Table 7 (cont'd). Resilient modulus test results for NH2.
NH 2-3
NH 2-4
Max.
σc
σ1
ω
γd
ω
γd
Temp
Mr
Mr
C
kg/m3 (pcf)
kg/m3 (pcf)
kPa (psi)
kPa (psi)
(%)
MPa (psi)
(%)
MPa (psi)
0.5
28 (4)
69 (10)
10.3
1754 (110)
0.34
511 (74,098)
10.2
1759 (110)
558 (80,958)
0.5
14 (2)
14 (2)
10.2
1759 (110)
705 (102,206)
0.5
14 (2)
28 (4)
10.3
1754 (110)
0.36
375 (54,382)
10.2
1759 (110)
0.26
617 (89,470)
0.5
14 (2)
41 (6)
10.3
1754 (110)
646 (93,687)
10.2
1759 (110)
609 (88,298)
0.5
14 (2)
55 (8)
10.3
1754 (110)
569 (82,532)
10.2
1759 (110)
555 (80,501)
0.5
14 (2)
69 (10)
10.3
1754 (110)
0.41
368 (53,420)
10.2
1759 (110)
0.38
534 (77,463)
0.5
41 (6)
14 (2)
10.2
1759 (110)
0.50
54 (7805)
0.5
41 (6)
28 (4)
10.3
1754 (110)
50 (7282)
10.2
1759 (110)
61 (8850)
0.5
41 (6)
41 (6)
10.3
1754 (110)
55 (7958)
0.5
41 (6)
14 (2)
10.2
1759 (110)
0.50
54 (7805)
0.5
41 (6)
28 (4)
10.3
1754 (110)
50 (7282)
10.2
1759 (110)
61 (8850)
0.5
41 (6)
41 (6)
10.3
1754 (110)
55 (7958)
0.5
28 (4)
14 (2)
10.3
1754 (110)
43 (6307)
10.2
1759 (110)
0.50
47 (6745)
0.5
14 (2)
14 (2)
10.3
1754 (110)
41 (5956)
10.2
1759 (110)
44 (6422)
20
41 (6)
14 (2)
10.3
1754 (110)
48 (7018)
20
41 (6)
28 (4)
10.3
1754 (110)
59 (8570)
20
28 (4)
14 (2)
10.3
1754 (110)
44 (6324)
20
14 (2)
14 (2)
10.3
1754 (110)
41 (6013)
tween the calculated subgrade temperatures at
flow model that is primarily used for calculating
Concord and Lebanon were similar. The air and
frost heave. As part of the frost heave calculations,
top of the subgrade temperatures for Concord are
the model calculates the temperature, moisture
shown in Figures 12 and 13. As seen in Figures 11
content, etc., in the base and subgrade as a func-
and 12, even though the mean air temperature
tion of time.
during the winter was around 10C, the mini-
The following typical pavement structures were
mum subgrade temperature was around 0 and
used in the analysis. For interstate and primary
3C. These results are probably applicable to all
pavement structures, there was 152 mm (6 in.) as-
parts of the state, except at locations in the higher
phalt concrete, over 610 mm (24 in.) of base, over
elevations. The mean air and top of subgrade tem-
305 mm (12 in.) of subbase, over the various
peratures under interstate and secondary highway
subgrades. For secondary roads, there was 76 mm
(3 in.) of asphalt concrete, over 406 mm (16 in.) of
pavements are presented in Table 12.
base, over 203 mm (8 in.) of subbase, over the
The mean temperatures in Table 12 were used
subgrades (Fig. 10). The base layer in this analysis
in most cases for determining the resilient modu-
lus. However, during the late winter early spring
is the combination of the crushed gravel and gravel
periods, there is a rapid change of temperature,
layers. The CRREL soil database was used to esti-
mate the thermal and hydraulic properties of the
Fig. 14a and b. For example, for the first half of
various pavement layers. For the base, subbase,
March, the subgrade temperature is on an aver-
age around 3C. The temperature for the remain-
and subgrade, selection was based on the grada-
ing part of the month hovers around 0C. In these
tion of the material. The minimum and maximum
air temperatures, based on 30 years of record were
instances, two temperatures are used to estimate
used to calculate the annual air freezing index
the resilient moduli for the month of March (Table
13).
(AFI). The design freezing index (DFI) is the aver-
The calculations for the effective resilient modu-
age of the three coldest years. The air tempera-
lus for the various subgrade soils are presented in
tures at Concord and Lebanon were used for the
Table 14 and are summarized in Table 15. The re-
analysis (Fig. 11). Once, the DFI is calculated for
silient modulus values in Table 14 were obtained
both locations, the closest air freezing index was
by straight line interpolation between the tempera-
chosen as the design air temperature for each site
respectively. It was found that the difference be-
tures in Figures 5 to 9. The relative damage (uf) in
9
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