JP4616111B2 - Quick setting material for cement and quick hardening cement composition - Google Patents

Description

  The present invention relates to a quick setting material for cement and a quick setting cement composition, and in particular, a quick setting material for cement that can be easily manufactured and exhibits good quick setting properties, and any desired setting using the quick setting material. The present invention relates to a quick-hardening cement composition capable of adjusting quick setting.

In recent years, in construction work for tunnels and underground spaces, a spraying 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 such a concrete spraying method, it is necessary to ensure the necessary minimum usable time (handling time) when preparing and handling the concrete and the like and to immediately harden the concrete and the like while spraying on the wall surface and the exposed surface.
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 jet cement clinker is a clinker containing a calcium silicate phase as a main component and containing about 20 to 30% by mass of C ₁₁ A ₇ · CaF ₂ as a fast-hardening component, and containing C ₁₂ A ₇ as a quick-hardening component. The amount is small and does not have sufficient rapid hardening, and is not satisfactory as a clinker for rapid hardening cement.
Irwin-based clinker is used as a clinker for quick-hardening cement because it contains 70% by mass 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.

In addition, the alumina cement clinker containing CA as a main component is inferior in rapid hardening as compared with the clinker containing C ₁₂ A ₇ as a main component.
Furthermore, the clinker whose main component is C ₁₂ A ₇ is, for example, an amorphous material obtained by once melting a clinker whose main component is C ₁₂ A ₇ as a main component, and then rapidly cooling the clinker. Although it is obtained by the method of synthesizing C ₁₂ A ₇ , the manufacturing method is complicated, and in this manufacturing method, a large amount of power is consumed because the melting method is used for melting the clinker. However, there is a problem that the manufacturing cost increases.

  There is also a quick-setting cement that adds rapid setting material to Portland cement to give rapid hardening, but usually it is necessary to add a large amount of quick setting material such as calcium aluminate or Irwin to Portland cement. For this reason, in addition to an increase in cost, there is a drawback that high quick setting properties 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 mass or more of a rapid setting material for hardened cement, and the rapid setting material is fixed 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, when using conventional quick setting materials, the quick setting is adjusted by adding an admixture such as a setter (handling time adjusting agent), and the range of adjustment of the quick setting is limited. ing.
Moreover, the cement composition which adds a quick setting material to Portland cement has the problem that it is difficult to express desired high quick setting performance.
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 properties, and is economically inexpensive.
Another object of the present invention is to secure a predetermined pot life by mixing with a cement clinker or the like at an arbitrary ratio using the quick setting material, and to provide any desired quick setting performance. It is to provide an economically inexpensive quick setting cement composition.

The present invention includes C ₃ A obtained by thermally decomposing C ₁₁ A ₇ · CaX ₂ (X represents halogen) and transferring from C ₁₁ A ₇ · CaX _2. This is achieved by finding that a quick-acting clinker having excellent performance and high activity can be obtained.
Moreover, it discovered that the quick setting material which has arbitrary quick setting property can be easily obtained by mixing the said quick setting clinker and the clinker from which this quick setting differs in arbitrary ratios. Has been achieved.

That is, the rapid setting material for cement of the present invention has a content of C ₁₂ A ₇ or C ₁₁ A ₇ · CaX ₂ (X represents halogen) in a state before thermal transition , and is 20 to 30% by mass, a first material and the C ₁₂ a ₇ or _{C 11 a 7 · CaX 2 (} X is a halogen) _{C 3} a of the active ingredient to produce by pyrolysis and metastasis at from 1380 to 1,450 ° C., the C _{3 It} does not contain A , and is obtained by mixing with a second material containing calcium aluminate as an active ingredient.
Preferably, the cement quick setting material of the present invention is a mixture of the first material and the second material in a mass ratio of 25:75 to 75:25 in the cement quick setting material. it shall be the features a.

  The rapid-hardening cement composition of the present invention includes the above-mentioned cement quick setting material of the present invention and cement, and preferably 10 to 100 parts of the cement quick setting material with respect to 100 parts by mass of cement. It is characterized by adding part by mass.

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.
Moreover, the cement composition of the present invention has any desired rapid setting performance and can be economically inexpensive.

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 is a first material containing, as an active ingredient, C ₃ A produced by thermally decomposing and transferring C ₁₂ A ₇ or C ₁₁ A ₇ .CaX ₂ (X represents halogen). And the second material containing calcium aluminate as an active ingredient without containing C ₃ A, and it is desirable that both the first material and the material 2 are powders. The quick setting material is a mixture containing these powders.
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 can be obtained.

First, the first material used for the cement quick setting material of the present invention will be described.
In order to produce calcium aluminate of C ₁₂ A ₇ or C ₁₁ A ₇ · CaX ₂ (X represents halogen), for example, based on the Bogue formula, calcareous raw material (eg, quicklime, slaked lime, limestone), alumina raw material (Example: aluminum hydroxide, alumina), and calcium fluoride raw material (example: fluorite) is 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, during the calcium aluminate _{clinker, C} 12 _{A 7} or _{C 11 A 7 · CaX 2 (} X is a halogen) is Ru contains 20 to 30% by weight before thermal transition state.
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.

Next, the 2nd material used for the quick setting material for cement of this invention is demonstrated.
The second material is a calcareous raw material (eg; quick lime, slaked lime, limestone), an alumina raw material (eg; aluminum hydroxide, alumina), as required, for example, based on the Borg formula, to produce calcium aluminate. A calcium fluoride raw material (fluorite) is blended, and the mixture is fired or melted in a heating furnace such as an electric furnace and cooled to obtain a calcium aluminate clinker.
The obtained clinker can contain C ₁₂ A ₇ , C ₁₁ A ₇ .CaX ₂ (X represents halogen), C ₂ A, CA, and C ₃ A as calcium aluminate. ₃ A is different from the first material in that it is important that C ₁₂ A ₇ or C ₁₁ A ₇ .CaX ₂ (X represents halogen) is not obtained by thermal decomposition transition.
Also, _C 3 S, may also contain a _{C 2} S and _C 4 AF and the like as components other than calcium aluminate.

The clinker of the first material containing C ₃ A obtained by heat-transferring the C ₁₂ A ₇ or C ₁₁ A ₇ · CaX ₂ (X represents halogen) thus obtained, and the heat It is desirable that the clinker of the second material containing calcium aluminate not containing C ₃ A obtained by the decomposition transfer is pulverized into a powder form.

The clinker for the first material and the clinker for the second material are preferably pulverized to have a Blaine 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. It is.
Further, the larger the Blaine specific surface area, the longer the grinding time is required, the lower the productivity and the higher the cost, so 5000-7000 cm ² / g is desirable.
Further, a grinding aid (diethylene glycol, triethanolamine, etc.) may be added when grinding.

Next, sulfate is blended into the clinker powder for the first material and the clinker powder for the second material.
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. Slaked lime is added to increase strength.

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.

Furthermore, the blending ratios of the clinker powder, the sulfate, and the slaked lime added as necessary are 60 to 90% by mass, 10 to 40% by mass, and 0 to 1% by mass, respectively. From the viewpoint of securing quick setting and handling time, it is preferable that the content is 65 to 85% by mass, 15 to 35% by mass, and 0 to 1% by mass, respectively.
In the above ratio, when the blending ratio of the clinker powder is less than 60% by mass, the quick setting property is reduced, and when it exceeds 90% by mass, the instantaneous setting occurs and the handling time cannot be obtained.
On the other hand, if the sulfate content is less than 10% by mass, the instant setting results in a short handling time, and if it exceeds 40% by mass, the rapid setting property is reduced, which is not preferable.

  The mixing method of the clinker powder, sulfate, and slaked lime constituting the first material and the second material is not particularly limited, and other materials may be added when the clinker is pulverized or after the clinker is pulverized. Even if the powdered materials are mixed together, any method can be applied as long as they can be mixed uniformly, and they may be mixed using a conventional mixing device so as to be blended in a ratio within the numerical range described above.

Thus prepared, the first material and the second material used in the cement quick setting material of the present invention are obtained, and the quick setting material of the present invention is a mixture of the first material and the second material. Can be obtained.
In the quick setting material, the quick setting property can be arbitrarily adjusted by adjusting the blending ratio of the first material and the second material at the time of use.
The blending ratio of the first material and the second material constituting the rapid setting material for cement of the present invention is 25:75 to 75:25, preferably 50:50 to 75:25, by mass ratio. This is desirable for effectively achieving the effects of the present invention.

The cement composition having the quick setting property of the present invention includes the quick setting material of the present invention and is mixed with cement, and 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 cement.
If the amount added is less than 10 parts by mass (outer percent), the quick setting 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 etc.) liquid or powder admixtures, 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) Reagents so that the clinker chemical composition after firing and firing the clinker has the composition shown in the upper part of Table 1 for the clinker 1 to 10 and the composition shown in the lower part of Table 1 for the clinker 11 Was added to prepare a clinker raw material.
The theoretical mineral compositions of clinker 1 to 10 and clinker 11 obtained by the Borg method based on the chemical composition of Table 1 are as shown in Table 2.

  The clinker raw 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 give clinker 1 to 10 and the calcination temperature to 1400 ° C. In the same manner, clinker 11 was obtained.

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.
From the above Table 2, from the clinker 9 and 10 _{C 3} A was 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 .
Further, the clinker 11 obtained by taking out from the electric furnace and rapidly cooling in the air was diffracted using the X-ray diffraction apparatus (manufactured by Rigaku Corporation; RAD-rC). The mineral composition of clinker 11 was as theoretical.

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.) The clinker 1 to 10 are blending ratios shown in the upper part of Table 3 and the clinker 11 is blending ratio shown in the lower part of Table 3 so that the molar ratio of SiO ₂ / Al ₂ O ₃ is 1.2. And were mixed uniformly to prepare each of the hydraulic compositions 1 to 10 and the hydraulic composition 11.

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 1-3, Reference Examples 1-2
1) First material used for cement quick setting material The hydraulic material 10 prepared in the above test example was used as the first material for quick setting material (rapid setting material A).
2) Second material used for cement quick setting material The hydraulic material 11 prepared in the above test example was used as the second material for quick setting material (rapid setting material B).

3) Preparation of mortar The first material (quick setting material A) and the second material (quick setting material B) were mixed at a ratio shown in Table 6 to obtain the quick setting materials of Examples 1 to 3. It was.
Further, as reference example 1, a quick setting material made only of the first material (quick setting material A) was prepared, and as reference example 2, a quick setting material made only of the second material (quick setting material B) was prepared.
The quick setting material, cement (manufactured by Sumitomo Osaka Cement Co., Ltd., trade name: jet cement), sand (Toyoura standard sand), setting agent (reagent; citric acid, manufactured by Wako Pure Chemical Industries, Ltd.), water and Admixtures (trade name: Mighty 150, manufactured by Kao Corporation) were blended at a ratio shown in Table 6 and uniformly kneaded to obtain mortars of Examples 1 to 3 and Reference Examples 1 and 2.

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

4) Handling time and reconstitution temperature test About the obtained mortar of Examples 1-3, Reference Examples 1-2, and Comparative Example 1, the handling time and reconstitution temperature were measured like the said test example.
The results are shown in Table 7.
Further, FIG. 3 shows the relationship between the blending ratio of the first material (quick setting material A) in the quick setting material, the handling time of the cement mortar, and the milling temperature.

As a result of the above measurement, the mortar that does not contain the rapid setting material of the present invention is inferior in rapid setting even when using jet cement which is a fast-curing cement. However, C ₁₁ A ₇ · according to Examples 1 to 3 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 for 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. The diagram which shows the relationship between the compounding ratio of the 1st material in the quick setting material (rapid setting material A), the handling time of cement mortar, and the refining temperature.

Claims (4)

The content of C ₁₂ A ₇ or C ₁₁ A ₇ · CaX ₂ (X represents halogen) in the state before thermal transition is 20 to 30% by mass, and the C ₁₂ A ₇ or C ₁₁ A ₇ · CaX ₂ (X represents halogen) at 1380 to 1450 ° C., which is generated by thermal decomposition and transition, and C ₃ A as an active ingredient, and a calcium aluminate that does not contain C ₃ A and is effective A quick setting material for cement, obtained by mixing a second material as a component. The rapid setting material for cement according to claim 1, wherein the first material and the second material are mixed in a mass ratio of 25:75 to 75:25. A rapid hardening cement composition comprising the cement quick setting material according to claim 1 or 2 and cement. The cement composition according to claim 3 , wherein 10 to 100 parts by mass of the cement rapid setting material is added to 100 parts by mass of cement.

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