1. CHAPTER 3 : PAVEMENT MATERIALS
• Road surface or pavement is the
durable surface material laid
down on an area intended to
sustain vehicular or foot
traffic, such as a road or walkway.
• In the past cobblestones and
granite setts were extensively used,
but these surfaces have mostly been
replaced by asphalt or concrete.
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2. MATERIAL USED IN HIGHWAY CONSTRUCTION
I. Aggregate
ii. Bitumen and asphalt
iii. Tar
iv. Cement
v. Steel reinforcement.
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3. AGGREGATE
•Coarse particulate material used in
construction, including sand, gravel, crushed
stone, slag, recycled concrete and geosynthetic
aggregates.
•Aggregates are a component of composite materials
such as concrete and asphalt concrete
•Aggregate serves as reinforcement to add strength to the
overall composite material.
•Due to the relatively high hydraulic conductivity value as
compared to most soils, aggregates are widely used in
drainage applications such as foundation and french
drains, septic drain fields, retaining wall drains, and road
side edge drains.
•Aggregates are also used as base material under
foundations, roads, and railroads.
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4. • Has been widely used since 1920–1930.
•The terms asphalt and bitumen are often used interchangeably to
mean both natural and manufactured forms of the substance. BITUMEN In AND ASPHALT
American English, asphalt (or asphalt cement) is the carefully refined
residue from the distillation process of selected crude oils. Outside
the U.S., the product is often called bitumen.
•The viscous nature of the bitumen binder allows asphalt concrete to
sustain significant plastic deformation, although fatigue from repeated
loading over time.
• Most asphalt surfaces are laid on a gravel base.
• In areas with very soft or expansive subgrades such as clay or peat,
thick gravel bases or stabilization of the subgrade with portland
cement or lime may be required.
•Asphalt is categorized as hot mix asphalt (hma), warm mix asphalt,
or cold mix asphalt.
•Hot mix asphalt is applied at temperatures over 300 F
• Warm mix asphalt is applied at temperatures of 200 to 250 degrees
F
•cold mix asphalt is often used on lower volume rural roads, where
hot mix asphalt would cool too much on the long trip from the asphalt
plant to the construction site.
•Advantages: low noise, relatively low cost compared
with other paving methods, and perceived ease of repair.
• Disadvantages:less durability than other paving
methods, less tensile strength than concrete, the tendency
to become slick and soft in hot weather and a certain amount of
hydrocarbon pollution to soil and groundwater or waterways.
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5. CEMENT
•Cement is a binder, a substance that sets and hardens
independently, and can bind other materials together.
•The word "cement" traces to the romans
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6. PORTLAND CEMENT
•Cement is made by heating limestone (calcium carbonate) with
small quantities of other materials (such as clay) to 1450 C in a
kiln.
•The resulting hard substance, called 'clinker', is then ground with
a small amount of gypsum into a powder to make 'Ordinary
Portland Cement', the most commonly used type of cement (often
referred to as OPC).
•Portland cement is a basic ingredient of concrete, mortar and
most non-speciality grout.
•The most common use for Portland cement is in the production of
concrete.
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7. STEEL REINFORCEMENT
•Also known as reinforcing
steel, reinforcement steel, or a deformed
bar, is a common steel bar, and is
commonly used as a tensioning device in
reinforced concrete and reinforced
masonry structures holding the concrete in
compression.
•usually formed from carbon steel, and is
given ridges for better mechanical
anchoring into the concrete.
•Rebar is available in different grades and
specifications that vary in yield
strength, ultimate tensile
strength, chemical composition, and
percentage of elongation.
•The grade designation is equal to the
minimum yield strength of the bar in ksi
(1000 psi) for example grade 60 rebar has
a minimum yield strength of 60 ksi. Rebar
is typically manufactured in grades
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40, 60, and 75.

8. Types And Grades Of Aggregate
Three main types of rock are used to produce
crushed rock aggregates:
Igneous
Solidified molten rocks (eg basalt, granite)
Sedimentary
Created by settlement of particles (eg gritstones) or
organic remains (eg limestone) in ancient seas
Metamorphic
Created by heat or pressure (eg
hornfels, quartzites)
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9. TYPES OF TESTS ON MATERIALS
a.Aggregate Impact Value Test
b. Polished Stone Value Test
c. Aggregate Crushing Value Test
d. Flakiness Index Test
e. Elongation Test
f. Penetration Test
g. Softening Test
h. Viscosity Test
i. Flash and Fire Point Test
j. Ductility Test
k.Floatation Test
l. Soundness Test.
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10. Aggregate Impact Value Test
BS 812: Part 112: 1990
• Determine aggregate resistance due to impact.
• Size aggregate : passing sieve 14mm and retain 10 mm.
• Agregate were filling into mould in one layer and will be
driven by rod in 25 times.
• Aggregate mass will be taken.
•Hammer with 13.5 to 14 kg will be release from the height
of 380mm and will driven in a 15 times on aggregate.
• After finished, aggregate will be sieve with size of sieve
is 2.36 mm.
• AIV were determine with a formulae :
AIV = mass of aggregate passing sieve of 2.36 mm x 100
%
total mass
< 30 % - pass
>30 % fail
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11. Polished STone Value Test
• Only conducted on aggregate that be used as a wearing coarse.
• Polishing value of aggregate show of aggregate resistance due to
wheel vehicles.
• Polishing level affect skid resistance of pavement.
• This test consist 3 stages:
i. Sample preparation
ii. Polishing sample
iii. Skid resistance measurement.
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12. Aggregate Crushing Value Test
BS812 : Part 110 : 1990
• To determine the strength of aggregate resistance to crushing
under the applied compressive load.
• Normal size : passing 14 mm sieve and 10 mm retain ( 3000 g )
• Aggregate were fill into mold in three layers and each layer were
driven by 25 times.
•Then inserted into the compression machine for 10 minutes and
will be compress by 400 KN load.
• Aggregate will be sieve in in 2.36 mm sieve and the mass will be
determined.
ACV = mass of aggregate passing sieve of 2.36 mm x 100 %
total mass
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13. Elongation Index
BS812 : Part 1: 1975
• To determine the percentage of the longest aggregate.
• Classified longest when longest dimension is more than 1.8
times from average size.
• Aggregate size to be tested is 63 mm to 6.3 mm.
EI = Retain mass x 100 %
Total mass
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14. Flakiness Index Test
BS 812 : Section 105.1 : 1989
•Purpose : To determine percentage of flat aggregate.
• Classified as flat when the thickness is less than 0.6 of average size.
• Aggregate to be tested is in size of 63 mm to 6.3 mm
FI = Mass of aggregate passing x100 %
Total mass
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15. Penetration Test
(AASHTO T49-84)
•To determine the hardness of the material.
•Defined as the distance (in 1 / 10) standard needle puncture
of the time, load and temperature are known.
•Using a standard needle under the load of 100 grams for 5
seconds at a temperature of 20 degrees celsius.
•High penetration value indicates the material is soft.
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16. SOFTENING TEST
•To determine the temperature at which
phase changes occur in the bitumen.
•Soft spot is defined as the temperature at
which bitumen is unable to support the
steel ball and began to soften.
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17. VISCOSITY TEST
To determine the viscosity of the bitumen.
Defined as the resistance of a fluid to flow.
Two types of viscosity : absolute or
dynamic viscosity and kinematic.
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18. Flash and Fire Point Test
When the bitumen is heated at high
temperatures, the vapor will be liberated
and embrace if any sources of ignition.
Flash point indicates the temperature at
which bitumen can be heated without
danger of fire generated in the presence of
the fire.
The method used is the Cleveland open
cup method.
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19. DUCTILITY TEST
This test is done to determine the ductility
of distillation residue of cutback bitumen,
blown type bitumen and other bituminous
products as per IS: 1208 – 1978. The
principle is : The ductility of a bituminous
material is measured by the distance in cm
to which it will elongate before breaking
when a standard briquette specimen of the
material is pulled apart at a specified
speed and a specified temperature.
The apparatus required for this test:
i) Standard mould
ii) Water bath
iii) Testing machine
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21. Objectives of asphalt mix design
The design of an asphalt mix is largely a matter of
selecting and proportioning materials to optimise
the engineering properties in relation to the desired
behaviour in service.
Procedures for designing asphalt mixes have been
generally developed around testing of dense graded
mixes and determination of optimum binder
content, although most tests can be used for other mix
types with suitable interpretation of results.
The overall objective for the design of dense graded
asphalt paving mixes is to determine (within the
limits of project specifications) a cost-effective
blend and gradation of aggregates and binder that
yields a mix
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22. Characteristics of asphaltic concrete mix
1.Sufficient binder to ensure a durable pavement;
2. Sufficient mix stability to satisfy the demands of
traffic without distortion or displacement;
3. Sufficient voids in the total compacted mix to allow
for a slight amount of in place compaction by traffic and
bitumen expansion due to temperature increases,
without flushing, bleeding and loss of stability;
4. A maximum void content to limit the permeability of
harmful air and moisture into the mix;
5. Sufficient workability to permit efficient placement
of the mix without segregation and without sacrificing
stability and performance;
6. For surface mixes, proper aggregate texture and
hardness to provide sufficient skid resistance.
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23. An overview of the design process
Asphalt mix design involves the following basic steps
that are similar in concept, regardless of the actual
tests and procedures used:
1. Selection of mix type.
2. Selection of component materials.
3. Combination of aggregates to meet target grading.
4. Selection of target binder content or range.
5. Mixing and compaction of asphalt mix to a density
that is representative of in-service conditions.
6. Measurement of volumetric properties of
compacted mix.
7. Mechanical testing of compacted samples, if
required.
8. Verification of design properties on samples of
manufactured asphalt, if required.
9. Selection of Job Mix.
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24. MARSHALL MIX DESIGN METHOD
- Developed by Bruce Marshall & the U.S.
Corps of
Engineers.
Objective: To determine the optimum
asphalt content for
a particular aggregate blend and asphalt to
be used.
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25. PROCEDURES:
1. Prepare asphalt concrete specimens (4 inches in
diameter & 2.5 inches in height) for a range of asphalt
content at and near the estimated optimum asphalt
content.
(A) Mixing temperature:
at asphalt viscosity of 170 20 cSt
(B) Compaction temperature:
at asphalt viscosity of 280 30 cSt
(C) Compactive Effort:
35, 50 or 75 blows with a Marshall hammer
(10 lbs, 18 inches drop) on each side of the specimen.
(D) Number of Samples:
3 replicates at each asphalt content
Typically, 5 different asphalt contents are used.
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26. ADDING ASPHALT TO AGGREGATE
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27. MIXING OF AGGREGATE AND ASPHALT
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28. Placing asphalt
mixture in a
compaction
mold
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29. Proving Ring
Flowmeter
Breaking Head
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30. 4. Plot
(A) Marshall Stability v.s. % Asphalt
(B) Marshall Flow v.s. % Asphalt
(C) % Air Voids v.s. % Asphalt
(D) Bulk Density v.s. % Asphalt
(E) % VMA v.s. % Asphalt
(F) % VFA v.s. % Asphalt
5. Obtain % Asphalt at 4% air voids
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32. % AC at 4% air voids: 6.7
6. Verify mix design criteria at the optimum
asphalt content. The five mix criteria to
check
against are:
(A) Marshall stability
(B) Marshall flow
(C) Air Voids
(D) VMA
(E) VFA
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