JP2008201605A - Rapid-hardening material for highly flowable hydraulic composition and highly flowable hydraulic composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rapid-hardening material for a highly flowable hydraulic composition capable of giving a rapid-hardening property without causing material segregation while maintaining the high flowability when used for a hydraulic composition such as a highly flowable mortar and a highly flowable concrete whose flowabilities are improved by mixing a water reducer. <P>SOLUTION: The rapid-hardening material for a highly flowable hydraulic composition contains calcium aluminate containing particles having a particle diameter of ≤10 μm as an effective component and the ignition loss of the calcium aluminate with a particle diameter of ≤10 μm is 1-2 wt.%. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fast-hardening material for a high-fluidity hydraulic composition that is blended and used for imparting fast hardening to a hydraulic composition such as cement paste, mortar, or concrete that exhibits high fluidity. Moreover, it is related with the high fluid hydraulic composition to which quick-hardening was provided.

It is known that the addition of calcium aluminate to cement can greatly accelerate the setting of cement. (For example, refer to Patent Document 1.) For this reason, cement paste, mortar, or concrete to which calcium aluminate is added is actively used in, for example, highly urgent construction and civil engineering, and the construction period is shortened. Yes. On the other hand, in construction and civil engineering work, cement paste, mortar or concrete with high fluidity is often used for the purpose of ensuring good workability, and such cement paste, mortar or concrete has high fluidity. It is indispensable to add a water-reducing agent (including those called dispersants and fluidizing agents) in order to develop the above. However, in high-fluid cement pastes, mortars, and concretes that contain a water reducing agent, adding calcium aluminate causes a difference in the dispersion state of cement and calcium aluminate in the aqueous slurry. There has been a problem that it is likely to occur. A thickener is generally used as a means for preventing material separation. (For example, refer to Patent Document 2.) On the other hand, when a thickener is added, it becomes difficult to obtain high fluidity, and when a large amount of a water reducing agent is blended in order to ensure high fluidity, the fluidity overtime rises. There is a possibility that the setting may be delayed and the rapid hardening may be lost.
JP 60-108352 A Japanese Patent Laid-Open No. 5-9049

  For this reason, in the present invention, a cement-based hydraulic composition having a fluidity improved by blending a water reducing agent is imparted with fast hardening without causing material separation and without reducing high fluidity. It is an object of the present invention to provide a fast-hardening material for a high-fluidity hydraulic composition. It is another object of the present invention to provide a highly fluid hydraulic composition that exhibits high fluidity and rapidly cures after setting without causing material separation.

  As a result of intensive investigations to solve the above problems, the present inventor has realized that a rapid hardening material containing calcium aluminate having a specific particle size with a specific ignition loss is mixed with a water reducing agent to be fluidized. The present inventors have obtained the knowledge that sufficient cementation can be imparted to a cement-based hydraulic composition without causing material separation, thereby completing the present invention.

  That is, the present invention is a fast-hardening material for high-fluidity hydraulic compositions represented by the following (1) to (3) and a high-fluidity hydraulic composition represented by (4) to (5). (1) A fast-hardening material for a high fluid hydraulic composition containing calcium aluminate containing particles having a particle size of 10 μm or less as an active ingredient, and the ignition loss of calcium aluminate having a particle size of 10 μm or less is 1 Fast-hardening material for highly fluid hydraulic compositions that is ˜2 wt%. (2) The high-fluidity hydraulic composition according to (1), wherein the calcium aluminate contains particles having a particle size exceeding 10 μm, and the ignition loss of the calcium aluminate exceeding 10 μm is 0.5% by weight or less. Fast hardwood. (3) The fast-curing material for high fluid hydraulic composition according to (1) or (2), further comprising an inorganic carbonate having a solubility in 100 g of water of 2 g or more. (4) A high-fluidity hydraulic composition comprising the quick-hardening material for high-fluidity hydraulic composition, cement, and a water reducing agent according to any one of (1) to (3). (5) The highly fluid hydraulic composition according to (4), further comprising a setting retarder.

  According to the present invention, for example, high-fluidity hydraulic compositions such as high-fluidity mortar and concrete can be easily imparted with fast hardening without causing material separation. Can be obtained in a short period of time.

The calcium aluminate used for the fast-hardening material for the high fluid hydraulic composition of the present invention essentially contains particles having a particle size of 10 μm or less, and the loss on ignition of the particles is in the range of 1 to 2% by weight. Shall. Here, calcium aluminate is a compound containing CaO and Al ₂ O ₃ as main chemical components, a solid solution, glassy material, or a mixture of any of these, and has hydration activity. , 12CaO · 7Al ₂ O ₃ , CaO · Al ₂ O ₃ , 3CaO · Al ₂ O ₃ , 11CaO · 7Al ₂ O ₃ · CaF ₂ , 4CaO · 3Al ₂ O ₃ · SO ₃ Can also be mentioned. In the present invention, among these calcium aluminates, those having a loss on ignition of 1 to 2% by weight and a particle size of 10 μm or less are used, but the calcium aluminate having a loss on ignition of 1 to 2% by weight is used. Can be suitably obtained, for example, by reacting with moisture or carbon dioxide. When the ignition loss of calcium aluminate with a particle size of 10 μm or less is less than 1% by weight, it is difficult to suppress the increase in fluidity over time as the blending amount of the water reducing agent increases to ensure high fluidity. This is not preferable because separation easily occurs. In addition, when the loss on ignition exceeds 2% by weight, the fine particles are likely to aggregate due to the influence of moisture in the atmosphere, so that calcium aluminate becomes coarse and becomes coarse, and it is difficult to suppress material separation. Therefore, it is not preferable.

  The content of the calcium aluminate particles having a particle size of 10 μm or less in the fast-hardening material for high fluid hydraulic composition of the present invention is preferably 20% by mass or more (including 100% by mass), more preferably 35% by mass. % Or more. If it is less than 20% by mass, suppression of material separation may be difficult, which is not appropriate.

  In addition, it is preferable that the fast-hardening material for high-fluidity hydraulic composition of the present invention contains calcium aluminate having a particle size of more than 10 μm in order to stably secure high fluidity while imparting fast-curing property. When calcium aluminate having a particle size exceeding 10 μm is contained, calcium aluminate particles having an ignition loss of 0.5% by weight or less are used. When the ignition loss of calcium aluminate having a particle size of more than 10 μm exceeds 0.5% by weight, the reaction activity is excessively lowered and sufficient quick hardening cannot be imparted. As the calcium aluminate having a loss on ignition of 0.5% by weight or less, for example, calcium aluminate that avoids contact with moisture, carbon dioxide, etc. as soon as possible immediately after production can be preferably mentioned. The content of calcium aluminate having a particle diameter of more than 10 μm in the present fast hardwood is preferably 20 to 80% by mass, more preferably 30 to 65% by mass. If the content is less than 20% by mass, the content effect may not be obtained. If the content exceeds 80% by mass, the content ratio of the calcium aluminate particles having a particle size of 10 μm or less is relatively reduced, making it difficult to suppress material separation. Sometimes.

  Moreover, it is preferable to contain and use the inorganic carbonate whose solubility with respect to 100g of water is 2g or more in the quick-hardening material for high fluid hydraulic compositions of this invention. More preferably, an inorganic carbonate having a solubility of 5 to 200 g in 100 g of water is used. Here, the value of solubility should just apply in the range of 5-35 degreeC in general. Any inorganic carbonate exhibiting the solubility can be used without any particular limitation. Specific examples include sodium carbonate, potassium carbonate, magnesium carbonate, and the like. Further, the inorganic carbonate is not limited in particle size and ignition loss. By containing an inorganic carbonate having a solubility in 100 g of water of 2 g or more, stable high fluidity can be maintained without losing fast hardness. Inorganic carbonates having a solubility in 100 g of water of less than 2 g hardly provide such an action. The inorganic carbonate content in which the solubility in 100 g of water in the fast-hardening material for a high fluid hydraulic composition of the present invention is less than 2 g is preferably 0.5 to 30% by mass, more preferably 1 to 20% by mass. To do. If it is less than 0.5% by mass, the effect of inclusion may not be obtained, and if it exceeds 30% by mass, it is difficult to ensure high fluidity, which is not suitable. In addition, salts other than carbonates are not suitable because it may be difficult to ensure stable fluidity or may impair the coagulation properties.

  In addition, the fast-hardening material for a high fluid hydraulic composition of the present invention may contain components other than those described above as long as the effects of the present invention are not substantially lost.

  Moreover, the high fluid hydraulic composition of the present invention comprises any of the above-mentioned fast-hardening materials for high fluid hydraulic compositions, cement, and a water reducing agent.

  The fast-hardening material for high-fluidity hydraulic composition used in the high-fluidity hydraulic composition of the present invention uses any one of the fast-hardening materials for high-fluidity hydraulic composition according to the aforementioned invention. The blending amount is preferably 5 to 100 parts by mass with respect to 100 parts by mass of cement. If it is less than 5 parts by mass, it will be difficult to impart fast-curing properties, and if it exceeds 100 parts by mass, the fluidity may be lowered.

  The cement used in the highly fluid hydraulic composition of the present invention may be any hydraulic cement. Specific examples include various portland cements such as normal, early strength, ultra-early strength, medium heat, and low heat, various mixed cements such as blast furnace cement and silica cement, and special cements such as white cement and ecocement. Further, two or more different cements may be used in combination, in which case one of them may be an alumina cement mainly composed of calcium aluminate.

  The water reducing agent used in the highly fluid hydraulic composition of the present invention is not particularly limited, and any high performance water reducing agent, high performance AE water reducing agent, AE water reducing agent, dispersant, fluidizing agent that can be used for mortar or concrete. Or a water reducing agent comprising a liquid or soluble powder. Examples of such a water reducing agent include, for example, naphthalenesulfonic acid formalin high condensate salt as an active ingredient, naphthalene sodium sulfonate formalin condensate as an active ingredient, naphthalenesulfonic acid sodium salt formalin polycondensate , Active ingredient of highly condensed aromatic sulfonic acid, active ingredient of modified lignin and highly condensed aromatic sulfonic acid complex, active ingredient of alkylallyl sulfonic acid, alkyl Those containing allyl sulfonate as an active ingredient, those containing an alkyl allyl sulfonic acid high condensate as an active ingredient, those containing an alkyl allyl sulfonate high condensate as an active ingredient, and alkyl naphthalene sulfonic acid formalin condensate as an active ingredient Naphthalenesulfonic acid modified lignin condensate as an active ingredient , Naphthalene sulfonic acid modified lignin condensate and lignin as active ingredients, modified lignin, alkylallyl sulfonic acid and active sustained polymer composite, active ingredients, polyalkyl sulfonic acid and reactive polymer Active ingredients, alkylallyl sulfonic acid high condensate and carboxyl group-containing polyvalent polymer as active ingredients, alkyl allyl sulfonate modified lignin co-condensate and modified lignin as active ingredients, lignin derivatives Those containing alkyl allyl sulfonate as an active ingredient, those containing polyalkyl allyl sulfone surfactant as an active ingredient, those containing alkyl allyl sulfonic acid formalin condensate as an active ingredient, polyalkyl allyl sulfonic acid compounds as active ingredients Melamine sulfonic acid condensate is effective Those containing melamine sulfonic acid compounds as active ingredients, those containing melamine sulfonic acid compounds and polyol composites as active ingredients, those containing highly condensed triazine compounds as active ingredients, triazine ring system high condensation Those having a salt surfactant as an active ingredient, those having a methylol melamine condensate as an active ingredient, those having a modified methylol melamine condensate as an active ingredient, a modified methylol melamine condensate and a carboxylic acid compound as active ingredients And those having a sulfonated melamine high condensate salt as an active ingredient, those having a polycarboxylic acid or a salt thereof as an active ingredient, and two or more of these may be used in combination. The content of the water reducing agent is preferably 0.02 to 2 parts by mass in terms of solid content with respect to 100 parts by mass of cement. If the amount is less than 0.02 parts by mass, high fluidity may not be obtained. If the amount exceeds 2 parts by mass, material separation may occur or the expression of fast curing may be reduced.

  Moreover, the high fluid hydraulic composition of the present invention preferably contains a setting retarder. In particular, when containing and using a water reducing agent having almost no set retarding action, it is recommended to use it in order to maintain a stable fluidity for a desired period. The setting retarder may be any as long as it can be used for mortar and concrete, and examples thereof include citric acid, tartaric acid, gluconic acid, heptonic acid, phosphoric acid, boric acid, lignin sulfonic acid, and salts thereof. . The content of the setting retarder is preferably 0.02 to 2 parts by mass with respect to 100 parts by mass of cement. If the amount is less than 0.02 parts by mass, the inclusion effect may not be obtained. If the amount exceeds 2 parts by mass, material separation may occur or the setting may be delayed too much.

  Further, the high fluid hydraulic composition of the present invention contains materials other than the above-mentioned fast-hardening material for high fluid hydraulic composition, cement and water reducing agent within a range that does not substantially lose the effects of the present invention. Also good. Examples of materials that can be used include swellable materials, plaster, shrinkage reducing agents, antifoaming agents, setting accelerators, water retention agents, rust preventives, anti-whitening agents, water repellents, antibacterials Agents, pozzolanic reactive fine powders, pigments, silica stone powder, limestone powder, polymer dispersions, re-emulsified powder resins, fibers, aggregates and the like.

  Moreover, the manufacturing method of the highly fluid hydraulic composition of this invention is not specifically limited, For example, it can manufacture by throwing a use material into a mortar and a grout mixer, knead | mixing by adding water. The amount of water added is not particularly limited, but in order to obtain high fluidity, approximately 20 to 100 parts by mass is recommended with respect to 100 parts by mass of cement. If the addition amount is less than this, it may be difficult to obtain a desired high flow, and if the addition amount is more than this, the material separation and strength development may be reduced.

  EXAMPLES Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to the examples shown here.

<Adjustment of calcium aluminate>
Alumina cement clinker as the calcium aluminate source (mass content of main components: Al ₂ O ₃ ; 52%, CaO; 38%, SiO ₂ ; 4%, Fe ₂ O ₃ ; 2%) is pulverized and classified to 10 μm Particles passing through the sieve mesh were collected. The collected particles were left in the room atmosphere until a predetermined loss on ignition was reached, and then stored in a sealed container. Here, the loss on ignition was measured according to JIS R 2522 “Analytical method of alumina cement for refractory”. By this method, four types of calcium aluminate having a particle size of 10 μm or less having a loss on ignition of 2.2 wt%, 1.8 wt%, 1.1 wt% and 0.6 wt% were prepared. The calcium aluminate is hereinafter referred to as A1 (with a loss on ignition of 2.2% by weight), A2 (with a loss on ignition of 1.8% by weight), A3 (with a loss on ignition of 1.1% by weight) and A4. (Loss on ignition is 0.6% by weight). In addition, by the same method, residual particles on the sieve that could not pass through the 10 μm sieve with the pulverized alumina cement clinker were also collected, and the loss on ignition was 1.1 wt%, 0.8 wt%, 0.3 wt%. And, four kinds of calcium aluminate exceeding 10 μm in particle size of 0.1% by weight were also prepared. The calcium aluminate is hereinafter referred to as A5 (with a loss on ignition of 1.1% by weight), A6 (with a loss on ignition of 0.8% by weight), A7 (with a loss on ignition of 0.3% by weight) and A8. (Ignition loss 0.1% by weight).

<Preparation of fast-hardening material>
A material selected from the calcium aluminates A1 to A8 and the following B1 to B2 (all commercially available reagents) is put into a high-speed fluidized mixing container so as to have the blending amount shown in Table 1, and the temperature is about 20 ° C. Were mixed for 1 minute under the above conditions to produce quick-hardening materials (present products S1 to S11, reference products S12 to S15).

B1; sodium carbonate (solubility at 20 ° C. in 100 g of water; 22 g)
B2: Potassium carbonate (solubility at 20 ° C. in 100 g of water; 112 g)

<Preparation of fast-curing mortar>
First, cement (C) and fine aggregate (G) so that the material and water selected from C-J shown below and the prepared quick-hardening materials (S1 to S15) and water are the amounts shown in Table 2. ) And water were put into a Hobart mixer and kneaded at a temperature of about 20 ° C. for 1 minute to prepare a base mortar. Subsequently, other materials such as quick-hardening materials were added to the base mortar, and further kneaded for about 1 minute to prepare a mortar.

C: Ordinary Portland cement (manufactured by Taiheiyo Cement Co., Ltd.)
D: Polycarboxylic acid-based high-performance water reducing agent (trade name “Core Flow NF-200”, manufactured by Taiheiyo Materials Co., Ltd.)
E: Naphthalene sulfonic acid-based high-performance water reducing agent (trade name “Mighty 100”, manufactured by Kao Corporation)
F: anhydrous gypsum (commercially available)
G: Fine aggregate (standard sand for cement strength test specified in JIS R 5201)
H: Lithium carbonate (commercially available reagent)
I: Cellulose ether type thickener (trade name “90SH-4000”, manufactured by Shin-Etsu Chemical Co., Ltd.)
J: Citric acid (commercially available reagent)

<Property evaluation of mortar>
About the produced mortar, fluidity | liquidity, material separation, and quick-hardness evaluation were performed with the following method.

<Evaluation of fluidity>
The flow rate of the mortar immediately after the production was measured in a test chamber maintained at a constant temperature of 20 ° C. by a method according to Japan Society of Civil Engineers standard JSCE-F521-1999, and used as an evaluation index of fluidity. The measurement results are shown in Table 3.

<Evaluation of material separation>
The bleeding occurrence state of the produced mortar was visually observed by a method according to the Japan Society of Civil Engineers standard JSCE-F532-1999. That is, the prepared fast-curing mortar was allowed to stand in a test chamber maintained at a temperature of 20 ° C., and no bleeding was observed immediately after the preparation of the fast-curing mortar until 1 hour later. It was judged that there was no bleeding, and the occurrence of bleeding was found to be “present”. The results are shown in Table 3.

<Evaluation of fast curing>
In a test chamber maintained at a temperature of 20 ° C., the mortar immediately after the preparation was filled in a cylindrical mold having an inner diameter of 5 cm and a height of 10 cm and left to stand. After 5 hours from completion of filling, the surface of the mortar in the mold was strongly pressed with a finger, and “×” indicates that it deformed even a little, and “◯” indicates that it did not deform. The results are shown in Table 3.

  From the results in Table 3, the quick-hardening material of the present invention can sufficiently suppress the material separation without substantially reducing the fluidity of the mortar even when used in a high fluidity mortar, and can be deformed in a short time. It can be seen that a hardened body that is extremely difficult to cause is obtained.

Claims (5)

A fast-hardening material for a high fluid hydraulic composition containing calcium aluminate containing particles having a particle size of 10 μm or less as an active ingredient, wherein the ignition loss of calcium aluminate having a particle size of 10 μm or less is 1 to 2 weights. % Fast-hardening material for highly fluid hydraulic compositions. The fast-hardening material for a high-fluidity hydraulic composition according to claim 1, wherein the calcium aluminate contains particles having a particle size exceeding 10 µm, and the ignition loss of the calcium aluminate exceeding 10 µm is 0.5 wt% or less. . Furthermore, the quick-hardening material for high fluid hydraulic compositions of Claim 1 or 2 containing the inorganic carbonate whose solubility with respect to 100g of water is 2g or more. The high fluid hydraulic composition formed by containing the quick-hardening material for high fluid hydraulic compositions in any one of Claims 1-3, cement, and a water reducing agent. The high fluid hydraulic composition according to claim 4, further comprising a setting retarder.