Focus on understanding the key issues associated with proper testing of asphalt binders and solutions to better perform these test.

1. Asphalt Testing for Precision, Accuracy and Maximum Throughput John Casola, Asphalt Market & Products Manager

6. Edge Contributions to the Measurement For 25mm Parallel Plates

7. Eliminate edge failures for extended testing by using a couette geometry (cup & bob) Master Curve data collection over long times and many temperatures

8. Glassy state materials are best tested as bars or rods in Torsion

13. Forced Convection vs. Radiant Plates Heat transfer is a function of velocity of the air flow moving past the heater and in direct contact with the plate Heat transfer is a function of distance from the heater & thermal conductivity of air Plates Gun Heater Heating Elements Dual Tc Plate & Air Cooling gas input Cooling gas input Tc from Plate

15. While you can use Forced Air Ovens for asphalt, accurate calibration of air flow and sample temperature are critical to performance. Heat transfer

18. Dual Heat Exchanger Peltier w/ Preheated Air Purge Peltier Element Tc PT-100 Dual Heat Exchangers w/ Preheated Purge Patent Pending Purge air

22. Time to Thermal Equilibrium is Key Depending on the heat transfer medium time to equilibrium can be long From the new AI ‘Best Practices Manual’ Start 10 min equilibration time from this point

24. Asphalt Sample loading time to Thermal Equilibrium Statistics should be used to determine the instruments time to thermal equilibrium

25. Water is the Best Heat Transfer Medium 25 times the thermal conductivity of air Thermal gradients are significant sources of errors. Here you can see a halving of the Modulus just by reducing the thermal gradients

29. Same Data as previous page (scales are set to be the same as the next page)

30. Addition of an Air Bath to the Chamber (the pre-conditioned purge gas is used to improve thermal conductivity to the edge of the sample)

31. Thermal Hysteresis is very small ( Δ of 1.5% in G* relates to ~ Δ of 0.075 o C or +/- 0.0375 o C)

35. Use Time Temperature Super Position; WLF above 0 o C and Arrhenius below

36. Williams Landel & Ferry TTS Shifted to 135 o C

39. Example of a Newtonian material Neat binder PG64-28 tested to MSCR at 64 o C

40. Example of a Visco-Elastic Binder Modified binder PG70-28 tested to MSCR at 70 o C 100Pa 3200Pa

41. Excessive inertia causes offsets between cycles PG 64-34 MSCR at 100Pa, 64 o C Max Strain ~40%

42. Without inertial effects; Max Strain ~60% PG 64-28 at 100Pa

43. The inertial contribution is greater at higher stress PG 64-34 MSCR at 3200Pa, 64 o C Max Strain +1500%

44. Without inertial effects; Max Strain ~2000% PG 64-28 at 3200Pa

45. With inertial effects; Max Strain 20% PG 70-22 at 100Pa Creep and Recovery 70-22 SBR 100 Pa 0.00E+00 5.00E+00 1.00E+01 1.50E+01 2.00E+01 2.50E+01 0.00E+00 2.00E+01 4.00E+01 6.00E+01 8.00E+01 1.00E+02 1.20E+02 time s Strain % Series1

46. Without inertial effects; Max Strain ~30% PG 70-28 at 100Pa

47. With inertial effects; Max Strain +600% PG 70-22 at 3200Pa

48. Without inertial effects; Max Strain +700% PG 70-28 at 3200Pa

49. With inertial effects; Max Strain 25% PG 67-38 at 100Pa

50. With inertial effects; Max Strain ~1000% PG 67-28 at 3200Pa