JP2012007063A - Asphalt for pavement, and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide asphalt for pavement excellent in flowability proof and crack resistance.SOLUTION: The asphalt for pavement includes (1) 50 to 70 mass% straight asphalt having the characters of ≥200 penetration (1/10 mm) at 25°C, 20 to 50°C softening point and 100 to 400 mm/s dynamic viscosity at 120°C, (2) 20 to 40 mass% solvent-deasphalted pitch (SDA pitch) obtained by the extraction treatment of residual oil containing at least one selected from normal pressure distillation residual oil obtained by distilling crude oil at normal pressure and reduced pressure distillation residual oil obtained by normal pressure distillation and reduced pressure distillation to the crude oil, with light reformate obtained by the catalytic reformation of naphtha fraction obtained by the fractionation in the normal pressure distillation of the crude oil as solvent, and having properties of 100 to 200°C softening point and 40 to 80 mass% asphaltene content; and (3) 5 to 15 mass% clarified oil (CLO) obtained as residual oil from a fluidized catalytic cracking device (FCC) and having properties of 80 to 190°C flash point, 20 to 100 mm/s dynamic viscosity at 50°C and 10 to 60 mass% aromatic content.

Description

  The present invention relates to asphalt for paving excellent in long-term serviceability of asphalt pavement and a method for producing the same. Specifically, the present invention relates to a paving asphalt excellent in fluid resistance and crack resistance and a method for producing the same.

Asphalt for pavement, straight asphalt with a penetration (1/10 mm) at 25 ° C. produced by distilling crude oil of 40-100 is generally used, but as a change in the situation surrounding asphalt pavement, In order to extend the pavement service life as long as possible due to the demand for increased stock and cost reduction of asphalt pavement, paving asphalt with excellent flow resistance and crack resistance is required.
Patent Document 1 (Japanese Patent Laid-Open No. 2001-262157) discloses a special crude oil mixture for the purpose of having a good serviceable temperature that does not cause rutting, fatigue cracking, and low-temperature cracking, which are causes of asphalt pavement damage. Production of straight asphalt containing residual oil obtained by distillation under reduced pressure and adjusted so that the penetration (1/10 mm) at 25 ° C. is 45 or more and 71 or less and the kinematic viscosity at 180 ° C. is 90 mm ² / s or less. A method is disclosed.
Further, in order to improve rutting, so-called semi-blown asphalt has been proposed in which a vacuum residue obtained by distilling crude oil is further produced by blowing air for several hours under heating at 200 to 300 ° C. ( Non-patent document 1).
However, these production methods require the use of a special crude oil or a complicated blowing operation (an operation in which air is blown for several hours under heating at 200 to 300 ° C.) in addition to a distillation operation. there were.

JP 2001-262157 A

Tada, Ito, “Asphalt”, Japan Asphalt Association, 1979, Vol. 157, p. 41

  Therefore, in the present invention, a complicated operation such as semi-browning is not performed, and a solvent ascending pitch (SDA pitch) having a high asphaltene content is blended with straight asphalt having a penetration (1/10 mm) at 25 ° C. of 200 or more. Thus, an object of the present invention is to provide a method for producing an asphalt for paving having excellent flow resistance and crack resistance and having a penetration of 10 to 100 at 25 ° C.

  In order to solve the above-mentioned problems, the present inventors have intensively studied the asphalt for paving and its manufacturing method. As a result, by mixing three kinds of base materials having specific properties, the flow resistance and crack resistance are improved. An excellent method for producing asphalt having a penetration of 10 to 100 at 25 ° C. has been completed.

That is, the present invention has the following characteristics: [1] (1) The penetration (1/10 mm) at 25 ° C. is 200 or more, the softening point is 20 to 50 ° C., and the kinematic viscosity at 120 ° C. is 100 to 400 mm ² / s. Having at least one selected from 50 to 70% by mass of straight asphalt, (2) atmospheric distillation residue obtained by atmospheric distillation of crude oil, and vacuum distillation residue obtained by atmospheric and vacuum distillation of crude oil The resulting residual oil is obtained by extraction treatment using light reformate obtained by catalytic reforming of a naphtha fraction fractionated by distillation of crude oil at atmospheric pressure, having a softening point of 100 to 200 ° C. and containing asphaltene Solvent removal pitch (SDA pitch) of 20 to 40% by mass having a property of 40 to 80% by mass, and (3) residual oil obtained from a fluid catalytic cracker (FCC) having a flash point of 80 to 80% 19 Pavement asphalt comprising 5 to 15% by mass of clarified oil (CLO) having a kinematic viscosity at 0 ° C. and 50 ° C. of ²⁰ to 100 mm ² / s and an aromatic content of 10 to 60% by mass About.

  Further, the present invention provides [2] in the above [1] having a property that the penetration (1/10 mm) at 25 ° C. is 10 to 100, the softening point is 44 to 50 ° C., and the viscosity at 60 ° C. is 150 Pa · s or more. It relates to the asphalt for paving as described.

The present invention also includes [3] 50 to 70% by mass of straight asphalt as described in [1] above and 5 to 15% by mass of clarified oil (CLO) as described in [1] above. A mixed base material having a degree (1/10 mm) of 250 or more and a kinematic viscosity at 120 ° C. of 100 to 250 mm ² / s is obtained, and then the solvent delamination pitch (SDA pitch) described in [1] is applied to the mixed base material. It is related with the manufacturing method of the asphalt for pavements characterized by mixing 20-40 mass%.

  In the present invention, [4] 20-40% by mass of the solvent removal pitch (SDA pitch) described in [1] and 5-15% by mass of the clarified oil (CLO) described in [1] are mixed. A mixed base material having a viscosity of 200 to 600 mPa · s at 200 ° C. is obtained, and then 50 to 70% by mass of the straight asphalt described in [1] is mixed with the mixed base material. It relates to a manufacturing method.

  According to the present invention, by mixing a predetermined amount of straight asphalt having a predetermined property, exfoliation pitch (SDA pitch) having a predetermined property, and clarified oil having a predetermined property, fluid resistance and crack resistance are mixed. It is possible to provide an asphalt for pavement having a penetration of 10 to 100 at 25 ° C. which has excellent properties.

The straight asphalt relating to the asphalt for paving of the present invention has a penetration (1/10 mm) at 25 ° C. of 200 or more, preferably 250 or more, and a softening point of 20 to 50 ° C., preferably 25 to 35 ° C., 120 ° C. The viscosity is 100 to 400 mm ² / s, preferably 150 to 300 mm ² / s.
When the penetration of straight asphalt at 25 ° C. deviates from the above range, the flow resistance of the paving asphalt is not preferable. When the softening point deviates from the above range, it is not preferable because the crack resistance of the asphalt for paving is inferior. When the kinematic viscosity at 120 ° C. deviates from the above range, the flow resistance of the asphalt for pavement decreases, which is not preferable.
Here, the penetration (1/10 mm) at 25 ° C., the softening point, and the kinematic viscosity at 120 ° C. are values determined based on JIS K2207 “Petroleum Asphalt”.

The straight asphalt used in the present invention can be produced from an atmospheric distillation residue obtained by subjecting crude oil to atmospheric distillation, a vacuum distillation residue obtained by subjecting crude oil to atmospheric distillation and vacuum distillation, and the like.
The crude oil for obtaining the straight asphalt may be any kind of crude oil as long as the straight asphalt having the above-mentioned properties can be obtained. Specifically, intermediate and naphthenic crude oils located between paraffinic and naphthenic crude oils are preferred. Examples include crude oil, Kuwait crude oil, Lattaway crude oil, Allian crude oil, eosin crude oil, and Solus crude oil. These crude oils can be used alone or in combination.
Moreover, as long as the predetermined straight asphalt properties are satisfied, other asphalt base materials other than the residual oil may be blended to form the straight asphalt according to the present invention.

  In order to obtain the asphalt for paving of the present invention, straight asphalt is blended in an amount of 50 to 70% by mass, preferably 55 to 65% by mass, and more preferably 50 to 60% by mass based on the total amount of paving asphalt. When the blending amount of straight asphalt is less than 50% by mass, the blending amount of CLO is increased, and smoke is generated during construction. On the other hand, if it exceeds 70% by mass, the SDA pitch blending amount is reduced, which is not preferable in terms of flow resistance.

The solvent removal pitch (SDA pitch) used in the present invention has a softening point of 100 to 200 ° C, preferably 120 to 180 ° C, and an asphaltene content of 40 to 80% by mass, preferably 50 to 75% by mass. It is what you have.
When the softening point of the SDA pitch is out of the above range, the flow resistance of the asphalt for pavement is lowered, which is not preferable. Moreover, when the asphaltene content in the SDA pitch deviates from the above range, the flow resistance of the asphalt for paving deteriorates, which is not preferable.
The softening point referred to here is a value measured by JIS K2207 “Petroleum Asphalt-Softening Point Test Method (Ring and Ball Method)”. Further, asphaltene is a value measured by the Petroleum Institute Standard JPI-5S-22-83 “Composition Analysis Method by Asphalt Column Chromatography”.

The solvent removal pitch (SDA pitch) according to the present invention is at least one selected from an atmospheric distillation residue obtained by atmospheric distillation of crude oil, and a vacuum distillation residue obtained by atmospheric distillation and vacuum distillation of crude oil. Is obtained by subjecting a light reformate obtained by catalytic reforming of a naphtha fraction fractionated by atmospheric distillation of crude oil to a solvent as a solvent.
The above-mentioned residual oil is an atmospheric distillation residue separated by atmospheric distillation of an oil by an atmospheric distillation apparatus used in a crude oil refining process, and / or the atmospheric distillation residue is further reduced in pressure. A vacuum distillation residue separated by distillation under reduced pressure is used. The residual oil according to the present invention may be an atmospheric distillation residual oil, a vacuum distillation residual oil, or a mixture of an atmospheric distillation residual oil and a vacuum distillation residual oil. Good.

  The aforementioned light reformate is preferably produced by the following method. First, crude oil is fractionated by an atmospheric distillation device to obtain a naphtha fraction (mainly a fraction of 30 to 230 ° C.). The naphtha fraction is fractionated in advance into a light naphtha fraction (for example, corresponding to a boiling point of 30 to 90 ° C.) and a heavy naphtha fraction (for example, corresponding to a boiling point of 80 to 180 ° C.) by an atmospheric distillation apparatus, and then hydrorefined. (Hydrodesulfurization treatment) may be performed, or after the naphtha fraction is treated with a hydrorefining (hydrodesulfurization treatment) apparatus, it may be fractionated into light naphtha and heavy naphtha. Subsequently, heavy naphtha (mainly boiling point 80 to 180 ° C.) is reformed by a catalytic reformer to obtain a reformate mainly composed of aromatic hydrocarbons. Thereafter, the reformate is separated into a light reformate mainly composed of a hydrocarbon having 5 carbon atoms and a C6 + fraction by a rectifier. The C6 + fraction is mainly composed of aromatic hydrocarbons having 6 or more carbon atoms, and other components such as saturated hydrocarbons, olefinic hydrocarbons, and naphthenic hydrocarbons having 6 or more carbon atoms. It is a waste. Each component contained in the light reformate and the C6 + fraction can be determined by, for example, GC (gas chromatograph) analysis (JIS K2536 “Petroleum product-component test method”) or the like. The separation conditions for the light reformate and the C6 + fraction are not particularly limited as long as they can be separated so that benzene is not included in the light reformate. For example, the C6 + fraction in the light reformate is 30% by volume or less. It adjusts suitably so that it may become. The light reformate thus obtained contains 6 to 12% by volume of butane, 60 to 70% by volume of pentane, and 10 to 30% by volume of hexane. The butane, pentane, and hexane referred to here may be a mixture of normal paraffins and isoparaffins having 4, 5, and 6 carbon atoms, respectively.

  The solvent escape pitch (SDA pitch) according to the present invention is obtained by subjecting the aforementioned residual oil to extraction treatment using the aforementioned light reformate as a solvent. When performing the extraction process, the residual oil and the solvent are mixed by a mixing device such as a mixer of the solvent extraction device, and then the solvent extraction device is maintained at a constant condition that is higher than the critical pressure of the solvent and lower than the critical temperature. To the asphaltene separation tank. In the asphaltene separation tank, asphalt contained in the residual oil precipitates, and the precipitate is continuously withdrawn from the bottom of the asphaltene separation tank, and a slight amount of solvent is removed by the stripper to remove the solvent removal pitch (SDA). Pitch). The oil extracted from the upper part of the asphaltene separation tank is used as deasphalted oil (DAO).

  When the residual oil is extracted using light reformate as a solvent, the extraction temperature is set to 150 ° C. to 200 ° C., and the flow rate ratio of the solvent to the residual oil (solvent / residual oil) is set to 5/1 to 8/1. It is preferable. The extraction temperature of the residual oil is appropriately determined according to the properties of the residual oil, and is adjusted so that the softening point of the solvent removal pitch becomes constant. When the extraction temperature is less than 150 ° C., the softening point of the solvent removal pitch exceeds 200 ° C., it becomes difficult to take out the solvent removal pitch from the solvent extraction apparatus, and the productivity of the solvent removal pitch decreases. If the extraction temperature exceeds 200 ° C., the softening point of the solvent removal pitch becomes less than 100 ° C., and the asphaltene content in the SDA pitch decreases, which is not preferable. Also, if the flow rate ratio of solvent to residual oil (solvent / residual oil) is less than 5/1, the amount of solvent is small, so the extraction efficiency in the asphaltene separation tank decreases, and the asphaltene content in the SDA pitch decreases. It is not preferable. If the ratio of solvent to residual oil (solvent / residual oil) exceeds 8/1, it is not preferable because the energy consumption of the solvent extraction device is increased by circulating more solvent than necessary, resulting in uneconomic operation. . In this way, it is possible to obtain a solvent debonding pitch having a softening point of 100 to 200 ° C. and an asphaltene of 40 to 80% by mass.

  In order to obtain the asphalt for paving of the present invention, 20 to 40% by mass, preferably 20 to 35% by mass, and more preferably 20 to 30% by mass of solvent removal pitch is added based on the total amount of asphalt for paving. When the blending amount of the solvent debonding pitch is less than 20% by mass, it is not preferable in terms of flow resistance. On the other hand, when the blending amount exceeds 40% by mass, it is not preferable in terms of cracking property.

The clarified oil (CLO) used in the present invention is a heavy gas oil, a vacuum gas oil, a deasphalted oil, a pyrolysis oil, an atmospheric residue, etc. obtained in a crude oil refining process using a fluid catalytic cracker (FCC). Is obtained as a residual oil after being fractionated into a light oil such as LPG, catalytic cracking gasoline, catalytic cracking kerosene, catalytic cracking light oil, etc. using a high-boiling fraction as a raw material. Although the properties of CLO differ depending on the operating conditions of the raw material and fluid catalytic cracker (FCC), the clarified oil (CLO) according to the present invention has a flash point of 80 to 190 ° C, preferably 85 to 185 ° C, preferably 50 ° C. The kinematic viscosity is 20 to 100 mm ² / s, preferably 25 to 90 mm ² / s, and the aromatic content is 10 to 60% by mass, preferably 20 to 55% by mass.

When the flash point of CLO deviates from the above range, the light fraction of the paving work evaporates and there is a risk of ignition, which is not preferable. Further, when the kinematic viscosity at 50 ° C. deviates from the above range, the blendability is lowered, which is not preferable. Furthermore, when the aromatic content deviates from the above range, the compatibility of the SDA pitch is lowered, which is not preferable.
The flash point here is a value obtained based on JIS K2265-4 “How to find the flash point-Part 4: Cleveland Opening Method”. The kinematic viscosity at 50 ° C. is JIS K2283 “crude oil and "Petroleum products-kinematic viscosity test method and viscosity index calculation method" is a value obtained based on "the aromatic content is a value obtained based on JPI-5S-22-83" composition analysis by asphalt column chromatography ". .

  In order to obtain the asphalt for paving of the present invention, 5 to 15% by mass, preferably 5 to 12% by mass, more preferably 5 to 10% by mass of clarified oil (CLO) based on the total amount of asphalt for paving. . If the blended amount of the clarified oil is less than 5% by mass, it is not preferable in terms of the compatibility of the SDA pitch. On the other hand, when the blending amount exceeds 15% by mass, it is not preferable in terms of smoke generation during construction.

The asphalt for paving of the present invention preferably has a penetration (1/10 mm) at 25 ° C. of 10 to 100, more preferably 60 to 100, and a softening point of preferably 44 to 50 ° C. at 60 ° C. The viscosity preferably has a property of 150 Pa · s or more. When the penetration at 25 ° C. (1/10 mm), the softening point, and the viscosity at 60 ° C. satisfy predetermined ranges, an asphalt for paving excellent in fluid resistance and crack resistance can be obtained.
Here, the penetration (1/10 mm) at 25 ° C., the softening point, and the kinematic viscosity at 120 ° C. are values determined based on JIS K2207 “Petroleum Asphalt”.

  About the manufacturing method of the asphalt for paving of this invention, as long as the predetermined paving asphalt is obtained, the mixing | blending and mixing method of the said 3 component can employ | adopt a usual means suitably.

For example, 50 to 70 mass% (based on the total amount of paving asphalt) of the above-mentioned predetermined straight asphalt and 5 to 15 mass% (based on the total amount of paving asphalt) described above are mixed, and 25 After obtaining a mixed base material having a penetration (1/10 mm) at 250 ° C. of 250 or more and a kinematic viscosity at 120 ° C. of 100 to 250 mm ² / s, the above-mentioned predetermined solvent debonding pitch (SDA) Pitch) 20 to 40% by mass (based on the total amount of paving asphalt) is preferably mixed to produce paving asphalt. First, straight asphalt and clarified oil (CLO) are mixed to form a mixed base material having a predetermined property, and then the solvent removal pitch (SDA pitch) is mixed with the mixed base material. In order to obtain the asphalt for use, it is possible to adjust the amount of solvent escape pitch (SDA pitch), which facilitates the production of the paving asphalt of the present invention.
Here, the penetration at 25 ° C. (1/10 mm) and the kinematic viscosity at 120 ° C. are values obtained based on JIS K2207 “Petroleum Asphalt”.

In addition, the above-mentioned predetermined solvent removal pitch (SDA pitch) 20 to 40% by mass (based on paving asphalt total amount) and the above-mentioned predetermined clarified oil (CLO) 5 to 15% by mass (based on paving asphalt total amount) After mixing to obtain a mixed base material having a viscosity at 200 ° C. of 200 to 600 mPa · s, the above-mentioned predetermined straight asphalt 50 to 70% by mass (based on the total amount of paving asphalt) is mixed with the mixed base material. It is also preferable to produce paving asphalt. First, solvent degreasing pitch (SDA pitch) and clarified oil (CLO) are mixed to form a mixed base material having a predetermined property, and then straight asphalt is mixed into the mixed base material. The amount of straight asphalt mixed can be adjusted in order to obtain the asphalt for use, and the production of the asphalt for paving of the present invention becomes easy.
In addition, the viscosity at 200 degreeC here is a value calculated | required based on the Petroleum Institute method JPI-5S-54-99 "viscosity test method by an asphalt rotational viscometer".

  In addition to the above-mentioned method for producing asphalt for paving, straight asphalt, solvent escape pitch (SDA pitch), and clarified oil (CLO) may be mixed together to produce paving asphalt. After mixing the solvent removal pitch to make a mixed base material, the mixed base material may be mixed with CLO to produce a paving asphalt.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

(Base material)
As a base material, straight asphalt 1 to 6 consisting of the vacuum distillation residue shown in Table 1, SDA pitch 1 to 9 obtained by extracting the vacuum distillation residue with light reformate, the residue of the fluid catalytic cracker (FCC) CLO1-6 which are oil were prepared. The properties of the base material were adjusted by changing the type of processing oil and processing conditions.

Example 1
Straight asphalt 1, SDA pitch 1, and CLO 1 were mixed to obtain paving asphalt 1, and the flow resistance and crack resistance of the paving asphalt 1 were evaluated. Table 2 shows the mixing ratio of the base materials, the properties of the asphalt for paving, and the evaluation results.

(Example 2)
Straight asphalt 2, SDA pitch 2, and CLO 2 were mixed to obtain paving asphalt 2, and the flow resistance and crack resistance of the paving asphalt 2 were evaluated. Table 2 shows the mixing ratio of the base materials, the properties of the asphalt for paving, and the evaluation results.

(Example 3)
The asphalt 3 for pavement was obtained by mixing the straight asphalt 3, SDA pitch 3, and CLO3, and the flow resistance and crack resistance of the pavement asphalt 3 were evaluated. Table 2 shows the mixing ratio of the base materials, the properties of the asphalt for paving, and the evaluation results.

Example 4
Straight asphalt 4 and CLO 4 are mixed to obtain a mixed base material having a penetration of 400 at 25 ° C., a softening point of 20 ° C. and a kinematic viscosity of 130 mm ² / s at 120 ° C., and then mixing SDA pitch 4 with the mixed base material. Pavement asphalt 4 was obtained, and the flow resistance and crack resistance of the pavement asphalt 4 were evaluated. Table 2 shows the mixing ratio of the base materials, the properties of the asphalt for paving, and the evaluation results.

(Example 5)
Straight asphalt 5 and CLO 5 are mixed to obtain a mixed base material having a penetration of 400 at 25 ° C., a softening point of 25 ° C., and a kinematic viscosity of 160 mm ² / s at 120 ° C., and then mixing SDA pitch 5 with the mixed base material. Asphalt 5 for pavement was obtained, and the flow resistance and crack resistance of the pavement asphalt 5 were evaluated. Table 2 shows the mixing ratio of the base materials, the properties of the asphalt for paving, and the evaluation results.

(Example 6)
Straight asphalt 4 and CLO 6 are mixed to obtain a mixed base material having a penetration of 350 at 25 ° C., a softening point of 30 ° C. and a kinematic viscosity of 190 mm ² / s at 120 ° C., and then mixing SDA pitch 6 with the mixed base material. Asphalt 6 for pavement was obtained, and the flow resistance and crack resistance of the pavement asphalt 6 were evaluated. Table 2 shows the mixing ratio of the base materials, the properties of the asphalt for paving, and the evaluation results.

(Example 7)
SDA pitch 3 and CLO3 are mixed to obtain a mixed base material with a penetration of 18 at 25 ° C., a softening point of 95 ° C. and a viscosity of 470 mPa · s at 200 ° C. Then, straight asphalt 3 is mixed with the mixed base material and then paved. Asphalt 7 was obtained, and the flow resistance and crack resistance of the paved asphalt 7 were evaluated by the test methods described below. Table 2 shows the mixing ratio of the base materials, the properties of the asphalt for paving, and the evaluation results.

(Example 8)
SDA pitch 5 and CLO5 are mixed to obtain a mixed base material with a penetration of 10 at 25 ° C., a softening point of 90 ° C. and a viscosity of 420 mPa · s at 200 ° C., and then mixed with straight asphalt 3 into the mixed base material. Asphalt 8 was obtained, and the flow resistance and crack resistance of the paved asphalt 8 were evaluated. Table 2 shows the mixing ratio of the base materials, the properties of the asphalt for paving, and the evaluation results.

Example 9
SDA pitch 1 and CLO1 are mixed to obtain a mixed base material with a penetration of 20 at 25 ° C., a softening point of 85 ° C. and a viscosity at 200 ° C. of 360 mPa · s, and then mixed with straight asphalt 1 into the mixed base material. Asphalt 9 was obtained, and the flow resistance and crack resistance of the paved asphalt 9 were evaluated. Table 2 shows the mixing ratio of the base materials, the properties of the asphalt for paving, and the evaluation results.

  Any of the asphalts for paving of Examples 1 to 9 exhibited excellent characteristics in flow resistance and crack resistance.

(Comparative Example 1)
Straight asphalt 6 having a low penetration and a high kinematic viscosity at 120 ° C., SDA pitch 7 and CLO 5 having a high softening point and a high asphaltene content are mixed to obtain asphalt 10 for paving. The fluidity and crack resistance were evaluated. Table 3 shows the mixing ratio of the base materials, the properties of the asphalt for paving, and the evaluation results. Even if the properties of the asphalt for paving were the same as those in the examples, both the flow resistance and crack resistance of the asphalt 10 for paving were insufficient.

(Comparative Example 2)
Pavement asphalt 11 was obtained by mixing straight asphalt 4, low softening point, and low asphaltene content SDA pitch 8 and CLO4, and the flow resistance and crack resistance of the pavement asphalt 11 were evaluated. Table 3 shows the mixing ratio of the base materials, the properties of the asphalt for paving, and the evaluation results. Even though the properties of the asphalt for paving were the same as those in the examples, both the flow resistance and crack resistance of the asphalt 11 for paving were insufficient.

(Comparative Example 3)
Without using straight asphalt, only SDA pitch 9 and CLO4 were mixed to obtain asphalt 12 for pavement, and the flow resistance and crack resistance of the pavement asphalt 12 were evaluated. Table 3 shows the mixing ratio of the base materials, the properties of the asphalt for paving, and the evaluation results. Even though the properties of the paving asphalt were the same as in the examples, the paving asphalt 12 was insufficient in crack resistance.

In addition, the flow resistance of the examples and comparative examples of the present application was evaluated by dynamic stability by a wheel tracking test, and the crack resistance was evaluated by a bending test.
The wheel tracking test and the bending test are the methods described in 3-7-3 “Wheel Tracking Test Method” and 3-7-5 “Bending Test Method” of the Japan Road Association “Pavement Test Method Handbook”, respectively. went. The outline of the test method is described below.

(Wheel tracking test)
An asphalt mixture obtained by heating and mixing asphalt and aggregate is put in a predetermined mold (300 × 300 × 50 mm), and a test piece is reciprocated in a constant temperature room at 60 ° C. with a small wheel with a specified load (686 ± 10 N). The amount of deformation (rubbing amount) at 60 minutes and 60 minutes is measured, the dynamic stability (times / mm) is determined, and the resistance of the mixture to rutting is evaluated.
The larger the value of the dynamic stability (DS), the better the flow resistance of the heated asphalt mixture at a high temperature. Generally, in order to prevent rutting, the dynamic stability needs to be 500 or more.

(Bending test)
An asphalt mixture obtained by heating and mixing asphalt and aggregate is put into a predetermined mold (300 × 300 × 50 mm) and shaped, and then a specimen having a shape of 300 × 100 × 50 mm is cut out to prepare a specimen, −10 After curing at 0 ° C., the specimen is set on a loading tester and concentratedly loaded at the center at a loading speed of 50 mm / min. The sample is loaded until the specimen breaks, showing the maximum load, and the load and amount of deformation are obtained, and the bending strength at break (at the maximum load) and strain at break are obtained.
In general, the larger the bending strength and strain value at break, the better the durability against cracking.

(Evaluation)
From the results of the wheel tracking test, when the dynamic stability was 500 (times / mm) or more, it was evaluated that “no rubbing occurred: ○”.
Furthermore, from the bending test results, it was evaluated that “no cracks: ○”, “cracks in some cases: Δ”, “with cracks: ×”.

  According to the present invention, a paving asphalt having excellent flow resistance and crack resistance is provided.

Claims (4)

(1) Straight asphalt having a property that the penetration (1/10 mm) at 25 ° C. is 200 or more, the softening point is 20 to 50 ° C., and the kinematic viscosity at 120 ° C. is 100 to 400 mm ² / s, (2) An atmospheric distillation residue obtained by atmospheric distillation of crude oil, a residue containing at least one selected from vacuum distillation residue obtained by atmospheric distillation and vacuum distillation of crude oil, and crude oil at atmospheric pressure Properties having a softening point of 100 to 200 ° C. and an asphaltene content of 40 to 80% by mass, obtained by subjecting a light reformate obtained by contact modification of a naphtha fraction obtained by distillation and distillation to a solvent. Solvent escape pitch (SDA pitch) of 20 to 40% by mass, and (3) residual oil obtained from a fluid catalytic cracker (FCC) having a flash point of 80 to 190 ° C. and a kinematic viscosity at 50 ° C. Asphalt for paving, characterized by comprising 5 to 15% by mass of clarified oil (CLO) having a property of ²⁰ to 100 mm ² / s and an aromatic content of 10 to 60% by mass.   The asphalt for paving according to claim 1, wherein the asphalt has a property that the penetration (1/10 mm) at 25 ° C is 10 to 100, the softening point is 44 to 50 ° C, and the viscosity at 60 ° C is 150 Pa · s or more. . The penetration (1/10 mm) at 25 ° C. is 250 or more by mixing 50 to 70% by mass of the straight asphalt according to claim 1 and 5 to 15% by mass of the clarified oil (CLO) according to claim 1. A mixed base material having a kinematic viscosity at 120 ° C. of 100 to 250 mm ² / s is obtained, and the mixed base material is mixed with 20 to 40% by mass of the solvent removal pitch (SDA pitch) according to claim 1. A method for producing asphalt for paving.   The viscosity at 200 ° C. is 200 to 600 mPa · s by mixing 20 to 40% by mass of the solvent removal pitch (SDA pitch) according to claim 1 and 5 to 15% by mass of the clarified oil (CLO) according to claim 1. A method for producing a paving asphalt, comprising: obtaining a mixed base material of s, and then mixing 50 to 70% by mass of the straight asphalt according to claim 1 into the mixed base material.