APPENDIX B: LABORATORY TESTS ON SOILS--PROCEDURE AND RESULTS
The remolding cone index (CI) test for sands
LABORATORY SOIL TESTS
with fines was performed following TM 5-33/
AFM 86-3, Vol. II, Chapter 9, Soils Trafficability.
A variety of laboratory tests were conducted
The soil was oven dried before conducting the
on Fort McCoy soil samples. The samples were
test. Using a 152.4-mm (6-in.) mold, material pass-
separated using a no. 4 (4.75-mm) sieve and oven
ing 19.0-mm (3/4-in.) sieve was compacted at
dried before testing. Tests and corresponding re-
lower than optimum density and moisture con-
sults are summarized in Table B1. Compaction
tent, then soaked to establish the in-situ moisture
test using ASTM Standard D 698 Method C and
content and density. A sampling tube approxi-
California Bearing Ratio (CBR) test using ASTM
mately 5 cm (2 in.) in diameter was inserted into
Standard D1883 were also performed on the Fort
the mold and the soil sample was extracted then
McCoy samples (ASTM 1985). There were diffi-
ejected into the remolding cylinder. The soil
culties when performing tests at wet of optimum
strength of the sample was determined using a
moisture content, which is typical of these types
cone penetrometer to measure the original and
of soil:
remolded CI as the base of the cone penetrate the
soil sample at each successive inch to a depth of
When performing the CBR test, water leaked
10 cm (4 in.). The original CI readings were mea-
out of the bottom of the mold, therefore the
sured first and the remolded CI readings were
moisture content on the top and bottom of
then measured after applying 25 blows with the
the sample were different.
drop hammer from a height of 15 cm (6 in.). The
When compacting the last layer of the mold
ratio of the remolded CI to the original CI is called
there were surface irregularities due to the
a remolding index (RI). Because of the soil type,
consistency of the soil. Figure B4 shows a
the moisture content and density varied from top
typical grain size distribution for a soil
to bottom. The samples were not homogeneous
sample, and Figure B1 shows graphs of mois-
and thus they gave nonrepetitive readings. Aver-
ture content vs. densities and CBR values of
age RIs are summarized in Table B1.
all the samples.
Table B1. Laboratory tests, locations and results.
Maximum dry
Optimum moisture
unit weight
kg/m3(lb/ft3)
Remolding
Soil classification
Specific gravity
Atterberg limits
content (%)
(ASTM Standard
(ASTM Standard
(ASTM Standard
(ASTM Standard
(ASTM Standard
index
Sample site
D 2487)
D 854)
D4318)
D 698, Method C)
D 698, Method C)
(RI)
Wooded trail
SP-SM (poorly graded
2.63
Nonplastic
8.2
1910 (118.8)
3.64
station 1+50
sand with silt)
Wooded trail
SM (silty sand
2.65
1.7 plasticity
10.9
1934 (120.3)
0.76
station 8+25
with gravel)
index
Wooded trail
SM (silty sand)
2.65
Nonplastic
11.4
1900 (118.2)
1.10
station 16+50
Pentagon trail
SP-SM (poorly graded
2.64
Nonplastic
8.4
1915 (119.1)
sand with silt)
Slope trail
SC (clayey sand)
2.71
Nonplastic
8.8
2069 (128.7)
Aggregate
GP-GM (poorly graded
2.80
Nonplastic
gravel with silt and sand
35
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