Asphalt Mix Evaluations: Case Study at San Francisco International Airport

Abstract

A forensic study of asphalt mix performance at the San Francisco International Airport (SFIA) using the simple shear test developed by the Strategic Highway Research Program is described. The study examined taxi ways subjected to stationary and slow movements of heavy aircraft wheel loads and covered a period of about 2.5 years. The results of the study indicate the need to modify (or change) current FAA criteria for mix design of asphalt mixes for heavy-duty airfield pavements, particularly for taxi ways used for takeoff operations and subjected to stop-and-go operations of heavy aircraft like the Boeing 747-400. Information presented suggests that the simple shear test conducted in repeated loading while the height of the specimen is maintained constant (RSST-CH) can be used as a replacement for the current FAA mix evaluation procedure using the Marshall test. Mix design criteria are presented and are based on satisfactory performance of a high-stability mix introduced at SFIA for taxiways.

Investigating High-Temperature PG Grade Adjustment Recommendations for Airfield Pavements

“…Historically, various airfield pavements have experienced severe asphalt rutting because of the selection of inadequately soft binders. A well-known case is that of the San Francisco International Airport ( 22 ), where investigations concluded that the soft binder, slow-moving traffic, and the high tire pressure of the Boeing 747-400 aircraft contributed to rutting distortions that occurred at the airfield ( 23 , 24 ). Additional occurrences of early-life asphalt rutting were also detected in several airports around the world, particularly busy airports in hot climates, such as those in Dubai, Kuala Lumpur, and several airports in Australia ( 21 , 22 ).…”