Asphalt composition

1. An asphalt composition, comprising:

an asphalt and an asphalt modifier,

wherein the asphalt modifier comprises a polyesteramide that contains an alcohol component-derived structural unit, a carboxylic acid component-derived structural unit, and a polyamide component-derived structural unit.

2. The asphalt composition according to claim 1 , wherein the polyesteramide has an [alcohol component/amide bond] ratio, which is a molar ratio of the alcohol component-derived structural unit to the amide bond in the polyamide component-derived structural unit, of 40/60 or more and 95/5 or less.

3. The asphalt composition according to claim 1 , wherein the polyesteramide has a solubility in toluene at 20° C. of 10 g/L or more.

4. The asphalt composition according to claim 1 , wherein the polyamide component-derived structural unit comprises one or more selected from the group consisting of nylon 6 and nylon 6,6.

5. The asphalt composition according to claim 1 , wherein the alcohol component-derived structural unit comprises one or more selected from the group consisting of an aliphatic diol, an aromatic diol, and a trihydric or higher polyhydric alcohol.

6. The asphalt composition according to claim 1 , wherein the alcohol component-derived structural unit comprises an alkylene oxide adduct of bisphenol A.

7. The asphalt composition according to claim 1 , wherein the carboxylic acid component-derived structural unit comprises one or more selected from the group consisting of an aliphatic dicarboxylic acid, an aromatic dicarboxylic acid, and a tribasic or higher and hexabasic or lower polybasic carboxylic acid.

8. The asphalt composition according to claim 1 , wherein the polyesteramide has a [carboxylic acid component/alcohol component] ratio, which is a molar ratio of the carboxylic acid component-derived structural unit to the alcohol component-derived structural unit, of 0.7 or more and 1.5 or less.

9. The asphalt composition according to claim 1 , wherein the polyesteramide has an acid value of 2 mgKOH/g or more and 40 mgKOH/g or less.

10. The asphalt composition according to claim 1 , wherein the polyesteramide has a hydroxyl value of 1 mgKOH/g or more and 50 mgKOH/g or less.

11. The asphalt composition according to claim 1 , wherein the asphalt modifier is contained in an amount of 0.1 parts by mass or more and 50 parts by mass or less relative to 100 parts by mass of the asphalt.

12. An asphalt mixture, comprising:

the asphalt composition according to claim 1 and an aggregate.

13. The asphalt mixture according to claim 12 , wherein the aggregate has a content of a powder component with a particle diameter of 150 μm or less of 8% by mass or more and 15% by mass or less.

14. An asphalt modifier, comprising:

a polyesteramide that contains an alcohol component-derived structural unit, a carboxylic acid component-derived structural unit, and a polyamide component-derived structural unit.

15. A method for producing the asphalt modifier according to claim 14 , the method comprising:

polycondensating an alcohol component, a carboxylic acid component, and a polyamide component to provide the polyesteramide.

16. A method for producing the asphalt mixture according to claim 12 , the method comprising:

polycondensating an alcohol component, a carboxylic acid component, and a polyamide component to provide the polyesteramide; and

mixing a heated aggregate, an asphalt, and the polyesteramide.

17. The method according to claim 16 , wherein the heated aggregate has a temperature of 130° C. or higher and 230° C. or lower.

18. The method according to claim 16 , wherein the mixing is performed at a temperature of 130° C. or higher and 230° C. or lower.

19. A method for paving a road, the method comprising:

laying the asphalt mixture according to claim 12 on a road to form an asphalt pavement material layer.

20. The method according to claim 19 , wherein the laying of the asphalt mixture comprises a process of compacting the asphalt mixture at a temperature of 100° C. or higher and 200° C. or lower.