JP6702238B2 - Hydraulic composition - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a hydraulic composition having a long-term strength-developing property and a large elongation rate.

  Blast-furnace cement containing cement clinker and slag powder has a low initial strength development of about 3 days old compared to ordinary Portland cement, but long-term strength development of 28 days old or more is not the same as ordinary Portland cement. It is known to be comparable. In order to improve the long-term strength development of a hardened product using a hydraulic composition containing slag powder at 28 days or older, for example, the Blaine specific surface area of the slag powder or cement contained in the hydraulic composition is adjusted. Physical methods such as increasing the content and decreasing the content of slag powder can be considered.

However, when increasing the Blaine specific surface area of slag powder or cement, energy is required for pulverization, which causes problems such as an increase in manufacturing cost and a decrease in fluidity of the hydraulic composition. Further, if the content of slag powder is reduced, the amount of slag powder generated as a by-product in steel production decreases, and the content of cement relatively increases, leading to an increase in manufacturing cost and CO ₂ However, there is a problem in that it cannot be linked to the reduction of the generation amount of.

The cement clinker contained in the hydraulic composition contains C ₃ S (alite), C ₂ S (beelite), C ₃ A (aluminate), and C ₄ AF (ferrite) as mineral compositions. .. In addition to physical means such as increasing the Blaine specific surface area of slag powder or cement and reducing the amount of slag powder used, the hydraulic composition is configured as a factor that affects the long-term strength development of the cured product. It may be possible to focus on the mineral composition of the cement used.

For example, in Patent Documents 1 to 4, focusing on the content of the M1 phase in C ₃ S in the mineral composition of the cement clinker, the content phase of the M1 phase in C ₃ S is 40% by mass or more. It is disclosed that, including a cement clinker, and in relation to the content of other components such as the Li content in the cement composition, the shrinkage reduction performance and the initial strength development are affected.

JP, 2005-231951, A JP, 2014-189456, A JP, 2013-147392, A JP 2012-025635 A

The present invention focuses on the mineral composition of cement clinker in addition to physical means such as increasing the Blaine specific surface area of slag powder and cement and reducing the amount of slag powder used. The present invention focuses on the content of the M1 phase in C ₃ S in the mineral composition as a factor affecting the long-term strength development, and the content of the M1 phase in C ₃ S is 40% by mass or less. By including a specific cement clinker of the above, it is possible to provide a hydraulic composition having a desired short-term strength development, a large long-term compression strength, and a long-term strength development with a large elongation. To aim.

As a result of intensive studies to achieve the above-mentioned object, the present inventors have found that the content of C ₃ S, which is one of the mineral compositions of cement clinker, and the M1 phase among the crystal polymorphs contained in C ₃ S. Content, a cement clinker having a specific amount of free lime (f-CaO), and less than 50% by mass of slag powder have a desired short-term compressive strength and long-term compression strength. The present invention has been completed by finding that the compressive strength of No. 3 is large and the elongation rate of long-term strength development is large. That is, the present invention is as follows.

[1] Cement clinker having C ₃ S of 50% by mass or more calculated by Borg formula, containing 40% by mass or less of M1 phase in C ₃ S, and having a content of free lime of 1.2% by mass or less And a slag powder, and the content of the slag powder is 1% by mass or more and less than 50% by mass based on the total mass, and a hydraulic composition.
[2] The hydraulic composition according to the above [1], wherein the amount of SO ₃ is 1.0 to 3.0 mass% based on the total mass.
[3] The hydraulic composition according to the above [1] or [2], which has a Blaine specific surface area of 3500 cm ² /g or more.
[4] the _{C 2} S is 10 to 25 wt% calculated by Borg type cement clinker, a _{C 3} A is 8-12 wt%, and _C 4 AF are 8-12 wt%, the above [1] ~ The hydraulic composition according to any one of [3].
[5] The hydraulic composition according to any one of [1] to [4], wherein the content of the slag powder is more than 5% by mass and 49% by mass or less based on the total mass.

  According to the present invention, it is possible to provide a hydraulic composition having a desired short-term compressive strength, a large long-term compressive strength, and a long-term strength-developing elongation rate.

Hereinafter, the preferred embodiments of the present invention will be described, but the present invention is not limited thereto.
The hydraulic composition according to the embodiment of the present invention has C ₃ S calculated by the Borg equation of 50% by mass or more, contains M1 phase in C ₃ S of 40% by mass or less, and has a content of free lime. It contains cement clinker of 1.2 mass% or less and slag powder, and the content of the slag powder is 1 mass% or more and less than 50 mass% based on the total mass.

[Cement clinker]
The cement clinker has C ₃ S calculated by the Borg equation of 50% by mass or more, contains 40% by mass or less of M1 phase in C ₃ S, and has a free lime (f-CaO) content of 1.2% by mass. % Or less.
Cement clinker, as mineralogy, _C 3 S (alite phase) consisting of _{3CaO · SiO 2, C 2 S} ( belite phase) consisting of 2CaO · SiO _2, consisting of _{3CaO · Al 2 O 3 C 3} A ( Aluminate phase) and C ₄ AF (ferrite phase) composed of 4CaO·Al ₂ O ₃ ·Fe ₂ O ₃ .

The mineral composition contained in the cement clinker can be calculated from the Borg equation shown in the following equations (1) to (4).
_{C 3 S = (4.07 × CaO} ) - (7.60 × SiO 2) - (6.72 × Al 2 O 3) - (1.43 × Fe 2 O 3 + 2.85 × SO 3) (1 )
C ₂ S=(2.87×SiO ₂ )−(0.754×C ₃ S) (2)
_{C 3 A = (2.65 × Al} 2 O 3) - (1.69 × Fe 2 O 3) (3)
C ₄ AF=3.04×F ₂ O ₃ (4)

Among the mineral compositions contained in the cement clinker, C ₃ S is known to affect the short-term strength development, and when the content of C ₃ S in the cement clinker is 50% by mass or more, a desired short-term strength can be obtained. It is possible to obtain a hydraulic composition having a large long-term compressive strength and a long-term strength-developing elongation rate while maintaining the compressive strength. If the C ₃ S contained in the cement clinker is less than 50% by mass, the desired short-term strength development cannot be obtained.
In the present specification, the elongation rate of long-term strength development refers to a value obtained by dividing the compressive strength of a long-term cured product by the compressive strength of a short-term cured product. For example, the value obtained by dividing the compressive strength of a 28-day-old cured product by the compressive strength of a 3-day-aged cured product is the elongation rate of strength development from 3 days to 28 days-old (“28 dS/3 dS”). It is referred to as). Further, the value obtained by dividing the compressive strength of the cured product of 7 days old by the compressive strength of the cured product of 3 days old, the elongation rate of the strength development from 3 days to 7 days old (“7dS/3dS” It is referred to as).

The cement clinker is calculated by Borg formula, _{C 2} S is 10 to 25 mass%, _{C 3} A is 8-12 wt%, and _C 4 are preferably AF is 8-12 wt%.
When each of the C ₃ S, C ₂ S, C ₃ A, and C ₄ AF mineral compositions of the cement clinker is in the above range, the desired short-term strength development is achieved, and the long-term compressive strength is large, and It is possible to provide a hydraulic composition having a long-term strength developing property and a large elongation rate.
The cement clinker has C ₃ S of 50 to 65 mass%, C ₂ S of 15 to 25 mass%, C ₃ A of 9 to 12 mass% and C ₄ AF of 8 to 11 mass% calculated by the Borg formula. It is more preferable that C ₃ S calculated by the Borg equation is 52 to 65 mass %, C ₂ S is 15 to 20 mass %, C ₃ A is 9 to 11 mass %, and C ₄ AF is 8 to 10 mass. % Is more preferable.

C ₃ S of the cement clinker includes 7 types of crystal polymorphs. The 7 types of crystal polymorphs include triclinic T1 phase, T2 phase, T3 phase, monoclinic M1 phase and M2 phase. , M3 phase, and R phase that is a rhombohedral crystal. Long when the content of M1 phase of _{C 3} S in the cement clinker (M1 _{/ C} 3 S) exceeds 40 _{wt% (M1 / C 3 S>} 0.4), the hydraulic composition comprising a slag powder Compression strength tends to be small. From the viewpoint of obtaining a long-term compressive strength is large cured product, the content of M1 phase in C _{3 S} in the cement clinker used in the hydraulic composition containing slag powder (M1 / C 3 _S) is 40 wt% or less (M1/C ₃ S≦0.4) is preferably 38 mass% or less (M1/C ₃ S≦0.38), and more preferably 36 mass% or less (M1/C ₃ S≦0.36). With the desired short-term strength development, in order to obtain a growth rate of long-term strength development, M1 phase in C _{3 S} in the cement clinker used in the hydraulic composition containing slag powder (M1 / C 3 _S) The content is usually 5 mass% or more, preferably 10 mass% or more.

The content of M1 phase in C _{3 S} in the cement clinker (M1 / C 3 _S) performs measurement by X-ray diffraction method for the cement clinker, by the X-ray diffraction profile obtained is analyzed by the Rietveld method Can be measured. The Rietveld method is a method for directly refining crystal structure parameters and lattice constants for the entire powder X-ray diffraction pattern.

  The cement clinker has a free lime (f-CaO) content of 1.2% by mass or less. Free lime (f-CaO) is free calcium oxide (CaO) remaining in the cement clinker without reacting with silicon dioxide or aluminum oxide when the cement raw material is fired. If the free lime contained in the cement clinker exceeds 1.2% by mass, the elongation rate of long-term strength development decreases. The content of free lime (f-CaO) in the cement clinker is preferably 1.0% by mass or less, more preferably 0.9% by mass or less, still more preferably 0.8% by mass or less, and usually 0%. 1 mass% or more. The content of free lime in the cement clinker can be measured by the method for quantifying JCAS I-01 free calcium oxide.

The content of MgO in the cement clinker is preferably 0.5 to 2.5% by mass. The MgO content contained in the cement clinker contributes to the formation of the M3 phase in C ₃ S, and when the MgO content is high, the content of the M1 phase in C ₃ S tends to be low. The MgO content in the cement clinker is more preferably 1.0 to 2.5 mass% with respect to the total amount (100 mass%) of the cement clinker. The MgO content in the cement clinker can be measured according to the chemical analysis method of JIS R 5202 cement or the fluorescent X-ray analysis method of JIS R 5204 cement.

The cement clinker has a C ₃ S content of 50 mass% or more calculated by the Borg formula, a M1 phase content of C ₃ S of 40 mass% or less, and a free lime content of 1.2. As long as the content is at most% by mass, the cement clinker used for the cement satisfying the standard of the ordinary Portland cement or the early strength Portland cement defined in JIS R5210 "Portland cement" can be used.

[Slag powder]
The hydraulic composition of the present disclosure contains slag powder, and the content of the slag powder is 1% by mass or more and less than 50% by mass based on the total mass. When the content of the slag powder in the hydraulic composition is 50% by mass or more, the elongation rate of strength development in the long term is large, but the compression strength of the cured product in the short term and the long term becomes small. The content of slag powder in the hydraulic composition is preferably more than 5 mass% and 49 mass% or less, more preferably 10 mass% or more and 49 mass% or less, and further preferably 20 mass% or more 49. The content is preferably not more than 30% by mass, more preferably more than 30% by mass and not more than 49% by mass.
The slag powder preferably has a basicity of 1.6 or more as specified in JIS R5211 "Blast furnace cement".

The slag powder has a Blaine specific surface area of preferably 3500 to 5000 cm ² /g, more preferably 3600 to 4900 cm ² /g, and further preferably 3650 to 4850 cm ² /g. When the Blaine specific surface area of the slag powder is 3500 to 5000 cm ² /g, the Blaine specific surface area of the hydraulic composition containing the slag powder can be set to 3500 cm ² /g or more, and the elongation rate of long-term strength development can be improved. A good hydraulic composition can be obtained. The Blaine specific surface area of the slag powder can be measured in accordance with JIS R5201 “Physical test method for cement”.

[SO ₃ amount]
The hydraulic composition preferably has an SO ₃ amount of 1.0 to 3.0 mass% based on the total mass. The SO ₃ amount of the hydraulic composition is more preferably 1.0 to 2.5% by mass, further preferably 1.5 to 2.5% by mass, and still more preferably, based on the total mass. It is 1.7 to 2.2 mass %. When the hydraulic composition contains an appropriate amount of SO ₃ , the production amount of ettringite when mixed with water can be appropriately controlled, and a decrease in strength development can be suppressed. When the amount of SO ₃ in the hydraulic composition is 1.0 to 3.0% by mass, fluidity can be ensured while suppressing deterioration in strength development. The amount of SO ₃ in the hydraulic composition can be measured according to JIS R 5202 “Cement chemical analysis method” or JIS R 5204 “Cement fluorescent X-ray analysis method”.

The hydraulic composition has a Blaine specific surface area of preferably 3500 cm ² /g or more. Blaine specific surface area of the hydraulic composition is more preferably 3500~4500cm ² / g, more preferably from 3500~4000cm ² / g. When the Blaine specific surface area of the hydraulic composition is 3500 cm ² /g, it is possible to obtain a hydraulic composition having a large long-term compressive strength and a long-term strength-developing elongation rate. The Blaine specific surface area of the hydraulic composition can be measured according to JIS R5201 "Physical test method for cement".

[Production of hydraulic composition]
As a method for producing a hydraulic composition, for example, a step of producing a cement clinker by firing a cement raw material in which each raw material is mixed, so as to obtain a composition capable of obtaining a target cement clinker, and the obtained cement clinker The step of crushing cement clinker, slag, and gypsum by adding gypsum so that the desired SO ₃ amount is obtained, or the obtained cement clinker is added with gypsum so that the desired SO ₃ amount is obtained, and the cement clinker is added. And gypsum are crushed to produce a cement composition, and slag and slag to which gypsum is added so that the target SO ₃ amount is obtained or only slag is crushed to produce slag powder having a desired brane specific surface area, Examples include a method of producing the cement composition and a slag powder by a step of mixing. The method for producing a hydraulic composition may include a step of pulverizing granular slag in advance before mixing with cement.

(Cement clinker raw material)
As the raw material of the cement clinker, compounds such as oxides and carbonates containing the elements constituting the cement clinker such as Ca, Si, Al and Fe can be used. Examples of natural raw materials include limestone, clay, silica stone, and iron oxide. In addition, examples of raw materials include raw materials for waste such as construction soil, blast furnace slag, and fly ash. The mixing ratio of the cement raw materials is not particularly limited, and the mixing ratio of the raw materials can be determined so that the desired mineral composition can be obtained.

(Baking)
Firing can be usually performed using an electric furnace or a rotary kiln. Firing to obtain the cement clinker may use stepwise firing. As the stepwise firing, for example, after performing the first firing at a specific first temperature for a predetermined time, the temperature is raised (or lowered) to a target temperature over a predetermined time, and a predetermined time is given. The second firing may be performed at a specific second temperature that has been raised (or lowered). For example, there is a method in which the cement raw material is subjected to a first firing at 1000° C. for 30 minutes, heated to 1450° C. in 30 minutes, and then subjected to a second firing at 1450° C. for 15 minutes to obtain a cement clinker. ..

(Mixed with plaster)
The obtained cement clinker can be mixed with and/or pulverized so as to have a target Blaine specific surface area by adding an amount of gypsum to a target SO ₃ amount to obtain a cement composition. A crusher such as a ball mill can be used for mixing and/or crushing.

(Mixed with slag powder)
The obtained cement composition can be mixed with slag powder and/or pulverized to obtain a hydraulic composition having a desired Blaine specific surface area. The slag powder may be obtained by crushing granular slag in advance and mixing it with cement as slag powder. A crusher such as a ball mill can be used for mixing and/or crushing.

  Next, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples.

(Examples 1 to 4, Reference Example 1 )
Raw materials such as limestone, silica stone, coal ash, clay, construction soil, sludge, iron source, and blast furnace slag meet JIS R5210 standard Portland cement standards, and M1 phase in C ₃ S is shown in Table 1. Formulated to have the composition shown. Adjustment of the content of M1 phase in _{C 3 S (M1 / C 3} S) was performed by the addition amount of magnesium oxide (MgO). Put the blended raw materials in an electric furnace, perform the first baking at 1000° C. for 30 minutes, then raise the temperature from 1000° C. to 1450° C. over 30 minutes, and further baking at 1450° C. for 15 minutes Then, it was rapidly cooled to obtain a normal Portland cement clinker having the mineral composition shown in Table 1.
Gypsum was added to the obtained ordinary Portland cement clinker so that the amount of SO ₃ became the value shown in Table 1, and mixed with a ball mill so that the Blaine specific surface area became 3350±50 cm ² /g, and the cement composition was obtained. Obtained. Gypsum was added in such an amount that the amount of SO ₃ in the obtained cement composition was 2.0±0.1% by mass.
The granular slag was crushed in advance using a ball mill so that the Blaine specific surface area was 4500±50 cm ² /g to obtain slag powder.
60 mass% of the cement composition and 40 mass% of the slag powder were mixed to obtain a hydraulic composition having a Blaine specific surface area shown in Table 1.

(Comparative Examples 1 to 3)
A cement clinker was produced in which the M1 phase in C ₃ S had the composition shown in Table 1, and a cement composition was produced in the same manner as in Example 1. No slag powder was mixed with the obtained cement composition to obtain hydraulic compositions of Comparative Examples 1 to 3.

(Comparative Examples 4-5)
Comparative Examples 4 to 5 were performed in the same manner as in Example 1 except that a cement clinker having a composition in which the M1 phase in C ₃ S exceeded 40 mass% (specifically, the composition shown in Table 1) was used. A hydraulic composition of was obtained.

Chemical analysis of cement clinker Based on JIS R5204 “Method for analyzing fluorescent X-ray of cement”, the content (mass %) of SiO ₂ , Al ₂ O ₃ , Fe ₂ O ₃ , CaO and MgO in the cement clinker was determined. It was measured.

Content of free lime (f-CaO) in the cement clinker The content of free lime (f-CaO) in the cement clinker was measured by the method of quantifying JCAS I-01 free calcium oxide.

Mineral composition of cement clinker Measurement of content (mass %) of SiO ₂ , Al ₂ O ₃ , Fe ₂ O ₃ , and CaO in the cement clinker measured according to “method of fluorescent X-ray analysis of cement” of JIS R5204 From the results, the mineral compositions of C ₃ S, C ₂ S, C ₃ A, and C ₄ AF were calculated based on the Borg equations (1) to (4).

Acquisition of content and X-ray diffraction profile of M1 phase in C ₃ S of cement clinker and identification of cement clinker Powder X-ray diffractometer (X'Part Powder, manufactured by Panalical Co., Ltd.) With the size: 0.17°, the scan speed: 0.1012°/s, the voltage: 45 kV, and the current: 40 mA, X-ray diffraction measurement was performed on the cement clinker of each Example and Comparative Example to obtain an X-ray diffraction profile. ..

Regarding the obtained X-ray diffraction profile, the software for crystal structure analysis provided in the powder X-ray diffraction apparatus (X'Part High Score Plus version 2.1b, manufactured by Panalytical Co., Ltd.) was used. Identification was performed. The minerals contained in the identified cement clinker are C ₃ S-M1 (M1 phase), C ₃ S-M3 (M3 phase), C ₂ S-α'(α' phase), and C ₂ S-β ( β phase), C ₃ A-cubic (cubic crystal), C ₃ A-ortho (orthorhombic crystal), C ₄ AF, gypsum (gypsum), bassanite (hemihydrate gypsum), K ₃ Na(SO ₄ ) ₂ , Potassium sulphate (K ₂ SO ₄ ) and beta-Arcanite (alkanite).

-Analysis by Rietveld method Next, the mass% of the cement clinker identified as described above was quantified using the analysis function by the Rietveld method installed in the software. Here, the basic crystal structure data (lattice constant, scale factor, etc.) of the cement clinker is input as the initial value from the ICDS (inorganic crystal structure database of the Chemical Information Society of Japan) to the cement clinker. Next, the lattice constant, scale factor, etc. were selected as parameters necessary for the refinement of the crystal structure parameters of the entire cement clinker, and the refinement operation was performed. Thereby, after the refinement operation is repeated by changing the parameters required for the refinement so that the theoretical profile is fitted to the actually measured X-ray diffraction profile, the scale factor refined finally, The content (mass %) of each mineral contained in the identified cement clinker was obtained. The sum of the _C 3 S-M1 phase amount and _C 3 S-M3 Airyo obtained by Rietveld analysis to calculate _{C 3} S amount (Rietveld quantitative _value), from C 3 S-M1 Airyo, C The M1 phase in ₃ S (M1/C ₃ S) was calculated. The results are shown in Table 1.

Blaine Specific Surface Area The Blaine specific surface area of the cement composition, the slag powder, and the hydraulic composition was measured according to JIS R5201 “Cement physical test method”. The results are shown in Table 1.

In compliance with SO ₃ amount JIS R5202 "Methods for chemical analysis of cement" it was measured SO ₃ amount of the cement composition. From SO ₃ content of the product of the content and cement composition of the cement composition of the hydraulic composition was calculated SO ₃ amount of hydraulic composition. The results are shown in Table 1.

Compressive Strength of Mortar The hydraulic compositions of each Example and Comparative Example have a water/cement ratio of 50% by mass in accordance with “11 Strength Test” of JIS R5201 “Cement Physical Test Method”. Water was added to prepare mortar containing each hydraulic composition, placed in three metal molds of 40×40×160 mm, and demolded after 20 to 24 hours in a humidity box to give mortar specimens. It was made. Three mortar specimens prepared for each material age were aged in water at 20° C., and the compressive strength at each material age was measured in accordance with “11 Strength test” of JIS R5201 “Physical test method for cement”. .. The value obtained by dividing the compressive strength at 7 days old by the compressive strength at 3 days old is defined as the elongation rate of the compressive strength at 7 days old (7dS/3dS), and the compressive strength at 28 days old is The value divided by the compressive strength at 3 days old was calculated as the elongation rate (28 dS/3 dS) at 28 days old compressive strength. The results are shown in Table 1.

As shown in Table 1, the mortar compressive strengths using the hydraulic compositions of Examples 1 to 4 and Reference Example 1 became larger when the compressive strength at the age of 3 days exceeded 18.0 N/mm ^2. The compressive strength increased to over 60 N/mm ² at 28 days old, and the elongation rate of 28 days old from 3 days old exceeded 2.7 and increased. From these results, the hydraulic compositions of Examples 1 to 4 and Reference Example 1 have a desired initial compressive strength, a long-term compressive strength, and a long-term strength-developing elongation-hardening curing. It was confirmed that the product was obtained.
On the other hand, as for the mortar compressive strength using the hydraulic compositions of Comparative Examples 1 to 3 containing no slag powder, the elongation rate from 3 days old to 28 days old was as small as 2.0 or less.
Also, _{C 3} content of M1 phase in S exceeds 40 _{mass% (M1 / C 3 S>} 0.4) ordinary Portland cement hydraulic composition of Comparative Example 4 and 5 using the clinker, 28 days The mortar compressive strength of the material age was less than 60 N/mm ² .

(Example 5-6, Example 2-3, and Comparative Example 6)
The content of free lime (f-CaO) was adjusted to the content shown in Table 2. The content of free lime (f-CaO) was adjusted by adjusting the firing time. Example 1 was repeated except that the content of free lime was changed and the ordinary Portland cement clinker having the mineral composition shown in Table 2 was obtained in the same manner as in Example 1 and that this ordinary Portland cement clinker was used. A hydraulic composition was obtained in the same manner as in 1. In the same manner as in Example 1, the ordinary Portland cement clinker, the cement composition, the slag powder, the mineral composition of the hydraulic composition, the chemical components, and the physical properties were measured to determine the compressive strength of the mortar using the hydraulic composition. It was measured. The results are shown in Table 2.

As shown in Table 2, as for the mortar compressive strength using the hydraulic compositions of Examples 5 to 6 and Reference Examples 2 to 3 , the desired initial compressive strength was obtained, and the compressive strength at 28 days old was obtained. Was greater than 60 N/mm ^2, and the elongation rate at 28 days old from 3 days old was greater than 2.8. From this result, it was confirmed that the hydraulic compositions of Examples 5 to 6 and Reference Examples 2 to 3 had a large elongation rate of long-term strength development.
On the other hand, the hydraulic composition of Comparative Example 6 containing ordinary Portland cement clinker having a large content of free lime (f-CaO) exceeding 1.2 mass% has a mortar compressive strength of 28 days old of 60 N/. It was as small as less than mm ² .

(Examples 7 to 11 )
Except that the cement composition using the ordinary Portland cement clinker shown in Table 3 and the slag powder having the Blaine specific surface area shown in Table 3 were mixed so that the Blaine specific surface area becomes the value shown in Table 3. A hydraulic composition was obtained in the same manner as in Example 1. In the same manner as in Example 1, the ordinary Portland cement clinker, the cement composition, the slag powder, the mineral composition of the hydraulic composition, the chemical components, and the physical properties were measured to determine the compressive strength of the mortar using the hydraulic composition. It was measured. The results are shown in Table 3.

As shown in Table 3, as for the mortar compressive strength using the hydraulic compositions of Examples 7 to 11 , the desired initial compressive strength was obtained, and the elongation percentage from 28 days old to 3 days old was obtained. Has grown to over 2.8. As shown in Example 7 , when the hydraulic composition has a Blaine specific surface area of less than 3500 cm ² /g, the elongation rate from 3 days old to 28 days old is larger than 2.8, but 28 days old. The material age was as small as less than 60 N/mm ² .

(Examples 12 to 14 and Comparative Example 7)
Except that the cement composition using the ordinary Portland cement clinker shown in Table 4 and the slag powder shown in Table 4 were mixed so that the mixing ratio of the cement composition and the slag powder would be the values shown in Table 4. A hydraulic composition was obtained in the same manner as in Example 1. In the same manner as in Example 1, the ordinary Portland cement clinker, the cement composition, the slag powder, the mineral composition of the hydraulic composition, the chemical composition, and the physical properties were measured to determine the compressive strength of the mortar using the hydraulic composition. It was measured. The results are shown in Table 4.

As shown in Table 4, as for the mortar compressive strength using the hydraulic compositions of Examples 12 to 14 , the desired initial compressive strength was obtained, and the elongation rate from 28 days old to 3 days old was obtained. Has grown to over 2.8. As shown in Comparative Example 7, when the content of slag powder in the hydraulic composition exceeds 50 mass% and increases, the elongation rate from 3 days old to 28 days old exceeds 2.8 but is large. , 28 days old compressive strength was less than 60 N/mm ² .

According to the present invention, to increase the Blaine specific surface area of the slag powder and cement, without the use of physical means such as reducing the amount of slag powder, manufacturing cost increases and CO ₂ generated by the use of physical means Provided is a hydraulic composition containing a specific amount of slag powder, which suppresses an increase in the amount of the compound and contains a specific cement clinker having a low M1 phase in C ₃ S and having a long-term strength-developing elongation rate. be able to.

Claims (4)

C ₃ S calculated by Borg formula is 50 to 65 mass %, C ₂ S is 15 to 25 mass %, C ₃ A is 9 to 12 mass %, and C ₄ AF is 8 to 11 mass %, and C is calculated. ₃ S contains M1 phase in 36 mass% or less, the content of free lime measured according to JCAS I-01 is 0.8 mass% or less cement clinker, and slag powder, and the slag powder Is 5% by mass or more and 49% by mass or less based on the total mass of the hydraulic composition. The hydraulic composition according to claim 1, wherein the SO ₃ amount is 1.0 to 3.0% by mass based on the total mass. The hydraulic composition according to claim 1, which has a Blaine specific surface area of 3500 cm ² /g or more.   The hydraulic composition according to any one of claims 1 to 3, wherein the content of the slag powder is more than 5% by mass and 49% by mass or less based on the total mass.