JP3193063B2 - Slag reduction agent, centrifugal molded product using the same, and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slag reducing agent and a method for producing a centrifugally molded product using the same, and more specifically, a pile, a pole, a steel pipe composite pile produced by centrifugally molding mortar or concrete, and The present invention relates to a slag reducing agent for reducing or preventing the occurrence of slag when manufacturing centrifugal force molded products such as steel pipe linings and fume tubes, and to a method for manufacturing a centrifugal force molded product using the same.

[0002]

2. Description of the Related Art Conventionally, when manufacturing concrete products such as piles and poles manufactured by centrifugal force forming, slag has always been squeezed out by centrifugal force.
This noro contains 20 to 40% by weight of cement and fine particles of sand in addition to water and is strongly alkaline, so it cannot be discharged outside the factory as it is for pollution prevention. At present, much time and money are spent on the sedimentation and filtration of wastewater and the neutralization of wastewater.

[0003] In order to prevent the generation of this slag, for example, a method of adding 2 to 5% of silica fume to cement, or a method of adding 100 parts by weight of Portland cement
2-10 parts by weight of silica fume and 6000-9000cm of brane
² / g of 5 to 20 parts by weight of mineral powder, a method of using a total amount of 15 parts by weight or more, further, for 100 parts by weight of Portland cement, silica fume, mineral powder, and 0.5 to 5 parts by weight of bentonite in a total amount of 1
A method for producing a centrifugally molded concrete product used so as to be 5 parts by weight or more has been proposed (JP-A-59-21
No. 5808, Japanese Unexamined Patent Publication No. 62-7654, etc.). These methods are intended to increase the water holding capacity by using concrete as a plastic concrete to reduce or prevent the generation of slag due to centrifugal force.

However, even in these methods, brands of cement, for example, types of ordinary cement and silica cement, brands and amounts of water reducing agents, compatibility of cement and water reducing agents, types of sand such as river sand and crushed sand are also used. There is a problem that the slag reduction effect varies due to the concrete slump and the like. In addition, in these methods, the slag prevention effect is unstable, and at the same time, silica fume, which is a main component, has to rely on imports from abroad, and the source is unstable and expensive, and There was a problem that the amount was large and uneconomical.

From the viewpoint of obtaining the plastic concrete, the present inventors have proposed a high-performance water reducing agent, such as bentonite, phlogopite, graphite, talc, zeolite, activated carbon, coal shell, diatomaceous earth, pearlite, and attapulgite. It has been proposed to use an inorganic powder in combination (Japanese Patent Laid-Open No. 63-22 / 1988).
No. 5564). Further, as a result of detailed examination from the viewpoint of slag reduction at the time of centrifugal force molding, it was found that among the above-mentioned inorganic powders from which a similar plastic concrete can be obtained, only bentonite can improve the slag reduction effect in a small amount. did. However, even with this, there was no way to solve the above problem.

[0005] The inventors of the present invention have conducted further intensive studies with the aim of being economical and further improving the slag prevention effect.
The present inventors have found that the use of a slag reducing agent containing a boron compound as an active ingredient enhances the slag reduction effect, and completed the present invention.

[0006]

That is, the present invention relates to a slag reducing agent containing boric acid or borate as an active ingredient, comprising boric acid or borate, a clay mineral and / or an inorganic powder as an active ingredient. And a centrifugal molding product characterized by adding the slag reducing agent to concrete having a unit cement amount of 350 to 600 kg / m ³ .

Hereinafter, the present invention will be described in detail.

The boric acid or borate according to the present invention includes boric acid, alkali metal salts or alkaline earth metal salts of boric acid, and salts such as ammonium borate, lead borate, and manganese borate. (Hereinafter borated)
That Gobutsu), of which the use of boric acid is most preferred.

As the boron compound, those commercially available for industrial use can be used as they are. When used alone, the amount of the boron compound used is at most 1. per m ^{3 of} concrete.
5 kg / m ³ is preferable, 1.0 kg / m ³ or less is more preferable, and 0.5 kg / m ³ or less is preferable.
~0.8kg / m ³ being most preferred. If the amount exceeds 1.5 kg / m ³ , the slag reduction effect tends to decrease, the retardation increases, and the concrete strength tends to decrease. If the amount is less than 0.5 kg / m ³ , the slag reduction effect tends to decrease.

It is preferable to use a clay mineral and / or an inorganic powder in combination with the boron compound from the viewpoint of enhancing the slag reduction effect. When the clay compound and / or the inorganic powder are used in combination with the boron compound, the amount of the boron compound used is at most
1.5 kg / m ³ is preferred, 1.0 kg / m ³ or less is more preferred, and
2~0.8kg / m ³ being most preferred.

The clay minerals include bentonite, acid clay, activated clay, clay, zeolite, talc, and clay minerals such as bauxite clay.

Examples of the inorganic powder include crushed products of amorphous silica such as silica fume, diatomaceous earth, aerosil and fused silica, aluminum hydroxide, calcium carbonate, and fine powder such as blast furnace slag and fly ash. Can be

Among the above clay minerals and inorganic powders, it is preferable to use bentonite and silica fume in combination.

Bentonite belongs to montmorillonites having a swelling property. The swelling property varies depending on the production area and the ore deposit, and those having a degree of swelling of about 5 to 40 by the ACC method (American Collid Campany standard) are commercially available. . Bentonite has a different effect of reducing slag depending on the degree of swelling, and it is preferable to use bentonite having a degree of swelling of 10 or more as the degree of swelling increases with an increase in swelling degree at the same amount.

[0015] The silica fume is an ultrafine amorphous silica produced as a by-product during the production of metallic silicon or a silicon alloy.

These clay minerals and / or inorganic powders may be used alone or in combination.
/ m ³ is preferable, and 15 kg / m ³ is more preferable.

Further, depending on the type and combination of the clay mineral and the inorganic powder, bentonite having a large anti-slag effect is 0.3 to 10 kg / m ³ when used alone, and 0.5 to 10 kg / m ³ when silica fume is used alone. m ³ , and more preferably 0.3 to 10 kg / m ³ when both are used in combination. Exceeds 20 kg / m ^3, unit water content increases to obtain the same slump, also not preferable because of which reduced strength due to an increase in the unit quantity of water Some clay minerals and inorganic powder, also a water reducing an increase in the unit quantity of water It is not preferable that the amount of the agent is suppressed by increasing the amount of the agent because the agent may have a negative effect on the slag reduction effect.

Further, when bentonite is used alone, or when bentonite and silica fume are used in combination, if the amount is less than 0.3 kg / m ^3, it is not preferable because the promoting effect of the slag reduction effect is small.

The ratio of the clay mineral and the inorganic powder used in combination is not particularly limited.

The fineness of the inorganic powder is not particularly limited, but is preferably equal to or higher than that of ordinary Portland cement, and those commercially available, such as bentonite, are usually used as they are without grinding. Is possible.

In the present invention, in order to enhance the slag reduction effect, in addition to ferrous sulfate such as ferrous sulfate and ferric sulfate, magnesium acetate, magnesium nitrate, magnesium sulfate, magnesium carbonate, basic magnesium carbonate, magnesium oxide , And magnesium compounds such as magnesium hydroxide, and aluminum sulfate, aluminum nitrate, sodium aluminate, potassium aluminate, alums,
It is also possible to use one or two or more selected from the group consisting of soluble aluminum such as alunite and calcined alunite.

[0022] These iron sulfate, magnesium compound, and the amount of soluble aluminum is preferably from 10 kg / m ³ at most, more preferably not more than 5 kg / m ^3, and most preferably 0.5~1kg / m ^3. Tend to decrease in strength is increased by an increase in unit water amount exceeds 10 kg / m ^3, when so adjust the slump in bulking water reducing agent without changing the unit water,
The viscosity inherent in the water reducing agent tends to be easily applied to concrete, and slag tends to be easily generated.

Examples of the cement according to the present invention include various portland cements such as ordinary / early high strength / very early strength / moderate heat, various mixed cements in which Portland cement is blended with blast furnace slag, fly ash or silica, and fine powder blast furnace slag. Including cement.

In the present invention, the concrete composition is not particularly limited, but the unit cement amount is 350 to
It is 600 kg / m ³ , and as the unit cement amount increases, the slag reduction effect increases, which is more preferable. However, usually 400 to 550 kg / m ³ is used from the viewpoint of economy and necessary physical properties such as strength.

Further, in the present invention, it is preferable to use a water reducing agent in combination. Here, examples of the water reducing agent include general water reducing agents and high-performance water reducing agents, and are not particularly limited in terms of components. Specifically, it is possible to use a general water reducing agent such as a lignin sulfonate, an oxycarboxylate, and a polyol or a high-performance water reducing agent. Among them, it is preferable to use a high-performance water reducing agent which has a large water reduction rate and can control the water reduction rate by the amount of water used. A high-performance water reducing agent is a water reducing agent having a large water reduction rate that does not cause air entrainment or excessive setting delay even when used in a relatively large amount, and also does not cause abnormal setting, such as polyalkylallyl sulfonate and melamine. Formalin resin sulfonate and the like. Generally, commercially available high-performance water reducing agents are those containing any one of the above as main components, and polyalkylallyl sulfonates include naphthalenesulfonic acid formalin condensate, methylnaphthalenesulfonic acid formalin condensate, and anthracene sulfone. Acid formalin condensates, etc., and as commercial products, Daio Kogyo Seiyaku Co., Ltd., such as Kao Corporation product names `` Mighty 100 '' and `` Mighty 150 ''
Product names such as "Cell Flow 110P", product names such as "Pole Fine 510N" manufactured by Takemoto Yushi Co., Ltd., "Sunflow PS" and "Sunflow PSR" manufactured by Sanyo Kokusaku Pulp Co., Ltd., and electrochemical There are trade names such as "FT-500" manufactured by Kogyo Co., Ltd., and as melamine formalin resin sulfonate, "Merment F-10" and "Merment F-20" by Showa Denko KK Master Builders Co., Ltd. product name "NL-4000" and the like.

In the present invention, the amount of the water reducing agent used for cement is, in the case of a general water reducing agent, the amount specified by the manufacturer or about 2 to 3 times that of the manufacturer, and is used within a range where abnormal coagulation does not occur. When using a high-performance water reducing agent as a water reducing agent, based on 100 parts by weight of cement, preferably 0.2 to 2.0 parts by weight, more preferably 0.3 to 1.5 parts by weight, more preferably 0.4 to 1.2 parts by weight in terms of solids. preferable. If the amount of the high-performance water reducing agent is less than 0.2 parts by weight, the concrete becomes plastic, the mixing water increases, and the strength tends to decrease.If it exceeds 2.0 parts by weight, the viscosity of the concrete increases, reducing slag. The effect tends to be small.

Although the concrete slump is not particularly limited, it is preferably 15 cm or less, more preferably 10 cm or less, because if it is too large, slag tends to occur. The method of mixing concrete may be a commonly used method.

The method of adding the slag reducing agent is as follows.
The kneading water may be dissolved or suspended in part or all of the kneading water and then charged into the mixer. Is done. Specifically, after weighing water and water reducing agent in a measuring instrument, add the slag reducing agent further, or add a separately measured slime reducing agent to the measuring instrument, and dissolve or suspend with a stirrer. It is possible to do.

The method of forming the centrifugal force is not particularly limited either, and is performed at a low speed of GNO.
It is preferable to carry out at a medium speed of 18 for 3 to 5 minutes and at a high speed of GNO. 30 to 3 for 5 to 5 minutes. In this case, the mortar or concrete hardly moves during the centrifugal force forming. Therefore, the low speed is preferably performed at GNO.3 or less for 3 minutes or more, and more preferably at GNO.1 to 2.5 for 3 minutes or more. The medium and high speeds are not particularly limited, but considering the case where the slump is as large as a pump stroke, the medium speed is GNO.
It is preferably from 50 to 2 minutes or more.

[0030]

The present invention will be described below in detail with reference to examples.

Example 1 Using the basic composition of concrete shown in Table 1, the type and amount of the boron compound were changed as shown in Table 2, the powder was added in the form of powder, the concrete was kneaded, and the diameter was 20 × length. 30 x thickness 5
A centrifugal force forming test specimen having a centrifugal force of 1 cm was formed, the amount of slag generated at this time was measured, and the compressive strength was measured 7 days after normal curing under normal pressure steam curing.

[Table 1]

For kneading the concrete, sand, crushed stone, cement, and a boron compound were put into a mixer together, kneaded for 20 seconds, kneaded for 90 seconds by adding kneading water in which a water reducing agent was dissolved, and kneading for 90 seconds. When the slump value changed, the slump was adjusted by adjusting the amount of the water reducing agent used, and the mixing water was adjusted to a constant amount.

In the centrifugal force forming, 18 kg of concrete is put into a mold having a diameter of 20 × length 30 × 5 cm in thickness, and the hollow portion of the mold is covered with a lid to prevent slag from leaking. Using the GNO. Calculated with the center diameter of the wall thickness, the GNO.
The concrete was kneaded from the mixer under centrifugal force forming conditions of 1 minute at GNO.5 medium speed and 1 minute at GNO.35 high speed, and then immediately formed.

The compressive strength was measured by pre-curing the specimens formed by centrifugal force at 20 ° C. for 4 hours, raising the temperature to 65 ° C. at a rate of 15 ° C./h, holding the steam for 4 hours, and then applying steam. The valve was stopped, allowed to cool naturally in the curing tank as it was until the next day, then taken out, removed from the mold, cured in a room at 20 ° C. until the age of 7 days, and the compressive strength was measured. Table 2 shows the results.

(Materials used) Cement: Ordinary Portland cement manufactured by Denki Kagaku Kogyo Co., Ltd., specific gravity 3.16 Sand: Himekawa, Niigata Prefecture, river sand, specific gravity 2.65 Crushed stone: Same as above, crushed stone, specific gravity 2.68 Water reducing agent α: Daiichi Kogyo Pharmaceutical ( Product name "Selflo-110P"
Main component: polyalkylallyl sulfonate, powder. Β: Showa Denko Co., Ltd. product name "Melment F-10" is a melamine formalin resin sulfonic acid salt-based powder. Boron compound: boric acid, reagent Same: sodium borate, reagent Same: calcium borate, reagent

In Table 2, the boron compound is expressed in terms of anhydride and expressed in (g) per m ^{3 of} concrete.
The water reducing agent is shown in parts by weight based on 100 parts by weight of cement.

[Table 2]

From Table 2, it can be seen that the boron compound has a remarkable effect of reducing the slag, and the preferred range of the amount of the boron compound used is 50%.
At ~ 800 g / m ³ , it is clear that the effect of the boron compound is significant.

Example 2 As shown in Tables 3 and 4, using the concrete composition shown in Table 1, a boron compound and a water reducing agent α were used, and a clay mineral and / or an inorganic powder were used. Performed similarly to 1. The results are shown in Tables 3 and 4. However, in the centrifugal force forming, GNO.40 was used for 3 minutes only at high speed, and was performed in a state where slag was easily generated.

In Tables 3 and 4, boron compounds, clay minerals, and inorganic powders are expressed in terms of (g) per 1 m ³ of concrete in terms of anhydride.
The parts by weight relative to parts by weight are shown.

[Table 3]

[Table 4]

(Materials used) Clay mineral A: Bentonite, swelling degree 20 or more, trade name "Tone" manufactured by Kanto Bentonite Industry Co., Ltd. b: Acid clay, trade name "acid clay" manufactured by Kanto Bentonite Industry Co., Ltd. c: Activated clay, Kanto Bentonite Industry Co., Ltd. product name "Galeon Earth" d: Clay, Kanto Bentonite Industry Co., Ltd. product name "SAM"
Clay "E: Zeolite, brand name" S "manufactured by Kanto Bentonite Industry Co., Ltd.
GW "f: Talc, trade name" Soapstone A "manufactured by Kanto Bentonite Industry Co., Ltd. Inorganic powder A: silica fume, trade name" SF Powder "manufactured by Nippon Heavy Chemical Industry Co., Ltd. B: Aerosil, manufactured by Nippon Aerosil Co., Ltd. Product name "Aerosil 50" C: Diatomaceous earth, Noto Wakura, calcined product D: Fused silica powder, manufactured by Denki Kagaku Kogyo Co., Ltd., bag filter product when crushed fused silica, approx. Aluminum hydroxide, reagent F: Calcium carbonate, reagent, sedimentability G: Blast furnace slag, Blaine specific surface area 4000 cm ² / g

Example 3 Using the concretes of Experiment Nos. 2-2 to 2-5, 2-9, and 2-10 in Table 3, as shown in Table 5, boron compounds, clay minerals, and minerals The powder was kneaded with concrete as an aqueous solution or suspension together with a water reducing agent in the kneading water, and the same centrifugal force molding method as in Example 2 was performed to measure the amount of slag generated. The results are also shown in Table 5.

[Table 5]

Example 4 Using the concretes of Experiment Nos. 2-4, 2-38, and 2-39 in Tables 3 and 4, as shown in Table 6, iron sulfate, magnesium compounds, and soluble aluminum Example 2 was carried out in the same manner as in Example 2 except that the type and the amount used were changed. The results are also shown in Table 6.

In Table 6, iron sulfate, magnesium compound, and soluble aluminum were calculated as (g
/ m ³ ). In addition, the slump variation was adjusted only with water so that the slump was within 6 ± 2 cm.

[Table 6]

(Materials used) Iron sulfate a: ferrous sulfate, reagent b) ferric sulfate, reagent magnesium compound c: magnesium sulfate, reagent d: magnesium nitrate, reagent e: magnesium acetate, reagent f : Magnesium carbonate, reagent g: magnesium hydroxide, reagent soluble aluminum h: aluminum sulfate, reagent i: aluminum nitrate, reagent j: sodium alum, reagent k: iron alum l: calcined alum Katsumitsusan, calcined and ground at 600 ℃, 91% purity

As a comparison, 1000 g (m / m ³ ) of magnesium sulfate was added to the plain concrete of Experiment No. 1-1 to similarly perform centrifugal molding. The amount of slag generated at that time is 320 ml
Met.

Example 5 Boric acid, bentonite, and ferrous sulfate were mixed in a weight ratio of 10: 8.
Table 7 in which the noro reduction agent mixed at 0:10 was mixed with the water reducing agent α.
To the concrete composition shown in Table 8 as shown in Table 8,
Centrifugal force molding was performed in the same manner as in Example 1, and the amount of slag generated was measured. The results are also shown in Table 8.

The amount of the slag reducing agent used was shown in (g) per m ^{3 of} concrete. When 1 kg of the slag reducing agent of the present invention was added to 1 m ³ of concrete, the unit water amount increased by 2 to ³ kg / m ³ at the same slump, but the slump was adjusted with the unit water amount.

[Table 7]

[Table 8]

Example 6 To the concrete composition shown in Table 9 using the water reducing agent α, 3 kg / m ^{3 of} the noroe reducing agent used in Example 5 was added, and only the high speed GN
Centrifugal force molding was performed in the same manner as in Example 2 except that the time was changed to 3 minutes at 0.45, and the amount of slag generated at that time was measured. Table 10 shows the results.

[Table 9]

[Table 10]

[0049]

As described above, the use of the slag reducing agent of the present invention makes it possible to reduce or completely prevent the slag generated when producing a centrifugal force molded product such as a pile. This not only significantly reduced the time and cost spent on slag treatment, but also eliminated the disposal of industrial waste, which was effective in protecting the environment.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ identification code FI C04B 22:06) (58) Investigated field (Int.Cl. ⁷ , DB name) C04B 22/06-22/16 C04B 28 / 02-28/12 B28B 21/30-21/34 B28B 1/20

Claims (3)

(57) [Claims] 1. A slag reducing agent comprising boric acid or a borate as an active ingredient. 2. Boric acid or borate, clay mineral and / or
Alternatively, a slag reducing agent containing an inorganic powder as an active ingredient. ^3. A method for producing a centrifugally formed product, comprising adding the norole reducing agent according to claim 1 to concrete having a unit cement amount of 350 to 600 kg / m ³ .