KR100949380B1 - Additive composition of warm-mix asphalt for low carbon dioxide green growth - Google Patents

Abstract

PURPOSE: An additive composition of warm-mix asphalt for low carbon dioxide generation is provided to lower the mixing and rolling temperature of a middle temperature asphalt and to improve high-temperature plasticity deformation resistance by using polyethylene-based wax and vegetable wax as an asphalt additive. CONSTITUTION: An additive composition of warm-mix asphalt for low carbon dioxide generation comprises polyethylene-based wax and vegetable wax. The low carbon additive comprises polyethylene-based wax and vegetable wax in a weight ratio of 20:1 - 1:2. The vegetable wax is modified palm wax and is prepared by performing hydrogenation of palm oil extracted from palm nuts to make palm wax, and then fusing NaOH and stearic acid in the palm wax.

Description

ADDITIVE COMPOSITION OF WARM-MIX ASPHALT FOR LOW CARBON DIOXIDE GREEN GROWTH}

The present invention relates to a low carbon additive for mesophilic asphalt mixtures. The present invention uses a polyethylene wax and a vegetable wax to improve the resistance to high temperature plastic deformation while reducing the mixing and compacting temperature of the middle temperature asphalt mixture, and the middle temperature asphalt mixture that can suppress the low temperature property degradation caused by using the polyethylene wax. It relates to a low carbon additive for.

In recent years, with the growing interest in the environment in pursuit of green growth, the reduction of carbon dioxide emission to prevent global warming has become an international concern. In addition to preventing global warming, this reduction in carbon dioxide emissions is drawing attention as it can create a commercial value of carbon credits.

More than 400 million tons of carbon credits were traded at the European Climate Exchange in Amsterdam, the world's largest in the year, and more than 50% of carbon credits were traded each year, increasing interest in carbon credits. have.

Asphalt concrete (asphalt mixture, asphalt concrete) pavement technology has been actively studied to reduce carbon dioxide emission in accordance with this atmosphere.

Among them, the most attention in terms of practicality and scale is the field of road pavement technology using a low carbon type asphalt mixture that can lower the mixing and compaction temperature during asphalt concrete pavement construction.

Typically, the asphalt mixture is prepared by adding asphalt, aggregate, filler, etc. to an asphalt mixing plant, and then heating and mixing these materials.

The asphalt mixture is manufactured through a process of heating to a high temperature of 160 ~ 200 ℃, the process of cooling to room temperature in the process of laying and compaction on the road.

The reason why the high temperature heating process is required for the production of asphalt mixture is that it is necessary to liquefy asphalt (Asphalt) in order for the asphalt to act as a binder of the aggregate.

Asphalt is mainly used for paving roads, and petroleum-based asphalt is mainly petroleum-based asphalt. (Straight Asphalt is mainly used. Such straight asphalt is commonly referred to as an asphalt binder.) Are manufactured.

As a result, asphalt (Asphalt) is heated and liquefied, and the adhesion of the liquefied asphalt is used for bonding aggregates.

Thus, the asphalt mixture used for pavement is made of a hot asphalt mixture (Hot-Mix Asphalt Mixture, simply referred to as 'HMA').

Therefore, a lot of energy is required to heat the asphalt mixture to a high temperature in order to manufacture the asphalt mixture, there is a problem that the emissions of harmful gases such as carbon dioxide (CO ₂ ) increases during the construction of the asphalt mixture.

In addition, the high-temperature asphalt mixture laid and compacted during pavement has a problem that workers are exposed to the risk of safety accidents along with the problem that the traffic opening time is delayed by the time required to cool near room temperature.

Recently, in order to solve these problems, Warm-Mix Asphalt Mixture (WMA), which can be mixed and compacted at a lower temperature than conventional heated asphalt mixture (HMA) by lowering the temperature sensitivity of the asphalt (called temperature sensitivity) Research is being actively conducted.

In other words, research is being actively conducted to reduce carbon dioxide emissions due to asphalt mixture pavement by lowering the mixing and compaction temperature of asphalt and aggregate.

Road paving technology using such a medium temperature asphalt mixture (WMA) is 110 ~ 150 ℃ temperature 30 ~ 40 ℃ lower than the temperature required to prepare the asphalt mixture compared to the conventional road paving technology by heated asphalt mixture (HMA) Since asphalt mixtures can be prepared from

(1) It can suppress the generation of various harmful gases in the production and construction of asphalt mixtures,

(2) It can reduce about 30% of petroleum fuel, which is the main culprit of greenhouse gas, in the production of asphalt mixture,

(3) Fast opening of traffic is possible by shortening curing time after construction of asphalt mixture,

(4) It has many advantages, such as ensuring no worker's safety because no harmful vapor or odor occurs at construction site.

The core mechanism of this medium-temperature asphalt mixture (WMA) paving technology is to improve the fluidity of asphalt, that is, the optimum viscosity of asphalt, which is a binder of aggregate, is expressed at a temperature as low as possible than the heated asphalt mixture (HMA), and also the optimum compaction degree. (Compaction Rate) It is a technique of lowering the viscosity to be expressed at a low temperature.

This viscosity-lowering technique was first introduced in 1956 by Dr. Ladis H.Csanyl of the University of Iowa, USA, by injecting steam into the asphalt to form a foamed asphalt with moisture and air in the asphalt to lower the viscosity by reducing the stress inside the asphalt. I introduced the technology.

Recently, since 2000, Europe has been injecting water instead of steam and forced emulsification of asphalt to lower the viscosity of asphalt, and zeolite instead of water. It has been developed to produce a foam-medium asphalt mixture (Foam-WMA), which emulsifies the asphalt by discharging water moistened in the asphalt.

Meanwhile, since 2005, a medium temperature asphalt mixture (WMA) using sasobit wax manufactured by waxes, ie, Fischer Tropsch Synthesis, has been reported at the National Center for Asphalt Technology (NCAT).

Normally, wax is a compound of several hundreds of molecular weight which is solid at room temperature and turns into a fluid when the temperature is increased. Such wax is added to asphalt to drastically reduce the viscosity of the asphalt above the melting temperature of the wax, and to solidify below the melting temperature. As a result, it is used as an additive to enhance the efficacy of mesophilic asphalt mixtures.

The polyethylene wax may be a wax produced as a by-product during the manufacture or processing of polyethylene. In particular, the sasobit wax may be a Fischer Tropsch Synthesis method among polyethylene waxes. Polyethylene wax produced.

There are three methods for producing such a polyethylene wax.

(1) obtaining polyethylene wax from low molecular weight by-products from the process of making polyethylene resin, or

(2) producing a polyethylene wax by thermal decomposition of the polyethylene resin to reduce the molecular weight;

(3) Prepared by Fischer Tropsch synthesis.

In general, it is known that the physical properties of polyethylene waxes are determined by the linearity and molecular weight of the main chain in the chemical structure.

In other words, the greater the linearity of the main chain of polyethylene wax, the higher the molecular regularity, the higher the crystallinity, the higher the physical properties such as melting point and hardness, and the higher the molecular weight of the polyethylene wax, the higher the melt viscosity and physical properties. It is known that it can be done.

As a result, polyethylene waxes obtained by pyrolysis of by-products or polyethylene resins in the process of making polyethylene resins have a lower melt linearity compared to polyethylene waxes produced by the Fischer Ropsch process to improve physical properties. The use as an additive in asphalt mixtures (WMA) has been limited.

However, Sasobit wax manufactured by Fischer Tropsch Synthesis process has more than 90% of its normal alkane structure, so compared to waxes produced by other methods. Has a long linear structure (Long Chin Aliphatic Hydrocarbon).

Therefore, Sasobit wax shows better physical properties as a low carbon additive than other polyethylene waxes.

Thus, Sasobit wax prepared by Fischer Tropsch Synthesis process has been used as a very effective low carbon additive in mesophilic asphalt mixtures.

However, polyethylene waxes such as Sasobit wax have very high temperature characteristics such as resistance to plastic deformation (Rutting, Permanent Deformation), while the stiffness increases and the stiffness change rate of asphalt after prolonged aging. As m-value was decreased, it was found that the low-temperature properties of asphalt generally decreased as the elasticity of asphalt decreased.

Accordingly, the conventional polyethylene wax is a low temperature crack of the asphalt mixture, which occurs mainly in winter, and is generated from the top of the pavement layer due to an unbalance of the temperature distribution of the pavement layer due to the asphalt mixture. There is a problem that there is a high possibility of acting as a factor causing the lateral characteristics of the pavement), there is a need to improve the problem of low temperature properties in the medium temperature asphalt mixture (WMA) using polyethylene wax as an additive.

The present invention, in order to solve the above-mentioned problems, lowering the low temperature properties of the medium temperature asphalt mixture using polyethylene wax prepared by Fischer Ropsch method, such as Sasobit wax, as well as polyethylene wax prepared by other methods We propose a new low carbon additive for medium temperature asphalt mixture that can prevent the phenomenon.

Thus, it is possible to effectively lower the mixing and compaction temperature of the medium-temperature asphalt mixture (WMA) to reduce the heating energy required when paving the road using the asphalt mixture to reduce the carbon dioxide emissions and thereby lay the foundation for green growth do.

In order to achieve the above technical problem, the present invention provides a low carbon additive for a medium temperature asphalt mixture prepared to reduce carbon dioxide emissions, and the low carbon additive has a predetermined weight of vegetable wax in the polyethylene wax added to the medium temperature asphalt mixture (WMA). Submixing.

The low carbon additive for mesophilic asphalt mixture according to the present invention is preferably drawn by mixing a polyethylene wax and a vegetable wax in a weight ratio of 20: 1 to 1: 2, the low carbon additive further contains an oil, The weight ratio of the polyethylene wax and the oil was 20: 1 to 2: 1.

Also preferably, the polyethylene wax has a melting point of 95 ° C to 125 ° C and a melting point of 140 ° C of 400 cPs (Centipoise) or less.

Also preferably, the vegetable wax is a palm wax prepared from palm oil extracted from coconut or modified palm wax in which the palm wax is fused with sodium hydroxide (NaOH) and stearic acid (CH ₃ (CH ₂ ) ₁₆ COOH). At least one.

Preferably, in the case of the modified palm wax, the weight ratio of the palm wax and the sodium hydroxide (NaOH) is 100: 3.5 to 100: 4.0, the weight ratio of the palm wax and the stearic acid is 100: 16.0 to 100: 27.5.

Also preferably, the palm wax has a melting point of 55 ° C to 65 ° C and the modified palm wax has a melting point of 80 ° C to 110 ° C.

Also preferably, the oil has a Kinematic Viscosity of 40 ° C of 20 to 300 cSt (centistokes, mm 2 / s).

According to the present invention, it is possible to produce an effective medium temperature asphalt mixture (WMA) by using a polyethylene wax prepared by other methods as well as a polyethylene wax manufactured by the conventional Fischer rope shoe method.

In addition, according to the present invention, by the addition of the vegetable wax in the production of polyethylene wax it is possible to prevent the low temperature property degradation phenomenon of the medium temperature asphalt mixture (WMA) using the polyethylene wax.

In addition, according to the present invention, if the medium-temperature asphalt mixture is prepared using the additive including the polyethylene wax and the vegetable wax, the melting time is not long, as well as the premix type as well as the plant mix type can produce asphalt in a short time The heating energy required for the manufacture of asphalt mixtures can be reduced, significantly reducing the amount of carbon dioxide that is the main culprit of global warming.

Furthermore, it is possible to perform asphalt concrete pavement construction by asphalt mixture while suppressing generation of various harmful gases generated during construction and installation of asphalt mixture.

Hereinafter, the low-carbon additive for mesophilic asphalt mixture according to the present invention will be described in detail.

The present invention is used in the medium temperature asphalt mixture (WMA) prepared by mixing the asphalt, additives, aggregates, etc. to lower the mixing and compaction temperature of the heated asphalt mixture (HMA), and added to the asphalt used in the medium temperature asphalt mixture To a low carbon additive.

In this case, the low carbon additive is used to modify physical properties of asphalt, and a polyethylene wax by Fischer Tropsch Synthesis is basically used.

 The production of medium temperature asphalt mixture (WMA) using such polyethylene wax can ensure the required fluidity when mixing aggregate and asphalt or compaction of medium temperature asphalt mixture, which not only lowers the working temperature of the asphalt but also improves the high temperature properties. It becomes possible.

In this case, the polyethylene wax according to the present invention has a melting point of 95 ° C to 125 ° C and a melt viscosity of 140 ° C or less of 400 cPs (Centipoise).

If the melting point of the polyethylene wax is lower than 95 ℃, the stiffness of the asphalt may be weakened when mixed with asphalt, and if the melting temperature is higher than 125 ℃ may not be a sufficient dissolution in the intermediate temperature mixture manufacturing step may be a problem. When the melt viscosity at 140 ° C. is higher than 400 cPs, the viscosity of the asphalt is so high that the neutralization of the asphalt mixture cannot be achieved.

On the other hand, if only the polyethylene-based wax having a long linear structure (Long Chin Aliphatic Hydrocarbon) manufactured by the Fischer Rope shoe method to obtain the performance improvement by the medium temperature asphalt mixture as described above, not only limited to the wax selection Low temperature cracks result in lowered physical properties.

Therefore, it is necessary to add another material in order to remove the limitation of the polyethylene-based wax and to prevent the low temperature properties while maintaining the high temperature characteristics.

Accordingly, the present invention adds a vegetable wax as a constituent of the additive for a moderate temperature asphalt mixture.

In other words, by using a low carbon additive containing a polyethylene wax and a vegetable wax to prepare a medium-temperature asphalt mixture (asphalt concrete) to prevent the lowering of physical properties.

At this time, the vegetable wax constituting the additive for the warm asphalt mixture is to be contained in a weight ratio of 20: 1 to 1: 2 of the polyethylene-based and vegetable wax, but preferably 5: 1 to 1: 2.

For example, the vegetable wax is preferably 5 to 200 parts by weight, preferably 20 to 200 parts by weight based on 100 parts by weight of the polyethylene wax.

The reason is that when the weight of the vegetable wax is less than 5 parts by weight, it is difficult to improve the low temperature properties of the medium temperature asphalt mixture (WMA), and when it exceeds 200 parts by weight, the high temperature properties of the medium temperature asphalt mixture (WMA) are deteriorated.

Since the vegetable wax is used for improving the low temperature properties of the medium-temperature asphalt mixture (WMA), the vegetable wax may be a vegetable wax generally used in the art, but the palm wax obtained from the vegetable palm oil extracted from the coconut is obtained through a hydrogenation process. It is preferable that it is a wax.

The melting temperature of the palm wax obtained through the hydrogenation process is 55 ~ 65 ℃.

On the other hand, the palm wax has a low melting point may have a limited effect of improving physical properties when mixed with asphalt. Therefore, in order to increase the melting point of palm wax, it is preferable to use palm wax modified with sodium hydroxide (NaOH) and stearic acid (CH ₃ (CH ₂ ) ₁₆ COOH).

The method for reforming the palm wax will be described in more detail. First, palm wax is added to a reactor to which a stirrer is maintained at 200 ° C. to melt the palm wax.

After melting the palm wax, sodium hydroxide (NaOH) is added 3.5 ~ 4.0 parts by weight to 100 parts by weight of palm wax and stirred for 30 minutes, the following chemical reaction proceeds to produce fatty acids (RCOOH).

Here, R1, R2 and R3 are alkyl groups having 12 to 16 carbons.

The produced fatty acid is subjected to a secondary chemical reaction with sodium hydroxide to form a sodium salt having a high melting point.

Here, R1, R2 and R3 are alkyl groups having 12 to 16 carbons.

In order to further increase the melting point of the modified palm wax, 16.0 to 27.5 parts by weight of stearic acid is added to 100 parts by weight of palm wax, and then stirred for about 2 hours. Thus, stearic acid reacts with sodium hydroxide to produce sodium stearic acid.

Where R4 is stearin.

As a result of the modification, a modified palm wax at a melting point of 80 to 110 ° C. in which sodium salt and unreacted palm wax were mixed as follows is finally produced.

Here, R1, R2 and R3 are alkyl groups having 12 to 16 carbons, and R4 is stearin.

When producing the low carbon additive, the palm wax and the modified palm wax may be used alone or in combination.

On the other hand, it is preferable to further add oil to the low carbon additive in order to further lower the viscosity of the asphalt mixture to achieve mesothermalization.

The oils to be added are paraffinic and naphtanic oils having a kinematic viscosity at 40 ° C. of 20 to 300 cSt, and preferably 5 to 50 parts by weight based on 100 parts by weight of polyethylene wax.

If the oil content is more than 50 parts by weight, the viscosity of the asphalt mixture is lowered, but the high temperature properties of the asphalt mixture are worse, and if the oil content is less than 5 parts by weight, the effect of reducing the viscosity of the asphalt mixture is not great.

Hereinafter, the present invention will be described in more detail based on experimental examples. However, the following experiments are merely illustrative of the present invention, and the scope of the present invention is not limited to the following experimental examples.

Experimental Example

(1) Experimental material

AP: Asphalt with 60 Penetration Grade 60 to 80 Penetration

PE-M: polyethylene wax with melting point 114 ℃, 140 ℃ viscosity 200cps and specific gravity 0.93

PE-H: polyethylene wax with melting point 115 ℃, 140 ℃ viscosity 800cps and specific gravity 0.93

Sasobit: Polyethylene wax from Sasol with melting point 112 ℃ and 140 ℃ viscosity 40cps (trade name sasobit)

Palm: Palm wax extracted from coconut with melting point of 60 ℃ and viscosity of 6 ℃

M-palm: A modified palm wax having a melting point of 100 ° C. and a viscosity of 15 cps at 140 ° C. obtained by reacting with palm wax 76.2%, sodium hydroxide 3.8% and stearic acid 20.0%.

Oil: Paraffinic oil with 40 ℃ kinematic viscosity of 100 cSt

(2) Preparation of Low Carbon Additives for Medium Temperature Asphalt Mixtures

The low carbon additive was prepared by adding about 300 g of polyethylene wax, palm wax, oil, etc. to a 1L reactor, heating and melting at 180 ° C., followed by melt mixing for 20 minutes with a stirrer. The melt-mixed additive was dropped into 3 L of cooling water and cooled to obtain an additive having a size of about 1 to 2 mm.

The composition ratios of the examples and comparative examples low carbon additive thus prepared are shown in [Table 1] and [Table 2]. The following tables are shown based on PHR (PER HUNDRED RESIN).

Unit (phr) Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 PE-M 100 100 100 100 100 100 Palm 20 60 200 60 30 5 M-palm - - - - 30 - oil - - - 30 - -

Unit (phr) Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 PE-M 100 100 - - - - PE-H - - 100 100 100 - Sasobit - - - - - 100 Palm - 250 - 250 60 - M-palm - - - - - - oil - - - - 70 -

Looking at the characteristics of Comparative Examples 1 to 6 prepared as described above are as shown in Table 3 below.

division unit Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Softening point ℃ 120 60 132 66 65 123 Viscosity (140 ℃) cPs 140 32 210 48 52 55 Trespassing 0.1mm 0.1 20.0 0.1 15.0 17.3 0.1 density g / cm 3 0.93 0.93 0.94 0.94 0.94 0.94

(3) Manufacture of moderately warmed asphalt (asphalt mixed with low carbon additive of the present invention)

3 parts by weight of an additive for a moderate temperature asphalt mixture was added to 100 parts by weight of the AP (asphalt) heated to 130 ° C., followed by stirring for 20 minutes using a high speed shear mixer at 2,000 rpm to completely melt the additive.

(4) Evaluation of mesophilic asphalt properties

Evaluation of the physical properties of each asphalt (AP), including the neutralized asphalt prepared by adding the additive according to the present invention was evaluated based on the PG test, the viscosity was measured by measuring a rotary viscometer. Physical properties of the neutralized asphalt of each Example and Comparative Example are shown in Table 4. Here, the content of the low carbon additive used is 3 parts by weight based on 100 parts by weight of the AP (asphalt).

 Low carbon additive Asphalt before aging Asphalt After RFTO Asphalt After PAV Viscosity (120 ℃, cps) Viscosity (140 ° C, cps) G ^* / sinδ (70 ° C, kPa) G ^* / sinδ (70 ° C, kPa) Stiffness (-12 ℃, MPa) m-value (-12 ℃) AP 1150 412 0.624 1.201 189 0.33 Example 1 950 330 3.254 4.112 200 0.32 Example 2 900 310 3.013 3.805 180 0.33 Example 3 790 290 1.251 2.101 166 0.35 Example 4 810 300 1.651 2.631 163 0.35 Example 5 910 315 3.282 4.382 195 0.33 Example 6 925 320 3.501 4.212 196 0.33 Comparative Example 1 1,067 385 4.276 4.423 245 0.28 Comparative Example 2 720 265 0.341 0.651 120 0.37 Comparative Example 3 1,250 450 4.783 5.023 275 0.27 Comparative Example 4 980 320 0.362 0.721 150 0.36 Comparative Example 5 730 290 0.461 0.891 140 0.37 Comparative Example 6 880 316 3.792 5.299 250 0.28 RTFO (Rolling Thin Film Oven): Simulates the aging of the process of mixing with aggregate and moving to the site at high temperature in the initial plant during the production of asphalt mixture PAV (Pressure Aging Vessel) Evaluation of Aging of Asphalt Mixtures Over (Use of 3 parts by weight of low-carbon additives in the Examples and Comparative Examples) G ^* / sinδ: Factors related to plastic deformation resistance of asphalt. M-value: Whether the brittle fracture is abrupt due to bending creep slope (0.3 or more)

As shown in Table 4, it can be seen that the low carbon additive according to the present invention exhibits excellent overall high and low temperature physical properties.

If the viscosity is 120 ~ 140 ℃ higher than AP or G * / sinδ is lower in Original and RTFO, it is difficult to be used as low carbon additive because of low plastic deformation resistance.

In addition, when the m-value value after the PAV is more than 0.3 or higher than the AP, it can be determined that the low temperature properties are excellent.

In Comparative Examples 1 and 3 using general polyethylene wax, G * / sinδ was higher in Original and RTFO, but the viscosity was similar or higher than that of PG 64-22 (KS F 2389; Asphalt common grade). It is found to be unsuitable for use.

In addition, in this case, the m-value after PAV is less than 0.3 and lower than PG 64-22, so that the low temperature property is not good, and thus it is vulnerable to fatigue and cracking, which may limit its use in low temperature areas.

The sasobit wax of Comparative Example 6, which is used as a low carbon additive, has a low viscosity and excellent plastic deformation resistance, so it can be used as an excellent low carbon additive in a hot area. However, like a general polyethylene wax, the m-value after the PAV is 0.3 or less. So it can be seen that the physical properties are not good.

On the other hand, the low carbon additives of Examples 1 to 6 according to the present invention can be used as a low carbon additive because the viscosity is 120 ~ 140 ℃ lower than PG 64-22, G * / sinδ is higher than PG 64-22 in Original and RTFO It can be seen that it has excellent plastic deformation resistance.

In addition, since after the PAV m-value value is 0.3 or more, it can be seen that it has a good high temperature plastic deformation resistance and excellent low temperature properties.

In addition, Comparative Examples 2 and 4 using excess palm wax may be used as low carbon additives due to their low viscosity. However, G * / sinδ values in Original and RTFO are lower than AP, making it difficult to use as asphalt additive for road pavement. It can be seen.

By using Example 2 by measuring the asphalt physical properties of the low carbon additive 0 to 10 parts by weight based on 100 parts by weight of AP are shown in [Table 5].

 Low Carbon Additives Content (phr) Asphalt before aging Asphalt After RFTO Asphalt After PAV Viscosity (120 ℃, cps) Viscosity (140 ° C, cps) G ^* / sinδ (70 ° C, kPa) G ^* / sinδ (70 ° C, kPa) Stiffness (-12 ℃, MPa) m-value (-12 ℃) 0 1150 412 0.624 1.201 189 0.33 One 950 380 1.955 2.450 185 0.33 3 900 310 3.013 3.805 180 0.33 5 850 290 4.813 5.912 176 0.34 10 810 275 6.812 7.813 173 0.35 RTFO (Rolling Thin Film Oven): Simulates the aging of the process of mixing with aggregate and moving to the site at high temperature in the initial plant during the production of asphalt mixture PAV (Pressure Aging Vessel) Evaluation of Aging of Asphalt Mixtures Over (Use of 3 parts by weight of low-carbon additives in 100 parts by weight of AP-5 in Examples and Comparative Examples) G ^* / sinδ: Factors related to plastic deformation resistance of asphalt. (300 MPa or less) m-value: Excessive brittle fracture due to bending creep slope (0.3 or more) The additive used is Example 2.

Through Table 5, it can be seen that the mesophilic asphalt, which changed the content of the low carbon additive of Example 2, improved high and low temperature properties as the content of the low carbon additive increased. Therefore, it is understood that the low carbon additive according to the embodiment of the present invention is preferable as an additive of the asphalt for the middle-temperature asphalt mixture because the low carbon additive plays a role of improving the plastic deformation resistance of the middle-temperature asphalt mixture and the lowering of the low-temperature physical properties as well as the viscosity-lowering effect. Can be.

Claims (9)

In the low carbon additive for medium temperature asphalt mixture containing polyethylene wax and vegetable wax,   The low carbon additive contains the polyethylene wax and the vegetable wax in a weight ratio of 20: 1 to 1: 2, The vegetable wax is a modified palm wax produced by melting and reacting sodium hydroxide (NaOH) and stearic acid (CH ₃ (CH ₂ ) ₁₆ COOH) to a palm wax prepared by hydrogenating palm oil extracted from a coconut. Low carbon additive for medium temperature asphalt mixture, characterized in that. The method of claim 1, The polyethylene wax has a melting point of 95 ℃ ~ 125 ℃, the low carbon additive for medium temperature asphalt mixture, characterized in that the melt viscosity at 140 ° C or less. According to claim 1, wherein the vegetable wax is low carbon additive for mesophilic asphalt mixture, characterized in that the palm wax produced by the hydrogenation of palm oil (Palm oil) extracted from the palm to the modified palm wax is further mixed. The method of claim 3, wherein The palm wax is a low carbon additive for mesophilic asphalt mixture, characterized in that the melting point is 55 ℃ ~ 65 ℃. delete The method of claim 1, The weight ratio of the hydrogenated palm wax and sodium hydroxide (NaOH) is 100: 3.5 to 100: 4.0, the weight ratio of the palm wax and stearic acid is 100: 16.0 to 100: 27.5, characterized in that Low Carbon Additives for Asphalt Mixtures. The method of claim 1, Melting point of the modified palm wax is low carbon additive for medium temperature asphalt mixture, characterized in that 80 ℃ ~ 110 ℃. The method of claim 1, The low carbon additive further contains an oil, wherein the weight ratio of the polyethylene wax and the oil is 20: 1 to 2: 1 low carbon additive for medium temperature asphalt mixture. The method of claim 8, The oil is a low-carbon additive for medium temperature asphalt mixture, characterized in that 40 ℃ kinematic viscosity (Kinematic Viscosity) is 20 ~ 300cSt.