30 June 2001
1. PURPOSE. This document establishes general concepts and criteria for the design of airfield
pavements for the U.S. Army, Navy, Air Force, and Marine Corps.
2. SCOPE. This document prescribes procedures for determining the thickness, material, and density
requirements for airfield pavements in nonfrost and frost areas. It includes criteria for the California
Bearing Ratio (CBR) procedure and elastic layered analysis for flexible pavements and the Westergaard
Analysis and elastic layered analysis for rigid pavements. The elastic layered analysis for rigid
pavements covers only plain concrete, reinforced concrete, and concrete overlay pavements.
REFERENCES. Appendix A contains a list of references used in these instructions.
4. UNITS OF MEASUREMENT. The unit of measurement system in this document is the International
System of Units (SI). In some cases inch-pound (IP) measurements may be the governing critical values
because of applicable codes, accepted standards, industry practices, or other considerations. Where
the IP measurements govern, the IP values may be shown in parenthesis following a comparative SI
value or the IP values may be shown without a corresponding SI value.
5. PAVEMENT. A pavement as used in this document is a surfaced area designed to carry aircraft
traffic and includes the entire pavement system structure above the subgrade. All slabs on grade
required to support aircraft loadings, whether interior (hangar floors) or exterior, are to be considered
a. Flexible Pavement. Flexible pavements are so designated due to their flexibility under load and
their ability to withstand small degrees of deformation. The design of a flexible pavement structure is
based on the requirement to limit the deflections under load and to reduce the stresses transmitted to the
natural subsoil. The principal components of the pavement include a bituminous concrete surface,
graded crushed aggregate base course, stabilized material, drainage layer, separation layer, and
subbase courses. A bituminous concrete surface course is hot mixed bituminous concrete designed as
a structural member with weather and abrasion resisting properties. It may consist of wearing and
binder or intermediate course. Figure 1-1 illustrates the components and the terminology used in flexible
pavements. Examples of all bituminous concrete pavements (ABC) and flexible pavements utilizing
stabilized layers are shown in Figures 1-2 and 1-3. Not all layers shown in the figures are required in
b. Rigid Pavement. A rigid pavement is considered to be any pavement system that contains
portland cement concrete as one element. Rigid pavements transfer the load to the subgrade by
bending or slab action through tensile forces as opposed to shear forces. The principal components of a
rigid pavement are the concrete slab, base course, drainage layer, and separation layer. However, a
stabilized layer may be required based on site conditions. Figure 1-4 illustrates the components of a
rigid pavement. The drainage and separation layer will normally serve as the base course. The
following pavements are considered to be rigid pavements:
(1) Plain concrete pavement is a nonreinforced jointed rigid pavement.