JP6900761B2 - 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, the cement mortar / concrete composition has excellent rapid hardness, excellent workability, and can suppress the occurrence of initial shrinkage cracks. And its manufacturing method.

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 humidity and wind, but it can be prevented by measures such as sprinkling a curing agent (water) 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 chemical shrinkage, which is a phase volume change caused by the hydration reaction of cement, and capillary voids, and occurs when 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 to secure a pot life of a cement composition containing calcium aluminate and a rapid-hardening component of gypsum because it 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 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 method for producing a cement mortar / concrete composition which can suppress initial shrinkage cracks due to self-shrinkage of a mortar / concrete structure at room temperature and has excellent initial strength development.

The cement mortar / concrete composition according to claim 1 contains (1) _{5 to 40% by mass of C 12} A ₇ minerals, 0.5 to 1.0% by mass of an alkali sulfate compound (in terms of sodium sulfate), and carbonic acid. lithium mass ratio of the content of (Li _{conversion) / C} 12 _{a 7} mineral phase 0.05 to 3 (weight%), hydrated lime, quicklime and calcium salt selected from the group consisting of calcium hydroxide (calcium hydroxide terms ) / C ₁₂ A ₇ series mineral phase content mass ratio is 3 to 40 (mass%), gypsum (anhydrous gypsum equivalent) / C ₁₂ A ₇ series mineral phase content mass ratio is 0.6 to 1 a .4, cement composition crystallite diameter _C 12 _{a 7} mineral phase as measured by X-ray diffraction is lattice constant 11.940~11.975Å at 150 to 500 nm, (2) gluconate and (3) Containing tartrate or tartrate, 0.05 to 0.6% by mass of gluconate (equivalent to gluconic acid) is added to the mass of the cement composition, and tartrate or tartrate (equivalent to tartrate). ) Is contained in an outer ratio of 0.05 to 0.6% by mass, which is a cement mortar-concrete composition.

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

The method for producing a cement mortar / concrete composition according to claim 3 is as follows: (1) _{5 to 40% by mass of C 12} A ₇ minerals and 0.5 to 1.0% by mass of an alkali sulfate compound (in terms of sodium sulfate). wherein, lithium carbonate (Li _{terms) / C} 12 weight ratio of the content of _{a 7} mineral phase 0.05 to 3 wt%, calcium hydroxide, calcium salt (calcium hydroxide selected from the group consisting of quick lime, and calcium hydroxide ) / C ₁₂ A ₇ series mineral phase content mass ratio is 3 to 40 mass%, gypsum (anhydrous gypsum) / C ₁₂ A ₇ series mineral phase content mass ratio is 0.6 to 1.4 There, the cement composition crystallite diameter _C 12 _{a 7} mineral phase as measured by X-ray diffraction is lattice constant 11.940~11.975Å at 150 to 500 nm, (2) gluconate, and (3 ) Tartrate or tartrate, based on the mass of the cement composition, gluconate (equivalent to gluconic acid) is divided by 0.05 to 0.6% by mass, and tartrate or tartrate (equivalent to tartrate) is excluded. It is a method for producing a cement mortar / concrete composition, which comprises blending so as to contain 0.05 to 0.6% by mass in proportion.

The method for producing a cement mortar / concrete composition according to claim 4 is the above-mentioned method for producing a cement mortar / concrete composition. and fired at 1250-1,400 ° C., the molded body after the firing by cooling at a cooling rate 40 ° C. / min or less, the crystallite size of the _C 12 _{a 7} mineral phase as measured by X-ray diffraction is at 150~500nm A method for producing a cement mortar-concrete composition, which comprises producing a cement mortar / concrete composition having a lattice constant of C _{12 A 7 series mineral phase of 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 containing cement mortar / concrete composition water. It means.

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, it is desired to formulate a cement composition containing a specific hard-hardening additive for cement in an arbitrary amount according to a desired initial strength while easily adjusting it with gluconate, tartrate, etc. in the field. It is easy to design to obtain the rapid hardness on site. For example, a cement mortar / concrete composition that has excellent initial strength development at room temperature such as 20 ° C and can suppress initial shrinkage cracks is manufactured on site. It becomes possible to do.

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) C} 12 _{A 7} mineral 5 to 40 wt%, including sulfuric acid alkali compound (sodium sulfate equivalent) 0.5 to 1.0 wt%, lithium carbonate ( Lithium equivalent) / C ₁₂ A _7- based mineral phase content ratio of 0.05 to 3 (mass%), calcium salt selected from the group consisting of slaked lime, quicklime and calcium hydroxide (calcium hydroxide equivalent) / The mass ratio of the content of the C ₁₂ A ₇ series mineral phase is 3 to 40 (mass%), and the mass ratio of the content of the gypsum (equivalent to anhydrous gypsum) / C ₁₂ A ₇ series mineral phase is 0.6 to 1.4. , and the cement composition crystallite diameter _C 12 _{a 7} mineral phase as measured by X-ray diffraction is lattice constant 11.940~11.975Å at 150 to 500 nm, (2) gluconate and (3 ) Tartrate and / or tartrate is contained, and 0.05 to 0.6% by mass of gluconate (equivalent to gluconic acid) is added to the mass of the cement composition, and the tartrate and / or tartrate (). It is a cement mortar-concrete composition characterized by containing 0.05 to 0.6% by mass in terms of tartrate acid).

Preferably, in the cement mortar-concrete composition of the present invention, it is desirable that 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.

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.

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

C ₁₂ A ₇ mineral phase is a calcium aluminate phases of the cement composition contained in cement mortar and concrete composition of the present invention, as described above, 5 to 40 wt%, preferably from 5 to 36 weight %, More preferably 10 to 30% by mass.
Such C ₁₂ A ₇ based mineral phase is added blended in the preparation of the cement composition, is desirably derived from a cement rapid hardening additive.
The inclusion of C ₁₂ A ₇ based mineral phase, preferably by including in the content, with sufficient rapid hardening and excellent initial strength can be obtained, having a sufficient pot life desired, the present invention The above effect can be obtained.
Irwin is not included in the cement composition used in the present invention.
The content of C ₁₂ A ₇ mineral phase is a calcium aluminate phases in the cement composition is, for example, can be measured by the following X-ray diffraction / Rietveld method.

_{The C 12} A ₇ series mineral in the cement composition used in the cement mortar / concrete composition of the present invention _{has a crystallite diameter of the C 12} A ₇ series mineral phase measured by X-ray diffraction of 150 to 500 nm, preferably 150. It is ~ 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 good fluidity that can secure the pot life 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 contained in the cement mortar / concrete composition of the present invention has a lattice constant of _{the C 12} A ₇ series mineral phase measured by X-ray diffraction of 11.940-11. It is of 975 Å.
By setting the lattice constant within such a range, it is possible to secure a predetermined fluidity and have excellent sharpness.
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 the gypsum (calcium sulfate) contained in the cement 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 the cement composition, the mass ratio of the content of the gypsum _{/ C} 12 _{A 7} based mineral phase 0.6 to 1.4, preferably included in a content such that 0.8 to 1.3 Is done. However, the gypsum content is an amount calculated as a total amount converted to _{CaSO 4 (anhydrite).}
The content of gypsum in the cement composition 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 used in the present invention, for example, alkali metal sulfates such as sodium sulfate and potassium sulfate can be exemplified.
The content of the alkali sulfate compound is 0.5 to 1 in the cement 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 Na 2} SO _{4 equivalent.} It is desirable that it is contained in an amount of 0.0% by mass, preferably 0.6 to 1.0% by mass.
By containing gypsum or alkali sulfate within the above range, the above-mentioned effects of the present invention can be more effectively exhibited.

Further, as the calcium salt in the cement composition contained in the cement mortar / concrete composition of the present invention, salts such as slaked lime and quick lime that are not sparingly soluble in water can be used, but calcium hydroxide is desirable.
Such calcium salt, in the cement composition, the mass ratio of the content of calcium salt (calcium hydroxide _{terms) / C} 12 _{A 7} mineral phase 3 to 40 (wt%), preferably from 5 to 35 (wt%) It is contained in such a content as. However, the calcium salt content is an amount calculated as a total amount converted to calcium hydroxide.

Also, lithium carbonate cement composition contained in cement mortar and concrete composition of the present invention, in the cement composition, lithium (Li terms) / C mass ratio of the content of ₁₂ A ₇ mineral phase carbonate It is contained in a content such that it is 0.05 to 3 (mass%), preferably 0.05 to 2.5 (mass%).
The content of calcium salt (calcium hydroxide equivalent) in the cement composition can be measured by, for example, the above-mentioned X-ray diffraction / Rietveld method, and the content of lithium carbonate (lithium equivalent) is For example, it can be measured using ICP emission spectroscopy.

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

Preferably, the cement composition may contain fluorine (F), which is derived from the contained hard-hardening additive for cement, and the content thereof is fluorine / C ₁₂ A ₇ system. It is desirable that the content of the mineral phase is such that the mass ratio is 0.8 to 4.0 (mass%), more preferably 1.5 to 3.5 (mass%).
For example, the fluorine content in Portland cement, which is a raw material, is at most 0.05% by mass, which is higher than the fluorine content (0.5 to 3.0% by mass) contained in the hard-hardening additive for cement. Since the amount is extremely small, most of the fluorine contained in the obtained cement composition is derived from the following hard-hardening additives for cement.
By setting the amount of F contained in such a range, it is possible to have more excellent initial strength development and to secure a sufficient pot life.

Further, the cement composition used in the present invention preferably has the following formula: C ₁₂ A ₇ series mineral phase lattice constant (Å) ≤ [(0.05-fluorine content (mass%))] /. it is particularly desirable to satisfy the C ₁₂ content of a ₇ based mineral phase (wt%) + 11.98, by having such relationship has excellent initial strength development, to ensure a pot life It will be more possible.

Further, in the cement composition, Ti is desirably substantially _free, the content of _C 12 _{A 7} based mineral phase (wt%) ≧ 83 × (TiO ₂ content (wt%) - 0. It is desirable to satisfy 3).

The cement composition used in the present invention may contain various organic acids such as a coagulation modifier (lignin sulfonic acid type, oxycarboxylic acid type, saccharide, etc.), if necessary, as long as it does not impair the above effects of the present invention. Alternatively, organic acid alkali metal salts and alkalinity metal salts) and water reducing agents (alkylallyl sulfonic acid type, naphthalene sulfonic acid type, melamine sulfonic acid type, polycarboxylic acid type, AE water reducing agent, high performance water reducing agent, high performance It can contain an admixture (including an AE water reducing agent).

The cement mortar / concrete composition of the present invention contains the cement composition having the above composition, gluconate, tartaric acid and / or tartaric acid, and thus has excellent initial strength development at room temperature and initial shrinkage. The occurrence of cracks can be suppressed, and the fluidity can be ensured.

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.

Further, the gluconate (gluconic acid equivalent) is 0.05 to 0.6% by mass, and tartaric acid or tartaric acid (tartaric acid equivalent) is 0.05 to 0. It is contained in 6% by mass.

The method for producing a cement mortar / concrete composition of the present invention contains (1) _{5 to 40% by mass of C 12} A ₇ minerals and 0.5 to 1.0% by mass of an alkali sulfate compound (in terms of sodium sulfate). Lithium carbonate (lithium equivalent) / C ₁₂ A _7- based mineral phase content of 0.05 to 3% by mass, calcium salt selected from the group consisting of slaked lime, fresh lime and calcium hydroxide (calcium hydroxide equivalent) The mass ratio of the content of the / C ₁₂ A ₇ series mineral phase is 3 to 40 mass%, and the mass ratio of the content of the gypsum (anhydrous gypsum) / C ₁₂ A ₇ series mineral phase is 0.6 to 1.4. , the cement composition crystallite diameter _C 12 _{a 7} mineral phase as measured by X-ray diffraction is lattice constant 11.940~11.975Å at 150 to 500 nm, (2) gluconate and (3) tartaric acid And / or tartrate, based on the mass of the cement composition, 0.05 to 0.6% by mass of gluconite (gluconic acid equivalent), and tartrate and / or tartrate (equivalent to tartrate). Is a method for producing a cement mortar / concrete composition, which is blended so as to contain 0.05 to 0.6% by mass of the above.

C ₁₂ A ₇ mineral calcium aluminate phase in cement mortar and concrete compositions prepared by the present invention, from the cement compositions, i.e., cement rapid hardening additives contained in the cement composition It is derived and is preferably contained in an amount of 5 to 40% by mass, more preferably 10 to 30% by mass.
Therefore, according _C 12 _{A 7} based mineral phase, the crystallite size of the _C 12 _{A 7} mineral phase as measured by X-ray diffraction lattice constants 150~500nm is 11.940～11.975Å.

The cement composition used in the method for producing a cement mortar / concrete composition of the present invention is a mixture of a hard-hardening additive for cement, gypsum, an alkali sulfate compound, a calcium salt, lithium carbonate and cement. It is prepared to have the above specific configuration.
The manufacturing method is not particularly limited, but specifically, a specific hard-hardening additive for cement, gypsum, an alkali sulfate compound, a calcium salt, lithium carbonate, cement, and C ₁₂ A ₇ minerals are used. 40 mass%, wherein the sulfuric acid alkali compound 0.5 to 1.0 wt%, lithium carbonate (Li _{terms) / C} 12 weight ratio of the content of _{a 7} mineral phase 0.05-3 (wt%) , Calcium salt (converted to calcium hydroxide) / C ₁₂ A ₇ series mineral phase content ratio is 3-40 (mass%), gypsum (converted to anhydrous gypsum) / C ₁₂ A ₇ series mineral phase content The mixture is blended so as to have a mass ratio of 0.6 to 1.4 and mixed uniformly to prepare a cement composition.

Specifically, the hard-hardening additive for cement to be blended in the above cement composition 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 a fluorine raw material such as fluorite. , Magnesium raw materials such as dolomite to be blended as needed are mixed and crushed, or crushed and mixed, and this powder blend is molded to obtain a molded product, which is heated by an electric furnace or the like. Bauxite and cool 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 blended in the preparation of the cement composition used in the present invention, the crystallite diameter of the _C 12 _{A 7} mineral phase as measured by X-ray diffraction is 150 to 500 nm, preferably 150~300nm It is a hard-hardening additive for cement having a lattice constant of 11.940 to 11.975 Å.
Crystallite size of C ₁₂ A ₇ based mineral phase, by a cement rapid hardening additive to such a range lattice constant containing the cement composition, while promoting the hydration activity, temperature of about 20 ° C. ambient temperature environment 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 the above method.

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 it is a hard-hardening additive for cement containing 0.0% by mass.
If 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 post-addition in the field, and the initial strength decreases. In some cases.

_{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%, the effect is not sufficiently obtained in 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 the cement composition obtained by post-adding the hard-hardening additive for cement to cement or the like can more effectively exhibit the above-mentioned effects of the present invention.

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.
C ₁₂ When crystallite size of A ₇ mineral phase is in such a range, a cement composition containing such a cement rapid hardening additive such as cement mortar and concrete obtained is blended with gluconate or tartrate, etc. However, good initial strength development can be obtained.

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 composition is obtained by powdering the fast-hardening additive for cement, and further comprising the gypsum, the alkali sulfate compound, the calcium salt and lithium carbonate, and any commercially available cement. ₁₂ a ₇ mineral 5 to 40 wt%, including sulfuric acid alkali compound (sodium sulfate equivalent) 0.5 to 1.0 wt%, lithium carbonate (Li _{conversion) / C} 12 _{a 7} based content of mineral phases mass ratio of 0.05 to 3 (weight%), the mass ratio of the content of calcium salt (calcium hydroxide _{equivalent) / C} 12 _{a 7} mineral phase 3 to 40 (wt%), gypsum (anhydrite equivalent) / C ₁₂ weight ratio of the content of a ₇ mineral phase if it is possible to uniformly blended so that 0.6 to 1.4, in particular its mixing method is not limited, the use of any mixing method Is possible.

Further, in the method for producing a cement mortar / concrete composition of the present invention, for example, a water reducing agent (alkylallyl sulfonic acid type, naphthalene sulfonic acid type, melamine sulfone) is used as long as it does not impair the above effects. Acid-based, polycarboxylic acid-based, AE water reducing agents, high-performance water reducing agents, high-performance AE water reducing agents), liquid or powder admixtures, and fine aggregates (river sand, sea sand, mountain sand, crushed sand, etc.) These mixtures), coarse aggregates (river gravel, sea gravel, crushed stones and mixtures thereof) and the like can be blended.

Specifically, the cement composition can be obtained by preliminarily blending gypsum, an alkali sulfate compound, a calcium salt, lithium carbonate, and a hard-hardening additive for cement, and even if cement is added and mixed, the gypsum and alkali sulfate can be mixed. Even if the compound, calcium salt, lithium carbonate, hard-hardening additive for cement and cement are mixed at the same time, any method can be used as long as they can be mixed uniformly.
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. The addition method is not particularly limited.

The cement composition thus obtained, gluconate, tartaric acid and / or tartaric acid can be blended as described above to produce a cement mortar / concrete composition.
Further, as described above, if necessary, for example, a water reducing agent (alkylallyl sulfonic acid type, naphthalene sulfonic acid type, melamine sulfonic acid type, polycarboxylic acid type, AE water reducing agent, high performance water reducing agent, high performance AE). (Including water reducing agents), liquid or powder admixtures, fine aggregates (river sand, sea sand, mountain sand, crushed sand and mixtures thereof), coarse aggregates (river gravel, sea gravel, crushed stones and their mixture). Mixture) and the like can also be blended.

For cement mortar concrete, for example, cement mortar concrete may be prepared by blending cement composition, gluconate, tartrate acid and / or tartrate with water, or cement composition and glucon in advance. Even if a cement mortar / concrete is prepared by blending a salt and tartrate acid and / or a mixture of tartrate and water, any method may be used as long as it can be mixed uniformly.
In particular, it is desirable that gluconate and tartaric acid or tartaric acid are dissolved in water that is premixed 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 thus obtained has excellent initial strength development even at room temperature of about 20 ° C., can suppress the occurrence of initial shrinkage cracks, and secures fluidity to ensure workability. It will also be possible to do.

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 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.
Obtained anhydrite powder for cement, anhydrous gypsum (trade name; non-clave, manufactured by Sumitomo Osaka Cement Co., Ltd.), Na ₂ SO ₄ (Glauber's salt: reagent), slaked lime (calcium hydroxide: reagent), lithium carbonate (Reagent) and early-strength Portland cement (PC: manufactured by Sumitomo Osaka Cement Co., Ltd.) were blended to prepare each cement composition having a content ratio as shown in Tables 3 to 5 below.
In Tables 3 to 5, lithium carbonate indicates a value in terms of lithium.

5) Analysis of minerals in the cement composition (C ₁₂ A ₇ series) and _{measurement of crystal lattice constants and crystallite diameter of the C 12} A ₇ series mineral phase by the same method as described in 3) above. the lattice constant and crystallite size of the crystalline content and C ₁₂ a ₇ mineral phase of C ₁₂ a ₇ mineral phase of each cementitious composition (Q) was measured.
These results are also shown in Tables 3-5.
Incidentally, C ₁₂ A ₇ mineral phase of the cement composition are those derived from the cement for rapid hardening additive.

6) Measurement of gypsum content and calcium salt content in cement composition The content of gypsum and calcium salt in each cement composition is determined by the same method as the XRD / Rietveld method described in 3) above. Each was measured. However, dihydrate gypsum and hemihydrate gypsum were calculated by converting them into anhydrous gypsum, CaSO ₄ amount (gypsum amount), and calcium salt was converted into calcium hydroxide.
The results are shown in Tables 3-5.

7) Measurement of the content of the alkali sulfate compound in the cement composition The content of the alkali sulfate compound in each cement composition is the amount of Na and K according to the method for analyzing the water-soluble component of cement (JCAS I-04). It was measured, shown in Table 3-5 and the results obtained by the sulfuric acid alkali compound content _{over Na} 2 SO ₄ conversion was total content as _Na 2 SO ₄ and _K 2 SO _4, respectively.

8) Slaked lime (calcium hydroxide) / C ₁₂ A ₇ series mineral phase (mass ratio of content), gypsum / C ₁₂ A ₇ series mineral phase (mass ratio of content), lithium carbonate / C ₁₂ A ₇ series mineral Phase (mass ratio of content)
The content of C ₁₂ A ₇ mineral phase of each cement composition than the value shown in Table 3-5, the content of slaked lime, the content of the gypsum content and lithium carbonate (anhydrite equivalent) (lithium conversion) more, slaked lime (calcium _{hydroxide) / C} 12 _{A 7} based mineral phase (weight ratio: weight%), gypsum (anhydrite _{equivalent) / C} 12 _{A 7} based mineral phase (weight ratio), lithium carbonate (Li conversion) / The C ₁₂ A ₇ series mineral phase (mass ratio: mass%) was calculated.
The results are shown in Tables 3-5.

7) Preparation of cement mortar composition Each of the above cement compositions (Examples 1 to 17, Comparative Examples 1 to 15, Control Example), sodium gluconate and tartaric acid are blended in the blending ratios shown in Tables 3 to 5. Each cement mortar composition was prepared. In Tables 3 to 5, sodium gluconate (gluconic acid equivalent) and tartaric acid are blended in the proportions shown in Tables 3 to 5 below with respect to 100 parts by mass of each cement composition. Each cement mortar composition was used. The cement composition as a control example is early-strength Portland cement (PC: manufactured by Sumitomo Osaka Cement Co., Ltd.) itself.
In Tables 3 to 5, sodium gluconate shows a value in terms of gluconic acid.

8) Preparation of mortar Each cement mortar composition (Examples 1 to 17, Comparative Examples 1 to 15, Control Example) and fine aggregate (sand (silica sand)), water and admixture (manufactured by Kao Corporation, trade name) : Mighty 150) was blended as shown in Table 6 below and kneaded uniformly to obtain each mortar.
In addition, sodium gluconate and tartaric acid in the cement mortar composition were used by dissolving them in water in advance.

9) Intensity measurement and flow value measurement For each of the mortars of Examples 1 to 17, Comparative Examples 1 to 15 and Control Examples obtained above, the intensity at 20 ° C. and the flow value at 20 ° C. were determined by JIS R. It was measured according to 5201.
The results are also shown in Tables 3 to 5 above.

10) Crack test Each mortar of Examples 1 to 17, Comparative Examples 1 to 15 and Control Examples obtained above 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 fixed by making a hole in the upper part of the formwork for a cylindrical specimen (φ5 × 10 cm) and inserting a bolt. 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 exhibits sufficient strength in a room temperature environment of about 20 ° C., has excellent hydration activity, exhibits good hardening performance, and causes initial shrinkage cracks due to self-shrinkage. Cement mortar and concrete that can be suppressed can be obtained, and can be applied to construction work of tunnels and lower spaces, civil engineering work, water stoppage work, road work, and building structures.

Claims (4)

(1) _{5 to 40% by mass of C 12} A ₇ series mineral, 0.5 to 1.0% by mass of alkali sulfate compound (sodium sulfate conversion), lithium carbonate (lithium equivalent) / C ₁₂ A ₇ series mineral phase mass ratio of the content is 0.05 to 3 (weight%), hydrated lime, quicklime and calcium salts (calcium hydroxide _equivalent) selected from the group consisting of calcium hydroxide _{/ C} 12 _{a 7} based content of mineral phases mass ratio of 3 to 40 (wt%), the mass ratio of the content of gypsum (anhydrite _{terms) / C} 12 _{a 7} mineral phase is 0.6 to 1.4, _{C 12} measured by X-ray diffraction A _7- based mineral phase containing a cement composition having a crystallite diameter of 150 to 500 nm and a lattice constant of 1.194 to 11.975 Å, (2) gluconate and (3) tartrate or tartrate, said cement composition. Gluconate (gluconic acid equivalent) is 0.05 to 0.6% by mass by external division and the tartrate or tartrate (tartrate acid equivalent) is 0.05 to 0.6% by mass with respect to the mass of the substance. A cement mortar-concrete composition characterized by containing%. 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) _{5 to 40% by mass of C 12} A ₇ series mineral, 0.5 to 1.0% by mass of alkali sulfate compound (sodium sulfate conversion), lithium carbonate (lithium equivalent) / C ₁₂ A ₇ series mineral phase mass ratio of 0.05 to 3% by weight of the content, slaked lime, the mass ratio of the content of quicklime and calcium salts (calcium hydroxide) selected from the group consisting of calcium hydroxide / C ₁₂ a ₇ mineral phases The mass ratio of the content of 3 to 40% by mass, gypsum (equivalent to anhydrous gypsum) / C ₁₂ A ₇ series mineral phase is 0.6 to 1.4, and the mass ratio of C ₁₂ A ₇ series mineral phase measured by X-ray diffraction is A cement composition having a crystallite diameter of 150 to 500 nm and a lattice constant of 11.94 to 11.975 Å, (2) gluconate, and (3) slaked acid or slaked salt were added to 100 parts by mass of the cement composition. On the other hand, it is characterized by blending 0.05 to 0.6 parts by mass of gluconate (equivalent to gluconic acid) and 0.05 to 0.6 parts by mass of the above-mentioned tartrate or tartrate (equivalent to tartrate). A method for producing a cement mortar / concrete composition. In the method for producing a cement mortar / concrete composition according to claim 3, the cement mortar / concrete composition is obtained by powdering a raw material, molding the powdered raw material, firing at 1250 to 1400 ° C., and molding after the firing. by cooling the body at a cooling rate 40 ° C. / min or less, the lattice constant of the _C 12 _{a 7} mineral phase crystallite diameter _C 12 _{a 7} mineral phase as measured by X-ray diffraction at 150~500nm 11. A method for producing a cement mortar-concrete composition, which is produced as 940 to 11.975 Å.

Images