JP2015081209A - Low hydration heat cement composition and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low hydration heat cement composition capable of reducing hydration heat of a cement composition while maintaining proper strength development property of mortar or concrete and a manufacturing method therefor.SOLUTION: There is provided a low hydration heat cement composition having the Mo content of 68 to 120 mg/kg and the Cu content of 330 to 440 mg/kg. The low hydration heat cement composition has the CS content of 30 to 40 mass%, the CS content of 40 to 55 mass%, the CA content of 1 to 8 mass%, and the CAF content of 7 to 15 mass%.

Description

  The present invention relates to a low-hydration heat cement composition and a method for producing the same.

  The heat of hydration of the cement composition is an exotherm when a component contained in the cement composition reacts with water to form a hydrate. In general, as the amount of hydrate produced increases, the strength of the mortar or concrete increases, but at the same time, the heat of hydration associated with the reaction of the cement composition with water also increases. In other words, it is a general tendency that the heat of hydration of the cement composition increases as the strength development of mortar and concrete increases.

  However, from the viewpoint of the durability of concrete, it is preferable that the heat of hydration of the cement composition is small. For this reason, a cement composition that can reduce the heat of hydration without deteriorating the strength of the concrete has been demanded by cement users who aim for concrete having excellent durability.

As a method for reducing the heat of hydration of a cement composition, for example, a method of controlling a main mineral composition (reduction of the amount of C ₃ S, C ₃ A, etc.) such as medium heat and low heat Portland cement clinker is known. (Patent Document 1). In addition, the mineral composition of the cement clinker is set within a specific range, and the Mo content per kg of the clinker is set to 30 mg or less, so that the heat of hydration is reduced and the strength development property is equivalent to that of the moderately heated cement. A cement composition that improves fluidity due to a water reducing agent is disclosed (Patent Document 2).

On the other hand, as a method for improving the strength development property of concrete, means such as “fineness of fineness (increasing the Blaine specific surface area)”, “increasing the amount of C ₃ S”, etc. are used (non-patent) Reference 1).

JP 61-097154 A JP 2013-87036 A

Japan Cement Association, “4. Types and uses of cement”, common sense of cement, 2004, pp. 11-17

However, the cement composition in which the amount of C ₃ S and the amount of C ₃ A proposed in the above-mentioned Patent Document 1 is controlled to a specific amount is more material than the conventional low-heat-generation mixed cement composition commercially available. The compressive strength at the age of 28 days or 91 days is lowered. That is, in the method of controlling the main mineral composition as in Patent Document 1, it is the actual situation that the strength development of the concrete also decreases when the heat of hydration of the cement composition is reduced.

  In addition to natural raw materials, cement clinker uses industrial waste, general waste, municipal waste incineration ash, and / or construction waste soil as a substitute for clinker raw materials. When the amount of waste used as a raw material increases, the Mo content also increases, and the Mo content per kg of clinker exceeds 30 mg. However, in the above-mentioned Patent Document 2, effects such as reduction in heat of hydration in a range where the Mo content per kg of clinker exceeds 30 mg have not been confirmed.

On the other hand, if the strength development of concrete is improved by means such as “to make the degree of fineness (increase the Blaine specific surface area)” or “increase the amount of C ₃ S” as in Non-Patent Document 1, hydration will occur. Heat increases.
In addition, when the amount of waste used increases, it becomes a region where the Mo content is larger than that of Patent Document 2, but this region has not been studied.

  The present invention has been made in view of the above circumstances, and is a low hydration heat cement composition capable of reducing the heat of hydration of a cement composition while maintaining appropriate strength development of mortar and concrete. And it aims at providing the manufacturing method.

  As a result of intensive studies to achieve the above object, the present inventors have found that the Mo (molybdenum) of the cement composition is used to reduce the heat of hydration of the cement composition while maintaining the strength development of mortar and concrete. The inventors found that it is effective to control the content and Cu (copper), and completed the present invention.

The present invention is a low-hydration thermal cement composition having a Mo content of 68 to 120 mg / kg and a Cu content of 330 to 440 mg / kg. The low-hydration thermal cement composition has a C ₃ S amount of 30 to 40% by mass, a C ₂ S amount of 40 to 55% by mass, a C ₃ A amount of 1 to 8% by mass, and a C ₄ AF amount, as calculated by the Borg formula. Is preferably 7 to 15% by mass.

  Further, the present invention provides limestone, quartzite, coal ash, clay, blast furnace slag, construction generation so that the Mo content in the cement composition is 68 to 120 mg / kg and the Cu content is 330 to 440 mg / kg. (A) a step of preparing a cement clinker by preparing and adjusting a raw material basic unit of a raw material selected from the group consisting of soil, sewage sludge, hydrocake, municipal waste incineration ash, and iron source; And a step (B) of mixing and pulverizing the obtained cement clinker and gypsum, and a method for producing a low-hydration thermal cement composition.

  According to the present invention, there is provided a low-hydration heat cement composition that reduces the heat of hydration on the age of 28 days to less than 330 J / g while maintaining the appropriate strength development of mortar and concrete, and a method for producing the same. be able to.

It is a figure which shows the relationship between Mo content in a cement composition, and the heat of hydration of a cement composition. It is a figure which shows the relationship between Mo content in a cement composition, and the mortar compressive strength of a cement composition. It is a figure which shows the relationship between Cu content in a cement composition, and the heat of hydration of a cement composition. It is a figure which shows the relationship between Cu content in a cement composition, and the mortar compressive strength of a cement composition.

  Hereinafter, preferred embodiments of the present invention will be described.

  The low hydration heat cement composition of the present invention has a Mo content of 68 to 120 mg / kg and a Cu content of 330 to 440 mg / kg.

  Mo and Cu contents are minor components of the cement composition. The present inventors have found that there is a correlation between the Mo content and Cu content of the cement composition and the heat of hydration of the cement composition. The low hydration thermal cement composition of the present invention reduces heat of hydration while maintaining appropriate strength development of mortar and concrete by controlling the Mo content and Cu content to be in a specific range. can do. The content of Mo and Cu in the cement composition is the content (mg) with respect to 1 kg (mass) of the cement composition. Standard test method JCAS I-52 2000 “ICP emission spectroscopic analysis and electric heating atomic absorption analysis” It can be measured according to "Method for quantifying trace components in cement by".

  The Mo content in the low-hydration heat cement composition is 68 to 120 mg / kg, preferably 68 to 110 mg / kg, more preferably 68 to 100 mg / kg, and still more preferably 70 to 95 mg / kg. kg. The Cu content in the low-hydration heat cement composition is 330 to 440 mg / kg, preferably 330 to 420 mg / kg, more preferably 330 to 380 mg / kg, and still more preferably 330 to 370 mg / kg. kg. When the Mo and / or Cu content of the low-hydration heat cement composition is out of the range, the effect of reducing the heat of hydration becomes small.

The low-hydration thermal cement composition of the present invention preferably has a C ₃ S amount of 30 to 40% by mass, a C ₂ S amount of 40 to 55% by mass, a C ₃ A amount of 1 to 8% by mass, and a C ₄ AF. The amount is 7 to 15% by mass, more preferably the C ₃ S amount is 30 to 40% by mass, the C ₂ S amount is 40 to 50% by mass, the C ₃ A amount is 2 to 7% by mass, and the C ₄ AF amount. Is 8 to 12% by mass, more preferably the C ₃ S amount is 32 to 38% by mass, the C ₂ S amount is 43 to 47% by mass, the C ₃ A amount is 3 to 6% by mass, and the C ₄ AF amount is The amount of C ₃ S is 34 to 37% by mass, the amount of C ₂ S is 43 to 45% by mass, the amount of C ₃ A is 3 to 5% by mass, and the amount of C ₄ AF is 9%. -10 mass%. When the mineral composition of the cement composition is within the above range, the strength of the cement composition can be improved while reducing the heat of hydration of the cement composition, and the strength development of mortar and concrete can be maintained. can do.

Here, the amount of C ₃ S (alite phase), the amount of C ₂ S (belite phase), the amount of C ₃ A (aluminate phase) and the amount of C ₄ AF (ferrite phase) in the cement composition are as follows: It is calculated by the Borg equation [1] to [4].

C ₃ S amount (% by mass) = 4.07 × CaO amount (% by mass) −7.60 × SiO ₂ amount (% by mass) −6.72 × Al ₂ O ₃ amount (% by mass) −1.43 × Fe ₂ O ₃ amount (% by mass) -2.85 × SO ₃ amount (% by mass) (1)
C ₂ S amount (% by mass) = 2.87 × SiO ₂ amount (% by mass) −0.754 × C ₃ S amount (% by mass) (2)
C ₃ A amount (mass%) = 2.65 × Al ₂ O ₃ (mass%) − 1.69 × Fe ₂ O ₃ (mass%)... [3]
C ₄ AF amount (mass%) = 3.04 × Fe ₂ O ₃ (mass%)... [4]

“CaO”, “SiO ₂ ”, “Al ₂ O ₃ ” and “Fe ₂ O ₃ ” in the formula are respectively the cement compositions of CaO, SiO ₂ , Al ₂ O ₃ and Fe ₂ O _{3 in} the cement composition. It is the content rate (mass%) with respect to the whole mass of a thing. These content ratios can be measured by JIS R 5202: 2010 “Cement chemical analysis method” or JIS R 5204: 2002 “Cement X-ray fluorescence analysis method”.

The low hydration heat cement composition of the present invention has a Na ₂ O content of preferably 0.10 to 0.30 mass%, more preferably 0.12 to 0.28 mass%, and even more preferably 0.15. It is -0.25 mass%, Most preferably, it is 0.17-0.20 mass%.
The low hydration thermal cement composition of the present invention preferably has a K ₂ O content of 0.10 to 0.40 mass%, more preferably 0.12 to 0.38 mass%, and even more preferably 0.15. It is -0.35 mass%, Most preferably, it is 0.20-0.30 mass%.
If the Na ₂ O or K ₂ O content of the low-hydration thermal cement composition is within the above range, the fluidity of the cement composition is maintained moderately, and the strength development of mortar and concrete is also maintained. In addition, the heat of hydration of the cement composition can be further reduced. The Na ₂ O content and K ₂ O content of the cement composition are the content ratio (mass%) with respect to the total mass, and this content ratio is in accordance with JIS R 5202: 1998 “Chemical analysis method of Portland cement”. Can be measured.

In addition, the low hydration heat cement composition of the present invention has an SO ₃ content of preferably 1.8 to 2.6% by mass, more preferably 1.9 to 2.5% by mass, and even more preferably 1.9. It is -2.4 mass%, Most preferably, it is 2.0-2.4 mass%. When the SO ₃ content of the low-hydration thermal cement composition is within the above range, while maintaining the fluidity of the cement composition appropriately, the strength development of mortar and concrete is also maintained, The heat of hydration can be further reduced. The SO ₃ content of the cement composition is a content ratio (mass%) with respect to the total mass, and this content ratio can be measured according to JIS R 5202: 1998 “Chemical analysis method of Portland cement”.

  The Zn content is a minor component of the cement composition. The Zn content in the cement composition is the content (mg) relative to 1 kg (mass) of the cement composition, the cement association standard test method JCAS I-52 2000 “Cement by ICP emission spectroscopy and electric heating atomic absorption spectrometry” It can be measured according to the "quantitative method of trace components in".

The Zn content in the low-hydration heat cement composition is preferably 440 mg / kg or more, more preferably 470 mg / kg or more, further preferably 500 mg / kg or more, particularly preferably 520 mg / kg or more. It is. Moreover, Zn content in a cement composition becomes like this. Preferably it is 650 mg / kg or less, More preferably, it is 610 mg / kg or less. The Zn content in the low-hydration thermal cement composition is preferably 440 to 650 mg / kg. When the Zn content in the low-hydration heat cement composition is 440 mg / kg or more, the heat of hydration at the age of 28 days can be reduced to 330 J / g or less. Further, when the Zn content in the low-hydration thermal cement composition is 440 mg / kg or more, the mortar compressive strength at the age of 28 days can be maintained at 60 N / mm ² or more.

  The method for producing the low-hydration thermal cement composition of the present invention is such that the Mo content of the cement composition is 68 to 120 mg / kg and the Cu content is 330 to 440 mg / kg, so that limestone, silica stone, coal ash , Clay, blast furnace slag, construction generated soil, sewage sludge, hydro cake, municipal waste incineration ash, and raw material units selected from the group consisting of iron sources are adjusted and prepared, and these raw materials are fired and cement clinker And a step (B) of mixing and pulverizing the obtained cement clinker and gypsum.

  Specifically, based on the sampled Mo and Cu contents of the cement composition, the correlation with the heat of hydration of the cement composition was measured, and the Mo content of the cement composition was 68 to 120 mg / kg, Cu By adjusting the raw material intensity of the cement clinker raw material so that the content is 330 to 440 mg / kg, and using the cement clinker obtained by firing this raw material, the Mo and Cu contents are within a specific range. Yes, a cement composition capable of reducing the heat of hydration at the age of 28 days to 330 J / g or less can be produced. The “raw material basic unit” means the mass (kg / t-clinker) of each raw material used in producing 1 ton of cement clinker.

  Compared with other cement clinker raw materials, tangled copper, limestone, and municipal waste incineration ash are raw materials containing a large amount of molybdenum (Mo) and copper (Cu). When adjusting the Mo and Cu contents of the cement composition, the raw material intensity of the raw material selected from the group consisting of municipal waste incineration ash, copper tangled and limestone, containing a large amount of molybdenum (Mo) and copper (Cu). A cement clinker having an Mo content of 68 to 120 mg / kg and a Cu content of 330 to 440 mg / kg is prepared by increasing or decreasing the amount, and using this cement clinker, the Mo content is 68 to 120 mg / kg. A cement composition having a kg and Cu content of 330 to 440 mg / kg can be produced.

  Examples of the raw material for the cement clinker in the step (A) include limestone, silica, coal ash, clay, blast furnace slag, construction generated soil, sewage sludge, hydrocake, municipal waste incineration ash, and iron source. Coal ash is generated from a coal-fired power plant or the like, and includes cinder ash, fly ash, clinker ash, and bottom ash. Examples of construction generated soil include residual soil, mud soil, waste soil, etc., which are generated as a result of construction work. Examples of sewage sludge include sludge, dry pulverized limestone, and incineration residues. Examples of the iron source include copper tangling and blast furnace dust.

  As the cement clinker raw material in step (A), limestone 900-1500 kg / t-clinker, silica 20-250 kg / t-clinker, coal ash 0-200 kg / t-clinker, clay 0-100 kg / t-clinker, blast furnace slag 0-100 kg / t-clinker, construction generated soil 0-150 kg / t-clinker, sewage sludge 0-100 kg / t-clinker, hydro cake 0-100 kg / t-clinker, municipal waste incineration ash 0-50 kg / t-clinker It is preferable to prepare an iron source 30-80 kg / t-clinker. Moreover, as a cement clinker raw material in (A) process, limestone 1000-1400 kg / t-clinker, silica 20-200 kg / t-clinker, coal ash 0-150 kg / t-clinker, clay 0-80 kg / t-clinker, Blast furnace slag 0-70kg / t-clinker, construction generated soil 0-100kg / t-clinker, sewage sludge 0-70kg / t-clinker, hydro cake 0-80kg / t-clinker, municipal waste incineration ash 0-40kg / It is more preferable to prepare a t-clinker and an iron source 40 to 70 kg / t-clinker.

  The cement clinker can be manufactured using an existing cement manufacturing facility such as an SP system (multistage cyclone preheating system) or an NSP system (multistage cyclone preheating system equipped with a calcining furnace).

  In industrial scale production, for example, a cement composition for quality control is first produced, the correlation between the Mo and Cu content and the heat of hydration of the cement composition is measured, and the Mo of the cement composition is measured. The raw material unit of cement clinker and firing conditions are adjusted so that the content is 68 to 120 mg / kg and the Cu content is 330 to 440 mg / kg, and the heat of hydration is reduced while maintaining the strength development. Possible cement compositions can be produced.

  Next, an embodiment of a method for producing a cement clinker used in the low-hydration thermal cement composition of the present invention will be described using an existing cement production facility of the NSP method. In addition, the manufacturing method of the low hydration thermal cement composition of this invention is not limited to the following embodiment.

  The method for mixing the raw materials of the cement clinker is not particularly limited, but it is preferable to pulverize and mix with a raw material pulverization mill, for example.

  The pulverized and mixed cement clinker raw material can be further fired by using existing equipment such as a suspension preheater and a rotary kiln. By adjusting the firing conditions such as the firing temperature and firing time of the cement clinker, it is possible to produce a cement composition in which the Mo content is adjusted to 68 to 120 mg / kg and the Cu content is adjusted to 330 to 440 mg / kg. A cement clinker can be obtained.

  The firing temperature of the cement clinker is not particularly limited, but when an NSP type cement manufacturing facility is used, the temperature of the cement clinker in the vicinity of the rotary kiln outlet is preferably 800 to 1700 ° C, more preferably 900 to 1600 ° C. More preferably, it is 1000-1500 degreeC. The firing time is 20 minutes to 2 hours, more preferably 30 minutes to 2 hours, and even more preferably 45 minutes to 1.5 hours.

  After the firing, the obtained cement clinker is preferably cooled to, for example, about 100 to 200 ° C. by a clinker cooler provided on the downstream side of the rotary kiln. The cooling rate is preferably 10 to 60 ° C./min, more preferably 15 to 45 ° C./min, and further preferably 15 to 30 ° C./min. When the cooling rate is in the range of 10 to 60 ° C./min, a low-hydration thermal cement composition capable of producing mortar or concrete having excellent strength development can be obtained.

  In the step (B) of the present invention, the low-hydration thermal cement composition can be produced by mixing and pulverizing a cement clinker and gypsum. The gypsum desirably satisfies the quality defined in JIS R 9151 “Natural gypsum for cement”, and specifically, dihydrate gypsum, hemihydrate gypsum, and insoluble anhydrous gypsum are preferably used.

In the step (B) of the present invention, the amount of SO ₃ in the cement composition is preferably 1.8 to 2.6% by mass, more preferably 1.9 to 2.5% by mass, based on the cement clinker. It is preferable to mix and grind gypsum so as to be preferably 2.0 to 2.4 mass%, particularly preferably 2.1 to 2.3 mass%. Although it does not restrict | limit especially as a grinding | pulverization method, The method of using classifiers, such as grinders, such as a ball mill, and a separator, is mentioned.

The brane specific surface area of the low-hydration thermal cement composition of the present invention is preferably 3000 to 4300 cm ² / g, more preferably 3200 to 4200 cm ² / g, and further preferably 3400 to 4100 cm ² / g. Particularly preferred is 3500-4100 cm ² / g. When the specific surface area of the brain is within the above range, it is possible to produce mortar or concrete having excellent strength development while reducing the heat of hydration.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated in detail, this invention is not limited to a following example.

(Examples 1-4, Comparative Examples 1-5)
[Cement clinker ingredients]
As raw materials for cement clinker, limestone, silica, coal ash, clay, blast furnace slag, construction generated soil, sewage sludge, hydrocake, municipal waste incineration ash and iron source (from copper, blast furnace dust) were used. The basic units of raw materials used were limestone 900-1500 kg / t-clinker, silica 20-250 kg / t-clinker, coal ash 0-200 kg / t-clinker, clay 0-100 kg / t-clinker, blast furnace slag 0-100 kg / T-clinker, construction generated soil 0-150kg / t-clinker, sewage sludge 0-100kg / t-clinker, hydrocake 0-100kg / t-clinker, municipal waste incineration ash 0-50kg / t-clinker, iron source Formulated with 30-80 kg / t-clinker.
Also, dihydrate gypsum was used to adjust the amount of SO _{3 in the} cement composition. Table 1 shows reference values for chemical components of limestone, quartzite, coal ash, and copper. In Table 1, ig. loss (ignition loss), SiO ₂ , Al ₂ O ₃ , Fe ₂ O ₃ , CaO, MgO and SO ₃ are expressed by mass%, and Mo, Cu and Zn are contained relative to 1 kg of the cement composition. Expressed in quantity (mg / kg). In Table 1, the symbol “<” represents less than. For example, limestone has a Mo content of less than 2.5 mg / kg.

The Mo content, Cu content, and Zn content of other raw materials other than limestone, silica stone, coal ash, and copper tangles are shown below. Mo content, Cu content, and Zn content were measured according to the Cement Association standard test method JCAS I-52 2000 “Method for quantifying trace components in cement by ICP emission spectroscopic analysis and electric heating atomic absorption analysis”. .
Clay (Mo content: <2.5 mg / kg, Cu content: 51.9 mg / kg, Zn content: 136 mg / kg)
-Construction soil (Mo content: <2.5 mg / kg, Cu content: 350 mg / kg, Zn content: 410 mg / kg)
・ Sewage sludge (Mo content: 6.3 mg / kg, Cu content: 310 mg / kg, Zn content: 676 mg / kg)
Hydro cake (Mo content: <2.5 mg / kg, Cu content: 7.3 mg / kg, Zn content: 43.5 mg / kg)
・ Blast furnace slag (Mo content: <2.5 mg / kg, Cu content: 3.9 mg / kg, Zn content: 21.6 mg / kg)
・ Blast furnace dust (Mo content: 10.3 mg / kg, Cu content: 146 mg / kg, Zn content: 6825 mg / kg)
-Municipal waste incineration ash (Mo content: 9.6 mg / kg, Cu content: 3917 mg / kg, Zn content: 5691 mg / kg)

  The raw material unit of the raw material of the cement clinker used in the examples is limestone 1000 to 1200 kg / t-clinker, construction generated soil 20 to 100 kg / t-clinker, silica stone 20 to 150 kg / t-clinker, coal ash 0 to 200 kg / t-clinker, clay 0-100 kg / t-clinker, blast furnace slag 0-100 kg / t-clinker, sewage sludge 0-100 kg / t-clinker, hydrocake 0-100 kg / t-clinker, municipal waste incineration ash 0-50 kg / T-clinker, and iron source 30-80 kg / t-clinker.

[Manufacture of cement clinker]
A cement clinker raw material was prepared, and the prepared raw material was baked in an NSP kiln at a maximum temperature of 1200 to 1500 ° C. to produce a cement clinker. The temperature of the cement clinker in the vicinity of the NSP kiln outlet was 1000 to 1500 ° C. The firing time was 45 minutes to 1.5 hours. The obtained cement clinker was cooled from 1000-1500 ° C. to 100-200 ° C. at a cooling rate of 10-60 ° C./min with a clinker cooler provided on the downstream side of the rotary kiln.

The obtained cement clinker was blended with dihydrate gypsum so that the content of SO ₃ in the cement composition was 2% by mass, and pulverized with an actual mill so that the specific surface area of the brain was 3900-4100 cm ² / g, A cement composition was obtained.

[Chemical composition of cement composition]
_SiO 2 of the resulting cement _{composition, Al 2 O 3, Fe 2} O 3, CaO, about SO 3, Na ₂ O and _{K 2} O, were determined content to the total mass ratio (% by weight). These content ratios were measured according to JIS R 5202: 1998 “Chemical analysis method of Portland cement”. Also, the Mo, Cu, and Zn contents in the cement composition are determined in accordance with the Cement Association standard test method JCAS I-52 2000 “Method for quantifying trace components in cement by ICP emission spectroscopic analysis and electric heating atomic absorption analysis”. Measured. The results are shown in Table 3.

[Mineral composition and physical properties of cement composition]
<Mineral composition of cement composition>
The mineral composition (C ₃ S amount, C ₂ S amount, C ₃ A amount and C ₄ AF amount) of the obtained cement composition was measured based on the Borg equation [1] to [4]. The results are shown in Table 4.
<Fineness of cement composition>
The fineness of the cement (Brain specific surface area) was measured according to JIS R 5201: 1997 “Cement physical test method”. The results are shown in Table 4.
<Mortar compressive strength>
The mortar compressive strength was measured at a material age of 28 days according to JIS R 5201: 1997 “Physical Test Method for Cement” using the obtained cement composition. The results are shown in Table 4.
<Heat of hydration of cement composition>
The heat of hydration of the cement composition at the age of 28 days was measured according to JIS R 5203: 1995 “Method of measuring heat of hydration of cement (heat of dissolution method)”. The results are shown in Table 4.

  1 shows the relationship between the Mo content of the cement composition and the heat of hydration, and FIG. 2 shows the relationship between the Mo content of the cement composition and the compressive strength. 3 shows the relationship between the Cu content and the heat of hydration, and FIG. 4 shows the relationship between the Cu content and the compressive strength of the cement composition. In FIG. 1 and 2, the numerical value described in parenthesis shows the numerical value of Cu content in each Example and a comparative example.

From the results shown in Tables 3 and 4 and FIGS. 1 to 4, the heat of hydration of moderately heated Portland cement specified in JIS R 5210 for both Examples and Comparative Examples (the age of 28 days is 330 J / g or less). Is pleased. Further, in Examples, by controlling the Mo content of the cement composition to 68 to 120 mg / kg and the Cu content to 330 to 440 mg / kg, the heat of hydration can be further reduced. / G or less heat of hydration. In addition, from the results shown in Tables 3 and 4 and FIGS. 2 and 4, there is no decrease in the mortar compression strength of the cement composition due to the influence of the Mo content and the Cu content of the cement composition, and the mortar compression at 28 days of age. By maintaining the strength at 60 N / mm ² or more and controlling the Mo content and Cu content of the cement composition, the heat of hydration can be reduced while maintaining the mortar compression strength. As shown in FIG. 1, it can be confirmed that there is a correlation between the Mo content and the heat of hydration, particularly in the cement compositions having the Mo content of Examples 1 to 4 of 68.7 to 91.4 mg / kg. It was. In addition, as shown in FIG. 3, in the cement compositions in which the Cu content in Examples 1 to 4 is 332 to 370 mg / kg and the Mo content is 68.7 to 91.4 mg / kg, the Cu content and water It was confirmed that there was a correlation with Japanese heat.

  From the results shown above, the Mo content of the cement composition is 68 to 120 mg / kg, and the Cu content is 330 to 440 mg / kg. A low-hydration heat cement composition in which the heat of hydration at the age of 28 days is reduced to less than 330 J / g and a method for producing the same can be provided.

Claims (8)

  A low-hydration thermal cement composition having a Mo content of 68 to 120 mg / kg and a Cu content of 330 to 440 mg / kg. The C ₃ S amount calculated by the Borg formula is 30 to 40% by mass, the C ₂ S amount is 40 to 55% by mass, the C ₃ A amount is 1 to 8% by mass, and the C ₄ AF amount is 7 to 15% by mass. Item 2. The low-hydration thermal cement composition according to Item 1. The low-hydration thermal cement composition according to claim 1 or 2, wherein the brane specific surface area is 3000 to 4300 cm ² / g. SO ₃ any one low heat of hydration cement composition according to claims 1 to 3 content is 1.8 to 2.6 mass%. Content of Na ₂ O is 0.10 to 0.30 wt%, and low heat of hydration of any one of claims 1 to 4 _{K 2} O content of 0.10 to 0.40 wt% Cement composition.   The low hydration thermal cement composition according to any one of claims 1 to 5, wherein the Zn content is 440 mg / kg or more. Limestone, quartzite, coal ash, clay, blast furnace slag, construction generated soil, sewage sludge, hydrous so that the Mo content in the cement composition is 68 to 120 mg / kg and the Cu content is 330 to 440 mg / kg. A step of preparing a cement clinker by preparing a raw material basic unit of a raw material selected from the group consisting of cake, municipal waste incineration ash and iron source, and baking these raw materials to produce a cement clinker;
A method for producing a low-hydration thermal cement composition, comprising the step (B) of mixing and pulverizing the obtained cement clinker and gypsum.   As the cement clinker raw material in the step (A), limestone 900-1500 kg / t-clinker, silica 20-250 kg / t-clinker, coal ash 0-200 kg / t-clinker, clay 0-100 kg / t-clinker, blast furnace slag 0-100 kg / t-clinker, construction generated soil 0-150 kg / t-clinker, sewage sludge 0-100 kg / t-clinker, hydro cake 0-100 kg / t-clinker, municipal waste incineration ash 0-50 kg / t-clinker The method for producing a low-hydration thermal cement composition according to claim 7, wherein an iron source 30-80 kg / t-clinker is prepared.