Harvard Miniature Compaction Apparatus (H-4165) Page 5 of 7
Instruction Manual Rev.0; August 01, 2003
Copyright 2003 Humboldt Mfg. Co., Norridge, IL. 60706, U.S.A.
All rights reserved. Printed in U.S.A.
6. Calculations
Calculate the moisture content and the dry weight of the soil as compacted for each trial,
as follows:
w = ___A – B___ X 100
B – C
And
W = ___W1___ __ X 100
W + 100
Where:
w = Percentage of moisture in the specimen
A = weight of container and wet soil
B = weight of container and dried soil,
C = weight of container
W = dry weight, in pounds per cubic foot of compacted soil and
w
1
= wet weight, in pounds per cubic foot
7. Moisture-Density Relationship
7.1 The calculations in Section-6 shall be made to determine the moisture content
and corresponding oven-dry weight (density) for each of the compacted soil
samples. The oven-dry weights per cubic foot (densities) of the soil shall be
plotted as ordinates and corresponding moisture contents as abscissas.
7.2 Optimum Moiture Content – When the densities and corresponding moisture
contents for the soil have been determined and plotted as indicated in paragraph
(6.1), it will be found that by connecting the plotted points with a smooth line, a
curve is produced. The moisture content corresponding to the peak of the curve
shall be termed the “optimum moisture content” of the soil under the above
compaction.
7.3 Maximum Density – The oven-dry weight per cubic foot of the soil at “optimum
moisture content” shall be termed “maximum density” under the above
compaction.
