KR20040070157A - Material to improve quality of asphalt concrete, and the manufacturing method thereof - Google Patents

Abstract

PURPOSE: A modifier chip for asphalt concrete (ascon) and its preparation method are provided, to prevent sintering deformation in hot weather and cracking in cold weather and to improve sliding resistance. CONSTITUTION: The method comprises the steps of preparing 1 part by weight of at least one modifier selected from the group consisting of a styrene-butadiene-styrene copolymer, a styrene-isoprene-styrene copolymer and low density polyethylene and 0.2-3 parts by weight of asphalt; heating the prepared asphalt at a temperature of 150-250 deg.C to melt it; adding slowly the prepared modified to the molten asphalt with maintaining the molten state of the asphalt by heating; extruding the obtained mixture with cooling; and pulverizing or cutting the cooled mixture to prepare a chip. Preferably the chip has a size of 5 mm or less.

Description

Modified chip of asphalt concrete and its manufacturing method

The present invention relates to an asphalt concrete modifier chip used to improve the quality of asphalt concrete (hereinafter referred to as "ascon"), and more specifically, a styrene butadiene styrene copolymer copolymer. Styrene: Ascon packaging is used for conventionally used ascon modifiers such as SBS, Styrene Isoprene Styrene, SIS, and Low Density Polyethylene (LDPE). The present invention relates to an improved ascon modifier chip and a method for manufacturing the same.

Ascon is a mixture of asphalt and coarse aggregates, fine aggregates, and pavement fillers (limestone powder, cement, etc.) at room temperature or at room temperature. However, the asphalt contained in ascon is sensitive to changes in temperature, and ascon pavement is a plastic deformation in summer, which causes severe bends in the pavement, which hinders the traffic of cars. In some cases, cracks in the package may greatly shorten the life of the package.

Ascon modifier is used to improve the problem of ascon, and combines with asphalt to change the physical properties of asphalt, to prevent plastic deformation in summer, to prevent the formation of winter cracking, and to increase the slip resistance of the package. Do it.

Ascon modifiers widely used in the prior art include SBS, SIS or LDPE, the concept that these modifiers act on the asphalt to change the physical properties of the asphalt is as shown in FIG. In other words, modifiers such as SBS, SIS, or LDPE are generally used by adding about 2-10% of the amount of asphalt used in ascon. When these modifier particles are combined with the asphalt particles, Plastic deformation of the asphalt is prevented, winter crack formation is prevented, and the slip resistance of the package is increased.

These modifiers are as follows.

SBS is a polymer copolymerized by random reaction of high elastic butadiene and hardened styrene. When it is dissolved at high temperature and put into asphalt, it is a hard ascon mixture at high common temperature and resistant to fatigue cracking at medium common temperature. It is an elastic mixture that can be used, and a mixture having an unchanging stiffness that can resist temperature cracking even at a low common temperature.

However, SBS is required to be heated at a high temperature of 150 ° C and a high shear mixing device, which is a special mixing device, in order for the physical property to be melted at a high temperature and mixed with the asphalt to be sufficiently mixed with the asphalt. Not only is it expensive, but also bulky, making it difficult to move to each asphalt plant. Therefore, in order to use SBS as an asphalt modifier, a heating device and a high shear mixing device are installed in an asphalt manufacturing plant, and SBS is pre-injected into the asphalt, mixed with asphalt sufficiently, and the asphalt containing the modifier is transported to the construction site. In order to do so, a separate asphalt tank should be installed at the asphalt concrete plant.

As such, the conventional method of using SBS as a modifier requires expensive equipment and requires a considerable time due to the complicated process. In addition, when the modifier is stored in a mixed state with the asphalt for a long time, separation of the asphalt and the modifier occurs and the effect of the modifier is not effective. Therefore, there is a problem in that it cannot be prepared in advance. Due to these problems, despite the excellence as a modifier of SBS, it is not yet widely used.

As the copolymer polymer of the same type as SBS, as the modifier of ascone, SIS, which is an elastomer, and asphalt polymer, which are widely used as a plastomer, include LDPE. To do this, high temperature heating device and high shear mixing device are required like SBS. Also, if the modifier is kept in the mixed state with asphalt for a long time, the separation phenomenon of the asphalt and the modifier may occur, so it may not be prepared and stored in advance. However, these modifiers are not widely used yet.

On the other hand, the ground waste tire can also be used as a modifier because its physical properties are similar to the copolymer polymer. Particularly, in the case of using the crushed waste tire as part of the road pavement, not only is it useful in terms of resource recycling, but also the elasticity of the crushed waste tire causes elasticity on the road, and thus there is an advantage in that the riding comfort is good when driving on the road. However, in the case of packaging by mixing the crushed waste tire with asphalt aggregate, etc., in the state where the crushed waste tire is not integrated with the asphalt but simply mixed, the crushed waste tire acts as a kind of foreign matter, and thus, deteriorates the durability of the package. Will result.

In order to solve the above problems in the use of grinding waste tires, there is a McDonald's method of the wet method. McDonald's method is a technology that uses 10-25% of crushed waste tires in asphalt and mixes the crushed waste tires and asphalt at high temperature and high speed at 190-220 ° C. for 30 minutes to 1 hour. That is, according to the McDonald's method, the asphalt and the crushed waste tires are mixed at a high speed at a high speed, so that the asphalt is firmly bonded to the crushed waste tire particles surface to form an integration.

However, in this McDonald's method, when the crushed waste tire and asphalt are continuously contacted at a high temperature for more than 12 hours, there is a possibility that the crushed waste tire is completely dissolved in the asphalt, thereby reducing the effect of injecting the crushed waste tire, As a result, a problem may occur in which the overall quality of the asphalt concrete is degraded. In addition, in order to apply the McDonald's method, expensive aging equipment is required, and a mobile large asphalt tank, aging equipment, crushed waste tire truck, asphalt truck, aging personnel, etc. must be prepared. The disadvantage is that it is beneficial.

Another method of integrating the grinding waste tire and asphalt is the method of Patent No. 394092 proposed by the inventor of the present invention, which first indirectly heats the grinding waste tire to gel the surface of the grinding waste tire, and thus 150-300 By mixing the asphalt heated to ℃ to produce a chip in which the ground (gelled) crushed waste tire particles and asphalt integrated. This method is very economical compared to the above-described McDonald's method because it can integrate the grinding waste tire and asphalt in a simple process.

The concept of a chip manufactured by the method of patent 394092 is as shown in Figs. 2A and 2B. That is, as shown in Fig. 2a, the surface of the pulverized waste tire is first gelled and asphalt is bound to the gelled surface to be integrated as a whole, and as shown in Fig. 2b, the asphalt integrated with the crushed waste tire is additionally added later. It naturally binds and mixes with the asphalt particles. Therefore, according to the method of patent 394092, the crushed waste tire is more firmly bonded with asphalt (not simply mixed).

However, the main purpose of using the crushed waste tires is to improve the riding comfort when driving the vehicle by providing environmental protection and resilience to the package through the recycling of resources, the use of crushed waste tires does not improve the durability of the package. Therefore, in the case of using the crushed waste tires, there is a need to separately devise a method for improving the durability of the package, and Patent No. 394092 does not provide a method for improving such durability.

The present invention has been made to solve the problems of the conventional modifiers, the object of the present invention is to provide a modifier chip that can be easily used without going through expensive devices or complicated processes. That is, the present invention aims to avoid the need for a separate expensive equipment or complicated process for adding the asphalt concrete to the asphalt concrete after mixing the asphalt to be integrated with the conventional modifiers to be integrated into the asphalt after the production of chips.

Another object of the present invention to improve the durability of the package while at the same time take full advantage of the use of grinding waste tires. In other words, the present invention by manufacturing and using a chip mixed with a grinding waste tire and a modifier material, while utilizing the advantages of using the grinding waste tire at the same time to prevent the problem of durability degradation that may be caused by using the grinding waste tire. The purpose is to make it possible.

1 is a conceptual diagram showing the action of the modifier in asphalt concrete,

Figure 2a is a conceptual diagram showing the combination of the grinding waste tire particles and asphalt,

FIG. 2B is a conceptual diagram illustrating that the bond of FIG. 2A is spread over the asphalt; FIG.

3a is a conceptual diagram showing the combination of asphalt and modifiers,

3B is a conceptual diagram illustrating a state in which asphalt is activated in the combination of FIG. 3A.

The reformer chip of the present invention is to be easily mixed with conventional asphalt, aggregate and SBS, SIS, LDPE, etc., without a separate heating device or high shear equipment. More specifically, the method of the present invention is melted by mixing the modified materials such as SBS, SIS, LDPE with asphalt, and then cooled by air-cooled or water-cooled while discharging them to a suitable size using a compressor or the like, and then grinder Or by grinding or cutting with a cutter to produce a chip of a predetermined size.

Hereinafter, the present invention will be described in detail.

The method of manufacturing a modifier chip of the present invention is a step of preparing 0.2-3 parts by weight of asphalt based on 1 part by weight of one or more of a modifier such as SBS, SIS, or LDPE, and 150-250 asphalt prepared in an electrical process. Heating process to make it into molten state, heating and mixing the modified materials into molten asphalt of electric process, and discharging the mixture of electric process to a predetermined size using extruder or the like by air or water cooling method. The cooling process, and the process of preparing a chip by grinding or cutting the cooled mixture of the electrical process to a suitable size.

The reformer chip of the present invention prepared as described above may be stored in an appropriate container, and then used in an ascon mixer together with other materials of ascon at the ascon packaging site.

Asphalt softens at about 60 ℃, while asphalt mixed with asphalt and aggregate fillers softens at about 150 ℃ or higher. The present invention utilizes such a phenomenon, and when the modifier chip of the present invention is put into an ascon mixer, the asphalt contained in the modifier chip of the present invention is softened in advance around 60 ° C (before other ascon materials are softened). Activator), which separates it from the modifier, so that the modifier particles are easily dispersed throughout the ascon (which subsequently softens around 150 ° C).

FIG. 3A illustrates the concept of the reformer chip of the present invention, and FIG. 3B illustrates the concept in which the asphalt of the reformer chip of the present invention is softened and activated. That is, as shown in Fig. 3a, when the modifier chip of the present invention is bound with asphalt, and softened in an asphalt concrete mixer, the asphalt is activated and separated from the modifier particles as shown in Fig. 3b. The particles are freely dispersed throughout the asphalt.

The use of asphalt as the main material in the present invention is because the asphalt melts well in heat and is easily dispersed in a material such as asphalt, which is the main material of asphalt concrete, and can be made quickly. As the asphalt used in the present invention, any one of road paving asphalt, cutback asphalt, brown asphalt, natural asphalt, tar and the like can be used. It is preferable to use the asphalt of the following low penetration.

In manufacturing the modifier chip of the present invention, it is preferable to use asphalt at 0.2-3 parts by weight with respect to 1 part by weight of the modifier. If asphalt is used in an amount of 3 parts by weight or more based on 1 part by weight of the modifier, the volume of the modifier chip, which is the final product, is too large to be inconvenient to transport or use. On the other hand, when asphalt is used in an amount of 0.2 parts by weight or less, the asphalt and the modifier are sufficiently There is a high possibility that the particles of the modifier may not be mixed and aggregated together. In this case, when the modifier chip is softened and dispersed in the asphalt concrete, the dispersion force may be insufficient, and thus, the mixing chip may not be sufficiently mixed with the entire asphalt.

In the mixing and mixing of the modifier to the molten asphalt, it is necessary to continue heating to maintain the temperature at 150-250 ° C. At this time, the fine filler may be added and mixed, but the fine filler is preferably added after the reforming material and the asphalt are sufficiently mixed. Examples of the fine filler include carbon black, stone powder, silica sand, and cement, and further mixing these fine fillers has the effect of improving the strength and durability of the asphalt concrete.

In the manufacture of the chip by cooling or pulverizing or cutting the mixed mixture, the size of the object to be crushed or cut is preferably as small as 5 mm or less, preferably 3 mm or less. The reason for reducing the size of the modifier chip of the present invention is to reduce the time it takes to soften in the asphalt concrete mixer.

On the other hand, the modifier chip of the present invention may be prepared by mixing the grinding waste tires. When the crushed waste tire is mixed with the modified chip of the present invention, it is possible to enjoy the effects of recycling the resources and elasticity of the road pavement, which are advantages of using the crushed waste tire, and at the same time, the summer season of ascon which is an advantage of using the modified material. It can enjoy the effects of plastic deformation prevention, winter crack formation prevention and durability enhancement.

In the present invention, a method of manufacturing a modified chip by mixing the crushed waste tires is mixed so that the crushed waste tires and oil asphalt, etc. are integrated, and then further mixed with the mixture of the modified material and asphalt (described above), It is made into a chip by binding with the crushed waste tire (integrated with).

The process of mixing the pulverized waste tire of the present invention to produce a modifier chip includes a step of indirectly heating the pulverized waste tire crushed to a size of 5 mm or less to 100-150 ° C. to gel the surface of the particles, and the surface of the electric process. A process of mixing 0.05-0.5 parts by weight of one of the materials asphalt, road asphalt, brown asphalt, natural asphalt and cutback asphalt to 1 part by weight of this gelled crushed waste tire; Adding 0.02-0.3 parts by weight of fine fillers such as cement and cement, adding a mixture of asphalt and a modified material such as SBS, SIS or LDEP to the mixture of the electrical process and heating and mixing at 150-250 ° C., the electrical process To cool the mixture in an air-cooled or water-cooled manner while discharging the mixture to a predetermined size using an extruder or the like, and pulverizing the cooled mixture of the electric process to an appropriate size. Or it is made of a process of manufacturing the chip by cutting.

In the above process, the grinding waste tire is heated to 100-150 ° C. in order to gel the surface of the grinding waste tire, but to prevent the particles from being excessively expanded. When the temperature is heated to 100 ° C. or less, gelation of the surface of the crushed waste tire is difficult, and when heated to 150 ° C. or more, the crushed waste tire particles may be over-expanded.

In integrating the crushed waste tire and asphalt in the above processes, the amount of asphalt used is 0.05-0.5 parts by weight based on 1 part by weight of the crushed waste tires, the amount of coating of the crushed waste tires is insufficient in the case of 0.05 parts by weight or less There is a concern that tires and asphalt may not be properly integrated (maturation), and in case of 0.5 parts by weight or more, asphalt is used in excess, and the volume of the modifier chip, the final product, is too large, which may cause inconvenience. to be.

In the above process, the reason for further mixing the fine fillers such as carbon black, stone silica sand powder, cement, etc. in the mixture of the grinding waste tire and asphalt is because the grinding waste tire is expanded at a high temperature of 150 ℃ to adhere the particles of the grinding waste tire. This is to prevent. If these fine fillers are used in an amount of 0.02 parts by weight or less, the adhesion of the crushed waste tire particles cannot be prevented sufficiently, and the use of these fine fillers is limited to 0.02-0.3 parts by weight since use of 0.3 parts by weight or more increases only unnecessary weight. It is desirable to.

In the above process, adding and mixing the asphalt mixture with the modified materials such as SBS, SIS, LDPE and heated to 150-250 ℃, to prevent the degradation of the package body durability that can be caused by the use of grinding waste tires and further This is to obtain the effect of preventing plastic deformation in summer and preventing cracking in winter. In dosing and mixing molten asphalt and modifiers, it is necessary to continue heating to maintain the temperature at 150-250 ° C.

At this time, the amount of the modifier and the asphalt mixture is determined in consideration of the amount of asphalt used for the entire asphalt asphalt. That is, the total amount of modifiers such as SBS, SIS or LDPE to be injected should be determined in consideration of 2-10% of the total amount of asphalt used as asphalt. Therefore, when the ratio of SBS, SIS, or LDPE contained in the modifier chip of the present invention is high, the input amount of the modifier chip of the present invention should be reduced, and conversely, when the content of these modifiers is small, You will have to do a lot of modifier chip input.

In the modifier chip manufacturing method of the present invention, sulfur, paraffin, glue, rosin, etc. may be mixed as necessary. Of course, if necessary, reinforcing fibers such as optical fibers, cellulose fibers, and polymer fibers may be added. By using such materials in the present invention, it is possible to maximize the quality of ascon.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated based on an Example.

(Example)

In the case of paving asphalt road for vehicle traffic by setting the 300m section, 100m of which is packed with general asphalt (hereinafter referred to as "packing A"), 100m is the modifier of the present invention (without crushed tire) Ascon packaging containing chips (hereinafter referred to as "packing B") will be described, and the remaining 100m is used ascon packaging (hereinafter referred to as "packing C") containing modified chip mixed with the crushed waste tire of the present invention. It was decided as follows.

In the present embodiment, the modifier used in the packaging B is completely heated by heating 90 kg of natural asphalt Gilsonite and 10 kg of carbon black to 200 ° C., and completely stirring SBS 60 kg while stirring with a stirrer. The mixture was mixed to make a mixture, and the mixture was poured into a water tank with a thickness of 30 cm and 0.5 cm, cooled, and immediately taken out and ground to a size of 5 mm with a rubber grinder. The modifier chips were manufactured in advance and weighed in 3 kg and stored in PP plastic packaging.

In the present embodiment, the modifier used in the packaging C was heated 100 kg of the crushed waste tires pulverized to 0.6 mm or less in a double-wall primary mixer equipped with a heat medium at 50 ° C., and 15 kg of brown asphalt was added thereto. After 5 minutes of mixing, 5 kg of cement was added and the mixture was heated and mixed at 140 ° C. while releasing the particles of the crushed waste tires, and 30 kg of mixed SBS and 30 kg of brown asphalt heated to 150-250 ° C. were added to the mixture. After mixing, the mixture was introduced into an extruder hopper, extruded, and pulled out to a diameter of 10 mm, cooled in a water bath, and then ground to 3 mm. The modifier chip was also manufactured in advance and weighed 3 kg and stored in a PP plastic package.

Package A is a typical ascon package without modifiers. In addition, the packaging B and the packaging C differed from the packaging A only in that the modified materials were used, and the materials used were almost the same as those of the general asphalt concrete package. In this embodiment, pavement A, pavement B, and pavement pavement were packaged on the top of the existing cement concrete pavement, and the materials used and ratios used in pavement A, pavement B, and pavement are shown in Table 2. .

Table 2

division asphalt aggregate Filler (CaCo ₃ ) Modifier system Remarks Packing A 5.5 91.5 3.0 - 100 unit : % Packing B 5.5 90.6 3.0 0.9 100 Packing C 5.5 90.0 3.0 1.5 100

The particle size and synthetic particle size distribution of the aggregate used in this example (gap particle size criteria: CaCo ₃ as filler 3%) are shown in Table 3.

Table 3

Checker (mm) 19 13 10 #4 #8 # 30 # 200 Remarks Passing weight percentage (%) 100 100 81.0 35.7 19.6 11.7 6.2 Aggregate used 100 90-100 70-90 24-42 15-25 5-15 3-7 Composite particle size distribution

In this embodiment, the above materials were heated and mixed at 155-163 ° C. and transported to a site by a dump truck. The modifier of package B was put in an ascon mixer on site and mixed and used immediately. In the field installation, it was installed in Hunisha according to the usual method, and then pledged to Macadam, Tandem Laura, and Tire Laura. In the case of Package C, however, tire rollers were not used. Since the use of tire rollers may cause the crushed waste tires to stick to the tire rollers, the tire rollers are generally not used in the ascon formulation using the crushed waste tires.

In this example, the package stability A, package B and package C was tested for dynamic stability, recovery modulus and the amount of wear, the results are shown in Table 4.

Table 4

Item Name Packing A Packing B Packing C standard Dynamic Stability (times / ㎜) 360 6,500 8,500 1,500 or more Recovery modulus of elasticity: 5 ° C (MPa) 9,540 3,550 2,500 - Abrasion amount (㎠) (labeling test) 1.270 0.350 0.310 -

As shown in Table 4, for package B and package C, the dynamic stability, which is the criterion for small deformation, was dramatically improved compared to package A without modifier, and the modulus of recovery elasticity at low temperature, which is the criterion for low temperature cracking, was used. It was found to be stabilized at 1/3 level compared to the unpacked package A, and the amount of wear by the labeling test was also improved to about 1/4 compared to the package A without the modifier.

The present invention relates to an improved ascon modifier and a method for producing the same, which can be easily applied to an ascon package, which is a conventionally used ascon modifier such as SBS, SIS, or LDPE, which is a copolymer polymer, and the ascon modifier of the present invention is used for the same. In addition to the ease of use, it is very useful to sufficiently improve ascon quality such as preventing plastic deformation in summer, preventing crack formation in winter and improving sliding resistance.

Claims (11)

Preparing 0.2-3 parts by weight of asphalt with respect to 1 part by weight of one or two or more mixtures of a modifier such as SBS, SIS or LDPE; Heating the asphalt prepared in the electrical process to 150-250 ° C. to make it molten; Gradually inputting and mixing the prepared modifier while heating to maintain the molten state of the asphalt of the electrical process; Cooling the mixture of the electric process while discharging to a predetermined size using an extruder; And pulverizing or cutting the cooled mixture of the electrical process to a predetermined size to produce chips. The method of claim 1, wherein the asphalt mixed with the modifier is asphalt having a penetration of 40 or less. The method of claim 1, wherein the size of the modifier chip produced is 5 mm or less. The method of claim 1, wherein one or two or more of carbon black, stone powder, silica sand, and cement are mixed. Indirectly heating the ground waste tire ground to a size of 5 mm to 100-150 ° C. to gel the surface of the particles; Mixing 0.05-0.5 parts by weight of one of heated asphalt, road asphalt, brown asphalt, natural asphalt and cutback asphalt, heated to 1 part by weight of the ground waste gel gelled in the electric process; Adding 0.02-0.3 parts by weight of fine fillers such as carbon black, stone powder, silica sand, and cement to the mixture of the above steps; Into the mixture of the above process, a mixture of one or more modifiers of SBS, SIS, or LDEP and selected asphalt among lumber asphalt, road asphalt, brown asphalt, natural asphalt and cutback asphalt is added and heated to 150-250 ° C. Process of doing; Cooling the mixture of the electric process while discharging to a predetermined size using an extruder; And manufacturing a chip by pulverizing or cutting the cooled mixture of the electrical process to a predetermined size. 6. The method of claim 5, wherein the asphalt mixed with the modifier is asphalt having a penetration of 40 or less. The method of claim 5, wherein the size of the modifier chip produced is 5 mm or less. 6. The method of claim 5, wherein one or two or more of carbon black, stone powder, silica sand, and cement are mixed. 6. The method of claim 5, wherein one or two or more of sulfur, paraffin, glue, and rosin are mixed. Asphalt concrete modifier chip produced by the method of claim 1. Asphalt concrete modifier chip prepared by the method of claim 5.