CH_3-Road_Construction_Technology_1658041305[1].ppt

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CHAPTER:6
Construction Equipment
Er. Ramchandra Yadav
POKHARA UNIVERSITY
SCHOLAR,
20/06/2022

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Topic Description Lecture
hours
3.1
3.2
3.3
Activities and techniques used in road construction
Activities: Earthwork and site clearance, Drainage works, Protection work,
Pavement works, and Miscellaneous works
Tools equipments and plants used in road construction
a) Tools: small hand tools and wheel borrows etc.
b) Equipments: Earthmoving, compaction, leveling, paving, lifting, transporting
etc.
c) Plants: i) Cement concrete plant ii) Asphalt concrete plant iii) Cold mixing
plant
iv) Aggregate crushing plant v) Screening plant vi) Washing plant vii) sand
blowing plant
Execution of earth work: Excavation, filling, compaction, soil stabilization,
preparation of sub grade and concept of mass haul diagram
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3.4 Construction of low cost road: Earthen, Gravel, and Water Bound Macadam
3.5 Construction of Prime Coat, Tack Coat and Seal coat
3.6 Construction of surface dressing
3.7 Construction of Otta-seal
3.8 Construction of Grouted and Penetration Macadam
3.9 Construction of different types bituminous premixes: Premix carpet, Bituminous
Bound Macadam, Bituminous Concrete (Asphalt Concrete)
3.10 Construction of Cement Concrete Pavement

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Definition
 Road construction technology is that branch of
transportation engineering which deals with all kinds
of activities and technology or operations for
changing existing ground to the designed shape,
slope and to provide all necessary facilities for
smooth, safe and efficient traffic operation which
includes the reconstruction of existing roads.
 As per nature, type of works, and elements of road to
be constructed various activities can broadly divided
into several works.

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Construction Activities
1 Earth work and site clearance
 Site clearance
 Earth work filling or embankment
 Excavation for cutting
 Excavation for borrow pit
 Excavation for structural foundation
 Disposal of surplus earth mass
2 Drainage works:
 Minor bridge
 Culverts
 Causeways
 Side drain
 Energy dissipating structures
3 Protection works
 earth retaining structures
 river training works
 gully control works
 land slide stabilization
 bridge protection works
 Anchor wall
4 Pavement works
 Sub-grade works
 Sub-base works
 Base works
 Surface works
5 Miscellaneous Works
 Road ancillaries
 Traffic sign/signal/marking
 Bio-engineering works

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Road construction Tools, Equipment and Plants
 Although the road construction may be done manually but it
takes lot of time to complete the road project.
 The quality of the works may not be achieved to the required
degree and which can not be maintained strictly by using
intensive labor force.
 While using the construction equipment the construction of
works can be completed with high degree of quality
construction and complete with in the allocated period.
 However in developing countries like Nepal most of the
contractor prefers to use more labor than to utilize
construction equipment because of cheep labor and
expensive equipment.
 A. TOOLS: -Hand shovel; Chisel; Peak; Spade; Hand
rammer; Brushes; Trowel; Wheel barrow etc.

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Roller
 Cylindrical roller-Light roller of iron, concrete or stone; drawn by
hand or bullocks. The size varies, but it is generally about 1 meter in
dia. and about 1.5 meter long. The ground pressure generated by this
type of roller is about 7 kg/cm2
 Sheep foot roller-The coverage area is about 8 to 12%.
The thickness of compacting layer is kept about 5 cm more than
the length of each foot. This type of roller mostly used for
compaction of cohesive soils such as heavy clays and silty clays and
not effective with sandy soils. Capacity: Pressure on the feet should
be 4 to 7 Kg/cm2 for light roller and 25 to 70 kg/cm2 for giant rollers

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Roller
 Pneumatic Roller- The roller consists of a heavily loaded wagon with
several rows of four to six closely spaced tyres. The tyre pressure may
be up to 7 kg/cm2 and the coverage of 80%. Used for compacting cold
laid bituminous pavements, soft base course materials or layers of
loose soil. These rollers are also suitable for compacting closely
graded sands, and fine-grained cohesive soils at moisture content
approaching their plastic limits.
Capacity: The gross weight of the roller is about 6 to 10 tonnes which
can be increased to 25 tonnes by ballasting with steel section or other
means

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Roller
 Smooth wheel roller-This type of roller consists of a large steel drum
in front and one or two wheels or drum on the rear end. Smooth wheel
rollers are most suitable for consolidating stone soling, gravel, sand,
hard core, ballast and surface dressings. Not suitable for consolidating
embankments and soft sub-grades, but are better suited than any
other plant for compacting silty and sandy soils and with fewer passes.
When the moisture content is a little more than optimum it will compact
more easily.
Capacity: The weight of tandem roller varies from 2 to 8 tonnes and
that of two wheeled roller varies from 8 to 10 tonnes. The ground
coverage provided by smooth wheeled roller is 100% and ground
pressure exerted by tandem rollers is about 10 to 17 kg/cm2.

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Roller
 Vibrating Roller-Vibratory Rollers are machines used to compact loose
soil or asphalt and are primarily used for roads and highway
construction. These machines also find application for ground
compaction / stabilization at construction sites.
Capacity: 10 tons to 12 tons soil compactors and 3.5 tons and 9 tons
tandem compactors with advanced features
 Grid rollers: These rollers have a cylindrical heavy steel surface
consisting of a network of steel bars forming a grid with squire holes and
may be ballasted with concrete blocks. Grid rollers provide high contact
pressure but little kneading action and are suitable for compacting most
coarse grained soils. Capacity: 5 tonnes net and 15 tonnes ballasted.

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Plants
 cement concrete plant
 asphalt plant
 cold premix mixing plant
 aggregate crusher plant
 screening plant
 washing plant
 sand blowing plant

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Construction Phases
 Highway construction project may be broadly divided
into two phases:
 Earthwork and preparation of Sub-grade, sub-
base and base course
 Pavement construction work

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Earth work-Mass Haul Diagram
 The principles of drawing a mass haul diagram are
illustrated in the figure given below:
 The MHD is plotted directly below the L-profile.
 The horizontal distances are the Chainage along the center
line.
 The ordinate at any station along the MHD indicates the
earthwork quantity accumulated upto that point, and is the
summation of the differences between cut and fill.
 The maximum (+) ordinate indicates a change from cut to fill
(D) and the minimum (-) ordinate indicates from fill to cut (A
and G).
 Upward sloping curves indicate (rising left to right) a cut.

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Mass haul diagram
Quantities
in
Cu.
M.
0
100
200
300
400
500
-100
-200
-300
-400
-500
0 A C D E F G
H J
B
Fill Cut
Ground Line
Road Surface
Fill
Base line
Station or Chainage
K
L
Mass haul Diagram

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Mass haul Diagram ( Cont….)
 Downward sloping (falling left to right) curves occur in a fill section
 peaks indicate a change from cut to fill and valleys occur when the
earthwork changes from fill to cut
 If the curve has steep slope it indicates heavy cuts or high fills. Flat
slopes indicate small earthwork quantities.
 A convex downward loop of the mass diagram indicates that the
haul from cut to fill is from left to right. A convex upward loop
indicates that the haul from cut to fill is from right to left.
 The balance point is defined as a point where the volume in
excavation balances the volume in embankment.
 Any line drawn parallel to the base line and intersecting two points
within the same curve indicates a balance of cut and fill between
these two points ( C and E). Such a line (HJ) is called a balancing
line.

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 The area between a balancing line and the mass
diagram as a measure of the haul between the
balance points. This area (hatched area) divided by
the maximum ordinate between the balance line
and the curve (KL) gives the average distance of
haulage of the cut to make the fill.
 When the earth excavation and the embankment
quantities balance at the end of the section, the
mass diagram curve would end at the base line at
the zero point.

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 Balance Point: It is the point where mass haul diagram
intersects the baseline (road way) and at this point the
volume of cut is equal to the volume of fill.
 Haul/Authorized haul:- The transportation of excavated
materials from its original position to its final location in the
work or to the other disposal area is called haul of
authorized haul.
 Free haul/Average haul: It is the distance to which the
contractor is supposed to move the earth without any
additional charge. It is the area of mass diagram between
balance points divided by the maximum ordinate of the curve
between the balance points. The charge for free haul is
covered by the unit rate of earthwork.

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 Over haul: The hauling in excess of the free haul distance
beyond the balance point is called overhaul and paid extra
rate.
 When the earth is excavated from the borrow area and
deposited on the embankment, its volume increases. But as
the compaction is done, the final volume of the compacted
bank becomes less than the borrow area volume. This is
known as shrinkage. The actual shrinkage factor depends
upon the soil deposit and may vary from 10 to 20 percent.
Economic Haul:
Dozer=90m, Scrapers=90-1500m and Trucks> 1500m

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Site Clearance
 Site clearance is the first operation to be started
just after completion of survey works for fixing the
road alignment and before the beginning of any
earth works for the road construction. Major works
to be done under this heading along the alignment
are as follows:
 Clearing hedges and shrubs at least covering toe
width.
 Removal of existing tree stump, and roots along the
alignment
 Removal of existing structures along the alignment.

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Earth work
It is the process to prepare the sub-grade level
bringing it to the desired grade and camber by
compacting adequately. The earth work may be
either in embankment (filling) or in excavation
(cutting) depending on the topography.

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Earth work and preparation of sub-grade
Earthwork and preparation of Sub-grade: It is the process
to prepare the sub-grade level bringing it to the designed
grade and shape by compaction of the earth layers
adequately. The earthwork may be either in embankment for
filling or in excavation for cutting depending on the original
ground level and the finalized vertical alignment of the road to
be constructed.
In order to reduce the cost of construction, it is necessary to
plan the movement of materials from cuts to the nearest fills
and decide on limits of economical haul and lift.
It is advantageous to plot a mass haul diagram to compute the
haulage details. The swelling and shrinkage factors may also
be considered in the excavation and filling of the earth.

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The preparation of sub-grade includes all operations just
before the placement of the pavement layers and
compacted over it. In all cases site should be cleared off
and grading is necessary to bring the vertical profile of
the sub-grade to designed grade and shape. It is most
essential to compact the top of formation level (sub-grade
level) adequately to the desired dry density before the
placement of the pavement layer.

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Material:- Soil having the following properties is
suitable for preparation of sub-grade.
Liquid limit (LL) < 75 % and Plasticity Index (PI) <
40.
Equipment: - Grader; Roller; tipper and water
tanker or manual spreading of water for small
projects.

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Construction steps
 Leveling of the completed earthwork to the designed
grade and shape by cutting or filling normally up to 20
cm. with the help of grader.
 Checking of moisture content and spreading of water if
necessary.
 Compaction of the leveled sub-grade layer.
Compaction is started from edge to centre on straight
section and from inner edge to outer edge on super
elevated section. This process will be followed during
compaction of any pavement layer.

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Quality control
 Conducting Atterberg’s limit and proctor density
tests on sub-grade material for its suitability.
 Checking of camber and grade as desired level.
 Checking of field moisture and field dry density
(95 % minimum).

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Embankment:
Whenever it is required to raise the sub-grade of a
highway above the existing ground level it becomes
necessary to construct embankments. The grade line
may be raised due to any of the following reasons.
 to keep the sub-grade above the high ground
water level
 to prevent damage to pavement due to surface
water and capillary water.
 to maintain the design standards of the highway
with respect to the vertical alignment

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Embankment:
The design elements in highway embankments for
filling are as follows:
i) Height ii) Fill material iii) Settlement iv)
Stability of foundation v) Stability of slopes
Material: - Soil is suitable for embankment filling having
the following properties.
Liquid limit (LL) < 75 % and Plasticity Index (PI) < 40.
Equipment: - Grader; Roller; tipper and water tanker
or manually for small projects.

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Embankment:
Construction steps for embankment filling
i) Laying layer by layer ii) Grading each layer
iii) Each layer is compacted with roller to the desired degree of
density before the next layer is placed.
Quality control
i)Conducting Atterberg’s limit and proctor density tests on filling
material for its suitability.
ii)Fixing of reference pegs to guide the execution team.
iii)Checking of field moisture and dry density of each layer (> 93
% and below 95 % on sub-grade).
iv)Proper finishing of formation slope as per design before
placing turf or bio-engineering.

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Excavation:
In the process of cutting or loosening and removing
earth including rock from its original position,
transporting and dumping it as a fill or spoil bank. Earth
excavation work may be divided as excavation or
cutting, grading and compaction.
The excavation for cutting may be needed in common
soil, soft rock, or even hard rock as per the design of
the vertical alignment. The selection of excavation
equipment and cost analysis is made based on the
stiffness of the materials to be excavated.

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Excavation:
The design elements in highway excavation for cuttings
are as follows:
i) Depth ii) Stability of foundation iii) Stability of
slopes iv) Accommodation of roadside drain
Material:- Soil is suitable for sub-grade preparation in
cutting having the following properties.
Liquid limit (LL) < 75 % and Plasticity Index (PI) < 40.
Equipment: - Excavator, Grader; Roller; tipper, Rock
Driller, and water tanker or manually for small projects.

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Excavation:
Construction steps for excavation or cutting
i) Excavation or cutting ii) Grading of sub-grade layer
iii) Compaction with the roller to the desired degree of density of
the sub-grade layer
Quality control
i)Conducting Atterberg’s limit and proctor density tests on sub-
grade material for its suitability.
ii)Fixing of reference pegs to guide the execution team.
iii)Checking of field moisture and dry density (> 95 %).
iv)Proper finishing of formation slope as per design before placing
turf or bio-engineering.

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Stabilization:
If the stability of the soil is not adequate for supporting wheel
loads the properties are improved by soil stabilization techniques.
Thus the principle of soil stabilized road construction is the
effective utilization of local soil and other suitable stabilizing
agents at a low cost.
It means the improvement of the stability or bearing
power of the soil by the use of controlled compaction,
proportioning, and the addition of a suitable admixture or
stabilizer. It deals with physical, physio-chemical, and
chemical methods to make the stabilized soil serve as a
pavement component material.

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Stabilization:
The basic principle in Soil Stabilization is
 Evaluating the properties of available soil
 Deciding the effective and economical method of stabilization
(depending upon the lacking property in the soil)
 Designing the stabilized soil mix for intended stability and durability
values.
 Adequate compaction of the stabilized soil layer.
After stabilization it may result in any one or more of the following
changes:
 Increase in stability, change in physical properties like density, and
swelling, change in physical character.
 Change in physio-chemical properties.
 Retaining the desired minimum strength by waterproofing.

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Stabilization:
Based on the above properties the various techniques of soil stabilization
may be grouped as follows:
 Proportioning technique - Locally available soils and aggregate
mixed in suitable proportion.
 Cement agents -Adding Portland cement, lime, bituminous
materials.
 Modifying agent -Portland cement, lime for highly clayey soil.
 Water proofing agents -Bituminous materials
 Water repelling agents -Organic compound (Vinsol resin, resinous
materials.
 Water retaining agents -Calcium chloride for non-cohesive soil
 Chemicals-Several chemicals < 0.5 % by weight of soil.

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Types of pavement construction
I Earth roads
II Gravel roads
III WBM roads
IV Soil stabilization roads
IV Bituminous or black top roads
 a. Interface treatments: prime coat, tack coat
 b. Surface dressing and seal coat
 c. Otta- seal
 d. Grouted or penetration type constructions
Penetration macadam
Built- up spray grout
 e. Premix:
Bituminous carpet
Bituminous bond macadam
Bituminous concrete (Asphalt concrete)
Sheet asphalt or rolled asphalt
Mastic asphalt
V Cement concrete roads
-Cement grouted layer
-Rolled concrete layer
-Cement concrete slab

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Construction of Earthen and Gravel
Roads

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Construction of Earth Roads
Introduction:
General- cheapest type of construction depends on the
type of soil available at site
Camber 1 in 20 to 1 in 25 (5% to 4%)
Steep camber helps to keep the pavement surface free
from standing water; otherwise the water would
damage the pavement section by softening it.

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Properties Value
Liquid limit <75%
Plasticity index <40%
Materials:
Earth available could be used but preferable
to have a soil properties as given below.

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 Tools and Equipment:
manually with hand tools or excavation
hauling compaction equipment may also
used for fast construction
Grader; Roller; tipper and water tanker or
manual spraying of water for small projects

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Construction procedure
Construction steps:
1. Soil survey- Beyond right of the way borrow pits,
materials should be free from organic matter. The
trees, shrubs, grass, roots and top soil are removed
before excavating earth for construction.
2. Location- centerline with wooden pegs and reference
pegs are fix
3. Preparation of sub-grade:
 Clearing site
 Grading cuts or fills to the desired grade
 Shaping of sub-grade
 Compaction before placing the pavement materials

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Construction procedures
4. Pavement construction: The borrow soil (more than
one soil type mixed to the desired proportion if
necessary) are dumped on prepared sub-grade
and pulverized. The field moisture content is
checked and additional water mixed if necessary
bring it up to OMC. Soil mixed spread rolled in
layers compacted thickness not more than 10cm.
5. Open Traffic: After few days of setting of compacted
earth. Choice of compaction equipment is based
on type of soil. At least 95% of dry density should
be achieved. Camber and grade are checked and
corrected if necessary

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Construction procedures
Quality control
 Conducting Atterberg’s limit and proctor density tests
on soil for its suitability.
 Checking of camber and grade.
 Checking of field moisture and field dry density (95 %
minimum).

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Construction of Gravel Roads
 Introduction:
It is considered superior to earth roads as they can
carry heavier traffic. Camber 1 in 25 to 1 in 30 (4% to
3.33%).
 Two types of construction methods:
 Feather edge type
 Trench type
Feather edge type
Trench Type

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Construction of gravel road
 Materials: Hard durable and strong varieties of
crushed stone or gravel of specified gradation is
used. Proper gradation is chosen to maintain
maximum density.
Plasticity Index (PI) :- 15 ~ 35 ; CBR > 60 %; FI < 30 %
and Gradation as per the specification usually 40 mm
down
 Tools and Equipment:
Grader; Roller; tipper and water tanker or manual
spraying of water for small projects

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Construction of gravel road:
Preparation: Gravel aggregates to be used for
construction is stacked along the sides of proposed
road
 Wooden pegs for centre line and reference pegs for
carriage way are driven
 Preparation of sub-grade: site clearance, grading -
cut or fill, trench excavation to desired depth and
width, compaction before spreading gravel

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 Pavement construction:
 Gravel aggregates are placed carefully in the trench so to avoid
segregation.
 Aggregates are spread with greater thickness at centre and less
towards the edges so as to obtain the desired camber.
 Compaction with smooth wheel roller or vibratory roller. The layer
is rolled with smooth wheeled rollers starting from edges and
proceeding towards the centre the width of roller in the longitudinal
direction and center to edge in curved elevated section.
 Some quantity of water may also be sprayed and rolling is done.
 The camber is checked and corrected time to time
 Opening to traffic:
 A few days after the final rolling and drying out the road is opened
to the traffic.

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Quality control :
 Conducting Atterber’s limit, gradation, CBR, Flakiness
Index and proctor density of the sub-base material for
its suitability.
 Checking of camber and grade as per specification.
 Checking of the field moisture and dry density (> 98
%).

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Construction of Water Bound Macadam Road
 Introduction: Water bound macadam is known after
the name of John Macadam. The main principle of
this pavement structure is that the crushed or broken
stone aggregates are bound together with stone dust
as filler material in presence of water by the action of
rolling or traffic compaction. Usually thickness of layer
is 8~30 cm and the compaction is done on thickness
8~15 cm as one layer. Normally camber is provided
2.5~3.5 %.

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 Material:- WBM roads can be made of either of the
following:-
 WBM roads with gravel including crushed gravel.
 WBM roads made with Hard broken stones
 WBM roads made with soft broken stones like brick
ballast, mixed with laterites, blast furnace slag etc.
The required materials are coarse aggregate; screening
aggregate and stone dust as filler materials. All the
aggregates should be clean, hard, strong, tough, durable
and free from excess of flaky, elongated, soft, disintegrated
particles and dirt.

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 Aggregate:- The aggregate should have the following
properties;
Properties of aggregate Value
Los Angeles abrasion value 40% Max.
Flakiness index 25% Max.
Plasticity Index for filler material <9%
Grading of filler materials Size Range, mm Screening Size, mm
1 90-40 12.5
2 63-40 10
3 50-25 10

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 Material:- WBM roads can be made of either of the
following:-
 WBM roads with gravel including crushed gravel.
 WBM roads made with Hard broken stones
 WBM roads made with soft broken stones like brick
ballast, mixed with laterites, blast furnace slag etc.
The required materials are coarse aggregate; screening
aggregate and stone dust as filler materials. All the
aggregates should be clean, hard, strong, tough, durable
and free from excess of flaky, elongated, soft, disintegrated
particles and dirt.

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 Equipment: Aggregate spreader; Roller; tipper and water
tanker or manual spraying of water for small projects.
 Construction steps
 Preparation of sub-grade as mentioned earlier.
 Materials required with compaction factor (about 20% extra)
are stacked along the road.
 Arrangement of the lateral confinement.
 Spreading of coarse aggregates with compacted thickness
8~15 cm.
 Compaction with smooth wheel roller or vibratory roller of 6
to 10 tones.

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 Application of screening aggregates and wet rolling to fill about
50% of total voids.
 Application of filler materials (stone dust) with PI value less or
equal to 9 in two thin successive layers.
 Finishing of the surface with 6 cm thick sand or earth sprinkling
with water and rolled.
 Making of shoulders and open to traffic after few days of
completion.
Quality control
 Conducting Atterber’s limit of filler material, gradation of aggregates,
Flakiness Index, Los Angele’s abrasion,
 CBR Value of aggregates for its suitability.
 Checking of camber and grade as per specification.

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Preparation of sub-base course
 Introduction: Construction of the sub-base course includes the
necessary activities conducted just before the placement of the base
layer and compacted over it bringing the vertical profile of the sub-base
course to the designed grade and shape. It is essential to compact the
top level of the sub-base adequately to the desired dry density before
the placement of the base course.
 Material: The material for the sub-base should be of clean, hard, strong,
tough, durable gravel or crushed stones. River bed material or soil mixed
quarry gravel or crusher run material is equally suitable for sub-base
having the following properties.
Liquid limit (LL) < 25 %; Plasticity Index (PI) < 6 %; CBR > 30 %; FI < 30
% and Gradation as per the specification usually 63 mm down.
 Equipment: Grader; Roller; tipper and water tanker or manual spraying
of water for small projects.

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Construction steps:
 Preparation of sub-grade and correct if necessary
 Transportation and dumping of approved sub-base material on
the approved sub-grade.
 Mixing of sub-base material at the site with the help of grader
spreading of water if necessary.
 Spreading to the required thickness considering compaction
factor and leveling of the sub-base material to the designed grade
and shape.
necessary.
 Compaction of the perfectly spread sub-base layer adequately.

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Quality control:
 Conducting Atterber’s limit, gradation, CBR, FI, and proctor
density of the sub-base material for its suitability.
 Checking of camber and grade as per design and
specification.
 Checking of field moisture and dry density (> 95 ~ 98 %

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Spreading of sub-base course
material
Mixing, Spreading and laying
of sub-base course material
Watering and Spreading of
sub-base course material
Spreading and leveling of sub-
base course
Watering and rolling by
vibratory roller
Quality monitoring for level

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Preparation of base course
 Introduction: Construction of base course includes the necessary
activities conducted just before the placement of the prime/tack coat or
wearing course and compacted over it bringing the vertical profile of the
base course to designed grade and shape. It is most essential to
compact the top level of base course adequately to the desired dry
density before the placement of the oncoming layer.
 Material: The material for base should be of hard, strong, durable
crushed stones. The crushed stone should be crushed either from
boulders or quarry stones with the following properties.
Plasticity Index (PI) – NP; CBR > 80 %; FI < 30 %; LAA < 40 % and
Gradation as per the specification.
 Equipment: Grader; Roller; tipper and water tanker or manual spraying
of water for small projects.

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Construction steps:
 Preparation of sub-base and correct if necessary
 Transportation and dumping of approved crushed stone base
material on the approved sub-base.
 Mixing of base material at site with the help of grader
spreading of water if necessary.
 Spreading to the required thickness considering compaction
factor and leveling of the crushed stone base material to the
designed grade and shape.
necessary.
 Compaction of the perfectly spread base layer.

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Quality control:
 Conducting Atterber’s limit, gradation, CBR, FI, LAA, and
proctor density of the base material for its suitability.
 Checking of camber and grade as per design and
specification.
 Checking of field moisture and dry density (> 98 %

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Dumping of base course material Mixing of base material by
grader
Watering of base course
material by tanker
Checking for leveling of base
course
Checking final level by
survey equipment
Watering and rolling of base
course

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Prime coat/Tack coat/Seal coat
 Introduction: A prime coat is applied on the relatively
pervious layer for example on a crushed stone base (CSB)
whereas a tack coat is applied on the relatively impervious
layer for example on the existing bituminous layer with low
viscosity cutback. The seal coat is applied at the final
finished surface of the pavement. The main function of the
prime coat/tack coat is to seal the pores; waterproof the
underlying layer to develop interface conditions for bonding.
 Material: The material for Prime coat/tack coat is either MC
30 or MC 70 cutback or bitumen emulsion. Straight run
bitumen can be used for tack coat where quick binding
action is required.

64
Construction steps:
 Preparation and intensive brooming /cleaning of the
underlying layer (on crushed stone base or existing
bituminous surface) to bring mosaic surface for better
penetration of spread cutback.
 Spreading of cutback on the approved underlying
layer as per the specified rate of application.
 Curing until the surface is dried.
 Opening the traffic.

65
Quality control:
 Testing of the cutback material for its suitability.
 Checking of cutback temperature before application.
 Checking the rate of the application of the cut back by
the tray and deep test.

66
Checking the finished base
course
Intensive primary broom with
hard and soft brushes and
removal of dust
Follow up broom and cleaning
before air compressor for the
application
Cleaning by air compressor
before the application of coat
Preparation of site just before
the application of prime coat
Application of prime coat by
using bitumen distributor

67
Surface Dressing
 Introduction: Surface dressing is one of the most common
and cost-effective techniques used in wearing course. The
main function of the surface dressing are;
 To provide a dust-free surface over a base course
 To provide a water proof layer to prevent infiltration of surface
water and
 To protect the base course
 There are three types of surface
dressing works that are Single
Bituminous Surface Dressing (SBSD),
Double Bituminous Surface Dressing
(DBSD) and Triple Bituminous Surface
Dressing (TBSD).

68
Surface Dressing
Materials:
 Bitumen :- Normally 80/100 grade Straight run bitumen
 Aggregate :- Clean, strong, hard and durable with
following properties:
Los Angeles abrasion value (LAA) 35% Max.
Aggregate Crushing Value (ACV) 30% Max.
Flakiness Index (FI) 25% Max.
Water absorption 1% Max.
Stripping value 25% Max.

69
Surface Dressing
Equipment's:
 Storage Tank with Bitumen Heating Device
 Mechanical Broom or Hand Brushes
 Air Compressor
 Bitumen Distributor
 Aggregate or Stone Chip Spreader
 Pneumatic Roller

70
Surface Dressing
Construction steps:
 Preparation and cleaning of the existing surface by
mechanical broom or hand brushes and air compressor
 Spreading of binder as per the specified rate of application
 Spreading of stone chipping as per the specified rate of
application
 Rolling with the help of a pneumatic roller of first or final
coat at least four passes (SBSD)
 Opening to traffic with a controlled lower speed (< 10
Kmph) for one or two weeks
 Broom and clean the loose chips

71
Surface Dressing
 Application of binder and stone chipping as per the specified rate of
application for the second coat
 Rolling with the help of a pneumatic roller of second or final coat at
least four passes (DBSD)
 Opening to traffic with a controlled lower speed (< 10 Kmph) for
one or two weeks
 Broom and clean the loose chips
 Application of binder and the stone chipping as per the specified
rate of application for the third coat
 Rolling with the help of a pneumatic roller of third or final coat at
least four passes (TBSD)
 Opening to traffic with controlled lower speed (< 10 Kmph) for one
or two weeks

72
Surface Dressing
Quality control:
 Checking the conditions of the equipment
 Checking the temperature of the binder
 Checking of dust content in stone chipping
 Tests conduction on binder at least penetration, viscosity and
ductility or availability of laboratory facility at site
 Conduction of tests on stone chipping at least Gradation, LAA,
ACV or AIV, FI, WA, Stripping Value or availability of
laboratory facilities
 Checking of rate of application of binder and stone chipping by
placing rectangular tray during spreading.

73
Surface Dressing
Precautions:
 Equipment condition should be in perfect running condition
before starting
 Excellent coordination between the labors, equipment and
supervisor should be maintained perfectly
 Never attempt to start the work when the ambient
temperature is below 16 0 C
 Back up filling of chips at missing space manually.
 Back up rolling by pneumatic roller. It is better to roll when
road surface attain high temperature.
 More rolling at curves and shaded areas.

74
Surface Dressing
Stuck of aggregate for surface
dressing in crusher plant
Bulk bitumen delivery at
construction site
Pouring of bitumen into the
storage tank at site
Washing of stone chipping
before transporting at site
Intensive brooming to clean
the existing surface
Use of air compressor to
remove dust

75
Surface Dressing
Heating of bitumen at required
temperature to spray at site
Spreading of chips Bitumen and chip spreader are
in ready position
Spraying of bitumen at
construction site
Application of chips over
bitumen
Rolling after spraying of chips
by pneumatic roller

76
Surface Dressing
Adequate arrangement of
different equipment's
Adequate spacing between
spreader and roller
Covering the laid bitumen by
chips
Back rolling by pneumatic roller
at specified temperature
Manual spraying of chips at
uncovered area
Escorting traffic to control the
speed to safeguard the surface

77
Otta Seal
 Introduction: Otta seal is the bituminous surfacing consisting of
graded aggregates ranging from natural gravel to crushed rock in
combination with relatively soft (low viscosity) binders, with or
without a sand cover seal.
 There are various types of Otta seal in terms of the number of
layers, type of aggregate grading and with or without sand cover
seal those are Single Otta Seal with or without sand cover seal with
aggregate grading “open”, “medium” or “dense” and Double Otta
Seal with or without sand cover seal with aggregate grading “open”,
“medium” and “dense”.

78
Otta Seal
Materials:
 Bitumen :- MC 3000 or MC 800 cut back
 Aggregate :- Clean, strong, hard and durable with following properties:
Aggregate Impact Value (ACV) 30% Max.
Plasticity Index <5% Preferable NP
Gradation as per the specification either open, medium or dense
Coarse sand:- Clean, hard and durable, Gradation all passes from 6.7 mm
with the following properties
Plasticity Index NP

79
Otta Seal
Equipment's:
 Air Compressor
 Aggregate Spreader
 Pneumatic Rollers

80
Otta Seal
Construction steps:
 Preparation and intensive cleaning of the existing surface by mechanical
broom or hand brushes and air compressor.
 Application of the prime coat at a specified rate if necessary in design.
 Spreading of binder as per the specified rate of application
 Spreading of the aggregate of specified grading as per the specified rate
of application
 Rolling by two pneumatic rollers at a minimum weight of 12 tons or more
on the day of construction.
 A minimum of 15 passes with a pneumatic roller is required over the
entire surface area.
 After the initial rolling is completed (on the day of construction) it is
advantageous to apply one pass with 10~12 tones static steel roller to
improve the embedment of the larger aggregate.

81
Otta Seal
 During the first two days after sealing, extensive rolling shall be
applied by a pneumatic roller to ensure all particles embedded in the
binder are properly coated. Daily a minimum of 15 passes with a
pneumatic roller shall be applied covering the entire surfaced area.
 Aggregates dislodged by traffic during the immediate post-
construction period shall be broom back into the wheel tracks during
the first 2~ 3 weeks, so that the aggregate particles are embedded
into the binder.
 Spreading of binder as per the specified rate of application.
 Spreading of sand as per the specified rate of application.
 Rolling with a pneumatic roller and curing the surface for four weeks.
 After 8~12 weeks second coat is executed following the above-
mentioned construction steps.

82
Otta Seal
Quality control:
 Checking the conditions of the equipment’s
 Conducting of tests on binder at least penetration, viscosity,
and ductility or availability of lab. facility at site
 Conducting tests on aggregates at least Gradation, LAA,
ACV or AIV, FI, PI or as availability of laboratory facilities.
 Checking of the rate of application of binder and aggregates
by placing a rectangular tray during spreading.

83
Otta Seal
Precautions:
before starting
 Broom dislodged aggregates into the wheel tracks to embed
in the layer.
 Caring immediate post construction, traffic management,
follow-up inspection etc.

84
Otta Seal
Spraying of MC 3000 bitumen
using distribute
Application of aggregate to
cover sprayed bitumen
Rolling by a pneumatic roller
after application of aggregate
Backup rolling by a pneumatic
roller
Finished surface of Otta seal Otta seal surface after
application of traffic

85
Grouted or Penetration Macadam
 Introduction: Depending upon the quantity of bitumen
spread penetration macadam is classified as full
grout when the bitumen penetrates to the full depth
and semi grout when bitumen penetrates up to about
half the depth. Full grout is adopted in regions of
heavy rainfall whereas semi grout on average rainfall
and traffic. The usual thickness of the layer is 7.5 cm
for full grout and 5 cm for semi grout.

86
Materials:
 Bitumen :- 80/100 grade Straight run bitumen
Stripping Value 25% Max.
Gradation of aggregates is chosen depending upon the thickness
of the layer. The maximum size of coarse aggregate and key
aggregate for 7.5 cm thick is 63 mm down and 25 mm down
respectively and for 5 cm thick 50 mm down and 20 mm down
respectively

87
Equipment's:
 Air Compressor
 Aggregate spreader.
 Pneumatic Roller/smooth wheel roller

88
Construction steps:
 Preparation and intensive cleaning of the existing surface by broom
and air compressor.
 Spreading of coarse aggregate as per the specified rate of
application.
 Dry rolling of the spread coarse aggregate at least with 10 ton
roller.
 Spreading of bitumen as per the specified rate of application.
 Spreading of key aggregate as per specified rate of application.
 Rolling of key aggregate at least with 10 ton roller.
 Application of seal coat before opening to traffic.
 Opening to traffic for smooth traffic movement.

89
Quality control:
 Tests conduction on binder at least penetration, viscosity, and
ductility or availability of laboratory facility at the site
 Conduction of tests on stone chipping at least Gradation, LAA,
AIV, FI, Stripping Value or availability of laboratory facilities
 Checking the rate of application of binder and stone chipping
by placing a rectangular tray during the spreading of binder
and stone chipping.

90
Precautions:
before starting

91
Spreading of coarse aggregate Rolling of aggregate Spraying of bitumen
Manual spreading of key
aggregate
Rolling of key aggregate Aggregate before seal
coating

92
Premix carpet
 Introduction: The bituminous carpet is a premix prepared from stone
chipping of 10 mm (passing 12 mm and retained on 6mm) to 12 mm
(passing 20 mm and retained on 12 mm) sizes, coarse sand above 6mm
size, and the bitumen binder. The thickness of such carpets varies from
2 or 2.5 cm.
Materials:

93
Premix carpet
Equipment's:
 Air Compressor
 Hot mix plant or manual mixing (for small area
coverage)
 Mechanical paver or manual

94
Premix carpet
Construction steps:
 Preparation and intensive cleaning of the existing surface by
broom and air compressor.
 Application of prime coat/tack coat.
 Production of the hot mix either in the hot mix plant or manual
mixing on trays.
 Spreading of mix with the help of mechanical paver or
manually.
 Rolling of laid mix with 10-ton roller.

95
Premix Carpet
Quality control:
 Tests conduction on binder at least penetration, viscosity, and
ductility or availability of laboratory facility at the site
 Conduction of tests on aggregates at least Gradation, LAA,
Precautions:
before starting

96
Premix carpet
Tack coating on finished prime
coated surface
Manually spreading of premix Rolling the premix by three
wheel roller

97
Bituminous Bound Macadam
 Introduction: The bituminous bound macadam is the premix which is
laid in the finished thickness of 5 or 7.5 cm, the size of the aggregate
depends on the thickness of the layer and the maximum size is limited to
37 mm in 7.5 mm thick premix. The layer of this type the pavement is
open graded premix and used as a base course. If laid as a surface
course at least a seal coat is necessary.
Materials:

98
Equipment's:
 Air Compressor
 Hot mix plant or manual mixing (for small area
coverage)
 Mechanical paver or manual

99
Construction steps:
 Preparation and intensive cleaning of the existing surface by
broom and air compressor.
 Application of prime coat/tack coat.
 Production of the hot mix either in the hot mix plant or manual
mixing on trays.
 Spreading of mix with the help of mechanical paver or
manually.
 Rolling of laid mix with 10-ton roller.

100
Quality control:
 Tests conduction on binder at least penetration, viscosity,
and ductility or availability of laboratory facility at the site

101
Precautions:
before starting

102
Tack coating on finished prime
coated surface
Manually spreading of premix Rolling the premix by three
wheel roller

103
Bituminous concrete (Asphalt Concrete)
 Introduction: It is the dense-graded premixed bituminous mixture
consisting of a carefully proportioned mixture of dry coarse aggregate,
fine aggregate, mineral filler, and bitumen. When properly designed with
an appropriate proportion of ingredients, it will provide a surfacing of
exceptionally durable and capable of carrying the heaviest traffic. It is the
highest quality of construction among the group of blacktop pavements.
 Materials:
Los Angeles abrasion value (LAA) 30% (for wearing) 35 % (for binder) (Max)

104
 Fine aggregate: - Fine aggregate should be free from clay, silt,
organic, and other deleterious matters and shall be non-plastic. It
shall consist of entirely crushed rock produced from stone having a
Los Angeles Abrasion of not more than 30. The sand equivalent of
the fine aggregate shall be not less than 60 and sodium sulfate
soundness, not more than 12. The grading requirements of the
combined mixture of coarse and fine aggregates should be as per
the specification.
 Mineral Filler: - Mineral filler shall consist of finely ground particles
of limestone, hydrated lime, ordinary Portland cement, or other
non–plastic mineral material. It shall be thoroughly dry and free
from lumps. At least 75 % (by weight) shall pass a 0.075 mm sieve
and 100 % shall pass a 0.425 mm sieve. The grading requirements
of mineral filler should be as per the specification.

105
Equipment's:
 Hand tools like shovel, wheelbarrow, etc.
 Air Compressor
 Tippers
 Hot mix plant
 Mechanical paver
 Edge cutter and core cutter machines

106
Construction steps:
 Intensive cleaning of underlying layer by labors with the help of
mechanical broom or hand brushes before asphalt concrete
laying activities.
 Cleaning of underlying layer by air compressor before the
commencement of asphalt concrete laying activities.
 Preparation of necessary equipment at laying site such as
bitumen distributor, mechanical paver, smooth wheel roller,
pneumatic roller, and laying team in the ready position to
receive the asphalt concrete mix and start spreading.
 Transportation of the AC mix with the help of a tipper. The mix
is covered for the preservation of temperature and
contamination.

107
 Application of tack coat before laying asphalt concrete mix.
 Delivery of AC mix on the hopper of the mechanical paver to
start asphalt concrete laying.
 Checking the temperature of the mix before delivering, during
laying, and before compaction. The temperature difference
should not be greater than 10 0C in each activity.
 During the laying of the asphalt concrete mix, good
coordination between the equipment and labours is very
important and shall be maintained.
 Checking the loose thickness manually.
 Follow-up level corrections by skilled labors.

108
 Finishing the asphalt concrete layer before compaction by skilled and
unskilled labor team for the level corrections at joints while laying on
next lane.
 Initial compaction of the asphalt concrete layer by smooth wheel roller.
 Follow up compaction by pneumatic roller. The rolling shall be continued
until the voids measured in the completed layer are within the
appropriate range.
 The average density after compaction shall not be less than 98 %. No
individual density shall be below 95 % of the average of the laboratory
specimens
 Cutting the edge of previously laid mix with edge cutter for laying mix on
next lane. The edge cut should be perfectly vertical.
 A core sample of the previously laid mix is taken out with the help of a
core cutter for further necessary laboratory tests.

109
Quality control:
 Checking the temperature of the binder and AC mix
 Conduction of tests on binder at least penetration, viscosity,
and ductility or availability of laboratory facility at the site
ACV, FI, and Stripping Value.
 Conduction of tests on AC mixes such as binder extraction,
gradation of the aggregate after extraction, density, Marshall
Stability, Marshall Flow, core analysis, and voids.

110
Precautions:
 Arrangement of material, tools, and equipment properly.
 Proper arrangement of skilled labor, unskilled labor, and operators during
laying.
 Proper joint cutting, and tack coating on both longitudinal and transverse
joints.
 Proper preparation of the site and intensive cleaning of the underlying layer
before laying of AC courses.
 Choose short routes and cover the mix for temperature preservation during
transportation.
 Controlling and monitoring the production temperature, laying temperature,
and compaction temperature.
 Proper coordination and communication between the laying site and asphalt
concrete plant location.
 Surface finishing with trained skilled labour.

111
Arrangement of asphalt concrete
plant at site
Cleaning of existing surface
before AC laying
Dust blowing by air compressor
Mechanical paver arrangement Transportation of Premix AC
(cover should be arranged)
Application of tack coat

112
Parallel delivery and laying of AC mix Checking loose thickness
manually
Finishing the AC layer before
compaction by skilled manpower
Initial compaction by vibratory
roller and pneumatic roller is
ready for follow-up compaction
Initial Compaction by smooth
wheel roller
Cutting the edge of previously
laid mix with edge cutter

113
Edge cutting-perfect vertical edge
cutting
Core sample collection for the
laboratory test

114
Cement concrete Pavement
 Introduction: Construction of cement concrete pavement consists
of the construction of the pavement itself and the design/placement of
joints. In general cement, pavement construction can be executed
either of the following methods:-
 Cement grouted layer: - On open-graded compacted aggregate (18 to
25 mm) cement sand slurry mix of (1:1.5 to 1:2.5) is spread over the
compacted aggregate to fill up the voids between the aggregates.
 Rolled concrete layer: - Hard concrete is prepared with an appropriate
ratio of aggregate, sand, cement, and least water for less plasticity
and is spread over the sub-grade to the required thickness of the layer
and then directly compacted by the roller.
 Cement concrete slabs: - Concrete slabs are constructed usually by
alternate bay method or continuous bay method depending upon the
traffic to be carried out on the constructed part or not.

115
Cement concrete pavement
 Materials:
 Cement :- Ordinary Portland Cement (OPC)
 Coarse Aggregate :- Clean, strong, hard and durable with following
properties:
 Fine aggregate:-Free from deleterious material either natural or crushed
sand.
Aggregate Crushing Value (ACV) <30%
Aggregate Impact Value (AIV) <30%
Los Angeles Abrasion Value (LAA) <35%
Soundness value < 12% in Na2So4 and < 16% in MgSo4

116
Equipment's:
 Concrete mixture
 Batching device
 Wheel barrow
 Needle vibrators
 Float
 straight edge
 Belt
 Brushes
 Edging tools
 concrete pavers

117
Construction steps:
 Preparation of sub-grade or sub-base
 Placing of forms and binding of reinforcement
 Batching of ingredient materials and mixing
 Transportation and placing of concrete
 Compaction and finishing
 Curing of cement concrete

118
Cement Concrete
Quality control:
 Making of concrete cubes for strength test.
 Proper curing covering with jute bags.

119
Cement Concrete
Precautions:
 Proper mixing and check for slump value of the concrete
 Proper form work to resist the imposed load
 Proper curing to attain full strength of the concrete

120
Cement Concrete
Laying of CC in the proposed site Leveling of CC after compaction
Dowel bar placement in CC
Pavement
Compaction by needle vibrator
THANK YOU VERY MUCH

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