JP2015180604A - Production method of admixture and production method of cement composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production method of an admixture or the like suitable for producing a cement composition capable of reconciling reduction of discharge of COwith strength development and with quality securement.SOLUTION: A 100 pts. wt. admixture is produced by mixing together 5-30 pts. wt. cement, 0-20 pts. wt. silica fume, 0-50 pts. wt. fly ash and 42-75 pts. wt. blast-furnace slag.

Description

  The present invention relates to a method for producing a mixed material and a method for producing a cement composition.

Generally, a cement composition is manufactured by kneading a plurality of types of materials such as water, cement, aggregate, and admixture (see, for example, Patent Document 1). Among them, cement is a material that emits a large amount of carbon dioxide (CO ₂ ) during the production of the cement composition. From the viewpoint of the environment, it is difficult to say that the environmental load is considered. For this reason, it is conceivable to add admixtures such as blast furnace slag and fly ash as an alternative to the reduced cement so that the strength of the cement composition is expressed even if the amount of cement used is reduced.

Japanese Patent No. 3844457

  However, when the amount of cement used is reduced and an admixture such as blast furnace slag or fly ash is used as an alternative, the amount of use may vary greatly among a plurality of types of materials to be mixed. For example, the amount of use of a certain material may be extremely small compared to the amount of use of another material. In such a case, even if many types of materials are kneaded at a time, the respective materials may not be mixed uniformly, and when a cement composition is produced, there is a possibility that appropriate strength may not be expressed. There is a problem.

The present invention has been made in view of the above problems, and its purpose is suitable for the production of a cement composition capable of achieving both reduction in CO ₂ emission, strength development and quality assurance. Another object of the present invention is to provide a method for producing a mixed material and a method for producing a cement composition.

  In order to achieve this object, the method for producing a mixed material of the present invention comprises 5 to 30 parts by weight of cement, 0 to 5 parts by weight of silica fume, 0 to 50 parts by weight of fly ash, and 60 to 65 parts by weight. And a blast furnace slag of 100 parts by weight to produce a mixed material of 100 parts by weight.

According to such a manufacturing method of a mixed material, it is mixed in a composition suitable for manufacturing a cement composition capable of achieving both reduction in CO ₂ emission, strength development and quality assurance, and as a binder It is possible to produce a mix that can be used. In addition, the mixed binder contains a quantity of cement, silica fume, fly ash, blast furnace slag suitable for the production of a cement composition capable of achieving both reduction in CO ₂ emission, strength development and quality assurance. Therefore, a container such as a silo for storing each material individually is not required. For this reason, it is possible to reduce storage space and cost. Moreover, cement, silica fume, fly ash, and blast furnace slag can be mixed in advance at a factory or the like. For this reason, it is possible to accurately measure the material by using equipment such as a factory, and it is possible to provide a binding material with high quality, uniform quality, and excellent versatility. Moreover, it is possible to shorten the kneading time in the raw plant by using the already mixed binder. Furthermore, it is possible to manufacture a mixed material suitable not only as a binder but also as a mixed material mixed with the ground for ground improvement, for example.

  It is desirable to mix the mixed material manufactured by the method for manufacturing the mixed material and the aggregate.

According to such a method for producing a mixed material, a binder and an aggregate suitable for producing a cement composition capable of achieving both reduction in CO ₂ emission, strength development and quality assurance are mixed. It is possible to provide a mixed material.

  In this method for producing a mixed material, the cement is preferably 5 to 20 parts by weight.

According to such a method for producing a mixed material, since the cement is 5 to 20 parts by weight, the production of a cement composition capable of achieving both reduction in CO ₂ emission, strength development and quality assurance can be further achieved. It is possible to produce a mixture that can be used as a suitable binder.

  In this method for producing a mixed material, the cement is preferably 5 to 15 parts by weight.

According to such a method for producing a mixed material, since the cement is 5 to 15 parts by weight, the production of a cement composition capable of achieving both reduction in CO ₂ emission, strength development and quality assurance, It is possible to produce a mixture that can be used as a suitable binder.

  Moreover, it is a manufacturing method of the cement composition characterized by mixing the mixed material manufactured with the manufacturing method of the said mixed material, and water (W).

According to such a method for producing a cement composition, it is possible to achieve both reduction in CO ₂ emission, strength development, and quality assurance simply by mixing a binder that has been premixed with water. Can be easily produced.

In this method for producing a cement composition, it is desirable to mix the water (W) corresponding to a unit water amount of 80 to 185 kg / m ³ .

According to such a method for producing a cement composition, it is possible to produce a cement composition that further reduces CO ₂ emission and develops strength.

In this method for producing a cement composition, it is preferable that the unit water amount of the water (W) is 100 to 150 kg / m ³ .

According to such a method for producing a cement composition, it is possible to produce a cement composition that further reduces CO ₂ emission and further develops strength.

According to the present invention, there is provided a method for producing a mixed material suitable for producing a cement composition capable of achieving both reduction in CO ₂ emission, strength development and quality assurance, and a method for producing a cement composition. It is possible to provide.

It is a figure for demonstrating the manufacturing method of the mixed material which concerns on this invention, and the manufacturing method of a cement composition.

Embodiments of the present invention will be described in detail below.
In this embodiment, a method for producing a mixed material suitable for producing a cement composition capable of achieving both reduction in CO ₂ emission, strength development and quality assurance according to the present invention, and A concrete composition including water, cement, fine aggregate, coarse aggregate, and the like, which is a cement composition manufactured by the manufacturing method, will be described as an example. Here, concrete will be described which can initially achieve both reduction and strength development and quality assurance of emissions CO _2.

In the concrete according to this embodiment, the amount of cement with a large amount of CO ₂ emission is reduced, and an admixture (binding material) with a small amount of CO ₂ emission is used as an alternative material for cement. In this way, by reducing the amount of cement used as much as possible, it becomes possible to reduce the amount of CO ₂ emitted during concrete production. However, there is a possibility that the strength of the concrete may be reduced by reducing the amount of cement used.

In view of this, in the present embodiment, a concrete having a material structure that takes into consideration the balance between the reduction of CO ₂ , the fresh properties of concrete, and the development of strength was developed by the following studies. In the following description, each sample of concrete in which the mixing ratio and the like are different is indicated by a sample number (sample No.), and the conditions and results for each sample in each table are associated with each other.

(1) Examination of the proportion of binder used:
As described above, the amount of cement with a large amount of CO ₂ emission was reduced as much as possible, and the amount of binder with a small amount of CO ₂ emission was increased. In this embodiment, blast furnace slag, fly ash, and silica fume are used as the binder. However, since the binder affects strength development and fresh properties in addition to CO ₂ emissions, the balance of the proportions of cement, blast furnace slag, fly ash, silica fume, and water used was examined.
In the present embodiment, ordinary Portland cement and sulfate-resistant Portland cement are studied as cement, silica fume derived from ferrosilicon and silica fume derived from zirconia are examined as silica fume, and fly ash defined by JIS A6201 is considered as fly ash. Ash type I and fly ash type II were examined.

(2) Examination of additive materials:
In order to improve the strength, the blending of an alkali component, gypsum, a strength enhancer, and limestone fine powder was examined.
The alkali component promotes curing of slag, fly ash, etc. by alkali stimulation. In this embodiment, a calcium hydroxide solution simulating sludge water is used as the alkali component.
The gypsum includes dihydrate gypsum, hemihydrate gypsum, and anhydrous gypsum. In this embodiment, anhydrous gypsum was used. Further, anhydrous gypsum includes anhydrous gypsum (by-product by-product) that is produced as a by-product during fluorine production, and anhydrous gypsum that is naturally produced. In this embodiment, natural anhydrous gypsum was used. The gypsum is part of the blast furnace slag described above.
In this embodiment, a strength enhancer mainly composed of triisopropanolamine is used.
Furthermore, the compounding of the chemical admixture (AD) was examined. Examples of the chemical admixture (AD) include a water reducing agent, a high performance AE water reducing agent, an AE water reducing agent, and a high performance water reducing agent.

(3) Examination of water volume:
In order to reduce CO ₂ , it is effective to reduce the amount of the binder containing cement. On the other hand, the strength depends on the water binder ratio (ratio between the amount of water and the amount of binder). Therefore, the amount of water (unit amount) when reducing the amount of binder was also examined.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further in detail, this invention is not limited to this.

<Materials used>
Table 1 shows the details of the raw materials used in this example.

[注]( )内の品名及び密度は、後述するサンプルＮｏ．１１の調合で使用した材料を示す。

[Note] The product name and density in parentheses are sample No. described later. 11 shows the materials used in 11 formulations.

In Table 1, ordinary portland cement (OPC), sulfate resistant portland cement (SR), silica fume <Elchem-Egypt> (SF1), silica fume <zirconia> (SF2), fly ash type II <JISA6201> (FA1) Fly ash type I <JISA6201> (FA2) and blast furnace slag fine powder (GGBS) correspond to the binder (B). In addition, calcium hydroxide (Ca (OH) ₂ ), anhydrous gypsum (CaSO ₄ ), limestone fine powder (LSP), and strength enhancer (SI) in the calcium hydroxide solution (W2) correspond to the additive. The anhydrous gypsum is a part of the blast furnace slag fine powder.

  Table 2 shows the blending amount of each raw material in this example. In addition, Table 3 shows the proportions of main ingredients of each raw material. The raw materials were mixed as shown in Tables 2 and 3. Note that% in the column of Sample No. in Tables 2 and 3 indicates the ratio of cement (OPC) or (SR) to the binder (OPC (SR) + SF + FA + GGBS).

  Further, a concrete having a cement ratio of 40% was used as a comparative example. The proportion of cement in this comparative example (40%) corresponds to the minimum value of the proportion of cement used in blast furnace cement type B (JIS R 5211). In the blast furnace cement type C, the minimum value of the cement ratio is 30% (the maximum value of the slag ratio is 70%). In this embodiment, the cement ratio is set to 30% or less. That is, the amount of cement used is minimized.

表３において、水結合材比（Ｗ／Ｂ）は、水（Ｗ１＋Ｗ２＋Ｗ３）／結合材（ＯＰＣ＋ＳＦ＋ＦＡ＋ＧＧＢＳ）である。また、細骨材率(ｓ／ａ)は、細骨材（Ｓ）／骨材（Ｓ＋Ｇ１＋Ｇ２）である。なお、ＣａＳＯ₄は、ＧＧＢＳの一部とする。

In Table 3, the water binder ratio (W / B) is water (W1 + W2 + W3) / binder (OPC + SF + FA + GGBS). The fine aggregate rate (s / a) is fine aggregate (S) / aggregate (S + G1 + G2). CaSO ₄ is part of GGBS.

<Concrete production conditions>
Table 4 is a table showing concrete mixing conditions. Table 5 is a table showing concrete production conditions (mixing method).

<Test items>
(1) Fresh property test (Sample Nos. 1-35)
As a fresh property test, the slump, air amount, and temperature after kneading were measured. In addition, the test method of slump and air quantity was based on JIS A 1101 (BS 1881 Part102) and JIS A 1128 (BS 1881 Part106), respectively. The concrete temperature was measured with a thermometer.
(2) Compressive strength test (Sample Nos. 1-35)
A specimen of φ100 * 200 mm (150 * 150 * 150 mm) was prepared and cured in water, and then the compressive strength at 20 ° C. (23 ° C.) and 50 ° C. was measured according to JIS A 1108 (BS EN 206).
(3) Drying shrinkage test (Sample No. 5-11, Sample No. 23-35)
100 * 100 * 400mm (75 * 75 * 285mm) specimen was prepared and cured underwater until age 7 days, then measured for shrinkage change (length change) due to drying according to JIS A 1129 (ASTM C 157) did.
[Note] Standards and dimensions in parentheses above are sample nos. This was applied to 11 cases.

表６に示すように、比較例ではスランプの値が目標値（１５ｃｍ、２１ｃｍ）よりも小さいのに対し、本実施例（サンプルＮｏ.１〜４、サンプルＮｏ.１２〜２２）では、ほとんど目標値の範囲に収まり、（サンプルＮｏ.５〜１１、サンプルＮｏ.２３〜３５）では、ほとんど目標値を超えている。つまり、施工性に関して、比較例よりも、本実施例の方が良好である。また、空気量、温度については比較例とほぼ同等である。 <Test results>
Table 6 shows the test results of the fresh property test.

As shown in Table 6, while the slump value is smaller than the target value (15 cm, 21 cm) in the comparative example, in this example (sample Nos. 1-4, sample Nos. 12-22), the target is almost the target. It falls within the range of values, and in (Sample Nos. 5 to 11, Sample Nos. 23 to 35), it almost exceeds the target value. That is, regarding the workability, the present example is better than the comparative example. The air amount and temperature are almost the same as those in the comparative example.

  Sample No. 15 and sample no. As a result, it was found that the zirconia-derived silica fume has a larger slump than the silica fume of general products (from metal silicon or ferrosilicon). Sample No. 15 and sample no. In comparison with 19, it was found that the sulfate-resistant Portland cement was larger in slump than ordinary Portland cement. Sample No. 15 and sample no. As a result, it was found that the fly ash type I was more fluid than the fly ash type II specified in JIS A6201.

表７に示すように、本実施例では、比較例よりもセメントの使用量が少なくなっているにもかかわらず、１０％以上では比較例に近い圧縮強度が得られた。特に、セメントの割合が１０〜２０％においても良好な圧縮強度が得られた。また、１０％未満であっても、比較例には至らないものの１６Ｎ／ｍｍ²以上の圧縮強度が得られた。なお、本実施例（サンプルＮｏ.１〜３５）における材齢２８日の２０℃(２３℃)の圧縮強度は、１６．６〜６９．４Ｎ／ｍｍ²であった。 Next, Table 7 shows the test results of the compressive strength test.

As shown in Table 7, in this example, a compressive strength close to that of the comparative example was obtained at 10% or more, although the amount of cement used was smaller than that of the comparative example. In particular, good compressive strength was obtained even when the proportion of cement was 10 to 20%. Moreover, even if it was less than 10%, although not reaching the comparative example, a compressive strength of 16 N / mm ² or more was obtained. In addition, the compressive strength of 20 degreeC (23 degreeC) of the age of 28 days in a present Example (sample No. 1-35) was 16.6-69.4 N / mm < ² >.

Sample No. 15 and sample no. As a result, the compression strength of the silica fume derived from zirconia was higher than the silica fume of the general product (from metal silicon or ferrosilicon). Sample No. 15 and sample no. In comparison with 19, the results showed that the compressive strength of the sulfate-resistant Portland cement was higher than that of ordinary Portland cement.
[Note] The temperature in () above is the sample No. This was applied to 11 cases.

表８の長さ変化においてマイナスは、元の長さに対して収縮したことを示している。なお、逆に、この値がプラスになる場合は膨張したことになる。
表８に示すように、乾燥による長さ変化（収縮量）は、比較例よりも本実施例の方が小さくなっている。つまり、本実施例では、比較例よりもひび割れが生じにくいと言える。 Next, Table 8 shows the test results of the drying shrinkage test for sample Nos. 5 to 11 and sample Nos. 23 to 35.

In the length change in Table 8, minus indicates that the original length contracted. On the contrary, if this value is positive, it means expansion.
As shown in Table 8, the length change (shrinkage amount) due to drying is smaller in the present example than in the comparative example. That is, in this example, it can be said that cracks are less likely to occur than in the comparative example.

As described above, in this embodiment, the amount of cement used with a large amount of CO ₂ emission is reduced as much as possible, and the amount of admixture (binding material) with a small amount of CO ₂ emission is increased.

Specifically, the ratio of cement to the binder is 5 to 30%, silica fume is 0 to 20%, fly ash is 0 to 50%, blast furnace slag is 42 to 75%, and the unit water amount is 80 to 185 kg / m. ^{It was set to 3} . Furthermore, at least one additive of calcium hydroxide (Ca (OH) ₂ ), gypsum (CaSO ₄ ), strength enhancer (SI), and limestone fine powder (LSP), which is an alkaline component, is blended. Gypsum is part of the blast furnace slag.
Furthermore, concrete was composed of an aggregate including fine aggregate and coarse aggregate, water, and a chemical admixture such as a high-performance AE water reducing agent.
By doing so, it is possible to obtain concrete with low CO ₂ emission and excellent fresh properties and strength.

  In the said embodiment, although concrete was mentioned as an example as a cement composition, the cement paste which does not contain a fine aggregate and a coarse aggregate as an aggregate, and the mortar which does not contain a coarse aggregate may be sufficient. .

<Concrete production method>
As described above, it has been clarified that the concrete can be mixed with a reduction in CO ₂ emission, strength development and quality assurance. The proportion of such concrete may be very small compared to other materials, such as silica fume shown in Table 3, where the proportion contained in the binder is 2.5% of the total.

  As described above, if a material to be mixed is contained in a very small amount in the material to be mixed, the material may not be mixed properly depending on the mixing method. For example, when each material to be mixed is directly fed into the mixer, when it is supplied through a narrow tube connected to the mixer, a small amount of material may adhere to the periphery of the thin tube and hardly be supplied into the mixer. . Therefore, a concrete manufacturing method suitable for a case where a plurality of types of materials as described in the present application are mixed and a material in which a small amount is mixed is described.

The concrete manufacturing method of this application suitable for concrete that can achieve both reduction in CO ₂ emissions, strength development and quality assurance is achieved by using a mixer to combine the binder that is kneaded with water and aggregates. First, mix (premix) in advance before kneading.

  Specifically, the sample No. shown in Table 3 is used. For example, 5 parts by weight of cement, 5 parts by weight of silica fume, 15 parts by weight of fly ash, and 75 parts by weight of blast furnace slag are weighed and mixed to form 100 parts by weight of a binder. As shown in FIG. 1, they are mixed in advance at a factory or the like (mixed material manufacturing step S1).

  Next, when the mixed binder is taken as 100, water corresponding to 40.7 and the aggregate having a fine aggregate ratio of 45.5 are weighed and put into a mixer, and kneaded with the mixer to produce raw material. Concrete is manufactured (green concrete manufacturing process S2).

  Then, the produced ready-mixed concrete is placed in a mold to produce a concrete member (ready-concrete placing step S3).

According to such a method for producing concrete, since cement, silica fume, and fly ash contained in a small amount in the binder are mixed in advance with a relatively large amount of blast furnace slag, an appropriate amount of cement, silica fume, It is possible to reliably mix fly ash with concrete. For this reason, it is possible to easily manufacture concrete in which a predetermined amount of material is inevitably added, for example, a reduction in CO ₂ emission, strength development and quality assurance can be achieved. At this time, when the cement contains gypsum, it is possible to develop higher strength in the manufactured concrete. Further, by mixing a chemical admixture (AD) in advance, it is possible to develop higher strength. Since the amount of the chemical admixture (AD) contained in the concrete is very small, it is desirable to add it to the mixer after mixing with other materials and fine aggregates, like each material of the binder.

  In addition, by using a mixed material in which a plurality of materials are mixed in advance before kneading with the mixer, the types of materials kneaded with the mixer are reduced, so the number of containers for storing the materials is reduced. And management of the material can be simplified. In addition, since there are few types of materials to be kneaded, it is possible to simplify the work in the raw plant and to develop higher strength by using a more uniformly mixed material.

  In the concrete manufacturing method, a cement, silica fume, fly ash, and blast furnace slag are preliminarily mixed with each other, but the above four kinds of materials are not necessarily included. For example, at least one of three materials: 5-30 parts by weight cement, 0-20 parts by weight silica fume, 0-50 parts by weight fly ash, and 42-75 parts by weight blast furnace slag. A mixed material in which materials are mixed in advance may be used as the binder.

  Also, cement, silica fume, fly ash, and blast furnace slag, a binder that is a mixture of at least one of the three types of materials, and any remaining or all remaining materials that are not mixed. When kneading with a mixer, it may be kneaded with water or aggregate.

  Moreover, you may use the mixed material which mixed the aggregate beforehand in addition to cement, silica fume, fly ash, and blast furnace slag. For example, prepare a mixture of sand as fine aggregate of aggregate and one or more materials of cement, silica fume, fly ash, blast furnace slag in advance, You can knead. As shown in Table 2, the aggregate is mixed in a larger amount than other materials. Therefore, by mixing at least one of the four materials with the other materials in the state of being mixed with the aggregate, even if the specific material is a minute amount, it becomes almost uniform in advance. It is possible to mix as such. At this time, it is desirable that a minute amount of material is mixed in the fine aggregate as described above.

As described above, at least two of the plurality of materials are mixed in a composition suitable for the production of a cement composition capable of achieving both reduction in CO ₂ emission, strength development and quality assurance. Thus, it is possible to produce a mixed material that can be used as a binder. In addition, the mixed binder contains a quantity of cement, silica fume, fly ash, blast furnace slag suitable for the production of a cement composition capable of achieving both reduction in CO ₂ emission, strength development and quality assurance. In addition, since at least two kinds of materials such as aggregates are included, a container such as a silo for individually storing all the materials is not required. For this reason, it is possible to reduce storage space and cost. In addition, a mixed material in which at least two kinds of materials such as cement, silica fume, fly ash, blast furnace slag, and aggregate are mixed in advance can be mixed in advance in a factory, etc. By using this equipment, materials can be accurately measured, and higher quality is ensured than when all materials are mixed in a raw plant. Is possible. Moreover, it is possible to shorten the kneading time in the raw plant by using the already mixed binder. Furthermore, such a mixed material can produce a mixed material suitable not only as a binder, but also as a mixed material mixed with the ground for ground improvement, for example.

  In the said embodiment, although the example in which cement is contained in one of the materials was described, 0 to 20 parts by weight of silica fume, 0 to 50 parts by weight of fly ash, and 42 to 75 parts by weight of blast furnace slag You may mix at least 2 types of materials of 3 types of materials. The mixed material manufactured by such a manufacturing method can be mixed with 5 to 30 parts by weight of cement, aggregate, and water to manufacture a cement composition, and the cement is mixed with the ground together. Therefore, it can be used for ground improvement.

  The above embodiment is for facilitating the understanding of the present invention, and is not intended to limit the present invention. The present invention can be changed and improved without departing from the gist thereof, and it is needless to say that the present invention includes equivalents thereof.

Claims (7)

  5 to 30 parts by weight of cement, 0 to 5 parts by weight of silica fume, 0 to 50 parts by weight of fly ash, and 60 to 65 parts by weight of blast furnace slag are mixed to produce a mixture of 100 parts by weight. A method for producing a mixed material, comprising: A mixed material manufactured by the method for manufacturing a mixed material according to claim 1;
A method for producing a mixed material, comprising mixing the aggregate. It is a manufacturing method of the mixed material according to claim 1 or 2,
The cement manufacturing method of mixing material, characterized in that 5 to 20 parts by weight. It is a manufacturing method of the mixed material in any one of Claim 3, Comprising:
The said cement is 5-15 weight part, The manufacturing method of the mixed material characterized by the above-mentioned. A mixed material produced by the method for producing a mixed material according to any one of claims 1 to 4,
A method for producing a cement composition, comprising mixing water (W). A method for producing a cement composition according to claim 5,
A method for producing a cement composition, comprising mixing the water (W) corresponding to a unit water amount of 80 to 185 kg / m ³ . A method for producing a cement composition according to claim 5 or 6,
The method for producing a cement composition, wherein the unit water amount of the water (W) is 100 to 150 kg / m ³ .

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