JP6663816B2 - High belite cement composition - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a high belite-type cement composition in which setting is promoted.

High-belite cement, such as low-heat Portland cement, is suitable for mass concrete applications that take advantage of its quality characteristics of extremely low hydration heat generation, and has good fluidity and workability, It has excellent strength development and durability for long-term aging. Further, since the amount of alite (C ₃ S) that consumes a large amount of heat energy in the cement clinker firing step is small, it theoretically exerts a function as a so-called low carbon cement that uses less energy in cement production. . Therefore, in recent years, demand for building materials and concrete products as a highly useful hydraulic material has been increasing. On the other hand, high-belite cements with a small amount of alite have been used for short-term aging up to 7 days. In addition, there is also a quality problem that it takes a long time to obtain a predetermined hardening strength because of the poor setting strength and the long setting time.

  Under these circumstances, with regard to Portland cement, although a method of increasing the amount of free lime (hereinafter, also referred to as “FL”) in cement is well known as a method of surely promoting the setting thereof, it is usually used in cement. In order to increase the amount of FL, it is necessary to lower the firing degree of the cement clinker by means such as lowering the firing temperature, or to use a raw material of the cement clinker having a coarse particle size. In addition, the thus obtained cement having a large amount of FL has an increased stimulus to the initial hydration reaction of the cement due to the Ca component eluted from the FL when it comes into contact with water, thereby promoting the setting of the cement. The larger the amount of alite, the smaller the amount of alite, resulting in inferior strength in short-term age. Therefore, it is considered that it is not always appropriate to adopt such a method for increasing the amount of FL in high-belite cement, which has a unique problem of low strength development at short-term age in the first place. Various techniques employing other means without being implemented have been developed.

For example, Patent Document 1 discloses a low heat containing 0.3 to 4.0% of a high belite cement and a hardening accelerator composed of potassium sulfate, sodium sulfate, magnesium sulfate, aluminum sulfate, potassium aluminum sulfate and sodium aluminum sulfate. A cement composition is disclosed, which attempts to develop concrete strength at a short age. In addition, Patent Document 2 discloses that low-heat Portland cement containing hemihydrate gypsum in an amount of at least 0.5% by mass in terms of SO ₃ contains, as a main component, at least one selected from the group consisting of oxycarboxylic acids and salts thereof. There is disclosed a technique of adding 0.01 to 0.5% by mass of a setting accelerator for low heat Portland cement to reduce the starting time and the ending time of the setting of low heat Portland cement by using such a technique. .

JP-A-11-157906 JP 2001-158651 A

  However, in any of the techniques described in the above-mentioned patent documents, it is necessary to separately add a predetermined setting accelerator in a predetermined amount, and it is also known that setting the wrong amount may delay setting instead. Therefore, in an actual use situation, a preliminary confirmation test on the optimum amount of the setting accelerator to be added is indispensable, and the process becomes complicated. In particular, in order to shorten the construction period and increase the number of rotations of the formwork, and to respond to the increasing demand in the construction and concrete product fields, it is desirable to reduce the setting time without fail. However, even if any of the above techniques is employed, it is not possible to effectively shorten the setting time while maintaining good strength development in short-term aging.

  Accordingly, an object of the present invention is to provide a high bead that can effectively shorten the setting time while maintaining good strength development of short-term age without using a special additive such as a setting accelerator. It is to provide a light cement composition.

  Therefore, the present inventors have studied variously, by containing a specific amount of gypsum including a specific amount of cement clinker and a specific amount of hemihydrate gypsum, free lime etc., good strength development of short-term age It has been found that a high belite-type cement composition capable of shortening the setting time while having the following properties can be obtained.

That is, the present invention provides the following components (X) and (Y):
(X) 1.5 to 2.5% by mass of free lime, 23 to 31% by mass of C ₃ S, 54 to 62% by mass of C ₂ S, 1 to 3% by mass of C ₃ A, and C ₄ AF 8 to 13% by mass, 0.5 to 1.0% by mass of MgO, and 0.10 to 0.31% by mass of SO ₃ , and the total amount of C ₃ A and C ₄ AF is 11 to 15% by mass. And (C) the cement clinker, and (Y) gypsum in an amount of 1.2 to 4.0 mass% in terms of SO _{3, and the} amount of gypsum in the component (Y) in terms of SO ₃ is 20 to 80 mass. % Of the high belite-based cement composition.

  ADVANTAGE OF THE INVENTION According to the high belite-type cement composition of this invention, although the amount of free lime is large, it can maintain high intensity | strength development in a short-term age, and can shorten a setting time effectively. Further, even in actual use, the process can be simplified without using a setting accelerator.

Hereinafter, the present invention will be described in detail.
The high-belite cement composition of the present invention comprises the following component (X) cement clinker, and component (Y) gypsum:
(X) free lime 1.5-2.5 _{mass%, C} 3 S (alite: 3CaO · SiO ₂₎ and 23 to 31 _{mass%, C} 2 S (belite: 2CaO · SiO ₂₎ and 54 to 62 _{wt%, C 3 a (3CaO ·} Al 2 O 3) _1-3% by weight, C 4 to _{AF (4CaO · Al 2 O 3} · Fe 2 O 3) 8~13 wt%, the MgO 0.5 A cement clinker containing 0.13 to 1.0% by mass, 0.10 to 0.25% by mass of SO ₃ , and a total amount of C ₃ A and C ₄ AF of 11 to 15% by mass; and (Y) SO ₃ It contains 1.2 to 4.0% by mass of gypsum in terms of reduced amount, and the amount of gypsum hemihydrate in the component (Y) in terms of SO ₃ is 20 to 80% by mass.

The high belite-based cement composition of the present invention contains 1.5 to 2.5% by mass of free lime (FL) and 23 to 31% of C ₃ S (Elite: 3CaO · SiO ₂ ) as component (A). _{mass%, C} 2 S (belite: 2CaO · SiO ₂₎ and 54 to 62 _{mass%, C 3 a (3CaO ·} Al 2 O 3) 1-3 _{wt%, C 4 AF (4CaO ·} Al 2 O 3 · _Fe 2 _{O 3)} 8 to 13 wt%, the MgO 0.5 to 1.0 wt%, and SO ₃ hints from 0.10 to 0.31 wt%, and the total of _{C 3} a and _C 4 AF Contains cement clinker in an amount of 11 to 15% by mass.

The C ₃ S content is 23 to 31% by mass in the component (A), and is a very important value that affects the setting time, strength development during short-term age, and hydration heat generation characteristics. If the amount of C ₃ S is less than 23% by mass, the effect of shortening the setting time cannot be sufficiently obtained even if the amount of C ₃ A or the amount of gypsum described later is adjusted, and furthermore, good strength is exhibited in short-term age. May not be maintained. On the other hand, when the amount of C ₃ S exceeds 31% by mass, the calorific value of hydration as a high belite cement composition may be excessively increased.

The C ₂ S amount is 54 to 62% by mass in the component (A). Since C ₂ S is positioned as an intermediate phase of the C ₃ S generation reaction in the cement clinker firing step represented by the following formula (x), the C ₂ S amount and the C ₃ S amount are basically one of the _two . Although it is related to decrease in association with the increase, the amount of C ₂ S in the cement clinker of the component (A) is extremely important particularly affecting the strength development property and the hydration heat generation property of the long-term age. Value. If the amount of C ₂ S is less than 54% by mass, there is a possibility that good strength developability and hydration heat generation characteristics in a long-term material age cannot be secured.
C ₂ S + FL → C ₃ S (x)

The amount of C ₃ A is 1 to 3% by mass in the component (A), the amount of C ₄ AF is 8 to 13% by mass in the component (A), and the amount of C ₃ A and C ₄ AF The total amount is 11 to 15% by mass. When the amount of C ₃ A exceeds 3% by mass, not only the fluidity and workability but also the hydration heat generation property may be deteriorated. When the amount of C ₄ AF exceeds 13% by mass, the fluidity may be deteriorated. And the workability may be deteriorated. If the total amount of C ₃ A and C ₄ AF is less than 11% by mass, the amount of the liquid phase in the baking step of the cement clinker may be too small, so that the baking of the cement clinker may be difficult. The effect of the belite-based cement composition as a low-carbon cement will be reduced.

The amount of free lime is 1.5 to 2.5% by mass in the component (A). When the amount of the free lime is less than 1.5% by mass, the effect of accelerating coagulation is reduced, and good strength development at short-term age may not be maintained. On the other hand, if the amount of free lime exceeds 2.5% by mass, the heat of hydration may increase too much. Therefore, the C ₃ S generation reaction in the baking step of the cement clinker represented by the above formula (x) is suppressed by using means such as adjusting the baking temperature so that the free lime amount becomes the above-mentioned predetermined amount. Is preferred.

The mineral composition of the so-called cement clinker, such as C ₃ S or C ₂ S, is a value obtained by the X-ray diffraction-Rietveld method. For example, the method described in JP-A-2007-67931 may be used. it can. As a method of calculating the mineral composition of such cement clinker, a Borg equation estimated from a chemical analysis value is often used, but the estimated value by the Borg equation is a value obtained on the assumption of an ideal chemical equilibrium. It deviates from the mineral composition of cement clinker, and it is not preferable to use it in the present invention.

The amount of MgO is 0.5 to 1.0% by mass in the component (A). If the MgO content is less than 0.5% by mass, the effect of accelerating coagulation may be reduced. If the MgO content exceeds 1.0% by mass, MIII-type C _3, which is inferior in strength development at short-term age, may be used. Since the amount of S increases, there is a possibility that good strength development at short-term age may not be obtained. Such an amount of MgO is preferably 0.6 to 0.9% by mass in the component (A).
The amount of MIII-type C ₃ S in the component (A) can be easily obtained by using the X-ray diffraction-Riet belt method. Further, the adjustment of the amount of MgO in the component (A) is preferably performed by adjusting the basic unit of high-MgO raw materials such as dolomite-based limestone, slowly cooled slag, and mafic to ultramafic-based rocks.

SO ₃ amount is from 0.10 to 0.31 wt% of SO ₃ in component (A). If the SO ₃ content is less than 0.10% by mass, it may not be possible to maintain good strength in short-term age, and if it exceeds 0.31% by mass, the effect of accelerating the coagulation may not be obtained. May be reduced. SO ₃ in component (A) preferentially shifts to the formation of type II anhydrous gypsum and clinker silicate phases (C ₃ S and C ₂ S) after more than half of the total amount of SO ₃ forms alkali sulfate. To form a solid solution. In the present invention, the SO ₃ content in the component (A) is small than typical Portland cement is to effectively suppress the SO ₃ solid solution amount of the C 3 _S and C _{2 S.}
The amount of SO ₃ in the component (A) is adjusted by using a raw material having a low sulfur content as a raw material for cement clinker and using coal or petroleum coke with low sulfur content for firing the cement clinker. Is preferred. The amount of SO ₃ is preferably 0.15 to 0.31% by mass in the component (A).

The amount of MgO and the amount of SO ₃ in the component (A) can be obtained using an official method such as JIS R 5202 “Chemical analysis method of Portland cement” or JIS R 5204 “Fluorescent X-ray analysis method of cement”. Mean analytical value.

In the present invention, the MgO solid solution amount (aM) in C ₃ S is preferably 0.6 to 0.8% by mass, more preferably 0.7 to 0.8% by mass, and The SO ₃ solid solution amount (aS) is preferably 0.05% by mass or less, and more preferably 0.01 to 0.04% by mass. Further, the MgO solid solution amount (bM) in C ₂ S is preferably 0.2 to 0.4% by mass, more preferably 0.2 to 0.3% by mass, and SO ₃ The solid solution amount (bS) is preferably from 0.1 to 0.3% by mass, and more preferably from 0.1 to 0.25% by mass. The solid solution amounts of MgO and SO ₃ in these two clinker mineral phases, C ₃ S and C ₂ S, were adjusted so that the mineral composition and the amounts of MgO and SO ₃ were included in the component (A). By using the designed cement clinker raw material and fuel and by using a manufacturing method described below, the cement clinker is obtained by firing the cement clinker so that the amount of free lime in the component (A) becomes the above-mentioned predetermined amount. Is preferred.

The amounts of MgO and SO ₃ (aM, aS, bM, bS) in C ₃ S and C ₂ S are determined by EPMA (electron beam microanalyzer), detectors and spectrometers for elemental analysis. It can be measured by using a scanning electron microscope (SEM) or the like. In addition, as a value of these solid solution amounts, an average value obtained by measuring 10 or more particles for each mineral phase is used.

Further, MgO content in the component (X) (xM) and SO ₃ amount (xS) is, MgO solid solution amount in the _{C 3} S (aM) and SO ₃ solid solution amount (aS), and in _{C 2} in S It is preferable that the following formulas (1) and (2) are satisfied together with the MgO solid solution amount (bM) and SO ₃ solid solution amount (bS).
xM × 0.5 <A × aM + B × bM (1)
xS × 0.5> A × aS + B × bS (2)
In the above formulas (1) and (2), A represents the content (% by mass) of C ₃ S in the component (X), and B represents the content (% by mass) of C ₂ S in the component (X). ), And the units of xM and xS are both mass%.

The amount of MgO and SO ₃ in the mineral composition of these components (A) and the amount of solid solution of MgO or SO _{3 in} C ₃ S or C ₂ S satisfy the above formulas (1) and (2). This makes it possible to obtain a high-belite-type cement composition that quickly sets, more easily and effectively, without deteriorating the strength development.

High belite cement compositions of the present invention, a gypsum component (Y), contains 1.2 to 4.0 mass% converted to SO ₃ content, preferably contains 1.5 to 2.5 wt% . Such component (Y), gypsum dihydrate, hemihydrate gypsum and anhydrous gypsum, and the like, hemihydrate gypsum content in the gypsum total amount (SO ₃ equivalent amount) of the component (Y) (SO ₃ equivalent amount) of It is preferably from 20 to 80% by mass. If the amount of gypsum hemihydrate contained in the total amount of gypsum of the component (Y) exceeds 80% by mass, the initial fluidity of the mortar or concrete may decrease, and if the amount of gypsum hemihydrate is less than 20% by mass, There is a possibility that the change over time in the fluidity of the mortar or concrete may become large.

  Examples of the method for measuring the amount of gypsum include thermal analysis (thermogravimetric analysis (TG), differential scanning calorimetry (DSC), etc.), X-ray diffraction-Riet belt method, and the like. From the viewpoint of more accurate analysis, a combined method of thermal analysis and X-ray diffraction-Rietveld method is used, in which the measurement results of gypsum dihydrate and hemihydrate gypsum by thermogravimetric analysis are reflected in the X-ray diffraction-Rietveld method. Is preferred. Further, as a sample container for thermal analysis used for thermal analysis, a container described in JP-A-6-242035 (only a hole having a diameter of 5 to 60 μm in a lid of the container, Otherwise, it is preferable to use a sealed metal container).

The Blaine specific surface area of the high belite-type cement composition of the present invention is preferably 3,100 to 3,800 cm ² / g, and more preferably 3,200 to 3,600 cm ² / g. If the value of the brane specific surface area exceeds 3,800 cm ² / g, fluidity and workability may be reduced, and the heat of hydration tends to be too large. On the other hand, if the value of the brane specific surface area is less than 3,100 cm ² / g, the effect of shortening the setting time may be reduced.
The measurement of the Blaine specific surface area may be performed according to the method described in JIS R 5201 “Physical Testing Method for Cement”.

As a raw material of the cement clinker of the component (A) used in the present invention, a general raw material used for producing Portland cement clinker can be used. As the raw material of such cement clinker, specifically, limestone, burnt lime, CaO raw material such as slaked lime, silica, SiO ₂ raw clay such as _Al 2 _{O 3} raw material such as clay, Tetsukasu, such as iron sludge Fe ₂ O ₃ raw material is exemplified.
Further, in the present invention, it is preferable to use an MgO raw material in addition to these raw materials. Specific examples of the MgO raw material include blast furnace slags such as dolomite-based limestone and slowly cooled slag, steelmaking slag, incinerated ash, and rocks such as serpentine.

Further, in addition to the above-mentioned raw materials, one or more types selected from industrial waste, general waste, and construction soil can be used as a part of the raw materials. Specific examples of such raw materials include coal ash, raw consludge, various sludges (for example, sewage sludge, purified water sludge, construction sludge, ironmaking sludge, etc.), boring waste soil, various incineration ash, molding sand, rock wool, waste Industrial waste such as glass, blast furnace secondary ash, construction waste, concrete waste, etc .; general waste such as sewage sludge dry powder, municipal waste incineration ash, shells, etc .; soil, residual soil, and waste soil generated from construction sites or construction sites And other soils generated by construction. Among them, it is preferable to use coal ash from the viewpoint of ease of use and the like.
The amount of the above-mentioned waste (one or more selected from industrial waste, general waste, and construction waste soil) is used in order to effectively utilize the waste and to secure a desired quality in cement. It is preferably 200 kg or less per ton of the product.

The fuel such as coal or petroleum coke used in the baking step of the cement clinker of the component (A) used in the present invention preferably has a lower sulfur content, and the fuel preferably has a sulfur content (dry base) of 0.5. % By mass, and more preferably 0.3% by mass or less.
The measurement of the sulfur content in the fuel may be performed according to the method described in JIS M 8813 “Coal and coke—elemental analysis method”.

  As a method of producing the cement clinker of the component (A) used in the present invention, the above-mentioned respective raw materials are blended and mixed so as to have a desired clinker mineral composition, and the obtained mixture is preferably prepared at 1,200 to 1, , 500 ° C, more preferably 1,250 to 1,450 ° C. At this time, the firing temperature may be appropriately controlled by an operation such as adjusting the amount of burning of fuel such as coal so that the free lime amount of the cement clinker becomes a predetermined value. As a guide for controlling the firing temperature, when the firing temperature (for example, the kiln exit temperature) increases by 50 ° C., the amount of free lime in the cement clinker decreases by 1% by mass.

  Hereinafter, the present invention will be specifically described based on examples, but the present invention is not limited to these examples.

[Production Example 1: Production of cement clinker]
After preparing special grade reagents such as calcium carbonate, silicon oxide, aluminum oxide, iron (III) oxide, magnesium oxide and sulfur trioxide so as to have the chemical composition shown in Table 1, the remaining amount of the 180 μm sieve was measured using a vibration type disk mill. Was once calcined at 1000 ° C. for 60 minutes using an electric furnace to perform decarbonation, and then pressure-formed into pellets (φ25 × h10 mm). Raw materials for firing ("raw materials" shown in Table 1) were prepared.
The sieving test was performed according to JIS Z8815 "General rules for sieving test method".

Next, the obtained raw material for firing was allowed to stand for 30 minutes in an electric furnace maintained at each of the firing temperatures shown in Table 1, and then cooled by cooling in air outside the furnace to obtain each cement clinker (CL-1). ~ CL-5). The chemical composition and mineral composition of the obtained cement clinker were determined according to the following method. Table 1 shows the results.
In addition, each cement clinker was adjusted so as to obtain 1 kg or more after firing.

《Chemical composition of cement clinker》
Based on JIS R 5204 "X-ray fluorescence analysis method of cement", the measured values were measured by an X-ray fluorescence analyzer ZSX100e (manufactured by Rigaku Corporation).

《Mineral composition of cement clinker》
The measured values were determined by the X-ray diffraction-Rietveld method, specifically according to the method of the following publication. Note that D8 ADVANCE (manufactured by Bruker AXS) was used as an X-ray diffractometer, and DIFFRAC ^plus TOPAS (Ver. 3) (manufactured by Bruker AXS) was used as analysis software.
Seiichi Hoshino et al .; Application of X-ray diffraction / Rietveld method in the determination of minerals in cement containing amorphous admixture, Proceedings of Cement and Concrete, No.59, pp.14-21 (2005)

Next, the chemical composition of the crystal particles of C ₃ S and C ₂ S in each of the cement clinkers (CL-1 to CL-5) obtained in Production Example 1 was measured using EPMA according to the following procedure. went.
Table 2 shows the results.

<< Chemical Composition of C ₃ S and C ₂ S Crystal Particles (MgO Solid Solution and SO ₃ Solid Solution) >>
The EPMA measurement sample was prepared by embedding a high belite cement clinker crushed to 5 mm or less in an epoxy resin and polishing the surface after curing the resin. JXA-8100 (manufactured by JEOL Ltd.) was used for EPMA measurement. Point analysis was performed at an acceleration voltage of 15 kV and a sample current of 5 × 10 ⁻⁸ A, and the average value was calculated after measuring 15 points for each sample.

[Production Example 2: Production of high belite-based cement composition]
Using the cement clinkers (CL-1 to CL-5) obtained in Production Example 1 and gypsum shown below, high belite-based cement compositions (HBC-1 to HBC-5) were produced.
Next, as a gypsum, using the drained gypsum (manufactured by Sumitomo Metal Co., Ltd.) and the hemihydrate gypsum obtained by heating the drained gypsum at 140 ° C., 100 mass of high belite cement composition %, The total of these gypsum (gypsum dihydrate + gypsum hemihydrate) was 2.0 mass% in terms of SO ₃ , and then, using a batch type ball mill, the Blaine specific surface area was 3400 ± 100 cm ² / g at the same time.
Incidentally, the total amount of gypsum and hemihydrate gypsum (SO ₃ conversion) rate of hemihydrate gypsum for (SO ₃ equivalent) was prepared so that all the 60 wt% to a high belite cement composition.

  Using the obtained high-belite cement composition, each property was evaluated according to the following methods. As Comparative Example 3, a commercially available low heat cement (made by Taiheiyo Cement) was used.

《Coagulation properties》
The setting time of each high-belite cement composition was measured in accordance with JIS R 5201 “Physical Testing Method for Cement”. Table 3 shows the results.

《Mortar compressive strength》
Strength development was evaluated by mortar compressive strength. However, since the sample amount was small, the following procedure was performed.

i) Kneading mortar 45 g of high belite cement composition, 135 g of standard sand (Section 5.1.3 of JIS R 5201 “Physical test method of cement”, Appendix 2) and 22.5 g of water (tap water) After kneading with a kneading spoon for 60 seconds, 95 seconds after water injection, kneading was performed for 30 seconds with a solder paste mixer (rotation speed: 300 rpm, manufactured by Sinky), and then kneading with a kneading spoon for 15 seconds again.

ii) Mortar molding One layer of the mortar was packed in a mold frame of 2 × 2 × 3 cm, vibrated by a table vibrator for 30 seconds, and the upper surface of the specimen was smoothed using a metal straight edge. Thereafter, after covering the surface of the test piece with a glass plate, the test piece was left standing in a humidity box (20 ± 1 ° C., relative humidity of 90% or more) and cured for a predetermined period.

iii) Measurement of mortar compressive strength Using a pressure plate for load, the maximum load (N) until crushing was measured at a loading speed of 600 ± 50 N / s at the center of the specimen.

iv) Calculation of mortar compressive strength Mortar compressive strength is obtained from the following equation. Table 3 shows the results.
Mortar compressive strength (N / mm ² ) = Maximum load (N) / 400

  From Table 3, Examples 1 to 3 which are the high belite cement compositions of the present invention, as compared with Comparative Examples 1 and 2, while maintaining the same strength development as the commercial cement of Comparative Example 3, It can be seen that both the starting time and the ending time of the setting can be effectively reduced.

Claims (5)

The following components (X) and (Y):
(X) a free lime 1.5-2.5 wt%, the C ₃ S 23 to 31 wt%, the C ₂ S 54-62 wt%, C ₃ A 1 to 3 wt%, the C ₄ AF 8 to 13% by mass, 0.5 to 1.0% by mass of MgO and 0.10 to 0.31% by mass of SO ₃ , and the total amount of C ₃ A and C ₄ AF is 11 to 15% by mass. in a cement clinker, and (Y) converted to SO ₃ amount contained gypsum is 1.2 to 4.0 wt%, and SO ₃ equivalent amount of hemihydrate gypsum in the component (Y) is 20 to 80 A high belite-type cement composition which is in a percentage by mass. MgO solid solution amount of C ₃ in S (aM) is a 0.6 to 0.8 wt%, and SO ₃ solid solution amount (aS) is, according to claim 1 or less 0.05 mass% High belite-based cement composition. MgO solid solution amount in the C ₂ S (bM) is a 0.2 to 0.4 wt%, and claim SO ₃ solid solution amount (bS) is 0.1 to 0.3 mass% 3. The high-belite cement composition according to 1 or 2. MgO content in the component (X) (xM) and SO ₃ amount (xS), MgO solid solution amount in the C ₃ S (aM) and SO ₃ solid solution amount (aS), and MgO solid during C ₂ S溶量(bM) and SO ₃ dissolved amount together (bS), the following equation (1) and high belite cement composition according to claim 1, which satisfies the equation (2).
xM × 0.5 <A × aM + B × bM (1)
xS × 0.5> A × aS + B × bS (2)
(Where A represents the content (% by mass) of C ₃ S in the component (X), B represents the content (% by mass) of C ₂ S in the component (X), and xM and xS The unit is mass%.) Blaine specific surface area, high belite cement composition according to any one of claims 1 to 4 is 3,100~3,800cm ² / g.