Highway Network System Report
Highway Network System Report
Highway Network System Report
April-May,2020-2021
Department of Civil Engineering
SNJB’S Late Sau. Kantabai Bhavarlalji Jain,
College of Engineering, Chandwad
Dist. Nashik
SNJB’S Late Sau. Kantabai Bhavarlalji Jain,
College of Engineering, Chandwad
Dist. Nashik
Department of Civil Engineering,
2020-21
Certificate
This is to certify that the Seminar Report entitled Title of your Seminar Topic Title of your Seminar
Topic submitted by Mr. JAIN GAURAV RAMESH is a record of bonafied work carried out by
him under the supervision and guidance of Prof. O.V. Vaidya in partial fulfillment of the
requirement for TE (Civil Engineering) course of Savitribai Phule Pune University, Pune in the
academic year 2020-2021.
Date:
Place: Chandwad
Prof. O.V.Vaidya
Seminar Guide
Examiner: ___________________________________________________________________
ACKNOWLEDGMENT
First and foremost, we wish to record our sincere gratitude to Management of this college and to
our or his valuable suggestions and guidance throughout the period of this report. We express our
sincere gratitude to our guide, Prof. O.V. Vaidya, Department of Civil Engineering, SNJB’s Late
Sau Kantabai Bhawarlalji Jain College of Engineering, Chandwad for guiding us in investigations
for this seminar and in carrying out experimental work. Our numerous discussions with his were
extremely helpful. We hold his in esteem for guidance, encouragement and inspiration received
from her. The seminar on Highway Network System was very helpful to us in giving the necessary
background in-formation and inspiration in choosing this topic for the seminar. Our sincere thanks
to Prof. O.V. Vaidya Seminar Coordinator for having supported the work related to this seminar.
Their contributions and technical support in preparing this report are great acknowledged.
1. INTRODUCTION
According to the PCA (Portland Cement Association), CTB (Cement Treated Base)
has provided economical, long lasting pavement foundation. These structures have
combined soil and/or aggregate with cement and water which compacted to high density.
The advantages of cement stabilization are several:
1. Cement stabilization increases the base material strength and stiffness, which reduces
deflection due to the traffic loads. This delays surface distresses such as fatigue, cracking
and extends pavement structure life.
2. Cement stabilization provides uniform and strong support, which results in reduced stresses
to the sub-grade. Testing indicates a thinner cement-stabilized layer can reduce stresses
more effectively than a thicker un-stabilized layer of aggregate. This reduces sub-grade
failure, pot-hole formation and rough pavement surface.
3. Cement stabilized base has greater moisture resistance to keep water out; this maintains the
higher strength of the structure.
4. Cement stabilization reduces the potential for pumping of sub-grade fines.
5. Cement stabilized base spread loads and reduces sub-grade stress.
The mixture shall be composed of existing sub-grade, base course and surface
course materials, and/or an imported soil aggregate, with Portland cement and water added.
The mixture shall contain not less than 4% cement by volume of compacted mixture, 1420
kg (94 pounds) of cement being considered as 1 cu m (1 cubic foot). At least 30 days before
the beginning of stabilizing operations, adequate quantities of soil and cement shall be
supplied to the Materials Division for determination of cement requirements. The Engineer
will specify, based on laboratory tests, the exact percentage of cement to be used.
Specimens of soil aggregate, cement, and water shall develop a compressive strength of a
least 2.7 M Pa (400 psi) in 7 days.
3. MATERIALS
The materials used shall comply with the following requirements:
3.1. WATER
Water used in mixing or curing shall be clean and free from injurious amounts of
oil, salt, or other deleterious substances. Where the source of water is relatively shallow, it
shall be maintained at such a depth and the intake so enclosed as to exclude grass, vegetable
matter, or other foreign materials.
3.2. CEMENT
Fly ash may be used as a partial replacement for the cement. Replacement amounts,
not exceeding 25% by weight, shall be determined through trial batch investigations using
the specific materials proposed for the project. Mixtures with fly ash shall meet the same
requirements as mixtures without fly ash. All trial batches required by this specification
shall be accomplished by the Contractor, observed by the Engineer, and approved by the
Engineer of Materials. Fly ash will not be allowed as a substitute for high early strength or
blended cements.
For in-place stabilization, the fly ash and cement shall be blended to form a
homogeneous mixture before application on the roadway.
The use of cement salvaged from used or discarded sacks will not be allowed.
Cement placed in storage shall be suitably protected. Any loss of quality occurring during
the storage period will be cause for rejection. If the cement furnished shows erratic behavior
under the field conditions incident to the mixing and placing of the mixture, or in the time
of the initial or final set, the Contractor will at once, without notice from the Engineer, cease
the use of that brand of cement and furnish material of such properties as to ensure quality
work conforming to these specifications.
4. CONSTRUCTION REQUIREMENTS
Sufficient equipment shall be available so that the work may proceed in proper
sequence to completion without unnecessary delay. Equipment, tools, and machinery used
shall be maintained in a satisfactory working condition.
The application of cement and mixing of the cement and soil aggregate will be
allowed only on an approved sub-grade, free of excess moisture. No work will be allowed
on a frozen sub-grade.
The operations shall be such as to prevent the drifting of cement or dust off the
right-of-way.
Prior to other construction operations, the existing roadbed, including the shoulders,
shall be brought to line and grade and shaped to the typical cross section of the completed
roadbed and compacted to sufficient density to prevent rutting under normal operations of
construction equipment. All soft areas shall be corrected to provide uniform stability.
4.2. PULVERIZING
After shaping and compacting the roadbed, the material to be processed shall be
scarified and pulverized before application of cement. Pulverizing shall continue during
mixing operations until a minimum of 80% by weight of the material, exclusive of coarse
aggregate, will pass a 4.75 mm (#4) sieve. Material retained on a 75 mm sieve and other
unsuitable material shall be removed.
FIG.3.PULVERIZING OF ROAD
The application and mixing of cement with the aggregate material shall be
performed according to one of the following methods:
When a central plant is used, the soil aggregate, cement, and water shall be mixed
in a pug mill either of the batch or continuous flow type. The plant shall be equipped with
feeding and metering devices that will add the soil aggregate, cement, and water into the
mixer in accurately proportioned amounts as determined by the laboratory design.
Aggregate and cement shall be dry-mixed sufficiently to prevent cement balls from forming
when water is added. Mixing shall continue until a uniform mixture of aggregate, cement,
and water has been obtained. The mixture shall be hauled to the roadway in trucks equipped
with protective covers. Immediately before spreading the mixture, the sub-grade or
foundation course shall be moistened and kept moist, but not excessively wet, until covered
by the mixture. The mixture shall be placed on the roadbed in a uniform layer by an
approved spreader or spreaders. No more than 60 minutes shall elapse between adjacent
spreader runs and not more than 60 minutes shall elapse between the time of mixing and the
beginning of compaction. The layer shall be uniform in depth, and in such quantity that the
completed base will conform to the required grade and cross section. Dumping of the
mixture in piles or windrows will not be permitted.
The moisture content of the mixture during compaction shall not vary more than
±5% from the optimum moisture. The surface of the treated roadway shall be reshaped to
the required lines, grade, and cross section after the mixture has been compacted. It shall
be scarified lightly to loosen any imprints left by the compacting or shaping equipment and
rolled thoroughly. The operation of final rolling shall include the use of pneumatic tired
rollers. The rolling shall be done in such manner as to produce a smooth, closely knit
surface, free of cracks, ridges, or loose material, and conforming to the crown, grade, and
line shown on the plans.
The density, surface compaction, and finishing operation shall not require more
than two hours.
Water shall be added, if necessary, during the finishing operation to maintain the
mixture at the proper moisture content for securing the desired surface.
Areas inaccessible to rollers or finishing and shaping equipment shall be
thoroughly compacted to the required density by other approved compacting methods and
shaped and finished as specified.
5.2.2. JOINTS
As soon as final compaction and finishing of a section has been completed, the base
shall be cut back perpendicular to the center line to a point where uniform cement content
with proper density has been attained and where the vertical face conforms to the typical
section shown on the plans. When the road mix method is used, a header shall be placed
against the vertical face of the finished section and securely staked in place. This header
shall be left in place until all mixing operations on the adjoining section have been
completed, after which the header shall be removed and the trench backfilled with
processed material. This material shall be compacted so that a well-sealed joint is formed
and a smooth riding surface is obtained.
As an alternate to using a header, the subsequent day's operation may be started
by cutting back into the previously placed course to the extent necessary to obtain uniform
grade and compaction.
The finished surface of the treated base course shall conform to the general surface
provided for by the plans. It shall not vary more than 6 mm (¼") from a 3 m (10')
straightedge applied to the surface parallel to the center line of the roadway, nor more than
12 mm (½") from a template conforming to the cross section shown on the plans. Excess
material shall be disposed of as directed.
Immediately after the rolling and shaping has been completed, the surface of the
treated base course shall be covered by a protective coating of asphalt to prevent loss of
moisture during the curing period and to serve as a prime coat for the later application of
wearing course. The asphalt shall comply with the requirements listed herein and shall be
applied by means of an approved pressure distributor at the rate of 0.4 to 1.1 L/sq m to
provide complete coverage without excessive runoff. The actual rate of application will be
determined by the Engineer. When used, emulsified asphalt shall be diluted with an equal
amount of water before application. At the time of application, the base shall be in a moist
condition. The protective coating of asphalt shall be maintained until the wearing surface
is placed. If the condition of the protective coating is satisfactory, no additional prime coat
will be required at the time of placement of the wearing surface.
Furnishing and placing asphalt will not be paid for separately, but full compensation
therefore will be considered included in the contract unit price bid for Processing Cement
Treated Base Course.
Finished portions of the roadway adjacent to construction that is travelled by
equipment used in constructing an adjoining section shall be protected by means
satisfactory to the Engineer. If earth covering is used on fresh bases, straw, hay, building
paper or similar material shall be placed under the earth so that the covering may be
removed without damage to the base.
The basic principles in bituminous stabilization are water proofing and binding. By
water proofing the inherent strength and other properties of the soil could be retained. In
case of the cohesion less soils the binding action is also important. Generally, both binding
and water proofing actions are provided to soil.
In granular soil the coarse grains may be individually coated and stuck together by
a thin film of bituminous materials. But in fine grained soils bituminous material plugs up
the voids between small soil clods, thus water proofing the compacted soil-bitumen.
The mechanics of asphaltic soil stabilization are discussed based upon the major
four factors for any given soil material:
1. Soil status
2. Asphaltic material
3. Mixing
4. Compaction and Curing.
A method of bituminous stabilization of soils is presented as related to soils
developing appreciable degrees of cohesiveness when moist and which may be stabilized
by the principle of waterproofing. this method is based upon the theory that soil, water, and
bituminous material, including asphalt, may be placed in such independent relative positions
within a compacted mass of mixture so that a definite system exists or tends to predominate.
The system consists essentially of soil-water mixtures which are waterproofed by
bituminous films held or absorbed on their surfaces.
Stabilization by waterproofing may be accomplished with:
1. Relatively small quantities of bitumen,
2. A minimum of mixer work and time,
3. Utilization of the economies accruing from intermediate soil moisture contents during
mixing and compaction
4. The more complete utilization of soils in situ due to the greater range of soils which
may be successfully treated.
The bituminous stabilization of soil utilizing supplementary admixtures was
investigated by the use of Portland cement, lime, and aqueous solutions of certain heavy
metal salts. data presented indicate that stabilization of soil with materials as cement, consist
of two separable and distinguishable functions, one an alteration of soil character reducing
the sensitiveness of the soil to physical changes induced by water, the other a cementation
of the altered particles of soil into a water- tight coherent mass.
The first function may be produced by small quantities of cement, and the second
by bitumen, yielding a dual or composite form of stabilization possessing high strength,
flexibility, and high immunity to action of water and temperature. These principles were
applied in two processes, one a pre-treatment of soil with cement which included mixing,
wetting, curing, and repulverization, while the other method consisted of mixing, in
consecutive order, the materials soil, cement, water, and bitumen, forming a mixture capable
of being immediately laid and compacted. The effects of different types of cement upon the
changes induced in soil were discussed. The character of the reactions induced in soil by
both cement and lime were discussed. The efficiency of lime as an admixture material for
bituminous stabilization was studied. The economic practicality of the use of cement and
lime as bituminous stabilization adjuncts was discussed with attention to the method of soil
dilution by aggregate as an alternative.
The determining factors associated with soil modification vs. soil stabilization may
be the existing moisture content, the end use of the soil structure and ultimately the cost
benefit provided. Equipment for the stabilization and modification processes include:
chemical additive spreaders, soil mixers, portable pneumatic storage containers, water
trucks, deep lift compactors, motor graders.
High-calcium and low-calcium class C fly ashes from the Soma and Tuncbilek
thermal power plants, respectively, in Turkey, were used for stabilization of an expansive
soil. An evaluation of the expansive soil-lime, expansive soil-cement, and expansive soil-
fly ash systems is presented. Lime and cement were added to the expansive soil at 0–8%
to establish baseline values. Soma fly ash and Tuncbilek fly ash were added to the
expansive soil at 0–25%. Test specimens were subjected to chemical composition, grain
size distribution, consistency limits, and free swell tests. Specimens with fly ash were
cured for 7 days and 28 days, after which they were subjected to free swell tests. Based on
the favorable results obtained, it can be concluded that the expansive soil can be
successfully stabilized by fly ashes.
to prevent the deeper soil layers from causing distress to the structures in response to the
seasonal climatic variations.
In addition, there exists a need for in-situ soil stabilization using lime in case of
distressed structures founded on expansive soil deposits. The physical mixing of lime and
soil in shallow stabilization method ensures efficient contact between lime and clay
particles of the soil. It however has limitation in terms of application as it is only suited for
stabilization of expansive soils to relatively shallow depths. Studies available have not
compared the relative efficiency of the lime pile technique and lime-soil mixing method in
altering the physico-chemical, index and engineering properties of expansive black cotton
soils.
There are large deposits of the desert sand in the regions of Rajasthan and other
places in India. It is really a great problem to construct roads across the desert mainly
because of non-availability of other suitable materials. There is also acute scarcity of water
in the desert regions. Hence a suitable stabilization technique seems to be the only
economical solution.
The desert sand deposits consist of fine grained uniformly graded sand with, rounded
particles. This renders the desert sand with poor stability. The cement requirement for
satisfactory stabilization is also very high in such soil. Due to scarcity of water, soil-cement
stabilization is all the more difficult as considerable water is needed for soil cement base
course construction.
Use of hot sand bitumen would result in satisfactory mix, provided some material
including filler can be added to give a proper gradation of the mix. In this connection mixing
of locally available kankar dust has been found to give satisfactory result. However use of
hot sand bitumen mix is not economical for sub base and base course construction. If cut
back is to be used, the requirement of mixing water content would be considerable.
The most promising bituminous material in desert region seems to be the emulsion.
As the emulsion contains about 50% of water content, the additional quantity of water
needed for mixing would be very less. During curing the water evaporates, the emulsion
breaks down and the bitumen stabilizes the sand. The stability of the mix could be improved
by the addition of kankar powder, and other material to improve the gradation.
Fly ash is one of the residues generated in combustion, and comprises the fine
particles that rise with the flue gases. Ash which does not rise is termed bottom ash. In an
industrial context, fly ash usually refers to ash produced during combustion of coal. Fly
ash is generally captured by electrostatic precipitators or other particle filtration
equipment’s before the flue gases reach the chimneys of coal-fired power plants, and
together with bottom ash removed from the bottom of the furnace is in this case jointly
known as coal ash. Depending upon the source and makeup of the coal being burned, the
components of fly ash vary considerably, but all fly ash includes substantial amounts
of silicon dioxide (SiO2) (both amorphous and crystalline) and calcium oxide (CaO), both
being endemic ingredients in many coal-bearing rock strata.
Toxic constituents depend upon the specific coal bed makeup, but may include one
or more of the following elements or substances in quantities from trace amounts to several
percent: arsenic, beryllium, boron, cadmium, chromium, chromium
VI, cobalt, lead, manganese, mercury, molybdenum, selenium, strontium, thallium,
and vanadium, along with dioxins and PAH compounds.
Fly ash has been used as a pozzolanic admixture in concrete for more than 50 years.
Earlier uses were largely confined concrete for more than 50 years. Earlier uses were
largely confined to low-calcium ashes from hard bituminous or anthracite coals. However,
increased demand for fly ash coupled with the declining availability of suitable low-
calcium ashes has attracted a wider variety of fly ashes to the marketplace in recent years..
8. RETAINING WALLS
A retaining wall is a structure designed and constructed to resist the lateral pressure
of soil when there is a desired change in ground elevation that exceeds the angle of repose
of the soil. The active pressure increases on the retaining wall proportionally from zero at
the upper grade level to a maximum value at the lowest depth of the wall. The total pressure
or thrust may be assumed to be acting through the center of the triangular distribution
pattern, one-third above the base of the wall. Retaining walls serve to retain the lateral
pressure of soil. The basement wall is thus one form of retaining wall. However, the term
is most often used to refer to a cantilever retaining wall, which is a freestanding structure
without lateral support at its top.
Typically retaining walls are cantilevered from a footing extending up beyond the
grade on one side and retaining a higher-level grade on the opposite side. The walls must
resist the lateral pressures generated by loose soils or, in some cases, water pressures.
Lateral earth pressures are typically smallest at the top of the wall and increase
toward the bottom. Earth pressures will push the wall forward or overturn it if not properly
addressed. Also, any groundwater behind the wall that is not dissipated by
a drainage system causes an additional horizontal hydrostatic pressure on the wall.
1. Gravity Wall
Gravity walls depend on the weight of their mass (stone, concrete or other heavy
material) to resist pressures from behind and will often have a slight 'batter' setback, to
improve stability by leaning back into the retained soil. For short landscaping walls, they
are often made from mortar less stone or segmental concrete units (masonry units). Dry-
stacked gravity walls are somewhat flexible and do not require a rigid footing in frost areas.
Home owners who build larger gravity walls that do require a rigid concrete footing can
make use of the services of a professional excavator, which will make digging a trench for
the base of the gravity wall much easier.
Earlier in the 20th century, taller retaining walls were often gravity walls made from
large masses of concrete or stone. Today, taller retaining walls are increasingly built as
composite gravity walls such as: geosynthetic or with precast facing; gabions (stacked steel
wire baskets filled with rocks); crib walls (cells built up log cabin style from precast
concrete or timber and filled with soil); or soil-nailed walls (soil reinforced in place with
steel and concrete rods).
2. CANTILEVERED WALLS:
Sheet pile retaining walls are usually used in soft soils and tight spaces. Sheet pile
walls are made out of steel, vinyl or wood planks which are driven into the ground. For a
quick estimate the material is usually driven 1/3 above ground, 2/3 below ground, but this
may be altered depending on the environment. Taller sheet pile walls will need a tie-back
anchor, or "dead-man" placed in the soil a distance behind the face of the wall, that is tied
to the wall, usually by a cable or a rod. Anchors are placed behind the potential failure
plane in the soil.
4. ANCHORED WALLS:
9. PAVEMENT
The pavement is crucial part of any road project and needs to withstand traffic load
without deteriorating or deforming to the extent that it becomes unusable during the design
life period.
The initial cost of rigid pavement is no doubt higher than that of flexible pavement.
In terms of lifecycle costing, however, rigid pavement has proved to be more economical
than flexible pavement. Experts point out that while selecting the type of pavement,
lifecycle cost and not the initial cost should be taken into consideration. The lifecycle cost
analysis takes into account the initial investment cost as well as the maintenance and
rehabilitation cost over the design life of the pavement structure. The initial cost of rigid
pavement can be brought down to some extent with fly ash mixed concrete. In such case,
the lifecycle cost reduces further. Rigid pavement is generally preferred for locations
experiencing heavy rainfall, waterlogged areas and areas having sub-grade soil with low
CBR (California Bearing Ratio) values.
Chip seals are applied in a three-part process. The asphalt emulsion binder is first
sprayed onto the pavement. This is followed immediately by an application of rock chips.
Finally, the rocks are pressed into the asphalt binder using a heavy roller. This process is
more appropriate for use on roads than on parking lots. Service life is usually 5 to 7 years.
The road takes on more of the colour of the rock used in the chip layer since it's not mixed
together with the asphalt binder, so use of lighter coloured aggregate here can make more
of a difference in cooling the road surface.
Emulsion sealcoats are the familiar pre-mixed products often seen in shopping
center parking lots or on driveways. They consist of a fine aggregate (rocks of small size)
in emulsion (suspended in water) with an asphalt binder. Emulsion sealcoats are brushed
on over existing pavements to seal small cracks and protect the surface. When used
properly they're expected to last 3 to 5 years. These products are usually black but are
occasionally made in gray or tan with the addition of zinc oxide, although this may cost a
bit extra.
Slurry seals combine an asphalt emulsion with graded aggregate (rocks of special,
even sizes). This mixture is then applied to existing pavement using a squeegee-like drag.
Slurry seals are expected to last 3 to 5 years. Like the emulsion sealcoat, slurry seals are
usually black but can be made gray or tan with the addition of zinc oxide
FIG.12.SLURRY SEALS
Asphalt surface coatings are painted or sprayed directly over clean asphalt. These
coatings are decorative, while also serving to protect the asphalt underneath. They come in
many colours, but the lightest colours have the highest solar reflectivity and stay coolest.
9.1.7. WHITE-TOPPING
FIG.14.WHITE-TOPPING
The prestressing technique has been applied to the highway pavements in recent
years. The prestressed pavement can be built in continuous length up to 120 m without
joints. Elimination of joints without inducing cracks in the pavement could be considered
advantageous, in view of the maintenance problems associated with the joints. To
accommodate higher loads, there is obvious tendency of increasing the thickness. It may
be realized that an increase in the thickness gives rise to a great temperature differential of
the slab and also greater frictional resistance. A thick slab is therefore undesirable as well
as costly. By providing a residual compressive stress to the slab by use of tendons etc, the
total tensile stress can fairly be neutralized and thus same unit thickness of prestressed
concrete pavement could support heavier loads than plain concrete pavement and can be
built for longer without joints.
Following are few observations for the design:
1. Length: A length up to about 120 m can be prestressed for the pavement.
2. Width: A width of 3.6 m for prestressed pavement is desirable and a longitudinal a joint
therefore should be provided.
3. Thickness: Because of the need to provide a required cover for tendons, the minimum
recommended thickness is 15 cm.
4. Stress magnitude: A minimum value of 22 kg/cm2 of prestress is recommended for 120
m long prestressed pavement slabs. A transverse prestress if required should be of 3 to
4 kg/cm2.
11. CONCLUSIONS
Traditionally highways were used by people on foot or on horses. Later they also
accommodated carriages, bicycles and eventually motor cars, facilitated by advancements
in road construction. In the 1920s and 1930s many nations began investing heavily in
progressively more modern highway systems to spur commerce and bolster national
defense.
India has an extensive road network of more than 3 million kms which is the second
largest in the world, Roads carry about 60% of the freight and nearly 85% of the passenger
traffic, Highways/Expressways constitute about 66,000 kms. The Government of India
spends about Rs.18000 crores (US $ 4 billion) annually on road development. These new
trends are initiative in the highway improvements. Now highways are well stabilized and
more secure. The costs in the construction as well as in maintenance are reduced. These
new trends are eco-friendly because the use of fly ash is used as an important material and
it is a residual of thermal power stations and in Free State, it is very harmful for the
environment. So, there is a great hope for the further improvement in these techniques.
12. REFRANCES
1. http://www.tacatc.ca/english/resourcecentre/readingroom/conference/conf2007/docs/s8/starr
y.pdf
2. http://freearticlehq.com/home/process-of-soil-stabilization/
3. http://www.tpub.com/content/engineering/14070/css/14070_427.htm
4. http://www.tpub.com/content/UFC1/ufc_3_250_11/ufc_3_250_110019.htm
5. http://flyashbricksinfo.com/construction/soil-stabilization-with-flyash.html
6. http://flyashbricksinfo.com/flyash-concrete.html
7. http://en.wikipedia.org/wiki/Retaining_wall
8. http://www.cleanaircounts.org/resource%20package/a%20book/paving/other%20pavings/co
olpave.htm
9. http://www.freepatentsonline.com/3182109.html
10. http://pubsindex.trb.org/view.aspx?id=283852
11. http://en.wikipedia.org/wiki/Highway
12. http://toostep.com/idea/what-are-the-modern-trends-happening-in-the-highway-construc