TM 5-822-5/AFM 88-7, Chap. 1
grade soils exhibit unacceptable swell and frost
50 pci, and when frost penetrates a frost-susceptible
heave potential. These soils can result in safety
material underlying the rigid pavement on small jobs
problems with differential joint elevations.
in frost areas. Where the flexural strength or
subgrade modulus is unknown, the design will be 6
inches of concrete with a 6-inch base course.
12-7. Concrete Driveways.
Contraction or construction joints pro- vided in a
Under normal conditions, rigid pavement for resi-
driveway will be designed and sealed in accordance
dential driveways will be either 6-inch plain con-
with chapter 15 or 16. Expansion joints consisting
crete or 5-inch reinforced concrete with 0.10 per-
of approved preformed bituminous filler or wood
cent of reinforcement steel. In plain concrete pave-
should be installed to surround or separate all
ment design, slab lengths will not exceed 15 feet
structures which project through or against the
with 12 feet recommended. For reinforced pave-
ment, slab lengths up to 30 feet may be used. The
residential driveways will be 6 inches thick and re-
12-8. Curbs, Gutters, and Shoulders.
inforced with a minimum of 0.05 percent of rein-
forcement steel when the following adverse condi-
For a discussion of the design of curbs, gutters, and
tions prevail: when concrete flexural strength is
shoulders, see paragraphs 8-8 and 8-11 of this
below 630 psi and the subgrade modulus k is below