JPH07291687A - Slag-reducing material, centrifugal molded article produced by using the material and its production - Google Patents

Abstract

PURPOSE:To provide a slag-reducing material having increased slag-reducing effect in the production of a centrifugal molded article by using a bentonite having specified swelling degree and maximum secondary particle diameter as a main component. CONSTITUTION:This slag-reducing material for centrifugal molding is composed mainly of a bentonite having a swelling degree of > 22 by A.C.C. method and the maximum secondary particle diameter of <=63mu. Although the swelling degree of the bentonite is higher the better from the viewpoint of slag-reducing effect, a bentonite having a swelling degree of > 22 and <=90 is used in this slag-reducing material. The use of a bentonite having a swelling degree exceeding 90 exceedingly increases the necessary unit water quantity and lowers the strength to an undesirable level. Abrupt change takes place in the slag-reducing effect at a particle diameter of 63mu in spite of the independency of the swelling degree, unit water content of concrete, slump, etc., on the grain size and a remarkable slag-reducing effect becomes noticeable at the particle diameter of <=63mu. It is supposed to be caused by the quick formation of a card house structure when particles of <=63mu diameter are kneaded together with concrete.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slag reducing material, a centrifugal force forming body using the same, and a method for producing the same, and more specifically, concrete piles, poles and steel pipe composite piles produced by centrifugally forming mortar or concrete. The present invention relates to a slag reducing material that reduces slag generated during manufacturing of concrete products such as steel pipe linings and fume pipes, a centrifugal force molded body using the same, and a manufacturing method thereof.

[0002]

2. Description of the Related Art Conventionally, concrete products manufactured by centrifugal force forming such as piles and poles are squeezed out by centrifugal force at the time of their production. This slag has 20 parts of fine powder such as cement and sand.
Since it is a strongly alkaline sludge containing up to 40% by weight, it cannot be discarded as it is outside the factory in order to prevent pollution. After the solid content is precipitated and filtered, the supernatant is neutralized and drained to remove the precipitate. Is dumped as industrial waste, but the current situation is that a lot of time and money is spent for that. In order to reduce the occurrence of this slag, the present inventors have
We proposed a slag reducing material containing bentonite as a main component, a centrifugal force molded body using the same, and a method for manufacturing the same.
3-247543, etc.).

However, this known slag reducing material is
It only mentions the degree of swelling of bentonite and the effect of reducing slag, and if the degree of swelling and the amount of addition are sufficient, the amount of unit cement in concrete is extremely small, and aggregates with small water retention such as crushed sand are used. When used or when the concrete slump is large due to pumping etc. into the form, there is a problem that the effect of reducing slag varies and the practical range is narrow.

The present inventor has made intensive studies for the purpose of solving the above problems and further improving the slag reduction effect, and as a result, the slag reduction effect is efficiently enhanced by using bentonite having a specific swelling degree and a specific particle size. Based on this finding, the present invention has been completed.

[0005]

That is, the present invention includes (1) A. C. C. Swelling degree according to the method exceeds 22, and the maximum secondary particle diameter is 63 μm or less.
Concrete for producing centrifugal force containing the above-mentioned slag reducing material and a high-performance water reducing agent, (3) Centrifugal force molded body obtained by centrifugally shaping the concrete according to (2), (4) Unit cement amount of 350 to 600kg / m ³ , water cement ratio 36-25
%, Slump is 0 to 18 cm, and a high-performance water reducing agent is blended in an amount of 0.05 to 1.5 parts by weight in terms of solid content with respect to 100 parts by weight of cement in concrete. Is a method of producing a centrifugal force molded body, which comprises subjecting concrete containing 0.2 to 15 kg / m ^{3 of} which is subjected to centrifugal force molding to steam curing and / or autoclave curing.

The present invention will be described in detail below. Bentonite used in the present invention is a kind of clay mineral containing montmorillonite as a main component and has swelling property.
And the swelling property of bentonite differs depending on the place of production and ore deposits, and the swelling degree can be increased by artificial refining, synthesis, chemical treatment, etc. Although preferred, A. C. C. The swelling degree according to the method (American Colloid Campany standard) used is in the range of more than 22 and 90, usually 25 or more is preferable, and 30 to 50 is more preferable.
When the degree of swelling exceeds 90, the unit amount of water becomes too large and the strength decreases, which is not preferable. In addition, A. C. C. The swelling degree by the method was determined by the following method. That is, 2.0 g of the sample is added to 100 ml of a graduated cylinder with a stopper, which is filled with 100 ml of purified water, in about 10 times and then stoppered. However,
The sample added previously is hardly attached to the inner wall, and the amount of one addition is adjusted so that the sample is smoothly deposited on the bottom of the cylinder, and after the sample added earlier is almost deposited, the next sample is added. After the completion of the addition, the mixture was left for 24 hours and the apparent volume (ml) of the sample deposited in the container was read. C. C. Swelling degree by the method (ml / 2
g).

Further, the bentonite used in the present invention is particles having a particle size of 63 μm or less. The method for adjusting bentonite having a particle size of 63 μm or less is not particularly limited, but for example, it is a method of pulverizing the bentonite or classifying it after pulverizing. From the viewpoint of enhancing the effect of reducing slag, the present inventors screened by a dry sieving method, and as a result of investigating the particle size of each secondary particle, as a result, depending on the particle size, the swelling property, the unit water amount of concrete, the slump, etc. Despite the fact that there is no difference at all, the effect of reducing slag changes drastically at 63 μm, and it is acknowledged that the effect of reducing slag is remarkably enhanced at 63 μm or less.

To clarify the reason, 2% of bentonite was added to cement, the cement paste was kneaded, and immediately after that, the fracture surface was observed with a scanning electron microscope while frozen with liquid nitrogen. It is inferred that a card house structure composed of sheet crystals of bentonite is formed on and between cement particles, and small honeycomb-like blocks are densely packed. It is considered that the water in the concrete is confined in this block and is prevented from moving by the centrifugal force, and as a result, the effect of reducing slag is obtained, but in the case of particles of 63 μm or less, it is mixed with the concrete. When mixed,
It is assumed that the card house structure as described above is formed in concrete at a high speed.

In the present invention, the amount of bentonite used is such that the greater the degree of swelling of bentonite,
A small amount of the slag reduction effect is exhibited, and moreover, it is more effective to reduce the slag by using water or a slurry together with water and a water reducing agent, etc. Bentonite 0.2 to 1 in ³
The range of 5 kg is preferable, 0.5 to 10 kg is more preferable, and 1.0 to 8 kg is the most preferable in view of the effect of reducing slag, securing strength and economical efficiency. When more than 15 kg of bentonite is used in 1 m ³ of concrete, the unit water amount becomes too large and the strength decrease tends to be large even if the swelling degree is small. If the amount of the water reducing agent is increased and the water-cement ratio is lowered so as not to reduce the strength, the concrete itself has a viscosity peculiar to the water reducing agent, and the slag reducing effect is reduced. If it is less than 0.2 kg, the degree of swelling is large, and even if it is used as a slurry, the effect of reducing slag is not obtained so much.

The centrifugal compact of the present invention has a unit cement amount of 350 to 600 kg / m ³ and a water cement ratio of 36 to 25%.
Then, the high-performance water reducing agent is based on 100 parts by weight of cement in concrete, 0.05 to 1.5 parts by weight of solid content and bentonite of 0.2 to 15 kg / m ^{3 are} mixed, and the concrete is kneaded. The slump is 0 to 15 cm, and it is obtained by steam curing and / or autoclave curing after being put into a mold by a filling method or by pumping, and centrifugal force molding.

Since the amount of unit cement affects the effect of reducing slag from the viewpoint of strengthening the water retention capacity, and when the other conditions are the same, the larger the amount of cement, the smaller the water-cement ratio. It also has a positive effect on strength.

Therefore, the unit cement amount, the water cement ratio,
The amount of high-performance water reducing agent used and the amount of water loss reducing material are
It has an organic connection and cannot be independently limited, but in order to secure the slag reduction effect and strength, the slag reduction material amount is in the range of 0.2 to 15 kg / m ³ . Therefore, the unit cement amount is required to be 350 to 600 kg / m ³ , and preferably the unit cement amount is 380 to 550 kg.
/ m ³ . If the unit amount of cement is less than 350 kg / m ³ , the water retention capacity will be small and the effect of reducing slag will be impaired.
If it exceeds ³ , not only is it uneconomical, but the paste layer on the inner surface of the pile or the like after centrifugal force forming becomes too thick, and it is easy to fall off due to shock during movement, which is not preferable.

As the cement used in the present invention, various kinds of portland cements such as normal, early strength, ultrafast strength, and moderate heat, various mixed cements obtained by blending these portland cements with blast furnace slag, fly ash, or silica, In addition, slag-based cement in which fine powder slag is mixed in accordance with JIS standards or higher, alumina cement used in steel pipe lining, and the like can be mentioned.

The reason why the concrete slump is limited to 0 to 18 cm is that if the slump is softer than 18 cm, the paste layer on the inner surface of the pile becomes too soft even if the occurrence of slag is reduced, and the impact is generated during movement. This is because it tends to fall off, which is not preferable, and conversely, the smaller the slump, the more the effect of reducing slag is exhibited. However, even with the same slump 0, a jumper is likely to occur at the end of the centrifugal molded body in a state where the slump cone does not clog well, so a more preferable slump is 1.0.
~ 15 cm.

The concrete used in the present invention has a water-cement ratio of 36 to 25%. When the water-cement ratio exceeds 36%, the concrete using the slag reduction material has a small amount of dehydration by centrifugal force molding, and the water-cement ratio of the centrifugal force molded body does not decrease.
It is difficult to secure the design strength of the IS PC pile of 500 kgf / cm ² , and the PHC pile can be steam-cured by autoclave curing or by using a high-strength admixture for steam curing. Even design strength of 800kgf /
It is difficult to secure cm ² . Also, in order to obtain concrete of less than 25%, it is necessary to increase the unit cement amount, and in this case too, the thickness of the paste layer on the inner surface of the pile after centrifugal molding becomes too thick, which may cause impact during movement. It is not preferable because it easily falls off. More preferably 3
4 to 26%.

The high-performance water reducing agent is necessary from the standpoint of promoting the anti-slag effect and increasing the water-cement ratio to 36 to 25% to secure the strength. A high-performance water reducing agent is a water reducing agent having a greater water reduction rate than conventional lignin sulfonates and the like, and commercially available high-performance water reducing agents include polyalkylallyl sulfonates and melamine formalin resin sulfonates. The main component is any one of a polymer, an aromatic aminosulfonate polymer, and a polycarboxylic acid salt, and there is a mixed type of these.

As the polyalkylallyl sulfonate-based high-performance water reducing agent, methylnaphthalenesulfonic acid formalin condensate, naphthalenesulfonic acid formalin condensate,
And anthracene sulfonic acid formalin condensate, etc., and commercially available products include Kao Corporation's trade names "Mighty 100", "Mighty 150", "Mighty 2000" series, etc. 110P "
Takemoto Yushi Co., Ltd. product name "Pole Fine 510N", Sanyo Kokusaku Pulp Company product name "Sunflow PS", "Sunflow HS700", etc., and Denki Kagaku Kogyo Co., Ltd. product name "FT
-500 "is a typical example, and examples of melamine formalin resin sulfonate-based high-performance water reducing agents include Showa Denko's trade names" Melment F-10 "and" Melment F-20 ".
Examples include Denka Grace's trade name “FT-3S”, and examples of aromatic amino sulfonates include Fujisawa Yakuhin's trade name “Palic 200” series.

Further, in the polycarboxylic acid salt system, an olefin-maleic acid copolymer system, an alkenyl ether-maleic anhydride copolymer system, an acrylate-acrylic acid ester copolymer system (wherein a carboxy group and a sulfonic acid group are included). Group-containing multi-component polymers and polyether carboxylic acid salts) and the like, and those to which a hydrolyzable polycarboxylic acid cross-linked product is added in order to enhance the slump retention property.

Examples of these commercially available products include a series of products such as "Darlex Super 200" manufactured by Denka Grace Co., Ltd., "Chupol HP11" manufactured by Takemoto Yushi Co., Ltd., and "Reobuild SP-8HS" manufactured by Pozzolis Co. It

When the amount of the high-performance water-reducing agent used is increased, the water-reducing property is increased and the water-cement ratio is lowered, so that the strength is also increased. However, from the viewpoint of preventing slag, an appropriate amount is indicated and the amount exceeds the appropriate amount. When added, no slag reducing effect is exhibited. The upper limit of the appropriate amount varies depending on the amount of the noro reduction material used and the method of adding the water reducing agent (simultaneous addition, post-addition, etc.). Polycarboxylic acid salt-based high-performance water reducing agents increase the water reduction rate with a smaller amount than other high-performance water reducing agents, but increasing the amount used increases the delay and leads to a decrease in strength. The amount of the salt-type high-performance water reducing agent used is 0.05 to 0.5 parts by weight in terms of solid content with respect to 100 parts by weight of cement, and the other high-performance water reducing agents are in the range of 0.3 to 1.5 parts by weight. If it is added and less than 0.05 parts by weight, the water reducing effect is small even with a polycarboxylic acid salt type,
Even if the other high-performance water reducing agent is added in an amount of more than 1.5 parts by weight, the water reduction rate does not increase and the viscosity is likely to occur. Even if the addition amount of the water-reducing material is increased, the water-reducing effect is hindered. Not preferable. More preferably, it is 0.1 to 0.3 parts by weight in the case of polycarboxylic acid salt-based high performance water reducing agent, and 0.4 to 1.2 parts by weight in the case of other high performance water reducing agents.

The atmospheric steam curing and autoclave curing methods in the present invention are not particularly limited, and it is preferable to use the above-mentioned high-strength admixture for securing strength in atmospheric steam curing. In general, gypsum-based ones are commercially available. It is also preferable to use a cement expansive material or the like in order to increase the adhesive force with the steel pipe. These cement admixtures have a fine powdery degree or have high hydration activity, and therefore enhance water retention and promote anti-slag effect.

The anti-lorosity material of the present invention is added when kneading mortar or concrete, and the kneading method may be a commonly used method. The addition method of the slag reducing material of the present invention is not particularly limited. Therefore, it may be added together when mixing the concrete as powder, or may be suspended in a part or all of the mixing water in the form of a slurry, and further mixed with a water reducing agent. You may suspend and mix in a part or all amount of mixing water. It is particularly preferable to add the slurry because the effect of preventing slag is exhibited in a smaller amount when the material is suspended and made into a slurry rather than in the powder state. In addition, as for the timing of addition, in the kneading method in which the water reducing agent is added later, it is more effective to add the water reducing agent and then add a part of the kneading water and the suspended slurry, even if the kneading time is short, to prevent slag. In the kneading method in which the water-reducing agent is added together with the water, it is preferable to suspend the water-reducing agent and the water-reducing agent together and to add them together with other concrete materials.

The centrifugal molding method according to the present invention uses a low speed,
A conventional method of performing in medium speed (medium speed I, medium speed II) or high speed in 3 to 4 steps is used, and it is not particularly limited. The low-speed G No. is the concrete to which the noro reduction material of the present invention is added, which is plastic, so that the axial extension is improved. Especially, in the case of a low slump such as a built-in type,
A low speed of 3G or less is preferred to prevent jumpers, and 0.5
2G is more preferable. Low speed rotation time is 0.5 min
The above is preferable, 1 min or more is more preferable, 2 to 6 mi
n is most preferred. When medium speed I and medium speed II are put in four stages as a whole, medium speed I is about 4 to 8 G for 0.5 min or more in order to make the wall thickness of the centrifugal force molded body uniform. In addition, as a medium speed II, the aggregates are arranged in the circumferential direction, and the slump is set to 5 to prepare for the high speed transition.
It is 12 to 20G when the height is lower than cm, and 8 to 15G when the slump is more than 5 cm, and 0.5 min.
It is preferable to perform the above, more preferably 1 min or more,
Most preferably, it is carried out for 2 to 5 minutes. High speed does not require any regulation or unification of G No. and rotation time, it has good tightness without slag and does not fall off due to shock during transportation. For example, slump by pumping In the case of high concrete or in the case of concrete which has a small amount of powder and has small water retention capacity such as crushed sand and has a small water retention capacity and is easy to tighten, a rotation time of about 20 G and a rotation time of about 1 min may be sufficient. On the other hand, in the case of a pile having a large diameter such as a large amount of powder, a strong water retention ability and a small slump, and a large diameter pile, it may be necessary for 20 minutes or more at about 30G.

[0024]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. Example 1 Bentonite having different swelling degrees was sieved with a dry sieve to prepare bentonites each having a particle size range. Add crushed sand, crushed stone, and cement + bentonite (that is, bentonite was added as powder in this case, simply added by replacing sand by weight) to a planetary-type capacity 100 liter mixer based on the concrete mix in Table 1. Then, the mixture was dry-stirred for 20 seconds, then an aqueous solution in which a high-performance water reducing agent was dissolved in kneading water was added, and the mixture was kneaded for 90 seconds to prepare 40 liters of concrete. The slump was measured. Put the produced concrete in a fixed amount of 18 kg in a formwork, and operate at a low speed of 2G x 3
min, medium speed I is 4G × 1min, medium speed II is 10G × 3min
Centrifugal force molding was performed at a high speed of 30 G × 5 min to prepare a centrifugal force molding test piece having an outer diameter of 20 × length of 30 × thickness of 5 cm, and the amount of slag generated at this time was measured. At this time, the hollow open portions at both ends of the mold were capped to prevent leakage of the generated glue, and centrifugal molding was performed. In addition, after 2 hours of pre-positioning the molded specimen, the temperature was raised to 80 ° C. at a heating rate of 20 ° C./hrs, held for 4 hours, then allowed to cool until the next day, and then demolded at a temperature of 20 ° C. ± 3. The sample was cured at room temperature in ° C for 28 days and the compressive strength was measured. The results are shown in Table 2. The slump value was adjusted by the addition amount of the high-performance water reducing agent while maintaining the water-cement ratio constant.

[0025]

[Table 1]

<Materials used> Cement: Normal Portland cement manufactured by Denki Kagaku Kogyo Co., Ltd. Crushed sand: Himekawa, Niigata Prefecture, crushed sand, specific gravity 2.64 Crushed stone: Himekawa, Niigata prefecture, crushed stone, specific gravity 2.64 High-performance water reducing agent A: Daiichi Kogyo Seiyaku Product name "Cell Flow"
110P ”Main component polyalkylallyl sulfonate system, powder Bentonite: a. Swelling degree 22 (A.C.C. method) natural product b. Swelling degree 25 (A.C.C. method) natural product c. Swelling degree 30 (A.C.C. method) natural product d. Swelling degree 45 (A.C.C. method) purified product e. Swelling degree 80 (A.C.C. method) Chemically modified with alkyltrialkoxysilane Commercially available bentonites a to e are 150, 90, 63, 4
Sieving with a 4 μm sieve, 150 μ above, 150-90 μ
m, 90-63 μm, 63-44 μm, 44 μm particle size distribution was obtained and used in the examples. I. 150μ above b. 150 to 90 μm c. 90-63 μm d. 63 to 44 μm e. Under 44 μm F. Non-sieving <Measurement method> • Slump value: according to JIS A1101 • Amount of slag: Measured using a graduated cylinder • Compressive strength: According to JIS A1108

[0027]

[Table 2]

It can be seen from Table 2 that when the degree of swelling of bentonite exceeds 22, the slag reducing effect differs between 63 μm above and below, and 63 μm below shows a remarkable slag reducing effect, regardless of the amount of addition.

Example 2 The same test as in Example 1 was carried out using the basic mix of concrete in Table 1, sieving with bentonite of c at 63 μm, and changing the addition amount using bentonite under 63 μm. The results are shown in Table 3. The high-performance water reducing agent used was the one used in Example 1 and a part of the high-performance water reducing agent B. In addition, in order to match the slump, the amount of the water reducing agent was changed and the water-cement ratio was kept constant, and the amount of the water reducing agent was unchanged, and the slump was partially adjusted with the unit amount of water. <Materials used> High-performance water reducing agent B: Denka Grace Co., Ltd. product name "Darlex Super 200" polycarboxylic acid salt type (solidified block)

[0030]

[Table 3]

From Table 3, it is assumed that the water-cement ratio is 63 μ.
The amount of high-performance water reducing agent used increases as the amount of bentonite below 1 m is increased, but the amount of high-performance water reducing agent exceeds 1.5 parts by weight even if bentonite is added to 15 kg / m ³ or more. The effect disappears and it is shown that the amount of the high performance water reducing agent is 1.5 parts by weight or less, preferably 1.2 parts by weight or less. Also, if the amount of high-performance water reducing agent is reduced, the effect of reducing slag does not become extremely small, but the rate of increase in the unit water amount for obtaining the same slump is large and the water cement ratio is 3
If it exceeds 6%, it tends to be difficult to secure the design strength of a pile of 500 kgf / cm ² , and the polycarboxylic acid salt type water reducing agent has a large water reducing action, but if the addition amount is increased, the addition amount is increased. If it is added in an amount of more than 0.5 part by weight, the retardation becomes large and it tends to be difficult to secure the strength.

Example 3 Experiment No. 2 of Example 2. For 2-5 to 8, the total amount of water, the water reducing agent, and bentonite are suspended and added to the slurry,
The same test as in Example 1 was performed. The results are shown in Table 4.

[0033]

[Table 4]

From Table 4, it is clearly shown that the addition of a slurry amplifies the effect of reducing slag and makes it easier to obtain strength.

Example 4 The same test as in Example 1 was conducted using concrete mixes in which the unit cement content and the water cement ratio shown in Table 5 were changed. As the bentonite, the bentonite of c under 63 μm was used, and the high performance water reducing agent was the same as in Example 1. In addition, measurement of the thickness of the paste layer on the inner surface was added to the test items. In addition, a concrete with a certain composition was used in which the unit water amount was increased or decreased and the slump was arbitrarily changed. The test results are shown in Tables 6-7.

<Measurement method used> Thickness of paste layer: After molding, insert a flat blade into the paste layer and measure.

[0037]

[Table 5]

[0038]

[Table 6]

[0039]

[Table 7]

Example 5 Using the concrete mix of Table 8, 0.7 m ³ of concrete was mixed for 90 seconds in a 1 m ³ pan mixer. The bentonite used was c bentonite having a thickness of 63 μm or less. In addition, bentoite was added as a slurry mixed with the whole amount of kneading water. Further, a high performance water reducing agent C and a high strength admixture for steam curing were used. Centrifugal force molding conditions are
Using mixed concrete, low speed 1.5G x 4 minutes,
Medium speed I is 4G x 1 minute, medium speed II is 15G x 3 minutes, high speed is 2
5G x 3 minutes, outer diameter 300mm x length 1m x 60mm
And two types of A type single piles having an outer diameter of 300 mm, a length of 3 m, and a thickness of 60 mm and an effective prestress of 40 kgf / cm ² .
The pile specifications are 6 bars for PC steel rods with an outer diameter of 8 mm.
As for the book and the spiral streak, ordinary iron wires having an outer diameter of 5 mm were arranged at intervals of 50 mm. In addition, concrete is filled by the filling method, and the blank for comparison is 5 vol. % Increased. The steam curing conditions are, after column curing, after curing for an hour, then raised to 75 ° C. at a rate of 20 ° C./hr and kept for 4 hours, then naturally cooled in the curing layer until the next day and demolded, The compressive strength of a single pile having an outer diameter of 300 mm × a length of 1 m × 60 mm and the static bending strength of a single pile having an outer diameter of 300 mm × a length of 3 m × a thickness of 60 mm were measured when the outdoor pile was cured for one week. The results are shown in Table 9. <Materials used> Cement: Normal Portland cement made by Denki Kagaku Kogyo Co., Ltd. Sand: Shogawa, Toyama Prefecture, sand, specific gravity 2.66 Crushed stone: Shogawa, Toyama Prefecture, crushed stone, specific gravity 2.66 High-performance water reducing agent C: Electrochemical industry Product name "FT-"
500 "Liquid polyalkylallyl sulfonate-based high-strength admixture with 43% solids: Denka Σ manufactured by Denki Kagaku Kogyo Co., Ltd.
1000 "<Measurement conditions> -Static bending strength: In accordance with JIS A5337

[0041]

[Table 8]

[0042]

[Table 9]

In the example of the present invention, no slag was generated, and 48 L / m ³ of slag was generated in the comparative pile, and as a result, the thickness of the pile was almost the same.

[0044]

【The invention's effect】

1. By using the bentonite containing the secondary particles having a swelling degree of more than 22 and 63 μm or less according to the present invention as a main component, it is possible to enhance the slag reduction effect during the production of the centrifugal force molded body. 2. By limiting the mix of concrete and the like, it is possible to reduce slag and to secure the strength, and it is possible to manufacture piles and the like having excellent bending strength as well as compressive strength. 3. By using the slag reducing material of the present invention,
Since it is possible to reduce the amount of slag that is discarded as industrial waste, it is useful for pollution prevention and environmental conservation.

Claims (4)

[Claims] 1. A. C. C. The swelling degree by the method is more than 22, and the maximum secondary particle diameter is 63 μm or less. 2. A concrete for producing centrifugal force, which comprises the slag reducing material according to claim 1 and a high-performance water reducing agent. 3. A centrifugal force molded body obtained by centrifugally molding the concrete according to claim 2. 4. The unit amount of cement is 350 to 600 kg /
m ^3, water cement ratio is 36 to 25%, slump 0-1
8 cm, high performance water reducer cement in concrete 10
0.05 to 1.5 parts by weight in terms of solid content is blended with 0 part by weight, and the slag reducing agent according to claim 1 is added to
A method for producing a centrifugal force molded body, which comprises subjecting concrete mixed with 15 kg / m ³ to centrifugal force molding, and steam curing and / or autoclave curing.