JP2007031182A - Quick setting material for cement and cement composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a quick setting material easily and economically manufactured at a low cost and having excellent quick setting property without requiring a special apparatus or equipment, and a quick hardening cement composition using the quick setting material, capable of securing a prescribed usable life, having excellent quick setting property, using portland cement and low in cost in economical view point. <P>SOLUTION: The quick setting material for cement contains C<SB>3</SB>A produced by thermally decomposing and shifting C<SB>12</SB>A<SB>7</SB>or C<SB>11</SB>A<SB>7</SB>-CaX<SB>2</SB>(X expresses halogen) as an active ingredient. The quick hardening cement composition is formed by containing the quick setting material for cement and cement. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a cement quick-setting material and a cement composition using the cement quick-setting material, and in particular, the cement quick-setting material and the quick setting material that are easy to manufacture and exhibit good quick hardening properties. The present invention relates to a cement composition.

In recent years, in construction work for tunnels and underground spaces, a spray construction method has been widely practiced in which a cement mixture such as mortar and concrete is sprayed and lined on a wall surface or an exposed surface to prevent collapse of the wall surface or the exposed surface.
In this concrete spraying method, concrete is prepared, and the minimum usable time (handling time) necessary for handling it is secured, and after spraying on the wall surface or exposed surface, the concrete is immediately cured. It is necessary to let
In addition, it is necessary to secure the pot life of mortar and concrete in water stoppage work and emergency work and to harden it immediately.

Conventionally, as a clinker used for a rapid-hardening cement, there are a jet cement clinker, an Irwin clinker whose main component is C ₄ A ₃ SO ₃ , an alumina cement clinker whose main component is CA, and the like.
There is also a method of obtaining amorphous C ₁₂ A ₇ by melting a clinker mainly composed of C ₁₂ A ₇ which is a rapid hardening component and then rapidly cooling it.

However, the conventional jet cement clinker is a clinker containing a calcium silicate phase as a main component and containing about 20 to 30% by weight of C ₁₁ A ₇ · CaF ₂ as a fast-hardening component, and is a rapid hardening component of C ₁₂ A ₇ . It is not satisfactory as a clinker for a rapid hardening cement because it has a low content and cannot exhibit sufficient rapid hardening.
Irwin-based clinker is used as a clinker for quick-hardening cement because it contains 70% by weight or more of erwin (C ₄ A ₃ SO ₃ ) having quick-hardening properties. There is a problem that it is inferior in rapid hardening at low temperatures.

Alumina cement clinker composed mainly of CA, compared to clinker mainly composed of C ₁₂ A _7, is inferior suddenly rigid, also, the clinker mainly composed of conventional C ₁₂ A _7, for example, It is manufactured by a method of synthesizing amorphous C ₁₂ A ₇ by once melting a clinker based on C ₁₂ A ₇ as a main component as described above, and then rapidly cooling it. The manufacturing method is complicated, and this manufacturing method has a problem that a large amount of electric power is consumed because the electrofusion method is used for melting the clinker, the electric power cost is increased, and the manufacturing cost is eventually increased.

  In addition, there is a quick setting cement that adds quick setting material to Portland cement to give quick setting, but usually a large amount of quick setting material such as calcium aluminate or Irwin is added to Portland cement. For this reason, in addition to an increase in cost, there is a disadvantage in that high quick setting cannot be obtained and there is a problem in strength.

In Japanese Patent Laid-Open No. 2002-293594, a predetermined hard working time can be secured, and as a hardened cement composition and a quick setting material that harden rapidly after the working time has passed, it has a certain range of lattice constants. A sintered body containing a crystalline C ₁₁ A ₇ · CaF ₂ solid solution is blended, and preferably 40% by weight or more, a rapid setting material for rapid hardening cement, and the rapid setting material is constant with respect to the base cement A hardened cement composition with added content is disclosed.

Japanese Patent Application Laid-Open No. 2003-267762 discloses calcium aluminate, sulfate, sodium aluminate having a molar ratio of NaO ₂ / Al ₂ O ₃ of less than 1.0, and Portland cement as a rapid setting material for concrete. A rapid setting material to be contained, wherein the amount of Na ₂ O in the quick setting material is 1.5 to 10.0% by mass, and the total amount of calcium aluminate, sulfate and sodium aluminate is 100 parts by mass. On the other hand, a quick setting material in which the amount of Portland cement is 1.0 part by mass or more is disclosed.

However, both of these conventional quick setting materials and quick setting cements require special raw materials and equipment to obtain the quick setting materials, which makes the manufacturing complicated and increases the manufacturing cost. In addition, a cement composition in which a quick setting material is added to Portland cement has a problem that it is difficult to express a quick setting performance as expected.
JP 2002-293594 A JP 2003-267762 A

Accordingly, an object of the present invention is to provide a cement quick setting material that is easy to manufacture, does not require special equipment and facilities, has excellent quick setting performance, and is economically inexpensive.
Another object of the present invention is to provide an economically inexpensive cement composition that can secure a predetermined pot life by using the cement quick setting material and exhibits excellent quick setting properties. It is.

The present invention contains C ₃ A obtained by thermally decomposing C ₁₂ A ₇ or C ₁₁ A ₇ · CaX ₂ (X represents halogen) and transferring from C ₁₁ A ₇ · CaX _2. This has been achieved by finding that a quick-acting clinker having excellent quick setting performance and high activity can be obtained.

That is, the rapid setting material for cement according to the present invention has C ₁₂ A ₇ or C ₁₁ A ₇ · CaX ₂ (X represents halogen) as C ₃ A produced by transferring by thermal decomposition as an active ingredient. It is characterized by doing.
The cement composition of the present invention is characterized by including the above-mentioned cement quick setting material of the present invention and cement.
Preferably, the cement composition of the present invention is characterized by adding 10 to 100 parts by mass of the cement quick setting material to 100 parts by mass of the cement.

The cement quick setting material of the present invention does not require special equipment or facilities, is easy to manufacture, has excellent quick setting properties, and can be economically inexpensive.
In addition, the cement composition of the present invention can secure a predetermined pot life, has excellent quick setting performance, and can be economically inexpensive.
Therefore, the present invention can be effectively applied to rapid hardening applications at work sites and the like.

The present invention is illustrated by the following preferred examples, but is not limited thereto.
The rapid setting material for cement of the present invention will be described.
The rapid setting material for cement according to the present invention contains C ₁₂ A ₇ or C ₁₁ A ₇ · CaX ₂ (X represents halogen) as a active ingredient which is C ₃ A produced by thermal decomposition and transition. .
Thus, by containing C ₃ A produced by thermally decomposing C ₁₂ A ₇ or C ₁₁ A ₇ · CaX ₂ , it has excellent quick setting properties, and does not require special equipment, and is inexpensive. A quick setting material is obtained.

First, to produce calcium aluminate of C ₁₂ A ₇ or C ₁₁ A ₇ · CaX ₂ (X represents a halogen), for example, based on the Borg formula, calcareous raw materials (eg, quicklime, slaked lime, limestone), alumina A raw material (eg; aluminum hydroxide, alumina) and a calcium fluoride raw material (eg, fluorite) are blended as necessary.
Next, the blended raw material is sufficiently fired at a temperature of, for example, 1380 ° C. to 1450 ° C., for example, for 1 to 2 hours to obtain a clinker.

At this time, C ₁₂ A ₇ or C ₁₁ A ₇ .CaX ₂ (X represents halogen) is once generated in the firing process, and when firing further proceeds, the generated C ₁₂ A ₇ or C ₁₁ A ₇ .CaX 2 is produced. ₂ (X represents halogen) undergoes thermal transition to produce C ₃ A.
Incidentally, not from mixed material as described above, (the X represents a halogen) _C 12 _{A 7} or _C 11 _A 7 · _CaX 2 prepared separately by firing a clinker containing again, heat metastasized _C 3 A May be generated.

Such calcium aluminate clinker includes C ₁₂ A ₇ , C ₁₁ A ₇ .CaX ₂ (X represents halogen), C ₃ S, C ₂ S, C ₄ AF and the like in addition to C ₃ A. It does not matter.
Preferably, the calcium aluminate clinker contains 20 to 30% by mass of C ₁₂ A ₇ or C ₁₁ A ₇ · CaX ₂ (X represents halogen) in a state before thermal transition. .
If it is 20% by mass or more, an effective amount of C ₃ A obtained by thermal transition for functioning as a quick setting material can be obtained, and if it is 30% by mass or less, it is good without being excessively melted. The clinker can be manufactured while maintaining proper properties.

Furthermore, the content ratio of C ₃ A thermally transferred from the clinker containing C ₁₂ A ₇ or C ₁₁ A ₇ · CaX ₂ (X represents halogen) is preferably 0.5 to 25% by mass in the clinker, More preferably, it is good to set it as 1-15 mass%.
Thus, by obtaining C ₃ A having a large crystal lattice size and high reactivity, a high rapid setting action can be exhibited.
The clinker containing C ₃ A obtained by heat-transferring the C ₁₂ A ₇ or C ₁₁ A ₇ · CaX ₂ (X represents halogen) is pulverized into a powder.

The clinker preferably has a brain specific surface area of 4500 cm ² / g or more, and if it is less than 4500 cm ² / g, good quick setting may not be obtained.
Further, the larger the specific surface area of the brain, the longer the pulverization time is required, the lower the productivity and the higher the cost. Therefore, the specific surface area of 5000 to 7000 cm ² / g is desirable.
Further, a grinding aid (diethylene glycol, triethanolamine, etc.) may be added when grinding.

Next, a sulfate is added to the calcium aluminate clinker powder containing C ₃ A.
The sulfate functions as a setting adjuster and is added to supplement the sulfate in the base material cement to which the quick setting agent is added.
Specific examples include alkali metal sulfates such as sodium sulfate (sodium sulfate) and potassium sulfate, alkaline earth metal sulfates such as magnesium sulfate and gypsum (calcium sulfate), and aluminum sulfate. Or the combined use of gypsum and mirabilite.
Examples of the gypsum include anhydrous gypsum, hemihydrate gypsum, dihydrate gypsum, or a mixture thereof.
Moreover, slaked lime is mentioned as a material which can be mix | blended as needed. The slaked lime is added for strength enhancement.

The fineness of these sulfates and slaked lime is not particularly limited, but is preferably 3000 cm ² / g or more.
In view of strength development and cost, a fineness of 4000 to 10000 cm ² / g is more preferable.
In this way, the rapid setting material for cement of the present invention is obtained.

The ratios of calcium aluminate clinker powder containing C ₃ A, sulfate, and slaked lime added as necessary, which constitute the quick setting material for cement of the present invention, are 70 to 90% by mass and 10 to 30, respectively. Mass%, 0 to 1 mass%.
From the viewpoint of ensuring quick setting and handling time, it is desirable that the calcium aluminate is 79 to 84% by mass, sulfate is 15 to 20% by mass, and slaked lime is 0 to 1% by mass.

In the above proportion, if the calcium aluminate containing C ₃ A is less than 70% by mass, the quick setting property is reduced, and if it exceeds 90% by mass, the instantaneous setting occurs and the handling time cannot be secured, which is not preferable.
On the other hand, if the sulfate content is less than 10% by mass, it is difficult to secure the handling time due to the instantaneous setting, and if it exceeds 30% by mass, the quick setting property is reduced, which is not preferable.

  The mixing method of the calcium aluminate clinker powder, sulfate, and slaked lime constituting the quick setting material is not particularly limited, and after blending in a ratio within the numerical range described above, it is mixed using a conventional mixing device. good.

The cement composition having the quick setting property of the present invention includes the above-described cement quick setting agent of the present invention and is mixed with cement. The quick setting material is blended with base mortar or base concrete. 10 to 100 parts by mass (outside split) is preferable with respect to 100 parts by mass of cement.
If the amount added is less than 10 parts by mass (outer percent), the quick setting property is reduced, and if it exceeds 100 parts by mass (outer percent), sufficient handling time cannot be obtained, which is not preferable.

  The cement used in the cement composition having rapid setting properties of the present invention includes mixed cements such as ordinary / early strong / moderate heat / low heat Portland cement, blast furnace cement, fly ash cement, jet cement, and one of these cements. Examples thereof include a cement whose part is replaced with limestone powder, silica fume and the like.

  In addition, setting retarders (lignin sulfonic acid, oxycarboxylic acid, various organic acids such as saccharides, alkali metal salts or alkaline earth metal salts of organic acids) and water reducing agents (alkyl allyl sulfonic acid, naphthalene sulfonic acid) , Melamine sulfonic acid, polycarboxylic acid, AE water reducing agent, high performance water reducing agent, high performance AE water reducing agent), liquid or powder admixture, fine aggregate (river sand, sea sand, mountain sand) , Crushed sand and mixtures thereof), coarse aggregate (river gravel, sea gravel, crushed stone and mixtures thereof) and the like.

Mortar and concrete can be produced by blending water into the cement composition using the above raw materials, and the method for producing these mortars and concretes is not particularly limited, and the raw material is used with a conventional mixer. Can be mixed.
These mortars and concretes can be applied to, for example, a wet spraying method, and a conventional apparatus can be used as it is as a spraying apparatus.

The present invention will be described based on the following examples and test examples.
Test example
1) Clinker raw materials were prepared by blending reagents so that the clinker chemical composition after firing and firing was as shown in Table 1.
The theoretical clinker mineral composition obtained by the Borg method based on the chemical composition of Table 1 is as shown in Table 2.

  The clinker material was baked in an electric furnace at each temperature shown in Table 5 for 1 hour, then taken out from the electric furnace and rapidly cooled in the air to obtain clinker 1 to 10.

2) Analysis of mineral composition Each of the obtained clinker 1 to 10 was diffracted using an X-ray diffractometer (manufactured by Rigaku Corporation; RAD-rC).
The results are shown in Table 2 above.

From Table 2, from the clinker 9 and 10 _{C 3} A, respectively, are detected 1 wt% and 10 wt%, from clinker 1-8 was not detected _{C 3} A.
Further, in the analysis, the amount of _C 11 _A 7 · CaF ₂ for clinker 9 and 10, it was confirmed that reduced than the theoretical amounts shown in Table 2.
From the above, C ₃ A detected from the clinker 9 and 10 is considered to be generated by thermal decomposition of C ₁₁ A ₇ · CaF ₂ .

3) Preparation of hydraulic composition Next, 100 parts by mass of each clinker was coarsely pulverized, 1 part by mass of sodium sulfate (sodium sulfate) was mixed with each clinker, and 0.08 parts by mass of pulverization aid (diethylene glycol) Was used to grind to a brain surface area of about 5200 ± 100 cm ² / g to obtain a clinker powder.
The clinker powder, anhydrous gypsum (trade name; non-clave, manufactured by Sumitomo Osaka Cement Co., Ltd.), hemihydrate gypsum (trade name; baked gypsum, manufactured by Wako Pure Chemical Industries, Ltd.) and slaked lime (Wako Pure Chemical Industries, Ltd.) Were mixed at a ratio shown in Table 3 so that the molar ratio of SiO ₂ / Al ₂ O ₃ was 1.2 and mixed uniformly to prepare hydraulic compositions 1 to 10.

4) Preparation of mortar Each hydraulic composition of 1 to 10 above, sand (Toyoura standard sand), setting agent (reagent; citric acid, manufactured by Wako Pure Chemical Industries, Ltd.), water and admixture (Kao Corporation) ) And trade name: Mighty 150) were blended in the proportions shown in Table 4 and uniformly kneaded to obtain mortars 1 to 10.

5) Handling time and milling temperature test The handling time was measured for each mortar obtained above.
For each handling time, a cone cone (350 g) having a diameter of 1 cm and a height of 2 cm was attached instead of the bigger needle of the condensation test method of JIS R5201-1997, and the time until the penetration degree was 1.5 mm was defined as the handling time.
The kneading temperature is a value obtained by measuring the temperature immediately after kneading after adding each material and water to obtain the mortar.
The results are shown in Table 5 and FIGS.

From Table 5, FIG. 1 and FIG. 2, the mortars 9 and 10 are greatly different from the mortars 1 to 8, the handling time is 0 minutes (instantaneous setting), and the refining temperature exceeds 40 ° C.
This shows that the hydraulic materials 9 and 10 used for the mortars 9 and 10 have high rapid setting performance and are suitable as quick setting materials.

Examples 1-2
Using the hydraulic material 9 prepared in the above test example as a quick setting material, the quick setting material, cement (manufactured by Sumitomo Osaka Cement Co., Ltd., trade name: jet cement), sand (Toyoura standard sand), setting agent ( Reagents: Citric acid, manufactured by Wako Pure Chemical Industries, Ltd.), water and an admixture (trade name: Mighty 150, manufactured by Kao Corporation) were blended in the proportions shown in Table 6, and kneaded uniformly. The mortars of Examples 1 and 2 were obtained.

Comparative Example 1
A mortar of Comparative Example 1 was obtained in the same manner as in Example 1 except that the hydraulic material that is a quick setting material was not used and the materials were blended in the ratios shown in Table 6.

About the obtained mortars of Examples 1 and 2 and Comparative Example 1, the handling time and the refining temperature were measured in the same manner as in the above test example.
The results are shown in Table 7.

As a result of the above measurement, the mortar that does not contain the quick setting material of the present invention is inferior in quick setting property even when jet cement which is a fast-setting cement is used, but C ₁₁ A ₇ · according to Examples 1 and 2 based on the present invention. It can be seen that the mortar using the rapid setting material containing C ₁₂ A ₇ which has been transferred by the thermal decomposition of CaF ₂ has rapid hardening and can ensure the handling time.

  The quick setting material of the present invention and the cement composition using the quick setting material are used for construction work of tunnels and underground spaces, civil engineering work, water stop work, spraying work on wall surfaces, repair work for emergency roads, etc. For example, the present invention can be usefully applied to a work location that is required to be quickly and quickly connected after the pot life has elapsed while ensuring a predetermined handling time.

The diagram which shows the relationship between the baking time of a clinker, and the handling time of the cement mortar using the said clinker. The diagram which shows the relationship between the baking time of a clinker, and the refining temperature of the cement mortar using the said clinker.

Claims (3)

The C ₁₂ A ₇ or _{C 11 A 7 · CaX 2 (} X is a halogen), by transferring by thermal decomposition, characterized in that an active ingredient _{C 3} A be generated, cement quick-setting materials . A cement composition comprising the cement quick setting material according to claim 1 and cement. The cement composition according to claim 2, wherein 10 to 100 parts by mass of a cement quick setting material is added to 100 parts by mass of cement.

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