JPS63156047A - Aid for centrifugal molding - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a centrifugal force forming aid for producing concrete products, and in particular, centrifugal force forming of humid pipes, concrete piles, steel pipe composite piles, balls, etc. This invention relates to a centrifugal forming aid for concrete products produced by

[Conventional technology and its problems]

Conventionally, the Huum Pipe 1 propulsion pipe, concrete pile, ball, steel pipe composite pile, and mortar or concrete lining in the steel/R are compacted and formed using centrifugal force.

However, in general, mortar and concrete have poor centrifugal formability, and for example, for humid pipes, which depend on the finish of the inner surface, it is customary to make the tube for 30 to 40 minutes, and after steam curing, the inner surface of the tube is Please note that the mortar layer often peels off.

In order to improve this, cement powder, new mortar, or anti-peeling agents are added to the inner surface of the tube in the final finishing step, and centrifugal force molding is performed. Furthermore, the centrifugal formability of mortar and concrete is further deteriorated by the addition of various water-reducing agents, so water-reducing agents are generally not used in pipes, mf linings, etc. where the inner surface finish is vital. It becomes.

However, with the revision of J-Engineering S, it has become safe to increase the strength of humu pipes, and at present, small amounts of water-reducing agents are used at full risk of deteriorating production efficiency and product yield (for example, Publication No. 56-160358). In addition, for concrete piles and eel temples where the quality of the inner surface finish is not an issue and high strength is required, we use full centrifugal force forming of concrete with the addition of a high-performance water reducing agent to reduce the water/cement ratio as much as possible. Manufactured using

Among various water reducing agents, the centrifugal formability of mortar and concrete to which this high-performance water reducing agent is added is particularly poor, resulting in a large amount of slag, the inner surface of the pipe not tightening, and its strength being lower than that of differential forming. It is known that on average it is about 10% lower than the standard.

The present inventors have proposed a method of using this high-performance water reducing agent in combination with oxycarpic acid or its salts in order to improve the centrifugal formability of mortar or concrete (Japanese Unexamined Patent Publication No. 59-69457). ). However, this method has the disadvantage that stable strength cannot be obtained depending on the amount of oxycarginic acid or its salts added and the temperature of the mortar or concrete, since the setting retardation effect is large.

10,000, the present inventors have discovered that concrete IJ-
In order to increase the strength of torn products, a method was proposed in which a relatively large amount of Ceracola was added (Japanese Unexamined Patent Publication No. 53-4902).

This technique has been generalized and spread, but the Ceracola type used at this time is a hard stone with the greatest strength effect. Hard slag can be easily obtained by heat-treating other ceracola at 350° C. or higher, but for economical reasons, slag that is produced as a by-product during hydrofluoric acid generation (hereinafter referred to as hydrofluoric acid ceracola) is usually used.

However, due to various circumstances, the production of Ceracola hydrofluoric acid was
It is decreasing year by year. Therefore, there is a need to achieve the same strength development effect as conventional products by adding a small amount, and to increase the strength so that other Ceracola types can be used as is.

The present inventors have discovered that the following points can be improved by adding aromatic calzynic acids regardless of the presence or absence of a water reducing agent and regardless of the type of Ceracola. I have reached the point where I have completed the .

(1) Tighten the inner surface of the tube to prevent inner surface peeling, reduce tube manufacturing time, and improve production efficiency.

(2) Improve the dehydration effect and stably obtain strength equal to or higher than that of the vibratory compacted specimen with the centrifugal force molded body.

(3) Achieve the conventional strength by adding a small amount of hard stone.

(4) Even when used with Ceracola other than Hard Setsuko, the same strength as before can be obtained.

In particular, the strength of (2) onwards is less affected by the concrete temperature and is suitable for industrial use.

[Means for solving problems]

That is, the present invention is an aromatic cal? It is a centrifugal forming aid for concrete products, which mainly contains phosphoric acids.

The present invention will be explained in detail below.

Aromatic carbic acids used in the present invention include benzoic acid,
Monocarboxylic acids such as salicylic acid, anisic acid, anthranilic acid and gallic acid; zocarboxylic acids such as phthalic acid, terephthalic acid and isophthalic acid; side chain carboxylic acids such as phenylacetic acid, mandelic acid and cinnamic acid; It is a sodium and potassium salt temple.

The amount of aromatic carboxylic acids used is 0.00 per cement.
It is 5 to 1.0 coul%, and the preferable range is 0.01 to 1
．． It is 0% by weight. If it is less than 0.005% by weight, the effect of use is small, and if it exceeds 1.0% by weight, it may exhibit strong setting retardation, which is not preferable in terms of strength.

As the Ceracola type, hard gypsum, rockable anhydrous gypsum, water gypsum, and semi-hydrous gypsum (hereinafter referred to as anhydrous gypsum, recirculated anhydrous, industrial water, and semi-water) are used, and the amount used is Ca804 per cement. The amount is at most 15% by weight, and the preferred range is from 2 to 13% by weight. 15
Even if it is used in excess of this weight percent, the strength will not increase, which is economically undesirable.

In addition, alkali metal carbonates, bicarbonates, sulfates, bisulfates, sulfites, 1-term sulfates, and calcium sulfites are used as ingredients that further enhance the centrifugal formability and the strength of the concrete product of the present invention. There are inorganic salts exclusively for magnesium sulfate and magnesium sulfate, and when these are used in combination, the amount used is at most 0.3% by weight based on the cement in terms of anhydride, and the preferred range is at most 0.1% by weight.

The dehydration property of concrete during centrifugal forming decreases in the order of sodium sulfate, sodium bicarbonate, potassium carbonate, potassium carbonate, sodium carbonate, ammonium carbonate, etc., but bisulfate, calcium sulfite, magnesium sulfate, and sodium carbonate Although they have a small effect on dehydration, they have a large effect on strength.

In addition to general water reducing agents such as stile, lignin sulfonate, and polyol, it is widely used in concrete product factories for high-strength concrete. There are high performance water reducing agents such as realkylaryl sulfonate type and melamine resin sulfonate type, the former is preferably used in the amount specified by the manufacturer, and the latter is preferably used at most 5% by weight (solid content equivalent) based on cement. .

The cement used in the production of mortar or concrete in the present invention includes various Portolan 1 cements such as normal, early strength, super early strength, moderate heat, and sulfate resistant, blast furnace slag, fly ash, silica, etc. It is a mixed cement,
In terms of strength, the larger the hydraulic coefficient, the higher the strength.

Further, the present invention maintains its effectiveness as a centrifugal molding aid even when a commercially available expansion material, silica hume, etc. are used in combination.

In carrying out the present invention, aromatic carboxylic acids, their salts, and gypsum may be directly added to the mixer together with other ingredients during mixing, or they may be dissolved or dispersed in a portion of the mixing water in advance. May be used. Further, the manufacturing method of centrifugal force-formed concrete products is carried out by a method normally performed on site.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to Examples.

% in each table is the amount of externally cut M in cement, converted into anhydrous or solid content, and those that are statically large, such as stone fF, are replaced with sand.

$ Example 1 Using the concrete formulation in Table 1, the type of aromatic carboxylic acids (first class reagent) and the amount of gold added were changed, and 20φx3
The centrifugal formability and compressive strength of centrifugal force test tubes of []tX5tcrIL were measured.

For centrifugal force forming, after placing the concrete into the formwork at a constant rate of 18 to 9, it was heated at a low speed of 5G for 3 minutes, at a medium speed of 15G for 3 minutes, and at a high speed of 3 minutes.
Centrifugal force molding was performed at 0 G for 3 minutes, and the moldability was judged by the thickness of the soft mortar layer on the -W inner surface (hereinafter referred to as slag layer thickness). The compressive strength is the centrifugally molded sample U.
Specimen 1 of 10 φ x 20 crrL packed with vibration.The following margin cement (c): ``i'' is made by Kei Kagaku Kogyo Co., Ltd., Kyotsu Portland cement, ratio! 3.16 Sand (S) Niigata prefecture Himeyo river sand, specific gravity 2 .65 crush
Stone (G):t Crushed stone, ratio:! ! 2.68 General water reducing agent: Lignosulfonate-based product name: “Comblast 211” manufactured by Toyaku Trading Co., Ltd. High performance water-reducing agent (a): Polyalkylaryl sulfonate-based product name: “Mighty 100” manufactured by Kako Co., Ltd. ” Powder (b): Melamine resin sulfonate product Showa Denko (red) product name “Melnont F-10J Powder” After 4 hours of preparation, the temperature was raised to 65°C for 3 hours, kept as it was for 4 hours, and then naturally heated. After cooling, d8 tax mold 24
Time compressive strength total measurement 1. Ta. The concrete cross-conducting was carried out at 307° for 3 minutes using a forced aO mixer, and the cross-conducting and pre-curing were carried out indoors at 20°C.

The measurement results are shown in Table-2.

Margin below In Table 2, experimental scraps 1 to 5 are comparative examples.

The aromatic oxycarboxylic acid of the present invention has a large effect on developing centrifugal force formability and strength at 0.005 to 1.0% by weight based on cement, and the preferable range is 0.01 to 0.51%. is shown.

Example 2 Experiment A similar test was conducted using concrete with a mix of flat plate 3 and scrap 12, but with different types and amounts of Ceracola.

The results are shown in Table-3.

Ceracola: Hydrofluoric acid by-product (plain value 4,5
00 儒2/g) 2 Water: Industrial use Water: 2 Dry water at 150℃ for 6 hours Soluble Anhydrous 2Hanhydrous Gold Redry for 6 hours at 200”C Table-6 Experiment 7% 28
-37 are comparative examples.

In the comparative example, the centrifugal force formability is poor (i.e., it takes a long time to finish the Hume tube, etc., and inner layer peeling is likely to occur), and the margin strength of the centrifugally formed test tube is lower than that of the 10φ x 20cWL photo-packed sample. becomes smaller.

In the examples using the centrifugal forming aid of the present invention, the centrifugal forming property is good and the inner surface is hard and firm, and the strength of the centrifugally applied test tube is always higher than that of the 10φ x 20cm test piece.
The absolute strength of the test tube was increased, and even with a small amount of Ceracola used, great strength was obtained.

Example 3 Experiments 438 and 40 were used for the comfleet mixer, and the effect of adding various inorganic salts was evaluated using 300φ x 1,000tm RC pipes (straight bar φ6B PC @ 6 steel bars, spiral bar φ6
The compressive strength of a short piece of 2H iron wire with a spacing of 50 u) was investigated.

Concrete temperature is 10℃, outside air @ 8℃, centrifugal molding is carried out by conventional method, and after pre-curing for 6 hours, it becomes 75” in 3 hours.
The sample was raised to temperature C and held as it was for 4 hours, then allowed to cool naturally in a curing tank, and the compressive strength was measured for 24 hours after demolding.

At the same time, a 10φX 2 (1 m) vibration packed specimen was also taken and similarly cured for comparison.

The results are shown in Table 4.

Centrifugal force molding was carried out by varying the type and amount of salicylic acid used (9) and the type and amount of inorganic carbonate used (see below).

As a centrifugal force molded body, the outer diameter is 20 cm, the length is 30 cm, and the thickness is 5 cI! Using L test pipe, concrete amount t-18
The centrifugal force molding was performed at a constant speed of 3G for 2 minutes, at a medium speed of 15G for 4 minutes, and at a high speed of 30G for 2 minutes, and the thickness of the slag layer was measured.

Same as sample a centrifugal force molding [, 10φ x 20CI! Concrete was completely placed in the L formwork using a rod vibrator, the specimen was molded, and after pre-curing at 20℃ for 4 hours, the temperature was raised to 65℃ at a rate of 15℃/h. ,6
The sample was kept at 5°C for 4 hours, then kept in a steam curing tank until the day of retention, and the strength was measured for 24 hours. Materials used are Example 1
It is similar to

The results are shown in Table-6.

In Table 6, Experiments 4666 to 70 are comparative examples, Experiment 4
671 to 100 are examples. In Experiment Nos. 66 to 70, the moldability was poor regardless of the type of water reducing agent and whether or not it was used. This is particularly the case when a high-performance water reducing agent is added, and the problem tends to worsen as the amount added is increased. As for strength, especially when a water-reducing agent is used, it is observed that the strength of the centrifugally formed test tube tends to be lower than that of the 10φ×20cIIL vibration-compacted specimen.

In the examples of the present invention, the centrifugal force formability is improved, and the compressive strength of the test tube is larger than the strength of the test sample.

Example 5 In experiment %77, concrete temperature and pre-curing temperature were 11:10°C (pre-curing time was 8 hours) and 60°C (
The same test as in Example 4 was conducted using a comparative example in which citric acid was added to the cement. The results are shown in Table 7.0 It can be seen from Table 7 that when the centrifugal force forming aid of the present invention is used, the influence of temperature on compressive strength is less than in Comparative Example Experiment 4101.102.

Below is the blank space Example 6 Experiment V; Using Conc I + -t of Experiment 68 and Experiment 77,
41 with an inner diameter of 600fi and a length of 2430mm! ! : A centrifugal force moldability test was conducted using muscle humerus canals.

The centrifugal force forming conditions are: 3G for 2 minutes after concrete is poured;
The inner surface was finished after 3 minutes at 15G and 4 minutes at 43G.

When the centrifugal force molding aid of the present invention was used, the product became firm after 4 minutes of centrifugal force was applied to the AQG, and the time required for centrifugal force molding was approximately 15 minutes. On the other hand, in the comparative example, about 6
It took 5 minutes, but it was cooked to a depth of about 1 inch inside the tube.

〔Effect of the invention〕

As described above in each embodiment, the effects of the present invention are as follows.

(1) Good compaction of the mortar and concrete layer on the inner surface of the tube through centrifugal force forming, good dewatering properties, and reduces or prevents the generation of slag (-1). Same as above.

In particular, when a water reducing agent is used in combination, the improvement effect is remarkable.

(2) The compressive strength of the specimen g formed by centrifugal force is always greater than the compressive strength of the photographically compacted specimen, and the dependence of concrete compressive strength on each occasion is small.

(3) Pipe making time is short and production efficiency is improved.

14) Centrifugal force FM, the compressive strength of the molded specimen was 10% higher than that of the conventional 10% addition of Cerakola when 5% of Cerakola was added.
Strength comparable to that of a photographically compacted specimen of φX20 can be obtained.

(5J The combined use of inorganic salts such as carbonates and sulfates of alkali metals has the effect of enhancing compressive strength, etc.

Claims (1)

[Claims] (1) A centrifugal forming aid used in the production of concrete products, whose main component is aromatic carboxylic acids.