modified lignin sulfonate as a main component (LS), those containing a polyalkylallyl sulfonate as a main component (NS), and those containing a melamine sulfonate as a main component. Examples thereof include those having a main component (MS) and those having a polycarboxylic acid as a main component (PC). One or more of these water reducing agents can be used,
It is preferable to contain 3 to 8% by weight, particularly 3 to 5% by weight in the admixture.

The admixture may further contain an antifoaming agent and a foaming agent. Examples of the defoaming agent include SN deformer (manufactured by San Nopco) and the like, and examples of the foaming agent include aluminum powder and iron powder. These antifoaming agents and foaming agents are preferably added in an amount of 0.01 to 0.2 part by weight, particularly 0.01 to 0.1 part by weight, based on 100 parts by weight of the admixture. Further, an expandable substance such as a lime-based expander and a calcium sulfoaluminate-based expander (CSA-based expander) can be added. When blending these expandable substances, 15 to 50% by weight in the admixture,
In particular, it is preferable to add 20 to 40% by weight.

[0012] Such an admixture is contained in an amount of 20 to 50 parts by weight, preferably 20 to 40 parts by weight, based on 100 parts by weight of cement. If the amount is less than 20 parts by weight, the fluidity becomes poor, and if it exceeds 50 parts by weight, material separation occurs.

As the component (B) of the present invention, a fine powder aggregate having a specific gravity of 2.7 or more and a particle size of 0.15 mm or less is used. component
The fine aggregate of (B) has a specific gravity of 2.7 or more and a particle size of 0.15 mm.
These are: Examples of such finely divided aggregates include iron grains, magnetite, iron sand, hematite, limonite, phosphorous iron, barite (barite), olivine, serpentine, converter blast slag, and steel fibers. . In particular, those having a specific gravity of 2.7 to 5 are preferable, and those having a specific gravity of 2.7 to 3.5 are more preferable.
Further, those having a particle size of not more than 0.045 mm and not less than 50% by weight are preferred. The fine powder aggregate is contained in an amount of 30 to 100 parts by weight, preferably 40 to 90 parts by weight, based on 100 parts by weight of the cement. If the amount is less than 30 parts by weight, the material separation cannot be sufficiently suppressed, and if it exceeds 100 parts by weight, the fluidity of the mortar is significantly reduced. In this case, the amount of water must be increased to secure the necessary fluidity for construction,
The specific gravity of the mortar becomes small.

The fine aggregate of the component (C) used in the present invention has a specific gravity of 2.7 to 4.8 and a particle size of more than 0.15 mm and 5 mm or less. If the particle size exceeds 5 mm, material separation easily occurs, and the filling property into small gaps decreases. As such fine aggregate, those similar to fine powder aggregate can be used. The fine aggregate is 180 to 390 parts by weight, preferably 300 to 370 parts by weight, based on 100 parts by weight of cement.
It is contained by weight. If the amount is less than 180 parts by weight, the amount of cement in the mortar becomes relatively large, so that the heat generation becomes large, and the possibility of the occurrence of thermal stress cracking becomes high.
Above the parts by weight, material separation occurs.

The mortar composition of the present invention can further contain a water-soluble polymer and a water-absorbing polymer, so that material separation can be further suppressed. Such water-soluble polymers include, for example, cellulose-based or acrylic resin-based thickeners; and the water-absorbing polymers include, for example, sodium acrylate resin.

The mortar composition of the present invention is obtained by mixing the above components, and the composition can be used by mixing with water. In addition, among the above components, first, (C) fine aggregate and water are mixed, and (A) an admixture, (B) finely divided aggregate, and cement are added to produce a mortar by further mixing. be able to. The mixing ratio of each component is preferably the same as described above.

The mortar composition of the present invention can be used for injection of radiation shielding walls, earthquake-resistant walls, sound insulation walls, substructures of mechanical equipment, and the like, and can be used as ordinary mortars and grout mortars. As the mortar hardened material, one having a dry specific gravity of 2.3 or more can be obtained, and one having a dry specific gravity of 2.15 or more specified for reinforced concrete work in JASS5N nuclear power plant facilities can be obtained. Furthermore, by compounding an intumescent substance,
It is also suitable as a filling mortar for nuclear facilities.

[0018]

The mortar composition of the present invention does not cause material separation even if the ratio of fine aggregate to cement is high, and has good fluidity. In addition, even when filling a mass mortar with a large wall thickness due to a small increase in temperature due to heat generation, thermal stress cracking is suppressed.

[0019]

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto.

Example 1 A mortar composition having the composition shown in Table 1 was produced. The components shown in the table were as shown below. The obtained mortar composition was mixed with water in an amount shown in Table 1 based on 100 parts by weight of cement in the composition, and non-separation characteristics (bleeding) were evaluated by the following method. The results are shown in Table 1.

(Cement) Ordinary Portland cement (specific gravity 3.16; manufactured by Taiheiyo Cement Co.) (fine powder aggregate) Peridotite aggregate (specific gravity 3.22;
15 mm or less, 0.045 mm or less is 50% by weight or more. (Fine aggregate) Peridotite aggregate (specific gravity 3.28; coarse grain ratio FM)
= 2.84; particle size more than 0.15 mm and 5 mm or less)

(Admixture 1) Water reducing agent: Melamine sulfonate formalin condensate-based high-performance water reducing agent (Merment F-10, manufactured by SKW) 4% by weight, thickener: methylcellulose 90SH30000 (manufactured by Shin-Etsu Chemical Co., Ltd.) 0 0.1% by weight (outside); Antifoaming agent; SN Deformer 14HP (manufactured by San Nopco) 0.1% by weight (outside); Blowing agent: aluminum powder (manufactured by Fukuda Metal Foil & Powder Industry) 0.02% by weight 96% by weight of ordinary Portland cement

(Admixture 2) Separation-preventing material: Silica ultrafine powder (Silica Fume, manufactured by Efaco) 45% by weight, Irwin type clinker powder (Clinker No.i described in JP-B-57-8057) 12% by weight %, Water reducing agent; naphthalene sulfonic acid formalin condensate-based high-performance water reducing agent (Mighty 100, manufactured by Kao Corporation) 5% by weight, defoamer: SN Deformer 14HP (manufactured by San Nopco) 0.1% by weight (outside percentage) , Foaming agent; aluminum powder (Fukuda Metal Foil & Powder Industry Co., Ltd.) 0.02% by weight (outside), filler: ordinary Portland cement 38% by weight

(Admixture 3) Separation-preventing material: Silica ultrafine powder (silica fume, manufactured by Efaco) 45% by weight, Irwin type clinker powder (Clinker No.i described in Japanese Patent Publication No. 57-8057) 12% by weight 38% by weight, water-reducing agent: naphthalene sulfonate formalin condensate-based high-performance water reducing agent (Mighty 100, manufactured by Kao Corporation) 5% by weight, defoamer; SN Deformer 14HP (manufactured by San Nopco) 0.1% by weight (outside), Blowing agent: aluminum powder (manufactured by Fukuda Metal Foil Powder) 0.02% by weight (outside)

(Admixture 4) Separation-preventing material: 60% by weight of siliceous ultrafine powder (silica fume, manufactured by Efaco), 10% by weight of Irwin clinker powder (Clinker No.i described in Japanese Patent Publication No. 57-8057) 26% by weight; water-reducing agent; naphthalenesulfonic acid formalin condensate-based high-performance water reducing agent (Mighty 100, manufactured by Kao Corporation) 4% by weight, defoamer; SN Deformer 14HP (manufactured by San Nopco) 0.1% by weight (outside), Blowing agent: aluminum powder (manufactured by Fukuda Metal Foil Powder) 0.02% by weight (outside)

(Evaluation method of non-separation characteristics) In accordance with JSCE-F542 filling mortar test method (draft) of JSCE Concrete Standard Specification Standard, kneaded mortar is filled, and the upper part is covered with a glass plate. After 3 hours, collect the bleeding water on the mortar surface. If there is no bleeding water, select ○, if there is bleeding water but a small amount that cannot be collected, and △ if there is bleeding water and can collect it. It evaluated as x.

[0027]

[Table 1]

From the results shown in Table 1, no material separation occurred in any of the mortar compositions of the present invention.

Test Example 1 A mixture of the mortar composition obtained in Example 1 and water was evaluated for temperature rise characteristics. That is, 400 cc of the mixture was collected in a plastic bag provided with a thermocouple, placed in a Dewar bottle, and a simple adiabatic temperature rise was measured. Table 2 shows the results. The mortar composition of the present invention (No.
In 8 and 9), the temperature rise was suppressed to 19 to 21 ° C.

[0030]

[Table 2]

Test Example 2 The mortar composition obtained in Example 1 was evaluated for fluidity at 20 ° C., kneading capacity, and compressive strength.
Table 3 shows the results.

(Evaluation Method) (1) Fluidity: The flow time of the J14 funnel was measured in accordance with the JSCE-F542 filling mortar test method (draft) edited by the Japan Society of Civil Engineers Standard Standard Specifications. The table flow was measured as the fluidity in the horizontal direction using a flow cone according to the JISR5201 cement physical test method. In this case, the spread of the mortar by pulling out the flow cone was measured without performing the table drop 15 times.

(2) Weight after kneading: JISA1174
The measurement was carried out in accordance with a method for testing the unit volume and mass of a polymer cement mortar that has not yet solidified and a test method (mass method) based on the mass of the amount of air. The weight mass was 400 cc, and the kneaded mortar was filled, and the kneading weight was calculated from the weight.

(3) Compressive strength: Measured in accordance with the compression test method of JSCE-F542 filling mortar test method (draft), edited by the Japan Society of Civil Engineers Standard Specifications for Concrete Specifications. That is,
A specimen of φ5 × 10cm was prepared, cured for 48 hours in a humid empty box at 20 ° C and 90% or more, then demolded and cured in water at 20 ° C until the age of 28 days. Was measured.

[0035]

[Table 3]

From the results shown in Table 3, all of the mortar compositions of the present invention have excellent fluidity in both J14 funnel falling time and table flow, and have a kneading capacity of 2.4 or more.
Compressive strength was high.

Test Example 3 With respect to the mortar composition obtained in Example 1, a kneaded mortar mixed with water was filled into a vinyl chloride tube having a diameter of 10 cm and a height of 1 m, and cut for each height after 3 days. do it,
The specific gravity was measured. Table 4 shows the results. The product of the present invention (N
In o.7 and 8), the difference in specific gravity between the upper and lower pipes was small, and it was confirmed that material separation did not occur.

[0038]

[Table 4]

Example 2 A mortar composition having the composition shown in Table 5 was produced in the same manner as in Example 1, and the non-separation characteristics (bleeding) were evaluated. However, the evaluation of non-separation characteristics was performed at 5 ° C. The results are shown in Table 5.

[0040]

[Table 5]

Test Example 4 The mortar composition obtained in Example 2 was tested.
In the same manner as in the above, fluidity, kneaded capacity and compressive strength were evaluated. However, each evaluation was performed at 5 ° C. Table 6 shows the results.

[0042]

[Table 6]

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) C04B 7: 345 C04B 7: 345 22:14 22:14 B 22:08 22:08 Z 22:14) 22 : 14) D 103: 30 103: 30 103: 32 103: 32 103: 44 103: 44 103: 48 103: 48 103: 50 103: 50 103: 60 103: 60 (72) Inventor Naoki Yamashita Koto, Tokyo 4-1-13 Toyo-ku, Toyo-Central Building Onodanai Co., Ltd. (72) Inventor Daisuke Izumi 4-1-13 Toyo, Toyo-Central Building Koto-ku, Tokyo Onodanai Co., Ltd.

Claims (2)

[Claims] (1) For 100 parts by weight of cement, (A)
(a ₁ ) Fine granulated blast furnace slag powder and / or pozzolan fine powder
(a ₂ ) an admixture 20 containing a substance that produces ettringite
To 50 parts by weight, (B) 30 to 100 parts by weight of finely divided aggregate having a specific gravity of 2.7 or more and a particle size of 0.15 mm or less, and (C) a specific gravity of 2.
Fine aggregate 1 with a particle size of more than 0.15 mm and less than 5 mm with a size of 7 to 4.8
A mortar composition containing 80 to 390 parts by weight. 2. (C) Specific gravity of 2.7 to 4.8 and particle size of 0.15 m
180 to 390 parts by weight of fine aggregate exceeding 5 m and not more than 5 mm are mixed with water to produce (A) (a ₁ ) granulated blast furnace slag fine powder and / or pozzolan fine powder and (a ₂ ) ettringite. 20 to 50 parts by weight of an admixture containing the substance, (B) 30 to 100 parts by weight of fine aggregate having a specific gravity of 2.7 or more and a particle size of 0.15 mm or less,
And a method for producing mortar, which comprises mixing and mixing 100 parts by weight of cement.