In a similar manner, point values of hydraulic
Table 6. Compaction test results--Mn/ROAD materials.
conductivity determined at various pore pressure
Maximum
Optimum
conditions were fit with a Gardner's form equa-
dry density water content Method
tion using a least squares approach to determine
Mg/m3 (lb/ft3)
Material
(wt %)
employed
the best fit parameters AK and β (Table 7).
Subgrade
ks
KH =
1206
1.89 (117.8)
15.5
CE-55
β
(3)
AK hp + 1
1206
1.69 (105.5)
18.0
CE-12
1206
1.64 (102.1)
20.4
CE-5
where KH = unsaturated hydraulic conductiv-
1232
1.99 (124.4)
11.9
CE-55
Class 3 special
ity (cm/hr)
stockpile
2.11 (131.8)
7.6
CE-55
stockpile
1.98 (123.7)
11.0
CE-12
(cm/hr)
Class 4 special
AK = Gardner's multiplier for hydrau-
stockpile
2.01 (126.0)
10.0
T-99*
lic conductivity
Class 5 special
β = Gardner's exponent for hydrau-
stockpile
2.12 (132.7)
8.1
T-99*
lic conductivity.
Class 6 special
stockpile
2.09 (130.4)
2.1
CE-55
Typical moisture retention and hydraulic con-
stockpile
1.93 (120.8)
4.0
CE-12
ductivity test results are shown in Figures 11
Notes:
and 12.
Tests conducted according to Army methods (MIL-STD-
621A):
Frost susceptibility
CE-55 (similar to AASHTO T-180/Modified Proctor);
Frost susceptibility tests were conducted
compactive effort: 2,630 kJ/m3 (55,000 ft-lb/ ft3)
using the procedures described in Chamberlain
CE-12 (similar to AASHTO T-99/Standard Proctor);
(1987). Frost susceptibility is determined by
compactive effort: 575 kJ/m3 (12,000 ft-lb/ft3)
CE-5--compactive effort: 239 kJ/m3 (5,000 ft-lb/ft3)
subjecting a soil sample to two freezing cycles
*Results of Mn/DOT testing
and determining the heave rate during the first
Table 7. Coefficients for hydraulic properties in the form of Gardner's
equations.
Moisture retention
Hydraulic conductivity
α
β
Material
Aw
AK
Subgrade
1206
0.002399
0.7134
0.0005713
2.6395
1232
0.002260
0.6790
0.001885
1.8129
Class 3 special
stockpile*
0.1735
0.3239
1647.1
0.7207
Class 4 special
6.59 105
TAS†
0.1520
0.2690
2.9620
Class 5 special
DGS
0.4961
0.3660
3.912
1.3930
Class 6 special
1.0729 106
blended**
1.0001
0.4444
5.8979
* "Stockpile" materials were furnished from stockpiles manufactured for Mn/
ROAD
† Substitute materials for modeling: TAS: taxiway A subbase; DGS: dense
graded stone
** "Blended" materials were created by mixing separate size fractions
13
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