Modified asphalt binders and asphalt paving compositions
View Patent ↗A method for forming a modified asphalt binder composition, the method comprising preparing a phosphorus pentasulfide-binder concentrate by introducing and mixing phosphorus pentasulfide and asphalt binder, where the phosphorus pentasulfide-binder concentrate includes greater than 0.5 parts by weight phosphorus pentasulfide per 100 parts by weight asphalt, preparing a polymer-binder concentrate by introducing and mixing polymer and asphalt binder, where the polymer-binder concentrate includes greater than 5 parts by weight polymer per 100 parts by weight asphalt, and introducing and mixing the phosphorus pentasulfide-binder concentrate with the polymer-binder concentrate to form a modified asphalt binder composition.
1. A method for forming a modified asphalt binder composition, the method comprising:
preparing a phosphorus pentasulfide-binder concentrate by introducing and mixing phosphorus pentasulfide and asphalt binder, where the phosphorus pentasulfide-binder concentrate includes greater than 0.5 parts by weight phosphorus pentasulfide per 100 parts by weight asphalt;
preparing a polymer-binder concentrate by introducing and mixing polymer and asphalt binder, where the polymer-binder concentrate includes greater than 5 parts by weight polymer per 100 parts by weight asphalt; and
introducing and mixing the phosphorus pentasulfide-binder concentrate with the polymer-binder concentrate to form a modified asphalt binder composition.
2. The method of claim 1 , where additional asphalt binder is introduced and mixed with the phosphorus pentasulfide-binder concentrate and the polymer-binder concentrate to form a modified asphalt binder composition includes greater than 2.0 parts by weight phosphorus pentasulfide per 100 parts by weight asphalt binder greater than 10 parts by weight polymer per 100 parts by weight asphalt binder.
3. The method of claim 2 , where additional asphalt binder is introduced and mixed with the phosphorus pentasulfide-binder concentrate and the polymer-binder concentrate to form a modified asphalt binder composition includes greater than 5.0 parts by weight phosphorus pentasulfide per 100 parts by weight asphalt binder and greater than 15 parts by weight polymer per 100 parts by weight asphalt binder.
4. The method of claim 2 , where additional asphalt binder is introduced and mixed with the phosphorus pentasulfide-binder concentrate and the polymer-binder concentrate to form a modified asphalt binder composition includes greater than 8.0 parts by weight phosphorus pentasulfide per 100 parts by weight asphalt binder and greater than 18 parts by weight polymer per 100 parts by weight asphalt binder.
5. The method of claim 1 , where the phosphorus pentasulfide-binder concentrate and the polymer-binder concentrate are prepared at one or more facilities, and where said step of introducing and mixing the phosphorus pentasulfide concentrate and polymer-binder concentrate takes place at a facility distinct from the one or more facilities where the phosphorus pentasulfide-binder and polymer-binder concentrate are prepared.
6. The method of claim 1 , where the phosphorus pentasulfide-binder concentrate and polymer-binder concentrate are transported before said step of introducing.
7. The method of claim 1 , where the modified asphalt binder composition is introduced with aggregate to form a paving composition.
8. The method of claim 1 , where the polymer is an unsaturated polymer including at least 5 non-conjugated double bonds per 100 carbon atoms in the polymer.
9. The method of claim 1 , where the phosphorus pentasulfide-binder concentrate and the polymer-binder concentrate are diluted with additional asphalt prior to said step of introducing and mixing.
10. The method of claim 1 , where the modified asphalt binder composition is diluted with additional asphalt after said step of introducing and mixing.