just need you to write Introduction and Background and Procedures for this lab MOISTURE-DENSITY RELATION (COMPACTION) TEST. I don’t want full report, I just need Introduction and Background and Procedures. I uploaded the experiment file check it.
lab_4_standard_proctor_compaction.pdf
Unformatted Attachment Preview
91
LAB 4
MOISTURE-DENSITY RELATION (COMPACTION) TEST
Purpose:
This laboratory test is performed to determine the relationship between the
moisture content and the dry density of a soil for a specified compactive effort.
The compactive effort is the amount of mechanical energy that is applied to the
soil mass. Several different methods are used to compact soil in the field, and
some examples include tamping, kneading, vibration, and static load compaction.
This laboratory will employ the tamping or impact compaction method using the
type of equipment and methodology developed by R. R. Proctor in 1933,
therefore, the test is also known as the Proctor test.
Two types of compaction tests are routinely performed: (1) The Standard
Proctor Test, and (2) The Modified Proctor Test. Each of these tests can be
performed in three different methods as outlined in the attached Table 1. In the
Standard Proctor Test, the soil is compacted by a 5.5 lb hammer falling a
distance of one foot into a soil filled mold. The mold is filled with three equal
layers of soil, and each layer is subjected to 25 drops of the hammer. The
Modified Proctor Test is identical to the Standard Proctor Test except it employs,
a 10 lb hammer falling a distance of 18 inches, and uses five equal layers of soil
instead of three. There are two types of compaction molds used for testing. The
smaller type is 4 inches in diameter and has a volume of about 1/30 ft3 (944 cm3),
and the larger type is 6 inches in diameter and has a volume of about 1/13.333 ft3
(2123 cm3). If the larger mold is used each soil layer must receive 56 blows
instead of 25 (See Table 1).
Engineering Properties of Soils Based on Laboratory Testing
Prof. Krishna Reddy, UIC
92
Table 1 Alternative Proctor Test Methods
Standard Proctor
ASTM 698
Material
For test
sample, use
soil passing
Mold
No. of
Layers
No. of
blows/layer
Note:
Modified Proctor
ASTM 1557
Method A
Method B
Method C
Method A
Method B
Method C
≤ 20%
Retained on
No.4 Sieve
>20%
Retained on
No.4
≤ 20%
Retained on
3/8” Sieve
>20%
Retained on
No.3/8”
<30%
Retained on
3/4” Sieve
≤ 20%
Retained on
No.4 Sieve
>20%
Retained on
No.4
≤ 20%
Retained on
3/8” Sieve
>20%
Retained on
No.3/8”
<30%
Retained on
3/4” Sieve
Sieve No.4
3/8” Sieve
¾” Sieve
Sieve No.4
3/8” Sieve
¾” Sieve
4” DIA
4” DIA
6” DIA
4” DIA
4” DIA
6” DIA
3
3
3
5
5
5
25
25
56
25
25
56
Volume of 4” diameter mold = 944 cm3 , Volume of 6” diameter mold = 2123 cm3
(verify these values prior to testing)
Engineering Properties of Soils Based on Laboratory Testing
Prof. Krishna Reddy, UIC
93
Standard Reference:
ASTM D 698 - Standard Test Methods for Laboratory Compaction
Characteristics of Soil Using Standard Effort (12,400 ft-lbs/ft3 (600 KN-m/m3))
ASTM D 1557 - Standard Test Methods for Laboratory Compaction
Characteristics of Soil Using Modified Effort (56,000 ft-lbs/ft3 (2,700 KN-m/m3))
Significance:
Mechanical compaction is one of the most common and cost effective
means of stabilizing soils. An extremely important task of geotechnical engineers
is the performance and analysis of field control tests to assure that compacted
fills are meeting the prescribed design specifications. Design specifications
usually state the required density (as a percentage of the “maximum” density
measured in a standard laboratory test), and the water content. In general, most
engineering properties, such as the strength, stiffness, resistance to shrinkage,
and imperviousness of the soil, will improve by increasing the soil density.
The optimum water content is the water content that results in the greatest
density for a specified compactive effort. Compacting at water contents higher
than (wet of ) the optimum water content results in a relatively dispersed soil
structure (parallel particle orientations) that is weaker, more ductile, less
pervious, softer, more susceptible to shrinking, and less susceptible to swelling
than soil compacted dry of optimum to the same density. The soil compacted
lower than (dry of) the optimum water content typically results in a flocculated soil
structure (random particle orientations) that has the opposite characteristics of
the soil compacted wet of the optimum water content to the same density.
Engineering Properties of Soils Based on Laboratory Testing
Prof. Krishna Reddy, UIC
94
Equipment:
Molds, Manual rammer, Extruder, Balance, Drying oven, Mixing pan,
Trowel, #4 sieve, Moisture cans, Graduated cylinder, Straight Edge.
Engineering Properties of Soils Based on Laboratory Testing
Prof. Krishna Reddy, UIC
95
Engineering Properties of Soils Based on Laboratory Testing
Prof. Krishna Reddy, UIC
96
Test Procedure:
(1)
Depending on the type of mold you are using obtain a sufficient
quantity of air-dried soil in large mixing pan. For the 4-inch mold
take approximately 10 lbs, and for the 6-inch mold take roughly 15
lbs. Pulverize the soil and run it through the # 4 sieve.
(2)
Determine the weight of the soil sample as well as the weight of the
compaction mold with its base (without the collar) by using the
balance and record the weights.
(3)
Compute the amount of initial water to add by the following method:
(a)
Assume water content for the first test to be 8 percent.
(b)
Compute water to add from the following equation:
water to add (in ml) =
(soil mass in grams )8
100
Where “water to add” and the “soil mass” are in grams. Remember
that a gram of water is equal to approximately one milliliter of water.
(4)
Measure out the water, add it to the soil, and then mix it thoroughly
into the soil using the trowel until the soil gets a uniform color (See
Photos B and C).
(5)
Assemble the compaction mold to the base, place some soil in the
mold and compact the soil in the number of equal layers specified by
the type of compaction method employed (See Photos D and E).
The number of drops of the rammer per layer is also dependent
upon the type of mold used (See Table 1). The drops should be
applied at a uniform rate not exceeding around 1.5 seconds per
Engineering Properties of Soils Based on Laboratory Testing
Prof. Krishna Reddy, UIC
97
drop, and the rammer should provide uniform coverage of the
specimen surface. Try to avoid rebound of the rammer from the top
of the guide sleeve.
(6)
The soil should completely fill the cylinder and the last compacted
layer must extend slightly above the collar joint. If the soil is below
the collar joint at the completion of the drops, the test point must be
repeated. (Note: For the last layer, watch carefully, and add more
soil after about 10 drops if it appears that the soil will be compacted
below the collar joint.)
(7)
Carefully remove the collar and trim off the compacted soil so that it
is completely even with the top of the mold using the trowel. Replace
small bits of soil that may fall out during the trimming process (See
Photo F).
(8)
Weigh the compacted soil while it’s in the mold and to the base, and
record the mass (See Photo G). Determine the wet mass of the soil
by subtracting the weight of the mold and base.
(9)
Remove the soil from the mold using a mechanical extruder (See
Photo H) and take soil moisture content samples from the top and
bottom of the specimen (See Photo I). Fill the moisture cans with
soil and determine the water content.
(10) Place the soil specimen in the large tray and break up the soil until it
appears visually as if it will pass through the # 4 sieve, add 2 percent
more water based on the original sample mass, and re-mix as in
step 4. Repeat steps 5 through 9 until, based on wet mass, a peak
Engineering Properties of Soils Based on Laboratory Testing
Prof. Krishna Reddy, UIC
98
value is reached followed by two slightly lesser compacted soil
masses.
Analysis:
(1)
Calculate the moisture content of each compacted soil specimen by
using the average of the two water contents.
(2)
Compute the wet density in grams per cm3 of the compacted soil
sample by dividing the wet mass by the volume of the mold used.
(3)
Compute the dry density using the wet density and the water content
determined in step 1. Use the following formula:
ρ
ρ =
d 1+ w
where: w = moisture content in percent divided by 100, and ρ = wet
density in grams per cm3.
(4)
Plot the dry density values on the y-axis and the moisture contents
on the x-axis. Draw a smooth curve connecting the plotted points.
(5)
On the same graph draw a curve of complete saturation or “zero air
voids curve”. The values of dry density and corresponding moisture
contents for plotting the curve can be computed from the following
equation:
ρ
1
× 100
w sat = w −
G
ρ
s
d
or
ρd =
ρw
1
w
+
100 Gs
Engineering Properties of Soils Based on Laboratory Testing
Prof. Krishna Reddy, UIC
99
where:
ρd = dry density of soil grams per cm3
Gs = specific gravity of the soil being tested (assume 2.70 if not given)
ρw = density of water in grams per cm3 (approximately1 g/cm3)
wsat = moisture content in percent for complete saturation.
Example Calculations:
Gs=2.7 (assumed)
ρw=1.0 g/cm3
Assumed wsat%
Calculated ρd (g/cm3)
8
2.22
10
2.13
12
2.04
14
1.96
16
1.89
18
1.82
(6) Identify and report the optimum moisture content and the maximum dry
density. Make sure that you have recorded the method of compaction
used (e.g., Standard Proctor, Method A) on data sheet.
Engineering Properties of Soils Based on Laboratory Testing
Prof. Krishna Reddy, UIC
100
EXAMPLE DATA
Engineering Properties of Soils Based on Laboratory Testing
Prof. Krishna Reddy, UIC
101
Moisture-Density (Compaction) Test
Data Sheets
Test Method: Standard Proctor, Method A (ASTM 698)
Date Tested: October 05, 2002
Tested By: CEMM315 Class, Group A
Project Name: CEMM315 Lab
Sample Number: Bag-1, 2’-6’
Visual Classification of Soil: Gray silty clay, trace fine sand, low plasticity, moist, CL
Water Content Determination:
1
Compacted Soil - Sample no.
2
3
MC = Mass of empty, clean can + lid (grams)
1A
1
7.78
1B
2
7.83
2A
3
7.71
2B
4
7.9
3A
5
7.5
3B
6
7.9
MCMS = Mass of can, lid, and moist soil (grams)
11.78
11.05
10.71
11 . 1
10.7
12 .0
MCDS = Mass of can, lid, and dry soil (grams)
11.48
10.81
10.41
10.75
10.3
11.52
MS = Mass of soil solids (grams)
3.70
2.98
2.7
2.85
2.84
3.62
MW = Mass of pore water (grams)
0.29
0.24
0.30
0.35
0.40
0.53
w = Water content, w%
7.9
8.1
11 . 1
10.9
12.5
13.1
Water content - Sample no.
Moisture can number - Lid number
4
Compacted Soil - Sample no.
5
6
4A
7
8.1
4B
8
7.6
5A
9
7.7
5B
10
7.65
MCMS = Mass of can, lid, and moist soil (grams)
11. 1
10.2
10.3
10.33
MCDS = Mass of can, lid, and dry soil (grams)
10.70
9.84
10.02
9.92
MS = Mass of soil solids (grams)
2.60
2.24
2.32
2.27
MW = Mass of pore water (grams)
0.40
0.35
0.4
0.39
w = Water content, w%
15.3
16.0
17. 1
17.6
Water content - Sample no.
Moisture can number - Lid number
MC = Mass of empty, clean can + lid (grams)
Engineering Properties of Soils Based on Laboratory Testing
Prof. Krishna Reddy, UIC
6A
6B
102
Density Determination:
Mold Volume=944 cm3
1
2
3
4
5
w = Assumed water content, w%
10
12
14
16
18
Actual average water content, w%
8.0
11.0
12.8
15.65
17
3457.2
3721.2
3909.0
3782.5
3715.2
1933
1933
1976.0
1849.5
1782.2
1524.2
1788.2
2176
2149
2082
3
Wet density, ρ , (g/cm )
1.615
1.894
2.093
1.959
1.888
3
Dry density, ρd , (g/cm )
1.50
1.71
1.86
1.69
1.61
Compacted Soil - Sample no.
Mass of compacted soil and mold
(grams)
Mass of mold (grams)
Wet mass of soil in mold (grams)
Dry Density, g/cm3
2.4
Zero Air Voids Curve
2.2
2.0
6
(Gs=2.7 assumed)
ρ dm ax
1.8
1.6
1.4
1.2
1.0
0
5
10
OMC
15
Water Content, w%
Optimum Moisture Content = 13.1 %
Maximum Dry Density = 1.87 g/cm3
Engineering Properties of Soils Based on Laboratory Testing
Prof. Krishna Reddy, UIC
20
103
BLANK DATA SHEETS
Engineering Properties of Soils Based on Laboratory Testing
Prof. Krishna Reddy, UIC
104
Moisture-Density (Compaction) Test
Data Sheets
Test Method:
Date Tested:
Tested By:
Project Name:
Sample Number:
Visual Classification of Soil:
Water Content Determination:
Compacted Soil - Sample no.
Water content - Sample no.
1
1A
2
1B
2A
3
2B
3A
3B
Moisture can number - Lid number
MC = Mass of empty, clean can + lid (grams)
MCMS = Mass of can, lid, and moist soil (grams)
MCDS = Mass of can, lid, and dry soil (grams)
MS = Mass of soil solids (grams)
MW = Mass of pore water (grams)
W = Water content, w%
Compacted Soil - Sample no.
Water content - Sample no.
4
4A
5
4B
5A
6
5B
Moisture can number - Lid number
MC = Mass of empty, clean can + lid (grams)
MCMS = Mass of can, lid, and moist soil (grams)
MCDS = Mass of can, lid, and dry soil (grams)
MS = Mass of soil solids (grams)
MW = Mass of pore water (grams)
W = Water content, w%
Engineering Properties of Soils Based on Laboratory Testing
Prof. Krishna Reddy, UIC
6A
6B
105
Density Determination:
Volume of mold=
Compacted Soil - Sample no.
1
2
3
4
5
6
w = Assumed water content, w%
Actual average water content, w%
Mass of compacted soil and mold (grams)
Mass of mold (grams)
Wet mass of soil in mold (grams)
3
Wet density, ρ , (kg/m )
3
Dry density, ρd , (kg/m )
2.6
Dry Density (g/cm3)
2.4
2.2
2.0
1.8
1.6
1.4
1.2
1.0
5
10
15
20
Water Content, w%
Optimum Moisture Content = _________________ %
3
Maximum Dry Density = ___________________ g/cm
Engineering Properties of Soils Based on Laboratory Testing
Prof. Krishna Reddy, UIC
25
...
Purchase answer to see full
attachment
