Asphalt Binder Aging Methods to Accurately Reflect Mixture Aging (2021) / Chapter Skim
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From page 173... ...
A-1 A P P E N D I X A Proposed Appendix X1 to AASHTO R 28, Modifications for 0.8 mm Thin Film Conditioning (12.5 g Binder Mass) and Commentary
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From page 174... ...
A-2 Asphalt Binder Aging Methods to Accurately Reflect Mixture Aging 1. Proposed Appendix X1 to AASHTO R 28, Modifications for 0.8 mm Thin Film Conditioning (12.5 g Binder Mass)
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From page 175... ...
Proposed Appendix X1 to AASHTO R 28, Modifications for 0.8 mm Thin Film Conditioning (12.5 g Binder Mass) and Commentary A-3 spirits, mineral oil, citrus-based solvents, toluene, or similar solvent followed by acetone to remove the solvent residue from the pans.
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From page 176... ...
A-4 Asphalt Binder Aging Methods to Accurately Reflect Mixture Aging electronic pressure sensor with ±0.5 kPa accuracy and readable to 2 kPa or less. A flow valve shall be installed on the vent port to regulate the flow of nitrogen or air into the vacuum vessel.
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From page 177... ...
Proposed Appendix X1 to AASHTO R 28, Modifications for 0.8 mm Thin Film Conditioning (12.5 g Binder Mass) and Commentary A-5 X1.4.3.5.
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From page 178... ...
A-6 Asphalt Binder Aging Methods to Accurately Reflect Mixture Aging Note X7 – Preheating the vessel to 10°C to 15°C above the conditioning temperature can be used to reduce the drop in PAV temperature during the loading process and minimize the time required to stability the system after loading to attain the required temperature.
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From page 179... ...
Proposed Appendix X1 to AASHTO R 28, Modifications for 0.8 mm Thin Film Conditioning (12.5 g Binder Mass) and Commentary A-7 X1.5.12.
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From page 180... ...
A-8 Asphalt Binder Aging Methods to Accurately Reflect Mixture Aging X1.5.20. Close the vacuum oven and maintain the temperature in the vacuum oven at 170°C ± 5°C for 15 ± 1 minutes without vacuum applied.
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From page 181... ...
Proposed Appendix X1 to AASHTO R 28, Modifications for 0.8 mm Thin Film Conditioning (12.5 g Binder Mass) and Commentary A-9 COMMENTARY FOR PROPOSED APPENDIX X1 TO AASHTO R28, MODIFICATIONS FOR 0.8 MM THIN FILM CONDITIONING (12.5 g BINDER MASS)
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From page 182... ...
A-10 Asphalt Binder Aging Methods to Accurately Reflect Mixture Aging Table A-1. Comparison of Christensen-Andersen Master Curve Parameters for 12.5 g, 20hr, 2.1 MPa PAV conditioning and 50 g, 40-hr, 2.1 MPa PAV conditioning.
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From page 183... ...
Proposed Appendix X1 to AASHTO R 28, Modifications for 0.8 mm Thin Film Conditioning (12.5 g Binder Mass) and Commentary A-11 Figure A-1.
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From page 184... ...
A-12 Asphalt Binder Aging Methods to Accurately Reflect Mixture Aging 3. The 3.2 mm film in AASHTO R 28 is formed by weighing 50.0 g of RTFOT residue into the pan and then allowing it spread out to fully coat the pan during conditioning.
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From page 185... ...
Proposed Appendix X1 to AASHTO R 28, Modifications for 0.8 mm Thin Film Conditioning (12.5 g Binder Mass) and Commentary A-13 the ATS PAV3 is somewhat cumbersome.
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From page 186... ...
A-14 Asphalt Binder Aging Methods to Accurately Reflect Mixture Aging method to rapidly level the sample holder while in the PAV to within 0.025 degrees and verify the levelness using a precision machinist level. For the ATS PAV, this can be accomplished by modifying the leveling ring to move the leveling screws outside of the holder, using fine thread screws, and providing a long handle adjustment wrench.
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From page 187... ...
Proposed Appendix X1 to AASHTO R 28, Modifications for 0.8 mm Thin Film Conditioning (12.5 g Binder Mass) and Commentary A-15 Using the absolute pressure of 0.15 atm specified in AASHTO R 28 for degassing, the 21 percent oxygen concentration of air reduces to less than 0.1 percent after three cycles.
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From page 188... ...
A-16 Asphalt Binder Aging Methods to Accurately Reflect Mixture Aging due to heat losses that occur when opening the oven to insert the loaded pans and during vacuum cycle purging. Based on Equation 1, high accuracy is not needed for the vacuum control or measurement.
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From page 189... ...
Proposed Appendix X1 to AASHTO R 28, Modifications for 0.8 mm Thin Film Conditioning (12.5 g Binder Mass) and Commentary A-17 X1.5.2.
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From page 190... ...
A-18 Asphalt Binder Aging Methods to Accurately Reflect Mixture Aging Note X8 describes how to load pans for the conditioning needed to perform binder grading and ΔTc determination. One hundred grams of binder will be conditioned at 3.2 mm thickness, and 100 g of binder will be conditioned at 0.8 mm film thickness.
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From page 191... ...
Proposed Appendix X1 to AASHTO R 28, Modifications for 0.8 mm Thin Film Conditioning (12.5 g Binder Mass) and Commentary A-19 X1.5.21.
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