AU2022419893A1 - Cement composition and method for producing same - Google Patents

Abstract

Provided are: a cement composition which has excellent mortar long-term strength even when the content of MgO in a Portland cement is high; and a method for producing a cement composition, the method being able to improve mortar long-term strength even when the content of MgO in a Portland cement is high.　This cement composition comprises: a Portland cement which satisfies (1) and (2); and 0.001-0.025 parts by mass of an alkanolamine with respect to 100 parts by mass of the Portland cement. (1): 0.55 ≤ MgO/Fe

Description

DESCRIPTION

Title of Invention

CEMENT COMPOSITION AND METHOD FOR PRODUCING SAME

Technical Field

[0001]

The present invention relates to a cement composition

and a method for producing the same.

Background Art

[0002]

Depending on raw material circumstances, a clinker

contains a minor component such as Mg, Na, or K, and the

content thereof changes.

For example, in Non Patent Literature No. 1, it is

known that a high MgO cement is substituted with Ca that is

the same alkali earth metal, and as disclosed in Non Patent

Literature No. 2, it is also known that, since the amount

of belite relatively decreases as a result of the

substitution, a long-term strength at 28-day age or the

like decreases. Non Patent Literature No. 3 obtains a

finding that the strength is likely to be improved even at

high MgO content by increasing S03.

[0003]

In addition, Patent Literature No. 1 discloses that,

when the MgO content in a calcined cement clinker exceeds

1.0% by mass, the strength development of cement at long

term age decreases, and thus raw materials are mixed such

that the MgO content in the calcined Portland cement

clinker is adjusted to 1.0% by mass or less.

Further, Patent Literature No. 2 discloses a cement

clinker where the content rate of 2CaO-SiO2 calculated by

Bogue calculation is 30% to 60% by mass, in which in the

cement clinker, the content rate of MgO is 1.2% by mass or

more and less than 1.9% by mass, and the content rate of S03

is 0.4% to 1.2% by mass.

Citation List

Patent Literature

[0004]

[Patent Literature No. 1] Japanese Laid-open Patent

Publication No. 2009-013023

[Patent Literature No. 2] Japanese Laid-open Patent

Publication No. 2018-65750

Non Patent Literature

[0005]

[Non Patent Literature No. 1] Crystal Chemistry of

Tricalcium Silicate Solid Solution, in 5th I.S.C.C, Vol. 1,

61-66 (1969)

[Non Patent Literature No. 2] Cement Technology

Annual Report Vol. 22, 62-66 (1968)

[Non Patent Literature No. 3] Cement Science and

Concrete Technology, Vol. 70

Summary of Invention

Technical Problem

[0006]

However, it is difficult to control the adjustment of

the high MgO cement component, and with the methods

described in Non Patent Literatures No. 1 to 3, the long

term strength cannot be stably maintained. Regarding this

problem, limestone as a raw material produced from a mine

may sometimes contain a large amount of dolomite, and the

produced cement has high MgO, which causes a variation in

the quality performance of concrete or the like. Therefore,

as in Patent Literature No. 1, the MgO content needs to be

decreased. Patent Literature No. 2 describes that, even

when the content rate of MgO in the cement is high, a

decrease in the long-term strength development of the

cement can be prevented. Nevertheless, the upper limit of

the MgO content rate needs to be less than 1.9% by mass.

[0007]

An object of the present invention is to provide: a

cement composition where a long-term strength of mortar is excellent even when a MgO content in a Portland cement is high; and a method for producing a cement composition where a long-term strength of mortar can be improved even when a

MgO content in a Portland cement is high.

Solution to Problem

[00081

The present invention provides the following <1> to

<10>.

<1> A cement composition including:

a Portland cement that satisfies (1) and (2) below;

and

0.001 to 0.025 parts by mass of alkanolamine with

respect to 100 parts by mass of the Portland cement, in

which

(1) 0.55 MgO/Fe2O3 + CL'S0 3 /SO 3 0.95, and

(2) 0 AC 4 AF,

in (1), MgO represents a mass (% by mass) of MgO in

the Portland cement, Fe203 represents a mass (% by mass) of

Fe203 in the Portland cement, SO 3 represents an amount (% by

mass) of the Portland cement in terms of S03, and CL'SO 3

represents an amount (% by mass) of a clinker of the

Portland cement in terms of S03, and

in (2), AC 4 AF represents a difference (R.C 4 AF - B.C4AF)

between a mass (% by mass) of R.C 4AF and a mass (% by mass) of B.C 4AF, where R.C 4AF represents a C 4 AF value of the

Portland cement measured by a powder X-ray diffractometer,

B.C 4 AF represents 3.04 x Fe203, and Fe203 in B.C4AF

represents a mass (% by mass) of Fe203 in the Portland

cement.

[00091

<2> The cement composition according to <1>,

in which in (1), MgO/Fe2O3 exceeds 0.35.

<3> The cement composition according to <1> or <2>,

in which the Portland cement is a normal Portland

cement where a content of C 3 S is 45% to 75% by mass, a

content of C 2 S is 5% to 25% by mass, a content of C 3 A is 7%

to 11% by mass, and a content of C 4 AF is 7% to 11% by mass

when calculated by Bogue calculation.

<4> The cement composition according to any one of

<1> to <3>,

in which a content of the alkanolamine is 0.005 to

0.02 parts by mass with respect to 100 parts by mass of the

Portland cement.

<5> The cement composition according to any one of

<1> to <4>,

in which the alkanolamine is at least one selected

from the group consisting of diethanol isopropanolamine,

triisopropanolamine, ethanol diisopropanolamine,

triethanolamine, N-methyldiethanolamine, and N-n- butyldiethanolamine.

[0010]

<6> A method for producing a cement composition, the

method including:

mixing a Portland cement that satisfies (1) and (2)

below and 0.001 to 0.025 parts by mass of alkanolamine with

respect to 100 parts by mass of the Portland cement, in

which

(1) 0.55 MgO/Fe2O3 + CL'S0 3 /SO 3 0.95, and

(2) 0 AC 4 AF,

in (1), MgO represents a mass (% by mass) of MgO in

the Portland cement, Fe203 represents a mass (% by mass) of

Fe203 in the Portland cement, SO 3 represents an amount (% by

mass) of the Portland cement in terms of SO 3 , and CL'SO 3

represents an amount (% by mass) of a clinker of the

Portland cement in terms of SO 3 , and

in (2), AC 4 AF represents a difference (R.C 4 AF - B.C4AF)

between a mass (% by mass) of R.C 4AF and a mass (% by mass)

of B.C4AF, where R.C4AF represents a C 4 AF value of the

Portland cement measured by a powder X-ray diffractometer,

B.C 4 AF represents 3.04 x Fe203, and Fe203 in B.C4AF

represents a mass (% by mass) of Fe203 in the Portland

cement.

[0011]

<7> The method for producing a cement composition according to <6>, in which in (1), MgO/Fe2O3 exceeds 0.35.

<8> The method for producing a cement composition

according to <6> or <7>,

in which the Portland cement is a normal Portland

cement where a content of C 3 S is 45% to 75% by mass, a

content of C 2 S is 5% to 25% by mass, a content of C 3 A is 7%

to 11% by mass, and a content of C 4 AF is 7% to 11% by mass

when calculated by Bogue calculation.

<9> The method for producing cement composition

according to any one of <6> to <8>,

in which an addition amount of the alkanolamine is

0.005 to 0.02 parts by mass with respect to 100 parts by

mass of the Portland cement.

<10> The method for producing cement composition

according to any one of <6> to <9>,

in which the alkanolamine is at least one selected

from the group consisting of diethanol isopropanolamine,

triisopropanolamine, ethanol diisopropanolamine,

triethanolamine, N-methyldiethanolamine, and N-n

butyldiethanolamine.

Advantageous Effects of Invention

[0012]

According to the present invention, it is possible to provide: a cement composition where a long-term strength of mortar is excellent even when a MgO content in a Portland cement is high; and a method for producing a cement composition where a long-term strength of mortar can be improved even when a MgO content in a Portland cement is high.

Brief Description of Drawings

[0013]

FIG. 1 is a graph where AC 4 AF values of Examples and

Comparative Examples under a condition** are plotted.

FIG. 2 is a graph where values of differences in

enhanced strength of mortar of Examples and Comparative

Examples at 7-day age and 28 age under a condition** are

plotted.

Description of Embodiments

[0014]

The notation of a numerical range of "AA to BB" in the

present specification means "AA or more and BB or less".

[0015]

<Cement Composition>

A cement composition according to the present

invention includes: a Portland cement that satisfies (1)

and (2) below; and 0.001 to 0.025 parts by mass of alkanolamine with respect to 100 parts by mass of the

Portland cement, in which

(1) 0.55 MgO/Fe2O3 + CL'S0 3 /SO 3 0.95, and

(2) 0 AC 4 AF,

in (1), MgO represents a mass (% by mass) of MgO in

the Portland cement, Fe203 represents a mass (% by mass) of

Fe203 in the Portland cement, SO 3 represents an amount (% by

mass) of the Portland cement in terms of SO 3 , and CL'SO 3

represents an amount (% by mass) of a clinker of the

Portland cement in terms of SO 3 , and

in (2), AC 4 AF represents a difference (R.C 4 AF - B.C4AF)

between a mass (% by mass) of R.C 4AF and a mass (% by mass)

of B.C4AF, where R.C4AF represents a C 4 AF value of the

Portland cement measured by a powder X-ray diffractometer,

B.C 4 AF represents 3.04 x Fe203, and Fe203 in B.C4AF

represents a mass (% by mass) of Fe203 in the Portland

cement.

Hereinafter, the Portland cement that satisfies (1)

and (2) will be referred to as "the Portland cement

according to the present invention" or simply "the cement

according to the present invention".

In other words, the cement composition according to

the present invention contains a clinker, gypsum, and

alkanolamine, in which the Portland cement containing the

clinker and the gypsum satisfies (1) and (2), and the content of the alkanolamine is in the above-described range.

[0016]

When the MgO content rate in the cement is high, for

example, 1.30% by mass or more, hydration of calcium

decreases, and the strength of mortar or the like

relatively decreases.

It is known that in order to improve the strength, an

auxiliary agent such as alkanolamine is used. The strength

that is expected to be increased by alkanolamine is a

short-term strength at less than 7-day age, and conversely

a long-term strength tends to decrease.

However, by configuring the content of the cement

composition as described above, the long-term strength of

mortar can be improved. Although the reason for this is not

clear, it is presumed to be due to the following reasons.

[0017]

[Condition (1)]

Condition (1) is that "MgO/Fe2O3 + CL'S0 3 /SO3" is 0.55

to 0.95.

Although the details are not clear, it is considered

that the phenomenon in which the mass of MgO increases with

respect to the mass of Fe203 or in which the amount (by

mass) of the clinker in terms of SO 3 increases with respect

to the amount (by mass) of the cement in terms of SO 3 relates to solid solution of ferrite phase. "MgO/Fe2O3

+ CL'S0 3 /SO3" can be considered a so-called index representing

the amount of solid solution of ferrite phase.

The alkanolamine added together with the Portland

cement in the present invention has a function of

dissolving iron or the like in ferrite phase in gel for

uniform penetration to promote watertightness and to

improve the strength of mortar. Therefore, it is considered

that, by dissolving magnesium and SO 3 in ferrite phase, the

mortar strength enhancement effect by alkanolamine is

further improved, and the long-term strength of mortar can

be further improved.

[0018]

When "MgO/Fe2O3 + CL'S0 3 /SO3" is less than 0.55, the

amount of solid solution of ferrite phase is small, the

mortar strength enhancement effect by alkanolamine cannot

be sufficiently obtained, and the long-term strength of

mortar is not excellent.

When "MgO/Fe2O3 + CL'S0 3 /SO 3 " exceeds 0.95, the

strength enhancement effect by alkanolamine is not likely

to be obtained, the amount of each of alkanolamine,

unreacted MgO, and unreacted MgSO4 is excessive such that

expansion cracks occur, and the strength of mortar cannot

be maintained.

From the viewpoint of further improving the long-term strength of mortar, "MgO/Fe2O3 + CL'S0 3 /SO3" is preferably

0.60 to 0.90 and more preferably 0.70 to 0.80.

[0019]

Further, in Condition (1), MgO/Fe203 preferably

exceeds 0.35.

It is considered that the mass of MgO with respect to

the mass of Fe203 in the cement represents the amount of

solid solution of C 4 AF, and when MgO/Fe2O3 exceeds 0.35, the

solid solution of C 4 AF can be promoted.

From the viewpoint of increasing the amount of solid

solution of ferrite phase, MgO/Fe2O3 is preferably 0.36 to

0.60 and more preferably 0.40 to 0.50.

[0020]

From the viewpoint of increasing the amount of solid

solution of alkanolamine, MgO in Condition (1), that is,

the mass of MgO in the cement is preferably 3.5% by mass or

less, more preferably 0.5% to 3.0% by mass, and still more

preferably 1.0% to 2.5% by mass.

[0021]

From the viewpoint of stabilizing the solid solution

of ferrite phase, Fe203 in Condition (1), that is, the mass

of Fe203 in the cement is preferably 2.0% to 4.0% by mass,

more preferably 2.5% to 3.5% by mass, and still more

preferably 2.7% to 3.4% by mass.

[0022]

From the viewpoint of promoting the solid solution of

C 4 AF and ensuring cement flowability, CL'S0 3 in Condition

(1), that is, the amount of the clinker in terms of SO 3 is

preferably 2.5% by mass or less, more preferably 0.2% to

2.0% by mass, and still more preferably 0.5% to 1.5% by

mass.

[0023]

From the viewpoint of ensuring cement flowability, the

range of SO 3 that is the denominator of CL'S0 3 /SO 3 in

Condition (1), that is, the amount of the cement in terms

of SO 3 is preferably 3.5% by mass or less, more preferably

0.5% to 3.0% by mass, and still more preferably 1.5% to

2.5% by mass.

[0024]

[Condition (2)]

Condition (2) is that AC4 AF is 0 point or more.

0 point represents that, for example, when C 4 AF

(R.C4AF) obtained by Rietveld analysis is 10.1% by mass,

C 4 AF (B.C4AF) calculated by Bogue calculation is 10.1% by

mass.

AC 4 AF represents a difference (R.C 4AF - B.C4AF) between

a mass of R.C 4AF and a mass of B.C 4AF, which is a difference

between C 4 AF (R.C 4 AF) obtained by Rietveld analysis and C 4 AF

(B.C4AF) calculated by Bogue calculation. In Bogue

calculation, magnesium is not considered. Therefore, the amount of solid solution of MgO can be estimated from AC 4 AF, and when the MgO content in the cement increases, AC 4 AF also increases. In the present invention, from the viewpoint of improving the long-term strength of mortar under the high

MgO condition, the condition that AC 4 AF is 0 or more is

adopted.

An increase in the amount of dissolution of ferrite

phase in which MgO is dissolved by alkanolamine affects the

strength enhancement. Therefore, AC 4 AF is preferably 0.3 to

1.5 points and more preferably 0.5 to 1.5 points.

[0025]

R.C 4AF is obtained from the following step.

First, the cement is measured by X-ray diffraction to

obtain a profile. The obtained profile is analyzed using a

Rietveld method, and the quantitative analysis of cement

minerals is executed.

The minerals to be analyzed are set to C 3 S-M1 (Ml

phase), C 3 S-M3 (M3 phase), C 2 S-a'H (a'H phase), C 2 S-@ (@

phase), C3A-cubic (cubic crystal), C3A-ortho (orthorhombic

crystal), and C 4 AF. In the Rietveld analysis, a refinement

operation is executed based on basic crystal structure data

of each of the minerals using a lattice constant, a scale

factor, and the like as parameters such that a measured

profile and a theoretical profile are fitted. Finally, the

mass ratio of each of the minerals is calculated from the refined scale factor, and the content rate (% by mass) of

R.C 4 AF is obtained.

Specific measurement conditions of the X-ray

diffractometer are shown in Examples.

[0026]

The Portland cement in the present invention is not

particularly limited as long as it satisfies Conditions (1)

and (2) described above. Portland cement such as normal

Portland cement, high-early-strength Portland cement,

ultra-high-early-strength Portland cement, white Portland

cement, sulfate resistant Portland cement, moderate heat

Portland cement, or low-heat Portland cement, blended

cement obtained by mixing blast furnace slag, fly ash, a

siliceous admixture (pozzolan), and the like, or special

cement such as alumina cement can also be used. In

particular, cement where the amount of ferrite phase in

Bogue calculation is 6% by mass or more is suitable.

[0027]

More specifically, it is preferable that the Portland

cement used in the cement composition according to the

present invention is a normal Portland cement where a

content of C 3 S (3CaO-SiO2) is 45% to 75% by mass, a content

of C 2 S (2CaO-SiO2) is 5% to 25% by mass, a content of C 3 A

(3CaO•Al2O3) is 7% to 11% by mass, and a content of C4AF

(4CaO•Al2O3•FeO3) is 7% to 11% by mass when calculated by

Bogue calculation.

In addition, in the Portland cement used in the cement

composition according to the present invention, C 4 AF

(R.C4AF) obtained by Rietveld analysis is preferably 7.5% to

12% by mass.

[0028]

(C 3 S, C 2 S)

By adjusting the content of C 3 S in the cement to be

45% by mass or more, the strength enhancement effect

obtained by the addition of alkanolamine is high, the

strength of mortar is excellent, and the flowability is

excellent. By adjusting the content of C 3 S in the cement to

be 45% by mass or more, the content of C 2 S having a

relatively poor grinding properties is low. As a result,

the grinding time required to obtain a certain Blaine's

specific surface area of the cement composition is reduced,

overgrinding of mainly minerals (C 3 S, C 3 A, and C 4 AF) other

than C 2 S having excellent grinding properties is suppressed,

and an increase in Blaine's specific surface area is

suppressed. In addition, in the strength enhancement

mechanism by the addition of alkanolamine, by selectively

dissolving C 4 AF in the clinker, the contact opportunity of

C 4 AF and water adjacent to C 4 AF increases, hydration is

promoted, and the strength is enhanced. By suppressing the

overgrinding of the clinker, clinker particles present as a composite of the minerals are not likely to be present as a single mineral, the dissolution of C 4 AF is likely to lead to the promotion of hydration of C 4AF. Accordingly, the strength enhancement effect by the addition of alkanolamine is likely to be obtained.

By adjusting the content of C 3 S in the cement to be

75% by mass or less, the long-term compressive strength of

the concrete can be sufficiently maintained.

By adjusting the content of C 2 S in the cement to be 5%

by mass or more, the long-term compressive strength of the

concrete can be sufficiently maintained.

By adjusting the content of C 2 S in the cement to be

25% by mass or less, the initial compressive strength of

the concrete can be sufficiently maintained.

[0029]

From the viewpoint of enhancing the strength and the

flowability, the content of C 3 S in the cement is more

preferably 50% to 70% by mass.

[0030]

(C 4 AF, C 3 A)

By adjusting the content of C 4 AF in the cement to be

7% by mass or more, the dissolution of C4AF caused by the

addition of alkanolamine is promoted, the reaction of C 3 S is

promoted, and the significant strength enhancement effect

can be exhibited.

By adjusting the content of C 4 AF in the cement to be

11% by mass or less, the amount of ferric hydroxide gel

produced by the dissolution of Fe ions in C4AF can be

suppressed, and the coating of the clinker particle

surfaces can be suppressed. Therefore, the delay of

hydration can be prevented.

The total content of C 4 AF and C 3 A is constant at 18%

by mass, when the content of C4AF in the cement increases,

the content of C 3 A decreases, and when the content of C 4 AF

in the cement decreases, the content of C 3 A increases.

From the viewpoint of enhancing the strength and the

flowability, the content of C 4 AF in the cement increases is

preferably 7% to 9% by mass and more preferably 8% to 9% by

mass.

[0031]

[Alkanolamine]

The cement composition according to the present

invention contains 0.001 to 0.025 parts by mass of

alkanolamine with respect to 100 parts by mass of the

Portland cement clinker in the present invention.

The alkanolamine also acts as a strength enhancing

agent.

When the content of the alkanolamine in the cement

composition according to the present invention is less than

0.001 parts by mass with respect to 100 parts by mass of the Portland cement clinker, the strength enhancement effect cannot be obtained. When the content of the alkanolamine in the cement composition according to the present invention exceeds 0.025 parts by mass with respect to 100 parts by mass of the Portland cement clinker, the enhancement effect of the initial strength is significant.

However, at 28-day age, the hydration structure is coarse

due to the high initial hydration activity, and thus the

strength enhancement effect cannot be obtained.

From the above-described viewpoint, the content of the

alkanolamine in the cement composition according to the

present invention is preferably 0.005 to 0.02 parts by mass

with respect to 100 parts by mass of the Portland cement

clinker according to the present invention.

[0032]

Examples of the alkanolamine include monoethanolamine,

diethanolamine, triethanolamine, monoisopropanolamine,

diisopropanolamine, triisopropanolamine,

methylethanolamine, methylisopropanolamine, N-n

butylethanolamine, N-methyldiethanolamine, N-n

butyldiethanolamine, N-methyldiisopropanolamine, diethanol

isopropanolamine, diisopropanolethanolamine,

tetrahydroxyethylethylenediamine, N,N,N',N'-tetrakis(2

hydroxypropyl)ethylenediamine, tris(2-hydroxybutyl)amine,

and other amines.

As the alkanolamine, only one kind may be used, or two

or more kinds may be used.

[00331

In particular, the alkanolamine is preferably at least

one selected from the group consisting of diethanol

isopropanolamine (DEIPA), triisopropanolamine (TIPA),

ethanol diisopropanolamine (EDIPA), triethanolamine (TEA),

N-methyldiethanolamine (MDEA), and N-n-butyldiethanolamine

(BDEA), more preferably at least one selected from the

group consisting of diethanol isopropanolamine (DEIPA),

triisopropanolamine (TIPA), ethanol diisopropanolamine

(EDIPA), and triethanolamine (TEA), and still more

preferably diethanol isopropanolamine (DEIPA).

[0034]

The alkanolamine generally has high viscosity.

Therefore, mixing is difficult, and the addition of the

alkanolamine is not suitable for the production of mortar.

Accordingly, it is preferable to add the alkanolamine as a

grinding aid in a finishing process of cement production.

In addition, when the alkanolamine is diluted with and

dissolved in water to be used, the mixing with the cement

is easy, and the cement composition according to the

present invention can be efficiently produced.

[00351

[Gypsum]

The cement composition according to the present

invention contains gypsum.

As the gypsum, any of gypsum anhydrite, gypsum

hemihydrate, or gypsum dihydrate can be used.

The content of the gypsum in the cement composition in

terms of SO 3 is preferably 0.5% to 2.5% by mass.

By adjusting the content of the gypsum in the cement

composition to be in the above-described range, the drying

shrinkage of the cement composition can be made

appropriate, and the strength exhibited by the cement

composition can be increased.

From the above-described viewpoint, the content of the

gypsum in the cement composition in terms of SO 3 is more

preferably 1.0% to 1.8% by mass.

The proportion of SO 3 in the gypsum can be measured

according to JIS R 5202:2010 "Methods for Chemical Analysis

of Portland Cement". The mass ratio of the gypsum in the

cement composition in terms of SO 3 can be obtained from the

blending amount of the gypsum and the proportion of S03 in

the gypsum.

[0036]

[Limestone]

The cement composition according to the present

invention may contain limestone in order to improve the

short-term strength and to reduce the emission amount of C02 with micronization.

The content of the limestone in the cement composition

is defined according to JIS R 5210:2009 "Portland Cement".

In the present invention, the limestone may be added in an

amount exceeding the range defined by the JIS standards.

The content of the limestone in the cement composition

is preferably 0% to 20% by mass, more preferably 0% to 10%

by mass, and still more preferably 2% to 5% by mass. The

content of the limestone being 0% by mass represents that

the limestone is not added for producing the cement

composition.

[0037]

[Other Components]

In the cement composition of the present invention,

fly ash, blast furnace slag, silica fume, or the like can

be further added for adjusting the flowability, the

hydration rate, the strength development, and the like.

[0038]

(Blaine's Specific Surface Area)

In the cement composition according to the present

invention, the Blaine's specific surface area is preferably

3000 to 3400 cm 2 /g.

When the Blaine's specific surface area is 3000 cm 2 /g

or more, the strength of mortar is not likely to decrease.

When the Blaine's specific surface area is 3400 cm 2 /g or less, a decrease in flowability is suppressed, a decrease in the dissolution of C 4 AF by the alkanolamine is suppressed, and the strength enhancement effect can be maintained.

From the viewpoint of further enhancing the strength,

the Blaine's specific surface area of the cement

composition is more preferably 3100 to 3300 cm 2 /g.

The Blaine's specific surface area of the cement

composition may be measured according to JIS R 5201:2015

"Physical Testing Method for Cement".

[00391

<Method for Producing Cement Composition>

A method for producing a cement composition according

to the present invention includes: mixing a Portland cement

that satisfies (1) and (2) below and 0.001 to 0.025 parts

by mass of alkanolamine with respect to 100 parts by mass

of the Portland cement, in which

(1) 0.55 MgO/Fe2O3 + CL'S0 3 /SO 3 0.95, and

(2) 0 AC 4 AF,

in (1), MgO represents a mass (% by mass) of MgO in

the Portland cement, Fe203 represents a mass (% by mass) of

Fe203 in the Portland cement, SO 3 represents an amount (% by

mass) of the Portland cement in terms of SO 3 , and CL'SO 3

represents an amount (% by mass) of a clinker of the

Portland cement in terms of SO 3 , and in (2), AC 4 AF represents a difference (R.C 4 AF - B.C 4AF) between a mass (% by mass) of R.C 4AF and a mass (% by mass) of B.C 4AF, where R.C 4AF represents a C 4 AF value of the

Portland cement measured by a powder X-ray diffractometer,

B.C 4 AF represents 3.04 x Fe203, and Fe203 in B.C4AF

represents a mass (% by mass) of Fe203 in the Portland

cement.

[0040]

The Portland cement used in the method for producing a

cement composition according to the present invention is

the same as the Portland cement containing the cement

composition according to the present invention, and a

preferable aspect thereof is also the same. That is,

MgO/Fe2O3 preferably exceeds 0.35, and in the cement

composition according to the present invention, the

Portland cement is preferably a normal Portland cement

where a content of C 3 S is 45% to 75% by mass, a content of

C 2 S is 5% to 25% by mass, a content of C 3 A is 7% to 11% by

mass, and a content of C 4 AF is 7% to 11% by mass when

calculated by Bogue calculation.

[0041]

The blending amount of the alkanolamine is the same as

the content of the alkanolamine in the cement composition

of the present invention, and a preferable range thereof is

also the same. That is, an addition amount of the alkanolamine is preferably 0.005 to 0.02 parts by mass with respect to 100 parts by mass of the Portland cement according to the present invention.

In addition, the blending amount of the limestone has

the same definition as the limestone content, and a

preferable range thereof is also the same.

[0042]

The alkanolamine used in the method for producing a

cement composition according to the present invention is

the same as the alkanolamine containing the cement

composition according to the present invention, and a

preferable aspect thereof is also the same.

That is, the alkanolamine used in the method for

producing a cement composition according to the present

invention is preferably at least one selected from the

group consisting of diethanol isopropanolamine,

triisopropanolamine, ethanol diisopropanolamine,

triethanolamine, N-methyldiethanolamine, and N-n

butyldiethanolamine.

The alkanolamine generally has high viscosity.

Therefore, mixing is difficult, and the addition of the

alkanolamine is not suitable for the production of mortar.

Accordingly, it is preferable to add the alkanolamine as a

grinding aid in a finishing process of cement production.

In addition, when the alkanolamine is diluted with and dissolved in water to be used, the mixing with the cement is easy, and the cement composition according to the present invention can be efficiently produced.

[0043]

The means for mixing the components in the method for

producing a cement composition according to the present

invention is not particularly limited. Examples of the

means include a mixer, a ball mill, a Roche mill, and an

air blending silo. The mixing time can be set in a range in

which it is determined that mixing is sufficiently

performed in the production of a typical cement

composition.

[0044]

In the production method, it is preferable that

grinding is performed such that the Blaine's specific

surface area of the cement composition is 3000 to 3400

cm 2 /g.

[0045]

In the method for producing a cement composition

according to the present invention, blast furnace slag, a

siliceous admixture, and fly ash can be further added in

addition to the addition of the Portland cement clinker

according to the present invention, the gypsum, the

limestone, and the alkanolamine.

In the present invention, blast furnace slag and siliceous admixture defined according to JIS R 5210:2009

"Portland Cement" can be used. Regarding the fly ash, not

only type-I fly ash and type-II fly ash but also type-III

fly ash and type-IV fly ash defined according to JIS R

5210:2009 "Portland Cement" can also be used.

Examples

[0046]

The present invention will be described in more detail

with reference to Examples. Note that the present invention

is not limited to the following Examples.

[0047]

<Component of Cement Composition>

The following materials were used in the production of

cement compositions.

1. Clinker

Normal Portland cement clinkers (manufactured by

SUMITOMO OSAKA CEMENT Co., Ltd.) having chemical

compositions and mineral compositions shown in Tables 1 and

2 were used. In Tables 1 and 2, HM represents hydraulic

modulus, SM represents silica modulus, and IM represents

iron modulus. In Tables 1 and 2, "'%" represents % by mass.

The chemical composition of the clinker was analyzed

with a glass bead method using a X-ray fluorescence

spectrometer (PRIMUS IV, manufactured by Rigaku

Corporation) in accordance with JIS R 5204:2019 "Chemical

Analysis Method of Cement by X-Ray Fluorescence". The

mineral compositions were calculated by Bogue calculation

from the obtained mass ratios of CaO, SiO 2 , A1 2 0 3 , and Fe203.

C3S = (4.07 x CaO) - (7.60 x SiO 2 ) - (6.72 x A1 2 0 3 )

(1.43 x Fe203)

C2S = (2.87 x SiO 2 ) - (0.754 x C 3 S)

C 3A = (2.65 x A1 2 0 3 ) - (1.69 x Fe203)

C4AF = 3.04 x Fe203

[00481

(Chemical Composition and Mineral Compositions of

Clinker)

The chemical composition and the mineral compositions

of the clinker are shown in Tables 1 and 2.

[0049]

[Table 1]

Table 1

SiO 2 A1 2 0 3 CaO MgO Fe 20 3 SO 3 (CL'SO 3 ) Na 20 K 20 P 2 0S

Comparative 22.07 5.55 63.42 1.04 2.75 Amount shown in Table 7 0.31 0.40 0.28 Example 1

Comparative 21.68 5.52 64.02 1.04 2.74 Amount shown in Table 7 0.38 0.42 0.23 Example 2

Comparative 20.89 5.70 64.11 0.95 3.00 Amount shown in Table 7 0.32 0.43 0.29 Example 3

Examples 21.09 5.73 62.83 1.26 3.25 Amount shown in Table 7 0.34 0.42 0.25 1 to 4

Example 5 20.89 5.71 63.45 1.29 3.01 Amount shown in Table 7 0.36 0.45 0.34

Example 6 20.88 5.71 63.55 1.43 2.73 Amount shown in Table 7 0.34 0.43 0.32

Amount shown in Table 7 Examples 21.01 5.70 63.67 1.64 2.61 (Example 7) or Table 9 0.31 0.43 0.29 7 and 22 (Example 22)

Example 8 21.07 5.66 60.86 2.16 3.34 Amount shown in Table 7 0.31 0.46 0.23

Example 9 20.71 5.68 63.08 1.94 2.69 Amount shown in Table 7 0.33 0.43 0.35

Example 10 20.98 5.71 63.01 1.80 2.53 Amount shown in Table 7 0.36 0.48 0.31

Example 11 20.78 4.71 61.06 3.24 3.06 Amount shown in Table 8 0.27 0.48 0.25

Example 12 20.89 5.72 62.95 1.83 2.73 Amount shown in Table 8 0.31 0.50 0.34

Example 13 21.80 5.73 64.70 0.00 3.16 Amount shown in Table 8 0.30 0.47 0.31

Example 14 21.52 5.85 64.60 0.00 2.86 Amount shown in Table 8 0.33 0.47 0.36

Example 15 20.16 5.51 60.89 2.77 3.37 Amount shown in Table 8 0.36 0.42 0.34

Example 16 21.82 5.76 63.76 0.90 2.73 Amount shown in Table 8 0.38 0.46 0.38

Example 17 21.66 5.64 64.82 0.82 2.44 Amount shown in Table 8 0.32 0.48 0.33

Example 18 21.77 5.74 65.57 0.28 2.41 Amount shown in Table 8 0.34 0.50 0.38

Example 19 21.15 5.84 64.25 0.30 2.72 Amount shown in Table 8 0.35 0.46 0.32

Example 20 21.15 5.82 62.96 1.64 2.61 Amount shown in Table 9 0.37 0.50 0.37

Example 21 21.12 5.85 62.95 1.64 2.61 Amount shown in Table 9 0.37 0.46 0.35

Comparative 20.35 5.96 62.68 1.93 2.87 Amount shown in Table 8 0.40 0.47 0.30 Example 4

Comparative 21.44 5.68 63.11 1.87 2.43 Amount shown in Table 8 0.32 0.43 0.35 Example 5

Comparative 20.71 5.68 61.32 2.71 2.67 Amount shown in Table 8 0.34 0.41 0.29 Example 6

Comparative 21.04 5.70 64.37 0.30 2.75 Amount shown in Table 8 0.33 0.46 0.32 Example 7

[00501

[Table 2]

Table 2

TiC 2 C3S C2 S C4 AF C 3A f.CaO HM SM IM

Comparative 0.33 49.2 26.3 8.4 10.1 0.72 2.09 2.66 2.02 Example 1

Comparative 0.34 54.8 20.9 8.3 10.0 0.69 2.14 2.62 2.01 Example 2

Comparative 0.33 59.6 15.0 9.1 10.0 0.60 2.16 2.40 1.90 Example 3

Examples 0.34 52.3 21.1 9.9 9.7 0.50 2.08 2.35 1.76 1 to 4

Example 5 0.33 56.8 17.1 9.1 10.0 0.70 2.13 2.40 1.90

Example 6 0.33 57.7 16.4 8.3 10.5 0.71 2.15 2.47 2.09

Examples 0.33 57.4 17.0 7.9 10.7 0.67 2.16 2.53 2.18 7 and 22

Example 8 0.35 44.8 26.7 10.2 9.4 0.54 2.01 2.34 1.70

Example 9 0.32 57.3 16.2 8.2 10.5 0.87 2.15 2.47 2.11

Example 10 0.34 55.0 18.7 7.7 10.9 0.64 2.14 2.55 2.26

Example 11 0.33 54.6 18.5 9.3 7.3 0.46 2.14 2.68 1.54

Example 12 0.35 55.1 18.4 8.3 10.5 0.65 2.15 2.47 2.10

Example 13 0.33 54.6 21.4 9.6 9.8 0.56 2.08 2.45 1.81

Example 14 0.35 56.0 19.6 8.7 10.7 0.57 2.10 2.47 2.04

Example 15 0.34 52.8 18.1 10.3 8.9 0.63 2.09 2.27 1.63

Example 16 0.35 51.1 24.1 8.3 10.7 0.60 2.09 2.57 2.11

Example 17 0.33 57.8 18.6 7.4 10.8 0.82 2.16 2.68 2.31

Example 18 0.34 59.4 17.7 7.3 11.1 0.67 2.15 2.67 2.38

Example 19 0.31 57.6 17.3 8.3 10.9 0.50 2.12 2.47 2.15

Example 20 0.32 52.7 21.0 7.9 11.0 0.74 2.11 2.51 2.23

Example 21 0.34 52.7 20.9 7.9 11.1 0.50 2.11 2.50 2.24

Comparative 0.37 56.3 16.0 8.7 10.9 0.51 2.13 2.30 2.08 Example 4

Comparative 0.34 52.3 22.1 7.4 10.9 0.52 2.12 2.64 2.33 Example 5

Comparative 0.35 50.2 21.6 8.1 10.5 0.61 2.10 2.48 2.12 Example 6

Comparative 0.30 59.8 15.3 8.4 10.5 0.71 2.14 2.49 2.07 Example 7

[0051]

2. Alkanolamine

•DEIPA: diethanol isopropanolamine [manufactured by

Tokyo Chemical Industry Co., Ltd.]

*TEA: triethanolamine [manufactured by Tokyo Chemical

Industry Co., Ltd.]

•TIPA: triisopropanolamine [manufactured by Tokyo

Chemical Industry Co., Ltd.]

•EDIPA: ethanol diisopropanolamine [manufactured by

Sigma-Aldrich LLC]

[0052]

3. Limestone

Calcium carbonate, special grade, manufactured by

KANTO CHEMICAL CO., INC., CaCO3: 99.5%

[0053]

4. Gypsum

Gypsum hemihydrate was used. Specifically, chemical

gypsum (CaSO4 (97.8 mol%)) was held in a drying machine at

120°C for 12 hours and used. The amount of gypsum in terms

of SO 3 was measured according to JIS R 5202:2015 "Method for

chemical analysis of cement". The composition of the

chemical gypsum is as shown in Table 3.

[0054]

[Table 3]

Table 3

SiO 2 A1 2 0 3 CaO Fe 2 0 3 SO 3 TiO 2 P 2 05

0.19 0.48 31.94 2.19 47.76 0.29 0.12

(% by Mass)

[0055]

<Production of Cement>

To the clinker shown in Tables 1 and 2, the limestone

was added such that the content thereof in the obtained

cement was 3.2% by mass, and the gypsum (the gypsum

hemihydrate) was added such that the composition was as

shown in Table 4. The components were mixed using a mixer

to obtain a cement. In Table 4, CL represents clinker. In

addition, "%" represents "% by mass".

[00561

[Table 4]

Table 4

Limestone Limestone CL (%) Gypsum (%) CL (%) Gypsum (%)

Comparative 92.2 4.6 3.2 Example 12 92.3 4.5 3.2 Example 1

Comparative 92.4 4.4 3.2 Example 13 95.0 1.8 3.2 Example 2

Comparative 93.4 3.4 3.2 Example 14 96.5 0.3 3.2 Example 3

Examples 93.0 3.8 3.2 Example 15 92.9 3.9 3.2 1 to 4

Example 5 92.8 4.0 3.2 Example 16 94.6 2.2 3.2

Example 6 93.0 3.8 3.2 Example 17 95.4 1.4 3.2

Examples Example 18 94.1 2.7 3.2 7 and 20 to 92.8 4.0 3.2 22 Example 19 95.6 1.2 3.2

Example 8 93.0 3.8 3.2 Comparative 94.0 2.8 3.2 Example 4

Example 9 93.2 3.6 3.2 Comparative 93.7 3.1 3.2 Example 5

Example 10 93.4 3.4 3.2 Comparative 92.6 4.2 3.2 Example 6

Example 11 92.2 4.6 3.2 Comparative 96.2 0.6 3.2 Example 7

[0057]

(Chemical Composition and Mineral Compositions of

Cement)

The chemical composition of the cement was measured

using the same method as that of the chemical composition

of the clinker, and the mineral compositions of the cement

were calculated using the same method as that of the

mineral compositions of the clinker. The results are shown

in Tables 5 to 9. In Tables 5 to 9, "%" represents % by

mass.

The values of "C4AF" in Table 6 are B.C4AF in the

present invention, and refer to the values in the column

"Bogue" of the column "C 4 AF (%)" in Tables 7 to 9. The

values in the column "Rietveld" of the column "C4AF (%) of

Tables 7 to 9 are R.C 4AF in the present invention, and are

C 4 AF values of the cement measured by a powder X-ray

diffractometer. Specifically, the measurement was performed

under the following measurement conditions using a Rietveld

analysis method using powder X-ray diffraction.

[00581

(Measurement Conditions)

•Powder X-ray diffractometer: X'Part Powder,

manufactured by Malvern Panalytical Ltd.

•Rietveld analysis software: X'Part High Score Plus

Version 2.1b, manufactured by Malvern Panalytical Ltd.

-X-ray tube: Cu (tube voltage: 45 kV, tube current: 40

mA)

-Slit: divergence slit-variable (irradiation width-12

mm, Antiscatter slit-2 0

) *Measurement range: 20 = 100 to 70° (step size:

0.0170)

-Scanning speed: 0.1012 0 /s

[00591

A proportion (% by mass) of each of the minerals of

the cement was obtained using an analysis function of

Rietveld method installed in the software, in accordance

with Joint experiment procedure manual 2 of document

"Report C-12 of Cement Chemistry Expert Committee,

Examination of differences in clinker mineral content due

to difference in measurement methods, Part 2, Chapter 4,

Examination of Quantification by Powder X-ray

Diffraction/Rietveld Analysis". In addition, the content

rate R.C 4AF (% by mass) of C 4 AF of each of Examples and

Comparative Examples was obtained with respect to 100% by

mass of the total proportion of the minerals.

[00601

The value in the column "A*" of the column "C4AF (%)"

in Tables 7 to 9 represents a difference (R.C 4 AF - B.C 4AF)

between the value (B.C 4AF) in the column "Bogue" in the

column "C 4 AF (%)" in Tables 7 to 9 and the value (R.C 4AF) in

the column "Rietveld" in the column "C 4 AF (%)" in Tables 7

to 9.

In addition, FIG. 1 is a graph where AC 4 AF values of

Examples and Comparative Examples under a condition** are

plotted.

[0061]

[Table 5]

Table 5

SiC 2 A1 2 0 3 CaO MgO Fe 2 0 3 SO3 Na 2 0 K 20 P 2 0S

Comparative 20.43 5.15 61.72 Amount shown in Table 7 0.29 0.37 0.26 Example 1

Comparative 20.11 5.13 62.34 Amount shown in Table 7 0.35 0.39 0.22 Example 2

pa 19.59 5.35 62.74 Amount shown in Table 7 0.30 0.40 0.27 Example 3

Examples 19.68 5.35 61.42 Amount shown in Table 7 0.32 0.39 0.24 1 to 4

Example 5 19.46 5.32 61.94 Amount shown in Table 7 0.34 0.42 0.32

Example 6 19.48 5.33 62.08 Amount shown in Table 7 0.32 0.40 0.30

Amount shown in Table 7 Examples 19.57 5.31 62.14 (Example 7) or Table 9 0.29 0.40 0.27 7 and 22 (Example 22)

Example 8 19.67 5.29 59.59 Amount shown in Table 7 0.29 0.43 0.22

Example 9 19.37 5.31 61.70 Amount shown in Table 7 0.31 0.40 0.33

Example 10 19.66 5.35 61.70 Amount shown in Table 7 0.34 0.45 0.29

Example 11 19.23 4.37 59.53 Amount shown in Table 8 0.25 0.44 0.24

Example 12 19.36 5.31 61.32 Amount shown in Table 8 0.29 0.46 0.32

Example 13 20.77 5.46 63.81 Amount shown in Table 8 0.29 0.45 0.30

Example 14 20.83 5.65 64.20 Amount shown in Table 8 0.32 0.45 0.35

Example 15 18.80 5.14 59.59 Amount shown in Table 8 0.34 0.39 0.32

Example 16 20.71 5.46 62.79 Amount shown in Table 8 0.36 0.44 0.36

Example 17 20.74 5.39 64.07 Amount shown in Table 8 0.31 0.46 0.32

Example 18 20.56 5.42 64.34 Amount shown in Table 8 0.32 0.47 0.36

Example 19 20.30 5.60 63.60 Amount shown in Table 8 0.34 0.44 0.31

Example 20 19.70 5.43 61.48 Amount shown in Table 9 0.35 0.46 0.35

Example 21 19.68 5.45 61.47 Amount shown in Table 9 0.35 0.43 0.33

Comparative 19.19 5.62 61.57 Amount shown in Table 8 0.38 0.44 0.29 Example 4

Comparative 20.15 5.34 61.88 Amount shown in Table 8 0.30 0.40 0.33 Example 5

Comparative 19.25 5.29 59.90 Amount shown in Table 8 0.32 0.38 0.27 Example 6

Comparative 20.32 5.49 63.90 Amount shown in Table 8 0.32 0.44 0.31 Example 7

[0062]

[Table 6]

Table 6

TiC 2 C 3S C2 S C4 AF C 3A f. CaO HM SM IM

Comparative 0.32 51.0 20.1 Amount shown in Table 7 8.8 0.66 2.12 2.55 1.80 Example 1

Comparative 0.33 56.0 15.5 Amount shown in Table 7 8.8 0.64 2.16 2.52 1.80 Example 2

Comparative 0.32 60.5 10.6 Amount shown in Table 7 8.9 0.56 2.19 2.32 1.72 Example 3

Examples 0.33 53.2 16.4 Amount shown in Table 7 8.6 0.46 2.11 2.27 1.61 1 to 4

Example 5 0.32 57.1 12.8 Amount shown in Table 7 8.9 0.65 2.16 2.31 1.72

Example 6 0.32 57.7 12.4 Amount shown in Table 7 9.3 0.66 2.18 2.38 1.88

Amount shown in Table 7 Examples 0.32 57.5 12.8 (Example 7) or Table 9 9.5 0.62 2.19 2.43 1.95 7 and 22 (Example 22)

Example 8 0.34 45.6 22.0 Amount shown in Table 7 8.2 0.50 2.04 2.26 1.55

Example 9 0.31 57.5 12.2 Amount shown in Table 7 9.3 0.81 2.18 2.38 1.89

Example 10 0.33 55.3 14.8 Amount shown in Table 7 9.7 0.60 2.17 2.45 2.01

Example 11 0.32 56.0 13.0 Amount shown in Table 8 6.3 0.42 2.17 2.56 1.39

Example 12 0.34 56.6 12.9 Amount shown in Table 8 9.3 0.60 2.17 2.38 1.87

Example 13 0.32 54.7 18.4 Amount shown in Table 8 8.9 0.53 2.12 2.38 1.67

Example 14 0.34 55.4 18.0 Amount shown in Table 8 9.9 0.55 2.13 2.41 1.89

Example 15 0.33 54.3 13.1 Amount shown in Table 8 7.8 0.59 2.12 2.19 1.49

Example 16 0.34 52.5 19.9 Amount shown in Table 8 9.7 0.57 2.12 2.49 1.92

Example 17 0.32 58.8 15.2 Amount shown in Table 8 9.9 0.78 2.19 2.60 2.09

Example 18 0.33 57.2 15.9 Amount shown in Table 8 10.1 0.63 2.18 2.58 2.13

Example 19 0.30 56.1 15.9 Amount shown in Table 8 10.0 0.48 2.15 2.40 1.96

Example 20 0.31 53.1 16.5 Amount shown in Table 9 9.8 0.69 2.14 2.42 1.99

Example 21 0.33 53.0 16.5 Amount shown in Table 9 9.8 0.46 2.14 2.40 2.00

Comparative 0.36 56.5 12.5 Amount shown in Table 8 9.9 0.48 2.16 2.23 1.89 Example 4

Comparative 0.33 53.0 17.8 Amount shown in Table 8 9.8 0.49 2.15 2.55 2.08 Example 5

Comparative 0.34 51.6 16.3 Amount shown in Table 8 9.3 0.56 2.14 2.38 1.89 Example 6

Comparative 0.29 58.9 13.9 Amount shown in Table 8 9.7 0.68 2.18 2.43 1.91 Example 7

[0063]

<Production of Cement Composition>

[Example 1]

As the cement composition to which amine was not

added, a cement shown in Tables 5 to 7 was used.

As the cement composition to which amine was added, a

composition consisting of alkanolamine (DEIPA) shown in

Table 7 and a cement shown in Tables 5 to 7 was prepared.

Specifically, alkanolamine was mixed with the cement such

that the concentration of alkanolamine was 10 ppm (0.001

parts by mass with respect to 100 parts by mass of the

cement) with respect to the total content of the cement and

the alkanolamine.

Next, the cement composition to which amine was not

added and the cement composition to which amine was added

were mixed and ground using a ball mill for a test such

that the value of the Blaine's specific surface area was

3300 cm 2 /g. As a result, each of the cement compositions

according to Example 1 was obtained.

[0064]

[Examples 2 to 19 and Comparative Examples 1 to 7]

As the cement composition to which amine was not

added, cements shown in Tables 5 to 8 were used.

Cement compositions to which amine was added were

obtained using the same method as that of Example 1, except

that the cement shown in Tables 5 to 8 was used and DEIPA

was added such that the concentration thereof with respect to the total content of the cement and DEIPA was as shown in Table 7 or 8.

Next, the cement composition to which amine was not

added and the cement composition to which amine was added

were mixed and ground using a ball mill for a test such

that the value of the Blaine's specific surface area was

3300 cm 2 /g. As a result, each of the cement compositions

according to Examples 2 to 19 and Comparative Examples 1 to

7 was obtained.

[00651

[Examples 20 to 22]

As the cement composition to which amine was not

added, cements shown in Tables 5, 6, and 9 were used.

Cement compositions to which amine was added were

obtained using the same method as that of Example 7, except

that alkanolamine shown in "Amine Kind" of Table 9 was used

as the alkanolamine instead of DEIPA.

Next, the cement composition to which amine was not

added and the cement composition to which amine was added

were mixed and ground using a ball mill for a test such

that the value of the Blaine's specific surface area was

3300 cm 2 /g. As a result, each of the cement compositions

according to Examples 20 to 22 was obtained.

[00661

<Evaluation of Cement Composition>

Using the cement composition to which amine was not

added and the cement composition to which amine was added

according to each of Examples and Comparative Examples, a

sample was formed according to JIS R 5201:2015 "Physical

Testing Method for Cement", and was measured in a mortar

compressive strength test.

A blending ratio of the sample was water: 11.1% by

mass, aggregate: 66.7% by mass, and cement: 22.2% by mass,

and a rectangular sample having a dimension of 40 mm x 40

mm x 160 mm was wrapped with a vinyl chloride resin and

cured.

[0067]

The compressive strength of mortar obtained using the

cement composition to which amine was not added is shown in

the column "Material Age (Not Added) (a)" of Tables 7 to 9,

and the compressive strength of mortar obtained using the

cement composition to which amine was added is shown in the

column "Material Age (Amine Added) (b)" of Tables 7 to 9.

As the numerical value increases, the mortar compressive

strength is higher.

[0068]

The column "A (b - a)" of Tables 7 to 9 shows a

difference (difference in strength) obtained by subtracting

the compressive strength of mortar obtained using the

cement composition to which amine was not added the compressive strength of mortar obtained using the cement composition to which amine was added. As the numerical value of the difference in strength increases, the strength enhancement effect is higher.

In addition, FIG. 2 is a graph where values of

differences in enhanced strength of mortar at 7-day age and

28 age under a condition** are plotted. Here, "Condition**"

represents a numerical value shown in the column

"Condition**" of Tables 7 to 9, and is "MgO/Fe2O3

+ CL'S0 3 /SO3" of Condition (1) of the Portland cement

according to the present invention.

01 m> m> mn mn mn m (n r- c~ (N

o D N (S (n (S (n (Nn' CD

( CD (N CD ( (S (S (S 0> L' CD (S (S L'

(Nl (Nl on o o n o n (N (Nn (N(N

(n m~ r- On mn (n m (n

CD CD Efl On On O

(S L, n EqLn L

oCDC 0 > C C D C

m - -

On On CD CD xf 0>On x CD x x m (N CD u CD On On4' 4q (SCDCD 4 4On 4

21 L n L 01

- ~c~ mn o- o oooo

o 0 NqanD r- 0nCD ~

( 0 0 N ( KO V~ 0> V CD C KO N

p~ c~ o 000

(9L n L n L n n L n L n L

o 1 (N Eq t~ N~ r-V ' ~0 q( 0 D 0 VrE > t(

Co j .n .nLn

(N N ( (N(N N ( ( (n (n

3 Qj O 0> ~ q C q q C > C ( >L C q E D >EnC CD 4)......................................

Q t ( t ( t ( N N ( N ( N

( 0> 0> 0 0 V E D K 0 q0 0>KQ qCj N( DVq

( r- r m nr

(N j (N r- (> cn (nCt ~ ' E

(D CD (n, (NVt EEqct

CD > 00 D CD 0 D V D C

4-4) 4 (9 10 1 0 1 j Q j Q j Q j Q Qj x x x x x x x 0 x x Eq El Eq KO 0> V4 CD CD V4 CD 1q CD4 U 11 0 1 I)

0

0

E-1 E

Co Ko Ko K

p 0 0

Q)

00

0 (N (N mn mn m

22 mn L

22l

m m

Qj

CD ~ (9~

0~ 00l 00 0

QmQj Q Ij » 00 0 0 00 4 4 '

[0072]

The difference in the strength of mortar shown in the

column "A (b - a)" of Tables 7 to 9 represents the degree

to which the strength of mortar obtained using the cement

composition to which amine was added was increased as

compared to the strength of mortar obtained using the

cement composition to which amine was not added. As the

numerical value increases on the positive side, the

strength enhancement effect is higher. When the result at

3-day age and the results at 7-day age and 28-day age are

compared to each other, it can be seen from that the

numerical value of A (b - a) at 7-day age or more is large,

and the strength enhancement effect is high. In addition,

the comparison between the results at 7-day age and 28-day

age is illustrated in FIG. 2, and it can be seen that the

strength enhancement effect at 28-day age is high.

Claims (8)

1. A cement composition comprising:

a Portland cement that satisfies (1) and (2) below;

and

0.001 to 0.025 parts by mass of alkanolamine with

respect to 100 parts by mass of the Portland cement,

wherein the Portland cement is a normal Portland

cement where a content of C 3 S is 45% to 75% by mass, a

content of C 2 S is 5% to 25% by mass, a content of C 3 A is 7%

to 11% by mass, and a content of C 4 AF is 7% to 11% by mass

when calculated by Bogue calculation,

(1) 0.55 MgO/Fe2O3 + CL'S0 3 /SO 3 0.95, and

(2) 0 AC 4 AF,

in (1), MgO represents a mass (% by mass) of MgO in

the Portland cement, Fe203 represents a mass (% by mass) of

Fe203 in the Portland cement, SO 3 represents an amount (% by

mass) of the Portland cement in terms of SO 3 , and CL'SO3

represents an amount (% by mass) of a clinker of the

Portland cement in terms of S03, and

in (2), AC 4 AF represents a difference (R.C 4 AF - B.C4AF)

between a mass (% by mass) of R.C 4AF and a mass (% by mass)

of B.C4AF, where R.C4AF represents a C 4 AF value of the

Portland cement measured by a powder X-ray diffractometer,

B.C 4 AF represents 3.04 x Fe203, and Fe203 in B.C4AF represents a mass (% by mass) of Fe203 in the Portland cement.

2. The cement composition according to claim 1,

wherein in (1), MgO/Fe2O3 exceeds 0.35.

3. The cement composition according to claim 1 or 2,

wherein a content of the alkanolamine is 0.005 to 0.02

parts by mass with respect to 100 parts by mass of the

Portland cement.

4. The cement composition according to any one of

claims 1 to 3,

wherein the alkanolamine is at least one selected from

the group consisting of diethanol isopropanolamine,

triisopropanolamine, ethanol diisopropanolamine,

triethanolamine, N-methyldiethanolamine, and N-n

butyldiethanolamine.

5. A method for producing a cement composition, the

method comprising:

mixing a Portland cement that satisfies (1) and (2)

below and 0.001 to 0.025 parts by mass of alkanolamine with

respect to 100 parts by mass of the Portland cement,

wherein the Portland cement is a normal Portland cement where a content of C3S is 45% to 75% by mass, a content of C 2 S is 5% to 25% by mass, a content of C 3 A is 7% to 11% by mass, and a content of C 4 AF is 7% to 11% by mass when calculated by Bogue calculation,

(1) 0.55 MgO/Fe2O3 + CL'S0 3 /SO 3 0.95, and

(2) 0 AC 4 AF,

in (1), MgO represents a mass (% by mass) of MgO in

the Portland cement, Fe203 represents a mass (% by mass) of

Fe203 in the Portland cement, SO 3 represents an amount (% by

mass) of the Portland cement in terms of SO 3 , and CL'SO 3

represents an amount (% by mass) of a clinker of the

Portland cement in terms of SO 3 , and

in (2), AC 4 AF represents a difference (R.C 4 AF - B.C4AF)

between a mass (% by mass) of R.C 4AF and a mass (% by mass)

of B.C4AF, where R.C4AF represents a C 4 AF value of the

Portland cement measured by a powder X-ray diffractometer,

B.C 4 AF represents 3.04 x Fe203, and Fe203 in B.C4AF

represents a mass (% by mass) of Fe203 in the Portland

cement.

6. The method for producing a cement composition

according to claim 5,

wherein in (1), MgO/Fe2O3 exceeds 0.35.

7. The method for producing cement composition according to claim 5 or 6, wherein an addition amount of the alkanolamine is

0.005 to 0.02 parts by mass with respect to 100 parts by

mass of the Portland cement.

8. The method for producing cement composition

according to any one of claims 5 to 7,

wherein the alkanolamine is at least one selected from

the group consisting of diethanol isopropanolamine,

triisopropanolamine, ethanol diisopropanolamine,

triethanolamine, N-methyldiethanolamine, and N-n

butyldiethanolamine.