KR20100012226A - Recycling asphalt concrete using cold recycled asphalt pavement by hot mixing method with hot mixture asphlt - Google Patents

Abstract

PURPOSE: A method for manufacturing a recycled asphalt concrete by heat blending using a room temperature ascon circulation aggregate is provided to obtain high strength recycled asphalt concrete with increased durability without using energy to heat the ascon circulation aggregate. CONSTITUTION: A method for manufacturing a recycled asphalt concrete by heat blending using a room temperature ascon circulation aggregate comprises the following steps: sequentially mixing an emulsifying asphalt binder and a cement with the room temperature ascon circulation aggregate; injecting a heated natural aggregate, an asphalt binder, and a filler and heating the mixture. After mixing the ascon circulation aggregate which comprises 10~66 weight% of the asphalt concrete with the emulsifying asphalt binder which comprises 0.1~5 weight% of the asphalt concrete for more than 3 seconds, a cement comprising 0.5~5 weight% of the asphalt concrete is added and mixed for more than 3 seconds.

Description

Recycled asphalt concrete using cold recycled asphalt pavement by hot mixing method with hot mixture asphlt}

The present invention relates to a heat-mixed recycled asphalt concrete and a method for producing the same using the asphalt mixed recycled concrete at room temperature, and more particularly, to install the additional dryer device and consume fuel in order to heat the recycled asphalt mixed asphalt. The present invention relates to a high-performance recycled asphalt concrete having high resistance to damage of plastic deformation, port holes, cracks, etc. due to environmental and traffic loads while improving the disadvantages of asphalt concrete, and a manufacturing method thereof.

Conventional heated recycled asphalt concrete uses ascone recycled aggregate within the range of about 30% by weight, which is weak in durability compared to general asphalt concrete, while failing to adequately cope with the deterioration of durability of recycled asphalt concrete due to the change of physical properties of ascone recycled aggregate. Performance, causing premature failure of the asphalt pavement. In other words, the conventional recycled asphalt concrete is crushed and sorted ascon circulating aggregate to the required particle size of KS standards, and then indirectly heated to a temperature of about 140, and put the heated natural aggregate, asphalt binder, filler, etc. together in the mixer It was prepared by the method of mixing. As known through recent domestic papers and related reports, asphalt pavement using recycled asphalt concrete has problems in durability such as frequent breakage of cracks and portholes after a common period of about two years. Is generating. The reason for this is that the moisture absorbed by water infiltration during the storage and use of Ascon recycled aggregate is not completely evaporated during the heating process for the production of recycled asphalt concrete. It causes peeling and the like to separate, which causes premature failure such as potholes and cracks. Therefore, in terms of durability, recycled asphalt pavement is relatively lower than general asphalt pavement, causing frequent pavement repair.

In addition, in order to produce the existing recycled asphalt concrete, it was necessary to install a cold bean, a metering facility, a heating dryer device for separately heating the asphalt concrete aggregate, so it was not possible to produce it without the improvement of the existing general asphalt plant facility. Therefore, in order to revitalize recycling of Ascon recycled aggregate in Korea, it is necessary to develop a new technology that can produce high-performance recycled asphalt concrete without a separate production facility.

In addition to the technology for producing heated recycled asphalt concrete, there is a room temperature recycled asphalt pavement method, which is a process of producing room temperature recycled asphalt concrete by mixing emulsified asphalt and natural aggregates in recycled aggregates of asphalt concrete in the field and the plant, and laying and compacting it on site. After a certain period of time, the traffic is opened. Therefore, it is known to be an unsuitable construction method on the motorway where traffic is frequent.

In order to overcome the problems of the existing recycled pavement process, it is necessary to use recycled asphalt concrete with new materials and compounding technologies satisfying the following conditions. Through this, recycled asphalt pavement with long service life and high durability is expected to be available for traffic and environmental loads.

First, premature breakage should be prevented with early opening of traffic after reclaimed asphalt pavement. Second, frequent maintenance and repacking should be suppressed through the improvement of durability by the environment and transportation. Third, it must have sufficient resistance to plastic deformation caused by heavy vehicles. Fourth, excellent workability should be maintained in the process of laying and compacting in the field, thereby ensuring long-term quality. Finally, it should be possible to produce high-quality recycled asphalt concrete without supplementing the additional facilities of ordinary asphalt plants.

Accordingly, the present invention relates to a high durability recycled asphalt concrete that solves the above problems and satisfactorily increases the recycling rate of asphalt concrete, while satisfying the common conditions of road pavement. Highly durable recycled asphalt without any additional equipment or facility by dispersing a certain amount of cement, emulsified asphalt binder or regeneration additive, SBR Latex or water-soluble epoxy or water-soluble acrylic or water-soluble urethane, or a modified additive mixed with one or two of water-soluble EVA. It is an object of the present invention to provide a heat-mixed recycled asphalt concrete and a method for producing the same, which can produce concrete and have high resistance to breakage due to heavy vehicles and climate.

In addition, the present invention is to recycle the construction waste material by using ascon recycled aggregate, which is embedded in the lower layer or landfill of road pavement or used as part of recycled asphalt concrete, for recycled asphalt concrete with superior durability and strength than conventional heated asphalt concrete. It is possible to expect national cost savings by avoiding frequent renovation work due to suppression of premature damage while improving the sex. In the present invention, since the ascon recycled aggregate is used at room temperature, it is convenient because it can be used immediately without heating the ascon recycled aggregate separately.

The present invention is a mixture of room temperature in the order of emulsified asphalt binder, cement in the order of the asphalt concrete ascon circulating aggregate, then heated natural aggregate, asphalt binder and filler (PE wax added in case of workability problems) Provided is a method for producing hot mixed recycled asphalt concrete using ascon recycled aggregate and asphalt concrete produced thereby.

In addition, the asphalt concrete aggregate is 10 ~ 66% by weight of the total asphalt concrete and 0.1 ~ 5% by weight of the total asphalt concrete is added to the mixture at room temperature for at least 3 seconds, after which the cement of the total asphalt concrete Add 0.5 to 5% by weight, mix at room temperature for 3 seconds or more,

The natural aggregate is heated at 160 ~ 300 ℃ 30 ~ 86% by weight of the total asphalt concrete, the asphalt binder is heated at 130 ~ 200 ℃ 2 ~ 10% by weight of the total asphalt concrete, the filler is total asphalt concrete 1 to 5% by weight of the heat-mixed recycled asphalt concrete using the recycled asphalt concrete at room temperature, characterized in that the process of heat-mixing for 30 to 60 seconds is also provided.

According to the present invention, it is possible to obtain a high-strength recycled asphalt concrete with high durability without the use of energy for heating the asphalt concrete aggregate in the production process of the conventional recycled asphalt concrete. Through this, it is possible to produce recycled asphalt concrete without additional facility improvement of the existing asphalt plant, and it has the effect of significantly improving the life of the recycled asphalt pavement by improving resistance to plastic deformation, peeling, cracking, etc., compared to the recycled asphalt concrete of the heating process. .

In addition, the present invention exhibits high physical properties while improving recycling of asphalt concrete aggregates by up to 20% or more, compared to conventional recycled asphalt mixtures. There is another effect.

According to the present invention, the mixture is mixed at room temperature in the order of emulsified asphalt binder and cement at room temperature (not required to be heated separately), followed by heating natural aggregate, asphalt binder, and filler (PE wax added for workability problems). Provided is a method for producing heated mixed recycled asphalt concrete using ascon recycled aggregate at room temperature, which is subjected to mixing, and the asphalt concrete produced thereby.

In addition, the asphalt concrete aggregate is 10 ~ 70% by weight of the total asphalt concrete and 0.1 ~ 5% by weight of the total asphalt concrete is added to the mixture at room temperature for 3 seconds or more, and then the cement of the total asphalt concrete Add 0.5 to 5% by weight, mix at room temperature for 3 seconds or more,

The natural aggregate is heated at 160 ~ 300 ℃ 30 ~ 90% by weight of the total asphalt concrete, the asphalt binder is heated at 130 ~ 200 ℃ 2 ~ 10% by weight of the total asphalt concrete, the filler is the total asphalt concrete 1 to 5% by weight of the method for producing a heat-mixed recycled asphalt concrete using the recycled asphalt concrete at room temperature, characterized in that the process of heat mixing for 30 to 60 seconds, and thereby provides asphalt concrete.

In addition, one or two or more of SBR Latex, a water-soluble epoxy, a water-soluble acrylic, a water-soluble urethane, a water-soluble EVA, a cement fastener, or a waterproofing material is selected as the water-soluble modifying additive in the emulsified asphalt binder. It is possible to add a further%, the cement may be any one of portland cement, crude steel cement, ultra-thin steel cement, cemented carbide cement.

In addition, it is also possible to further add 0.1 to 5% by weight of the pigment in the total asphalt concrete in the mixing process of the heated natural aggregate.

Hereinafter, it will be described in detail for each trick for asphalt concrete production.

Step 1: Prepare Ascon Recycled Aggregate

Ascon circulating aggregate is crushed and pulverized according to KS standard for each base, middle layer, surface layer, etc., and this is measured as 10 ~ 70% by weight of the total asphalt concrete and put into the mixer at room temperature. The moisture content of ascon recycled aggregate is managed at least 5%, and it is reasonable to manage at 1% or less. In order to manage the moisture content of Ascon recycled aggregate, tents should be covered in open air to prevent the inflow of water in rainy weather and, if possible, separated and stored in roofing facilities with roof facilities. If the moisture content of ascon recycled aggregate is more than 5%, it is difficult to control the temperature and remove water, so it is reasonable to increase the heating temperature of natural aggregate or adjust the amount of cement to 3 ~ 5% by weight.

Second step: emulsified asphalt binder, or optionally water soluble Reform Additive  Etc

Emulsified asphalt binder or regenerative additive is added to 0.1 ~ 5% by weight of total asphalt concrete and optionally water-soluble modifier (SBR Latex or water-soluble epoxy, water-soluble acrylic, water-soluble urethane, water-soluble EVA) Seed selection) is mixed by 0.1-2% by weight of the total asphalt concrete by spraying for at least 3 seconds.

The purpose of injecting the emulsified asphalt binder and the regeneration additive in the above is to reinforce the coating between the asphalt asphalt aggregate and the asphalt binder, and to promote the hydration with the cement put into the three stages, thereby providing a higher adhesive strength with the aggregate. This also helps to improve adhesion. It also helps to improve the film adhesion between the heated asphalt binder and the aggregate, which is added in step 4.

In addition to the emulsified asphalt binder, a water-soluble modifier SBR Latex, a water-soluble epoxy, a water-soluble acrylic, a water-soluble urethane, or a water-soluble EVA may be used, which is for reinforcing elasticity of the asphalt binder film. In addition, when additional rigidity reinforcement is required to suppress cracks, etc., depending on the traffic volume, waste tire rubber chips of 0.5 mm or less may be used, and PP, PE, carbon black, etc. may be added in parallel.

Third step: cement input

After the second step is completed, the cement is mixed at room temperature for at least 3 seconds by adding 0.1-5% by weight of the total asphalt concrete to room temperature. The purpose of the use of cement is for the discharge of water contained in the recycled asphalt asphalt, promoting the curing by moisture absorption and hydration reactions such as emulsified asphalt binder and water-soluble modifier. That is, the surplus of water added helps the continuous curing of the cement.

Here, cement fasteners or waterproofing materials may be used in the second stage for early curing of cement, and when not using this, crude steel cement or crude steel cement, cemented carbide cement, etc. may also be applied.

Fourth step: heated natural aggregate, asphalt binder and filler  input

After the mixing of the three stages is completed, the natural aggregate of the required particle size crushed and pulverized according to the use such as the base layer, the middle layer, and the surface layer by KS standards is measured at 30 to 90% by weight of the total asphalt concrete, and heated to 160 to 300 ℃. Add and mix. Next, the asphalt binder heated to 130 ~ 200 ℃ sprayed and mixed with 2 to 10% by weight of the total asphalt concrete. During this process, 1 ~ 5% by weight of the asphalt concrete, mixed with one or two kinds of lime powder, slaked lime or recovered dust, is added to the asphalt concrete to increase the resistance and increase the peel resistance of the asphalt concrete. The total mixing time of this step is preferably carried out about 30 to 60 seconds.

The temperature of the recycled asphalt concrete after the production process is managed to be maintained between 130 ~ 200 ℃, and transported to the site using a dump truck that can maintain the temperature, and then reclaimed asphalt by laying by manpower or finisher, etc. Complete the packaging.

And, in addition, in order to eliminate the problems of production and construction workability due to high viscosity in the production of asphalt mixture, PE wax can be added 0.1 to 1% by weight of the total asphalt concrete after the addition of asphalt binder.

In addition, the present invention can be applied to the production of water permeable and drainable mixtures depending on the particle size of the asphalt concrete aggregate and natural aggregate.

Permeable pavement refers to pavement that has the function of infiltrating rainwater through the package and reducing it into the soil as shown in <Figure 1>. Up to now, it has been used mainly for roadways, parking lots, and pavement, where light weight vehicles such as sidewalks and passenger cars pass. Water-permeable packaging generally consists of a filter layer (sand layer), an auxiliary base layer, a base layer and a surface layer on the hearth, and does not have an adhesive layer between the prime coat and the tack coat. The permeable pavement mixture is a mixture having a high permeability coefficient of about 10 to 2 cm / sec, and generally uses an open particle mixture composed of relatively small grains containing little fine aggregate to increase the porosity. It consists of a cross-sectional structure such as

Drainage packaging aims to drain rainwater out of the pavement on the road surface quickly. Asphalt mixture used for drainage pavement is used for the surface layer or base layer, and the structure does not penetrate below the base layer or subbase layer. Unlike permeable pavements, it must have conditions that allow the passage of heavy vehicles. A typical cross section of a drainage pavement is shown in Figure 3 below.

Aggregates used for the drainage packaging are as follows. That is, the drainage pavement has a large influence on the quality of the asphalt mixture because the bulk, weight and shape of the coarse aggregate are composed of coarse aggregate. Therefore, in selecting aggregate, the wear rate and shape of coarse aggregate are used as important quality standards. Table 1 below shows the quality specifications of coarse aggregates applied to drainage packaging in Japan and Korea.

Item unit Japan Road Association Korea Expressway Corporation Korea Road Traffic Association Specific gravity (cover) - 2.45 or more 2.5 or more 2.45 or more Water absorption % 3.0 or less 3.0 or less 3.0 or less Stability Test Loss % 12 or less 12 or less - Wear loss % 30 or less 35 or less 30 or less Flat and long piece content % below 10 20 or less - Cover Area % - 95 or more

Although the quality standards of aggregates do not differ significantly between Japan and Korea, the content of flat and long pieces is limited to less than 10% in Japan and less than 20% in Korea Highway Corporation. In addition, Japan's flat and feldspar regulations are the same as ASTM D 4791, which means that the ratio of aggregate thickness and length includes both segregation and feldspar. The KS F 2575 regulation applied by Korea Expressway Corporation specifies that the ratio of the width to the thickness of aggregate particles or the ratio of the length to the width is more than three times. When measured by the KS regulation method, the content of the segregation stone is calculated less than the ASTM method. This reflects domestic aggregate production.

In addition, looking at the particle size distribution of the aggregate for drainage packaging, using the selected aggregate to determine the compounding ratio to satisfy the synthetic particle size of the standard particle size range of the drainage packaging mixture of <Table 2> and porosity is about 20%.

 Nominal Dimension of Sieve Particle size range Mixture Type (20mm) Mixture Type (13mm)   Passing Mass Percentage (%) 26.5 mm 100 - 20 mm 95-100 100 13 mm 64-84 90-100 5 mm 10-31 11-35 2.5mm 10-20 10-20 0.08mm 3 ~ 7 37 Asphalt amount (%) 4 ~ 6

In addition, the permeable packaging is also in accordance with the above.

Hereinafter, with reference to the accompanying Tables 3 to 4 describe the test results (effects) of the present invention.

Heat-mixed recycled asphalt concrete using the ascon recycled aggregate at room temperature according to the present invention and its manufacturing method can be used for new asphalt pavement and repacking, etc. It is a method implemented to dramatically improve the life of the packaging.

In the embodiment of the present invention, the ascon recycled aggregates having a predetermined particle size distribution are sorted and crushed to 20 mm or less according to KSF 2572, and then 750 kg is put into a mixer at room temperature, and then 10 kg of an emulsified asphalt binder (RSC-4) is put there for 5 minutes. After mixing 40kg of cement was mixed at room temperature for 5 seconds. Next, 1070 kg of natural aggregate heated to 250 ° C. and 85 kg of asphalt binder (penetration degree 60-80) heated to 160 ° C. and filler 40 kg were added thereto, followed by heat mixing for 40 seconds.

The present invention prepared with the above composition showed significantly higher physical properties than general asphalt concrete in terms of stability (25 ° C.), porosity, and dynamic stability, and in particular, dynamic stability showed very superior performance compared to modified asphalt concrete.

Table 3 below shows aggregate particle size distribution of recycled asphalt concrete used by the present applicant.

 division  % Sieve weight 25 19 13 10 No4 No8 No30 No50 No100 No200 Particle size distribution 100 100 74.0 61.7 42.7 30.3 16.4 12.7 7.3 6.1 standard 100 90-100 69-84 56-74 35-55 23-38 10-23 5-16 3-12 2-10

Table 4 below shows the quality test results of the recycled asphalt concrete used by the present applicant.

division Production temperature Stability (kgf) Flow value (0.01 cm) Porosity (%) Identification stability (times / mm) Field Density (kg / m ³ ) Test specification 152 2,120 25 5.2 12,500 2,294 standard 130-180 500 or more 20-40 3-6 - -

1 is a schematic view showing a process for producing a heat-mixed recycled asphalt concrete according to the present invention.

Claims (9)

Asphalt concrete manufacturing method using the asphalt concrete aggregate at room temperature, Mixing at room temperature in order of emulsified asphalt binder and cement in an ascon circulating aggregate at room temperature; And Heating and mixing the natural aggregate, asphalt binder and filler; Method for producing a heated mixed reclaimed asphalt concrete using ascon recycled aggregate at room temperature. In claim 1, The asphalt concrete aggregate 10 ~ 66% by weight of the total asphalt concrete, emulsified asphalt binder 0.1 ~ 5% by weight of the total asphalt concrete is mixed at room temperature for 3 seconds or more, and then the cement is 0.5 ~ of the total asphalt concrete Add 5% by weight and mix at room temperature for at least 3 seconds, The natural aggregate is heated at 160 ~ 300 ℃ 30 ~ 86% by weight of the total asphalt concrete, the asphalt binder is heated at 130 ~ 200 ℃ 2 ~ 10% by weight of the total asphalt concrete, the filler is total asphalt concrete Method for producing a heat-mixed recycled asphalt concrete using ascon recycled aggregate at room temperature, characterized in that 1 to 5% by weight of the heat-mixing process for 30 to 60 seconds. In claim 2, In the emulsified asphalt binder, one or two or more of SBR Latex, water-soluble epoxy, water-soluble acrylic, water-soluble urethane, water-soluble EVA, cement fastener, or waterproofing material are selected as water-soluble modifying additives by 0.1 to 2% by weight of total asphalt concrete. Method for producing a heat-mixed recycled asphalt concrete using ascon circulating aggregate at room temperature, characterized in that the addition. In claim 1, The cement is a method of producing hot mixed recycled asphalt concrete using ascon circulating aggregate at room temperature, characterized in that using any one of portland cement, crude steel cement, ultra-thin cement, super fast cement. In claim 2, Method for producing a heat-mixed recycled asphalt concrete using the asphalt concrete aggregate at room temperature, characterized in that the addition of 0.1 to 5% by weight of the total asphalt concrete in the mixing process of the heated natural aggregate. In claim 2, After removing the recycled asphalt mixture at room temperature, the asphalt concrete is added with 0.1 to 1% by weight of PE wax in order to eliminate the problems of production and workability due to high viscosity. Method of producing a heated mixed recycled asphalt concrete using the. In claim 2, Method for producing a heat-mixed recycled asphalt concrete using ascon circulating aggregate at room temperature having a particle size distribution for permeable or drainable asphalt pavement. In claim 7, Method for producing a heat-mixed recycled asphalt concrete using ascon recycled aggregate at room temperature, characterized in that the addition of 0.1 to 5% by weight of the waste tire rubber chip to the asphalt pavement to further strengthen the asphalt pavement. Asphalt concrete produced by the heat-mixing type recycled asphalt concrete manufacturing method using the asphalt concrete of the ambient temperature of any one of Claims 1-8.

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