AU2022246322B2

AU2022246322B2 - Cement composition and method for producing same

Info

Publication number: AU2022246322B2
Application number: AU2022246322A
Authority: AU
Inventors: Koki IMAZU; Kensuke Kanai; Shohei Sasaki
Original assignee: Sumitomo Osaka Cement Co Ltd
Current assignee: Sumitomo Osaka Cement Co Ltd
Priority date: 2021-03-26
Filing date: 2022-01-24
Publication date: 2023-07-27
Anticipated expiration: 2042-01-24
Also published as: CN116249680A; JP2022151074A; NZ797549A; AU2022246322A1; KR102593416B1; WO2022201818A1; KR20230025501A; CN116249680B; JP6966012B1

Abstract

A cement composition comprising: an ordinary Portland cement clinker in which the contained amounts of C

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]

Various studies have been made to improve the strength of

mortar and concrete.

For example, in Patent Literature No. 1, in order to

provide admixtures or cement compositions for mortar or concrete

used in civil engineering structures or concrete secondary

products that have the effect of increasing both 7-day strength

and 28-day strength, an admixture containing trialkanolamine

and diethylene glycol, and a cement composition containing

cement and the admixture is disclosed.

In addition, for example, in Patent Literature No. 2, in

manufacturing buildings, civil engineering structures, and

concrete secondary products, in order to provide cement

admixtures and cement compositions improved to be able to overcome the drawback of low initial strength of fly ash and actively blend fly ash with cement to be used, a cement composition containing cement admixture that contains fly ash, trialkanolamine, and 0.05 to 0.5 parts by weight of diethylene glycol with respect to 100 parts by weight of fly ash or a cement admixture containing cement, diethylene glycol, and trialkanolamine, and furthermore, a cement composition containing cement, fly ash, trialkanolamine, and diethylene glycol are disclosed.

Citation List

Patent Literature

[00031

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

Publication No. 2000-203909

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

Publication No. 2000-281404

[0003a]

Any discussion of the prior art throughout the

specification should in no way be considered as an admission

that such prior art is widely known or forms part of common

general knowledge in the field.

Summary of Invention

Technical Problem

[0004]

However, flowability of the cement compositions described

in Patent Literature No. 1 and Patent Literature No. 2 has not

been studied.

An object of the present invention is to provide a cement

composition having high strength and excellent flowability, and

a method for producing the same.

[0004a] Unless the context clearly requires otherwise, throughout

the description and the claims, the words "comprise",

"comprising", and the like are to be construed in an inclusive

sense as opposed to an exclusive or exhaustive sense; that is

to say, in the sense of "including, but not limited to".

Solution to Problem

[0005]

The present invention provides the following <1> to <7>.

<1> A cement composition containing: an ordinary Portland

cement clinker containing 51% to 62% by mass of C 3 S and 7% to

10% by mass of C 4 AF, which are calculated by Bogue's formula;

a gypsum; a limestone; and an auxiliary agent containing

alkanolamine, in which a content of the alkanolamine in a total

amount of the ordinary Portland cement clinker, the gypsum, and the auxiliary agent is 10 to 210 mg/kg, a content of the limestone in a total amount of the ordinary Portland cement clinker, the gypsum, the auxiliary agent, and the limestone is 3% to 10% by mass, a unit cell volume of C 4 AF is more than 0.4290 nm 3 , and

Blaine specific surface area is 2,800 to 3,500 cm 2 /g.

[00061

<2> The cement composition according to <1>, in which a

content of the auxiliary agent in the total amount of the ordinary

Portland cement clinker, the gypsum, and the auxiliary agent

is 80 to 350 mg/kg.

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

which the auxiliary agent contains an aliphatic polyhydric

alcohol.

<4> The cement composition according to any one of <1> to

<3>, in which a content of the gypsum in the total amount of

the ordinary Portland cement clinker, the gypsum, and the

auxiliary agent is 0.7% to 2.8% by mass in terms of SO 3 .

<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 diethanolisopropanolamine,

triisopropanolamine, ethanoldiisopropanolamine,

N-methyldiethanolamine, and Nn-butyldiethanolamine.

<6> The cement composition according to any one of <3> to

<5>, in which the aliphatic polyhydric alcohol is at least one

selected from the group consisting of glycerin and diethylene glycol.

[0007]

<7>Amethod for producing a cement composition including:

producing the cement composition according to any one of <1>

to <6> by mixing an ordinary Portland cement clinker that

contains 51% to 62% by mass of C 3 S and 7% to 10% by mass of C 4AF,

which are calculated by Bogue's formula, and that has a unit

cell volume of C4AF of more than 0. 4290 nm 3 , a gypsum, a limestone,

and an auxiliary agent containing alkanolamine such that a

blending amount of the alkanolamine in a total amount of the

ordinary Portland cement clinker, the gypsum, and the auxiliary

agent is 10 to 210 mg/kg and a blending amount of the limestone

in a total amount of the ordinary Portland cement clinker, the

gypsum, the auxiliary agent, and the limestone is 3% to 10% by

mass.

Advantageous Effects of Invention

[0008]

According to the present invention, it is possible to

provide a cement composition having high strength and excellent

flowability, and a method for producing the same.

Description of Embodiments

[0009]

The notation of a numerical range from "AA to BB" in the present specification means "equal to or higher than AA and equal to or lower than BB".

[0010]

A cement composition of the present invention contains an

ordinary Portland cement clinker containing 51% to 62% by mass

of C3S and 7% to 10% by mass of C 4 AF, which are calculated by

Bogue's formula, a gypsum, a limestone, and an auxiliary agent

containing alkanolamine, in which a content of the alkanolamine

in a total amount of the ordinary Portland cement clinker, the

gypsum, and the auxiliary agent is 10 to 210 mg/kg, a content

of the limestone in a totalamount of the ordinary Portland cement

clinker, the gypsum, the auxiliary agent, and the limestone is

3% to 10% by mass, a unit cell volume of C 4 AF is more than 0.4290

nm 3 , and Blaine specific surface area is 2,800 to 3,500 cm 2 /g.

[0011]

A cement composition is usually obtained by calcinating

blended raw materials in a rotary kiln to obtain clinker, adding

gypsum and limestone to the obtained clinker, and pulverizing

those materials by a finishing mill until a desired Blaine

specific surface area is achieved.

In a case of pulverizing cement by the finishing mill, it

is common practice to add a dispersant such as diethylene glycol

to products to be pulverized, thereby preventing a decrease in

pulverization efficiency caused by agglomeration of particles.

Strength development, which is a major physical property of

ordinary Portland cement, is generally controlled by adjusting

raw material blending and cement fineness (Blaine specific

surface area). The Blaine specific surface area of the cement

composition is adjusted in the pulverization step by the

finishing mill, and is a factor controlling the strength level

at each material age, so that the Blaine specific surface area

is regarded as a quality control item.

[0012]

In acase where the Blaine specificsurface areaincreases,

the initial strength of mortar and concrete increases in

particular, but the flowability during kneading of cement paste

is reduced, which causes the reduction of work efficiency. In

a case where the amount of chemical admixture is increased to

maintain flowability, the cost is increased, and in a case where

the amount of water is increased, drying and shrinkage of a cured

product are increased, resulting in promoting cracking of the

cured product and impairing durability.

[0013]

In a case where cement is stored in a silo, the higher the

Blaine specificsurface area, the higher the reactivity ofcement

particles with moisture, carbon dioxide, and the like in the

air. Therefore, the hydration activity of surfaces of the

cement particles is lowered, and so-called weathering is likely

to occur. Weathered cement causes problems such as abnormal setting after pouring water, reduced flowability, and reduced strength of a cured product.

Calcium hydroxide formed on the surfaces of the cement

particles by weathering reacts with carbon dioxide to form

calcium carbonate, which promotes agglomeration of the cement

particles. As a result, lumps are generated in the silo, which

also causes a so-called consolidation.

[0014]

Therefore, it is preferable to reduce the Blaine specific

surface area of the cement composition as much as possible within

a range in which the desired strength is obtained. In addition,

from the viewpoint of production, it is preferable to reduce

the Blaine specific surface area of the cement composition. As

described above, the Blaine specific surface area of the cement

composition is adjusted in the pulverization step by the

finishing mill, and reducing the Blaine specific surface area

leads to power reduction during the operation of the finishing

mill.

[0015]

In addition, the strength development can be controlled

by adjusting a ratio of limestone in the raw materials, in

addition to adjusting the Blaine specific surface area. For

example, the ratio oflimestone in the rawmaterials is increased

to increase the amount of alite in cement minerals, and

particularly the strength development at the initial stage of hydration is increased.

In this way, the amount of limestone in the clinker raw

materials can be relatively increased, and the amount of alite

in the generated cement minerals can be increased to enhance

the strength. However, in a case where the amount of alite

increases, the raw materials for cement become difficult to

calcinate, thereby the amount of fuel required for calcinating

increasing. An increase in a raw material unit consumption of

limestone and an increase in the amount of coal used as the main

fuel also contribute to an increase in carbon dioxide emissions.

[0016]

On the other hand, the cement composition of the present

invention keeps the Blaine specific surface area of the cement

composition low, enhances the strength while suppressing the

amount of limestone in the clinker raw materials, and is

excellent in flowability. Although the reason for this is not

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

[0017]

Alkanolamine, whichis an auxiliary agent containedin the

cement composition of the present invention, dissolves

specifically aferrite phase amongfourminerals ofalite, belite,

aluminate, and ferrite, which are main cement minerals, thereby

enabling the strength of the cement to be enhanced.

Specifically, alkanolamine dissolves the ferrite phase present

on surfaces of cement particles synthesized from various minerals to increase surface areas of the cement particles, and the cement minerals inside come into contact with water to promote hydration. In addition, iron hydroxide produced by dissolution of ferrite covers surfaces of clinker particles and inhibits the diffusion ofCaions andthe like eluted fromclinker minerals such as alite, thereby inhibiting hydration. Thus, it is considered that alkanolamine also has the effect ofpromoting the hydration of alite because alkanolamine also has the effect of dissolving Fe ions of the iron hydroxide.

The cement composition of the present invention will be

described in detail below.

[0018]

[Blaine Specific Surface Area]

The cement composition of the present invention has a

Blaine specific surface area of 2,800 to 3,500 cm 2 /g.

In a case where the Blaine specific surface area is lower

than 2,800 cm 2 /g, alkanolamine has a hydration promoting effect,

but mortar strength decreases. In a case where the Blaine

2 specific surface area is higher than 3,500 cm /g, the flowability

decreases, and the dissolution of C4AF by alkanolamine is limited,

resulting in a strength enhancement effect cannot be obtained.

From the viewpoint of further enhancing the strength, the

Blaine specific surface area of the cement composition is

preferably 3,000 to 3,400 cm 2 /g, and more preferably 3,150 to

3,350 cm 2 /g.

The Blaine specificsurface area of the cement composition

maybe measured according to JIS R 5201:2015 "Method for Physical

Testing of Cement".

[0019]

[Clinker]

The clinker used in the cement composition of the present

invention is an ordinary Portland cement clinker containing 51%

to 62% by mass of C 3 S and 7% to 10% by mass of C4AF, which are

calculated by Bogue's formula.

A total amount of C3S(3CaO-SiO 2 ) and C2S(2CaO-SiO 2 ) in the

clinker is constant at approximately 88% by mass, and in a case

where C3S is 51% to 62% by mass, a content of C2S is 16% to 27%

by mass. In addition, A total amount of C 3 A(3CaO-Al 2O 3 ) and

C 4 AF(4CaO-A1 2 0 3 -FeO3) in the clinker is constant at approximately

18.5% by mass, and in a case where C 4 AF is 7% to 10% by mass,

a content of C 3 A is 8.5% to 12.5% by mass.

[0020]

(C3S and C2S)

In a case where the content of C3S in the clinker is less

than 51% by mass, the mortar strength is not excellent, and even

though the mortar strength can be increased, the flowability

is not excellent. In addition, the strength enhancement effect

obtained by the addition of alkanolamine cannot be expected due

to the following reasons.

[0021]

In a case where the content of C 3 S in the clinker is less

than 51% by mass, a content of C 2 S, which has the relatively poor

pulverizability, increases. As a result, a pulverization time

required to obtain a certain Blaine specific surface area of

the cement composition is longer, and minerals other than C 2 S

(C 3 S, C 3 A, and C4AF), which have good pulverizability,

over-pulverize to increase the Blaine specific surface area.

In addition, an increase in opportunities making C 4 AF come into

contact with water of adjacent C 4 AF is caused by the strength

enhancement mechanismbymeans ofadding alkanolamine to promote

hydration and enhance the strength by selectively dissolving

C 4 AF in the clinker. However, in a case where the clinker is

over-pulverized, clinker particles in which various minerals

originally exist in combination tend to exist as individual

minerals, so that dissolution of C 4 AF does not lead to promotion

of hydration of C 4AF. Therefore, the strength enhancement

effect by the addition of alkanolamine cannot be obtained.

[0022]

In a case where the content of C 3 S in the clinker is more

than 62% by mass, the raw materials for cement become difficult

to calcinate, unreacted lime (f. CaO) increases, and the amount

of fuel consumption increases in the production of the clinker,

which are not preferable.

From the viewpoint of enhancing the strength and

flowability and suppressing the amount of fuel consumption, the content of C 3 S in the clinker is preferably 53% to 61% by mass, and more preferably 55% to 59% by mass.

[0023]

(C 4 AF and C 3 A)

In a case where the content of C 4 AF in the clinker is less

than 7% by mass, the content of C 4 AF is too small. Thus, the

promotion of a reaction of C 3 S by the promotion of dissolution

of C 4 AF is limited, and a remarkable strength enhancement effect

cannot be exhibited, even though alkanolamine is added. In

addition, in the efficient production of the clinker, since it

is necessary to keep the amount of a liquid phase (C 3 A + C4AF)

constant, a decrease in C 4 AF means a relative increase in C 3 A,

and in a case where the amount of C 3 A increases, the flowability

deteriorates due to the formation of a large amount of needle

crystal ettringite produced by a reaction between C 3 A and gypsum

during initial hydration.

[0024]

In a case where the content of C 4 AF in the clinker is more

than 10% by mass, alkanolamine dissolves C 4 AF on surfaces of

clinker particles, and the hydration of C 3 S is temporarily

promoted, but a large amount of iron hydroxide gel produced by

the dissolution of Fe ions in C 4 AF thickly covers the surfaces

of the clinker particles, which causes hydration to be delayed.

From the viewpoint of enhancing the strength and

flowability and suppressing the amount of fuel consumption, the content of C 4 AF in the clinker is preferably 7% to 9% by mass, and more preferably 8% to 9% by mass.

[0025]

[Unit cell volume of C 4AF]

A unit cell volume of C 4 AF is higher than 0.4290 nm 3

. In a case where the unit cell volume of C 4 AF is equal to

3 or lower than 0.4290 nm , the solubility of C 4 AF by alkanolamine

is low. Therefore, the hydration promoting effect of C 3 S is not

obtained, and the mortar strength is lowered.

The unit cell volume of C 4 AF is preferably equal to or

higher than 0.4295 nm 3 , and more preferably equal to or higher

3 than 0.4300nm . Although the upper limit ofthe unit cellvolume

of C4AF is not particularly limited, the upper limit is usually

equal to or lower than 0.4320 nm 3 .

The unit cell volume of C 4 AF can be calculated by whole

pattern fitting (WPF) analysis from the lattice constant of C 4 AF

measured by using the Rietveld analysis method with powder X-ray

diffraction.

[0026]

[Auxiliary Agent]

The cement composition of the present invention contains

an auxiliary agent containing alkanolamine, and a content of

alkanolamine in a total amount of the ordinary Portland cement

clinker, the gypsum, and the auxiliary agent is 10 to 210 mg/kg.

The auxiliary agent specifically means a grinding aid, alkanolamine also acts as a strength enhancing agent. The auxiliary agent may contain components other than alkanolamine, and examples thereof include an aliphatic polyhydric alcohol.

In a case where the content of alkanolamine in the cement

composition of the present invention is less than 10 mg/kg, a

concentration is too low to promote hydration of alite by the

dissolution of C 4AF. As a result, the strength enhancement

effect cannot be obtained. In a case where the content of

alkanolamine in the cement composition of the present invention

is higher than 210 mg/kg, the enhancement effect of the initial

strength is remarkable. However, at a material age of 28 days,

the hydration structure is coarse due to the high initial

hydration activity, and as a result, the strength enhancement

effect cannot be obtained.

[0027]

(Alkanolamine)

Examples of alkanolamine include monoethanolamine,

diethanolamine, triethanolamine, monoisopropanolamine,

diisopropanolamine, triisopropanolamine, methylethanolamine,

methylisopropanolamine, Nn-butylethanolamine,

N-methyldiethanolamine, Nn-butyldiethanolamine,

N-methyldiisopropanolamine, diethanolisopropanolamine,

diisopropanolethanolamine, tetrahydroxyethylethylenediamine,

N,N,N',N'-tetrakis(2-hydroxypropyl)ethylenediamine,

tris(2-hydroxybutyl)amine, and other amines.

Only one kind of alkanolamine may be used, or two or more

kinds thereof may be used.

[0028]

Among these, alkanolamine is preferably at least one

selected from the group consisting ofdiethanolisopropanolamine

(DEIPA), triisopropanolamine (TIPA),

ethanoldiisopropanolamine (EDIPA), N-methyldiethanolamine

(MDEA), and Nn-butyldiethanolamine (BDEA), more preferably at

least one selected from the group consisting of

diethanolisopropanolamine (DEIPA), triisopropanolamine (TIPA),

and N-methyldiethanolamine (MDEA), and still more preferably

diethanolisopropanolamine (DEIPA).

[0029]

(Aliphatic Polyhydric Alcohol)

The auxiliary agent preferably contains an aliphatic

polyhydric alcohol.

The aliphatic polyhydric alcohol preferably has 3 to 20

carbon atoms, and more preferably 3 to 10 carbon atoms.

The aliphatic polyhydric alcohol preferably has 2 to 8

hydroxyl groups, and more preferably 2 to 4 hydroxyl groups.

The aliphatic polyhydric alcohol preferably has a

molecular weight of 70 to 420, and more preferably 70 to 210.

[0030]

Specific examples of the aliphatic polyhydric alcohol

include glycols such as ethylene glycol, diethylene glycol, and polyethylene glycol; glycerin and the like. Only one kind of the aliphatic polyhydric alcohol may be used, or two or more kinds thereof may be used.

The aliphatic polyhydric alcohol is preferably at least

one selected fromthe groupconsistingofglycerin anddiethylene

glycol, and diethylene glycol is more preferably included.

[0031]

In addition, a content of the auxiliary agent in the total

amount of the ordinary Portland cement clinker, the gypsum, and

the auxiliary agent is preferably 80 to 350 mg/kg.

Hereinafter, a "total of the auxiliary agents" means the

"content of the auxiliary agent in the total amount of the

ordinary Portland cement clinker, the gypsum, and the auxiliary

agent".

In a case where the total of the auxiliary agents is equal

to or higher than 80 mg/kg, the cement composition is excellent

in pulverizability. That is, in a case where the clinker, the

gypsum, and the limestone are added andpulverizedby aball-mill,

pulverized products are less likely to adhere to a medium, and

the inhibition of pulverization is suppressed. In a case where

the total of the auxiliary agents is equal to or lower than 350

mg/kg, floodability is excellent. That is, an air-entraining

property of kneaded products is suppressed, a decrease in the

strength is suppressed, and the flowability of powder does not

increase more than necessary. Thus, the cement composition is difficult to slip during transportation on a belt conveyor, conveyance on up-grade is easy, and slipping down on down-grade is prevented due to its own weigh. As a result, it is possible to efficiently transport the cement composition.

The total of the auxiliary agents is more preferably 100

to 350 mg/kg, and still more preferably 150 to 300 mg/kg, from

the viewpoint of further improving pulverizability and

floodability.

[0032]

[Limestone]

The cement composition of the present invention contains

limestone.

The limestone has a content of 3% to 10% by mass in the

totalamount ofthe ordinary Portlandcement clinker, the gypsum,

the auxiliary agent, and the limestone.

Hereinafter, the "content of the limestone" means a

"content of the limestone in the total amount of the ordinary

Portland cement clinker, the gypsum, the auxiliary agent, and

the limestone".

In a case where the content of the limestone is less than

3% by mass, the strength enhancement effect cannot be obtained.

Usually, ettringite, which is produced during the initial

hydration, undergoes a reaction of conversion into monosulfate

as the hydration of cement proceeds. However, coexistence of

the limestone and alkanolamine contributes to the strength enhancement by the promotion of the addition to monocarbonate or hemihydrate. However, in a case where the content of the limestone is less than 3% by mass, the reaction does not occur remarkably, which does not lead to the strength enhancement.

In a case where the content of the limestone is more than

10% by mass, the unit amount of the clinker in the cement

decreases, resulting in a decrease in mortar strength.

The content ofthe limestone is preferably 3% to 9% bymass,

and more preferably 4% to 8% by mass, from the viewpoint of

further enhancing the strength.

[00331

[Gypsum]

The cement composition of the present invention contains

gypsum.

Acontent of the gypsumin the totalamount of the ordinary

Portland cement clinker, the gypsum, and alkanolamine is

preferably 0.7% to 2.8% by mass in terms of SO 3 .

Hereinafter, the "content of the gypsum" means a "content

of the gypsumin the total amount of the ordinary Portland cement

clinker, the gypsum, the alkanolamine".

By setting the content of the gypsumwithin the above range,

the setting time of the cement composition, the flowability after

pouring water, and change over time thereof can be appropriately

maintained, and the strength development, and drying and

shrinkage can be made appropriate as properties after hardening.

From the above viewpoint, the content of the gypsum is more

preferably 0.8% to 2.5% by mass, and still more preferably 0.9%

to 2.0% by mass in terms of SO 3

. The content of the gypsum can be measured according to JIS

R 5202:2010 "Method for chemical analysis of Portland cement".

A mass ratio of the gypsum in the cement composition in terms

of SO 3 can be obtained from the amount of the blended gypsum and

a ratio of SO 3 contained in the gypsum.

As the gypsum, any one of anhydrous gypsum, hemihydrate

gypsum, and dihydrate gypsum can be used.

[0034]

[Other Component]

In the cement composition of the present invention, a fly

ash, a blast-furnace slag, a silica fume, or the like can be

further added for adjusting flowability, hydration rate,

strength development, and the like.

[0035]

Amethod for producing a cement composition of the present

invention is a method for producing the cement composition of

the present invention by mixing an ordinary Portland cement

clinker that contains 51% to 62% by mass of C3S and 7% to 10%

by mass of C 4AF, which are calculated by Bogue's formula, and

that has a unit cell volume of C 4 AF of more than 0.4290 nm 3 , a

gypsum, a limestone, and an auxiliary agent containing alkanolamine such that a blending amount of the alkanolamine in a total amount of the ordinary Portland cement clinker, the gypsum, and the auxiliary agent is 10 to 210 mg/kg and a blending amount of the limestone in a total amount of the ordinary Portland cement clinker, the gypsum, the auxiliary agent, and the limestone is 3% to 10% by mass.

The blending amount of the alkanolamine is the same as the

content of the alkanolamine in the cement composition of the

present invention, and the preferred range is also the same.

In addition, the blending amount of the limestone is synonymous

with the content of the limestone described above, and the

preferred range is also the same.

[00361

The order, timing, and other conditions of adding the

auxiliary agent, the gypsum, and the limestone to the clinker

are not particularly limited. For example, the gypsum and the

limestonemaybe added to the clinker andmixed, and the auxiliary

agent may be then added and mixed, or the auxiliary agent may

be added to the clinker, and the gypsum and the limestone may

be then added.

[0037]

The means for mixing each component in the method for

producing a cement composition of the present invention is not

particularly limited. Examples thereof include mixers,

ball-mills, roche-mills, and air-blending silos. The mixing time can be set within a range in which it is determined that sufficient mixing is carried out in the normal production of a cement composition.

[00381

In the present production method, pulverization is

preferably carried out so that the Blaine specific surface area

of the cement composition is 2,800 to 3,500 cm 2 /g.

[00391

In the method for producing a cement composition of the

present invention, a blast-furnace slag, a siliceous admixture,

and a fly ash can be further added in addition to adding the

ordinary Portland cement clinker, the gypsum, the limestone,

and the auxiliary agent containing alkanolamine.

In the present invention, the blast-furnace slag and

siliceous admixture defined in JIS R 5210:2009 "Portland cement"

can be used. Regarding the fly ash, in addition to the fly ash

type I and fly ash type II defined in JIS R 5210:2009 "Portland

cement", the fly ash type III and fly ash type IV can also be

used.

Examples

[0040]

The present invention will be described in more detail

below with reference to Examples. The present invention is not

limited to the following Examples.

[0041]

The following materials were used in the production of

cement compositions.

1. Clinker

Seven types of A to G ordinary Portland cement clinkers

(manufactured by SUMITOMO OSAKA CEMENT Co., Ltd.) were used.

Chemical compositions and mineral compositions are shown in

Table 1. The chemical composition of the clinker was analyzed

by the glass beads method by using a fluorescent X-ray measuring

device (PRIMUS IV, manufactured by Rigaku Corporation) in

accordance with JIS R 5204:2019 "Method for fluorescent X-ray

analysis of cement". The mineral compositions were calculated

by using Bogue's formula from the obtained mass ratios of CaO,

Si0 2 , A1 203, and Fe203. In Table 1, HMmeans the hydraulicmodulus,

SM means the silica modulus, and IM means the iron modulus.

C3S= (4.07 x CaO) - (7.60 x Si0 2 ) - (6.72 x A1 2 0 3 ) - (1.43

x Fe203)

C2S = (2.87 x Si0 2 ) - (0.754 x C3S)

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

C 4 AF = 3.04 x Fe203

[0042]

"Unit cell volume of C 4 AF" in Table 1 is calculated by WPF

analysis from a lattice constant of C 4 AF measured by using the

Rietveld analysis method with powder X-ray diffraction.

(Measurement Condition)

-Powder X-ray diffractometer: X7Pert PROmanufactured by

Malvern Panalytical Ltd.

•Rietveld analysis software: HighScore Plusmanufactured

by Malvern Panalytical Ltd.

- X-ray tube bulb: Cu (tube voltage: 45 kV, tube electric

current: 40 mA)

• Slit: divergence slit-variable (irradiation width-12mm,

Antiscatter slit-2°)

Measurement range: 100 to 70° (step width: 0.01670)

Scanning speed: 0.1013 0 /s o n m mo m ycl C> m C> mn 00 0 0 0

0N 0 0 0 0 (N ( (NiN (N

(

(0

4)) (Nl CDl CDl Ct 0n 0 tL0c 0c>0 0n 0n 0n m~ 0~ 0~ 0~ Ct~L 0 0~ C~3 3n n M ~ 2' L' '

CDT coC c D ~ C

2 1 0 0 0

KO C O Ct K D V

[0044]

2. Auxiliary Agent

(1) Alkanolamine

- DEIPA: Diethanolisopropanolamine [manufactured by

Tokyo Chemical Industry Co., Ltd.]

- TIPA: Triisopropanolamine [manufactured by Tokyo

Chemical Industry Co., Ltd.]

- EDIPA: Ethanoldiisopropanolamine

[Manufactured by Sigma-Aldrich Japan K.K.]

- MDEA: N-methyldiethanolamine [manufactured by Tokyo

Chemical Industry Co., Ltd.]

- BDEA: Nn-butyldiethanolamine [manufactured by Tokyo

Chemical Industry Co., Ltd.]

(2) Aliphatic Polyhydric Alcohol

DEG: Diethylene glycol [manufactured by KANTO KAGAKU.]

[0045]

3. Limestone

Calcium carbonate, special grade, manufactured by KANTO

KAGAKU., CaCO3: 99.5%

4. Gypsum

Hemihydrate gypsum was used. Specifically, calcium

sulfate dihydrate, grade 1, manufactured by FUJIFILM Wako Pure

Chemical Corporation, CaSO4 of 98.0+% held for 12 hours at 120°C

in a dryer was used. The gypsum in terms of S03 was measured

according to JIS R 5202:2015 "Method for chemical analysis of cement".

[0046]

[Example 1]

2.7% by mass of hemihydrate gypsum (1.5% by mass in terms

of hemihydrate gypsum SO3 ) and 4.5% by mass of limestone were

added to 92.8% by mass (*) of a clinker that is a type A clinker,

and mixed by a mixer. Next, as shown in Table 2, each of

diethanolisopropanolamine (DEIPA) and diethylene glycol (DEG)

was blended by 10 mg/kg and 190 mg/kg, as auxiliary agents, to

a total amount of the clinker, the gypsum, and the auxiliary

agents. Next, mixing and pulverizing were carried out with a

ball-mill so that the Blaine specific surface area value was

in a range of 3,200 ± 50 cm 2 /g, thereby obtaining a cement

composition of Example 1.

Regarding the amount with (*), a total of the clinker and

the auxiliary agent is 92.8% by mass, but the amount of the

auxiliary agent is an extremely smallamount that hardly affects

the amount of the clinker when considered as a percentage of

the total of the clinker and the auxiliary agent, and it can

be said that the amount of the clinker is 92.8% by mass. The

same applies to Examples other than Example 1 and Comparative

Examples.

[0047]

Regarding the blending amount of the gypsum, since the

gypsum in terms of SO 3 acts on the clinker, hemihydrate gypsum was blended so that the hemihydrate gypsum in terms of SO 3 /(a total amount of the clinker + the auxiliary agent + the hemihydrate gypsum) was 1.5% in all of Examples and Comparative

Examples.

[0048]

[Examples 2 to 19, and 23 to 26, and Comparative Examples

1 to 4, and 7 to 12]

Cement compositions were obtained in the same manner as

in Example 1, except that clinkers having the types shown in

Tables 2 and 3 were used as the clinker, the limestone was blended

in the amount shown in Tables 2 and 3, and auxiliary agents

[alkanolamine, and optionally an aliphatic polyhydric alcohol

(DEG)] having the types and amounts of the column "Auxiliary

agent" shown in Tables 2 and 3, were blended as the auxiliary

agent, and those materials were mixed and pulverized by a

ball-mill so that the Blaine specific surface area values were

within a range of ±50 cm 2 /g shown in Tables 2 and 3.

In Comparative Examples 1 and 2, alkanolamine was not

blended. In addition, in Comparative Example 2 and the like

where the numerical value in the column of "DEG" is 0, diethylene

glycol was not blended.

[0049]

[Comparative Example 5]

2.8% by mass of hemihydrate gypsum (1.5% by mass in terms

of hemihydrate gypsum SO3 ) and 1.0% by mass of limestone were added to 96.2% by mass of a clinker that is a type A clinker, and mixed by a mixer. Next, as shown in Table 3, each of diethanolisopropanolamine (DEIPA) and diethylene glycol (DEG) was blended by 50 mg/kg and 150 mg/kg, as auxiliary agents, to a total amount of the clinker, the gypsum, and the auxiliary agents. Next, mixing and pulverizing were carried out with a ball-mill so that the Blaine specific surface area value was in a range of 3,200 ± 50 cm 2 /g, thereby obtaining a cement composition of Comparative Example 5.

[00501

[Example 20]

2.7% by mass of hemihydrate gypsum (1.5% by mass in terms

of hemihydrate gypsum SO3 ) and 3.2% by mass of limestone were

added to 94.1% by mass of a clinker that is a type A clinker,

and mixed by a mixer. Next, as shown in Table 3, each of

diethanolisopropanolamine (DEIPA) and diethylene glycol (DEG)

was blended by 50 mg/kg and 150 mg/kg, as auxiliary agents, to

a total amount of the clinker, the gypsum, and the auxiliary

agents. Next, mixing and pulverizing were carried out with a

ball-mill so that the Blaine specific surface area value was

in a range of 3,200 ± 50 cm 2 /g, thereby obtaining a cement

composition of Example 20.

[0051]

[Example 21]

2.6% by mass of hemihydrate gypsum (1.5% by mass in terms of hemihydrate gypsum SO3 ) and 6.5% by mass of limestone were added to 90.9% by mass of a clinker that is a type A clinker, and mixed by a mixer. Next, as shown in Table 3, each of diethanolisopropanolamine (DEIPA) and diethylene glycol (DEG) was blended by 50 mg/kg and 150 mg/kg, as auxiliary agents, to a total amount of the clinker, the gypsum, and the auxiliary agents. Next, mixing and pulverizing were carried out with a ball-mill so that the Blaine specific surface area value was in a range of 3,200 ± 50 cm 2/g, thereby obtaining a cement composition of Example 21.

[0052]

[Example 22]

2.5% by mass of hemihydrate gypsum (1.5% by mass in terms

of hemihydrate gypsum SO3 ) and 9.5% by mass of limestone were

added to 88.0% by mass of a clinker that is a type A clinker,

and mixed by a mixer. Next, as shown in Table 3, each of

diethanolisopropanolamine (DEIPA) and diethylene glycol (DEG)

was blended by 50 mg/kg and 150 mg/kg, as auxiliary agents, to

a total amount of the clinker, the gypsum, and the auxiliary

agents. Next, mixing and pulverizing were carried out with a

ball-mill so that the Blaine specific surface area value was

in a range of 3,200 ± 50 cm 2/g, thereby obtaining a cement

composition of Example 22.

[0053]

[Comparative Example 6]

2.5% by mass of hemihydrate gypsum (1.5% by mass in terms

of hemihydrate gypsum SO3 ) and 11.0% by mass of limestone were

added to 86.5% by mass of a clinker that is a type A clinker,

and mixed by a mixer. Next, as shown in Table 3, each of

diethanolisopropanolamine (DEIPA) and diethylene glycol (DEG)

was blended by 50 mg/kg and 150 mg/kg, as auxiliary agents, to

a total amount of the clinker, the gypsum, and the auxiliary

agents. Next, mixing and pulverizing were carried out with a

ball-mill so that the Blaine specific surface area value was

in a range of 3,200 ± 50 cm 2/g, thereby obtaining a cement

composition of Comparative Example 6.

[0054]

1. Pulverizability

10 kg of high chromium balls with T9.5 mm were charged,

as pulverizing media, into a ball-mill with TO. 4 m x 0.72 m

(volume of about 90 L), and the cement compositions of Examples

andComparative Examples were addedasproducts tobe pulverized.

Amillrotation speedwas set to 60 times/min, and apulverization

time was measureduntil the Blaine specific surface area reached

3,200 cm 2 /g.

The shorter the pulverization time, the more excellent the

pulverizability of the cement composition. The pulverization

time is preferably lower than 68 minutes. The results are shown

in the column of "Pulverization effect" shown in Tables 2 and

3.

[0055]

2. Floodability

A repose angle, collapse angle, and dispersion degree of

the cement compositions of Examples and Comparative Examples

were measured by using a powder tester (TP-X) manufactured by

Hosokawa Micron Powder Systems. to apply the measurement results

to a floodability index table of the tester, thereby obtaining

a floodability index.

The lower the floodability index, the more excellent the

cement composition is in the floodability. The index is

preferably lower than 75. The results are shown in the column

of "Floodability index" of Tables 2 and 3.

[00561

3. Mortar Strength

The strength of each of mortars obtained by using the

cements of Examples and Comparative Examples was evaluated

according to JIS R 5201 "Method for Physical Testing of Cement".

The higher the numerical value, the higher the strength

of the mortar obtained by using the cement composition, and the

2 tolerance is higher than 60 N/mm . The results are shown in the

column of "Mortar strength" of Tables 2 and 3.

[0057]

4. Flowability

The flowability of each of the mortars obtained from the cement compositions was evaluated according to JIS R 5201 "Method for Physical Testing of Cement".

Specifically, 1.0% of a high-performance water reducing

agent [manufactured by Kao Corporation, tradename "Mighty150"]

was added to the cement compositions of Examples and Comparative

Examples to prepare mortars, and a flow value of each of the

obtainedmortars wasmeasuredwheneachmortar stopped spreading

after a cone was removed without performing 15 falling motions.

The higher the flow value, the more excellent the

flowability of the mortar obtained from the cement composition.

The tolerance is higher than 160 mm. The results are shown in

the column of "0 stroke flow" of Tables 2 and 3.

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Claims

1. A cement composition comprising:

an ordinary Portland cement clinker comprising 51% to 62%

by mass of C 3 S and 7% to 10% by massof C 4AF, which are calculated

by Bogue's formula;

a gypsum;

a limestone; and

an auxiliary agent comprising alkanolamine,

wherein a content of the alkanolamine in a total amount

of the ordinary Portland cement clinker, the gypsum, and the

auxiliary agent is 10 to 210 mg/kg,

a content of the limestone in a total amount of the ordinary

Portland cement clinker, the gypsum, the auxiliary agent, and

the limestone is 3% to 10% by mass,

a unit cell volume of C 4 AF is more than 0.4290 nm 3 , and

a Blaine specific surface area of the cement composition

is 2,800 to 3,500 cm 2 /g.

2. The cement composition according to claim 1, wherein

a content of the auxiliary agent in the total amount of the

ordinary Portland cement clinker, the gypsum, and the auxiliary

agent is 80 to 350 mg/kg.

3. The cement composition according to claim 1 or 2, wherein the auxiliary agent further comprises an aliphatic polyhydric alcohol.

4. The cement composition according to any one of claims

1 to 3, wherein a content of the gypsum in the total amount of

the ordinary Portland cement clinker, the gypsum, and the

auxiliary agent is 0.7% to 2.8% by mass in terms of SO 3

.

5. The cement composition according to any one of claims

1 to 4, wherein the alkanolamine is at least one selected from

the group consisting of diethanolisopropanolamine,

triisopropanolamine, ethanoldiisopropanolamine,

N-methyldiethanolamine, and Nn-butyldiethanolamine.

6. The cement composition according to claim 3, wherein

the aliphatic polyhydric alcohol is at least one selected from

the group consisting of glycerin and diethylene glycol.

7. A method for producing a cement composition

comprising:

producing the cement composition according to any one of

claims 1 to 6 by mixing an ordinary Portland cement clinker that

comprises 51% to 62% by mass of C 3 S and 7% to 10% by mass of C 4AF,

which are calculated by Bogue's formula, and that has a unit

cell volume of C 4 AF of more than 0. 4290 nm 3 , a gypsum, a limestone, and an auxiliary agent comprising alkanolamine such that a blending amount of the alkanolamine in a total amount of the ordinary Portland cement clinker, the gypsum, and the auxiliary agent is 10 to 210 mg/kg and a blending amount of the limestone in a total amount of the ordinary Portland cement clinker, the gypsum, the auxiliary agent, and the limestone is 3% to 10% by mass.