Recently the standard asphalt specifications for construction of airports were updated to include Asphalt Pavement Analyzer (APA) results. The December 2018 FAA Advisory Circular states “P-401:…added use of the Asphalt Pavement Analyzer…eliminating the need to run stability and flow when using the Marshall Methods and allowing the same asphalt design criteria in Table 1 to apply regardless of which mix design method is selected, Marshall or Gyratory.”
Asphalt contractors must submit their asphalt designs meeting the following criteria:
Table 1 – Asphalt Design Criteria from FAA AC 150/5370-10H Item P-401
The APA procedure has shown mixes that meet the requirements above perform well under aircraft loading. The APA is preferred on airport pavements projects serving aircraft greater than 60,000 pounds. If APA is not available in an area, compacted mix design samples may be sent to a laboratory that has an APA.3
The test method AASHTO T 340 describes a procedure for testing the rutting susceptibility of hot mix asphalt. Most commonly the wheel is tracked across the sample for 8,000 passes. It takes approximately 2.5 hours to complete 8,000 passes, but samples must be conditioned for 6 hours prior to running the test.
Asphalt Testing Solutions & Engineering (ATS) offers FAA asphalt mix designs for asphalt contractors, including TSR and APA testing all in-house at its Jacksonville, Florida laboratory.
1Test specimens for TSR shall be compacted at 7 ± 1.0% air voids. In areas subject to freeze-thaw, use freeze-thaw conditioning in lieu of moisture conditioning per ASTM D4867.
2AASHTO T 340 at 100 psi hose pressure at 64°C test temperature may be used in the interim. If this method is used the required value shall be less than 5mm @ 8,000 passes
3excerpt from USDOT FAA Advisory Circular – Standard Specifications for Construction of Airports – 12/21/18
