JP6900760B2 - Cement mortar / concrete composition and its manufacturing method - Google Patents

Description

The present invention relates to a cement mortar / concrete composition and a method for producing the same. In particular, a cement mortar having excellent rapid hardness at room temperature, excellent workability, and capable of suppressing the occurrence of initial shrinkage cracks. The present invention relates to a concrete composition and a method for producing the same.

Cracks that occur in the early stages of concrete construction are called initial cracks, and there are several types of initial cracks.
For example, subsidence cracks are cracks that occur due to bleeding in concrete, which causes the concrete surface to subside, and the difference in the amount of subsidence. Subsidence cracks can be reduced by suppressing bleeding.

Among the initial cracks, the shrinkage cracks caused by restraining the shrinkage are particularly problematic.
The causes of shrinkage cracks include self-shrinkage of the concrete itself, drying shrinkage, and temperature shrinkage in which heat of hydration is accumulated inside the concrete structure and then dissipated to dissipate heat, which are the causes of shrinkage cracks.
Such shrinkage cracks have a problem that, for example, when the strength is increased, self-shrinkage becomes large and it becomes difficult to suppress the cracks.

Drying shrinkage is related to curing conditions such as temperature and wind, but it can be prevented by measures such as sprinkling a curing agent (water, etc.) on the surface of the structure after construction.
The temperature shrinkage is a shrinkage that occurs when the temperature inside the structure rises due to the heat of hydration of cement and falls, and tensile stress is generated due to the restraint of reinforcing bars and the like, and cracks occur.
Self-shrinkage is a shrinkage that combines the chemical shrinkage, which is a phase volume change caused by the hydration reaction of cement, and the capillary voids, and occurs whenever the cement reacts and hardens. In particular, the self-shrinkage of a material such as a hardened material in which cement rapidly hydrates and hardens is particularly large, and cracks are likely to occur.

Conventionally, as a cement having a fast-hardening property, there is a hard-hardening cement such as a jet cement. As clinker used in these cement, jet cement clinker, C ₄ A ₃ Irwin system to SO ₃ as a main component clinker, alumina cement clinker or the like composed mainly of CA is used.
There is also a method of obtaining _{amorphous C 12} A _{7 by melting a clinker containing C 12} A ₇ as a main component, which is a rapidly hardening component, and then quenching the clinker.

In particular, the conventional jet cement clinker is a clinker containing about 20 to 30% by mass _{of C 11} A ₇ and CaF ₂ as a fast-curing component containing a calcium silicate phase as a main component _{, and C 11} A ₇ CaF ₂ and C ₄ AF. It is formed by forming a melt phase such as. _{Therefore, if the content of C 12} A ₇ which is a rapid-hardening component is set to the above range or more, the melt phase becomes too large and the clinker melts, which makes it very difficult to manufacture, for example, in actual equipment.

Irwin system clinker has been utilized as a rapid hardening cement for clinker since contain Irwin (C 4 _A 3 _{SO 3)} at least 70 mass% with rapid hardening, the characteristics of the rapid-hardening component, the rapid hardening There is a problem of inferiority.
Furthermore, alumina cement clinker composed mainly of CA, compared to clinker mainly composed of C ₁₂ A _7, rapid hardening poor.

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 for a cement composition containing calcium aluminate and a gypsum hard-hardening component to obtain sufficient hard-hardening properties and to have sufficient fluidity to secure a pot life.

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 gypsum 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 with respect to 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 condition for maximizing the hydration activity do not always match, and it has been difficult to design for maximizing the hydration activity of the fast-hardening component.
Further, it is difficult to promote the hydration reaction, effectively suppress the occurrence of initial shrinkage cracks due to self-shrinkage, 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 provide a cement mortar / concrete composition having excellent hardness, exhibiting sufficient initial strength, suppressing the occurrence of initial shrinkage cracks due to self-shrinkage, and having excellent workability. It is to provide the manufacturing method.

In particular, it is an object of the present invention to provide a cement mortar / concrete composition capable of suppressing initial shrinkage cracks due to self-shrinkage of a mortar / concrete structure at room temperature and having excellent initial strength development, and a method for producing the same.

Cement mortar and concrete composition of claim 1, wherein the (1) and the cement rapid hardening additive material containing C ₁₂ A ₇ based mineral phase, and gypsum, and sulfuric acid alkali compound, slaked lime, the quick lime and calcium hydroxide comprising comprising calcium salt and lithium carbonate selected from the _{group, C} 12 _{a 7} based mineral with 36-55 wt%, 0.3 to 1.7 wt% of sulfuric acid alkali compound (sodium sulfate equivalent), lithium carbonate (Li Containing 0.01 to 1.3% by mass of calcium salt (converted to calcium hydroxide) selected from the group consisting of slaked lime, quicklime and calcium hydroxide, gypsum (converted to anhydrous gypsum) / C ₁₂ a mass ratio of the content of _7-based mineral phase is 0.5 to 1.2, and the crystallite size lattice constant 150~500nm of _C 12 _{a 7} mineral phase as measured by X diffraction 11. Containing 940-1.1975 Å cement admixture, (2) cement, (3) gluconate, and (4) tartrate or tartrate, relative to the total weight of the cement admixture and cement. , Gluconate (converted to gluconic acid) is contained in an external ratio of 0.05 to 0.6% by mass, and the tartrate or tartrate (converted to tartrate) is contained in an external ratio of 0.05 to 0.6% by mass. It is a cement mortar / concrete composition.

Cement mortar and concrete composition of claim 2, in the cement mortar and concrete compositions, the _C 12 _{A 7} based mineral phase _C 11 _A 7 _CaX 2 (X is halogen) and a mixed phase of _C 12 _{A 7} It is a cement mortar / concrete composition characterized by being.

The method according to claim 3 cement mortar and concrete compositions described includes (1) a cement rapid hardening additive material containing C ₁₂ A ₇ based mineral phase, and gypsum, and sulfuric acid alkali compound, lithium carbonate, slaked lime and a calcium salt selected from the group consisting of quick lime, and calcium _{hydroxide, C} 12 _{a 7} based mineral 36-55% by weight, 0.3 to 1.7 wt% sulfuric acid alkali compound (sodium sulfate equivalent), carbonate Contains 0.01 to 1.3% by mass of lithium (equivalent to lithium) and 1 to 14% by mass of a calcium salt (equivalent to sodium hydroxide) selected from the group consisting of slaked lime, quicklime and calcium hydroxide, and gypsum (anhydrous gypsum). (Conversion) / C ₁₂ A _7- based admixture for cement with a mass ratio of the content of the mineral phase of 0.5 to 1.2, (2) cement, (3) gluconate, and (4) tartrate or The amount of tartrate is 0.05 to 0.6% by mass of gluconate (equivalent to gluconic acid) relative to the total mass of the admixture for cement and cement, and the amount of tartrate or tartrate (equivalent to tartrate). Is a method for producing a cement mortar / concrete composition, which comprises blending the cement mortar and concrete composition so as to contain 0.05 to 0.6 (mass%) in an outer ratio.

The method for producing a cement mortar / concrete composition according to claim 4 is the method for producing a cement mortar / concrete composition. by baked to cool at a cooling rate 40 ° C. / min or less at ℃, _C 12 _{a 7} lattice constant mineral phase crystallite diameter _C 12 _{a 7} mineral phase as measured by X-ray diffraction is at 150~500nm Is a method for producing a mortar-concrete composition, which is produced as 11.940 to 11.975 Å.

Here, the cement mortar / concrete composition means a mortar composition or concrete composition before being mixed with water, and the cement mortar / concrete means a mortar or concrete mixed with water.

The cement mortar-concrete composition of the present invention has excellent rapid hardness at room temperature, exhibits sufficient initial strength, is also excellent in workability, and can suppress the occurrence of initial shrinkage cracks due to self-shrinkage. It can be done.

Further, in addition to the above effects, it is possible to secure a certain pot life with a predetermined fluidity, and it is possible to secure workability having excellent pumping property, for example.

Further, the method for producing a cement mortar / concrete composition of the present invention can effectively prepare the cement mortar / concrete composition of the present invention.

In particular, while easily adjusting an admixture for cement containing a specific hard-hardening additive for cement in an arbitrary amount according to a desired initial strength, together with an arbitrary cement, gluconate, tartrate, etc. in the field. A cement mortar / concrete composition that can be manufactured by adding it, facilitates designing to obtain the desired rapid hardness in the field, has excellent initial strength development at room temperature, and can suppress initial shrinkage cracks. It will be possible to manufacture on-site.

It is a figure which shows typically the formwork for carrying out a crack test.

The present invention will be described in the following form, but the present invention is not limited thereto.
Cement mortar and concrete composition of the present invention, (1) a cement for rapid hardening additive material containing C ₁₂ A ₇ based mineral phase, and gypsum, and sulfuric acid alkali compound, slaked lime, the group consisting of quick lime, and calcium hydroxide and a calcium salt and a lithium carbonate being more _{selected, C} 12 _{a 7} based mineral with 36-55 wt%, sulfuric acid alkali compound 0.3 to 1.7% by weight (sodium sulfate equivalent), lithium carbonate (Li conversion) the 0.01 to 1.3 wt%, slaked lime, quick lime and calcium salt selected from the group consisting of calcium hydroxide (calcium hydroxide equivalent) containing 1-14 wt%, gypsum (anhydrite equivalent) _{/ C 12} the mass ratio of the content of a ₇ mineral phase is 0.5 to 1.2, the crystallite size of the _C 12 _{a 7} mineral phase as measured by X-ray diffraction lattice constant at 150 to 500 nm 11.940 Containing ~ 11.975 Å of cement admixture, (2) cement, (3) gluconate, and (4) tartrate and / or tartrate, relative to the total weight of the cement admixture and cement. It contains 0.05 to 0.6% by mass of gluconate (equivalent to gluconic acid) and 0.05 to 0.6% by mass of tartrate and / or tartrate (equivalent to tartrate). Cement mortar / concrete composition.

Preferably, in the cement mortar-concrete composition of the present invention, the C ₁₂ A ₇ series mineral phase is preferably a mixed phase of _{C 11} A ₇ CaX ₂ (halogen) and C ₁₂ A _7.

By having the above structure, the cement mortar / concrete composition of the present invention has excellent initial strength development at room temperature, can suppress the occurrence of initial shrinkage cracks, secures fluidity, and improves workability. It will also be possible.

C ₁₂ A ₇ mineral phase is a calcium aluminate phases of the cement admixture for composition contained in cement mortar and concrete composition of the present invention, as described above, 36 to 55 wt%, preferably from 40 to 52 It is contained in% by mass.
Such C ₁₂ A ₇ based mineral phase is added blended in the preparation of the cement admixture for the composition, it is derived from a cement rapid hardening additive.
The inclusion of C ₁₂ A ₇ based mineral phases, preferably with the inclusion in the content, cement mortar and concrete composition of the present invention is sufficiently steep rigid and excellent initial strength is obtained even at room temperature It is possible to obtain the above-mentioned effect of the present invention having a desired sufficient pot life.
Irwin is not included in the cement admixture used in the present invention.
The content of C ₁₂ A ₇ mineral phase is a calcium aluminate phase in the resultant cement admixture for composition, for example, it can be measured by the following X-ray diffraction / Rietveld method.

_{The C 12} A ₇ series mineral in the cement admixture used in the cement mortar / concrete composition of the present invention preferably has a crystallite diameter of _{the C 12} A ₇ series mineral phase measured by X-ray diffraction of 150 to 500 nm. Is 150-300 nm.
When _{the crystallite diameter of the C 12} A ₇ series mineral phase is within such a range, excellent initial strength development and pot life can be ensured, 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 (apparatus: D4 Endeavor manufactured by Bruker Co., Ltd., analysis software: Topas).
Tube voltage: 45kV Tube current: 40mA

_{Further, the C 12} A ₇ series mineral in the cement admixture composition has a lattice constant of 11.94 to 11.975 Å of _{the C 12} A ₇ series mineral phase measured by X-ray diffraction.
By setting the lattice constant within such a range, it is possible to secure a predetermined fluidity and have excellent rapid hardness, and to obtain the above-mentioned effect of the present invention.
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 (apparatus: X'Pert MPD manufactured by PANalytical Co., Ltd., analysis software: HighScorePlus). ..
Tube voltage: 45kV Tube current: 40mA

Examples of gypsum (calcium sulfate) in the cement admixture composition contained in the cement mortar / concrete composition of the present invention include anhydrous gypsum, hemihydrate gypsum, dihydrate gypsum, or a mixture thereof.
Such gypsum in cement admixture composition, the mass ratio of the content of the gypsum _{/ C} 12 _{A 7} mineral phase from 0.5 to 1.2, preferably the amount contained such that 0.7-1.1 Included in. However, the gypsum content is an amount calculated as a total amount converted to _{CaSO 4 (anhydrite).}
Further, the content of gypsum in the cement admixture composition can be measured by, for example, the above-mentioned X-ray diffraction / Rietveld method.

Further, as the alkali sulfate compound in the cement mixture composition contained in the cement mortar / concrete 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 the alkali sulfate compound is 0.3 in the cement admixture composition, which is obtained by measuring the amount of Na and the amount of K according to JCAS I-04 and _{converting all of them into the total amount converted to Na 2} SO _4. It is desirable that the content is in an amount of ~ 1.7% by mass, preferably 0.5 to 1.5% by mass.

Further, as the calcium salt in the cement admixture composition contained in the cement mortar / concrete 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 used. It is desirable that all the calcium salts are contained in an amount of 1 to 14% by mass, preferably 2 to 12% by mass in terms of calcium hydroxide.
Further, the cement admixture composition contained in the cement mortar / concrete composition of the present invention contains 0.01 to 1.3% by mass of lithium carbonate in terms of lithium, preferably 0.01 to 1.0% by mass. It is desirable that it be contained.
The content of the calcium salt (calcium hydroxide equivalent) in the obtained mixed composition for cement can be measured by, for example, the above-mentioned X-ray diffraction / Rietveld method, and lithium carbonate (lithium equivalent). The content of can be measured using, for example, ICP emission spectroscopy.

By blending a cement admixture composition containing gypsum, an alkali sulfate compound, a calcium salt and lithium carbonate within the above range, the cement mortar / concrete composition of the present invention can effectively exhibit the above effects. It will be possible.

Preferably, the mixed composition for cement may contain fluorine (F), which is derived from the contained hard-hardening additive for cement, and the content thereof is fluorine / C ₁₂ A. _{It is desirable that the content of the 7-} based mineral phase is such that the mass ratio is 0.6 to 4.0% by mass, more preferably 1.0 to 3.5% by mass.
When the amount of F contained is in such a range, it has more excellent initial strength development, it is possible to secure a sufficient pot life, and the above-mentioned effect of the present invention can be more effectively exhibited. ..

Further, the above-mentioned cement admixture composition is preferably preferable because it can be further excellent in strength development for 3 hours by satisfying the following formula.
X = -0.93 (F / Q) -Qa + 11.98 ≧ 0
In the above formula, F represents fluorine content of cement admixture composition (mass%), Qa is the lattice constant of the C ₁₂ A ₇ mineral phase of a cement admixture composition (Å), Q is miscible cement It represents the content (mass%) of the C ₁₂ A _{7 mineral phase in the composition.}

Further, in the above cement admixture composition, preferably, be the C 3 _A is desirably not substantially _{contained, C 3 A / C 12 A} 7 minerals ≦ 7 (wt%) desirable.
This is because when C ₃ A increases, _{the content of the C 12} A ₇ series mineral phase decreases, so that sufficient initial strength may not be obtained.

_{Further, it is desirable that Ti, Fe, C 2} S and C ₂ AS are substantially not contained in the above-mentioned cement admixture composition _{, and at most, TiO 2} / C ₁₂ A ₇ ≤ 1.4 (mass). %), _{It is desirable that Fe 2} O ₃ / C ₁₂ A ₇ ≦ 2.0 (mass%). As a result, the initial strength development (3 hours after construction, etc.) is further improved. _{The TiO 2} and Fe ₂ O ₃ in the mixed composition for cement are derived from the contained hard-hardening additive for cement.

By making the cement admixture composition described above, the cement mortar / concrete composition of the present invention mixed with any cement, gluconate salt, and tartaric acid or tartaric acid salt available on the market can be obtained even at room temperature. , The initial strength development is excellent, the occurrence of initial shrinkage cracks can be suppressed, and the fluidity can be ensured.

The cement mortar-concrete composition of the present invention contains the above-mentioned cement admixture, any cement, gluconate, tartrate acid and / or tartrate, and the total mass of the cement admixture and cement. Gluconate (gluconic acid equivalent) is contained in an amount of 0.05 to 0.6% by mass and the tartrate and / or tartrate (in terms of tartrate) is contained in an amount of 0.05 to 0.6% by mass.

As the cement, any commercially available cement can be applied, for example, early-strength Portland cement, ultra-early-strength Portland cement, ordinary Portland cement, moderate heat Portland cement, low heat Portland cement, sulfate-resistant Portland cement, etc. At least one type selected from fly ash cement, blast furnace cement, silica cement and the like can be exemplified.

Examples of the gluconate salt contained in the cement mortar / concrete 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.

C ₁₂ A ₇ mineral calcium aluminate phase of cement mortar and concrete composition of the present invention, from the cement admixture composition, i.e., cement rapid hardening additives contained in the cement admixture for composition are those derived from, crystallite diameter _C 12 _{a 7} mineral phase as measured by X-ray diffraction lattice constants 150~500nm is 11.940～11.975Å.

By having the above-mentioned structure, the cement mortar-concrete composition of the present invention has excellent initial strength development, can suppress the occurrence of initial shrinkage cracks, and can secure fluidity.

The cement mortar / concrete composition of the present invention may be used, for example, 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). Acid-based, AE water reducing agents, high-performance water reducing agents, high-performance AE water reducing agents), liquid or powder admixtures, fine aggregates (river sand, sea sand, mountain sand, crushed sand and mixtures thereof) and , Coarse aggregate (river gravel, sea gravel, crushed stone and mixtures thereof) and the like can be contained.

Method for producing a cement mortar and concrete composition of the invention comprises (1) a cement rapid hardening additive material containing C ₁₂ A ₇ based mineral phase, and gypsum, and sulfuric acid alkali compound, lithium carbonate, slaked lime, quick lime and a calcium salt selected from the group consisting of calcium _{hydroxide, C} 12 _{a 7} based mineral 36-55% by weight, 0.3 to 1.7 wt% sulfuric acid alkali compound (sodium sulfate equivalent), lithium carbonate ( Contains 0.01 to 1.3% by mass of lithium salt (converted to calcium hydroxide) and 1 to 14% by mass of calcium salt (converted to calcium hydroxide) selected from the group consisting of slaked lime, quicklime and calcium hydroxide, and gypsum (converted to anhydrous gypsum). / C ₁₂ A _7- based admixture for cement with a mass ratio of the content of the mineral phase of 0.5 to 1.2, (2) cement, (3) gluconate and (4) tartrate and / or tartrate Gluconate (converted to gluconic acid) was added to 0.05 to 0.6% by mass based on the total mass of the mixed composition for cement and cement, and tartrate and / or tartrate (converted to tartrate). ) Is blended so as to contain 0.05 to 0.6% by mass in an outer ratio, which is a method for producing a cement mortar / concrete composition.

Further, in the method for producing an admixture for cement used in the cement mortar / concrete composition of the present invention, a hard-hardening additive for cement, gypsum, an alkali sulfate compound, a calcium salt and lithium carbonate are mixed and used for the above cement. The mixed composition is prepared to have the above-mentioned specific composition.
The manufacturing method is not particularly limited, but specifically, a specific hard-hardening additive for cement, gypsum, an alkali sulfate compound, a calcium salt and lithium carbonate are used, and C ₁₂ A ₇ minerals have a mass of 36 to 55 mass. %, Alkaline sulfate compound (converted to sodium sulfate) is 0.3 to 1.7% by mass, lithium carbonate (converted to lithium) is 0.01 to 1.3% by mass, and calcium salt (converted to calcium hydroxide) is 1 to 14%. wt%, gypsum weight ratio of (anhydrite converted) / C ₁₂ a ₇ based content mineral phase is formulated such that 0.5 to 1.2, and uniformly mixed, the cement admixture composition To prepare.

Specifically, the hard-hardening additive for cement to be blended in the cement admixture is a calcium raw material such as fresh lime and limestone, an aluminum raw material such as aluminum hydroxide and alumina, bauxite and band shale, and fluorine such as fluorite. Raw materials, magnesium raw materials such as dolomite to be blended as needed, etc. are mixed and crushed, or crushed and mixed, and this powder mixture is molded to obtain a molded product, which is heated by an electric furnace or the like. Bauxite is fired in a furnace and cooled to prepare a hard-hardening additive for cement.
In addition, those which are raw materials of Ti and Fe contained in the obtained hard-hardening additive for cement (for example, red iron oxide) are not positively blended. Ti and Fe contained in the hard-hardening 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.

Furthermore, cement rapid hardening additive to be incorporated in the production of the cement admixture composition, crystallite diameter _C 12 _{A 7} mineral phase as measured by X-ray diffraction is 150 to 500 nm, preferably 150~300nm , A fast-hardening additive having a lattice constant of 11.940 to 11.975 Å.
Crystallite size of C ₁₂ A ₇ mineral phase, the cement rapid hardening additive to such a range lattice constant comprises the cement admixture composition, by further comprising the cement mortar and concrete compositions, the hydrated active While promoting, shrinkage due to hydration activity can be reduced, and excellent initial strength development and good fluidity that can secure pot life can be obtained.
The crystallite diameter and the lattice constant are values measured by the same measuring method as described above.

In particular, preferably, cement rapid hardening additive comprises C ₁₂ A ₇ mineral phase 70 mass% or more, not including the C 3 _A Ti and Fe substantially, even included as impurities in the raw material C ₃ A is 5.0% by mass or less, Ti is 1.0% by mass or less in terms of _{TiO 2 , Fe is 1.5% by mass or less in terms of Fe 2} O ₃ , and F is 0.5 to 3 by mass. It is desirable that the material is a fast-hardening additive containing 0.0% by mass.
When C ₃ A exceeds 5.0% by mass, the content of the C ₁₂ A ₇ series mineral phase decreases, so that sufficient rapid hardness cannot be obtained by addition in the field, and the initial strength decreases. There is.

_{Further, C 2} S and C ₂ AS are substantially not contained in the hard-hardening additive for cement containing the C ₁₂ A ₇ series mineral phase as a main component and having a C ₃ A content of a certain level or less. desirable.
The term "substantially free" means that these mineral phases are not prevented from being produced by _{SiO 2, which is an impurity contained in the raw material, and are not actively produced and contained.} It is desirable that the total content of C ₂ S and C ₂ AS is at most 10% by mass or less.
This allows the content of C ₁₂ A ₇ mineral phase is a calcium aluminate phase in order not to reduce the above range.

Incidentally, such a cement rapid hardening additive, as described below, 1250-1400 ° C., preferably by being prepared by firing at from 1300 to 1360 ° C., _{C 3} S is not that most generated, substantially Not included. Further, since _{Fe 2} O ₃ in the cement quenching additive _{is 1.5% by mass or less, C 4} AF is hardly produced and is substantially not contained.

Further, it is desirable that the hard-hardening additive for cement does not positively contain Ti and does not substantially contain Ti.
Substantially not contained means that Ti does not prevent the case where it is produced by impurities contained in the raw material, and does not mean that Ti is positively contained.
For example, the Ti content is 1.0% by mass or less, preferably 0.5% by mass or less in terms of _{TiO 2 oxide.}
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 Ti related to the formation of the melt phase.
By substantially not containing TiO ₂ and setting the content at most to the above-mentioned content or less, the initial strength development (3 hours after construction, etc.), which is rapid hardness, is excellent.
When including more than 1.0 mass% of Ti in terms of TiO _{2, C 3} A ends up generating more than 5.0 mass%, no effect is obtained of the present invention.

Further, it is desirable that the hard-hardening additive for cement does not positively contain Fe and does not substantially contain Fe.
Substantially not contained means that Fe does not prevent the case where it is produced by impurities contained in the raw material, and it is not positively contained.
For example, the Fe content is 1.5% by mass or less, preferably 1.0% by mass or less in terms of _{Fe 2} O _{3 oxide.}
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, which is related to the formation of the melt phase.
When the Fe ₂ O ₃ contains more than the content, C ₁₂ lattice constant of A ₇ mineral phase is increased, it becomes possible to initial strength development is steeper rigid (3 hours after installation, etc.) is poor, less Is more preferable.

Further, it is desirable that the hard-hardening additive for cement further contains 0.5 to 3.0% by mass, preferably 1.0 to 2.5% by mass of F.
By setting the content of F contained in the hard-hardening additive for cement within the above range, the C ₁₂ A ₇ series mineral phase is stably generated, and _{the lattice constant of the C 12} A ₇ series mineral phase becomes the appropriate range. The hydration activity can be enhanced, and by including the hard-hardening additive for cement in the cement mortar / concrete composition, the above-mentioned effect of the present invention can be more effectively exhibited.

The hard-hardening additive for cement is obtained by pulverizing and mixing the compounding raw materials and molding the mixed powder to obtain a molded product at a temperature of, for example, 1.25 to 1400 ° C., preferably 1300 to 1360 ° C., sufficiently, for example, 0. It can be produced by firing for 5 to 3 hours and then cooling at a cooling rate of 40 ° C./min or less, preferably 5-40 ° C./min. The raw materials are blended so as to have the above content ratio.
The thus obtained cement rapid hardening additive, there is no possible to require the generation of a certain amount of the melt phase, can be hydrated activity of C ₁₂ A _7-based solid solution is expressed sufficiently As described above, Ti, Fe, etc. are substantially not contained, and the content thereof is adjusted so as to be equal to or less than the above content, and the cement is post-added to be excellent in initial strength, which is rapid hardness. Become.

In this way, the molded product obtained by molding the raw material mixed powder is fired and cooled at a cooling rate of 40 ° C./min or less, preferably 5 to 40 ° C./min, so that the C ₁₂ A ₇ system measured by X-ray diffraction is used. crystallite size of the mineral phase is 150 to 500 nm, preferably 150 to 300 _nm, the lattice constant of the _C 12 _{a 7} mineral phase is 11.940～11.975Å, it is possible to produce a cement rapid hardening additive ..

Since the degree of hydration activity, that is, the degree of rapid hardening is different due to the difference in crystallite diameter, in order to secure the pot life and obtain the rapid hardening, calcination is performed at the above-mentioned firing temperature and the above-mentioned cooling. By setting the speed, a hard-hardening additive for cement having a crystallite diameter in the range of 150 to 500 nm can be obtained. Further, by setting the optimum range of 150 to 300 nm, the rapid hardness becomes more excellent.
When the crystallite diameter of the C ₁₂ A ₇ mineral phase is in such a range, such a rapid hardening additive such as cement admixture composition containing were added to cement, obtained cement mortar and concrete is the proper flow It is possible to maintain the property and obtain good initial strength development.

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, because good hard-hardening may not be obtained if the ^{specific surface area is less than 4500 cm 2 / g.} Is.
Further, if the specific surface area of the brain is too large, the fluidity is adversely affected, the pulverization 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.

The cement admixture for composition, the cement rapid hardening additives into powder, and further gypsum, and sulfuric acid alkali compound, a calcium salt and lithium carbonate, C ₁₂ A ₇ based mineral with 36-55 wt% alkali compound is 0.3 to 1.7 mass% sulfuric acid, lithium carbonate 0.01 to 1.3 wt%, 1 to 14% by weight of calcium salt, by weight of the content of the gypsum _{/ C} 12 _{a 7} mineral phases As long as the mixture can be uniformly blended so that the ratio is 0.5 to 1.2, the mixing method is not particularly limited, and 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 _{converted to Na 2} SO _{4, the} total amount, all calcium salts are the total amount converted to calcium hydroxide, and all lithium carbonate is the amount converted to lithium.

Specifically, even if a hard-hardening additive for cement is added to a mixture obtained by premixing gypsum, an alkali sulfate compound, a calcium salt and lithium carbonate, gypsum, an alkali sulfate compound, a calcium salt and lithium carbonate are mixed. And even if the fast-hardening additive for cement is mixed at the same time, any method can be used as long as it can be mixed uniformly.

The cement mortar / concrete composition of the present invention can be produced by blending the cement mixture composition thus obtained, cement, gluconate, tartrate acid and / or tartrate salt. The gluconate (gluconic acid equivalent) is 0.05 to 0.6% by mass, and the tartrate and / or tartrate (tartrate equivalent) is 0.05 to 0.6% by mass based on the total amount of the cement mixture and the cement. It is blended so as to be contained in an amount of 0.05 to 0.6% by mass.

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 powder admixture, fine aggregate (river sand, sea sand, mountain sand, crushed sand and their mixture), coarse aggregate (river gravel, sea gravel, crushed stone and their mixture), etc. can do.

Further, the method of mixing with water when preparing a cement paste, mortar, concrete or the like using the cement mortar / concrete composition of the present invention is not particularly limited, and after blending in a predetermined ratio, the cement mortar / concrete composition is blended in a predetermined ratio. Mixing may be performed using a conventional mixing device.

Specifically, a cement mortar / concrete may be prepared by blending an admixture for cement, any cement, gluconate, tartrate and / or tartrate with water, or for cement. Even if a cement mortar / concrete is prepared by blending a mixed composition, cement, and a mixture of gluconate and tartrate acid and / or tartrate and water in advance, any method can be used as long as it can be mixed uniformly. It doesn't matter.
In particular, it is desirable that gluconate and tartaric acid or tartaric acid are dissolved in advance in water to be blended when preparing cement mortar / concrete.
In addition, the above-mentioned admixtures and aggregates added as needed may be added at the same time as cement or the like if they can be mixed uniformly, or may be added sequentially, or when kneaded with water when preparing mortar or the like. It is not particularly limited whether it is added to or by any addition method.

The cement mortar / concrete of the present invention thus obtained has excellent initial strength development even at room temperature, can suppress the occurrence of initial shrinkage cracks, secures fluidity, and secures workability. It will also be possible.

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, silicon dioxide, 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 intended to be actively contained).

Each of the above-mentioned hard-hardening additive raw materials for cement was pressure-molded, and 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, and each of them shown in Table 2. A hard-hardening additive for cement was obtained.

2) _{Measurement of content of TiO 2} , Fe ₂ O ₃ , F component, etc. JIS R 5204 of each of the obtained hard-hardening additives for cement using a fluorescent X-ray analyzer (manufactured by PANalytical Co., Ltd .; Axios). _{The content ratio of the contained TiO 2,} Fe ₂ O _3, F component, etc. was measured by the analysis according to the above.
These results are shown in Table 2.

3) Mineral analysis of hard-hardening additives for cement (C ₁₂ A ₇ series and C ₃ A)
Using the X-ray diffraction / Rietveld method (apparatus: PANalytical X'Pert MPD, analysis software: HighScorePlus), the obtained hard-hardening additives for cement were used to obtain C ₁₂ A ₇ series and C ₃ A minerals. The content ratio and the lattice constant of the crystals of the _{C 12} A _{7 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 C 12} A ₇ series mineral phase was measured using the crystal structure of _{C 11} A ₇ CaF _2.

The crystallite diameter of the crystals of the C ₁₂ A ₇ series mineral phase is determined by the X-ray diffraction / Rietveld method (device: D4 Endeavor manufactured by Bruker, analysis software: Topas) using _{the C 11} A ₇ CaF _{2 crystal structure.} Measured by.
Tube voltage: 45kV Tube current: 40mA
The results are shown in Table 2.

4) Preparation of the admixture composition for cement Next, each of the above-mentioned hard-hardening additives 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.
Obtained anhydrite powder for cement, anhydrous anhydrite (trade name; non-clave, manufactured by Sumitomo Osaka Cement Co., Ltd.), Na ₂ SO ₄ (Glauber's salt: reagent), slaked lime (calcium hydroxide: reagent) and lithium carbonate (Reagent) was blended in the blending ratios shown in Tables 3 to 5 below to prepare mixed composition compositions for cement.
In Tables 3 to 5, lithium carbonate indicates a value in terms of lithium.

5) Measurement of mineral content (C ₁₂ A ₇ series) _{in the admixture for cement and crystal lattice constant and crystallite diameter of the C 12} A ₇ series mineral phase The same method as described in 3) above. _{The content of the C 12} A ₇ series mineral phase (Q) in each mixture composition for cement, _{the lattice constant of the crystal of the C 12} A ₇ series mineral phase, and the crystallite diameter were measured.
These results are shown in Tables 3-5.
Incidentally, C ₁₂ A ₇ mineral phase of a cement admixture composition, is derived from the cement for rapid hardening additive.

6) Anhydrite / C ₁₂ A ₇ series mineral phase in the admixture for cement (mass ratio of content)
And C ₁₂ A ₇ mineral phase content of the cement admixture composition which is measured by the above 5), than the amount of anhydrite of the cement admixture composition shown in Table 3-5, each cement _{Anhydrite / C 12} A ₇ series mineral phase (mass ratio) in the mixed composition for use was calculated.
The results are shown in Tables 3-5.

_{7) C 3} A / C ₁₂ A ₇ mineral phase (mass%), TiO ₂ / C ₁₂ A ₇ mineral phase (mass%), Fe ₂ O ₃ / C ₁₂ A ₇ mineral phase (mass%) in the admixture for cement. mass%)
In Table 2 of _{C 3 A, TiO 2, Fe} 2 O 3 amount and the cement admixture composition in amounts and Table 3-5 cement for rapid hardening additive for cement admixture composition in Table 3-5 From the content (mass%) of the C ₁₂ A _{7 mineral phase in the substance, C 3} A / C ₁₂ A ₇ mineral phase (mass%), TiO ₂ / C ₁₂ A ₇ mineral phase (mass%), Fe ₂ The O ₃ / C ₁₂ A ₇ mineral phase (% by mass) was calculated. All, C ₃ A / C ₁₂ A ₇ mineral phase ≤ 7 (mass%), TiO ₂ / C ₁₂ A ₇ mineral phase ≤ 1.4 (mass%), Fe ₂ O ₃ / C ₁₂ A ₇ mineral phase It satisfied ≦ 2.0 (mass%). _{The C 12} A ₇ mineral phase, C ₃ A mineral phase, TiO _{2 and} Fe ₂ O ₃ in the admixture for cement are derived from the above-mentioned hard additive for cement.

8) Preparation of cement mortar composition A combination of the obtained mixed composition for cement, sodium gluconate and tartaric acid in early-strength Portland cement (PC: manufactured by Sumitomo Osaka Cement Co., Ltd.) as shown in Tables 3-5. Each cement mortar composition was prepared by blending in proportions.
In Tables 3 to 5, sodium gluconate (gluconic acid equivalent) and tartaric acid are added to the total mass of 100 parts by mass of the mixed composition for each cement and early-strength Portland cement in Tables 3 to 3 below. Each cement mortar composition was prepared by blending in the ratio shown in 5.

9) Preparation of mortar Each cement mortar composition (Examples 1 to 14, Comparative Examples 1 to 15), fine aggregate (silica sand), water and admixture (Mighty 150: manufactured by Kao Corporation) are shown in Table 6 below. The mortars were obtained by mixing them as they were and kneading them uniformly.
In addition, sodium gluconate and tartaric acid in the cement mortar composition were used by dissolving them in water in advance.

10) Intensity measurement and flow value measurement For each of the mortars of Examples 1 to 14 and Comparative Examples 1 to 15, the intensity for 3 hours at 20 ° C. and the flow value at 20 ° C. were measured according to JIS R 5201.
The results are also shown in Tables 3 to 5 above.

11) Crack test Each mortar of Examples 1 to 14 and Comparative Examples 1 to 15 was subjected to a crack test at 20 ° C. as follows.
A mortar specimen was prepared according to JSCE-F506 (How to prepare a cylindrical specimen for compressive strength test of mortar or cement paste). However, as shown in FIG. 1, the formwork used was one in which a hole was made in the upper part of the formwork for a cylindrical specimen (φ5 × 10 cm) and bolts were inserted to fix the formwork.
For the evaluation of cracks, the length of cracks generated on the upper surface of the specimen (upper surface of the bolt) after 3 hours of kneading was measured in units of 5 mm (rounded up), and a state of 5 mm or less was accepted.
These results are shown in Tables 3-5.

The cement mortar-concrete composition of the present invention can exhibit sufficient strength in a normal temperature environment, exhibit excellent hydration activity and good rapid hardening performance, and suppress the occurrence of initial shrinkage cracks due to self-shrinkage. It can be applied to construction work of tunnels and lower spaces, civil engineering work, water stoppage work, road work, and building structures.

Claims (4)

Wherein (1) the cement rapid hardening additive material containing C ₁₂ A ₇ based mineral phase, and gypsum, and sulfuric acid alkali compound, slaked lime, and quick lime and calcium salts and lithium carbonate selected from the group consisting of calcium hydroxide , C ₁₂ A ₇ series minerals 36-55% by mass, alkali sulfate compounds (sodium sulfate equivalent) 0.3-1.7% by mass, lithium carbonate (lithium equivalent) 0.01-1.3% by mass, slaked lime, quick lime and calcium salt selected from the group consisting of calcium hydroxide (calcium hydroxide equivalent) containing 1-14 wt%, the weight ratio of gypsum (anhydrite equivalent) / C ₁₂ a ₇ based content mineral phases There is 0.5 to 1.2, for cement admixture composition crystallite diameter _C 12 _{a 7} mineral phase as measured by X-ray diffraction is lattice constant 11.940~11.975Å at 150~500nm , (2) Cement, (3) Gluconate and (4) Tartrate or Tartrate, and gluconate (equivalent to gluconic acid) is divided by the total mass of the mixed composition for cement and cement. A cement mortar-concrete composition comprising 0.05 to 0.6% by mass and 0.05 to 0.6% by mass of the tartrate acid or tartrate salt (converted to tartrate acid) in an external division. The cement according to claim 1, wherein the C ₁₂ A ₇ series mineral phase is a mixed phase of _{C 11} A ₇ CaX ₂ (X is a halogen) and C ₁₂ A _7. Mortar / concrete composition. (1) and the cement rapid hardening additive material containing C ₁₂ A ₇ based mineral phase, and gypsum, and sulfuric acid alkali compound, lithium carbonate, slaked lime, a calcium salt selected from the group consisting of quick lime, and calcium hydroxide , C ₁₂ A ₇ series minerals are 36 to 55% by mass, alkali sulfate compounds (sodium sulfate equivalent) are 0.3 to 1.7% by mass, lithium carbonate (lithium equivalent) is 0.01 to 1.3% by mass, slaked lime, quick lime and calcium salt selected from the group consisting of calcium hydroxide (calcium hydroxide equivalent) is contained 1 to 14% by mass, the mass ratio of the content of gypsum (anhydrite equivalent) / C ₁₂ a ₇ mineral phases Cement admixture, (2) cement, (3) gluconate and (4) tartrate or tartrate, with respect to the total mass of the cement admixture and cement. Then, gluconate (converted to gluconic acid) is blended so as to contain 0.05 to 0.6% by mass in external proportion and the tartrate or tartrate (converted to tartrate acid) in an external proportion of 0.05 to 0.6% by mass. A method for producing a cement mortar / concrete composition, which comprises the above. In the method for producing a cement mortar / concrete composition according to claim 3, the cement mortar / concrete composition is formed by pulverizing and mixing the raw materials, and firing at 1250 to 1400 ° C., and the cooling rate is 40 ° C./min or less. _{By cooling with, the crystallite diameter of the C 12} A ₇ series mineral phase measured by X-ray diffraction is 150 to 500 nm, and _{the lattice constant of the C 12} A ₇ series mineral phase is 11.940 to 11.975 Å. A method for producing a mortar / concrete composition.

Images