submitted to the department of civil engineering
TRANSCRIPT
ROAD MAINTENANCE PRACTICESIN BANGLADESH
625.761991ABD A THESIS ON
SUBMITTED TO THE DEPARTMENT OF CIVIL ENGINEERING,BANGLADESH UNIVERSITY OF ENGINEERING AND TECHNOLOGY, DHAKAIN PARTIAL FULFILMENT OF THE REQUIREMENTS
FOR THE DEGREE OF
POST GRADUATE DIPLOMA IN GEOTECHNICAL ANDTRANSPORTATION ENGINEERING
UNDER
AIT - BUET JOINT PROGRAMME
BY
I'1D_ ABDUS SABUR
FEBRUARY, 1991
1111111111111111111111111111111111#80266#
,
ROAD MAINTENANCE PRACTICESTN BANGJ~AJ~ESJcI
A THESIS
BYMD. ADJ~US SABUR.
APPllOV61lAS TO STYLE ANIl CONTENT IIY
----~~~~---MIl.SYEIlNOOIl-UD-IlEEN AHMEDAssociate ProfessorDepartment of Civil EngineeringIIUET., Ilhaka.
1M_. ~_~_~_Ilil.Mil. MAZHAllllL HOQUEAssociate ProfessorDepartment of Civil EngineeringIIllET,Ilhaka.
Dil. MllHAMMAIl ZAKARIAAssociate ProfessorIlepartment of Civil EngineeringIIllET,Dhaka
Chairman(Supervisor)
Hember
~Iember
INDEX
Synopsis
Acknowledgment
List of Tables
List of Figures
Appendix
CHAPTER - 1 INTRODUCTION
1.1 General Introduction
1.2 Importance and Significance of Road Maintenance
1.3 Objectives of the Project Study
1.4 Quantity and Characteristics of Roads andHighways in Bangladesh
1.5 Definition, Implications of Road Maintenance
1.6 Classification of Road Maintenance
CHAPTER - 2 REVIEW OF LITERATURE
2.1 Introduction
2.2 Pavement Evaluation
I
II
IV
V
1-15
1
1
6
6
16-30
16
16
2.2.1
2.2.2
Deduct Value or Deduct Point Method
Present Serviceability Index (PSI) Method
16
18
,2.3 Roughness Measurements
2.3.1 Method for Measurement of Roughness
2.4 Method for Measuring Deflection Value
19
19
21
2.4.1 Analysis of Deflection Data 24
2.5 Maintenance Activities 26
2.5.1
2.5.2
Routine Maintenance
Special Maintenance
26
27
2.5.3
2.5.4
2.5.5
Betterments
Rehabilitative Maintenance
Emergency Works
27
28
29
EVALUATION TECHNIQUE FOR MAINTENANCE
Evaluation of Road Maintenance Needs
Evaluation Techniques
CHAtTER - 3
3.1
3.2
3.2.1
3.2.2Maintenance of Paved Roads
Maintenance of unpaved Roads
31-39
31
32
32
38
Thickness of Overlay
DisintegrationSkid hazard
Maintenance Operations
SYMPTOMS, CAUSES AND TREATMENT OF ROAD FAILURESCracking
Distortion
40-55
40
41
42
43
46
46
50
52
53
Maintenance of Roadway Surfaces
Maintenance of Shoulders
Maintenance of Drainage Structures
4.5.1
4.5.2
4.5.3
4.6
CHAPTER - 4
4.1
4.2
4.3
4.4
4.5
CHAPITR - 5
5.1
5.2
5.3
5.4
5.5
CHAPITR - 6
6.1
ROAD MAINTENANCE MANAGEMENT
Introduction
Maintenance Manpower
Maintenance Manpower in Bangladesh
Mechanization and Equipment Planning
Management of Funds
ROAD MAINTENANCE PRACTICES IN BANGLADESHIntroduction.
56-63
56
56
56
58
61
64-83
64
6.2 Road Construction and Maintenance Organisations 646.3 Problems of Road Maitenance in Bangladesh 68
6.3.1 Problems for Arrangement of Traffic 686.3.1.1 Works on Edges and Shoulders 736.3.1.2 Restricting the Traffic to One Lane 74•6.3.1.3 Working in the Centre of 75the Carriageway6.3.1.4 Diversions 76
6.3.2 Financial Capacity 786.3.3 Institutional Capacity 78
6.4 Existing Road Maintenance Technique 796.5 Financial Pattern for Maintenance (Upazila road) 82
CHAPTER - 7 RESEARCH FINDINGS AND RECOMMENDATIONS 84-867.1 Findings 847.2 Recommendations 86
REFERENCES 94
I
Evaluation techniques for sUccessful maintenance works. are
SYNOPSIS
In recent times rand networks in Bangladesh are expanding much faster than
corresponding increases in maintenance budgets and insti tutional
capnci ties. In this research various aspect of road maintenance works are
reviewed. To this end, road kilometrege for various categories of roads arestudied.
re"iewed. Symptoms, causes and treatments for road failures are highlighted
for routine as well as for periodic maintenance. This study showed that
fund spent fOl' maintenance is not quite adequate. Appropriate or scientif ic
methods for maintenance are not yet devised and documented in the countr~'.
Standard maintenance procedures and materials to be used in .maintenance are
disclJssed. Manpower and equipments required for maintenance are alsoincluded in this study.
ACKNOWLEDGMENT
The author expresses his heartiest gratitude and profound indebtness to
Mr. Syed Noor-Ud-Deen Ahmed, Associate Professor, Department of Civil
Engineering for his affectionate guidance, help, encouragement and active
co-operation in making this report possible. His keen interest on the
topic and valuable advise throughout the study were of great help. and
acted as a prime mover is materializing the project report.
The author expresses his gratitude to Dr. Alamgir Mujibul Hoque, Professor
and Head, Department of Civil Engineering, for sincere co-operation and
encouragement.
The aqthor expresses gratitude to all the senior executives involved in
construction and maintenance related activities for contributing their
valuable opinion.
The support, co-operation and encouragelDent of colleagues are also
acknowledged with thanks.
II
LIST OF TABLES
TABLE-I. 1 Road Network Under RHD in Selected YearsTABLE-I. 2 Road Network Under RHD in Mid 1988~TABLE-I. 3 Road Kilometrege in different OrganisationsTABLE-I. 4 Total Paved Road under RHD according to WidthTABLE-2.1 Deduct Values for Flexible PavementTABLE-2.2 Asphalt Pavement Rating Form
TABLE-4.1 Recommendations for Patching Material
TABLE-5.1 Road Maintenance Staff for a Typical Road Division
TABLE-5.2 The Machineries, Equipments for Maintenanceowned by the Roads and Highways Department
TABLE-5.3 Equipment owned by Typical Road Division
TABLE-5.4 The Average Annual Expenditure for Maintenanceby Roads and Highways Department
TABLE-5.5 The Average Annual Expenditure forMaintenance by Road Type
TABLE-5.6 Annual Maintenance Expenditure of differentRoad Circles in Bangladesh
TABLE-6.1 Types of Maintenance Works done by Roads andHighways Department
III
7
11
12
12
1730
50
5759.
60
61
62
62
83
FIGURE-lo1
F1GURE-2.1
FIGURE-2.2
FIGt'RE-2.3
FIGliRE-2.4
FIGURE-2.5
FIGURE-2.6
FI Gt'RE-4. 1
FIGERE-4.2
FIGERE-4.3
FIGURE-4.4
FIGERE-4.5
FIGURE-4.6
FI Gt'RE-6. 1
FIGtllE-6.2
FI GtllE-6. 3
FI GlJllE-6. 4
FI Gt'RE-6. 5
LIST OF FIGUR.ES
Road map of Bangladesh
Diagramatic Arrangement of Bump-Integrator
Benkelman Beam
Diagramatic Arrangement of Deflection Beam
The Thickness of Bituminous Premix Overlay Required
Asphalt Concrete Overlay ThicknessCondition Rating
Photograph Showing Potholes
Photograph Showing Water Stagnant
Photograph Showing Alligator Cracking or Map Cracking
Photograph Showing Shallow Depression
Steps for Repairing Potholes
Photograph Showing of Repairing Potholes
Standard Traffic Signals
Sign Layout for Edge Working
Sign Layout for Lane Closure
Sign Layout for Centre Line Working
Sign Layout for Diversion
IV
13
20
22
23
25
25
30
4444
4545
48
49
71
73
7576
77
A.
APPENDIX
Particle Size Distribution for Gravel Surfacing. 88-93B. Grading for Cracked Rock Patching Material.C. . Requirements for Premixed Macadam used for Patching MaterialD. Recommended Chipping Size.
E. Spraying Temperatures.
F. Road Condition Survey Form.
G. Road Classifiction and Geometric Standards.
v
CHAPTER - 1INTRODUCTION
1.1 GENERAL INTRODUCTION
It is an established fact that development and improvement of
transportation systems and services are essential to the healthy
socio-economic growth of a nation. This is true for developing
countries particularly the least developed countries like Bangladesh
where transportation systems and services have not yet achieved a
level of acceptance in relation to quality, quantity, efficienq',
convenience and safety.
Bangladesh is a populous country with a geographical area of only
1,43,410 Sq. Km. and confronted with the problem of accommodating an
ever-growing huge population on a very limited land area and even more
limited natural resources. This dichotomous situation puts Bangladesh
in a condition in which every attention need to be given in the
investment of its very limited financial and natural resources in the
spheres of feeding, housing, educating and providing related services
and facilities for the attainment of an improved quality of meaningful
life.
1.2 IMPORTANCE AND SIGNIFICANCE OF ROAD MAINTENANCEOf manifold services and facilities needed for improved human .life
transportation is one of the most important. In fact, transportation
is a kind of service which is owned and utilized by the entire
population. Basic quality of transportation and transportation
related services are as such major determinants of so called
1
developments, progress and prosperity which are so often acclaimed as
being achieved.
It is said that the level of discipline achieved by any nation is
reflected on traffic scenes and behaviors. A cursory look at these
parameters on roads and rails in Bangladesh represents melancholy
pictures. The common experience on roads and highways is one of
indiscipline and chaos in which multimodal vehicles are competing to
utilize very limited road spaces without paying any heed to general
courtesy and general sense of discipline. Precarious road conditions
arising out of poor or no road maintenance makes the situation worse
and more vulnerable. It appears that very little attention is paid
and very little amount of money is spent on road maintenance which is
so very important for the upkeep of the huge investment made on roads
and highways out of very limited national funds. It must be
emphasized that keeping roads and highways in serviceable and well-
maintained condition is a very important responsibility of all
concerned organisations. Stated differently, it is the right and
privilege of the citizens of Bangladesh to get the quality of roads
and highways services which are afforded by well maintained roads and
other transport facilities. Any departure or negligence from these
responsibilities on any ground whatsoever reflect and represent a
credibili ty gap between the road builders- maintainers and the road
users.
The importance of road maintenance lies mainly in the need to protect
the substantial investment that has been made on highways.
Furthermore, the significance of the maintenance function is seen in
2
the vital need to continue the economic and social benefits that are
derived from the public road system. The travelling public is
actually aware of the condition of public streets and highways. The
need for road maintenance may be clear to most engineers but is not soclear to the layman.
The three main reasons for maintaining a road are:
i. To prolong the life of the road.
ii. To reduce vehicle operating costs.
iii. To keep the road serviceable.
i. To Prolong the Life of the Road
Roads deteriorate due to the damaging actions of traffic and
climate. Heavy trucks and buses cause most damage to roads. The
damage caused by a loaded vehicle follows a power law so that if
the axle load is increased by a factor of two the damage is
increased by a factor of approximately twenty. Thus a small
number of overloaded lorries can cause a disproportionate amountof damage.
Water in all forms causes a road to deteriorate. If the road is
subject to flooding, the road may break up in a very short period
of time. Rainfall, if allowed to collect on the road surface or
shoulders, eventually finds its way into the road structure with
consequential rapid damage. Planned maintenance should be such
that the road is at all times capable of carrying the applied
traffic loads and the drainage system must be maintained so that
water does not enter the road pavement.
3
The quality of the original construction must be of adequate
standard to prevent rapid deterioration of the road. However,
construction cost must always be balanced against the available
funds. 1t is economically sound to build a road to a certain
standard and then provide additional strengthening overlays as a
part of a planned maintenance system.
Failing to maintain a road is virtually the same as failing to
put oil in a car, a little negligence can have expensive
consequences.
ii. To Reduce Vehicle Operating Costs
The largest single import into Bangladesh is petroleum oil. A
large proportion of this is used in motor fuels (gasoline or
diesel). Traffic is presently growing at a rate of between 7 and
10% per annum and most of this growth is accounted for by
commercial vehicles. The cost of vehicular travel is reflected
in almost all walks of life, high transport costs mean less
competitive exports and reduced economic activity. Valuable
foreign exchange must always be earned to finance oil imports.
If a road is badly maintained with a rough or potholed riding
surface, the costs to vehicles travelling on the roads are
increased due to:
a. Using more fuel
b. Transporting less goods in a given time
c. Increased repair and maintenance costs
d. Increased tyre wear
e. Shorter vehicle life.
4
Extensive economic studies have shown that vehicle operating
costs are closely related to road roughness. The smoother the
road the lower the vehicle operating costs. In national terms a
better maintained road network means a lower oil import burdenand more competitive exports. It has been shown that if even a
•small decrease in roughness of the road network could be
achieved, the savings in vehicle operating costs would far
outweigh the additional maintenance costs (Reference No.12).
iii. To Keep the Road Serviceable
If the roads are closed due to flooding, landslips, cuIvert or
bridge failure etc., communications are disrupted with serious
social and economic consequences. Strenuous, and generally
expensive, efforts are always made to restore communications inthe minimum time.
It is a fact that the many such emergencies could be prevented
if attention is given to the standards of construction andregular inspection and maintenance actions.
It is commonly found that maintenance is not properly carried outbecause:
1. People often do not fully realize the importance of roadmaintenance.
ii. Maintenance presents muchthan new construction. greater problems of management
iii. New road construction is more popular with some people thanroad maintenance works.
iv. Insufficient funds are allocated for maintenance.
v. Maintenance is more difficult to plan and supervise than newconstruction because roads are spread throughout thecountry, not concentrated in one particular place.
5
economic advantage to both owner and taxpayer.
and owners of roadway pavements. For users, both automobiles and
Maintenance can provide major economic advantages to both users
"
In addition, roads
undertaken with the~
more miles of modern roads can be provided.
The project study on road maintenance wasobjectives of studying:
shorter time for less cost than new roads can be built, providing
maintenance when operated on safe, smooth pavements. For owners,commercial vehicles become more fuel efficient and require less
can remain in use while being modernized with asphalt, and old
roads frequently can be improved and put back into service in a
1.3 OBJECTIVES OF THE PROJECT STUDY:
1. The existing road maintenance practices followed by differentorganisations in Bangladesh.
ii. Evaluation technique to be followed for maintenance purpose.
iii. Suggestion for improved maintenance practices in Bangladesh.
1.4 QUANTITY AND CHARACTERISTICS OF ROADS AND HIGHWAYS IN BANGLADESH:
In Bangladesh roads and highways facilities are very limited compared
to even moderately developed countries. According to statistics from
Roads and Highways Department Bangladesh had only 600 Kms. of 'high
type' roads at the time of partition of India. After the independence
oC Bangladesh there was a total of 4025 Kms. of roads of which 3460
KIIs.where 'high type', that is mostly bituminous pavements and the
remainder was brick-soled or stablized earth roads. According to the
same source about 9000 Kms. of roads have been built on the post
independence period of which 4557 Kms. nearly belong to the high typeroad category.
6
ROAD NETWORK UNDER ROADS AND HIGHWAYS DEPARTMENT(RHD) IN SELECTED YEARS
historical development or road network, under Roads and Highways
TABLE - 1.1
on
(In Kilometre)
High type Low type Totalroads(a)* roads(b)**
600 6002500 225 27253160 242 34023460 565 40254285 1407 56924775 2600 73756218 4695 109137218 5103 12321
following table present .information in selected yearsThe
1982
1971
1965
1960
1947
Department since 1947.
1980
Year
1985
1988
Source: Roads and Highways Department, Dhaka.
* 'High type' roads refer to paved roads having asphalt and cementconcrete surface.
** 'Low type' roads refer to infrastructure comprising brick paved,partly paved, stone/gravel and earthen roads.
According to another statistical information from the Roads and
Highways Department the total quantum of 'high type' roads built upto
June 30, 1988 amounts to 7156 Kms. A breakdown of these high type
road kilometrege in relation to width of road pavement is summarizedbelow
7
------------------------------------------------------------------------------------------------------------------------------------------Source: Roads and Highways Department as on 30.06.1988.
244.58379.1218.04550.6824.701. 61
349.93327.3579.12
1281.41590.4585.31
2713.57
Road length 1Kml
Road length 1Kml
Below 3.663.66
3.96 to 5.185.496.71
Over 6.71
Below 3.663.66
3.96 to 5.185.496.71
Over 6.71
NATIONAL HIGHWYS (paved)
Pavement width 1M}
Total:
REGIONAL HIGHWAYS (paved)
Pavement width 1M}
----------------------------------------------------------------------Total: 1218.73----------------------------------------------------------------------Source: Roads and Highways Department as on 30.06.1988.FEEDER ROADS (Paved)
Pavement width 1M} Road length 1KmlBelow 3.66 232.753.66 1003.403.96 to 5.18 66.425.49 253.966.71 54.91Over 6.71 7.78---------------------------------------------------------------------Total: 1619.23---------------------------------------------------------------------
Source: Roads and Highways Department as on 30.06.1988.
8
UPAZILA CONNECTING ROADS (Paved)
Pavement width iMlBelow 3.66
3.663.96 to 5.18
5.496.71
Over 6.71
Road length lKml793.46710.8133.8855.566.813.22---------------------------------------------------------------------Total: 1603.74---------------------------------------------------------------------
Source: Roads and Highways Department as on 30.06.1988.
TOTAL PAVED ROAD UNDER ROADS AND HIGHWAYS DEPARTMENTCategory of Road
National HighwaysRegional HighwaysFeeder RoadsUpazila Connecting Roads
Road length lKml2713.571218.731619.231603.74
Percentage
38172322---------------------------------------------------------------------
Total: 7155.27 100---------------------------------------------------------------------Besides the •high type' roads stated above the Roads and Highways
Department also have some roads which are either partly paved or aregravel or earthen roads.
summarized below:Total roads other than •high type' are
----------------------------------------------------------------------Category of Roads Present Condition
-----------------------------------HBB orPartlypaved
Gravelroad
Earthenroad
----------------------------------------------------------------------1. National Highways 63.06 25.55
+32.422. Regional Highways 129.32 21.713. Feeder Roads 512.81 106.89 722.14+42.254. Upazila Connecting Roads 1358.50 20.00 1876.29+198.05----------------------------------------------------------------------
2063.69 126.89 2645.69+272.72----------------------------------------------------------------------
+ In the form of tracks as on 30.06.1988.Source: Roads and Highways Department as on 30.06.1988.
9
KUTCHA ROAD :(in Kms)---------------------------------------------------------------------------
Authority 1984-85 1985-86 1986-87 1987-88 1988-89---------------------------------------------------------------------------l. Zila Parishad
2. Pourashava/Poura Corporation
3. Upazi1a Parishad
4. Union Parishad
16936
3299
22581
101774
16452
3339
23065
102016
16049
3403
23306
102420
15936 15759
3468 3742
24516 27420
104196 107259---------------------------------------------------------------------------144590 144872 145178 148114 154180---------------------------------------------------------------------------
Source: Local Govern.ent Engineering Bureau (LGEB).
Roads under Pourashava/Poura Corporations are maintained by their ownstaff. Pourashavas cannot afford to spend amount liberally on road
maintenance and development, because their own source of income from
taxes is very limited. They have to provide a number of services and
utilities such as water supply, sanitation, electricity etc. in
addition to road construction and maintenance.
Besides Roads and Highways Department, a major part of the remaining
roads are constructed and maintained by the local bodies in
conjunction with the engineer of L.G.R.D. Ministry. Their maintenancework is very slow and rare. Their maintenance work is not quiteregular. Maintenance is usually undertaken on emergent basis when the
road condition is deplorable. The total road kilometrege under localbodies is given below:
10
ROAD KILOMETREGE UNDER LOCAL BODIES
PUCCA ROAD (Paved)(in kms)---------------------------------------------------------------------------
Authority 1984-85 1985-86 1986-87 1987-88 1988-89---------------------------------------------------------------------------1. Zila Parishad 4210 4516 4759 5000 52422. Pourashava/
Poura Corporation 4241 4379 4336 4690 50003. Upazila Parishad 444 455 468 484 5004. Union Parishad---------------------------------------------------------------------------
8895 9350 9563 10174 10742---------------------------------------------------------------------------Source: Local Govern.ent Engineering Bureau (LGEB)
TABLE - 1.2
ROAD NETWORK UNDER RHO IN MID 1988
---------------------------------------------------------------------------Length in km----------------------------------------
Category ofroads
Pavedroad
Partlypaved orbrick pavedroad
Earthenroad
Total
---------------------------------------------------------------------------1. National Highways 2714 63 58 28352. Regional Highways 1219 129 22 13703. Feeder roads 1619 513 764 2896---------------------------------------------------------------------------
4.
Sub-Total:Percentage:
Upazila connectingroads
555278.12
1604
7059.90
1359
84411. 88
2075
7101100.00
5038---------------------------------------------------------------------------
Total:Percentage:
715658.97
206417.01
291424.02
12134100.00---------------------------------------------------------------------------
11
177056100.00
15709488.74
20641.16
1789810.10
Total:Percentage:
TABLE-1.3
ROAD KILOMETREGE IN DIFFERENT ORGANISATIONS(Upto Mid 1988)
below:Total road kilometrege according to types of road is given in the table
---------------------------------------------------------------------------Authority Paved Partly Paved Earthen/ Total Percentage ofroad or brick Kutcha paved road/paved road road earthen road----------------------------------------------------------------------------1. Roads and Highways 7156 2064 2914 12134 40/2Department
2. Zila Parishad 5242 15759 21001 29/103. Pourashava/ 5000 3742 8742 28/2.3Poura Corporation4. Upazila Parishad 500 27420 27920 3/17.45. Union Parishad 107259 107259 -/68.3---------------------------------------------------------------------------
---------------------------------------------------------------------------
TABLE-1.4
TOTAL PAVED ROAD UNDER RHD ACCORDING TO WIDTH
---------------------------------------------------------------------------Double Lane(5.49-7.32m)
Total Percentage---------------------------------------------------------------------------1. National Highways 1958 2714 722. Regional Highways 578 1219 483. Feeder Roads 317 1619 20
41604
7156
66
2919
Upazila Connecting RoadsTotal :---------------------------------------------------------------------------
4.
---------------------------------------------------------------------------
12
A map illustrating the ro"d network of Bano;ladesh is shown in Fig.I.!
u
•
H 0
Fig.!.l
ROAD MAP OF
BANGLADESH
,".',i ,",4'p '''.u••••• 14 •••• _
Road ~ap of Bangladesh.
A
•N
,I
(Source Roads and Highways Department, Dhaka)
13
1.5 DlFINITION, IMPLICATIONS OF ROAD MAINTENANCE:'Maintenance' is defined as the preserving and keeping of each type of
~way, structure and facility as nearly as possible in its original
aondition as constructed or as subsequently improved and the operation
of highway facilities and services to provide satisfactory and safetransportation. Maintenance is no improvement works to upgrade the~d for traffic growth or the replacement of the capital elements of
the road such as the pavement, bridges etc. Maintenance includes both
physical maintenance activities and traffic service activities.
The maintenance needs of a road network can be predicted fairly
accurately from a set of structural characteristics, such as age,
climate, traffic, design standards, construction quality. The safety
and convenience of traffic using the road are governed to a large
extent by the quality of maintenance. The operation-economics of road
transport is influenced by the degree of maintenance imparted to the
read. The life of an asset can be preserved and prolonged if adequate
maintenance measures are undertaken in proper time. The propermaintenance of roads, therefore, assumes greater significance in suchsituations.
1.6 CLASSIFICATION OF ROAD MAINTENANCE:
Maintenance cooperations can be classified as follows:
i. Routine Maintenance, embracing work items such as filling of
potholes and repairing of cracks which are required to be carried
out by the maintenance staff almost round the year;
14
ii. Periodic Maintenance, covering more extensive maintenance
operations such as applying a seal or renewal coat which are
required to be done periodically every few years;
iii. Rehabilitative Maintenance, operations required to bring a
deteriorated road back upto the original standard;
iY. Improvements, minor improvements, widening etc. which are too
small to involve a construction unit;
v. Emergency Repairs, repairs required immediately to restore
communications.
ID a perfectly maintained road system there should not be any
rehabilitative maintenance. A planned programme of routine and
periodic maintenance should prevent deterioration to a state where
rehabilitation is required. Rehabilitative maintenance is always more
expensive than regular routine and periodic maintenance.
Mayso called emergency repairs should never OCcur. A high proportion
of emergencies could be prevented by proper construction standards andregular maintenance.
15
2.1 INTRODUCTION
comfort and an increased level of safety is vehicular movement.
CHAPTER-2
REVIEW OF LITERATURE
springs, shock absorber etc., increased ridingsuspension system,
The major hindrance to smooth vehicular movements on a road surface
aay be caused by a number of factors such as poor surface texture,
faulty finishing, potholes, cracks, corrugations, rutting and pavement
deformations. These factors inhibit the need for pavement evaluation.
One of the most desirable characteristics of good road pavement is a
reasonably smooth riding surface. A smooth pavement surface brings a
number of .advantages some of which include higher vehicle operating
speed, less fuel consumption and eventual fuel economy, less wear and
tear of vehicle tyres, less changes in vehicle spare parts such as
2.2 PAVEMENT EVALUATION
Pavement evaluation is a technique of assessing the condition of a
pavement, both structurally and from the point of view of surfacecharacteristics. It is also known as pavement condition survey andrating of pavement. Evaluation of pavements can be done by a number
of methods some of which are briefly discussed below.
2.2.1 Deduct Value or Deduct Point Method
A simple but quite widespread method was developed initially at the
Texas A & M University and is known as Deduct Value or Deduct Point
Method. In this method, Certain deduct points are associated withspecific values of various distress factors.
16
The deduct points
TABLE-2.1
5
(3 )
10
15
10
15
20
10
15
2
7
8
(2 )
8
12
12
18
12
o5
5
5
(1)
10
10
15
10
Degrees of Extent or Amount of DistressDistress -- _
Slight
Moderate
Severe
Slight
Moderate
Severe
Slight
Moderate
Deduct values for flexible pavementTypes of Distress---------------------------------------------------------------------
---------------------------------------------------------------------Ilutting
---------------------------------------------------------------------Ravelling
---------------------------------------------------------------------Flushing
points are then subtracted from an established "Perfect" score
indicate the relative importance of the distress type. These deduct
(Reference No.5).Table 2.1, gives the deduct points for various levels of distress
(usually 100) to arrive at the overall rating score of the pavement.
17
5
20
101520
1520
25
10
20
40
2
7
18
81218
10
15
20
15
30
5
o5
7
15
51015
10
15
20
Severe
SlightModerateSevere
Slight
Moderate
Severe
Good
Fair
Poor
---------------------------------------------------------------------Corrugations
---------------------------------------------------------------------Alligatorcracking
---------------------------------------------------------------------Patching
Failures------------------------------------------------------------------------------------------------------------------------------------------
--------------
Deduct Points for CrackingLongitudinal Cracking
Sealed Partially Sealed Not Sealed(1) (2) (3) (1) (2) (3) (1) (2) (3)Slight 2 5 8 3 7 12 5 10 15Moderate 5 8 10 7 12 15 10 15 20Severe 8 10 15 12 15 20 15 20 25Transverse CrackingSlight 2 5 8 3 7 10 3 7 12Moderate 5 8 10 7 10 15 7 12 15Severe 8 10 15 10 15 20 12 15 20
Source Principles and practices of Highway Engineering by L.R.Kadiyali, 1984.
2.2.2 Present Serviceability Index (PSI) Method
One of the major contributions of AASHO Road Test was the develpment
of a rating system involving the measurement of pavement deformation,
riding quality and the extent of cracking and patching. The rating
is known by the term present serviceability Index (PSI) and is
probably the most widely used pavement rating measure is existence
today. The following equations give the value of PSI for flexible andrigid pavements:Flexible Pavements
PSI = 5.03 - 1.91 log(1 + SV) - 1.38(RD)' - 0.01 {C + P
Rigid Pavements :
PSI = 5.41 - 1.78 log(l + SV) - 0.09 {C + PIn the above equations:
PSI = Present Serviceability Index
18
~ = Slove variance over a 22.5 cm length, giving an index of thelongitudinal profile
RD = Rut depth under a 1.2 m straight edge
C = Percent of total area showing distress in terms of crackedarea
P = Percent of total area showing distress in terms of patchedarea.
In the AASHO Test, the longitudinal profile was monitored by theCROLE profilometer.
2.3 RlJUGHNESS MEASUREMENTS:
The riding quality of a pavement is determined to a large extent by
its structural adequacy , the traffic load repetitions it has been
subjected to, the specifications adopted for the surfacing initiallyand the maintenance inputs. Hence a measure 0 f the pavemen tPerformance can be obtained by monitoring its roughness.
2.3.1 Method for Measurement of Roughness:
The equipment called bump-integrator for measuring the roughness ofthe pavement is shown in Figure 2.1. It consists essentially of asingle - wheeled trailor, comprising rectangular chassis within which
a pneumatic - tyred wheel is mounted, the load and tyre size being ofa standard type. The wheel, enclosed by a mudguard, support thechassis through two single-leaf springs, one on each side of the
.heel. The springs are anchored to the front end and shackled to the
rear end of the chassis through ball - bearing fixtures.
19
The process involved is as follows:
I. At first, the distance the bump-integrator has travelled iscalculated. This is achieved by multiplying the number in the
wheel revolutions column by the known distance the wheel travelsin one revolution.
2. Now, having worked out the distance travelled and knowing the
time taken, the speed of the integrator is calculated.
Speed =Distance
Time
Figure-2.1 : Diagraaaatic Arrange.ent of Apparatus
Source : Bump Integrator Measure.ents in Routine Assess.ent ofHighway .aintenance needs by W.G. Keir.
20
•
3. The irregularity index is calculated as follows:
Integrator counter value x number ofwheel revolutions in one mile-------------------------------------
Recorded number of wheel revolutions
4. There is a correction made on the basis that recorded values
decrease by 2 percent for each mile per hour above 20 mph
(32 km/hr) and increase similarly below 20 mph (32 km/hr).
Normally, three runs are averaged to produce an overall 'r'
irregularity index value which is rounded up and down and quotedas a whole number.
2.4 METHOD FOR MEASURING DEFLECTION VALUE
The Benkelman Deflection Beam is shown in Figure 2.2 is used formeasuring deflection value.
deflection is as follows:The procedure of measuring the rebound
1. Ten points are selected along the outer wheel path for each lane.
2. The rear dual wheel assembly of the truck is brought near the
marked point and the Probe of the beam is inserted between the
dual wheels so that the top rests on the road where the
deflection is to be measured. The dual wheels are centred over
the marked point. A dual - type truck axle with a standard load(18 KIP) is used for the test.
21
,r
SEE VIEW-.- BATTER'" ."
"'OJUSTASLfII("'R LEG
F:lONl' lfGS
''''1.1. aeARING 'IVOT
Figure-2.2 : Benkelaan Beaa
Source : Asphalt overlays for Highway and street Rehabilitation, theAsphalt Institute, Manual Series No.17 (MS-17) June 1983Edition)
22
o 2-44mfa.':Jb l'22m(4ft}c O,30m(1tt)
d 0:91';'(J't)e.. ~:..~~lm ,2fO
effective." ..lenoth" t;74m(2lt;
-', ~.;..~
I a h~,bd =i---c-, . --"-.e -'----I: + .: + . : I. I In-, Erev~t;an\ f\ I --'1'1 .' I r-'------,--,
Shoe \ . I ./ / " . ./ ..L I .1 .l Dimensions~~~ -7"m~'7,;; \<' . 7'\rnZialpos.ltion Initiol ~slUon ~ Twl,n RecOrding . I
8 r wtree15NT • Pi t dIal' Base Sing e~he~~~i" . .ec\m ~nQmiC: test" : ~ • \>'0 '7t gaUr 'reme 'oot,::"'~&~~~[~~7~W U- \ LI . ~I. Ettectlve lenoth of beam I
Figure-2.3 Diagraaaatic Representation of the Deflection Bea.(Benke IIIan Bel1lllType)
Source TRRL Laboratory Report 935-1980.
23
3. The dial gauge reading noted initially in the position describedin step 2 above.
4. The truck is driven forward at a slow speed and dial gauge
readings are taken when the truck stops at 2.7 m and 9m form themeasuring point.
5. Pavement temperature is recorded.
6. The final and the intermediate dial readings are subtract fromthe initial reading.
2.4.1 Analysis of Deflection Data
The first step in analysing deflection survey data, after corrections
for temperature etc. is to make a simple check on the variability ofmeasurements. The recommended procedure as follows:
1. The mean of ten consecutive values (1.a km of road if 100 mspacing is adopted) are calculated.
2. The mean value plus and minus one third of the mean provide therange within which the ten readings should lie;
3. Deflections which differ more than one third from the mean areconsidered as out of the range.
Deflections are divided into homogeneous groups fixing most
appropriate chainage limits and based on data in each section, "mean
plus standard deviation value" is computed and used for the
computation of the overlay thickness. Through these procedure
sections requiring deferent overlay thicknesses are separated fromsections where reconstruction is needed.
24
I '
70
II
-I
,I
i'';
II
•
60'-50 mm
I-J'0'75 t!"m (30)( 10 in l
1.2:i
.' ..
40 ~OMeasUred' C:eflectlon
;t_ .... _
iII .
0.7.5
The Thickness of Bituminous Premix Overlay Required toReduce the Deflection of a Payment to Three DesignatedValues.
0.000 '0.0:1:0 0.040 0.060 0.080 0.100 0,120 C,UO 0.160 0.180AnD,INCHES
TRRL Laboratory Report 935-1980.
" RRD. MM0.50 "1.00 1,50 '00 . 2.50 _~.99'" " I I
'" EAL,'SO " 10,000,000• '""~ :llxj" 12
$,000,000~~~~mO~"" 10i~. '"",0 '" • 2.000,000.u ~~!:;"'200 • U
1;000.000~< ~u% '":Ee;'" ., 500,000~<
>~ 12S200,000~o
" 100 100,000~>
" 50,000020,000" 10.000
" s.ooo
Asphalt overlays for Highway and Street Rehabilitation. TheAsphalt institute Manual Series No.17 (MS-17) June, 1983.
25
20
a00
00
Figure-2.4
..--.
Source
Figure-2.5: Asphalt Concrete over lay thickness required to reducepayment deflections from a measured to a designdeflection value (rebound test).
1(Xl,
i
--'/:i ;,
Source
2
4
6
a
' .•'"o"C•>ox
'E•"Co•gE
""0'
2.5 MAINTENANCE ACTIVITIES :
2.5.1 Routine Maintenance - Normal repair and maintenance of highway
facility as near to the originally constructed condition but not
inducing better improvement work. Routine maintenance comprisesi. Surface maintenance:
Heavy grading
Light grading
Soil aggregate surface patching
Skin patching of paved road
Minor repair of asphalt pavement
Concrete joint sealing
Road - way cleaning etc.
ii. Shoulders, side road, approaches and median strips maintenance:Shoulder grass cutting
Shoulder patching
Shoulder light grading etc.
Repairs to median, approaches etc.
iii. Drainage system maintenance:
Drainage cleaning
Culvert cleaning and repairing
iv. Road side maintenance:
Side slope repairing
Road side grass cutting
Maintenance to road side development etc.
26
v. Traffic service operation maintenance:
Traffic marking maintenance
Maintenance of road sign, guide posts, guide rails, guardrails, right of.way posts and km posts.
Maintenance of traffic signals and road lighting.
vi. Maintenance and repair of structures:
Bridge maintenance
Box and pipe culvert maintenance
Miscellaneous structures (retaining wall, tunnels etc.)
2.5.2 Special Maintenance
Special maintenance of the highway facilities as near as possible to
the originally constructed condition usually the same as routine work
but involved more work at greater cost.
Asphalt seal - coating (more than 600 m2/km)
Asphalt surface levelling or redressing
Surface regravelling (more than 400 m2/km)
Major repair of shoulders, side road approaches and median stripsMajor side slope repairing
Dust palliatives
2.5.3 Betterments:
Though it does not fall under maintenance, it is sometimes done fromthe maintenance funds. It includes improvement and repair works to
highway facilities to a condition better than originally constructede.g.
Improvement of geometry
Pavement and shoulder widening and improvement
27
Base stabilization
Improvement of surface
Replacement and extension of minor structures
Construction of minor retaining walls
Erosion protection and paving of ditches
Provision of rest areas, bus stops, and shelters
Installation of traffic signal, road lighting, road signs, guideposts, right of way posts and km posts
Planning and landscaping.
2.5.4 Rehabilitative Maintenance:
The condition of some roads will be such that simple resealing or
overlaying will only be temporary expedients to hold the roadtogether for a short time. In these cases where roads havedeteriorated so badly that complete failure is in evidence, the only
solution is to completely rehabilitate the road pavement. This is an
expensive operation and it is always preferable to carry out regular
preventative periodic maintenance than to let a road deteriorateuntil it needs rehabilitation.
At the present time in Bangladesh a high percentage of the major road
network needs rehabilitation before a proper preventative maintenance,system can be implemented. This will require a large injection offunds over a limited period of time to bring the roads back upto an
acceptable standard. Rehabilitative maintenance work should becarried out in strict priority order.
28
When carrying out rehabilitation work maximum use should be made of
the materials from the old road pavement. Rehabilitation work isnormally be done by contract.
Areas of road requiring rehabilitative maintenance will normally be
clearly shown from the road condition survey forms, and approximate
quantities and costings may be obtained. For detailed estimating and
design of the rehabilitative maintenance works some additional
testing (e.g. subgrade CBR) may be required.
2.5.5 E.ergency Works:
Some emergency work wi11 always occur but all too often so called
eaergency works may be traced to faulty construction or lack of
preventative maintenance. As emergency work may fluctuate widely from
year to year depending on the weather conditions it is necessary to
allow emergency funds to be carried over from one financial year to
the next so that only the average emergency budget over a period ofyears is considered.
There are no means of assessing true emergency works from the roadcondition survey forms. Historical data will show that some roadsare more prone to emergency works than other roads. However, ifareas marked critical on the road condition survey forms are
neglected they will soon become so called emergency repair. Table-2.2
below shows Asphalt Pavement Rating Form.
29
TABLE-2.2
ASPHALT PAVEMENT RATING FORM
STREET OR ROUTE
LENGTH OF PROJECT
PAVEMENT TYPE
CITY OR COUNTRY
WIDTH
DATE
.(Note : A rating of 'a' indicates defect does not occur)Defects RatingTransverse Cracks .Longitudinal Cracks ...........•................Alligator Cracks ..•....•.......................Shrinkage Cracks ..•.....•......................Rutting .............•..........•..•............Corrugations .Raveling ...............••...............•.•.•..Shoving or Pushing ..............•.........•....Pot Holes .............•.........•...........••.Excess Asphal t .......................•.......•.Polished Aggregate ......•............•.......••Deficient Drainage •................•........•••Overall Riding Quality (0 is excellent;10 is very poor) .........................•....•
0-50-50-10
. 0-50-100-50-50-100-100-100-50-10
0-10
•
Sum of DefectsCondition Rating = 100 Sum of Defects= 100 - -------
Condition Rating =
-Asphalt pavement rating form.
RECONSTRUCTION OVERLAY ROUTINEMAINTENANCE
20o... .1///////////////////////
40 60 80 100Figure-2.6: Condition Rating as a general indicator of type
maintenance.
Source : Asphalt overlays for Highway and Street Rehabilitation. TheAsphalt Institute, Manual Series No. 17 (MS-17) June, 1983, Edition).
30
CHAPTER - 3EVALUATION TECHNIQUE FOR MAINTENANCE
3.1 EVALUATION OF ROAD MAINTENANCE NEEDS
The first step in the planning of maintenance of roads, streets and
llghways is the evaluation of existing pavements in terms of physical
condi tion, structural capaci ty, roughness etc. For this purpose,
condition surveys may be undertaken for the visual assessment of the
pavement. Such surveys would cover not only the type but also the
aagnitude of the distress and its location.
Apart from visual surveys, pavement surface evaluation based on
riding quality (i.e. road roughness) and skid resistance should also
from the basis for taking maintenance decisions.
Necessary information about routine maintenance needs will be readily
available as the maintenance staff are expected to be continuously
in touch with the physical condition of the road. However, for
periodic renewal requi rements and a long-term maintenance strategy,
condi tion surveys carried out at a fixed frequency are a must. At
least two condition surveys are conducted on each stretch of road
eyery year, one before and other after the monsoon.,
Based on the condition evaluation, the causes for the various defects
observed should be examined and a decision taken whether to initiate
a particular maintenance activity.
Where distress on the pavement has reached a stage where pot-holes
exist and deter the smooth operation of vehicles, the situation
should be rectified immediately. For other defects like cracking,
31
ravelling etc. the optional strategy should be determined having
regard to the various factors involved including the availability of
financial resources, and a decision taken whether to go in fortemporary measures like seal/renewal coat or tostrengthen/reconstruct the pavement.
3.2 EVALUATION TECHNIQUES
For maintenance purposes, roads are generally classifiedtypes:
1. Paved road.
2. Unpaved road.
into two
3.2.1 Maintenance of Paved Roads:
'Before going for actual maintenance activities, the factor involved
in maintenance requirements and guides for the maintenance activitiesmust be assessed.
Inadequacies in roads in general are related to a number of factors
which include increase in traffic volume, inadequate initial design
in relation to traffic volume, use of substandard or inferior quality
materials. Poor construction quality control and poor quality of
routine and special maintenance operations due especially to budgetconstraints.
For assessment of road maintenance works should be the factors asoutlined below to be investigated:
1. Road Inventory: It includes evaluation of pavement conditions,
shoulders, major and minor structures, drainage, stability ofslopes, ridii adequacy, gradients etc.
32
Z. Pavement Inventory : It consists of identifying and evaluating
any kind of "Pavement distress manifestation" (cracking,
deformations, defects, joint deficiencies) for flexible and riidpavements.
3. Traffic study, projections, potential development schemes in
agriculture, mining, forestry, industry fishing etc.
•. Present serviceability Index (PSI) concept.
1. lIoadInventory :
The design of many old roads are based on anticipated traffic volumes
which are less than actual traffic volumes. If a geometric
eyaluation indicates narrowness of pavements to accommodate actual
traffic, if the curves are too sharp, if available sight distance is
too short, or if the pavements surface is distorted, these
deficiencies should be rectified immediately. In such cases,
bricksoled asphalt pavement can be used to widen pavement, to improve
road alignment, to re-establish cross-section and improve shouldersfor any type of existing pavement structure.
I.provements to the cross-section of existing pavement sho~ld conform
to standards for median widths, safety features, cross slopes,
shoulder slopes, and ditches or other drainage features.
2. Pavement Inventory:
Pavement inventories for the purpose of maintenance include measures
of skid resistance, riding quality, structural capacity and surfacedistress. "Surface distress" includes ravelling, cracking and
channeling (rutting) or other forms of asphalt pavement distortions;
in portland cement concrete pavements it includes cracking and
33
spalling, pumping and faulting at joints. Evaluating pavement
condition involves assessing the current state of these distresses
and an estimation of the time when the distresses might reach a
critical or terminal level of serviceability - a level in which
maintenance is urgently needed.
Evaluation techniques for asphalt pavements fall into two general
categories. The first, the deflection procedure in which pavement
deflection are measured and analyzed in relation to traffic. Thisprocedure has the advantage of directly measuring the responses ofthe in-place pavement structure to traffic loading. The secondcalled the effective thickness procedure, uses relationships between
subgrade strength, pavement structure and traffic loading. Convenient
means of classifying the surface condition at a deflection test point
are detailed below:
Classification of Road Surface Condition-----------------------------------------------------------------Deformation under a 2-meterlong straight - edge
Degree of cracking (visiblecracks)
-----------------------------------------------------------------Classification:Index :
Deformation : Classification : Crack length/: Index : unit area
-----------------------------------------------------------------01 Less than 10 mm C1 NilO2 10 mm to 14 mm C2 Not greater than 1 m/m203 15 mm to 19 mm C3 Greater than 1 m/m2
not greater , , 2 m/m204 20 mm to 25 mm C4 Greater than 2 m/m2
not , , , , 5 m/m205 Greater than 25 mm C5 Greater than 5 m/m2
(revelling & pothol-ing imminent, immed-iate maintenancerequired)-----------------------------------------------------------------
Source: TRRL Laboratory Report 935 - 1980.
34
Deflection values are most useful when they are accompanied by other
indicators of pavement performance. Measurement of rut depths,
cracking in the wheelpaths and crack depths are simple measures of
pavement condition that can easily be made at the same time when
deflection surveys are being carried out. Deformation or rut depth in
the wheelpaths can be measured by placing a two-meter straightedge
transversely to the road over the deflection test point, any
deformation below the straightedge being measured with a calibratededge.
An assessment of the amount of cracking at a deflection test point
can be made by measuring the linear cracking within a one-meter
square frame. It is done by placing the frame over the deflection
test point with one side parallel to the edge of the road such that
it encloses the maximum length of cracking. The cracks can be
'Chalked in' and measured with a flexible tape.
The measurement of pavement surface deflection under a standard
wheel load is a common practice in many countries. In this regard,
the best known instrument for deflection measurement is the Benkelman
Beam which measures the deflection, at creep speed, between the tyres
of a dual-type truck axle with a standard load (18 KIP). About 250
tests/day over a distance of 5 km can be taken and tolerable criteria
.ay be developed for various pavement types in different regions.
Attempts to automate the Benkelman Beam have been made successfully
in the French "Deflectograph". In this case, a short beam is
.echanically moved as the carrying truck moves forward. Both wheel
paths are tested every 4 m at 2 km/hr with an output of 16 lane
35
km/day. Some degree of sensitivity is sacrificed as against a faster
output.
There are also other instrument like 'Curviameter', 'Dynafleet',
'Pavement Profiter' or 'Road-Rater' for deflection tests.
Surface deflection measurements do not provide any measure of
absolute properties of pavement, but can be related to the
composition and quality of pavement layers, subgrade properties and
axle load repetitions.
3. Traffic Study:'
Traffic analysis are made based on existing and anticipated future
development of an area. While considering the design and
construction of a new road or upgrading an existing one, it is a
commonpractice to undertake traffic volume count and classification
surveys at suitable times and intervals in order to assess as
accurately as possible the Average Annual Daily Traffic (AADT). In
such a survey, the class of vehicle is also identified and records
are tabulated in standard forms. Projections of future traffic
growth are made, based on past records when available, and assessment
are made of generated and developmental traffic. These values are
used in commondesign procedures. But once the road is constructed
and opened to traffic, the monitoring of traffic usage is often a
bapazard undertaking and sometimes neglected altogether despite the
fact that the traffic density is a fundamental factor in proper
assessment of pavement performances and the timing of maintenances.
Along with traffic usage, the vehicles mix and axle-loadings should
also be monitored as overloading of vehicles is a serious problem in
36
a developing country like ours. Implementation of a procedure to
statistically monitor the loadings of heavy good vehicles would
provide a useful, if not essential, input in a totally integrated
highway maintenance programme.
4. Present Serviceability Index (PSI) Canadian Good Road Association(CGRA)Concept :
The present serviceability concept describes present serviceability
as the ability of a specific section of pavement to provide a smooth
and comfortable ride at that particular time of rating. The ability
can be quantified by a value called Present Serviceability Index
(PSI) .
Generally, pavements do not become totally impossible but they
frequently show distress either functionally, where patching and/or
resurfacing can overcome the discomfort of the road user, or
structural failure where the pavement is -no longer capable of
sustaining traffic loads and remedial measures require overlaying or
reconstruction. The causes of distress or failure of the pavement
may be induced by traffic - high gross loads (General over
stressing), high tyre loads (local over stressing), high repeated
loading (fatique effects) and may also be due to poor design or
construction or maintenance.
The PSI of a section of pavement on a road is defined as the mean
opinion of members of a rating panel on the present ability of that
pavement in its present condition, and without regard to the
geometries of the road section, to serve safely, comfortably and
conveniently, high-speed, high volume mixed automobile and truck
37
traffic. The panel is composed of a small number (generally five) of
persons. The opinion of the panel members is recorded on a linear
scale wi th a range of 0.0 to 10.0 representing extremely poor to
extremely good pavement surfaces respectively.
lhe PSI generally indicates how well the section of pavement is
serving the traffic using it at the time of rating.
riding quality as measured by PSI, is as follows:
PSI Riding quality
0-2 Very poor2-4 Poor4-6 Fair6-8 Good8-10 Very good
The relative
It has been shown that new pavement surfaces have PSI values of
between 8.0 and 9.5. Experience has also indicated that pavements
are on the average, resurfaced or reconstructed at a PSI value of
4.5. Thus, the terminal PSI value of 4.5 can be used to define the
life of a pavement.
3.2.2 Maintenance of Unpaved Roads
Normally there are two types of unpaved roads, viz:
a. Earthen Roads which are constructed using natural soil found on
the route.
b. Gravel Roads which are surfaced with a layer of improved material
stronger than natural soil.
With proper maintenance an unpaved road can provide a good level of
service for traff ic volumes upto several hundred vehicles per day.
38
The purpose of maintenance is to provide a smooth passage for
vehicles by repairing damages caused by a combination of the weatherand the traffic.
The first objective of maintenance is to keep the road in such acondition that it sheds water quickly.
,If the road does not shed
water, the surface will become soft and ruts and pot holes will
quickly appear and make earthen roads impossible.
Maintenance is needed to restore a good camber on the road to enablewater to drain off quickly. This is best achieved by regular
grading. On gravel roads, grading is needed to restore gravel from
the shoulders which has been lost from the road surface and to remove
the deep pot holes and corrugations.
In dry seasons, dragging the road surface may be effective in
providing smooth passage for vehicles and in stopping the formation
of corrugations. This may be carried out with a motor grader or with
a drag towed by a tractor or other vehicle. The object is to remove
loose material from the road surface.
Soft spots on the road may need to be patched. Patching can also be
used for general repairs to the road surface when equipment is notavailable.
As the surface of gravel road wears away, new gravel must be added
before rapid deterioration of the surface starts. Regravelling mayalso be used to correct other defects when these become severe and
may also be used to improve an engineered earth road to gravel road.
39
I CHAPrER-4
SYMPrOMS, CAUSES AND TREATMENT OF ROAD FAILURES
The types of defects in bituminous surfacing are grouped under four
categories as follows:
4.1 CRACK!NG
Cracking takes many forms. Simple crack filling may be the right
treatment in some cases. In others, complete removal of the affected
area and the installation of drainage may be necessary before
effective repairs can be carried out. Types of distresses in
asphaltic road pavements due to cracking, their symptoms, probable
causes and possible remedial treatment are summarized below
Types ofdistress
1. Hair -linecrack
2. Alli-gatorcracks
3. Reflec-tioncracks
4. Edgecracks
Symptoms
Short and finecracks at closeintervals onthe surface.
Interconnectedcracks forminga series ofsmall blocks.
Cracks inasphalt over-lays whichreflect thecrack patternin the pavementstructureunderneath.Crack near andparallel topavement edge.
40
Probable causes
Insufficient bitu-men excessivefilter or impropercompaction.
Excessi ve deflec-tion of surfaceover unstablesubgrade.
Due to joints andcracks in thepavement layerunderneath.
Lack of lateral(shoulders)supportand settlement ofunderlyingmaterials.
Possible typeof treatment
The treatment willdepend on whetherpavement is struc-turally sound, orunsound. Where thepavement is struc-turally sound,thecracks should befilled with a lowviscosity binder ora slurry seal orfog seal dependingon the width ofcracks Unsoundcracked pavementswill need strength-ening or rehabilit-ation treatment.
5. Shrin-kagecracks
4.2 DISTORTION
Interconnectedcracks forminga series oflarge blocks,with sharpcorners andangles.
Volume'change inthe asphalt mixor in the baseor subgrade.
Pavement distortion is any change of the pavement surface from its
original shape. It usually is caused by such things as too little
co.paction of the pavement courses, too many fines in surface
mixtures, too much asphalt, swelling of underlying courses, or
settlements.
Types of distresses in asphaltic road pavements due to distortion,
their symptoms, probable causes and possible remedial treatment are
suamarized below:
Types ofdistress
Symptoms Causes Possible typesof treatment
1. Rutting Longitudinaldepressionwhich developsin the wheeltracks.
Consolidation orlateral movementof underlyingcourses or dis-placement in as-phalt surfacedue to traffic.
Removal of thesurface lalyer inthe affected areaand replacementwith freshmaterial.
2. Corrug-ations
3. Shallowdepres-sion
Formation ofregular un-dulations.
Localizedshallowdepressions.
41
Lack of stabilityof the asphaltmix.
Presence of in-adequatelycompactedpockets.
Scarification andrelaying of surf-acing,or cuttingof high spots andfilling of lowspots.
Filling with premixmaterials.
4. Settle- Upward dis- Expansion of ice Deep patching shouldment placement due in the lower be done for perma-and to Sub-grade courses of the nent repair.upheaval swelling. pavement or the
subgrade.
5. Utility Due to cut Lac of adequatedepres- for utility compaction ofsians. installation backfil material.
or repair.
4.3 DISINTEGRATIONDisintegration is the breaking up of a pavement into small, loosefragments. This includes the dislodging of aggregate particles. If
not stopped in its early stages, it can progress until the pavementrequires complete rebuilding. Types of distresses, symptoms,
probable causes and possible types of treatment for disintegrationare summarized below:
Types ofdistress
Symptoms I Probable Causes Possible type oftreatment
Lack of compactionduring construct-tion, too littleasphalt, disinte-grating aggregate
1. Potholes
2. Ravelling
3. Edge,breaking
Bowl-shapedholes fromlocali zed pave-ment disintegra-tion.
Progressive se-paration ofaggregate part-cles in a pave-ment, from sur-face downward orfrom the edgesinward.Irregular break-age of pavementedges.
42
Limited quantityof asphalt or ex-cessively thinsurface or toomany or too fewfines or poordrainage.
Water infiltrat-tion,poor lateralsupport fromshoulders, in-adequate strengthof pavement edgesetc.
Filling potholes withpremix material, orpanetration patching.
Application of cut-back covered withcoarses and orsllurry seal orpremix renewal coat.
Cutting the affectedarea to regular sec-tions and rebuildingwith simultaneousattention paid to theproper constructionof shoulders.
4.4 SKID HAZARD
Few dry pavements are slippery. But there are a number of things
than can make a pavement slippery when wet. The smooth pavement
condition usually is the result of a film of asphalt on the surface,
a polished aggregate in the surface course. The object of a skid
hazard improvement is to restore the pavement surface to a condition
where water can flow around most of the surface aggregate particles,
leaving contact between tire and aggregate. Types of distresses,
sFlptoms, causes and remedial treatment for skid hazard discussed
below:
Types of Symptoms Probable CausesI
Possible types ofdistress treatment
1. Bleeding Upward movement Excess of asphalt Sand blinding, openor of asphalt in in one or more graded premix liquidflushing an asphalt pavement layers. seal coat,burning ofasphalt excess binder,
removal of affectedarea.
2. Polished Aggregate not Characteristics Application of liqu-aggregate covered by of some rocks id seal, fog seal or
asphalt. (Limestone) slurry seal depend-ing on the extent ofdamage.
43
PHOTOGRAPH SHOWING SOME CASE STUDIES
,
•
Figure-4.1 Pot holes on road at Raapura Road, Dhaka
figure-4.2 Water Stagnant on roads near Mohakhali, Dhaka
44
Figure-4.3 Alligator Cracking or Map Cracking onroads at Tejgaon Industrial Area, Dhaka.
, Figure-4.4 Shallow Depression on Road side near New Market, Dhaka
45
4.5 MAINTENANCE OPERATIONSIn Chapter-3 , a discussion has been made about types of failures,
evaluation for maintenance etc. It is convenient to categorize the
practices in terms of the following types of classes of highwaymaintenance, the maintenance of :
1. Road way surfaces;
2. Shoulders and approaches;
3. Road sides;
4. Drainage structures.
4.5.1 Maintenance of Road Way Surfaces
Patching:
When road failure is due to a poor mixture or gradation of materials
it is usually necessary to remove the unsuitable material and
replace it with suitable materials of the proper gradation.
Patching may consist simply of an application of a thin coat of
bituminous material to an area where cracking or ravelling appears
and spreading a coarse mineral aggregate over the affected area.
Care must be exercised in the application of the proper amount of
bituminous material in order to prevent bleeding, with the resultingslipperiness of the repaired surface.
For permanent repair of a deep patch the procedure is as describedbelow :
a. Remove the surface and base as deep as necessary to reach firm
support, extending at least a foot into good pavement outside the
cracked area. Some of the subgrade will also have to be removed.
46
Make the cut square or rectangular with faces straight andvertical.
b. If water is a cause of the failure, install drainage.
c. Apply a tack coat to the vertical faces.
d. Backfill the hole with a graded hot asphalt plant mix. If the
asphalt mixture is not available, make backfill with a goodgranular base material.
e. Compact in layers if the hole is more than 6 inch deep by usinghand rammers or a small vibrating hammer.
f. Full depth asphalt mix placed directly, needs no prime.
g. If granular base is used it should be primed.
h. Use a straightedge or a straight line to check the quality. andthe alignment of the patch.
47
•
Materials :
The materials used for patching will depend on those present in the
existing road. Recommended materials are given in the Table-4.1.
In Figure-4.5 steps for repairing a Pothole is given.
(1) Untreated Pot hole
~~. "o .•.q:.o',4:D.;4,: .••.. 9. , .. ;'O',o".-d .•••• P. <t:J:~ .• a:: ..Q .•4.:•....•• ;o::~ ..r7:...••'..•: ~ '0' .,:".
(2) Surface and base removedto firm support
•
(31 Tack coat applied • (4) Full depth asphalt mixtureplaced and being compacted
. ",'
(5) Finished patch compacted to levelof surrounding pavement
Figure-4.5 : Steps for repairing a Pothole.Source: Road Maintenance Handbook Volume-I, United Nations
Economic Commission for Africa
48
REPAIRING OF POTHOLES
Figure-4.6 Repairing of Pothole by Dhaka Municipal Corporationon New Airport Road, Dhaka.
49
TABLE-4.1
RECOMMENDATIONS FOR PATCHING MATERIAL
Layer
Base
Existing Material
GravelRepair Material
Gravel of at least as goodquality as the original.
plusor
Cement stabilised,bitumenstabilised,crushed rock orbitumen macadam.
Gradedfines,premix
crushed rocksoil cementmacadam.
Surface Surface dressing( New, thin )
Surface dressings whichhave built up to severalcentimeters thickness andpremix surfaces.
Binder andchippings
Premix macadam plus sealof binder and chippings.
Source: Overseas Role Note 2, TRRL 1981.
Specifications for suitable gravels, which may be used for patchinghave been given in the Appendix. These are suitable forstabilisation with 5-10 percent of cement. If crushed rock is used
for the patching material, gradings are shown in Appendix.
4.5.2 Maintenance of Shoulders:
The importance of properly maintaining the shoulders or berms is
realized when their intended functions are understood. The mosti.portant functions of shoulders are to provide space for vehicles
leaving the travelled surface of the roadway, to facilitate running
off of surface water from the pavement to the nearby drainage ditches
and to support the edge of pavement or road surface. Shouldersshould be kept stable, smooth, and with proper elevation and cross
slope. The most common defect is depressions in the shoulders along
the edge of the pavement which defeat the important functions of the
50
shoulders. It creates a traffic hazard, collects and holds dirty
water which may be splashed upon pedestrians. Most shoulders on
existing highways in Bangladesh are of natural or untreated soil and
the maintenance organization must make it mandatory to properly
maintain the shoulder in its natural condition or to improve it as
the volume of traffic increases or when the funds permit.
A well-graded gravel shoulder will provide a satisfactory all-weather
shoulder for light traffic; the maintenance of shoulders of this type
will follow a pattern similar to that of soil aggregate surfaces.
This will include the dragging and blading of the shoulder surface
for the proper slope and the filling of any ruts. It may be
necessary to replace worn out and lost materials at periodic
intervals. This work can be done with a light motor grader.
The condition of the shoulder for all paved roads should also be
examined and rated along with the pavement condition. The shoulder
may be of bituminous concrete, bituminous seal, gravel turfed.
51
Rating for shoulder may be done as per proforma given below:
Rating Bituminousconcrete
Bituminousseal
Gravel Grass
Very Smooth; Smooth; Well trimmed Full coverGood 1 No patches No patches and compact mowed to pave-
ment level.
Good 2 Smooth; Minor Minor rutting 25-50 mm buildFew patches patching confined to up above pave-
outside ment level.shoulder.
Fair 3 Some potholes Some pot holes Minor cross Bare gap at(Less than minor edge rutting by edge of10% by area) rutting erosion. Loose bitumen.
stone averagedia 14 mm.
Poor 4 Pot holed Pot holed over Longitudinal Unmowed buildover 30% by 30% by area rutting by up over 30 mmarea. Iunrepaired) erosion at edge of solid so as(unrepaired) of bitumen to pond water
(depth of rut adjacent to14 mm). edge of
bitumen.
4.5.3 Maintenance of Drainage Structures:
Proper drainage maintenance requires that all structures and
appurtenances pertaining to removal of water from the highway have to
be kept in good working condition so as to provide free and
unobstructed flow. Generally, maintenance operation consist of
those relating to:
i. surface drainage;
i1. ditches and
iii.subsurface drainage, storm sewers, culverts etc.
Water have a harmful effect on shoulders, slopes, ditches and other
features. High water velocities can cause erosion which, when
52
\
severe, can lead to the road being cut. Alternatively; low
velocities in drainage facilities can lead to silt being deposited
which, in turn, can lead to a blockage, blockage often result in
further erosion.
Good surface drainage is maintained by having the pavement surface as
water-proof as possible and by having such crown and surface
smoothness that the water will flow freely to the road edge and on to
the shoulder.
Similarly, shoulders are maintained flush with the pavement and
smooth enough to provide for free flow of water away from the edge of
the road and across the shoulder to the side ditch in out sections or
down slope of fill sections.
However, proper highway design can contribute
maintenance difficulties due to inadequate drainage.
to eliminate
For example, if
pavement and bases or sub-bases have to be constructed in a trench, a
proper subgrade drainage either by constructing shoulders of porous
materials or by placing pipe drains through the shoulders can
contribute to ease of maintenance.
4.6 THICKNESS OF OVERLAYOverlay thickness for flexible highway pavements are determined by
means of deflection measurements. Measurements are generally made
using the Benkelman Beam although large scale measurements can be
made using a device such as
53
i. California continuous deflectometer or
ii. Dynaflect.
Using the Benkelman Beam shown in Figure 9 pavement deflections are
obtained for the project under study by testing the outer wheel-path
at a minimum of ten locations selected within each section of equal,
or nearly equal. The random sampling technique is used to select the
test locations. A Representative Rebound Deflection (RRD) value is
the mean of measured rebound deflections, which have been adjusted
for temperature and most critical period of the year, plus two
standard deviations. This value encompasses approximately 97 percent
of all deflections measured.
OVERLAYSThere is an important distinction between 'maintenance' and other
pavement rehabilitation techniques, including 'overlays'.
less than 25 mm (1 in) thick, for example, are
Overlays,
considered
maintenance, and overlays of greater thickness are considered capital
improvements. The purpose of overlay design is to determine the
appropriate thickness of either an asphalt or granular layer which,
when placed on an existing pavement, will overcome the strength
deficiencies of the pavement and retain its own structural integrity
throughout the design period.
BASIC PRINCIPLESThe pavement deflection caused by a standard axle load is an
indication of the rate at which permanent pavement deformation will
occur under traffic. As the functional adequacy of the pavement is
54
dependent, in part, on this permanent deformation, a relationship
between the cumulative number of standard axle loads and measured
surface deflection can be developed. Using this relationship a
design deflection can be determined for any particular trafficloading.
The Representative Rebound Deflection equals ( x + 2s)
fc where x = the arithmetic mean of the individual values that
have been adjusted for temperature.
s = standard deviation.
f = temperature adjustment factor.
c = critical period adjustment factor.
Standard deviation, s = .f ------n - 1
If all deflection measurements are made at the same temperature then
the adjustment can be applied to the mean deflection value.
55
CHAPTER-5ROAD MAINTENANCE MANAGEMENT
5.1 INTRODUCTION
The key to good management is careful planning and programming of
the work to e done. The main objectives of maintenance management
are the allocation of available maintenance resources according to
actual needs and priorities, increasing the productivity, the
development of uniform ways for doing the work, and the monitoringand evaluation of the outputs for the continuous improvement of thesystem.
5.2 MAINTENANCE MANPOWERMaintenance of road in developing countries like Bangladesh is labour
intensive and therefore, the output depends upon "labour
productivity". The operations require use of skilled and unskilled
workers. Right type of persons should be employed for every type of
work. While female labour can be good transporters for small loads,
only skilled male laboures should be employed for work like
bituminous construction. Regular training regarding works to be
carried out, use of tools, plant and materials, etc. should bei.ported to those workers.
5.3 MAINTENANCE MANPOWER IN BANGLADESHIn Bangladesh Roads and Highways Department maintains the large
portion of the roads and highways. Roads and Highways Department has
divided Bangladesh into ten road circles, consisting of two or more
56
road divisions. Each Road Division has a maintenance gangconsisting of work assistants and coolies. On roads where pothole
repair is needed they take the necessary repairing materials on truck
and repair the potholes. They cannot use roller everywhere because
use of roller is not economic for small repairs and at far distances.
Road maintenance staff for a typical road division under Roads andHighways Department is given in the Table 5.1.
TABLE-5.1
ROAD MAINTENANCE STAFF FOR A TYPICAL ROAD DIVISIONUNDER ROADS AND HIGHWAYS DEPARTMENT
Sl. Name of the Post No. of Post TotalNo. holder1. Professional:
i. Executive Engineer 1i i. Sub-Divisional Engineer 3
iii. Assistant Engineer 1 52. Technical Staff :
i. Sectional Officer 11 113. Skilled Technicians
i. "ark Assistant 69
ii. Jeep driver 4
iii. Truck driver 5iv. Roller driver 7
v. Mechanic 8
vi. Assistant Mechanic 11vii. Mason 8
vii i.Carpenter 3 115
57
51.No.
Name of the Post No. of Postholder
Total
4- Non-Skilled Labourers
i. Cooly
ii. Peon
iii. Chowkidar
iv. Road guard
v. Helper
vi. Boatman
189
9
13
27
16
3 257Source : Roads and Highways Department, Dhaka.
The maintenance activities can be conveniently done by maintenance
gangs (size of each gang varying from 3 to 7 persons depending on
workload) with the supporting hand tools (shovel, hoe, hammer,
masons, tools, basket, iron and wooden rammers etc.) and equipments
like small roller (for compaction), tar boilers and mini truck (3tonner) for movement of equipments and labourers.
5.4 MECHANISATION AND EQUIPMENT PLANNING
The spectrum of technologies available for maintenance of roads
ranges from labour based to equipment based, although the relativeproportions can differ substantially. The socia-economicrequirements in Bangladesh is basically for labour based maintenance
to provide employment to a large number of people but it may be
necessary to use special equipment to achieve a specified quality in
the end product of certain activities, such as the use of (a) roller
for compaction on (b) grit spreader and bitumen distributor for good
surface dressing. Even the labour based methods use equipment in the
58
form of hand tools and equipment based approaches use labour in the
form of operator. The machineries, equipment owned by the Roads and
Highway Department is given in the Table 5.2
TABLE-5.2
The Machineries, Equipments for Maintenance owned by Roads andHighways Department (June, 1990)
51.No. Name of Equipment
1. 3 - Wheeled Static Road Roller
2. 2 - Wheeled Static Road Roller
3. Pneumatic Tyre Roller
4. Soil Compactor 12/18 Ton
5. Bull Dozer Crawler
6. Bull Dozer ,Tyre
7. Scraper
8. Motor grader
9. End loader tyre
10. End loader crawler
11. Water Tanker
12. Dump Truck
13. Tractor Trailor
14. Flat bed truck
15. Mobile crane
16. Mobile servicing unit
17. Mobile bitumen mixer
59
•
No. ofEquipment
412
37
74
54
36
6
11
60
36
5
40
36
10
297
1
21
21
81.No. Name of Equipment
18. Mobile Generator
19. Forklift Truck
20. Road marking machine
Source: Roads and Highways Departaent, Dhaka.
No. ofEquipment
30
5
2
The equipment owned by a typical Road Division of Roads and Highways
Department is given in the Table-5.3
TABLE-5.3Equipment Owned by two Typical Road Division of Roads and HighwaysDepartment
81. No. Name of Equipment No.of Equipment(Division - 1)
No.of Equipment(Division - 2)
1.
2.
3.
4.
5.
6.7.
Source
Water Tanker 3 2
Flat bed Truck 6 6
Mobile bitumen mixer 2 1
Mobile servicing unit 1 1
Roller(a) 3 - Wheeled Static Roller 8 4
(b) 2 - Wheeled Static Roller 1 2
Concrete mixer 1 4
Bitumen boiler 3 2
Roads and Highways Department, Dhaka.
60
5.5 MANAGEMENT OF FUNDS
Maintenance funds are allocated from the revenue budget, so that it
is very scarce in a developing country like Bangladesh. Financial-allocation for routine maintenance are therefore allocated of a fixed
sum per mile plus a variable sum for pavement repairs. The amounts
allocated may also vary with the type of road and/or traffic volume.
The fixed sum per mile is generally determined from previous
~xperience and the cost of pavement repairs may be deduced from the
road condition.
The average annual road maintenance expenditure of Roads and HighwaysDepartment is given in Table-5.4.
TABLE-5.4
THE AVERAGE ANNUAL EXPENDITURE FOR MAINTENANCE OFROADS AND HIGHWAYS DEPARTMENT
(Taka in lakhlYear A11oc- Pay Material Equipment/ Misce- Special Ferry
ation Transpor- 11aneous repairtat ion
1985-86 4100.00 515.26 751.54 180.92 296.74 1952.68 1065.011986-87 4900.00 608.49 620.47 333.82 284.95 1933.82 1342.631987-88 6150.00 696.16 767.12 346.20 279.25 2870.83 1571. 901988-89 7500.00 775.13 816.28 411. 61 621.54 3117.96 2055.761989-90 8000.00 829.31 901.32 499.10 720.21 3423.32 2721. 32
Source: Roads and Highways Departaent, Dhaka.
61
The average annual expenditure for maintenance by road type is given
in the Table-5.5
TABLE-5.5
AVERAGE ANNUAL EXPENDITURE FOR MAINTENANCE BY ROADTYPE
Type of the Total Length Average width of Average annualRoads (in km) pavement expenditure per km
(in m) (Taka in lac)
National 2834.60 6.71 0.91Highway
Regional 1369.76 5.49 0.79Highway
Other Roads 8059.90 3.66 0.16Source : Roads and Highways Department, Dhaka.
The annual road maintenance expenditure of different road circles ofRoads and Highways Department is given in the Table-5.6
TABLE-5.6
ANNUAL ROAD MAINTENANCE EXPENDITURE OF DIFFERENTROAD CIRCLES IN BANGLADESH (1989-90)
(ROADS AND HIGHWAYS DEPARTMENT)
(Taka in Lakh)51- Name of RHD Total Departmen- Special Ferry TotalNo. Circle Length tal Expen Repair Mainten-
(in km) -diture ance
1- Dhaka road 980.46 365.60 1205.48 747.25 2318.33circle
2. Mymensingh 1382.37 188.27 350.46 86.00 624.73road circle
3. Chittagong 1232.03 262.73 297.88 560.61road circle
62
(Taka in Lakh)5l. Name of RHD Total Departmen- Special Ferry TotalNo. Circle Length tal Expen Repair Mainten-
• (in km) -diture ance
4. Sylhet road 1960.90 404.67 452.27 165.93 1022.87circle
5. CHT road 428.96 30.65 80.06 110.71circle
6. Khagrachari 192.75 4.76 24.64 29.40road circle
7. Rajshahi road 1275.83 240.54 282.82 24.59 547.95circle
8. Jessore road 1530.32 358.42 437.00 186.79 982.21circle
9. Rangpur road 1741.21 162.16 556.52 718.68circle
10. Barisal road 1475.43 159.42 260.10 229.44 648.96circle
12180.26 2177.22 3947.23 1440.00 7564.45
Source: Roads and Highways Department, Dhaka.
~'(j<;jJ
63
CHAPTER-6
ROAD MAINTENANCE PRACTICES IN BANGLADESH
6.1 INTRODUCTION
Road transport plays a significant role in the economic development
of Bangladesh. For this reason a significant part of the national
budget is spent in road building and maintenance. Even if the design
and construction of the road conform to requirements and standards,
maintenance is still needed. A poorly maintained road is not only
inconvenient to the users and detrimental to the road itself but it
is highly uneconomic. So road maintenance is quite important. Due
to lack of maintenance, roads deteriorate quickly. On the other
hand, proper maintenance prolongs the life and improves the quality
of service of roads and highways.
6.2 ROAD CONSTRUCTION AND MAINTENANCE ORGANISATIONS
Before going into the details of road maintenance procedure as
followed in Bangladesh a brief discussion on various organisations
entrusted with the construction and maintenance of roads streets and
highways in Bangladesh seems to be in order. In Bangladesh a major
portion of roads and highways are constructed and maintained by the
Roads and Highways Department (RHD). Local bodies like Zila
Parishads, Pourashavas/Poura Corporations, Upazila Parishads, Union
Parishads etc. also build substantial amounts of roads of different
fuoctional classifications within their jurisdictions.
The Roads
constructingand Highways Department is mainly responsible
and maintaining inter-district and inter-city roads
64
forin
Bangladesh. The total road kilometrege within the jurisdiction of
the Roads and Highways Department is shown in Table-1.2.
The Roads and Highways Department maintains ten road circles each
having two or more road divisions. Each road division is entrusted
with the task of constructing and maintaining the roads within its
jurisdiction. Construction of roads in Bangladesh is financed mainly
from development budget, while road maintenance is financed mainlyfrom revenue budget.
Besides, these normal road jurisdictions there are many large and
special road projects which are constructed, rehabilitated and
maintained by the Roads and Highways Department. Due to scarcity of
local resources these types of projects are financed by different
international organisations such as the Asian Development Bank (ADB),
the World Bank etc. These kinds of roads are sometimes undertaken•
during emergent situations such as floods etc. A brief description
of such' projects under the Roads and Highways Department is givenbelow :
Project Title
1. Feeder Roads'Improvement Project
2. Road ImprovementProject
65
Location and Jurisdiction
*To improve 300 kms of roads in thedistricts of Mymensingh, Tangail,Jamalpur, Sherpur, Netrokona andKishorganj.
*To improve 330 kms of selectedportion of national roads (Daudkandito Feni, Dohazari to Cox's Bazar,Daulatdia to Faridpur, Faridpur toJhenidah and Jhenidah to Kushtia.)
3.
Project Title
Road Rehabilitation andMaintenance Project.
Location and Jurisdiction
*Repair and Resealing of about 100 kmsof selected portions of national roads(Dhaka to Daudkandi, Feni toChittagong, Chittagong to Dohazari).
*Rehabilitation of 132 kms of roads(Dasuria-Natore-Rajshahi).
*Maintenance programme of 2000 kmof priority road in North-west andSouth-west.
Besides Roads and Highways Department, a significant part of the
road system is constructed and maintained by local bodies. At
present, such local bodies in Bangladesh possess the following roadkilometreges:a. lila Parishads - 21,000 kms of feeder roads having crest width
of 6m to 7.3m connecting UpazilaQuarters and other Growth Centres withnearly arterial road system.
Headthe
b.
c.
Pourashavas/Poura Corporations
UpazilaParishads
About 9000 kms of urban roads within theterritorial jurisdiction of the Pourashavas.
About 28000 kms of rural roads having crestwidth of 3.65m to 4.6m connecting Unions toUpazila Head Quarters and important localmarkets.
d. Union Parishads- About 1,08,000width of 2.43mand farms toQuarters.
kms ofto 3.65mlocal
roads having crestconnecting villagesmarkets/Union Head
The responsibility for the construction and maintenance of national
and regional district roads rests on the Roads and HighwaysDepartment. The Zila Parishads mainly maintains and develops feeder
roads including inter-upazila roads which connect Upazilas and other
important growth centres with the abutting arterial road system.
The Zila Parishads have substantial financial resources at their
disposal and they spent a substantial portion (approximately 70%) of
66
their resources for the construction and maintenance of feeder roads.
The sources of funds are as enumerated below :
a. Normal revenUe income - Land transfer fee, income from assets,lease of ferry ghats etc.
b. Works programme grants.
c. Special foreign aided projects.
d. Divisional Development Board funds.
There are four Municipal Corporations i.e Dhaka, Chittagong, Rajshahi
and Khulna and eighty eight Pourashavas. Except Dhaka and Chittagong
Municipal Corporations, most of 'the Pourashavas are going through
considerable financial constraints. Their resource bases are narrow
and their share of Development Assistance Fund compared to upazila
parishads is too inadequate. Due to resource constraints most ofthere pourashavas are not in a position to meet theirresponsibilities of properly maintaining municipal roads. Most ofthe Pourashavas do not have adequate technical personnel andequipments.
The Upazila Parishads are adjudged as the nuclei of development.
They have their own programmes of construction and improvement ofroads. These roads mainly connect important markets and union
headquarters within the upazilas. With the exception of some brick-
surfaced roads these consists mainly of kutcha or earthen roads. The
road construction and maintenance works of upazila parishads are
mainly undertaken by resources from Development Assistance Fund andFood for Works Programme (FFWP).
67
T~ Union Parishads have certain responsibilities theconstruction and maintenance of roads within their jurisdictions.
These consists mainly of small kutcha roads connecting villages and
bazars within the union parishads. Those works are undertaken with
their own resources as well as shares receiving from the DevelopmentAssistance Fund and Food For Works Programme.
6.3 PROBLEMS OF ROAD MAINTENANCE IN BANGLADESH
6.3.1 Problems for Arrangement of Traffic:
Since maintenance operations involve considerable hardship,inconvenience and hazard to traffic and also hazards to maintenance
workmen all possible precautions should be taken to make safe
arrangements for traffic. These include erection of barriers, signs,
red flags and lights. The maintenance locations are surrounded by
white and red stripped barriers, fences and directional cones to
guide the approaching vehicles onto another line. Efforts should be
made to confine work in half the pavement width at a time, leavingthe other half for use by the traffic. Where this is not possible,diversion roads may have to be constructed or the traffic diverted tosome other alternative routes.
Selecting and positioning temporary road signs, theprinciples should be applied.
following
i. Traffic control devices must always be in a good and usablecondition;
ii. Traffic control devices must always be visible;
iii. Traffic control devices must be correctly located;
iv. Traffic control devices must be properly mounted and fixed andmust possess adequate stability.
68
T~ following plans show traffic control devices for maintenance
sites on paved and unpaved roads. They are proposed with the
intention of assisting those responsible for the sign posting of
maintenance sites in choosing suitable traffic control devices andtheir locations.
. _.
Men working ahead
Carrigeway narrows
Carrigeway narrowsto left
69
Keep left here
'.0..~\.I:,. .
Keep right here
Speed reduction(maximum speed BOkm/h)
Carrigeway narrowsto right End of work site
Detour100m IDetour>
Detour 100 m ahead
Turn right
Detour necessary to right
;,"'--~.," ~~ "
, .~'.--
Turn left
ooo
--_._-o ;? Standared Heights and Burried~ -~._ Depth for Traffic Signs
70
oo
Barrier Drum Traffic Cone(Other sizes also available)
•.Stop/Go Paddle forTraffic Controller
"; ."
Lane Closed Barrier Warning Flag
Color: White/red/whiteor All redor All orange
Figure-6.I Showing different Traffic Signals Completion and Removalof temporary signs.
Source Road Maintenance handbook, Volume-I, United Nations EconomicCommission for Africa.
71
All temporary signs must be removed as soon as the work they relateto is complete. The procedure includes
Clean tools;
Load all tools, equipment and reusable materials on to truck;
Collect all traffic warning signs and cones, wipe clean and loadonto truck, stacking them carefully;
Check that nothing has been left behind and that the site isclean and neat.
Maintenance work can be divided in the following four categories fromthe point of view of safety and traffic control :
i. Repairing the edges of the carriageway, shoulders, cleaning out
drains, cutting grass etc. where carriageway is not affected;
ii. Repairing the carriageway restricting to one lane while trafficcan be allowed on the other lane;
iii. While working on the centre line such as centre line marking/
painting necessitating the traffic to use restricted width oneither side;
iv. Total closure of the road necessitating use of diversion due towidening/reconstruction of an existing road.
72
6.3.1.1 WORKS ON EDGES AND SHOULDERS
The positioning of the cautionary signs for this category are
illustrated in Figure-6.2. Before starting the work, all warning
signs should be installed in the following manner. 'Men at work'
should be placed 200 M before approaching the work area and
'Restriction Ends' sign should be displayed 200 M beyond the work
.area. When the work is completed, these signs should be removed inthe reverse order.
Figure-6.2 : Sign layout for edge working.
Source Overseas road Note-2. Maintenance Technique for DistrictEngineers.
73
6.3.1.2 RESTRICTING THE TRAFFIC TO ONE LANE
At times, the traffic is to be restricted to one lane only due to
repairs being carried out in the other lane such as major patch
repairs, etc. The position of various cautionary and warning signs
are illustrated in Figure-6.3, which are to be installed before
start of the work the following sequence :
i. 'Men at work' sign to be put up 200M before commencement of thework;
ii. 'Narrow Road Ahead' should be at 100M ahead of work area;
iii. 'Keep left/right' sign to be placed at the commencement point
of the work and next to the barriers on the either end of thework area;
iv. 'Barriers' should be placed on both sides of the work area;
v. Drums painted white and black should be placed at 9M interval
for guiding the traffic. In the approaches tare to be kept ina tapered manner;
vi. 'Restriction Ends' sign should be installed 200M beyond thework area.
74
In addition to the above. a watchman should be present at thebarrier to control the traffic at all times.
CJY4QlFigure-6.3 : Sign Layout for Lane Closure
Source Overseas Road Note-2, Maintenance Technique for DistrictEngineers.
6.3.1.3 WORKING IN THE CENTRE OF THE CARRIAGEWAY
While working in the centre of the carriageway. adequate attention
has to be paid from the safety point of view, for example.
marking/painting of centre line. The positioning of the various
cautionary and warning signs are illustrated in Figure 6.4 The
sequence of installation of these signs are the same as in the
traffic arrangement to one lane. Except in this case, the vehicles
will keep onlJ' to the left in each direction. When the work is
.completed. it should be ensured that the signs are removed in thereverse order.
75
rT1/{2J.'VI .
Figure-6.4 : Sign Layout for Centre line working.
Source : Overseas Road Note-2, Maintenance Technique for DistrictEngineers.
6.3.1.4 DIVERSIONS
In the interest of safety and convenience of traffic, appropriate
.easures must be taken whenever traffic on any section of a road is
to be diverted to another route, or made to separate from its
normal path into another. Basic principles to be kept in mind are
(i) that the traffic must be guided properly where it is required
to follow an alternate facility; (ii) given a clear warning of anyhazards that may be present ahead.
After the diversion has been completed and before work starts,
warning signs, barriers and cones must be placed around the work
area. The layout shown in Figure-6.5 is recommended. Signs mustbe placed in the following order :
1. 'Men working' signs should be placed 200 meters in frontof the work area.
76
2. 'Turn left/right ahead' signs should be placed 100 meters infront of the work area.
3. 'Turn left/right' arrows should be placed immediately beforethe start of the diversion.
4. Cones should be placed diagonally across the road to lead intothe diversion.
5. 'Keep left/right' arrows should be placed at the ends of thelines of cones.
6. 'Barriers' should be placed behind the line of cones.
7. 'Road clear' signs should be placed 200 meters beyond the endsof the diversion.
Signs, lights, barriers and other traffic control devices
should be kept maintained ln a satisfactory condition until
such time as the traffic is restored and allowed to follow itsnormal path.
Figure-6.5 : Sign Layout for Diversion.Source Overseas Road Note-2, Maintenance Technique for District
Engineers.
77
TRAFFIC SAFETY AT NIGHT
Traffic safety substantially decreases at night time during maintenance.
Necessary lighting arrangements may be made during night with flashing
lights when required. The barricade should be protected with red warning
lamps at night which should stay lit from sunset to sunrise. In addition,
alternate black and white diagonal strips should be marked on these for
effective advance warning preferably with reflecltorised paint.
6.3.2 Financial Capacity
The capacity to pay for road maintenance from domestic sources
depends on a country resources. Gross National Product (GNP) per
capita may thus be a good index of financial capacity, but some
governments are able to capture more of it than others. And of the
fiscal intake, the allocation to highways is a political decision•
about national priorities.
6.3.3 Institutional Capacity:
The differences in Gross National Product (GNP) per capita and its
rate of change, the ratio of network length to Gross National
Product, the age distribution of roads and the volume of traffic - do
not fully account for the variation in road conditions from country
to country. Institutional capacity has several facts. One is the
size of labour forces that can be applied to the activity. Othersare the soundness of the maintenance strategy - type, level and
timing of intervention and the managerial and operation efficiency
with which the strategy is executed. This depend, in turn, on suchfactors as governmental commitment, institutional structure,managerial ability, staff quality, accountability and incentives.
78
6.4 EXISTING ROAD MAINTENANCE TECHNIQUE
Techniques for the evaluation of roadway pavement conditions have
been discussed in detail in Chapter-3. Types of maintenance works
done by the Roads and Highways Department is given in Table 6.1. But
the most important and crucial consideration is the technology ofproperly and economically maintaining roads.
pursued.
In Bangladesh appropriate and scientific or engineering methods have
not yet been devised and documented. Field crews do the job in their
own way under the supervision of a Field Maintenance Engineer. Proper
evaluation and assessment as well as maintenance planning is old,
sometime methods are inadequate. Budgeting cost estimations are not
in keeping with modern techniques. Priorities are seldom determined
on the basis of factual data and national interest. In the developed
world where manpower is limited but resources are not very limited
machines and automatic or semi-automatic process are
Accordingly research documents on such methods are abundant. But in
the developing countries like Bangladesh where population pressure is
heavy, employment opportunities are limited and resource limitations
are significant, labour intensive methods are highly encouraged.
Techniques and procedures for such labour intensive methods areneither well documented nor well researched.
The methods adopted for the maintenance work for the roads within the
jurisdiction of the Roads and Highways Department are discussedbelow:
79
At present roads are maintained by surfacing with pea-grave Is-bitumen
.ix. This Premix Bituminous Surface (PBS) deteriorates by cracking
and ravelling quite quickly. It lacks durability under heavy traffic
and often requires bituminous surface seal coat to provide for the
required waterproofing quality. Construction methods are labour-
oriented but often lacks quality control. In most of the cases pea-
gravels or shingles are heated in trays over an open fire and hot
bitumen mixed in with band hoes. During the mixing operation in
trays, little control over bitumen temperature and the uniformity of
.ixing is exercised. Aggregates are seldom properly graded and often
lacks mechanical bondage. Premix Bituminous Surface materials are
sometimes blended in mechanical mixer/heaters. In such cases the
quality of the mix improves considerably but handling is slower and
the temperature of the mix decreases appreciably before application
to the road. A cold mix cannot function properly as a tack coat.
Repairing of pot holes, application levelling courses etc. are done
by the grouting method which often lacks quality control. Sometimes
bitumen is heated on open trays and then applied directly on the road
on eye estimation without proper temperature control. The quantity of
the bitumen required for the purpose is not accurately estimated. If
excess bitumen is used the surface bleeds during scorching heat. In
the event the percentage of bitumen used in the mix is less than the
required amount proper binding is not ensured. Items like pot hole
repairs, levelling courses etc. are also done with premixed materials
consisting f graded aggregates and bitumen emulsions or cut-backs. In
such cases appropriate technology using labour intensive method isadopted.
80•
81
above
Maintenance of feeder roads under project support is an important
issue. Normally a road generally needs a period of three to four
years for the completion of its construction. Maintenance problems
emerges after the road has been in service for a certain period of
time. These maintenance works are obviously of routine type for thefollowing categories of roads :
i. Herring-Bone-Bond (HBB) - Shoulder maintenance (Earth work) plus
the replacement of damaged bricks usually set in herring-bone-bonds.
Maintenance programmes adopted by local bodies (Upazila Parishads)are as discussed below :
ii. Water Bound Macadam (WBM) - Shoulder maintenance (Earth work)
plus the re-surfacing of macadam pavements where ruts and pot-holes are formed.
Besides maintenance of various road surfaces as stated
iii. Bituminous Shoulder maintenance (Earth work) plus the
carpeting, surface painting and seal coating and pot holesrepair.
clearance of slit and weeds in the bridge/culvert openings are also
needed now and then. Since the life expectancies of feeder roads
vary from three to seven year a gradual maintenance programme should
be prepared and followed by each upazila and be closely co-ordinated
with the District Executive Engineer who has the responsibility of
scrutinizing all maintenance proposals and arrange for allocation of
rollers (5-7 tons) needed for such maintenance works should be
equipments like tar boiler, hand compactor, wheel borrows etc. should
provided by the Executive Engineer from the district pool and he
Other small
provide necessary hand tools including tar boilers (where needed) to
the upazilas to perform the maintenance works. Only the small road
funds as being practiced by the donor agencies. The project should
should co-operate in such schedules 'of operation.
be procured by the upazilas for their maintenance gangs.
6.5 FINANCIAL PATTERN FOR MAINTENANCE (UPAZILA ROADS)
During the life of the project Upazila Parishad should undertake themaintenance responsibilities as follows:
Upazila GOB Donor(own resource)
1st year maintenance 100%2nd year maintenance 15% 25% 60%3rd year maintenance 35% 25% 40%4th year maintenance 40% 25% 35%
After the project period is over, the upazila parishad should bear
the total cost of maintenance of the completed feeder roads. The
resources for such maintenance works should come from the UpazilaDevelopment Assistance (UDA) fund.
82
•
5. Jungle cutting.
7. Earth work in road embankment and bridge approaches.
workofNameSI.No.
1. Surface maintenance including patch repair, pot holes repair,minor undulations.
TABLE-G. ITYPES OF MAINTENANCE WORKS DONE BY ROADS AND HIGHWAYS DEPARTMENT
2. Pre-mixed seal coat with tack coat surface painting.
3. Levelling, dressing of shoulder slopes and berms as required,shoulder maintenance.
4. Cutting and clearance of drains and clearance of beds of bridges,culverts etc. including training are required.
6. Maintenance of mile post, boundary pillars, lane marks, singsetc.
8. Baily bridges (wooden decks).
83
CHAPTER-7
RESEARCH FINDINGS AND RECOMMENDATIONS
7.1 FINDINGS
The findings of this research are summarized as follows
1. Road network in Bangladesh is presently classified mainly into
five categories such as national highways, regional highways,
feeder roads, urban roads and rural roads. Detailed
characteristics of these roads are shown in appendix-G. Total
paved roads (7156 km) under Roads and Highways Department in the
national highway category about 72% are double-lane paved, double
lane roads in the Regional highways, feeder roads and Upazila
connecting roads under the Roads and Highways Department are 48%,
20% and 4% respectively. These data shown in Table- 1.4
2. Roads and Highways Department is the main organisation for
constructing and maintaining roads and highways in Bangladesh.
Total roads under Roads and Highways is 12134 km of which 7156
km. Paved road, 2064 km partly paved or brick paved and 2914 kmearthen road.
Of the total road kilometrege in Bangladesh as of mid-1988 only
11% of the roads are paved or partly paved and the remaining are
earthen or kutcha roads. The total amount of paved or partly
paved roads is approximately 20,000 km. These data shown in Table1.3.
84
4. Annual allocation of funds for road maintenance has increased
•Corporation, Upazila Parishad, Union Council are respectively
13%, 5%, 17% and 65%. These data shown in Table 1.3.
in 1989-90
period was
the annual
from Tk.4100.00 lakh in 1985-86 to Tk. 8000.00 lakh
(Table-5.6). The average allocation during these
Tk.6,130 lakh. Average incremental growth in
where the total quantum of these roads is approximately 165,000
km only 6.5% are paved and the remaining 93.5% are earthen or
kutcha roads. The percentage distribution of the total roads
constructed and maintained by Zila Parishad, Pourashava/Poura
3. Besides roads and Highways Department local bodies like Zila
Parishad, Pourashava/Poura Corporation, Upazila Parishad, Union
Council construct and maintain a substantial amount of roads
maintenance allocation was around 18%.
5. The average annual maintenance expenditure per kilometre is Tk.62,000.00. 1t is seen that the average annual expenditure on
maintaining one kilometre of road is Tk. 91,000.00 lakh for
national highway, Tk.79,000.00 for regional highway andTk.16,OOO.00 for other categories of road.
85
through routine or periodic maintenance.
As a result, the adverse effects
From this study it is found that if timely allotment is made of
sufficient funds to the concerned organisation road maintenance
programmes must improve. If timely allotment of fund is not made
damages to roads are intensified by natural calamities, likeflood, excess rain etc.
cummulate and render most of the roads beyond economic repair
6. Equipment and machineries for maintenance owned by different
organisations is generally satisfactory. But the distribution todifferent field offices is not done properly.
8. Though the organisation engaged for maintenance activities. have
adequate manpower for maintenance works but no organisation have
sufficient manpower and equipment for evaluation of existing
pavements in terms of physical condition, structural capacity,roughness etc.
our country is
adequate maintenance
of the professional,proportion
there areintensive,staffs. The
As the maintenance of roads and highways inmainly labour
engineers and
technical, skilled and non-skilled labour is 1:2:23:52. This isgiven in Table 5.1.
7.
9. Appropriate and scientific or engineering methods have not yet
been devised and documented. Field crews do the job in their own
way under the supervision of a Field Maintenance Engineer.
86
2. Fund requirement for proper and timely maintenance must be
estimated by the concerned organisations in appropriate time.Sufficient fund for maintenance to be assured.
road
forcontrol
evaluation forQuality
road maintenance work,
be done properly.maintenance materials must be assured.
RECOMMENDATIONS1. Before going for
condition should
7.2
4. Departments and organisations concerned with road maintenance
works should take steps to acquire adequate number of equipments
and machineries in order to undertake maintenance works speedilyand effectively.
maintaining the roads must chalk out a. programme of road
maintenance at the end of the year. This must be placed to the
appropriate authority so that allocation of funds can give as perrequirement.
3. Department and organisations which are responsible for
5. Upazila connecting roads must be considered for maintenance andaccordingly allotment should be given.
6. Training of all personnel involved in maintenance is an integral
part of the maintenance function. Such training, as may be
required by the operating and maintenance personnel must beassured by the concerned organisations.
87
APPENDIXA. PARTICLE SIZE DISTRIBUTION FOR GRAVEL SURFACING
B. GRADING FOR CRUSHED ROCK PATCHING MATERIAL
as Sieve •• Passing~
37.50 mm 10020.00 80 10010.00 55 805.00 40 602.36 30 50
600.00 II m 15 3075.00 II m 5 15
Source Overseas Road Note-2, TRRL 1981.
88
C. REQUIREMENTS FOR PREMIXED MACADAM USED FOR PATCHING MATERIAL
14 mm nominal size
BS Sieve (mm) % Passing
20.00 100
14.00 90 100
10.00 55 75
6.30 25 45
3.35 15 25
75.00 Jl m 2 6
Binder Content 4 5%
Source: Overseas Road Note-2, TRRL 1981.
D. RECOMMENDED CHIPPING SIZE (mm)
Lane Traffic Category
Twe ofSurface
Approximate number of commercial vehicles currently carriedper day in the lane under consideration
(1) (2) I (3) I (4) I (5)Over-2000 1000-2000 200-1000 20-200 Less than 20
Very hard 10 mm 10 mm 6 mm 6 mm 6 mm
Hard 14 14 10 6 6
Normal 20** 14 14 10 6
Soft * 20** 14 14 10
Very Soft * * 20** 14 10
* Unsuitable for surface dressing.** 20 mm chippings may be used for remedial treatment where trafficspeeds are low. Very particular care should be taken when using20 mm chippings to ensure that no loose chippings remain on thesurface when the road is opened to unrestricted traffic as thereis a high risk of wind screen breakage.
Source : Overseas Road Note-2, TRRL 1981.
89
F. ROAD CONDITION SURVEY FORM
Source: Overseas Road Note-2, TRRL 1981.
80 - 90
35 45
Temperature
55 - 65
105 - 115
125 - 135
140 - 150
150 - 160
155 - 165
165 - 175
Slot Jets'c
95 - 115
65 - 80
50 60
115 - 135
140 - 155
160 - 170
165 - 175
170 - 190
180 - 200
Atomising jets'c
Spraying
E. SPRAYING TEMPERATURES
Grade
MC - 250
MC - 70
Cutback grades
MC - 30
MC - 800
MC -3000
Penetration grades
400/500
280/320
180/200
80/100
ROAD N~~E: ROAD SECTION NO.
.SHEET START POINT:
DISTANCE FROMLAST RECORD metres
INSPECTIOR:DATE:
90
Record No.Record Type.
Locationidentifi-cation
GENERAL
VerticalALIGNMENTS Horizontal
Flood Height
Cut/FillLEFT HeightSIDE SLOPE Slope
Type
LEFT SIDE WidthDRAINS Type
LEFT WidthSHOULDER Type
WidthTypeAgeLeft EdgeCamber
CARRIAGEWAY CrackingPotholesRuttingRoughnessRight Edge
RecommendedMaintenanceActions
RIGHT WidthSHOULDER Type
RIGHT SIDE WidthDRAINS Type
.Cut/FillRIGHT HeightSIDE SLOPE Slope
Type
Source The Road Maintenance Proble., Hodgkinson, W.G.
91
G. ROAD CLASSIFICATION AND GEOMETRIC STANDARDS
S1. Type of Roads DefinitionNo. ( Crest width) (pavement width) (shoulder width)(in each side)
1. 2 34 5 6
A. ARTERIAL ROADS
1. National National Highways form the major arterialsystem Highways and are defined as roadsconnecting the national capital with thedivisional and district headquarters, portcities,places of economic, commercial andstrategic importance, and other importantpoints as decided from time to time on thebasis of traffic requirements.
Category-itA" 12.192 m 6.71 m 2.75 m(40'-0") (22'-0") (9'-0")Category-liB" 12.192 m 5.86 m 3.36 m(40'-0") (18'-0") (11'-0")
2. RegionalHighways Regional Highways refer to roads connecting differ
-ent regions with each other, not connected bynational highways.
Category-"Alf
Category-liB"
10.98 m(36'-0")
10.98 m(36'-0")
5.86 m(18' -0" )
3 •. 66 m(12'-0")
2.75 m(12'-0")
3.66 m(12'-0")
3. District Roads District Roads may be defined as roads connectingSub-divisional Headquarters and important commer-cial centres of the district with each other andthe road system.
9.144m(30'-0")
92
3.66 m(12'-0")
2.75 m(9'-0")
B. FEEDER ROADS
4.88 m(16'-0")
Roads connecting Villages and farms to localmarkets.
1. 83 m(6'-0")
3.66 m(12'-0")
Roads connecting Upazila Headquarters and othergrowth centres with the arterial road system.
Roads connecting Union HQ's/Markets with the Upa-zila H.Q. or the road system.
7.32 m(24'-0")
RURAL ROADSUpazila Roads
Union Roads
c.
3.66 m(12' -0")
Village Roads Roads connecting mosques, weels, & different parasof the Villages.2.44 m(8'-0")
Source Roads and Highways Departaent, Dhaka.
93
REFERENCES
1. 'ASPHALT OVERLAY FOR HIGHWAY AND STREET REHABILITATION' The AsphaltInstitute, Manual Series No.17(MS-17), June, 1983.
2. 'A DEFLECTION SURVEY TECHNIQUE FOR PAVEMENT EVALUATION IN DEVELOPINGCOUNTRIES' by H.R. Smith.
3. 'CODE OF PRACTICE FOR MAINTENANCE OF BITUMINOUS SURFACES OF HIGHWAYS'IRC : 82-1982.
4. 'POCKET BOOK FOR HIGHWAY ENGINEERS', IRC, NEW Delhi, 1983.
5. 'PRI.NCIPLES AND PRACTICE OF HIGHWAY ENGINEERING' by L.R.Kadiyali,1984.
6. 'ROAD MAINTENANCE HANDBOOK VOLUME I', United NationsCommission for Africa.
Economic
7. 'HIGHWAY ENGINEERING' Wright, P.H. & Paquette R.J., John Witey andSons.
8. 'OVERSEAS ROAD NOTE 2', Maintenance Technique for District Engineers.
9. '~~NUAL FOR MAINTENANCE OF ROADS', IRC, 1983.
10. 'JOURNAL OF THE INSTITUTION OF ENGINEERS', BANGLADESH., by Md.Majid, Md. Eunus Sikdar and Syed Noor-Ud-deen Ahmed, Vol.16,January, 1988.
AbdulNo.1,
11. '20AD CONSTRUCTION AND MAINTENANCE ACTIVITIES OF THE LOCAL BODIES' areport by LGEB.
12. 'THE ROADmaterialsDepartment,
MAINTENANCE PROBLEM' Hodgkinson, W.G. SAARC Seminar onand costs of Road construction, Roads and HighwaysDhaka, Bangladesh, 1984.
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