Warm Mix Asphalt Yellowstone National Park Brad Neitzke Western Federal Lands Highway Division

Project Location

Project Details 11.2 Kilometers / 6.93 Miles 11.2 Kilometers / 6.93 Miles Evaluated 2 technologies Evaluated 2 technologies –Advera –Sasobit 28,400 metric tons of mix total 28,400 metric tons of mix total –1/3 of the tonnage per mixture

Final Mixture Quantities 12,200 metric tons of Control Mix 12,200 metric tons of Control Mix 8,750 metric tons of Advera Mix 8,750 metric tons of Advera Mix 7,450 metric tons of Sasobit Mix 7,450 metric tons of Sasobit Mix

Mix Design Details Hveem mix design Hveem mix design –5.3% asphalt content by mix –1.0% hydrated lime added –19 mm mix –12.6% VMA Superpave mix design Superpave mix design –75 Gyration mix –5.2% asphalt content by mix –12.4% VMA

Paving Details Binder Type – PG Binder Type – PG Placed in two 2” lifts Placed in two 2” lifts Mix Temperature ≈ 325°F Mix Temperature ≈ 325°F Placement Temperature ≈ 315°F Placement Temperature ≈ 315°F 90 minute one way haul 90 minute one way haul 7 vibe passes Ingersoll Rand DD vibe passes Ingersoll Rand DD finish passes Ingersoll Rand SD-77 3 finish passes Ingersoll Rand SD-77 Paving started August 21, 2007 Paving started August 21, 2007

Advera Admixture Added at a rate of 0.3% by weight of mix Added at a rate of 0.3% by weight of mix Blown in at the plant – Under binder Blown in at the plant – Under binder Initial mix temp ≈ 275°F Initial mix temp ≈ 275°F Eventual mix temp ≈ 250°F Eventual mix temp ≈ 250°F Same roller pattern Same roller pattern Started paving August 26, 2007 Started paving August 26, 2007

Sasobit Admixture Added at a rate of 1.5% by weight of binder Added at a rate of 1.5% by weight of binder Blown in at the plant – Under binder Blown in at the plant – Under binder Used same port as Advera Used same port as Advera Initial mix temp ≈ 275°F Initial mix temp ≈ 275°F Eventual mix temp ≈ 245°F Eventual mix temp ≈ 245°F Same roller pattern Same roller pattern Started paving August 30, 2007 Started paving August 30, 2007

Data Tested for PG Property No Additive 1.5% Sasobit Rotational Vis, Pa٠s Mass change, % DSR Original, kPa DSR RTFO, kPa DSR PAV, kPa BBR Stiffness BBR m-Value

Mixture Locations

Density Comparison Control Mixture Control Mixture –Average = 93.2% s = Advera Mixture Advera Mixture –Average = 93.9% s = Sasobit Mixture Sasobit Mixture –Average = 93.4% s = 1.157

What Have We Learned Field density achieved in all cases Field density achieved in all cases Saved ≈ 20% in fuel at the plant Saved ≈ 20% in fuel at the plant Temperature at plant hard to regulate Temperature at plant hard to regulate Mix handled similarly Mix handled similarly Workers noted no handling difficulties Workers noted no handling difficulties No smoke No smoke Additives don’t seem to affect mix design Additives don’t seem to affect mix design Sasobit stiffens binder Sasobit stiffens binder

What’s Next More testing by WFLHD More testing by WFLHD –Volumetrics –Recovered asphalt properties –TSR –Rut (Hamburg and APA) Field monitor Field monitor WRI testing and evaluation WRI testing and evaluation FHWA Field Lab data / report FHWA Field Lab data / report

Comments to the TWG Focus on items for success Focus on items for success Good paving practices Good paving practices Performance analysis for equal evaluation Performance analysis for equal evaluation Only one chance Only one chance

QUESTIONS????