Verification of Current Los Angeles (LA) Abrasion Test Criterion for Aggregate Degradation in Airfield Asphalt Pavements

Low-quality mineral aggregates can potentially lead to production, construction, and long-term performance-related problems in asphalt concrete pavements. Therefore, effective qualification criteria for mineral aggregates are paramount. This study was performed to investigate the effectiveness of the Los Angeles abrasion (LAA) test to assess the abrasion resistance of coarse aggregates commonly used in airfield asphalt paving. The LAA test acceptance criteria currently specified by state departments of transportation were examined and compared to the current Department of Defense criterion. Additionally, recent experiences during a forensic evaluation to identify potential sources of excessive presence of foreign object debris on an airfield runway are also briefly discussed in this report. The LAA test and associated acceptance criterion in Unified Facilities Guide Specification (UFGS) 32 12 15.13 were evaluated by testing 24 aggregate sources from various US locations. Also, the Micro-Deval abrasion test was performed as a surrogate abrasion resistance test. Sufficient evidence was not found to suggest adjustments to current LAA test criterion or to recommend the use of an alternative abrasion test. The current UFGS specifications should be improved to provide a more thorough aggregate testing protocol and detailed guidelines regarding aggregate sampling and testing frequency during design and construction of asphalt pavements.