KR101785086B1 - Warm temperature asphalt modifier and asphalt mixture using the same - Google Patents

Abstract

The present invention relates to a mesophilic asphalt modifier and an asphalt mixture using the same. More particularly, the present invention relates to a synthetic wax having a solid phase releasing property which is incompatible with any of the organic-inorganic compounds, and a synthetic wax comprising styrene and butadiene, And a mixture thereof in a solid state in a small granular state to increase the compatibility, thereby improving the durability and noise reduction characteristics as well as the compaction property by reducing the melt viscosity of the asphalt, and an asphalt mixture using the modifier asphalt modifier.

Description

Warm temperature asphalt modifier and asphalt mixture using same Asbestos modifier and asphalt mixture using same

The present invention relates to a mesophilic asphalt modifier and an asphalt mixture using the same. More particularly, the present invention relates to a synthetic wax having a solid phase releasing property which is incompatible with any of the organic-inorganic compounds, and a synthetic wax comprising styrene and butadiene, And a mixture thereof in a solid state in a small granular state to increase the compatibility, thereby improving the durability and noise reduction characteristics as well as the compaction property by reducing the melt viscosity of the asphalt, and an asphalt mixture using the modifier asphalt modifier.

The medium-temperature asphalt technology means that the additive which lowers the viscosity of the asphalt binder in the process of producing the heated asphalt mixture is added or the micro-cells are generated and dispersed in the asphalt by the foaming effect using the water or the foaming agent, To improve the mixing property of the aggregate with the asphalt binder and to improve the compaction of the asphalt mixture during the compaction operation due to the bearing action of the microcapsules contained in the mixture when the asphalt mixture is laid.

Thus, in order to increase the use of mesophase asphalt mixtures, additives such as modifiers are added to modify the mesophase asphalt mixture. Two main types of modifying are the addition of wax (hydrocarbon-based modifier) to asphalt foaming or asphalt .

At this time, the foaming is based on the principle of adding water to the asphalt and evaporating the water to form the foam on the asphalt, which tends to reduce the viscosity of the mixture and improve the adhesion.

The wax also lowers the viscosity to improve the flow of the mixture due to the lubricating effect, thereby facilitating compaction.

In particular, examples of asphalt-modified waxes include Sasobit (R) (Sasol Wax, South Africa), a microcrystalline long chain aliphatic hydrocarbon derived from coal gasification using the Fischer-Tropsch (FT) process, Based low molecular weight esterified waxes and higher molecular weight hydrocarbons such as Asphaltan B (R) (Romonta GmbH, Amstorf, Germany).

Typically, in applications to mesophilic asphalt mixtures, the wax modifier constitutes about 2 to 4 weight percent of the mixture.

Nonetheless, mechanical properties similar to high temperature asphalt mixtures, such as degree of compaction, adhesion and stripping, resistance to fatigue, rutting, cracking, There is a continuing need for a modifier for mesophase asphalt mixtures which can enhance resistance to oxidation and the like.

Korea No. 10-2009-0129546 (Dec. 17, 2009), 'A composition of mesophilic asphalt modifier or mesophilic modified asphalt for the production of mesophilic asphalt concrete mixture' Korea Patent Registration No. 10-1233006 (Feb. 23, 2013), 'Polyphosphate modifier for application to mesophilic asphalt' Korean Patent Registration No. 10-1166155 (Jul. 10, 2012), 'Middle Temperature Asphalt Modification Additive and Middle Temperature Asphalt Concrete Mixture' A modifier composition for a low-carbon mesothermal asphalt mixture expressing a public grade PG 64-22 or PG 70-22 and a method for preparing an asphalt mixture using the same, Korean Patent Laid-Open No. 10-2012-0115337 (Oct. 17, 2012), "Polymer-Modified Asphalt Having Crosslinking Agent and Manufacturing Method"

SUMMARY OF THE INVENTION Accordingly, the present invention has been made to solve the above-mentioned problems occurring in the prior art, and an object of the present invention is to provide a synthetic wax having solid phase releasing characteristics that are not compatible with any of the organic-inorganic compounds and a synthetic wax having styrene / butadiene- Is mixed with a solid phase in a small pellet state rather than by solution polymerization to increase the compatibility, thereby improving the durability and noise reduction characteristic as well as the compaction property by reducing the melt viscosity of the asphalt, and an asphalt mixture using the modifier asphalt modifier. There is a main purpose.

In order to achieve the above-mentioned object, the present invention provides a process for producing a polyester resin having a molecular weight of 2,000-5,500 Da, a melting point of 120-140 占 폚, a viscosity of 350 CP-800CP based on 130 占 폚, a density of 0.9-0.95, an Acid Number (mmgKOH / g) 59 wt% of the specified FT wax (Fischer-Tropsch Wax); 33% by weight of styrene-butadiene-styrene (SBS), and a powdery SBR (Styrene-Butadiene Rubber) having a residual powder of 50mesh.

Also, the present invention relates to an asphalt mixture comprising an AP-5 asphalt binder, wherein 3.0 to 3.5 parts by weight of the moderate asphalt modifier is added to the asphalt mixture based on 100 parts by weight of the AP-5 asphalt binder, Lt; RTI ID = 0.0 > PG 64-22. ≪ / RTI >

Also, the present invention relates to an asphalt mixture comprising an AP-5 asphalt binder, wherein 4.0 to 4.5 parts by weight of the moderate asphalt modifier is added to the asphalt mixture based on 100 parts by weight of the AP-5 asphalt binder, Lt; RTI ID = 0.0 > PG 70-22. ≪ / RTI >

Also, the present invention relates to an asphalt mixture comprising an AP-5 asphalt binder, wherein 4.6-5.0 parts by weight of the moderate asphalt modifier is added to the asphalt mixture based on 100 parts by weight of the AP-5 asphalt binder, Gt; asphalt < / RTI > modifier, characterized in that the asphalt mixture is made to be PG 76-22.

Also, the present invention relates to an asphalt mixture comprising an AP-5 asphalt binder, wherein 5.1-5.5 parts by weight of the moderate asphalt modifier is added to the asphalt mixture based on 100 parts by weight of the AP-5 asphalt binder, Wherein the asphalt modifier is a PG 82-22.

According to the present invention, a synthetic wax having a solid phase releasing characteristic that is not compatible with any organic-inorganic compound and a synthetic rubber polymer of styrene and butadiene are mixed in a solid state in a small pellet state instead of solution polymerization to increase compatibility Thereby decreasing the melt viscosity of the asphalt and improving the durability and noise reduction characteristics as well as compaction.

Accordingly, it is possible to obtain an effect of lowering the production temperature while increasing the compatibility level of AP-5 from PG 64-22 to the maximum PG 82-22 according to the addition amount of the modifier according to the present invention.

Hereinafter, preferred embodiments according to the present invention will be described in detail.

Before describing the present invention, the following specific structural or functional descriptions are merely illustrative for the purpose of describing an embodiment according to the concept of the present invention, and embodiments according to the concept of the present invention may be embodied in various forms, And should not be construed as limited to the embodiments described herein.

In addition, it should be understood that the embodiments according to the concept of the present invention include various modifications, equivalents, and alternatives included in the spirit and technical scope of the present invention, .

The moderate asphalt modifier according to the present invention is composed of 59 weight% of F-T wax (Fischer-Tropsch wax), 33 weight% of styrene-butadiene-styrene (SBS) and styrene-butadiene rubber (SBR).

At this time, the wax used as a moderate temperature additive should have a solid phase release property which is incompatible with any oil-inorganic compound.

That is, when the wax is present as a molten phase in the straight asphalt, it is possible to reduce the melt viscosity of the asphalt by reducing the adhesive stress between the straight asphalt like moisture of the foamed asphalt.

Thus, since such waxes have typical thermoplastic physical-chemical properties, phase changes to solid at a temperature lower than the melting point. In the case of the asphalt binder modified with wax, the melting point of the asphalt is increased below the melting point of the wax, As the hardness increases, the plastic deformation resistance of the asphalt is improved.

Therefore, the selection point of the wax to be considered as priority is the melting point and the melt viscosity. In the basic choice of wax, when the wax has a melting point lower than the common temperature of the asphalt concrete pavement, it acts to increase the fluidity even under the common condition. Therefore, the wax having a melting point of 80 ° C. or more, which is the required temperature of common asphalt, Should be selected.

For this reason, the present invention utilizes F-T wax, which is a polymer substance composed of a minute and long aliphatic hydrocarbon chain.

However, it should not be possible to use simple FT waxes in order to maintain the characteristics of low temperature asphalt, increase of compaction, reduction of noise and improvement of low temperature elasticity, and the molecular weight, melting point, viscosity, density and acid value (mmgKOH / g) .

In other words, only the specific F-T wax described below can satisfy the modifier properties according to the present invention.

To this end, the F-T wax according to the present invention should have a melting point higher than 115 ° C which is the temperature of the mesophase asphalt binder. Therefore, the melting point of the F-T wax according to the present invention should be 120-140 ° C. The reason for this limitation is to prevent the material separation from occurring even if the F-T wax is dispersed in the medium-temperature asphalt binder molecules and reheated.

Further, in case of molecular weight, it should be kept high in order to secure sufficient elasticity even at a low temperature. Considering that the molecular weight of general petroleum wax is 400-600 Da, it is maintained 50 times or more, preferably 2,000-5,500 Da This is good.

In addition, viscosity, density and acidity should maintain a viscosity of 350 CP-800 CP at 130 ° C in order to maintain a low penetration, maintain a density of 0.9-0.95 and maintain an acid value of 16.

In summary, the FT wax added as a modifier according to the present invention has a molecular weight of 2,000-5,500 Da, a melting point of 120-140 ° C, a viscosity of 350 CP-800CP based on 130 ° C, a density of 0.9-0.95, an acid number (mmg KOH / g) Should be used.

As a result, the phase change from solid to solid at a temperature lower than the melting point of the mesophase asphalt increases the hardness of the asphalt, thereby increasing the resistance to plastic deformation of the asphalt.

In addition, when the content of the FT wax exceeds 59 wt%, the performance of the SBS is decreased, which may result in lowering the temperature reversible cross-linking of the SBS molecules, thereby lowering the elasticity. By weight, and less than 59% by weight, especially less than 55% by weight, can not be added to the asphalt modifying property, it should be added in an amount of 59% by weight, preferably 55-59% by weight.

On the other hand, the styrene-butadiene-styrene (SBS) is a block-shaped polymer having a polystyrene moiety attached to a central polybutadiene moiety. At low temperatures, the polystyrene moiety of the polymer chains in the asphalt binder structure is aggregated to form domains, When heat is applied, it is reduced again to styrene molecule, so it dissolves well in asphalt.

In particular, the SBS forms a network between the SBS polymer chain and the asphalt molecule to absorb and relieve the stress transmitted to the inside of the asphalt. At the high temperature, the SBS serves as an elastic body such as a spring, It is responsible for the restoration function.

In the present invention, it should be added in the range of 33 wt%, more preferably 30-33 wt% for stirring, stress absorption and buffering. When it exceeds 33 wt%, the elasticity is improved but the ability to agitate with the asphalt binder If it is added in an amount of less than 30% by weight, it is difficult to obtain a desired elastic force in mesophilic asphalt. Therefore, it should be limited to the above range.

The above-mentioned SBR (Styrene-Butadiene Rubber) is a synthetic rubbery rubbery material comprising styrene and butadiene, and has good adhesion, abrasion resistance and aging stability. Typical examples thereof include latex.

The addition of SBR to mesophase asphalt has the advantage of reducing penetration, increasing softening point, increasing elongation, increasing viscosity at high temperature, and greatly improving temperature sensitivity.

However, since conventional SBR is in a solution-polymerized state, it is difficult to be pulverized. Therefore, it has been used in an emulsion state called so-called latex by adjusting the concentration in a solution polymerization state.

Therefore, when SBR was added to moderate asphalt reforming, it was very difficult to formulate due to the problem of material separation and steam generation when high temperature asphalt was added.

Accordingly, in the present invention, SBR is pulverized to a small size at a very low temperature and pulverized into small granules of about 50 mesh, thereby enhancing compatibility with other additives, and solving not only material separation problems but also steam generation problems .

Here, the technique of pulverizing the SBR with a small pellet at a cryogenic temperature is based on a technique of pulverizing a waste tire at an ultra-low temperature. It is preferable to keep the particle size range because the compounding characteristics are the most excellent when the particle size is 50mesh Do.

According to the present invention, it is possible to reduce the production temperature while increasing the compatibility level of AP-5 from PG 64-22 to the maximum PG 82-22 according to the addition amount of the modifier according to the present invention.

In addition, in the present invention, attapulgite in a fiber state and polybutene having excellent resistance to ultraviolet ray resistance and discoloration resistance can be further added to enhance heat resistance and elasticity.

That is, attapulgite and 5-10 parts by weight of polybutene may be further added to the mesophilic asphalt modifier based on 100 parts by weight of the F-T wax.

In this case, in order to strengthen the elasticity and increase the heat resistance due to the improvement of the elongation due to the fibrous structure, at least 15 to 20 parts by weight of FT wax may be added based on 100 parts by weight of the FT wax. have.

In order to enhance the modifying characteristics of the medium-temperature asbestos U by increasing the ultraviolet rays, heat and chemical stability, preventing the deformation of the SBR, maintaining the high viscosity, and securing the lubricity by suppressing the carbon residue material at high temperature, 5 to 10 parts by weight based on 100 parts by weight of the composition.

In order to improve the apparent volume change of the asphalt binder such as foamed asphalt, and to improve the workability, dimensional stability, and sound absorption property, mesophilic asphalt is mixed with a medium temperature asphalt modifier in a weight ratio of dichloroethane and methylene chloride of 1: 2.5-3.5 parts by weight based on 100 parts by weight of the wax may be further added.

The mixture is foamed by stirring the aggregate and the asphalt binder at a moderate temperature, especially around 130 캜, and imparts properties similar to foamed asphalt to mesophase asphalt.

Meanwhile, the present invention constitutes an asphalt mixture using the mesophilic asphalt modifier, wherein the asphalt binder of the asphalt mixture uses AP-5.

The asphalt mixture is prepared by adding 3.0-5.5 parts by weight of the moderate asphalt modifier based on 100 parts by weight of the AP-5 asphalt binder.

For example, 3.0-3.5 parts by weight of the moderate asphalt modifier can be added to make a modified asphalt mixture of AP-5 having a publicity grade PG 64-22.

In addition, 4.0-4.5 parts by weight of the moderate asphalt modifier can be added to make a modified asphalt mixture of AP-5 having a compatibility grade PG 70-22.

In addition, by adding 4.6-5.0 parts by weight of the moderate asphalt modifier, a modified asphalt mixture of the public performance grade PG 76-22 of AP-5 can be made.

In addition, by adding 5.1-5.5 parts by weight of the moderate asphalt modifier, a modified asphalt mixture of AP-5 having the publicity class PG 82-22 can be prepared.

As described above, the present invention has an advantage that the production temperature can be reduced while raising the compatibility rating of AP-5 from PG 64-22 to the maximum PG 82-22 according to the amount of moderate asphalt modifier added.

The asphalt mixture may further contain 5.5-8.5 parts by weight of granule type cellulose as the basis of 100 parts by weight of the AP-5 asphalt binder. The granule type cellulose may have a binding force between the aggregate and the asphalt binder Thereby increasing the tensile strength of the asphalt mixture and thereby suppressing the plastic deformation of the asphalt.

Hereinafter, examples will be described.

[Example]

Samples of the same size, including modifiers, were prepared to confirm the characteristics of the asphalt mixture using the mesophase asphalt modifier according to the present invention.

For comparison, the conventional material was made of AP-5, which is a general asphalt mixture that does not contain a modifier; Inventive material 1 was a mixture of 59 weight% of FT wax specified with a molecular weight of 2,500 Da, a melting point of 130 占 폚, a density of 350 CP based on a viscosity of 130 占 폚, a density of 0.9 and an acid number (mmgKOH / g) of 16 and a styrene-butadiene- By weight, based on 100 parts by weight of the AP-5 asphalt binder, of a moderate asphalt modifier consisting of 8% by weight of powdered SBR (Styrene-Butadiene Rubber) having a degree of powder of 33% by weight and 50mesh; Inventive material 2 was prepared by adding 17 parts by weight of attapulgite and 7 parts by weight of polybutene to a moderate asphalt modifier based on 100 parts by weight of the F-T wax, Inventive material 3 was prepared by adding 3.0 parts by weight of a mixture of decolloethane and methylene chloride at a weight ratio of 1: 1, based on 100 parts by weight of the F-T wax, Inventive material 4 was prepared by further adding 6.5 parts by weight of granule type cellulosic fiber based on 100 parts by weight of an AP-5 asphalt binder to an asphalt mixture containing a modifier such as Inventive Material 1.

At this time, the compaction temperature of each sample was 135 ° C for conventional materials and 130 ° C for invention materials 1-4.

The Marshall stability and flow values of each sample were measured as shown in Table 1.

division Conventional material Inventory 1 Inventory 2 Inventory 3 Invention 4 Stability 11,463 13,144 13,147 13,146 13,145 Flow value 31 35 34 35 35

In addition, the wheel tracking test (KS F 2374) was performed to evaluate the resistance to plastic deformation by repeated wheel loads. The load was 686 N, the ground pressure was 628, and the test temperature was 60 ° C.

The test results are shown by the dynamic stability obtained from the wheel tracking test and the final settlement depth. As shown in Table 2, the inventive materials were found to maintain dynamic stability of 4 times or more than the conventional material and a lower settling depth.

division Dynamic Stability (DS), times / mm Final settlement depth (mm) Conventional material 1,501 3.45 Inventory 1 5,120 2.19 Inventory 2 5,127 2.01 Inventory 3 5,123 2.11 Invention 4 5,122 2.10

In addition, to evaluate the crack resistance at low temperature, a flexural test was performed at -10 ° C and 20 ° C.

The specimens were placed in a low-temperature chamber at -10 ° C and 20 ° C, cured for at least 6 hours, and loaded at the center of the specimen at a loading speed of 50 mm / min.

Then, the flexural strength and the deformation amount at the time of fracture were measured in the load deformation curve obtained from the test.

Also, the toughness, which is widely used for evaluating the crack resistance, was calculated.

As a result of the test, the flexural strength decreased with increasing temperature, and strain and toughness increased.

In addition, the tensile strength was measured from an indirect tensile strength test.

The tensile strengths of the conventional and inventive materials 1, 2, 3 and 4 were 3.07 MPa, 4.03 MPa, 4.12 MPa, 4.11 MPa, 4.08 MPa.

Further, to determine the penetration degree, each sample was subjected to 60 g of a saline solution of 200 g according to ASTM D5-06 at 4.4 캜.

As a result, the penetration of the inventive materials 1, 2, 3, and 4 was much smaller than that of the conventional material.

Claims (5)

59 wt% of FT wax (Fischer-Tropsch Wax) having a molecular weight of 2,000-5,500 Da, a melting point of 120-140 캜, a viscosity of 350 CP-800 CP based on 130 캜, a density of 0.9-0.95 and an acid number (mmg KOH / g) Wow; 33% by weight of styrene-butadiene-styrene (SBS), and a powdery SBR (Styrene-Butadiene Rubber) having a residual powder of 50 mesh,
The moderate asphalt modifier may be modified to improve the modifying properties of the asphalt through heat resistance, thermal and chemical stability,
15 to 20 parts by weight of attapulgite, 5 to 10 parts by weight of polybutene, and a mixture 2.5: 1 by weight of dichloroethane and methylene chloride in a weight ratio of 1: 1, based on 100 parts by weight of the FT wax -3.5 parts by weight of the modified epoxy resin is further added.
An asphalt mixture comprising an AP-5 asphalt binder,
Wherein the asphalt mixture is added with 3.0-3.5 parts by weight of the moderate asphalt modifier according to claim 1 based on 100 parts by weight of the AP-5 asphalt binder so that the compatibility grade of AP-5 is PG 64-22. Asphalt mixture with modifier.
An asphalt mixture comprising an AP-5 asphalt binder,
Wherein the asphalt mixture is added with 4.0 to 4.5 parts by weight of the moderate asphalt modifier according to claim 1 based on 100 parts by weight of the AP-5 asphalt binder so that the compatibility rating of AP-5 is PG 70-22. Asphalt mixture with modifier.
An asphalt mixture comprising an AP-5 asphalt binder,
Wherein the asphalt mixture is added with 4.6-5.0 parts by weight of the moderate asphalt modifier according to claim 1 based on 100 parts by weight of the AP-5 asphalt binder so that the compatibility rating of AP-5 is PG 76-22. Asphalt mixture with modifier.
An asphalt mixture comprising an AP-5 asphalt binder,
Wherein the asphalt mixture contains 5.1-5.5 parts by weight of the moderate asphalt modifier according to claim 1 based on 100 parts by weight of the AP-5 asphalt binder, and the co-grade of AP-5 is PG 82-22. Asphalt mixture with modifier.