Concrete Road Pavement
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Sep 25, 2016
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About This Presentation
Industrial Training Report On Concrete Road Pavement Submitted by Awinash Tiwari To The Department Of Civil Engineering Krishna Institute Of Engineering And Technology ghaziabad.
Slide Content
1
A
Summer Training Report
On
CONSTRUCTION OF CEMENT CONCRETE PAVEMENT
At
UTTAR PRADESH PUBLIC WORKS DEPARTMENT
CONSTRUCTION DIVISION -1, GORAKHPUR (U.P)
SUBMITTED BY:-
AWINASH TIWARI
BRANCH: CE, 4th Year
ROLL NO. 1302900036
SUBMITTED TO:-
DEPARTMENT OF CIVIL ENGINEERING
K.I.E.T ,GHAZIABAD
A
Summer Training Report
On
CONSTRUCTION OF CEMENT CONCRETE PAVEMENT
At
UTTAR PRADESH PUBLIC WORKS DEPARTMENT
CONSTRUCTION DIVISION -1, GORAKHPUR (U.P)
SUBMITTED BY:-
AWINASH TIWARI
BRANCH: CE, 4th Year
ROLL NO. 1302900036
SUBMITTED TO:-
DEPARTMENT OF CIVIL ENGINEERING
K.I.E.T ,GHAZIABAD
2
3
ACKNOWLEDGEMENT
I express my satisfaction on the completion of this summer training
program and project report submission as a part of the curriculum for the degree
of Bachelor of Technology, Civil Engineering. I express my deepest gratitude to
my supervisor and mentor Mr. SHIV KUMAR SINGH SIR and MR. ARWIND
KR. NAMDEV SIR for his kind guidance during the entire period of training.
His consistent support and advices has helped me to complete this research
project successfully. Also I thank all the members of PUBLIC WORKS
DEPARTMENT, CONSTRUCTION DIVISION-1, GORAKHPUR, U.P. for
their kind support. They have always been a source of inspiration to me.
DATE: - 05/08/2016
AWINASH TIWARI
College: K.I.E.T GZB
Branch: CE, 4th Year
Roll No.130200036
ACKNOWLEDGEMENT
I express my satisfaction on the completion of this summer training
program and project report submission as a part of the curriculum for the degree
of Bachelor of Technology, Civil Engineering. I express my deepest gratitude to
my supervisor and mentor Mr. SHIV KUMAR SINGH SIR and MR. ARWIND
KR. NAMDEV SIR for his kind guidance during the entire period of training.
His consistent support and advices has helped me to complete this research
project successfully. Also I thank all the members of PUBLIC WORKS
DEPARTMENT, CONSTRUCTION DIVISION-1, GORAKHPUR, U.P. for
their kind support. They have always been a source of inspiration to me.
DATE: - 05/08/2016
AWINASH TIWARI
College: K.I.E.T GZB
Branch: CE, 4th Year
Roll No.130200036
4
TABLE OF CONTENTS
S. NO. CONTENT PAGE NO.
1 PUBLIC WORKS DEPARTMENT: AN OVERVIEW 5
2 INTRODUCTION 6
3 WHAT IS ROAD OR PAVEMENT? 8
4 TYPES OF PAVEMENTS 9
5 TYPES OF CONCRETE PAVEMENT 11
6 MINERALS USED 12
7 CEMENT
8 SAND
9 AGGREGATE
10 PROPORTIONING 16
11 PROCEDURE TO CONSTRUCT PAVEMENT 17
12 PREPARATION OF THE SUB- GRADE OR BASE
COARSE
18
13 MIXING AND TRANSPORTATION OF CONCRETE 19
14 PLACING OF CONCRETE 21
15 SLIPFORM CONCRETE PAVING 22
16 EXECUTION OF JOINTS 25
17 CURING 28
18 PROTECTION OF THE CONCRETE PAVEMENT 29
19 SPECIAL MEASURES 31
20 OPENING TO TRAFFIC 33
21 COST ANALYSIS OF RIGID PAVEMENT 34
22 CONCLUSION
TABLE OF CONTENTS
S. NO. CONTENT PAGE NO.
1 PUBLIC WORKS DEPARTMENT: AN OVERVIEW 5
2 INTRODUCTION 6
3 WHAT IS ROAD OR PAVEMENT? 8
4 TYPES OF PAVEMENTS 9
5 TYPES OF CONCRETE PAVEMENT 11
6 MINERALS USED 12
7 CEMENT
8 SAND
9 AGGREGATE
10 PROPORTIONING 16
11 PROCEDURE TO CONSTRUCT PAVEMENT 17
12 PREPARATION OF THE SUB- GRADE OR BASE
COARSE
18
13 MIXING AND TRANSPORTATION OF CONCRETE 19
14 PLACING OF CONCRETE 21
15 SLIPFORM CONCRETE PAVING 22
16 EXECUTION OF JOINTS 25
17 CURING 28
18 PROTECTION OF THE CONCRETE PAVEMENT 29
19 SPECIAL MEASURES 31
20 OPENING TO TRAFFIC 33
21 COST ANALYSIS OF RIGID PAVEMENT 34
22 CONCLUSION
5
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: 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.
6
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.
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.
7
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 SadakYojana 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.
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 SadakYojana 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.
8
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.
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.
9
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.
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.
10
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.
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.
11
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.
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.
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.
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.
12
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-
1.CEMENT
Cement is abinder, 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 describemasonryresembling modernconcretethat
was made from crushed rock with burntlimeas binder. Thevolcanic ashand
pulverizedbrickadditives 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
ofhydration, a chemical reaction between theanhydrouscement 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
ofmortarin masonry, and ofconcrete, a combination of cement and an
aggregateto form a strong building material.
• TYPES OF CEMENT:-
a. Portland cement
Portland cement is by far the most common type of cement in general use
around the world. This cement is made by heatinglimestone(calcium carbonate)
with small quantities of other materials (such asclay) to 1450 °C in akiln, in a
process known ascalcinations, whereby a molecule ofcarbon dioxideis liberated
from the calcium carbonate to formcalcium oxide, or quicklime, which is then
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-
1.CEMENT
Cement is abinder, 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 describemasonryresembling modernconcretethat
was made from crushed rock with burntlimeas binder. Thevolcanic ashand
pulverizedbrickadditives 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
ofhydration, a chemical reaction between theanhydrouscement 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
ofmortarin masonry, and ofconcrete, a combination of cement and an
aggregateto form a strong building material.
• TYPES OF CEMENT:-
a. Portland cement
Portland cement is by far the most common type of cement in general use
around the world. This cement is made by heatinglimestone(calcium carbonate)
with small quantities of other materials (such asclay) to 1450 °C in akiln, in a
process known ascalcinations, whereby a molecule ofcarbon dioxideis liberated
from the calcium carbonate to formcalcium oxide, or quicklime, which is then
13
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
ofgypsuminto 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 ofconcrete,mortarand most non-specialtygrout. The most
common use for Portland cement is in the production of concrete. Concrete is a
composite material consisting ofaggregate(gravelandsand), cement, andwater.
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.
b. 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.
c. 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
wherevolcanic ashesare available.
d. Portland silica fume cement
Addition ofsilica fumecan 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
2.SAND
Sand is a naturally occurringgranularmaterialcomposed 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 nontropicalcoastalsettings issilica(silicon
dioxide, or SiO2), usually in the form ofquartz.
The second most common type of sand iscalcium carbonate, for
examplearagonite, which has mostly been created, over the past half billion
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
ofgypsuminto 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 ofconcrete,mortarand most non-specialtygrout. The most
common use for Portland cement is in the production of concrete. Concrete is a
composite material consisting ofaggregate(gravelandsand), cement, andwater.
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.
b. 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.
c. 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
wherevolcanic ashesare available.
d. Portland silica fume cement
Addition ofsilica fumecan 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
2.SAND
Sand is a naturally occurringgranularmaterialcomposed 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 nontropicalcoastalsettings issilica(silicon
dioxide, or SiO2), usually in the form ofquartz.
The second most common type of sand iscalcium carbonate, for
examplearagonite, which has mostly been created, over the past half billion
14
years, by various forms of life, likecoralandshellfish. It is, for example, the
primary form of sand apparent in areas where reefs have dominated the
ecosystem for millions of years like theCaribbean.
3.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 concreteis 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
years, by various forms of life, likecoralandshellfish. It is, for example, the
primary form of sand apparent in areas where reefs have dominated the
ecosystem for millions of years like theCaribbean.
3.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 concreteis 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
15
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.
A. 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.
B. 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.
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.
A. 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.
B. 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.
16
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 .
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 .
17
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 SUB - 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;
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 SUB - 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;
18
• 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.
• 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.
19
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.
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.
20
21
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.
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.
22
SLIP FORM CONCRETE PAVING
• PREPARATION OF THE TRACK RUNWAY
The quality of the runway for the tracks of the paving equipment [10] 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.
SLIP FORM CONCRETE PAVING
• PREPARATION OF THE TRACK RUNWAY
The quality of the runway for the tracks of the paving equipment [10] 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.
23
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.
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.
24
• 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.
• 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.
25
• 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
• 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
26
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.
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.
27
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.
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.
28
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
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
29
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
[43]. 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 skinof 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.
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
[43]. 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 skinof 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.
30
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.
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.
31
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
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
32
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 %.
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 %.
33
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.
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.
34
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.
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.
35
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 RIGID 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
PAVEMENT
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.
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 RIGID 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
PAVEMENT
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.
36
CEMENT CONCRETE PAVEMENT VS BITUMINOUS
PAVEMENT- A COST ANALYSIS
CEMENT CONCRETE PAVEMENT VS BITUMINOUS
PAVEMENT- A COST ANALYSIS
37
38
39
CONCLUSION
India„iseconomical 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 PradhnMantri gram SarakYojana(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.
CONCLUSION
India„iseconomical 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 PradhnMantri gram SarakYojana(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.
40
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