Variability of Ignition Furnace Correction Factors (2017)

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D-1 To: NCHRP Project 9-56 Round-Robin Study Participants Subject: Ignition Furnace Tests Thank you for your willingness to participate in the NCHRP Project 9-56 ignition method round-robin study. All tests should be conducted following AASHTO T 308. You are required to conduct ignition tests for asphalt content determination and mechanical analysis of extracted aggregate. For the purpose of this study, your laboratory will be receiv- ing 16 samples of hot mix asphalt. These samples correspond to four mixes, four samples per mix. You are required to test three samples per mix (Label Mix1–Sample 1, Mix1–Sample 2, Mix 1–Sample 3, etc.). One extra sample per mix is provided if needed. You can use this sample if any unpredictable problem arises with Samples 1 through 3. In order reduce variability associated with multi-operator testing, it is required that one technician be designated to conduct these tests. Determining the Asphalt Content of Hot Mix Asphalt by Ignition Method (AASHTO T 308) If your unit is a convention-type furnace (Thermolyne or Gilson), the test temperature for samples from Mixes 1 through 3 should be 1,000°F, and for samples from Mix 4, the test temperature should be 900°F. If your unit is an infrared- type furnace (Troxler), the burning profile for samples from Mixes 1 through 3 should be the default, and for samples from Mix 4, the setting temperature should be Option 1. The following table summarizes this sequence. Sample ID Test Temperature (Thermolyne/Gilson) Burning Profile (Troxler Only) Mix 1–Sample 1 1,000°F Default Mix 1–Sample 2 Mix 1–Sample 3 Mix 1–Sample 4 Mix 2–Sample 1 Mix 2–Sample 2 Mix 2–Sample 3 Mix 2–Sample 4 Mix 3–Sample 1 Mix 3–Sample 2 Mix 3–Sample 3 Mix 3–Sample 4 Mix4–Sample 1 900°F Option 1 Mix4–Sample 2 Mix4–Sample 3 Mix4–Sample 4 Assume that the samples you are receiving are moisture free. Test samples according to the test method and report the information requested in a sample data sheet. You are not required to determine the correction factor; for the purpose of this study use a correction factor of 0.00 for all samples. Mechanical Analysis of Extracted Aggregate (AASHTO T 30 or ASTM D5444) Perform a gradation analysis on the residual aggregate according to the AASHTO or ASTM method. Report the mass of material removed by washing over the 75 µm (No. 200) sieve and report the result to the nearest 0.1 g. Report the total material passing each sieve in a data sheet. The total material passing the 75 µm sieve must include the material removed by washing and the material in the pan after dry sieving. Please complete the round-robin testing within 2 weeks of receiving the samples. A p p e n d i x d Instructions to Round-Robin Participants and Data Report

D-2 Round-Robin Study — Data Report