Lesson 2/Learning Event 2
CBR base of 80, and which is used by C-130E aircraft, the minimum pavement thickness is 3 inches.
The minimum base thickness for an Air Force airfield is 6 inches. The minimum base thickness for an
Army airfield is 4 inches.
Additional information about design gear loads can be found in TM 5-330.
Flexible pavement designs must provide sufficient compaction of the subgrade and each pavement layer
to prevent objectionable settlement under concentrated and repeated traffic. Compaction requirements
are given in Lesson 1, Figure 4. Flexible pavement designs must also provide adequate thickness of
quality pavement components above the subgrade to prevent detrimental subgrade deformation,
excessive deflection of the pavement surface, and excessive tensile strain in the surface pavement
material under traffic. In addition, the flexible pavement design must provide a stable, weather resistant,
wear resistant, and non-skid surface.
From the procedures included herein, the total thickness of the pavement, as well as the thicknesses of
individual courses may be determined. These thicknesses, together with the minimum thicknesses for
surface and base courses, provide the basis for pavement section design. See Table 13 for an outline of
the flexible pavement thickness design procedure.