JP6988689B2 - Cement composition and its manufacturing method, cement mortar manufacturing method - Google Patents

Description

The present invention relates to a cement composition, a method for producing the same, and a method for producing a cement mortar composition, and in particular, it is possible to impart good initial strength development not only at room temperature but also at high temperatures such as summer. The present invention relates to a cement composition, a method for producing the same, and a method for producing a cement mortar, which are excellent in workability by ensuring a sufficient predetermined fluidity and a sufficient pot life.

In recent years, in the construction of tunnels and underground spaces, a spraying method has been widely practiced in which a cement mixture such as mortar or concrete is sprayed onto a wall surface or an exposed surface to line it to prevent the wall surface or the exposed surface from collapsing.
In such a concrete spraying method, concrete, etc. is prepared, the minimum usable time (handling time) required for handling it is secured, and after spraying on the wall surface or exposed surface, the concrete, etc. is immediately hardened. I need to let you.
In addition, it is necessary to secure the usable time of mortar and concrete and to cure them immediately even in water stoppage work and emergency work.

Conventionally, as a cement having a sharp hardness, there is a hard-hardening cement such as a jet cement. Examples of the clinker used for these cements include jet cement clinker, _{Irwin clinker containing C4A3SO 3} as a main component, and alumina cement clinker containing CA as a main component.
There is also a method of obtaining amorphous C12A7 by melting a clinker containing C12A7, which is a rapidly hardening component, as a main component, and then quenching the clinker.

In particular, the conventional jet cement clinker is a clinker containing calcium silicate phase as a main component and C11A7 / CaF ₂ as a fast-curing component in an amount of about 20 to 30% by mass, and produces a melt phase such as _{C11A7CaF 2 or C4AF.} It will be. Therefore, if the content of C12A7, which is a rapidly hardening component, is set to the above range or more, the amount of the melt phase becomes too large and the clinker melts, which makes it very difficult to manufacture, for example, in actual equipment.

Irwin-based clinker is used as a clinker for hard-hardening cement because it contains 70% by mass or more of _{Irwin (C4A3SO 3) having sharp-hardness.} There is the problem of being inferior.
Further, the alumina cement clinker containing CA as a main component is inferior in rapid hardness to the clinker containing C12A7 as a main component.

On the other hand, as a cement composition, it has been conventionally practiced to add calcium aluminate and gypsum to Portland cement in order to impart rapid hardness.
However, it has been difficult to secure a pot life with a cement composition containing calcium aluminate and a gypsum rapid-hardening component, which has sufficient rapid-hardness and sufficient fluidity.

Therefore, Japanese 2014-201462 (Patent Document 1), CaO35~50 _{mass%, Al} 2 O 3 35 to 50 wt% and _SiO 2 7 to 18% by weight of amorphous Shitsudo in chemical composition 70 ^{The content of particles having a brain specific surface area of 4000 to 9000 cm 2} / g and more than 30 μm, which is obtained by crushing an ultrafast-hardening clinicer of% or more, is 5% by mass or less, and the content of particles less than 1.0 μm is 5% by mass. A cement composition containing 25 to 200 parts by mass of plaster with respect to 100 parts by mass of an ultrafast-hardening crushed product of% or less is described in Japanese Patent Application Laid-Open No. 2014-196245 (Patent Document 2) as cement, water, and nitrite. Contains calcium, polycarboxylic acid-based water reducing agent and melamine-based water reducing agent, 2 to 5 parts by mass of calcium nitrite, 0.1 to 2.5 parts by mass of polycarboxylic acid-based water reducing agent, and melamine per 100 parts by mass of cement. A cement composition containing 0.1 to 2.5 parts by mass of a water reducing agent is disclosed.

However, it is difficult to promote the hydration reaction to obtain the desired rapid hardness, for example, sufficient strength for 3 hours, and to secure sufficient fluidity of the cement, which provides a necessary appropriate amount of melt phase. This is because the conditions for formation and the solid solution state of the fast-hardening component, that is, the conditions for maximizing the hydration activity do not always match, and it was difficult to design for maximizing the hydration activity of the fast-hardening component.
Furthermore, it was difficult to promote the hydration reaction and secure the fluidity to improve the workability.

Japanese Unexamined Patent Publication No. 2014-201462 Japanese Unexamined Patent Publication No. 2014-196245

An object of the present invention is to exhibit sufficient strength not only at room temperature but also at high temperature such as in summer, exhibit excellent hydration activity and good hardening performance, and secure sufficient fluidity for construction. It is an object of the present invention to provide a cement composition and a method for producing the same, and a method for producing a cement mortar, which are excellent in properties.

The cement composition according to claim 1 contains a hard-hardening additive for cement containing 70% by mass or more of a C12A7-based mineral phase, gypsum, an alkali sulfate compound, a calcium salt excluding gypsum, boric acid, and cement. And gluconic acid, and tartaric acid or tartaric acid salt,
5 to 40% by mass of C12A7 minerals and 0.5 to 1 of alkaline sulfate compounds (in terms of sodium sulfate) in the total mass of the fast-hardening additive for cement, gypsum, alkaline sulfate compound, calcium salt, boric acid and cement. It is contained in mass%, and the mass ratio of the content of the calcium salt (calcium hydroxide equivalent) / C12A7 series mineral phase is 3 to 40 (mass%), and the content of gypsum (anhydrous plaster equivalent) / C12A7 series mineral phase. The mass ratio of the above is 50 to 150 (mass%), and the mass ratio of the content of the boric acid / C12A7 mineral phase is 1.5 to 7 (mass%).
Gluconate (equivalent to gluconic acid) is divided into 0.05 to 0.6% by mass based on the total mass of the hard additive for cement, gypsum, alkali sulfate compound, calcium salt, boric acid and cement. It is a cement composition characterized by containing 0.05 to 0.6% by mass of the above-mentioned tartaric acid or tartaric acid salt (in terms of tartaric acid) in an external ratio.

In the cement composition of請Motomeko 1, wherein the C12A7 based mineral phase C11A7CaX2 (X is halogen) Ru mixed phase der of and C12A7.

The method for producing a cement composition according to claim 2 includes a hard-hardening additive for cement containing 70% by mass or more of a C12A7 mineral phase, gypsum, an alkali sulfate compound, a calcium salt excluding gypsum, and boric acid. , Cement, gluconic acid, gypsum acid or gypsum salt salt, and the C12A7-based mineral phase is a mixed phase of C11A7CaX2 (X is a halogen) and C12A7.
5 to 40% by mass of C12A7 minerals and 0.5 to 1 of alkaline sulfate compounds (in terms of sodium sulfate) in the total mass of the fast-hardening additive for cement, gypsum, alkaline sulfate compound, calcium salt, boric acid and cement. It is contained in% by mass, and the mass ratio of the content of the calcium salt (calcium hydroxide equivalent) / C12A7 series mineral phase is 3 to 40 (mass%), and the content of gypsum (anhydrous plaster equivalent) / C12A7 series mineral phase. The calcium salt, gypsum and boric acid are added so that the mass ratio of the calcium salt is 50 to 150 (mass%) and the mass ratio of the content of the boric acid / C12A7 mineral phase is 1.5 to 7 (mass%). Mix and mix
Gluconic acid salt (gluconic acid equivalent) is divided into 0.05 to 0.6% by mass based on the total mass of the fast-hardening additive for cement, gypsum, alkaline sulfate compound, calcium salt, tartaric acid, and cement. A method for producing a cement composition, which comprises blending the tartaric acid or tartaric acid salt (in terms of tartaric acid) so as to contain 0.05 to 0.6% by mass in an outer ratio.

The method for producing a cement composition according to claim 3 is the method for producing a cement composition according to claim 2 , wherein the hard-hardening additive for cement is formed by powdering and mixing raw materials at 1250 to 1400 ° C. It is a method for producing a cement composition, which is produced by firing and cooling at a cooling rate of 40 ° C./min or less.

The method according to claim 4 cement mortar described, the cement composition of claim 1 Symbol placement, by mixing with water In preparing the mortar, a gluconate and tartrate or tartaric acid salt of the cement composition Cement, which is previously dissolved in water and mixed with a hard-hardening additive for cement in a cement composition, gypsum, an alkali sulfate compound, a calcium salt excluding gypsum, boric acid, and cement. This is a method for manufacturing mortar.

In the cement composition of the present invention, the obtained cement mortar or the like can sufficiently secure a predetermined fluidity to obtain excellent workability, and at the same time, improve the hydration activity to obtain an excellent desired initial 3 hours. Can show strength.

Therefore, it can be effectively applied at work sites, etc. in hard-hardening applications, and it is possible to secure sufficient pot life not only at room temperature but also at high temperatures of 30 ° C or higher in summer, and the workability is good. It becomes possible to do.
Further, it is possible to have the fluidity of the cement mortar or the like obtained by the present invention, for example, which improves the pumping property.

Further, the method for producing a cement composition of the present invention can effectively prepare the cement composition of the present invention.
Further, the method for producing a cement mortar of the present invention can sufficiently secure a predetermined fluidity to obtain excellent workability, and improve hydration activity to exhibit a desired excellent initial strength for 3 hours. It is possible to effectively produce cement mortar.

The present invention will be described in the following form, but the present invention is not limited thereto.
The cement composition of the present invention comprises a rapid-hardening additive for cement containing 70% by mass or more of a C12A7-based mineral phase, gypsum, an alkali sulfate compound, a calcium salt excluding gypsum, boric acid, cement, and the like. Contains gluconic acid and tartaric acid or tartrate,
5-40% by mass of C12A7 minerals and 0.5 of alkali sulfate compounds (in terms of sodium sulfate) with respect to the total mass of the fast-hardening additive for cement, gypsum, alkaline sulfate compound, calcium salt, boric acid and cement. ~ 1% by mass, and the mass ratio of the content of the calcium salt (calcium hydroxide equivalent) / C12A7 series mineral phase is 3 to 40 (mass%), and the gypsum (anhydrous plaster equivalent) / C12A7 series mineral phase. The mass ratio of the content is 50 to 150 (mass%), and the mass ratio of the content of the boric acid / C12A7 mineral phase is 1.5 to 7 (mass%).
Gluconic acid salt (gluconic acid equivalent) is divided into 0.05 to 0.6% by mass based on the total mass of the hard additive for cement, gypsum, alkaline sulfate compound, calcium salt, tartaric acid, and cement. It is a cement composition containing 0.05 to 0.6% by mass of the above-mentioned tartaric acid or tartaric acid salt (in terms of tartaric acid) in terms of external percentage.

In the cement composition of the upper Symbol present invention, the C12A7 based mineral phase Ru mixed phase der of C11A7CaX ₂ (halogen), and C12A7.

The hard-hardening additive for cement contained in the cement composition of the present invention contains 70% by mass or more of a C12A7-based mineral phase, which is a calcium aluminate phase, and preferably 83% by mass or more.
The hard-hardening additive for cement contained in the cement composition of the present invention is for promoting a solid phase reaction by introducing a molding process for molding raw material powder at the time of production and firing and cooling in a specific temperature range. It is possible to maximize the hydration activity of the C12A7-based mineral phase, which is a rapidly hardening component, without the need to control the formation of the melt phase.

Therefore, the C12A7-based mineral phase can be contained in a high content and the hydration activity can be improved, and as a result, the above-mentioned effect of the present invention can be sufficiently exhibited.
If the content of the C12A7-based mineral phase is less than 70% by mass, sufficient rapid hardness cannot be obtained, the initial strength is lowered, and the above-mentioned effect of the present invention cannot be obtained.
_{Here, C12A7 and C11A7 / CaX 2} (X is a halogen such as F, Cl, Br, etc.) correspond to the C12A7-based mineral phase, and a mixed phase thereof may be used.
It should be noted that the hard-hardening additive for cement used in the present invention does not substantially contain Irwin.

As described above, the C12A7-based mineral phase, which is the calcium-aluminate phase contained in the cement composition of the present invention, contains a hard-hardening additive for cement, gypsum, an alkali sulfate compound, and a calcium salt excluding gypsum in the cement composition. It is contained in 5 to 40% by mass, preferably 10 to 30% by mass, based on the total mass of gypsum and cement.
By including the C12A7-based mineral phase in the above-mentioned content, sufficient rapid hardness and excellent initial strength can be obtained not only at room temperature but also at high temperature, and the above-mentioned effect of the present invention has a desired sufficient pot life. Can be obtained.
Further, the content of the C12A7-based mineral phase, which is the calcium aluminate phase, in the cement composition of the present invention can be measured by, for example, the following X-ray diffraction / Rietveld method.

As for the C12A7-based mineral, the C12A7-based mineral phase measured by X-ray diffraction preferably has a crystallite diameter of 150 to 500 nm, more preferably 150 to 300 nm.
When the crystallite diameter of the C12A7-based mineral phase is within such a range, more excellent initial strength development and pot life can be secured, and good fluidity and the like can be obtained.
The crystallite diameter is a value measured by powder X-ray diffraction, and is a value measured by an X-ray diffraction / Rietveld method (device: D4 Endeavor manufactured by Bruker Co., Ltd., analysis software: Topas).
Tube voltage: 45kV Tube current: 40mA

Further, in the C12A7 series mineral, the lattice constant of the C12A7 series mineral phase measured by X-ray diffraction is preferably 11.94 to 11.975 Å.
By setting the lattice constant in such a range, it is possible to more effectively secure the fluidity and to exert the effect of the present invention having more excellent rapid hardness.
The lattice constant is a value measured by powder X-ray diffraction, and is a value measured by using an X-ray diffraction / Rietveld method (device: X'Pert MPD manufactured by PANalytical Co., Ltd., analysis software: HighScorePlus). ..
Tube voltage: 45kV Tube current: 40mA

Examples of the gypsum (calcium sulfate) contained in the cement composition of the present invention include anhydrous gypsum, hemihydrate gypsum, dihydrate gypsum, or a mixture thereof.
Such gypsum is contained in the cement composition so that the mass ratio of the content of the gypsum / C12A7-based mineral phase is 50 to 150 (mass%), preferably 60 to 140 (mass%). However, the gypsum content is an amount calculated as a total amount converted to _{CaSO 4 (anhydrite).}
By setting such a mass ratio, initial strength development and pot life can be ensured, and good fluidity can be obtained.
Further, the content of gypsum in the miscible composition for cement can be measured by, for example, the above-mentioned X-ray diffraction / Rietveld method.

Further, as the alkali sulfate compound contained in the cement composition of the present invention, for example, alkali metal sulfates such as Glauber's salt (sodium sulfate) and potassium sulfate can be exemplified.
The content of such an alkali sulfate compound is determined by measuring the amount of Na and the amount of K in accordance with JCAS I-04 and _{converting all of them into a total amount converted into Na 2} SO ₄ , and adding the rapid hardness for cement to the cement composition. It is desirable that the content is 0.5 to 1% by mass, preferably 0.6 to 1% by mass, based on the total mass of the material, gypsum, the alkali sulfate compound, the calcium salt excluding gypsum, boric acid and cement.
By setting such a mass ratio, initial strength development and pot life can be ensured, and good fluidity can be obtained.

Further, as the calcium salt other than gypsum contained in the cement composition of the present invention, for example, salts such as slaked lime and quicklime that are not sparingly soluble in water can be used, but calcium hydroxide is desirable, and all calcium salts are used. In terms of calcium hydroxide, the mass ratio of the content of calcium salt / C12A7-based mineral phase excluding gypsum in the cement composition is 3 to 40 (mass%), preferably 5 to 35 (mass%). Included in content.
However, the gypsum content is an amount calculated as a total amount converted into calcium hydroxide.
By setting such a mass ratio, good initial strength development can be ensured.
Further, the content of the calcium salt (calcium hydroxide equivalent) in the obtained cement composition can be measured by, for example, the above-mentioned X-ray diffraction / Rietveld method.

Further, the boric acid contained in the cement composition of the present invention has a content such that the mass ratio of the content of the boric acid / C12A7 mineral phase is 1.5 to 7% by mass, preferably 2 to 6% by mass. Included in.
By setting such a mass ratio, initial strength development and pot life can be ensured, and good fluidity can be obtained.

Further, as the cement contained in the cement composition of the present invention, any cement available on the market can be applied, for example, early-strength Portland cement, ultra-early-strength Portland cement, ordinary Portland cement, moderate heat Portland cement, and the like. At least one type selected from low heat Portland cement, sulfate resistant Portland cement, fly ash cement, blast furnace cement, silica cement and the like can be exemplified.

Further, the cement composition of the present invention contains gluconate, tartaric acid and / or tartaric acid, and a fast-hardening additive for cement, gypsum, an alkali sulfate compound and gypsum in the cement composition of the present invention. Gluconate (converted to gluconic acid) is 0.05 to 0.6% by mass and the above-mentioned tartaric acid and / or tartaric acid (converted to tartaric acid) is added to the total mass of calcium salt, boric acid and cement to be excluded. It contains 0.05 to 0.6% by mass.
As a result, the cement composition of the present invention can have excellent initial strength development and fluidity that sufficiently secures pot life not only at room temperature but also at high temperature.

Examples of the gluconate salt contained in the cement mortar composition of the present invention include gluconic acid and sodium gluconate.
Further, examples of the tartrate salt include sodium tartrate, potassium tartrate, and the like.

The cement composition of the present invention comprises the above-mentioned hard-hardening additive for cement, gypsum, an alkali sulfate compound, a calcium salt excluding gypsum, boric acid, cement, gluconic acid, and tartaric acid or tartrate. By including the content ratio or the content ratio, the initial strength development can be excellent not only at room temperature but also at high temperature, and fluidity can be ensured to improve workability.

Further, in the cement composition of the present invention, as long as it does not impair the above effects, for example, a water reducing agent (alkylallyl sulfonic acid type, naphthalene sulfonic acid type, melamine sulfonic acid type, polycarboxylic acid) can be used. Systems, AE water reducing agents, high-performance water reducing agents, high-performance AE water reducing agents), liquid or powdered admixtures, fine aggregates (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 can be contained.

The method for producing the cement composition of the present invention is described above.
Hard additive for cement containing 70% by mass or more of C12A7 mineral phase, gypsum, alkali sulfate compound, calcium salt excluding gypsum, boric acid, cement, gluconic acid, tartaric acid or tartaric acid salt. The C12A7-based mineral phase is _{a mixed phase of C11A7CaX 2} (halogen) and C12A7.
5 to 40% by mass of C12A7 minerals and 0.5 to 1 of alkaline sulfate compounds (in terms of sodium sulfate) in the total mass of the fast-hardening additive for cement, gypsum, alkaline sulfate compound, calcium salt, boric acid and cement. It is contained in% by mass, and the mass ratio of the content of the calcium salt (calcium hydroxide equivalent) / C12A7 series mineral phase is 3 to 40 (mass%), and the content of gypsum (anhydrous plaster equivalent) / C12A7 series mineral phase. The calcium salt, gypsum and boric acid are added so that the mass ratio of the calcium salt is 50 to 150 (mass%) and the mass ratio of the content of the boric acid / C12A7 mineral phase is 1.5 to 7 (mass%). Mix and mix
Gluconic acid salt (gluconic acid equivalent) is divided into 0.05 to 0.6% by mass based on the total mass of the fast-hardening additive for cement, gypsum, alkaline sulfate compound, calcium salt, tartaric acid, and cement. This is a method for producing a cement composition, wherein the tartaric acid or tartaric acid salt (in terms of tartaric acid) is blended so as to contain 0.05 to 0.6% by mass in an outer ratio.

The hard-hardening additive for cement to be blended in the cement composition includes calcium raw materials such as fresh lime and limestone, aluminum hydroxide, alumina, aluminum raw materials such as bauxite and band spores, and fluorine raw materials such as fluorite, if necessary. Magnesium raw materials such as dolomite to be mixed are mixed, crushed, or crushed and mixed, and this powder mixture is molded to obtain a molded product, which is then used in a heating furnace such as an electric furnace. Bauxite and cool to prepare a fast-hardening additive for cement.

In addition, those which are raw materials of Ti and Fe contained in the obtained hard additive for cement (for example, red iron oxide) are not positively blended. Ti and Fe contained in the hardened additive for cement to be blended may be contained as an impurity in the compounding raw material, and may be contained as a result, but are not positively contained.
That is, since the hard-hardening additive for cement does not require the formation of a certain amount of melt phase, it is not necessary to positively contain Fe and Ti which are related to the formation of the melt phase.

The hard-hardening additive for cement is obtained by pulverizing and mixing the compounding raw materials and molding the mixed powder. It can be produced by baking for 5 to 3 hours and then cooling at a cooling rate of 40 ° C./min or less, preferably 5-40 ° C./min.
Since the hard-hardening additive for cement thus obtained does not require the formation of a certain amount of melt phase, the hydration activity of the C12A7-based solid solution can be sufficiently exhibited. It contains C12A7 in an amount of 70% by mass or more.

In particular, the hard-hardening additive for cement ^{is preferably used after being pulverized to a brain specific surface area of 4500 cm 2} / g or more, whereby further good hard-hardening can be obtained.
Further, if the specific surface area of the brain is too large, the fluidity is adversely affected, the crushing time is required, the productivity is lowered, and the cost is high ^{. Therefore, 5000 to 7000 cm 2} / g is desirable.
Further, when pulverizing, a pulverizing aid (diethylene glycol, triethanolamine, etc.) may be added.

In the cement composition, the hard additive for cement is powdered, and further, gypsum, an alkali sulfate compound, calcium salt excluding gypsum, boric acid, cement, gluconic acid, tartrate acid or tartrate, and cement are added. C12A7-based minerals account for 5 to 40% by mass, and alkaline sulfate compounds (in terms of sodium sulfate) 0.5 to 1 in the total mass of calcium salts, boric acid, and cement excluding hardened additives, gypsum, alkaline sulfate compounds, and gypsum. In addition to blending so as to be contained in mass%, the mass ratio of the content of the calcium salt / C12A7-based mineral phase in the cement composition is 3 to 40 (mass%), and the content of gypsum (anhydrous plaster equivalent) / C12A7-based mineral phase is contained. The calcium salt, gypsum and boric acid so that the mass ratio of the amount is 50 to 150 (mass%) and the mass ratio of the content of the boric acid / C12A7-based mineral phase is 1.5 to 7 (mass%). Gluconate (equated to gluconic acid) is added to the total mass of the hard-hardening additive for cement, gypsum, alkali sulfate compound, calcium salt, boric acid, and cement, and 0.05 to 0 is added. It is blended so as to contain 0.6% by mass and the above-mentioned tartrate or tartrate (converted to tartrate) in an external ratio of 0.05 to 0.6% by mass, but the mixing method is not particularly limited as long as it can be uniformly blended. , Any mixing method can be used.

The gypsum content is an _{amount calculated as a total amount converted to CaSO 4} (anhydrous gypsum), and the content of the alkali sulfate compound is the amount of Na or K according to JCAS I-04. All measured and are the _{total amount converted to Na 2} SO ₄ conversion, and all calcium salts are the total amount converted to calcium hydroxide.

Specifically, a hard-hardening additive for cement is added and mixed with a mixture obtained by previously mixing cement, gypsum, an alkaline sulfate compound, a calcium salt and boric acid, and gluconate, tartrate acid and / or Even if it is mixed with tartrate, or if it is mixed with cement, gypsum, alkaline sulfate compound, calcium salt, boric acid and a fast-hardening additive for cement, and gluconate and tartrate and / or tartrate at the same time, it is uniform. Any method can be used as long as it can be mixed.

Further, as described above, gluconate, tartaric acid and / or tartaric acid are used with respect to the total mass of the quenching additive for cement, gypsum, alkali sulfate compound, calcium salt excluding gypsum, boric acid and cement. It is blended so that the gluconate (converted to gluconic acid) is contained in an amount of 0.05 to 0.6% by mass and the tartaric acid and / or the tartrate (converted to tartaric acid) is contained in an amount of 0.05 to 0.6% by mass. do.

Further, if necessary, for example, a water reducing agent (including an alkylallyl sulfonic acid type, a naphthalene sulfonic acid type, a melamine sulfonic acid type, a polycarboxylic acid type, an AE water reducing agent, a high performance water reducing agent, and a high performance AE water reducing agent). , Liquid or powdery 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), etc. can do.

Further, the method of mixing with water when preparing a cement paste, mortar, concrete, etc. using the cement composition of the present invention is not particularly limited, and the cement composition is blended in a predetermined ratio and then mixed conventionally. It may be mixed using an apparatus.

Specifically, a cement composition containing a hard-hardening additive for cement, gypsum, an alkali sulfate compound, calcium salt excluding gypsum, boric acid, cement, gluconate, tartrate acid and / or tartrate and the like. Even if a cement mortar is prepared by mixing with water, a hard-hardening additive for cement, gypsum, an alkali sulfate compound, calcium salt excluding gypsum, boric acid, cement, gluconate, tartrate acid and / or tartrate salt. Etc. can be mixed with water to prepare cement mortar, or a mixture of hard additive for cement, gypsum, alkaline sulfate compound, calcium salt excluding gypsum, boric acid and cement, and gluconate in advance. And / or a mixture of tartrate acid and / or tartrate and water may be mixed to prepare a cement mortar, or any method may be used as long as it can be mixed uniformly.
In particular, it is desirable that the gluconate salt and tartaric acid or tartaric acid salt are previously dissolved in water to be blended when preparing the cement mortar.
Further, the above-mentioned admixtures and aggregates to be added as needed may be added at the same time as cement mortar or the like if they can be mixed uniformly, may be added sequentially, or may be kneaded with water when preparing the mortar or the like. It is not particularly limited whether it is added at the time or by any addition method.

Further, the boric acid contained in the cement mortar is mixed with water in advance, and then mixed with a hard-hardening additive for cement, gypsum, an alkali sulfate compound, calcium salt excluding gypsum, cement and the like. No effect can be obtained, and the effect of the present invention can be obtained by using it in the cement composition, that is, by mixing it with the powder side.

The cement mortar thus obtained has excellent initial strength development not only at room temperature but also at high temperature, and can secure fluidity and workability.

The present invention will be described with reference to the following examples, comparative examples and test examples.
_{1) Preparation of hard-hardening additives for cement CaCO 3} , SiO ₂ , Al ₂ O ₃ , Fe ₂ O ₃ , MgO, TiO ₂ , CaF ₂ so that the target chemical composition of the hard-hardening additives for cement is shown in Table 1. The raw materials for the fast-hardening additive for each cement were prepared by mixing and pulverizing each of the reagents of the above.

Here, SiO ₂ , Fe ₂ O ₃ , and TiO ₂ are calcium oxide raw materials such as quicklime, slaked lime, and limestone, aluminum hydroxide, alumina, and bauxite when actually producing a hard-hardening additive for cement in an actual machine. When aluminum raw materials such as bauxite and bauxite, fluorine raw materials such as bauxite, and magnesium raw materials such as dolomite to be blended as necessary are used, SiO ₂ , Fe ₂ O ₃ , and TiO ₂ may be contained as impurities as a result. Therefore, it is used assuming such a case (it is not positively contained).

Each of the above-mentioned hard additive materials for cement was pressure-molded, each molded body was fired in an electric furnace at 1300 ° C. for 30 minutes, and then cooled at each cooling rate shown in Table 2 to be cooled in each of the cooling rates shown in Table 2. A hard additive for cement was obtained.

2) _{Measurement of the content of SiO 2} , Al ₂ O ₃ , TIO ₂ , Fe ₂ O ₃ , F component, etc. The obtained hard additive for cement was used as a fluorescent X-ray analyzer (manufactured by PANalytical). ) Was analyzed according to JIS R 5204, and _{the content ratios of SiO 2} , Al ₂ O ₃ , TIO ₂ , Fe ₂ O ₃ , F component and the like contained were measured.
The results of these chemical compositions are shown in Table 2.

3) Mineral analysis of hardened additives for cement (C12A7 series)
Using the X-ray diffraction / Rietveld method (equipment: X'Pert MPD manufactured by PANalytical Co., Ltd., analysis software: HighCorePlus), the obtained fast-hardening additive for cement is used for the content ratio of C12A7 series and C3A minerals. The lattice constants of the crystals of the C12A7 series mineral phase were measured.
Tube voltage: 45kV Tube current: 40mA
The results are shown in Table 2. Here, the lattice constant of the crystal of the C12A7 series mineral phase was measured using the crystal structure _{of C11A7CaF 2.}

The crystallite diameter of the crystal of the C12A7 series mineral phase was measured by the X-ray diffraction / Rietveld method (device: D4 Endeavor manufactured by Bruker Co., Ltd., analysis software: Topas) using the _{C11A7CaF 2 crystal structure.}
Tube voltage: 45kV Tube current: 40mA
The results are shown in Table 2.

4) Preparation of Cement Composition Next, the above-mentioned hard-hardening additive for cement ^{was pulverized to a brain specific surface area of about 5200 ± 200 cm 2} / g to obtain a hard-hardening additive powder for each cement.
Hardened additive powder (Q) for each cement obtained, anhydrous gypsum (commercially available, brain specific surface area 6800 cm ² / g), Na ₂ SO ₄ (sodium gluconate: reagent), slaked lime (calcium hydroxide: reagent) boric acid (Reagent), early-strength Portland cement (manufactured by Sumitomo Osaka Cement, PC), sodium gluconate and slaked acid were blended in the blending ratios shown in Tables 3 to 7.

In Tables 3 to 7, hard additive powder for cement (Q), anhydrous gypsum (commercially available product, brain specific surface area 6800 cm ² / g), Na ₂ SO ₄ (portland: reagent), slaked lime (calcium hydroxide: Reagents) Boric acid (reagent) and early-strength Portland cement (manufactured by Sumitomo Osaka Cement, PC) are hard additive powder (Q) for cement, slaked gypsum (commercially available, brain specific surface area 6800 cm ² / g), Na _2. The content ratio of SO ₄ (salt glass: reagent), slaked lime (calcium hydroxide: reagent) boric acid (reagent) and early-strength Portland cement (Sumitomo Osaka cement, PC) in the total mass is shown, and sodium gluconate (gluconic acid). (Conversion) and tartrate acid are hard additive powder for cement (Q), anhydrous gypsum (commercially available, brain specific surface area 6800 cm ² / g), Na ₂ SO ₄ (cement glass: reagent), slaked lime (calcium hydroxide: reagent). Boric acid (reagent) and early-strength Portland cement (manufactured by Sumitomo Osaka Cement, PC) are hard additive powder (Q) for cement, slaked gypsum (commercially available, brain specific surface area 6800 cm ² / g), Na ₂ SO ₄ The ratio of slaked lime (calcium hydroxide: reagent) boric acid (reagent) and early-strength Portland cement (manufactured by Sumitomo Osaka Cement, PC) to the total mass is shown.

5) Measurement of mineral content (C12A7 series), etc. in the cement composition The content of the C12A7 series mineral phase (Q) in each cement composition is measured by the same method as described in 3) above. , The lattice constants and crystallite diameter of the crystals of the C12A7 series mineral phase were also measured.
The measurement results of the content of the C12A7 mineral phase (Q) are shown in Tables 3 to 7 below.
The lattice constant of the C12A7-based mineral phase (Q) in all cement compositions is about 11.955 Å, and the crystallite diameter is about 214 nm. The hard-hardening additive for cement used in the cement composition (in Table 2). It was equivalent to the hard additive material B) for cement.

6) Content of alkaline sulfate compound (in terms of sodium sulfate) in the cement composition The content of the alkaline sulfate compound in the cement composition is measured by measuring the amount of Na and the amount of K according to JCAS I-04, and all are Na. and the total amount in terms of ₂ SO ₄ terms, the results are shown in Table 3-7.

7) Calcium salt excluding gypsum in cement composition (calcium hydroxide equivalent) / C12A7 mineral phase (mass% of content)
The amount of slaked lime in each cement composition shown in Tables 3 to 7 as the content of calcium salt (calcium hydroxide equivalent) excluding gypsum in the cement composition, and each cement composition measured in 5) above. From the measured value of the content of the C12A7-based mineral phase in the cement composition, the calcium salt (calcium hydroxide equivalent) / C12A7-based mineral phase (Q) (mass ratio) excluding the gypsum in each cement composition was calculated.
The results are shown in Tables 3-7.

8) Gypsum in cement composition (equivalent to anhydrous gypsum) / C12A7-based mineral phase (Q) (mass% of content)
The content of gypsum in the cement composition was measured by the X-ray diffraction / Rietveld method described in 3) above, _{and the total amount converted into CaSO 4} (anhydrous gypsum) was taken as the content of gypsum.
From the content of gypsum (in terms of anhydrous gypsum) in the cement composition thus obtained and the measured value of the C12A7-based mineral phase content in each cement composition measured in 5) above, the cement composition The gypsum inside (equivalent to anhydrous gypsum) / C12A7-based mineral phase (mass% of content) was calculated.
The results are shown in Tables 3-7.

9) Boric acid / C12A7 mineral phase (Q) (% by mass) in cement composition
From the content of the C12A7-based mineral phase in each cement composition measured in 5) above and the blending amount of boric acid shown in Tables 3 to 7, the boric acid / C12A7-based mineral phase (mass) in each cement composition. %) Was calculated.
The results are shown in Tables 3-7.

10) Preparation of mortar Table 8 below shows each cement composition (Examples 1 to 17, Comparative Examples 1 to 14), fine aggregate (silica sand), water and admixture (Mighty 150: manufactured by Kao Corporation). Each mortar was prepared by blending.
The total amount of calcium salt, boric acid and cement excluding gypsum, gypsum, alkali sulfate compound and gypsum in the cement composition is shown as "X" in Table 8.
Further, sodium gluconate and tartaric acid in the cement composition were used by dissolving them in kneading water in advance.
In addition, sodium gluconate and tartrate acid are mixed with the total amount (X) of the hard additive for cement, gypsum, alkali sulfate compound, calcium salt excluding gypsum, boric acid and cement in the cement composition. Shows the percentage of gypsum.

In Comparative Example 15, the cement composition shown in Table 7, fine aggregate (quartz sand), water, an admixture (Mighty 150: manufactured by Kao Corporation) and boric acid were blended as shown in Table 9 below, and each mortar was blended. Was prepared.
The total amount of the hard-hardening additive for cement, gypsum, alkali sulfate compound, calcium salt excluding gypsum, and cement in the cement composition is shown as "Y" in Table 9.
In addition, sodium gluconate and tartaric acid in the cement composition were previously dissolved in kneaded water together with boric acid before use.
In addition, sodium gluconate, tartrate acid, and boric acid are blended in the total amount (Y) of the cement steep-hardening additive, gypsum, alkali sulfate compound, calcium salt excluding gypsum, and cement in the cement composition. Shows the percentage of gypsum.

11) Strength measurement and flow value measurement For each mortar of Examples 1 to 17 and Comparative Examples 1 to 15, the strength at 35 ° C. and the flow value at 35 ° C. were applied to JIS R 5201 (physical test method for cement). It was measured according to the above.
Moreover, as the end time, the end time of each mortar was measured according to JIR R5201. However, as the closing needle, a conical needle having a diameter of 1 inch and a height of 2 inches was used, and the time when the penetration depth became 1.5 mm was defined as the setting (closing) time.
The results are also shown in Tables 3 to 7 above.
From Comparative Example 15, it can be seen that the effect of the present invention is not exhibited when boric acid is dissolved in kneaded water and blended.

INDUSTRIAL APPLICABILITY The present invention can have fluidity that secures sufficient pot life not only in a normal temperature environment but also in a high temperature environment, and can exhibit good initial strength. Therefore, it is possible to develop a tunnel in summer. It can be applied particularly effectively to construction work, civil engineering work, water stoppage work, road work, and building structures in the lower space.

Claims (4)

Hard additive for cement containing 70% by mass or more of C12A7 mineral phase, gypsum, alkali sulfate compound, calcium salt excluding gypsum, boric acid, cement, gluconic acid, tartaric acid or tartaric acid salt. The C12A7-based mineral phase is a mixed phase of C11A7CaX2 (X is a halogen) and C12A7.
5 to 40% by mass of C12A7 minerals and 0.5 to 1 of alkaline sulfate compounds (in terms of sodium sulfate) in the total mass of the fast-hardening additive for cement, gypsum, alkaline sulfate compound, calcium salt, boric acid and cement. It is contained in mass%, and the mass ratio of the content of the calcium salt (calcium hydroxide equivalent) / C12A7 series mineral phase is 3 to 40 (mass%), and the content of gypsum (anhydrous plaster equivalent) / C12A7 series mineral phase. The mass ratio of the above is 50 to 150 (mass%), and the mass ratio of the content of the boric acid / C12A7 mineral phase is 1.5 to 7 (mass%).
Gluconate (equivalent to gluconic acid) is divided into 0.05 to 0.6% by mass based on the total mass of the hard additive for cement, gypsum, alkali sulfate compound, calcium salt, boric acid and cement. A cement composition comprising the above-mentioned tartaric acid or tartaric acid salt (in terms of tartaric acid) in an external division of 0.05 to 0.6% by mass. Hard additive for cement containing 70% by mass or more of C12A7 mineral phase, gypsum, alkali sulfate compound, calcium salt excluding gypsum, boric acid, cement, gluconic acid, tartaric acid or tartaric acid salt. The C12A7-based mineral phase is a mixed phase of C11A7CaX2 (X is a halogen) and C12A7.
5 to 40% by mass of C12A7 minerals and 0.5 to 1 of alkaline sulfate compounds (in terms of sodium sulfate) in the total mass of the fast-hardening additive for cement, gypsum, alkaline sulfate compound, calcium salt, boric acid and cement. It is contained in% by mass, and the mass ratio of the content of the calcium salt (calcium hydroxide equivalent) / C12A7 series mineral phase is 3 to 40 (mass%), and the content of gypsum (anhydrous plaster equivalent) / C12A7 series mineral phase. The calcium salt, gypsum and boric acid are added so that the mass ratio of the calcium salt is 50 to 150 (mass%) and the mass ratio of the content of the boric acid / C12A7 mineral phase is 1.5 to 7 (mass%). Mix and mix
Gluconic acid salt (gluconic acid equivalent) is divided into 0.05 to 0.6% by mass based on the total mass of the hard additive for cement, gypsum, alkaline sulfate compound, calcium salt, tartaric acid, and cement. A method for producing a cement composition, which comprises blending the tartaric acid or tartaric acid salt (in terms of tartaric acid) so as to contain 0.05 to 0.6% by mass in an outer ratio. In the method for producing a cement composition according to claim 2, the hard-hardening additive for cement is formed by powdering and mixing raw materials, firing at 1250 to 1400 ° C., and cooling at a cooling rate of 40 ° C./min or less. A method for producing a cement composition, which is characterized by being produced by the above. A cement composition according to claim 1 Symbol placement, when preparing the water were mixed mortar, dissolved in water in advance and gluconate and tartrate or tartaric acid salt of the cement composition, cement composition A method for producing cement mortar, which comprises mixing a hard-hardening additive for cement, gypsum, an alkali sulfate compound, a calcium salt excluding gypsum, boric acid, and cement.