Investigation of Airfield Pavement Failure at Cairo East Air Base

摘要

This report is an analysis of an asphalt concrete overlay that had beenconstructed on an aircraft parking apron and taxiway. The asphalt concrete overlay had exhibited significant deformation and depressions under parked aircraft traffic. The performance of the unstable asphalt concrete pavement was unacceptable. Laboratory tests were performed on asphalt concrete specimens to determine asphalt cement, aggregate, and asphalt concrete mixture properties. This analysis was to evaluate the in-place asphalt concrete material for compliance with specifications, determine possible causes for pavement failure, suggest procedures to avoid these problems in the future, and recommend options for the repair of this airfield pavement. Evaluation of the asphalt concrete material indicated that poor performance was due to improperly designed and produced asphalt concrete mixture. Several factors contributed to the unstable mixture: (1) aggregate gradations were consistently out of specification and were gap graded, (2) amount of natural sand in both the surface course and intermediate course was extremely high, and (3) mix designs for the surface course and intermediate course mixtures did not meet the minimum requirements of the specification.