KR20230098449A - Asphalt modifier, manufacturing method thereof, manufacturing apparatus and asphalt concrete composition - Google Patents

Abstract

The present invention relates to an asphalt modifier, a method for preparing the same, a manufacturing apparatus, and an asphalt concrete composition. slag adhering to the plastic; And an additive combined with the plastic; includes, is formed of a granulated material having a specific gravity equal to or greater than that of asphalt, and can uniformly modify asphalt.

Description

Asphalt modifier, manufacturing method thereof, manufacturing apparatus and asphalt concrete composition {Asphalt modifier, manufacturing method thereof, manufacturing apparatus and asphalt concrete composition}

The present invention relates to an asphalt modifier, a manufacturing method thereof, a manufacturing apparatus, and an asphalt concrete composition, and more particularly, an asphalt modifier capable of uniformly modifying asphalt, a manufacturing method thereof, a manufacturing apparatus, and an asphalt concrete composition.

Asphalt includes types such as natural asphalt, petroleum-based asphalt, and tar for paving. Among these asphalts, petroleum-based asphalt has excellent adhesion, extensibility, and water absorption, and is mainly used for paving roads. However, petroleum-based asphalt has disadvantages such as low softening point, weak weather resistance, and weak cohesion, so it is used as modified asphalt that is modified by adding various modifiers to suit the characteristics of the place where it is used.

On the other hand, plastic is used as an industrial material not only for various household items, but also for parts manufacturers and molding companies because of its excellent convenience and chemical resistance. A large amount of plastic is produced as disposable products, and after use, it can be collected and recycled as waste plastic. Recently, a plan to use waste plastic as an asphalt modifier has been attempted. Waste plastic not only reforms asphalt, but also improves durability and lifespan of roads by increasing bonding strength with aggregates used in asphalt concrete. However, since the waste plastic has a specific gravity lower than that of asphalt, when mixed with asphalt, it floats to the top of the asphalt and does not sufficiently reform the asphalt.

KR 10-1031531 B

The present invention provides an asphalt modifier capable of uniformly modifying asphalt, a manufacturing method, a manufacturing apparatus, and an asphalt concrete composition.

The present invention provides an asphalt modifier, a manufacturing method, a manufacturing apparatus, and an asphalt concrete composition capable of improving the pavement life of a road.

The present invention provides an asphalt modifier, a manufacturing method, a manufacturing apparatus, and an asphalt concrete composition capable of reducing environmental pollution.

Asphalt modifier according to an embodiment of the present invention, plastic; slag adhering to the plastic; And an additive combined with the plastic; includes, and may be formed into a granulated material having a specific gravity equal to or greater than that of asphalt.

Specific gravity may be 1.0 to 1.2.

Based on the weight of 100 phr (parts per hundred rubber) of the plastic, the slag may include 1 to 30 phr and the additive may include 1 to 60 phr.

The plastic includes waste plastic, and the waste plastic may include at least one of polyethylene, polypropylene, polyethylene terephthalate, polystyrene, and polycarbonate.

The slag may contain 5% by weight or less of CaO based on the total amount of the slag.

The slag includes at least one of blast furnace slag, steelmaking slag, and ferronickel slag, and may have a particle size of 1 to 100 μm.

The additive may include synthetic rubber including at least one of acrylonitrile-butadiene rubber, butyl rubber, ethylene-propylene rubber, and styrene-butadiene-styrene; and a wax comprising at least one of paraffin wax, polyethylene wax, and polypropylene wax; may include at least one of them.

The slag may be disposed to be dispersed in the plastic in the form of particles, or the plastic may be disposed in the core of the granulated material, and the slag may be disposed in the surface layer of the granulated material.

The length of the assembly may be 0.1 to 4 mm.

Asphalt concrete composition according to an embodiment of the present invention, asphalt; the asphalt modifier described above; And aggregate; may include.

With respect to 100 parts by weight of the asphalt, the asphalt modifier may include 1 to 10 parts by weight and the aggregate may include 1,000 to 2,000 parts by weight.

A process of preparing plastic and slag according to an embodiment of the present invention; determining the amount of the plastic and the slag so that the specific gravity of the asphalt modifier to be produced is equal to or greater than that of the asphalt; A process of manufacturing a molded body by melting and extruding a predetermined amount of plastic and slag; and crushing the molded body to prepare an asphalt modifier in the form of particles.

The process of manufacturing the molded body may include preparing a core by injecting the plastic into an extruder and extruding the plastic at a temperature equal to or higher than the melting point of the plastic; and attaching the slag to the deep portion to form a surface layer portion.

The process of attaching the slag may include supplying the slag to the molded body; and press-injecting the slag into the surface of the core by extruding the core and the slag.

The process of press-injecting the slag may be performed before the core part is solidified.

Mixing unit for mixing the plastic and additives according to an embodiment of the present invention; A molding unit for producing a molded body by melting and extruding plastic and additives; and a coating unit installed on the molding unit to attach slag to the molding body.

The molding unit may include an extruder body having a space formed therein, an inlet for injecting the plastic, and an outlet for discharging the main raw material; a screw formed on the extruder body to move the plastic from the inlet side to the outlet side; A die formed to have a smaller inner diameter than the inner diameter of the extruder body and connected to the outlet, wherein the coating unit includes a coater installed on the die so as to surround the outside of the molded body extruded from the die; and a feeder for supplying slag to the coater.

The coating machine, the coater body in which a passage for passing the molded body is formed; and an opening formed in the coater body to allow slag discharged from the feeder to flow into the passage.

A space communicating with the opening and the passage may be formed inside the coater.

It may further include a pressurizer installed in the feeder to press the slag into the opening.

According to an embodiment of the present invention, an asphalt modifier with improved dispersibility in asphalt can be manufactured using slag and waste plastic generated in the steelmaking process. The specific gravity of the asphalt modifier can be controlled by slag to uniformly modify asphalt. In addition, it is possible to improve the bonding strength between the asphalt and the aggregate during the manufacture of asphalt concrete. Therefore, the strength and durability of paved roads can be improved by using the asphalt concrete composition.

In addition, it is possible to reduce the manufacturing cost of the asphalt modifier, which is a high value-added product, by using the waste, and it is possible to suppress or prevent environmental pollution caused by the waste.

1 is a flow chart showing a process for preparing an asphalt concrete composition according to an embodiment of the present invention.
2 is a view showing an asphalt modifier manufacturing facility according to an embodiment of the present invention.
3 shows an asphalt modifier production facility according to a variant of the present invention.
4 is a flowchart sequentially showing a method for manufacturing an asphalt modifier according to an embodiment of the present invention.
5 is a flowchart sequentially showing a method for manufacturing an asphalt modifier according to a modified example of the present invention.
6 is a cross-sectional view conceptually showing an asphalt modifier manufactured by a method for manufacturing an asphalt modifier according to an embodiment and a modified example of the present invention.

Hereinafter, embodiments of the present invention will be described in more detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, only these embodiments will complete the disclosure of the present invention, and will fully cover the scope of the invention to those skilled in the art. It is provided to inform you. Like reference numerals designate like elements in the drawings.

The asphalt modifier according to an embodiment of the present invention may include plastic, slag attached to the plastic, and additives combined with the plastic, and may be formed into a granulated material having a specific gravity equal to or greater than that of asphalt.

Plastics may include thermoplastics that melt when heated and change back to a solid state when cooled. At this time, the plastic is polyethylene (hereinafter referred to as PE), polypropylene (hereinafter referred to as PP), polyethylene terephthalate (hereinafter referred to as PET), polystyrene (hereinafter referred to as PS) , Polycarbonate (hereinafter referred to as PC) and the like. Here, polyethylene may include high density polyethylene (HDPE) and low density polyethylene (LDPE). Plastics may include waste plastics collected from household waste and industrial waste.

Slag may include various slags generated in the steelmaking process, and may include CaO in an amount of 5% by weight or less. Alternatively, the slag may include 0 wt% to 3 wt%, or 0.01 to 2.0 wt% of CaO. Such slag may include ferronickel slag generated in the process of manufacturing ferronickel molten steel. Alternatively, the slag may include ferronickel slag, blast furnace slag, converter slag, electric furnace slag, or the like, or slag whose components are adjusted to contain 5% by weight or less of CaO by mixing the slags with additional auxiliary materials. may be In this case, the smaller the CaO content contained in the slag, the better. This is because CaO has the property of absorbing moisture, so when blast furnace slag, steelmaking slag, and electric furnace slag containing a large amount of CaO are contained in the asphalt modifier, the asphalt concrete paved on the road absorbs moisture and loses strength or cracks. Losing problems can arise. Therefore, it is possible to manufacture a high-strength molded article using only ferronickel slag containing less CaO components than other slags. Alternatively, ferronickel slag, blast furnace slag, converter slag, and electric furnace slag may be mixed to contain 5% by weight or less of CaO based on the total weight of the slag to adjust the components of the slag, and then used to prepare the asphalt modifier. Alternatively, a separate auxiliary material is mixed with at least one slag of ferronickel slag, blast furnace slag, converter slag, and electric furnace slag to contain 5% by weight or less of CaO based on the total weight of the slag, and the components of the slag are adjusted. It can also be used to make asphalt modifiers. In other words, the slag used in the molded body can be prepared by mixing slags having different contents of CaO with each other. At this time, the CaO content may be adjusted to 5% by weight or less by mixing slag with a high CaO content and slag with a low CaO content. Alternatively, slag having a CaO content of more than 5% by weight and a supplementary material containing a large amount of SiO ₂ may be mixed, and slag having a CaO content adjusted to 5% by weight or less may be used to prepare an asphalt modifier. For example, an asphalt modifier may be prepared by mixing 5% by weight of blast furnace slag and 95% by weight of ferronickel slag based on the total weight of the blast furnace slag and ferronickel slag.

Meanwhile, the specific gravity of asphalt is about 1.0 to 1.03, and the specific gravity of plastic is about 0.9 to 0.95. Accordingly, when the plastic is added to the asphalt and mixed, there is a problem that the plastic is not easily mixed into the asphalt and floats on the asphalt. Therefore, if the specific gravity of the plastic is equal to or higher than that of the asphalt, the plastic can be easily incorporated into the asphalt and dispersed. Slag can function as a specific gravity regulator to increase the specific gravity of plastics. The slag may have a particle size of the order of 100 μm or less, or 1 to 80 μm, or 10 to 50 μm. The smaller the particle size of the slag, the easier it is to control the specific gravity of the asphalt modifier, but there is a problem of scattering during handling. On the other hand, if the particle size of the slag is too large, the plastic of the asphalt modifier is melted by the heat of the asphalt, and after the slag is separated from the plastic, it forms a precipitate under the asphalt, that is, the asphalt concrete, thereby lowering the homogeneity of the asphalt concrete. there is a problem.

Slag may be contained in an amount of 1 to 30 phr or 5 to 20 phr based on 100 phr (part per hundred rubber) of plastic in the asphalt modifier. Here, phr represents parts by weight of slag per 100 parts by weight of plastic.

The specific gravity of slag is about 2.5 to 2.8, and the specific gravity of the asphalt modifier can be increased to about 1 to 2 or 1.03 to 1.5 depending on the content. At this time, if the slag content is too small, the specific gravity of the asphalt modifier is lower than 1, so the asphalt modifier cannot be uniformly dispersed in the asphalt. On the other hand, if the content of slag is too large, the specific gravity of the asphalt modifier is increased and the asphalt modifier can be uniformly dispersed in the asphalt. However, there is a problem in that the plastic of the asphalt modifier is melted by the heat of the asphalt, and after the slag is separated from the plastic, it is precipitated in a large amount under the asphalt, that is, the asphalt concrete, thereby lowering the homogeneity of the asphalt concrete.

The additive is combined with the plastic of the asphalt modifier to reduce the melting temperature of the plastic, thereby improving mixing performance between the asphalt modifier and asphalt and improving physical properties of asphalt concrete. These additives may include at least one of synthetic rubber and wax.

Synthetic rubber can improve plastic deformation and crack resistance of asphalt concrete by external force. That is, synthetic rubber can extend the life of a road by increasing the resilience of asphalt concrete by using its viscosity and self-elasticity. In addition, synthetic rubber can prevent low-temperature cracking of asphalt concrete. Such synthetic rubber may include at least one of acrylonitrile-butadiene rubber, styrene-butadiene rubber, butyl rubber, ethylene-propylene rubber, and styrene-butadiene-styrene. Synthetic rubber may be contained in the asphalt modifier in an amount of 30 phr or less, or 0 to 20 phr based on 100 phr of plastic. At this time, synthetic rubber can improve plastic deformation and crack resistance of asphalt concrete and prevent low-temperature cracking, but if the content thereof is too large, the strength of asphalt concrete is lowered.

The wax lowers the melting temperature of the asphalt modifier and serves to improve mixing between the asphalt modifier and the asphalt. In addition, the wax serves to improve the efficiency of work using asphalt concrete, such as road paving work, by reducing the viscosity (melt viscosity) of asphalt concrete to impart fluidity to asphalt concrete. The wax has a melting temperature of about 50 to 160° C., and the melting temperature varies depending on the molecular weight. The molecular weight of this wax may be adjusted to have a melting temperature of about 90 to 110°C. The wax may be contained in an amount of 1 to 30 phr, or 3 to 20 phr based on 100 phr of plastic in the asphalt modifier. At this time, if the content of the wax is too small, it is difficult to lower the melting temperature and viscosity of the plastic of the asphalt modifier, and the mixing property with the asphalt is lowered, and the viscosity of the asphalt concrete is relatively high, so the road pavement efficiency may be lowered. On the other hand, if the content of the wax is too large, the melting temperature and viscosity of the plastic of the asphalt modifier may be lowered to improve mixing with the asphalt, but the viscosity of the asphalt concrete may be excessively lowered, resulting in deterioration in road pavement efficiency.

The additive may be contained in an amount of 1 to 60 phr based on 100 phr of plastic in the asphalt modifier. For reference, the synthetic rubber constituting the additive has a specific gravity of about 0.9 to 0.94, and the wax has a specific gravity of about 0.9 to 0.95.

An asphalt composition may be prepared using the asphalt modifier prepared as described above.

1 is a flow chart showing a process for preparing an asphalt concrete composition according to an embodiment of the present invention.

The method for producing an asphalt concrete composition according to an embodiment of the present invention includes the process of preparing asphalt (S100), the process of preparing asphalt modifier (S200), the process of preparing aggregate (S300), the prepared asphalt, A process of preparing asphalt concrete by mixing the asphalt modifier and the aggregate (S400) may be included. Asphalt concrete prepared in this way can be used for paving roads.

In the process of preparing the asphalt, petroleum-based asphalt may be prepared in a liquid phase by heating it to 150 to 200 °C or 160 to 180 °C.

The process of preparing the aggregate includes coarse aggregate having a particle size of greater than 5 mm and less than or equal to 25 mm or about 10 mm to 15 mm, and a particle size of about 0.1 to 5 mm or 1 inner 3 mm of fine aggregate and smaller particle size than the fine aggregate. It can be prepared by dividing it into fine aggregate. In this case, the aggregate may include at least one of granite, marble, limestone, blast furnace slag, and steelmaking slag. In this case, the aggregate may be provided in an amount of 1,000 to 2,000 parts by weight or 1,200 to 1,700 parts by weight based on 100 parts by weight of asphalt.

Asphalt modifiers can be used to compensate for the disadvantages of asphalt with low softening point, weatherability and cohesion. These asphalt modifiers may include plastics, slags and additives. Here, plastics and additives are used as actual asphalt modifiers, and slag can be used as a specific gravity modifier to uniformly disperse plastics and additives in asphalt. That is, since the specific gravity of plastics and additives is smaller than that of asphalt, there is a problem of phase separation without being uniformly mixed with asphalt. Therefore, the performance of asphalt or asphalt concrete can be improved by adjusting the specific gravity of the asphalt modifier to be similar to, equal to, or greater than that of asphalt using slag so that the asphalt modifier can be uniformly mixed in the asphalt. The asphalt modifier may be provided in an amount of 1 to 10 parts by weight or 3 to 7 parts by weight based on 100 parts by weight of asphalt.

An asphalt concrete composition may be prepared by mixing the asphalt, aggregate, and asphalt modifier thus prepared.

Hereinafter, a method and apparatus for manufacturing an asphalt modifier according to an embodiment of the present invention will be described.

2 is a view showing an asphalt modifier manufacturing facility according to an embodiment of the present invention.

Referring to FIG. 2, an asphalt modifier manufacturing facility according to an embodiment of the present invention includes a mixing unit 100 for mixing raw materials for preparing an asphalt modifier, and melt-extruding the mixed raw materials, for example, the mixture to manufacture a molded body. It may include a molding unit 200 for processing and a crushing unit 300 for preparing an asphalt modifier in the form of particles by crushing the molded body. In addition, the asphalt modifier manufacturing facility may include a control unit (not shown) for controlling operations of the mixing unit 100, the forming unit 200, and the crushing unit 300.

The mixing unit 100 may uniformly mix plastic, slag, and additives. The mixing unit 100 may include a container 110 forming a space capable of accommodating plastic, slag, and additives therein, and an agitator 120 installed in the container 110 to mix the plastic, slag, and additives. can

The container 110 may have an open top so that plastic, slag and additives contained therein may be injected therein. A stirrer 120 may be installed such that a part thereof is inserted into the container 110 and rotated. The stirrer 120 may include a rotating shaft 122 and at least one wing 124 formed to protrude from an outer surface of the rotating shaft 122 . At this time, the rotating shaft 122 penetrates the container 110 and is disposed to extend vertically, and the rotating shaft 122 may be rotated by rotational force provided by the motor 126 .

The mixing unit 100 is not limited thereto and may be variously changed as long as it can uniformly mix plastic, slag, and additives. For example, the mixing unit 100 may be provided as a drum mixer capable of mixing plastic, slag, and additives by rotating the container 110 itself without having a separate stirrer.

The molding unit 200 may manufacture the molded body E by melting and extruding the plastic, slag, and additives, for example, the mixture mixed in the mixing unit 100 . The molding unit 200 includes an extruder body 212 forming a space capable of accommodating the mixture, a screw 230 rotatably formed inside the extruder body 212, and a die connected to the extruder body 212 ( 220) may be included. In addition, the molding unit 200 may include a heating means 240 formed on the extruder body 212 to melt the plastic accommodated in the extruder body 212 .

The extruder body 212 may form a space capable of accommodating and moving the mixture therein. The extruder body 212 may be formed in a hollow shape extending in one direction, for example, in a horizontal direction, and may be formed in a substantially cylindrical shape with both sides open, for example. One side of the extruder body 212 is formed to be opened to install the screw 230, and the other side of the extruder body 212 may be used as an outlet 216 for discharging the mixture to the die 220. And the upper part of the extruder body 212 may be formed with an inlet 214 for injecting the mixture. The inlet 214 may be formed in a hopper shape to easily inject the mixture into the extruder body 212 . However, the shape of the inlet 214 is not limited thereto and may be variously changed. The inlet 214 is formed at the rear in the extruder body 212 in the direction in which the mixture moves or in the direction in which the mixture is extruded, and the outlet 216 may be formed in the front in the direction in which the mixture moves or in the direction in which the mixture is extruded. there is.

The die 220 may be connected to the outlet 216 of the extruder body 212, have an inner diameter smaller than the inner diameter of the extruder body 212, and may be formed in a hollow shape with both sides open. The inner space of the die 220 may be formed in various shapes so that the mixture of the modified slag and plastic may be extruded into a desired shape. For example, when forming the molded body E to have a rectangular plate shape, the inner space of the die 220 may be formed to have a cross-sectional shape of a rectangular slit shape. Alternatively, when the molded object E is formed to have a cylindrical bar shape, the inner space of the die 220 may be formed to have a circular cross-sectional shape.

The screw 230 may be disposed inside the extruder body 212 along a direction in which the extruder body 212 extends. At this time, one side of the screw 230 may be rotatably connected to one open side of the extruder body 212 through a connecting means 231 such as a bearing. Also, the other side of the screw 230 may be disposed to extend to a connection portion between the extruder body 212 and the die 220 . The screw 230 is rotated by the drive of the driver 232 provided in the extruder body 212 to move the mixture injected into the extruder body 212 toward the outlet 216 through the die 220 to the extruder body ( 212) can be extruded out of it.

A heating means 240 may be formed on the extruder body 212 to heat the extruder body 212 . The heating means 240 can heat the extruder body 212 to a temperature equal to or higher than the melting point of the plastic, and is formed along the longitudinal direction of the extruder body 212 so that the plastic can maintain a temperature equal to or higher than the melting point inside the extruder body 212. It can be.

The control unit may control the heating means 240 to adjust the temperature of the extruder body 212 in the direction in which the extruder body 212 extends or in the direction in which the mixture is extruded.

Through this configuration, the mixture is injected into the extruder body 212, moves along the inside of the extruder body 212 by the rotation of the screw 230, and is extruded out of the extruder body 212 through the die 220 to form a molded product. (E) can be prepared.

The molding unit 200 may continuously form the molded body E by extruding the mixture. The molded body E thus formed may be crushed by the crushing unit 300 and formed into particles having a certain size, for example, the asphalt modifier M in the form of pellets. As shown in FIG. 2 , the crushing unit 300 may be provided with a pair of rollers that are rotatable and have projections formed on the outer circumferential surface so as to crush the molded body E while passing it therebetween. However, the crushing unit 300 is not limited thereto and may be variously changed.

3 is a view showing an asphalt modifier manufacturing facility according to a modified example of the present invention.

Referring to FIG. 3, an asphalt modifier manufacturing facility according to a modified example of the present invention includes a mixing unit 100 for mixing plastic and an additive, and a molding unit 200 for manufacturing a molded body by melting and extruding the plastic and an additive. And it may include a coating unit 400 installed on the molding unit 200 to attach the slag to the molding. In addition, the asphalt modifier manufacturing facility may include a control unit (not shown) for controlling operations of the mixing unit 100, the molding unit 200, the coating unit 400, and the crushing unit 300.

The asphalt modifier manufacturing facility according to the modified example of the present invention has a structure almost similar to the asphalt modifier manufacturing facility of the above-described embodiment, except that the coating unit 400 is further provided. Therefore, the structure of the coating unit 400 will be described here, and descriptions of the mixing unit 100, the molding unit 200, and the crushing unit 300 will be omitted.

The coating unit 400 may form a coating layer by attaching slag to an extruded product extruded from the molding unit 200, that is, a molded body. The coating unit 400 includes a coater 410 installed in the die 220 so as to surround the outside of the molded body extruded from the die 220 of the molding unit 200, and a feeder for supplying slag to the coater 410 ( 420) may be included.

The coater 410 includes a coater body 411 having a passage 413 for passing the molding E therein, and a coater body 411 to introduce slag discharged from the feeder 420 into the passage 413. It may include an opening 412 formed in ). The coater body 411 may be formed in a hollow shape with both sides open so that the molded object E extruded from the die 220 can pass therethrough. The passage 413 formed in the coater body 411 may be coupled to the die 220 . The inner diameter of the coater body 411, that is, the diameter of the passage 413, is greater than the inner diameter of the die 220 on the side where the molded object E is introduced, and may be the same as the inner diameter of the die 220 on the side where the molded object is discharged. . This is to sufficiently supply the slag flowing into the passage 413 to the molded body E and press-inject the slag into the molded body. In addition, a space (not shown) communicating with the opening 412 and the passage 413 may be formed inside the coater body 411 . At this time, the space may communicate with the passage 413 at one location or at a plurality of locations in the circumferential direction of the coater body 411 . This is to supply slag to the molded object E at a plurality of positions in the circumferential direction of the coater body 411 .

A feeder 420 may be installed on top of the coater 410 to supply slag to the opening 412 . At this time, the feeder 420 is formed in a substantially hopper shape, may be installed to be spaced apart from the coater 410, or may be installed to be coupled to the coater 410.

Meanwhile, since the molded object extruded from the die 220 moves within the coater body 411 , slag discharged from the feeder 420 may not smoothly flow into the coater body 411 . Accordingly, a pressurizer 430 may be installed in the feeder 420 to press the slag into the coater body 411 . At this time, the pressurizer 430 may be provided with a screw feeder or the like capable of forcibly moving the slag by rotation.

Hereinafter, a method for preparing an asphalt modifier according to an embodiment of the present invention will be described.

4 is a flowchart sequentially showing a method for manufacturing an asphalt modifier according to an embodiment of the present invention.

Referring to FIG. 4, the method for manufacturing an asphalt modifier according to an embodiment of the present invention includes a process of preparing a raw material including plastic and slag (S211, S212, and S213) and a process of extruding the raw material to manufacture a molded body (S215). ) and crushing the molded body to prepare an asphalt modifier in the form of particles (S216).

Plastic for manufacturing the asphalt modifier may be prepared (S211). Plastics may include household waste, waste plastic collected from industrial waste, and waste vinyl. Collected plastic, such as waste plastic, can be washed to remove impurities and then crushed. At this time, the plastic may be crushed to have a size of 5 mm or less, about 0.1 to 4 mm, or about 2 to 3 mm. The size of the shredded plastic may be 5 mm or less in the largest part of the width, length, and thickness. If the size of the shredded plastic is too small, it may scatter when the shredded plastic is introduced into the container 110 or the extruder body 212 . On the other hand, if the size of the plastic is too large, it may not be easily melted during the extrusion process, so that a melt of the plastic may not be formed in the extruder body 212 . Accordingly, it is difficult to uniformly disperse the slag in the plastic melt.

Slag for preparing an asphalt modifier may be prepared (S212). At this time, the slag may include various slags generated in the steelmaking process, and may include CaO at 5% by weight or less. Alternatively, the slag may include 0 wt% to 3 wt%, or 0.01 to 2.0 wt% of CaO. Such slag may include ferronickel slag generated in the process of manufacturing ferronickel molten steel. Alternatively, the slag may include ferronickel slag, blast furnace slag, converter slag, electric furnace slag, or the like, or slag whose components are adjusted to contain 5% by weight or less of CaO by mixing the slags with additional auxiliary materials. may be

In the process of preparing slag, slag having a certain size may be selected. In the process of screening slag, slag having a particle size of 100 μm or less, 1 to 80 μm, or 10 to 50 μm may be selected. The smaller the particle size of the slag, the easier it is to control the specific gravity of the asphalt modifier, but there is a problem of scattering during handling. On the other hand, if the particle size of the slag is too large, the plastic of the asphalt modifier is melted by the heat of the asphalt, and after the slag is separated from the plastic, a precipitate is formed on the lower part of the asphalt, that is, the asphalt concrete. The problem of lowering the homogeneity of the asphalt concrete there is

In addition, an additive for preparing an asphalt modifier may be prepared (S213). At this time, the additive may be at least one of synthetic rubber and wax, and may be provided in a particle or powder state so as to be melt-extruded with plastic.

The synthetic rubber may include at least one of acrylonitrile-butadiene rubber, styrene-butadiene rubber, butyl rubber, ethylene-propylene rubber, and styrene-butadiene-styrene. Synthetic rubber may be prepared to be contained in the asphalt modifier in an amount of 30 phr or less, or 0 to 20 phr based on 100 phr of plastic.

The wax may include at least one of paraffin wax, polyethylene wax, and polypropylene wax. The wax may be prepared as a powder having a particle size of 3 mm or less, or about 0.1 to 2 mm. The wax may be prepared to be contained in an amount of 1 to 30 phr, or 3 to 20 phr based on 100 phr of plastic in the asphalt modifier.

The additive may be prepared to contain about 1 to 60 phr based on 100 phr of plastic in the asphalt modifier.

When the plastic, slag, and additives are prepared as described above, the prepared plastics and additives may be put into the container 110 and mixed by uniformly stirring using the stirrer 120. When the mixture of plastic and additives is prepared in this way, the mixture and slag may be introduced into the extruder body 212 through the inlet 214 . The extruder body 212 may be heated prior to introducing the mixture and slag into the extruder body 212 . The extruder body 212 may be heated by the heating means 240 and may be heated to a temperature higher than the melting point of plastic, for example, about 50 to 100° C. higher than the melting point of plastic. For example, when the asphalt modifier is manufactured using PE having a melting point of about 130 ° C, the extruder body 212 may be heated to about 180 to 230 ° C. Alternatively, when the asphalt modifier is manufactured using PET having a melting point of about 240 ° C, the extruder body 212 may be heated to about 290 to 340 ° C.

When the extruder body 212 is sufficiently heated, the mixture and slag may be injected into the inlet 214 of the extruder body 212 . The mixture and slag injected into the extruder body 212 are moved toward the discharge port 216 of the extruder body 212 by the rotation of the screw 230, the mixture is melted and the slag is dispersed in the melt of the mixture, and the die 220 It can be extruded out of the extruder body 212 through the molded body (E). While continuously injecting the mixture and slag prepared in this way into the inlet 214, the molded body E can be continuously manufactured. In addition, the crushing unit 300 crushes the molded body E extruded through the die 220 to produce an asphalt modifier M having a particle form having a certain size, for example, a pellet form. Thereafter, the crushed asphalt modifier may be dried at about 50 to 100 ° C. or 60 to 80 ° C. for about 24 hours to about 36 hours.

Hereinafter, a method for manufacturing an asphalt modifier according to a modified example of the present invention will be described.

5 is a flowchart sequentially showing a method for manufacturing an asphalt modifier according to a modified example of the present invention.

Referring to FIG. 5, the method for manufacturing an asphalt modifier according to a modified example of the present invention includes preparing raw materials including plastic, slag, and additives (S221, S222, and S223), and melting and extruding the plastic and additives to form a molded body. It may include a process of manufacturing (S225), a process of attaching slag to the molded body (S226), and a process of preparing an asphalt modifier in the form of particles by crushing the molded body to which the slag is attached (S227).

The asphalt modifier manufacturing method according to the modified example of the present invention is different from the asphalt modifier manufacturing method according to the embodiment described above, except for the position where slag is injected, and the rest of the process is almost the same. Therefore, hereinafter, a process different from the asphalt modifier manufacturing method according to the embodiment will be described in detail, and the remaining processes will be briefly described.

When the plastic, slag, and additives are prepared, the plastics and additives may be put into the container 110 and mixed uniformly by stirring.

Next, the mixture of plastic and additives may be taken out of the container 110 and melt-extruded while being introduced into the inlet 214 of the extruder body 212 to manufacture a molded body. In addition, the slag may be supplied to the feeder 420 of the coating unit 400 and injected into the opening 412 of the coater 410 .

The molded body extruded through the die 220 passes through the passage 413 of the coater 410 and comes into contact with the slag injected through the opening 412 . In addition, the molded body and the slag pass through the passage 413 of the coater 410 by the molded body subsequently extruded from the extruder body 212, and the slag may be pressed by the inner surface of the coater 410. Accordingly, the molded body and slag are extruded out of the coating machine 410, and the slag is press-injected from the surface of the molded body to form a coating layer on the surface of the molded body.

The molded body exiting the coater 410, that is, the molded body to which slag is attached, may be crushed in the crushing unit 300 to be manufactured into a granulated material, for example, an asphalt modifier in the form of particles or pellets. Thereafter, the crushed asphalt modifier may be dried at about 50 to 100 ° C. or 60 to 80 ° C. for about 24 hours to about 36 hours.

When the asphalt modifier is produced in this way, the specific gravity of the asphalt modifier can be increased by the slag, and the asphalt modifier can be uniformly dispersed in the asphalt to improve the mixability. In addition, since the asphalt modifier is uniformly distributed in the asphalt, cohesion and bonding strength between the asphalt and the aggregate may be improved.

6 is a cross-sectional view conceptually showing an asphalt modifier manufactured by a method for manufacturing an asphalt modifier according to an embodiment and a modified example of the present invention, and FIG. 6(b) is a cross-sectional view of the asphalt modifier manufactured by the method for manufacturing the asphalt modifier according to a modified example of the present invention.

Referring to (a) of FIG. 6 , it can be seen that the slag in the asphalt modifier is uniformly dispersed in the plastic and the additive, and exists in an attached state with them. As such, the slag may exist to be dispersed in the asphalt modifier, but may exist only in the surface layer portion of the asphalt modifier.

Referring to (b) of FIG. 6, the molded body made of plastic and additives in the asphalt modifier may form a core, and the slag may form a surface layer on the surface of the molded body. In this case, since the slag forms the surface layer of the asphalt modifier, the melting time of the plastic and additives located in the deep part by the heat of the asphalt is delayed, so that the slag is more uniformly dispersed in the asphalt than when the slag is uniformly dispersed throughout the asphalt modifier. It can be.

Hereinafter, the results of testing the performance of the asphalt modifier prepared under various conditions will be described.

Experimental example 1

Slag, plastics and additives were prepared to make asphalt modifiers. At this time, ferronickel slag was used as the slag, polyethylene was used as the plastic, and polyethylene wax was used as the additive. Based on 100 phr of polyethylene, 30 phr of polyethylene wax was added to a Henschel mixer and mixed at 500 rpm for 5 minutes. Thereafter, a mixture of polyethylene and polyethylene wax and ferronickel slag were put into a twin screw extruder, and melt-extruded at a temperature of 180 to 220 ° C. at a speed of 30 to 100 rpm to prepare a molded body. After crushing the prepared molded body and processing it with an asphalt modifier in the form of particles, it was dried at 80 ° C. for 24 hours or more.

Thereafter, asphalt (straight asphalt), aggregate, and asphalt modifier were put into a mixing container, and stirred at a temperature of 160 ° C. at a speed of 300 to 500 rpm for 5 to 10 minutes to prepare an asphalt concrete composition. At this time, 10 parts by weight of the asphalt modifier was used with respect to 100 parts by weight of asphalt, and the aggregate was 700 parts by weight of coarse aggregate having a particle size of about 5 to 13 mm and 1,100 parts by weight of fine aggregate having a particle size of about 0.1 to 5 mm ( Aggregate suitable for KS F 2357) and 90 parts by weight of fine aggregate having a smaller particle size than fine aggregate were used.

Experimental Example 2

An asphalt modifier and an asphalt concrete composition were prepared in the same manner as in Experimental Example 1, except that 30 phr of styrene butadiene styrene was additionally used as a plastic when preparing the asphalt modifier.

Experimental example 3

An asphalt concrete composition was prepared using only asphalt and aggregate without using an asphalt modifier, and the asphalt concrete composition was prepared in the same manner as in Experimental Example 1.

Experimental example 4

As an asphalt modifier, a mixture of styrene butadiene styrene, a polyolefin resin, and a fatty acid metal salt was used, and an asphalt concrete composition was prepared in the same manner as in Experimental Example 1.

Experimental example 5

As an asphalt modifier, a mixture of a rubber-based resin and a thermoplastic polymer was used, and an asphalt concrete composition was prepared in the same manner as in Experimental Example 1.

Each of the asphalt concrete compositions prepared in Experimental Examples 1 to 5 was placed in a cylindrical mold having a diameter of 101.6 mm and a height of 76.2 mm, and compacted at least 75 times per minute using a compactor to prepare specimens. Thereafter, the specimen was immersed in a water bath at 60 ± 1 ° C., and then placed in a Marshall tester to perform a Marshall stability test. The Marshall stability test is a test that measures the resistance to plastic deformation as a test applied when designing a mixture for an asphalt concrete composition. In the Marshall stability test, a disk-shaped specimen is mounted vertically in a Marshall tester, and pressurized at a speed of 50 mm/min with a pressurized body arranged in the vertical direction of the specimen, and the maximum load and corresponding deformation until the specimen is destroyed. to measure At this time, the maximum load applied to the specimen when the specimen is destroyed is called the Marshall stability. This test is performed while maintaining the specimen at 60°C.

Marshall stability was measured 4 times for each experimental example, and the measurement results are summarized in Table 1 below.

Primary (N) Secondary (N) cubic (N) 4th order (N) Average (N) Standard Deviation Experimental example 1 10,089 9,724 8,612 9,527 9,488.00 628 Experimental Example 2 10,524 9,931 9,220 10,239 9,978.50 560 Experimental example 3 8,155 7,328 6,036 6,827 7,086.50 889 Experimental example 4 10,424.4 8,207 7,128 7,808 8,405.25 1,410 Experimental example 5 9,270 7,186 6,267 5,461 7,046.00 1,641

Referring to Table 1, in the case of Experimental Examples 1 and 2 in which specimens were prepared using the asphalt modifier according to an embodiment of the present invention, the average value of Marshall stability was measured to be 9,000 or more, and Experimental Example 3 without using the asphalt modifier And, it can be seen that it is significantly superior to Experimental Examples 4 and 5 in which specimens were prepared using a conventional asphalt modifier. It is understood that this is because the slag contained in the asphalt modifier is uniformly dispersed in the asphalt and the asphalt is uniformly reformed, thereby increasing the bonding strength between the asphalt and the aggregate. In addition, in the case of Experimental Examples 1 and 2, it can be seen that the standard deviation of the Marshall stability is significantly lower than that of Experimental Examples 3 to 5. This means that the asphalt was uniformly modified and the aggregate was evenly dispersed throughout the asphalt concrete composition.

According to the above results, the asphalt modifier can be uniformly dispersed in the asphalt by increasing the specific gravity of the asphalt modifier using slag. Accordingly, the asphalt can be uniformly modified and the aggregate can be uniformly dispersed in the asphalt. In addition, it was confirmed that a high-quality asphalt concrete composition can be manufactured by improving the bonding strength between the asphalt and the aggregate.

Although the present invention has been described with reference to the accompanying drawings and preferred embodiments described above, the present invention is not limited thereto, and is limited by the claims described below. Therefore, those skilled in the art can variously modify and modify the present invention within the scope not departing from the technical spirit of the claims to be described later.

100: Mixing unit 200: Molding unit
300: crushing unit 400: coating unit

Claims (20)

plastic;
slag adhering to the plastic; and
Including; additives combined with the plastic;
An asphalt modifier formed of granules having a specific gravity equal to or greater than that of asphalt. The method of claim 1,
An asphalt modifier having a specific gravity of 1.0 to 1.2. The method of claim 2,
Based on the weight of 100 phr (parts per hundred rubber) of the plastic,
The asphalt modifier comprising 1 to 30 phr of the slag and 1 to 60 phr of the additive. The method of claim 1,
The plastic includes waste plastic,
The waste plastic is an asphalt modifier comprising at least one of polyethylene, polypropylene, polyethylene terephthalate, polystyrene, and polycarbonate. The method of claim 1,
The slag is an asphalt modifier containing 5% by weight or less of CaO based on the total amount of the slag. The method of claim 1,
The slag includes at least one of blast furnace slag, steelmaking slag, and ferronickel slag, and has a particle size of 1 to 100 μm. The method of claim 1,
The additive is
synthetic rubber containing at least one of acrylonitrile-butadiene rubber, butyl rubber, ethylene-propylene rubber, and styrene-butadiene-styrene; and
wax containing at least one of paraffin wax, polyethylene wax, and polypropylene wax; An asphalt modifier comprising at least one of The method of claim 1,
The slag is arranged to be dispersed in the form of particles in the plastic,
The asphalt modifier wherein the plastic is disposed in the deep portion of the granulated product, and the slag is disposed in the surface layer portion of the granulated product. According to any one of claims 1 to 8,
Asphalt modifier wherein the length of the granules is 0.1 to 4 mm. asphalt;
The asphalt modifier according to any one of claims 1 to 8; and
Asphalt concrete composition comprising; aggregate. The method of claim 10,
For 100 parts by weight of the asphalt,
The asphalt concrete composition comprising 1 to 10 parts by weight of the asphalt modifier and 1,000 to 2,000 parts by weight of the aggregate. The process of preparing plastic and slag;
determining the amount of the plastic and the slag so that the specific gravity of the asphalt modifier to be produced is equal to or greater than that of the asphalt;
A process of manufacturing a molded body by melting and extruding a predetermined amount of plastic and slag; and
An asphalt modifier manufacturing method comprising: crushing the molded body to prepare an asphalt modifier in the form of particles. The method of claim 12,
The process of manufacturing the molded body,
Injecting the plastic into an extruder and extruding the plastic at a temperature equal to or higher than the melting point of the plastic to prepare a core; and
Asphalt modifier manufacturing method comprising the; step of attaching the slag to the core portion to form a surface layer portion. The method of claim 13,
The process of attaching the slag,
supplying slag to the molded body; and
An asphalt modifier manufacturing method comprising: extruding the core and the slag and press-injecting the slag into the surface of the core. The method of claim 14,
The process of injecting the slag is performed before the core part solidifies. Mixing unit for mixing the plastic and additives;
A molding unit for producing a molded body by melting and extruding plastic and additives; and
Asphalt modifier manufacturing equipment comprising a; coating unit installed in the forming unit to attach slag to the forming body. The method of claim 16
The molding part,
an extruder body having a space formed therein, an inlet for injecting the plastic, and an outlet for discharging the main raw material;
a screw formed on the extruder body to move the plastic from the inlet side to the outlet side;
A die formed to have a smaller inner diameter than the inner diameter of the extruder body and connected to the outlet,
The coating part,
A coater installed on the die to surround the outside of the molded body extruded from the die; and
Asphalt modifier manufacturing equipment comprising a; feeder for supplying slag to the coater. The method of claim 17
The coating machine,
Coater body in which a passage for passing the molded body is formed; and
Asphalt modifier manufacturing equipment comprising: an opening formed in the coater body to allow the slag discharged from the feeder to flow into the passage. The method of claim 18
Asphalt modifier manufacturing equipment in which a space communicating with the opening and the passage is formed inside the coating machine. The method of claim 18
Asphalt modifier manufacturing equipment further comprising a pressurizer installed in the feeder to press the slag into the opening.

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