JP2008230903A - Cement-based composition and cement-based mixture powder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cement-based composition which can sufficiently develop functions of a thickening admixture composed of the combination of two kinds of water-soluble low-molecular compounds. <P>SOLUTION: The cement-based composition is manufactured by using first powder obtained by adsorbing a first water-soluble low-molecular compound selected from cationic surfactants onto the surface of a fumed silica and by drying it and second powder composed of a second water-soluble low-molecular compound selected from anionic aromatic compounds as a thickening admixture, and by blending and kneading the first powder, the second powder, cement, fine aggregate, expanding agent powder and a carboxyl group-based polyether-based water reducing agent in addition of water. Wherein the water content is in a range of 350-380 kg/m<SP>3</SP>, the ratio of water to the binding material is in a range of 34.5-48.0%, the sum of the blending amounts of the first powder and the second powder is in a range of 40.0-49.5 kg/m<SP>3</SP>, and the blending amount of the carboxyl group-based polyether-based water reducing agent is in a range of 2.05-3.00 kg/m<SP>3</SP>. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a cementitious mixture powder containing a powdery thickening admixture composed of two types of water-soluble compounds, and a cementitious composition obtained by adding water to the cementitious mixture powder and kneading. is there.

Conventionally, a fast-strength water-resistant concrete composition to which a thickening admixture comprising a first water-soluble compound selected from cationic surfactants and a second water-soluble compound selected from anionic aromatic compounds is added as an admixture. And high flow mortar compositions have been proposed.
When the first water-soluble low molecular weight compound and the second water-soluble low molecular weight compound are mixed in the cement at a certain ratio, the first water-soluble low molecular weight compound and the second water-soluble low molecular weight compound are mixed. The admixture functions as a thickener to ensure an appropriate viscosity by electrically arranging with the compound to form a pseudo polymer, and also has fluidity even when the viscosity increases to some extent. There is no loss. Therefore, if the above additive is used as a thickening additive, a concrete composition excellent in fluidity and fresh concrete retention with time, and mortar excellent in fluidity and self-leveling properties, both of which have been difficult to achieve in the past. A composition can be obtained.
In addition, when the ratio of the first water-soluble low-molecular compound and the second water-soluble low-molecular compound is 1: 1, the most excellent characteristics are obtained (for example, Patent Documents 1 to 3). reference).
Japanese Patent Laid-Open No. 2005-281888 JP 2005-28109 A JP 2006-176597 A

By the way, when the first water-soluble low molecular weight compound and the second water-soluble low molecular weight compound are added simultaneously, the first water-soluble low molecular weight compound and the second water-soluble low molecular weight compound are heterogeneous. Since the pseudo polymer is formed in such a state, kneading for a long time is required in order to obtain the desired characteristics by forming the pseudo polymer in a homogeneous state.
Therefore, when producing the early-strength water-resistant concrete composition, first, after adding a second water-soluble low molecular weight compound to cement, water, fine aggregate and kneading to produce a kneaded product, The first water-soluble low molecular weight compound was added to the kneaded product and kneaded again, and finally the coarse aggregate was added and kneaded. Since the low-molecular compound and the second water-soluble low-molecular compound are easily bonded, a polymer is formed in a state where the low-molecular compound is not sufficiently mixed with the cement even in re-kneading, and thus the function of the thickener is sufficiently exhibited. There was a problem that it was not possible.
Such a problem is not limited to the production of the above-mentioned fast-strength water-resistant concrete composition and high-fluidity mortar composition, and other cement compositions containing the above thickening admixture, such as other concrete compositions and mortar compositions. It is also a problem when manufacturing.

  The present invention has been made in view of the conventional problems, and a cement-based composition capable of sufficiently exhibiting the function of a thickening admixture formed by combining two kinds of water-soluble low-molecular compounds, and this It aims at providing the cementitious mixture powder used in order to manufacture a cementitious composition.

The invention according to claim 1 of the present application is the first powder and anion obtained by adsorbing and drying a first water-soluble low molecular weight compound selected from cement, an expanding material powder and a cationic surfactant on the surface of silica fume. A mixture containing a second powder composed of a second water-soluble low-molecular compound selected from water-soluble aromatic compounds, a fine aggregate, and a carboxyl group-based polyether water reducing agent powder Cement-based composition kneaded with water, wherein water is 350.0 to 380.0 kg / m ³ , the ratio of water to the binder is 34.5 to 48.0%, the first powder of the amount and the second powder sum 40.0~49.5kg / m ³ and the amount of, the amount of the carboxyl group-based polyether-based water reducing agent 2.05~3.00kg / m ³ It is characterized by being in the range of.
The invention according to claim 2 is a first powder obtained by adsorbing a first water-soluble low molecular weight compound selected from a cement, an expanding material powder and a cationic surfactant on the surface of silica fume and drying the first powder. A binder containing a second powder composed of a second water-soluble low-molecular compound selected from an anionic aromatic compound, a fine aggregate, and a powder of a carboxyl group-based polyether water reducing agent were mixed. The cement-based mixture powder, wherein the sum of the blending amount of the first powder and the blending amount of the second powder is 3.63 to 6.79% by weight with respect to the cement and the expansion material powder. It is characterized by being.

According to the present invention, the first water-soluble low molecular weight compound selected from cationic surfactants and anions, which are thickeners added to a cement-based composition obtained by kneading cement, water and fine aggregate The second water-soluble low molecular weight compound selected from the aromatic compounds is in the form of powder, and the blending amount of the thickener powder is in the range of 40.0 to 49.5 kg / m ^3. Therefore, it is possible to effectively exert the thickening effect by the addition of the above thickener, and it has a moderate viscosity, excellent fluidity, material separation resistance, and is excellent in water inseparability. Can be obtained. The powder of the first water-soluble low molecular weight compound is obtained by adsorbing the first water-soluble low molecular weight compound on the surface of silica fume and drying it to form a powder. The powder is a powder obtained by drying the second water-soluble low-molecular compound as it is. At this time, in order to surely realize the excellent characteristics of the cementitious composition, the amount of water per unit volume is in the range of 350.0 to 380.0 kg / m ³ , and the ratio of water to the binder is set. In addition to the range of 34.5 to 48.0%, 2.05 to 3.00 kg / m ^{3 of} a carboxyl group-based polyether water reducing agent needs to be added.

  Also, the first water-soluble low-molecular compound selected from cement and expansion powder and a cationic surfactant is sprayed onto silica fume and adsorbed and dried, and then selected from the first powder and an anionic aromatic compound. A cement-based mixture powder comprising a binder containing a second powder composed of a second water-soluble low-molecular compound, a fine aggregate, and a carboxyl group-based polyether water reducing agent powder ( If premix powder is prepared in advance, just adding coarse aggregate and water or water and kneading them together will provide moderate viscosity, excellent fluidity, and material separation resistance. It is possible to obtain a cement-based composition that is also excellent in separability. At this time, it is important that the sum of the blending amount of the first powder and the blending amount of the second powder is 3.63 to 6.79% by weight with respect to the cement and the expansion material powder. Thereby, the outstanding characteristic of the said cementitious composition is realizable reliably.

Hereinafter, the cementitious composition which concerns on the best form of this invention is demonstrated.
The cementitious composition according to the best mode of the present invention contains a cement admixture in cement, water, and fine aggregate, and a first water-soluble substance selected from cationic surfactants as a thickening admixture. It is a mortar composition using an admixture containing a low-molecular compound and a second water-soluble low-molecular compound selected from anionic aromatic compounds.
In this example, a powder (first powder) obtained by spraying the first water-soluble low-molecular compound on the cement and fine aggregates and adsorbing the first water-soluble low-molecular compound on silica fume and adsorbing it to dry. And the second water-soluble low molecular weight compound is mixed in the form of a powder (second powder) obtained by drying the second water-soluble low molecular weight compound. A cement-based mixture powder prepared by adding a cement-based mixture of a carboxyl group-based polyether water reducing agent powder, an expansion material powder, and an antifoaming agent powder was prepared. A mortar composition is prepared by adding water to the body and kneading. Although it is not an essential requirement for antifoaming agents, foaming occurs during kneading, increasing the amount of air in the mortar, which may cause a decrease in strength, a decrease in specific gravity, etc. It is better to keep it.
In this example, not only is the second water-soluble low-molecular compound dried to form a powder, but also the first water-soluble low-molecular compound that does not easily become powder is sprayed on the silica fume surface. Since the adsorbed and dried powder is used, and the cement admixture, expansion material, and antifoaming agent are also mixed as powder and mixed with cement and fine aggregate, they are added and kneaded. Compared to the case where the first water-soluble low molecular weight compound and the second water-soluble low molecular weight compound are separately added, the first and second water-soluble low molecular weight compounds and the cement are uniformly mixed. The kneading can be performed. Therefore, not only the thickening effect of the thickening admixture can be exhibited sufficiently, but also the hydration / kneading work can be performed only once, so that the cementitious composition can be produced efficiently.
In this example, a thickening admixture powder in which the first powder and the second powder are mixed is prepared in advance, and the thickening admixture powder, carboxyl group is added to cement and fine aggregate. A pre-mix material is prepared by adding and mixing the powder of the water-based polyether water reducing agent, the powder of the antifoaming agent, and the powder of the expansion material. At this time, the first water-soluble low-molecular compound in the first powder and the second water-soluble low-molecular compound as the second powder have a ratio of 1: 1. It is preferable to mix the powder and the second powder.

The cement used in this example is not particularly limited. Portland cement such as ordinary Portland cement, early-strength Portland cement, moderately hot Portland cement, white Portland cement, etc. made from limestone, clay, iron oxide, etc. Alternatively, a mixed cement such as blast furnace cement, fly ash cement, or silica cement can be used.
As the fine aggregate, silica sand obtained from river sand is mainly used.
As the first water-soluble low molecular weight compound used in the present invention, a quaternary ammonium salt type cationic surfactant is preferable, and an additive mainly composed of an alkyl ammonium salt is particularly preferable. The second water-soluble low molecular weight compound is preferably a sulfonate having an aromatic ring, and particularly preferably an additive having an alkylallyl sulfonate as a main component.
In this example, as the cement admixture, a carboxyl group-containing polyether water reducing agent excellent in compatibility with the thickening admixture is blended.
Further, a lime composite expansion material is used as the expansion material, and a silicon-based antifoaming agent is used as the antifoaming agent.

なお、評価実験に使用した材料は以下の通りである。
セメント ；普通ポルトランドセメント：密度 3.16g/cm³
細骨材 ；珪砂：４号，５号，６号：密度 2.58g/cm³
膨張材 ；エントリガイト・石灰複合系膨張材（商品名；デンカパワーＣＳＡ）
：密度 3.10g/cm³
水 ；水道水：密度 1.00g/cm³
増粘性混和剤 ；アルキルアリルスルフォン酸塩基系及びアルキルアンモニウム系混合特殊分散剤（商品名；ビスコトップ１００Ｐ）
セメント混和剤；カルボキシル基含有ポリエーテル系減水剤（商品名；マイティ２１Ｐ）
消泡剤 ；シリコン系消泡剤（商品名；ＦＳアンチフォームDC2-4248S） Thickening admixtures, cement admixtures, and water binders to determine the preferred formulation for obtaining a mortar composition that has moderate viscosity, excellent fluidity, material separation resistance, and excellent water inseparability The ratio and the unit water content were changed, and the mortar composition was tested for viscosity, fluidity, in-water separability, air content, and material non-separation characteristics. The aptitude range was determined to be within the evaluation value shown.
Table 1 below shows each evaluation item, test method, and evaluation value.

The materials used in the evaluation experiment are as follows.
Cement: Ordinary Portland cement: Density 3.16g / cm ³
Fine aggregate: Silica sand: No. 4, 5, 6: Density 2.58g / cm ³
Expansion material: Entry guide / lime composite expansion material (trade name: DENKA POWER CSA)
: Density 3.10g / cm ³
Water ： Tap water: Density 1.00g / cm ³
Thickening admixture: Alkyl allyl sulfonate group and alkyl ammonium mixed special dispersant (trade name: Viscotop 100P)
Cement admixture; Carboxyl group-containing polyether water reducing agent (trade name; Mighty 21P)
Antifoaming agent: Silicone antifoaming agent (trade name; FS Antifoam DC2-4248S)

FIG. 1 is a diagram showing the composition of a mortar composition when the amount of thickening admixture (Vt) used is changed. W / B is a water binder ratio, W is water, C is cement, and CSA is an expansion material. , S is fine aggregate, Vt is a thickening admixture, and SP is a cement admixture. In order to keep the water binder ratio constant, the amount of cement was reduced by the amount of the thickening admixture.
Moreover, FIGS. 2-5 is a graph which respectively shows the relationship between the usage-amount of a thickening admixture (Vt), 20 cm flow time, a 5-minute flow, pH, and the air quantity. The curve or straight line in the graph is a function approximation of the above relationship, and the usage amount when the curve or straight line is within the evaluation value of each evaluation item is the appropriate usage range of the thickening admixture (Vt). It was.
From FIG. 2 to FIG. 5, the suitable usage amount range of the thickening admixture (Vt) satisfying the suitability value of the 20 cm flow time which is the evaluation value of viscosity is 37.0 to 49.5 kg / m ³ , and the fluidity It can be seen that the appropriate use amount range satisfying the suitability value of the 5-minute flow which is the evaluation value is 35.0 to 57.0 kg / m ³ . Moreover, the suitable usage amount range that satisfies the appropriate value of pH, which is the evaluation value of inseparability in water, is 39.0 to 60.0 kg / m ³ , and the appropriate usage amount range that satisfies the evaluation value of the air amount is 0 to 51. It can be seen that it is 5 kg / m ³ . Moreover, the suitable usage-amount range with respect to the material non-separation characteristic from which bleeding is set to 0 was 40.0-60.0 kg / m < ³ >.
From the above results, when the range of the amount of thickening admixture (Vt) used is 40.0 to 49.5 kg / m ³ , the viscosity, fluidity, non-separability in water, It can be seen that all of the evaluation values can be satisfied for the air amount and the material non-separation characteristics.

Moreover, FIG. 6 is a figure which shows the mixing | blending of the mortar composition when changing the usage-amount of a cement admixture (SP), and FIGS. 7-10 is the usage-amount of a cement admixture (SP), and a 20 cm flow, respectively. It is a graph which shows the relationship with time, 5 minutes flow, pH, and the air quantity.
From FIG. 7 to FIG. 10, the appropriate usage amount range that is the range of the usage amount of the cement admixture (SP) that satisfies the viscosity evaluation value is 2.05 to 3.25 kg / m ³ , and the evaluation value of fluidity is It can be seen that a satisfactory range of suitable usage is 1.65 to 3.70 kg / m ³ . In addition, the appropriate use amount range satisfying the evaluation value of inseparability in water is 0 to 3.00 kg / m ³ , and the appropriate use amount range satisfying the evaluation value of air amount is 1.30 to 4.00 kg / m ³ . I understand that there is. Moreover, the suitable usage-amount range with respect to the material non-separation characteristic from which bleeding is set to 0 was 0-3.00 kg / m < ³ >.
When these results are combined, the range of the appropriate amount of the cement admixture (SP) that satisfies the evaluation values for viscosity, fluidity, underwater inseparability, air content, and material inseparability is 2 It turns out that it is 0.05-3.00 kg / m < ³ >.

FIG. 11 is a diagram showing the composition of the mortar composition when the water binder ratio (W / B) is changed, and FIGS. 12 to 15 show the water binder ratio (W / B) and the 20 cm flow time, respectively. It is a graph which shows the relationship with 5 minute flow, pH, and the air quantity.
From FIG. 12 to FIG. 15, the appropriate range of the water binder ratio that satisfies the viscosity evaluation value is 34.5 to 62.5%, and the appropriate range that satisfies the fluidity evaluation value is 33.0 to 66.66. It turns out that it is 0%. It can also be seen that the suitability range that satisfies the evaluation value of inseparability in water is 30.0 to 48.0%, and the suitability range that satisfies the evaluation value of air amount is 30.0 to 61.0%. Moreover, the suitable usage-amount range with respect to the material non-separation characteristic from which bleeding is set to 0 was 30.0-60.0%.
When these results are combined, the suitability range of the water binder ratio (W / B) satisfying the evaluation values for all of the viscosity, fluidity, underwater inseparability, air amount, and material inseparation characteristics is 34. It turns out that it is 0.5 to 48.00%.

なお、上記表では、増粘性混和剤の適正な配合量を、上記第１の粉体の配合量と第２の粉体の配合量との和で表わしているが、これを、上記第１の水溶性低分子化合物と上記第２の水溶性低分子化合物の単位水量に対する適正な配合割合にすると、０．５２〜０．７１重量％となる。 Moreover, FIG. 16 is a figure which shows the mixing | blending of the mortar composition when changing unit water amount (W), and FIGS. 17-20 are respectively unit water amount (W), 20 cm flow time, 5 minute flow, pH, And it is a graph which shows the relationship with air amount.
From FIG. 12 to FIG. 15, the appropriate range of the unit water amount (W) that satisfies the viscosity evaluation value is 350.0 to 387.5 kg / m ³ , and the appropriate range that satisfies the fluidity evaluation value is 330.0. It turns out that it is -380.0 kg / m < ³ >. In addition, the suitability range that satisfies the evaluation value for inseparability in water is 310.0 to 397.5 kg / m ³ , and the suitability range that satisfies the evaluation value for air amount is 317.5 to 430.0 kg / m ^3. I understand. Moreover, the suitable usage-amount range with respect to the material non-separation characteristic from which bleeding is set to 0 was 310.0-390.0 kg / m < ³ >.
When these results are combined, the suitability range of the unit water amount (W) satisfying those evaluation values for all of the viscosity, fluidity, in-water inseparability, air amount, and material inseparation property is 350.0 to 380. It can be seen that it is 0.0 kg / m ³ .
A summary of the above results is shown in Table 2 below.

In the above table, the proper blending amount of the thickening admixture is represented by the sum of the blending amount of the first powder and the blending amount of the second powder. When an appropriate blending ratio of the water-soluble low-molecular compound and the second water-soluble low-molecular compound with respect to the unit water amount is 0.52 to 0.71% by weight.

As described above, in the present embodiment, the first water-soluble low molecular weight compound selected from the cationic surfactants is adsorbed on the silica fume surface and dried, and the anionic aromatic compound is selected. And the second powder composed of the second water-soluble low molecular weight compound as a thickening admixture, and the first and second powders, the cement, the fine aggregate, the expansion material powder, and the carboxyl group-based poly. A cement-based mixture powder (premix powder) mixed with an ether-based water reducing agent powder was prepared, and added to this cement-based mixture powder and kneaded to produce a mortar composition. The thickening effect of the admixture can be sufficiently exhibited. At this time, the amount of water per unit volume of the mortar composition is 350.0 to 380.0 kg / m ³ , and the ratio of water and binder (cement, expansion material, first and second powders) is 34. 50.0 to 48.0%, the sum of the blending amount of the first powder and the blending amount of the second powder is 40.0 to 49.5 kg / m ³ , and the carboxyl group-based polyether water reducing agent It is important that the blending amount is in the range of 2.05 to 3.00 kg / m ³ , and as a result, the mortar has an appropriate viscosity, excellent fluidity, material separation resistance, and also excellent in water inseparability. A composition can be obtained.
Also, in this example, a premix powder prepared by mixing a binder and fine aggregate was prepared in advance, and the mortar composition was produced by adding water and kneading to this, greatly increasing production efficiency. Can be improved.

  In the above embodiment, the mortar composition containing the thickening admixture has been described. However, the present invention is not limited to this, and the first and second powders, the cement, the fine aggregate, and the expansion material powder. If a cement-based mixture powder prepared by premixing a carboxylic group-based polyether-based water reducing agent powder is prepared, and the cement-based mixture powder, coarse aggregate and water are mixed and kneaded, fluidity and fresh concrete can be obtained. It is possible to obtain a concrete composition that is excellent in retention over time and excellent in water inseparability and material separation resistance.

  As described above, according to the present invention, since the thickening effect of the thickening admixture can be sufficiently exerted, it has an appropriate viscosity, excellent fluidity, material separation resistance and is inseparable in water. In addition, an excellent cementitious composition can be obtained. Moreover, since the cementitious mixture powder of the present invention is a premix material, kneading is only required once, so that the production efficiency can be greatly improved.

It is a figure which shows the mixing | blending of the mortar composition used for the evaluation test. It is a figure which shows the relationship between the usage-amount of a thickening admixture, and 20 cm flow time. It is a figure which shows the relationship between the usage-amount of a thickening admixture, and a 5-minute flow. It is a figure which shows the relationship between the usage-amount of a thickening admixture, and pH. It is a figure which shows the relationship between the usage-amount of a thickening admixture, and the air quantity. It is a figure which shows the mixing | blending of the mortar composition used for the evaluation test. It is a figure which shows the relationship between the usage-amount of a cement admixture, and 20 cm flow time. It is a figure which shows the relationship between the usage-amount of a cement admixture, and a 5-minute flow. It is a figure which shows the relationship between the usage-amount of cement admixture, and pH. It is a figure which shows the relationship between the usage-amount of a cement admixture, and the air quantity. It is a figure which shows the mixing | blending of the mortar composition used for the evaluation test. It is a figure which shows the relationship between a water binder ratio and 20 cm flow time. It is a figure which shows the relationship between a water binder ratio and a 5-minute flow. It is a figure which shows the relationship between water binder ratio and pH. It is a figure which shows the relationship between a water binder ratio and air quantity. It is a figure which shows the mixing | blending of the mortar composition used for the evaluation test. It is a figure which shows the relationship between unit water quantity and 20 cm flow time. It is a figure which shows the relationship between unit amount of water and a 5-minute flow. It is a figure which shows the relationship between unit amount of water and pH. It is a figure which shows the relationship between unit water quantity and air quantity.

Claims (2)

A first water-soluble low-molecular compound selected from cement, an expanding material powder and a cationic surfactant is adsorbed onto the surface of silica fume and dried, and a second water-soluble selected from an anionic aromatic compound. A cement-based composition that is kneaded by adding water to a mixture containing a binder containing a second powder composed of a low molecular weight compound, a fine aggregate, and a carboxyl group-based polyether water reducing agent powder. Thus, the amount of water is 350.0 to 380.0 kg / m ³ , the ratio of water to the binder is 34.5 to 48.0%, the blending amount of the first powder and the blending of the second powder Cement-based, characterized in that the sum of the amount is 40.0 to 49.5 kg / m ³ , and the amount of the carboxyl group-based polyether water reducing agent is 2.05 to 3.00 kg / m ^3. Composition.   A first water-soluble low-molecular compound selected from cement, an expanding material powder and a cationic surfactant is adsorbed onto the surface of silica fume and dried, and a second powder selected from an anionic aromatic compound. A cement-based mixture powder obtained by mixing a binder containing a second powder composed of a water-soluble low-molecular compound, a fine aggregate, and a carboxyl group-based polyether water reducing agent powder, The sum of the blending amount of the first powder and the blending amount of the second powder is 3.63 to 6.79% by weight with respect to the cement and the expansion material powder. body.

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