3. DEFINITION OF SOIL
The term Soil has various meanings, depending
upon the general field in which it is being
considered.
O To a Pedologist ... Soil is the substance existing on
the earth's surface, which grows and develops plant
life.
OTo a Geologist ..... Soil is the material in the relative
thin surface zone within which roots occur, and all
the rest of the crust is grouped under the term
ROCK irrespective of its hardness.
4. O To an Engineer .... Soil is the un-
aggregated or un-cemented deposits of
mineral and/or organic particles or
fragments covering large portion of the
earth's crust.
DEFINITION OF SOIL
5. SoilSoil is a natural body comprised of solids
(minerals and organic matter), liquid, and
gases that occurs on the land surface,
occupies space, and is characterized by
one or both of the following: horizons, or
layers, that are distinguishable from the
initial material as a result of additions,
losses, transfers, and transformations of
energy and matter or the ability to support
rooted plants in a natural environment.
SoilSoil is the oldest and most complex
engineering material.
7. Soil FormationSoil Formation
Parent
Rock
Residual
Soil (remain
at the original
place)
Transported Soil
(moved and
deposited to other
places)
- weathering (by
physical & chemical
agents) of parent
rock
- weathered and
transported far away
by wind, water and
ice
8. Transported Soils
Glacial soils: formed by transportation and
deposition of glaciers.
Alluvial soils: transported by running water and
deposited along streams.
Lacustrine soils: formed by deposition in quiet
lakes (e.g. soils in Taipei basin).
Marine soils: formed by deposition in the seas
Aeolian soils: transported and deposited by the
wind (e.g. soils in the loess plateau, China).
Colluvial soils: formed by movement of soil from
its original place by gravity, such as during
landslide
9.
10. BASIC DEFINITION AND PHASE RELATIONSBASIC DEFINITION AND PHASE RELATIONS
O SOIL is composed of solids, liquids, and gases.
O The solid phase may be mineral, organic matter, or
both.
O The spaces between the solids (soil particles) are
called voidsvoids.
O If all the voids are filled with water, the soil is
saturatedsaturated. Otherwise, the soil is unsaturated.
O If all the voids are filled with air, the soil is said to be
drydry.
O Water is often the predominant liquid and air is the
predominant gas.
13. O VOID RATIO; eVOID RATIO; e : The ratio of the volume of voids
(Vv) to soil volume (Vs).
Void ratios of real coarse-grained soils vary between
1 and 0.3. Greater than 1 for clay soils.
O POROSITY; nPOROSITY; n : The ratio of the volume of voids
(Vv) to total volume (V).
0 ≤ n ≤ 1
O RELATIONSHIP BETWEEN VOID RATIO AND
POROSITY
or
s
v
V
V
e =
V
V
n v
=
n
n
e
−
=
1 e
e
n
+
=
1
14. O WATER CONTENT;WATER CONTENT; ωω : The ratio of the amount
of water (Ww) in the soil (Ws) and expressed as a
percentage.
O DEGREE OF SATURATION; SDEGREE OF SATURATION; S : The ratio of the
volume water (Vw) to volume of voids (Vv) and
expressed as a percentage.
0% ≤ S ≤ 100%
%100x
W
W
s
w
=ω
%100x
V
V
S
v
w
=
15. O Completely dry soil S = 0 %
Completely saturated soil S = 100% or
1
Unsaturated soil (partially saturated soil)
S = Vw/Vv = (ωGs)/e
or
Se = ωGs
16. O UNIT WEIGHT, ƔUNIT WEIGHT, Ɣ : The ratio of weight to volume
γt = (Gs + Se) γw
(1 + e)
O SPECIFIC GRAVITY; GSPECIFIC GRAVITY; GSS : The ratio of unit weight
of soil to unit weight of water
or
O RELATIVE DENSITY; DrRELATIVE DENSITY; Dr :
w
w
w
V
W
=γ
s
s
s
V
W
=γ
V
W
=γ
w
s
Gs
γ
γ
=
%100
minmax
max
x
ee
ee
Dr o
−
−
=
w
VsWs
Gs
γ
/
=
17. Special Cases for Unit WeightSpecial Cases for Unit Weight
O Saturated unit weight (S=1):
γsat = [(Gs + e)/(1 + e)] γw
O Dry unit weight (S=0):
γd = Ws/V = [Gs /(1 + e)] γw
O Effective or Buoyant (submerged) unit weight
is the weight of a saturated soil, surrounded
by water per unit volume of soil.
γ’ = γsat – γw = [(Gs - 1)/(1 + e)] γw
18. Example #1:Example #1:
O A soil sample has a void ratio
of 0.8, degree of saturation of
0.9 and Gs of 2.68. Using SI
units compute, total unit
weight, dry unit weight, water
content, and saturated unit
weight.
19. O A saturated sample of soil in a water
content container weighed 60g. After
drying in air its weight was 50g. The
container weighed 10g. Specific gravity
of the soils was 2.7. Determine
O water content
O void ratio
O total unit weight
O dry unit weight
Example #2:Example #2:
20. O The dry density of a sand with a porosity
of 0.387 is 1600 kg/m³.
O Calculate the void ratio of the soil.
O Calculate the specific gravity of soil
solids.
O Calculate the effective density of the soil
in kg/m³.
Example #3:Example #3:
21. O The void ratio of a soil is 0.85. What is
the percentage error of the bulk unit
weight if the soil were 95% saturated
and assumed to be totally saturated?
Assignment:Assignment:
22. O PARTICLE SIZE DISTRIBUTIONPARTICLE SIZE DISTRIBUTION is a
screening process in which coarse fractions of
soil are separated by means of series of sieves.
O Particle sizes larger than 0.074 mm (U.S. No.
200 sieve) are usually analyzed by means of
sieving.
O Soil materials finer than 0.074 mm (#200
material) are analyzed by means of
sedimentation of soil particles by gravity
(hydrometer analysis).
Determination of Particle SizeDetermination of Particle Size
DistributionDistribution
23. There are two methods that generally
utilized to determine the particle size
distribution of soil:
1. Sieve AnalysisSieve Analysis (for particle sizes >
0.075mm in diameter)
2. Hydrometer AnalysisHydrometer Analysis ( for particle
sizes < 0.075mm in diameter )
24. Sieve AnalysisSieve Analysis
O It is performed
by shaking the
soil sample
through a set of
sieves having
progressively
smaller
openings.
25.
26. The grain size analysis (sieve analysis) is a method
to determine the relative proportions of grain sizes
that make up a given soil.
Apparatus Required:
1. Stack of Sieves including pan and cover
2. Balance (with accuracy to 0.01 g)
3. Rubber pestle and Mortar ( for crushing the soil if
lumped or conglomerated)
4. Mechanical sieve shaker
5. Oven
Notice: The balance to be used should be sensitive to
the extent of 0.1% of total weight of sample taken.
27. Procedure:
1. Obtain 500
g of oven-dry
representativ
e soil sample
(for the
largest
particle of
4.75 mm).
29. Procedure:
3. Stack sieves on a
pan from No. 200
progressing up to
increasing larger
sizes. It is desired
to have 100%
passing for the top
sieve; this sieve
may be excluded
from the stack.
Pour the soil in the
top sieve. Place
cover on top sieve.
30. Procedure:
4. Place the stack
in a mechanical
shaker. Shake
for
approximately
10 to 15
minutes.
34. Hydrometer AnalysisHydrometer Analysis
O It is based on the
principle of
sedimentation of
soil grains in water.
O Used to extend the
distribution curve of
particle shape and
to predict the
particle size less
than 200 sieve.
35. Procedure:
1. Take the fine soil from the bottom pan of
the sieve set, place it into a beaker, and add
125 mL of the dispersing agent (sodium
hexametaphosphate (40 g/L)) solution. Stir the
mixture until the soil is thoroughly wet. Let
the soil soak for at least ten minutes..
36. Procedure:
2. While the soil is soaking, add 125mL of dispersing
agent into the control cylinder and fill it with distilled
water to the mark. Take the reading at the top of the
meniscus formed by the hydrometer stem and the
control solution. A reading less than zero is recorded
as a negative (-) correction and a reading between
zero and sixty is recorded as a positive (+) correction.
This reading is called the zero correction. The
meniscus correction is the difference between the
top of the meniscus and the level of the solution in
the control jar (usually about +1).
37. Procedure:
2. Shake the control cylinder in such a way that
the contents are mixed thoroughly. Insert the
hydrometer and thermometer into the control
cylinder and note the zero correction and
temperature respectively.
3. Transfer the soil slurry into a mixer by adding
more distilled water, if necessary, until mixing
cup is at least half full. Then mix the solution
for a period of two minutes.
38. Procedure:
4. Immediately transfer the soil slurry into the
empty sedimentation cylinder. Add distilled
water up to the mark.
5. Cover the open end of the cylinder with a
stopper and secure it with the palm of your
hand. Then turn the cylinder upside down and
back upright for a period of one minute. (The
cylinder should be inverted approximately 30
times during the minute.)
(6) Set the cylinder down and record the time.
Remove the stopper from the cylinder.
39. Some commonly used measures are:Some commonly used measures are:
O a) Effective size: (D10)
It is the diameter in the particle size distribution
curve corresponding to 10% finer. (maximum
size of the smallest 10% of the soil)
O b) Uniformity Coefficient : Cu =D60/D10
It is the ratio of the maximum diameter of the
smallest 60% to the effective size.
A well graded soil will have
Cu > 4 for gravel
Cu > 6 for sand
40. O c) Coefficient of Curvature:
Cc = (D30)²/(D60*D10)
D30 is the diameter corresponding the 30% finer
O d) Clay Fraction: (CF)
It is the percentage by dry mass of particles
smaller than 0.002mm (2μm), and is an
index property frequently quoted relation to
fine grained soils (soils with 50% or more
finer than 63μm). It has a strong influence
on the engineering properties of fine
grained soils.
41. O e) Well-Graded Material – Contains
particles of a wide range of sizes. The
smaller particles fill the spaces left between
the larger particles; therefore the soil has
greater strength than a poorly graded soil,
and lower permeability.
O f) Poorly – Graded Material – Contains
a large portion of uniformly sized particles.
This particular soil has larger voids in its
structure and poor strength along with high
permeability.
42. O Soil A: Well Graded
O Soil B: Poorly Graded
O Soil C: Uniform
44. O PURPOSE:
To classify the soil into a group according
to the soil behavior and physical shape.
O TYPE OF CLASSIFICATION:
CLASSIFICATION BY VISUAL
AASHTO
USCS (UNIFIED SOIL CLASSIFICATION SYSTEM)
O SOIL TESTS
ATTERBERG LIMIT
SIEVE ANALYSIS
HYDROMETER ANALYSIS
45. CLASSIFICATION BY VISUALCLASSIFICATION BY VISUAL
Carried out by direct observation (visual
examination) to the sample and approximate
the type of soil by:
Color
Smell
Sense/Feeling
Endurance (strength, durability)
Swelling (enlarge or expand)
Sedimentation
46. AASHTOAASHTO
American Association of State Highway andAmerican Association of State Highway and
Transportation OfficialsTransportation Officials
O The soil classified into 7 major categories (A-
1 to A-7)
O Based on:
The result of Sieve Analysis
Atterberg Limits
O The soil quality based on Group Index
Calculation.
47. AASHTO
O GROUP INDEX
O F = The percentage of soil pass sieve no. 200
)10)(15(01.0)}40(005.02.0){35( −−+−+−= PIFLLFGI
Subgrade Group Index Value
Very good Soil Class A-1-a (0)
Good 0 – 1
Medium 2 – 4
Bad 5 – 9
Very Bad 10 - 20
48. GROUP INDEX
Rules:
O If GI < 0, GI = 0
O GI ∈ Integer Number
O No upper limit of GI
O For coarse grained,
O GI = 0 for A-1-a, A-1-b, A-2-4, A-2-5 and A-3
O GI =0.01(F-15)(PI-10) for A-2-6 and A-
2-7
AASHTO
49.
50. USCS (UNIFIED SOILUSCS (UNIFIED SOIL
CLASSIFICATION SYSTEM)CLASSIFICATION SYSTEM)
O First, developed by Arthur Casagrande for
wartime airfields construction in 1943, the
system was modified and adopted for regular
use by Army Corps of Engineers and then by
Bureau of Reclamation in 1952 as the
Unified Soil Classification System
(Casagrande 1948).
O Currently, it is adapted in ASTM and
periodically updated.
51. O The system uses simple six major symbols and four
modifiers as in the following:
Major symbols:
G – Gravel S – Sand
M – Silt C – Clay
O – Organic Pt – Peat
Modifiers:
W – Well graded (for gravel and sand)
P – Poorly graded (for gravel and sand)
H – High plasticity (for silt, clay, & organic soils)
L – Low plasticity (for silt, clay, & organic soils)
52. O Soil classification determined base on the
soil parameter i.e.:
- Diameter of soil particle
Gravel : pass sieve no.3 but retained at
sieve no. 4
Sand : pass sieve no. 4 but retained at
sieve no. 200
Silt and Clay : pass sieve no. 200
- Coefficient of soil uniform
- Atterberg Limits
53. Soil Consistency
Soil consistency provides a means of
describing the degree and kind of cohesion
(solidity) and adhesion (union or grip) between
the soil particles as related to the resistance of
the soil to deform or rupture.
Soil Behave Like:
SOLID at very low moisture
content
LIQUID at very high moisture
content
54. CONSISTENCY
O Consistency is the term used to describe
the degree of firmness (e.g., soft, medium,
firm, or hard) of a soil.
O The consistency of a cohesive
(interconnected) soil is greatly affected by the
water content of the soil.
O A gradual increase of the water content may
transform a dry soil from solid state to a
semi-solid state, to a plastic state, and after
further moisture increase, into a liquid state.
55. CONSISTENCY
O The water content at the corresponding
junction points of these states are known as
the shrinkage limit, the plastic limit, and the
liquid limit, respectively.
56. Soil Consistency - Atterberg Limits
Depending on Moisture Content soil can be
divided into:
Shrinkage
Limit (SL)
Plastic Limit (PL)
Liquid Limit (LL)
Plasticity Index
(PI) = PL - LL
MoistureContent(w)
+
-
Liquidity
Index (LI)
LI = 0
LI = 1
1. Solid
2. Plastic
3. Liquid
57. SOIL INDICESSOIL INDICES
Index Definition Correlation
Plasticity PI = LL - PL Strength,
compressibility,
compactibility….
Liquidity LI = ( MC – PL )/PI Compressibility
and stress rate
Shrinkage SI = PL – SL Shrinkage
potential
Activity of clay Ac = PI/µ Swell potential
where µ = percent of soil finer than 0.002 mm (clay size)
59. DESCRIPTION OF SOIL BASED ONDESCRIPTION OF SOIL BASED ON
LIQUIDITY INDEXLIQUIDITY INDEX
Liquidity Index State
LI < 0 Semi-solid state – high strength,
brittle fracture is expected
0.7 < Ac < 1.2 Plastic state – intermediate strength,
soil deforms like a plastic material
Ac > 1.2 Liquid state – low strength, soil
deforms like a viscous fluid
60. DESCRIPTION OF SOIL BASED ONDESCRIPTION OF SOIL BASED ON
PLASTICITY INDEXPLASTICITY INDEX
Plastic Index Description
0 Non-plastic
1 – 5 Slightly Plastic
5 – 10 Low Plasticity
10 – 20 Medium Plasticity
20 – 40 High Plasticity
> 40 Very High Plasticity
61. Liquid LimitLiquid Limit
Liquid Limit (LL)Liquid Limit (LL) is defined as the
moisture content at which soil begins to
behave as a liquid material and begins to
flow.
(Liquid limit of a fine-grained soil gives the
moisture content at which the shear
strength of the soil is approximately
2.5kN/m2
)
64. LIQUID LIMITLIQUID LIMIT
Procedures :
Step 1. Preparation of Soil (purpose: create small
grains of soil, which absorb water readily)
A. Grind the soil with pestle and mortar (try to
maintain the natural moisture content of the soil).
B. Place soil in a #40 sieve and shake the sieve over
a mixing bowl. Some soil may not pass through the
sieve. Take the non-passing soil and repeat part A
and B, until approximately 200 grams pass the sieve.
C. Weigh three tares on a balance and record the
weight.
65. LIQUID LIMITLIQUID LIMIT
Procedures :
Step 2. Mixing of Soil (purpose: mix soil with
distilled water to form a paste).
A. Add small amount of distilled water to soil sample
in the mixing bowl.
B. Mix soil with spatula.
C. Repeat A and B until soil is consistent and pasty.
67. LIQUID LIMITLIQUID LIMIT
Procedures :
Step 3. Place Soil in Liquid Limit Device (purpose:
begin testing soil)
A. Use a spatula to place the soil in the cup of the
liquid limit device.
B. Fill the cup evenly to a depth of 10 mm. Smooth
the soil with the spatula to remove entrapped air and
form a smooth surface.
69. LIQUID LIMITLIQUID LIMIT
Procedures :
Step 4. Make a Groove in the Soil (purpose:
separate soil in two equal parts).
A. Clean grooving tool with a paper towel.
B. With the grooving tool, make a groove in the soil
from back to front. Be careful not to disturb the soil
next to the groove. The groove should be through the
center of the cup.
71. LIQUID LIMITLIQUID LIMIT
Procedures :
Step 5. Testing (purpose: find how many blows it takes
to close gap).
A. Turn the crank of the liquid limit device at a rate of two
drops per second.
B. Record the number of drops required to close a 20
mm. length of the groove.
C. With a clean spatula, immediately remove a slice of
soil from across the closed gap.
D. Place the slice in a pre-weighed labeled tare. Then
weigh the tare and slice on a balance and record the
weight.
E. Place the tare and slice in the drying oven for 1-2 days.
73. LIQUID LIMITLIQUID LIMIT
Procedures :
Step 5. Additional Sampling (purpose: record more
data to find accurate liquid limit).
A. Perform several more tests by repeating steps 2-5,
but add more distilled water or air dry soil sample.
B. Perform tests until least one sample is obtained in
the ranges: 15-25, 20-30, 25-35, and 30-40 blows. It
is best to try to obtain a sample in the 15-25 blow
range first, 20-30 blow range second, 25-35 blow
range third, and 30-40 blow range last. This is
because it is easier to add moisture to the soil than to
take it away.
75. Liquid Limit – Flow Index
Flow Index
IndexFlowCalculate
WorkGroup
N2=30N1=20
w1=44
w2=39
76. Liquid Limit - Measurement
Second Method
Fall Cone Method BS1377
77. Liquid Limit - Measurement
Liquid Limit (LL) at d = 20 mm
78. FALL CONE METHOD
O Fall cone test (cone penetration test) offers more
accurate method of determining both the liquid limit
and the plastic limit.
O In this test, a cone with apex angle of 30° and total
mass of 80 grams is suspended above, but just in
contact with, the soil sample.
O The cone is permitted to fall freely for a period of 5
seconds. The water content corresponding to a cone
penetration of 20 mm defines the liquid limit.
O The liquid limit is difficult to achieve in just a single
test.
79. FALL CONE METHOD
O In this regard, four or more tests at different
moisture content is required.
O The results are plotted as water content (ordinate,
arithmetic scale) versus penetration (abscissa,
logarithmic scale) and the best-fit straight line (liquid
state line) linking the data points is drawn.
O The liquid limit is read from the plot as the water
content on the liquid state line corresponding to a
penetration of 20 mm.
81. Plastic Limit - DefinitionPlastic Limit - Definition
The moisture content (%) at which the soil
when rolled into threads of 3.2mm (1/8 in) in
diameter, will crumble.
Plasticity Index (PI): is a measure of the
range of the moisture contents over which a
soil is plastic.
PI=LL-PL
82. Plastic Limit - Measurement
First Method
ASTM D-4318
PL = w% at dia. 3.2 mm (1/8 in.)
83. Plastic Limit - MeasurementPlastic Limit - Measurement
Second
Method
Fall Cone
Method
BS1377
Plastic Limit (PL) at d = 20 mm
84. Plasticity Index - Definition
Plasticity Index is the difference between
the liquid limit and plastic limit of a soil.
PI = LL – PL
85. Plasticity Index - Definition
PI (%) = 4.12 IF (%)
PI (%) = 0.74 IFC (%)
89. O Soil compactionSoil compaction is defined as the method of
mechanically increasing the density of soil.
O it is a physical process to decrease the voids of soil
by static or dynamic loading.
O In construction, this is a significant part of the
building process.
O If performed improperly, settlement of the soil could
occur and result in unnecessary maintenance costs
or structure failure.
90. O PURPOSE
O Improving the soil quality
by:
- Increasing the shear
strength of soil
- Improving the bearing
capacity of soil
O Reduces the settling of
soil
O Reduces the soil
permeability
O To control the relative
volume change
91. TYPES OF COMPACTION
4 types of compaction effort on soil:
* Vibration
* Impact
* Kneading
* Pressure
92. O BASIC THEORYBASIC THEORY
Developed by R.R. Proctor on 1920 with 4
variables :
# Compaction efforts (Compaction Energy)
# Soil types
# Water content
# Dry Unit Weight
O LABORATORY COMPACTION TESTLABORATORY COMPACTION TEST
* Standard Proctor Test
* Modification Proctor Test
94. STANDARD PROCTORSTANDARD PROCTOR
TESTTESTO The soil is compacted at cylindrical tube.
O Specification of test and equipment:
Hammer weight = 2,5 kg (5,5 lb)
Falling height = 1 ft
Amount of layers = 3
No. of blows/layer = 25
Compaction effort = 595 kJ/m³
Soil type = pass sieve no. 4
95. O The test is carried out several time
with different water content.
O After compaction, the weight,
moisture content and unit weight of
samples are measured.
O Test Standard :
AASHTO T 99
ASTM D698
96. MODIFIED PROCTOR TESTMODIFIED PROCTOR TEST
O The soil is compacted at cylindrical tube.
O Specification of test and equipment:
Hammer weight = 4.5 kg (10 lb)
Falling height = 1.5 ft
Amount of layers = 5
No. of blows/layer = 25, 56
Compaction effort = 2693 kJ/m³
Soil type = pass sieve no. 4
97. O The test is carried out several time with
different water content.
O After compaction, the weight, moisture
content and unit weight of samples are
measured.
O Test Standard :
AASHTO T 180
ASTM D1557
99. Type of CompactionType of Compaction
EquipmentEquipment
O Rubber Tire Roller
O Smooth Wheel Roller
O Sheepsfoot Roller
O Grid Roller
O Baby Roller
O Vibrating Plate
100. Rubber Tire RollerRubber Tire Roller
O A heavily loaded wagon
with several rows of three
to six closely spaced tires
with tire pressure may be
up to about 700 kPa and
has about 80% coverage
(80% of the total area is
covered by tires).
O This equipment may be
used for both granular
and cohesive highway
fills.
101. Smooth Wheel RollerSmooth Wheel Roller
O Compaction equipment
which supplies 100%
coverage under the
wheel, with ground
contact pressures up to
400 kPa and may be
used on all soil types
except rocky soils.
O Mostly use for
proofrolling subgrades
and compacting asphalt
pavements.
102. SheepsfootSheepsfoot RollerRoller
O This roller has many round or rectangular
shaped protrusions or “feet” attached to a steel
drum.
O The area of these protusions ranges from 30 to
80 cm².
O Area coverage is about 8 – 12% with very high
contact pressures ranging from 1400 to 7000
kPa depending on the drum size and whether
the drum is filled with water.
O The sheepsfoot roller is best suited for cohesive
soils.
104. Grid RollerGrid Roller
O This roller has about
50% coverage and
pressures from 1400
to 6200 kPa, ideally
suited for compacting
rocky soils, gravels and
sand.
O With high towing
speed, the material is
vibrated, crushed, and
impacted.
105. BabyBaby
RollerRollerO Small type of
smooth wheel
roller yang, which
has pressure
ranges from 10 to
30 kPa.
O The performance
base on static
weight and
vibration effect.
106. Vibrating PlateVibrating Plate
O Compaction equipment,
which has plate shape.
In Indonesia this
equipment sometimes
called as “stamper”.
O Usually used for narrow
area and high risk when
use large compaction
equipment like smooth
wheel roller etc.
108. Dynamic CompactionDynamic Compaction
O The dynamic compaction method involves
dropping a heavy weight repeatedly on the
ground at regularly spaced intervals.
O The weight is typically between 80 and 360
kN, and the height changes from 10 to 30m.
O The impact of the free drop of weight creates
stress waves that densify the soil to a
relatively large depth.
O The method is effectively used for sandy soils
but is also applied to silt and clay soils.
109. O In order to indicate the level of compaction relative
to the densest and the loosest compaction level for
a given specific soil, most for granular soils, relative
density (Dr) is introduced and is defined in the
following equation:
Dr = ( emax – e ) x 100%
emax - emin
O When the in-situ soil’s void ratio is in its loosest (e =
emax) state, then, Dr = 0%. If it is in its densest (e =
emin), Dr = 100%.
110. O Maximum void ratio:
emax = Gs γw - 1
γmin
O Minimum void ratio:
emin = Gs γw - 1
γmax
111. Compaction CurveCompaction Curve
O After the experiment, a set of wet unit weight
and water content are measured.
O The compaction effectiveness, however, is
compared in terms of increased dry unit
weight of the specimen instead of total unit
weight.
γt = (1+w) Gs γw = (1+w) γd
1+e
γd = Gs γw = γt
1+e 1+w
112. Example #1:
O Computation of test data:
A B
Water
Content
Total Unit
Wt.
2.3 15.80
4.5 17.18
6.7 18.83
8.5 19.72
10.8 20.04
13.1 19.34
15 18.45
C
Dry Unit Wt.
15.45
16.44
17.65
18.18
18.08
17.10
16.04
114. Specification of CompactionSpecification of Compaction
in the Fieldin the Field
O After the compaction curve for a given soil is
obtained from laboratory tests, the
specification of compaction in the field is
made.
O Relative compaction (R.C.) is defined as
R.C. =R.C. = γγd,fieldd,field (x 100%)(x 100%)
γγd,maxd,max
115. Example #2:
O At a borrow site, sandy soil was excavated.
The soil had total unit weight of 19.3 kN/m³,
water content of 12.3%, and specific gravity
of 2.66. the soil was dried, the maximum
and minimum void ratio tests were
performed, and maximum void ratio is 0.564
and minimum void ratio is 0.497 were
obtained. Determine the relative density of
the soil at the borrow site.
117. O AsphaltAsphalt is a dark brown to black cementitious
material in which the predominating constituents
are bitumens that occur in nature or are
obtained in petroleum processing (according to
ASTM). Also called asphalt cement or asphalt
bitumen.
O Bitumen (according to ASTM) is a class of black
or dark-colored (solid, semisolid, or viscous)
cementitious substances, natural or
manufactured, composed principally of high
molecular weight hydrocarbons, of which
asphalts, tars, pitches, and asphaltites are
typical.
118. ConsistencConsistenc
yy
O Asphalts are thermoplastic materials because
they gradually liquefy when heated.
O They are characterized by their consistency or
ability to flow at different temperatures.
O Consistency is the term used to described the
viscosity or degree of fluidity of asphalt at any
particular temperature.
O Asphalt cements are graded, based on
ranges of consistency at a standard
temperature.
119. PurityPurity
O Asphalt cement is composed almost entirely of
bitumen, which, by definition, is entirely soluble in
carbon disulfide.
O Refined asphalts are almost pure bitumen and
are usually more than 99.5% soluble in carbon
disulfide. Impurities, if they are present, are inert
(inactive).
O Normally, asphalt cement is free of water or
moisture as it leaves the refinery.
O If any water is inadvertently present, it will cause
the asphalt to foam when it is heated above
100°C (212°F).
120. SafetySafety
O Asphalt foaming is a safety hazard, and
specifications usually requires that asphalt not
foam at temperature up to 175°C (347°F).
O Asphalt cement, if heated to a high enough
temperature, will release fumes that will flash in
the presence of a spark or open flame. The
temperature at which this occurs is called the
flashpoint.
121. Specifications and Tests for AsphaltSpecifications and Tests for Asphalt
CementCement
SpecificationsSpecifications
OAsphalt cement is commercially available in
several standard ranges of consistency
(grades).
OFor many years these ranges were based on
measurements by the penetration test only;
asphalt cement was available in five standard
grades: 40-50, 60-70, 85-100, 120-150, and
200-300
122. SpecificationsSpecifications
O The softest (200-300) penetration grade is
moderately firm at room temperature; at this
temperature gentle finger pressure indents
the surface of the sample.
O The hardest (40-50) penetration grade is of a
consistency permitting only a slight thumb
print being made under firm pressure when
the material is at room temperature.
123. SpecificationsSpecifications
O There are two series of viscosity grades by
which asphalt cement is available.
O One consists of grades AC–2.5, AC–5, AC–10,
AC–20, AC–40, and AC–30, with numerical
values indicating the viscosity in hundreds of
poises at 60°C.
O The SI unit of viscosity is 1Pa-s and is
equivalent to 10P.
O The allowable tolerance for each grade is
+20%.
124. SpecificationsSpecifications
O The other series consists of grades AR-1000,
AR-2000, AR-4000, AR-8000, and AR-16000
with the numerical values indicating the
viscosity in poises but with the viscosity being
measured after the asphalt has been
subjected to the rolling thin film oven test.
O The AR series may be interpreted as an “Aged
Residue” series.
O The tolerance on these grades is +25%.
125. Tests for Asphalt CementTests for Asphalt Cement
O The following are the tests for asphalt cement:
O 1. Viscosity Test
O 2. Penetration Test
O 3. Flash Point Test
O 4. Thin Film Oven Test
O 5. Rolling Thin Film Oven Test
O 6. Ductility Test
O 7. Solubility Test
177. Apparent Specific Gravity (Gsa) of the
total combined mineral aggregate
O Calculate the apparent specific gravity (Gsa) of the
total combined mineral aggregate by substituting the
apparent specific gravity of the aggregate in the
formula for the bulk specific gravity (Gsb).
O Note 1: Test results shall be carried out to three
decimal places.
O Note 2: The bulk specific gravity of mineral filler is
difficult to determine.
O However, if the apparent specific gravity of mineral
filler is used instead, the error is usually negligible.
