Samples of pavements from 14 states across the United States were obtained to evaluate the aggregate properties that affect rutting. Twelve pavements had provided excellent service for five or more years and 30 pavements had experienced premature rutting in less than five years of service. The aggregates from cores obtained at 0.3 meter (1 foot) intervals across each pavement were tested for gradation and maximum aggregate size, fractured face count, and the National Aggregate Association Flow Test. The cores were also tested for in-place void content and asphalt cement content. The remaining cores were reheated and recompacted using the Gyratory Testing Machine (GTM).

The data show that aggregate properties have little effect on rutting when the voids are low. When the voids are above 2.5%, mixes with higher fractured face counts and more angular fine aggregate are more resistant to premature rutting.