JP3390078B2 - 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.

Further, as the cement admixture for grout, those containing an ordinary expansive substance and a superplasticizer as main components have been proposed (Japanese Patent Publication No. 48-9331 and Japanese Patent Publication No. 56-6381). . However, all of these materials
It is a material that excels in workability and filling properties and that allows grout work to be completed smoothly, but recently, the performance required for grout materials has increased significantly, and in some cases these physical properties cannot be satisfied in some cases. Met.

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 applied 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 compound containing a CaO raw material, an Al ₂ O ₃ raw material, and a CaSO ₄ raw material, which is CaO, Al ₂ O ₃ , And CaSO ₄
Is used as an active ingredient, and the component ratio in the mineral is CaO / Al ₂ O ₃ molar ratio of 6.5 to 18, CaSO ₄ / Al ₂ O ₃
A cement admixture for grout, comprising an expansive substance having a Blaine value of 4,000 cm ² / g or more with a molar ratio of 1.5 to 4 and a fluidizing agent, wherein the expansive substance, the fluidizing agent, and A cement admixture for grout, which comprises a mixture of crystalline calcium aluminate, and a cement composition comprising cement and the cement admixture for 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, as the Al ₂ O ₃ raw material, bauxite, aluminum residual ash, etc., and as the CaSO ₄ raw material, anhydrous gypsum,
Hemihydrate gypsum, dihydrate gypsum, etc. are mentioned. 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 mixing ratio of the various raw materials in the present invention is such that, as the chemical composition of the expanding substance as a product, the CaO / Al ₂ O ₃ molar ratio is 6.5 to 18, and the CaSO ₄ / Al ₂ O ₃ molar ratio is 1.5 to. It is necessary to adjust the ratio to be 4, and the CaO / Al ₂ O ₃ molar ratio is 8-12.
Therefore, it is preferable to set the CaSO ₄ / Al ₂ O ₃ molar ratio to 2-3. If the CaO / Al ₂ O ₃ molar ratio is less than 6.5, it may not be possible to obtain sufficient expandability when used in mixed cement, and if it is used in excess of 18, the strength development may decrease. Further, if the CaSO ₄ / Al ₂ O ₃ molar ratio is less than 1.5, sufficient expandability may not be obtained, and if it is used in excess of 4, expansion manifestation may be delayed and expansion failure may occur.

In the present invention, the desulfurization temperature of gypsum varies greatly depending on the blending ratio of the raw material mixture and the content of impurities. Therefore, the firing temperature at the time of firing is not particularly limited. The temperature is preferably about 1,100 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 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 expanded material 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. If it is less than 4,000 cm ² / g, breathing tends to occur. Also, when it exceeds 9,000 cm ² / g,
It is difficult to grind until it exceeds 9,000 cm ² / g, and it tends to be difficult to expect an increase in its use effect.

The superplasticizer used in the present invention is one which imparts fluidity to a cement kneaded product, and examples thereof include a condensate of polyalkylallyl sulfonate, a condensate of naphthalene sulfonate, and 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 is a starch that is decomposed by heating with an acid to make it soluble in cold water, and is also known as 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 is usually composed of an expansive substance and a superplasticizer, and the expansive substance, the amorphous calcium aluminate described later, 0.5 to 13 parts by weight is preferable, and 2 to 10 parts by weight is more preferable, in 100 parts by weight of the cement admixture for grout, which comprises a cement and a fluidizing agent. 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. Its melting temperature varies with impurities, but is usually 1,500
-1,700 ° C is preferable.

In the present invention, the amorphous calcium aluminate preferably has a CaO content of 35 to 45% by weight. If the CaO content is less than 35% by weight, the expandability and strength development may be insufficient, and if it exceeds 45% by weight, the fluidity may decrease and the workability may deteriorate.

The particle size of the amorphous calcium aluminate is not particularly limited, but the Blaine value is 2,000 to 6,0.
00 cm ² / g is preferred. If it is less than 2,000 cm ² / g, sufficient expandability may not be obtained, and if it exceeds 6,000 cm ² / g, fluidity may deteriorate.

The amount of the amorphous calcium aluminate used is preferably 10 to 40 parts by weight in 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 swelling substance and the superplasticizer, or the mixture of the swelling substance, the amorphous calcium aluminate and the superplasticizer is used as a cement admixture for grout.

The amount of the cement admixture for grouting according to the present invention varies depending on the purpose of use, but is preferably 3 to 15 parts by weight, and 5 to 12 parts by weight based on 100 parts by weight of the total amount of cement admixture for cement and grout. More preferably parts by weight. 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 resistance to material separation and preventing breathing.

Here, the latent hydraulic substance refers to a pozzolanic substance which does not have hydraulic properties by itself and exerts hydraulic properties by reacting with an alkali. Specifically, blast furnace slag, fly ash, silica fume, And silica flour. In the present invention, one or more of these can be used. The blending amount of the latent hydraulic substance in the present invention is not particularly limited, but is usually 10 in total of the cement composition comprising cement and a cement admixture for grout.
It is preferably less than 80 parts by weight with respect to 0 parts by weight.
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 used for producing a cement kneaded product 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.

[0028]

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

Example 1 CaO raw material, Al ₂ O ₃ raw material, and CaSO ₄ raw material were used, and the mixture was fired using a rotary kiln at a maximum firing temperature of 1,400 ° C., and the obtained clinker was crushed to obtain a Blaine value. Various swelling substances were obtained by adjusting to 7,000 ± 200 cm ² / g. 93 parts by weight of cement, 90 parts by weight of expansive substance, 8.5
Cement admixture for grout (hereinafter referred to as cement admixture) consisting of 1 part by weight and 1.5 parts by weight of superplasticizer (hereinafter referred to as cement admixture) was added in an amount of 7 parts by weight in a total of 100 parts by weight of cement and the cement admixture. Mortar was prepared by mixing 100 parts by weight of aggregate and 35 parts by weight of water. 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. The composition of the swelling substance is
According to JIS R 5202, the amounts of CaO, Al ₂ O ₃ , and SO ₃ were analyzed, and the amount of SO ₃ was converted to CaSO ₄ to obtain it.

<Materials used> CaO raw material: limestone powder, limestone powder from Omi mine of Denki Kagaku Kogyo Al ₂ O ₃ raw material: aluminum residual ash, CaSO ₄ raw material of Nihonkaisui Kako: anhydrous gypsum expansive substance of Shin-Akita Kasei A: CaO: Al ₂ O ₃ : CaSO ₄ molar ratio = 4: 1: 2.5 Swelling substance B: CaO: Al ₂ O ₃ : CaSO ₄ molar ratio = 6.5: 1: 2.5 Swelling substance C: CaO: Al ₂ O ₃ : CaSO ₄ molar ratio = 8: 1: 2.5 Expansion material D: CaO: Al ₂ O ₃ : CaSO ₄ molar ratio = 10: 1: 2.5 Expansion material E: CaO: Al ₂ O ₃ : CaSO ₄ molar ratio = 12: 1: 2.5 Swelling substance F: CaO: Al ₂ O ₃ : CaSO ₄ molar ratio = 18: 1: 2.5 Swelling substance G: CaO: Al ₂ O ₃ : CaSO ₄ molar ratio = 20: 1: 2.5 Swelling substance H: CaO : Al ₂ O ₃ : CaSO ₄ Molar ratio = 10: 1: 1 Expansion material I: CaO: Al ₂ O ₃ : CaSO ₄ Molar ratio = 10: 1: 1.5 Expansion material J: CaO: Al ₂ O ₃ : CaSO ₄ Molar ratio = 10: 1: 2 Swelling substance K: CaO: Al ₂ O ₃ : CaSO ₄ Molar ratio = 10: 1: 3 Swelling substance L: CaO: Al ₂ O ₃ : CaSO ₄ Molar ratio = 10 1: 4 Expansion material M: CaO: Al ₂ O ₃ : CaSO ₄ molar ratio = 10: 1: 5 Cement α: Denki Kagaku Kogyo Co., Ltd. ordinary Portland cement fluidizer a: Daiichi Kogyo Seiyaku Co., Ltd. Cell flow 110
P ”, the main component polyalkylallyl sulfonate fluidizer b: product name“ Quinflow 750 ”manufactured by Sanyo Kasei Co.,
Main component Polycarboxylate Fine aggregate: Niigata Prefecture Himekawa produced water: Tap water

<Measurement method> J ₁₄ funnel value: Measured according to the measurement of the consistency by J funnel of the 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.

[0032]

[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.

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

[0035]

[Table 2]

Example 3 Example 3 was repeated except that the expansive substance D was crushed to change the particle size. The results are shown in Table 3.

[0037]

[Table 3]

Example 4 The total amount of cement and cement admixture using expansion material D
Example 2 was repeated except that the amount of cement admixture in 100 parts by weight was changed. The results are shown in Table 4.

[0039]

[Table 4]

Example 5 The same procedure as in Example 2 was carried out except that the expanding substance D was used and the kind and amount of the superplasticizer were changed. 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 used> Fluidizing agent c: trade name “Mighty 100” manufactured by Kao Corporation, main component naphthalene sulfonate fluidizing agent d: trade name “HIDEX 106” manufactured by Nippon Constarch Co., Ltd.,
Main ingredient dextrin

[0042]

[Table 5]

Example 6 Using swelling substance D, varying the amount of superplasticizer consisting of 8.5 parts by weight of superplasticizer a and 1.5 parts by weight of superplasticizer b,
Further, the same procedure as in Example 2 was carried out except that a fluidizing agent consisting of 8.5 parts by weight of fluidizing agent a and 1.5 parts by weight of fluidizing agent b was used. 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.

[0044]

[Table 6]

Example 7 65 parts by weight of each expanding substance, amorphous calcium aluminate
(A-CA) A cement admixture consisting of 25 parts by weight, 8.5 parts by weight of superplasticizer a, and 1.5 parts by weight of superplasticizer, 7 parts by weight out of a total of 100 parts by weight of cement and cement admixture. The same procedure as in Example 1 was carried out except that it was compounded. 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. Melted mixed raw material at 1,650 ℃, chilled clinker obtained by rapid cooling, Blaine value 3,410 cm ² /
g, CaO content 41%

[0047]

[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.

[0049]

[Table 8]

Example 9 A total of cement and cement admixture was used, using expansion material D
Example 8 was repeated except that the amount of cement admixture in 100 parts by weight was changed. The results are shown in Table 9.

[0051]

[Table 9]

Example 10 The procedure of Example 8 was repeated, except that the expanding substance D was used and the amount of the fluidizing agent was changed. 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.

[0053]

[Table 10]

Example 11 The same procedure as in Example 8 was carried out except that the expanding substance D was used and the kind and amount of A-CA were changed. 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 to be used> A-CA: A mixed raw material mixed so as to have a CaO / Al ₂ O ₃ molar ratio of 10:10 was melted at 1,650 ° C. and rapidly cooled to obtain a clinker. Blaine value 3,150 cm ² /
g, CaO content 35% A-CA: A raw material mixed so that the molar ratio of CaO / Al ₂ O ₃ is 10: 7 is melted at 1,650 ° C. and rapidly cooled to obtain a clinker. Blaine value 3,090 cm ² /
g, CaO content 44% A-CA Ni: CaO / Al ₂ O ₃ was mixed at a mixing ratio of 10:11, the mixed raw material was melted at 1,650 ° C., and rapidly cooled to obtain a clinker. Blaine value 3,010 cm ² /
g, CaO content 33% A-CA E: CaO / Al ₂ O ₃ mixed raw materials blended so as to have a molar ratio of 10: 6 were melted at 1,650 ° C. and rapidly cooled to obtain a clinker. Blaine value 2,980 cm ² /
g, CaO content 48%

[0056]

[Table 11]

[0057]

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 FI E02D 3/12 E02D 3/12 // (C04B 28/02 C04B 22:14 D 22:14 24:02 24:02 24:04 24:04) 103: 30 103: 30 111: 70 111: 70 C09K 103: 00 C09K 103: 00 (56) References JP-A-53-99228 (JP, A) JP-A-56-149358 (JP, A) ) JP-A-2-221141 (JP, A) JP-A-57-96808 (JP, A) JP-A-58-20763 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C04B 22/00-22/16 C09K 17/00-17/52

Claims (3)

(57) [Claims] 1. An expansive substance produced by heat-treating a mixture containing a CaO raw material, an Al ₂ O ₃ raw material, and a CaSO ₄ raw material,
O, Al ₂ O ₃ , and CaSO ₄ consisting of minerals with active ingredients,
Moreover, the CaO / Al ₂ O ₃ molar ratio of the component ratio in the mineral is 6.5.
A cement admixture for grouting, comprising an expanding substance having a Blaine value of 4,000 cm ² / g or more and a CaSO ₄ / Al ₂ O ₃ molar ratio of 1.5 to 4 and a fluidizing agent. 2. An expansive substance produced by heat-treating a mixture containing a CaO raw material, an Al ₂ O ₃ raw material, and a CaSO ₄ raw material, which is Ca
O, Al ₂ O ₃ , and CaSO ₄ consisting of minerals with active ingredients,
Moreover, the CaO / Al ₂ O ₃ molar ratio of the component ratio in the mineral is 6.5.
Grout containing an expansive substance having a Blaine value of 4,000 cm ² / g or more, a CaSO ₄ / Al ₂ O ₃ molar ratio of 1.5 to 4, an amorphous calcium aluminate, and a fluidizing agent. Cement admixture for. 3. A cement composition for grout comprising cement and the cement admixture for grout according to claim 1 or 2.