PWD, national highway
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About This Presentation
made by-
shivam srivastava (+918923701449)
Slide Content
A Project Report on
ROAD CONSTRUCTION
Public Work Department
National Highway - 330
(Sultanpur)
04
th
June- 03
th
July 2015
Submitted By: Submitted to:
Devnath Prem Chandra Verma
B.Tech 4
th
Year (CE) Faculty
RKGEC, Ghaziabad RKGEC, Civil Department
Ghaziabad
PUBLIC WORKS
DEPARTMET
PROJECT REPORT
DEVNATH | B-TECH 4
th
YEAR
2015
ROAD CONSTRUCTION
Public Work Department
National Highway - 330
(Sultanpur)
04
th
June- 03
th
July 2015
Submitted By: Submitted to:
Devnath Prem Chandra Verma
B.Tech 4
th
Year (CE) Faculty
RKGEC, Ghaziabad RKGEC, Civil Department
Ghaziabad
PUBLIC WORKS
DEPARTMET
PROJECT REPORT
DEVNATH | B-TECH 4
th
YEAR
2015
Certificate
This is to certify that the report entitled “ROAD CONSTRUCTION (
National Highway - 330)” compiled by Mr. Devnath, under my supervision.
Mr. Prem Chandra Verma
(Faculty)
RKGEC, Civil Department
Ghaziabad
This is to certify that the report entitled “ROAD CONSTRUCTION (
National Highway - 330)” compiled by Mr. Devnath, under my supervision.
Mr. Prem Chandra Verma
(Faculty)
RKGEC, Civil Department
Ghaziabad
Acknowledgements
I express my sincere gratitude to Mr. Prem Chandra Verma, Project
guide of my project work who took been interested on my project
work and guided me all along till the completion of my project work.
The success and final outcome of this project required a lot of
guidance and assistance from many people of the bridge workshop
and I am extremely fortunate to have got all this all along the
completion of this project work.
I am also greatly inbeated his, for his valuable suggestion in the
preparation of the paper.
Whatever I have done is only due to such guidance and assistance and
I would not forget to thank them.
Finaly, I greatful acknowledge my family member and my friends for
their love, support and constant encouragement during the study.
Devnath
B.Tech 4
th
Year (CE)
1230900021
I express my sincere gratitude to Mr. Prem Chandra Verma, Project
guide of my project work who took been interested on my project
work and guided me all along till the completion of my project work.
The success and final outcome of this project required a lot of
guidance and assistance from many people of the bridge workshop
and I am extremely fortunate to have got all this all along the
completion of this project work.
I am also greatly inbeated his, for his valuable suggestion in the
preparation of the paper.
Whatever I have done is only due to such guidance and assistance and
I would not forget to thank them.
Finaly, I greatful acknowledge my family member and my friends for
their love, support and constant encouragement during the study.
Devnath
B.Tech 4
th
Year (CE)
1230900021
PUBLIC WORKS DEPARTMENT: AN OVERVIEW
Public Works Department (PWD), under the Ministry of Public Works
department, is the pioneer in construction arena of Uttar Pradesh. Over about
four centuries, PWD could successfully set the trend and standard in the state`s
infrastructure development. It plays a pivotal role in the implementation of
government construction projects. It also undertakes projects for autonomous
bodies as deposit works.
Public works Department has highly qualified and
experienced professionals forming a multi-disciplinary team of civil, electrical
and mechanical engineers who work alongside architects from the Department
of Architecture. With its strong base of standards and professionalism
developed over the years, PWD is the repository of expertise and hence the first
choices among discerning clients for any type of construction project in Uttar
Pradesh. Besides being the construction agency of the Government, it performs
regulatory function in setting the pace and managing projects for the country's
construction industry under the close supervision of the Ministry of Housing
and Public Works.
The Public works Department has highly qualified and
experienced professionals forming a multi-disciplinary team of civil, electrical
and mechanical engineers who work alongside architects from the Department
of Architecture. As a sister organization falling under the administrative control
of the Ministry of Public Works department, the latter works well with the PWD
in providing service to the nation. With its strong base of standards and
professionalism developed over the years, the PWD is the repository of
expertise and hence the first choices among discerning clients for any type of
construction project in Bangladesh.
It is recognized as a leader and pacesetter in the
construction industry because of its consistently superior performance.
Public Works Department (PWD), under the Ministry of Public Works
department, is the pioneer in construction arena of Uttar Pradesh. Over about
four centuries, PWD could successfully set the trend and standard in the state`s
infrastructure development. It plays a pivotal role in the implementation of
government construction projects. It also undertakes projects for autonomous
bodies as deposit works.
Public works Department has highly qualified and
experienced professionals forming a multi-disciplinary team of civil, electrical
and mechanical engineers who work alongside architects from the Department
of Architecture. With its strong base of standards and professionalism
developed over the years, PWD is the repository of expertise and hence the first
choices among discerning clients for any type of construction project in Uttar
Pradesh. Besides being the construction agency of the Government, it performs
regulatory function in setting the pace and managing projects for the country's
construction industry under the close supervision of the Ministry of Housing
and Public Works.
The Public works Department has highly qualified and
experienced professionals forming a multi-disciplinary team of civil, electrical
and mechanical engineers who work alongside architects from the Department
of Architecture. As a sister organization falling under the administrative control
of the Ministry of Public Works department, the latter works well with the PWD
in providing service to the nation. With its strong base of standards and
professionalism developed over the years, the PWD is the repository of
expertise and hence the first choices among discerning clients for any type of
construction project in Bangladesh.
It is recognized as a leader and pacesetter in the
construction industry because of its consistently superior performance.
INTRODUCTION
Development of a country depends on the connectivity of various places with
adequate road network. Roads are the major channel of transportation for
carrying goods and passengers. They play a significant role in improving the
socio-economic standards of a region. Roads constitute the most important
mode of communication in areas where railways have not developed much and
form the basic infra-structure for the development and economic growth of the
country. The benefits from the investment in road sector are indirect, long-term
and not immediately visible. Roads are important assets for any nation.
However, merely creating these assets is not enough, it has to be planned
carefully and a pavement which is not designed properly deteriorates fast. India
is a large country having huge resource of materials.
If these local materials are used properly, the cost of
construction can be reduced. There are various type of pavements which differ
in their suitability in different environments. Each type of pavement has its own
merits and demerits. Despite a large number of seminars and conference, still in
India, 98% roads are having flexible pavements. A lot of research has been
made on use of Waste materials but the role of these materials is still limited. So
there is need to take a holistic approach and mark the areas where these are
most suitable. India has one of the largest road networks in the world (over 3
million km at present).For the purpose of management and administration, roads
in India are divided into the following five categories.
National Highways (NH)
State Highways (SH)
Major District Roads (MDR)
Other District Roads (ODR)
Village Roads (VR)
The National Highways are intended to facilitate
medium and long distance inter-city passenger and freight traffic across the
country. The State Highways are supposed to carry the traffic along major
centres within the State. Other District Roads and Village Roads provide
villages accessibility to meet their social needs as also the means to transport
agriculture produce from village to nearby markets. Major District Roads
provide the secondary function of linkage between main roads and rural roads.
Point of view geographic and population of the state is the nation's largest state.
State Industrial, economic and social development of the state and the
population of each village is absolutely necessary to re-connect to the main
roads. In addition to state important national roads, state roads and district roads
Development of a country depends on the connectivity of various places with
adequate road network. Roads are the major channel of transportation for
carrying goods and passengers. They play a significant role in improving the
socio-economic standards of a region. Roads constitute the most important
mode of communication in areas where railways have not developed much and
form the basic infra-structure for the development and economic growth of the
country. The benefits from the investment in road sector are indirect, long-term
and not immediately visible. Roads are important assets for any nation.
However, merely creating these assets is not enough, it has to be planned
carefully and a pavement which is not designed properly deteriorates fast. India
is a large country having huge resource of materials.
If these local materials are used properly, the cost of
construction can be reduced. There are various type of pavements which differ
in their suitability in different environments. Each type of pavement has its own
merits and demerits. Despite a large number of seminars and conference, still in
India, 98% roads are having flexible pavements. A lot of research has been
made on use of Waste materials but the role of these materials is still limited. So
there is need to take a holistic approach and mark the areas where these are
most suitable. India has one of the largest road networks in the world (over 3
million km at present).For the purpose of management and administration, roads
in India are divided into the following five categories.
National Highways (NH)
State Highways (SH)
Major District Roads (MDR)
Other District Roads (ODR)
Village Roads (VR)
The National Highways are intended to facilitate
medium and long distance inter-city passenger and freight traffic across the
country. The State Highways are supposed to carry the traffic along major
centres within the State. Other District Roads and Village Roads provide
villages accessibility to meet their social needs as also the means to transport
agriculture produce from village to nearby markets. Major District Roads
provide the secondary function of linkage between main roads and rural roads.
Point of view geographic and population of the state is the nation's largest state.
State Industrial, economic and social development of the state and the
population of each village is absolutely necessary to re-connect to the main
roads. In addition to state important national roads, state roads and district roads
and their proper broad be made to improve the quality of traffic point of view is
of particular importance.
Public Works Department to build roads and improve connectivity in rural
zones, Other District Road and State broad and improvement of rural roads and
main routes narrow construction of zones and depleted bridges and brides
reconstruction of the bases are transacted on a priority basis. Also under
Pradhanmantri Gram Sadak Yojana and pre-fabricated construction of rural
roads linking the work of other district roads broad Kilometres the scale bases
are edited.
Successful operation of various schemes for the Public Works
Department engineers and supervisory boards in different districts of the
engineer‟s office has been settled. Activities by planning, execution, and quality
control etc. remove impediments find joy in relation to the supervision over the
activities are focused. Various schemes operated by the Department of the
Office of the Regional Chief Engineers and Chief Engineers office.
of particular importance.
Public Works Department to build roads and improve connectivity in rural
zones, Other District Road and State broad and improvement of rural roads and
main routes narrow construction of zones and depleted bridges and brides
reconstruction of the bases are transacted on a priority basis. Also under
Pradhanmantri Gram Sadak Yojana and pre-fabricated construction of rural
roads linking the work of other district roads broad Kilometres the scale bases
are edited.
Successful operation of various schemes for the Public Works
Department engineers and supervisory boards in different districts of the
engineer‟s office has been settled. Activities by planning, execution, and quality
control etc. remove impediments find joy in relation to the supervision over the
activities are focused. Various schemes operated by the Department of the
Office of the Regional Chief Engineers and Chief Engineers office.
Fig (1) National Highway (NH)
Fig (2) Major District Road (MDR)
Fig (3) Village Road (VR)
Fig (2) Major District Road (MDR)
Fig (3) Village Road (VR)
WHAT IS ROAD OR PAVEMENT?
Pavement or Road is an open, generally public way for the passage of vehicles,
people, and animals.
Pavement is finished with a hard smooth surface. It helped make them durable
and able to withstand traffic and the environment. They have a life span of
between 20 – 30 years.
Road pavements deteriorate over time due to-
The impact of traffic, particularly heavy vehicles.
Environmental factors such as weather, pollution.
PURPOSE
Many people rely on paved roads to move themselves and their products rapidly
and reliably.
FUNCTIONS
One of the primary functions is load distribution. It can be characterized by
the tire loads, tire configurations, repetition of loads, and distribution of traffic
across the pavement, and vehicle speed.
Pavement material and geometric design can affect quick and efficient
drainage. These eliminating moisture problems such as mud and pounding
(puddles). Drainage system consists of:
Surface drainage: Removing all water present on the pavement surface,
sloping, chambers, and kerbs.
Subsurface drainage: Removing water that seep into or is contained in the
underlying subgrade.
Pavement or Road is an open, generally public way for the passage of vehicles,
people, and animals.
Pavement is finished with a hard smooth surface. It helped make them durable
and able to withstand traffic and the environment. They have a life span of
between 20 – 30 years.
Road pavements deteriorate over time due to-
The impact of traffic, particularly heavy vehicles.
Environmental factors such as weather, pollution.
PURPOSE
Many people rely on paved roads to move themselves and their products rapidly
and reliably.
FUNCTIONS
One of the primary functions is load distribution. It can be characterized by
the tire loads, tire configurations, repetition of loads, and distribution of traffic
across the pavement, and vehicle speed.
Pavement material and geometric design can affect quick and efficient
drainage. These eliminating moisture problems such as mud and pounding
(puddles). Drainage system consists of:
Surface drainage: Removing all water present on the pavement surface,
sloping, chambers, and kerbs.
Subsurface drainage: Removing water that seep into or is contained in the
underlying subgrade.
TYPES OF PAVEMENTS
There are various types of pavements depending upon the materials used; a
briefs description of all types is given here-
FLEXIBLE PAVEMENTS -
Bitumen has been widely used in the construction of flexible pavements for a
long time. This is the most convenient and simple type of construction. The cost
of construction of single lane bituminous pavement varies from 20 to 30 lakhs
per km in plain areas. In some applications, however, the performance of
conventional bitumen may not be considered satisfactory because of the
following reasons-
In summer season, due to high temperature, bitumen becomes soft resulting
in bleeding, rutting and segregation finally leading to failure of pavement.
In winter season, due to low temperature, the bitumen becomes brittle
resulting in cracking, ravelling and unevenness which makes the pavement
unsuitable for use.
In rainy season, water enters the pavement resulting into pot holes and
sometimes total removal of bituminous layer.
In hilly areas, due to sub-zero temperature, the freeze thaw and heave cycle
takes place. Due to freezing and melting of ice in bituminous voids, volume
expansion and contraction occur. This leads to pavements failure.
The cost of bitumen has been rising continuously. In near future, there will
be scarcity of bitumen and it will be impossible to procure bitumen at very high
costs.
RIGID PAVEMENTS -
Rigid pavements, though costly in initial investment, are cheap in long run
because of low maintenance costs. There are various merits in the use of Rigid
pavements (Concrete pavements) are summarized below:-
Bitumen is derived from petroleum crude, which is in short supply globally
and the price of which has been rising steeply. India imports nearly 70% of the
petroleum crude. The demand for bitumen in the coming years is likely to grow
steeply, far outstripping the availability. Hence it will be in India's interest to
explore alternative binders. Cement is available in sufficient quantity in India,
There are various types of pavements depending upon the materials used; a
briefs description of all types is given here-
FLEXIBLE PAVEMENTS -
Bitumen has been widely used in the construction of flexible pavements for a
long time. This is the most convenient and simple type of construction. The cost
of construction of single lane bituminous pavement varies from 20 to 30 lakhs
per km in plain areas. In some applications, however, the performance of
conventional bitumen may not be considered satisfactory because of the
following reasons-
In summer season, due to high temperature, bitumen becomes soft resulting
in bleeding, rutting and segregation finally leading to failure of pavement.
In winter season, due to low temperature, the bitumen becomes brittle
resulting in cracking, ravelling and unevenness which makes the pavement
unsuitable for use.
In rainy season, water enters the pavement resulting into pot holes and
sometimes total removal of bituminous layer.
In hilly areas, due to sub-zero temperature, the freeze thaw and heave cycle
takes place. Due to freezing and melting of ice in bituminous voids, volume
expansion and contraction occur. This leads to pavements failure.
The cost of bitumen has been rising continuously. In near future, there will
be scarcity of bitumen and it will be impossible to procure bitumen at very high
costs.
RIGID PAVEMENTS -
Rigid pavements, though costly in initial investment, are cheap in long run
because of low maintenance costs. There are various merits in the use of Rigid
pavements (Concrete pavements) are summarized below:-
Bitumen is derived from petroleum crude, which is in short supply globally
and the price of which has been rising steeply. India imports nearly 70% of the
petroleum crude. The demand for bitumen in the coming years is likely to grow
steeply, far outstripping the availability. Hence it will be in India's interest to
explore alternative binders. Cement is available in sufficient quantity in India,
and its availability in the future is also assured. Thus cement concrete roads
should be the obvious choice in future road programmes.
Besides the easy available of cement, concrete roads have a long life and
are practically maintenance-free.
Another major advantage of concrete roads is the savings in fuel by
commercial vehicles to an extent of 14-20%. The fuel savings themselves can
support a large programme of concreting.
Cement concrete roads save a substantial quantity of stone aggregates and
this factor must be considered when a choice pavements is made.
Concrete roads can withstand extreme weather conditions – wide ranging
temperatures, heavy rainfall and water logging.
Though cement concrete roads may cost slightly more than a flexible
pavement initially, they are economical when whole-life-costing is considered.
Reduction in the cost of concrete pavements can be brought about by
developing semiself- compacting concrete techniques and the use of closely
spaced thin joints. R&D efforts should be initiated in this area.
should be the obvious choice in future road programmes.
Besides the easy available of cement, concrete roads have a long life and
are practically maintenance-free.
Another major advantage of concrete roads is the savings in fuel by
commercial vehicles to an extent of 14-20%. The fuel savings themselves can
support a large programme of concreting.
Cement concrete roads save a substantial quantity of stone aggregates and
this factor must be considered when a choice pavements is made.
Concrete roads can withstand extreme weather conditions – wide ranging
temperatures, heavy rainfall and water logging.
Though cement concrete roads may cost slightly more than a flexible
pavement initially, they are economical when whole-life-costing is considered.
Reduction in the cost of concrete pavements can be brought about by
developing semiself- compacting concrete techniques and the use of closely
spaced thin joints. R&D efforts should be initiated in this area.
TYPES OF CONCRETE PAVEMENTS
1. PLAIN CONCRETE OR SHORT PAVEMENT SLABS
This type of pavement consists of successive slabs whose length is limited to
about 25 times the slab thickness. At present it is recommended that the paving
slabs not be made longer than 5, even if the joints have dowels to transfer the
loads. The movements as a result of fluctuations in temperature and humidity
are concentrated in the joints. Normally, these joints are sealed to prevent water
from penetrating the road structure. The width of the pavement slabs is limited
to a maximum of 4.5 m.
2. REINFORCED CONCRETE
Continuously reinforced concrete-
Continuously reinforced concrete pavements are characterised by the absence of
transverse joints and are equipped with longitudinal steel reinforcement. The
diameter of the reinforcing bars is calculated in such a way that cracking can be
controlled and that the cracks are uniformly distributed (spacing at 1 to 3 m).
The crack width has to remain very small, i.e. less than 0.3 mm.
Reinforced pavement slabs
Reinforced concrete pavement slabs are almost never used, except for inside or
outside industrial floors that are subjected to large loads or if the number of
contraction joints has to be limited.
1. PLAIN CONCRETE OR SHORT PAVEMENT SLABS
This type of pavement consists of successive slabs whose length is limited to
about 25 times the slab thickness. At present it is recommended that the paving
slabs not be made longer than 5, even if the joints have dowels to transfer the
loads. The movements as a result of fluctuations in temperature and humidity
are concentrated in the joints. Normally, these joints are sealed to prevent water
from penetrating the road structure. The width of the pavement slabs is limited
to a maximum of 4.5 m.
2. REINFORCED CONCRETE
Continuously reinforced concrete-
Continuously reinforced concrete pavements are characterised by the absence of
transverse joints and are equipped with longitudinal steel reinforcement. The
diameter of the reinforcing bars is calculated in such a way that cracking can be
controlled and that the cracks are uniformly distributed (spacing at 1 to 3 m).
The crack width has to remain very small, i.e. less than 0.3 mm.
Reinforced pavement slabs
Reinforced concrete pavement slabs are almost never used, except for inside or
outside industrial floors that are subjected to large loads or if the number of
contraction joints has to be limited.
Steel fibre concrete
The use of steel fibre concrete pavements is mainly limited to industrial floors.
However, in that sector they are used intensively. For road pavements steel fibre
concrete can be used for thin or very thin paving slabs or for very specific
application.
Site Clearance:
General:
Site clearing generally consists of the cutting and/or taking down, removal and
disposal of everything above ground level, including objects overhanging the
area to be cleared such as tree branches, except such trees, vegetation, structures
or parts of structures and other things which are designated in the contract to
remain or be removed by others to which the engineer directed to be left
undisturbed.
The material to be cleared usually but not necessarily is limited to trees, stumps,
logs, brush, undergrowth, long grasses, crops, loose vegetable matter and
structure.
The entire road area shall be cleared as described above, unless otherwise
shown on the drawing and/or directed by the engineer.
The use of steel fibre concrete pavements is mainly limited to industrial floors.
However, in that sector they are used intensively. For road pavements steel fibre
concrete can be used for thin or very thin paving slabs or for very specific
application.
Site Clearance:
General:
Site clearing generally consists of the cutting and/or taking down, removal and
disposal of everything above ground level, including objects overhanging the
area to be cleared such as tree branches, except such trees, vegetation, structures
or parts of structures and other things which are designated in the contract to
remain or be removed by others to which the engineer directed to be left
undisturbed.
The material to be cleared usually but not necessarily is limited to trees, stumps,
logs, brush, undergrowth, long grasses, crops, loose vegetable matter and
structure.
The entire road area shall be cleared as described above, unless otherwise
shown on the drawing and/or directed by the engineer.
Setting out:
The right of way (R.O.W) shall be surveyed and set out before any site
clearance is cleared out. Wooden pegs usually indicate the surveyed rights of
ways.
Procedure for setting out:
1. Fixing of centre line of alignment by using total station, theodelite.
2. Calculating curvature and refractures (for curves and embankment) by using
auto levels or dumpy level.
3. To establish traverse bench mark (TBM) at required intervals adjacent to
alignments.
4. Location of levels at major conflict junctions.
5. To mark the longitudinal and cross sectional pavement structure.
6. To make efficient, minimum and desired sight distance at major conflicts
and terrain and also setting out of horizontal curves throughout the alignment
was done by using theodolite and total survey station.
Steps involved in surveying:
??? Benchmark
??? Temporary benchmark at regular intervals.
??? Centre line marking
??? Road markings
??? Profile marking (for longitudinal and cross sectional structures)
??? Establishment of different levels providing gradients as per to design
considering different factors like-
Surveying using dumpy level.
The right of way (R.O.W) shall be surveyed and set out before any site
clearance is cleared out. Wooden pegs usually indicate the surveyed rights of
ways.
Procedure for setting out:
1. Fixing of centre line of alignment by using total station, theodelite.
2. Calculating curvature and refractures (for curves and embankment) by using
auto levels or dumpy level.
3. To establish traverse bench mark (TBM) at required intervals adjacent to
alignments.
4. Location of levels at major conflict junctions.
5. To mark the longitudinal and cross sectional pavement structure.
6. To make efficient, minimum and desired sight distance at major conflicts
and terrain and also setting out of horizontal curves throughout the alignment
was done by using theodolite and total survey station.
Steps involved in surveying:
??? Benchmark
??? Temporary benchmark at regular intervals.
??? Centre line marking
??? Road markings
??? Profile marking (for longitudinal and cross sectional structures)
??? Establishment of different levels providing gradients as per to design
considering different factors like-
Surveying using dumpy level.
Plants and equipments:
Site clearing of trees, vegetation, undergrowth, bushes and minor structures are
carried out by dozers and or hydraulic excavators. Trees that cannot be felled by
the aforesaid equipment shall be felled by using saws.
Major structures that cannot practically be cleared by hydraulic excavators
and/or dozers, these demolitions can be carried out using pneumatic tools,
explosives and/or otherspecialized equipment depending on the size and type of
structures. Before commencing explosive demolition all necessary permits and
licenses will be obtained and a blasting plan detailing the size of charges,
locations of holes, system of detonation and safety precaution will be forwarded
to the engineer together with the request sheets.
Image: Double barrel Asphalt Premix plant.
Site clearing of trees, vegetation, undergrowth, bushes and minor structures are
carried out by dozers and or hydraulic excavators. Trees that cannot be felled by
the aforesaid equipment shall be felled by using saws.
Major structures that cannot practically be cleared by hydraulic excavators
and/or dozers, these demolitions can be carried out using pneumatic tools,
explosives and/or otherspecialized equipment depending on the size and type of
structures. Before commencing explosive demolition all necessary permits and
licenses will be obtained and a blasting plan detailing the size of charges,
locations of holes, system of detonation and safety precaution will be forwarded
to the engineer together with the request sheets.
Image: Double barrel Asphalt Premix plant.
Image: Aggregate Crusher
Sequence of works:
Prior to the commencement of the site clearance, the following shall be carried
out either independently or jointly with the Engineer’s Representative.
(I) The right of ways (R.O.W) shall be surveyed and set out according to
the data stated in the drawings.
(II) Photographs shall be taken of structures, landscaping trees and
shrubs, fences, telephone and electrical poles and other if they are
payable under individual measured item apart from the general site
clearance in the bill of quantities.
(III) The above site clearance items shall be measured according to the
method of measurement jointly with the Engineer’s Representatives.
The location of these items shall be identified according to the survey
data or offsets from the centerline of the proposed alignment in road
construction.
(IV) Prior to demolition of existing buildings, liaison with the respective
authorities terminates the utilities supply to the building.
(V) Removal of landscaping trees and shrubs shall be carried out with the
prior approval of the concerned authority.
(VI) Fencing or others that are to be relocated or salvaged shall be carried
out according to the drawings or as per the instructions given by
Engineer.
(VII) Obtain confirmation that the employer or relevant authority have
acquired the right of way lands.
(VIII) Access roads to the site shall be constructed if required to enable
vehicles, equipment and plants to be brought in it.
(IX) Solid waste dumps sites shall be predetermined within or outside the
site for the dumping of the site clearing materials.
(X) The site clearance then shall be proceeded to clear the trees,
vegetation, undergrowth, bushes and minor structures by hydraulic
excavators or dozers.
Prior to the commencement of the site clearance, the following shall be carried
out either independently or jointly with the Engineer’s Representative.
(I) The right of ways (R.O.W) shall be surveyed and set out according to
the data stated in the drawings.
(II) Photographs shall be taken of structures, landscaping trees and
shrubs, fences, telephone and electrical poles and other if they are
payable under individual measured item apart from the general site
clearance in the bill of quantities.
(III) The above site clearance items shall be measured according to the
method of measurement jointly with the Engineer’s Representatives.
The location of these items shall be identified according to the survey
data or offsets from the centerline of the proposed alignment in road
construction.
(IV) Prior to demolition of existing buildings, liaison with the respective
authorities terminates the utilities supply to the building.
(V) Removal of landscaping trees and shrubs shall be carried out with the
prior approval of the concerned authority.
(VI) Fencing or others that are to be relocated or salvaged shall be carried
out according to the drawings or as per the instructions given by
Engineer.
(VII) Obtain confirmation that the employer or relevant authority have
acquired the right of way lands.
(VIII) Access roads to the site shall be constructed if required to enable
vehicles, equipment and plants to be brought in it.
(IX) Solid waste dumps sites shall be predetermined within or outside the
site for the dumping of the site clearing materials.
(X) The site clearance then shall be proceeded to clear the trees,
vegetation, undergrowth, bushes and minor structures by hydraulic
excavators or dozers.
Filling For Embankment:
Construction method:
The embankment shall be constructed to the level, heights, widths and slopes
shown on the drawing with following procedures.
General:
The area to receive fill shall be sampled and tested below topsoil in accordance
with the specification. If the test results indicate that the material is for suitable
to receive fill then a request of Approval starting compaction of existing ground
will be submitted. Before starting the compaction of the existing ground the
topsoil will be stripped from the area, either to a thickness agreed from the soil
sampling holes or as directed on site by the Engineer or his designated staff and
afterwards measured by leveling. After compacting the existing ground to
specified standard density tests will be carried out and a Request for Approval
to start filling will be submitted. Where it is the intention to commence filling
will be commence by cutting to firm material, for cross fill.
Fill materials for use in forming embankments shall be suitable material
obtained from excavation cuttings or borrow pits.
Prior to commencement of the works, the selected sample from the source of
cutting or borrow pits shall be sent for laboratory test.
Trial compaction shall be carried out at the designated area of the site to
determine the pattern of compaction for type of material to be used. This shall
include the use of compaction plant and the number of passes in relation to the
loose depth of material to achieve desired compaction. The approximate
quantity of water required per unit area to bring the fill close enough to the
Optimum Moisture Content to achieve the specified compaction standard
economically shall be computed and thereafter uniformly mixed throughout the
material depth and width to be compacted.
After the required passes for compaction has been accepted, the filling shall be
carried out in layer not exceeding 200 mm compacted depth and shall be
compacted by the compaction plant as used and achieved in the trial areas.
The density test shall be carried out in every compacted layer of approx. 200
mm depth and the Nos. of test shall be done in accordance with the MORT&H
specification.
The Engineer’s Site representative will witness the test and the result sent to the
Engineer for approval to proceed further with next layer.
Construction method:
The embankment shall be constructed to the level, heights, widths and slopes
shown on the drawing with following procedures.
General:
The area to receive fill shall be sampled and tested below topsoil in accordance
with the specification. If the test results indicate that the material is for suitable
to receive fill then a request of Approval starting compaction of existing ground
will be submitted. Before starting the compaction of the existing ground the
topsoil will be stripped from the area, either to a thickness agreed from the soil
sampling holes or as directed on site by the Engineer or his designated staff and
afterwards measured by leveling. After compacting the existing ground to
specified standard density tests will be carried out and a Request for Approval
to start filling will be submitted. Where it is the intention to commence filling
will be commence by cutting to firm material, for cross fill.
Fill materials for use in forming embankments shall be suitable material
obtained from excavation cuttings or borrow pits.
Prior to commencement of the works, the selected sample from the source of
cutting or borrow pits shall be sent for laboratory test.
Trial compaction shall be carried out at the designated area of the site to
determine the pattern of compaction for type of material to be used. This shall
include the use of compaction plant and the number of passes in relation to the
loose depth of material to achieve desired compaction. The approximate
quantity of water required per unit area to bring the fill close enough to the
Optimum Moisture Content to achieve the specified compaction standard
economically shall be computed and thereafter uniformly mixed throughout the
material depth and width to be compacted.
After the required passes for compaction has been accepted, the filling shall be
carried out in layer not exceeding 200 mm compacted depth and shall be
compacted by the compaction plant as used and achieved in the trial areas.
The density test shall be carried out in every compacted layer of approx. 200
mm depth and the Nos. of test shall be done in accordance with the MORT&H
specification.
The Engineer’s Site representative will witness the test and the result sent to the
Engineer for approval to proceed further with next layer.
On the fill slope, the filling shall be in layer and with extended extra width for
cut back to form the compacted slope.
Prior to the commencement of massive cut/fill, the haul roads shall be
constructed with sufficient width for to and fro traffic and to ensure smooth
movement of the plant.
Excavators shall be deployed for excavation and loading the cut material on the
dump trucks for filling. At the filling area, the dump trucks transport the
material to the spread spot and tip from one end. One bulldozer or grader shall
be used for spreading the material into loose layers to the thickness indicated by
the compacted thickness or less. Water shall be spread and mixed in as required
until the whole layer is of one uniform moisture content and the vibrating roller
shall be used for compacting the layer. Field Density tests shall carry out, and if
the results indicate compliance with the specification then a Request for
Approval to place the next layer will be submitted. The slope trimming shall be
completed after the pavement and shoulders are completed.
The trimmed slope is to be turned, if specified
Subsoil drain:
General:
This work shall include the supply and installation of subsoil drains constructed
in accordance with the contract specification at the locations and in accordance
with the lines, levels and grades as shown on the drawings and or as directed by
the Engineer.
Materials:
Concrete pipes ar polyvinyl chloride (PVC) pipes for the subsoil drains shall
comply with the relevant contract specification.
Filter material used in the construction of subsoil drains shall consist of
hard, clean, crushed rock or gravel having a grading limits given in the
specification. The aggregate crushing value of the material shall not exceed
30%.
The filler cloth shall be geotextile fabric as specified in the contract.
Construction method:
Excavation of longitudinal and cross trenches shall be carried out all in
accordance with the approximate provisions of specification and drawings. At
the completion of excavation, Request for Approval forms for placing filter
materials will be submitted to the Engineer.
cut back to form the compacted slope.
Prior to the commencement of massive cut/fill, the haul roads shall be
constructed with sufficient width for to and fro traffic and to ensure smooth
movement of the plant.
Excavators shall be deployed for excavation and loading the cut material on the
dump trucks for filling. At the filling area, the dump trucks transport the
material to the spread spot and tip from one end. One bulldozer or grader shall
be used for spreading the material into loose layers to the thickness indicated by
the compacted thickness or less. Water shall be spread and mixed in as required
until the whole layer is of one uniform moisture content and the vibrating roller
shall be used for compacting the layer. Field Density tests shall carry out, and if
the results indicate compliance with the specification then a Request for
Approval to place the next layer will be submitted. The slope trimming shall be
completed after the pavement and shoulders are completed.
The trimmed slope is to be turned, if specified
Subsoil drain:
General:
This work shall include the supply and installation of subsoil drains constructed
in accordance with the contract specification at the locations and in accordance
with the lines, levels and grades as shown on the drawings and or as directed by
the Engineer.
Materials:
Concrete pipes ar polyvinyl chloride (PVC) pipes for the subsoil drains shall
comply with the relevant contract specification.
Filter material used in the construction of subsoil drains shall consist of
hard, clean, crushed rock or gravel having a grading limits given in the
specification. The aggregate crushing value of the material shall not exceed
30%.
The filler cloth shall be geotextile fabric as specified in the contract.
Construction method:
Excavation of longitudinal and cross trenches shall be carried out all in
accordance with the approximate provisions of specification and drawings. At
the completion of excavation, Request for Approval forms for placing filter
materials will be submitted to the Engineer.
Filter cloth shall then be placed to cover the perimeter of the longitudinal trench
excavated, with the top open to facilitate the placement of filter material.
Subsoil cross pipe is then laid in the cross trench at minimum 1% slope, with
the inlet face covered with filter cloth and the outlet being free outfall. The inlet
of cross pipe is to be imbedded in the filter material fill placed in the
longitudinal trench. Care shall be taken against damage of filter cloth during the
construction stage. Filter material shall be placed in longitudinal trench and
uniformly compacted. The filter cloth shall be closed at top and backfilled with
soil. At the completion of placing filter materials a Request for Approval for
placing compacted backfill will be submitted. During backfilling random field
density check tests will be carried out.
Granular Sub-Base:
General:
Sub base is the lowest of all the pavement layers consisting of natural sand,
mooram, gravel, crushed stone or combination thereof necessary to comply with
the grading requirements of Table 400-1 Grading I.
Materials:
Prior to the laying of sub base, a Request for Approval of Material shall be
submitted which will indicate compliance with the specified properties of sub
base material.
Fraction of material passing the 22.4 mm sieve shall have a soaked CBR
of 30% or greater.
The fraction passing the 0.425 mm sieve shall have Liquid Limit not
greater than 25 and a Plasticity Index not greater than 6.
The soaked 10% fines value (KN) shall be greater than 50.
If the water absorption is greater than 2% the Soundness Test IS 383 shall
be carried out.
The grading shall be as follows:
SEIVE SIZE (MM) PERCENTAGE PASSING
75 100
53 80-100
26.5 55-90
9.5 35-65
4.75 25-55
2.36 20-40
0.425 10-25
0.075 3-10
excavated, with the top open to facilitate the placement of filter material.
Subsoil cross pipe is then laid in the cross trench at minimum 1% slope, with
the inlet face covered with filter cloth and the outlet being free outfall. The inlet
of cross pipe is to be imbedded in the filter material fill placed in the
longitudinal trench. Care shall be taken against damage of filter cloth during the
construction stage. Filter material shall be placed in longitudinal trench and
uniformly compacted. The filter cloth shall be closed at top and backfilled with
soil. At the completion of placing filter materials a Request for Approval for
placing compacted backfill will be submitted. During backfilling random field
density check tests will be carried out.
Granular Sub-Base:
General:
Sub base is the lowest of all the pavement layers consisting of natural sand,
mooram, gravel, crushed stone or combination thereof necessary to comply with
the grading requirements of Table 400-1 Grading I.
Materials:
Prior to the laying of sub base, a Request for Approval of Material shall be
submitted which will indicate compliance with the specified properties of sub
base material.
Fraction of material passing the 22.4 mm sieve shall have a soaked CBR
of 30% or greater.
The fraction passing the 0.425 mm sieve shall have Liquid Limit not
greater than 25 and a Plasticity Index not greater than 6.
The soaked 10% fines value (KN) shall be greater than 50.
If the water absorption is greater than 2% the Soundness Test IS 383 shall
be carried out.
The grading shall be as follows:
SEIVE SIZE (MM) PERCENTAGE PASSING
75 100
53 80-100
26.5 55-90
9.5 35-65
4.75 25-55
2.36 20-40
0.425 10-25
0.075 3-10
Laying equipment:
The following plants are required for the laying of sub-base:-
(i) Motor Grader
(ii) Tipper Trucks
(iii) Vibratory Roller
(iv) Water Tanker
Wet Mix Macadam:
General:
Wet mix macadam (WMM) is a base material in road pavement structure,
which is batched from a mixing plant, and laid in position with a paver.
Materials:
WMM consists of crushed graded aggregate and granular material pre mixed
with water.
Equipments:
Constructional plants required are as follows:-
A) WMM MIXING
PLANT
1
B) PAVER 1
C) MOTOR GRADER 1
D) VIBRATORY
ROLLER
1
E) TIPPER 3
The following plants are required for the laying of sub-base:-
(i) Motor Grader
(ii) Tipper Trucks
(iii) Vibratory Roller
(iv) Water Tanker
Wet Mix Macadam:
General:
Wet mix macadam (WMM) is a base material in road pavement structure,
which is batched from a mixing plant, and laid in position with a paver.
Materials:
WMM consists of crushed graded aggregate and granular material pre mixed
with water.
Equipments:
Constructional plants required are as follows:-
A) WMM MIXING
PLANT
1
B) PAVER 1
C) MOTOR GRADER 1
D) VIBRATORY
ROLLER
1
E) TIPPER 3
Procedures:
Work shall commence on site upon Approval and Acceptance of the sub-base
layer.
The wet mix macadam shall be plant mixed with moisture content within
reasonable limits of the Optimum Moisture Value, as determined in accordance
with IS 2720 (Part 8).
The approved wet mix macadam shall be delivered to site by tipper trucks. To
prevent the loss of moisture, the materials shall be covered, if necessary.
(i) The wet mix macadam shall be laid by using a paving machine.
(ii) Segregation at localized areas shall be made good by back casting
with fines or by immediate removal and replacement of the freshly
laid wet mix macadam.
(iii) Transverse joint shall be lapped and longitudinal joints due to
stoppage of work will have the loose removed before paving resumes.
(iv) Compaction shall be carried out using vibratory roller and as per
specifications.
(v) The surface of the wet mix macadam shall be finished to the grade
and line as required by the drawings, and within specified tolerance
limits.
(vi) On completion of laying and compaction, approval of the Engineer
will be obtained for compliance with the specified requirement, before
proceeding with the next layer.
(vii) Sampling of mixture shall be carried out at the plant or site.
Work shall commence on site upon Approval and Acceptance of the sub-base
layer.
The wet mix macadam shall be plant mixed with moisture content within
reasonable limits of the Optimum Moisture Value, as determined in accordance
with IS 2720 (Part 8).
The approved wet mix macadam shall be delivered to site by tipper trucks. To
prevent the loss of moisture, the materials shall be covered, if necessary.
(i) The wet mix macadam shall be laid by using a paving machine.
(ii) Segregation at localized areas shall be made good by back casting
with fines or by immediate removal and replacement of the freshly
laid wet mix macadam.
(iii) Transverse joint shall be lapped and longitudinal joints due to
stoppage of work will have the loose removed before paving resumes.
(iv) Compaction shall be carried out using vibratory roller and as per
specifications.
(v) The surface of the wet mix macadam shall be finished to the grade
and line as required by the drawings, and within specified tolerance
limits.
(vi) On completion of laying and compaction, approval of the Engineer
will be obtained for compliance with the specified requirement, before
proceeding with the next layer.
(vii) Sampling of mixture shall be carried out at the plant or site.
MINERALS USED
Concrete is widely used in domestic, commercial, recreational, rural and
educational construction. Communities around the world rely on concrete as a
safe, strong and simple building material. It is used in all types of construction;
from domestic work to multi-storey office blocks and shopping complexes.
Despite the common usage of concrete, few people are aware of the
considerations involved in designing strong, durable, high quality concrete.
There are mainly three materials used primarily-
Cement
Sand
Aggregate
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, who
used the term caementicium to describe masonry resembling modern concrete
that was made from crushed rock with burnt lime as binder. The volcanic ash
and pulverized brick additives that were added to the burnt lime to obtain a
hydraulic binder were later referred to as cementum, cimentum, cement, and
cement.
Cements used in construction can be characterized as being
either hydraulic or nonhydraulic. Hydraulic cements (e.g., Portland cement)
harden because of hydration, a chemical reaction between the anhydrous cement
powder and water. Thus, they can harden underwater or when constantly
exposed to wet weather. The chemical reaction results in hydrates that are not
very water-soluble and so are quite durable in water. Non-hydraulic cements do
not harden underwater; for example, slaked limes harden by reaction with
atmospheric carbon dioxide. The most important uses of cement are as an
ingredient in the production of mortar in masonry, and of concrete, a
combination of cement and an aggregate to form a strong building material.
Concrete is widely used in domestic, commercial, recreational, rural and
educational construction. Communities around the world rely on concrete as a
safe, strong and simple building material. It is used in all types of construction;
from domestic work to multi-storey office blocks and shopping complexes.
Despite the common usage of concrete, few people are aware of the
considerations involved in designing strong, durable, high quality concrete.
There are mainly three materials used primarily-
Cement
Sand
Aggregate
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, who
used the term caementicium to describe masonry resembling modern concrete
that was made from crushed rock with burnt lime as binder. The volcanic ash
and pulverized brick additives that were added to the burnt lime to obtain a
hydraulic binder were later referred to as cementum, cimentum, cement, and
cement.
Cements used in construction can be characterized as being
either hydraulic or nonhydraulic. Hydraulic cements (e.g., Portland cement)
harden because of hydration, a chemical reaction between the anhydrous cement
powder and water. Thus, they can harden underwater or when constantly
exposed to wet weather. The chemical reaction results in hydrates that are not
very water-soluble and so are quite durable in water. Non-hydraulic cements do
not harden underwater; for example, slaked limes harden by reaction with
atmospheric carbon dioxide. The most important uses of cement are as an
ingredient in the production of mortar in masonry, and of concrete, a
combination of cement and an aggregate to form a strong building material.
TYPES OF CEMENT:-
Portland cement
Portland cement is by far the most common type of cement in general use
around the world. This cement is made by heating limestone (calcium
carbonate) with small quantities of other materials (such as clay) to 1450 °C in a
kiln, in a process known as calcinations, whereby a molecule of carbon dioxide
is liberated from the calcium carbonate to form calcium oxide, or quicklime,
which is then blended with the other materials that have been included in the
mix. 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-specialty grout. The most
common use for Portland cement is in the production of concrete. Concrete is a
composite material consisting of aggregate (gravel and sand), cement, and
water. As a construction material, concrete can be cast in almost any shape
desired, and once hardened, can become a structural (load bearing) element.
Portland cement may be grey or white.
Portland fly ash cement
It contains up to 35% flyash. The fly ash is pozzolanic, so that ultimate strength
is maintained. Because fly ash addition allows lower concrete water content,
early strength can also be maintained. Where good quality cheap fly ash is
available, this can be an economic alternative to ordinary Portland cement.
Portland pozzolana cement
Its includes fly ash cement, since fly ash is a pozzolana , but also includes
cements made from other natural or artificial pozzolans. In countries where
volcanic ashes are available.
Portland silica fume cement
Addition of silica fume can yield exceptionally high strengths, and cements
containing 5– 20% silica fume are occasionally produced. However, silica fume
is more usually added to Portland cement at the concrete mixer.
Portland cement
Portland cement is by far the most common type of cement in general use
around the world. This cement is made by heating limestone (calcium
carbonate) with small quantities of other materials (such as clay) to 1450 °C in a
kiln, in a process known as calcinations, whereby a molecule of carbon dioxide
is liberated from the calcium carbonate to form calcium oxide, or quicklime,
which is then blended with the other materials that have been included in the
mix. 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-specialty grout. The most
common use for Portland cement is in the production of concrete. Concrete is a
composite material consisting of aggregate (gravel and sand), cement, and
water. As a construction material, concrete can be cast in almost any shape
desired, and once hardened, can become a structural (load bearing) element.
Portland cement may be grey or white.
Portland fly ash cement
It contains up to 35% flyash. The fly ash is pozzolanic, so that ultimate strength
is maintained. Because fly ash addition allows lower concrete water content,
early strength can also be maintained. Where good quality cheap fly ash is
available, this can be an economic alternative to ordinary Portland cement.
Portland pozzolana cement
Its includes fly ash cement, since fly ash is a pozzolana , but also includes
cements made from other natural or artificial pozzolans. In countries where
volcanic ashes are available.
Portland silica fume cement
Addition of silica fume can yield exceptionally high strengths, and cements
containing 5– 20% silica fume are occasionally produced. However, silica fume
is more usually added to Portland cement at the concrete mixer.
SAND
Sand is a naturally occurring granular material composed of finely divided rock
and mineral particles. The composition of sand is highly variable, depending on
the local rock sources and conditions, but the most common constituent of sand
in inland continental settings and nontropical coastal settings is silica (silicon
dioxide, or SiO2), usually in the form of quartz. The second most common type
of sand is calcium carbonate, for example aragonite, which has mostly been
created, over the past half billion years, by various forms of life, like coral and
shellfish. It is, for example, the primary form of sand apparent in areas where
reefs have dominated the ecosystem for millions of years like the Caribbean.
AGGREGATE
Aggregates are inert granular materials such as sand, gravel, or crushed stone
that, along with water and Portland cement, are an essential ingredient in
concrete. For a good concrete mix, aggregates need to be clean, hard, strong
particles free of absorbed chemicals or coatings of clay and other fine materials
that could cause the deterioration of concrete. Aggregates, which account for 60
to 75 percent of the total volume of concrete, are divided into two distinct
categories-fine and coarse. Fine aggregates generally consist of natural sand or
crushed stone with most particles passing through a 3/8-inch (9.5-mm) sieve.
Coarse aggregates are any particles greater than 0.19 inch (4.75 mm), but
generally range between 3/8 and 1.5 inches (9.5 mm to 37.5 mm) in diameter.
Gravels constitute the majority of coarse aggregate used in concrete with
crushed stone making up most of the remainder. Natural gravel and sand are
usually dug or dredged from a pit, river, lake, or seabed. Crushed aggregate is
produced by crushing quarry rock, boulders, cobbles, or large-size gravel.
Recycled concrete is a viable source of aggregate and has been satisfactorily
used in granular sub bases, soil-cement, and in new concrete. Aggregate
processing consists of crushing, screening, and washing the aggregate to obtain
proper cleanliness and gradation. If necessary, a benefaction process such as
jigging or heavy media separation can be used to upgrade the quality.
Once processed, the aggregates are handled and stored in a way that minimizes
segregation and degradation and prevents contamination. Aggregates strongly
influence concrete's freshly mixed and hardened properties, mixture
proportions, and economy. Consequently, selection of aggregates is an
important process. Although some variation in aggregate properties is expected,
characteristics that are considered when selecting aggregate include:-
grading
durability
Sand is a naturally occurring granular material composed of finely divided rock
and mineral particles. The composition of sand is highly variable, depending on
the local rock sources and conditions, but the most common constituent of sand
in inland continental settings and nontropical coastal settings is silica (silicon
dioxide, or SiO2), usually in the form of quartz. The second most common type
of sand is calcium carbonate, for example aragonite, which has mostly been
created, over the past half billion years, by various forms of life, like coral and
shellfish. It is, for example, the primary form of sand apparent in areas where
reefs have dominated the ecosystem for millions of years like the Caribbean.
AGGREGATE
Aggregates are inert granular materials such as sand, gravel, or crushed stone
that, along with water and Portland cement, are an essential ingredient in
concrete. For a good concrete mix, aggregates need to be clean, hard, strong
particles free of absorbed chemicals or coatings of clay and other fine materials
that could cause the deterioration of concrete. Aggregates, which account for 60
to 75 percent of the total volume of concrete, are divided into two distinct
categories-fine and coarse. Fine aggregates generally consist of natural sand or
crushed stone with most particles passing through a 3/8-inch (9.5-mm) sieve.
Coarse aggregates are any particles greater than 0.19 inch (4.75 mm), but
generally range between 3/8 and 1.5 inches (9.5 mm to 37.5 mm) in diameter.
Gravels constitute the majority of coarse aggregate used in concrete with
crushed stone making up most of the remainder. Natural gravel and sand are
usually dug or dredged from a pit, river, lake, or seabed. Crushed aggregate is
produced by crushing quarry rock, boulders, cobbles, or large-size gravel.
Recycled concrete is a viable source of aggregate and has been satisfactorily
used in granular sub bases, soil-cement, and in new concrete. Aggregate
processing consists of crushing, screening, and washing the aggregate to obtain
proper cleanliness and gradation. If necessary, a benefaction process such as
jigging or heavy media separation can be used to upgrade the quality.
Once processed, the aggregates are handled and stored in a way that minimizes
segregation and degradation and prevents contamination. Aggregates strongly
influence concrete's freshly mixed and hardened properties, mixture
proportions, and economy. Consequently, selection of aggregates is an
important process. Although some variation in aggregate properties is expected,
characteristics that are considered when selecting aggregate include:-
grading
durability
particle shape and surface texture
abrasion and skid resistance
unit weights and voids
absorption and surface moisture
Grading refers to the determination of the particle-size
distribution for aggregate. Grading limits and maximum aggregate size are
specified because grading and size affect the amount of aggregate used as well
as cement and water requirements, workability.
FINE AGGREGATE
Fine aggregate shall consist of sand, or sand stone with similar characteristics,
or combination thereof. It shall meet requirements of the State Department of
Transportation of Uttar Pradesh , Section 501.3.6.3 of the Standard
Specifications for Highway and Structure Construction, current edition.
abrasion and skid resistance
unit weights and voids
absorption and surface moisture
Grading refers to the determination of the particle-size
distribution for aggregate. Grading limits and maximum aggregate size are
specified because grading and size affect the amount of aggregate used as well
as cement and water requirements, workability.
FINE AGGREGATE
Fine aggregate shall consist of sand, or sand stone with similar characteristics,
or combination thereof. It shall meet requirements of the State Department of
Transportation of Uttar Pradesh , Section 501.3.6.3 of the Standard
Specifications for Highway and Structure Construction, current edition.
COARSE AGGREGATE
Coarse aggregate shall consist of clean, hard, durable gravel, crushed gravel,
crushed boulders, or crushed stone. It shall meet the requirements of the State
Department of Transportation of Uttar Pradesh , Section 501.3.6.4 of the
Standard Specifications for Highway and Structure Construction, current
edition.
Aggregate Equation
Coarse aggregate shall consist of clean, hard, durable gravel, crushed gravel,
crushed boulders, or crushed stone. It shall meet the requirements of the State
Department of Transportation of Uttar Pradesh , Section 501.3.6.4 of the
Standard Specifications for Highway and Structure Construction, current
edition.
Aggregate Equation
PROPORTIONING
The following table sets forth the master limits of the job mix for the several
grades of concrete, and designates the quantities of materials and relative
proportions for each grade of concrete. For Air-Entrained High-Early-Strength
Concrete, as required or permitted when High-Early-Strength Cement is used,
the proportions shall be as given in the table.
The quantities of aggregates set forth in the tabulations are for oven dry
materials having a bulk specific gravity of 2.65. For aggregates having a
different specific gravity, the weights shall be adjusted in the ratio that the
specific gravity of the material used bears to 2.65 .
The following table sets forth the master limits of the job mix for the several
grades of concrete, and designates the quantities of materials and relative
proportions for each grade of concrete. For Air-Entrained High-Early-Strength
Concrete, as required or permitted when High-Early-Strength Cement is used,
the proportions shall be as given in the table.
The quantities of aggregates set forth in the tabulations are for oven dry
materials having a bulk specific gravity of 2.65. For aggregates having a
different specific gravity, the weights shall be adjusted in the ratio that the
specific gravity of the material used bears to 2.65 .
PROCEDURE TO CONSTRUCT PAVEMENTS
During construction of a cement concrete pavement, various steps are taken as
below-
Survey of proposed work is done by experienced engineers or by any
expert of survey, site survey includes geographical details, soil properties and
site investigation.
After survey , a team of experienced engineers and architecture prepare
detailed plan of work with the help of various soft ware's.
After that a engineer prepares detailed estimate of proposed work and
also prepares a estimate regarding equipments required and labours
requirements.
Now excavation is done with the help of automatic machines and then a
equipment is used to cut nearby trees and root removal process.
And after these construction of soil sub grade , base coarse and then
construction of concrete slab is done.
PREPARATION OF THE SU B- GRADE OR BASE
COARSE
The road sub grade has to be prepared carefully, in order to realize everywhere a
pavement structure of an adequate and uniform thickness. This allows to
provide a homogeneous bond between the concrete slab and its foundation
which is important for the later behaviour of the pavement structure.
For roads with a base, drainage of the water must be provided. Mud, leaves, etc.
have to be removed.
When the base is permeable, it should be sprayed with
water in order to prevent the mixing water from being sucked out of the
concrete. However, if the base is impermeable (e.g. if the concrete is placed on
a watertight asphalt concrete interlayer) it can be necessary under warm weather
conditions to cool down this layer by spraying water on the surface.
The following points are important for roads without a foundation:
Drainage of all surface water;
Good compaction of the sub grade;
Filling and compaction of any ruts caused by construction traffic;
It is forbidden to level the sub grade by means of a course of sand. If the
sub grade has to be levelled, it is advisable to do this by using a granular
material: either slag or coarse aggregate e.g. with a grain size 0/20;
Provide an additional width of the sub grade for more lateral support. It
must always be avoided that water is sucked from the cement paste into the
During construction of a cement concrete pavement, various steps are taken as
below-
Survey of proposed work is done by experienced engineers or by any
expert of survey, site survey includes geographical details, soil properties and
site investigation.
After survey , a team of experienced engineers and architecture prepare
detailed plan of work with the help of various soft ware's.
After that a engineer prepares detailed estimate of proposed work and
also prepares a estimate regarding equipments required and labours
requirements.
Now excavation is done with the help of automatic machines and then a
equipment is used to cut nearby trees and root removal process.
And after these construction of soil sub grade , base coarse and then
construction of concrete slab is done.
PREPARATION OF THE SU B- GRADE OR BASE
COARSE
The road sub grade has to be prepared carefully, in order to realize everywhere a
pavement structure of an adequate and uniform thickness. This allows to
provide a homogeneous bond between the concrete slab and its foundation
which is important for the later behaviour of the pavement structure.
For roads with a base, drainage of the water must be provided. Mud, leaves, etc.
have to be removed.
When the base is permeable, it should be sprayed with
water in order to prevent the mixing water from being sucked out of the
concrete. However, if the base is impermeable (e.g. if the concrete is placed on
a watertight asphalt concrete interlayer) it can be necessary under warm weather
conditions to cool down this layer by spraying water on the surface.
The following points are important for roads without a foundation:
Drainage of all surface water;
Good compaction of the sub grade;
Filling and compaction of any ruts caused by construction traffic;
It is forbidden to level the sub grade by means of a course of sand. If the
sub grade has to be levelled, it is advisable to do this by using a granular
material: either slag or coarse aggregate e.g. with a grain size 0/20;
Provide an additional width of the sub grade for more lateral support. It
must always be avoided that water is sucked from the cement paste into the
substructure or the base. This can be accomplished by either moderately
moistening the sub grade, or by applying a plastic sheet on the substructure of
the pavement. The latter work must be done with care, to prevent the sheet from
tearing or being pulled loose by the wind.
MIXING AND TRANSPORT OF CONCRETE
CONCRETE MIXING PLANT
The concrete mixing plant must have a sufficient capacity in order to be able to
continuously supply concrete to the paving machines. The mix constituents and
admixtures have to be dosed very accurately. The number of aggregate feed
bins has to equal at least the number of different aggregate fractions. The bins
shall have raised edges to prevent contamination of the aggregate fractions. The
equipment for loading the materials shall be in good condition and shall have
sufficient capacity to be able to continuously feed the bins. The bucket of the
loaders shall not be wider than the bins. The content of the cement silos and the
water tank are in proportion to the production rates.
moistening the sub grade, or by applying a plastic sheet on the substructure of
the pavement. The latter work must be done with care, to prevent the sheet from
tearing or being pulled loose by the wind.
MIXING AND TRANSPORT OF CONCRETE
CONCRETE MIXING PLANT
The concrete mixing plant must have a sufficient capacity in order to be able to
continuously supply concrete to the paving machines. The mix constituents and
admixtures have to be dosed very accurately. The number of aggregate feed
bins has to equal at least the number of different aggregate fractions. The bins
shall have raised edges to prevent contamination of the aggregate fractions. The
equipment for loading the materials shall be in good condition and shall have
sufficient capacity to be able to continuously feed the bins. The bucket of the
loaders shall not be wider than the bins. The content of the cement silos and the
water tank are in proportion to the production rates.
For small works, permanent concrete mixing plants are often called on. In that
case, mixing plants that are inspected and that can deliver Indian quality
certification concrete should be used. Furthermore it is useful and even essential
to have a communication system between the concrete mixing plant and the
construction site in order to coordinate the batching and paving operations.
TRANSPORT OF THE CONCRETE
Sufficient trucks must be available to continuously supply the paving machines.
The number depends on the yield at the construction site, the loading capacity
of the trucks and the cycle time (i.e. the transport time plus the time required to
load and unload a truck). The loading capacity and the type of truck to be used
depend on the nature of the work, the haul roads and the concrete paving
machines.
Usually, the specifications prescribe that the concrete has to be
transported in dump trucks as paving concrete consists of a relatively dry mix
having a consistency that makes transport and unloading in truck mixers
difficult. Furthermore, dump trucks can discharge the concrete faster. For small
works and in urban areas, the use of truck mixers is increasingly accepted.
Under these circumstances an admixture (e.g. a superplastisizer ) can be mixed
in just before discharging the concrete. The necessary measures have to be
taken to prevent changes of the water content and temperature of the concrete
during transport. To this end, the specifications prescribe to cover the dump
trucks by means of a tarpaulin.
PLACING THE CONCRETE
Usually the concrete is placed using slip form paving machines which applies
for all categories of roads. This equipment meets both the requirements for
quality and for the envisaged rate of production. Conventional concreting trains
riding on set up rails, are hardly used any more for roadwork's in our country.
For this reason this manner of execution will not be dealt with here. However,
the technique of manually placing the concrete using forms is still applied in
certain cases, such as for the construction of roundabouts with a small diameter,
at intersections, for repair work or when the execution conditions are such that
slip form pavers cannot be utilized. This occurs increasingly often in urban
areas for the construction of pavement surfaces of exposed aggregate and
possibly coloured concrete.
case, mixing plants that are inspected and that can deliver Indian quality
certification concrete should be used. Furthermore it is useful and even essential
to have a communication system between the concrete mixing plant and the
construction site in order to coordinate the batching and paving operations.
TRANSPORT OF THE CONCRETE
Sufficient trucks must be available to continuously supply the paving machines.
The number depends on the yield at the construction site, the loading capacity
of the trucks and the cycle time (i.e. the transport time plus the time required to
load and unload a truck). The loading capacity and the type of truck to be used
depend on the nature of the work, the haul roads and the concrete paving
machines.
Usually, the specifications prescribe that the concrete has to be
transported in dump trucks as paving concrete consists of a relatively dry mix
having a consistency that makes transport and unloading in truck mixers
difficult. Furthermore, dump trucks can discharge the concrete faster. For small
works and in urban areas, the use of truck mixers is increasingly accepted.
Under these circumstances an admixture (e.g. a superplastisizer ) can be mixed
in just before discharging the concrete. The necessary measures have to be
taken to prevent changes of the water content and temperature of the concrete
during transport. To this end, the specifications prescribe to cover the dump
trucks by means of a tarpaulin.
PLACING THE CONCRETE
Usually the concrete is placed using slip form paving machines which applies
for all categories of roads. This equipment meets both the requirements for
quality and for the envisaged rate of production. Conventional concreting trains
riding on set up rails, are hardly used any more for roadwork's in our country.
For this reason this manner of execution will not be dealt with here. However,
the technique of manually placing the concrete using forms is still applied in
certain cases, such as for the construction of roundabouts with a small diameter,
at intersections, for repair work or when the execution conditions are such that
slip form pavers cannot be utilized. This occurs increasingly often in urban
areas for the construction of pavement surfaces of exposed aggregate and
possibly coloured concrete.
SLIP FORM CONCRETE PAVING
PREPARATION OF THE TRACK RUNWAY
The quality of the runway for the tracks of the paving equipment is undoubtedly
one of the most important factors that contribute to the realisation of a smooth
pavement surface. In connection therewith, the following criteria have to be
met:-
sufficient bearing capacity, so that the slip form paver can proceed without
causing deformations;
good skid resistance to prevent the tracks from slipping, especially when
paving on a slope;
good evenness to avoid that the self-levelling systems have to compensate for
excessive differences in height. The track runway is a determining factor for the
steering and consequently its surface has to at least as smooth as the concrete
paving surface itself. The runway surface has to be permanently cleaned prior to
the passage of the tracks.
The track runway has to be wide enough taking into account:
the greatest width of the paving machine plus an extra width (especially on
embankments);
the necessary space for placing the sensor lines.
PREPARATION OF THE TRACK RUNWAY
The quality of the runway for the tracks of the paving equipment is undoubtedly
one of the most important factors that contribute to the realisation of a smooth
pavement surface. In connection therewith, the following criteria have to be
met:-
sufficient bearing capacity, so that the slip form paver can proceed without
causing deformations;
good skid resistance to prevent the tracks from slipping, especially when
paving on a slope;
good evenness to avoid that the self-levelling systems have to compensate for
excessive differences in height. The track runway is a determining factor for the
steering and consequently its surface has to at least as smooth as the concrete
paving surface itself. The runway surface has to be permanently cleaned prior to
the passage of the tracks.
The track runway has to be wide enough taking into account:
the greatest width of the paving machine plus an extra width (especially on
embankments);
the necessary space for placing the sensor lines.
EXECUTION
The supply of the concrete has to be arranged in such a way that a continuous
placement can be guaranteed without detrimental interruptions as each standstill
can cause unevenness's. This implies a sufficient capacity of the concrete
mixing plant and of the means of transportation of the concrete.
The concrete is discharged:
either directly in front of the machine, using dump trucks. The concrete must
be discharged gradually, in order to limit the drop height. A crane is often
necessary, especially for larger working widths, in order to adequately spread
the concrete mix;
or in the bin of a side feeder, for example if transport by dump trucks on the
foundation is impossible because of the presence of dowel chairs or
reinforcement steel;
or in a supply container, from which the concrete is scooped with a crane.
It cannot be overemphasised that properly spreading the concrete in front of the
slip form paving machine is very important for the final quality of the work,
especially with regard to the smoothness. It is of great importance that in front
of the slip form paver, a constant and sufficient amount of concrete is available
at all times so that a continuous paving process can be guaranteed. The paver
should never be used to push the concrete forward. For large casting widths the
concrete is preferably spread either by means of a placer/spreader machine that
operates in front of the paver or, by the slip form paver itself (side feeder,
spreading augers, wagon,…). The use of a placer/spreader, allows the slip form
paver to proceed more steadily. The distance between the placer/spreader and
the slip form machine has to be kept small enough to limit changes in the water
content of the concrete mix.
The paving rate has to match the concrete delivery
rate, but the consistency of the concrete and the evenness of the track runways
must also be taken into consideration. In practice, the optimum speed of the
paving machine lies between 0.75 and 1 m/min. A steady progress of the paving
operations without detrimental interruptions guarantees quality, whatever type
of machine is used.
All regulating devices of the paving machine have to be
tuned before any paving is started. However, this regulation should also be
monitored during the entire course of the paving process and adjusted if
necessary, so that the concrete pavement is executed correctly: thickness,
flawless edges, surface smoothness.
The supply of the concrete has to be arranged in such a way that a continuous
placement can be guaranteed without detrimental interruptions as each standstill
can cause unevenness's. This implies a sufficient capacity of the concrete
mixing plant and of the means of transportation of the concrete.
The concrete is discharged:
either directly in front of the machine, using dump trucks. The concrete must
be discharged gradually, in order to limit the drop height. A crane is often
necessary, especially for larger working widths, in order to adequately spread
the concrete mix;
or in the bin of a side feeder, for example if transport by dump trucks on the
foundation is impossible because of the presence of dowel chairs or
reinforcement steel;
or in a supply container, from which the concrete is scooped with a crane.
It cannot be overemphasised that properly spreading the concrete in front of the
slip form paving machine is very important for the final quality of the work,
especially with regard to the smoothness. It is of great importance that in front
of the slip form paver, a constant and sufficient amount of concrete is available
at all times so that a continuous paving process can be guaranteed. The paver
should never be used to push the concrete forward. For large casting widths the
concrete is preferably spread either by means of a placer/spreader machine that
operates in front of the paver or, by the slip form paver itself (side feeder,
spreading augers, wagon,…). The use of a placer/spreader, allows the slip form
paver to proceed more steadily. The distance between the placer/spreader and
the slip form machine has to be kept small enough to limit changes in the water
content of the concrete mix.
The paving rate has to match the concrete delivery
rate, but the consistency of the concrete and the evenness of the track runways
must also be taken into consideration. In practice, the optimum speed of the
paving machine lies between 0.75 and 1 m/min. A steady progress of the paving
operations without detrimental interruptions guarantees quality, whatever type
of machine is used.
All regulating devices of the paving machine have to be
tuned before any paving is started. However, this regulation should also be
monitored during the entire course of the paving process and adjusted if
necessary, so that the concrete pavement is executed correctly: thickness,
flawless edges, surface smoothness.
Some machines are equipped with a dowel bar inserter or an anchor bar (also
called tie-bar) inserter. Dowel bars are inserted in the fresh concrete down to the
correct elevation after the vibrator but before the tamper bar. The dowel bar
inserter preferably operates in a continuous
operation. Every precaution must be taken to place the dowels correctly and not
to disrupt the evenness of the concrete surface (composition of the concrete,
paving speed, etc.).
The use of a 'super smoother' (longitudinal floating tool) is highly
recommended and in some specifications it is even made compulsory whenever
a slip form paver is used and especially for pavements for high speed roads. The
super smoother is a beam float suspended from the backside of the slip form
machine and that moves back and forth in the longitudinal direction while
simultaneously traversing the freshly finished concrete surface. It allows to
eliminate small finishing errors or any remaining high and low spots behind the
slip form paver. This improves the driving comfort and limits the nuisance
caused by unevenness's with a short wave length (noise, vibrations). Small
traces of cement slurry produced after the passage of the super smoother, are
subsequently removed by dragging a section of burlap or a drag plate. The super
smoother can also be used for other road categories, including bicycle paths.
MEASURES TO OBTAIN A GOOD EVENNESS
A good evenness depends primarily on the following factors:-
A concrete mix with an uniform consistency, adapted to the paving machines
and the working circumstances,
A regular supply of concrete and a uniform spreading in front of the paver,
Correct operation of the paving machines, which in turn depends on the
setting of the forms or the sensor lines, the quality of the track runways, the
regulation of the sensors, etc.,
Steady progress of the paver, without interruptions and with a speed
compatible with the consistency of the concrete and the working circumstances,
use of specific tools or equipment to eliminate small bumps after the paving
machines: correction beam, super smoother, etc.
called tie-bar) inserter. Dowel bars are inserted in the fresh concrete down to the
correct elevation after the vibrator but before the tamper bar. The dowel bar
inserter preferably operates in a continuous
operation. Every precaution must be taken to place the dowels correctly and not
to disrupt the evenness of the concrete surface (composition of the concrete,
paving speed, etc.).
The use of a 'super smoother' (longitudinal floating tool) is highly
recommended and in some specifications it is even made compulsory whenever
a slip form paver is used and especially for pavements for high speed roads. The
super smoother is a beam float suspended from the backside of the slip form
machine and that moves back and forth in the longitudinal direction while
simultaneously traversing the freshly finished concrete surface. It allows to
eliminate small finishing errors or any remaining high and low spots behind the
slip form paver. This improves the driving comfort and limits the nuisance
caused by unevenness's with a short wave length (noise, vibrations). Small
traces of cement slurry produced after the passage of the super smoother, are
subsequently removed by dragging a section of burlap or a drag plate. The super
smoother can also be used for other road categories, including bicycle paths.
MEASURES TO OBTAIN A GOOD EVENNESS
A good evenness depends primarily on the following factors:-
A concrete mix with an uniform consistency, adapted to the paving machines
and the working circumstances,
A regular supply of concrete and a uniform spreading in front of the paver,
Correct operation of the paving machines, which in turn depends on the
setting of the forms or the sensor lines, the quality of the track runways, the
regulation of the sensors, etc.,
Steady progress of the paver, without interruptions and with a speed
compatible with the consistency of the concrete and the working circumstances,
use of specific tools or equipment to eliminate small bumps after the paving
machines: correction beam, super smoother, etc.
EXECUTION OF JOINTS
All the equipment that is necessary to make joints in the fresh or hardened
concrete must be present at the construction site. The saw blades have to be
suitable to the quality of the concrete, i.e. to the hardness and the abrasion
resistance of the aggregates. It is useful to have spare equipment available in
case of a defect. The beam for making a construction joint shall be rigid and
shall allow the realization of a straight joint perpendicular to the axis of the
road. This beam has to be adapted to the type of pavement (jointed pavement,
continuously reinforced concrete pavement).
TRANSVERSE JOINTS -
1. CONTRACTION JOINTS
Crack onsets are executed to avoid uncontrolled (“wild”) cracking of the
concrete by shrinkage. Contraction joints have a crack onset which extends to a
depth of one third of the slab thickness and can be equipped with dowels. On
main roads, the contraction joints are usually made by sawing. The saw cutting
should occur as soon as possible, usually between 5 and 24 hours after
placement of the concrete. It is obvious that the concrete should have hardened
sufficiently in order to prevent the edges of the joint from being damaged. In
case of high temperatures, special equipment is available to execute saw cutting
within 3 hours subsequent to the placement of the concrete. In that case, light
equipment is used to make saw cuts of about 2.5 cm deep. Every saw cut that
has not instigated a crack within 24 hours is deepened up to 1/3 of the slab
thickness. Making crack onsets for contraction joints in the fresh concrete is a
technique that is practically no longer applied except for country roads or
municipal roads whenever the traffic intensity and evenness requirements
permit so. To make such a joint, a thin steel blade (no more than 6 mm thick) is
vibrated into the fresh concrete to a depth of 1/3 of the slab thickness. The joint
can be made both with flexible and with rigid joint strips. In the first method, a
thin plastic strip twice as wide as the depth of the crack point plus 2 cm is laid
on the fresh concrete. The steel blade is positioned in the middle of the strip and
is subsequently vibrated into the fresh concrete. In the second method the rigid
joint strip is inserted into a groove priory made by vibrating the steel blade in
the concrete. The top of the strip must be flush with the pavement surface.
After having made the crack onset, the concrete surface along the joint should
be smoothened again. However, manual corrections should be kept to a
minimum as much as possible, since they can cause spalling of the joint edges
later.
All the equipment that is necessary to make joints in the fresh or hardened
concrete must be present at the construction site. The saw blades have to be
suitable to the quality of the concrete, i.e. to the hardness and the abrasion
resistance of the aggregates. It is useful to have spare equipment available in
case of a defect. The beam for making a construction joint shall be rigid and
shall allow the realization of a straight joint perpendicular to the axis of the
road. This beam has to be adapted to the type of pavement (jointed pavement,
continuously reinforced concrete pavement).
TRANSVERSE JOINTS -
1. CONTRACTION JOINTS
Crack onsets are executed to avoid uncontrolled (“wild”) cracking of the
concrete by shrinkage. Contraction joints have a crack onset which extends to a
depth of one third of the slab thickness and can be equipped with dowels. On
main roads, the contraction joints are usually made by sawing. The saw cutting
should occur as soon as possible, usually between 5 and 24 hours after
placement of the concrete. It is obvious that the concrete should have hardened
sufficiently in order to prevent the edges of the joint from being damaged. In
case of high temperatures, special equipment is available to execute saw cutting
within 3 hours subsequent to the placement of the concrete. In that case, light
equipment is used to make saw cuts of about 2.5 cm deep. Every saw cut that
has not instigated a crack within 24 hours is deepened up to 1/3 of the slab
thickness. Making crack onsets for contraction joints in the fresh concrete is a
technique that is practically no longer applied except for country roads or
municipal roads whenever the traffic intensity and evenness requirements
permit so. To make such a joint, a thin steel blade (no more than 6 mm thick) is
vibrated into the fresh concrete to a depth of 1/3 of the slab thickness. The joint
can be made both with flexible and with rigid joint strips. In the first method, a
thin plastic strip twice as wide as the depth of the crack point plus 2 cm is laid
on the fresh concrete. The steel blade is positioned in the middle of the strip and
is subsequently vibrated into the fresh concrete. In the second method the rigid
joint strip is inserted into a groove priory made by vibrating the steel blade in
the concrete. The top of the strip must be flush with the pavement surface.
After having made the crack onset, the concrete surface along the joint should
be smoothened again. However, manual corrections should be kept to a
minimum as much as possible, since they can cause spalling of the joint edges
later.
2. EXPANSION JOINTS
Expansion joints are only used exceptionally. In these rare cases, they have to
meet the necessary requirements so as not to cause difficulties later.
The execution of expansion joints requires special attention when using slip
form paving machines.
Special attention shall be paid to the following:
The wooden joint filler board shall be firmly attached to the base
by means of metal stakes, so that it cannot move while the concrete is being
placed;
The height of the joint filler board shall be slightly(2 to 3 cm)
shallower than the thickness of the concrete slab, in order not to hinder the
placement of the concrete. As soon as the slip form paving machine has passed,
the concrete above the joint filler board shall be removed over a width at least
equal to the thickness of the board, so that no “concrete arch” is made at the top
of the joint;
Expansion joints shall always be provided with dowels, even for
roads with less intense traffic. At one end of each dowel a cap filled with a
compressible material accommodates the movements of the concrete.
3. CONSTRUCTION JOINTS
Construction joints also called end-of-day or working joints - are made at the
end of the daily production or when the paving process is interrupted for at least
2 hours. The face of these joints is plane, vertical and perpendicular to the axis
of the pavement. They are always doweled. Upon resuming the paving the fresh
concrete is placed against the concrete that has already hardened. The concrete
is consolidated on both sides of the joint with a separate manual needle vibrator.
Expansion joints are only used exceptionally. In these rare cases, they have to
meet the necessary requirements so as not to cause difficulties later.
The execution of expansion joints requires special attention when using slip
form paving machines.
Special attention shall be paid to the following:
The wooden joint filler board shall be firmly attached to the base
by means of metal stakes, so that it cannot move while the concrete is being
placed;
The height of the joint filler board shall be slightly(2 to 3 cm)
shallower than the thickness of the concrete slab, in order not to hinder the
placement of the concrete. As soon as the slip form paving machine has passed,
the concrete above the joint filler board shall be removed over a width at least
equal to the thickness of the board, so that no “concrete arch” is made at the top
of the joint;
Expansion joints shall always be provided with dowels, even for
roads with less intense traffic. At one end of each dowel a cap filled with a
compressible material accommodates the movements of the concrete.
3. CONSTRUCTION JOINTS
Construction joints also called end-of-day or working joints - are made at the
end of the daily production or when the paving process is interrupted for at least
2 hours. The face of these joints is plane, vertical and perpendicular to the axis
of the pavement. They are always doweled. Upon resuming the paving the fresh
concrete is placed against the concrete that has already hardened. The concrete
is consolidated on both sides of the joint with a separate manual needle vibrator.
LONGITUDINAL JOINTS
Longitudinal joints run parallel to the axis of the road and are only necessary if
the pavement is wider than 4.5m. They can be provided with tie bars.
1. LONGITUDINAL CONTRACTION / BENDING JOINTS
These joints are realised between adjacent concrete lanes that are executed
simultaneously. They are saw cut in the hardened concrete, no later than 24
hours after the concrete has been placed. The depth is at least 1/3 of the
thickness of the slab.
2. LONGITUDINAL CONSTRUCTION JOINTS
These are joints between two adjacent concrete lanes that are executed
successively.
Longitudinal joints run parallel to the axis of the road and are only necessary if
the pavement is wider than 4.5m. They can be provided with tie bars.
1. LONGITUDINAL CONTRACTION / BENDING JOINTS
These joints are realised between adjacent concrete lanes that are executed
simultaneously. They are saw cut in the hardened concrete, no later than 24
hours after the concrete has been placed. The depth is at least 1/3 of the
thickness of the slab.
2. LONGITUDINAL CONSTRUCTION JOINTS
These are joints between two adjacent concrete lanes that are executed
successively.
CURING
Curing is the process of increasing hydration in cement; after setting the
concrete, curing process is done till 20 to 25 days.
There are some method of curing-
Shading concrete works
Covering with hessian & gunny bags
Sprinkling of water
By ponding
Membrane curing
PROTECTION OF THE CONCRETE PAVEMENT
1. PROTECTION AGAINST DRYING OUT
The quality of hardened concrete, and in particular, the durability of the surface,
depends directly on the protection of the fresh concrete against drying out. It is
detrimental both to the strength and to the shrinkage (risk of cracks forming)
and also to the durability when the fresh concrete loses water. As a result of
their large exposed areas, pavements are greatly subjected to drying out. E.g. at
an ambient temperature of 20°C, a relative humidity of 60 %, a temperature of
the concrete of 25°C and a wind speed of 25 km/h, 1 litre of water will
evaporate every hour from every m2of pavement surface. Note that the upper
Curing is the process of increasing hydration in cement; after setting the
concrete, curing process is done till 20 to 25 days.
There are some method of curing-
Shading concrete works
Covering with hessian & gunny bags
Sprinkling of water
By ponding
Membrane curing
PROTECTION OF THE CONCRETE PAVEMENT
1. PROTECTION AGAINST DRYING OUT
The quality of hardened concrete, and in particular, the durability of the surface,
depends directly on the protection of the fresh concrete against drying out. It is
detrimental both to the strength and to the shrinkage (risk of cracks forming)
and also to the durability when the fresh concrete loses water. As a result of
their large exposed areas, pavements are greatly subjected to drying out. E.g. at
an ambient temperature of 20°C, a relative humidity of 60 %, a temperature of
the concrete of 25°C and a wind speed of 25 km/h, 1 litre of water will
evaporate every hour from every m2of pavement surface. Note that the upper
surface layer (a few cm thick) of the concrete only contains about 4 litres of
water per m2.
A curing compound is usually used to protect road concrete against drying out
This coating is sprayed on the concrete top surface and on the vertical surfaces
immediately after the paving train has passed and, if applicable, after the
concrete surface has been broomed. In case of an exposed aggregate finish, the
setting retarder must also have the property that it protects the concrete against
drying out. If not, the concrete must be covered with a plastic sheet as soon as
the setting retarder is applied. As stated above, subsequent to the removal of
the skin of concrete mortar, the concrete is protected against drying out a second
time by spraying a curing compound or by covering the surface with a plastic
sheet. The latter method is particularly used in urban areas on coloured exposed
aggregate concrete. The curing compound has to be applied at a rate of at least
200 g/m2 and its effectiveness coefficient shall be greater than 80%. Curing
compounds are pigmented white or have a metallic gloss so as to better reflect
sunlight which limits the warming up of the concrete.
2. PROTECTION AGAINST RAIN
Concreting is stopped if it rains. Furthermore, the necessary measures have to
be taken to prevent that the concrete surface is washed out by rain. This applies
both to freshly spread concrete that has not been compacted yet and to
smoothed concrete. Plastic sheets or mobile shelters are suitable means of
protection.
3. PROTECTION AGAINST FROST
When concrete is placed in cold weather (see also § 8.4.1) the pavement surface
has to be effectively protected against frost in such a way that the temperature at
the surface of the concrete does not drop below + 1 ºC for 72 hours after
placement. This protection can consist of, for example, non-woven geotextile or
polystyrene foam plates with ballast.
4. PROTECTION AGAINST MECHANICAL INFLUENCES
(TRAFFIC SIGNPOSTING)
Every necessary measure shall be taken to protect the fresh concrete from
damage due to all kinds of mechanical influences (cars, bicycles, pedestrians,
animals, etc.).
In urban areas these measures are even more necessary.
water per m2.
A curing compound is usually used to protect road concrete against drying out
This coating is sprayed on the concrete top surface and on the vertical surfaces
immediately after the paving train has passed and, if applicable, after the
concrete surface has been broomed. In case of an exposed aggregate finish, the
setting retarder must also have the property that it protects the concrete against
drying out. If not, the concrete must be covered with a plastic sheet as soon as
the setting retarder is applied. As stated above, subsequent to the removal of
the skin of concrete mortar, the concrete is protected against drying out a second
time by spraying a curing compound or by covering the surface with a plastic
sheet. The latter method is particularly used in urban areas on coloured exposed
aggregate concrete. The curing compound has to be applied at a rate of at least
200 g/m2 and its effectiveness coefficient shall be greater than 80%. Curing
compounds are pigmented white or have a metallic gloss so as to better reflect
sunlight which limits the warming up of the concrete.
2. PROTECTION AGAINST RAIN
Concreting is stopped if it rains. Furthermore, the necessary measures have to
be taken to prevent that the concrete surface is washed out by rain. This applies
both to freshly spread concrete that has not been compacted yet and to
smoothed concrete. Plastic sheets or mobile shelters are suitable means of
protection.
3. PROTECTION AGAINST FROST
When concrete is placed in cold weather (see also § 8.4.1) the pavement surface
has to be effectively protected against frost in such a way that the temperature at
the surface of the concrete does not drop below + 1 ºC for 72 hours after
placement. This protection can consist of, for example, non-woven geotextile or
polystyrene foam plates with ballast.
4. PROTECTION AGAINST MECHANICAL INFLUENCES
(TRAFFIC SIGNPOSTING)
Every necessary measure shall be taken to protect the fresh concrete from
damage due to all kinds of mechanical influences (cars, bicycles, pedestrians,
animals, etc.).
In urban areas these measures are even more necessary.
SPECIAL MEASURES
WORKABILITY PERIOD
It must always be ensured that the concrete is processed as quickly as possible,
certainly within 2 hours after batching including the surface treatment and the
protection measures. In hot, dry weather an even shorter workability time has to
be observed (maximum 90 minutes). Unless special precautions are taken that
have been approved by the manager of the works, concrete can only be laid if
the air temperature at 1.5 m above ground under thermometer
shelter does not exceed 25°c. Furthermore, all necessary measures shall be
taken to keep the water content of the concrete as constant as possible from the
time of batching until completion of the placement
.
PAVING INTERRUPTIONS
Whenever the supply of concrete is interrupted, the driver of the paving
machine shall immediately take the necessary measures to lower the speed of
the paving train and to ensure that the machine stops as little as possible. For a
short interruption, the machine should be stopped before the deposited concrete
in the vibrating chamber has dropped to such a level that the vibrators become
visible. If the supply is interrupted for more than 60 minutes (45 min. in hot
weather), a construction joint has to be made. Upon a long-lasting defect of the
paving equipment, the supply of fresh concrete has to be stopped immediately
and an attempt must be made to complete the current paving phase. If the
circumstances and the elapsed workability time no longer make a proper
completion possible, the concrete, that has been deposited but not yet finished,
has to be removed. To achieve a continuous profile, particular care is taken of
the execution of the construction joints, both at the end of the day and every
time work is resumed. The concrete is compacted preferably with a separate
vibrating needle before the paving machine is passing in order to obtain
properly compacted concrete on both sides of the joint.
PLACEMENT OF CONCRETE ON A SLOPE
When placing concrete on a slope of less than 4 % it is recommended to work
uphill, in order to prevent tension cracks at the surface. Furthermore, the
consistency of the concrete and the working speed of the paver have to be
adapted to the working conditions. However, if the longitudinal slope is more
than 4 %, unevenness can occur as concrete falls back when the machines have
passed. In that case, a suitable composition of the concrete mix has to be
realized and it is recommended to work downhill. It must be ensured that
WORKABILITY PERIOD
It must always be ensured that the concrete is processed as quickly as possible,
certainly within 2 hours after batching including the surface treatment and the
protection measures. In hot, dry weather an even shorter workability time has to
be observed (maximum 90 minutes). Unless special precautions are taken that
have been approved by the manager of the works, concrete can only be laid if
the air temperature at 1.5 m above ground under thermometer
shelter does not exceed 25°c. Furthermore, all necessary measures shall be
taken to keep the water content of the concrete as constant as possible from the
time of batching until completion of the placement
.
PAVING INTERRUPTIONS
Whenever the supply of concrete is interrupted, the driver of the paving
machine shall immediately take the necessary measures to lower the speed of
the paving train and to ensure that the machine stops as little as possible. For a
short interruption, the machine should be stopped before the deposited concrete
in the vibrating chamber has dropped to such a level that the vibrators become
visible. If the supply is interrupted for more than 60 minutes (45 min. in hot
weather), a construction joint has to be made. Upon a long-lasting defect of the
paving equipment, the supply of fresh concrete has to be stopped immediately
and an attempt must be made to complete the current paving phase. If the
circumstances and the elapsed workability time no longer make a proper
completion possible, the concrete, that has been deposited but not yet finished,
has to be removed. To achieve a continuous profile, particular care is taken of
the execution of the construction joints, both at the end of the day and every
time work is resumed. The concrete is compacted preferably with a separate
vibrating needle before the paving machine is passing in order to obtain
properly compacted concrete on both sides of the joint.
PLACEMENT OF CONCRETE ON A SLOPE
When placing concrete on a slope of less than 4 % it is recommended to work
uphill, in order to prevent tension cracks at the surface. Furthermore, the
consistency of the concrete and the working speed of the paver have to be
adapted to the working conditions. However, if the longitudinal slope is more
than 4 %, unevenness can occur as concrete falls back when the machines have
passed. In that case, a suitable composition of the concrete mix has to be
realized and it is recommended to work downhill. It must be ensured that
enough concrete is deposited in front of the paving machine to prevent the
concrete from sliding down. Concrete pavements have been successfully
executed on slopes of 10 to 12 %. At one time the slope was even 18 %.
concrete from sliding down. Concrete pavements have been successfully
executed on slopes of 10 to 12 %. At one time the slope was even 18 %.
OPENING TO TRAFFIC
Usually, a concrete pavement is only opened to traffic 7 days after the concrete
has been laid and after, in the presence of all parties, any possible cracks have
been recorded. A concrete pavement of less than 7 days old, can be opened to
traffic if the contractor provides proof that the concrete has reached the
minimum compressive strength stipulated in the specifications. Presently,
special compositions of the concrete mix allow an early opening to traffic, i.e.
between 24 and 48 hours after placement. These mixes are used, for example,
for pavement repair works to reduce the nuisance to the public as much as
possible. It is pointless to talk about quality if not all employees, each at his
own level, make a special effort to understand the rules of good practice,
upgrade their know-how and act accordingly.
COST ANALYSIS OF RIGID PAVEMENTS
The selection criteria of type of pavement, flexible or rigid, should be based not
on the initial cost of construction but life cycle cost, which includes the
discounted maintenance and pavement strengthening costs that are incurred
during the design life of the pavement.
INITIAL COST
This is the cost of construction of the pavement which mainly depends upon the
pavement thickness, governed by the strength of sub grade soil and traffic
loading, cost of materials and cost of execution of the work. the above have a
wide range of variability across the country and is difficult to generalise.
MAINTENANCE COST
The maintenance cost includes the maintenance of pavement during the design
life of pavement to keep the pavement at the specified service level.
In case of rural roads, maintenance of these roads is to be done by the respective
state government from its available financial resources. most of the states have
poor past performance record to maintain such low volume roads through other
schemes, mainly because of having inadequate funds for maintenance of road
infrastructure in the state.
Usually, a concrete pavement is only opened to traffic 7 days after the concrete
has been laid and after, in the presence of all parties, any possible cracks have
been recorded. A concrete pavement of less than 7 days old, can be opened to
traffic if the contractor provides proof that the concrete has reached the
minimum compressive strength stipulated in the specifications. Presently,
special compositions of the concrete mix allow an early opening to traffic, i.e.
between 24 and 48 hours after placement. These mixes are used, for example,
for pavement repair works to reduce the nuisance to the public as much as
possible. It is pointless to talk about quality if not all employees, each at his
own level, make a special effort to understand the rules of good practice,
upgrade their know-how and act accordingly.
COST ANALYSIS OF RIGID PAVEMENTS
The selection criteria of type of pavement, flexible or rigid, should be based not
on the initial cost of construction but life cycle cost, which includes the
discounted maintenance and pavement strengthening costs that are incurred
during the design life of the pavement.
INITIAL COST
This is the cost of construction of the pavement which mainly depends upon the
pavement thickness, governed by the strength of sub grade soil and traffic
loading, cost of materials and cost of execution of the work. the above have a
wide range of variability across the country and is difficult to generalise.
MAINTENANCE COST
The maintenance cost includes the maintenance of pavement during the design
life of pavement to keep the pavement at the specified service level.
In case of rural roads, maintenance of these roads is to be done by the respective
state government from its available financial resources. most of the states have
poor past performance record to maintain such low volume roads through other
schemes, mainly because of having inadequate funds for maintenance of road
infrastructure in the state.
LIFE CYCLE COST ANALYSIS
Life cycle cost analysis can be defined as a procedure by which a pavement
design alternative will be selected , which will provide a satisfactory level of
service at the lowest cost design life.
RIGID PAVEMENT DESIGN AND COSTOF CONSTRUCTION PER
KILOMETERS
The design of rigid pavement depends upon the CBR value of sub grade ,
design axle load of commercial vehicles during the design life, which is
generally 20 years or more for rural roads, a typical pavement composition for
rural road is given below :( refer: SP:62-2004):
MAINTENANCE COST OF R IGID PAVEMENT
The average yearly maintenance cost of rigid pavement will be about Rs.
10000per km for a single lane rural road to cover filling of sealing compound in
the joints, requires of concrete spalling etc.
LIFE CYCLE COST ANALYSIS OF RIGID PAVEME NT
Period of analysis has been considered as 20 years, being the design life of
concrete pavement in rural area. the discount rate of 10% has been taken.
inflation rate of 5% has been considered for future rise in prices of materials.
Life cycle cost analysis can be defined as a procedure by which a pavement
design alternative will be selected , which will provide a satisfactory level of
service at the lowest cost design life.
RIGID PAVEMENT DESIGN AND COSTOF CONSTRUCTION PER
KILOMETERS
The design of rigid pavement depends upon the CBR value of sub grade ,
design axle load of commercial vehicles during the design life, which is
generally 20 years or more for rural roads, a typical pavement composition for
rural road is given below :( refer: SP:62-2004):
MAINTENANCE COST OF R IGID PAVEMENT
The average yearly maintenance cost of rigid pavement will be about Rs.
10000per km for a single lane rural road to cover filling of sealing compound in
the joints, requires of concrete spalling etc.
LIFE CYCLE COST ANALYSIS OF RIGID PAVEME NT
Period of analysis has been considered as 20 years, being the design life of
concrete pavement in rural area. the discount rate of 10% has been taken.
inflation rate of 5% has been considered for future rise in prices of materials.
CEMENT CONCRETE PAVEMENT VS BITUMINOUS
PAVEMENT- A COST ANALYSIS
PAVEMENT- A COST ANALYSIS
CONCLUSION
India economical growth plan of over 6% per annum for the next 20 years will,
to a great extent, depend on an efficient road infrastructure, not only national
highways but other roads too, including link roads for rural connectivity, which
can provide fast movement of goods and people with safety and economical
cost to the user. government of India has drawn up Pradhn Mantri gram Sarak
Yojana(PMGSY) for implementation of rural connectivity. it is estimated that in
the next 7 years, road works under PMGSY worth Rs. 1,20,000 crores are to be
constructed .
Since road pavements are an important part of these projects,
costing about 50% of the investment , a careful evaluation of the alternatives is
necessary to make the right choice on a rational basis, which may be
comparatively more beneficial to the nation.
India economical growth plan of over 6% per annum for the next 20 years will,
to a great extent, depend on an efficient road infrastructure, not only national
highways but other roads too, including link roads for rural connectivity, which
can provide fast movement of goods and people with safety and economical
cost to the user. government of India has drawn up Pradhn Mantri gram Sarak
Yojana(PMGSY) for implementation of rural connectivity. it is estimated that in
the next 7 years, road works under PMGSY worth Rs. 1,20,000 crores are to be
constructed .
Since road pavements are an important part of these projects,
costing about 50% of the investment , a careful evaluation of the alternatives is
necessary to make the right choice on a rational basis, which may be
comparatively more beneficial to the nation.
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