JP2928316B2 - Slag reduction agent - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a slag reducing agent for a centrifugally molded product, and more specifically, a pile, a pole, a steel pipe composite pile manufactured by centrifugally molding mortar or concrete, and The present invention relates to a slag reducing agent that reduces or prevents the occurrence of slag during the production of centrifugal force molded products such as steel pipe linings and fume tubes.

<Conventional technology and its problems> Conventionally, when manufacturing concrete products such as piles and poles manufactured by centrifugal force forming, squeeze is squeezed out by centrifugal force. In addition to water, this noro contains fine particles of 20-40% by weight of cement and sand in addition to water, and because it is highly alkaline, it cannot be discharged outside the factory as it is in terms of pollution prevention. There have been problems such as a large amount of time and cost required for the solid content settling / filtration treatment and wastewater neutralization treatment.

In order to prevent the generation of slag, there is known a method in which a setting accelerator such as aluminum sulfate is added while concrete is poured into a formwork to perform centrifugal molding (Japanese Patent Application Laid-Open No. 61-104804). ).

However, in this method, although the separation of the solid content can be suppressed, the amount of the strongly alkaline water to be dehydrated is rather increased, so that there is a problem that a neutralization tank for treating this is required. .

The present inventors have conducted intensive studies from the viewpoint of not producing water or slag at all, and as a result, used soluble aluminum compounds such as aluminum sulfate and limes, or soluble aluminum compounds and limes and specific inorganic powder. And
By kneading with mortar or concrete, the inventors have found that the above-mentioned problems can be solved and completed the present invention.

<Means for Solving the Problems> That is, the present invention provides (1) a slag reducing agent for a centrifugal force molded product containing a soluble aluminum compound and lime as main components,
(2) The slag reducing agent for a centrifugally molded product according to claim 1, further comprising an inorganic powder.

 Hereinafter, the present invention will be described in detail.

The soluble aluminum compound according to the present invention is one or more selected from the group consisting of aluminum sulfate, aluminum nitrate, sodium aluminate, potassium aluminate, alum, alunite and calcined alunite. Yes, those commercially available for industrial use can be used as they are.

The amount of the soluble aluminum compound used is preferably at most 3 parts by weight, more preferably 2 parts by weight or less, and most preferably 0.05 to 1.5 parts by weight in terms of anhydride, based on 100 parts by weight of cement in mortar or concrete. . If the amount is more than 3 parts by weight, the tendency for the strength to decrease further increases due to an increase in the amount of kneading water, and furthermore, the mortar or concrete may cause rapid setting, which is not preferable.

The limes according to the present invention are quicklime and slaked lime, and also quicklime contained in the expansive material can be used, which promotes the noro reduction effect of the soluble aluminum compound,
In addition, it has the effect of increasing the setting and hardening speed of mortar or concrete and increasing the strength. These are usually commercially available as they are.

The amount of lime used is preferably at most 5 parts by weight, more preferably 0.05 to 3 parts by weight, based on 100 parts by weight of cement in mortar or concrete. If the amount exceeds 5 parts by weight, the setting promoting action is too strong, and the strength tends to decrease, which is not preferable.

The inorganic powder according to the present invention, bentonite, acid clay, activated clay, clay, clay minerals such as zeolite and talc, silica fume, aerosil and diatomaceous earth,
Further, ultra-fine silica having a maximum particle size of about 60 μm, which is collected by a back filter when crushing silica such as fused silica, and the like, among which bentonite and silica fume have a large effect of promoting slag reduction and are preferred. It is.

Bentonite has a swelling property, and its swelling property differs depending on the locality and mineral deposits.
Those having a degree of swelling of about 5 to 40 according to ampany 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.

Further, silica fume is amorphous silica as an ultrafine powder that is by-produced during the production of metallic silicon or a silicon alloy.

The amount of these inorganic powders used is preferably at most 5 parts by weight, more preferably 3 parts by weight or less, based on 100 parts by weight of cement in mortar or concrete, and is preferably from 0.05 to 5 parts by weight.
More preferred is 2 parts by weight. If it exceeds 5 parts by weight, the amount of kneading water increases and there is a component that lowers the strength, which is not preferable.

 The slag reducing agent of the present invention is preferably used in combination with a water reducing agent.

The slag reducing agent may be used as it is as a powder. However, by using a water reducing agent and, if necessary, dispersing in part or all of the kneading water and using it in a slurry form, the slag reduction can be reduced more effectively in a small amount. Can be performed.

Examples of the water reducing agent used in the present invention include a general water reducing agent and a high-performance water reducing agent, and the components are not particularly limited. 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 further 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 anthracenesulfonic acid. Formalin condensate and the like, and as a commercially available product, “Mighty 10
“0” and “Mighty 150”, such as “Cell Flow 110P” manufactured by Daiichi Kogyo Seiyaku Co., Ltd., “Pole Fine 510N” manufactured by Takemoto Yushi Co., Ltd. “Sanyo Kokusaku Pulp Co., Ltd.” There are "Sunflow PS" and "Sunflow PSR", and the product name "FT-500" manufactured by Denki Kagaku Kogyo Co., Ltd. As the melamine formalin resin sulfonate, the product name "Showa Denko Co., Ltd." Examples include "Melment F-10" and "Melment F-20", and the trade name "NL-400" manufactured by Nisso Master Builders Co., Ltd.

In the present invention, the amount of the water reducing agent used for cement may be the amount specified by the manufacturer or 2
It is used in an amount of up to about three times and in a range where abnormal coagulation does not occur.

When using a high-performance water reducing agent as a water reducing agent,
0.3 to 2.0 parts by weight, preferably 0.4 to 1.8 parts by weight, more preferably 0.5 to
1.5 parts by weight is more preferred. As the amount of high-performance water reducing agent used increases, the water reduction rate increases,
The slag increases and the required amount of the slag reducing agent of the present invention for reducing the slag increases. When the amount of the high-performance water reducing agent used is less than 0.3 parts by weight and the slag reducing agent of the present invention is used, the concrete becomes plastic, the mixing water increases, the strength tends to decrease, and when it exceeds 2.0 parts by weight, It is not preferable because the viscosity of the concrete increases and the effect of the slag reducing agent tends to decrease.

The cements used in the present invention are various kinds of Portland cements such as ordinary, fast strong, super fast strong, and moderate heat, various mixed cements in which Portland cement is blended with blast furnace slag, fly ash or silica, and cements containing fine powder blast furnace slag, etc. It is.

The method of adding the slag reducing agent of the present invention may be directly put into a mixer as a powder and kneaded, but it is more effective to use a water reducing agent and, if necessary, a slurry suspended in water. Yes, specifically, it is preferable that water, a water reducing agent and a slime reducing agent are simultaneously measured in a measuring instrument, stirred to form a suspension, and then put into a mixer and kneaded.

The kneading method is not particularly limited, and a method usually used in the production of mortar or concrete can be used.

The centrifugal force forming method is also not particularly limited, and is a conventional method of G No. 3 to 5 at a low speed of 1 to 3 minutes, a medium speed of G No. 12 to 18 at a medium speed of 3 to 5 minutes, and a G No. 30 to It is preferable to carry out at a high speed of 40 for 3 to 5 minutes, but the mortar or concrete using the slag reducing agent of the present invention, for example, when the slump is as low as 3 cm or less, the mortar or concrete hardly moves during centrifugal molding, so For example, it is preferable to perform low speed at G No. 3 or less for 3 minutes or more. When G No.3 is exceeded, it is 1
Junkers are likely to be formed along the circumferential direction at an inner side of about 2 cm, and mortar or concrete may not spread to the end unless centrifugal molding is performed for 3 minutes or more.
At medium speed, there is no need to be particular about the G No. and the centrifugal force forming time. The high speed is preferably G No. 27 or more when calculated from the inner diameter up to the inside of the tube thickness of the centrifugal molded body. If G is less than 27, mortar or concrete may not be formed properly on the inner surface. The high-speed time is preferably 1 minute or more.

Furthermore, vibration centrifugal molding, which is performed while vibrating at a low or medium speed, is preferable because it does not easily produce a jumper even with mortar or concrete that is difficult to move with plastic, and the finish of the molded body is improved.

<Example> Hereinafter, the present invention will be described in detail based on examples.

Example 1 Using the basic concrete composition shown in Table 1, Table 2
As shown in (a), aluminum sulfate (a primary reagent) was used as a soluble aluminum compound, β slaked lime (digested gas-burned lime, under 88μ) was used as limes, the amount of use was changed, and concrete was kneaded. Place 18 kg of concrete in a × 30 ^l × 5 ^t formwork, cover the hollow part of the formwork so that noro does not leak, and calculate the G No. Using G No.2 at low speed for 4 minutes, G
The mixture was kneaded under the conditions of centrifugal force forming for 2 minutes at medium speed of No. 5 and 2 minutes at high speed of G No. 35, and after 15 minutes, a centrifugally formed body was formed, and the amount of squeezed out was measured.

Similarly, create a concrete specimen of φ10 × 20cm,
Pre-curing at 20 ℃ for 4 hours, then raise to 65 ℃ at a heating rate of 15 ℃ / h. After steam curing for 4 hours, stop the steam valve and let it cool naturally in the curing tank until the next day. Then, after taking out, after being removed from the mold, it was cured in a room at 20 ° C. until the age of 7 days, and then the compressive strength was measured.

In addition, when the soluble aluminum compound and the lime were used, the increase / decrease in the unit water amount was kneaded without correction. The amount of water used and the slump value are shown in Table 2 together with the test results.

The slag reducing agent of the present invention was mixed with cement to make sand or crushed stone and dry concrete, and kneading water was added thereto to knead the concrete.

<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 Soluble aluminum compound a: Aluminum sulfate, Wako Pure Chemical ( Co., Ltd. Class 1 reagent Lime β: slaked lime, calcined in a gas-burning lime oven, pulverized through 88μ through water, digested with water Example 2 As shown in Table 3, the same procedure was performed as in Example 1 except that the type of the soluble aluminum compound was changed and a water reducing agent was used in combination. The results are shown in Table-3.

<Materials used> Soluble aluminum compound b: calcined alum, potassium alum from Katsumitsuyama, Hiroshima prefecture, crushed to a 3,000 cm ² / g brane, 600 ° C
C: Aluminum nitrate, first grade reagent manufactured by Wako Pure Chemical Industries, Ltd. d: sodium aluminate, first grade reagent manufactured by Wako Pure Chemical Industries, Ltd. e: Potassium alum, Wako Pure Chemical Industries, Ltd. 1st grade water reducing agent a: manufactured by Daiichi Kogyo Seiyaku Co., Ltd.
0P "Polyalkylallyl sulfonate-based powder.

In Table 3, the water reducing agent, the soluble aluminum compound and the limes are shown in parts by weight based on 100 parts by weight of the cement. When the water reducing agent is a powder, the soluble aluminum compound and the limes are mixed, and cement, sand and The crushed stone was added when kneading, and then water was added to adjust the celite.

In addition, the water reducing agent is dissolved in the kneading water and added to the dry kneaded dry concrete containing the slag reducing agent. Among the soluble aluminum compounds, those with water of crystallization are converted to anhydrides, and those containing impurities are converted to active ingredients. As kneaded.

As shown in Table 3, the addition of a soluble aluminum compound alone has a small effect of reducing the generation of slag, but it is shown that the use of limes reduces or prevents the generation of slag.

The soluble aluminum compound has an effect of adding from 0.05 part by weight with respect to 100 parts by weight of the cement, and the noro reduction effect increases as the amount used increases, but when the amount exceeds 3 parts by weight, the strength increases due to an increase in the unit water amount. The rate of decrease is large, and the strength of plain with no water reducing agent added may be broken, which is not preferable.

Lime shows a use effect even at about 0.05 parts by weight with respect to 100 parts by weight of cement, and promotes the noro reduction effect as the amount used increases, contributing to an increase in strength. Probably because the expression rate becomes too high, resulting in a decrease in strength.
And the concrete of Example of Experiment No. 2-3 and the concrete of Example of Experiment No. 2-10 were molded into a formwork of φ10 × 20 cm, immediately put into a curing tank at 60 ° C., and then compressed for 3 hours. Strength is each
It is 50, 80 and 250 kg f / cm ² , and it is recognized that the combination of the soluble aluminum compound and the lime significantly accelerates the setting hardening.

Example 3 As shown in Table 4, the procedure was performed in the same manner as in Example 1 except that aluminum sulfate was used as a soluble aluminum compound, the types and amounts of limes and water reducing agents were changed, and concrete was kneaded. The results are shown in Table-4.

<Materials> Lime α: calcined lime, calcined in a gas-burning lime oven and crushed to a size of 88 μm. Water reducing agent b: Trade name “Melment F-1” manufactured by Showa Denko KK
0 "Principal melamine formalin resin sulphonate powder.

C: Denka Grace Co., Ltd. product name “Darlex WRDA” Standard addition amount cement × 0.25%, lignin sulfonate-based, liquid.

Reference Example 1 As shown in Table 5, the same procedure as in Example 1 was performed except that inorganic powder was used in place of limes. The results are shown in Table-5.

<Materials> Inorganic powder A: bentonite, trade name "Premium Gel" manufactured by Kanto Bentonite Industry Co., Ltd. 35 swelling degree by ACC method B: Bentonite, trade name "sizing" manufactured by Toyshun Mining Co., Ltd.
CC method swelling degree 10 C: Acid clay, Kanto bentonite industry name "acid clay" D: Activated clay, Kanto bentonite industry name "Galeon earth" E: Clay, Kanto bentonite industry ) Product name "SA
M clay ”F: Zeolite, brand name“ SGW ”manufactured by Kanto Bentonite Industry Co., Ltd. G: Talc, brand name“ Soapstone A ”manufactured by Kanto Bentonite Industry Co., Ltd. H: Silica fume, manufactured by Nippon Heavy Chemical Industry Co., Ltd. Name "SF powder" I: Aerosil, Nippon Aerosil Co., Ltd. product name "Aerosil 50" J: Diatomaceous earth, calcined product from Noto Wakura K: Fused silica, manufactured by Denki Kagaku Kogyo Co., Ltd., crushed fused silica Back filter product, maximum particle size 50μ As shown in Table-5, the inorganic powder of the clay mineral or the silica substance promotes the slag reduction effect of the soluble aluminum compound from about 0.05 part by weight with respect to 100 parts by weight of the cement. Even if it is added in excess, the strength is reduced only by an increase in the unit water amount, which is not economically preferable.

Example 4 As shown in Table 6, the same operation as in Example 1 was performed except that a soluble aluminum compound, limes, an inorganic powder and a water reducing agent were used. The results are shown in Table-6.

Example 5 Experiment Nos. 2-4, 2-7 to 9, 2-16 to 18, 2 in Table 3
-22, Experiment Nos. 4-1 to 4 in Table 5, Experiment No. 5 in Table 6
For each of the components 1-3 and the water reducing agent, a suspension was prepared with the whole amount of kneading water, and added to the dry kneaded dry concrete,
Centrifugal force forming was performed in the same manner as in Example 1, and the amount of slag generated was measured. The results are shown in Table-7.

As shown in Table 7, the slag reducing agent of the present invention effectively reduces slag in a small amount by using a water reducing agent and each component in advance as a suspension, rather than adding it as a powder. Or it is recognized that it can be completely prevented.

<Effect of the Invention> 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 during the production of a pile or the like. Costs can be significantly reduced.

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁶ identification code FI B28B 21/30 B28B 21/30 (58) Investigated field (Int.Cl. ⁶ , DB name) C04B 22/14 C04B 22/08 C04B 22/06 B28B 21/30 B28B 1/20

Claims (2)

(57) [Claims] 1. A slag reducing agent for a centrifugally molded product mainly comprising a soluble aluminum compound and limes. 2. A slag reducing agent for a centrifugally molded product according to claim 1, further comprising an inorganic powder.