TM 5-822-13/AFJMAN 32-1018
Table 5-1. Operations Per Coverage Ratio, Flexible Pavements.
(1)
(3)
(5)
(2)
(4)
Contact
Load
Operations
Standard
Width*
Wander**
Range
Deviation†
per
Configuration
kips
in,
Coverage
in.
in.
Passenger Cars. Trucks. Buses. etc,
Pneumatic tires
64.37
single axle,
5.63
21.46
0-5
9.59
52.86
6.25
5-10
7.14
17.62
single wheels
0-10
44.25
14.75
6.75
Single axle,
2.95
10-20
41.20
13.73
2.64
7.20
dual wheels
2.37
20-30
39.60
13.20
7.77
54.37
18.13
4.05
0-10
5.63
Tandem axle,
48.50
16.16
2.73
10-15
7.50
single wheels
49.38
16.46
10-15
5.63
1.93
Tandem axle,
38.75
12.92
1.23
15-20
8.25
dual wheels
37.00
1.03
20-50
9.00
12.34
Forklift Trucks
Pneumatic tires
Single axle,
44.88
14.93
3.52
10-35
5.63
dual wheels
Solid rubber tires
8.36
17.00
Single axle,
0-5
5.00
51.00
7.00
6.00
50.00
16.67
5-10
single tires
5.90
7.00
49.00
16.34
10-20
Tracked Vehicles
Solid rubber
18.92
1.43
0-20
11.22
56.75
grousers
0.89
12.00
37.00
12.34
20-35
0.55
12.00
21.00
7.00
35-50
0.43
5.92
50-70
14.25
17.75
0.33
70-120
17.25
4.75
1.58
Traffic lane width (Pw) - 11 ft (except for solid-rubber-tired fork-
Note:
lift trucks; Pw - 7 ft), Tw - average tire width from table 3-1.
Spacing between dual wheels(s) - 2 in., Ws - average wheel spacing
from table 3-1.
truck where Cw - Tw.
**Wander (Bw) for single wheels or track - Pw - (Ws + Cw); for dual
wheels, Bw - Pw - (W, + 1.75 Tw + S).
†Standard deviation (a) - Bw/3.
temperature and initial stress. The initial stress is converted to initial strain in order to yield criteria based on
the tensile strain of the bituminous concrete.
(2) An alternate method for determining values of limiting tensile strain for bituminous concrete is the
use of the provisional laboratory fatigue data employed by Heukelom and Klomp (1964). These data are pre-
sented in appendix C in the form of a relationship between stress, strain, load repetitions, and elastic moduli of
bituminous concrete. The data may be approximated by the following equation
Allowable coverage = 10x
(eq 5-2)
where
X = 5 log SA + 2.665 log10 (E/14.22) + 0.392
SA= tensile strain of asphalt (in./in.)
E = elastic modulus of the bituminous concrete (psi)
The equation used to determine the allowable tensile strain at the bottom of the asphalt layer is:
Allowable strain , AC = 10 -A
(eq 5-3)
5-2
Previous Page
