JPH08333145A - Cement admixture, cement composition, and grouting material - Google Patents

Abstract

PURPOSE: To obtain a cement composition free from bleeding as a grouting material, excellent in resistance to material segregation, and good in dimensional stability (esp. initial dimensional stability), by using a cement admixture incorporated with a cement expanding agent, fluidizing agent and carbonaceous matter. CONSTITUTION: This cement admixture is obtained by incorporating 100 pts.wt. of a cement admixture with (A) 20-80 pts.wt. of a cement expanding agent >=4000cm<2> /g in Blaine value, (B) 0.5-13 pts.wt. of a powdery or liquid fluidizing agent such as a polyalkyl allyl sulfonate condensate, naphthalenesulfonate condensate, polycarboxylic acid salt or dextrin and (C) 20-80 pts.wt. of a carbonaceous substance having <=100μm average particle diameter and <3wt.% moisture content. The cement composition is obtained by incorporating 100 pts.wt. of a cement composition comprising cement and an admixture incorporated with 3-15 pts.wt. of the above cement admixture. The grouting material is obtained by kneading this cement composition with water.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention mainly relates to a cement admixture, a cement composition, used in the field of civil engineering / construction,
And grout material.

[0002]

2. Description of the Related Art In the field of civil engineering and construction, when constructing a large-scale concrete structure having a complicated shape, it is impossible to complete this concrete structure at once, In addition, each part of the concrete structure must be assembled or joined to complete the work. However, this method has a problem that a complete concrete structure cannot be integrated and a void is generated between the parts.

Therefore, for the purpose of integrating the concrete structure, a grout method of injecting a grout material having good fluidity is generally performed.

Physical properties required for this grout material include no shrinkage, good fluidity, excellent retention, and no bleeding, but the original purpose of the grout material is Is to integrate the structure. The most impediment to achieving this goal is the initial shrinkage of the uncured grout composition.

Conventionally, as a method for preventing such initial shrinkage, a grout composition containing fluid coke as a main component has been proposed (JP-A-3-199285). However, when this grout composition is used, there has been a problem that dimensional change becomes unstable in the middle to long term.

The present inventors have made various efforts to solve the above problems, and as a result, by using a specific cement admixture for grout, they have obtained the knowledge that the above problems can be solved and completed the present invention. I arrived.

[0007]

Means for Solving the Problems That is, the present invention is a cement admixture containing a cement expansive material, a fluidizing agent, and a carbonaceous material, and a cement containing cement and the cement admixture. The composition is a grout material containing the cement composition.

The present invention will be described in more detail below.

The cement expansive material (hereinafter referred to as expansive substance) used in the present invention is not particularly limited, and for example, calcium sulfaluminate-based expansive material or lime-based expansive material can be used. The raw material of the expansive substance, depending on the purity and cost, can be arbitrarily selected, and is not particularly limited, for example, as a CaO raw material,
CaCO ₃ substances such as limestone and slaked lime and Ca (OH) ₂ substances are Al ₂ O
_As raw materials, bauxite, aluminum residual ash, etc., and as CaSO ₄ raw materials, anhydrous gypsum, half-water gypsum,
And gypsum dihydrate and the like. In addition, impurities such as SiO ₂ , Fe ₂ O ₃ , CaF ₂ , MgO, and TiO ₂ existing in the raw material are
There is no particular limitation as long as the object of the present invention is not substantially impaired. The expansive substance can be obtained by heat-treating these raw materials. The heat treatment temperature during the heat treatment is not particularly limited, but the heat treatment temperature is usually 1.
It is preferably 100 to 1,600 ° C. The method of mixing the raw materials is not particularly limited, and an ordinary method can be used. The heat treatment method for producing the expanded substance is not particularly limited, and for example, any method such as firing with a rotary kiln or melting with an electric furnace is possible. Fineness of inflation material is preferably 4,000 cm ² / g or more in Blaine value, 6,000 ² / g or more is more preferable. Fineness of 4,000 cm ²
If it is less than / g, sufficient breathing suppressing effect and long-term dimensional stability may not be obtained. The amount of expansion material used is
20 to 80 parts by weight is preferable, and 40 to 60 parts by weight is more preferable, in 100 parts by weight of a cement admixture (hereinafter referred to as admixture) composed of an expansive substance and a fluidizing agent or a carbonaceous substance described later. If it is less than 20 parts by weight, breathing or material separation may occur, and if it exceeds 80 parts by weight, shrinkage of the uncured cement composition may increase.

As the fluidizing agent used in the present invention, a condensate of polyalkylallyl sulfonate (hereinafter referred to as PAS), a condensate of naphthalene sulfonate (hereinafter referred to as NS), a polycarboxylic acid salt (hereinafter referred to as PC) ), And dextrin (hereinafter referred to as DX) and the like. The fluidizing agent is
Although both powder and liquid can be used, it is preferable to use the powdered fluidizing agent from the viewpoint that mixing and kneading can be simplified at the time of construction. Specifically, as PAS, the trade name "Cell Flow" manufactured by Daiichi Kogyo Seiyaku Co., Ltd. and the trade name "IP" manufactured by Idemitsu Petrochemical Co., Ltd.
Examples of NS include the product name "Mighty" manufactured by Kao Corporation and the product name "Sanyo Revelon P" manufactured by Sanyo Chemical Industries. Further, examples of the PC include a product name “Quinflow” manufactured by Mitsubishi Kasei Co., Ltd. Furthermore, DX refers to starch that has been decomposed by heating with an acid to make it soluble in cold water, and is also known as roasted dextrin.
All these fluidizers can be used in powder form,
In the present invention, it is possible to use one or more of these. The amount of the superplasticizer varies depending on the type of the superplasticizer used and cannot be uniquely determined, but usually 100% by weight of the cement admixture composed of an expansive substance, a superplasticizer, and a carbonaceous substance. Of these, 0.5 to 13 parts by weight is preferable. If the amount of the fluidizing agent used is less than 0.5 parts by weight, sufficient fluidity may not be obtained, and if it exceeds 13 parts by weight, the strength development may deteriorate.

The carbonaceous material used in the present invention is not particularly limited, and examples thereof include flue coke, petroleum coke, coal coke, anthracite, and carbon black, and one or more of these are used. Can be used. The carbonaceous material has an average particle size of 100 μm.
The following is preferable, and 50 μm or less is more preferable. If the average particle size of the carbonaceous material exceeds 100 μm, the effects of the present invention may not be sufficiently exhibited. The water content of the carbonaceous material is the amount of water contained in the carbonaceous material, and the smaller the water content, the larger the expansion amount when uncured. Specifically, it is preferably less than 3% by weight, more preferably 1% by weight or less. If the water content of the carbonaceous substance is 3% by weight or more, the effects of the present invention may not be sufficiently exhibited. The amount of carbonaceous material used is
In 100 parts by weight of the admixture, 20-80 parts by weight is preferable, 40-60
More preferably parts by weight. If it is less than 20 parts by weight, the initial expansion effect of the uncured cement composition is not sufficient, and if it exceeds 80 parts by weight, breathing or material separation may be likely to occur.

The amount of the admixture used in the present invention varies depending on the purpose of use, but is usually 3 to 15 parts by weight, preferably 5 to 100 parts by weight of a cement composition (hereinafter referred to as composition) consisting of cement and the admixture. 12 parts by weight is more preferred. If it is less than 3 parts by weight, sufficient dimensional stability may not be obtained, and if it exceeds 15 parts by weight, it may overexpand.

Examples of the cement include various types of portland cements such as normal, early strength, ultrafast strength, and moderate heat, various mixed cements obtained by mixing these portland cements with a pozzolanic substance, and alumina cement.

In the method for mixing the cement admixture and the cement composition of the present invention, the respective materials may be mixed at the time of construction, or part or all of them may be mixed in advance. As a mixing device used when producing a cement kneaded product containing the cement composition and water of the present invention, any existing stirring device can be used,
For example, a tilting barrel mixer, an omni mixer, a V-type mixer, a Henschel mixer, a Nauta mixer and the like can be used.

In the present invention, in addition to the composition, metal powder such as aluminum powder and iron powder, setting regulator, AE agent, AE water reducing agent, high performance AE water reducing agent, thickener, bone such as sand and gravel Materials, cement rapid hardening materials, rust preventives, antifreezing agents, polymer emulsions, clay minerals such as bentonite and montmorillonite, ion exchangers such as zeolite, hydrotalcite and hydrocalumite, inorganics such as aluminum sulfate and sodium sulfate One or more of sulfates, inorganic phosphates, boric acid and the like can be used together within a range that does not substantially impair the object of the present invention.

[0016]

The present invention will be described in detail below with reference to examples.

Example 1 An admixture comprising an expanding substance and a carbonaceous substance a shown in Table 1 was prepared in 10 parts by weight of superplasticizer A. 9 parts by weight of the prepared admixture was used in 100 parts by weight of the composition, and 100 parts by weight of sand and 35 parts by weight of water were mixed to prepare a mortar. The produced mortar was observed for the presence or absence of breathing, and the J ₁₄ funnel value, compressive strength, and expansion coefficient were measured. The results are also shown in Table 1.

<Materials used> Expanding substance α: calcium sulphoaluminate type, fine powder obtained by crushing “Denka CSA # 20” manufactured by Denki Kagaku Kogyo, Blaine value 6,100 cm ² / g Inflating substance β: lime type, Chichibu Fine powder obtained by crushing Onoda Cement's "Onoda Expan", Blaine value 6,150 cm ² /
g Cement: Ordinary Portland cement manufactured by Denki Kagaku Kogyo Co., Ltd., Blaine value 3,200 cm ² / g Superplasticizer A: PAS, Daiichi Kogyo Seiyaku Co., Ltd. trade name “Selflo-110P”, powdery carbonaceous material a: TOSCO company Made "Flude Coke"
Dried product, water content 0.2% by weight, average particle size 43μm Sand: Niigata Prefecture Himekawa 5mm sewage: Tap water

<Measurement method> Breathing: Measured according to JIS A 1123 J ₁₄ funnel value: J ₁₄ funnel flow-down value after 30 minutes from kneading, according to the measurement of the consistency by J funnel of JSCE standard Compressive strength: 4 Specimen of × 4 × 16cm was prepared and JIS A 11
According to 08, the compressive strength for one day is measured. Expansion coefficient: Appendix of "Construction Guideline for Expansive Concrete Design (Draft)" Appendix 2. Initial expansion and contraction rate measured according to the document "Method for measuring expansion rate of filled mortar using expansion material". However, -in the table indicates a contraction side, and + indicates an expansion side.

[0020]

[Table 1]

Example 2 The procedure of Example 1 was repeated, except that an admixture consisting of 45 parts by weight of the expanding substance α, the fluidizing agent shown in Table 2, and 45 parts by weight of the carbonaceous substance a was prepared. However, in the case of changing the amount of the fluidizing agent used, the amounts of the expansive substance and the carbonaceous substance were increased / decreased by 10 parts by weight, respectively. The results are also shown in Table 2.

<Materials used> Superplasticizer B: NS, product name “Mighty 100” manufactured by Kao Co., Ltd. Superplasticizer C: PC, product name “Quinflow 7” manufactured by Sanyo Kasei Co., Ltd.
50 ”Superplasticizer D: DX, product name“ HI ”manufactured by Nippon Constarch Co., Ltd.
DEX106 ”Superplasticizer E: Superplasticizer A / Superplasticizer C Weight ratio of 85/15 Mixture Superplasticizer F: Superplasticizer B / Superplasticizer D Weight ratio of 85/15

[0023]

[Table 2]

Example 3 The same procedure as in Example 1 was carried out except that the admixture consisting of the expanding substance and the carbonaceous substance shown in Table 3 was prepared in 10 parts by weight of the superplasticizer A. The results are also shown in Table 3.

<Materials used> Carbonaceous substance b: commercially available carbon black, water content 0.1% by weight, average particle size 27 μm Carbonaceous substance c: crushed and dried anthracite from Hongai, 0.2% by weight water content, average particle size 36 μm

[0026]

[Table 3]

Example 4 An admixture consisting of 45 parts by weight of expansion substance α, 10 parts by weight of superplasticizer A, and 45 parts by weight of carbonaceous substance a was prepared, and the admixture shown in Table 4 was mixed in 100 parts by weight of the composition. Except for the above, the same procedure as in Example 1 was performed. The results are also shown in Table 4.

[0028]

[Table 4]

[0029]

EFFECTS OF THE INVENTION By using the cement admixture of the present invention, there is no bleeding and excellent material separation resistance,
Moreover, it is possible to obtain a cement composition having good dimensional stability, particularly, initial dimensional stability.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location // C04B 103: 30 103: 60 111: 70

Claims (3)

[Claims] 1. A cement admixture containing a cement expansive material, a fluidizing agent, and a carbonaceous substance. 2. A cement composition comprising cement and the cement admixture according to claim 1. 3. A grout material containing the cement composition according to claim 2.