MS Transportation Engineering

2. PAVEMENT MATERIALSPAVEMENT MATERIALS
ENGINEERINGENGINEERING
(CE-862)(CE-862)
Lec-01 (Lab 1)
Fall Semester 2016
Dr. Arshad Hussain
arshad_nit@yahoo.com , Office Room#111, Tel: 05190854163,
Cell: 03419756251
National Institute of Transportation (NIT)
National University of Science and Technology (NUST)
NUST Campus, Sector H-12, Islamabad

3. SOIL Testing

4. •Most common tests include:
• Plasticity (Atterbergs limits)
• Sieve Analysis
• Moisture
• Unit Weight
• Proctor
• CBR

5. AtterbergAtterberg
 Albert Atterberg was a Swedish chemist and agricultural scientist.
 Conducted studies to identify the specific minerals that give a clayey soil its
plastic nature
 Stated that depending on the water content, soil may appear in four states:
 Solid (no water)
 semi-solid (brittle, some water)
 plastic (moldable)
 liquid (fluid)
 In each state the consistency and behavior of a soil is different and thus so
are its engineering properties.
 The boundary between each state can be defined based on a change in the
soil's behavior.

6. Atterberg LimitsAtterberg Limits
(Non-Plastic )
Plasticity Index
Wpl wll
Plastic Limit Liquid Limit
Water Content
w%=0
Solid LiquidPlasticBrittle

7. Plastic limitPlastic limit
The plastic limit (PL) is the water content
(w%) where soil starts to exhibit plastic
behavior.

8. Liquid limitLiquid limit
The liquid limit (LL) is
the water content
where a soil changes
from liquid to plastic
behavior
Determined using a
Casagrande cup (lab)
or cone penetrometer
(field)

9. Shrinkage limitShrinkage limit
The shrinkage limit (SL) is the water
content where further loss of moisture
will not result in any more volume
reduction
The shrinkage limit is much less
commonly used than the liquid limit and
the plastic limit.

10. Use of Plasticity IndexUse of Plasticity Index
 The PI is the difference between the liquid limit and the
plastic limit (PI = LL-PL).
 The plasticity index is the size of the range of water
contents where the soil exhibits plastic properties.
 Meaning:
◦ High PI tend to be clay
◦ Low PI tend to be silt
◦ PI of 0 tend to have little or no silt or clay.

11. Use of Liquid & Plastic LimitsUse of Liquid & Plastic Limits
Used internationally for soil identification
and soil classification (AASHTO)

12. Liquid LimitLiquid Limit
Procedures: To perform the liquid limit
test, one must place a soil paste in the cup.
A groove is then cut at the center of the
soil pat with the standard grooving tool. By
the use of the crank-operated cam, the cup
is lifted and dropped from a height of 10
mm (0.394 in.). The moisture content, in
percent, required to close a distance of
12.7 mm (0.5 in.)

13. Liquid LimitLiquid Limit
along the bottom of the groove after 25
blows is defined as the liquid limit. 25 blows
is defined as the liquid limit. It is difficult to
adjust the moisture content in the soil to
meet the required 12.7 mm (0.5 in.)
closure of the groove in the soil pat at 25
blows. Hence, at least three tests for the
same soil are conducted at varying
moisture contents, with the number of
blows, N, required to achieve closure
varying between 15 and 35.

14. Liquid LimitLiquid Limit
along the bottom of the groove after 25
blows is defined as the liquid limit. 25 blows
is defined as the liquid limit. It is difficult to
adjust the moisture content in the soil to
meet the required 12.7 mm (0.5 in.)
closure of the groove in the soil pat at 25
blows. Hence, at least three tests for the
same soil are conducted at varying
moisture contents, with the number of
blows, N, required to achieve closure
varying between 15 and 35.

15. Liquid limit (LL) determination

16. NEED AND SCOPE
 Liquid limit is significant to know the stress history and general
properties of the soil met with construction. From the results of
liquid limit the compression index may be estimated. The
compression index value will help us in settlement analysis. If the
natural moisture content of soil is closer to liquid limit, the soil can
be considered as soft if the moisture content is lesser than liquids
limit, the soil can be considered as soft if the moisture content is
lesser than liquid limit. The soil is brittle and stiffer.

17. 150g air dry soil passing # 40sieve.
Add 20% of water-mix thoroughly.
Place a small sample of soil in LL device(deepest part
about 8-10mm).
Cut a groove(2mm at the base).
Run the device, count the number of blows, N.
Stop when the groove in the soil close through a
distance of 12.7 mm
Procedure:-

18. Take a sample and find the moisture content.
Run the test three times[N~(10-20), N~(20-30) and
N~(35-45)].
Plot number of blows vs moisture content and
determine the liquid limit(LL)( moisture content at 25
blows).
Procedure:-

19. OBSERVATIONS
Details of the sample:.......
Natural moisture
content:........
Room temperature:..............
Determinatio
n Number
1 2 3 4
Container
number
Weight of
container
Weight of
container +
wet soil
Weight of
container +
dry soil
Weight of
water
Weight of dry
soil
Moisture
content (%)
No. of blows
19

20. COMPUTATION / CALCULATION
Draw a graph showing the relationship between water content
(on y-axis) and number of blows (on x-axis) on semi-log graph.
The curve obtained is called flow curve. The moisture content
corresponding to 25 drops (blows) as read from the represents
liquid limit. It is usually expressed to the nearest whole number.
20

21. Flow curve for liquid limit determination of a clayey silt:-
21

22. Plastic LimitPlastic Limit
In the laboratory, the plastic limit is defined
as the moisture content (%) at which a
thread of soil will just crumble when rolled
to a diameter of 1/8in. (3.18 mm).

23. Plastic Limit (PL)
The plastic limit (PL) is defined as the moisture content (%) at
which the soil when rolled into threads of 3.2 mm in diameter ,
will crumble. It is the lower limit of the plastic stage of soil.
Procedure:
Take 20g of soil passing # 40 sieve into a dish.
Add water and mix thoroughly.
Prepare several ellipsoidal-shaped soil masses by quizzing the soil with
your hand.
Put the soil in rolling device, and roll the soil until the thread reaches
3.2mm.
23

24. Continue rolling until the thread crumbles into several pieces.
Determine the moisture content of about 6g of the crumbled soil.
24

25. Grain Size DistributionGrain Size Distribution
 To know the relative proportions of different grain
sizes.
25
An important factor influencing the
geotechnical characteristics of a coarse grain
soil.
Not important in fine grain soils.
Significance of GSD:
S.N.P.I.T.& R.C.

26. Grain Size DistributionGrain Size Distribution
 In coarse grain soils …... By sieve analysis
26
Determination of GSD:
fine grain soils …... By hydrometer analysisIn
Sieve Analysis
Hydrometer Analysis
soil/water
suspension
hydrometer
stack of sieves
sieve shaker
S.N.P.I.T.& R.C.

27. Sieve AnalysesSieve Analyses
27S.N.P.I.T.& R.C.

28. Sieve AnalysisSieve Analysis
28S.N.P.I.T.& R.C.

29. Sieve Designation - LargeSieve Designation - Large
29
Sieves
larger than
the #4 sieve
are
designated
by the size
of the
openings in
the sieve
S.N.P.I.T.& R.C.

30. Sieve Designation - SmallerSieve Designation - Smaller
30
10
openings
per inch
# 10 sieve
1-
inch
Smaller sieves are
numbered according to
the number of openings
per inch
S.N.P.I.T.& R.C.

31. 31
Sieving procedure
(1) Write down the weight of each sieve as well as the bottom pan
to be used in the analysis.
(2) Record the weight of the given dry soil sample.
(3) Make sure that all the sieves are clean, and assemble them in the
ascending order of sieve numbers (#4 sieve at top and #200 sieve at
bottom). Place the pan below #200 sieve. Carefully pour the soil
sample into the top sieve and place the cap over it.
(4) Place the sieve stack in the mechanical shaker and shake for 10
minutes.
(5) Remove the stack from the shaker and carefully weigh and
record the weight of each sieve with its retained soil. In addition,
remember to weigh and record the weight of the bottom pan with its
retained fine soil.
S.N.P.I.T.& R.C.

32. 32
S.N.P.I.T.& R.C.

33. 33
S.N.P.I.T.& R.C.

34. 34
Data Analysis:
(1) Obtain the mass of soil retained on each sieve by subtracting
the weight of the empty sieve from the mass of the sieve + retained
soil, and record this mass as the weight retained on the data sheet.
The sum of these retained masses should be approximately equals
the initial mass of the soil sample. A loss of more than two percent
is unsatisfactory.
(2) Calculate the percent retained on each sieve by dividing the
weight retained on each sieve by the original sample mass.
(3) Calculate the percent passing (or percent finer) by starting with
100 percent and subtracting the percent retained on each sieve as a
cumulative procedure.
S.N.P.I.T.& R.C.

35. Sieve SizesSieve Sizes
35(Das, 1998)
(Head, 1992)
S.N.P.I.T.& R.C.

36. 36S.N.P.I.T.& R.C.

37. 37S.N.P.I.T.& R.C.

38. 38
For example: Total mass = 500 g,
Mass retained on No. 4 sieve = 9.7 g
For the No.4 sieve:
Quantity passing = Total mass - Mass retained
= 500 - 9.7 = 490.3 g
The percent retained is calculated as;
% retained = Mass retained/Total mass
= (9.7/500) X 100 = 1.9 %
From this, the % passing = 100 - 1.9 = 98.1 %
S.N.P.I.T.& R.C.

39. 39
Grain size distributionGrain size distribution
0.0001 0.001 0.01 0.1 1 10 100
0
20
40
60
80
100
Particle size (mm)
%Finer
S.N.P.I.T.& R.C.

40. 40
Grading curves
0.0001 0.001 0.01 0.1 1 10 100
0
20
40
60
80
100
Particle size (mm)
%Finer
W Well graded
U Uniform
P Poorly graded
S.N.P.I.T.& R.C.

41. Proctor Compaction TestProctor Compaction Test
Test developed to help
specify levels (%)
compaction (1933).
Ralph R. Proctor first
defined this standard
compaction test in
Engineering News
Record

42. Proctor Compaction ProcedureProctor Compaction Procedure
Soil is air dried, pulverized
& passed thru #4 sieve.
Separated into 4 to 6 samples.
Adjust the water content of each sample by
adding water.

43. Using the proctor mould (1/30th cubic foot)
place & compact soil in 3 layers.
Each layer should receive 25 drops of the
compaction hammer.
Proctor Compaction ProcedureProctor Compaction Procedure

44. Proctor Compaction ProcedureProctor Compaction Procedure
After the last layer, use a straight edge to
trim the excess soil leveling to the top of
the mould.

45. Proctor Compaction ProcedureProctor Compaction Procedure
Determine the weight of the mould with
the compacted moist soil.
Extrude from mould and collect a sample
for water content determination.
Repeat for each sample over a range of
moisture contents.

46. Proctor Compaction ProcedureProctor Compaction Procedure
After collecting all
pertinent weights,
calculate dry density
and plot vs. water
content

47. Typical Proctor DataTypical Proctor Data
1 2 3 4 5 6 7 8 9
Mold (lbs)
Mold + Wet
Soil (lbs) Moist Soil (lbs)
Moist Unit Wt.
(pcf)
Mass of Can
(g)
Mass Can +
Moist Soil (g)
Mass of Can +
Dry Soil
Moisture
Content Dry Unit Wt.
9.31 13.23 3.92 117.60 61.00 273.50 249.70 0.13 104.43
9.20 13.60 4.40 132.00 61.00 280.00 249.20 0.16 113.44
9.31 13.52 4.21 126.30 61.00 242.90 214.90 0.18 106.86
9.30 13.34 4.04 121.20 61.00 306.70 265.60 0.20 100.93
9.20 13.25 4.05 121.50 61.00 222.60 190.20 0.25 97.14
9.31 13.16 3.85 115.50 61.00 212.20 178.10 0.29 89.45
(Line 3)/(1/30) (Line 4)/(1+Line 8)

48. Graph from Proctor DataGraph from Proctor Data

49. CALIFORNIA BEARING RATIO (CBR)
METHOD
Typical Testing Machine

50. IntroductionIntroduction
The California Bearing Ratio devised by
engineers of the California Division of
Highways in nine years period to 1938.
Most universally accepted pavement design
methods.
A standard penetration-type load-deformation
test is carried out, and using the values
obtained from the test from an empirical
design chart, the pavement thickness are
calculated.

51. CBR LABORATORY TESTCBR LABORATORY TEST
Specimen may be
• Prepared
• In-situ
Mould
• 150mm diameter
• 127.3mm height
• Separate base plate
• A collar

52. The specimen is soaked and the expansion is
measured.
Load is applied by the loading frame through a
cylinder plunger of 50mm diameter and
penetration is measured.
Rate of penetration is maintained at
1.25mm/minute.
Loads are recorded for 2.5 and 5.0mm.
Load is expressed as a percentage of the
standard load at the respective deformation
level, and is known as the CBR value.

53. CBR EquipmentCBR Equipment
Typical Testing Machine Soaking Samples

54. CBR Test – Load-CBR Test – Sample Preparation
CBR EquipmentCBR Equipment

55. California Bearing Ratio (CBR)California Bearing Ratio (CBR)
Load a piston at a
constant rate
See what load it
takes to make it
penetrate a known
amount

56. CBR EquationCBR Equation






=
y
x
CBR 100
x = material resistance or the unit load on the piston
(pressure) for 2.5 mm or 5 mm of penetration
y = standard unit load (pressure) for well graded
crushed stone.
For 2.5 mm of penetration = 1000 psi
For 5.0 mm of penetration = 1500 psi

57. ThanksThanks