KR102237499B1 - Asphalt modifier using rubber powder and modified asphalt mixture using the same - Google Patents

Abstract

The present invention relates to an asphalt modifier using rubber powder and a modified asphalt mixture using the same. Asphalt modifier using rubber powder according to the present invention includes rubber powder, polyoctenamer, zinc oxide (ZnO), stearic acid, sulfur, n-cyclohexyl benzothiazyl-2-sulfenamide (CBS) and tetramethyl thiuram disulfide (TMTD). Asphalt modifier using rubber powder according to the present invention improves asphalt properties such as heat resistance, abrasion resistance, crack prevention, etc., allows recycling of waste tires or waste rubber, which are industrial by-products that are discarded after use, and does not contain heavy metals, etc., and thus can be safely used without worrying about environmental pollution.

Description

Asphalt modifier using rubber powder and modified asphalt mixture using the same {ASPHALT MODIFIER USING RUBBER POWDER AND MODIFIED ASPHALT MIXTURE USING THE SAME}

The present invention relates to an asphalt modifier using rubber powder and a modified asphalt mixture using the same, and in more detail, asphalt properties such as heat resistance, abrasion resistance, and crack prevention are improved, and waste tires or waste rubber, which are industrial by-products discarded after use, are recycled. It is possible and does not contain heavy metals, so it relates to an asphalt modifier using rubber powder that can be safely used without fear of secondary environmental pollution, and a modified asphalt mixture using the same.

In Korea's asphalt-paved roads since the 1990s, various types of road damage such as plastic deformation, cracks, potholes, etc. have rapidly increased due to the rapid increase in traffic volume, weight increase and enlargement of vehicle loads, and changes in the atmospheric environment such as high temperatures and heavy rains in summer. Is increasing.

Particularly, micro-cracks are generated in the pavement due to shrinkage/expansion due to temperature change, and rainwater penetrates into the generated crack, causing partial subsidence of the roadbed. The cracks increase in the form of cracks going back to the existing pavement layer due to the subsidence in the layer.

The cracks generated in the paved road increase the risk of causing a traffic accident, cause a huge cost loss due to road maintenance, and further accelerate the early damage of the road, thereby significantly reducing the life of the road.

In general, asphalt refers to a black or blackish brown semi-solid bite material that remains after the hard part of the components of petroleum has been evaporated naturally or by an artificial method. It has a characteristic that gradually changes to a liquid phase.

The asphalt is used as a bonding material or an adhesive material because it has excellent adhesion and excellent adhesion to mineral materials, and is also used as a waterproof material because it is not soluble in water and is impermeable. In addition, the viscosity can be changed according to the purpose of use, so the workability is also excellent. Because of these advantages and characteristics, asphalt has a wide range of applications and is used for various purposes such as road pavement, repair, such as dam construction, waterproofing, general industrial use, and agricultural use.

Looking at the case where the asphalt is applied to road pavement, it is rare that the asphalt itself is usually used, and it is used as asphalt concrete formed by blending with an aggregate and a filling material. The aggregate serves as a frame in asphalt concrete to provide support, load distribution, and friction resistance, and is divided into coarse aggregates, which are mainly used for crushed stone, and fine aggregates, mainly used for crushed sand and steel sand.

In addition, the filling material used to fill the voids of coarse aggregates and fine aggregates is mixed with asphalt to improve peeling resistance, and fine powders of inorganic materials such as stone powder are mainly used.

On the other hand, the asphalt is liquefied according to an increase in temperature without a clear melting point and transferred to a liquid phase, and a change in consistency according to temperature is very large. The degree of this change is called temperature sensitivity. If the temperature sensitivity of asphalt is too high, cracks due to brittleness may occur in the asphalt concrete structure made of it under low temperature conditions, and plastic deformation due to severe ductility occurs under high temperature conditions. In addition to the temperature sensitivity of asphalt, durability of asphalt concrete is determined by various conditions such as tensile strength and elasticity.

Asphalt modifiers mixed with asphalt or added during the production process of asphalt concrete are widely used for the purpose of improving the performance of asphalt pavements by improving the durability and fluid resistance of such asphalt concrete. As concerns about various types of road damage are increasing due to high temperatures, etc., efforts for the application of asphalt modifiers and research and development of new materials are increasing.

The above-described conventional asphalt modifier makes asphalt excellent in quality as a binder for road pavement, but can be applied at the production site by adding only a facility for adding an asphalt modifier without having to replace the existing asphalt concrete production equipment. There is an advantage that it is possible.

However, since the conventional asphalt modifier as described above is manufactured using a new raw material, the manufacturing cost is relatively high, and there is a problem of being wasted in terms of resource recycling.

Domestic registered patent No. 10-1505829 (registered on March 19, 2015) Domestic registered patent No. 10-0862057 (registered on September 30, 2008) Domestic registration patent No. 10-1551002 (registered on September 01, 2015)

The present invention improves asphalt properties such as heat resistance, abrasion resistance, and crack prevention, and can recycle waste tires or waste rubber, which are industrial by-products discarded after use, and does not contain heavy metals, so it can be used safely without fear of secondary environmental pollution. It is to provide an asphalt modifier using rubber powder and a modified asphalt mixture using the same.

Asphalt modifier using rubber powder according to the present invention is rubber powder, polyoctenamer, zinc oxide (ZnO), stearic acid, sulfur, CBS (n-cyclohexyl benzothiazyl-2- sulfenamide) and tetramethyl thiuram disulfide (TMTD).

The rubber powder may be a ground tire rubber (GTR) powder.

13 to 17 parts by weight of the polyoctenamer, 1 to 2 parts by weight of zinc oxide (ZnO), 0.2 to 0.8 parts by weight of stearic acid based on 100 parts by weight of the ground tire rubber (GTR) powder , Sulfur (Sulfur) 0.5 to 1.2 parts by weight, CBS (n-cyclohexyl benzothiazyl-2-sulfenamide) 0.5 to 1.2 parts by weight and tetramethyl thiuram disulfide (TMTD; tetramethyl thiuram disulfide) 0.05 to 0.5 parts by weight included in a weight ratio I can.

Based on 100 parts by weight of the ground tire rubber (GTR) powder, 15 parts by weight of the polyoctenamer, 1.5 parts by weight of zinc oxide (ZnO), 0.5 parts by weight of stearic acid, and 0.8 parts by weight of sulfur After mixing at a weight ratio of 0.8 parts by weight of CBS (n-cyclohexyl benzothiazyl-2-sulfenamide) and 0.2 parts by weight of tetramethyl thiuram disulfide (TMTD), stirring at a rate of 800 to 1000 times/min And, it may be prepared including a process of curing for 5 to 30 minutes at a temperature of 150 to 200 ℃.

The waste tire rubber powder is collected by separating the bead wire scrap and the waste tire rubber from the waste tire, heating the collected bead wire scrap to remove foreign substances adhering to the iron core, and removing the heated bead wire scrap. After taking it out from the heating furnace and cooling it, the cooled bead wire scrap is cut in units of a certain length, the cut bead wire scrap is immersed in the mixed solution, the cut bead wire scrap immersed in the mixed solution is separated from the purified water. After washing and drying, the collected waste tire rubber is crushed to produce rubber powder, the crushed waste tire rubber powder is carbonized, and the dried bead wire scrap and the waste tire rubber powder are mixed to prepare a mixture. , After heating the mixture to carbonize, it may be produced through a process of extrusion and pulverization.

In the step of heating the collected bead wire scrap to remove foreign substances attached to the iron core, heating of the separated bead wire scrap is 15 to 25 at a temperature of 700 to 800°C after inserting the bead wire scrap into a heating furnace. Can be run for minutes.

In the step of cooling the heated bead wire scrap after taking it out of the heating furnace, cooling of the heated bead wire scrap may be performed by leaving the heated bead wire scrap at a temperature of 30 to 50°C for 3 to 5 hours. .

After cutting the cooled bead wire scrap in units of a certain length, in the step of immersing the cut bead wire scrap in a mixed solution, the cutting of the bead wire scrap is cut in length units of 0.5 to 2.5 cm, and the mixed solution is Thiourea compounds 0.1 to 1% by weight, persulfate 0.01 to 0.15% by weight, amino acids 0.001 to 0.005% by weight, surfactant 0.005 to 0.01% by weight, and the remaining amount of purified water.

In the step of carbonizing the crushed waste tire rubber powder, it may be performed by allowing the crushed waste tire rubber powder to remain in a carbonizer at a temperature of 700 to 750° C. for 5 to 10 minutes and then pass.

In the step of preparing a mixture by mixing the dried bead wire scrap and waste tire rubber powder, the mixture is mixed in a weight ratio of 1 to 5 parts by weight of dried bead wire scrap and 30 to 40 parts by weight of waste tire rubber powder. I can.

In the step of heating and carbonizing the mixture, extruding and pulverizing, the mixture is carbonized at a temperature of 750 to 800°C for 1 to 10 minutes, and then extruded by pressing at a pressure of ^{10 to 20 kgf/cm 2, and the pressurized extruded} The mixture can be ground to a diameter of 0.1 to 2 mm.

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Details of other embodiments are included in the detailed description.

The asphalt modifier using rubber powder according to the present invention improves asphalt properties such as heat resistance, abrasion resistance, and crack prevention, and can recycle waste tires or waste rubber, which are industrial by-products that are discarded after use, and does not contain heavy metals. It can be used safely without fear of environmental pollution.

Advantages and features of the present invention, and a method of achieving them will become apparent with reference to the embodiments described below in detail. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided so that the disclosed content may be thorough and complete and the spirit of the present invention may be sufficiently conveyed to those skilled in the art.

The terms used in the present application are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. Terms such as those defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning of the related technology, and should not be interpreted as an ideal or excessively formal meaning unless explicitly defined in the present application. Does not.

Hereinafter, the asphalt modifier using the rubber powder according to the present invention will be described in more detail.

Asphalt modifiers according to the present invention are rubber powder, polyoctenamer, zinc oxide (ZnO), stearic acid, sulfur, CBS (n-cyclohexyl benzothiazyl-2-sulfenamide) and tetra Methyl thiuram disulfide (TMTD).

In addition, the asphalt modifier according to the present invention is 13 to 17 parts by weight of the polyoctenamer, 1 to 2 parts by weight of zinc oxide (ZnO), and 0.2 parts by weight of stearic acid based on 100 parts by weight of the rubber powder. To 0.8 parts by weight, sulfur (Sulfur) 0.5 to 1.2 parts by weight, CBS (n-cyclohexyl benzothiazyl-2-sulfenamide) 0.5 to 1.2 parts by weight and tetramethyl thiuram disulfide (TMTD; tetramethyl thiuram disulfide) 0.05 to 0.5 parts by weight It can be included in a weight ratio.

The rubber powder can be used by powdering rubber. For example, as the rubber, diene rubber, olefin rubber, acrylic rubber, fluorine-containing rubber, urethane rubber, epichlorohydrin rubber (epichloro Hydrin homopolymer CO, copolymer ECO of epichlorohydrin and ethylene oxide, copolymer further copolymerized with allyl glycidyl ether, etc.), chlorosulfonated polyethylene, propylene oxide rubber (GPO), ethylene-vinyl acetate Copolymer (EAM), polynorbornene rubber, and modified rubbers thereof (such as acid-modified rubber) can be exemplified. These rubbers may be used alone or in combination of two or more. Among these rubbers, usually diene rubber, olefin rubber, acrylic rubber, fluorine-containing rubber, urethane rubber, and the like are widely used from a practical viewpoint.

Diene rubber includes, for example, natural rubber (NR), isoprene rubber (IR), isobutylene isoprene rubber (butyl rubber) (IIR), butadiene rubber (BR), and diene-based monomers such as chloroprene rubber (CR). polymer; For example, acrylonitrile-diene copolymer rubbers such as acrylonitrile butadiene rubber (nitrile rubber) (NBR), nitrile chloroprene rubber (NCR), and nitrile isoprene rubber (NIR); Styrene-diene copolymerization of styrene-butadiene rubber (SBR, for example, random copolymer of styrene and butadiene, SB block copolymer composed of styrene blocks and butadiene blocks, etc.), styrene chloroprene rubber (SCR), styrene isoprene rubber (SIR), etc. Includes rubber and the like. Hydrogenated rubbers such as hydrogenated nitrile rubber (HNBR) are also included in the diene rubber.

Examples of the olefinic rubber include ethylene propylene rubber (EPM), ethylene propylene diene rubber (EPDM, etc.), and polyoctenylene rubber.

Acrylic rubbers include rubbers containing alkyl acrylate as a main component, such as ACM, a copolymer of alkyl acrylate and a crosslinkable monomer containing chlorine, ANM, a copolymer of alkyl acrylate and acrylonitrile, alkyl acrylate and carboxyl groups, and/or A copolymer of an epoxy group-containing monomer, an ethylene acrylic rubber, etc. can be illustrated.

Fluorine-containing rubbers include rubbers using fluorine-containing monomers, for example, copolymers of vinylidene fluoride and perfluoropropene, and ethylene tetrafluoride if necessary, copolymers of ethylene tetrafluoride and propylene, and ethylene tetrafluoride and purple. FFKM, a copolymer of luoromethyl vinyl ether, and the like can be exemplified.

Examples of the urethane rubber (U) include polyester-type urethane elastomers, polyether-type urethane elastomers, and the like.

As modified rubber, acid-modified rubber, such as carboxylated styrene butadiene rubber (X-SBR), carboxylated nitrile rubber (X-NBR), carboxylated ethylene propylene rubber (X-EP(D)-M), etc. And rubbers having a carboxyl group or an acid anhydride group of.

In the asphalt modifier according to the present invention, the rubber powder is waste rubber powder, which is an industrial by-product that is discarded after use to reduce resource recycling and manufacturing cost, more specifically, ground tire rubber (GTR) powder. Can be

The waste rubber powder is generally obtained from waste tire rubber (GTR), etc., and the material is generally used in the art and is not particularly limited, but, for example, the most commonly used ethylene It may be any one or more selected from propylene rubber (EPDM), natural rubber (NR), styrene butidiene rubber (SBR), neoprene rubber (CR), and nitrile rubber (NBR).

As the rubber powder, activated waste tire rubber powder (GTR) may be used, and the activated waste tire rubber powder may increase bonding strength by surface treatment on the rubber powder, and activated by surface treatment. It may be a waste tire rubber powder having a surface.

The activated rubber powder can be obtained by activating waste rubber powder, for example, waste tire rubber powder by surface treatment, and the technology for activating the waste rubber is well known in the art, and fine grinding technology (size reduction) and desulcanization techniques.

The fine pulverization technology is to improve the reactivity in subsequent processes by increasing the surface area through granulation of the lump rubber form, and the desulfurization technology is a crosslinking agent added to the compound rubber to impart elasticity and resilience, which are the properties of rubber materials It is a technology that reverses the crosslinked structure (polysulfide bond) formed while the rubber product is molded and restores it to the state of the raw material rubber before molding.

Activation of waste rubber may be performed by an appropriate method among methods known in the art. The surface treatment for activating pegomu may include one or more selected from the group consisting of physical desulfurization treatment and chemical desulfurization treatment.

Specifically, these waste rubber activation methods known in the art include ozone treatment, ultrasonic treatment, microwave treatment, corona discharge method, supercritical water method, UV treatment, thermal decomposition method, De-Link System, hydrolysis method, catalytic method, etc. , After adding a desulfurization agent such as thiazole or paraffinic oil to the rubber scrap crushed within 5mm with the De-Link System, desulfurization reaction occurs at high temperature and high pressure in the autoclave, or high shear kneading in a Hakke Mixer, etc. As a result, a method of inducing a desulfurization reaction physically and chemically is widely used.

In this embodiment, in consideration of specific process conditions, etc., a suitable method may be selected from among methods known in the art to activate and use waste rubber powder, or commercially available surface-activated waste rubber powder may be used.

The polyoctenamer is a cyclic macromolecule having a crystalline structure exhibiting a low viscosity at a temperature above the melting point. Macromolecules have a high proportion of double bonds, so crosslinking is possible and provides a rubbery polymer. Importantly, when the polyoctenamer melts, it has a viscosity and tack comparable to honey. These properties of the molten material help to mix the asphalt cement with Ground Tire Rubber (GTR).

A number of double bonds leave a number of sites useful for polyoctenamer to react with sulfur in useful sites, e.g. asphalt components, especially asphaltenes and martenses, and to react with sulfur on the surface of GTR or flake rubber. While forming another major component of the binder composition. Once cooled and crosslinked, the polyoctenamer is not sticky at all and reduces the adhesion of the GTR/asphalt binder, so there is little pickup of asphalt from the road surface to make it easier to roll even if the road is hotter.

As the polyoctenamer, for example, the trade name Vestenamer (VESTENAMER™, manufactured by Evonik) may be used, and a preferred form of the polyoctenamer is trans-polyoctenamer, which is also It is designated as "trans-octenamer rubber" (TOR). Two types of Bestenamer™ trans-polyoctenamer are commercially available: "8012" is a material with a trans content of about 80% (cis content of 20%) and a melting point of about 129°F/54°C, and "6213" "Silver is a material with a trans content of about 60% (cis content of 40%) and a melting point of about 86°F/30°C. These two polymers have a double bond every 8 carbon atoms in the ring. A preferred form of TOR used in the practice of the present invention is about 80% of the trans content (20% of the cis content).

The zinc oxide (ZnO) is used as a vulcanization accelerator to further accelerate the reaction, and the stearic acid may be used as a lubricant or plasticizer capable of uniformly dispersing the compositions.

The sulfur causes an ionic reaction to significantly lower the generation efficiency of radicals, and can trap the generated radicals.

The CBS (n-cyclohexyl benzothiazyl-2-sulfenamide), tetramethyl thiuram disulfide (TMTD) is used as a vulcanization accelerator (organic accelerator, radical generator), and the tetramethyl thiuram disulfide (TMTD ) Not only vulcanizes (or crosslinks) the rubber, but can also be directly bonded by a crosslinking reaction.

Asphalt modifiers according to the present invention are used as ground tire rubber (GTR) powder, polyoctenamer, zinc oxide (ZnO), stearic acid, sulfur, and n-cyclohexyl benzothiazyl-2 (CBS). -sulfenamide) and tetramethyl thiuram disulfide (TMTD) are mixed, and then mixed, compressed, and cured through conventional processes.

For example, the present invention is based on 100 parts by weight of ground tire rubber (GTR) powder, the polyoctenamer 15 parts by weight, zinc oxide (ZnO) 1.5 parts by weight, stearic acid (Stearic acid) 0.5 parts by weight , Sulfur (Sulfur) 0.8 parts by weight, CBS (n-cyclohexyl benzothiazyl-2-sulfenamide) 0.8 parts by weight and tetramethyl thiuram disulfide (TMTD; tetramethyl thiuram disulfide) 0.2 parts by weight after mixing in a weight ratio of 800 to 1000 times By preparing an asphalt modifier including a step of stirring at a rate of /min and curing for 5 to 30 minutes at a temperature of 150 to 200°C, an asphalt modifier of physical properties as shown in [Table 1] below can be obtained.

Properties Unit Value Hardness Shore A 64~74 Tensile strength MPa 4.5~8.5 Elongation at Break % 150~300 Modulus MPa 2.0~3.0 Rebound resilience % 50~60

Meanwhile, the ground tire rubber (GTR) powder in the asphalt modifier according to the present invention may be a ground tire rubber (GTR) powder manufactured by the following manufacturing method.

First, the bead wire scrap and the waste tire rubber can be separated and collected from the waste tire.

Separation of the bead wire scrap and the waste tire rubber from the waste tire in the above step can be performed using a known tire core removal facility system, which is a technique known to those of ordinary skill in the art. Description will be omitted.

Next, the collected bead wire scrap may be heated to remove foreign substances adhering to the iron core.

The heating of the separated bead wire scrap in the above step may be performed for 15 to 25 minutes at a temperature of 700 to 800°C after the bead wire scrap is put into the heating furnace. By heating the separated bead wire scrap, the bead It can be removed by melting foreign substances attached to the wire.

Thereafter, the heated bead wire scrap may be removed from the heating furnace and then cooled.

The cooling of the heated bead wire scrap in the above step may be performed by allowing the heated bead wire scrap to stand at a temperature of 30 to 50° C. for 3 to 5 hours.

Subsequently, after the cooled bead wire scrap is cut in units of a predetermined length, the cut bead wire scrap may be immersed in the mixed solution.

In the above step, by immersing the cut bead wire scrap in a mixed solution in which an acid component, etc. is dissolved, various harmful gas residues remaining in the cut bead wire scrap or other fine foreign substances such as heavy metals can be completely removed. For example, the cutting of the bead wire scrap may be cut in length units of 0.5 to 2.5 cm.

In the above step, the mixed solution is prepared by mixing a thiourea compound, a persulfate, an amino acid, a surfactant, and purified water, and the mixed solution is 0.1 to 1% by weight of the thiourea compound, and 0.01 to 0.15% by weight persulfate. , 0.001 to 0.005% by weight of amino acids, 0.005 to 0.01% by weight of surfactant, and the remaining amount of purified water.

The thiourea compound may be used to stably maintain the bead wire scrap in the mixed solution so that foreign matter can be removed, the thiourea compound is thiourea (NH ₂ ) ₂ CS or the general formula (R1R2N)( R3R4N)C=S (here, R1, R2, R3, and R4 are each independently selected from a hydrogen atom, an ethyl group, or a methyl group).

The persulfate may be used as an oxidizing agent to remove various harmful gas residual components or other fine foreign substances such as heavy metals remaining in the bead wire scrap. As the persulfate, ammonium persulfate ((NH ₄ ) ₂ S ₂ O ₈ ) , Any one or more selected from sodium persulfate (Na ₂ S ₂ O ₈ ) or potassium persulfate (K ₂ O ₈ S _{2) may be used.}

The amino acid provides an environment in which various harmful gas residual components or other fine foreign substances such as heavy metals remaining in the bead wire scrap can be safely removed, and can act as a blocking agent for metal ions as well as a buffer against changes in acidity. , The amino acid is an amino acid having 3 to 10 carbon atoms, and the amino acid may be any one or more selected from the group consisting of isoleucine, arginine, proline, tyrosine, glutamic acid, glutamine, and glycine.

The surfactant may be such that the composition constituting the mixed solution is uniformly dispersed in the mixed solution, and the surfactant may include a nonionic surfactant and a cationic surfactant, and the cationic surfactant is the nonionic surfactant. It may be included in a weight ratio of 1 to 10 parts by weight based on 100 parts by weight of the active agent.

Any one or more selected from the group consisting of polyethylene glycol, polyethylene glycol methyl ether, polyethylene glycol monoallyl ether and polyethylene glycol bisphenol-A ether may be used as the nonionic surfactant, and cetyltrimethylammonium as the cationic surfactant Any one or more selected from the group consisting of chloride, cetyltrimethylammonium bromide, cetylammonium chloride, and cetylammonium bromide may be used.

Next, the bead wire scrap cut and immersed in the mixed solution may be separated, washed in purified water, and then dried.

In the above step, the bead wire scrap from which fine residual foreign matter has been removed by being immersed in the mixed solution is separated, and the bead wire scrap is washed with purified water and then dried at a temperature of 40 to 50°C to remove moisture remaining in the bead wire scrap. can do.

Next, the collected waste tire rubber may be crushed to produce rubber powder.

Crushing of the waste tire rubber collected in the above step may be performed using a crusher known in the art, and a detailed description thereof will be omitted for convenience of explanation and clarity of the technical idea of the present invention.

Subsequently, the crushed waste tire rubber powder may be carbonized.

In the above step, the rubber powder can be carbonized by passing the crushed waste tire rubber powder through a known device such as a carbonizer.For example, the carbonizer is contained in the raw material by indirect heating method in a closed low oxygen atmosphere. It is a facility that vaporizes volatile components, and the heat source is hot air and is treated by a pyrolysis gasification treatment method. Characteristics are reduction method that does not generate pollutants due to oxidation, hardly generates waste, can manufacture carbides as a resource, can recover energy from oil and dry gas, and is advantageous for maintenance due to simple facilities. It is a pollution-free resource facility that does not generate and dioxins.

In addition, in the above step, the crushed waste tire rubber powder may be carbonized by allowing the crushed waste tire rubber powder to remain in a carbonizer at a temperature of 700 to 750°C for 5 to 10 minutes and then pass through.

Next, a mixture may be prepared by mixing the dried bead wire scrap and waste tire rubber powder.

In the above step, the mixture consisting of the dried bead wire scrap and waste tire rubber powder may be mixed in a weight ratio of 1 to 5 parts by weight of dried bead wire scrap and 30 to 40 parts by weight of waste tire rubber powder.

Next, the mixture is heated and carbonized, then extruded and pulverized to produce a waste tire rubber (GTR).

In the above step, the mixture is carbonized at a temperature of 750 to 800°C for 1 to 10 minutes, and then ^{extruded by pressing at a pressure of 10 to 20 kgf/cm 2} , and the pressurized mixture is 0.1 to 2 mm using a known grinder. Ground Tire Rubber (GTR) can be manufactured by pulverizing to a diameter of.

Hereinafter, a modified asphalt mixture using the asphalt modifier according to the present invention will be described in more detail.

The modified asphalt mixture using the asphalt modifier according to the present invention is prepared including an asphalt modifier using rubber powder, and the asphalt modifier using the rubber powder is included in an amount of 5 to 25% by weight based on the total weight of asphalt, and the asphalt mixture It may be included in an amount of 0.5 to 2.5% by weight based on the total total weight.

In the modified asphalt mixture using the asphalt modifier according to the present invention, the asphalt mixture may be prepared by injecting the asphalt modifier using the rubber powder into the existing asphalt mixture (ascon), and the configuration of the existing asphalt mixture (ascon) is a known configuration. For convenience of explanation and clarity of the technical idea of the present invention, a detailed description thereof will be omitted.

In the case where the asphalt modifier using the rubber powder exceeds the above upper limit range in the modified asphalt mixture using the asphalt modifier according to the present invention, the manufacturing cost is increased, so that it is not competitive with the existing product and is included below the above lower limit range. In this case, the viscosity of the asphalt may become too high, resulting in a problem of deteriorating workability.

In the modified asphalt mixture using the asphalt modifier according to the present invention, the asphalt modifier using the rubber powder may be used as the asphalt modifier prepared by the above method, and the asphalt modifier using the rubber powder is as described above. Description will be omitted.

Hereinafter, examples of the asphalt modifier using the rubber powder and the modified asphalt mixture using the same according to the present invention will be described in more detail.

<Example 1>

(1) Preparation of asphalt modifier

Based on 100 parts by weight of ground tire rubber (GTR) powder, 15 parts by weight of polyoctenamer, 1.5 parts by weight of zinc oxide (ZnO), 0.5 parts by weight of stearic acid, 0.8 parts by weight of sulfur , CBS (n-cyclohexyl benzothiazyl-2-sulfenamide) 0.8 parts by weight and tetramethyl thiuram disulfide (TMTD; tetramethyl thiuram disulfide) was mixed at a weight ratio of 0.2 parts by weight and then stirred at a rate of 900 times/min, and 180 to An asphalt modifier was prepared including a process of curing for 20 minutes at a temperature of 181°C.

(2) Preparation of asphalt composition

500 g of asphalt (AP-5, SK) was put into the mixing container (heating mantle), and the asphalt modifier prepared in the above example was 15% by weight based on the total weight of asphalt while stirring at 185°C at a high shear rate of 3,000 rpm. It was added in an amount of.

<Example 2> Asphalt modifier and asphalt composition preparation

In the manufacture of the asphalt modifier of Example 1, polyoctenamer 16 parts by weight, zinc oxide (ZnO) 1 part by weight, stearic acid 0.7 Except for mixing in a weight ratio of 0.6 parts by weight of sulfur, 0.6 parts by weight of n-cyclohexyl benzothiazyl-2-sulfenamide (CBS) and 0.4 parts by weight of tetramethyl thiuram disulfide (TMTD) An asphalt composition was prepared in the same manner as in Example 1.

<Example 3> Asphalt modifier and asphalt composition preparation

In the manufacture of the asphalt modifier of Example 1, 13 parts by weight of polyoctenamer, 2 parts by weight of zinc oxide (ZnO), 0.2 parts by weight of stearic acid based on 100 parts by weight of ground tire rubber (GTR) powder. Except for mixing in a weight ratio of 1.1 parts by weight of sulfur, 1.1 parts by weight of CBS (n-cyclohexyl benzothiazyl-2-sulfenamide) and 0.08 parts by weight of tetramethyl thiuram disulfide (TMTD) An asphalt composition was prepared in the same manner as in Example 1.

<Comparative Example> Asphalt modifier and asphalt composition preparation

In the preparation of the asphalt modifier of Example 1, an asphalt modifier was prepared using only ground tire rubber (GTR) powder, and the asphalt modifier was added in an amount of 15% by weight based on the total weight of the asphalt composition.

1. Evaluation of properties of modified asphalt composition

The physical properties of the modified asphalt composition including the asphalt modifier prepared in the above Examples and Comparative Examples were measured by the following method, and the results are shown in Table 2 below.

(1) softening point

The softening point is a measure of the high-temperature properties of modified asphalt measured according to ASTM (American Society Testing and Materials) D36. When heated at 5℃ per minute with water or glycerin, the specimen starts to soften and is located on the specimen with a diameter of 9525mm and a weight of 35g. The temperature was measured when the beads were sagging by 1 inch.

(2) phase separation temperature

50 g of the modified asphalt composition was improved in an aluminum tube, left in an oven at 180° C. for 72 hours, and then divided into three portions, and the softening points of the upper and lower portions were measured by ASTM D36 method, and the temperature difference was calculated.

(3) viscosity

Viscosity was measured at 135°C, 160°C and 180°C according to ASTM D4402 under the conditions of spindle 27 using a Brookfield DV-II+ Pro Model.

division Stirring time (Hr) Example 1 Example 2 Example 3 Comparative example Softening point
(℃) 3 82.8 83.1 83.4 86 4 75.1 75.8 75.9 83.2 5 64.3 65.1 65.7 82.3 Phase separation temperature
(T, ℃) 3 15.6 16.2 16.8 34.2 4 6.9 7.3 7.5 22.5 5 1.8 2.1 2.2 23.1 Viscosity
(cps) 135℃
5 1640 1660 1685 1725 160℃ 585 620 635 715 180℃ 310 330 335 375

Referring to [Table 2], it was confirmed that physical properties such as softening point, phase separation temperature, and viscosity were improved in the case of the asphalt composition including the asphalt modifier according to the example compared to the asphalt composition of the comparative example.

2. Measurement of properties of modified asphalt mixture

A modified asphalt mixture was prepared using the asphalt composition prepared according to Examples and Comparative Examples, and the results are shown in the following table.

(1) Preparation of general modified asphalt mixture

division Mixture composition (% by weight) Mixed aggregate Fiber additives
(Cellulose fiber) Modification
Asphalt composition Aggregate (13mm) Stone powder (6mm) Filler (slaked lime) Example 1 45.2 44.8 4 0.2 5.8 Example 2 45.3 44.8 4 0.2 5.7 Example 3 45.1 44.8 4 0.4 5.7 Comparative example 45.2 44.8 4 0.3 5.7

(2) General modified ascon quality standards

Mixture type Assembly drawing
Ascon Density
Ascon Fineness
Ascon Density gap
Ascon Density
Ascon Maximum particle diameter (20mm) (20mm) (13mm) (13mm) (13mm) (20F) (13F) Number of pledges (times) 50 (75) 50 Stability (N) More than 6,000 More than 6,000
(7,500 or more) More than 6,000 Flow value
(1/100cm) 20 to 40 Void (%) 3~7 3~6 3~7 3~5 Saturation (%) 65~85 70~85(65~80) 65~85 75~85 Indirect tensile strength
(N/㎟) 0.8 or more Toughness
(N*㎜) 8,000 or more Tensile strength after immersion
Indices 0.7 or more

(3) result

division PG grade Marshall stability
(N) Flow value
(1/100cm) Seal
Intensity ratio
(TSR) dynamic
Stability
(Times/mm) 6000
More than Baseline
20-40 Baseline
0.75 or more More than 2000 Example 1 76-22 11258 32 0.77 4523 Example 2 76-22 11598 31 0.79 4685 Example 3 76-22 12501 33 0.82 4589 Comparative example 76-22 9345 36 0.76 2894

In the above, a preferred embodiment of the present invention has been described with reference to the accompanying drawings, but those of ordinary skill in the art to which the present invention pertains, the present invention is in other specific forms without changing the technical spirit or essential features It will be appreciated that it can be implemented. Therefore, it should be understood that the exemplary embodiment described above is illustrative in all respects and is not limiting.

Claims (6)

Rubber powder, polyoctenamer, zinc oxide (ZnO), stearic acid, sulfur, n-cyclohexyl benzothiazyl-2-sulfenamide (CBS) and tetramethylthiuram disulfide (TMTD) ; tetramethyl thiuram disulfide),
The rubber powder is used as a waste tire rubber (GTR) powder,
13 to 17 parts by weight of the polyoctenamer, 1 to 2 parts by weight of zinc oxide (ZnO), 0.2 to 0.8 parts by weight of stearic acid, based on 100 parts by weight of the ground tire rubber (GTR) powder , Sulfur 0.5 to 1.2 parts by weight, CBS (n-cyclohexyl benzothiazyl-2-sulfenamide) 0.5 to 1.2 parts by weight and tetramethyl thiuram disulfide (TMTD; tetramethyl thiuram disulfide) 0.05 to 0.5 parts by weight And
The waste tire rubber powder,
Separately collect bead wire scrap and waste tire rubber from waste tires,
Heating the collected bead wire scrap to remove foreign substances attached to the waste tire core,
The heated bead wire scrap is removed from the heating furnace and then cooled,
After cutting the cooled bead wire scrap in units of a certain length, the cut bead wire scrap is immersed in the mixed solution,
Separating the bead wire scrap cut and immersed in the mixed solution, washed in purified water, and dried
The collected waste tire rubber is crushed to produce rubber powder,
Carbonizing the crushed waste tire rubber powder,
Mixing the dried bead wire scrap and waste tire rubber powder to prepare a mixture,
Asphalt modifier using rubber powder, characterized in that produced through the process of heating and carbonizing the mixture, then extruding and pulverizing. delete delete delete delete delete