TM 5-822-5/AFM 88-7, Chap. 1
CHAPTER 1
INTRODUCTION
(5) Modulus of rupture (flexural strength) for
1-1. Purpose.
concrete pavements.
This manual provides criteria for the design of
b. Rigid Pavements. The rigid pavement design
pavements for roads, streets, walks, and open stor-
procedure presented herein is based upon the criti-
age areas at U.S. Army and Air Force installations.
cal tensile stresses produced within the slab by the
vehicle loading. Correlation between theory, small-
1-2. Scope.
scale model studies, and full-scale accelerated traf-
This manual provides criteria for plain concrete,
fic tests have shown that maximum tensile stresses
reinforced concrete, flexible pavements, and design
in the pavement occur when the vehicle wheels are
for seasonal frost conditions. These criteria include
tangent to a free or unsupported edge of the
subgrade and base requirements, thickness designs,
pavement. Stresses for the condition of the vehicle
and compaction requirements, criteria for stabilized
wheels tangent to a longitudinal or trans-verse joint
layers, concrete pavement joint details, and
are less severe because of the use of load-transfer
devices in these joints to transfer a portion of the
load to the adjacent slab. Other stresses, because of
1-3. References.
their cyclic nature, will at times be additive to the
Appendix A contains a list of references used in this
vehicle load stresses and include restraint stresses
manual.
resulting from thermal expansion and contraction of
the pavement and warping stresses resulting from
1-4. Selection of Pavement Type.
moisture and temperature gradients within the
Rigid pavements or composite pavements with a
pavement. Provision for those stresses not induced
rigid overlay are required for the following areas.
by wheel loads is included in design factors
a. Vehicle Maintenance Areas.
developed empirically from full-scale accelerated
b. Pavements for All Vehicles with Nonpneuma-
traffic tests and from the observed performance of
tic Tires.
pavements under actual service conditions.
c. Open Storage Areas with Materials Having
c. Flexible Pavement. The design procedure
Nonpneumatic Loadings in Excess of 200 psi.
used by the Corps of Engineers and the Air Force
d. Covered Storage Areas.
to design flexible pavements is generally referred to
e. Organizational Vehicle Parking Areas.
as the California Bearing Ratio (CBR) design pro-
f. Pavements Supporting Tracked Vehicles.
cedure. This procedure requires that each layer be
g. Vehicle Wash Racks.
thick enough to distribute the stresses induced by
h. Vehicle Fueling Pads.
traffic so that when they reach the underlying layer
Except for architectural or special operational re-
they will not overstress and produce excessive
quirements, all other pavements will be designed
shear deformation in the underlying layer. Each
based upon life-cycle cost analysis.
layer must also be compacted adequately so that
traffic does not produce an intolerable amount of
1-5. Basis of Design.
added compaction. Use ASTM D 1557 compaction
effort procedures to design against consolidation
a. Design Variables. The prime factor influenc-
under traffic.
ing the structural design of a pavement is the load-
carrying capacity required. The thickness of
1-6. Computer Aided Design.
pavement necessary to provide the desired load-
carrying capacity is a function of the following five
In addition to the design procedures presented
principal variables-
herein, computer programs are available for deter-
(1) Vehicle wheel load or axle load.
mining pavement thickness and compaction re-
(2) Configuration of vehicle wheels or tracks.
quirements for roads, streets, and open storage
(3) Volume of traffic during the design life of
areas. These programs are contained on the floppy
pavement.
disk appendix E located in pocket to cover 3.
(4) Soil strength.
a. Development. Computer programs have been
1-1
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