Geology Reference
In-Depth Information
Data collected in this test should include the following:
DATA
Mass of total air-dried soil sample
Mass of fraction retained on No. 10 sieve (washed and oven-dried)
For sieve analysis of coarse aggregate:
Mass retained on each sieve
For hygroscopic moisture correction factor:
Mass of container plus air-dried soil
Mass of container plus oven-dried soil
Mass of container
For sieve analysis of fine aggregate:
Mass of container plus air-dried soil for hydrometer analysis
Mass of container
Mass retained on each sieve
For hydrometer analysis:
Hydrometer reading and temperature for each specified
elapsed time
The calculations for this particular test are quite extensive:
CALCULATIONS
1. Compute the percentage of sample retained on the No. 10 sieve by
dividing mass of fraction retained by total mass of original sample
and multiplying by 100.
2. Compute the percentage of sample passing through the No. 10 sieve
by subtracting the previous value from 100.
3. For the sieve analysis of the coarse aggregates, compute the total
percentage that passed each sieve by subtracting the summation of
the mass retained on this and all previous sieves (beginning with
the sieve with the largest screen opening) from the mass of the orig-
inal sample, dividing this difference by the mass of the original sam-
ple, and multiplying the quotient by 100.
4. Compute the hygroscopic moisture correction factor by dividing the
mass of the oven-dried soil by the mass of the air-dried soil.
5. In order to determine the sieve analysis for the fine aggregates and
for use in computing the hydrometer analysis, the calculated mass
of the total oven-dried hydrometer analysis sample must be deter-
mined by multiplying the mass of the air-dried sample for hydrom-
eter analysis by the hygroscopic moisture correction factor, dividing
the product by the percentage of sample passing the No. 10 sieve,
and multiplying the quotient by 100. Denote this quantity
M
for
later use.
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