KR102189540B1 - Aramid fiber reinforcement for asphalt and asphalt mixture containing it and asphalt pavement method using it - Google Patents

Abstract

The present invention relates to an asphalt mixture including an aramid fiber reinforcement material for asphalt and an asphalt paving method using the same. An objective of the present invention is to reinforce the properties of asphalt by using the properties of aramid fiber and induce a uniform distribution of aramid fiber by controlling the viscosity of the asphalt to reinforce all parts of the asphalt evenly. The asphalt mixture including an aramid fiber reinforcement material for asphalt according to the present invention is composed of asphalt, aggregate, and an aramid fiber reinforcement material for asphalt. The aramid fiber reinforcement material for asphalt is made by forming a coating layer of a medium temperature additive on aramid fibers. The medium temperature additive is a viscosity and friction reducing agent that is mixed and coated with the aramid fibers in a ratio of 1 : 0.9 to 1.1 based on weight and melts when mixed with asphalt to reduce the viscosity of the asphalt to induce the uniform mixing of the aramid fibers. The asphalt mixture is manufactured by wet mixing in which the asphalt and the aggregate are first mixed, and then 0.8 to 3 parts by weight of the aramid fiber reinforcement material for asphalt is mixed with respect to 100 parts by weight of the asphalt at a temperature at which the coating layer of the aramid fiber reinforcement material for asphalt is melted.

Description

Aramid fiber reinforcement for asphalt and asphalt mixture containing it and asphalt pavement method using it}

The present invention relates to an asphalt reinforcement and an asphalt mixture, and more particularly, to an asphalt mixture and an asphalt paving method including an aramid fiber reinforcement for asphalt capable of uniform reinforcement in all parts through control of viscosity while reinforcing the stiffness of asphalt. About.

This part provides background information related to the content of the present application, and is not necessarily prior art.

Methods to extend the life of asphalt pavement include a method of using a chemical modifier and a method of using a grid-shaped geotextile.

The method of using a chemical modifier is a method of increasing the viscosity of the asphalt binder by melting petroleum-based (SBS or SBR) polymer particles in the asphalt binder. Excessive cost and difficulty in quality control, energy cost increase due to increase in mixture production temperature, low temperature There is a difficulty in practical application due to the possibility of cracking due to increased brittleness of the material.

The method of using grid-shaped geotextiles is a method of laminating geotextiles woven in a grid form in the middle.Because of the large volume of geotextiles, handling (storage, transport, etc.) is not good and geotextiles are used as a separate operation. As it must be constructed, the constructability is not good and the construction cost increases.

Registered Patent No. 10-1925512 is coated with a synthetic resin having a melting point of 105 to 115°C on a bundle of glass fibers with a diameter of 10 to 20 μm and a length of 5 to 30 mm, with a length of 5 to 30 mm and a diameter of 1 to 5 mm. A first stiffener in the form of a seal; A second stiffener in the form of a cylinder having a diameter of 3 to 5 mm and a height of 3 to 6 mm by coating a synthetic resin having a melting point of 105 to 115°C on the industrial by-product powder; And a reinforcing grating consisting of a slope disposed in a vehicle driving direction and a weft disposed in a direction orthogonal to the inclination, and a synthetic resin film attached to the reinforcing grating, and is constructed to cover the layer boundary of the road. Anisotropy in which the number of slopes of the area corresponding to the driving part is greater than the number of slopes of the area not corresponding to the driving part of the vehicle wheel

Grid reinforcement; As an asphalt paving method using a multi-directional and planar reinforcing asphalt reinforcing material comprising: (a) preparing an asphalt mixture by mixing an aggregate and an asphalt binder, a first reinforcing material, and a second reinforcing material; (b) constructing by covering the anisotropic grid reinforcement on the pavement surface of the road; (c) installing the asphalt mixture prepared in step (a) on an anisotropic grid reinforcement to construct it; (d) applying an anisotropic grid reinforcement over the laid asphalt mixture to construct it; It is an asphalt paving method that includes, and uses a cylindrical reinforcement with a diameter of 3 to 5 mm and a height of 3 to 6 mm rather than a grid type, but the effect of increasing rigidity is weak because it cannot be mixed in a uniform distribution with asphalt.

Registered Patent No. 10-1925512

The present invention is to solve the above-described problems, reinforcing the properties of asphalt by using the properties of aramid fibers, and inducing a uniform distribution of aramid fibers through the control of the viscosity of the asphalt to uniformly reinforce all parts of the asphalt It is an object of the present invention to provide an asphalt mixture and an asphalt paving method comprising an aramid fiber reinforcement for asphalt.

The aramid fiber reinforcement for asphalt according to the present invention is made by forming a coating layer of a medium temperature additive on aramid fiber, and the medium temperature additive is a viscosity and friction reducing agent that induces uniform mixing of the aramid fiber by reducing the viscosity of the asphalt. It is characterized in that the mixture is coated with the aramid fiber in a ratio of 1: 0.9 to 1.1 based on the weight.

Asphalt mixture containing aramid fiber reinforcement for asphalt according to the present invention is composed of asphalt, aggregate and aramid fiber reinforcement for asphalt, and the aramid fiber reinforcement for asphalt is mixed with 0.8 to 3 parts by weight based on 100 parts by weight of the asphalt. It is characterized in that it is mixed and used at a temperature at which the coating layer of the aramid fiber reinforcement material for asphalt is melted.

According to the asphalt mixture and asphalt paving method including the aramid fiber reinforcement material for asphalt according to the present invention, the properties of the aramid fiber (tensile strength, toughness, heat resistance, high strength, high modulus of elasticity, etc.) are applied to asphalt by mixing aramid fiber with asphalt. It has the effect of prolonging the life of the asphalt by giving it, and it is mixed with asphalt and constructed through the installation process of asphalt without installing it as a separate process, so workability and workability are very excellent, and also coating on aramid fiber when mixed with asphalt Since the resulting viscosity and friction reducing agent reduces the viscosity of the asphalt and distributes aramid fibers evenly, a uniform reinforcing effect can be expected in all parts of the asphalt pavement, thereby improving the reliability of asphalt pavement.

1 is a photograph of an aramid fiber reinforcement for asphalt according to the present invention.
Figure 2 is a photograph showing that the aramid fiber reinforcement for asphalt according to the present invention in a twisted form.
3 is a photograph showing a state in which the coating layer of the aramid fiber reinforcement material for asphalt is melted according to the present invention.
Figure 4 is a graph showing the breaking strength characteristics of the aramid fiber reinforcement for asphalt according to the present invention.
5 is a graph showing the CT index characteristics of an aramid fiber reinforcement for asphalt according to the present invention.
6 is a graph showing the fatigue test characteristics of the aramid fiber reinforcement for asphalt according to the present invention.
7 to 12 are graphs showing the dynamic modulus test characteristics of the aramid fiber reinforcement for asphalt according to the present invention.
13 is a graph showing the plastic deformation resistance test characteristics of the aramid fiber reinforcement for asphalt according to the present invention.

In the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, a detailed description thereof will be omitted. In addition, terms to be described later are terms defined in consideration of functions in the present invention, which may vary depending on the intention or custom of users or operators. Therefore, the definition should be made based on the contents throughout this specification.

The aramid fiber reinforcement for asphalt according to the present invention is made by coating aramid short fibers with a viscosity and friction reducing agent that is a medium temperature additive.

1. Short aramid fibers.

Aramid fibers are aromatic polyamide fibers that are resistant to heat and are durable, and the amide bond -CONH combines aromatic rings such as benzene gora to form a polymer polyamide. It has excellent tensile strength, toughness, heat resistance, high strength and high modulus of elasticity.In the present invention, a bundle type of twisted fiber yarns having a length of 15 mm to 25 mm and having multiple strands (preferably 4 to 8 strands) is used, which will be described later. It is proved through tests of fatigue cracking, dynamic elasticity, and plastic deformation.

Aramid fibers are in the state of short fibers based on the final state of use, and the surface of the long fibers is coated with a medium temperature additive and then cut into short fibers of the length. After coating it with the medium temperature additive, it is possible to use both.

Aramis fiber is used in 0.8 to 3 parts by weight based on 100 parts by weight of asphalt, and if less than 0.8 parts by weight is used, the effective ingredient of aramid fiber is low and the effect is weak. If it exceeds 3 parts by weight, workability is poor or the characteristics of the asphalt mixture Can't keep it.

Preferably, the density of the aramid fibers is in the range of about 10% based on 1.42 g/cm 3, and the diameter of the bundle aramid fibers is in the range of about 10% based on 0.71 mm.

2. Mid-temperature additive.

The medium temperature additive reduces viscosity and friction to lower the viscosity so that the aramid fibers are evenly distributed on the asphalt. Mid-temperature additives are mainly composed of a mixture of polyethylene wax and vegetable wax (a variety of mixing ratios such as 1:1 by weight are possible) and reduce the viscosity of asphalt and the friction between asphalt and aggregate, so that it is the same even at a temperature of 20 degrees lower than that of low general heating asphalt. Compaction and blendability can be secured, but it is used here to improve fiber distribution.

The viscosity and friction reducing agent, which is a medium temperature additive, is coated on aramid fibers and used in the state of a coating layer, that is, mixed with asphalt. In this mixing process, the coating layer is destroyed and phase changes to a liquid phase, improving the fluidity of asphalt to make the aramid fibers uniform. It is possible to mix by distribution.

The viscosity and friction reducing agent is in the form of a powder (it is coated after melting, so the particle size of the powder is not limited) and is coated on the aramid fiber through melting.

The density of the viscosity and friction reducing agent is within 10% based on 0.98g/cm3, the melting point is 145~155℃, and the coating thickness is within 10% based on 0.19mm.

The viscosity and friction reducing agent is used in a ratio of 1: 0.9 to 1.1 based on the weight of the aramid fiber.

That is, the asphalt reinforcement material of the finally produced aramid fiber preferably has a diameter of about 10% based on 1.09mm.

A method for producing an aramid fiber reinforcement for asphalt according to the present invention is as follows.

1. Material preparation.

Twisted aramid fibers (long fiber form) as materials, and viscosity and friction reducing agents of powder as medium temperature additives are prepared, respectively.

In addition, a coating facility for coating a medium temperature additive on aramid fibers is prepared. The coating equipment is a chamber in which the medium temperature additive of the powder is accommodated (for example, a tubular melting chamber in which both sides in the longitudinal direction are opened, and an aramid fiber having an inner diameter smaller than that of the melting chamber at the outlet side of the melting chamber) Including a coating tube of the diameter through which is passed), a heating facility to melt the intermediate temperature additive contained in the chamber, a drying facility to dry the reinforcement material (long fiber form) of the aramid fiber coated with the intermediate temperature additive, cutting the reinforcing material in the form of long fibers Includes cutting equipment.

When the aramid fiber is supplied in an untwisted state, a facility for twisting the aramid fiber is further included.

2. Melting of medium temperature additives.

The viscosity and friction force reducing agent of the powder is put in the chamber, and the viscosity and friction force reducing agent is dissolved in a gel type using the heating equipment. The temperature at which the viscosity and friction reducing agent is melted is 120~130℃. That is, the melting temperature for the coating of the viscosity modifier is lower than the melting point (for example, 10 to 20% lower than the melting point), because when it is melted to the melting point, it changes to a liquid state and flows down, making it difficult to coat. The temperature at which the viscosity and frictional force reducing agent is melted varies depending on the type of viscosity and the frictional force reducing agent, and thus is not limited to the above temperature value.

3. Coating.

Aramid fibers in the form of long fibers are passed through the chamber at a speed of, for example, 3 m/mins to coat the aramid fibers with a viscosity and friction reducing agent. Specifically, the aramid fibers in the form of long fibers are coated with a liquid viscosity and friction reducing agent while passing through the melting chamber, and the coating layer is stabilized while passing through the coating tube.

The coating of the viscosity and friction force reducing agent is not limited to the above-described method, and a method of immersing the aramid fiber in a tank containing the viscosity and friction force reducing agent, and spraying or spraying a liquid viscosity and friction force reducing agent may be used.

4. Dry.

After finishing the coating, dry the aramid fiber reinforcement in the form of long fibers.

The drying temperature is 20-25℃ and the drying time is around 1 minute.

5. Cutting.

The dried aramid fiber reinforcement is cut.

The asphalt mixture containing the aramid fiber reinforcement according to the present invention is made of a mixture of asphalt, aggregate and aramid fiber reinforcement, and the mixing ratio of the aggregate is not limited to a numerical value because it is the same as the mixing ratio used in the asphalt mixture field.

Mixing methods include dry mixing and wet mixing, and wet mixing does not cause scattering of the aramid fiber reinforcement, and blendability is also superior to dry mixing.

Dry mixing is to first mix the aramid fiber reinforcement and aggregate (the mixing time varies depending on the mixing amount), and then the asphalt is mixed with this mixture, and the wet mixing is to mix the aggregate and asphalt first and then the aramid fiber reinforcement to this mixture. . In the case of the wet type, it is possible to mix the aramid fiber reinforcement in one operation, or divide the total mixing amount by the same mixing ratio and mix it in two or more operations at a regular time (for example, 15 seconds).

In both dry and wet mixing, the melting point of the viscosity and friction reducing agent is used as the mixing temperature so that the coating layer of the aramid fiber reinforcement material is melted, and thus the aramid fiber reinforcement material is mixed in the asphalt in a uniform distribution by lowering the viscosity of the asphalt.

The asphalt pavement method using an asphalt mixture containing an aramid fiber reinforcement for asphalt according to the present invention is a planarization process in which the pavement surface is flattened with a leveler-The asphalt mixture of the present invention is applied to the flattened pavement surface (base layer) to the pavement thickness. It is based on a paving process of compacting after laying, and preferably, the asphalt mixture of the present invention is mixed and used before the paving process.

<Example>

1. Materials.

Prepare the same amount of the viscosity and frictional force reducing agent of the six-stranded multi-aramid fiber (long fiber) and powder (fine powder).

2. Manufacture of aramid fiber reinforcement.

end. coating.

The viscosity and friction force reducing agent is put in a melting facility, and the heating facility is turned on to make the melting facility at a melting temperature (120 to 130° C.), and therefore, the viscosity and friction force reducing agent of the powder is phase-changed into a gel state.

In this state, the aramid fibers are passed through the melting equipment to coat the aramid fibers with a viscosity and friction reducing agent.

I. dry.

Dry the aramid fiber coated with the viscosity and friction reducing agent.

All. cut.

The dried aramid fiber is cut into a length of 19 mm (17 to 22 mm) to prepare an aramid fiber reinforcement (see FIGS. 1 to 3).

3. Characteristic test.

After mixing asphalt and aggregate (5% by weight of asphalt, 95% by weight), an asphalt specimen was prepared by mixing aramid fiber reinforcement. Asphalt specimens (LAB-dry, LAB-wet) were prepared using two methods, dry and wet.

As a comparative group for comparison with the present invention, basic (Ctrl) mixed with only asphalt and aggregate, Comparative groups 1,2 (COM-dry, COM-wet) mixed with Chinese aramid fiber reinforcement (dry, wet), UNC (non Coated yarn) was prepared.

end. Fatigue crack test.

The fatigue crack test specimen was made into a cylindrical shape of 150 (diameter) X 62 mm (height), and the sample had a porosity of 4ㅁ0.5%.

Equipment (DTS-30) was used, and the test conditions were seating load: 0.1Kn, load application: 50mm/min, test temperature: 20℃.

As shown in FIG. 4, it was confirmed that the specimen of this example had a higher breaking strength than the other comparative groups, and in particular, the wet specimen was larger.

As shown in FIG. 5, it was confirmed that the specimen of this example had a larger CT-index (fatigue crack resistance) than the other comparative groups, and that the wet specimen was also larger.

As shown in FIG. 6, it was confirmed that the specimen of this example has superior fatigue cracking properties than other comparative groups.

I. Dynamic modulus test.

The specimen for the dynamic modulus test was 150 (diameter) X 170 (height) mm, and after coring, it was 100 (diameter) X 150 (height) mm, and dried at room temperature (25° C.) for 2 days. The porosity is 7ㅁ0.5%.

3 The jig was attached to the specimen and cured for 24 hours at the test temperature (110, 4, 21, 37℃), the load frequency was 25, 10, 5, 1, 0.5, 0.1 Hz, and the load type was sine wave.

As can be seen in FIGS. 7 to 12, it was confirmed that the specimen of this example had a higher modulus of elasticity compared to the comparative groups, and eventually, the fatigue crack resistance is expected to be greater.

All. Plastic deformation test.

The sample for plastic deformation test is 100 (diameter) X 150 (height) mm, and the porosity is 7ㅁ0.5%.

The test conditions are a test temperature of 50°C, a cyclic axial load of 600 kPa, a ground pressure of 30 kPa, and a restraining pressure of 0 kPa.

As shown in FIG. 13, it was confirmed that the specimen of this example had good plastic deformation resistance compared to the comparative groups, and the uncoated aramid fiber was the worst.

Claims (6)

It is composed of asphalt, aggregate and aramid fiber reinforcement for asphalt,
The aramid fiber reinforcement for asphalt is made by forming a coating layer of a medium temperature additive on the aramid fiber, and the medium temperature additive is coated with the aramid fiber in a ratio of 1: 0.9 to 1.1 based on weight, and melted when mixed with asphalt. It is a viscosity and friction reducing agent that induces uniform mixing of the aramid fibers by reducing the viscosity of the asphalt,
It is characterized in that it is manufactured by wet mixing by mixing 0.8 to 3 parts by weight of the aramid fiber reinforcement for asphalt with respect to 100 parts by weight of the asphalt at a temperature at which the asphalt and aggregate are first mixed and then the coating layer of the aramid fiber reinforcement for asphalt is melted. Asphalt mixture containing aramid fiber reinforcement for asphalt. The asphalt mixture comprising an aramid fiber reinforcement for asphalt according to claim 1, wherein the viscosity and friction reducing agent is in a powder state and is melted at a temperature of a melting point and then coated on the aramid fiber. The aramid fiber for asphalt according to claim 1 or 2, wherein the aramid fiber reinforcement for asphalt is in the form of a short fiber cut into 17 to 22 mm after coating and drying the aramid fiber with the viscosity and friction reducing agent. Asphalt mixture containing reinforcement. delete delete A first step of flattening the paved road surface;
After the first step, using an asphalt mixture comprising an aramid fiber reinforcement for asphalt, characterized in that it comprises a second step of laying and then compacting the asphalt mixture comprising the aramid fiber reinforcement for asphalt according to claim 1 on the pavement surface. Asphalt paving method.

Images