Warm mix paving composition w/lubricating antistrip additive
The present invention provides an asphalt paving composition including an essentially water-free, non-foamed warm mix asphalt binder composition modified with lubricating antistrip additives that can be mixed with uncompacted aggregate to provide a warm mix paving composition of the aggregate adequately coated with the essentially water-free, non-foamed binder and lubricating antistrip additive. This warm mix paving composition may be mixed at temperatures of 280° F. or lower and may be compacted at temperatures of 260° F. or lower that are below mixing and compacting temperatures of similar paving compositions that do not contain the disclosed lubricating antistrip additives.
1. An asphalt paving composition comprising functionally dry, essentially water-free, non-foamed asphalt binder containing lubricating antistrip additive mixed with uncompacted aggregate to provide a warm mix paving composition of the aggregate adequately coated with the functionally dry, essentially water-free, non-foamed asphalt binder and lubricating antistrip additive, wherein the lubricating antistrip additive reduces the mixing and compaction temperature of the warm mix paving composition such that the paving composition is produced at and is at a temperature of 280° F. or lower and can be compacted at a temperature of 260° F. or lower, and if the warm mix paving composition also comprises a lubricating wax, then the lubricating wax is 0.5 weight percent or less of the asphalt binder weight.
2. An asphalt paving composition according to claim 1 wherein the lubricating antistrip additive is a liquid.
3. An asphalt paving composition according to claim 1 wherein the lubricating antistrip additive comprises a surfactant.
4. An asphalt paving composition according to claim 3 wherein the lubricating antistrip surfactant provides improved moisture resistance to the warm mix asphalt paving composition.
5. An asphalt paving composition according to claim 3 wherein the lubricating antistrip additive comprises a cationic surfactant.
6. An asphalt paving composition according to claim 1 wherein the lubricating antistrip additive comprises a phosphate ester.
7. An asphalt paving composition according to claim 1 wherein the lubricating antistrip additive comprises an amine.
8. An asphalt paving composition according to claim 1 wherein the lubricating antistrip additive comprises a polyamine.
9. An asphalt paving composition according to claim 1 wherein the lubricating antistrip additive comprises an ethoxylated tallow diamine.
10. An asphalt paving composition according to claim 1 wherein the lubricating antistrip additive lowers the dry tensile strength of the warm mix paving composition.
11. An asphalt paving composition according to claim 1 wherein the lubricating antistrip additive provides a warm mix paving composition having little or no visually verifiable debonding of the asphalt binder composition from the aggregate.
12. An asphalt paving composition according to claim 1 wherein the asphalt binder containing lubricating antistrip additive was at a temperature of 280° F. or lower prior to being mixed with the uncompacted aggregate.
13. An asphalt paving composition according to claim 1 wherein the warm mix paving composition is produced at and is at a temperature of 220-240° F.
14. An asphalt paving composition according to claim 1 wherein the warm mix paving composition can be compacted at a temperature of 205-225° F.
15. An asphalt paving composition according to claim 1 wherein the warm mix paving composition when paved and compacted has a compacted density 91% or higher compared to maximum theoretical density.
16. An asphalt paving composition according to claim 1 wherein the lubricating antistrip additive is about 0.1-1.0 weight percent of the asphalt binder weight.
17. An asphalt paving composition according to claim 1 wherein the lubricating antistrip additive is about 0.2-1.0 weight percent of the asphalt binder weight.
18. An asphalt paving composition according to claim 1 comprising an amount of lubricating antistrip additive of about 0.1-0.5 weight percent of the asphalt binder weight.
19. An asphalt paving composition according to claim 1 wherein the lubricating antistrip additive provides sufficient lubrication so that the aggregate can be adequately coated at a warm mix temperature 30-50° F. lower than the temperature needed to coat the aggregate without the lubricating antistrip additive.
20. An asphalt paving composition according to claim 1 wherein the lubricating antistrip additive provides sufficient lubrication so that the aggregate can be adequately coated at a warm mix temperature more than 50° F. lower than the temperature needed to coat the aggregate without the lubricating antistrip additive.
21. An asphalt paving composition according to claim 1 wherein the lubricating antistrip additive provides sufficient lubrication so that the aggregate can be adequately coated at a warm mix temperature as much as 100° F. lower than the temperature needed to coat the aggregate without the lubricating antistrip additive.
22. An asphalt paving composition according to claim 1 wherein the lubricating antistrip additive provides sufficient lubrication so that the warm mix paving composition can be compacted at a warm mix temperature 30-50° F. lower than a comparison temperature needed for compaction of an asphalt and aggregate mixture that does not contain the lubricating antistrip additive.
23. An asphalt paving composition according to claim 1 wherein the lubricating antistrip additive provides sufficient lubrication so that the warm mix paving composition can be compacted at a warm mix temperature more than 50° F. lower than a comparison temperature needed for compaction of an asphalt and aggregate mixture that does not contain the lubricating antistrip additive.
24. An asphalt paving composition according to claim 1 wherein the lubricating antistrip additive provides sufficient lubrication so that the warm mix paving composition can be compacted at a warm mix temperature as much as 100° F. lower than a comparison temperature needed for compaction of an asphalt and aggregate mixture that does not contain the lubricating antistrip additive.
25. An asphalt paving composition according to claim 1 wherein the asphalt binder is a Performance Graded (PG) asphalt binder.
26. An asphalt paving composition according to claim 1 wherein the asphalt binder comprises a polymer-modified, acid-modified or polymer- and acid-modified binder.
27. An asphalt paving composition according to claim 1 wherein the aggregate includes up to 100 weight percent reclaimed asphalt pavement (RAP).
28. An asphalt paving composition according to claim 1 wherein a blend of the asphalt binder and lubricating antistrip additive has a measured maximum normal force no more than about 5.5 Newtons at 90° C. using a dynamic shear rheometer with a 50 μm gap.
29. An asphalt paving composition according to claim 1 wherein a blend of the asphalt binder and lubricating antistrip additive has a measured maximum normal force no more than about 3 Newtons at 90° C. using a dynamic shear rheometer with a 50 μm gap.
30. An asphalt paving composition according to claim 1 wherein the warm mix paving composition contains less than 5 weight percent water.
31. An asphalt paving composition according to claim 1 wherein the warm mix paving composition contains less than 1 weight percent water.
32. An asphalt paving composition according to claim 1 wherein the warm mix paving composition contains less than 0.5 weight percent water.
33. A method of making a warm mix paving composition comprising the steps of:
(a) adding a lubricating antistrip additive to an asphalt binder to provide an asphalt binder composition, and
(b) mixing the asphalt binder composition with aggregate to coat the aggregate and produce a functionally dry, essentially water-free, non-foamed warm mix paving composition at a warm mix temperature of 280° F. or lower, wherein if the warm mix paving composition also comprises a lubricating wax, then the lubricating wax is 0.5 weight percent or less of the asphalt binder weight.
34. A method according to claim 33 , wherein the lubricating antistrip additive provides sufficient lubrication so that the aggregate can be adequately coated at a warm mix temperature 30-50° F. lower than the temperature needed to coat the aggregate without the lubricating antistrip additive.
35. A method according to claim 33 , wherein the lubricating antistrip additive provides sufficient lubrication so that the aggregate can be adequately coated at a warm mix temperature more than 50° F. lower than the temperature needed to coat the aggregate without the lubricating antistrip additive.
36. A method according to claim 33 , wherein the lubricating antistrip additive provides sufficient lubrication so that the aggregate can be adequately coated at a warm mix temperature as much as 100° F. lower than the temperature needed to coat the aggregate without the lubricating antistrip additive.
37. An asphalt paving composition consisting essentially of functionally dry, essentially water-free, non-foamed asphalt binder containing lubricating antistrip additive mixed with uncompacted aggregate to provide a warm mix paving composition of the aggregate adequately coated with binder and lubricating antistrip additive, wherein the lubricating antistrip additive reduces the mixing and compaction temperature of the warm mix paving composition such that the paving composition is produced at and is at a temperature of 280° F. or lower and can be compacted at a temperature of 260° F. or lower.
38. An asphalt paving composition comprising functionally dry, essentially water-free, non-foamed asphalt binder containing lubricating antistrip additive mixed with uncompacted aggregate to provide a warm mix paving composition of the aggregate adequately coated with the functionally dry, essentially water-free, non-foamed asphalt binder and lubricating antistrip additive, wherein the lubricating antistrip additive is about 0.1-1.0 weight percent of the asphalt binder weight and reduces the mixing and compaction temperature of the warm mix paving composition such that the paving composition is produced at and is at a temperature of 220-240° F. and can be compacted at a temperature of 205-225° F.