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The thirteen properties that will need to be entered through the SDG’s user interface are shown on the Material
Details screen above and defined below. Further definitions of these properties can be found in Part 5 of the
SDG Operators Handbook. Examples of a gradation report and compaction test are on the following pages.
The Material ID is any identifier that can associate the material being evaluated with its test report. A report
number or sample number should be entered here. For the example shown, 08.0527 is the Soil ID. Do not
enter letters or characters as part of the Soil ID.
The Description should be a used to describe the material and help make a visual association with the material
being tested. Dark Brown Sand is used for this example.
The Max Dry Density is the maximum practically achievable density a soil can have. This value is determined
experimentally by performing a “Proctor” Test (ASTM D 1557). 129.9 pounds per cubic foot is taken directly
from the example compaction test report.
The Optimum Moisture Content is the water content (%) at which the material can be compacted to its
maximum dry density. This is determined experimentally by performing a “Proctor” Test (ASTM D 1557).
7.6% is taken directly from the example compaction test report.
PL and LL are the plastic and liquid limits used to describe the plasticity of materials with a high silt and clay
content. They are determined by following the test procedure outlined by ASTM D 4318. This example is a
sandy material so PL and LL are input as 0.0. If plasticity tests had been performed on this material, the results
would be given on the gradation report.
Cu and Cc are the Coefficient of Uniformity and Coefficient of Curvature of the material. They are calculated
values that are typically used describe the particle size distribution a soil. In this example, Cu = 4.4 and Cc =
0.94
% Gravel is the summation of the coarse and fine gravel in a sample of material. Some gradation test results
will report this as a single value while others will break it down into the coarse and fine fractions. The SDG
only recognizes the total percentage of gravel so the coarse and fine fractions will need to be added together
before entering them. The gradation report shown breaks the gravel content out into Fine and Coarse fractions
so those will need to be added together. 1.3% + 5.1% = 6.4%
% Sand is the summation of the coarse, medium and fine sand in a sample of material. Some gradation
test results will report this as a single value while others will break it down into the coarse, medium and fine
fractions. The SDG only recognizes the total percentage of sand so the coarse, medium and fine fractions will
need to be added together before entering them. The gradation report shown breaks the sand down into coarse,
medium, and fine fractions, so the percent sand in the example shown is 8.1% + 31.3% +48.2% = 87.6%.
% Fines is the summation of the silt and clay in a sample of material. Some gradation test results will
report this as a single value while others will break it down into the fractions of silt and clay. The SDG only
recognizes the total percentage of fines so the coarse, silt and clay fractions will need to be added together
before entering them. In this example, the percent fines is 6.0%.
Part 7: Explanation of Gradation and Compaction Reports
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