C
F
50
10
Concord (Secondary)
5
40
0
30
Subgrade
5
20
10
Air Temperature
10
15
27 Feb
3 Mar
8 Mar
13 Mar
18 Mar
23 Mar
28 Mar
2 Apr
a. Secondary road at Concord, New Hampshire.
C
F
50
10
Concord (Interstate/Primary)
5
40
0
30
Subgrade
5
20
Air Temperature
10
10
15
27 Feb
3 Mar
8 Mar
13 Mar
18 Mar
23 Mar
28 Mar
2 Apr
b. Primary (interstate) road at Concord.
Figure 14. Example of a rapid change of subgrade temperature during thawing.
20