JP2023028446A - Hydraulic cement composition and cement-concrete composition - Google Patents

Abstract

To provide a cement composition that prevents deterioration in strength due to displacement without impairing the features of alumina cement and has excellent neutralization resistance.SOLUTION: Provided is a hydraulic cement composition which contains 100 pts.mass of a binder composed of 5 to 90 pts.mass of alumina cement and 95 to 10 pts.mass of a latent hydraulic material, and also contains 5 to 300 pts.mass of a non-hydraulic compound, and in which the non-hydraulic compound is one kind of, or two or more kinds selected from a group consisting of γ-2CaO-SiO2, 3CaO-2SiO2, α-CaO-SiO2 and calcium magnesium silicate, and the non-hydraulic compound contains Li and a content ratio of Li in the non-hydraulic compound is 0.001 to 1.0 mass% in terms of oxide.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to hydraulic cement compositions and cement-concrete compositions mainly used in the fields of civil engineering and construction.

Alumina cement has many unique properties, such as higher initial strength than Portland cement, hardening under low temperature conditions, and excellent durability against erosion by sulfates (see Non-Patent Document 1). .
However, concrete using alumina cement cannot avoid the problem of a decrease in long-term strength.
In addition, concrete using alumina cement has a problem that its resistance to carbonation is lower than concrete using Portland cement of the same strength.

The cause of these problems with alumina cement is that at room _temperature , _{CaO.Al2O3.10H2O} (CAH10) _, the main _{hydrate of} alumina cement _, becomes _{3CaO.Al2O3.6H2O} ( _C3AH2O ). ₆ ) is unavoidable, and the porosity increases with this transition, resulting in a decrease in strength and poor neutralization resistance.
For this reason, in the civil engineering and construction fields, despite its excellent initial strength and high durability, the use of alumina cement for structural members has been avoided, and it has been used exclusively as a castable refractory lining material for high-temperature furnaces. rice field.
Known techniques for preventing the transition of the main hydrates of this alumina cement include a method of using granulated blast furnace slag in combination, a method of using calcium carbonate in combination, and a method of using gypsum in combination (Patent See Document 1, Patent Document 2, Non-Patent Document 2, and Non-Patent Document 3).

However, although these methods can prevent the reduction in strength due to transfer, they do not consider neutralization resistance, and higher neutralization resistance has been desired.

W. Chernin, Cement and Concrete Chemistry, pp. 181-193, Gihodo Publishing, 1969 Fentiman, C.H.: Cement and Concrete Research, Vol.15, No.4, pp.622-630, 1985 Tomomitsu Sugi et al.: Annual Report of Cement Technology, No.30, pp.118-122, 1976

JP-A-60-180945 JP-A-2005-53723

As a result of diligent efforts, the present inventors have solved the problems of the prior art by using a specific material, preventing a decrease in strength due to transfer without impairing the characteristics of alumina cement, and furthermore neutralization resistance. The present inventors have completed the present invention based on the knowledge that a hydraulic cement composition using an alumina cement having excellent properties can be obtained.

100 parts by mass of a binder consisting of 5 to 90 parts by mass of alumina cement and 95 to 10 parts by mass of a latent hydraulic material, and 5 to 300 parts by mass of a non-hydraulic compound, wherein the non-hydraulic The compound is one or more selected from the group consisting of γ-2CaO·SiO ₂ , 3CaO·2SiO ₂ , α-CaO·SiO ₂ and calcium magnesium silicate, and the non-hydraulic compound contains Li. and the content of Li in the non-hydraulic compound is 0.001 to 1.0% by mass in terms of oxide.
Further, the present invention is a hydraulic cement composition in which the content of sulfur in the non-hydraulic compound is 1% by mass or less in terms of oxides, and a cement-concrete composition containing the hydraulic cement composition.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to obtain a cement composition that prevents a decrease in strength due to transfer without impairing the features of alumina cement, and is also excellent in neutralization resistance.

The present invention will be described in detail below.
Parts and percentages used in the present invention are based on mass unless otherwise specified.
The term "cement concrete" as used in the present invention is a generic term for cement paste, mortar and concrete, and the term "cement concrete composition" as used in the present invention is a generic term for cement compositions, mortar compositions and concrete compositions. It is something to do.

<Alumina cement>
Although any kind of commercially available alumina cement can be used as the alumina cement used in the present invention, those specified in the former JIS R 2511:1995 "Alumina cement for refractories" are preferred.

<Latent hydraulic material>
The latent hydraulic substance used in the present invention is not particularly limited, and specific examples include quenched slag fine powder such as granulated blast furnace slag, fly ash, silica fume, and rice husk ash (rice husk ash). It is possible to use one or more of these in the present invention.
The amount of the latent hydraulic material to be used is 10 to 95 parts by mass, preferably 50 to 80 parts by mass, per 100 parts by mass of the binder consisting of the alumina cement and the latent hydraulic material. When the amount of the latent hydraulic substance used is 10 to 95 parts by mass, the effect of preventing alumina cement hydrate transition is increased, and the desired strength can be obtained.

<Non-hydraulic compound>
The non-hydraulic compound of the present invention is one or more selected from the group consisting of γ-2CaO·SiO ₂ , 3CaO·2SiO ₂ , α-CaO·SiO ₂ and calcium magnesium silicate, and is non-hydraulic. It is preferable that the compound contains Li, and the content of Li in the non-hydraulic compound is 0.001 to 1.0% by mass in terms of oxide. In addition, the content of Li in the non-hydraulic compound is preferably 0.005 to 1.0% by mass in terms of oxide, more preferably 0.010 to 0.90% by mass. More preferably, it is 0.015 to 0.80% by mass. It is presumed that this predetermined amount of Li promotes the formation of vaterite, which is a type of calcium carbonate, in the carbonation of CSH (calcium silicate hydrate). It is thought that a denser cured state is obtained, and the neutralization resistance tends to be higher.
Here, "contains Li in the non-hydraulic compound" means that the non-hydraulic compound contains Li ₂ O as a chemical composition (existence can be confirmed by ICP emission spectrometry), but X-ray diffraction It refers to a state in which Li ₂ O is not identified by measurement (a clear peak of Li ₂ O is not observed), and simply refers to a state in which a non-hydraulic compound and a Li compound are not physically mixed. Such a state can be obtained by mixing each raw material and heat-treating it at a high temperature of 1,000° C. or more. Each component and the like will be described below.

(γ-2CaO-SiO ₂ )
γ-2CaO.SiO ₂ is a compound represented _by 2CaO.SiO ₂ and is known as a low temperature phase _. It is completely different from β-2CaO·SiO ₂ . All of these are represented by 2CaO.SiO ₂ , but have different crystal structures and densities.

( _3CaO.2SiO2 )
3CaO.2SiO ₂ is a mineral containing CaO in pseudowollastonite and is called rankinite. Although it is a chemically stable mineral with no hydration activity, it has a relatively large carbonation (salt) promoting effect.

(α-CaO.SiO ₂ )
α-CaO·SiO ₂ (α-type wollastonite) is a compound represented by CaO·SiO ₂ and is known as a high-temperature phase. β-CaO·SiO ₂ is a low-temperature phase. They are completely different. All of these are represented by CaO.SiO ₂ , but have different crystal structures and densities.

Naturally occurring wollastonite is the low temperature phase β-CaO.SiO ₂ . β-CaO SiO ₂ has needle- _like crystals and is used as an inorganic fibrous material such as wollastonite fiber. There is no salinization promoting effect.

(calcium magnesium silicate)
Calcium magnesium silicate is a general term for CaO--MgO-- _SiO.sub.2 -based compounds, and in the present embodiment, it is Merwinite represented by _{3CaO.MgO.2SiO.sub.2} ( _{C.sub.3MS.sub.2} ) _. Mervinite achieves a relatively large carbonation (salinization) promoting effect.

<Li>
The above non-hydraulic compounds may be one or two or more, but the content of Li in the non-hydraulic compound is 0.001 to 1.0% by mass in terms of oxide, and 0.005 to 0.005 It is preferably 1.0% by mass, more preferably 0.010 to 0.90% by mass, even more preferably 0.015 to 0.80% by mass. When the Li content is 0.001% or more and 1.0% by mass or less in terms of oxide, the effect of promoting carbonation can be easily obtained. The content of Li in terms of oxide can be measured by the method described in Examples.
When two or more non-hydraulic compounds are used, the content of Li means the content of Li in terms of oxide with respect to the total of two or more non-hydraulic compounds.

Among the above non-hydraulic compounds, especially γ-2CaO SiO ₂ is accompanied by a pulverization phenomenon called dusting during production, so it requires less energy for pulverization than other compounds, It is preferable in that the neutralization promoting effect is relatively large, and on the other hand, when combined with alumina cement at a low water binder ratio, the neutralization suppressing effect is very large.

The non-hydraulic compound according to the present embodiment is obtained by blending CaO raw material, SiO ₂ raw material, MgO raw material and Li raw material in a predetermined molar ratio and heat-treating the mixture. CaO raw materials include, for example, calcium carbonate such as limestone, calcium hydroxide such as slaked lime, by-product slaked lime such as acetylene by-product slaked lime, fine powder generated from waste concrete mass, and the like. Examples of SiO ₂ raw materials include silica stone, clay, and various siliceous dusts generated as industrial by-products such as silica fume and fly ash. Examples of MgO raw materials include magnesium hydroxide, basic magnesium carbonate, and dolomite. Moreover, lithium carbonate etc. can be mentioned as a Li raw material. If the CaO raw material, SiO ₂ raw material, or MgO raw material contains Li, it is not necessary to newly add the Li raw material. From the reduction of non-energy-derived CO ₂ emissions during heat treatment, one selected from industrial by-products containing CaO, such as by-product slaked lime, fine powder generated from waste concrete mass, municipal garbage incineration ash and sewage sludge incineration ash, or Two or more types can be used. Among them, it is more preferable to use by-product slaked lime, which contains less impurities than other industrial by-products.

As by-product slaked lime, by-product slaked lime produced in the acetylene gas production process by the calcium carbide method (there are wet and dry products depending on the acetylene gas production method), and the wet dust collection process of the calcium carbide electric furnace. Examples include acetylene by-product slaked lime such as by-product slaked lime contained in the dust captured by. The by-product slaked lime contains, for example, 65 to 95% by mass (preferably 70 to 90% by mass) of calcium hydroxide, 1 to 10% by mass of calcium carbonate, and 0.1 to 6.0% of iron oxide. % by mass (preferably 0.1 to 3.0% by mass). These ratios are measured by fluorescent X-ray analysis and weight loss determined by differential thermogravimetric analysis (TG-DTA) (Ca(OH) ₂ : around 405°C to 515°C, CaCO ₃ : around 650°C to 765°C). can be confirmed by The volume average particle diameter measured by laser diffraction/scattering method is about 50 to 100 μm. Furthermore, in JIS K 0068 "Method for Determining Moisture Content of Chemical Products", the moisture content measured by the loss-on-drying method is preferably 10% by mass or less. Further, sulfur compounds such as CaS, Al ₂ S ₃ and CaC ₂ ·CaS may be contained, but the content is preferably 2% by mass or less.

The above heat treatment at a high temperature of 1,000° C. or higher is not particularly limited, but can be performed, for example, by using a rotary kiln or an electric furnace. Although the heat treatment temperature is not uniquely determined, it is usually carried out in the range of about 1,000 to 1,800.degree. C., and often in the range of about 1,200 to 1,600.degree.

This embodiment can also use industrial by-products containing the non-hydraulic compounds previously described. At this time, impurities coexist. Such industrial by-products include steelmaking slag and the like.

Although the CaO raw material and the _SiO2 raw material may contain impurities, they pose no particular problem as long as they do not impair the effects of the present invention. Specific examples of impurities include Al ₂ O ₃ , Fe ₂ O ₃ , TiO ₂ , MnO, Na ₂ O, K ₂ O, S, P ₂ O ₅ , F, B ₂ O ₃ and chlorine. be done. Coexisting compounds include free calcium oxide, calcium hydroxide, calcium aluminate, calcium aluminosilicate, calcium ferrite, calcium aluminoferrite, calcium phosphate, calcium borate, magnesium silicate, leucite (K ₂ O, Na ₂ O).Al ₂ O ₃ .SiO ₂ , spinel MgO.Al ₂ O ₃ , magnetite Fe ₃ O ₄ , and sulfur compounds such as CaS, Al ₂ S ₃ and CaC ₂ .CaS mentioned above.

Among these impurities, the content of S (sulfur) in the non-hydraulic compound is preferably 1.0% by mass or less, more preferably 0.7% by mass or less in terms of oxide (SO ₃ ). More preferably, it is 0.5% by mass or less. When the content is 1.0% by mass or less, a sufficient effect of promoting carbonation (salting) can be obtained, and the aggregation and hardening properties can be set within an appropriate range. The content of S in terms of oxide (SO ₃ ) can be adjusted by adding, for example, calcium sulfate to the non-hydraulic compound, and can be confirmed by measurement by fluorescent X-ray analysis. Note that S (sulfur) in the non-hydraulic compound may be present in an amount of about 0.2% by mass in terms of oxide.

The content of γ-2CaO·SiO ₂ in the non-hydraulic compound is preferably 35% by mass or more, more preferably 45% by mass or more. Also, the upper limit of the content of γ-2CaO·SiO ₂ is not particularly limited. Among steelmaking slags, electric furnace reduction slag or stainless steel slag having a high γ-2CaO·SiO ₂ content is preferred.

In addition, from the viewpoint of making the effect of the non-hydraulic compound more likely to be expressed, the chemical components include 0.001 to 1.0 parts by mass of Li ₂ O and 45 to 45 parts by mass of CaO in 100 parts by mass of the non-hydraulic compound. It preferably contains 70 parts by weight, 30 to 55 parts by weight of SiO ₂ and 0 to 10 parts by weight of Al ₂ O ₃ . The Li ₂ O content can be measured by the method described in Examples below. Also, CaO, SiO ₂ and Al ₂ O ₃ can be measured by fluorescent X-ray analysis.
As chemical components, in 100 parts by mass of the non-hydraulic compound, Li ₂ O is 0.002 to 0.5 parts by mass, CaO is 60 to 70 parts by mass, SiO ₂ is 30 to 45 parts by mass, and Al ₂ O ₃ is It is more preferable to contain 0.5 to 5 parts by mass.
Furthermore, as chemical components, the total of Li ₂ O, CaO, SiO ₂ , and Al ₂ O ₃ in 100 parts by mass of the non-hydraulic compound is preferably 90 parts by mass or more, and is 95 to 100 parts by mass. is more preferable.

Examples of the method for quantifying the non-hydraulic compound in the non-hydraulic compound include the Rietveld method using powder X-ray diffraction.

Although the Blaine specific surface area of the non-hydraulic compound is not particularly limited, it is preferably 1,500 cm ² /g or more, and the upper limit is preferably 8,000 cm ² /g or less. Among them, 2,000 to 6,000 cm ² /g is more preferable, and 4,000 to 6,000 cm ² /g is most preferable. When the Blaine specific surface area is 2,000 cm ² /g or more, good material separation resistance is obtained, and the carbonation (salt) promotion effect is sufficient. In addition, when it is 8,000 cm ² /g or less, the power required for pulverization is not large, which is economical, and weathering is suppressed, so that deterioration of quality over time can be suppressed.

The amount of the non-hydraulic compound used is 5 to 300 parts by mass, more preferably 10 to 100 parts by mass, per 100 parts by mass of the binder composed of alumina cement and latent hydraulic material. When the amount of the non-hydraulic compound used is 5 to 300 parts by mass with respect to 100 parts by mass of the binder consisting of the alumina cement and the latent hydraulic material, the effect of suppressing neutralization can be obtained.

The particle size of the hydraulic cement composition of the present invention ^is not particularly limited because it depends on the purpose and application of use. ,000 cm ² /g is more preferred. If it is less than 3,000 cm ² /g, the effects of the present invention may not be sufficiently obtained.

The amount of water used in the present invention varies depending on the type and composition of the materials used, so it is not uniquely determined, but usually the water / alumina cement ratio is preferably 25 to 60% by mass, and 30 to 50% by mass. is more preferred. When the content is 25% by mass or more, the necessary amount of the water reducing agent used in combination for obtaining a predetermined workability does not become excessive, and when it is 60% by mass or less, sufficient strength development is obtained.

In the present invention, in addition to the hydraulic cement composition of the present invention, an aggregate, a water reducing agent, a high performance water reducing agent, an AE water reducing agent, a high performance AE water reducing agent, a fluidizing agent, an antifoaming agent, a thickener, an anti- Cement admixtures or cement admixtures such as rust agents, antifreeze agents, polymer dispersions for cement admixture, shrinkage reducing agents, setting modifiers, clay minerals such as bentonite, and anion exchangers such as hydrotalcite, vinylon fibers, One or more of fibrous materials such as acrylic fibers and carbon fibers can be used as long as the object of the present invention is not substantially impaired.

The method of mixing each material in the present invention is not particularly limited, and each material may be mixed at the time of construction, or a part or all of them may be mixed in advance.
As a mixing device, any existing device can be used, and examples thereof include a tilting mixer, an omni mixer, a Henschel mixer, a V-type mixer, and a Nauta mixer.

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to these examples.

<Experimental example>
The binder contains the alumina cement and the latent hydraulic substance shown in Table 1, the total amount is 100 parts by mass, the water / alumina cement ratio is 45% by mass, and the binder / sand ratio is 1/3 (mass ratio). Then, a mortar composition was prepared by replacing the non-hydraulic compound shown in Table 1 with the same amount of sand as the non-hydraulic compound, and stirred to prepare a mortar. At this time, the water reducing agent was added to the mortar so that the flow value of the mortar was 175±5 cm. The prepared mortar was removed from the mold at a material age of 1 day, and cured in water at 20° C. to prepare a hardened mortar. For the hardened mortar, compressive strength was measured and a neutralization acceleration test was conducted. Table 1 shows the results.

[Materials used]
・Alumina cement: commercial product, Blaine value 4,750 cm ² /g, density 3.01 g/cm ³
・Latent hydraulic substance A: Ground granulated blast furnace slag, commercial product, Blaine value 6,200 cm ² /g, density 2.90 g/cm ³
・Latent hydraulic substance B: fly ash, commercial product, Blaine value 4,400 cm ² /g, density 2.35 g/cm ³
・Latent hydraulic substance C: silica fume, commercial product, Blaine value 135,000 cm ² /g, density 2.30 g/cm ³
Latent hydraulic material D: A mixture of latent hydraulic material A and latent hydraulic material B at a mass ratio of 1:1.
• Non-hydraulic compound A: Li-containing γ-2CaO·SiO ₂ . First-class calcium carbonate and first-class silicon dioxide are mixed at a molar ratio of 2:1, and the content of Li in the mixture is 0.01% by mass in terms of oxide (Li ₂ O) (of which First-class lithium carbonate and calcium sulfate were mixed so that the content of _SO3 was 0.5% by mass (internally divided substitution), and the content of Li and the content of _SO3 were measured by fluorescence. Confirmed by X-ray analysis. The mixture was heat-treated at 1,400° C. for 2 hours, allowed to cool to room temperature, and pulverized to a Blaine specific surface area of 4,000 cm ² /g.
- Non-hydraulic compound A1: The content of Li in the non-hydraulic compound is 0.001% by mass (internal substitution) in terms of oxide (Li ₂ O), the content of SO ₃ is 0.5% by mass ( The same as non-hydraulic compound A, except that first-class lithium carbonate and calcium sulfate were mixed so as to be internal substitution), and the content of Li and the content of _SO3 were confirmed by fluorescent X-ray analysis. was made.
- Non-hydraulic compound A2: The content of Li in the non-hydraulic compound is 1.0% by mass (internal substitution) in terms of oxide (Li ₂ O), and the content of SO ₃ is 1.0% by mass ( The same as non-hydraulic compound A, except that first-class lithium carbonate and calcium sulfate were mixed so as to be internal substitution), and the content of Li and the content of _SO3 were confirmed by fluorescent X-ray analysis. was made.
- Non-hydraulic compound A3: The content of Li in the non-hydraulic compound is 0.0005% by mass (internal substitution) in terms of oxide (Li ₂ O), and the content of SO ₃ is 1.0% by mass ( The same as non-hydraulic compound A, except that first-class lithium carbonate and calcium sulfate were mixed so as to be internal substitution), and the content of Li and the content of _SO3 were confirmed by fluorescent X-ray analysis. was made.
· Non-hydraulic compound A4: The content of Li in the non-hydraulic compound is 1.5% by mass (internal substitution) in terms of oxide (Li ₂ O), the content of SO ₃ is 1.2% by mass ( The same as non-hydraulic compound A, except that first-class lithium carbonate and calcium sulfate were mixed so as to be internal substitution), and the content of Li and the content of _SO3 were confirmed by fluorescent X-ray analysis. was made.
• Non-hydraulic compound B: Li-containing α-CaO·SiO ₂ . First-class calcium carbonate and first-class silicon dioxide were mixed at a molar ratio of 1:1, and the content of Li in the mixture was 0.0005 to 1.00 in terms of oxide (Li ₂ O). Reagent grade lithium carbonate was mixed to 1% (internal substitution). The mixture was heat-treated at 1,500° C. for 2 hours, allowed to cool to room temperature, and pulverized to a Blaine specific surface area of 4,000 cm ² /g.
• Non-hydraulic compound C: β-2CaO·SiO ₂ . Reagent grade 1 calcium carbonate and reagent grade 1 silicon dioxide are mixed at a molar ratio of 2:1, heat-treated at 1,400° C. for 2 hours, allowed to cool to room temperature, pulverized and analyzed by XRD to obtain γ-2CaO. The same heat treatment was repeated until the _SiO2 peak was no longer confirmed. After confirming the peak of only β-2CaO·SiO ₂ , the Blaine specific surface area was set to 4,000 cm ² /g.
The content of Li in terms of oxide in the non-hydraulic compound was measured by an ICP emission spectrometer (manufactured by Hitachi High-Tech Science, VISTA-PRO). Then, from the absolute calibration curve method using a diluted mixture for ICP (XSTC-22 manufactured by SPEX), it was confirmed that the Li content was the same as the charged amount. In addition, the measurement conditions are as follows.
・ Li measurement wavelength: 670.783 nm
・ BG correction: fitting curve method ・ Standard solution for calibration curve: Used by diluting the mixed solution for ICP (manufactured by SPEX, XSTC-22) ・ Calibration curve range: 0 to 5 mg / L (0 mg / L, 0.1 mg /L, 0.5mg/L, 1mg/L, 5mg/L 5-point calibration curve)
Quantification by absolute calibration curve method Further, the S content in terms of oxide in the non-hydraulic compound was measured by fluorescent X-ray analysis.
・Water: Tap water ・Water reducing agent: Naphthalene sulfonic acid-based high performance water reducing agent, commercial product ・Sand: JIS standard sand

[Measuring method]
· Compressive strength A test specimen with dimensions of 4 × 4 × 16 cm was prepared, cured in water at 20°C according to JIS R 5201, and the compressive strength was measured at the time of 28 days of material age. Furthermore, the compressive strength was measured after being immersed in water for one year under an environment of 60°C. Three samples were measured for each example, and the average value was taken as the compressive strength shown in Table 1.
・ Neutralization depth A specimen with dimensions of 4 × 4 × 16 cm was prepared, and after curing in water at 20 ° C until the age of 28 days, 30 ° C under atmospheric pressure, relative humidity 60%, carbon dioxide gas concentration 5% We promoted neutralization in the environment of Eight weeks after the start of accelerated neutralization, a bending load was applied to the specimen to prepare a cross section substantially perpendicular to the longitudinal direction of the specimen. Then, according to JIS A 1152, a phenolphthalein alcohol solution was applied to the cross section, and the distance from the outer edge of the cross section to the reddish-purple colored portion was measured along the outer edge with a vernier caliper at intervals of 10 mm. , and the average value thereof was taken as the neutralization depth shown in Table 1.

From Table 1, it can be seen that the compressive strength of the hardened mortars shown in Examples after one year of immersion does not decrease as compared with the compressive strength of 28 days of material age, so that it is possible to prevent a decrease in strength due to transfer. Since the neutralization depth is relatively small, it was found to be excellent in neutralization resistance.

<Modification>
When preparing the mortar composition according to the above examples, coarse aggregate may be added to prepare a concrete composition. In this case, the concrete is prepared by stirring, cured, and hardened. You can make a body. Further, when preparing the mortar composition according to the above examples, the amount of sand may be 0 parts by mass (no sand added) to prepare a cement composition (hydraulic cement composition). In this case, a cement paste can be prepared by stirring, and then cured to prepare a hardened cement body. Such a hardened concrete or hardened cement can prevent a decrease in strength due to transfer and is excellent in neutralization resistance, as in the above examples.

Claims (3)

100 parts by mass of a binder consisting of 5 to 90 parts by mass of alumina cement and 95 to 10 parts by mass of a latent hydraulic material, and 5 to 300 parts by mass of a non-hydraulic compound,
the non-hydraulic compound is one or more selected from the group consisting of γ-2CaO·SiO ₂ , 3CaO·2SiO ₂ , α-CaO·SiO ₂ and calcium magnesium silicate;
A hydraulic cement composition containing Li in the non-hydraulic compound, wherein the content of Li in the non-hydraulic compound is 0.001 to 1.0% by mass in terms of oxide. 2. The hydraulic cement composition according to claim 1, wherein the content of sulfur in said non-hydraulic compound is 1% by mass or less in terms of oxide. A cement-concrete composition comprising the hydraulic cement composition according to claim 1 or 2.