JP3390080B2 - Cement admixture and cement composition for grout - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly relates to a cement admixture and a cement composition for grout used in the civil engineering and construction industry.

[0002]

2. Description of the Related Art Cement is a widely used material because it can produce large structures at low cost, but it has the problem of shrinking, and many cements are used to compensate for this shrinkage. Cement admixtures have been proposed (JP-A-53-13650, JP-A-53-31170, etc.). These cement admixtures impart expandability and are excellent materials for supplementing shrinkage of cement.

As a cement admixture for grout, there has been proposed a cement admixture containing an ordinary expansive substance and a fluidizing agent as main components (Japanese Patent Publication No. 48-9331 and Japanese Patent Publication No. 56-6381).
Issue bulletin). However, all of these materials are excellent in workability and filling property and can smoothly complete the grout work, but recently, the physical properties required for the grout material have been remarkably increased, and these physical properties are satisfied. The reality is that there are cases where it cannot be done.

The required physical properties of the grout material include no shrinkage, good fluidity, excellent retention, and no bleeding, and all of these required properties are satisfied. Required to do so.

Recently, cement compositions containing finely ground blast furnace slag, fly ash and other latent hydraulic substances have been positively used for the purpose of improving fluidity and preventing breathing.

[0006] However, conventional cement admixtures for grout do not exhibit sufficient expandability even when admixed with a cement composition containing a latent hydraulic substance, have poor non-shrinkability, and have the desired structure. There was a problem that it was not possible to integrate them.

The present inventor has conducted various studies to solve the above problems, and as a result, obtained the knowledge that the above problems can be solved by using a specific cement admixture, and completed the present invention. .

[0008]

Means for Solving the Problems That is, the present invention is an expansive substance produced by heat-treating a mixture containing a CaO raw material and a CaSO ₄ raw material, and is composed of a mineral containing CaO and CaSO ₄ as active ingredients. And, the amount of CaSO ₄ in the mineral is 10 to 50 parts by weight in a total of 100 parts by weight of CaO and CaSO ₄ Blaine value 4,000 cm
A cement admixture for grouting, which comprises a swelling substance of ² / g or more and a fluidizing agent, wherein the grouting is obtained by blending the swelling substance, the fluidizing agent and amorphous calcium aluminate. A cement admixture for use in cement, which comprises a cement and a cement admixture for the grout.

The present invention will be described in more detail below.

The raw material of the expansive substance used in the present invention can be arbitrarily selected depending on the purity and cost and is not particularly limited. For example, the CaO raw material is CaCO such as limestone or slaked lime. ₃ quality and Ca (OH) ₂ quality,
Further, examples of the CaSO ₄ raw material include anhydrous gypsum, hemi-water gypsum, and dihydrate gypsum. The mixing of impurities such as SiO ₂ , Fe ₂ O ₃ , CaF ₂ , MgO, and TiO ₂ existing in the raw material is not particularly limited as long as it does not substantially impair the object of the present invention.

The blending ratio of various raw materials in the present invention is such that CaSO ₄ in the expanded material as a product is 1 in total of CaO and CaSO _4.
It is necessary to be 10 to 50 parts by weight in 00 parts by weight, and preferably 20 to 40 parts by weight.
When CaSO ₄ is less than 10 parts by weight, the strength development may deteriorate, and when it exceeds 50 parts by weight, sufficient dimensional stability may not be obtained.

[0012] In the present invention, the desulfurization temperature of gypsum varies greatly depending on the mixing ratio of raw materials and the content of impurities. Therefore, the firing temperature at the time of firing is not particularly limited, but it is usually from 1,100 to 1,600. C. is preferable. 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 expansive 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.

The particle size of the expansive substance is 4,000 cm ² in terms of Blaine value.
/ g or more, preferably 5,000-9,000 cm ² / g, 6,000-
7,000 cm ² / g is more preferable. Breathing is likely to occur at less than 4,000 cm ² / g, and 9,000 c at more than 9,000 cm ² / g.
It is difficult to grind until it exceeds m ² / g, and there is a tendency that an increase in its use effect cannot be expected.

The fluidizing agent used in the present invention is one that imparts fluidity to a cement kneaded product, and is, for example, a polyalkylallyl sulfonate condensate, a naphthalene sulfonate condensate, or a polycarboxylic acid. Examples thereof include acid salts and dextrin. Specifically, as condensates of polyalkylallyl sulfonates, trade name "Cellflow 110P" manufactured by Daiichi Kogyo Seiyaku Co., Ltd., trade name "IPC" manufactured by Idemitsu Petrochemical Co., Ltd., and condensation of naphthalene sulfonates As a thing
The product name "Mighty 100" manufactured by Kao, the product name "Sanyo Revelon P" manufactured by Sanyo Chemical Co., Ltd., and the polycarboxylate include the product name "Quinflow 750" manufactured by Mitsubishi Kasei. The dextrin refers to a starch that is decomposed by heating with an acid to be soluble in cold water, and is also known as a roasted dextrin. All of these fluidizing agents can be used in the form of powder, and in the present invention, one or more of these can be used.

The blending amount of the superplasticizer of the present invention cannot be uniquely determined depending on each material, but it usually consists of an expansive substance and a superplasticizer, and the expansive substance, amorphous calcium aluminate described later, And preferably 0.5 to 13 parts by weight in 100 parts by weight of cement admixture for grout consisting of a fluidizing agent,
2 to 10 parts by weight is more preferable. If it is less than 0.5 part by weight, sufficient fluidity may not be obtained, and if it is used in excess of 13 parts by weight, strength development may be deteriorated.

The amorphous calcium aluminate used in the present invention is obtained by melting a CaO raw material and an Al ₂ O ₃ raw material and quenching the resulting clinker. Melting temperature varies depending on impurities, but is 1,500 to 1,700 ℃
Is preferred.

Amorphous calcium aluminate has a Ca content
It is preferable that the O content is 35 to 45% by weight. CaO content is
If it is less than 35% by weight, the expandability may be insufficient.
If it exceeds the weight%, the fluidity may be lowered and the workability may be deteriorated.

The particle size of the amorphous calcium aluminate is not particularly limited, and the Blaine value is 2,000 to 6,000.
cm ² / g is preferred. If it is less than 2,000 cm ² / g, sufficient dimensional stability may not be obtained, and if it exceeds 6,000 cm ² / g, the fluidity may deteriorate.

The amount of the amorphous calcium aluminate used is preferably 10 to 40 parts by weight, preferably 20 to 40 parts by weight, based on 100 parts by weight of the cement admixture for grouting, which comprises an expansive substance, amorphous calcium aluminate and a fluidizing agent. 30 parts by weight is more preferred. If it is less than 10 parts by weight, the strength development may be poor, and if it exceeds 40 parts by weight, sufficient dimensional stability may not be obtained.

In the present invention, the expanding material and the superplasticizer, or the expanding material, the amorphous calcium aluminate and the superplasticizer are used as a cement admixture for grout.

The amount of the cement admixture for grout according to the present invention varies depending on the purpose for which it is used, but usually 3 out of 100 parts by weight of cement and the cement admixture for grout is used.
-15 parts by weight is preferable, and 5-12 parts by weight is more preferable.
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.

Here, as the cement, normal, early strength,
Super early strength, and various Portland cements such as moderate heat, various mixed cements obtained by mixing a pozzolanic substance with these Portland cements, and alumina cements, and the like, but particularly mixed cements for the grout of the present invention cement admixture The effect is remarkable when used.

Further, it is preferable to use cement in combination with a latent hydraulic substance from the viewpoint of increasing the resistance to material separation and preventing bleeding.

Here, the latent hydraulic substance refers to a pozzolanic substance which does not have hydraulic properties by itself and exhibits hydraulic properties by reacting with an alkali, and specifically, blast furnace slag, fly ash, and silica fume. And silica flour. In the present invention, one or more of these can be used. The compounding amount of the latent hydraulic substance is not particularly limited, but it is usually preferably less than 80 parts by weight with respect to 100 parts by weight of the total of the cement composition including the cement and the cement admixture for grout. If the compounding amount of the latent hydraulic substance exceeds 80 parts by weight, the initial strength development may be deteriorated.

Any existing stirring device can be used as a mixing device for producing a cement kneaded product by using the cement admixture for grout or the cement composition of the present invention. A mixer, an omni mixer, a V-type mixer, a Henschel mixer, a Nauta mixer, etc. can be used. The materials may be mixed at the time of construction, or a part or all of them may be mixed in advance.

In the present invention, in addition to the cement admixture for cement and grout, a setting regulator, an AE agent, an AE water reducing agent,
High performance AE water reducing agent, thickening agent, aggregate such as sand and gravel, cement rapid hardening material, rust preventive, antifreeze, polymer emulsion, clay mineral such as bentonite, zeolite, hydrotalcite, and hydrocalumite One or two or more of ion exchangers such as aluminum sulfate, inorganic sulfate such as aluminum sulfate and sodium sulfate, inorganic phosphate, boric acid, and metal powder such as aluminum powder and iron powder. It is possible to use them together so long as the purpose is not substantially impaired.

[0027]

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

Example 1 Limestone powder was used as a CaO raw material, and natural anhydrous gypsum was used as a CaSO ₄ raw material, and the mixture was burned at a maximum firing temperature of 1,40.
The clinker obtained was calcined at 0 ° C. using a rotary kiln, and the resulting clinker was adjusted to a Blaine value of 7,000 ± 200 cm ² / g to obtain expanded materials having different CaSO ₄ amounts as shown in Table 1. A cement admixture for grout (hereinafter referred to as cement admixture) consisting of 93 parts by weight of cement, 90 parts by weight of expansion material, 8.5 parts by weight of superplasticizer a, and 1.5 parts by weight of superplasticizer b,
Cement and a cement admixture were mixed in a total of 100 parts by weight, and further 100 parts by weight of fine aggregate and 35 parts by weight of water were mixed to prepare a mortar. The J ₁₄ funnel value of the produced mortar after 30 minutes from kneading was measured, and the presence or absence of breathing was observed, and a 4 × 4 × 16 cm test piece was prepared to measure the compressive strength and the expansion coefficient. The results are shown in Table 1. After the 1-day age measurement, underwater curing was performed. Further, the composition of the expansive substance, according to JIS R 5202, analyze the amount of CaO and SO ₃ ,
It was calculated by converting the amount of SO ₃ into CaSO ₄ .

<Materials used> CaO raw material: Limestone powder from Aomi mine, Denki Kagaku Kogyo, 4,2
30cm ² / g CaSO ₄ Raw material: Natural anhydrous gypsum, Blaine value 5,830cm ² / g Cement α: Denki Kagaku Kogyo Co., Ltd. ordinary Portland cement superplasticizer a: Daiichi Kogyo Seiyaku Co., Ltd. trade name “Cellflow 110P”
Main component polyalkylallyl sulfonate fluidizer b: Product name "Quinflow 750" manufactured by Sanyo Kasei Co., Ltd. Main component polycarboxylate fine aggregate: Made in Himekawa, Niigata prefecture, specific gravity 2.63 Water: Tap water

<Measurement method> J ₁₄ funnel value: Measured according to the measurement of consistency by J funnel of JSCE standard Breathing: Measured according to JIS A 1123 Compressive strength ： Compressive strength expansion rate of specimen for 1 day : JSCE "Expanded Concrete Design and Construction Guidelines"
(Draft) ”, Appendix 2. Initial expansion and contraction rate measured according to the appendix "Expansion measurement method of filling mortar using expansion material" showing "Construction procedure of filling mortar using expansion material (draft)" However, in the table-is the contraction side, + Indicates the expansion side.

[0031]

[Table 1]

Example 2 Example 2 was repeated except that blast furnace cement was used as the cement. The results are shown in Table 2.

<Materials used> Cement β: Blast furnace cement (Class B) manufactured by Denki Kagaku Kogyo Co., Ltd.

[0034]

[Table 2]

[0035] Example 3 CaSO ₄ is, except that it has changed the particle size by pulverizing inflation material a total of 30 parts by weight in 100 parts by weight of CaO and CaSO _4, was performed in the same manner as in Example 2. The results are shown in Table 3.

[0036]

[Table 3]

Example 4 CaSO ₄ uses 30 parts by weight of the expansive substance in 100 parts by weight of CaO and CaSO _4, and the total amount of cement and cement admixture is 100.
Example 2 was repeated except that the amount of cement admixture was changed with respect to parts by weight. The results are shown in Table 4.

[0038]

[Table 4]

[0039] Example 5 CaSO ₄ is, using the inflation material a total of 30 parts by weight in 100 parts by weight of CaO and CaSO _4, similarly, except that it has changed the type and amount of fluidizing agent and Example 2 went. The results are shown in Table 5. However, when the amount of superplasticizer was changed, the amount of cement admixture was kept constant and the amount of expandable material was increased or decreased.

<Materials to be used> Fluidizing agent c: product name “Mighty 100” manufactured by Kao Corporation, main component naphthalene sulfonate fluidizing agent d: product name “HIDEX 106” manufactured by Nippon Konstarch Co., Ltd., main component dextrin

[0041]

[Table 5]

Example 6 CaSO ₄ uses 30 parts by weight of the expanding material in 100 parts by weight of CaO and CaSO ₄ in total, and 8.5 parts by weight of superplasticizer a and 1.5 parts of superplasticizer b1.5 are used.
Example 2 except that the amount of the superplasticizer consisting of 4 parts by weight and the superplasticizer consisting of 8.5 parts by weight of superplasticizer a and 1.5 parts by weight of superplasticizer b was used. I went the same way. The results are shown in Table 6. However, when the amount of superplasticizer was changed, the amount of cement admixture was kept constant and the amount of expandable material was increased or decreased.

[0043]

[Table 6]

Example 7: 93 parts by weight of cement, 65 parts by weight of expanding material, 25 parts by weight of amorphous calcium aluminate (A-CA), fluidizer a8.
Example 1 was repeated except that the cement admixture consisting of 5 parts by weight and 1.5 parts by weight of the fluidizing agent b was mixed in an amount of 7 parts by weight based on 100 parts by weight of the total amount of cement and the cement admixture.
The results are shown in Table 7.

<Materials used> CaO raw material: calcium carbonate, reagent first grade Al ₂ O ₃ raw material: aluminum oxide, reagent first grade A-CAi: so that the molar ratio of CaO / Al ₂ O ₃ is 10: 8.
A mixture of a CaO raw material and an Al ₂ O ₃ raw material, melted at 1,650 ° C and rapidly cooled to obtain crushed clinker, Blaine value 3,410 cm ² / g, CaO content 41%

[0046]

[Table 7]

Example 8 Example 7 except that cement β was used as the cement.
I went the same way. The results are shown in Table 8.

[0048]

[Table 8]

Example 9 CaSO ₄ uses 30 parts by weight of the expansive substance in 100 parts by weight of CaO and CaSO ₄ in total, and the total amount of cement and cement admixture is 100.
Example 8 was repeated except that the amount of cement admixture in parts by weight was changed. The results are shown in Table 9.

[0050]

[Table 9]

[0051] Example 10 CaSO ₄ is, using the inflation material a total of 30 parts by weight in 100 parts by weight of CaO and CaSO _4, conducted in the same manner except that varying amounts of the flow agent of Example 8 It was The results are shown in Table 10. However, when the amount of the fluidizing agent was changed, the amount of the cement admixture was kept constant and the amounts of the expansive substance and A-CA were increased or decreased by the same amount.

[0052]

[Table 10]

[0053] Example 11 CaSO ₄ is, using the inflation material a total of 30 parts by weight in 100 parts by weight of CaO and CaSO _4, as in Example 8 except that varying the type and amount of A-CA Went to. The results are shown in Table 11.
However, when changing the amount of A-CA, the amount of the cement admixture was kept constant and the amount of the expansive substance was increased or decreased.

<Materials used> A-CA so that the molar ratio of CaO / Al ₂ O ₃ is 10:10.
A mixture of a CaO raw material and an Al ₂ O ₃ raw material was melted at 1,650 ° C. and rapidly cooled to obtain crushed clinker, a Blaine value of 3,150 cm ² / g, and a CaO content of 35% A-CA. Adjust the CaO / Al ₂ O ₃ molar ratio to 10: 7
A mixture of a CaO raw material and an Al ₂ O ₃ raw material was melted at 1,650 ° C. and rapidly cooled to obtain crushed clinker, a Blaine value of 3,090 cm ² / g, and a CaO content of 44% A-CA Ni: Adjust the CaO / Al ₂ O ₃ molar ratio to 10:11
A mixture of CaO raw material and Al ₂ O ₃ raw material was melted at 1,650 ° C. and rapidly cooled to obtain crushed clinker, Blaine value of 3,010 cm ² / g, CaO content of 33% A-CA E: Adjust the CaO / Al ₂ O ₃ molar ratio to 10: 6
A mixture of a CaO raw material and an Al ₂ O ₃ raw material, melted at 1,650 ° C and rapidly cooled to obtain crushed clinker, Blaine value 2,980 cm ² / g, CaO content 48%

[0055]

[Table 11]

[0056]

EFFECTS OF THE INVENTION By using the cement admixture for grout of the present invention, a good grout effect can be obtained even in a cement composition containing a latent hydraulic substance.

─────────────────────────────────────────────────── ─── Continued Front Page (51) Int.Cl. ⁷ Identification Code FI C04B 24:26 C04B 24:04 24:04 14:02 Z 14:02) 103: 30 103: 30 111: 70 111: 70 C09K 103: 00 C09K 103: 00 (58) Fields investigated (Int.Cl. ⁷ , DB name) C04B 22/00-22/16

Claims (3)

(57) [Claims] 1. An expansive substance produced by heat-treating a mixture containing a CaO raw material and a CaSO ₄ raw material, which is composed of a mineral containing CaO and CaSO ₄ as effective components, and has an amount of CaSO ₄ in the mineral. Is a cement admixture for grout, which contains a fluidizing agent and an expansive substance having a Blaine value of 4,000 cm ² / g or more, which is 10 to 50 parts by weight in a total of 100 parts by weight of CaO and CaSO ₄ . 2. An expansive substance produced by heat-treating a mixture containing a CaO raw material and a CaSO ₄ raw material, which is composed of a mineral containing CaO and CaSO ₄ as effective components, and has an amount of CaSO ₄ in the mineral. Contains 10 to 50 parts by weight in a total of 100 parts by weight of CaO and CaSO ₄ , an expansive substance having a Blaine value of 4,000 cm ² / g or more, amorphous calcium aluminate, and a fluidizing agent. Cement admixture for grout. 3. A cement composition comprising cement and the cement admixture for grout according to claim 1 or 2.