Laboratory 2
Hydrometer Analysis
Atterberg Limits
Sand Equivalent Test
INTRODUCTION
Grain size analysis is widely used for the classification of soils and for specifications of soil
for airfields, roads, earth dams, and other soil embankment construction. The hydrometer
analysis determines the relative proportions of fine sand, silt and clay contained in a given soil
sample. A knowledge of the range of moisture content over which a soil will exhibit a certain
consistency is beneficial to the understanding of how a soil might behave when used as a
construction material. The Atterberg limits, which include the liquid limit and plastic limit, are
readily accepted in the engineering community as an objective measure of consistency.
When coarse soil particles (sand and gravel) are used as a construction material, their
suitability and behavior is influenced by the amount of clay fines that may be present after
processing. The Sand equivalent test, developed to provide and indication of the clay content
of a coarse aggregate, may be used as an indicator for specification compliance.
HYDROMETER ANALYSIS
A hydrometer analysis is required to determine the particle size distribution for that portion of
the soil which passes through a No. 200 sieve (0.075 mm). The test is conducted on that
fraction of a soil sample which passes through a No. 10 sieve (2 mm); however the sand
particles in excess of 0.075 mm settle almost immediately and thus little information about
their size and relative proportion is obtained during this test. Mechanical sieve analyses are
commonly used to determine the relative distribution of soil particles greater than 0.075 mm.
When both the mechanical and hydrometer methods are performed on the same soil, the
analysis is said to be a combined analysis.
The hydrometer method depends on Stoke’s equation for the terminal velocity of a falling
sphere. Stoke’s equation was developed for perfect spheres whereas most silt and clay
particles are platey shaped. Furthermore, clay particles have a tightly bound layer of
adsorbed water which remains on the particle as it falls through the water column, resulting in
a greater resisting surface than that of the clay particle alone. Notwithstanding these
discrepancies, the hydrometer method is accepted as being of value in attempting to learn
the diameter and proportion of the smallest soil particles.
1
Prior to the conduct of the hydrometer test, the hydrometer bulb (151 H) is calibrated to the
dispersing solution and prevalent test temperatures. This is simply accomplished by obtaining
hydrometer readings in a 5g/l sodium hexametaphosphate solution at two or more
temperatures. The 151 H hydrometer bulb is manufactured to provide a reading of 1.000
when placed in pure distilled water at 21 oC. Because the sodium hexametaphosphate
solution has a specific gravity greater than 1, a hydrometer reading in excess of 1.000 will be
obtained. The difference between this reading and unity is considered as a composite
correction factor which is applied to all subsequent hydrometer readings of the soil-water
suspension.
To provide reasonably accurate results, a soil sample must be completely broken down into
individual soil grain prior to testing. This is accomplished by thorough wetting and mixing of
the soil in a dispersing agent.
A concentrated solution of water and sodium
hexametaphosphate (40g/l) is used for this purpose. After complete dispersion, the soil-water
suspension is introduced into a 1 litre settlement tube and diluted with distilled water such that
the resulting sodium hexametaphosphate solution a concentration of 5g/l. Successive, timed
measurements of the specific gravity of the soil-water suspension, using a calibrated
hydrometer bulb, provides an indication of the maximum size of a soil particle still in
suspension and the proportion of soil fines still in suspension. These values are then used to
compute the percent of soil by weight finer than a given diameter.
ATTERBERG LIMITS
When clay minerals are present in fine grained soil, the soil can be remolded in the presence
of some moisture without crumbling. In the early 1900's, a Swedish soil scientist named Albert
Atterberg proposed a set of six rather arbitrary states of soil moisture content to assist
agriculturists in determining field agricultural conditions. He termed the divisions between
these six states as limits, known as the shrinkage, cohesive, sticky, plastic and liquid
limits. The methods suggested by Atterberg to determine the moisture contents associated
with each limit were highly empirical and not very applicable to engineering. In 1942, Arthur
Casagrande revised the original agricultural definitions, dropped the cohesive and sticky
limits, and developed procedures that could be adopted for engineering applications.
It has been found that the water contents corresponding to the transitions from one state to
another usually differ for clays having different physical properties in the remolded state, and
are approximately equal for clays having similar physical properties. Therefore, the limiting
water contents, or limits, may serve as index properties useful in the classification of clays.
Actually, as the soil-water mixture passes from one state to another, there is no abrupt change
in the physical properties. The Atterberg limit tests, therefore, are arbitrary tests that have
been adopted to define the limiting values. The Atterberg limits vary with the amount of clay
present, the type of clay mineral, and the nature of the ions adorbed on the clay surface.
2
Unlike finer soil particles, gravels and sands do not possess the required cohesiveness which
permits the Atterberg limits tests to be performed. However, the finer sands and silts often
contain sufficient clay coatings to permit the tests to be successfully completed. Thus the
Atterberg tests are performed on only that soil fraction which passes through a No. 40 sieve
(0.425 mm).
Shrinkage Limit
The shrinkage limit is defined as the moisture content at which no further volume change
(reduction) occurs with a further reduction in moisture content. An alternative definition defines
the shrinkage limit as the moisture content representing the amount of water required to fill the
voids in a given cohesive soil at its minimum void ratio obtained by drying.
Plastic Limit
The plastic limit is defined as the moisture content at which a soil thread just begins to crack
and crumble when rolled to a diameter of 1/8" (3 mm).
Liquid Limit
The liquid limit is defined as the moisture content at which a 2-mm-wide groove in a soil pat
will close for a distance of ½" (12.5 mm) when dropped 25 times in a standard brass cup,
falling 1 cm each time at a rate of 2 drops per second.
SAND EQUIVALENT TEST
Most granular soils and fine aggregates are mixtures of desirable coarse partiles, sand, and
undesirable clay or plastic fines. The sand equivalent test is intended as a rapid field
correlation test to indicate the relative proportions of clay-like or plastic fines and dust in
granular soils and fine aggregates that pass the No. 4 (4.75 mm) sieve size. The test assigns
an empirical value to the relative amount, fineness, and character of clay-like material present
in a test specimen. A minimum sand equivalent value may be specified to limit the
permissible quantity of clay-like fines in an aggregate.
3
CEEN 162 - Geotechnical Engineering - Laboratory Session No. 2
Grain Size Determination (Hydrometer Method), Atterberg Limits, Sand Equivalent Test
OBJECTIVE: To obtain data necessary for the classification of a soil.
EQUIPMENT: 151H Hydrometer bulb, scale, sodium hexametaphosphate dispersion solution, mixing
apparatus, beaker, sedimentation cylinder, thermometer, liquid limit device, porcelain dish, spatula, balance,
moisture content cans, glass plate, distilled water, drying oven, sand equivalent apparatus, working calcium
chloride solution.
REFERENCE SPECIFICATIONS: ASTM D 422-63, D 2419-74
LAB PROCEDURES:
Part 1 - Hydrometer Calibration (Data Sheet 1)
1.
Select and clean a 151H hydrometer bulb and record the identifier number.
2.
Obtain hydrometer calibration readings in each of the the 1 L graduated cylinders filled with a 5g/L
solution of sodium hexametaphosphate in distilled water. Record the temperature of the solutions to
0.5 oC.
Part 2 - Sedimentation Test (Data Sheet 2)
1.
Obtain a 100 g sample of air-dried soil (minus #10 soil from Lab 1) and place in a 400-mL beaker.
Cover with 125 mL of concentrated sodium hexametaphosphate solution (40g/L). Stir until the soil is
thoroughly wetted and allow to soak for at least 15 minutes. After soaking transfer the soil-water slurry
from the beaker into the dispersion cup, washing any residue from the beaker with distilled water. Add
distilled water, if necessary, to fill the dispersion cup approximately half full. Mix the suspension in
the mixer for 1 min.
2.
Immediately after mixing, wash the specimen into a 1 L graduated cylinder and add enough distilled
water to bring level to the 1 L mark.
3.
Mix soil and water in cylinder by placing a rubber stopper over the open end and turning the graduate
upside down and back for 1 min. The number of turns during this minute should be approx. 60,
counting the turn upside down and back as two turns. Any soil remaining in the bottom of the cylinder
during the first few turns should be loosened by vigorous shaking of the cylinder while it is in the
inverted position.
4.
After shaking, replace the cylinder on the table, start the timer, and insert the hydrometer in the
suspension. Record the hydrometer readings ( top of the meniscus formed by the suspension around
the stem) at elapsed times of ½, 1, 1-½ 2, 5, 10, 20, 30, 40, 60 and 80 minutes.
Part 3- Liquid Limit Test (Data Sheet 3)
1.
Dry sieve the soil remaining from Lab 1 through a No. 40 sieve. Obtain a 200 g sample of the soil
which passes the No. 40 sieve, either by discarding excess soil or by adding additional soil from the
control jar.
2.
Check the fall height of the liquid limit cup using the end of the grooving tool and adjust as necessary.
Record the mass of 5 marked moisture cans to the nearest 0.01g. Three will be available for the liquid
limit test and two for the plastic limit test.
4
CEEN 162 - Geotechnical Engineering - Laboratory Session No. 2
Grain Size Determination (Hydrometer Method), Atterberg Limits, Sand Equivalent Test
3.
Place the 200 g of soil on a glass plate and add about 15 ml of distilled water. Mix soil and water
thoroughly using an alternate of repeated stirring, kneading and chopping action with the spatula.
Continue adding water at the rate of 1 to 3 milliliter increments and thoroughly mix each increment into
the soil before adding the next. Enough water should be thoroughly mixed to produce a consistency
that will require 25 to 35 drops of the cup to cause the groove to close.
4.
Place a portion of the prepared soil mixture in the cup of the liquid limit device at the point where the
cup rests on the base, squeeze it down, and spread it into the cup to a depth of about 10 mm at its
deepest point, tapering it to form an approximately horizontal surface. Take care to eliminate air
bubbles from the soil pat but form the pat with as few strokes as possible. Heap the unused soil on
the glass plate and cover with an inverted storage dish or wet towel.
5.
Form a groove in the soil pat by drawing the tool through the soil on a line joining the highest point to
the lowest point on the rim of the cup. Hold the grooving toll against the surface of the cup and draw
in an arc, maintaining the tool perpendicular to the surface of the cup. Avoid tearing the sides of the
soil groove and do not permit the soil pat to slide in the cup. Up to six strokes are permitted to form
the groove.
6.
Using a continual motion of the crank, lift and drop the cup at the rate of two drops per second. Record
the number of drops of the cup required to cause the two halves of the soil pat to flow together for a
distance of 13 mm (1/2 in).
7.
Remove a slice of soil approximately the width of the spatula, extending from edge to edge of the soil
cake at right angles to the groove and including that portion of the groove in which the soil flowed
together. Record the mass of the moist soil and moisture tin to the nearest 0.01g. Place the tin in
a drying oven.
8.
Return the soil remaining in the cup to the glass plate. Wash and dry the cup and grooving tool and
reattach the cup to the carriage. Remix the entire soil specimen on the glass plate adding distilled
water to increase the water content of the soil and decrease the number of blows required to close the
groove to between 20 to 30 blows.
9.
Repeat Steps 4 through 8 for at least two additional trials producing successively lower blow counts
to close the groove. One of the trials shall be for closure requiring 20 and 30 blows and one for closure
between 15 and 25 blows.
10.
Record the mass of the oven dried soil and moisture tin to the nearest 0.01g.
Part 4 - Plastic Limit Test (Date Sheet 3)
1.
Select a 20 g portion of the soil from the material remaining after the liquid limit test. Reduce the water
content of the soil to a consistency at which it can be rolled without sticking to the hands by spreading
and mixing continuously on the glass plate. The drying process may be accelerated by blotting with
paper that does not add any fiber to the soil, such as hard surface paper toweling.
5
CEEN 162 - Geotechnical Engineering - Laboratory Session No. 2
Grain Size Determination (Hydrometer Method), Atterberg Limits, Sand Equivalent Test
2.
From the 20 g mass, select a portion of 1.5 to 2.0 g and form into an ellipsoid. Cover the remaining
soil with a moist towel. Roll this mass between the palm or fingers and the glass plate with just
sufficient pressure to roll the mass into a thread of uniform diameter throughout its length. When the
diameter of the thread becomes 3 mm, break the thread into several pieces. Squeeze the pieces
together, knead between the thumb and first finger of each hand, reform into an ellipsoid, an re-roll.
Continue to alternate rolling, gathering, kneading, and re-rolling until the thread crumbles under the
pressure required for rolling and the soil can no longer be rolled into a 3 mm diameter thread.
3.
Gather the portions of the crumbled thread together and place in a moisture tin and immediately cover.
4.
Repeat steps 2 and 3 until the moisture tin contains at least 6 g of moist soil. Record the mass of
the moist soil and tin (without cover) to the nearest 0.01g. Place the moist soil and tin in a drying
oven.
5.
Repeat steps 2 through 4 to produce another moisture tin containing at least 6 g of soil. Record the
mass of the moist soil and tin (without cover) to the nearest 0.01g. Place the moist soil and tin in a
drying oven.
6.
Record the mass of the oven dried soil and moisture tin to the nearest 0.01g.
Part 5 - Sand Equivalent Test (Data Sheet 4)
1.
Obtain a 500 g sample of soil passing the No. 4 sieve. Fill one tin measure to the brim or slightly
rounded above the brim.
2.
Siphon approximately 4 in of working calcium chloride solution into the plastic cylinder. Pour the soil
sample into the cylinder using the funnel to avoid spillage. Allow the wetted specimen and cylinder
to stand for approximately 10 min.
3.
After the 10 min soaking period, hold the cylinder in a horizontal position and shake vigorously in a
horizontal linear motion from end to end. Shake the cylinder 90 cycles (back and forth motion) in
approximately 30 seconds using a throw of 9 inches.
4.
Irrigate the sample using the working calcium chloride solution by forcing the irrigator tip through the
material to the bottom of the cylinder while the solution is flowing. Continue stabbing and twisting the
irrigator tip until the cylinder is filled to the 15 inch graduation mark. Raise the irrigator tube slowly
without stopping the flow so that the liquid level is maintained at about the 15 inch mark. Regulate the
flow just before complete removal of the irrigator tip so that the final fluid level is at the 15 inch mark.
5.
Allow the cylinder and contents to stand undisturbed for 20 minutes after the removal of the irrigator
tube.
6.
Record the level of the top of the clay suspension after the 20 minute rest period. Place the weighted
foot assembly over the cylinder and gently lower the assembly until it comes to rest on top of the sand.
Tilt the assembly towards the gradations on the cylinder until the indicator touches the inside of the
cylinder. Subtract 10 inches for the level indicated by the extreme top edge of the indicator and record
this value as the sand reading.
6
CEEN 162 - Geotechnical Engineering - Laboratory Session No. 2
Grain Size Determination (Hydrometer Method), Atterberg Limits, Sand Equivalent Test
CALCULATIONS:
1.
Using the hydrometer calibration data from Data Sheet 1, prepare a linear plot of the composite
correction factor vs temperature and develop an equation to predict the composite correction factor for
any intermediate temperature. Using the equation below, complete Data Sheet 2 to determine the grain
size distribution of the soil sample. Plot these results in combination with Lab 1 dry sieve data and
develop a single, smooth grain size distribution curve for the soil sample.
The percentage (P) of soil remaining in suspension and the largest diameter (D) of soil in suspension
at the level of the hydrometer are calculated as:
P '
1000 G S P10
D ' K
where: P =
GS =
P10=
Ms =
R=
D=
K=
L=
T=
R & 1
GS & 1
MS
L
T
percentage of soil in suspension, %
specific gravity of soil particles (Lab 1)
percent of original soil sample which passes No.10 sieve (Lab 1)
dry mass of soil, g
corrected hydrometer reading (hydrometer reading - composite correction factor)
diameter of soil particle, mm
constant depending temperature and specific gravity of the soil (Table 1)
effective depth, equal to the distance from the surface of the suspension to the level at which
the density of the suspension is being measured, cm (Table 2).
time of hydrometer reading, min.
2.
Using the liquid limit data from Data Sheet 3, determine the moisture content of each container of soil
after oven drying. Plot the results of the liquid limit tests as discrete data points, each with
corresponding blow count and moisture content. Data should be plotted on semi-logarithmic paper
with the moisture content as ordinates on the arithmetic scale and blow counts as abscissas on the
log scale. Draw the best fit straight line through each set of data to obtain the flow curve. Report the
liquid limit (LL) of the soil as the water content corresponding to the intersection of the flow curve with
the 25 blows abscissa, rounded to the nearest whole number.
3.
Using data from Data Sheet 3, compute the moisture content for each of the plastic limit trials. Report
the plastic limit (PL) of the soil as the average of these two values, rounded to the nearest whole
number.
4.
Compute the sand equivalent (SE) for each sample to the nearest 0.1%. If the calculated SE is not
a whole number, report the SE to the next higher whole number (i.e., 41.2 = 42). Prepare a plot of the
sand equivalent vs % clay. Comment on the computed SE values based on the % clay in the soil
sample.
7
CEEN 162 - Geotechnical Engineering - Laboratory Session No. 2
Grain Size Determination (Hydrometer Method), Atterberg Limits, Sand Equivalent Test
DATA SHEET 1
HYDROMETER CALIBRATION DATA
Hydrometer
Reading
Temperature of 5g/L
Sodium
Hexametaphosphate
Solution
C
SOIL DATA
Weight of Beaker, g
Weight of Beaker + Dried Soil, g
Weight of Dried Soil, g (Ms)
P10 (Lab 1)
Specific Gravity of Soil Solids, GS, (Lab 1)
8
Composite
Correction
Factor
CEEN 162 - Geotechnical Engineering - Laboratory Session No. 2
Grain Size Determination (Hydrometer Method), Atterberg Limits, Sand Equivalent Test
DATA SHEET 2
Time
Elapsed
Time
min
Hydrom.
Reading
Temp
o
C
Comp.
Corr.
Factor
Corr.
Hydrom.
Reading
R
9
K
Factor
(Table 1)
Effective
Depth
(Table 2)
L
Percent of
Soil in
Suspension
Particle
Diameter
mm
CEEN 162 - Geotechnical Engineering
Laboratory Session No. 3 - Liquid Limit and Plastic Limit Tests
LAB DATA SHEET 3
LIQUID LIMIT TESTS
Trial 1
Trial 2
Moisture Tin Number
Moisture Tin Wt, g
Number of Drops
Wt. Wet Soil + Tin, g
Wt. Oven-Dry Soil + Tin, g
Calculations
Wt. Water, g
Wt. Oven-Dry Soil, g
Moisture Content, w,%
PLASTIC LIMIT TESTS
Trial 1
Moisture Tin Number
Moisture Tin Wt, g
Wt. Wet Soil + Tin, g
Wt. Oven-Dry Soil + Tin, g
Calculations
Wt. Water, g
Wt Oven-Dry Soil, g
Moisture Content, w, %
10
Trial 2
Trial 3
CEEN 162 - Geotechnical Engineering - Laboratory Session No. 2
Grain Size Determination (Hydrometer Method), Atterberg Limits, Sand Equivalent Test
DATA SHEET 4
SAND EQUIVALENT DATA
Soil
Sample
Clay
Reading
inch
Sand
Reading
inch
100% S
95%S - 5%C
90%S - 10%C
Lab Sample
(1) Sand Equivalent = 100% x (Sand Reading / Clay Reading)
11
Sand
Equivalent
(1)
Table 1: Values of K for Computing Particle Diameter in Suspension
Temperature
o
C
Gs
2.45
2.50
2.55
2.60
2.65
2.70
2.75
2.80
16
0.01510
0.01505
0.01481
0.01457
0.01435
0.01414
0.01394
0.01374
17
0.01511
0.01486
0.01462
0.01439
0.01417
0.01396
0.01376
0.01356
18
0.01492
0.01467
0.01443
0.01421
0.01399
0.01378
0.01359
0.01339
19
0.01474
0.01449
0.01425
0.01403
0.01382
0.01361
0.01342
0.01323
20
0.01456
0.01431
0.01408
0.01386
0.01365
0.01344
0.01325
0.01307
21
0.01438
0.01414
0.01391
0.01369
0.01348
0.01328
0.01309
0.01291
22
0.01421
0.01397
0.01374
0.01353
0.01332
0.01312
0.01294
0.01276
23
0.01404
0.01381
0.01358
0.01337
0.01317
0.01297
0.01279
0.01261
24
0.01388
0.01365
0.01342
0.01321
0.01301
0.01282
0.01264
0.01246
25
0.01372
0.01349
0.01327
0.01306
0.01286
0.01267
0.01249
0.01232
26
0.01357
0.01334
0.01312
0.01291
0.01272
0.01253
0.01235
0.01218
27
0.01342
0.01319
0.01297
0.01277
0.01258
0.01239
0.01221
0.01204
28
0.01327
0.01304
0.01283
0.01264
0.01244
0.01225
0.01208
0.01191
29
0.01312
0.01290
0.01269
0.01249
0.01230
0.01212
0.01195
0.01178
30
0.01298
0.01276
0.01256
0.01236
0.01217
0.01199
0.01182
0.01165
12
Table 2: Effective Depth vs 151 H Hydrometer Reading
Corrected
Hydrometer
Reading
Effective
Depth, L
(cm)
Corrected
Hydrometer
Reading
Effective
Depth, L
(cm)
1.000
16.3
1.020
11.0
1.001
16.0
1.021
10.7
1.002
15.8
1.022
10.5
1.003
15.5
1.023
10.2
1.004
15.2
1.024
10.0
1.005
15.0
1.025
9.7
1.006
14.7
1.026
9.4
1.007
14.4
1.027
9.2
1.008
14.2
1.028
8.9
1.009
13.9
1.029
8.6
1.010
13.7
1.030
8.4
1.011
13.4
1.031
8.1
1.012
13.1
1.032
7.8
1.013
12.9
1.033
7.6
1.014
12.6
1.034
7.3
1.015
12.3
1.035
7.0
1.016
12.1
1.036
6.8
1.017
11.8
1.037
6.5
1.018
11.5
1.038
6.2
1.019
11.3
13
CEEN 162 - Lab 2
Hydrometer Calibration Data
4.50
Composite Correction Factor
4.00
3.50
3.00
2.50
2.00
1.50
21
22
23
Temperature, C
14
24
25
CEEN 162 - Hydrometer Test Results
100
90
80
70
% Passing
60
50
40
30
20
10
0
0.001
0.01
0.1
Grain Size, mm
15
1
10
CEEN 162 - Liquid Limit Test Results
30
28
26
Water Content, %
24
22
20
18
16
14
12
10
1
10
Drops
16
25
100
CEEN 162 - Geotechnical Engineering - Laboratory Session No. 2
Grain Size Determination (Hydrometer Method), Atterberg Limits, Sand Equivalent Test
EXAMPLE DATA SHEET 1
HYDROMETER CALIBRATION
Hydrometer
Reading
Temperature of Sodium
Hexametaphosphate
Solution (5g/L)
Composite
Correction
Factor
1.004
21.5
.004
1.002
24.5
.002
SOIL DATA
Weight of Beaker, g
325.8
Weight of Beaker + Dried Soil, g
425.7
Weight of Dried Soil, g
99.9
P10 (Lab 1)
89.5
Specific Gravity of Soil Solids, GS, (Lab 1)
2.75
17
CEEN 162 - Geotechnical Engineering - Laboratory Session No. 2
Grain Size Determination (Hydrometer Method), Atterberg Limits, Sand Equivalent Test
EXAMPLE DATA SHEET 2
Time
Elapsed
Time
min
Hydrom.
Reading
Temp
o
C
Comp
Corr
Factor
K
Factor
(Table 1)
(1)
Corr
Hydrom
Reading
R
(2)
Percent of
Soil in
Suspension
Particle
Diameter
mm
(3)
Effective
Depth
(Table 2)
L
(4)
(5)
(6)
9:04:00
0
9:05:30
1.5
1.0380
23.5
0.0026
1.0354
0.012783
6.9
49.9
0.027
9:06:00
2
1.0370
23.5
0.0026
1.0344
0.012783
7.2
48.5
0.024
9:06:30
2.5
1.0360
23.5
0.0026
1.0334
0.012783
7.5
47.1
0.022
9:07:30
3.5
1.0340
23.5
0.0026
1.0314
0.012783
8.0
44.3
0.019
9:10:00
6
1.0310
23.0
0.0029
1.0281
0.012790
8.9
39.6
0.016
9:14:00
10
1.0280
23.0
0.0029
1.0251
0.012790
9.7
35.4
0.013
9:24:00
20
1.0260
23.0
0.0029
1.0231
0.012790
10.2
32.5
0.009
9:34:00
30
1.0250
23.0
0.0029
1.0221
0.012790
10.4
31.1
0.008
9:44:00
40
1.0240
23.0
0.0029
1.0211
0.012790
10.7
29.7
0.007
9:54:00
50
1.0240
23.1
0.0028
1.0212
0.012789
10.7
29.8
0.006
0.012790
11.0
28.3
0.005
10:04:00
60
1.0230
23.0
0.0029
1.0201
(1) Determined from equation developed from hydrometer calibration data
(2) Hydrometer reading - composite correction factor
(3) Determined from Table 1 based on temperature and specific gravity of soil solids
(4) Determined from Table 2 based on corrected hydrometer reading
(5) Calculated based on equation provided; P = fn {Gs, P10, Ms, R}
(6) Calculated based on equation provided; D = fn {K, L, T}
CEEN 162 - Geotechnical Engineering
Laboratory Session No. 2 - Liquid Limit and Plastic Limit Tests
18
EXAMPLE DATA SHEET 3
LIQUID LIMIT TESTS
Trial 1
Trial 2
Trial 3
A1
D1
E4
25.2
24.9
25.1
28
22
18
Wt. Wet Soil + Tin, g
45.2
46.2
46.5
Wt. Oven-Dry Soil + Tin, g
41.8
42.3
42.3
Wt. Water, g
3.4
3.9
4.2
Wt. Oven-Dry Soil, g
16.6
17.4
17.2
Moisture Content, w,%
20.5
22.4
24.4
Moisture Tin Number
Moisture Tin Wt, g
Number of Drops
Calculations
PLASTIC LIMIT TESTS
Trial 1
Trial 5
Moisture Tin Number
A2
J2
Moisture Tin Wt, g
24.8
25.3
Wt. Wet Soil + Tin, g
30.9
32.2
Wt. Oven-Dry Soil + Tin, g
30.2
31.4
Wt. Water, g
0.7
0.8
Wt Oven-Dry Soil, g
5.4
6.1
Moisture Content, w, %
13.0
13.1
Calculations
19
CEEN 162 - Geotechnical Engineering - Laboratory Session No. 2
Grain Size Determination (Hydrometer Method), Atterberg Limits, Sand Equivalent Test
DATA SHEET 4
SAND EQUIVALENT DATA
Soil
Sample
Clay
Reading
inch
Sand
Reading
inch
Sand
Equivalent
(1)
100% S
4.3
4.1
96
95%S - 5%C
4.4
3.8
87
90%S - 10%C
5.3
3.6
68
Lab Sample
13.2
1.1
9
(1) Sand Equivalent = 100% x (Sand Reading / Clay Reading)
20
CEEN 162 - Lab 2
Hydrometer Calibration Data
4.5
Y = 0.018333 - 0.000667 X
Composite Correction Factor (x10^-3)
4.0
3.5
3.0
2.5
2.0
1.5
21
22
23
Temperature, C
21
24
25
CEEN 162 - Hydrometer Test Results
100
90
80
70
% Passing
60
50
40
30
20
10
0
0.001
0.01
0.1
Grain Size, mm
22
1
10
CEEN 162 - Liquid Limit Test Results
30
28
26
Water Content, %
24
LL = 21.6 = 22
22
20
18
16
14
12
10
1
10
Drops
23
25
100
CEEN 162 - Sand Equivalent Test Results
100
90
80
Sand Equivalent
70
60
50
40
30
20
10
0
0
10
20
30
40
50
% Clay
24
60
70
80
90
100