1. Introduction

1.2 Airfield Paving

The earlier editions (1991 and 2000) of this Handbook focused on roadway paving. A major change in this new edition is greater emphasis on airfield paving, with additional discussion on practices unique to airfield work. The differences between roadway and airfield standard practices are covered on a topical basis as warranted throughout the Handbook, not necessarily as separate sections but as expanded discussion. References may be made to both the FAA and Department of Defense (DoD) airfield paving standards and specifications.

A major change in this new edition of the Handbook is that it places greater emphasis on airfield paving, with additional discussion on practices unique to airfield work.

The FAA’s standard asphalt paving specification for airfields is Item P-401 found in advisory circular 150/5370-10H. The DoD’s standard asphalt paving specification for airfields is Unified Facilities Guide Specification (UFGS) 32 12 15.13. While these two airfield specifications have some similarities regarding materials, gradations, joints, etc., they also contain many differences, especially concerning QC and acceptance.

For several reasons, airfield pavements provide unique challenges compared to roadway pavements, and these challenges affect the paving process.

First, the tire pressures of aircraft wheels are much greater than those of truck tires. Large commercial aircraft have tire pressures ranging from 150 to 250 pounds per square inch (psi), while large trucks have tire pressures ranging from 85 to 110 psi. Military fighter aircraft can have tire pressures that exceed 300 psi. These extremely high tire pressures, especially when combined with slow-moving or standing loads, can cause a newly paved asphalt surface to be prone to rutting, shoving, or scuffing unless the mix is designed, produced, placed, and compacted in a manner that ensures sufficient stability.

A second reason is that airfield pavements must be designed, constructed, and maintained in a manner that does not produce foreign object debris (FOD), a term very familiar to those involved in airfield pavements and operations. FOD is any debris that can be ingested in a jet engine and cause damage, leading to major flight safety concerns as well as costly engine repairs. Because of FOD concerns, airfield pavements must be kept at a higher serviceability level than highway pavements.

A third reason is that paving on airfields (shown in Figure 1) drastically disrupts airfield traffic operations compared to traffic disruption caused by roadway paving. For most highway paving, traffic can be diverted but remain open by closing one or a few lanes. For airfield paving, the entire runway or taxiway must typically be closed because closing partial width on a runway or taxiway to keep traffic open is not an option.

A fourth reason is that airfield specifications typically have very stringent smoothness requirements, so the paving process requires more attention than “everyday” roadway paving.

All these reasons and more explain why paving on airfields is referred to as the “high-wire act” of asphalt paving.

The FAA’s standard asphalt paving specification for airfields is Item P-401 found in advisory circular 150/5370-10H. The DoD’s standard asphalt paving specification for airfields is Unified Facilities Guide Specification (UFGS) 32 12 15.13.