JP2000072523A - Sulfur concrete product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prepare a sulfur concrete product capable of being demolded immediately after compacting and having strength enabling itself to be handled as a molded product by mixing sulfur with a specific quantity of fine-grain mineral, by heating a mixture up to a temperature of the melting point of sulfur or higher and by compacting it. SOLUTION: This sulfur concrete product is prepared by mixing 1 pt.vol. sulfur with 1-20 pts. vol. fine-grain mineral. The fine-grain mineral is e.g. rock powder, blast furnace slug powder, fly ash, or the like and fly ash is esp. suitable. It is pref. to use a mixture of sulfur passing through a sieve having 0.75 mm mesh size with fine-grain mineral having >=2,000 cm2/g Blaine specific surface area, or to use a product prepared by mixing sulfur with fine-grain mineral and then by crushing the mixture up to >=1,000 cm2/g Blaine specific surface area. It is possible to produce a product sparing decreasing the strength, causing no crack or the like due to shrinkage in cooling and excellent in compactness and surface smoothness even when the content of fine-grain mineral is larger than that of sulfur by adjusting grain sizes of sulfur and fine-grain mineral. The sulfur concrete product may include aggregate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a concrete product using a sulfur composition comprising sulfur and a fine mineral substance powder. More specifically, it is a sulfur concrete product that has a smooth surface and excellent durability by increasing the quantity ratio of mineral fine powder by pulverizing sulfur and mineral fine powder to suppress cracking. The purpose of the present invention is to provide a sulfur concrete product which can be immediately demolded later.

[0002]

2. Description of the Related Art Conventionally, sulfur mortar or sulfur concrete in which an aggregate is mixed with sulfur has been known. A conventional sulfur concrete product is manufactured by pouring a material that has been heated and melted into a paste into a mold, and then cooling and solidifying it. For this reason, it takes a long time until the mold is released from the mold, and there is a problem of low productivity.

[0003] Mineral powders (fillers) are added to sulfur concrete in order to prevent sulfur from being breathed and separating from the aggregate, and to improve the plasticity of the concrete. This filler prevents the generation of cavities (voids) caused by shrinkage when the sulfur is cooled and solidified, and also contributes to an increase in strength. However, since the filler itself does not have curability, the strength generally decreases as the amount of the filler added increases, and it is difficult to obtain a homogeneous mixture. Therefore, in conventional sulfur concrete, the amount of filler added is often less than 1 part by volume per 1 part by volume of sulfur. For this reason, the formation of voids due to the solidification shrinkage of sulfur cannot be sufficiently prevented, and there is a problem that cracks are likely to occur.

[0004]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems in a sulfur concrete product. Since it does not require accelerated curing after being placed in a mold, it can be demolded in a short time, and The preferred embodiment in which the particle size of the sulfur and the filler is adjusted is a sulfur concrete having a smooth surface and excellent denseness with little decrease in strength even when the mixing amount of the filler is larger than sulfur, and hardly causing cracks and voids. Offer products.

[0005]

That is, the present invention relates to a sulfur concrete product having the following constitution. (1) A mixture obtained by mixing 1 part by volume or more and 20 parts by volume or less of a mineral fine powder with respect to 1 part by volume of sulfur is heated to the melting point of sulfur or more, and then compacted to obtain a compact having self-formity. A sulfur concrete product characterized by the following. (2) The sulfur concrete product according to the above (1), wherein a mixture containing an aggregate together with sulfur and a mineral powder is used. (3) The sulfur concrete product according to the above (1) or (2), wherein a mixture of sulfur having a particle size of 0.75 mm sieve and a fine mineral powder having a particle size of at least 2000 cm ² / g of Blaine specific surface area is used. (4) Mixing sulfur and mineral powder and pulverizing the mixture to obtain a Blaine specific surface area of 1000 cm ² / g or more
(1) or (2) sulfur concrete products.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below based on embodiments. The sulfur concrete product of the present invention,
A mixture of 1 part by volume of sulfur and 1 part by volume or more to 20 parts by volume of a mineral substance powder is heated above the melting point of sulfur (115 ° C. or more) and compacted. This is a molded article having It should be noted that having the self-molding property means that the molded article has a strength that can be removed from the mold.
Specifically, the molded body does not lose its shape even after carrying out, removing, or carrying out simple surface processing, and preferably has a compressive strength of, for example, 2 kg / cm ² or more. By heating the above mixture of sulfur and mineral fines above the melting point of sulfur, bringing the sulfur into a molten state and compacting it,
Sulfur acts to bond the fine mineral powder, and a molded article having good self-formity is obtained in the same way as molding using sand containing a small amount of water is less likely to collapse than using dry sand.

[0007] As the sulfur of the present invention, elemental sulfur can be used. As such sulfur, sulfur produced by-product in the oil refining process can be used. By using this by-product sulfur, it is possible to promote effective use of industrial by-products and to reduce waste, which is preferable from the viewpoint of environmental consideration.

[0008] Rock powder, blast furnace slag powder, fly ash and the like can be used as the mineral fine powder. In addition,
In particular, fly ash is a fine powder and can be used without the need for pulverization, and is one of the most suitable materials for use in the present invention from the viewpoint of effective use of industrial by-products.

[0009] The sulfur concrete product of the present invention is preferably (A) a mixture of sulfur and a mineral fine powder having a Blaine specific surface area of 2000 cm ² / g or more through a 0.75 mm sieve, or
(B) Sulfur and a mineral substance fine powder are mixed and pulverized to have a Blaine specific surface area of 1000 cm ² / g or more. By adjusting the sulfur and mineral fine powder to the above particle size, even if the mineral fine powder is blended in more than sulfur, the strength of the product is small and the cracks due to cooling shrinkage etc. Excellent sulfur concrete products can be obtained.

The compounding amount of the sulfur and the mineral fine powder is 1 part by volume or more, preferably 1.5 parts by volume or more, more preferably 2 parts by volume or more with respect to 1 part by volume of sulfur. is there. When the amount of the fine mineral powder is less than 1 part by volume, cracks and voids may be generated due to shrinkage when sulfur is cured. On the other hand, in particular, when the mineral fine powder is adjusted to 2 parts by volume or more with respect to 1 part by volume of sulfur by adjusting the particle size, the mixture maintains a powdery state even when heated to a temperature higher than the melting point of sulfur, and the paste is formed. No. The paste is easy to entrain air bubbles,
This tendency is remarkable in pastes with a high mineral content.
A compact without entrained air bubbles can be obtained by pressurizing and consolidating the mixture in a powder state.

The amount of the fine mineral powder to be added is suitably about 20 parts by volume or less, and preferably 10% in the case of the above (a) using a mixture of sulfur and fine mineral powder whose particle size has been adjusted in advance.
The volume is preferably not more than 20 parts by volume, and in the case of the above (b), in which sulfur is mixed with the fine powder of mineral matter and then pulverized to adjust the particle size, the amount is preferably not more than 20 parts by volume. In the case of (b) above, the sulfur covers the surface of the mineral substance fine powder at the time of pulverization, so that a high-strength product can be obtained even when the amount of the mineral substance powder added is large. When the amount of the mineral fine powder exceeds 20 parts by volume, it is difficult to obtain strength suitable for practical use.

The above mixture of sulfur and mineral fine powder may further contain aggregate. As the aggregate, those used for ordinary cement concrete can be used. Although the size and amount of the aggregate depend on the use and purpose of the sulfur concrete product, it is generally appropriate that the particle size is from 0.15 to 40 mm, and the amount is in the mixture of sulfur and fine mineral powder. 4
0-80% by volume is suitable.

The sulfur concrete product of the present invention is obtained by heating the above mixture of sulfur and mineral fine powder and then pressing and compacting the mixture. The heating of the sulfur mixture may be performed by charging the sulfur mixture into a mold and heating in the mold, or
After the sulfur mixture is heated in advance, it may be poured into a mold.
By the way, since the use efficiency of the mold is reduced in the method of heating after being charged into the mold, the sulfur mixture is heated in advance to the melting point of sulfur (115 ° C.) or more to enhance the productivity of the product. It is preferable to cast in

The pressure for consolidating the mixture heated above the melting point of sulfur is suitably at least 0.01 MPa. The density of the product increases according to the strength of the pressing force, and the strength also increases. In order to consolidate more effectively with a small pressure, it is preferable to apply vibration during pressurization. After pressurization, it is cooled to obtain the sulfur concrete product of the present invention.

Since the sulfur concrete product of the present invention has a high mixing ratio of the fine mineral powder, even if the mixed raw material is heated to a temperature higher than the melting point of sulfur, it does not form a paste like conventional sulfur concrete, but particularly sulfur. When the amount of the fine mineral powder is 2 parts by volume or more with respect to 1 part by volume, the more the amount of the fine mineral powder becomes, the more the plastic remains in the powder state. Therefore, this mixture is cast into a mold. By performing the compaction, a self-molding molded body having a strength that can be released immediately after the compaction is obtained. Therefore,
After the sulfur concrete product of the present invention is poured into a formwork,
It is not necessary to carry out curing as in the prior art, and can be immediately removed from the mold by pressurizing and consolidation, and a product can be obtained in a short time. For this reason, the number of uses of the mold is high and productivity is improved.

As described above, since the sulfur concrete product of the present invention can be released immediately after compaction, extrusion molding can be used as a method for producing the product. If a simple cooling device is installed on the outlet side of the molding machine (form) as needed, the material can be put in from one side of the mold, and the material can be extruded while being pressed and condensed by a jack or the like, and the compact can be formed. It can be manufactured efficiently.

[0017]

As described above, the sulfur concrete product of the present invention does not require curing and has a self-molding property, so that it can be released from the mold in a short time and has high production efficiency. Furthermore, since the sulfur concrete product of the present invention is dense and excellent in acid resistance, a smelting plant, a chemical plant,
Environments that handle acids such as food factories, acidic soils, rivers,
Suitable for structures and compacts in hot spring areas and in environments that come into contact with acidic water from sewers. Especially in an acidic environment where pΗ is 4 or less,
Its durability is significantly better than normal cement concrete.

[0018] Specifically, the sulfur concrete product of the present invention can be used as an assembling embankment (embankment) wall as a material for civil engineering work.
Stacking block (retaining wall), L-shaped retaining wall (slope protection and earth retaining),
Suitable for sheet piles, etc., and U-shaped grooves, side grooves,
Building blocks, piles, fume pipes, and reefs and wave-dissipating products such as pedestrian road boundary blocks, L-shaped blocks, flat plates, interlocking blocks, etc.
It is suitable for a rectangular block used for breaking a wave. Above all, products whose cross-sectional shape of the whole product does not change, such as sheet piles, U-shaped grooves, side grooves, pedestrian road boundary blocks, L-shaped blocks, flat plates, interlocking blocks, concrete blocks for construction, piles, fume pipes (pipe) And the like are suitable for pressure consolidation molding and are suitable for the product of the present invention. It is.

[0019]

EXAMPLES Example 1 Sulfur (D750) having a particle size of 0.75 mm through a sieve and fly ash (D2800) having a Blaine specific surface area of 2800 cm ² / g were blended in the volume ratio shown in Table 1, and this was mixed with a Hobart mixer. After mixing for 1 minute, put this mixture in a mold (diameter 5 cm x height 10 cm)
Heat to 125 ° C and use a plunger (diameter 4.9 mm) to reach 0.0
Immediately after applying a pressure of 5 N / mm ² to consolidate, the mold was removed to obtain a molded product. The temperature of the molded body at the time of demolding was about 120 ° C., and the time required for removing the mold after the heated raw material was put into the mold was about 7 minutes. This molded product was subjected to an acid durability test. Also, instead of sulfur having the above particle size, a 5 mm sieve was used to pass through the sieve.
Mixture using sulfur (D5000) with 75mm sieve residue 90vol%
(Sample No. 4) and a mixture (sample No. 5) using fly ash (D1500) having a Blaine specific surface area of 1500 cm ² / g in place of the above particle size (D2800) to produce a similar specimen, It was subjected to a durability test. In this acid durability test, test specimens (sample Nos. 1 to 5) were immersed in an acidic solution (1N hydrochloric acid and 1N sulfuric acid), and the weight reduction rate and compressive strength up to 26 weeks were measured.
The results are shown in Table 2. On the other hand, as a comparative example, the same test was performed on a mixture of sulfur and fly ash whose particle size was not adjusted at a volume mixing ratio (FA / sulfur) of 0.5 (Sample No. 6). In addition, cement concrete (mixing ratio: W /
C50%, s / a46%, unit weight ^{kg / m 3: W150, C300} , S849, G1039)
Was placed in a mold (diameter 5 cm x height 10 cm), molded by vibrating with a table pipe, and then subjected to steam curing at 60 ° C for 3 hours to obtain a molded product (Sample No. 7). Tested. Specimen No. 6 cannot be pressed and consolidated because it becomes a paste by heating at 125 ° C.
It was molded by tapping the sides lightly with a mallet and allowed to cool to room temperature. These results are summarized in Table 2.

As shown in Table 2, the sulfur concrete product of the present invention (samples Nos. 1 to 5) hardly lost its weight even when immersed in acid, as compared with ordinary cement concrete (sample No. 7). Also, the compressive strength hardly changes. In addition, fine sulfur (D75
The use of (0) is preferable since the compressive strength is higher than that of using slightly coarse sulfur (D5000). Similarly, it is preferable to use fine fly ash (D2800) than fly ash having a slightly coarser particle size (sample No. 5) because of its higher compressive strength.

[0021]

[Table 1]

[0022]

[Table 2]

Example 2 Using the sulfur concrete product of sample No. 1 shown in Table 1,
When m-square blocks were manufactured, the average manufacturing time per block was about 1 hour. On the other hand, Comparative Sample No. 6 in Table 1
When a similar block is manufactured using the above method, the average time required for casting and then leaving at room temperature for cooling and demolding is 4 to 5 hours. Even in the case of cooling, the time required for demolding was 2 hours, and the production time was significantly long.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hajime Nagayama 2-14-1, Nishishinbashi, Minato-ku, Tokyo F-term (reference) 4G012 PA01 PA27 PA14

Claims (4)

[Claims] 1. A molded product having a self-forming property by heating a mixture obtained by mixing 1 part by volume or more and 20 parts by volume or less of a mineral substance powder with respect to 1 part by volume of sulfur to a temperature higher than the melting point of sulfur and then consolidating the mixture. A sulfur concrete product characterized by the following. 2. The sulfur concrete product according to claim 1, wherein a mixture containing an aggregate together with sulfur and mineral fines is used. 3. The sulfur has a particle size of 0.75 mm through the sieve,
3. The sulfur concrete product according to claim 1, wherein the mineral fine powder uses a mixture having a particle size of at least 2000 cm ² / g of Blaine specific surface area. 4. The sulfur concrete product according to claim 1, wherein sulfur and mineral powder are mixed and pulverized to a Blaine specific surface area of 1000 cm ² / g or more.