JP2019043806A - Quick-hardening material and quick-hardening cement composition - Google Patents

Abstract

To provide a quick-hardening material capable of producing a quick-hardening cement composition that provides a hardened body having an excellent dimensional stability, a high strength-developing property, and an excellent appearance, in both the atmospheric curing and the underwater curing, and also can provide the quick-hardening material having a good storage stability.SOLUTION: A quick-hardening material of this invention comprises an amorphous calcium aluminate, gypsum, and AlO-SObased compound. The content of gypsum is 50-120 parts by mass to 100 parts by mass of the amorphous calcium aluminate, and the content of AlO-SO-based compound is 5-20 parts to 100 parts by mass of the amorphous calcium aluminate. Furthermore, the AlO-SO-based compound is amorphous, and has the weight reduction of 5 - 40 mass% when heated at 500°C.SELECTED DRAWING: None

Description

  BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a rapid-harding material for accelerating the hardening of hydraulic materials such as cement and concrete, and a rapid-setting cement composition using the same.

  As a quick-harding material that gives quick-hardening to hydraulic materials such as cement and concrete, using calcium aluminate and gypsum, or auin and gypsum, etc Hard cement compositions have been proposed (eg, Patent Documents 1 to 3). This quick-hardening cement composition can be hardened in several minutes to several tens of minutes after being placed in a mold, and can exhibit practical strength capable of being demolded after several hours. Therefore, rapid hardening cement compositions are widely used in mortars, grout mortars, and the like for emergency construction or emergency repair such as paving concrete for highways where short opening of road traffic is required.

  In addition, since needle-like ettringite formation increases the bulk volume of crystals, it is also used as an expansive material that compensates for drying shrinkage (for example, Patent Documents 4 and 5). In fact, there is also proposed a rapid-hardening material capable of providing appropriate expansivity by the formation of ettringite by using calcium aluminate and gypsum, or auine and gypsum, etc. (for example, Patent Documents 6 and 7).

  However, when a rapid-hardening cement composition containing the above-described rapid-hardening material is cured at a low temperature, ettringite may be generated late to cause extremely excessive expansion. In particular, this excessive expansion often occurs when the amount of quick-hardening material used is large or when the water-powder ratio is small, and it is difficult to achieve both the desired expansivity and rapid-hardness. There was a problem. Furthermore, in the conventional rapid-hardening cement composition, the surface property of the surface to be driven is likely to be deteriorated, and even if the surface to be driven is finished with a iron, spots and irregularities are easily generated on the surface as it hardens. Therefore, there also existed a problem that the hardened | cured material excellent in aesthetics was not obtained.

With respect to the above-mentioned problems, Patent Document 8 discloses that the shrinkage rate in air curing is independent of curing temperature by combining specific calcium aluminates, cement, gypsum, alkali metal carbonate and setting retarder. A hydraulic cement composition has been proposed which gives a hardened body which is small and has a low expansion rate even in water curing.
Further, Patent Document 9 discloses atmospheric curing and water by combining cement containing calcium silicate mineral as a main component, calcium aluminates, clay mineral calcined at 1000 ° C. or less, sulfate and lithium carbonate. Rapid hardening cement compositions have been proposed which give hardened bodies with good dimensional stability during any curing.
Moreover, the method of mix | blending fatty acids with a cement composition is proposed by patent document 10 and 11 as a method of suppressing the dew point accompanying hardening, and the unevenness | corrugation on the surface.

On the other hand, Patent Document 12 uses a quick-hardening material containing quick-hardening component, gypsum, and aluminum sulfate as an acidic substance to give a cured product having good initial strength development and also to use a hardening time due to temperature change. It is reported that a rapid-hardening cement composition which changes slowly and can maintain fluidity is obtained.
Further, Patent Document 13 discloses at least one selected from the group of calcium aluminate particles coated with hydrate, calcium sulfate, and aluminum sulfate (aluminum sulfate), alkali metal sulfate, and alkali metal carbonate. It has been reported that a quick-hardening cement composition capable of securing a long pot life and capable of forming a hardened body excellent in short-time strength can be obtained by using a quick-hardening material containing There is.
In addition, Patent Document 14 uses a quick-harding material containing calcium sulfoaluminate hydrate formed by mixing calcium aluminate, gypsum and hydrous compound by a high speed shear method having a rotational speed of 20 m / s or more. It is reported that the rapid hardening cement composition which can secure a pot life and is excellent in storage stability is obtained by this, and a sulfate (aluminum sulfate) is mentioned as an example of a water-containing compound.

  On the other hand, in Patent Documents 15 to 17, a quick-setting agent containing calcium aluminate, an alkali metal sulfate and an aluminum sulfate as a quick-setting agent added to shorten a setting time in a mortar or concrete composition used for spraying Has been reported.

Japanese Patent Publication No. 49-30683 Unexamined-Japanese-Patent No. 03-12350 JP, 2002-68795, A Patent No. 4424261 Japanese Patent Application Laid-Open No. 7-232944 JP-A-7-215745 JP 2007-51014 A JP 2012-140294 A JP, 2014-122129, A JP 02-97443 A JP, 2008-195574, A Unexamined-Japanese-Patent No. 2001-253753 JP, 2005-60154, A International Publication No. 2014/203788 Japanese Patent Laid-Open No. 2000-302503 Japanese Patent Application Laid-Open No. 2002-053357 WO 2015/182170

However, hydraulic cement compositions containing carbonate in advance as in Patent Documents 8 and 9 have a problem that their performance tends to deteriorate when stored, and in particular, their pot life tends to change. Furthermore, since patent document 9 makes a clay mineral essential, the influence on fresh property is large, and it can be used only for a specific use.
Moreover, when fatty acids are added like patent document 10 and 11, there exists a problem that initial stage strength expression property falls.
Moreover, although it teaches that patent documents 12-14 can obtain the rapid-hardening material which gives the hardened | cured material excellent in initial stage strength expression property by using aluminum sulfate, although aluminum sulfate is secured, aluminum sulfate There is no teaching that the addition and blending ratio of B. affects the storage stability of the quick-hardening material and the dimensional stability (length change) of the cured product.

Moreover, the quick-setting agent of patent documents 15-17 uses aluminum sulfate for the purpose of promoting the setting of an extremely early stage, and these documents show that aluminum sulfate is the storage stability of a quick-setting agent, and a hardening object. There is no teaching about affecting dimensional stability.
Furthermore, since hydraulic materials such as calcium aluminate are strongly alkaline, when they are premixed with acidic aluminum sulfate, storage stability, strength of the cured product, etc. may be reduced, and construction speed and There was a problem in making a single material for the purpose of rationalization of construction such as improvement of handling property.

The present invention has been made to solve the above-mentioned problems, and a rapid-hardening cement composition which provides a cured product excellent in dimensional stability, strength development and aesthetic appearance in any of atmospheric curing and underwater curing. It is an object of the present invention to provide a quick-hardening material that can be produced and has good storage stability.
Another object of the present invention is to provide a rapid-hardening cement composition which gives a cured product which is excellent in dimensional stability, strength developing property and aesthetic appearance in any of atmospheric curing and underwater curing.

As a result of various investigations in view of the above situation, the present inventors combined an amorphous calcium aluminate, gypsum, and an Al ₂ O ₃ -SO ₃ -based compound having specific properties at a predetermined blending ratio. It has been found that a rapid hardwood capable of solving all the above problems can be obtained, and the present invention has been completed.

That is, the present invention comprises 50 to 120 parts by mass of gypsum and 5 to 20 parts by mass of an Al ₂ O ₃ -SO ₃ compound with respect to 100 parts by mass of amorphous calcium aluminate, and the Al ₂ O ₃ -SO ₃ compound is amorphous, weight loss when ignited at and 500 ° C. is steeper hardwood from 5 to 40 wt%.
Moreover, this invention is a rapid-hardening cement composition containing a cement and the said rapid-hard material.

According to the present invention, it is possible to manufacture a rapid-hardening cement composition which gives a cured product excellent in dimensional stability, strength development and appearance in any of atmospheric curing and underwater curing, and also has good storage stability. It is possible to provide some quick hardwood.
Further, according to the present invention, it is possible to provide a rapid-hardening cement composition which gives a cured product excellent in dimensional stability, strength developing property and aesthetic appearance in any of atmospheric curing and underwater curing.

Hereinafter, the present invention will be described in detail. In the present specification, parts and% are indicated on a mass basis unless otherwise specified.
Sudden hard material of the present invention include amorphous calcium aluminate, gypsum and Al ₂ O ₃ -SO ₃ compound.

The amorphous calcium aluminate used in the present invention is mainly composed of CaO and Al ₂ O ₃ obtained by heating and melting a raw material containing calcia, a raw material containing alumina, etc. It is a general term for amorphous materials having hydration activity. For example, amorphous calcium aluminate can be obtained by contacting a calcium aluminate clinker melted in an electric furnace with compressed air or water and quenching it. Here, in the present specification, the term "main component" means that the proportion of the entire component exceeds 50% by mass.

The molar ratio of CaO (CaO / Al ₂ O ₃ ) to amorphous calcium aluminate to Al ₂ O ₃ is not particularly limited, but is preferably 1.3 to 2 from the viewpoint of hydration activity, strength development, etc. And more preferably 1.5 to 2.0. When this molar ratio is less than 1.3, hydration activity and initial strength development may decrease. On the other hand, when this molar ratio exceeds 2.3, a very high heating temperature for quenching and a quenching operation from the temperature are required for vitrification, and the manufacturing cost is increased.

The vitrification rate of the amorphous calcium aluminate is not particularly limited, but is preferably 90% or more, more preferably 95% or more from the viewpoint of rapid hardening, initial strength development and the like. If the vitrification ratio is less than 90%, rapid hardening, initial strength development, etc. may be reduced.
The crystalline part of the amorphous calcium aluminate is not particularly limited, but may be, for example, calcium aluminate such as 3CaO · Al ₂ O ₃ , 12CaO · 7Al ₂ O ₃ or the like, or gellenite due to an additive derived from the raw material or unavoidable impurities , Calcium alumino ferrite, calcium ferrite and the like.

  Here, the vitrification rate of amorphous calcium aluminate can be determined by powder X-ray diffraction / liet belt analysis. Specifically, a predetermined amount of an internal standard substance such as aluminum oxide or magnesium oxide is added to a measurement sample, sufficiently mixed in an agate mortar or the like, and then powder X-ray diffraction measurement is performed. Thereafter, the measurement result is analyzed by quantitative software to determine the amount of mineral produced, and the remaining portion is taken as the vitrification rate of the clinker. As quantitative software, "SIROQUANT" manufactured by Sietronics can be used.

The fineness of the amorphous calcium aluminate is not particularly limited, but the brane specific surface area is preferably 4000 to 7000 cm ² / g, more preferably 5000 to 6000 cm ² / g. If the brane specific surface area is less than 4000 cm ² / g, rapid hardness, initial strength development and the like may be reduced. On the other hand, even if the brane specific surface area exceeds 7000 cm ² / g, further improvement of the effect can not be expected, and the workability may be lowered. It is also uneconomical because it takes time to grind it.

  The gypsum used in the present invention is not particularly limited, and anhydrous gypsum, hemihydrate gypsum, and gypsum dihydrate can be used. The gypsum may be used singly or in combination of two or more. Among these, anhydrous gypsum is preferable from the viewpoint of setting property and strength development.

The particle size of gypsum is not particularly limited as long as it is a range generally used for cement etc., but in view of setting property and strength developing property, the brane specific surface area is preferably 3000 cm ² / g or more, more preferably 4500 cm ² / g or more. If the brane specific surface area is less than 3000 cm ² / g, the caking and / or initial strength development may decrease. The upper limit of the brane specific surface area is not particularly limited, and the larger the value, the better. However, it is preferably 9000 cm ² / g or less from the viewpoint of production cost and the like.

  The amount of gypsum used is 50 to 120 parts by mass, preferably 80 to 100 parts by mass, with respect to 100 parts by mass of amorphous calcium aluminate. If the amount of gypsum used is less than 50 parts by mass, the setting property is reduced, and long-term strength development can not be sufficiently obtained. On the other hand, if the amount of gypsum used exceeds 120 parts by mass, the initial setting is delayed, and the initial strength developing property is reduced or the expansion becomes excessive.

The Al ₂ O ₃ -SO ₃ -based compound used in the present invention is amorphous and has a weight loss (ignition loss) of 5 to 40% by mass when ignited at 500 ° C. If the Al ₂ O ₃ -SO ₃ -based compound is not amorphous, the storage stability of the quick-hardening material prepared by mixing it with a hydraulic material exhibiting strong alkalinity such as calcium aluminate decreases.
Whether Al ₂ O ₃ -SO ₃ compound is amorphous it can be determined by X-ray diffraction analysis. Specifically, if the X-ray diffraction spectrum of the Al ₂ O ₃ -SO ₃ -based compound is broad, it can be judged to be amorphous.

Moreover, initial stage strength expression property falls that the weight loss at the time of igniting at 500 degreeC is less than 5 mass%. On the other hand, when the weight loss when ignited at 500 ° C. exceeds 40% by mass, the storage stability is lowered. The weight loss at the time of ignition at 500 ° C. is preferably 10 to 40% by mass from the viewpoint of stably improving the strength development and storage stability.
Here, in the present specification, the loss on ignition at 500 ° C. (loss on ignition) means the loss on ignition of the Al ₂ O ₃ —SO ₃ compound at 500 ° C. for 1 hour, It is calculated by the following equation (1).
Ignition weight loss = (m-m ') / m × 100 (1)
m: Mass of Al ₂ O ₃ -SO ₃ series compound before ignition m ': Mass of Al ₂ O ₃ -SO ₃ series compound after ignition

Al ₂ O ₃ -SO ₃ compounds can be prepared using the Al ₂ O ₃ source and SO ₃ source. As the manufacturing method, the method is not particularly limited, for example, the method of heat treatment after mixing Al ₂ O ₃ source and SO ₃ source, is directly chemically reacting Al ₂ O ₃ source and SO ₃ source, Al ₂ O It is possible to use a method in which the _three sources and the SO ₃ source are introduced into a solvent such as pure water and mixed and then chemically reacted. In these methods, by controlling the production conditions, it is possible to obtain an Al ₂ O ₃ —SO ₃ -based compound having the above-mentioned properties. For example, in the case of using a method in which an Al ₂ O ₃ source and an SO ₃ source are introduced into a solvent and mixed and then subjected to a chemical reaction, the Al ₂ O ₃ -SO ₃ based compound is controlled by controlling conditions such as reaction temperature. You can adjust the weight loss on ignition.

The Al ₂ O ₃ source is not particularly limited, and aluminum sulfate, aluminate, and other inorganic aluminum compounds, organic aluminum compounds, and aluminum complexes can be used.
The sulfate of aluminum is not particularly limited, and examples thereof include ammonium alum, aluminum hydroxysulfate, and aluminum sulfate.
The aluminate is not particularly limited, and examples thereof include lithium aluminate, sodium aluminate, potassium aluminate, calcium aluminate, and magnesium aluminate.
Other inorganic aluminum compounds are not particularly limited. For example, bauxite, aluminum oxide, aluminum hydroxide, aluminum chloride, aluminum phosphate, aluminum nitrate, aluminum fluoride, polyaluminum chloride, aluminum hydroxide hydroxide, synthetic hydrotalcite Site, and aluminum metasilicate and the like.

The organic aluminum compound is not particularly limited, and examples thereof include aluminum stearate, aluminum oxalate, aluminum isopropoxide, and aluminum formate.
The aluminum complex is not particularly limited, and examples thereof include tris (8-hydroxyquinolinato) aluminum and the like.
A single species can be used as the Al ₂ O ₃ source, but two or more species may be used in combination. Further, among the various Al ₂ O ₃ sources described above, aluminum sulfate is preferred in view of high solubility in water, low production cost and excellent setting property.

The SO ₃ source is not particularly limited, but in addition to elemental sulfur such as sulfur and sulfur, sulfide, sulfuric acid, sulfate, sulfite, sulfite, thiosulfate, thiosulfate, organic sulfur compounds, etc. Can be used.
Although it does not specifically limit as a sulfide, For example, magnesium sulfide, calcium sulfide, iron sulfide, and phosphorus pentasulfide etc. are mentioned.
The sulfate is not particularly limited, and examples thereof include aniline sulfate, aluminum sulfate, ammonium sulfate, magnesium sulfate, manganese sulfate, barium sulfate, calcium sulfate, sodium alum, potassium alum, ammonium alum, and hydroxylamine sulfate.

The sulfite is not particularly limited, and examples thereof include ammonium bisulfite and calcium sulfite.
The thiosulfate is not particularly limited, and examples thereof include ammonium thiosulfate and barium thiosulfate.
The organic sulfur compound is not particularly limited, and examples thereof include sulfonic acid derivatives, salts of sulfonic acid derivatives, mercaptan, thiophene, thiophene derivatives, polysulfone, polyether sulfone, and resins such as polyphenylene sulfide.
Although a single species can be used as the SO ₃ source, two or more species may be used in combination. Further, among the various SO ₃ sources described above, sulfates are preferable, and ammonium alum is most preferable, from the viewpoints of high solubility in water, low manufacturing cost, and excellent aggregation.

The Al ₂ O ₃ -SO ₃ compound preferably has a true density of 1.9 to 2.3 g / cm ³ from the viewpoint of improving initial strength development and storage stability. If the true density is less than 1.9 g / cm ³ , storage stability may be reduced. On the other hand, if the true density exceeds 2.3 g / cm ³ , the initial strength development may decrease.
Here, the true density of the Al ₂ O ₃ -SO ₃ based compound can be measured using a commercially available densitometer.

The Al ₂ O ₃ -SO ₃ based compound has a BET specific surface area of preferably 5 m ² / g or less, more preferably 3 m ² / g or less, from the viewpoint of workability (useful time). If the BET specific surface area exceeds 5 m ² / g, the workability (working time) may be reduced, and the time and effort of the pulverization treatment may be increased, leading to an increase in cost.
Here, the BET specific surface area of the Al ₂ O ₃ -SO ₃ -based compound can be measured using a commercially available BET specific surface area measuring device.

An Al ₂ O ₃ -SO ₃ compound has a peak at a chemical shift of -0.51 to -23.21 ppm in the spectrum obtained by solid ²⁷ Al-NMR, from the viewpoint of improving the strength development and storage stability. And its half width is preferably 5 ppm or more. When the chemical shift of the peak is larger than -0.51 ppm, it is difficult to mix with calcium aluminate and storage stability may decrease even if it can be mixed. On the other hand, if the chemical shift of the peak is smaller than -23.21 ppm, the effect of improving the strength development may not be obtained. When the half width is less than 5 ppm, the effect of improving strength development and storage stability may not be sufficiently obtained.

Here, solid-state ²⁷ Al-NMR measurement of the Al ₂ O ₃ -SO ₃ -based compound is carried out using a commercially available measuring device, for example, a superconducting nuclear magnetic resonance device “ECX-400” manufactured by Nippon Denshi Co., Ltd. It can be done on condition.
Observation nucleus: ²⁷ Al
Sample tube rotation speed: 10 KHz
Measurement temperature: Room temperature Pulse width: 3.3 μsec (90 ° pulse)
Wait time: 5 seconds External standard: Aluminum nitrate

An Al ₂ O ₃ -SO ₃ compound is an SO ₄ group with respect to a peak area derived from OH group stretching vibration in a spectrum obtained by FT-IR from the viewpoint of improving strength development and storage stability of a rapid hard material. The ratio of peak areas derived from stretching vibration is preferably 0.2 to 3.0. If the ratio of peak areas is less than 0.2, the effect of improving the initial strength expression may not be obtained. On the other hand, when the ratio of peak areas exceeds 3.0, storage stability may be reduced.

Here, FT-IR (Fourier transform infrared spectroscopy) of the Al ₂ O ₃ -SO ₃ based compound is performed by the ATR method using a commercially available FT-IR apparatus, for example, Frontier manufactured by Perkin Elmer. Can.
In the present specification, a peak derived from OH group stretching vibration to appear around the 3000 cm ^-1, the area of the peak centered at 3000 cm ^-1, and a peak area derived from the OH group stretching vibration. Furthermore, peaks derived from SO ₄ group stretching vibration to appear around the 1100 cm ^-1, the area of the peak centered at 1100 cm ^-1, and a peak area derived from the SO ₄ group stretching vibration.
The ratio of the peak area derived from the SO ₄ group stretching vibration to the peak area derived from the OH group stretching vibration is calculated by dividing the peak areas derived from the peak areas derived from the SO ₄ group stretching vibration OH group stretching vibration can do.

The amount of the Al ₂ O ₃ -SO ₃ compound used is 5 to 20 parts by mass with respect to 100 parts by mass of the amorphous calcium aluminate. If the amount used is less than 5 parts by mass, dimensional stability is reduced. On the other hand, if the amount used exceeds 20 parts by mass, the long-term strength development decreases.

The quick-hardening material of the present invention can contain, as an optional component, a component known in the art as long as the effects of the present invention are not impaired, in addition to the components described above.
The quick-hardening material of the present invention can be prepared by mixing the above-mentioned components. The mixing method is not particularly limited, and mixing may be performed using a commercially available mixer or the like.

Generally, when aluminum sulfate is used together with an alkaline calcium aluminate to prepare a quick-hardening material, the storage stability tends to decrease, but the quick-hardening material of the present invention is a specific aluminum sulfate (Al ₂ O _3- Since the SO ₃ -based compound) and the specific calcium aluminate are combined in a predetermined ratio, the storage stability is difficult to reduce. Therefore, the rapid-hardening material of the present invention can be stored for a long time without performing a special storage method, a construction method or a handling method, and one of the materials for the purpose of rationalization of construction such as improvement of construction speed and handleability. Materialization becomes possible.
The quick-hardening material of the present invention can be prepared into a quick-hardening cement composition by blending into cement. The quick-hardening cement composition of the present invention prepared using the quick-hardening material of the present invention can give a cured product excellent in dimensional stability, strength development and appearance in any of atmospheric curing and underwater curing. .

  The amount of the quick-harding material used in the quick-hardening cement composition may be appropriately adjusted depending on the application, but typically it is preferably 5 to 35 parts by weight based on 100 parts by weight in total of cement and quick-harding material. It is preferably 10 to 30 parts by mass, more preferably 15 to 25 parts by mass. If the amount used is less than 5 parts by mass, initial strength development may not be sufficiently obtained. On the other hand, if the amount used exceeds 35 parts by mass, long-term strength development may not be sufficiently obtained.

  As cement used in the present invention, various Portland cements such as normal, early strong, ultra early strong, low heat, moderate heat, and various mixed cements obtained by mixing blast furnace slag, fly ash or silica with these Portland cements, limestone Examples include filler cement in which powder, blast furnace slowly cooled slag fine powder and the like are mixed, municipal waste incineration ash, and portland cement such as environmentally friendly cement (eco cement) manufactured using sewage sludge incineration ash as a raw material. These can be used singly or in combination of two or more.

The rapid hardening cement composition of the present invention may contain, in addition to the above components, known components generally used in cement compositions as long as the effects of the present invention are not impaired.
For example, the rapid hardening cement composition of the present invention can include a setting retarder to impart a delaying effect on setting. The retarder is not particularly limited, and examples thereof include citric acid, gluconic acid, tartaric acid, malic acid, or salts thereof, boric acid, borates such as sodium borate, phosphates, alkali metal carbonates, One or more selected from the group consisting of inorganic salts such as alkali metal bicarbonates, saccharides and the like. Among these, one or more types selected from the group of citric acid, citrate, tartaric acid, tartrate, and alkali metal carbonate are preferable from the viewpoint of adjustment of curing time and initial strength development.
The amount of setting retarder used is difficult to determine uniquely because it needs to be adjusted depending on the working (useful) time. For example, in the present invention, in the case where the amount is adjusted so that the rapid hardening cement composition hardens in accordance with the work (useful) time for 15 to 60 minutes, 100 parts by mass of the rapid hardening cement composition is preferable. Is preferably 0.1 to 4 parts by mass, more preferably 0.2 to 3 parts by mass, and still more preferably 0.3 to 2 parts by mass. If the amount used is out of the above range, sufficient working (useful) time may not be secured, or strength development may be reduced.

  Other known components include cement additives, fine aggregates such as sand, coarse aggregates such as gravel, expansive agents, water reducing agents, AE water reducing agents, high performance water reducing agents, high performance AE water reducing agents, antifoamer , Thickeners, conventional antirust agents, antifreeze agents, shrinkage reducing agents, setting agents, clay minerals such as bentonite, anion exchangers such as hydrotalcite, slags such as blast furnace granulated slag, blast furnace slowly cooled slag, etc. And limestone, bauxite and the like.

  Hereinafter, the present invention will be described in more detail by way of examples and comparative examples, but the present invention is not construed as being limited thereto.

<Material used for quick hard material>
Amorphous calcium aluminate: Amorphous CA clinker, CaO / Al ₂ O ₃ molar ratio 1.7 (amorphous clinker corresponding to the composition of C 12 A 7). Limestone (CaO content 57% by mass, Al ₂ O ₃ content 1.1% by mass, MgO content 0.35% by mass, SiO ₂ content 0.67% by mass) as calcia source, bauxite (CaO as alumina source) Using a content of 0.75 mass%, an Al ₂ O ₃ content of 72 mass%, an MgO content of 0.31 mass%, an SiO ₂ content of 4.7 mass%), melting at 1650 ° C. and quenching Synthesized. The vitrification rate is 98% and the brane specific surface area is 6000 cm ² / g.
Gypsum: Commercial ground anhydrous gypsum, Blaine specific surface area 6000 cm ² / g
Al ₂ O ₃ -SO ₃ compounds: aluminum hydroxide (reagent, 99% purity), was used sulfuric acid (reagent, purity: 99%), and pure water as a raw material. The aluminum hydroxide and sulfuric acid solvent 2: 3 were mixed with 10 molar ratio, by reacting the mixture was heated to a predetermined temperature, to prepare an Al ₂ O ₃ -SO ₃ compound.

<Material used for quick setting cement composition>
Cement: Normal Portland cement, Blaine specific surface area 3200 cm ² / g, specific gravity 3.15
Fine aggregate: JIS standard sand, commercial product Set-up delay agent: citric acid, commercial product Solvent: pure water

Example 1
The aluminum hydroxide and the solvent sulfate 2: 3 were mixed with 10 molar ratio of the mixture by reaction by heating to a temperature shown in Table 1, to prepare an Al ₂ O ₃ -SO ₃ compound. The obtained Al ₂ O ₃ -SO ₃ compounds were evaluated for X-ray diffraction, loss on ignition, true density, BET specific surface area, solid ²⁷ Al-NMR, and FT-IR. The results of each evaluation are shown in Table 1.

<Measurement method>
X-ray diffraction: It measured using RIGAKU Multi-Flex. The measurement was performed under the conditions of 2θ: 5 ° to 60 °, 5 ° / min, with a tube voltage-tube current of 40 KV-40 mA. Moreover, analysis software used PDXL. In the evaluation of X-ray diffraction, if the X-ray diffraction spectrum was broad, it was judged as amorphous, and the others were judged as crystalline.
Ignition weight loss: The weight loss when ignited at 500 ° C. for 1 hour using a muffle furnace manufactured by Isuzu Seisakusho Co., Ltd. was measured, and calculated based on the above equation (1).
True density: Measured using a dry-type automatic densitometer (Acupic II 1340) manufactured by Micromeritics.
BET specific surface area: Measured by the BET single-point method using a monosorb (MONOSORB) manufactured by Yuasa Ionics.
Solid ²⁷ Al-NMR: Conducted under the above conditions using a superconducting nuclear magnetic resonance apparatus (ECX-400) manufactured by JEOL Ltd., and measured the chemical shift and the half width of the peak.
FT-IR: Measured using a Perkin Elmer Frontier. For measurement, after performing background measurement using a single reflection ATR, the sample was set, and the sample surface was measured by 16 times of scanning. The measurement results are output as absorbance on the vertical axis (Y axis) and wave number on the horizontal axis, and peak area (integral value) derived from OH group stretching vibration and peak area (integral value) derived from SO ₄ group stretching vibration Calculated by analysis software (Spectrum manufactured by Perkin Elmer).

(Example 2)
The quick-hardened wood was obtained by blending and mixing the crushed amorphous CA clinker, gypsum, and the Al ₂ O ₃ -SO ₃ based compound (No. F) obtained in Example 1 in the proportions shown in Table 2. Prepared.
Next, using this quick-hard material, 20 parts by weight of quick-hard material, 150 parts by weight of fine aggregate, 50 parts by weight of water, 0.8 parts by weight of citric acid, with respect to a total of 100 parts by weight of cement and quick-hard material The rapid curing cement composition was prepared by blending and mixing parts by mass at room temperature (20 ° C.).
Moreover, the rapid-hardening cement composition which is not mix | blending rapid-hardening material was also prepared as a comparison (No. 1-1). This rapid hardening cement composition is prepared by blending 150 parts by mass of fine aggregate, 50 parts by mass of water and 0.8 parts by mass of citric acid at room temperature (20 ° C.) with 100 parts by mass of cement. did.
The compressive strength, the rate of change in length, and the different color pattern were evaluated for the rapid-hardening cement composition obtained above. These evaluation methods were performed as follows.

<Measurement method>
Compressive strength: A 4 × 4 × 16 cm test body was prepared according to JIS R5201, and the compressive strength after 3 hours and 28 days was measured. In addition, the test body was demolded 3 hours after shaping | molding, and it cured in water (20 degreeC) after that.
Length change rate: Free shrink according to "JIS A1129-3 Measurement method of length change of mortar and concrete-Part 3: Dial gauge method Annex A (reference) Free shrink strain test method by drying mortar and concrete" The strain was measured. Specifically, three hours after molding the test body, it is demolded to measure the base length, and after curing in water (20 ° C.) and in the air (20 ° C., 60 RH%) to a material age of 28 days The length change rate of the base length was measured.
Distinctive color pattern: The presence or absence of white spots (spots) on the surface of the cured product (material age: 28 days) of the rapidly setting cement composition was visually confirmed. In this evaluation, those with white spots are indicated by x, those with few spots or spots are hard to see Δ, and those without spots are indicated by o.
The above evaluation results are shown in Table 2.

As shown in Table 2, the rapid-hardening cement composition containing the quick-hardening material according to the present invention shows little change in length (that is, excellent dimensional stability) in both air curing and water curing, And the hardened | cured material excellent in strength expression was provided (No. 1-5 to 1-6 and 1-10 to 1-11).
On the other hand, the quick-hardening cement composition containing no quick-hardening material and the quick-hardening cement composition containing quick-hardening material not having a predetermined composition has a compressive strength, a rate of change in length and an appearance 1 One or more gave an inadequate hardening body (No.1-1-1-4, 1-7-1-9, and 1-12).

(Example 3)
100 parts by mass of gypsum and each Al ₂ O ₃ -SO ₃ system shown in Table 3 with respect to 100 parts by mass of crushed amorphous CA clinker, using the Al ₂ O ₃ -SO ₃ based compound prepared in Example 1 A quick hard material was prepared by blending and mixing 10 parts by mass of the compound.
Next, using this quick-hard material, 20 parts by weight of quick-hard material, 150 parts by weight of fine aggregate, 50 parts by weight of water and citric acid at room temperature (based on 100 parts by weight in total of cement and quick-hard material) Rapid setting cement compositions were prepared by blending and mixing at 20 ° C. In addition, the compounding quantity of citric acid was adjusted so that the usable time of the rapid hardening cement composition might be about 45 minutes.
About the quick-hardening cement composition obtained above, while evaluating compressive strength, a rate of change in length, and a different color pattern in the same manner as in Example 2, the pot life was measured.
The pot life was measured according to JIS A1147 "Concrete setting test method", by measuring the initial time of the prepared rapid setting cement composition. The rapid hardening cement composition was evaluated as the usable time since it can be filled up to just before the initial development time.
The above evaluation results are shown in Table 3.

As shown in Table 3, the rapid-hardening cement composition containing the quick-hardening material according to the present invention shows little change in length (that is, excellent dimensional stability) in both air curing and water curing, And the hardened | cured material excellent in strength expression was provided (No.2-4-2-14).
On the other hand, a rapid-hardening cement composition containing a quick-hardening material using an Al ₂ O ₃ -SO ₃ -based compound not having predetermined properties has one of the compressive strength, the rate of change in length, and the appearance. The above gave the inadequate hardened | cured material (No.2-1-2-3 and 2-15-2-17).

(Example 4)
After preparing a quick-hardening material in the same manner as in Example 3, the material was put in a plastic bag, sealed, and stored for 3 months under the conditions of temperature 20 ° C. and humidity 60%. Thereafter, a rapid curing cement composition was prepared at the same blending ratio as in Example 3. Next, about the obtained rapid-hardening cement composition, it carried out similarly to Example 3, and measured compressive strength, the rate of change of length, a different color pattern, and pot life time. The results are shown in Table 4.

As can be seen by comparing the results in Tables 3 and 4, the quick-hardening wood of the present invention showed almost no change in pot life even after storage for 3 months. In addition, the quick-hardening cement composition containing quick-hardening wood after storage has little change in length (that is, excellent dimensional stability) in both air curing and water curing, and is excellent in appearance and strength development. To give a cured product.
On the other hand, quick-hard materials using an Al ₂ O ₃ -SO ₃ -based compound not having predetermined properties, when stored for 3 months, showed a significant change in pot life. Moreover, in the rapid-hardening cement composition which mix | blended the rapid-hardening material after storage, the fall of the intensity | strength expression property of a hardened | cured material or the increase in a length change rate were confirmed.

  As can be seen from the above results, according to the present invention, it is possible to produce a rapid-hardening cement composition which gives a cured product excellent in dimensional stability, strength development and appearance in any of atmospheric curing and underwater curing. In addition, it is possible to provide a quick-hardening material having good storage stability. Further, according to the present invention, it is possible to provide a rapid-hardening cement composition which gives a cured product excellent in dimensional stability, strength developing property and aesthetic appearance in any of atmospheric curing and underwater curing.

  The quick-hardening material and quick-hardening cement composition of the present invention can be suitably used in the field of civil engineering and construction since it has the above-mentioned properties.

Claims (6)

50 to 120 parts by mass of gypsum and 5 to 20 parts by mass of Al ₂ O ₃ -SO ₃ compounds with respect to 100 parts by mass of amorphous calcium aluminate, wherein the Al ₂ O ₃ -SO ₃ compounds are non-crystalline Quick-hardening material which is of a quality and has a weight loss of 5 to 40% by mass when ignited at 500 ° C. True density of 1.9~2.3g / cm ^3, sudden hard material according to claim 1 of the Al ₂ O ₃ -SO ₃ compound. The quick-hardening material according to claim 1 or 2, wherein a BET specific surface area of the Al ₂ O ₃ -SO ₃ -based compound is 5 m ² / g or less. The Al ₂ O ₃ -SO ₃ based compound has a peak at a chemical shift of −0.51 to −23.21 ppm and a half width of 5 ppm or more in a spectrum obtained by solid ²⁷ Al-NMR. The quick hard material according to any one of claims 1 to 3. The Al ₂ O ₃ -SO ₃ based compound, in a spectrum obtained by FT-IR, the ratio of the peak area derived from the SO ₄ group stretching vibration to the peak area derived from the OH group stretching vibration 0.2-3. The quick-hardening material according to any one of claims 1 to 4, which is 0.   The rapid-hardening cement composition containing a cement and the quick-hardening wood as described in any one of Claims 1-5.