JP6433775B2 - Goose asphalt composition - Google Patents

Description

  The present invention relates to a goose asphalt composition which is excellent in fluidity and suitable for exerting the strength required for heavy traffic pavement.

  Steel bridge slabs and elevated roads are more durable than ordinary asphalt pavement due to the increase in traffic volume in recent years, and also goose asphalt that is excellent in impact tracking due to traffic load and bending flexure. Is used. In addition, since goose asphalt has almost no voids, it has high water tightness and can also function as a waterproof layer. Furthermore, this goose asphalt has a higher fluidity during paving than general asphalt. For this reason, when using goose asphalt for pavement construction, this high fluidity is used to pour it onto the construction base made of steel floor and lay it flat on the asphalt finisher. In this process, it is possible to fill the goose asphalt to every corner such as bolts and stepped portions of the joints in the steel deck.

  Goose asphalt is formed by blending an aggregate and a filler into an asphalt composition obtained by mixing asphalt with a modifying material such as natural asphalt such as Trinidad lake asphalt or thermoplastic elastomer.

  Various techniques for spreading such goose asphalt with an asphalt finisher have been proposed in the past (see, for example, Patent Document 1).

JP 2013-147858 A

  By the way, with the recent significant increase in traffic, problems such as rutting are not negligible even on iron bridges and elevated roads paved with goose asphalt. For this reason, it is expected to develop a new goose asphalt that can be pavement by pouring using the high fluidity as well as the conventional goose asphalt while improving the resistance to rutting (DS value). In particular, the aging of bridges and expressways paved during the high growth period has become serious, and when repairing these, the need to replace with new goose asphalt with excellent resistance to rutting was also revealed. .

  Therefore, the present invention has been devised in view of the above-mentioned problems, and the object of the present invention is pavement by pouring using the resistance to rutting (DS value) and high fluidity as in the past. It is to provide a possible goose asphalt composition.

The goose asphalt composition according to the first invention of the present application is derived from styrene based on (a) 76% by mass to 90% by mass of base asphalt and (b) the total mass of the polymer, with the total mass of the composition being 100% by mass. It is characterized by containing 10 mass%-24 mass% of styrene-butadiene-styrene block copolymer saturated hydrogenated products whose content of a repeating unit is 50 mass%-70 mass%.

The goose asphalt composition according to the second invention of the present application is the styrene-butadiene-styrene block copolymer saturated hydrogenated product 16 in which the content of the repeating unit derived from styrene is 60% by mass to 70% by mass in the first invention. It is characterized by containing mass%-22 mass%.

The goose asphalt composition according to the third invention of the present application is the first invention or the second invention, further comprising (d) a polycyclic diterpene compound having 20 carbon atoms and having a carboxy group, wherein the total mass of the composition is 100% by mass. It is characterized by containing 2 mass%-1.5 mass%.

  According to the present invention having the above-described configuration, it is possible to provide goose asphalt with high fluidity, so that a layer made of goose asphalt can be formed on the steel floor based on the pouring method, particularly compaction. Therefore, it is possible to reduce construction labor and control construction costs.

  In addition, the goose asphalt to which the present invention is applied can be filled up to every corner of the tightening member or the like protruding from the surface of the steel floor based on its high fluidity, and minute voids remain inside the pavement. Can be prevented.

It is a figure which shows the example which paves a goose asphalt composition on the construction base surface which consists of a steel floor. It is a figure for demonstrating the detail of the measuring method of DS value. It is a figure which shows the example of subsidence amount (mm) with respect to test time (minute) when the measurement test start time of DS value is made into the starting point.

  Hereinafter, embodiments of the goose asphalt composition to which the present invention is applied will be described in detail.

  The goose asphalt composition to which the present invention is applied includes base asphalt, SEBS having a styrene content of 50 to 70%: 10% by mass to 24% by mass, a polycyclic diterpene having 20 carbon atoms having a carboxyl group: 0. 2 to 1.5% by mass is contained. Hereinafter, the details of each component composition and the reason for limiting the content thereof will be described. The mass% in each component composition below is simply described as%.

Base asphalt The base asphalt used in the goose asphalt composition to which the present invention is applied is broadly classified and contains solvent deasphalted asphalt and petroleum solvent extracted oil. Solvent deasphalted asphalt is obtained by extracting a lubricating oil component with a solvent from a vacuum distillation residue obtained in a step of distilling an atmospheric distillation residue of crude oil under reduced pressure. Petroleum-based solvent extraction oil is extracted oil produced in the solvent extraction process when producing lubricating oil from crude oil.

Solvent removal asphalt: 30-80%
In the present invention, it is desirable to use propane deasphalted asphalt using propane or propane and butane as a solvent among the solvent deasphalted asphalt.

For example, propane deasphalted asphalt has a penetration of 12 (1/10 mm) at 25 ° C. under JIS K2207, a softening point of 63.5 ° C., a viscosity at 180 ° C. of 132 mPaS, and a density at 15 ° C. of 1062 kg / m ³ . Some may be used. However, these physical properties in propane-deasphalted asphalt are merely examples, and it is needless to say that the present invention is not limited thereto.

  When the content of the solvent deasphalting asphalt is less than 30%, the ratio of petroleum-based solvent extracted oil increases, so that the rutting resistance cannot be improved. On the other hand, if the asphalt content exceeds 80%, the ratio of petroleum solvent extracted oil decreases, and it becomes difficult to flow at the working temperature and the workability is lowered. Further, the compatibility with the hydrogenated thermoplastic elastomer may be lowered. Therefore, the content of the solvent deasphalting asphalt is set to 30 to 80%.

Petroleum solvent extraction oil (extract): 10-40%
The role of the extract is to increase the solubility of the SEBS in the base asphalt and prevent the occurrence of separation in the storage stability. If the amount of SEBS added is large, the amount of extract necessary to be added also increases. In addition, when the extract is added more than necessary with respect to the added amount of SEBS, the strength decreases.

  The extract content relative to the entire goose asphalt composition is determined in consideration of the dynamic stability (DS value) in the wheel tracking test indicating the penetration, softening point, and strength. The content of the extract with respect to the entire asphalt composition is preferably 10 to 40% by weight.

SEBS having a styrene content of 50 to 70%: 10% to 24%
SEBS eliminates double bonds by completely hydrogenating the butadiene block in the styrene-butadiene-styrene block copolymer (SBS), greatly improving heat resistance and weather resistance compared to SBS. . However, since the flexibility of the molecular chain is changed by this hydrogenation treatment, the addition effect given to the modified asphalt is also different from that of SBS. The SEBS may be replaced with any material other than SEBS, such as SEPS, as long as the double bond is eliminated by completely hydrogenating the butadiene block. Then, the case where this SEBS is adopted will be described as an example.

The reason for adopting SEBS is that goose asphalt is actually constructed at about 240 ° C, so it decomposes and gels in normal SBS, but SEBS can maintain its properties sufficiently even at high operating temperatures. It is. SEBS needs to have a styrene content in a range of 50 to 70% and a 23 ° C. density in a range of 940 kg / m ³ or more. When the styrene content is lower than 50%, the ratio of butylene ethylene is increased, and these increase the viscosity more remarkably. This significant increase in viscosity will cause a significant decrease in the fluidity of the overall resulting composition. On the other hand, when the styrene content exceeds 70%, the viscosity is remarkably lowered as the ratio of butylene ethylene decreases, and the fluidity becomes higher. However, the strength of the entire composition cannot be expressed in accordance with such a significant decrease in viscosity, and the DS value is greatly reduced. Preferably, the styrene content is 50-70% and the 23 ° C. density is 940-980 kg / m ³ .

  SEBS more preferably has a styrene content of 60 to 70%, thereby making it possible to further prevent an increase in viscosity and to further suppress the decrease in viscosity, thereby improving the strength of the entire composition. It becomes.

  In addition, in the goose asphalt to which the present invention is applied, there is an aim of improving both the DS value and preventing brittle fracture due to hardening by adding elastic SEBS having the above-described configuration.

  The lower limit of SEBS content is 10%. This is because when the SEBS content is less than 10%, the strength is lowered and the DS value is significantly lowered. The upper limit of SEBS content is 24%. If the SEBS content exceeds 25%, the viscosity of the resulting composition will increase too much, resulting in poor fluidity and poor construction efficiency when performing the casting method. Therefore, the SEBS content is set to 10% or more and 24% or less. The SEBS content is desirably 16 to 22%, and more desirably 17 to 22%. By setting it as such a range, it becomes possible to raise the balance between an increase in strength and an improvement in fluidity.

C20 polycyclic diterpene having a carboxyl group: 0.2 to 1.5%
In the present invention, it is preferable to add an anti-peeling agent in order to prevent exfoliation of the asphalt composition and the aggregate.

  Resin acid can be preferably used as the anti-peeling agent, but the resin acid is a C20 polycyclic diterpene having a carboxyl group, and is abietic acid, dehydroabietic acid, neoabietic acid, pimaric acid, isopimaric acid, It is a rosin containing any one or more of parastrinic acid.

  As the resin acid, in addition to the above-mentioned rosin, disproportionated rosin, dimer acid or trimer acid originating from abietic acid, or a mixture of two or more of these can be used.

  As the rosin, gum rosin, wood rosin, tall oil rosin and the like are used. These rosins can be classified as gum rosin, wood rosin, etc. as described above depending on the origin, raw materials, and collection method, but are obtained as a residual component at the time of steam distillation of pine resin. This rosin is a mixture containing, as components, abietic acid, parastrinic acid, neoabietic acid, dehydroabietic acid, pimaric acid, sandaracopimaric acid, isopimaric acid and the like. This rosin usually softens at about 80 ° C. and melts at 90-100 ° C. Note that rosin contains various resin acids such as abietic acid, dehydroabietic acid, dihydroabietic acid, tetrahydroabietic acid, parastrinic acid, neoabietic acid, and levopimaric acid. It may be used alone.

  In the present invention, gum rosin is used as a preferred rosin, but is not limited thereby.

  If the content of the resin acid is less than 0.2%, the effect of the resin acid is not sufficient, and it is impossible to prevent peeling and improve the compatibility as a final product. On the other hand, when the content of the resin acid exceeds 1.5% by weight, not only the effect of preventing the peeling and improving the compatibility is saturated, but also the amount of the expensive resin acid added. There arises a problem that the raw material cost is significantly increased due to the increase. Moreover, even if the resin acid content exceeds 1.5%, the prevention of peeling and the improvement of compatibility are not significantly improved, but it is disadvantageous in terms of raw material costs. For this reason, it is desirable that the content of the resin acid is 0.2 to 1.5% (more preferably 0.2 to 1%).

  Some anti-peeling agents also have a performance as a lubricant, and in addition to the above-described anti-peeling effect, these act as a lubricant that improves compaction during construction and rolling.

  The goose asphalt composition having the above-described component composition is paved on a construction base surface made of a steel floor 3, for example, as shown in FIG. In such a case, the goose asphalt composition is manufactured in the asphalt plant so as to have the above-described component composition, further blended with coarse aggregate and filler, and further cooked at about 200 to 240 ° C. with a dedicated transport vehicle, at the construction site. It is conveyed to. Then, the heated goose asphalt 2 is poured onto the steel floor 3 using a dedicated asphalt finisher. In this process, the goose asphalt 2 to which the present invention composed of the above-mentioned components is applied has very high fluidity. For this reason, only by pouring the goose asphalt 2 into the steel floor 3, it becomes possible to fill the corners of the tightening member 4 such as a bolt protruding from the surface of the steel floor 3 and a stepped portion (not shown). For this reason, compared with the rolling compaction method, filling can be realized with less construction labor. Incidentally, a waterproof adhesive layer made of epoxy or the like may be provided between the steel floor 3 and the goose asphalt 2. Finally, a general asphalt concrete 1 is filled in the upper layer of the goose asphalt 2 to pave it.

  Thus, in the goose asphalt 2 to which the present invention is applied, since the pouring method is adopted, it is not necessary to perform a process such as compaction after the layer made of the goose asphalt 2 is formed on the steel floor 3. It is possible to reduce construction labor and control construction costs.

  Further, the goose asphalt 2 to which the present invention is applied can be filled into every corner of the tightening member 4 and the like protruding from the surface of the steel floor 3 based on its high fluidity, and the inside of the pavement is minute. It is possible to prevent the voids from remaining. Further, by applying the goose asphalt 2 to which the present invention is applied, it is possible to improve the rutting resistance (DS value). In particular, when the goose asphalt 2 is used for pavement of the bridge, the bridge girder itself is greatly shaken by the vehicle traveling on the bridge. Even in such a case, by applying the goose asphalt 2 to which the present invention is applied, It is possible to improve the rutting property (DS value). In particular, replacement of goose asphalt 2 used for such paving requires that the primary asphalt concrete be peeled off once, so once paved, it will continue to be used for 20-30 years. However, according to the present invention having the above-described configuration, it is possible to suitably exhibit the rutting resistance for 20 to 30 years or more. In particular, by exhibiting excellent rutting resistance in the goose asphalt 2 in the lower layer of the asphalt concrete 1, the durability of the entire pavement including the upper asphalt concrete 1 is improved.

  The present invention will be specifically described below with reference to test methods, examples and comparative examples used in the present invention, but the present invention is not limited to these examples. In the following examples, when only% is described, it indicates mass%.

  In the present invention, as shown in Table 1, a performance test consisting of fluidity (Luel), DS value, penetration, viscosity at 180 ° C., and softening point is performed on the sample obtained for experimental investigation. Hereinafter, a detailed test method will be described. The fluidity and DS value are a mixture test in which aggregates are mixed, and the penetration, viscosity, and softening point are all the test results of the asphalt composition alone. The numerical values in each component composition in Table 1 indicate the content (% by mass).

  First, regarding the fluidity, aggregate was mixed with 12 kg of the prepared goose asphalt mixture under the conditions shown in Table 3, and the fluidity was measured.

  The fluidity of the goose asphalt mixture was determined based on the results of the Luel fluidity test. This Luel fluidity test is performed based on C002 “Luel fluidity test method of goose asphalt mixture” (hereinafter referred to as C002) of “Handbook of Pavement Survey / Test Method” edited by Japan Road Association.

  In this Luer fluidity test, the mixing of the goose asphalt mixture first follows the “C001 goose asphalt mixture penetration test method” in the “Pavement Survey and Test Method Handbook”. For sample preparation, representative samples with no variation in quality are collected according to C002, and the temperature of the sample is about 200-260.

  In the test procedure, the sample is put to the edge of the container of the Luel flowability tester described in C002. At this time, if the temperature of the sample is higher than the planned test temperature, the sample is allowed to cool to the test temperature while slowly stirring with an appropriate tool. When the sample reaches the target test temperature, immediately pass the shaft of the bell wiped with the sample adhering to the surface through the guide hole of the support, and place it at the center of the sample surface with the upper part of the shaft. Next, the mass of 995 g of the bell shaft is released to penetrate the sample under its own weight. The time required to pass from the underline of the index in which the upper end of the guide hole is engraved on the shaft to the upper line (interval of 5 cm) is measured with a stopwatch. This time is Luel fluidity. Also measure the temperature of the sample where the bell penetrated.

  Such a fluidity test is performed 3 to 4 times by changing the test temperature within a range of 200 to 260 ° C., and a relationship between the temperature and the fluidity is obtained to obtain a Luer fluidity of 240 ° C. In this example, if the obtained Luer fluidity value of 240 ° C. is 3 seconds or more and 20 seconds or less, it is determined that the fluidity is excellent (◯), and if it is out of the above range, the fluidity. Is inferior (x).

  The DS value (dynamic stability) is used exclusively as an index for measuring the strength of the road pavement. In this case, the DS value may be used as an evaluation index, and may be applied not only to road pavement but also to any use including a waterproof material and an adhesive material.

  Hereinafter, a method for measuring the DS value will be described. The DS value (dynamic stability) is an index for evaluating the flow resistance (hardness of rutting) of an asphalt composition at a high temperature, and is measured using a wheel tracking tester. The wheel tracking test is carried out at 60 ° C. assuming a summer road surface. A specimen prepared by mixing an asphalt composition with an aggregate (stone obtained by crushing rocks) adjusted to a predetermined particle size described in Table 2 described later is cured at 60 ° C. for 5 hours or more, and the wheels are allowed to travel for 1 hour. For example, as shown in FIG. 2, the specimen 5 consisting of 30 × 30 × 5 cm was cured. The time from the actual preparation of the specimen to the start of the measurement of the DS value is not particularly limited, but the property may change when stored at a high temperature for a long period of time. Therefore, in general, after preparing 1.8 kg of the asphalt composition of the present invention, it is put into an iron can having a diameter of 16 cm, a height of 17 cm, and a plate thickness of 1 mm, and is allowed to cool to room temperature, thereby completing the preparation of the asphalt composition. Within 48 hours, the asphalt composition is placed in an air circulation oven kept at 240 ° C. while being put in an iron can, and is kept for 3 hours and heated.

  Next, the test specimen 5 is reciprocated at a pace of 42 times / minute in the direction of the arrow in the drawing while applying a downward load of 686 N (70 kgf or 70 kg weight) by the wheel 11. By the way, the traveling position by the wheels 11 is the same traveling path without shifting.

  FIG. 3 shows an example of the amount of subsidence (mm) with respect to the test time (minutes) when the DS value measurement test start time is the starting point. As the test time increases starting from the test start time, the amount of settlement due to the reciprocating travel of the wheel 11 increases. This amount of subsidence is the subsidence depth (mm) from the surface of the specimen 5 to the depth direction.

  When measuring the DS value, the amount of settlement from the start of the first test to 45 minutes before is not taken into account. The reason for this is to evaluate the flow resistance in its original meaning because the amount of settlement is determined from the initial test start time to 45 minutes before the elapsed time, based on factors such as meshing with the added aggregate. It is because it becomes impossible.

  When measuring the DS value, focus is on the deformation amount d (mm) of the asphalt composition in 15 minutes from 45 minutes to 60 minutes, starting from the test start time. This d can be calculated by calculating the difference between the amount of settlement after 60 minutes from the test start time and the amount of settlement after 45 minutes from the test start time. The DS value can be obtained from the following equation (2).

DS value (times / mm) = Number of tires run from 45 minutes to 60 minutes (times) / d (mm) (2)
Can be obtained from When the reciprocation frequency by the wheel 11 is 42 (times / minute), the following equation (2) ′ can be rewritten by modifying the equation (2).
DS value (times / mm) = 630 (times) / d (mm) (2) '

  The numerator of the formula (2) ′ means 42 (times / minute) × 15 (minutes) = 630 (times). In other words, the DS value can be obtained from the number of times the tire travels for 15 minutes with respect to d (mm). The higher the DS value, the smaller the amount of deformation of the asphalt composition itself, which means that the material is more resistant to digging and has a higher strength.

  In addition, DS value is not tested using only an asphalt composition, but the aggregates (crushed stone, limestone powder, etc.) shown in Table 2 and the predetermined conditions described later for the asphalt composition are the same as in actual road pavement. Measure using a specimen that was mixed and molded.

  A specific method for measuring the DS value using the goose asphalt composition to which the present invention is applied will be described below.

  A crushed stone made of hard sandstone is used as the aggregate, and stone powder obtained by pulverizing limestone is used to prepare a fine granule (constituent component having a small particle diameter) to prepare a specimen. Materials other than the above-mentioned crushed stone and stone powder such as sea sand and recovered dust are not used because they cause DS value fluctuations.

  The stone powder obtained by pulverizing limestone used for adjusting the particle size of the aggregate is JIS A 5008 “limestone powder for pavement”. The passing mass percentage is 100% at 600 μm sieve, 90-100% at 150 μm, 75 μm. 70 to 100%, and the water content is 1% or less.

  Aggregates other than stone powder use crushed stone made of hard sandstone, and satisfy the properties shown in (1) to (6) below.

(1) Water absorption is less than 1.5%, desirably less than 1.0%. (JIS A 1110)
Here, crushed stone having a water absorption rate of 0.64% is used. When the water absorption rate of the aggregate is high, the aggregate absorbs the coated asphalt, and as a result, the amount of asphalt in the mixture is small. In addition, aggregates with high water absorption greatly change the amount of asphalt absorbed depending on the humidity during use and the wet state of the surface, and as a result, the amount of asphalt in the mixture varies.

  Therefore, in order to keep the amount of asphalt in the mixture constant, the water absorption needs to be less than 1.5%, desirably less than 1.0%.

(2) apparent density 2.60 g / cm ³ or more, 2.70 g / cm ³ or less (JIS A 1110)
Here, crushed stone having an apparent density of 2.66 g / cm ³ was used.

(3) Stability 6% or less, desirably 3% or less (JIS A 1122)
Here, crushed stone having a stability of 2.4% was used. The term “stability” as used herein defines stability against freezing and thawing. The smaller the stability number, the less aggregate destruction during freezing and thawing. The pavement design and construction guidelines stipulate that it is 12% or less, but in order to suppress variations in the properties of aggregates, it is half of the guidelines.

(4) Abrasion weight loss 20% or less, desirably 15% or less (JIS A 1121)
Here, crushed stone with a weight loss of 12.6% was used. The abrasion loss test is a test for evaluating the hardness of the aggregate and the resistance to abrasion, that is, the durability of the aggregate. Since rutting increases when the abrasion loss exceeds 20% (see Non-Patent Document 1), the abrasion loss is 20% or less, preferably 15% or less.

(5) Soft stone amount of 5.0% or less, desirably 3.0% or less (JIS A 1126)
Here, crushed stone with 2.5% soft stone was used. The amount of soft stone is a test for determining whether scratches are attached by a brass bar (Mohs hardness 3-4), and is a test for determining whether the aggregate is harder or softer than brass. The amount of soft stone is a test for evaluating the hardness of the aggregate and the resistance to abrasion, that is, the durability of the aggregate, in the same manner as in the abrasion loss test. The amount of soft stone generally needs to be 5% or less. (See pavement survey and test method manual A008.)

(6) The content of slender or flat stone pieces is 10.0% or less, preferably 5.0% or less (pavement design and construction guidelines (regulation values) and pavement survey / test method manual A008 (test method)).
Here, a crushed stone having an elongated or flat stone piece content of 2.8% was used. As the stone pieces here, those having a major axis / minor axis ratio of 3 or more are generally used as elongated or flat stone pieces. When elongated or flat stone pieces are mixed, there is a possibility that the specimen for paving or testing is likely to be deformed with respect to a load from a certain direction. That is, if a large number of slender or flat stone pieces are mixed, they are oriented in the same direction and are more easily deformed than a load perpendicular to a load parallel to that direction.

  Therefore, when measuring the rutting resistance (DS value), unless the amount of slender or flat stone pieces mixed in is limited, the obtained value will fluctuate greatly.

  A crushed stone and stone powder satisfying these properties were used as aggregates, the aggregate composition shown in Table 2 was adjusted, and specimens were prepared under the conditions shown in Table 3.

  Actually, the preparation of the specimen consists of mixing the asphalt composition and the aggregate. The mixing is 1056 g of asphalt composition heated to 180 ° C. and 10944 g of aggregate prepared by heating to 180 ° C. and synthesizing to the above-mentioned particle size (hereinafter, the adjusted particle size is referred to as synthetic particle size).

  First, 1056 g of asphalt composition was put into a mixer, and 10944 g of aggregate was put into the mixer, and then the asphalt composition and aggregate were mixed for 1 hour. In addition, the temperature at the time of mixing will be about 260 degreeC.

  These asphalt compositions and aggregates that had been mixed were placed in a form for wheel tracking test (inner dimensions 30.0 cm in length, 30.0 cm in width, and 5.0 cm in depth).

なお、混合の使用した装置は、直径２００ｍｍ 高さ２５０ｍｍとされている。また、混合後転圧を行うことなく、そのままの状態で型枠に流し込み、試験を行っている。

In addition, the apparatus used for mixing is 200 mm in diameter and 250 mm in height. In addition, the test is performed by pouring into the mold as it is without performing rolling after mixing.

  The penetration (25 ° C.) was measured by JIS K 2207 “Petroleum Asphalt—Penetration Test Method”. This value is preferably about 10 to 20 (0.1 mm).

  Viscosity (180 ° C.) was measured under the conditions of JPI-5S-54-99 “Viscosity Test Method Using Asphalt Rotational Viscometer” at a measuring temperature of 180 ° C., a spindle SC4-21, a spindle rotation speed of 50 rpm. did.

  The softening point was measured by JIS K 2207 “Petroleum Asphalt—Softening Point Test Method”.

  Hereinafter, in the modified asphalt composition to which the present invention is applied, examples and comparative examples for verifying the effect will be described in detail.

In Table 1, the properties of the used propane deasphalting asphalt include typical penetration of 12 (1/10 mm), softening point of 63.5 ° C., and density at 15 ° C. of 1062 kg / m ³ . Is. The extract used has a typical property of kinematic viscosity at 60 ° C. of 542 mm ² / s and density at 15 ° C. of 976.6 kg / m ³ .

The SEBS1 used has a styrene content of 67%, and therefore is in the range specified in the present invention, and has a 23 ° C. density of 970 kg / m ³ or more. SEBS2 has a styrene content of 42%, is outside the range defined in the present invention, and has a 23 ° C. density of 930 kg / m ³ .

  In Examples 1 to 7, SEBS1 is 10% by mass to 24% by mass, and all are included in the range defined in the present invention.

  All of Examples 1 to 7 were excellent in fluidity, and the DS value exceeded 200 times / mm, indicating excellent rutting resistance.

  Among these Examples 1-7, Examples 3-7 contain SEBS1: 16 mass% -22 mass% which is styrene content 60-70%, As a result, DS value is 300 times. / Mm or more. Also, the fluidity was excellent.

  Moreover, since Examples 4-7 contain 17 mass%-22 mass% of styrene content, DS value is 500 times / mm or more, and the fluidity | liquidity is also excellent. It was.

  On the other hand, in Comparative Example 1, the content of SEBS1 is 8%, which is lower than the lower limit of SEBS defined in the present invention. For this reason, when the DS value is measured, when the tire is run on the mixture specimen mixed with the aggregate, the tire sinks too much, and the measurement itself becomes impossible.

  In Comparative Example 2, SEBS has a styrene content of 60 to 70%, but the SEBS content exceeds 22%. For this reason, although DS value was 300 times / mm or more, fluidity had deteriorated. Moreover, since the styrene content of SEBS to be used was less than 50% in Comparative Example 3, although the DS value was 300 times / mm or more, the fluidity was deteriorated.

1 Asphalt Concrete 2 Goose Asphalt 3 Steel Floor 4 Tightening Member 5 Specimen 11 Wheel

Claims (3)

When the total mass of the composition is 100% by mass,
(A) 76% by mass to 90% by mass of base asphalt;
(B) Styrene-butadiene-styrene block copolymer saturated hydrogenated 10 mass% to 24 mass%, wherein the content of repeating units derived from styrene is 50 mass% to 70 mass % with respect to the total mass of the polymer. A goose asphalt composition characterized by comprising. Styrene content of the repeating unit derived from styrene is 60 wt% to 70 wt% - butadiene - claim 1, characterized in that it contains styrene block copolymer saturated hydrogenated products 16 wt% to 22 wt% Goose asphalt composition. As a further 100 wt% of the total weight of the composition, according to claim, characterized in that it contains polycyclic diterpene compounds 0.2 wt% to 1.5 wt% of 20 carbon atoms having (d) is carboxy sheet group The goose asphalt composition according to 1 or 2.

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