TM 5-822-5/AFM 88-7, Chap. 1
or tar) should normally be based on economy.
The bituminous materials used in paving are as-
7-2. Criteria for Bituminous Pavements.
phaltic or tar products as listed in TM 5-822-8/
AFM 88-6, Chap 9. Although asphalts and tars re-
The basic criteria for selection and design of bitu-
semble each other in general appearance, they do
minous pavements are contained in TM 5-822-8
not have the same physical or chemical character-
which includes the following criteria:
a. Selection of bitumen type.
istics. Tars are affected to a greater extent by tem-
b. Selection of bitumen grade.
perature changes and whether conditions; however,
c. Aggregate requirements.
they tend to have better adhesive and penetrating
d. Quality requirements.
properties than asphalts. Generally asphalt surface
e. Types of bituminous pavements.
courses are preferred to tar surface courses. The
selection of the type of bituminous material (asphalt