2. CONTENT
1. BLACK TOP
•1.1 INTODUCTION
•1.2 CONSTRUCTION TECHNIQUES OF BITUMINOUS CONSTRUCTION
2. CONCRETE PAVEMENT
•2.1 INTRODUCTION
•2.2 CONSTRUCTION STEPS FOR CEMENT CONCRETE PAVEMENT SLAB
3. EQUIPMENTS USED FOR ROAD CONSTRUCTION
•3.1 INTRODUCTION
•3.2 EQUIPMENTS
4. HILLY ROAD
•4.1 INTRODUCTION
•4.2 FEATURES OF HILLY ROAD
4. 1.1 Introduction
The black top construction is in extensive use in developing nations like
India, where the cement as a construction material is in great demand
for large number of other engineering projects. Depending on traffic
demands , stage development is also possible in the case of bituminous
roads. Bituminous pavements are in common use in India and abroad.
It is possible to construct relatively thin bituminous pavement layers
over an existing pavement. Therefore, these are commonly adopted as
wearing course. Flexible pavement could be strengthened in stages by
constructing bituminous pavement layers one after another in a certain
period of time unlike the cement concrete pavement construction.
5. 1.2 Construction Techniques Of Bituminous Construction
The following construction techniques are in use:-
Interface treatments like prime coat and tack
coat.
Surface dressing and
Seal coat.
6. Interface treatment
Surface of the existing pavement layer is to be
cleaned to remove dust and dirt and a thin
layer of bituminous binder is to be sprayed
before the construction of any type of
bituminous layer over this surface. This
treatment with bituminous material is called
interface treatment which is necessary to
provide the necessary bond between the old
and the new layers. The interface treatment
may either be a prime coat or tack coat and
in some cases, the prime coat followed by a
tack coat.
7. PRIME COAT
Bituminous prime coat is the first application of
a low viscosity liquid bituminous material over
an existing porous or absorbent pavement
surface like the WBM base course. The main
object of priming is to plug in the capillary
voids of the porous surface and to bond the loose
mineral particles on the existing surface, using
a binder of low viscosity which can penetrate
into the voids. The bituminous primer is
sprayed uniformly using a mechanical sprayer
at a rate of 7.3 to 14.6 kg/m2 area, depending on
the porosity of the surface. The primed surface is
allowed to cure for at least 24 hours, during
which period no traffic is allowed.
8. TACK COAT
Bituminous tack coat is the application of
bituminous material over an existing
pavement surface which is relatively
impervious like an existing bituminous
surface or a cement concrete pavement or a
pervious surface like WBM which has
already been treated by a prime coat. Tack
coat is usually applied by spraying
bituminous material of higher viscosity like
the hot bitumen at the rate of 4.9 to 9.8
kg/m2 area depending in the type of the
surface.
9. BITUMINOUS SURFACE DRESSING
Bituminous Surfacing Dressing (BSD) is provided over an existing pavement to serve as thin
wearing coat. The single coat surface dressing consists of a single application of bituminous
binder material followed by spreading of aggregate cover and rolling. The principal of this
method is illustrated in fig:
When the surface dressing is similarly done in two layers, it is called ‘two coat bituminous
surface dressing’. Where better adhesion is required, aggregates pre-coated with bituminous
binder are used instead of conventional surface dressing and this technique is called
‘Bituminous Surface Dressing with Pre-coated Aggregates’. The main functions of BSD
are:-
• To serve as a thin wearing course of pavement and to protect the base course.
• To water proof the pavement surface and to prevent infiltration of surface water.
• To provide dust-free pavement surface in dry weather and mud-free pavement in wet
weather.
10. SEAL COAT
The seal coat is a very thin surface treatment or a single coat surface
dressing which is usually applied over an existing black top surface. A
premixed sand bitumen (hot mix) seal coat is also commonly used over
the premixed carpet .Seal coat is usually recommended as a top coat
over certain bituminous pavements which are not impervious, such as
open graded bituminous constructions like premixed carpet and
grouted macadam. Seal coat is also provided over an existing
bituminous pavement which is worn out. The main functions of seal
coat are:
To seal the surfacing against the penetration of water.
To develop skid resistance texture.
To enliven an existing dry or weathered bituminous surface.
12. INTRODUCTION
The cement concrete pavement maintains a very high recognition
among the engineer and the road users alike. Due to the excellent
riding surface and pleasing appearance, the cement concrete roads
are very much preferred. It is also a matter of fact that the life of
cement concrete road is much more than any other type of
construction. This is why the engineers have inherent confidence in
the use of cement concrete for any kind of construction project.
13. Construction procedure of concrete slab
Preparation of subgrade and sub-base:
The subgrade or sub-base for laying of the concrete slabs
should comply with the following-
that no soft spots are present in the subgrade or sub-base.
that the uniformly compacted subgrade or sub-base
extends at least 30cm on either side of the width to be
connected.
that the subgrade is properly drained.
that the minimum modules of subgrade reaction obtained
with a plate bearing test is 5.54 kg/cm2.
14. Placing of forms:
The steel or wooden forms are used for this purpose . The steel
forms are of M.S. channel section and their depth is equal to the
thickness of the pavement. When set to grade , the maximum deviation
of the top surface of any section from a straight line is not exceeded by
3mm.
wooden forms are dressed on side ; these have minimum base
width of thickness of 10 cm for slab thickness of 20 cm and minimum
base width of 15 cm for slabs over 20 cm thick. They should not deviate
more than 3 mm froma straight edge of 3 m in length.
15. Batching andmixing :
After determining the proportion of ingredients for the field mix, the fine
aggregates and coarse aggregates are proportioned by weight in a weight-batching
plant and placed into the hopper along with the necessary quantity of cement .
The mixing of concrete is done in a batch mixer which will ensure a
uniform distribution of the materials throughout the mass, so that the mix is
uniformin color and is homogenous.
The batch of cement, fine aggregate and coarse aggregate is led together
into the mixer. The water for mixing in introduced into the drum within the first 15
seconds of mixing. The mixing of each batch is commenced within 1 and ½ minute
after all the materials are placed in the mixer.
16. Transporting and placing of concrete:
The cement concrete is mixed in
quantities required for immediate use and is
deposited on the soil sub grade or sub-base to the
required depth and width of the pavement
section within the form work in continuous
operation. Care is taken to see that no
segregation of materials results while the
concrete is being transported from the mixer to
its placement. The spreading is done uniformly.
17. Compaction and finishing: The surface of pavement is
compacted either by means of a power-driven finishing
machine or by a vibrating hand screed. For areas where
the width of the slab is very small as at the corner of
road junctions, etc., hand consolidation and finishing
may be adopted.
Concrete as soon as placed, is struck off uniformly
and screened to the crown and cross-section of the
pavement to conformthe grade.
The tamper is placed on the side forms and is
drawn ahead in combination with a series of lifts
and drops to compact the concrete.
18. CURING OF CEMENT CONCRETE
The entire pavement surface of the newly laid cement concrete is cured in accordance with the
following methods:
INITIAL CURING: The surface of the pavement is entirely covered with burlap ,cotton or jute
mates .prior or being placed, the mates thoroughly saturated with water and are placed with the
wet side down to remain in intimate contact with the surface.
FINAL CURING : The final curing is done with any one of the following methods:
Curing with wet soil exposed edges of the slab are banked with a soil berm. A blanket of sandy
soil free from stones is placed .The soil is thoroughly kept saturated with water for 14 days.
IMPERVIOUS MEMBRAME METHOD: Use of an impervious membrane which does not impart
a slippery surface to the payment is used. Liquid is applied under pressure with a spray nozzle to
cover the entire surface with a uniform film. It hardens with 30 minutes after its application. The
liquid is applied immediately after the surface finishing.
20. The Crawler Tractor
A construction vehicle that moves on
tracks instead of wheels. The tracks
spread the vehicle’s weight over a larger
surface area, enabling the tractor to exert
a lower force per unit area on the ground.
This allows the tractor to safely traverse
over moister ground.. When a dozer blade
is attached to the front of the crawler
tractor it is commonly known as a
"bulldozer". With a loader attachment, it
becomes a crawler loader.
21. The Hydraulic Excavator
The hydraulic excavator is most commonly used
for digging rocks and soil, but with its many
attachments it can also be used for cutting steel,
The hydraulic excavator are used for
breaking concrete, drilling holes in the earth,
laying gravel onto the road prior
to paving, crushing rocks, steel, and concrete, and
even mowing landscapes. Hydraulic excavators
have an operating weight of 20,000 pounds (9,072
kg) or higher.
22. Motor Scraper
Motor scrapers, also known as self-propelled
scrapers, are large motorized
machines used for digging, hauling and
leveling out materials in a variety
of construction jobs. Running on
massive rubber tires, these machines
quickly move large quantities of earth
around a construction site.
23. The Wheel Loader
The wheel loader, also known as a front end
loader or bucket loader, is one of the most
widely used machines in construction today
and is noted for its extreme versatility and
payload capacity to perform multiple tasks
at a low cost. Wheel loaders are primarily
used in construction applications such as
material handling, digging, load-and-carry,
road building, and site preparation.
Some models even come in waste handling
versions.
24. The Motor Grader
A motor grader, known as patrol, or maintainer, is a
piece of heavy machinery used to create a smooth,
wide, flat surface. Traditionally, the grader is used
for road maintenance its main function is to flatten
surfaces before the application of asphalt. Presently,
these machines are also commonly used for fine
grading, spreading, and earthmoving. They can be
used for clearing debris and brush, as well as for
snow removal. A variety of attachments convert the
motor grader into a more versatile machine,
enabling the machine to do things such as dig
shallow holes.
25. The Rollers
Rollers are used to compact loose
foundation, such as soil ,
gravel, asphalt,
and bituminous materials and are
primarily used
for construction or agriculture appl
ications. The rolling process ensures
that foundations are compacted
thoroughly so the materials are
solid and do not come loose.
26. The Compactors
Compactors are machines frequently used
to compact materials such as soil in order to
increase its density for construction. In
addition, compactors are utilized in landfill
tasks. Common varieties are plate tampers
(also known as rammers), vibratory plates,
compactors (also known as tamping foot
rollers), and vibratory pad foot compactors.
27. Asphalt Road Paver
A paver is an engineering vehicle
used to lay asphalt on roadways. It is
normally fed by a dump truck. A
separate machine, a roller, is then
used to press the hot asphalt mix,
resulting a smooth, even surface.
The sub-base being prepared by use
of a grader to trim crushed stone to
profile after rolling
29. 4.1 Introduction
Hilly regions have steep topography, difficult and
hazardous terrain, high altitude areas and extreme
climatic conditions. Planning, alignment, design,
construction and maintenance of roads in hilly terrain
are quite different and pose difficult problems in
comparison to those for roads in plain terrain. Roads
passing through such hilly terrain and leading to
towns and villages located on hills are called ‘hill
roads’.
30. 4.2 Features of hilly roads
As far as possible the hill road should be aligned along the
stable side of the hill slope in order to prevent future land-slides
and related problems after the construction of the hill road.
In order to limit the gradient, the length of the hill road is
increased by planning zigzag alignment of the road.
An effective surface and sub-surface drainage system is to be
planned, designed and constructed in order to keep the road
stretches safe without getting washed out during heavy rains.
Also a large number of cross drainage structures such as
culverts and bridges are required to enable the streams and
rivers to cross the road, without causing damages to the hill
road.
31. Prepared and presented by-
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KENEDDY NARZARY(CIT/11/CT/013)
RAJU BRAMHA (CIT/12/CT/020)
PURNA ABHILASH MALLICK
(CIT/12/CT/003)
MURARI KUMAR (CIT/12/CT/013)
ROSEY BARO (CIT/12/CT/017)
JEWMA DAIMARY (CIT/12/CT/024)
BLACK TOP
CONCRETE
PAVEMENT
EQUIPMENTS USED FOR
ROAD CONSTRUCTION
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SHIVAM CHOUDHARY (CIT/12/CT/ET/029)
DEBRAJ DAS (CIT/12/CT/010)
HILLY ROADS