Study of causes of failures and remedies on road

STUDY OF CAUSES OF FAILURES AND REMEDIES ON ROAD | 2015-16
S.S.V.P.S.’s B.S.D. C.O.E. Dhule 1
A Project Report On
STUDY OF CAUSES OF FAILURES
AND REMEDIES ON ROAD
Submitted to
North Maharashtra University, Jalgaon (MS)
BY
SONAWANE SWAPNIL DILIP
BRAHMANKAR VIVEK SURESH
PATIL SHANTANU SANJAY
THAKUR DIPAK VINOD
PATIL UMAKANT BARIKRAO
DEPARTMENT OF CIVIL ENGINEERING
S.S.V.P.S.’s B.S.D. COLLEGE OF ENGINEERING,
DHULE-424005
2015-2016

INDEX
Sr No Content Page No
1
1.1
1.2
1.3
1.4
CHAPTER 1 Introduction
History of road development
Necessity and importance of roads
Objectives of study
Scopeof study
03
04
05
05
2
2.1
2.2
CHAPTER 2 Literature Review
General
General types of road failures
06
07
3
3.1
3.2
3.3
3.4
3.5
CHAPTER 3 Methodology
General
Case study
Material Testing
Drainage overview
Suggestion for treatment for existing pavement
12
15
21
35
43
4 Conclusion 45
5 Reference 46

CHAPTER 1
INTRODUCTION
1.1 History of road development:
Thousands of years before urban planning, motor vehicles, or even the wheel, the first roads
appeared on the landscape. Just as molecules coalesced into cells and cells into more complex
organisms, our first roads were spontaneously formed by humans walking the same paths over
and over to get water and find food. As small groups of people combined into villages, towns
and cities, networks of walking paths became more formal roads. Following the introduction of
the wheel about 7,000 years ago, the larger, heavier loads that could be transported showed the
limitations of dirt paths that turned into muddy bogs when it rained. The earliest stone paved
roads have been traced to about 4,000 B.C. in the Indian subcontinent and Mesopotamia.
To help support the movement of legions throughout their empire, the Romans developed
techniques to build durable roads using multiple layers of materials atop of deep beds of crushed
stone for water drainage. Some of those roads remain in use more than 2,000 years later, and the
fundamental techniques form the basis of today's roads.
Modern road-construction techniques can be traced to a process developed by Scottish
engineer John McAdam in the early 19th century. Mc-Adam topped multi-layer roadbeds with a
soil and crushed stone aggregate that was then packed down with heavy rollers to lock it all
together. Contemporary asphalt roads capable of supporting the vehicles that emerged in the 20th
century built upon McAdams' methods by adding tar as a binder.
The actual process of road building has changed dramatically over the past century, going
from large gangs of workers with picks and shovels to enormous specialized machines.
Rebuilding existing roads starts with peeling up existing pavement, grinding it and dumping it
straight into trucks for reuse later as aggregate for new roads. After grading the surface, pavers
come in and lay down fresh, continuous sheets of asphalt followed directly by the rollers.
1.1.1 Indian history:
The first evidence of road development in the Indian-subcontinent can be traced back to
approximately 2800 BC from the ancient cities of Harappa and Mohenjo-Daro of the Indus
Valley Civilization. Ruling emperors and monarchs of ancient India had constructed roads to
connect the cities. Archaeological excavations give us fresh information about road connectivity
in ancient India. The Grand Trunk Road was built by Sher Shah Suri in 1540-45
connecting Sonargaon near Dhaka in Bangladesh with Peshawar in modern-day Pakistan linking
several cities from in India.
India inherited a poor road network infrastructure at the time of its independence in 1947.
Beyond that, between 1947 and 1988, India witnessed no new major projects, and the roads were
poorly maintained. Predominantly all roads were single lane, and most were unpaved. India had

no expressways, and less than 200 kilometers of 4-lane highways. In 1988, an autonomous entity
called the National Highways Authority of India was established in India by an Act of
Parliament, and came into existence on 15 June 1989. The Act empowered this entity to develop,
maintain and manage India's road network through National Highways. However, even though
the Authority was created in 1988, not much happened till India introduced widespread
economic liberalization in the early 1990s. Since 1995, the authority has privatized road network
development in India, and by May 2014 delivered a state wise lengths of over 92,851 kilometers
of National Highways, of which 22,757 kilometers are 4-lane or 6-lane modern highways.
1.2 Necessity and Importance of roads:
Highway engineering means the art of designing, constructing and maintaining public roads.
Roads are considered to be one of the most cost effective and preferred modes of transportation.
It is easily available and accessible to all sections of the society. It facilitates the movement of
both men and materials from one place to another within a country. It helps to bring about
national integration as well as provide for countries overall socio-economic development. It is a
key infrastructural unit which links to other modes of transportation like railway, shipping,
airways etc. Hence an efficient and well established road network is inevitable for promoting
trade and commerce as well as meeting the needs of sound transportation system in the country.
Road construction should have the highest priority in development plan of our country. In this
era of liberalization, road infrastructure has come under immense pressure due to increasing axle
loads and increase in traffic. Improvement of roads is essential for the development of the
industries and societies as the whole. It is also essential provided all weather roads to rural areas
to help and to reach the benefits of development in science and modern technology to the poor
and backward people living in distant villages.
1.2.1 Indian scenario:
The importance of roads in a vast country like India can scarcely be exaggerated. A system of
well-designed ,well-constructed and well maintained roads is essential for country’s economy
and cultural development. The roads also have to play a vital role in the defense of our country.
It can be stated in general that India’s deficiency in the matter of roads has contributed very
largely to her poor development in agriculture, Commercial and industrial fields.
The road network of India is about 3.3 million Kilometers, one of the largest road network in the
world which includes national highways covering about 65,000 Kilometers, state highways
covering about 2 lack Kilometers and rural and urban roads covering nearly 3 million kilometer.
In India, department of road transport and highways, under the ministry of shipping, road
transport and highways, is the main authority concern with development of road ways. Is has
overall responsibility for planning, construction and road development of national highways in
the country.

1.3 OBJECTIVES OF THE STUDY
Roads in our country have been classified as
1. Asian highway (AH)
2. National highways (NH)
3. State highway (SH)
4. Major District Roads (MDR)
5. Other District Roads (ODR)
6. Village Roads (VR)
Each type of above roads is designed by authorities considering various aspect, such as traffic
intensity, soil bearing capacity, need of road and strategic importance etc. If a road is constructed
exactly as per norms and regulations given, then arises the problems and life of road is reduced
significantly. Ultimately progress of country is affected..
The specific objectives of this study were:
1. To identify the different locations of pavement distress in MDR.
2. The frequency of pavement distress present on this MDR stretch.
3. To study possible causes of these distresses and at meantime suggesting remedies and
solutions for these distresses.
4. To assess the performance of the MDR.
1.4 Scope of the study
Site observations of flexible pavement distress in various countries indicate frequent
occurrence of longitudinal (top-down) cracking from the top surface layer. However, due to the
complexity of tire/pavement interaction resulting from tire geometry and loading conditions, the
accurate and fully representative distribution of surface stresses remains partly unknown. The
study of flexible pavement distress is advantageous for the highway engineers because of the
following reasons:-
1. It gives us the most accurate reason for the pavement distress/failure which makes the
repairing work easy.
2. The knowledge about pavement distress enables us able to make more efficient and high
performance pavement.
3. Hence, high performance pavement ensures efficient traffic flow and safety to the
passengers.
4. Moreover, the study of pavement distress in an area helps in the improvement in design
of the pavement, which may be so more effective in the area.

CHAPTER 2
LITERATURE REVIEW
2.1 GENERAL
Any kind of road, at some point of time in future after its construction is bound to fail and it
needs to be reconstructed. Life of each type of road varies as per various factors, such as
standard of construction, provision of thickness of road, use of standard material and machinery
etc. but if the failure of a road occurs before its anticipated period of failure then there is mistake
in procedure, which needs to be found out and studied, so as not to repeat it in future road
construction activities.
 Gerritsen et al. (1987) conducted a field study in the Netherlands on the occurrence of
surface cracking in asphalt pavements, and on the potential causes of surface cracking.
Static indirect tensile tests were performed on core samples collected; they showed that
the asphalt concrete outside of the wheel paths tended to have low strength characteristics
at low temperatures.
 Matsuno and Nishizawa (1992) examined longitudinal surface cracking in asphalt
pavements in Japan. Visual observations indicated that the cracking appeared 1 to 5 years
after the road’s construction typically occurred in the passing lane. It was also observed
that the cracks were within or very close to the wheel paths. In addition, cracks did not
appear in shadowed areas such as near an overpass bridge.
 Collop and Cebon (1995) examined the potential of longitudinal surface fatigue cracking
in asphalt pavements using different analytic and numerical solutions. From 2D plane
strain elastic half-space solution, the author concluded that there is singularity in surface
stresses at both ends of the contact if a discontinuity in shear tractions is assumed. The
authors concluded that shear tractions between the tire and the pavement induce high
local tension around the edge of the contact patch, which may lead to surface longitudinal
cracks that propagate by thermal fatigue.
 Dauzats and Rampal (1987) surveyed several pavement sections located in the south of
France. In this area, pavements are subjected to extreme thermal stresses. Longitudinal
surface cracks in these sections were observed 3 to 5 years after construction of the road
containing a slow lane and a fast lane. The longitudinal cracks were located on the
centerline side of the slow lane. It also observed that the appearance of cracks fluctuated
with the seasons.
A try has been made by considering a sample road to study its failures, solution on failures
such that they would not have occurred and maintenance of existing road pavement.

2.2 General types of road pavement failure are:
2.2.1 Potholes
Potholes are what most people think of
when they think of pavement failures.
These are usually non-functional
pavement areas where the pavement has
completely failed, exposing the base
aggregate beneath it. Potholes usually
pose liability issues such as causing
vehicular suspension damage, or tripping
hazards if they reside within pedestrian
walkways.
Potholes are often the result of several years of failing pavement in areas of fatigue where
pre-emptive repair was not done until the area has completely failed.
Potholes should be sawcut around the entire failing area, excavated, and base repaired using
fresh crust stone quarry available near by the site. Then proper placement of the asphalt design
specification. The asphalt design specification varies from job to job.
2.2.2 Fatigue cracks
Fatigue is one of the most common
types of failure that occurs in asphalt.
Fatigue often presents a cracking
pattern that slightly resembles the back
of an alligator or a spider web, which is
why these cracks are often referred to as
alligator cracking or spider webbing.
These types of failures are often the
result of insufficient support in the
underlying base structure due to either insufficient design and construction or water
penetration that has resulted in a weakened base.
In cases where the fatigue is considered non-severe and remains relatively stable, a thin
coat of crack reflection treatment can be applied followed by an asphalt overlay of the
fatigued area.
In the cases where the fatigue is more severe, exhibiting larger spaces between the pieces
suggesting more movement, the area should be saw cut, excavated or milled. The base
structure should be repaired and the asphalt then replaced.

2.2.3 Blowout
A blowout is an extreme form of pothole
that occurs when the base under the failure
has completely failed, often leading the
surrounding asphalt to "blow-out" along the
edges.
Blowouts often require extensive base
repair and/or reconstruction. Given the
severity of the failure, it is crucial to ensure
that root cause is identified and repaired along with the failed area. Often times these types of
failures are "fixed" without root-cause being addressed, only to fail again.
These types of failures suggest an underlying lack of support within the base structure itself.
These repairs often require complete base reconstruction, often with subgrade stabilization
techniques to be applied, such as cement sub-grade stabilization and/or Geogrid placement.
2.2.3 ReflectionCracks
Reflection cracks tend to occur whenever older cracked asphalt or concrete is overlaid with a
fresh layer of asphalt typically about 1" to 2" thick. The cracks underneath the new asphalt
eventually will reflect up through the new layer of asphalt.
This is typically the result of the original pavement structure and the overlay moving relative
to each other. This movement tends to wear on the underside of the new asphalt and work its
way upward to the surface, resulting in a crack in the new asphalt that is identical to the crack
underneath.
Cracks in the original asphalt will reflect up through the overlay given time.
The rate at which the reflection occurs can be adjusted using several surface treatment
techniques prior to applying the overly. These include Bituminous Surface Treatment (otherwise
known as BST, chip seal, or permaflex), applying a bitumen non-woven geotextile fabric, or
replacing the worst areas of fatigue prior to an overlay.
The thicker the overlay asphalt layer, the longer the time required for cracks to reflect through.

2.2.4 Sinkhole
Sinkholes are often the result of subsurface
drainage that erodes the underlying support
substructures of the pavement. Over time, this
erosion results in a cavity underneath the
pavement.Sinkholes are often observed as an
area that has a sudden and often significant drop
in elevation, sometimes resulting in a complete
open cavity that may pose significant liability
risk.
Sinkholes located in the drive lanes that support significant traffic should be repaired
immediately as they can result in significant failures overnight.
It is crucial to ensure that root cause is properly identified and repaired while repairing the
sinkhole itself. Often times these types of failures can be caused by plumbing, sewer, or drainage
leaks. Additional causes may be drainage avenues opening along laid utility lines underground.
2.2.5 Block / Shrinkage Cracks
Block cracks, otherwise referred to as shrinkage
cracks, present themselves as linear cracks several
feet apart but often at different angles.
These types of cracks often appear in older
asphalt that sees a light traffic loading. They are the
result of the asphalt being allowed to shrink
horizontally with little stress being applied vertically
as the asphalt ages.
These typically should be filled with and sealed with
a hot pour crack filler material to prevent water
penetration.

2.2.6 Rutting
Rutting involves depressions in the pavement that occur
within the wheel tracks of vehicles. This is usually due to
insufficient load-bearing capability of the asphalt/base design
within that area.
It most often occurs in fatigued drive lanes, or close to
overly stressed areas such as at stop signs, or in front of
dumpster pads.
2.2.7 Raveling
Raveling occurs when the stone aggregate
that was originally part of the pavement
begins to break free from its bonds with the
asphalt. Typically this tends to occur on older
pavements that have already oxidized.
Over time as more and more aggregate
breaks free from the asphalt, the asphalt loses
significant load-bearing capability and will
begin to prematurely fail in the areas that have
exhibited the most raveling and bears the most traffic-loading.
The typical repair for this type of situation is to overlay the raveling asphalt with a new layer
of fresh asphalt. Typically 1.5" to 2" of new asphalt is recommended.
2.2.8 Slippage Cracks
These types of cracks develop as a result of an
overlay layer "slipping" across the underlying
asphalt, resulting in cracks that resemble a
smudge. The most frequent cause of these types
of cracks is usually insufficient tack coat on the
underlying pavement prior to the surface asphalt
being applied.
These cracks often reveal themselves in
stressed areas where traffic loading is increased
due to either turning or stopping. The most common repair for these issues is full-depth asphalt
replacement.

2.2.10 Shoving / Corrugation
These types of failures present bumps or corrugations where the surface asphalt has been
"shoved" or bunched up. This is most often the result of extreme horizontal stress caused where
heavy traffic loads typically stop or start.
The most common repair for these areas is to perform full-depth repair. This exposes the base,
allowing for any base weaknesses to be repaired.
2.2.11 SeamCracks
Seam cracks develop along the joints of asphalt
where different paving pulls come together. These
usually exhibit themselves as long linear cracks that
should simply be crack filled on a regular basis.
If left unsealed, these cracks can become central
points for fatigue as water seeps under pavement.
Once a seam crack opens wider into a fatigued area,
it should be treated as a fatigue area since
adequately sealing these types of cracks is difficult.
2.2.12 Peeling
Peeling typically occurs on pavement that had
previously been overlaid with asphalt and the overlay
layer of asphalt has begun to fail as a result of
underlying fatigue "reflecting" up through the overlay
layer.
This usually occurs many years after the overlay
has been installed. The overlay layer oxidizes, and
becomes brittle and much more susceptible to the
underlying fatigue cracking reflecting through. Once the fatigue failure has reflected through, the
overlay now exhibits the same fatigue failure as the underlying asphalt.
The pieces from the overlay tend to break free, exposing the original, fatigued asphalt
beneath it.

The only permanent repair for these areas is a complete removal and replacement of the
entire failed area along with the underlying fatigued asphalt.
2.2.13 Bleeding
Bleeding occurs when the asphalt contains too
much asphalt cement relative to the aggregate. In
these cases, the asphalt cement tends to "bleed"
thorough the surface.
These types of issues are typically still
functional but present an unsightly appearance to
the pavement. Typical repairs for these areas are to
either apply a chip seal application using absorbent
aggregate or to mill off the top layer of asphalt and apply a new course of hot mix asphalt that
contains a lower asphalt cement content.
CHAPTER 3
METHEDOLOGY
3.1 GENERAL
In this project, an attempt has been made to know the basic causes of failures of flexible road
pavement. As it has been discussed previously, there are various types of failures, but it is
necessary to know the causes of those failure. It means we must to know the overall causes of
failure, so that we can work upon them & prevent those failures in future.
Generally, failure of road pavement occurs because of following reasons:
1. Use of substandard material
2. Low bearing capacity of sub strata
3. Improper or no provision of drainage
4. Improper supervision at site
5. Faulty workmanship
6. Tendency of taking more profit of contractor
7. Inadequacies in the initial design, specifications and construction standards of the
bituminous layers
One by one, all the above points have been explained in order to know thoroughly the causes of
failure.
1. Use of substandard material:
Use of inferior materials:

If the materials employed in the construction of flexible pavements do not comply with the
standard requirements, the structural behavior of the pavement is affected.
 Aggregates
Requirement for aggregates:
Adhesionwith bitumen: Aggregate should be have less affinity with water as compared with the
bituminous material.
Cementation: The binding quality of road of the road aggregate depends on its ability to form its
own binding material under traffic so as to make the rough broken stone pieces grip together to
resist displacement by traffic.
Durability: The durability of an aggregate indicates its resistance to the action of weather
therefore it is desirable that road aggregate should possess sufficient soundness to resist the
action of weather so that life of road made with may be prolonged.
Hardness: The road aggregate should be reasonably hard to offer resistance to the action of
abrasion and attrition. The abrasive action is very severe for roads which are used by the steel
tyred vehicles.
Shape: The shape of aggregate may be rounded, angular, flaky or elongated the flaky and
elongated.
Strength: The road aggregates should be sufficiently strong to withstand the stresses developed
due to the wheel loads of traffic.
Toughness: toughness of an aggregate is that property which enables the aggregate to resist
fracture when struck with a hammer and is necessary in a road metal to withstand the impact
blows caused by traffic. It’s desirable that the road aggregate is reasonably tough.
Test such as abrasion test, crushing test, impact test, shape test, soundness test,
specific gravity test and stripping value test carried out in a lab on the samples of road aggregate
to ascertain their properties.
 Bitumen
Bituminous materials are also called binders and when they are used in combination with
mineral aggregate, they have to perform no. of functions.
Objectives of bitumen are:-
Binding effect: bitumen binds to surface particles together and loss of material from
surface by suction under moving vehicle is checked.
Cushion: it acts as a cushioning material on surface and absorbs impact, friction.
Resistance to weathering agencies: if properly selected bituminous material is used
surface can resist actions of wind and the sun.
Sealing of surface: when used with dense graded granular material, its seals the surface
against ingress of water and thus damage s prevented.

Test such as ductility test, flash and fire point test, float test, penetration test, softening point
test, viscosity test etc. can be carried out to check the standard of bitumen.
2. Low bearing capacityof sub strata:
Following are the reasons for low bearing capacity of sub strata
a) Inadequate strength: the poor mix proportioning or inadequate thickness of pavement
may lead to the lack of stability or strength of sub base or base course.
b) Inadequate wearing course: if the wearing course is of inadequate thickness or if it is
totally absent, the sub base are exposed to the damaging effects of the climatic agencies
and the traffic.
c) Loss of lateral confinement: if lateral confinement is not provided for granular sub base,
the action of traffic causes the materials of these courses to spread out.
d) Loss of binding action: the repeated stress applications lead to the internal movements of
aggregate in sub base courses and ultimately the composite mass or structure of layers
gets disturbed. Thus the loss of binding action is developed and it leads load transmitting
property of the pavement layer.
3. Improper or no provision of drainage:
The water should be prevented from reaching the road structure wherever possible or attempt
should be made to remove it quickly from the road surface by laying a well-designed drainage
system. Following are the defects due to improper drainage:
a) it allows the washing out of highway portions and causes excessive erosion leading to the
formation of the gullies along the road sides or road embankments.
b) It causes considerable damage to the shoulders and pavement edge due to the presence of
excess of water
c) it causes the failure of bituminous pavement due to the stripping of bitumen from aggregate
like loosening or detachment of some of the bituminous pavements and formation of the pot
holes.
d) It is the prime cause of failure in rigid pavements due to mud pumping by the presence of
water in fine subgrade soil.
e) It leads to the failure of earth slopes because of excess moisture causes increase in weight and
thus the stress is also increase which ultimately reduces the strength of soil mass.
f) It leads to the formation of waves and corrugations in flexible pavement
h) it leads to the freezing action due to moisture held in the soil and result in heaving with
consequent breaking up or shattering of road surface or pavement.
4. Improper supervision at site:
Improper supervision by the site engineer will ultimately lead to reducing the life of road.
Proper supervision is required for achieving the economic road. Proper utilization of construction
materials will significantly affect the cost of road construction. Lack of supervision decreases the
durability of road. Proper supervised roads will reduce the traffic intensity and frequency of
accidents. Proper supervision will reduce the accidents on site.

5. Faulty workmanship:
Using unskilled labors will cause excessive and improper use of materials and adopting faulty
& wrong methods of construction. Hence the reliability of constructed structure is also reduced.
It will increase the cost as well as the time needed to complete road construction.
6. Tendencyof taking more profit of contractor:
Due to this tendency of contractors, use of low quality material is done in constructing the
road ,also ,outdated practices of road construction are used ,which result in poor quality roads
and more time as well as money is spent than what is needed. So, supervising engineers need
to pay more attention in work and take strict actions if needed.
3.2CASE STUDY
For studying causes of the failure of road, our group has taken a case study of a flexible
pavement.
For taking a problematic road for our case study purpose, we approached Mr. S.D.
Suryawanshi, who is a deputy engineer in public work sub-division, Dhule. We requested him to
suggest a problematic road for our study purpose (letter seeking permission has been
attached),He cooperated with us and permitted us to study Dhule-Vadjai-Saundane road (Major
District Road 27).
Geology of area – this road stretch of Dhule-Vadjai-Saundane road km 0/000 to 21/200,
passes through semi Murum terrain.
We selected those patches on the road , where rate of failure was more. For that purpose, 4
patches of about 200-400 meter in length were selected. Positions of the patches has been shown
below.
In our first reconnaissance, we found out that the road was in a poor condition, there were
number of potholes on road at frequent intervals. Also, there was erosion of bituminous surface
and an uneven settlement could be seen on the road. There were longitudinal cracks onsite. Also
condition of drainage was quite poor, it needed maintenance. So, overall maintenance.

3.2.1 Details ofdistress found in MDR 27
The basic reason for pavement distresses along the Highway and flexible pavement in general
is a resultant of poor implementation of mix design and poor workmanship followed by lack of
timely maintenance. Details of the distresses found in MDR 27 starting from 80 Feet road are
tabulated in following Table.
Patch 1 (0/000 km to 0/600 km)
No. Location from start point Type Length (mm) Depth (mm)
1 0/200 Pothole 2000 130
2 0/220 Pothole 1330 127
3 0/250 Pothole 3990 117
4 0/330 Pothole 3002 119
Stripping 490
5 0/450 Pothole 2503 112
Stripping 620
Edge raveling 2000
6 0/470 Pothole 2600 129
Alligator cracking 1005
7 0/520 Longitudinal cracking 12850
Patch 2 (2/000 km to 2/500 km)
1 2/200 Pothole 2000 130
2 2/270 Pothole 1330 127
Stripping 540
3 2/340 Pothole 3990 117
4 2/400 Pothole 3002 119
Stripping 490
5 2/450 Pothole 2503 112
Stripping 620
Edge raveling 2000

Patch 3 (6/400 km to 6/800 km)
1 6/440 Pothole 2000 130
2 6/525 Pothole 1330 127
Stripping 540
3 6/560 Pothole 3990 117
4 6/600 Pothole 3002 119
Stripping 490
6 6/720 Pothole 2600 129
Alligator cracking 1005
3.3.3 MATERIALTESTING
1. AGGREGATE
On MDR 27, after analyzing the conditions on the road, there were many reasons,
because of which the failure of the road occurred. As has been mentioned above, the
various causes of failures, some of them were found on this road too. One by one, each
type of failure has been explained.
First cause of failure that was analyzed was use of substandard material in the
construction of road.
For that purpose, trial pits at various places on that particular road were dug. Samples of
all the materials, such as aggregates,moorum, bouldersetc.weretaken. Laboratory tests on
all this type of materials was done to assess their properties. Their resultant properties
were compared with those of standard values of the materials and by this, it was assessed
if material used in road construction was of substandard quality.
First ,quality of aggregates taken from trial pits was checked ,for that, various
laboratory tests, such as aggregate crushing test, aggregate impact test etc. were
performed and their standard was checked. Following is the details of the tests:

i)Aggregate Impact Test
IMPORTANCE
1. Aggregate impact value test gives an indication of aggregate’s toughness property (i.e.
property of a material to resist impact)
2. The test equipment and the test procedure are quite simple and it determines the resistance
to impact of stone aggregates simulating field condition.
3. This test can be performed even at construction site or at stone quarry, as the apparatus is
simple and portable
4. .Aggregate impact value test also gives an indirect indication of the strength characteristics
of aggregate.
5. Aggregate impact value of a sample also depends on the shape factors such as flakiness
index and elongation index of the aggregates.
Procedure:-
The test sample consists of aggregates sized 10.0 mm 12.5 mm. Aggregates may be dried by
heating at 100-110° C for a period of 4 hours and cooled.
(i) Sieve the material through 12.5 mm and 10.0mm IS sieves. The aggregates
Passing through 12.5mm sieve and retained on 10.0mm sieve comprises the test
Material.
(ii) Pour the aggregates to fill about just 1/3 rd depth of measuring cylinder.
(iii) Compact the material by giving 25 gentle blows with the rounded end of the

Tamping rod.
(iv) Add two more layers in similar manner, so that cylinder is full.
(v) Strike off the surplus aggregates.
(vi) Determine the net weight of the aggregates to the nearest gram (W).
(vii) Bring the impact machine to rest without wedging or packing up on the level plate, block or
floor, so that it is rigid and the hammer guide columns are vertical.
(viii) Fix the cup firmly in position on the base of machine and place whole of the test
sample in it and compact by giving 25 gentle strokes with tamping rod.
(ix) Raise the hammer until its lower face is 380 mm above the surface of aggregate sample in
the cup and allow it to fall freely on the aggregate sample. Give 15 such blows at an interval of
not less than one second between successive falls.
(x) Remove the crushed aggregate from the cup and sieve it through 2.36 mm IS sieves until no
further significant amount passes in one minute. Weigh the fraction passing the sieve to an
accuracy of 1 gm. Also, weigh the fraction retained in the sieve.
Compute the aggregate impact value. The mean of two observations, rounded to nearest whole
number is reported as the Aggregate Impact Value.
Impact Value
Aggregate Impact value =
𝑤2
𝑤1
x100
Where,
W1=Original weight of oven dry sample
W2=Weight of material passing 2.36 mm I.S. sieve
W1=624 gm.
W2=192 gm.
Aggregate Impact Value=
𝑤2
𝑤1
x100
=
192
624 x100
=30.76 %
Classification of aggregates using Aggregate Impact Value is as given below:

Aggregate Impact Value Classification
<10% Exceptionally Strong
10 – 20% Strong
20-30% Satisfactory for road surfacing
>30% Weak for road surfacing
The result shows that aggregates used are weak for road surfacing.

ii)Crushing Test
Importance:-
This test helps to determine the aggregate crushing value of coarse aggregates as per IS: 2386
(Part IV) – 1963. The apparatus used is cylindrical measure and plunger, Compression testing
machine, IS Sieves of sizes – 12.5mm, 10mm and 2.36mm
Procedure:-
(i)Put the cylinder in position on the base plate and weigh it (W)
(ii)Put the sample in 3 layers, each layer being subjected to 25 strokes using the tamping rod,
care being taken in the case of weak materials not to break the particles and weigh it (W1)
(iii)Level the surface of aggregate carefully and insert the plunger so that it rests horizontally on
the surface, care being taken to ensure that the plunger does not jam in the cylinder.
(iv) Place the cylinder with plunger on the loading platform of the compression testing machine.
(v)Apply load at a uniform rate so that a total load of 40T is applied in 10 minutes.
(vi)Release the load and remove the material from the cylinder.
(vii)Sieve the material with 2.36mm IS sieve, care being taken to avoid loss of fines.
(viii)Weigh the fraction passing through the IS sieve (W2)

Calculations
Aggregate crushing value =
𝑤2
𝑤1
x100
Where,
W1= total weight of dry sample
W2= weight of material passing 2.36 mm I.S sieve
W1= 4.414 kg
W2= 1.549 kg
Aggregate crushing value=
𝑤2
𝑤1
x100
=
1.549
4.414
x100
= 35.09 %
Aggregate crushing value for surface course should be within 30% ,so,from above results ,we
can see that results are not satisfactory.

3.3.3 SUB SOIL
As explained earlier quality of materials taken from bore pits are to be checked. So, after testing
of aggregates, bearing capacity of sub grade soil is checked. For that purpose, CBR Test
(California bearing ratio) in lab was done. It has been explained below.
CALIFORNIA BEARING RATIO:
California bearing ratio is the ratio of force per unit area required to penetrate in
to a soil mass with a circular plunger of 50mm diameter at the rate of 1.25mm /Min.
APPARTUS
 Moulds 2250cc capacity with base plate, stay rod and wing nut confirming to 4.1,
4.3 and 4.4 of
IS: 9669-1980.
Collar confirming to 4.2 of IS: 9669-1980.
 Spacer Disc confirming to 4.4 of IS: 9669-1980.
 Metal rammer confirming to IS: 9189-1979.
 Expansion measuring apparatus with the adjustable stem, perforated plates, tripod
confirming and to weights confirming to 4.4 of IS: 9669-1980.
 Loading machine having a capacity of at least 5000kg and equipped with a
movable head or base that travels at a uniform rate of 1.25mm / min for use in
forcing the penetration plunger in to the specimen.
 Penetration plunger confirming to 4.4 of IS: 9669-1980.
 Dial gauge two numbers reading to 0.01mm.
 IS sieves 37.50 or 22.50 or 19mm and 4.75mm.
 Miscellaneous apparatus such as mixing bowl, straight edge, scales, soaking tank,
drying oven, filter paper, dishes and calibrated measuring jar.

PROCEDURE
 There are two types of methods in compacting soil specimen in the CBR moulds
i. Static Compaction method.
ii. Dynamic Compaction method.
We have used dynamic compaction method for this particular samples of soil.
 The material used in the above two methods shall pass 19mm sieve for fine grained
soils and 37.50mm sieve for coarse materials up to 37.50mm.
 Replace the material retained on 19mm sieve by an equal amount of material
passing 19mm sieve and retained on 4.75mm sieve
 Replace the material retained on 37.50mm sieve by an equal amount of material
passing 37.50mm sieve and retained on 4.75mm sieve.
Dynamic Compaction
 Take representative sample of soil weighing approximately 6kg and mix
thoroughly at OMC.
 Record the empty weight of the mould with base plate, with extension collar
removed (m1).
 Replace the extension collar of the mould.
 Insert a spacer disc over the base plate and place a coarse filter paper on the top of
the spacer disc.
 Place the mould on a solid base such as a concrete floor or plinth and compact the
wet soil in to the mould in five layers of approximately equal mass each layer being
given 56 blows with 4.90kg hammer equally distributed and dropped from a height
of 450 mm above the soil.
 The amount of soil used shall be sufficient to fill the mould, leaving not more thanabout
6mm to be struck off when the extension collar is removed.
 Remove the extension collar and carefully level the compacted soil to the top ofthe mould
by means of a straight edge.
 Remove the spacer disc by inverting the mould and weigh the mould withcompacted soil
(m2).
 Place a filter paper between the base plate and the inverted mould.
 Replace the extension collar of the mould.
 Prepare two more specimens in the same procedure as described above.
 In both the cases of compaction, if the sample is to be soaked, take representativesamples
of the material at the beginning of compaction and another sample ofremaining material
after compaction for the determination of moisture content.
 Each sample shall weigh not less than 100g for fine-grained soils and not less than500 for
granular soils.
 Place the adjustable stem and perforated plate on the compacted soil specimen inthe
mould.
 Place the weights to produce a surcharge equal to the weight of base material
andpavement to the nearest 2.5kg on the perforated plate.
 Immerse the whole mould and weights in a tank of water allowing free access ofwater to
the top and bottom of specimen for 96 hours.

CALCULATION OF CBR FROM LOAD PENETRATION CURVE
 Plot the load penetration curve in natural scale, load on Y - axis and penetration onX –
axis as shown in Fig: 2.9.2.
 If the curve is uniformly convex upwards although the initial portion of the curvemay be
concave upwards due to surface irregularities make correction by drawinga tangent to the
upper curve at the point of contra flexure as below
 Take the intersection point of the tangent and the X – axis as the origin.
 Calculate the CBR values for penetration of 2.50mm and 5.00mm.
 Corresponding to the penetration value at which CBR is to be desired, take thecorrected
load values from the load penetration curve and calculate the CBR fromthe equation
California Bearing Ratio =PT/PS x100
PT = Corrected unit test load corresponding to the chosen penetration from load
penetration curve
PS = Total standard load for the same depth of penetration, which can be taken
from the Table below
Standard loads at specified penetrations
Penetration depth
(mm)
Unit Standard load
Kgf/ cm2
Total Standard load
(Kgf)
2.50 70 1370
5.0 105 2055
7.50 134 2630
10.0 162 3180
12.50 183 3600

Observationtable:
Sample 1
Penetration (mm) Load (kg)
0.5 24.45
1.0 47.27
1.5 66.83
2.0 94.54
2.5 122.25
3.0 145.077
3.5 167.89
4.0 195.60
4.5 221.688
5.0 244.50
5.5 265.70
6.0 286.88
6.5 308.07
7.0 334.15
7.5 356.97
8.0 374.90
0
50
100
150
200
250
300
350
400
0 1 2 3 4 5 6 7 8 9
Load(kg)
Penetration (mm)
Y-Values

Calculations:
For 2.5mm penetration,
CBR Value =
122.25
1370
x100
= 8.92%
For 5mm penetration,
CBR Value =
244.50
2055
x100
= 11.89%
As we have to take minimum value from above, therefore CBR Value of above soil
sample 8.92%.
Sample 2
Penetration (mm) Load (kg)
0.5 21.19
1.0 42.38
1.5 65.20
2.0 89.65
2.5 114.1
3.0 138.55
3.5 158.11
4.0 187.45
4.5 208.64
5.0 226.57
5.5 244.5
6.0 267.32
6.5 286.88
7.0 317.85
7.5 340.67
8.0 350.45

Calculations:
For 2.5mm penetration,
CBR Value =
114.1
1370
x100
= 8.33%
For 5mm penetration,
CBR Value =
226.57
2055
x100
= 11.03%
As we have to take minimum value from above, therefore CBR Value of above soil
sample 8.33%.
0
50
100
150
200
250
300
350
400
0 1 2 3 4 5 6 7 8 9
Y-Values

3.3.3 Designofpavement
Available data:
Area of plunger= 19.6cm2
Average CBR Value= 8.33
Traffic intensity = 3491 vehicles/day
As the traffic intensity is 3491 vehicles per day, curve F will be used to determine the
total thickness of pavement.
Thus the total thickness or depth of thickness or depth of pavement construction, as
read curve F from above CBR design chart, is to be 450mm.
For MDR 27 , Actual design thickness provided is as follows
Total pavement thickness= 350mm
Composition of total thickness is as follows
1. GSB(Granular Sub-base)
Grade layer 2 = 175mm
Grade layer 3 = 100mm
2. BBM(Bituminous Bound Macadam)= 75mm
3. Carpet seal =20mm
4. Liquid seal coat

Conclusionof pavement Thickness
As from above readings, it can be concluded that the actual thickness provided is less
thanrequired thickness to be provided.
So , provision of less pavement thickness is one of the main reasons of the earlier failure of road.
3.4 Drainage Overview
Water is the main contributor to the wear and damage of low-volume rural roads. The water
can be in the form of ground water, surface water (streams and rivers) or rain and it can
damagethe road in several ways:
• By washing away the soil (erosion and scouring),
• By making the road body less resistant to traffic (i.e. weakening the load bearing capacity),
• By depositing soils (silting) which may obstruct the passage of water, or
• By washing away entire sections of the road or its structures.
Damage and wear to the road can be reduced if the flow of water is controlled. Minor
damages can easily be repaired as part of the regular maintenance provided to the road and its
structures. If the flow of water is not properly managed, the deterioration of the road will be
more serious and occur more rapidly. This will lead to higher maintenance demands and in the
worst cases result in serious damage which may obstruct the passage of traffic.
Various drainage measures are applied to effectively deal with the water arriving at the road.
Surface water arrives directly on the road as rain, as runoff from the surrounding areas, or in
streams and rivers. In flat terrain, the entire area around the road may be inundated with water
during the rainy season. In addition, water also travels underground which can have an impact on
the quality of the road. An efficient drainage system is therefore essential to allow water to flow
off and away from the road as quickly as possible. This is achieved by a system consisting of the
following components:
•Road surface drainage which enables the water to flow off the road surface,
•Side drains which collect and lead the water away from the road,
• Road embankments in flood prone terrain, lifting the road surface well above the highest flood
levels
• Catch-water drains which catch surface water before it reaches the road,
• scour checks, preventing erosion in the ditches by slowing down the flow of the water,
• Culverts which lead the water from the side drains under the road to the other (lower) side,
• Bridges and drifts which allows the road to cross rivers and streams in a controlled manner
throughout the seasons.

3.4.1 RoadSurface Drainage
Drainage of the road surface is provided by shaping the carriageway with a camber or a cross slope. The
combination of stagnant water on the road surface and traffic can quickly cause erosion of the road
surface.
Secondly, if surface water penetratesinto the road body, it reduces the loadbearing capacity of the
pavement, which may cause further damage to the road. To avoid these problems, it is important to secure
adequate drainage of the road surface.
On most roads, the camber is roof shaped with the highest point at the road. Centre line, with a
descending gradient towards the road shoulders. On narrower local roads, the camber may be constructed
as a continuous slope from one side of the road to the other. This is referred to as a cross-slope.
3.4.2 RoadPavement
The pavement constitutes an essential part of the drainage of the road. A dense and strong
surface, together with the cross-slope on the carriageway ensures that rainwater does not enter
the foundation of the road, but instead is lead off to the side of the road.
Potholes provide a good example of the destructive effects of water and traffic. When the surface
pavement has been worn down to the extent that potholes penetrate the surface, allowing water to
enter into the layers underneath, the deterioration of the road will accelerate.
Unless patching is carried out as soon as possible, the hole in the surface layer continues
expanding, also eroding the soils underneath.
3.4.3 Side Drains
The function of the side drains (or
ditches) is to collect water from the
carriageway and surrounding areas and lead
it to an exit point where it can be safely
discharged.
The side drains need to have sufficient
capacity to collect all rainwater from the
road carriageway and dispose of it quickly
and in a controlled manner to minimize
damage. Sides drains can be constructed in three forms: V-shaped, rectangular or as a trapezoid.

3.4.4 Culverts
Culverts are the most common cross
drainage structure used on roads. They
are built using a variety of materials, in
different shapes and sizes, depending on
the preferred design and construction
practices. Culverts are required in order
to
(i) Allow natural streams to cross the
road, and
(ii) Discharge surface water from drains
and the areas adjacent to the road.
Culverts form an essential part of the
drainage system on most roads, andmost
road construction or rehabilitation works
include the installation or repair of
culverts.
3.4.5 Drifts
Drifts provide an efficient and economic method of allowing water to cross from one side of a
road to the other. In the case of drifts, the water is actually allowed to pass on top ofthe road
surface. As a result, the road surface needs special protection to stand up to the forces from the
flow of water. This is usually done by constructing a stone packed or concrete surface where the
water will pass. The level of the drift is lower than the road on each side, to make sure that water
does not spill over onto the unprotected road surface. Drifts are normally constructed to pass
river streams which are dry during long periods of the year. If the waterway has a continuous
flow of water throughout the year, the use of other cross-drainage solutions such as culverts,
vented fords or bridges should be considered.

3.4.6 Vented Fords
Vented ford s, also referred to
as causeways, can provide a cost-
effective alternative to culverts
and bridges. While drifts are
appropriate for streams which dry
out during periods of the year,
vented fords are commonly used
for crossing rivers and streams
which carry a minimal flow of
water through the dry season. The
advantage of the ford is that it is a
relatively inexpensive structure
appropriate for both narrow and
wide river crossings. Vented
fords use a combination of culvert
pipes to discharge water under the
road during low water f lows, and
a drift slab allowing water to
overtop the structure during high water flows.
Drainage Problemon MDR:
As mentioned earlier, one of the main reasons for failure of the road is improper or no
provision of drainage on the road.
Because of no provision of drainage system, water directly comes in contact with the
road surface and also with the sub base, which causes the pavement to lose its strength, so, it is
necessary to drain off the water from above and below the road.
As has been observed on MDR 27, there was provision of side drains and also at some
places, it was maintained, butat most of the length, it was not. At most of the places ,where road
passes through residential area, the water was seen to be accumulated in drains and also,
overflowed which directly comes in contact with the road surface, it might also cause health
problems in the locality.
Also, wherever there was cross drainage work provided or proposed in the planning, it wasn’t
properly maintained, there were blockages and no proper gradient was provided.
Due to poor condition of road surface, camber was not maintained on road, so, there
were problems of water drainage from surface in monsoon.
As there are lots of factories of power loom and other small industries, its used water
was directly disposed on the road, which directly came in contact of road surface for prolonged
time.
Below are the photographs of damaged drainage system and remedies on it.

In the photograph, water from industrial area can be seen directly disposed on the road
and due to continuation of this for prolonged time, water penetrates inside and reduces the load
bearing capacity.
In the above photograph because of improper slope of sewer water is not passing properly and
also there is accumulation of debris.
So proper provision of slope and regular cleaning is necessary.

In the above picture, CD work has been provided on the road, but due to accumulation of dirt and
debris, so water on higher elevation is not passing through the drain pipe which makes it useless
and also it causes water to penetrate in sub base of road pavement and ultimately causing failure
of road.

In the above picture, we can see the blockage because of soil amassment, which prevents the
flow of water.
As there is crossing, provision of slab or drain pipe is necessary.

In the above picture, because of illegal construction, water cannot pass resulting in penetration
under road pavement.

3.5 Suggestion for treatment ofexisting pavement
For MDR 27 , as there are many damages like potholes ,cracks ,bleeding ,etc. so ,a proper
maintenance treatment is needed to be given. Following treatments will be useful to prolong the
life of existing pavement and it will be more useful.
 Patch repair work.
 Surface treatment and
 Resurfacing.
Patch Repair Work:-
Patch repairs are done when localized pot holes are developed on the surface of the road. The
process of patch repair or repairing a pot hole be done under following stages.
I. Cutting pot holes:-
The areas of pot holes should be marked in rectangular fashion on the surface of road. Marked
areas are then cut in rectangular shape and all the affected materials from it are removed. Depth
of the pot hole is cut in such a way that all the affected depth is dug out till sound base is
encountered.
II. Cleaning of cut pot holes:-
Cut pot holes are thoroughly cleaned of all dust and loose materials and a priming coat is
applied.
III. Preparing premix:-
Course aggregate and bitumen are taken and heated if facilities are there and mixed in desired
proportion to have a premix. If facilities for heating are not available, cold process using
emulsion of cut backs, for preparing premix may be adopted. While preparing premix it should
be ensured that prepared premix is similar in composition as that had been used in the original
construction of the road.

IV. Filling the Premix and Compaction:-
The prepared premix is filled in the prepared and primed pot hole and is compacted using hand
rammer. After ramming some sand or grit is spread on the compacted pot hole and re-
compaction is done with rammers. The rammed and finished surface of the pot hole should be
kept slightly higher than the original level to allow for further compaction under traffic.
Surface Treatment:-
Surface of the bituminous road may be spoiled by bleeding action of the excess bitumen, used
during its construction, this may cause rutting, shoving or waving of the surface of the road.
Such a trouble can be ratified by spreading stone grit on the surface so that excess bitumen is
absorbed by it. Rolling is also done to develop good bond between existing surface and blotting
material used to absorb excess bitumen.
Bituminous binders also get oxidized due to ageing and develop fine cracks in the
pavement surface. Such aged surface, can be renewed by applying seal coat or renewal coat. If
due to oxidization of volatilization of binders, surface, have been damaged considerably surface
treatment may be applied.
Resurfacing:-
As at some places on existing pavement some surfaces are totally worn out so re-surfacing is
recommended for those patches. Resurfacing operation consists of clearing the road surface,
applying bitumen, applying grit, and lastly rolling, as is done in surface dressing process.

CONCLUSION
 The average depth of potholes found in NH-52A is 100-130mm deep, exceeding the
limits. And the deepest pot hole found being 170mm.
 The interval of the pavement distress found is too frequent and well exceeded the
standard limits.
 Quality of aggregates as per crushing test did not give satisfactory result was below
standard limit. Also, in testing of subsoil, in CBR test, after analysis of thickness of
pavement to be given, it was observed that road thickness provided was less as per what
it should have been given as per the experimental analysis.
 In drainage overview on MDR, many flaws were found, which has lead the road towards
its failure. No proper provision of camber throughout the road was provided. Proper
gradient of drains is not maintained. Cleaning of drains is not done, resulting in
accumulation of water, also there were blockages on cross drainage works. So, it forms
one of the forms of the main reasons of failure.
 Any road is designed and built considering the traffic intensity and impact load coming
on it. When these factors exceed their values, pavement gradually starts to degrade. On
MDR, because of impact of dumpers carrying aggregates, sub grade failure and cracking
has been seen.
 Use of standard materials, construction under proper supervision and repairing as per
type of failure using modern techniques will be beneficial for increasing life of road.
 The most required probable treatments for surveyed distresses are overlay, patching and
shoulder improvement.

REFERENCES
1. Highway Engineering , Charotar Publications by S.C. Rangwala
2. Indian Road Congress (2001) “Guidelines for the design of flexible pavements”
Jamnagar House, Shahjahan Road, New Delhi-110 001, India
3. Indian Road Congress, (2001), “Specification for Road and Bridge Works”, 4th Revision,
Ministry of Road Transport and Highways, Government of India, New Delhi-110001
4. IS 5640 (1970) Methods of tests for determining aggregate impact value. Page (48-53)
5. IS 2386 Part 4 test for determining crushing value. (Page 85-88)
6. IS 2720-16 (1987)Method of tests for soils ,part-16: Laboratory Determination of CBR
Page (103-112)
7. Khanna S.K., and Justo, C.E.G.,(2001) “Highway Engineering”, Published by Nem
Chand & Bros., Civil lines, Roorkee 247667, India.
8. Kumar R.S.,(2001), “Textbook of Highway Engineering”, Published by Universities
Press Private Limited, Himayatnagar, Hydrabad 500029, India.

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