KR102392632B1 - Aggregate using oyster shell and its manufacturing method - Google Patents

Abstract

The present invention relates to an aggregate composition including oyster shells and a manufacturing method thereof. More specifically, the aggregate composition is configured by including 10 to 40% by weight of oyster shells, 25 to 40% by weight of sand, 1 to 15% by weight of fly ash, and 1 to 15% by weight of silica fume so as to expand use for utilizing a waste resource while reducing marine pollution and simultaneously improve mechanical properties such as tensile strength and chemical properties such as an antibacterial effect.

Description

Aggregate using oyster shell and its manufacturing method

The present invention relates to an aggregate composition comprising oyster shells and a method for preparing the same, and more specifically, 10 to 40 wt% of oyster shells, 25 to 40 wt% of sand, 1 to 15 wt% of fried ash and 1 to silica fume It is a technical field related to an aggregate composition comprising oyster shells, characterized in that it comprises 15% by weight.

Oyster farming in the southern and western seas of Korea is a major source of income for nearby fishermen and is a smooth supply of domestic oyster demand. However, most of the cultured oysters are sold only after removing the shells, and the discarded shells remain as waste. 250,000 to 300,000 tons of oyster shells are discharged every year, and they are emerging as major sources of marine and residential pollution.

The oyster shells and coated sand used for oyster farming are classified as general waste and should be disposed of by farmed fishermen, but effective disposal is impossible due to problems such as securing a landfill, collection and transportation of oyster shells and coating companies. Not only are there difficulties, but most of the disposal itself is dependent on landfills, which greatly affects the pollution of the coast.

The composition of the oyster shell is slightly different depending on the culture method and the length of storage, but calcium carbonate is about 95% by weight (wt%), and the rest is composed of organic substances such as protein, fat, and chitin. Chitin is a major component of the exoskeleton of crustaceans and is a type of mucopolysaccharide in which N-Acetyl-D-glucosamine is combined with β-1, 4, and when this chitin is deacetylated, chitosan is produced. do. These chitin and chitosan are not only non-toxic, but also are natural polymeric cations that do not cause environmental pollution by participating in the synthesis and decomposition of organisms. Recently, these materials have been widely used in various industrial fields such as environmental wastewater flocculants, heavy metal adsorbents, and protein recovery agents as potential user resources. In addition, the function as a natural antibacterial agent using chitin and chitosan derivatives is also emerging as one of the applications of chitosan. In this regard, Sudarshan et al. reported that chitosan lactate and chitosan hydroglutamate, which are chitosan derivatives, are excellent antimicrobial substances against general E. coli.

However, despite the excellent properties described above, there was a problem that the coating yarn used for oyster shells and oyster culture was not properly utilized due to excessive processing cost and low processing efficiency according to volume or weight.

Republic of Korea Patent Publication No. 10-1994-0001208 (June 15, 1998)

The present invention is a technology devised to solve the problems according to the prior art described above, and by recycling the conventional discarded oyster shells and coating sand used for oyster farming, it reduces marine pollution and expands the use of waste resources at the same time And, it aims to provide an aggregate manufactured by an aggregate manufacturing method including an oyster shell that can simultaneously improve mechanical properties such as tensile strength of the aggregate and chemical properties such as antibacterial effect.

The present invention is characterized in that it comprises 10 to 40% by weight of oyster shells, 25 to 40% by weight of sand, 1 to 15% by weight of fried ash and 1 to 15% by weight of silica fume in order to realize the desired purpose as described above. It provides an aggregate composition comprising oyster shells.

In addition, the oyster shell of the present invention is characterized in that it is immersed in an aqueous solution in which any one or a plurality of basic substances selected from sodium hydroxide, calcium hydroxide, aluminum hydroxide, potassium hydroxide, magnesium hydroxide, sodium hydrogen carbonate and ammonia are dissolved.

In addition, the oyster shell of the present invention includes a first oyster shell having a particle size of 0.1 to 3 mm, a second oyster shell having a particle size of 3.1 to 5 mm, and a third oyster shell having a particle size of 5.1 to 10 mm. It is characterized in that it is configured.

In addition, the oyster shell of the present invention, 1 to 30% by weight of the first oyster shell, 1 to 20% by weight of the second oyster shell, and 1 to 15% by weight of the third oyster shell, based on the total weight of the oyster shell do it with

In addition, the aggregate composition of the present invention is characterized in that it comprises 0.1 to 10% by weight of the shell waste coating sand crushed material.

In addition, the crushed material of the shell waste coating sand of the present invention is characterized in that using the crushed material to a size of 0.1 to 10mm.

In addition, the method for producing an aggregate containing the oyster shell of the present invention includes a preparation step of preparing oyster shells, sand, fried ash, and silica fume, washing the oyster shells prepared in the preparation step, and putting them in a drying furnace at 80 to 120 ° C. After the heating step, after the heating step, a drying step of drying the oyster shells, after the drying step, the crushing step of crushing the oyster shells and after the crushing step, crushed oyster shells and sand, fried ash, silica fume It is characterized in that it comprises a first mixture preparation step of preparing a first mixture by mixing.

In addition, the crushing step of the present invention includes a first crushing step of crushing the oyster shell to have a particle size of 0.1 to 3 mm, a second crushing step of crushing the oyster shell to have a particle size of 3.1 to 5 mm, and 3.1 to 5 mm It is characterized in that it comprises a third crushing step of crushing the oyster shell to have a particle size of.

In addition, the mixing step of the present invention is characterized in that it comprises a second mixture manufacturing step of preparing a second mixture by mixing the shell coating sand crushed material with the first mixture of the mixing step.

The aggregate composition comprising oyster shells according to the present invention presented as described above and a method for producing the same include 10 to 40% by weight of oyster shells, 25 to 40% by weight of sand, 1 to 15% by weight of fried ash, and 1 to 15% by weight of silica fume. By including it, it is possible to reduce marine pollution, expand the use of waste resources, and simultaneously improve mechanical properties such as tensile strength and chemical properties such as antibacterial effect.

1 is a flowchart showing a method for manufacturing an aggregate comprising oyster shells according to a preferred embodiment of the present invention.

Hereinafter, the cement composition containing the oyster shell according to the present invention and the building panel, the flooring material and the reinforcing earth block including the oyster shell prepared therefrom will be described in more detail by way of Examples and Comparative Examples. However, the embodiments introduced below are provided as examples so that the spirit of the present invention can be sufficiently conveyed to those skilled in the art.

Therefore, the present invention is not limited to the embodiments presented below and may be embodied in other forms, and the embodiments presented below are only described to clarify the spirit of the present invention, and the present invention is not limited thereto.

At this time, unless there are other definitions in the technical terms and scientific terms used, it has a meaning commonly understood by a person of ordinary skill in the art to which this invention belongs, and in the following description, it may unnecessarily obscure the subject matter of the present invention. A description of possible known functions and configurations will be omitted.

Also, the singular forms used in the specification and appended claims may also be intended to include the plural forms unless the context specifically dictates otherwise.

In addition, the drawings introduced below are provided as examples so that the spirit of the present invention can be sufficiently conveyed to those skilled in the art. Therefore, the present invention is not limited to the drawings presented below and may be embodied in other forms, and the drawings presented below may be exaggerated to clarify the spirit of the present invention. Also, like reference numerals refer to like elements throughout.

Also, the singular forms used in the specification and appended claims may also be intended to include the plural forms unless the context specifically dictates otherwise.

In describing the components of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only for distinguishing the elements from other elements, and the essence, order, or order of the elements are not limited by the terms. When it is described that a component is “connected”, “coupled” or “connected” to another component, the component may be directly connected or connected to the other component, but another component is formed between each component. It should be understood that elements may also be “connected,” “coupled,” or “connected.”

The present invention relates to an aggregate composition comprising oyster shells and a method for preparing the same, and more specifically, 10 to 40 wt% of oyster shells, 25 to 40 wt% of sand, 1 to 15 wt% of fried ash and 1 to silica fume It is a technology related to an aggregate composition comprising oyster shells, characterized in that it comprises 15% by weight.

The oyster shell, which is a main component in the present invention, is

It is said that about 240,000 tons of oyster shells are generated annually in the coastal areas of Tongyeong, Geoje, and Goseong-gun, Gyeongnam, of which about 60,000 tons are recycled as oyster seedlings and shell fertilizer, and about 60,000 tons are used for reclamation of public waters. Therefore, about 120,000 tons, or 50% of the total, are untreated and are stored in the surrounding coast, which is a factor of environmental pollution as well as aesthetics.

The component of the oyster shell consists of calcium carbonate (97.24%), gypsum and others (2.76%), and has been used in small amounts as fertilizer and feed since ancient times. , is widely used in cosmetics and pharmaceuticals. In addition, the oyster shell contains phosphorus and calcium, so when it is mixed with other ingredients, especially cement, it produces calcium phosphate like human bones and has very high strength. cracks can be prevented.

Here, the composition of the oyster shell is slightly different depending on the culture method and the length of storage, but calcium carbonate is about 95% by weight (wt%), and the rest is composed of organic substances such as protein, fat, and chitin in addition to the phosphorus mentioned above. Chitin is a major component of the exoskeleton of crustaceans and is a type of mucopolysaccharide in which N-Acetyl-D-glucosamine is combined with β-1, 4, and when this chitin is deacetylated, chitosan is produced. do. These chitin and chitosan are not only non-toxic, but also are natural polymeric cations that do not cause environmental pollution by participating in the synthesis and decomposition of organisms. Recently, these materials have been widely used in various industrial fields such as environmental wastewater flocculants, heavy metal adsorbents, and protein recovery agents as potential user resources. In addition, the function as a natural antibacterial agent using chitin and chitosan derivatives is also emerging as one of the applications of chitosan. In this regard, Sudarshan et al. reported that chitosan lactate and chitosan hydroglutamate, which are chitosan derivatives, are excellent antibacterial substances against general E. coli.

The present invention, paying attention to the advantages of oyster shells as described above, discovered that, when organic matter is first removed from oyster shells and the remaining components are modified to produce aggregates, they exhibit antibacterial and antifungal functions along with increased strength. has been completed

In the present invention, the oyster shells are preferably added in the form of powder, the first oyster shell having a particle size of 0.1 to 3 mm, the second oyster shell having a particle size of 3.1 to 5 mm, and a particle size of 5.1 to 10 mm. It can be used by pulverizing it with the third oyster shell.

In addition, it is preferable to use the first oyster shells crushed to a particle size of 0.1 to 3 mm. When crushed to a particle size of less than 0.1 mm, the amount of oyster shells scattered in the air during crushing This may increase or the mechanical properties of the aggregate may not be properly expressed. If crushed particles with a particle size exceeding 3 mm are used, the consistency of the product may be reduced when manufacturing the aggregate as the content of the second oyster shell increases. It is preferable to use a crushed product with a particle size within the above range because a problem of deterioration of quality may occur.

In addition, the first oyster shell is preferably added in an amount of 1 to 30% by weight based on the total weight of the composition. , when added in excess of 30% by weight, the addition amount of the other composition is lowered, which may cause a problem that the mechanical properties desired by the operator are not properly expressed when manufacturing the aggregate, so it is preferable to add it in a weight% within the above range.

More preferably, it is good to add 15 to 25% by weight based on the total weight of the composition.

It is preferable to use the second oyster shells crushed to a particle size of 3.1 to 5 mm. When using those crushed to a particle size of less than 3.1 mm, the content of the first oyster shells increases as the content of the first oyster shells increases. Consistency may deteriorate and quality may deteriorate, and when crushed products with a particle size exceeding 5 mm are used, as the content of the third oyster shell increases, the consistency of the product decreases when manufacturing aggregates, resulting in quality deterioration. Problems may arise, so it is preferable to use a particle size within the above range.

In addition, the second oyster shell is preferably added in an amount of 1 to 20% by weight based on the total weight of the composition. , when added in excess of 20% by weight, the addition amount of the other composition is lowered, and there may occur a problem that the mechanical properties desired by the operator are not properly expressed when manufacturing the aggregate, so it is preferable to add it in a weight% within the above range.

More preferably, it is good to add 10 to 18% by weight based on the total weight of the composition.

It is preferable to use the third oyster shells crushed to a particle size of 5.1 to 10 mm. When using crushed oyster shells with a particle size of less than 5.1 mm, as the content of the second oyster shells increases, when manufacturing aggregate The consistency of the product may be lowered, which may cause quality deterioration, and if crushed to a particle size exceeding 10 mm is used, the third oyster shell may not agglomerate well, resulting in deterioration of workability. It is preferable to add it in weight % within.

More preferably, it is good to add 8 to 15% by weight based on the total weight of the composition.

In addition, the third oyster shell is preferably added in an amount of 1 to 20% by weight based on the total weight of the composition. , when added in excess of 20% by weight, the addition amount of the other composition is lowered, and there may occur a problem that the mechanical properties desired by the operator are not properly expressed when manufacturing the aggregate, so it is preferable to add it in a weight% within the above range.

More preferably, it is good to add 10 to 14% by weight based on the total weight of the composition.

In addition, it is preferable to remove the organic matter and salt adhering to the surface of the oyster shell, and after completely removing the salt by repeating the operation of immersing in a water tank containing distilled water for 4 to 6 hours and taking it out 2 to 3 times, an aqueous solution of a basic substance It is preferable to remove organic matter, especially protein, from the surface by immersion again in the

In addition, the basic material is not limited to the type as long as it can dissolve protein, and examples thereof include sodium hydroxide, calcium hydroxide, aluminum hydroxide, potassium hydroxide, magnesium hydroxide, sodium hydrogen carbonate and ammonia, and these are independent or a mixture of two or more.

The basic material is preferably mixed with water to a concentration of 1 to 10% by weight, and then immersed in the water. At this time, the oyster shell is preferably finely pulverized using a pulverizing means such as a planetary mill to enhance the protein dissolution effect. In addition, the basic substance solution is preferably stirred for 1 to 5 hours at 50 to 200 rpm at 80 to 100 ℃ after adding the powder of the oyster shell.

In addition, the oyster shell is a mixture of oyster shells 60 to 80 parts by weight or hydrochloric acid and nitric acid in 100 parts by weight of 30 to 40% by weight hydrochloric acid and 80 to 120 parts by weight of oyster shells, 60 to 65 parts by weight of nitric acid 100 parts by weight after protein removal It is preferable to gradually add 60 to 100 parts by weight of oyster shells to 100 parts by weight of the inorganic acid while stirring, and then neutralize them by shaking and dissolving them for 12 to 36 hours.

In addition, it is preferable to modify the surface of the oyster shell with a hydrophobic material to increase mechanical properties by suppressing structural changes that may occur due to the hydration reaction between the oyster shell and cement when concrete is manufactured by mixing the oyster shell with cement.

In general, oyster shells contain a large amount of chitosan, and the chitosan is produced by hydrolysis of chitin derived from natural crustacean shells. . However, due to the hydration phenomenon of chitosan, the structure of the three-dimensional structure changes in the aqueous solution phase, which has the disadvantage of acting as a crack inside the cement. To solve this, the surface is modified with a hydrophobic component.

The hydrophobic modification of the chitosan is to induce hydrophobicity by introducing another molecule to the amine group (-NH ₂ ) expressing water solubility, wherein the molecule does not limit the molecular weight, but a biodegradable polymer so that it can be appropriately decomposed as needed It is preferable to be

Examples of the biodegradable polymer include poly-lactide-co-glycolide (PLGA, Poly(lactide-co-glycolide)), polyglycolide (PGA, Poly(Glycolic acid)), polylactide (PLA, Poly (Lactic acid)) and polycaprolactone (PCL, Poly(Caprolactone)), etc., which may be used alone or two or more, and the molecular weight is also not limited, but preferably 500 to 1,000 based on the weight average molecular weight.

The modification of the chitosan is mixed with 50 to 200 parts by weight of the biodegradable polymer based on 100 parts by weight of the oyster shell powder, and at this time, DMF (dimethylformamide), DMSO (dimethylsulfoxide), dichloromethane, and an organic solvent such as dichloromethane. The reforming can be carried out by allowing it to stand for 1 to 7 days.

In the present invention, sand as a component is

In general, sand used in the production of aggregates, such as natural sand and regenerated sand, may be used, but various kinds of sand may be used, without being limited thereto.

The natural sand has various colors such as dark yellow, white, black, and green, and refers to particles between 0.02 and 2 mm composed of small fragments of rocks and minerals distributed in the soil, and silicon dioxide is most abundant in the form of quartz. has been Since quartz is the most abundant compound of oxygen and silicon among elements constituting the earth's crust, it is widely distributed in nature, is chemically and structurally stable, has relatively high hardness compared to surrounding materials, and withstands weathering well.

The reclaimed sand refers to sand that has been re-used so that the sand used for dredged soil, waste sand, and waste casting sand among industrial waste can be reused. It can be used that is put into the pulverized to a size of 0.1 to 5mm.

In relation to the above, the sand is preferably added in an amount of 25 to 45% by weight based on the total weight of the composition, but when it is added in an amount of less than 25% by weight, there may occur problems in that physical durability, chemical stability, etc. are lowered, and 45% by weight is added. When added in excess of %, the addition amount of the other composition is reduced, which may cause a problem in that tensile strength or antibacterial properties are not properly expressed.

More preferably, 35 to 40% by weight is added based on the total weight of the composition.

In the present invention, the component of the fly ash (FLY-ASH) is

Also called fly ash, it refers to the fine granular scattering recovered by the material dust collector contained in the combustion waste gas generated in thermal power plants, etc. mainly composed of silicon dioxide (SiO ₂ ) and aluminum oxide (Al ₂ O ₃ ). It is used to improve fluidity, reduce bleeding, reduce hydration calorific value, suppress alkali aggregate reaction, and improve concrete watertightness.

In addition, the fried ash is preferably added in an amount of 1 to 15% by weight based on the total weight of the composition. When it is added in an amount of less than 1% by weight, the strength of the aggregate cannot be properly expressed. , it is preferable to add in a weight% within the above range because the amount of the other composition may be reduced, so that the tensile strength, antibacterial property, etc. may not be properly expressed.

More preferably, it is good to add 5 to 10% by weight based on the total weight of the composition.

Silica fume, which is a component in the present invention, is

It is a silica particle admixture with a fineness of 0.1 μm (micrometer) or more obtained by an electrostatic precipitator using ultra-fine silicon by-products generated during silicon manufacturing, and it can fill the voids between the aggregate particles to obtain high strength and high durability.

In addition, the silica fume is preferably added in an amount of 1 to 15% by weight based on the total weight of the composition. When added in an amount of less than 1% by weight, the strength and durability of the aggregate prepared by mixing with other compositions may not be properly expressed. When it is added in excess of 15% by weight, the amount of the other composition is reduced, which may cause problems in that tensile strength, antibacterial properties, etc. are not properly expressed.

More preferably, it is good to add 5 to 10% by weight based on the total weight of the composition.

Shell coating yarn as a component in the present invention

Polyvinyl Chloride (PVC) forming the outer shell is coated on a core yarn made of any one or a plurality of materials selected from polypropylene (PP), polyethylene (PE), and polystyrene (PS). Since it is not deteriorated by seawater and has excellent tensile strength that can support a certain weight even in waves, it is widely used for aquaculture of fish and shellfish such as oysters or algae such as seaweed. It is a single-use product that cannot be disposed of.

In addition, the polypropylene is a polymer of propylene, and has excellent mechanical properties such as tensile strength, impact strength, and surface strength. It is the lightest among plastics and is used in various fields such as housings of electric devices, automobile parts, miscellaneous goods, and containers.

The polyethylene is a polymer obtained by polymerization of ethylene as a monomer, and is one of the synthetic polymers called polycholepin, does not easily discolor by sunlight, is strong in heat, is easy to process, , household goods, toys, etc. are used in various fields.

The polystyrene is an amorphous polymer obtained by radical polymerization of styrene, and is a colorless and transparent thermoplastic resin. It is transparent, easy to process, non-toxic, and is used in various fields such as disposable cups, packaging containers for sweets, cushioning materials, interior decorations, toys, office supplies, and electrical insulation materials.

The polyvinyl chloride is one of the most widely used thermoplastic plastics, even vinyl chloride resin. Because polyvinyl chloride is a hard material in nature, phthalates (phthalates, DEHP, DINP, DBP, etc.) plasticizers or adipic acid (adipates, DHEA, etc.) plasticizers are used to increase flexibility and elasticity, It is processed into a product, has a waterproof function, and has good durability.

In addition, the shell coating sand is preferably added in an amount of 0.1 to 10% by weight based on the total weight of the composition. If it is, the amount of the other compositions is reduced and the antibacterial properties, etc. described above may not be properly expressed.

In addition, it is preferable to use the shell coating yarn crushed to a size of 0.1 to 10 mm. When using a shell coating yarn crushed to a particle size of less than 0.1 mm, aggregation occurs between the shell coating yarns in the process of crushing the shell coating yarns. There may be a problem in that mixing with other compositions is not performed properly, and if crushed particles with a particle size exceeding 10 mm are used, a problem of increasing the size of the aggregate may occur when mixing with other compositions to prepare aggregate. It is preferable to use those crushed to a size within the above range.

Hereinafter, as shown in FIG. 1, a detailed description will be given of a method for manufacturing an aggregate including an oyster shell of the present invention as described above.

First, the preparation step (S10) of preparing oyster shells, sand, fried ash, and silica fume and the heating step (S20) of washing the oyster shells prepared in the preparation step (S10), putting them in a drying furnace, and heating at 80 to 120 ° C. After the heating step (S20), the drying step (S30) of drying the oyster shells, and after the drying step (S30), the crushing step (S40) of crushing the oyster shells and the crushing step (S40) After the crushing oyster shells , is configured to include a first mixture manufacturing step (S50) of preparing a first mixture by mixing sand, fried ash, and silica fume.

Specifically, the preparation step (S10) prepares oyster shells, sand, fried ash, and silica fume.

In the heating step (S20), after washing the oyster shell prepared in the preparation step (S10), it is put in a drying furnace and heated at 80 to 120° C. to remove foreign substances and moisture from the surface of the oyster shell.

In the drying step (S30), after the heating step (S20), the oyster shells are dried at room temperature of 20 to 25°C.

In the crushing step (S40), the oyster shells dried in the drying step (S30) are crushed using a crusher generally used.

In addition, the crushing step (S40) includes a first crushing step (S41) of crushing the oyster shells to have a particle size of 0.1 to 3 mm and a second crushing step of crushing the oyster shells to have a particle size of 3.1 to 5 mm ( S42) and a third crushing step (S43) of crushing the oyster shell to have a particle size of 5.1 to 10mm may be included.

In the first crushing step (S41), after the drying step (S30), the oyster shells are crushed to have a particle size of 0.1 to 3 mm to prepare a first oyster shell.

In the second crushing step (S42), after the drying step (S30), a second oyster shell is prepared so that the oyster shell has a particle size of 3.1 to 5 mm.

In the third crushing step (S43), after the drying step (S30), the oyster shells are crushed to have a particle size of 5.1 to 10 mm to prepare a third oyster shell.

In the first mixture preparation step (S50), after the crushing step (S40), crushed oyster shells, sand, fried ash, and silica fume are mixed to prepare a first mixture.

In addition, the first mixture manufacturing step 50 may be configured to include a second mixture manufacturing step of preparing a second mixture by mixing the shell coating sand crushed material with the first mixture.

Therefore, the aggregate is prepared by evenly mixing the oyster shells, sand, fried ash, silica fume, and shell coating sand crushed material.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the following examples are only examples for explaining preferred embodiments of the present invention, and the present invention is not limited by the following examples.

The method of measuring the physical properties of the specimens prepared in Examples and Comparative Examples and the specifications of the materials used are as follows.

(Specification)

The specifications of the material are shown in Table 1 below.

Specifications 1st oyster shell Average particle diameter 0.1 to 3 mm 2nd oyster shell Average particle diameter 3.1 to 5 mm 3rd oyster shell Average particle diameter 5.1 to 10 mm sand Average particle diameter 0.02 to 2mm fried ash Average particle size 10 to 100 μm Silica fume Fineness 0.1 μm Shredded shell coated sand Average particle diameter 0.1 to 10 mm

(Measurement of compressive strength and flexural strength)

The experiment was conducted in accordance with KS F 2545 (Method for measuring compressive strength and flexural strength of aggregate for concrete), and the average value was calculated by repeating measurements three times.

(Examples 1 to 4 and Comparative Examples 1 to 2)

After sufficiently mixing the compositions in the weight % shown in Table 2 to prepare aggregates, the physical properties of the specimens were measured.

Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 1st oyster shell 20 20 12 One - 20 2nd oyster shell 12 12 12 23 - 14 3rd oyster shell 12 9 12 20 - 12 sand 38 38 38 38 38 38 fried ash 8 8 8 8 8 8 Silica fume 8 8 8 8 8 8 Shredded shell coated sand 2 2 8 2 46 - Compressive strength (MPa) 39.8 36.4 33.7 31.3 23.6 30.9 Flexural strength (MPa) 26.6 25.8 23.7 22.3 17.2 18.9

As shown in Table 2, it can be seen that the aggregate specimen prepared according to the present invention has excellent compressive strength and flexural strength. Specifically, Example 1, in which the first oyster shell was added in a higher weight percent than the second and third oyster shells, and the second oyster shell and the third oyster shell were added in the same weight percent, both had good compressive strength and flexural strength. was confirmed. However, in Example 4, where the amounts of the second and third oyster shells deviated from the standard values, the compressive strength and flexural strength decreased compared to Example 1, so that the first, second, and third oyster shells It can be seen that the amount of addition must be adjusted within a certain range.

In addition, in the case of Comparative Example 1 in which the first oyster shell, the second oyster shell, and the third oyster shell of the composition were not added and only the crushed shell-coated sand was added, and Comparative Example 2 to which the crushed shell-coated sand was not added, the compressive strength and It can be seen that the flexural strength decreased compared to Examples 1 to 4, indicating that the addition amount of the first oyster shell, the second oyster shell, the third oyster shell, and the crushed shell coated sand should be adjusted within a certain range.

The above description is merely illustrative of the technical spirit of the present invention, and various modifications and variations will be possible without departing from the essential characteristics of the present invention by those skilled in the art to which the present invention pertains. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention, but to explain, and the scope of the technical spirit of the present invention is not limited by these embodiments. The protection scope of the present invention should be construed by the claims below, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

Claims (9)

Sodium hydroxide, calcium hydroxide, aluminum hydroxide, potassium hydroxide, magnesium hydroxide, sodium bicarbonate and ammonia, oyster shells are immersed in an aqueous solution in which any one or a plurality of basic substances are dissolved. after, 80 to 120 parts by weight of oyster shells in 100 parts by weight of 30 to 40% by weight hydrochloric acid, 60 to 80 parts by weight of oyster shells in 100 parts by weight of 60 to 65% by weight nitric acid, or 60 to 80 parts by weight of mixed inorganic acid of hydrochloric acid and nitric acid After adding 100 parts by weight and then dissolving for 12 to 36 hours, based on 100 parts by weight of oyster shell 50 to 200 parts by weight of any one or two or more biodegradable polymers selected from polylactide coglycolide, polyglycolide, polylactide and polycaprolactone are mixed, and dimethylformamide, dimethylsulfoxide, dichloro 10 to 40% by weight of oyster shells, 25 to 40% by weight of sand, 1 to 15% by weight of fried ash and 1 to 15% by weight of silica fume, 0.1 to 10mm of oyster shells mixed in an organic solvent selected from methane and left for 1 to 7 days It is composed of 0.1 to 10% by weight of crushed shell coating yarn crushed to size,
The oyster shell,
The first oyster shell having a particle size of 0.1 to 3 mm;
a second oyster shell having a particle size of 3.1 to 5 mm; and
The third oyster shell having a particle size of 5.1 to 10 mm;
It consists of
The oyster shell,
Based on the total weight of the oyster shell, the first oyster shell 1 to 30% by weight, the second oyster shell 1 to 20% by weight, and the third oyster shell 1 to 15% by weight Aggregate composition comprising oyster shells characterized in that.
delete delete delete delete delete In the method for producing an aggregate comprising the oyster shell according to claim 1,
Sodium hydroxide, calcium hydroxide, aluminum hydroxide, potassium hydroxide, magnesium hydroxide, sodium hydrogen carbonate, and immersing the oyster shell in an aqueous solution in which any one or a plurality of basic substances selected from ammonia are dissolved, 80 to 120 parts by weight of oyster shells in 100 parts by weight of 30 to 40% by weight hydrochloric acid, 60 to 80 parts by weight of oyster shells in 100 parts by weight of 60 to 65% by weight nitric acid, or 60 to 80 parts by weight of mixed inorganic acid of hydrochloric acid and nitric acid 100 parts by weight was added and then dissolved for 12 to 36 hours. Then, based on 100 parts by weight of oyster shell, 50 to 200 parts by weight of any one or two or more biodegradable polymers selected from polylactide coglycolide, polyglycolide, polylactide and polycaprolactone are mixed, and dimethylformamide; A preparation step (S10) of preparing oyster shells, sand, fried ash, and silica fume, which are mixed with an organic solvent selected from dimethyl sulfoxide and dichloromethane and left for 1 to 7 days;
After washing the oyster shells prepared in the preparation step (S10), put them in a drying furnace and heating step (S20) of heating at 80 to 120 ℃;
After the heating step (S20), a drying step (S30) of drying the oyster shells;
After the drying step (S30), crushing step (S40) of crushing the oyster shell;
After the crushing step (S40), a first mixture manufacturing step (S50) of mixing crushed oyster shells with sand, fried ash, and silica fume to prepare a first mixture;
consists of,
The crushing step (S40) is,
A first crushing step of crushing the oyster shell to have a particle size of 0.1 to 3mm (S41);
a second crushing step of crushing the oyster shell to have a particle size of 3.1 to 5 mm (S42);
A third crushing step of crushing the oyster shell to have a particle size of 5.1 to 10mm (S43);
A method for producing an aggregate comprising an oyster shell, characterized in that it comprises a.
delete delete

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