Process for preparing an asphalt mixture

1. A process for preparing an asphalt mixture from recycled asphalt pavement (RAP), virgin aggregate, filler and first and second binder materials, comprising steps of

(a) transporting RAP through a first drum and thereby heating the RAP to a temperature of from 70 to 130° C.;

(b) transporting virgin aggregate through a second drum, thereby heating the virgin aggregate to a temperature of from 90 to 130° C.;

(c) adding a first binder material to the RAP in the first drum to provide treated RAP; and

(d) supplying the treated RAP from the first drum to a mixing zone, supplying the virgin aggregate from the second drum to the mixing zone, supplying filler to the mixing zone, supplying a second binder material to the mixing zone, and mixing to provide the asphalt mixture;

wherein the first binder material is a mineral oil or an oil of vegetable or animal origin, wherein the second binder material comprises a hard bitumen component having a penetration at 25° C. of less than 100 1/10mm (measured according to EN 1426 at 25° C.) and further comprises a soft bitumen component having a viscosity of less than 0.3 Pa·s at 100° C. (measured according to EN 13302 at 100° C.), and wherein the hard bitumen component is added as a bitumen emulsion or as a foamed bitumen.

2. A process according to claim 1 , wherein some or all of the RAP is derived from porous asphalt.

3. A process according to claim 1 , wherein the asphalt mixture is a porous asphalt mixture.

4. A process according to claim 1 , wherein the hard bitumen component is added as a foamed bitumen.

5. A process according to claim 1 , wherein in step (d) the treated RAP and the virgin aggregate are added to the mixing zone prior to addition of the filler and the second binder material.

6. A process for preparing an asphalt mixture from recycled asphalt pavement (RAP), virgin aggregate, filler and first and second binder materials, comprising steps of

(a) transporting RAP through a first drum and thereby heating the RAP to a temperature of from 70 to 130° C.;

(b) transporting virgin aggregate through a second drum, thereby heating the virgin aggregate to a temperature of from 90 to 130° C.;

(c) adding a first binder material to the RAP in the first drum to provide treated RAP; and

(d) supplying the treated RAP from the first drum to a mixing zone, supplying the virgin aggregate from the second drum to the mixing zone, supplying filler to the mixing zone, supplying a second binder material to the mixing zone, and mixing to provide the asphalt mixture;

wherein the first binder material is a soft bitumen component having a viscosity of less than 0.3 Pa·s at 100° C. (measured according to EN 13302 at 100° C., wherein the second binder material comprises a hard bitumen component having a penetration at 25° C. of less than 100 1/10mm (measured according to EN 1426 at 25° C.) and wherein the hard bitumen component is added as a bitumen emulsion or as a foamed bitumen.

7. A process according to claim 6 , further comprising: supplying the treated RAP from the first storage vessel to a mixing zone, supplying the virgin aggregate from the second drum to the mixing zone, supplying filler to the mixing zone, supplying a second binder material to the mixing zone, and mixing to provide the asphalt mixture.

8. A process according to claim 7 , wherein the second binder material further comprises a soft bitumen component having a viscosity of less than 0.3 Pa·s at 100° C. (measured according to EN 13302 at 100° C.).

9. A process according to claim 7 , wherein treated RAP is retained in the first storage vessel for a period of from 5 to 60 minutes.

10. A process according to claim 7 , wherein some or all of the RAP is derived from porous asphalt.

11. A process according to claim 7 , wherein the asphalt mixture is a porous asphalt mixture.

12. A process according to claim 7 , wherein the hard bitumen component is added as a foamed bitumen.

13. A process according to claim 7 , wherein the treated RAP and the virgin aggregate are added to the mixing zone prior to addition of the filler and the second binder material.

14. A process according to claim 12 , further comprising: supplying the treated RAP from the first storage vessel to a mixing zone, supplying the virgin aggregate from the second storage vessel to the mixing zone, supplying filler to the mixing zone, supplying a second binder material to the mixing zone, and mixing to provide the asphalt mixture.

15. A process according to claim 14 , wherein the second binder material further comprises a soft bitumen component having a viscosity of less than 0.3Pa·s at 100° C. (measured according to EN 13302 at 100° C.).

16. A process according to claim 14 , wherein treated RAP is retained in the first storage vessel for a period of from 5 to 60 minutes.

17. A process according to claim 14 , wherein some or all of the RAP is derived from porous asphalt.

18. A process according to claim 14 , wherein the asphalt mixture is a porous asphaltmixture.

19. A process according to claim 14 , wherein the hard bitumen component is added as a foamed bitumen.

20. A process according to claim 14 , wherein the treated RAP and the virgin aggregate are added to the mixing zone prior to addition of the filler and the second binder material.

21. A process for preparing an asphalt mixture from recycled asphalt pavement (RAP), virgin aggregate, filler and first and second binder materials, comprising steps of

(a) transporting RAP through a first drum and thereby heating the RAP to a temperature of from 70 to 130° C.;

(b) transporting virgin aggregate through a second drum, thereby heating the virgin aggregate to a temperature of from 90 to 130° C.;

(c) adding a first binder material to the RAP in the first drum to provide treated RAP;

(d) supplying the treated RAP from the first drum to a first storage vessel; and

(e) supplying the treated RAP from the first storage vessel to a mixing zone, supplying the virgin aggregate from the second drum to the mixing zone, supplying filler to the mixing zone, supplying a second binder material to the mixing zone, and mixing to provide the asphalt mixture;

wherein the first binder material is a mineral oil or an oil of vegetable or animal origin, wherein the second binder material comprises a hard bitumen component having a penetration at 25° C. of less than 100 1/10mm (measured according to EN 1426 at 25° C.) and further comprises a soft bitumen component having a viscosity of less than 0.3 Pa·s at 100° C. (measured according to EN 13302 at 100° C.), and wherein the hard bitumen component is added as a bitumen emulsion or as a foamed bitumen.

22. A process according to claim 21 , wherein treated RAP is retained in the first storage vessel for a period of from 5 to 60 minutes.

23. A process according to claim 21 , wherein some or all of the RAP is derived from porous asphalt.

24. A process according to claim 21 , wherein the asphalt mixture is a porous asphalt mixture.

25. A process according to claim 21 , wherein the hard bitumen component is added as a foamed bitumen.

26. A process according to claim 21 , wherein in the treated RAP and the virgin aggregate are added to the mixing zone prior to addition of the filler and the second binder material.

27. A process according to claim 26 , further comprising: supplying the treated RAP from the first storage vessel to a mixing zone, supplying the virgin aggregate from the second storage vessel to the mixing zone, supplying filler to the mixing zone, supplying a second binder material to the mixing zone, and mixing to provide the asphalt mixture.

28. A process according to claim 27 , wherein treated RAP is retained in the first storage vessel for a period of from 5 to 60 minutes.

29. A process according to claim 27 , wherein some or all of the RAP is derived from porous asphalt.

30. A process according to claim 27 , wherein the asphalt mixture is a porous asphalt mixture.

31. A process according to claim 27 , wherein the hard bitumen component is added as a foamed bitumen.

32. A process according to claim 27 , wherein the treated RAP and the virgin aggregate are added to the mixing zone prior to addition of the filler and the second binder material.