KR20160070403A - Liquid-typed warm-mix asphalt modifier enhanced for high- and low-temperatures' properties and manufacturing method and warm-mix modified asphalt mixture comprising the same - Google Patents

Abstract

An embodiment of the present invention relates to a liquid-type warm-mix asphalt modifier composition, a manufacturing method thereof, and a manufacturing method of warm-mix modified asphalt and a warm-mix modified asphalt mixture including the liquid-type warm-mix asphalt modifier composition. The liquid-type warm-mix asphalt modifier composition includes: 100 parts by weight of a low temperature reinforcing agent represented by a Formula 1; 50-100 parts by weight of styrene-butadiene-styrene block copolymer; and 30-70 parts by weight of a viscosity decreasing agent selected from a polyethylene glycol-based nonionic surfactant. According to the present invention, when manufacturing the warm-mix modified asphalt in a premix type, the modifier composition has fluidity at the room temperature, thereby being inputted into asphalt manufacturing facilities at the room temperature without an additional treatment such as heating, and has improvement in the mixing speed of asphalt and the modifier composition. In addition, phase separation does not occur even when stored for a long time after manufacturing the asphalt, a high temperature property and a low temperature property of the asphalt is simultaneously enhanced, and construction at the temperature lower than the temperature for general asphalt is possible.

Description

TECHNICAL FIELD [0001] The present invention relates to a mesophilic modifier composition for a liquid phase asphalt having excellent high temperature and low temperature properties, and to a mesophilic modified asphalt admixture using the modified mesophilic modified asphalt admixture and a mesophilic modified asphalt admixture MODIFIED ASPHALT MIXTURE COMPRISING THE SAME}

TECHNICAL FIELD The present invention relates to a modifier composition for medium temperature asphalt which is excellent in high temperature and low temperature physical properties of a liquid phase, a process for producing the modifier, a mesophilic modified asphalt using the same, and a process for producing a mesophilic modified asphalt mixture. More particularly, A modifier composition for middle temperature asphalt which can be added to an asphalt production facility without any additional treatment due to its fluidity at room temperature, the mixing speed with the asphalt is improved, and phase separation does not occur even after long-term storage after the production of the asphalt; A modified mesophilic asphalt using the same, and a process for producing a mesophilic modified asphalt mixture.

As the criteria for distinguishing the performance of the asphalt, there are the penetration grade and the compatibility grade.

The degree of penetration is classified as the classification of asphalt based on the degree of penetration of asphalt measured in accordance with ASTM D946. The penetration grade is defined as the penetration of asphalt into the asphalt for the specified load and time at the reference temperature do. Specifically, the degree of penetration is an index representing the hardness of asphalt at 25 ° C, and is a value indicating the depth of penetration of the needles in 0.1 mm increments when they are pressed for 5 seconds with a force of 100 g with a needle of the needle specified in the asphalt , And the lower the penetration value, the harder the asphalt is. Based on these intrusions, asphalt is classified into five standard grades: 40 to 50, 60 to 70, 85 to 100, 120 to 150 and 200 to 300. That is, asphalt having an invasion degree of 40 to 50 is harder than asphalt having an invasion degree of 200 to 300. There are two types of road pavement asphalt which are produced domestically and have penetration degree of 85 ~ 100 (AP-3) grade and penetration degree of 60 ~ 70 (AP-5) grade.

Other grades that distinguish the performance of asphalt are the grades in the form of 'PG XX-YY' where XX stands for high temperature grade and -YY stands for low temperature grade. The high temperature grade means that the asphalt pavement is well tolerated at high temperature and medium load and can be interpreted as having excellent resistance to plastic deformation. The low low temperature grade means that it is resistant to low temperature cracking. For example, PG 58-22 indicates that the expected maximum use temperature of the package is 58 ° C and the minimum service temperature is -22 ° C. A typical grade of road pavement asphalt used in Korea is PG 64-22.

In cryogenic regions such as Canada and Russia, cold weather is very cold in the winter, and cold cracking occurs easily in asphalt pavement. This low-temperature cracking accelerates the breakage of asphalt pavement and shortens the lifetime of the asphalt pavement. Therefore, in order to improve the long-term performance of the road, the problem of low temperature cracking in the asphalt pavement should be solved.

In order to solve this problem, it is necessary to use low-temperature asphalt as the PG rating. However, in general, asphalt has a drawback in that plastic deformation may occur in the summer when the minimum use temperature is lowered and the maximum use temperature is also lowered.

As a method for improving the compatibility level of asphalt, a method of using a polymer type modifier such as a styrene-butadiene-styrene block copolymer, a polyolefin resin, a styrene-butadiene rubber, a waste tire powder or the like is mixed and used. Asphalt whose physical properties are improved by these additives is referred to as 'modified asphalt'. Styrene-butadiene-styrene block copolymer is the most widely used additive for the production of modified asphalt. These asphalt modifiers are difficult to mix with asphalt, so a high-speed shear mixer should be used, and a modified styrene-butadiene-styrene block copolymer- Asphalt can increase the maximum temperature of the cooperability grade, but it can not lower the minimum temperature to improve the low temperature cracking. Therefore, it is necessary to develop a modifier that improves both the maximum use temperature and the minimum temperature simultaneously. For example, when 4 wt% of a styrene-butadiene-styrene block copolymer is mixed with 96 wt% of PG 64-22 asphalt, the mixture should be stirred for at least 1 hour with a high-speed shear mixer at a temperature of 160 ° C or higher. The high-temperature properties are improved by 70-22, but the low-temperature properties are not improved.

Asphalt pavement conditions and the asphalt pavement used in the Canadian cryogenic area (-26 ~ -39 ℃) were analyzed by Boutin, 2nd Eurasphalt & Eurobitume Congress 2000 Proc. 0267.uk. PVN (Pen-Vis Number) is closely related to low-temperature cracking of asphalt pavement in low temperature regions. According to the results of his presentation, when PVN is higher than 0.6, low-temperature cracking does not occur. As the PVN is larger, the low-temperature cracking is better. When the PVN is lower than 0.6, PVN is an index calculated using the viscosity of asphalt measured at 135 ° C and the penetration measured at 25 ° C, and the calculation method of PVN is as follows.

As can be seen from the above equation, asphalt having a high viscosity at 135 ° C and at 25 ° C has a higher PVN value. However, in general, as the viscosity increases, the penetration decreases. As a result, it is necessary to develop a method of increasing the PVN of the asphalt to improve the low-temperature cracking.

On the other hand, the manufacturing method of road modified asphalt concrete (ascon) can be broadly divided into a plant mix type and a premix type. The plant mix type is a method in which asphalt is added to the asphalt plant by mixing the aggregate and the asphalt at the Ascon plant. The premix type is a method in which the asphalt is pelletized or crumbed in the form of pellets or crumb type modifier (for example, styrene-butadiene- Copolymer or the like) is added and melted to produce modified asphalt, which is then transferred to an ascon factory to mix the aggregate and the modified asphalt to produce the ascon.

The premix type is generally used in asphalt pavement because it is possible to mass-produce the asphalt and reforming agent by melt mixing at 160-200 ° C in the melting facility. However, in the premix type, a separate equipment such as a high shear mixer is required to dissolve the modifier in the asphalt, and a phase separation phenomenon may occur in which the modifier and the asphalt are separated during long-term storage or transportation. To suppress such phase separation, a separate method such as a crosslinking agent should be introduced. Therefore, it is necessary to develop a modifier that does not cause phase separation without special prescription, and it is possible to manufacture easily with simple agitation or convection only when a premix type modifier is manufactured without a separate mixing equipment.

In recent years, studies on a Warm-Mix Asphalt Mixture (WMA) which mixes and compaction of an asphalt mixture at 20-40 ° C. lower temperature than the hot-mix asphalt mixture (HMA) have. This technique of producing a mesophilic asphalt mixture is referred to as a mesophilic technique. The mesophilic technique lowers the construction temperature to minimize the short-term aging of the asphalt due to the high temperature, thereby improving the low temperature properties. Generally, the heated asphalt mixture is manufactured and installed at 150 to 180 ° C. In this process, aging of the asphalt due to heat occurs and the asphalt hardens. When the aged asphalt is hardened, it is easily broken at low temperature and adversely affects the low temperature properties. Therefore, application of the mesophilic technique is required when manufacturing the asphalt modifier for improving low temperature properties of the asphalt.

However, in the case of some wax type of mid-temperature additives, low-temperature properties may be weakened on the basis of PG grade, and it is necessary to develop a middle-temperature technique which does not affect low-temperature properties. For example, in the case of sasobit, which is widely used as a moderate additive, when the PG grade is measured, it is improved to high-temperature properties by mixing 2wt% of PG 64-22 asphalt with 98wt%, but low temperature properties are rather poor.

The object of the present invention is to provide an asphalt-modified asphalt which can be put into an asphalt production facility at room temperature without any additional treatment such as heating, A modifier composition for medium temperature asphalt which is capable of simultaneously improving the high temperature property and the low temperature property of the asphalt even at a long term storage and can be installed at a temperature lower than that of a general asphalt, a method for producing the modifier asphalt, And to provide a method for producing a mesophilic modified asphalt mixture.

In one embodiment of the present invention,

[Chemical Formula 1]

[Wherein m is an integer of 2 to 4 and n is an integer of 6 to 12.]

50 parts by weight of styrene-butadiene-styrene block copolymer; And 30 to 70 parts by weight of a viscosity-decreasing agent selected from polyethylene glycol-based nonionic surface-active agents.

According to another embodiment of the present invention,

[Chemical Formula 1]

[Wherein m is an integer of 2 to 4 and n is an integer of 6 to 12.]

100 parts by weight of a low temperature reinforcing agent and 50 to 100 parts by weight of a styrene-butadiene-styrene block copolymer are stirred at room temperature to absorb a low temperature reinforcing agent in a styrene-butadiene-styrene block copolymer; Adding to the mixture 30 to 70 parts by weight of a viscosity reducing agent selected from polyethyleneglycol-based nonionic surfactants; Heating the mixture to 140-170 < 0 >C; Stirring while maintaining the temperature until the styrene-butadiene-styrene block copolymer is completely melted; And cooling the mixture to room temperature to obtain a liquid type modifier composition. The present invention also provides a method for producing a liquid type asphalt mesophilic modifier composition.

In another aspect of the present invention, there is provided a mesophilic modified asphalt comprising 3 to 5% by weight of the liquid phase asphalt mesophilic modifier composition and 95 to 97% by weight of asphalt.

According to another aspect of the present invention, there is provided a process for preparing a liquid phase asphalt mesophilic modifier composition, Adding 3 to 5% by weight of the liquid phase asphalt mesophilic modifier composition to 95 to 97% by weight of heated asphalt; And adding the mixture to the heated aggregate and mixing the mixture. The present invention also provides a method for producing a mesophilic modified asphalt mixture.

Since the modifier composition according to the present invention is in the form of a liquid having fluidity at room temperature, it can be directly added to asphalt without any additional treatment such as heating when it is applied to manufacture of premix type moderate modified asphalt, Since it is dispersed in asphalt in a short time due to flow only, there is no need for a separate modifier melting facility.

Also, the modified asphalt prepared using the modifier composition according to the present invention does not undergo phase separation even when stored for a long period of time.

In addition, the moderate modified asphalt using the modifier composition according to the present invention can improve the high temperature property and low temperature property of the asphalt simultaneously by the modifier, thereby improving the long term common use of the road in the cryogenic region, This is possible.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view showing the form of a styrene-butadiene-styrene block copolymer. FIG.
Fig. 2 is a graph of the number of turns compaction and% theoretical maximum density to obtain the compaction energy.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, numerous specific details are set forth, such as specific elements, which are provided to aid a more thorough understanding of the present invention, and it is to be understood that the present invention may be practiced without these specific details, It will be obvious to those who have. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

One embodiment of the present invention is a compound of formula

[Chemical Formula 1]

[Wherein m is an integer of 2 to 4 and n is an integer of 6 to 12.]

50 parts by weight of styrene-butadiene-styrene block copolymer; And 30 to 70 parts by weight of a viscosity-decreasing agent selected from polyethylene glycol-based nonionic surface-active agents.

The low temperature reinforcing agent contained in the mesophilic modifier composition for liquid phase asphalt of the present invention improves the low temperature properties of asphalt and dissolves the styrene-butadiene-styrene block copolymer.

The low-temperature reinforcing agent is preferably an aliphatic diester having a good coexistence with asphalt and having a low freezing point, and preferably an aliphatic diester having the structure of the formula (1) in order to impart flexibility to the asphalt at low temperatures.

If the number of aliphatic carbon atoms (n) is less than 6, the solubility parameter of the styrene-butadiene-styrene copolymer is lowered, The compatibility with the butadiene-styrene block copolymer is not good and phase separation occurs, making it difficult to prepare a liquid phase reforming agent.

In one form, the low temperature enhancer preferably has a Hansen solubility parameter of 16 to 18 in order to improve compatibility with the styrene-butadiene-styrene block copolymer.

Further, in one form, the low-temperature reinforcing agent preferably has a freezing point of -50 ° C or lower in order to improve low-temperature properties, and it is preferable that the flash point is 190 ° C or higher for use in asphalt.

The styrene-butadiene-styrene block copolymer included in the mesophilic modifier composition for liquid phase asphalt of the present invention improves the physical properties of the asphalt at high temperature.

The styrene-butadiene-styrene block copolymer in an amount ranging from 50 to 100 parts by weight based on 100 parts by weight of the low temperature reinforcing agent may be included in the liquid phase modifier for modifying the modifier for asphalt. If the amount of the styrene-butadiene-styrene block copolymer is less than 50 parts by weight, the physical properties of the asphalt binder may deteriorate at a high temperature. If the amount exceeds 100 parts by weight, the viscosity of the modifier may become too high or solid.

In one form, the styrene-butadiene-styrene block copolymer preferably has a weight average molecular weight ranging from 50,000 to 200,000 g / mol, more preferably from 60,000 to 150,000 g / mol. When the weight average molecular weight of the styrene-butadiene-styrene block copolymer is less than 50,000 g / mol, the effect of modifying high-temperature physical properties of the asphalt becomes small. When the weight average molecular weight exceeds 200,000 g / mol, the viscosity and phase transition temperature become too high, It is difficult to melt in asphalt, and phase separation phenomenon can occur after the production of modified asphalt.

In one form, the styrene-butadiene-styrene block copolymer may have a styrene content of preferably 20-40 wt%, more preferably 25-35 wt%. If the styrene content is less than 20% by weight, the elasticity may be insufficient and the physical properties such as softening point of the modified asphalt may be deteriorated. If the styrene content is more than 40% by weight, the plastic property may become strong and the asphalt modifying effect may not be exerted.

In one form, the styrene-butadiene-styrene block copolymer preferably has a vinyl content of 30 to 60 wt% in butadiene. When the vinyl content is less than 30% by weight, phase separation may occur. When the vinyl content is more than 60% by weight, the glass transition temperature is increased and the low temperature properties of the asphalt are adversely affected.

In one form, the styrene-butadiene-styrene block copolymer may be any of those having a linear, branched or tapered structure (see FIG. 1). However, a branched copolymer is preferred for preventing the viscosity of the modifier from increasing and for imparting fluidity, and a copolymer having a tapered structure in the styrene block may be preferable for improving the melt dispersion rate.

The viscosity reducing agent contained in the mesophilic modifier composition for a liquid phase asphalt of the present invention enhances the low-temperature properties of the asphalt and lowers the packing temperature of the asphalt.

Based on 100 parts by weight of the low temperature reinforcing agent, the viscosity reducing agent may be contained in the amount of 30 to 70 parts by weight in the mesophase modifier for liquid phase asphalt. When the amount of the viscosity reducing agent is less than 30 parts by weight, the mesophilic effect is insufficient. When the amount of the viscosity reducing agent is more than 70 parts by weight, compatibility with the styrene-butadiene-styrene block copolymer is deteriorated to melt the styrene-butadiene-styrene block copolymer There is a difficulty.

In one form, the viscosity reducing agent may be selected from polyethylene glycol-based nonionic surfactants, for example, polyoxyethylene alkyl ethers or polyoxyethylene glycol fatty acid esters.

In one form, the viscosity reducing agent may be a polyethylene glycol-based nonionic surfactant having a freezing point of -30 占 폚 or lower. If the freezing point is higher than -30 ° C, the low-temperature properties of the asphalt may be affected.

In one embodiment, the mesophilic modifier composition for a liquid phase asphalt of the present invention may further comprise at least one additive selected from the group consisting of a tackifier, an antioxidant, a heat stabilizer, an antistatic agent and a lubricant.

According to another embodiment of the present invention,

[Chemical Formula 1]

[Wherein m is an integer of 2 to 4 and n is an integer of 6 to 12.]

100 parts by weight of a low temperature reinforcing agent and 50 to 100 parts by weight of a styrene-butadiene-styrene block copolymer are stirred at room temperature to absorb a low temperature reinforcing agent in a styrene-butadiene-styrene block copolymer; Adding to the mixture 30 to 70 parts by weight of a viscosity reducing agent selected from polyethyleneglycol-based nonionic surfactants; Heating the mixture to 140-170 < 0 >C; Stirring while maintaining the temperature until the styrene-butadiene-styrene block copolymer is completely melted; And cooling the mixture to room temperature to obtain a liquid type modifier composition. The present invention also relates to a process for producing a liquid phase asphalt mesophilic modifier composition.

In the method of preparing the liquid phase asphalt modifier composition according to an embodiment of the present invention, the low temperature reinforcing agent and the styrene-butadiene-styrene block copolymer are sufficiently stirred to absorb the low temperature strengthening agent into the styrene-butadiene-styrene block copolymer A viscosity reducing agent is added. This is for dissolving the copolymer by a low temperature reinforcing agent compatible with the styrene-butadiene-styrene block copolymer. When the viscosity-reducing agent which is not compatible with the styrene-butadiene-styrene block copolymer is first put in or introduced simultaneously, It is difficult to make a liquid reforming agent.

In one form, at least one additive selected from the group consisting of a tackifier, an antioxidant, a heat stabilizer, an antistatic agent and a lubricant may be further added when the viscosity reducer is added.

The constituents of the liquid phase asphalt mesophilic modifier composition, the effect, the content and the like of each of the liquid phase asphalt mesophilic modifier compositions have been described above in the examples of the modifier composition. Therefore, in the present embodiment, detailed description thereof will be omitted in order to avoid repetition.

Another embodiment of the present invention relates to a mesophilic modified asphalt comprising 3 to 5% by weight of the liquid phase asphalt mesophilic modifier composition and 95 to 97% by weight of asphalt.

Asphalt can be any asphalt commonly used for road pavement. Asphalt can generally be classified according to ASTM D946 penetration test results. The typical asphalt pavement asphalt produced in Korea is 85 ~ 100 (AP-3) and 60 ~ 70 (AP-5).

According to another embodiment of the present invention, there is provided a process for preparing a liquid phase asphalt mesophilic modifier composition, Adding 3 to 5% by weight of the liquid phase asphalt mesophilic modifier composition to 95 to 97% by weight of the heated asphalt; And admixing the mixture to the heated aggregate and mixing the mixture.

In one form, the weight ratio of asphalt to aggregate may range from 3.5: 96.5 to 6.0: 94.0.

In one form, the heating temperature of the asphalt is from 150 to 180 캜, and the heating temperature of the aggregate may be in the range of from 110 to 140 캜.

Hereinafter, the present invention will be described in more detail by way of examples. However, the following examples are illustrative of the present invention, and the scope of the present invention is not limited to the following examples.

[Example]

(1) Experimental material

The materials used for producing the moderate modifier for asphalt in this and comparative examples are as follows.

1) SBS / 10/20-L: A linear styrene-butadiene-styrene block copolymer having a styrene content of 33 wt%, a weight average molecular weight of 100, OOO g / mol and a vinyl content of 20 wt%

2) SBS / 10/40-L: A linear styrene-butadiene-styrene block copolymer having a styrene content of 33 wt%, a weight average molecular weight of 100, OOO g / mol and a vinyl content of 40 wt%

3) SBS / 25/40-L: A linear styrene-butadiene-styrene block copolymer having a styrene content of 33% by weight, a weight average molecular weight of 250, OOO g / mol and a vinyl content of 40%

4) SBS / 4/40-L: A linear styrene-butadiene-styrene block copolymer having a styrene content of 33% by weight, a weight average molecular weight of 40, OOO g / mol and a vinyl content of 40%

5) SBS / 10/40-LT: linear styrene-butadiene-styrene block copolymer having a styrene content of 33 wt%, a weight average molecular weight of 100, OOO g / mol and a vinyl content of 40 wt%

6) SBS / 15/40-R: a styrene-butadiene-styrene block copolymer having a styrene content of 33 wt%, a weight average molecular weight of 150, OOO g / mol and a vinyl content of 40 wt%

7) Low Temperature Reinforcement-8: di-adipate with m = 4 and n = 8 in formula (1)

8) Low Temperature Reinforcement -14: di-adipate with m = 4 and n = 14 in formula (1)

9) Viscosity reducing agent-L: Polyoxyethylene alkyl ether having a solidification point of 25 占 폚

10) Viscosity reducing agent-H: Polyoxyethylene alkyl ether having a solidification point of 35 占 폚

11) Asphalt (AP): The penetration at 25 ° C is 100, the viscosity at 135 ° C is 270 cps and the public grade is PG 58-28 asphalt

(2) Preparation of moderate modifier for asphalt according to Examples and Comparative Examples

According to the composition ratios shown in Tables 1 and 2 below, an intermediate modifier was prepared as follows.

The low temperature reinforcing agent and the styrene-butadiene-styrene block copolymer were placed in a reactor equipped with a stirrer at room temperature and stirred until the styrene-butadiene-styrene block copolymer sufficiently absorbed the low temperature strengthening agent. A viscosity reducing agent was added to the stirring mixture, and the reactor was heated to 140-170 占 폚. Styrene-butadiene-styrene block copolymer was stirred while maintaining the temperature until it was fully melted. Thereafter, the mixture was cooled to room temperature to obtain an intermediate modifier for asphalt.

(3) Experimental Example 1: Preparation and characterization of modifier for asphalt

1) Modifier form and miscibility

From the viewpoint of the shape of the modifier, the modifying agent produced by the above production method was cooled to room temperature and judged to be acceptable if it had fluidity at room temperature or not. In addition, from the viewpoint of compatibility between the materials, after the modifier was prepared, it was allowed to stand at room temperature for 24 hours, and when the layer separation or solid matter occurred, it was rejected. The results are shown in Table 1.

If there is fluidity at room temperature, it can be mixed with asphalt without storage or treatment for transporting from the storage container to the asphalt. However, if there is no fluidity, there is inconvenience of processing such as heating for transportation in the storage container.

2) Evaluation of solubility (dispersibility) of asphalt modifier

One of the objects of the present invention is to prepare a mesophilic modified asphalt without any additional stirring equipment in a short time. For this evaluation, 4 wt% of the modifier prepared in the asphalt heated to 160 ° C was added, and the mixture was stirred at 500 rpm for 3 minutes, and then the visual observation and the upper and lower samples were taken to measure the softening point. If the untreated or unmixed modifier was found as a result of visual observation, it was rejected. After 5 minutes of stirring, samples were taken from the upper and lower parts. If the difference in softening point was within 2 캜, the sample was accepted. If the temperature was over 2 캜, it was judged to be rejected. The results are shown in Table 1.

3) Evaluation of Phase Separation Characterization of Moderate Modifier

In wet type modified asphalt, it is important that the material does not undergo phase separation during long-term storage. The mesophase modified asphalt prepared by adding 4wt% of a modifier to asphalt heated to 160 ℃ was put into a tube with a length of 20 cm and a diameter of 2.5 cm and stored at 163 ℃ for 72 hours. After 72 hours, the asphalt in the tube was cured at room temperature below 25 ° C and the softening point was measured. If the difference between the upper and lower softening points is less than 2 캜, it is judged to be acceptable. The results are shown in Tables 1 and 2.

Example Comparative Example One 2 One 2 3 4 5


Modifier composition
(Parts by weight)
Low Temperature Reinforcement-8 100 100 100 100 100 100 Low Temperature Reinforcement-14 100 SBS / 10/40-L 70 90 30 120 70 70 70 Viscosity reducing agent-L 50 Viscosity reducing agent-H 50 50 50 50 50 100 Modifier form pass pass pass fail fail fail pass Miscibility between materials pass pass pass - fail fail pass Dispersibility evaluation pass pass pass - - - pass Phase separation evaluation
(? T) pass
2 ℃ pass
2 ℃ pass
2 ℃ fail
4 ℃ - - pass
2 ℃

According to Table 1, the content of the styrene-butadiene-styrene block copolymer in Comparative Example 2 was high and became solid at room temperature. In Comparative Example 3, the compatibility of the low temperature reinforcing agent and the styrene-butadiene- The styrene-butadiene-styrene block copolymer was phase-separated at room temperature after the preparation of the modifying modifier because the content of the viscosity reducing agent was large in Comparative Example 4. From the results shown in Table 1, it is judged that Comparative Examples 2 to 4 are composition ratios which are not suitable as the modifier for modifying the present invention.

Example Comparative Example One 3 4 6 7 8




Modifier
Composition
(Parts by weight)


Low Temperature Reinforcement-8 100 100 100 100 100 100 Low Temperature Reinforcement-H 50 50 50 50 50 50 SBS / 10/20-L 70 SBS / 10/40-L 70 SBS / 25/40-L 70 SBS4 / 40-L 70 SBS / 10/40-LT 70 SBS / 15/40-R 70 Modifier form pass pass pass pass fail pass Dispersibility evaluation pass pass pass pass - pass Phase separation evaluation
(? T) pass
2 ℃ pass
1 ℃ pass
1 ℃ fail
8 ℃ fail
10 ℃ pass
2 ℃

According to Table 2, in the case of Comparative Example 6, the vinyl content of the styrene-butadiene-styrene block copolymer was low and the phase separation occurred. In Comparative Example 7, the viscosity of the styrene-butadiene-styrene block copolymer was high, In addition, it was judged to be rejected because of phase separation. From the results in Table 2, it is judged that Comparative Examples 6 and 7 are composition ratios which are not suitable as the modifying modifier of the present invention.

On the other hand, Examples 1 to 4 were suitable for the shape and dispersibility of the modifier for modifying the temperature, and in particular, the styrene-butadiene-styrene block copolymer (Examples 3 and 4) into which branching and tapered blocks were introduced was linear styrene-butadiene -Styrene block copolymer (Example 1). ≪ tb > < TABLE > From these results, it can be seen that each component constituting the modifier should be optimized in order to satisfy the characteristics such as ease of use, dispersibility and phase separation.

(4) Experimental Example 2: Evaluation of high temperature and low temperature properties of the moderate modified asphalt

The high temperature and low temperature properties of the modified asphalt using the modifier for modifying the temperature were evaluated using Examples 1 to 4 and Comparative Examples 1, 5, and 8, which had no problems in manufacturing and use. Modified asphalt was prepared by mixing 4 wt% of modifier prepared in asphalt heated to 160 ℃ and thoroughly mixing.

1) Performance evaluation

The high temperature and low temperature properties of the mesophilic modified asphalt prepared using the mesophilic modifier prepared in the above Examples and Comparative Examples were evaluated based on the PG test.

The high temperature grade was evaluated by DSR before and after the RTFO (Rolling Thin Film Oven, thin film heating test) by PG evaluation method, and the low temperature grade was evaluated by using BBR after PVA (Pressure Aging Vessel). The results are shown in Tables 3 and 4 below.

2) PVN evaluation

To determine the low-temperature cracking properties of modified asphalt, the PVN (Pen-vis Number) was calculated by measuring the viscosity at 135 ° C and the penetration at 25 ° C using the PVN calculation formula described above. If the PVN is higher than 0.6, it is judged to be acceptable. If the PVN is lower than 0.6, it is judged to be rejected. The results are shown in Table 5 below.

3) Flexural bending test of asphalt binder

Maximum flexural stress (MPa), maximum flexural deformation (mm), flexural deformation (MPa), and flexural deformation (MPa) at 0 ° C, -5 ° C, -10 ° C and -20 ° C at a load of 100 mm / min according to KS F 2491 The bending stiffness (MPa) was measured and the low temperature behavior of the modified asphalt was determined. The results are shown in Tables 6 to 9 below.

Modifier

PG high temperature rating
High temperature rating RTFO I After RTFO G ^* / sin?
(58 < 0 > C, kPa) G ^* / sin?
(64 ° C, kPa) G ^* / sin?
(58 < 0 > C, kPa) G ^* / sin?
(64 ° C, kPa) AP 58 1.35 - 2.42 - room
city
Yes
One 64 - 1.31 - 2.38 2 64 - 1.52 - 2.93 3 64 - 1.12 - 2.21 4 64 - 1.42 - 2.62 ratio
School
Yes One 58 2.12 0.52 3.43 - 5 64 - 1.23 - 2.32 8 58 1.98 - 2.90 -

G ^* / sin?: Plastic strain resistance-related factor of asphalt

(RTFO 1.0 or higher and RTFO 2.2 or higher to obtain a high temperature common rating at that temperature)

Modifier

asphalt
PG rating Low temperature rating After PAV BBR Stiffness
(-24 < 0 > C, MPa) m-value
(-18 DEG C) m-value
(-24 ° C) AP 58-28 430 0.31 0.23 room
city
Yes
One 64-34 270 0.36 0.30 2 64-34 298 0.38 0.31 3 64-34 220 0.39 0.33 4 64-34 240 0.38 0.31 ratio
School
Yes One 58-34 260 0.39 0.32 5 64-28 370 0.34 0.28 8 58-34 250 0.37 0.32

Stiffness: Asphalt stiffness at low temperature due to flexural creep stiffness (standard 300 MPa or less)

m-value: Whether abrupt brittle fracture (standard 0.3 or more) is caused by flexural creep slope

  - At 18 ° C, the low temperature rating -28

- At 24 ° C, the low temperature rating -34

According to Tables 3 and 4, it can be seen that the mesophilic modified asphalt containing the mesophilic modifier of Examples 1 to 4 is improved both at high temperature property and at low temperature property. In the case of Comparative Example 1, the effect of improving the high-temperature physical properties was not so low due to the low content of the styrene-butadiene-styrene block copolymer. In Comparative Example 5, the low temperature properties were not improved by using the viscosity reducing agent having a low solidifying point. In the case of Comparative Example 9, the styrene content of the styrene-butadiene-styrene block copolymer was so low that the effect of improving the physical properties at high temperature was not significant. It can be seen from the above examples and comparative examples that the difference in improvement of physical properties of asphalt occurs depending on the type of the styrene-butadiene-styrene block copolymer and the viscosity reducing agent.

Modifier 135 ° C Viscosity (cps) 25 ° C penetration (dmm) PVN Judgment AP 270 100 -0.83 fail room
city
Yes
One 350 98 -0.45 pass 2 370 96 -0.39 pass 3 340 100 -0.47 pass 4 355 97 -0.44 pass ratio
School
Yes One 300 100 -0.67 fail 5 330 96 -0.56 pass 8 300 98 -0.68 fail

According to the above Table 5, it was found that the modified asphalt containing the modifier of Modification Examples 1 to 4 had improved properties at high temperature and low temperature by the PG grade, and that the low temperature crack resistance was also improved by PVN. However, Comparative Examples 1 and 8 failed to satisfy the PG grade and PVN, so that the improvement of the high temperature and low temperature properties and the low temperature crack resistance were not significant, and in Comparative Example 5, the PVN was satisfied but the PG low temperature grade was not satisfied.

Type of binder

unit
0 ℃ Example Comparative Example 9 One 2 3 4 AP Break condition
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○
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○ Maximum load (P) N 74 82 79 76 117 The amount of displacement at maximum load (d) mm 9.25 9.21 9.23 9.24 9.14 Maximum bending stress (δ) MPa 1.11 1.23 1.19 1.14 1.75 Maximum flexural strain (ε) - 0.17 0.17 0.17 0.17 0.17 Deflection MPa 0.19 0.21 0.21 0.20 0.30 Bending stiffness MPa 6.41 7.11 6.88 6.59 10.23 Variance
Coefficient Flexural deformation (within 30%) % 6 8 10 7 2 Bending stiffness (within 20%) % 2 3 2 3 2

Type of binder

unit
-5 ℃ Example Comparative Example 9 One 2 3 4 AP Break condition
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○
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○ Maximum load (P) N 107 141 133 126 174 The amount of displacement at maximum load (d) mm 9.35 8.75 8.91 9.17 8.82 Maximum bending stress (δ) MPa 1.60 2.12 2.00 1.89 2.61 Maximum flexural strain (ε) - 0.18 0.16 0.17 0.17 0.17 Deflection MPa 0.28 0.35 0.33 0.33 0.43 Bending stiffness MPa 9.15 12.93 11.98 10.99 15.78 Variance
Coefficient Flexural deformation (within 30%) % 4 11 15 8 13 Bending stiffness (within 20%) % 4 8 7 4 12

Type of binder

unit
-10 ° C Example Comparative Example 9 One 2 3 4 AP Break condition
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○
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× Maximum load (P) N 165 267 191 176 301 The amount of displacement at maximum load (d) mm 9.07 8.63 8.75 8.88 8.55 Maximum bending stress (δ) MPa 2.48 4.01 2.87 2.64 4.51 Maximum flexural strain (ε) - 0.17 0.16 0.16 0.17 0.16 Deflection MPa 0.42 0.65 0.47 0.44 0.72 Bending stiffness MPa 14.59 24.75 17.50 15.81 58.19 Variance
Coefficient Flexural deformation (within 30%) % 10 8 4 18 12 Bending stiffness (within 20%) % One 12 14 6 7

Type of binder

unit
-20 ° C Example Comparative Example 9 One 2 3 4 AP Break condition
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× Maximum load (P) N 396 418 412 407 434 The amount of displacement at maximum load (d) mm 4.05 2.56 3.53 3.84 1.97 Maximum bending stress (δ) MPa 5.93 6.27 6.18 6.11 6.51 Maximum flexural strain (ε) - 0.08 0.05 0.07 0.07 0.04 Deflection MPa 0.46 0.30 0.41 0.44 0.25 Bending stiffness MPa 77.8 130.6 93.6 84.9 175.5 Variance
Coefficient Flexural deformation (within 30%) % 15 16 8 13 20 Bending stiffness (within 20%) % 12 10 8 11 8

According to Tables 6 to 9, the low-temperature behavior characteristics were obtained by performing a flexural bending test at various temperatures (0 ° C, -5 ° C, -10 ° C and -20 ° C). In order to obtain excellent low temperature crack resistance, Failure of the asphalt should not occur in order to prevent brittle fracture of the mixture. In addition, it can be seen that the lower temperature properties are improved as the variation of the maximum deformation and the maximum deformation occurring at the maximum load according to the temperature change is smaller. In Examples 1 to 4, flexibility at low temperatures was secured by using a low-temperature reinforcing agent, and no breakage occurred even at 20 占 폚. In Example 2, the styrene content of the styrene-butadiene-styrene block copolymer was high and the effect of improving the flexibility at the low temperature was the smallest. Comparative Example 9 was a straight asphalt without additives, and fracture occurred at 10 占 폚. It can be seen from the above Examples and Comparative Examples that there is a difference in flexibility improvement at low temperatures depending on the content of the low temperature reinforcing agent.

(5) Experimental Example 3: Preparation of a mixture of intermediate-modified modified asphalt

The mesophilic additive prepared as described above was added to the asphalt heated to 130 DEG C and mixed uniformly. Thereafter, the mixture of the asphalt and the mesophilic additive was added to the aggregate heated to 130 DEG C and mixed, The asphalt mixture of Example 9 was prepared. The sum of the amount of the asphalt and the warming additive used was made to be 5.3% by weight based on the total weight of the asphalt mixture. Comparative Example 9 is a straight asphalt mixture prepared at 160 캜 without using additives.

The amount of asphalt and the amount of mesophilic additive used and the temperature at which the mixture is prepared are shown in Table 10 below. The amount of the asphalt and the warming additive is expressed based on the sum of the amount of the asphalt and the amount of the warming additive used.

(6) Experimental Example 4: Evaluation of high temperature and low temperature physical properties of a mixture of modified mesophase asphalt

1) Porosity after compaction and densification energy indicators (Densification Energy Indies)

The mesophase effect of the asphalt mixture was evaluated by measuring porosity and densification energy indices after compaction. Compared with the asphalt mixture compaction at 160 ° C without using the mesophilic additive, it was evaluated that the porosity was the same or lower than that of the asphalt mixture. FIG. 2 shows a graph of the number of turn compaction times and the theoretical maximum density to obtain the compaction energy. If the number of turns compaction is displayed on the graph with the volume change, then the area under the graph curve can represent the amount of energy required for the density change. Here, the volume change according to the number of turning compaction is determined as a ratio of the mixture density calculated by the theoretical maximum density (Gmm) and the number of turning compaction times. Assuming that the theoretical maximum density is 100%, the actual density of the 150 asphalt concrete specimens is measured, and the density of the specimen is calculated according to the height measured by the turn compaction, and then divided by the calculated density This is the theoretical maximum density (% Gmm).

In order to obtain the compaction energy index (CEI) in the Superpave turn compaction design, the area under the graph curve with Nini and% theoretical maximum density of 92% in the graph of the number of turns and% theoretical maximum density Left hatched portion in FIG. 2). The compaction energy index refers to the compaction energy that must be applied to the asphalt mixture to obtain the density required during the application of the pavers and rollers. Here, it is assumed that Nini is eight times as the number of turn compaction times representative of the paver compaction. Generally, the Super Pave Nini is in the range of 7 to 10 times depending on traffic volume, but 8 times of turning compass is moderate. And at the end of construction, the initial density by roller compaction can be defined at the appropriate porosity. Most US specifications specify that the asphalt pavement should be made up to about 92% of the theoretical maximum density when used as a roller. If the compaction energy index is lower, it means that the lower the energy index, the more energy can be used.

After opening the traffic at 92% of the theoretical maximum density, the asphalt pavement continues to be densified while receiving the traffic load. In order to obtain the Traffic Densification Index (TDI) by traffic, one of two methods is generally used. % The area below the graph curve with the theoretical maximum density between 92% and 96% or the area under the curve with a value between 92% and 98% is defined as the TDI (Traffic Density Index) by traffic. In this study, however, the area under the curve from the theoretical maximum density of 92% to 150 times of turning compaction (the right shaded portion in FIG. 2) is calculated by using the result of 150 times turning compaction, Is defined as a densification index (TDI). Since the TDI value reflects the maximum density at which permanent deformation can occur in asphalt pavement, the larger the TDI value, the greater the energy value required to reach the maximum density due to the design traffic volume and the traffic load.

2) Dynamic Stability

The wheel tracking test is a kind of dynamic repetitive creep test. It was developed by TRRL in the UK. By simulating the plastic deformation or kneading behavior of a vehicle during heavy road conditions, KS F 2374 The plastic deformation resistance of the asphalt mixture at high temperature was evaluated. The dynamic stability (DS, rev / mm) is evaluated to be excellent in resistance to permanent deformation as the result is larger.

3) Resistance to fatigue cracks and cold cracks

Indirect Tensile Strength Test The indirect tensile strength (MPa) and toughness (N · mm) of asphalt mixtures were measured at a load of 50 mm / min according to KS F 2382.

Indirect Tensile Strength Test is a test simulating the stress condition at the lower part of the asphalt concrete layer at the time of traffic load operation or at the surface layer where the temperature change is severe, that is, tensile region. Test method that can evaluate the resistance to fatigue crack and low temperature crack to be. Toughness is expressed as the energy per unit volume applied to the destruction. That is, not only the stress required for the fracture is large, but also the strain (torsion) leading to fracture is large, and the toughness is strong when the absorption energy is large. That is, in a single material, the stress and the twist are not large at the same time, and the composite material in which two materials having different characteristics are combined is excellent in toughness. The resistance to fatigue crack and cold crack at -10 ℃ and -20 ℃ was evaluated. The evaluation results are shown in Table 10.

division Example Comparative example One 2 3 4 One 5 8 9 Modifier composition
(Parts by weight) Low Temperature Reinforcement-8 100 100 100 100 100 100 100 Viscosity reducing agent-L 50 Viscosity reducing agent-H 50 50 50 50 50 50 SBS / 10/40-L 70 90 30 70 SBS / 4/40-L 70 SBS / 10/40-LT 70 SBS / 15/40-R 70 Heavy-duty additive usage
(weight%) 4 4 4 4 4 4 4 0 Asphalt usage (% by weight) 96 96 96 96 96 96 96 100 Mixture production temperature (캜) 135 135 135 135 135 135 135 155 Compaction temperature (캜) 115 115 115 115 115 115 115 135 Porosity (%) 4.0 3.9 3.8 3.9 3.9 4.0 3.9 4.0 Densification
Energy index CEI 115 ℃ 45.9 54.1 49.1 47.8 44.2 81.3 94.8 131.2 135 ℃ 35.4 51.6 39.7 37.6 32.4 67.4 79.2 94.2 155 ℃ 32.1 42.7 37.2 34.4 31.9 52.4 56.3 59.0 TDI 115 ℃ 522.9 462.9 492.3 501.1 547.2 361.4 342.7 322.9 135 ℃ 553.0 516.4 537.7 542.0 573 392.2 386.2 361.6 155 ℃ 578.7 547.6 559.4 562.7 592.6 481.2 477.5 460.6 Dynamic Stability (times / mm) 636 681 607 618 520 564 582 508 Toughness (N · mm) -10 ° C 39,000 37,500 38,100 38,700 36,800 36,750 36,825 36,250 -20 ° C 34,855 32,872 33,176 33,982 31,237 31,492 31,267 30,424

4) Evaluation

[Evaluation of effect of mesophilic]

As can be seen from the above Table 10, Examples 1 to 4 exhibited lower CEI and higher TDI values than Comparative Example 9 which did not use the warming additive. From these results, it can be confirmed that the compaction performance and the mid-temperature performance of the asphalt mixture of Examples 1 to 4 are excellent. Therefore, the use of the mesophilic additive of the present invention can exert excellent physical properties even when the asphalt mixture is produced at a low temperature.

[Evaluation of Resistance to Plastic Deformation at High Temperature]

From Table 10, it can be seen that comparing the dynamic stability values of Examples 1 to 4 and Comparative Example 9, the styrene-butadiene-styrene block copolymer is added to improve the plastic deformation resistance at high temperature of the asphalt mixture. As can be seen from Examples 1 and 2, the higher the content of styrene-butadiene-styrene, the better the resistance to plastic deformation at high temperatures, but the lower the resistance to cracking at low temperatures, It is possible to confirm that a proper content ratio should be applied.

[Evaluation of crack resistance at low temperature]

It can be seen from Table 10 that the toughness values of Examples 1 to 4 and Comparative Examples 1, 5, 8, and 9 were comparable to those of Comparative Example 5 using viscosity reducing agent-L in Examples 1 to 4 at -10 ° C and 20 ° C, Or as compared with Comparative Example 9 using straight asphalt, it is confirmed that the low-temperature crack resistance is excellent.

In addition, when the toughness values of Examples 1 to 4 and Comparative Examples 5 and 8 were compared, it was confirmed that the toughness values of the styrene-butadiene-styrene block copolymer It can be confirmed that Examples 1 to 4 have excellent low-temperature cracking properties because they exhibit a larger toughness value than Comparative Example 8 using different types of coalescence.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments or constructions. Various changes, substitutions and alterations can be made hereto without departing from the spirit and scope of the invention. It will be clear to those who have knowledge.

Claims (20)

(1)
[Chemical Formula 1]

[Wherein m is an integer of 2 to 4 and n is an integer of 6 to 12.]
100 parts by weight of a low temperature reinforcing agent represented by the following formula:
50 to 100 parts by weight of a styrene-butadiene-styrene block copolymer; And
30 to 70 parts by weight of a viscosity reducing agent selected from polyethylene glycol-based nonionic surfactants
A moderate modifier composition for liquid phase asphalt.
The method according to claim 1,
Wherein the low temperature enhancer has a Hansen solubility parameter of 16 to 18
Liquid asphalt mesophilic modifier composition. The method according to claim 1,
Wherein the low temperature reinforcing agent has a freezing point of -50 캜 or lower and a flash point of 190 캜 or higher
Liquid asphalt mesophilic modifier composition.
The method according to claim 1,
The styrene-butadiene-styrene block copolymer has a weight average molecular weight of 50,000 to 200,000 g / mol, a styrene content of 20 to 40% by weight, and a vinyl content of butadiene of 30 to 60% by weight
Liquid asphalt mesophilic modifier composition.
The method according to claim 1,
The styrene-butadiene-styrene block copolymer is a branched or tapered structure.
Liquid asphalt mesophilic modifier composition.
The method according to claim 1,
Wherein the viscosity reducing agent is a polyethylene glycol-based nonionic surfactant having a solidifying point of -30 캜 or lower
Liquid asphalt mesophilic modifier composition.
The method according to claim 1,
Wherein the viscosity reducing agent is a polyoxyethylene alkyl ether or a polyoxyethylene glycol fatty acid ester
Liquid asphalt mesophilic modifier composition.
The method according to claim 1,
And at least one additive selected from the group consisting of a tackifier, an antioxidant, a heat stabilizer, an antistatic agent and a lubricant
Liquid asphalt mesophilic modifier composition.
(1)
[Chemical Formula 1]

[Wherein m is an integer of 2 to 4 and n is an integer of 6 to 12.]
100 parts by weight of a low temperature reinforcing agent and 50 to 100 parts by weight of a styrene-butadiene-styrene block copolymer are stirred at room temperature to absorb a low temperature reinforcing agent in a styrene-butadiene-styrene block copolymer;
Adding to the mixture 30 to 70 parts by weight of a viscosity reducing agent selected from polyethyleneglycol-based nonionic surfactants;
Heating the mixture to 140-170 < 0 >C;
Stirring while maintaining the temperature until the styrene-butadiene-styrene block copolymer is completely melted; And
And cooling the solution to room temperature to obtain a liquid type modifier composition
A method for preparing a liquid phase asphalt mesophilic modifier composition.
10. The method of claim 9,
Wherein the low temperature enhancer has a Hansen solubility parameter of 16 to 18
A method for preparing a liquid phase asphalt mesophilic modifier composition.
10. The method of claim 9,
Wherein the low temperature reinforcing agent has a freezing point of -50 캜 or lower and a flash point of 190 캜 or higher
A method for preparing a liquid phase asphalt mesophilic modifier composition.
10. The method of claim 9,
The styrene-butadiene-styrene block copolymer has a weight average molecular weight of 50,000 to 200,000 g / mol, a styrene content of 20 to 40% by weight, and a vinyl content of butadiene of 30 to 60% by weight
A method for preparing a liquid phase asphalt mesophilic modifier composition.
10. The method of claim 9,
The styrene-butadiene-styrene block copolymer is a branched or tapered structure.
A method for preparing a liquid phase asphalt mesophilic modifier composition.
10. The method of claim 9,
Wherein the viscosity reducing agent is a polyethylene glycol-based nonionic surfactant having a solidifying point of -30 캜 or lower
A method for preparing a liquid phase asphalt mesophilic modifier composition.
10. The method of claim 9,
Wherein the viscosity reducing agent is a polyoxyethylene alkyl ether or a polyoxyethylene glycol fatty acid ester
A method for preparing a liquid phase asphalt mesophilic modifier composition.
10. The method of claim 9,
Wherein at least one additive selected from the group consisting of a tackifier, an antioxidant, a heat stabilizer, an antistatic agent and a lubricant is further added at the time of adding the viscosity reducer
A method for preparing a liquid phase asphalt mesophilic modifier composition. A process for the preparation of a liquid phase asphalt mesophilic modifier composition comprising 3 to 5% by weight of a liquid phase asymmetric modifier composition according to any one of claims 1 to 8 and 95 to 97% by weight of asphalt
Moderate modified asphalt.
17. A process for producing a liquid asphalt mesophilic modifier composition, comprising: preparing a liquid asphalt mesophilic modifier composition according to any one of claims 9 to 16;
Adding 3 to 5% by weight of the liquid phase asphalt mesophilic modifier composition to 95 to 97% by weight of heated asphalt; And
Adding the mixture to the heated aggregate and mixing
A method for producing a mesophase modified asphalt mixture.
19. The method of claim 18,
Wherein the weight ratio of the asphalt to the aggregate ranges from 3.5: 96.5 to 6.0: 94.0
A method for producing a mesophase modified asphalt mixture.
19. The method of claim 18,
The heating temperature of the asphalt is 150-180 ° C, and the heating temperature of the aggregate is 110-140 ° C.
A method for producing a mesophase modified asphalt mixture.

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