UNIT- 4 Traffic English Engineering (1).pptx

TRANSPORTATION ENGINEERING
UNIT- 4

SOIL
• The soil in highway design construction is the basic ingredient
that forms intermediate support for the embankment. It is
used extensively for highways so that it can support the road,
and all the other load heavy transportation can get
distributed over the pavement design. In the structure of the
highway, the soil is used in the embankment and subgrade of
the pavement.

CBR Test on SOIL
The California Bearing Ratio (CBR) test is a fundamental geotechnical
investigation used to assess the strength and bearing capacity of soil. Its
primary application lies in evaluating the suitability of soil for pavement
construction, like roads, runways, and parking lots.
• Objective:
– The CBR test measures the resistance of a soil sample to penetration by
a standardized plunger. This penetration resistance indirectly reflects
the soil's ability to support applied loads
• Apparatus:
CBR Mold: A cylindrical steel mold with a diameter of 150 mm and a
height of 175 mm. CBR mold
Compaction Hammer: A metal hammer used to compact the soil sample
in the mold to a specific density.

Penetration Device: A loading machine equipped with a plunger that
penetrates the soil sample at a controlled rate. Penetration device
Dial Gauge: Measures the penetration depth of the plunger with high
accuracy
Procedure:
Sample Preparation:
• The soil sample is collected and sieved to remove particles larger than 20
mm.
• The sample is mixed with water and compacted in the CBR mold using the
compaction hammer to achieve a specific density, mimicking real-world
conditions
Soaking (Optional):
• The CBR test can be performed on soaked or unsoaked samples. Soaking
simulates the effect of moisture on the soil's bearing capacity, particularly
crucial for pavements exposed to weather.

Penetration Test:
• The penetration device pushes the
plunger into the soil sample at a
controlled rate of 1.25 mm per minute.
• The force required to penetrate the
sample to depths of 2.5 mm and 5.0 mm
is measured using a proving ring and
recorded.
Calculations:
The CBR value is a dimensionless percentage
calculated as the ratio of the measured penetration force to the standard force
required for a reference crushed stone material at the same penetration depth.
CBR at 2.5 mm penetration = (Force at 2.5 mm / Standard force at 2.5 mm) ×
100%
CBR at 5.0 mm penetration = (Force at 5.0 mm / Standard force at 5.0 mm) × 100%

Field California Bearing Ratio (CBR)
Test
The Field California Bearing Ratio (CBR) test is a crucial geotechnical
investigation technique employed to evaluate the in-situ bearing capacity and
strength characteristics of soil. It plays a vital role in the design and
construction of pavements such as roads, highways, and airport runways,
enabling engineers to determine the appropriate thickness and composition of
pavement layers based on the underlying soil's load-bearing capabilities.
Equipment:
• Portable loading frame and hydraulic jack: For applying controlled,
calibrated loads to the soil.
• Standard steel plunger: Of specified diameter (typically 50mm) for
penetrating the soil surface.
• Dial gauge: For precise measurement of the plunger's penetration depth.

• Surcharge weight: Simulates the weight of pavement layers above the test
location.
• Soil compaction mold and hammer (optional): For preparing a remolded
soil sample in the laboratory (useful for comparative testing).
Procedure:
• Site preparation: A level, undisturbed area of the soil surface is cleared
and trimmed to a defined diameter.
• Plunger seating: The plunger is carefully placed on the soil surface and a
small seating load is applied to ensure proper contact.
• Surcharge placement: The surcharge weight is positioned on top of the
plunger, replicating the anticipated overburden pressure from the
pavement layers.
• Load application: A steadily increasing load is applied to the plunger using
the hydraulic jack, with penetration depth meticulously recorded at
predetermined intervals (usually 2.5mm and 5mm).

• Load-penetration curve: The recorded load-penetration data is plotted on
a graph, forming a characteristic curve.
• CBR value calculation: The CBR value is determined by dividing the load
required to achieve a specific penetration depth (typically 2.5mm or 5mm)
by the corresponding load for a standard crushed stone material at the
same penetration depth, and then multiplying by 100.
In conclusion
the Field CBR test offers a valuable tool for assessing the suitability of soil for
supporting pavement structures. Its robust yet straightforward approach
makes it a vital component of geotechnical investigations, ensuring pavement
designs are optimized for durability and performance.

The Modulus of Subgrade Reaction
The ground beneath our feet might seem solid, but its hidden properties play a
crucial role in the stability of everything we build upon it. Enter the modulus of
subgrade reaction (k), a critical parameter that quantifies the support
provided by the soil. Think of it as a measure of the soil's "springiness" - how
much it will deform under the weight of structures like buildings and roads.
Determination of Modulus of Subgrade reaction of soil/Plate Load Test
In this test, the strength of soil is determined in the form of modulus of
subgrade reaction (K), which is extensively used in the design of rigid
pavement. It is a field test.
Procedure
1. Clean the ground surface at which the test is to be done.
2. Keep the standard test plate of 750mm size on the ground.

3. Above this keep some stacking plates on which keep the hydraulic jack.
4. At the top keep the reaction beam.
5. Apply a seating load of 0.75N/mm2 for a few minutes and release.
6. Now apply a load increment sufficient to cause a settlement of 0.75mm.
Keep the load until the rate of settlement becomes less
than 0.025mm/min.
7. Record the average settlement using a set of dial gauges placed on the
stacking plates. 8. Now increase the load to cause a further settlement of
0.75mm and repeat the procedure. 9. Repeat the test for a few more
loads.
10. Now plot the settlement values along X-axis and corresponding Bearing
pressure values along Y-axis.
11. From this plot find the Bearing pressure corresponding to an average
settlement of A=0.025cm (0.25mm). K =P (kg/cm²) 0.125

Plate Bearing Test for Modulus of Sub-grade Reaction
The modulus of sub-grade reaction is an important parameter in the design of
flexible pavements. It is defined as the force required to produce unit
deformation in the sub-grade soil. The modulus of sub-grade reaction is
evaluated from the plate bearing test.
Plate Bearing Test
The plate bearing test is a field test used to determine the bearing capacity
and settlement characteristics of soils. The test involves loading a circular
plate of known diameter and weight onto the soil surface and measuring the
settlement of the plate under a known load. The test is repeated at different
loads and the settlement measurements are used to determine the modulus
of sub-grade reaction.
Steps in Plate Bearing Test
The following are the steps involved in the plate bearing test for the
evaluation of the modulus of sub-grade reaction:
1. Preparation of Test Site: A test site is prepared by excavating the soil to a
depth of at least 1.5 times the diameter of the plate.

2. Placing of Plate: The plate is placed on the soil surface and leveled.
3. Loading of Plate: The plate is loaded with a known load and the
settlement of the plate is measured using a dial gauge or a surveying
instrument
4. Repeat Loading: The loading is repeated at different loads and the
settlement measurements are recorded.
5. Calculation of Modulus of Sub-grade Reaction: The modulus of sub-grade
reaction is calculated using the following formula:
K = (q/p) x (D/A)
Where,
o K = Modulus of sub-grade reaction
o q = Incremental load applied to the plate
o p = Settlement of the plate under the load
o D = Diameter of the plate
o A = Depth of the plate in the soil

Conclusion :
Thus, the plate bearing test is a simple and reliable method for the evaluation
of the modulus of sub-grade reaction. It is an essential parameter in the
design of flexible pavements, as it helps to determine the thickness of the
pavement layers and the required strength of the sub-grade soil.

Tests on Aggregates
SPECIFIC GRAVITY OF AGGREGATE
Objective:
Specific Gravity is defined as the ratio of Weight of Aggregate to the Weight
of equal Volume of water. The specific gravity of an aggregate is considered to
be a measure of strength or quality of the material. Aggregates having low
specific gravity are generally weaker than those with high specific gravity. This
property helps in a general identification of aggregates.
Apparatus Required:
1. Wire Mesh Bucket
2. Setup of Specific Gravity Test
3. Pycnometer

Procedure:
Procedure For Specific Gravity Determination For Aggregate Coarser Than
6.3mm
1. About 2 kg of aggregate sample is taken, washed to remove fines and
then placed in the wire basket. The wire basket is then immersed in water,
which is at a temperature of 220C to 320C.
2. Immediately after immersion the entrapped air is removed from the
sample by lifting the basket 25 mm above the base of the tank and allowing
it to drop, 25 times at a rate of about one drop per second.
3. The basket, with aggregate are kept completely immersed in water for a
period of 24 ± 0.5 hour.
4. The basket and aggregate are weighed while suspended in water, which
is at a temperature of 220C to 320C.
5. The basket and aggregates are removed from water and dried with dry
absorbent cloth.
6. The surface dried aggregates are also weighed.
7. The aggregate is placed in a shallow tray and heated to about 1100C in
the oven for 24 hours. Later, it is cooled in an airtight container and weighed.

Procedure For Specific Gravity Determination Of Aggregate Finer Than
6.3mm
1. A clean, dry pycnometer is taken and its empty weight is determined.
2. About 1000g of clean sample is taken into the pycnometer, and it is
weighed.
3. Water at 270C is filled up in the pycnometer with aggregate sample, to
just immerse sample
4. Immediately after immersion the entrapped air is removed from the
sample by shaking pycnometer, placing a finger on the hole at the top of the
sealed pycnometer.
5. Now the pycnometer is completely filled up with water till the hole at the
top, and after confirming that there is no more entrapped air in it, it is
weighed.
6. The contents of the pycnometer are discharged, and it is cleaned.

7. Water is filled up to the top of the pycnometer, without any entrapped
air. It is then weighed.
8. For mineral filler, specific gravity bottle is used and the material is filled
upto one-third of the capacity of bottle.
The rest of the process of determining specific gravity is similar to the one
described for aggregate finer than 6.3 mm.
General Remarks:
1. The specific gravity of aggregates normally used in construction ranges
from about 2.5 to 3.0 with an average value of about 2.68.
2. Specific gravity of aggregates is considered as an indication of strength.
Material having higher Specific Gravity is generally considered as having
higher strength. Water absorption of aggregate is a measure of porosity. This
value is considered as a measure of resistance to frost action, and as a
measure of sustaining weathering action.

FLAKINESS AND ELONGATION INDEX
OF AGGREGATE
Objective:
Particle shape and surface texture influence the properties of freshly mixed
concrete more than the properties of hardened concrete. Rough-textured,
angular, and elongated particles require more water to produce workable
concrete than smooth, rounded compact aggregate. Consequently, the cement
content must also be increased to maintain the water-cement ratio. Generally,
flat and elongated particles are avoided or are limited to about 15 % by weight
of the total aggregate.
Apparatus Required:
• Balance
• Sieves
Sieves required are 63, 50, 40, 31.5,
25, 20, 16, 12.5, 10 and 6.3 mm
(Based on requirement and Gradation of Aggregate)
• Thickness Gauge- For Flakiness Index
• Length Gauge- For Elongation Index
(Length Gauge have length equal to 1.8 times the mean dimension of the aggregate.)

Procedure:
• A quantity of aggregate shall be taken sufficient to provide the minimum
number of 200 pieces of any fraction to be tested.
• The sample shall be sieved with the sieves specified in Table 1
• Separation of Flaky material- Each fraction shall be gauged in turn for thickness
on a metal gauge of the pattern shown in Fig. 3, or in bulk on sieves having
elongated slots. The width of the slot used in the gauge or sieve shall be of the
dimensions specified in co1. 3 of Table 1 for the appropriate size of material.
• The total amount passing the gauge shall be weighed to an accuracy of at least
0.1 percent of the weight of the test sample.
• The Flakiness Index is the total weight of the material passing the various
thickness gauges or sieves, expressed as a percentage of the total weight of
the sample gauged.
• Separation of Elongated Material- Each fraction shall be gauged individually for
length on a metal length gauge of the pattern shown in Fig. 4. The gauge length
used shall be that specified in co1. 4 of Table 1 for the appropriate size of
material.

• The total amount retained by the
length gauge shall be weighed to
an accuracy of at least 0.1 percent
of the weight of the test sample.
• The elongation index is the total
weight of the material retained
on the various length gauges,
expressed as a percentage of the
total weight of the sample gauged.
Calculation:
• The Flakiness Index on an aggregate is =
Total weight passing Flakiness Gauge x 100 / Total weight of test sample
=_________(%)
• The Elongation Index on an aggregate is =
Total weight retained on Elongation Gauge x 100 / Total weight of test
sample =________(%)

Angularity Number Test for
Aggregates
Purpose:
• Measures the degree of angularity (sharpness and irregularity of shape) of
aggregate particles.
• Angularity significantly affects the performance of aggregates in construction
materials, especially concrete and pavements.
Procedure:
Sieve Aggregate: Separate aggregate into different size fractions using standard
sieves.
Fill Measuring Cylinder: Fill a 3-liter measuring cylinder with a single size fraction
of aggregate in three layers.
Compact Each Layer: Compact each layer by tamping 100 times with a rounded-
end metal rod.
Measure Weight and Volume: Weigh the compacted aggregate (W) and record
the volume of the cylinder (V).

Calculate Voids Content: Determine the
percentage of voids (Vv) using the formula:
Vv = (V - W/ρ) x 100
where ρ is the bulk density of the aggregate.
Determine Angularity Number:
Calculate the angularity number (AN)
using the formula:
AN = (67 - 100W/(Vρ))
Interpretation
• AN = 0: Perfectly rounded aggregate (33% voids).
• AN = 11: Highly angular aggregate (44% voids).
• Typical AN for construction aggregates range from 0 to 11.
Importance of Angularity Number:
• Concrete: Angular aggregates improve bonding with cement
paste, enhancing strength, stiffness, and durability.
• Pavements: Angular aggregates provide better interlocking and resistance to
deformation under load.
• Mix Design: AN helps select appropriate aggregate gradations and
proportions for specific applications

WATER ABSORPTION TEST ON
AGGREGATE
Objective:
Water absorption gives an idea on the internal structure of aggregate.
Aggregates having more absorption are more porous in nature and are
generally considered unsuitable, unless found to be acceptable based on
strength, impact and hardness tests.
Apparatus Required:
• Wire Mesh Bucket
Wire basket of not more than 6.3mm mesh or a
perforated container of convenient size with thin
wire hangers for suspending it from the balance.
• Setup of Water Absorption Test
The setup consists of container for filling water and suspending the wire
basket in it and an airtight container of capacity similar to that of basket, a
shallow tray and two dry absorbent clothes.

Procedure:
Procedure For Aggregate Coarser Than 6.3mm:
• About 2 kg of aggregate sample is taken,washed
to remove fines and then placed in the wire basket.
The wire basket is then immersed in water, which
is at a temperature of 220C to 320C.
• Immediately after immersion the entrapped air
is removed from the sample by lifting the basket
25 mm above the base of the tank and allowing it
to drop, 25 times at a rate of about one drop per
second.
• The basket, with aggregate are kept completely
immersed in water for a period of 24 ± 0.5 hour.
• The basket and aggregate are weighed while suspended in water, which is at
a temperature of 220C to 320C.

• The basket and aggregates are removed from water and dried with dry
absorbent cloth.
• The surface dried aggregates are also weighed.
• The aggregate is placed in a shallow tray and heated to 100 to 1100C in the
oven for 24 ± 0.5 hours. Later, it is cooled in an airtight container and
weighed.
Calculation:
• Weight of saturated aggregates in air: W1 g =
• Weight of oven dry aggregates in air: W2 g =
• Water Absorption (%)= [(W1-W2)*100]/W2 =

IMPACT VALUE OF AGGREGATE
Objective:
The aggregate impact value gives a relative measure of the resistance of an
aggregate to sudden shock or impact, which in some aggregates differs from its
resistance to a slow compressive load.
Apparatus Required:
• Fig. 1: Balance
Balance should be accurate upto 1 g
• Fig. 2: Sieves
Seives required are 12.5, 10.0 and
2.36 mm
• Fig. 3: Impact Testing machine
Weight of hammer is 13.5 to 14.0 kg
and Height of Fall is 380±5 mm

Procedure:
• The test sample shall consist of aggregate the whole of which passes a 12.5
mm IS Sieve and is retained on a 10 mm IS Sieve. The aggregate comprising the
test sample shall be dried in an oven for a period of four hours at a
temperature of 100 to 110°C and cooled.
• The measure shall be filled about one-third full with the aggregate and tamped
with 25 strokes of the rounded end of the tamping rod. Further similar quantity
of aggregate shall be added and a further tamping of 25 strokes given. The
measure shall finally be filled to overflowing, tamped 25 times and the surplus
aggregate struck off, using the tamping rod as a straight edge. The net weight
of aggregate in the measure shall be determined to the nearest gram (Weight
A).
• The impact machine shall rest without wedging or packing upon the level plate,
block or floor, so that it is rigid and the hammer guide columns are vertical.
• The cup shall be fixed firmly in position on the base of the machine and the
whole of the test sample placed in it and compacted by a single tamping of 25
strokes of the tamping rod.

• The hammer shall be raised until its lower face is 380 mm above the upper
surface of the aggregate in the cup, and allowed to fall freely on to the
aggregate. The test sample shall be subjected to a total of 15 such blows each
being delivered at an interval of not less than one second.
• The crushed aggregate shall then be removed from the cup and the whole of it
sieved on the 2.36 mm IS Sieve until no further significant amount passes in one
minute. The fraction passing the sieve shall be weighed to an accuracy of 0.1 g
(Weight. B).
• The fraction retained on the sieve shall also be weighed (Weight C) and, if the
total weight (C+B) is less than the initial weight (Weight A) by more than one
gram, the result shall be discarded and a fresh test made. Two tests shall be
made.
Calculation:
• The ratio of the weight of fines formed to the total sample weight in each test
shall he expressed as a percentage, the result being recorded to the first
decimal place:
Aggregate Impact Value = (B/A) X 100
where, A = weight in g of saturated surface - dry sample,
B = weight in g of fraction passing through 2.36 mm IS Sieve

LOS ANGELES ABRASION VALUE OF
AGGREGATE
Objective:
Abrasion test is carried out to test the hardness property of aggregates. The principle
of Los Angeles abrasion test is to find the percentage wear due to relative rubbing
action between the aggregate and steel balls used as abrasive charge.
Apparatus Required:
 Balance
Balance should be accurate upto 1 g
 Sieves
Sieves required are 80, 63, 50, 40, 25, 20,
12.5, 10, 6.3, 4.75 (as per gradation of aggregate)
and 1.7 mm
 Los Angeles Testing Machine
Inside Length = 50 cm and Inside
Diameter = 70 cm
 Abrasive Charges
Diameter = 48 mm and Weight = 390 to 445 g

Procedure:
A. Gradation Of Aggregate
Gradation of the Aggregate should be carried out so as to assess the Grade of
the Aggregate (A to G)
Procedure For Los Angeles Abrasion Test:
• The test sample shall consist of clean aggregate which has been dried in an
oven at 105 to 110°C to substantially constant weight and shall conform to
one of the gradings shown in Table 1. The grading or gradings used shall be
those most nearly representing the aggregate furnished for the work.
• The test sample and the abrasive charge shall be placed in the Los Angeles
abrasion testing machine and the machine rotated at a speed of 20 to 33
rev/min. For gradings A, B, C and D, the machine shall be rotated for 500
revolutions; for gradings E, F and G, it shall be rotated for 1000 revolutions
as mentioned in Table 2.
• The machine shall be so driven and so counter-balanced as to maintain a
substantially uniform peripheral speed. If an angle is used as the shelf, the
machine shall be rotated in such a direction that the charge is caught on
outside surface of the angle.

• At the completion of the test, the material shall be discharged from the
machine and a preliminary separation of the sample made on a sieve
coarser than the l.70 mm IS Sieve.
• The material coarser than the 1.70 mm IS Sieve shall be washed dried in an
oven at 105 to 110°C to a substantially constant weight, and accurately
weighed to the nearest gram (B).
Calculation:
• The difference between the original weight and the final weight of the test
sample is expressed as a percentage of the original weight of the test
sample. This value is reported as the percentage of wear.
Aggregate Abrassion Value = ((A-B)/A) X 100
• where,
A = weight in gm of oven-dried sample.
B = weight in gm of fraction retained on 1.70 mm IS Sieves after washing
and oven-dried upto constant weight.

AGGREGATE CRUSHING VALUE TEST
Objective:
The aggregate crushing value gives a relative measure of the resistance of an
aggregate to crushing under a gradually applied compressive load. With
aggregate of aggregate crushing value 30 or higher, the result may be
anomalous, and in such cases the ten percent fines value should be determined
instead.
Apparatus Required:
 Balance
Balance should be accurate upto 1 gm
 Sieve (12.5 mm, 10.0 mm and 2.36 mm)
 Mould, Measuring Cylinder with Plunger
15-cm diameter open-ended steel cylinder, with
plunger and base-plate, of the general form and
dimensions and a straight metal tamping rod. For
measuring the sample, cylindrical metal measure
of sufficient rigidity to retain its form under rough usage and of the following
internal dimensions: Diameter 11.5 cm and Height 18.0 cm

Procedure:
• The material for the standard test shall consist of aggregate passing a 12.5
mm IS Sieve and retained on a 10 mm IS Sieve, and shall be thoroughly
separated on these sieves before testing.
• The aggregate shall be tested in a surface-dry condition. If dried by heating,
the period of drying shall not exceed four hours, the temperature shall be
100 to 110°C and the aggregate shall be cooled to room temperature before
testing.
• The appropriate quantity may be found conveniently by filling the cylindrical
measure in three layers of approximately equal depth, each layer being
tamped 25 times with the rounded end of the tamping rod and finally
leveled off, using the tamping rod as a straight-edge.
• The weight of material comprising the test sample shall be determined
(Weight A) and the same weight of sample shall be taken for the repeat
test.
• The cylinder of the test apparatus shall be put in position on the base plate
and the test sample added in thirds, each third being subjected to 25
strokes from the tamping rod. The surface of the aggregate shall be
carefully levelled and the plunger inserted so that it rests horizontally on
this surface, care being taken to ensure that the plunger does not jam in the
cylinder.

• The apparatus, with the test sample and plunger in position, shall then be
placed between the platens of the testing machine and loaded at as uniform
a rate as possible so that the total load is reached in 10 minutes. The total
load shall be 400 kN.
• The load shall be released and the whole of the material removed from the
cylinder and sieved on a 2.36 mm IS Sieve for the standard test. The fraction
passing the sieve shall be weighed (Weight B).
Calculation:
• The ratio of the weight of fines formed to the total sample weight in each
test shall be expressed as a percentage, the result being recorded to the first
decimal place:
Aggregate Crushing Value = (B/A) X 100
• Where, A = weight of oven-dried sample
B = weight in 'g' of fraction passing through 2.36 mm IS sieve.

Attrition Test For Aggregates
Objective:
Attrition is defined as the surface rubbing under some heavy loads tend to make
the interlocking abilities considerably weaker. This test is used to determine the
measure of the rate of the granular particles wear also termed as the resistance to
abrasion value.
Apparatus:
 Deval machine
 Sieves with IS: 1.7mm, 4.75mm, 10mm
12.5mm, 20mm, 25mm, 40 mm
 Weighing balance (5 to 10 kg measuring
capacity)
 Oven for dehydrating
 Tray

Method:
• Sample adopted is to be compatible with conditions stated in the above
table..
• Aggregates must be well cleaned and dried in the oven with temperature
range of 110
• A grouping is considered in accordance with standards.
• Sample is placed in the machine, then enclosed with the lid.
• Machine is than subjected to revolutions at 30-33 rev/min with a total of
10000 cycles with a consistent speed balanced all around.
• Machinery is paused after the set of cycles completed with the sample
removed onto some plate.
• These are then subjected under standard strainers with the dust passing
through sieve of 1.7mm.
• The weight is dependent on the specific gravity as stated in standard.

Observations:
• Sample weight (original), W1 = _______ g
• Sample weight (retained), W2 = _______ g
• Weight of sample passing the IS Sieve of 1.7mm = W1– W2 = _______ g
Attrition value (Deval) = (W1– W2)*100
Precautions:
• The sample is to be properly cleaned.
• The machine is cleaned properly.
• The sample is subjected towards proper
set of revolutions.
• Proper sieving is performed

Soundness test of Aggregate
Objective:
To determine the resistance of aggregate against weathering action and to
check durability of aggregates.
Apparatus:
 Balance: 500gm (0.1gm least count)
5000gm (1gm least count)
 Oven
 Sieve: 80 mm, 63 mm, 40 mm, 31.5 mm,
25 mm,20 mm, 16 mm, 12.5 mm, 10 mm,
8.0 mm, 4.75 mm, 4.0 mm, 2.36 mm, 1.18 mm,
600 micron, 300 micron, 150 micron
 Wire mesh basket
 Container

Chemicals:
• Sodium Sulphate Solution
• Magnesium Sulphate Solution
Preparation of sample:
Take any two-sieve size and sieve the sample.
Take the 100gm of retained material for
further test.
For example: For Fine aggregates: For course Aggregate:

Procedure:
• Take the weight of sample as W1 gm.
• Immerse the sample in solution either of sodium sulphate or magnesium
sulphate at least for 16 to 18 hours.
• After that remove sample from solution and drain the solution completely
and allow it to drain for 15 minutes.
• Dry the sample in oven at 105 to 1100C temperature
• Repeat this immerging and drying process 5 times for individual sample.
• After 5th cycle note down the dry weight of sample as W2 gm.
Result:
Percentage loss = (W1-W2) x 100/W2

DETERMINATION OF POLISHED STONE
VALUE
The polished stone value (PSV) gives a measure of the resistance of road stone to the polishing
action of vehicle tyres under conditions similar to those occurring on the surface of a road.
Apparatus
• (i) Accelerated Polishing Machine (With a road wheel with a flat periphery to fix 14
specimens of stone aggregates, 2 solid rubber tyred wheels 200 mm dia, and two feeding
mechanism for abrading sand and emery powder) rigidly mounted on a level, firm, concrete
base.
• (ii) IS test sieves of size 10, 8, 0.425, 0.300, 0.212 and 0.150 mm.
• (iii) Mould of size 90.6 mm x 44.5 mm for the preparation of test specimen of stone
aggregate.
• (iv) Release agent or liquid car polish.
• (v) Abrading sand passing 425 micron, 85-100% passing 300 micron, 20-50% passing 212
micron and 0-5% passing 150 micron IS sieve.
• (vi) Emery powder 100% passing 60 micron sieve and more than 70% passing 2 micron IS
sieve
• (vii) Polyester resin and hardener.
• (viii) Clean flexible plastic sheets for cutting strips to fix the samples to the polishing machine.
• (ix) Pendulum type friction tester.

Preparation of test specimen
• a) About 3 kg of clean stone aggregate sample, all passing through 10 mm and retained on 8 mm IS test
sieves which are not flaky or elongated is collected for the preparation of the test specimen.
• b) Prepare a stiff paste of cement mortar with equal proportion of cement and sand of similar grading as
the abrading sand.
• c) Place a thin layer of this mortar inside the specimen mould.
• d) Carefully place the selected particles of the aggregate sample over the mortar in a single layer, as
closely as possible and to cover an area of 90.6 x 44.5 mm, with flat surface of the aggregates lying on the
bottom of the mould.
• e) Fill the space between the particles up to 3 quarters of its depth with fine sand (Passing 0.212 mm
sieve) and level it with fine haired brush.
• f) The exposed internal faces and top edges of the metal moulds shall be lightly coated with release agent,
using a fine haired brush.
• g) Mix the hardener with resin and fill the mould to over flowing with mixed resin. The excess resin can be
trimmed off using a knife after 5 to 10 minutes
• h) After the resin has completely set (About 30 minutes from mixing), remove the specimen from the
mould, brush off the loose sand and subject to polishing after a further 30 minutes.
• i) Clean the moulds, tools etc with solvent.
• j) The mould as well as the prepared sample is flat across the width 44.6 mm but these are curved along
the length 90.5 mm as an arc of a circle diameter 406 mm.
• k) A minimum of two such test specimens are prepared using each sample of stone aggregates.

Measurement of friction of polished specimen
• Pendulum type friction tester is used to determine the coefficient of friction or the skid resistance value of the test specimen.
• a) Keep the friction test apparatus and slider in a room where the temperature is controlled at 20±2°C for at least 2 hours before the
test begins and for duration of the test.
• b) Keep the friction tester on a firm level surface and adjust the leveling screws such that the column is vertical.
• c) The hinge of the pendulum unit is raised and fixed on the column such that the rubber slider does not touch the ground surface and
the pendulum can swing freely.
• d) The pendulum arm is released from the horizontal rest position by pressing the button and the pendulum is allowed to swingfreely,
moving the dead pointer along.
• e) If the pointer reads zero of the graduated scale, the calibration is with zero error. If not, the friction adjustment screw head at the
hinge is adjusted by tightening or loosening as required, until repeat trial of free swing of the pendulum results in pointershowing zero
reading on the graduated scale.
• f) One of the specimens of aggregate which was subjected to accelerated polishing is rigidly fixed in the slot provided withits longer
side lying in the track of the pendulum swing.
• g) The hinge of the pendulum is adjusted such that the sliding length of the rubber shoe along the specimen is 75 mm. The hinge of the
pendulum unit is fixed in this position by tightening the fixing head.
• h) The surfaces of the specimen and the rubber shoe are copiously wetted with clean water.
• i) The pendulum and the pointer are released from the horizontal position by pressing the button. The pointer reading from the
graduated scale is recorded to the nearest whole number and is noted as the „Skid Number? or the Polished Stone Value.
• j) Perform this operation 5 times, each time wetting the specimen. Record the mean of the last three readings to the nearest0.1.
• k) After this test, the sample is removed from the slot and the process repeated with the second sample is fixed in position.If the mean
value of the two specimens of the same material differs by more than 3%, the result is discarded and test is repeated with fresh
specimens. This procedure may be repeated a number of times using new specimens until two values are within this limit.
• l) The samples are tested in the order 13, 1, 10, 3, 5, 12, 8, 7, 11, 6, 4, 9, 12, 14. 6. Report The mean of the two values of the skid
number or coefficient of friction expressed as percentage, is reported as the Polished Stone Value (PSV) of the stone aggregate to the
nearest whole number.
•

Tests on Bitumen
Objective:
To determine the penetration value of the given bitumen sample
Apparatus:
 Penetrometer
 Sample cup
 Water bath for maintaining a temperature
of 25˚C.
 Thermometer
 Specified needle
 Stop watch
PENETRATION TEST OF BITUMEN

Experimental Procedure:
1. Pour the bitumen sample into the container of 35 mm depth.
2. Cool in atmosphere at a temperature between 15-30 ˚C for 60 to 90
minutes.
3. Place the container in the water bath maintained at a temperature of
25 ˚C for 60 to 90 minutes.
4. Place the sample under the penetrometer and adjust the screw so
that the tip of needle just touches the surface of the bitumen sample.
5. Take the initial reading and press the knob for 5 seconds. Take the
final reading.
6. Make at least three such measurements.

SOFTENING POINT TEST
Objective:
To determine the softening point of the given
bitumen sample
Apparatus:
 Ring & Ball apparatus
 Water bath
 Stirrer
 Thermometer
 Beaker
 Heating device etc.

Experimental Procedure :
1. Preparation of test sample: Heat the material to a temperature between
75-100 ° C above its softening point; stir until it is completely fluid and free
from air bubbles and water. If necessary, filter it through IS sieve 30. Place
the rings on a metal plate which has been coated with a mixture of equal
parts of glycerine and dextrin. After cooling for 30 minutes in air, level the
material in the ring by removing the excess material with a warmed, sharp
knife.
2. Assemble the apparatus with the rings, thermometer and ball guides in
position.
3. Fill the bath with distilled water to a height of 50mm above the upper
surface of the rings. The starting temperature should be 5 °C.

4. Apply heat to the bath and stir the liquid so that the temperature rises at
a uniform rate of 5 ± 0.5 °C per minute.
5. As the temperature increases the bituminous material softens and the
balls sink through the rings carrying a portion of the material with it.
6. Note the temperature when any of the steel balls with bituminous
coating touches the bottom plate.

FLASH AND FIRE POINT TEST OF
BITUMINOUS MATERIAL
Objective:
To determine the flash and fire point of given bitumen samples by Pensky-
Martens
Need and Scope:
Bituminous materials leave out volatiles at high temperatures depending
upon their grade. These volatile catch fire causing a flash. This condition is
very hazardous, and it is therefore essential to qualify this temperature for
each bitumen grade.
FLASH POINT: The flash point of a material is the lowest temperature at which
the vapour of the substance momentarily takes fire in the form of flash under
specified condition of test.
FIRE POINT: The fire point is the lowest temperature at which the material
gets ignited and burns under specified condition of test.

Apparatus:
1. Pensky-Martens closed tester consisting of cup, lid, stirrer, shutter, flame
exposure device.
2. Thermometer (0-350 C) with sensitivity of 0.1 C

1. The material is filled in the cup up to a filling mark.
2. The lid is placed to close the cup in a closed system. All accessories
including thermometer of the specified range are suitably fixed.
3. The bitumen sample is then heated. The flame is lit and adjusted in such a
way that the size of a bleed is of 4mm diameter.
4. The heating is done at the rate of 5o C to 6o C per minute.
5. The stirring is done at the rate of approximately 60 revolutions per
minute.
6. The test flame is applied at intervals depending upon the expected flash
and fire points.
7. First application is made at least 17o C below the actual flash point and
then at every 1 o C to 3o C.
8. The stirring is discontinued during the application of the test flame.

VISCOSITY TEST OF BITUMINOUS
MATERIAL
Objective:
To determine the viscosity of given bitumen sample by Tar Viscometer
Need and Scope:
Viscosity is defined as inverse of fluidity. Viscosity thus defines the fluid property
of bituminous material. The degree of fluidity at the application temperature
greatly influences the ability of bituminous
material to spread, penetrate into the
voids and also coat the aggregates and
hence affects the strength characteristics
of the resulting paving mixes.

Apparatus:
 Tar Viscometer with 4mm and
10mm orifices
( The apparatus consists of main parts like)
 cup,
 valve,
 water bath,
 sleeves,
 stirrer,
 receiver,
 and thermometer etc
(i) The tar cup is properly levelled and water in the bath is heated to the
temperature specified for the test and is maintained throughout the test.
Stirring is also continued.

ii. The sample material is heated at the temperature 200C above the
specified test temperature, and the material is allowed to cool. During this
the material is continuously, stirred
iii. When material reaches slightly above test temperature, the same is
poured in tar cup, until the levelling peg on the valve rod is just immersed.
In the graduated receiver (cylinder), 25ml of mineral or one percent by
weight solution of soft soap is poured. The receiver is placed under the
orifice.
iv. When the sample material reaches the specified testing temperature
within +/- 0.10C and is maintained for five minutes, the valve is opened.
v. The stopwatch is started, when cylinder records 25ml. The time is
recorded for flow up to a mark of 75ml (i.e., 50ml of test sample to flow
through the orifice).

DUCTILITY TEST OF BITUMEN
Objective:
To determine the ductility value of the given bitumen sample.
Need and Scope:
In the flexible pavement construction where bitumen binders are used, it is of
significance that the binders form ductile film around the aggregate. The
binder material which does not possess sufficient ductility would crack when
flexed or elongated. Ductility is expressed as the distance in centimetres to
which a standard briquette of bitumen can be stretched before the thread
breaks. The test is conducted at 27 º C +/- 0.5 º C at a rate of pull of 50 +/- 2.5
mm per minute.

Apparatus:
1. Ductility machine
2. Briquette mould
3. Knife
Sample Preparation:
1. Apply grease on the glass plate.
2. Arrange the end pieces and side pieces of the briquette mould on a glass
plate. Apply grease on the insides of the side pieces of the mould.
3. Heat the bitumen sample to a pouring consistency and carefully pour into
the mould.

1. Allow the sample to cool in air for about 30 to 40 minutes.
2. Immerse the mould with the plate in a water bath maintained at 27º C for 30
minutes
3. Take out the mould and cut off excess bitumen, if any, with a sharp hot knife.
4. Replace the mould back in water for 85 to 90 minutes, at 27º C
5. With the help of hot knife, remove the side pieces of the mould and separate
the sample from the plate
6. Carefully place the sample in the ductility machine on the plate provided. Fix
the ends of the mould to the plate.
7. Note the initial reading on the scale provided on the machine. It should be 0
(zero)
8. Start the ductility machine. The sample stretches and a thread is formed in
the middle. The sample stretches at a uniform rate of 50 2.5mm per minute.
9. The thread formed at the middle breaks after some distance. The distance up
to which the sample stretches before the thread breaks is recorded as the
ductility value.

Elastic recovery
AIM OF THE EXPERIMENT:
To determine the elastic recovery of bituminous material.
APPARATUS REQUIRED FOR THE TEST :
• Ductility machine and Mould
• Scissors & Oven
• Thermometer
• Water Bath for conditioning specimen
• Scale (Measuring up to 25 cm. with accuracy of +/- 1 mm.)

TEST DESCRIPTION :
The elastic recovery of modified bitumen is evaluated by comparing recovery
of thread after conditioning specimen for 60 min at specified temperature
and the specimen is elongated up to 10 cm deformation in a ductility motion.
This is mainly intended to assess the degree of bitumen modification at
quality of modified bitumen.
The elastic recovery is calculated with the use of the following formula:
Elastic Recovery (%) 10-x /X 100 (where x length of recombined specimen)
RELEVANCE AND IMPORTANCE :
This test is done to optimize dose of polymeric additives in bitumen and also
helps in assessing the quality of or polymer-modified asphalt cement in
laboratory
TEST PROCEDURE :
1. The sample is asphalt cement or polymer-modified asphalt cement,
carefully heat the sample in a covered container to prevent local
overheating until has become sufficiently fluid to pour. Use an oven set at
135 +/- 5°C (275 +/-10°F) for sample heating.

2. Prepare the test specimens in a set of three moulds as per dimensions
given in the figure 1 and conditions prescribed in the test methods of IS
1208. After sample preparation, thoroughly stir the sample and pour into
the mould.
3. Elongate the test specimen at the specified rate to a deformation of
10cm at the rate of 5 +/- 0.25cm/min. immediately cut the test specimen
into two halves at the midpoint using the scissors. Allow the specimen to
remain in the testing machine in water bath in an undisturbed condition
at the specified temperature for a period of 60 min.
4. After the 60 min time period, carefully move the elongated half of the test
specimen back in to the position near the fixed half of the test specimen
so the two pieces of changed bitumen just touch. If the specimen ends
have sagged, carefully lift them to their original level prior to adjusting
the ends to touch. Record the total length of the specimen with the
severed ends just touching each other

Modified Bituminous
 Modified Bitumen is a highly specialized blend of bitumen with high
quality polymer which is manufactured under carefully controlled
conditions in a "State of Art" plant.
 Modified Bitumen is an exceptionally versatile product with enhanced
properties that makes it suitable for wearing course application under
special conditions like high rainfall and high traffic areas
Advantage of modified bitumen
 Lower susceptibility to daily and seasonal temperature variation.
 Higher resistance to deformation at high pavement temperature.
 Better age resistance properties.
 Higher fatigue life for mixes.
 Better adhesion between aggregate and binder.
 Prevention of cracking and reflective cracking

Types of Modified Bitumen:
 A variety of additives are used for modification of Bitumen.
 The degree of modification depends on type of Modifier, its dose and
nature of Bitumen.
The most commonly used Modifiers are:
Synthetic Polymers
Plastomeric Thermoplastics
 Low Density Polyethylene(LDPE)
 Ethylene Vinyl Acetate
Elastomeric Thermoplastics
 Styrene Isoprene Styrene (SIS)
 Styrene Butadiene Styrene Block Copolymer

Natural Rubber
 Latex Powder
 Rubber Powder
Crumb Rubber
 Crumb Rubber without additives
 Crumb Rubber with additives

Benifits
 Since other components of the cost of construction remains same except
for the binder, the overall increase in the cost of construction is approx.
15-25%.
 However, the field trials have proved that frequency of overlaying can be
minimized and the maintenance cost can be reduced to about 22-30%
excluding the cost of interest, safety and comfort to the road user.

CRUMB RUBBER
 Crumb rubber is a recycled rubber produced from
automotive and truck scrap tires.
Crumb rubber modified bitumen :
Bitumen +Additives (Modifiers/Treated Crumb Rubber)
Crumb Rubber Modified Bitumen is Conventional Bitumen with treated
Crumb Rubber Additive at high temperature which results in
 Lower susceptibility to temp. variatio
 Higher resistance to deformation at
high temperature
 Better Age Resistance Properties
 Higher Fatigue Life of Mixes
 Better Adhesion Properties

Natural rubber :
Natural rubber also called India rubber, as initially produced, consist of
polymers of the organic compound isoprene, with minor impurities of other
organic compounds plus water.
Natural rubber modified bitumen
 Natural rubber modified bitumen is used for prolongation of life of state
roads.
 The need to adopt rubber for the use of construction of the roads mainly
that it reduces the cost of construction and also recycled rubber is used as it
minimize the environment pollution.

Polymer modified bitumen
Polymer modified bitumen material bring benefits in terms of better and
longer lasting roads and saving in total road life costing.
The main polymer used to modify bitumen are:
 1. Natural rubber
 2. Styrene-butadiene-styrene (SBS)
 3. Ethylene-vinyl acetate (EVA)

Critical parameters controlling in
bituminous concrete mixture design
In bituminous concrete mixture design, several critical parameters work together
to achieve the desired performance characteristics for specific applications. These
parameters control crucial aspects like strength, flexibility, durability, and
workability of the asphalt pavement. Here's a closer look at some of the most
important ones:
1. Binder Content:
This parameter directly impacts the cohesion and flexibility of the mix. A higher
binder content creates a more flexible pavement but decreases its stability and
susceptibility to rutting under heavy traffic. Conversely, a lower binder content
leads to a stronger pavement but increases its cracking potential. Finding the
optimal balance is crucial for long-lasting performance.

2. Aggregate Gradation:
The distribution of different aggregate sizes, from coarse to fine, is key to
achieving a dense, well-packed mix with minimal air voids. A well-graded mix
ensures:
• Stability: Larger aggregates provide internal support, while smaller ones
fill the gaps between them.
• Durability: A dense mix resists water infiltration and minimizes internal
stresses.
• Workability: The right gradation enhances the mix's ability to be properly
mixed, placed, and compacted.

3. Air Voids:
While minimal air voids are desirable for strength and water resistance, some are
necessary for compressibility and drainage. Excessive air voids, however, weaken
the mix and make it susceptible to cracking. Optimizing the air void content
requires careful selection of binder content and aggregate gradation.
4. Binder Properties:
Different types of asphalt binders possess varying viscosity, stiffness, and aging
resistance. Choosing the right binder based on traffic volume, climate, and
expected pavement life is critical. For example, a stiffer binder might be suitable
for high-traffic roads, while a more flexible one might be preferred in colder
climates to resist cracking.

5. Production and Compaction Temperatures:
Maintaining proper temperatures during mixing, laying, and compacting the
asphalt is crucial for workability and adhesion. Deviations from optimal
temperatures can lead to segregation, poor compaction, and premature
pavement failure.
6. Additional Additives:
In some cases, engineers might use additives like fibers, polymers, or
modifiers to enhance specific properties. These can improve crack resistance,
fatigue life, or resistance to specific environmental factors like deicing salts.

Some of the desirable properties
required by a Bitumen Mix are
 Proper binding of the particles present in the bitumen mix. This facilitate
waterproofing properties.
 The traffic demand has to meet adequately by having sufficient stability
 The bitumen mix have to be economical
 The bitumen mix must have sufficient workability to help construction
procedures
 Voids must me intentionally left so that compaction during traffic can be
performed
 The mix must be flexible to face the changing temperature conditions

Blending of Aggregates
The blending of aggregates a process in which two, thre or more of
aggregates, which have different types of sources and sizes, are mixed
together to give a blend with a specified gradation.
The blending of aggregates is done because
 There are no individual sources, sizes, and types of aggregates (natural or
artificial) that individually can supply aggregate of gradation to meet a
specific or desired gradation.
 It is more economical to use some natural sands or rounded aggregates in
addition to crushed or manufactured aggregates, and this process (mixing
natural and crushed) cannot be held without using a blending operation.
 Regardless of which method will be used, there are two important pieces
of information that must be known before finding the proportion values.
These are the sieve analysis of each material, and the limits of desired
specifications.

Method for Combining Aggregates
Mathematical procedures are available to determine an optimum combination
of aggregates, but the "Trial and Error Method" guided by a certain amount of
reasoning is the most practical procedure to determine a satisfactory combination
and the one we will demonstrate
Trial and Error Method
Step 1 - Obtain the required data.
The gradation of each material must be determined. b. The design limits for the
type of mix must be obtained.
Step 2 - Select a target value for trial blend.
The target value for the combined gradation must be within the design limits
of the specifications. This value now becomes the target for the combined
gradation.
Step 3 - Estimate the proportions.
Estimate the correct percentage of each aggregate needed to get a combined
gradation near the target value. For example, if aggregates are combined, a
possible combination may be 30% of Aggregate 1 and 70% of Aggregate 2.

Step 4 - Calculate the combined gradation.
This calculation will show the results of the estimate from Step 3. The
method of calculating the combined gradation will be shown in the example
problem.
Step 5 - Compare the result with the target value.
If the calculated gradation is close to the target value, no further adjustments need
to be made; if not, an adjustment in the proportions must be made 73% and the
calculations repeated. The second trial should be closer due to the "education"
received from the first. The trials are continued until the proportions of each
aggregate are found that will come close to the target value. If the aggregates will
not combine within the design range, it may be necessary to use or add different
materials.

Rothfuch's Method (Equaled areas):
Graphical Methods:
There are different types of graphical methods which can be used to find the
proportions of each types of aggregates to obtain the blending of aggregate
which are placed inside the zone of specification (upper and lower limits).
Rothfuch's Method (Equaled areas):
The following steps are used in this method for finding the blending of
aggregates which is approximately the closest to the mid points of the
specification.
1. Using the graph paper and draw the X-axis's length 1.5 of the vertical axis
(Y-axis) to create a rectangular shape (MQNO).

2. The vertical axis (Y-axis) represents the passing (%) and starts from zero
to 100. while, the horizontal axis(X-axis) represents the location of sieve sizes.
3. Draw the diagonal MN of the rectangle
4. Use the mid point values of the specification on Y-axis (passing %) and
project them on the diagonal (MN) and from the intersection points drop
dawn vertically to find the locations of the sieve sizes on the X-axis.

5.Plot the gradations of aggregate A, B, and C on the graph.
6.Select a line passing through each gradation curve. The selected line must
cross the lines ON and MQ. During passing the selected lines through the
curve several areas are created above and blow its, the main criteria of
choosing the selected line is the above and below areas must be equaled to
achieve this condition, the line needs to move in anyways.
7. In the above example the selected lines are: I-II for Agg. A, III-IV for Agg. B,
and V-VI for Agg. C as shown in figure.
8. Plot lines between points II - III and IV - V. These lines cross the diagonal line
(MN) in points f and k.

Introduction to Advanced Concretes
for Road applications
Advanced concretes for road applications refer to innovative concrete
materials and technologies that are specifically designed to meet the
demanding requirements of modern road construction. These advanced
concretes offer enhanced performance characteristics compared to traditional
concretes and are often developed to address specific challenges such as
durability, sustainability, and cost-effectiveness in road infrastructure.
Some examples of advanced concretes for road applications include:

High-Performance Concrete (HPC):
HPC is a type of concrete that is designed to have superior strength, durability,
and workability compared to conventional concrete. It often incorporates
advanced admixtures and optimized mix designs to achieve these properties,
making it suitable for use in bridges, pavements, and other critical
infrastructure where high strength and durability are essential.

Self-Consolidating Concrete (SCC):
SCC is a highly flowable and non-segregating concrete that can fill formwork
and encapsulate reinforcement without the need for mechanical
consolidation. SCC is particularly useful in road construction where congested
reinforcement or complex formwork makes
traditional concrete placement challenging.

Fiber-Reinforced Concrete (FRC):
FRC contains fibers, such as steel, synthetic, or natural fibers, which enhance
its toughness, ductility, and resistance to cracking. FRC can be used in road
pavements to improve the crack resistance and durability of concrete
structures.

Ultra-High-Performance Concrete (UHPC):
UHPC is a type of concrete known for its exceptional strength, durability,
and ductility. It is often used in bridge construction and other
infrastructure projects where high-performance materials are required.
UHPC can offer significant advantages in road construction due to its
superior mechanical properties and durability.

Green Concrete:
Green concrete refers to concrete that incorporates recycled materials,
such as fly ash, slag, or recycled aggregate, to reduce its environmental
impact. Green concrete can be used in road construction to promote
sustainability and reduce the carbon footprint of infrastructure projects.

Nanoconcrete:
Nanoconcrete incorporates nano-sized particles, such as nanosilica or
nanoparticles, to enhance the mechanical properties and durability of concrete.
Nanoconcrete can offer improved strength, durability, and resistance to
environmental degradation, making it suitable for use in road pavements
exposed to harsh conditions
These advanced concretes for road applications are continually evolving as new
materials and technologies are developed. They offer the potential to improve
the performance, longevity, and sustainability of road infrastructure, contributing
to safer and more durable transportation systems.

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