Soil Mechanics - II
Practical Portion
Experiment No. 07
Class Outlines

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Determination of Field Density
Sand Replacement Method
Determination of Lab Density
Standard Proctor Compaction Test
Modified Proctor Compaction Test
Experiment No. 07(a)
Designation


ASTM:
D 1556-64 (1982)
AASHTO: T 191-93 (1996)
Apparatus

Sand-cone apparatus .

Tray with hole

Balance
Stove or oven.
Hand chisels for digging test hole
Container for moisture samples (tin cans).
Container for retaining excavated soil
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Apparatus
Excavated test
hole
ASTM, AASHTO sand-cone apparatus
BS sand replacement apparatus
Procedure

Determine the volume of the bottle or cylinder and attachments
including the volume of the valve.

Determine the bulk density of the sand to be used in the field test

Determine the weight of sand required to fill the funnel.

Determine the density of soil in place
Calculations


Calculate the volume of the density apparatus as follows:
V1 = G
Where, V1 = Volume of density apparatus, in cubic centimeters.
G = Grams of water required to fill the apparatus.
Calculate the density of the sand as follows:
 sand 
W
V1
W = Grams of sand required to fill the apparatus.
V1 = Volume of apparatus in cubic centimeters as determined in 1st step
 Calculate the in-place density of the soil as follows:
V 
b 
W2  W3

W1
V
sand
Calculations
Where,
V = Volume of test hole or volume of the excavated soil.
W2 = Weight of sand used to fill the test hole and funnel.
W3 = Weight of sand in funnel
W1 = Weight of soil excavated from the test hole

Calculate the dry density of the soil in place as follows:
Dry density of soil =
d 
b
m
1
100
Where, ‘m’ is the moisture content determined as follows from the sample
taken at step (4-g.).
m 
Mass of water
Mass of dry soil
 100
Experiment No. 07(b)
Designation


ASTM:
D 698-70
AASHTO: T 99-97
Apparatus


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Mold with detachable collar and detachable
base plate .
Rammer with a mass of 2.5-kg. (5.5–lb)
Weighing Balance
Drying oven .
Straightedge for trimming the soil
Sieve No. 4 (4.75-mm.)
Containers for moisture content
determination
Apparatus
Compaction mold and hammers
Procedure

Take 3-kg. soil passing 4.75-mm. (No.4) sieve .

Thoroughly mix the selected sample with sufficient
water to dampen it to approximately 4-percent below
the expected optimum moisture content .

Compact the soil in the mold with collar attached, in
three approximately equal layers to give a total
compacted depth of 125-mm. (5-in) .

Following compaction of each of the first two layers,
any soil adjacent to the mold walls that has not been
compacted or extends above the compacted surface
shall be trimmed and be evenly distributed on top of
the layer
Procedure

Compact each layer by 25 uniformly distributed blows
of the rammer dropping free from a height of 305-mm.
(12-in.) above the level of the soil .

After compaction, remove the collar, trim the
compacted soil even with the top of the mold, and
determine the weight of mold and soil in kilograms or
pounds .

For weight recorded in kilograms, multiply the weight
of the compacted specimen and the mold, minus the
weight of the mold, by 1060, and record the result as
the wet density of the compacted soil, γb in kilograms
per cubic meter .
Procedure

For weight recorded in pounds, multiply the weight
of the compacted specimen and the mold, minus
the weight of the mold, by 30, and record the
result as wet density of the compacted soil, γb, in
pounds per cubic foot .

Remove the material from the mold and take a
representative sample to find the moisture content

Thoroughly break the molded specimen and add
to remaining portion of the test sample .

Add water to increase the moisture content of the
soil by one to two percent and repeat the above
procedure for each increment of water added
Procedure

Continue this series of determinations until there
is either a decrease or no change in the wet
density of compacted soil .

If the soil particles are fragile and grain size will be
reduced by repeated compaction, separate and
new sample shall be used in each test repetition

Calculate the moisture content and the dry density
of the compacted soil for each trial, and determine
the Moisture-Density Relationship as follows .
Moisture-Density Relationship

The dry densities of the soil shall be plotted as
ordinates and the corresponding moisture content
as abscissas .
γd max
Dry
density
mopt
Water content
Procedure

Optimum Moisture Content:
The moisture content corresponding to the peak of
the moisture-density curve is termed the
“Optimum Moisture Content” of the soil.

Maximum Density:
The dry density of the soil at optimum moisture
content is termed “maximum density”
Observations & Calculations
Observations for moisture content determination
Test repetitions
Test data
1
Row -1
weight of can + wet soil
Row -2
weight of can + dry soil
Row -3
Wt. of water
(row.1-row.2)
(gm)
Row -4
weight of can, (gm)
Row -5
weight of dry soil, (gm)
(row.2-row.4)
Row -6
Moisture content, m%
(row.3/row.5)
2
3
4
5
6
Observations & Calculations
Observations for determination of Density = Weight/Volume (kg/m3)
Test repetitions
Test data
1
Row -1
Wt. of water added for each trial
Row -2
Moisture content, m%
Row -3
weight of soil + mold, (gm)
Row -4
weight of mold, (gm)
Row -5
weight of soil (gm) [kg]
(row.3-row.4)
Row -6
Wet density (kg/m3)
Row.5*1060
Row -7
Dry density (kg/m3)
2
3
4
5
6
Graph
Moisture ~ Density Relationship
1800
Dry Density
1750
1700
1650
1600
1550
1500
5
10
15
Moisture Content
20
25
Experiment No. 07(b)
Designation


ASTM:
D 1557-70
AASHTO: T 180-97
Apparatus




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
Mold with detachable collar and detachable
base plate .
Rammer 4.54-kg. (10-lb.)
Weighing Balance
Drying oven .
Straightedge for trimming the soil
Sieve No. 4 (4.75-mm.)
Containers for moisture content
determination
Apparatus
Compaction mold and hammers
Procedure
All the steps are same as in Standard
Proctor Compaction Test except;

Mould will be filled in five (5) equal layers instead of
three(3).

Weight of the Rammer used will be 4.54 kg (10lb)
instead of 2.5kg (5.5lb).

Height of drop of the Rammer will be 18-in instead of
12-in.