THE EFFECTIVENESS OF PAVEMENT REHABILITATION AT KUALA
LUMPUR KARAK HIGHWAY
ONN BIN ABDUL RANI
A Project Report submitted in partial fulfillment of the
requirements for award of the degree of
Master of Science (Construction Management)
Faculty of Civil Engineering
Universiti Teknologi Malaysia
MAY,2007
iii
Specially dedicated to my beloved father, mum, my sisters, brothers and all my
friends.
iv
ACKNOWLEDGEMENT
I would like to express my appreciation to many people who have contributed to
successful completion of this project paper. Most especially, I thank my supervisor,
for all his entire guidance, advices and suggestions in preparing this project. To all
examiners, thank you for the suggestion, comment and ideas for overall my project.
My gratitude and sincere thank also goes to all my course mate and friends who
participate by offering their helping making this project a reality.
And last but not least, thanks to all my beloved family especially my father, mother
and my sisters who have contributed in giving me the moral support, encouragement
and understanding in carrying out the project to such great degree. Thank you for
being there whenever I need you all.
Thank you……….
v
ABSTRACT
General function of a pavement is to provide a safe and comfortable riding
surface to road users. However, pavement distress is major problems faced by
contractor. Pavement rehabilitation is essential which can be improve and remain the
functional of the roads networks and can be retard of deterioration. Since
rehabilitation of pavement is a vital and continuous activity, maintenance shall be
done effectively to avoid any reoccurrence and repeatedly works. Thus, in fulfill and
meet pavement goals, the aim of this study is to determine sources of pavement
distress and to determine the effectiveness of rehabilitation works in term of cost,
quality and time at Kuala Lumpur Karak Highway. In view to the above, a thorough
planning and scheduling had been organized on the methodology such as reading,
adopting literature review, combination of analyzing of case study and adopting of
actual data on site. The process of data collection involved obtaining data from
contract document, bill of quantity, consultant reports and operations report. Then,
the data are presented and analyzed conjunction with the aim and objectives of this
study. In conclusion, some sources of distress identified to improve the effectiveness
of pavement rehabilitation implemented at KL Karak Highway.
vi
ABSTRAK
Fungsi utama permukaan jalan adalah menyediakan keselamatan dan
keselesaan kepada pengguna. Sungguhpun begitu, kerosakkan permukaan jalan
merupakan pemasalahan terbesar kepada kontraktor. Pembaikpulihan jalan, adalah
amat penting dimana ianya dapat meningkatkan dan mengekalkan fungsi jalan serta
ianya dapat mengekang kerosakkan jalan yang berterusan. Oleh kerana pembaikan
jalan adalah penting dan merupakan satu aktiviti yang berterusan, penyelenggaran
jalan hendaklah hendaklah dijalankan secara berkesan agar ianya tidak berterusan
rosak. Oleh itu, tujuan bagi kajian ini adalah untuk menentukan punca-punca
kerosakkan jalan dan menentukan keberkesanan pembaikpulihan jalan daripada segi
masa, kos dan kualiti. Kajian kes ini akan dijalankan di Lebuhraya Kuala Lumpur
Karak. Sehubungan dengan itu, satu perancangan yang menyeluruh telah dilakukan
terhadap kaedah-kaedah yang digunakan iaitu merangkumi daripada pembacaan,
kajian literature, kombinasi kajian kes dan data daripada tapak. Proses bagi
mendapatkan data-data telah diperolehi melalui kontrak dokumen, bill of quantity,
laporan jururunding dan laporan operasi. Seterusnya, data-data yang diperolehi akan
dipersembah dan dianalisis berdasarkan kajian kes yang dijalankan. Akhirnya, satu
kesimpulan untuk kajian ini didapati seperti kajian dijalankan. Sebagai kesimpulan,
punca-punca kerosakkan jalan yang dikenalpasti adalah meningkatkan keberkesanan
kerja-kerja pembaikpulihan jalan.
vii
TABLE OF CONTENT
CHAPTER
1
TITLE
PAGE
DECLARATION
ii
DEDICATION
iii
ACKNOWLEDGEMENT
iv
ABSTRACT
v
ABSTRAK
vi
LIST OF TABLES
xii
LIST OF FIGURES
xiii
LIST OF ABBREVIATIONS
xv
INTRODUCTION TO STUDY
2
1.1
Introduction
1
1.2
Problem of Study
2
1.3
Aim and Objectives of Study
3
1.4
Scope of Study
4
1.5
Methodology
4
FLEXIBLE PAVEMENT
2.1
Introduction
6
2.2
Pavement Behavior and Performances
6
2.2.1
Pavement Component and Materials
6
2.2.1.1 Surfacing
7
2.2.1.2 Road Base
8
2.2.1.3 Sub Base
8
viii
2.3
2.4
2.5
2.2.1.4 Sub Grade
8
Functions of Flexible Pavement
9
2.3.1
Road user Requirement
10
2.3.2
Engineering Requirement
11
Failure Definitions
12
2.4.1
Failure Modes
12
2.4.2
Failure Manifestations
12
2.4.3
Failure Mechanism
13
2.4.4
Pavement Behavior
14
Types and Sources of Pavement Distress
15
2.5.1
Crack
15
2.5.1.1 Crocodile Cracks
16
2.5.1.2 Block Cracks
17
2.5.1.3 Longitudinal Cracks
19
2.5.1.4 Transverse Cracks
20
2.5.1.5 Crescent Shaped Cracks
21
2.5.1.6 Edge Cracks
23
Surface Deformation
25
2.5.2.1 Rutting
25
2.5.2.2 Corrugations
27
2.5.2.3 Shoving
28
Surface Defects
30
2.5.3.1 Bleeding
30
2.5.3.2 Ravelling
32
2.5.3.3 Polishing
33
2.5.3.4 Delimination
34
2.5.2
2.5.3
3
2.5.4 Patch
36
2.5.5 Pothole
37
2.5.6 Edge Cracks
38
2.5.6.1 Edge Cracks
38
2.5.6.2 Edge Drop-offs
40
METHOD OF REHABILITATION
3.1
Introduction
41
ix
3.2
Selection Procedure
41
3.3
Rehabilitation Options
43
3.3.1 Restoration
43
3.3.2
Resurfacing Structural
44
3.3.3
Reconstruction
45
3.4
Restoration
46
3.5
Rejuvenating
47
3.5.1 Crack Sealing
48
3.5.2
Cutting and Patch
49
3.5.3
Thin Bituminous Overlays
53
3.5.3.1 Surface Dressings
53
3.5.3.2 Slurry Seals
55
3.5.3.3 Thin Hot Mix
56
3.6
3.7
4
5
Resurfacing
58
3.6.1 Resurfacing on Cracked Surfaces
59
3.6.2
61
Resurfacing on Rutted Surfaces
3.6.3 Resurfacing on Bleeding Surface
62
3.6.4
Resurfacing on Corrugated Surface
62
3.6.5
Resurfacing on Weathered Surface
62
Reconstruction
63
RESEARCH METHODOLOGY
4.1
Introduction
67
4.2
Determination of the Research Objectives
67
4.3
Literature Review
68
4.4
Data Collections
68
4.5
Data Analysis
69
DATA COLLECTIONS AND ANALYSIS
5.1
Introduction
71
5.2
To determined sources of pavement distress
72
5.2.1
Water Factor
72
5.2.1.1 Pavement Infiltration
74
5.2.1.2 Water Seepage from Raise of
x
Water Table
5.3
6
74
5.2.1.3 Water Seepage from Higher Level
75
5.2.2
Diesel Spillage Factor
75
5.2.3
Climbing Lane Factor
77
To Evaluate the Effectiveness of
Pavement Rehabilitation
78
5.3.1
Time
79
5.3.2
Quality
80
5.3.3
Cost
84
DISCUSSION OF RESULTS
6.1
Introduction
87
6.2
To determined sources of pavement distress
87
6.2.1
Water Factor
88
6.2.1.1 Pavement Infiltration
88
6.2.2.2 Water Seepage from Raise of
Water table
6.3
7
88
6.2.2.3 Water Seepage from Higher Level
89
6.2.2
Diesel Spillage Factor
89
6.2.3
Climbing Lane Factor
90
To Evaluate the Effectiveness of
Pavement Rehabilitation
90
6.3.1
Time
91
6.3.2
Quality
91
6.3.3
Cost
92
CONCLUSIONS AND RECOMMENDATIONS
7.1
Introduction
93
7.2
Conclusion and Recommendation
93
7.3
Recommendation for further study
95
REFERENCES
96
xii
LIST OF TABLE
TABLE NO.
2.1
TITLE
Relationship between failure mode,
manifestation and probable mechanism
2.2
29
Possible causes and probable treatments of
Bleeding
2.1.2
27
Possible causes and probable treatments of
Shoving
2.11
26
Possible causes and probable treatments of
Corrugated
2.10
24
Possible causes and probable treatments of
Rutting
2.9
22
Possible causes and probable treatments of
edge cracks
2.8
21
Possible causes and probable treatments of
crescent shaped cracks
2.7
19
Possible causes and probable treatments of
transverse cracks
2.6
18
Possible causes and probable treatments of
longitudinal cracks
2.5
17
Possible causes and probable treatments of
block cracks
2.4
13
Possible causes and probable treatments of
crocodile cracks
2.3
PAGE
31
Possible causes and probable treatments of
Raveling
32
xiii
2.13
Possible causes and probable treatments of
Polishing
2.14
34
Possible causes and probable treatments of
Delimination
35
2.15
Severity levels of pothole
37
2.16
Possible causes and probable treatments of
Pothole
2.17
Possible causes and probable treatments of
Edge breaks
2.18
37
39
Possible causes and probable treatments of
edge drops
40
5.1
Comparison Average between JPS and KLK
73
5.2
Diesel Spillage at Kuala Lumpur Karak Highway
years 2004-2006
5.3
76
Breakdown and Stopped Vehicle at Kl Karak
Highway (2004-2006)
77
5.4
Time to Complete Pavement Rehabilitation Works
79
5.5
Differences JKR specification with concessionaire
81
5.6
Types of Pavement Distress
82
5.7
Cost Distributions on Pavement Rehabilitation at
KLK Highway (Contract Amount)
5.8
84
Cost Distribution on Pavement Rehabilitation at
KLK Highway Based on Site Activity
86
xiv
LIST OF FIGURES
FIGURE NO.
TITLE
PAGE
1.1
Research methodology sequence
4
2.1
Sources of subsurface water in pavement (FHWA, 1992)
9
2.2
Typical serviceability requirement for different
class of road AASHO (AASHO road test)
10
2.3
Stresses and strains in a bituminous pavement.
15
2.4
Photograph of crocodile cracks
17
2.5
Photograph of block cracks
18
2.6
Photograph of longitudinal cracks
20
2.7
Photograph of transverse cracks
21
2.8
Photograph of crescent shaped cracks
23
2.9
Photograph of edge cracks
24
2.10
Photograph of rutting
26
2.11
Photograph of corrugated
28
2.12
Photograph of shoving
29
2.13
Photograph of bleeding
31
2.14
Photograph of raveling
33
2.15
Photograph of polishing
34
2.16
Photograph of delimination
35
2.17
Photograph of potholes
38
2.18
Photograph of edge breaks
39
5.1
Comparison average graf between JPS and KLK
74
5.2
Diesel Spillage at Kuala Lumpur Karak Highway
years 2004-2002
5.3
Breakdown and Stopped Vehicle at Kl Karak
76
xv
Highway (2004-2006)
78
5.4
Total of NCR recorded during pavement rehabilitation
82
5.5
Total of Defects Recorded after Pavement Rehabilitation
83
5.6
Cost Distributions on Pavement Rehabilitation at
KLK Highway (Contract Amount)
5.7
85
Cost Distributions on Pavement Rehabilitation at
KLK Highway Based on Site Activity
86
xvi
LIST OF ABBREVIATIONS
ADT
-
Average Daily Traffic
IKRAM
-
Institut Kerja Raya Malaysia
ISSA
-
International Slurry Seal Assocation
MHA
-
Malaysia Higway Authority
NCR
-
Non Conforming Records
SAMI
-
Stress Absorbing Membrane Interlayer
CHAPTER 1
INTRODUCTION TO STUDY
1.1
Introduction
Flexible pavements almost are being used at all networks of local roads,
federal roads, expressway, highways and others road in our country. It is important
that of these flexible pavements meet the required of pavement performances goals.
Once the construction of the pavement works is completed, it is most essential to
implement pavement preventive maintenance that emphasizes keeping roads in good
condition through early application of maintenance treatments.
Pavement maintenance and rehabilitation major and minor incorporates all
activities undertaken to provide and maintain serviceable roadways. Huge amount of
money or capital had already being invested in the construction of roads and
highways. In this country, several highways had been constructed namely North
South Highways, East Coast Expressway, Penang Bridge, Shah Alam Expressway,
Kulim-Butterworth Expressway, Seremban – Port Dickson Hihgway, Malaysia –
Singapura Second Crossing Expressway, Sungai Besi Highway, Cheras – Kajang
Highway, Damansara Puchong Highway, Ampang Kuala Lumpur Elevated
Highway, Lebuhraya Penyuraian Trafik Kuala Lumpur Barat (SPRINT), Lebuhraya
2
Baru Pantai (NPE), Lebuhraya Lingkaran Penyuraian Trafik Kajang (SILK),
Lebuhraya Koridor Guthrie (GCE) and Kuala Lumpur - Karak Highway. Huge
amount of money would also be invested on the continuous maintenance of
highways which is vital to ensure road worthiness, safety and end user satisfaction.
Kuala Lumpur Karak Highway was privatise in year October 1994,
responsible on operations and maintenance of highways. Kuala Lumpur - Karak
highway start from KM 19.20 and ends at KM 79.20 with total length will be 60km.
On August 2004, highway concessionaire was executing theirs major project at Kl
Karak, pavement rehabilitation. This project is divided to six main packages and was
awarded to three main contractors with sum of contract amounting around RM
60,000,000.
1.2
Problem Of Study
Since 2004, several problems are frequently encountered during operations
and maintenance of KL Karak Highways. Some of the problems such as ageing of
operations and services building, slope stability, highways safety and flexible
pavement distress.
However, flexible pavement distress is a major problem faced by
concessionaire of KL Karak Highway during their operations and maintenances. The
problems during operations were identified as follows:
1. Poorly identifying type of flexible pavement distresses
2. Poorly identifying sources of pavement distresses
3. Ineffectively corrective maintenance of pavement
4. Poorly identifying method of rehabilitations.
3
5. Poorly implementation method of rehabilitations during constructions
1.3
Aim And Objectives Of Study
The aim of this study is to evaluate the Pavement Rehabilitation as a method
to repair the existing pavement in order to meet pavement performances goals and to
fulfill the standard requirement. The study will cover the pavement behaviour and
performances, types of distresses in flexible pavement, sources of pavement
problems, selection methods or options of rehabilitations and standard specifications
requirement during constructions works. This study will evaluate the performance of
flexible pavement from completed pavement rehabilitation and to ensure that the
initial objectives are achieved. To achieve the above aim, the following objectives
are identified:
1.
To determine sources of pavement distress at Kuala Lumpur Karak
Highway
2.
To evaluate the effectiveness of pavement rehabilitation in term of
time, cost and quality at Kuala Lumpur Karak Highway
1.4
Scope of Study
The scope of this study shall be on the highway flexible pavement on the
problem at Kuala Lumpur - Karak Highways and limited to year 2004 until
2006.
4
1.5
Brief of Methodology
The methodology used in conducting this research is through literature
search. The literature search for the study obtained through are journal papers,
conference papers, technical reports, books and websites browsing to understand and
meet the objectives of the study. Besides that, the data for study has been generated
using methodology case study. The overall sequence of research process undertaken
is shown in Figure 1.1.
Determining the Research Objective and Scope
Literature Review
Data Collections
Case Study
Data Analysis
Discussion
Conclusion and Recommendation
Case Study
Figure 1.1 Research methodology sequence
CHAPTER 2
FLEXIBLE PAVEMENT
2.1
Introduction
This chapter is on the literature study of pavement behavior in performances
pavement distress, method of maintenance, method of rehabilitation and finally on
the effectiveness of corrective action.
2.2
Pavement Behavior and Performances
2.2.1
Pavement components and materials
A flexible pavement is a layered structure consisting of the sub base, road
base and the surface overlying the natural ground or subgrade.
7
2.2.1.1 Surfacing
The surfacing is the upper layer of the pavement which fulfils the following
requirements:
a) To provide an even, non- skidding and good riding quality surface.
b) To resist wear and shearing stress by traffic
c) To prevent water from penetrating into underlying pavement layers
d) To be capable of surviving a large number of repeated loading without
distress
e) To withstand adverse environmental conditions.
The form of bituminous surfacing commonly used can either be thick or thin.
Thick bituminous surfacing normally consists of crushed mixed aggregates, bitumen
and filler. Most types of plant mixed surfacing in Malaysia are asphalt concrete or
bituminous macadam. Currently constructed thin surfacing are surface dressings and
slurry seals.
Thick bituminous surfacing provides additional strength to the pavement and
seal the pavement from water ingress. Thin surfacing does not give direct additional
strength. It merely protects the pavement from water and provides a skid resistant
riding surface.
8
2.2.1.2 Road base
The road base is the main structural layer of the pavement which spread the
load from heavy vehicles thus protecting the underlying weaker layers. Its functions
are to reduce the compressive stress in the subgrade and the sub base to an
acceptable level and to ensure that the magnitude of the flexural stresses in the
surfacing will not lead to cracking. Unbound crushed mixed aggregates have been
widely used as road base material throughout the country. Granite and limestone are
readily available in most areas in Malaysia and have historically been the major
sources of aggregate for road bases. (IKRAM, 1992).
2.2.1.3 Sub base
The sub base is secondary load spreading layer underlying the road base. It
normally consists of lower grade granular material as compared to that of the road
base. Sand and laterites are commonly used and are easily available. This layer also
serves as a separating layer preventing contamination of the road-base by the sub
grade and also acts as a preparatory layer for road base construction. (Poniah, 1995).
2.2.1.3 Sub grade
The sub grade refers to the soil under the pavement within depth of
approximately one meter the sub base. It is the upper layer of earthworks prepared
for subsequent construction of the pavement layers described above. It can either be
natural undisturbed soil or compacted soil obtained from elsewhere and placed as fill
material. The strength of the subgrade layer is important as the thicknesses of the
upper layers are dependent on it.
9
There are many sources of water that can enter the pavement subgrade. These
include; surface infiltration through porous or cracked pavements, lateral seepage
from saturated median ditches, capillary water rising from the underlying water table
and high groundwater table. This is shown in Figure 2.1 (CDOT Drainage Design
Manual). Subsurface drainage system can be provided to remove or control
groundwater from these sources and minimize impacts on highways projects.
Pavement Infiltration
Seepage from
Higher Ground
Capillary Action
Vapor Movements
Rising Water Table
Water Table
Figure 2.1 Sources of Subsurface Water in Pavements (FHWA, 1992)
2.3
Functions Of Flexible Pavement
The general function of road pavement is to provide safe and comfortable
riding surface for the road users. Its condition with respect to these characteristics is
normally assessed by two groups of people, namely the user and the road engineers.
10
2.3.1
Road user requirements
A safe and comfortable riding surface is what the road users normally
require. The aesthetic aspect of it is also a concern but will receive considerable
attention only on heavily trafficked pavements. The life of the pavement perceived
by the users will be primarily related to its ridding quality. Road pavements that do
not provide a safe and comfortable ridding surface will trigger the road user
awareness as to the increase in vehicle operating cost. The user requirement for a
road pavement can be quantified in terms of serviceability index. The term
serviceability was first introduced during the AASHO Road Test to represent
pavement performance. The road pavement was given a rating in terms of ridding
comfort by various drivers with a value of as the highest index of serviceability and
0 as the lowest. A terminal serviceability of 2.5 was suggested as the condition when
major rehabilitation works (See Figure 2.2).
LOW VOLUME ROADS
TRUNK ROADS
HIGHWAYS
5
EXCELLENT
Figure 2.2
4
GOOD
3
FAIR
2
POOR
1
VERY
POOR
Typical Serviceability requirement For Different class of Road
AASHO (AASHO Road Test)
11
2.3.2
Engineering Requirements
The engineer is mostly concern with whether the road will achieve its design
life. The rate of deterioration is also major concern. A rapid of deterioration requires
immediate intervention. The road user may not aware of the occurrence of early
deterioration since the ridding quality may be acceptable. In contrast the engineer
must be alert to such problems as early maintenance enhances the road
performances.
It is thus necessary to understand the behavior and performances of under
Malaysia conditions. In evaluating and rehabilitating a road pavement in this
country, where the environmental factors are different from Western nations, there
are dangers in applying those rehabilitation solutions that have been obtained
elsewhere as they may not suit conditions in this country without some modification.
It is important that road user and engineering needs must be properly
balanced to suit budget requirements and maximizes benefit through appropriate
methods of maintenance. Experience elsewhere has indicated that prompt
maintenance can indeed save expensive reconstruction costs.
12
2.4
Failure Definitions
2.4.1
Failure Modes
The predominant failure modes are fracture, distortion and disintegration
(Manual for the Long Term Pavement Performance Project-DC, 1993). Fracture
normally occurs in thick bituminous layers. Distortion manifests itself in any of
pavement layers and will normally appear on the bituminous surface as rutting or
other forms of deformation. Disintegration normally takes place on the bituminous
surfacing while loss of aggregates is a common manifestation of this failure mode.
2.4.2
Failure manifestations
Each component of the pavement layers may contribute to failures. The most
difficult task is to identify which layer is the cause of primary failures of the road.
Failure in flexible pavement most commonly manifests itself as cracking or
deformation (Skokie, 1993). These defects can be visually identified and measured
using appropriate techniques.
13
2.4.3
Failure Mechanism
Extensive research established the various mechanisms that cause road
failure. Some common mechanisms are repeated axle loading, excessive loading,
thermal and moisture changes, material densification, consolidation of sub grade,
shear in sub grade abrasion by traffic, chemical degradation, degradation of
aggregate and hardening of the bitumen.
Early detection of these mechanisms during the evaluation process can help
in identifying the probable remedy. Suitability and accuracy of evaluation
procedures and analysis are dependent on accurate identification of actual modes of
failure. The relationship between failure mode, their manifestations and probable
mechanism is as shown in Figure 2.1.
Table 2.1
Relationship between failure mode, manifestation and probable
mechanism
Mode
Manifestation
Common Mechanism
Fracture
Cracking
Excessive loading, repeated loading,
moisture changes and age hardening.
Distortion
Permanent Deformation
Excessive loading, creep, densification,
consolidation, moisture changes
Disintegration Stripping and Ravelling
Lack of adhesion, chemical aggression,
abrasion by traffic, degradation of
aggregate.
14
2.4.4
Pavement Behavior
Repeated axle loading, the environment, soil characteristics and drainage are
some factors that affect pavement behavior (Skokie, 1989). Stresses and strains are
induced in the pavements layers by both influences of traffic and environmental
stresses, an example of latter being diurnal temperatures. The bituminous surfacing
also suffers from tensile strains at the bottom and the top of the layer. The road base,
the sub base and sub grade are mainly subjected to compressive stresses.
Theoretically, pavements behave as a composite material under go ideal
condition. This condition exists only when the pavement materials are homogenous
and isotropic and the adhesion between the component layers is perfect. A point on
the pavement subjected to moving load will deflect temporarily. The size of
deflection is determined by the elastic properties, characteristic of the components
materials and the loadings nature and magnitude. The temporary deflection will be
rebound after the load has been removed away from the spot. This deflection is
usually referred to as the transient deflection. Stresses and strains in a bituminous
pavement are as shown in Figure 2.1.
15
Wearing Course
1
1
3
Binder Course
2
Base Course
Sub Base
4
Sub Grade
1,2: Tensile Straints
3,4: Compressive Stresses
Figure 2.3
Stresses and strains in a bituminous pavement.
2.5
TYPES AND SOURCES OF PAVEMENT DISTRESS
2.5.1
Crack.
Cracks are fissures resulting from partial or complete fractures of the
pavement surface. Road pavement surface cracking can happen in a wide variety of
patterns, ranging from isolated single crack to an interconnected pattern extending
over the entire pavement surface. The detrimental effects associated with the
presence of cracks are; loss of water proofing of the pavement layers, loss of load
spreading ability of the cracked material, pumping and loss of fines from the base
course, loss of riding quality through loss of surfacing and loss of appearance.
16
The loss of spreading ability and water proofing, usually lead to accelerate
deterioration of the pavement condition. The possible causes of crack include
depression, fatigue life of the surfacing being exceeded, reflection of cracks in
underlying layers, shrinkage and poor construction joints. There are few types of
cracks, such as crocodile cracks, block cracks, longitudinal cracks, transverse cracks
and crescent shaped cracks.
2.5.1.1 Crocodile cracks
Crocodile cracks are also known as alligator, chicken wire, fish net,
polygonal and fatigue cracks. Crocodile cracks is a interconnecting cracks caused by
fatigue failure of the asphalt concrete surface under repeated traffic loading (See
Figure 2.4). The cracking initiates at the bottom of the asphalt surface (or stabilize
base) where tensile stress and strain is highest under a wheel load. The cracks
propagate to the surface initially as a series of parallel cracks. After repeated traffic
loading the cracks connect, forming many-sided, sharp-angled pieces that developed
that pattern. The block size can range from 100mm to about 300mm. Severity levels
of crocodile cracks are:
Low
Interconnected or interlaced hairline cracks running parallel to each
other, cracks not spalled
Moderate
A pattern of articulated pieces formed by cracks that may be lightly
spalled. Cracks may be sealed.
High
Pieces more severely spalled at edges and loosened; pieces rock under
traffic; pumping may exist.
Measurements to be taken are area affected, predominant crack width and
predominant cell width. The possible causes and probable treatments are as shown in
Table 2.2.
17
Table 2.2
No
1
Possible causes and probable treatments of crocodile cracks
Possible Causes
Inadequate
Probable Treatments
pavement Strengthen the pavement or reconstruction
thickness
2
Low modulus base
Strengthen the base or reconstruction
3
Brittle base
Base recycling or reconstruction
4
Poor base drainage
Improve the drainage and reconstruct
5
Brittle wearing course
Replace or treat wearing course
Figure 2.4:
Photograph of crocodile cracks
2.5.1.2 Block cracks
Block cracks are also known as ladder cracks. Block cracks are
interconnected cracks forming a series of block, approximately rectangular in shape
(See Figure 2.5). Block sizes are usually greater than 300mm and can be exceed
3000mm. Severity Levels of block cracks are:
Low
Blocks defined by unspalled cracks with a mean width of 3 mm or
less, cracks with sealant in good condition.
18
Moderate
Blocks defined by moderately spalled cracks; cracks with a mean
width greater than 3 mm.
High
Blocks well defined by severely spalled cracks.
Measurements to be taken are area affected, predominant crack width and
predominant cell width. The possible causes and probable treatments are as shown in
Table 2.3.
Table 2.3
Possible causes and probable treatments of block cracks
No
Possible Causes
1
Joints in underlying layer
2
Shrinkage
and
fatigue
Probable Treatments
Crushed aggregate overlay
of Replace
underlying cemented materials
3
cemented
materials
Shrinkage cracks (due to bitumen Seal cracks or replace bituminous
hardening) in bituminous surfacing
4
underlying
Fatigue
cracks
in
embrittled Cut and patch or crushed aggregate
bituminous wearing course
Figure 2.5:
surfacing
overlay.
Photograph of block cracks
19
2.5.1.3 Longitudinal cracks
Longitudinal Cracks are also known as line cracks. Longitudinal cracks are
crack which are usually straight and parallel to the centre line, situated at or near the
middle of the lane (See Figure 2.6). It can happen singly or as series of almost
parallel cracks or with some limited branching. Severity levels of longitudinal cracks
are:
Low
Cracks with low severity or no spalling; mean unsealed crack width
of 3 mm or less
Moderate
Cracks with moderately severe spalling; mean unsealed crack width
greater than 3 mm; sealant material in bad condition
High
Cracks with high severity spalling
Measurements to be taken are width of dominant crack, length of dominant
crack, spacing and area affected. The possible causes and probable treatments are as
shown in Table 2.4.
Table 2.4
Possible causes and probable treatments of longitudinal cracks
No
Possible Causes
1
Reflection of shrinkage cracks
2
Poorly
Constructed
Probable Treatments
Cut and patch
paving
lane
bituminous surfacing
3
Displacement
of
in Replace
bituminous
surfacing
joints
at
pavement Reconstruction of joints
widening
4
Differential settlement between cut and fill
Reconstruction
5
Reflection of joints in the underlying base
Crushed aggregate overlay
or reconstruction of joints.
20
Figure 2.6:
Photograph of longitudinal cracks
2.5.1.4 Transverse cracks
Transverse cracks are unconnected cracks running transversely (relatively
perpendicular to pavement centre line) across the pavement (See Figure 2.7).
Severity levels of transverse cracks are:
Low
Cracks with low severity or no spalling; mean unsealed crack width
of 3 mm or less; sealant material in good condition.
Moderate
Cracks with moderate severity spalling; mean unseals crack width of
greater than 3mm; sealant material in bad condition.
High
Cracks with high severity spalling.
Measurements to be taken are width of predominant crack, length of
dominant crack, spacing and area affected. The possible causes and probable
treatments are as shown in Table 2.5.
21
Table 2.5
Possible causes and probable treatments of transverse cracks
No
Possible Causes
Probable Treatments
1
Reflection of shrinkage cracks
2
Construction
joint
in
Cut and patch
bituminous Crack sealant
surfacing
3
Structural failure of Portland Cement
Reconstruction of base
4
Shrinkage crack bituminous surfacing
Seal
cracks
or
replace
bituminous surfacing
5
Reflection of joints in the underlying Crushed aggregate overlay or
base
reconstruction of joints.
Figure 2.7:
Photograph of transverse cracks
2.5.1.5 Crescent shaped cracks
Crescent shaped cracks also known as parabolic, slippage and shear cracks.
These types of cracks are half moon or crescent shaped cracks, commonly associated
with shoving, often occurring in closely spaced parallel group (See Figure 2.8). It is
mainly associated with bituminous layer only. Severity levels of edges cracks are:
22
Low
Cracks with no breakup or shoving.
Moderate
Cracks with some breakup or shoving.
High
Cracks with considerable breakup or shoving
Measurements to be taken are width of predominant crack, length of
dominant crack, and area affected. The possible causes and probable treatments are
as shown in Table 2.6.
Table 2.6
No
1
Possible causes and probable treatments of crescent shaped cracks
Possible Causes
Probable Treatments
Lack of bond between wearing course Cut and patch
and the underlying layers
2
Low modulus bases course
Reconstruction of base
3
Thin wearing course
Bituminous overlay
4
Dragging of pavers during laying when Cut and patch
bituminous mix temperatures were low
5
High stress due to braking and Bituminous overlay with stiffer
acceleration movements
mix or use high compaction
mix.
23
Figure 2.8:
Photograph of crescent shaped cracks
2.5.1.6 Edge cracks
Edge cracks are also crescent shaped or fairly continuous cracks, parallel to,
and usually within 300mm to 600mm on the pavement edge (See Figure 2.9). They
usually occur when paved shoulders do not exist. Severity levels of edges cracks are:
Low
Cracks with no breakup or raveling
Moderate
Cracks with some breakup or raveling
High
Cracks with considerable breakup or raveling along edge
Measurements to be taken are width of predominant crack, length of
dominant crack, and area affected. The possible causes and probable treatments are
as shown in Table 2.7.
24
Table 2.7
Possible causes and probable treatments of edge cracks
No
1
Possible Causes
Excessive
traffic
loading
Probable Treatments
at Widen the pavement or strengthen
pavement edge
2
the pavement edge
Poor drainage at pavement edge and Improve drainage and shoulder
shoulder
3
Inadequate pavement width which Widen treatment
forces traffic too close to pavement
edge
4
Insufficient bearing support
Figure 2.9:
Reconstruction
Photograph of Edge Cracks
25
2.5.2
Surface Deformation
Deformation takes place when a road surface undergoes changes from its
original constructed profile. It may occur after construction due trafficking or
environmental influences. In some cases, deformation may be built into a new
pavement owing to inadequate control during construction. It influences the ridding
quality of pavement may reflect structural inadequacies. It may lead to cracking of
the surface layer. The major types of surface deformation are; rutting, corrugation,
depression and shoving.
2.5.2.1 Rutting
Rutting is longitudinal deformation or deformation or depression in the wheel
paths which occur after repeated applications of axle loading (See Figure 2.10). It
may occur in one or both wheel paths of a lane.
A part from that, degradation of asphalt due to diesel spills on roads also
resulted in longitudinal cracking and rutting (Brian Balwin, Onuma Carmody and
Terry Collins). There are two types of pavement degradation due to diesel; rapid
degradation (0-2 weeks) and residual degradation (> 2 weeks). Severity levels of
rutting are:
Low
Rut depths of less than 12mm (measured under a transverse 1.2m
straight edge.
Moderate
Rut depths of between 12mm to 25mm (may include slight
longitudinal cracks)
High
Rut depths of greater than 25mm (may include multiple longitudinal
or crocodile cracks)
26
The possible causes and probable treatments are as shown in Table 2.8.
Table 2.8
Possible causes and probable treatments of rutting
No
1
Possible Causes
Probable Treatments
Inadequate pavement thickness
Strengthening
overlay
or
reconstruction
2
Inadequate
compaction
of Reconstruction
structural layers
3
Unstable bituminous mixes
Replace
or
recycle
bituminous
surfacing or use stiffer mix
4
Unstable shoulder material which Shoulder improvement and overlay
do not provide adequate lateral rutted
support
5
Overstressed
area
with
bituminous
surfacing.
subgrade
which Reconstruction
deforms permanently
6
Unstable granular bases or sub- Base or sub base strengthening
bases
Figure 2.10: Photograph of rutting
27
2.5.2.2 Corrugations
Corrugations are regular transverse undulations, closely spaced alternate
valleys and crests with wavelengths of less than 2000mm (See Figure 2.11).
Generally, it will be result in a rough ride and will become worse with time. Severity
levels of corrugations are:
Low
Noticeable (based on observation of its appearance and its effect on
riding quality).
Moderate
Rough ride.
High
Very rough ride. Vehicle may lose control because of its presence.
Measurements to be taken are maximum depth under 1200mm straight edge,
crest to crest spacing and length of pavement affected. The possible causes and
probable treatments are as shown in Table 2.9.
Table 2.9
Possible causes and probable treatments of corrugated
No
1
Possible Causes
Probable Treatments
Inadequate stability of bituminous Replace bituminous surface
surface
2
Compaction of base in wave form
3
Faulty paver behavior with some Replace the faulty mixes and
mixes
4
6
correct the faulty behavior
Heavy traffic on steep downgrade or Mill off corrugated surface and
upgrade
5
Base reconstruction
replace with stiffer mix
Stopping at intersection stop lights or Mill off corrugated surface and
roundabout
replace with stiffer mix
Inadequate stability of base course
Base construction.
28
Figure 2.11: Photograph of corrugated
2.5.2.3 Shoving
Shoving is the bulging of the road surface generally parallel to the direction
of traffic and/or horizontal displacement of surfacing materials, mainly in the
direction of traffic where braking or acceleration movements occur, caused by traffic
pushing against the pavement (See Figure 2.12). Transverse shoving may arise with
turning movements. Severity Levels of shoving are:
Low
Noticeable. (Based on observation of its appearance and its effect on
riding quality)
Moderate
Rough ride.
High
Very rough ride. Vehicle may lose control because of its presence.
Measurements to be taken are maximum depth of bulge under 1200m straight
edge from high point. The possible causes and probable treatments are as shown in
Table 2.10
29
Table 2.10
Possible causes and probable treatments of shoving
No
1
Possible Causes
Low stability
Probable Treatments
Mill off and replace the
bituminous surfacing
2
Lack of bond between asphalt surface and Replace
bituminous
underlying layer which may be caused by surfacing with lower binder
excessive tack coat acting as lubricant
3
content mix
Unstable granular base reflecting through Base construction
the surface
4
5
Stop and start vehicles at intersection or Mill off and replace with
roundabout.
stiffer mix
Inadequate pavement thickness
Bituminous
reconstruction
Figure 2.12: Photograph of shoving
overlay
or
30
2.5.3 Surface defects
Surface defects cover loss of surfacing materials, loss of surface micro and
macro textures. While they do not usually indicate pavement structural inadequacy,
they have a significant influence on the serviceability and safety of a pavement,
especially with regard to skid resistance, maneuverability and riding quality. Some
defects, may lead to subsequent loss of pavement integrity. The major types of
surface defects are; bleeding, ravelling, polishing and delamination.
2.5.3.1 Bleeding
Bleeding is also known as flushing, fatting, slick and black spot. Bleeding is
a film of bituminous material on the pavement surface that creates a shiny, glasslike,
reflecting surface that usually becomes quite sticky (See Figure 2.13). Bleeding is
the presence of free bitumen binder on the surface resulting from upward migration
of the binder, causing low texture depth and inadequate tyre to stone contact. It is
most likely to occur in the wheel paths during hot weather. Severity levels of
bleeding are:
Low
Colouring of pavement surface visible.
Moderate
Distinctive appearance with excess bitumen already free.
High
Free bitumen which gives the pavement surface a wet look. Tyre
marks are evident.
Measurements to be taken are affected area and percentage by area of stone
immersed. The possible causes and probable treatments are as shown in Table 2.11
31
Table 2.11
Possible causes and probable treatments of bleeding
No
1
Possible Causes
Probable Treatments
Excessive application of binder with respect Apply hot sand to blot up
to the stone size. On hot days the binder the excess binder
expands into air voids; if volume of air voids
is too low, continued expansion results in
lower stability of the mix with the
consequence that traffic will force out
excess binder to the surface.
2
Paving over flushed surfaces. The excess Apply
hot
sand
bitumen on the old surface may be pumped aggregate seal coat.
up through the new paving over period of
time.
3
Paving over excessively primed surfaces
Figure 2.13: Photograph of bleeding
Apply hot sand
or
32
2.5.3.2 Ravelling
Ravelling is the progressive disintegration of the pavement surface by loss of
binder or aggregates or both (See Figure 2.14). Severity levels are:
Low
Wearing away of the aggregate of binder has started but has not
progressed significantly.
Moderate
Aggregate and/or binder have worn away and the surface texture is
becoming rough and pitted. Loose particles generally exist.
High
Aggregate and/or binder have worn away and the surface texture is
very rough and pitted.
The possible causes and probable treatments are as shown in Table 2.12.
Table 2.12
Possible causes and probable treatments of raveling
No
Possible Causes
Probable Treatments
1
Insufficient bitumen content
2
Poor adhesion of bitumen binder to Thin bituminous overlay
aggregate
particles
due
Thin bituminous overlay
to
wet
aggregate
3
Inadequate compaction or construction Thin bituminous overlay
during wet weather
4
Deterioration
aggregate
of
binder
and/or Thin bituminous overlay
33
Figure 2.14: Photograph of raveling
2.5.3.3 Polishing
Polishing is the smoothening and rounding of the upper surface of the road
stone, exposing coarse aggregate which are glossy in appearance and smooth to the
touch (See Figure 2.15). It usually occurs in the wheel paths.
Severity levels are not applicable on determining of polishing. However the
degree of polishing may be reflected in a reduction of skid resistance. The possible
causes and probable treatments are as shown in Table 2.13.
34
Table 2.13
Possible causes and probable treatments of polishing
No
1
Possible Causes
Probable Treatments
Inadequate resistance to polishing of surface The bituminous overlay of
aggregates particularly in areas of heavy use of stiffer mix
traffic movements or where high stresses are
developed between surface and tyres
2
Use
of
naturally
smooth
uncrushed Thin bituminous overlay.
aggregates
Figure 2.15: Photograph of polishing
2.5.3.4 Delimination
Delimination also known as peeling, surface lifting, seal break and flaking.
Delimination is the loss of a discrete and large (minimum 0.01 square metre) area of
the wearing course (See Figure 2.16). Usually there is a clear delineation of the
wearing course and the layer below. Severity levels of delimination are:
35
Low
Peeling of the layers has started but has not progressed significantly.
Surface area peeled off is less than 0.1m2.
Moderate
Surface area peeled off is between 0.1m2 to 2.5m2. Severe crocodile
cracks in and around the peeled off area.
High
A group of more than two (2) moderate delaminations along a short
stretch of road.
Measurements to be taken are thickness of layer(s) peeled off, area of
invidual delaminations and number of delaminations. The possible causes and
probable treatments are as shown in Table 2.14.
Table 2.14
Possible causes and probable treatments of delimination
No
1
Possible Causes
Inadequate cleaning or inadequate tack Mill off and re-lay upper
cot before placement of upper layers.
2
Probable Treatments
layers.
Seepage of water through asphalt, Replace wearing course or thin
especially in cracks, to break bond bituminous overlay
between surface and lower layers.
3
Weak,
loose
layer
immediately Reconstruction of weak layers
underlying seal
4
Adhesion of surface binder to vehicle Thin bituminous overlay.
tyres
36
Figure 2.16: Photograph of delimination
2.5.4
Patch
A patch is a repaired section of pavement where a portion of the pavement
where a portion of the pavement surface has been removed and replaced. It may or
may not be associated with either a loss of serviceability (a part from a loss of
appearance) or structural adequacy of the pavement. Defects can occur within a
patch can be further defect where it is raised or depressed below the level of the
pavement surface. Severity Levels
Low
Patch in good condition or has low severity distress of any type.
Moderate
Patch has moderate severity distress of any type.
High
Patch has high severity distress of any type.
37
2.5.5
Pothole
Pothhole is bowl shaped cavity in the pavement surface resulting from the
loss of wearing course and binder course materials (See Figure 2.17). It is produced
when traffic breaches small pieces of the pavement surface allowing the entry of
water. This spots then disintegrates because of the weakening of the base course or
poor quality surfacing. Free water collecting in the hole and the underlying base
accelerates pothole development. Severity levels of potholes are as shown in Table
2.15.
Table 2.15
Severity levels of pothole
AREA (square metre)
DEPTH (mm)
< 0.1
0.1-0.3
> 0.3
< 25
Low
Low
Moderate
25-50
Moderate
Moderate
High
>50
Moderate
High
High
Measurements to be taken are depth of pothole, area of pothole and number
of potholes at each severity level. The possible causes and probable treatments are as
shown in Table 2.16.
Table 2.16
No
Possible causes and probable treatments of pothole
Possible Causes
Probable Treatments
1
Loss of surface course
Patching
2
Moisture entry to base course through a Cut and patch
cracked pavement surface
3
Load associated disintegration of base
Base reconstruction
38
Figure 2.17
2.5.6
Photograph of potholes
Edge Cracks
Edge defects occur along the interface of flexible pavement and the shoulder,
and are most significant where the shoulder is unsealed. (See Figure 2.18) The
detrimental effects edge defects include reduction of pavement width, loss of quality
of ride and possible loss of control of vehicle, channeling of water at the edge of the
pavement leading to erosion of shoulder and finally entry of water into base. Two
types of edge cracks are edge break and edge drop-off.
2.5.6.1 Edge breaks
Edge breaks occur when the edge of the bituminous surface are fretted or
broken. Measurements to be taken are length over which break occurs and maximum
39
width of surfacing loss. The possible causes and probable treatments are as shown in
Table 2.17.
Table 2.17
No
Possible causes and probable treatments of edge breaks
Possible Causes
Probable Treatments
1
Inadequate pavement width
Widen the pavement
2
Alignment which encourages drivers to Pavement
widening
and
travel on pavement edge.
realignment
3
Inadequate edge support
Shoulder strengthening
4
Edge drop-off
Strengthening and leveling of
shoulder with road surface
5
Loss of a adhesion to base
Cut and patch or bituminous
overlay.
Figure 2.18: Photograph of edge breaks
40
2.5.6.2 Edge drop-offs
Edge drop-ff is the difference in elevation between the traffic lane and
outside shoulder; typically occurs when the outside shoulder settles or erodes (See
Figure 2.19). It is not usually considered a defect if the drop-off is less than 25mm.
The possible causes and probable treatments are as shown in Table 2.18.
Table 2.18
No
Possible causes and probable treatments of edge drop offs
Possible Causes
Probable Treatments
1
Inadequate pavement width
Widen the pavement
2
Shoulder material with inadequate Replace shoulder material and
resistance to erosion and abrasion.
3
Resurfacing
of
pavement
resurfacing of shoulder
reconstruct
without Leveling of shoulder with road
surface
Figure 2.19: Photograph of edge drop offs
41
CHAPTER 3
METHODS OF REHABILITATION
3.1
Introduction
Chapter 3 is concerned with the methods of rehabilitation of highway
pavement. It discuss on selection procedure and rehabilitation options.
3.2
Selection Procedure
The selection procedure heavily on engineering judgment but other
factors such as costs, construction feasibility, effects on the gridline and the road
user are also be considered as well. There are three stages to be followed,
identifying problems, identifying probable alternatives and selecting the
preferred solution.
42
Stage 1: Identifying Problem
As a first step the mode of failure of the existing pavement need to be
identified. At this point, constraints on the project such as the design life of the
rehabilitation section should be identified.
Stage 2. Identifying Probable Alternatives
Based on the pavement evaluation, a number of alternative methods of
rehabilitation should be selected. These are tested against the feasibility of
design, construction constraints and requirement of service life.
Stage 3. Selecting the Preferred Solution
Those alternatives, which pass these criteria, are further analyzed by
considering their life-cycle costs and other non-monetary constraints. Finally, the
preferred rehabilitation alternative is selected for detailed design. The engineer
should not rule out using different techniques on one project. It may be more
cost effective to do this than select a common method of rehabilitation for the
whole project.
Each alternative technique is evaluated first on the merit of its design and
construction feasibility. Consideration should be given to the problems of
construction during monsoon periods, for instance. Care must be taken where
roads pass under bridges. For traffic and safety purpose, the vertical clearance
underneath a bridge should be maintained and this will limit the allowable
overlay thickness. Other factors to consider include traffic control requirement,
disturbance to the public, the need for staged construction, and the availability of
plants and materials.
43
3.2
Rehabilitation Options
The rehabilitation of flexible pavements encompasses a broad range of
activities which could be grouped into three categories namely; restoration,
resurfacing (structural) and reconstruction (Sacramento, 2000).
The choice of any specific rehabilitation technique depends on the
condition of the existing pavement. The conditions that apply for one project
may be different from another. For this reason, rehabilitation techniques will
change from one project to another or within one single project. Although other
factors are involved, the performance and cost-effectiveness of type of
rehabilitation technique will depends primarily on the existing pavement
condition.
In the first phase of the pavement’s life, its condition is good and its rate
of deterioration is normally low. At this stage, routine maintenance should be
considered, as it may be more cost-effective than carrying out major
maintenance later in the life of the pavement.
3.2.1
Restoration
As the pavement condition deteriorates further, particularly when distress
such as cracking and polishing of the aggregate become apparent, the restoration
rehabilitation option is warranted. Some techniques that maintain the
serviceability of the pavement include:
44
i)
Rejuvenating the aged surface using chemical
ii)
Sealing the cracks
iii)
Blinding polished and flushed surfaces with hot aggregates
iv)
Applying thin bituminous overlays
v)
Cutting affected area and patching with new bituminous mixes
vi)
Recycling the affected surface
The surface recycling and ‘cut and patch’ alternatives should be considered
especially when the deterioration of the pavement is more advanced but has not
reached the stage where a structural overlay is necessary.
Successful restoration works achieves one or more of the following: it repairs
the existing distress, decreases the rate of increase of roughness, and slows down
the subsequent pavement deterioration by arresting the mechanism causing the
distress. For example crack sealing will prevent water from entering the
pavement thus preventing failure in the lower layers.
3.2.2
Resurfacing structural
As the cumulative traffic load increases the fatigue life of the surfacing is
exceeded, which eventually manifests itself in the form of cracking in the wheel
path (crocodile cracking). When the pavement has suffered severe and extensive
structural damage, restoration works may not be cost-effective. Structural
improvement would then become a cost-effective option. It is therefore
45
important to determine when a pavement requires structural improvements as
opposed to restorative work. This can be done by carrying out a pavement
evaluation exercise to determine the structural integrity of the pavement can do
this.
Resurfacing is currently the most popular method of rehabilitating
distressed pavement in Malaysia. It involves the placement of fresh material on
the existing surfacing which improves riding quality and provides additional
structural strength. It is necessary to design the overlay thickness in order to to
achieve the desired design life.
The most commonly used resurfacing materials are; thick asphalt
overlays and granular overlays. Resurfacing can be applied to all types of
distressed surfacing, but pre-treatment is sometimes necessary before resurfacing
is actually carried out.
3.2.3
Reconstruction
A pavement that is allowed to deteriorate further will eventually reach a
state where the deterioration is so advanced that even a thick overlay would be
less cost effective than the reconstruction option. Reconstruction of the
pavement layers will be necessary when any of the layers has deteriorated
beyond economical repair. Depending on the layers needing repair,
reconstruction can be categorized into full or partial reconstruction. Full
reconstruction is needed when the existing sub grade has deteriorated and
become unstable. Partial reconstruction is carried out when only the road base or
the sub base layers have deteriorated.
46
In order to determine the extent of reconstruction required, the pavement
structure will have to be examined by carrying out an evaluation pf the existing
pavement condition. This can be done using non-destructive methods or by
digging trial pits to the condition of the lower pavement layers. However,
digging trial pits should be avoided as much as possible because the reinstate
works usually do not bring back the pavement to existing conditions. This will
result in a depression on the road surface.
When the failure of the road base is very extensive, the road base can be
recycled along with asphalt surfacing either by adding additional aggregate or
cement to stabilize the new road base material. The contraction of recycled
stabilized road bases requires specialized machinery. Standard plants are not
suitable for this type of contraction.
3.4
Restoration
Restoration is designed to restore the surface to a suitable condition for
placement of an additional stage of contraction or otherwise to perform
satisfactorily for a substantial period of time. These techniques include
rejuvenation; patching, cold techniques include rejuvenation, patching, cold
milling, crack sealing and surface recycling.
The restoration option is suitable for pavement with good structural
integrity of standard deflection lower than 0.5 mm. It is best applied to pavement
with distress limited to the surfacing. Block cracking, stripping, crack, reveling,
polishing, bleeding and aged surfacing are the typical types of failure suitable for
restoration techniques.
47
3.5
Rejuvenating
Hardened or aged bituminous surfacing can be restored by spraying a
later of bitumen or polymer modified bitumen to improve its existing condition.
Rejuvenating agents have been introduced as an alternative as they can restore
the original properties of the bitumen. The effect of rejuvenating agents has not
been studied in the Malaysian environment. Currently the available products
claimed that the rejuvenating agents could replace the correct choice of
rejuvenating agent depends on careful study and the bitumen condition in the
wising surface as it will dictate the type and amount of rejuvenating chemical to
be used. There are 3 aspects to be considered in rejuvenating;
1)
Conditional of use: Age hardening had been described earlier as a major
contributory factor to deterioration of bituminous surfacing. The top millimeters
of the surfacing suffer the most severe hardening. Thin surfacing which suffer
from this affects will look dry. For thick asphalt, crack may occur from the top
where rejuvenating chemical can be applied. Laboratory tests are needed to
identify the degree of improvement and thus the most correct use of rejuvenating
chemicals. Excess introduction of polymeric constituents may affect the bitumen
properties. As such, precautions should be taken to eliminate the possible
introduction of other problems such as bleeding, a slippery surface and
weakening of existing asphalt. The cost of rejuvenating agents should be
compared to the increased life of pavement to establish its cost effectiveness.
2)
Construction: The application of the rejuvenating chemical is simply to
carry out. There is no special equipment needed for this work. On a larger size
job, it may be economical to use a mechanical sprayer.
Since the chemical used tend to there a layer of residual oils on the road
surface. Slowing down the traffic during the initial period is very important.
48
3)
Reliability: the performance of the rejuvenating chemical depends upon
how deep the chemical are drawn down into the bituminous layers. This is
dependent on the bituminous layer. This is dependent on the density of the
surfacing. A dense mix such as the asphalted concrete Wearing course will
experience little draw down. Rejuvenating chemical are useful when used with
other methods such as the surface recycling, where the chemical are used to
replenish the lost chemical constituents in the asphalt.
3.5.1
Crack Sealing
Crack sealing is a cheap restoration alternative which would seal the
crack from ingress of water. Small or fine crack (<3mm wide) may be filled with
crack fillers. In additional, fine sand or fine aggregates may be added to fill up
larger cracks. The major benefit to be gained from proper sealing is that it
reduces water infiltration into the crack (Eaton, 1992). There are 3 aspects to be
considered in crack sealing:
1)
Conditions of use: Crack sealing is normally carried out for
environmentally induced block crack where environment is the major controlling
factor of such failures. Fatigue related cracks which are sealed only provide short
term benefit. The performance of crack sealants will depend on the age of the
pavement and traffic loading. It is also best done where the road is structurally
strong.
There are several different types of crack sealants and each has its own
unique properties. Hot or cold bituminous products are generally used. Sealant
material available includes rubber asphalt. Low modulus silicone and petroleumbase sealants. Each of the best materials has different durability, bonding,
49
extensibility and other properties. Only the best available sealant should be used
for long lasting performance. Crack sealing should be carried out as a means of
deterring ingress of water into the pavement layers.
2)
Construction: Before cracks are sealed it is better to remove dirt and
loose material from the cracks. These are done using air compressors. Care must
be taken to ensure safety of vehicles before opening to traffic. Any loose
material must be swept away. If sand is used as additional filler allowing slow
moving traffic can help the embedment of the small particles into the cracks.
Excess filler material must be removed since this could reduce the skid
resistance of the surface.
3)
Reliability: Crack sealants will not completely fill the full depth of the
cracks. Only the top few millimeters are filled. Because of this, the use of crack
seals is limited to those cracks which have not propagated completely through
the surfacing.
3.5.2
Cutting and Patching
Cutting and patching is the replacement of deteriorated asphalt surfacing
with suitable bituminous mix, place and compacted to similar level to adjacent
undeteriorated asphalt. There are two types of bituminous patching material
which are commonly used; hot-mix asphalt and cold mix asphalt.
These mixtures vary widely in quality composition and cost. Bituminous
patching mixtures must have sufficiently good properties. The required
properties are:-
50
(i)
Stability – to resist shoving and rutting
(ii)
Cohesiveness – should stick to host material
(iii)
Resistance to water – impermeable
(iv)
Durable – resist wear
(v)
Workability – easily handle and construction
(vi)
Storage ability – can be stored without deteriorating for immediate
works
The performance of a bituminous patch depends on quality of the
materials and construction technique. There are 5 aspects to be considered in
bituminous patch:
1)
Conditions of use:
For pavement with localized surface failure,
cutting out the failed areas and patching it with new bituminous mix should
restore the pavement. The cut and patch method is also a means of pre-treating
the existing pavement before a resurfacing work. It is designed to remove the
existing cracks and thereby eliminate reflection cracks. However, the cracks
have to be removed totally as cracks in the lower will eventually cause reflection
cracks on the new layer.
For pavement with rutting caused by the instability of the wearing course
mix, the cut and patch alternative is also suitable. This type of failure is mostly
found on climbing layer must be removed prior to being replaced with a stiffer
mix.
51
2)
Construction: Even though the construction of patching does not
require special equipment, proper construction technique is still
important. On many occasions, the construction is not carried out
properly causing the patched area to fail early.
The correct
construction method is described below.
a) Marking. The boundaries identified to be patched should be
market. Straight line markings are preferred. All deteriorated
areas should be included with allowance for joints. These
boundaries can be change doing cutting to allow for initially
undetected damage.
b) Cutting. The area marked for patching should be neatly cut and
removed using a proper asphalt cutting tools. A vertical unbroken cut
will enhance adhesion and promote efficient compaction.
c) Cleaning and drying. The surface under the new patch must be
clean, dry and free from loose material. Air blowing followed by
vacuum cleaning is recommended for efficient cleaning and draying.
d) Tack Coating. A thin bituminous layer is normally sprayed
uniformly on the prepared surface prior to patching hot-mix to
promote adhesion between the new layer and the cut surface. For
small jobs, low-pressure hand sprayer can be used, whereas a
bitumen sprayer is suitable for large areas. Tack coat materials
available include; cut-back bitumen, bitumen emulsion and synthetic
resin. Tack coating should not be applied if cold-mix asphalt is used,
unless the patch surface is made of concrete. The tack coat can soften
the cold-mix and promote shoving and stripping.
e) Filling. The material can be placed in several lifts. A single lift
should not exceed 100 mm thick. Filling is normally carried out
manually. Shovels should be used and raking is not advisable to
reduce segregation. Hand tamping at edges and corners can also be
52
carried out with a hand rammer. The surrounding surface must be
kept clean spilled filling material.
f) Compaction. Vibratory rolling is the best method for compacting
patched area. By rolling the edges first the filling will pinch into the
hole. The center of the patch is rolled first, moving outwards towards
the edges with each succeeding passes. This will tighten the adhesion
around the edges. The roller should rest completely on the patched
are and not partly on the old pavement.
g) Cleaning up and checking joints. Cleaning up is essential for a
comprehensive patching job. Checking the finished product
especially the joints should be carried out. The edge or joints of the
patch should be sealed using bituminous material similar to crack
sealants described earlier. The life of the patch is often dependent on
how well the joints are made.
h) Cold Milling. If extensive patching is required or if the proposed
patches are too close to each other, then cold milling can be
considered as an option. A milling machine is required for this work.
This machine can cut the deteriorated surfacing to be depth and width
as required. The maximum depth and width depends on the machine
type and specifications. The milled material can be salvage or
recycled. Patching should then be carried out using an asphalt paver.
3)
Reliability: The performance of a patched are depends heavily on the
type of mix used and the construction standard. If constructed properly, this
alternative would be able to last the life of the untreated sections. But if poorly
constructed, this alternative can increase the roughness of the road section.
53
3.5.3
Thin bituminous overlays
Thin bituminous overlays provide a feasible alternative for low cost
pavement surface restoration. It improves the surface riding condition and can
extend the service life of a pavement. It can also be used as short term measure
to address specific distress condition. Most commonly used thin asphalt overlays
are; surface dressings, slurry seals (Thin seal mixtures) and thin hot mix
overlays.
3.3.3.1 Surface Dressings
A surface dressing is an application of followed with an aggregate cover
in a single or multiple applications. In double surface dressings the larger sized
stoned are place in the first application with the smaller sized stoned in the
second application to fill in the voids in the first layer. The aggregates used have
t be cleaned and free from dust. This will facilitate cohesion between the
aggregates and the bitumen. If dusty aggregates are used, then pre-coating them
first is more suitable.
1)
Conditions of use: Surface dressing has been commonly used as a
wearing course on low volume roads. It has also been used as a resurfacing
technique to treat surface failure on these types of roads. The potential use of the
surface dressings to restore distressed bituminous pavement has not been fully
demonstrated in Malaysia, even though it is greatly used in Australia and the
United Kingdom. Apart from being able to restore the riding quality of the road
surface, it has other advantages. The high bitumen content of a surface dressing
layer means thicker bitumen film will be coating the aggregates. This will
improve resistance to ageing making the surfacing more durable. At present,
limited local experience in the use of surface dressings on asphalt curette
surfaces restricts its application on high volume roads because of the worry that
54
loose stones may pose hazards to the traffic. Furthermore, the long construction
period may cause traffic disruption. As such it is proposed that the use of surface
dressings on asphalted concrete surfaces be limited to low volume roads with
Average Daily Traffic (ADT).
When using surface dressings on aspartic concrete surfaces, a proper
design needs to be carried out. The design guideline from the Transport Research
Laboratory Oversea Road Note 3 specifies the rate of spray of the binder and the
aggregates as important to the performance of the surface dressings. The
hardness of the flakiness of the aggregates is important considerations too. The
hard surface will not allow any penetration of the aggregates for embedment and
because of this; a suitable binder is needed to ensure the stone are not whipped
off by traffic.
The use of modified bitumen, fibers or special aggregate may improve
the construction procedure and enhance the performance will increase its
applicably on high volume roads.
2)
Construction: The construction of the surface dressings requires the
binder to be sprayed using a mechanical sprayer and the aggregates to be spread
by a specially designed chipping spreader. These are inexpensive and are easily
available locally.
Traffic control immediately after the surface dressing have been applied, is
important. This is due to the loose chippings which still need kneading by the
traffic tyres. During this period, at least 2 hours after application for normal
bitumen, the speed of the traffic have to be low. This period may be reduced if
modified benders are used.
55
3)
Reliability:
If the surface dressing is constructed on a road that is
structurally sound, it will last a long time. The thicker bitumen film thicknesses
ensure the flexibility of the layer and would reduce age hardening. Because of
this, the use of surface dressings as a restoration alternative should be
encouraged. In Malaysia where the intense sunlight does create problems with
the rate of ageing, the surface dressings wearing course may last longer than a
thin aspartic concrete layer.
3.5.3.2 Slurry seals
Slurry seals are a mixture of aggregates, water and filler (usually cement)
bound with bitumen emulsion, and mixed in-situ prior to laying using
specialized equipment. It has potential for both corrective and preventive
maintenance of asphalt surfacing. However, it is not a structural layer.
Application of slurry seal is known to retard the hardening process of the top
portion of aspartic concrete surfacing.
There are three types of slurry seals, namely Type I, II and III as
specified by the International Slurry Seal Association (ISSA). The aggregate
size, filler and the residual bitumen from the emulsion govern the classifications.
Nominal 4.75 mm aggregate size is specified for Type I whilst size 9.5 mm for
Type II and III. The emulsion specified should be checked for compatibility with
the aggregate and the desires setting time. Slow setting cationic emulsion is
normally used.
1)
Conditions of use: The nature of the existing surfacing and the expected
traffic level govern the appropriate use of slurry seals. It is not suitable for shape
correction or for use at heavily loaded pavement with interconnected cracks or
more advanced cracks. Slurry seal should not be applied on structurally weak
areas. Conventional slurry seals using slow setting emulsion need a long curing
56
time, therefore application is not advisable when rain is expected. Rain water can
wash away the emissions, breaking aggregate bondage and destroying the slurry.
Localized pavement defect edges must be repaired before applying the slurry
seals. Modified emulsion, fibbers or special aggregates can improve the
properties and performance of slurry seal. Their conditioned of use is similar to
the surface dressings described above and may be extended to higher class of
roads.
2)
Construction: Construction of the slurry seals requires special paving
equipment. A more powerful and faster mixed is required if the modified
emulsions are used. It is also desirable to have experienced contractors to do the
job. The long curing time is about 3 to 4 hour for the normal slurry seal make it
necessary for the provision of proper traffic control. This is especially difficult to
carry out in built-up areas. Usually, sand is used traveling over the slurry. The
inclusion of modifiers to the emulsion usually shortens the curing time to about
30 minutes.
3)
Reliability: Slurry seals are effective in areas where the primary problem
is excessive oxidation and hardening of the existing surface. They may also be
used to improve the friction characteristics of polished surfaces at low traffic
levels. However, when used in areas where the pavement deflections are high
and the surface is suffering from cracks (block and crocodile crack), the slurry
seal will crack very quickly and should no be used.
3.5.3.3 Thin hot mix
Thin hot mix asphalt is an asphalt mix which is normally less than 40
mm thick. Any type of hot asphalt mix or modified mix can be used. The thin
57
asphalts layer is mainly to correct surface deficiencies and will not add much
structural strength to the road.
Apart from the normal asphalt concrete, fiber-reinforced ultra-thin mix
and the porous asphalt mix fall into this category. The fiber-reinforced ultra-thin
mix is popularly used in Europe with success. The introduction of the fibers
increases the fines mix, theory allowing more binder to be added. This additional
binder in the will help I preventing ageing of the binder.
The porous asphalt mix is also popular in Europe. This mix is designed
with high void contents to allow for free draining of surface water. The high
voids are also able to absorb traffic type noise, which makes it popular n built-up
areas. To ensure stability of the mix the use of modified binders may be
necessary.
1)
Conditions of use: Thin hot mixes can be applied at areas subjected to
low deflection. It is not meant to correct structural failures and severe rutting.
Surfacing that suffer from polishing, stripping, bleeding can be overlaid with
thin hot mixes. Suitable tack coats must be used prior to laying the thin overlays.
Strong adhesion with the existing surface is necessary otherwise delimitation and
flaking can occur.
The present practice of providing a thin overlay (up to 40 mm overlay)
without giving due consideration to the structural needs is not a good practice. If
laid on top of the existing asphalt layer without prior treatment to the cracked
surface, the cracks reflect through the new layer as early as within 3 months
depending on the deflection and the traffic intensity of the road. It is therefore
very important that cracked sources must be treaded before overlay.
58
The fiber-reinforced ultra thin mix and the porous asphalt mix are
applicable on road surfaces with good structural integrity. These mixes are
necessary. Traffic can run on the mix as soon as the rolling is completed. But in
the case of the porous asphalt, it is necessary to leave the mix for a couple of
hours before opening to traffic.
2)
Reliability: The aggregate gratings and bitumen type and amount used in
this mix will affect the performance of the layer. Because of its thin nature, the
steel roller resulting in loose aggregates would crush bigger sized aggregates.
Apart from that, the bitumen film thickness will influence the life of the layer.
In Malaysian pavement constructed with porous asphalt have
performance very well. Its reliability depends on the design of the mix and the
type of binder used. The clogging of this type of mix with time may reduce its
ability to drain water.
3.6
RESURFACING
Resurfacing is the placement of fresh material on an existing surfacing to
enhance its structural strength. Asphalt resurfacing is the most popular method
of pavement rehabilitation in Malaysia (Interim Guide to evaluation and
rehabilitation of flexible road pavements, 1992). When done properly, this
method is appropriate since the addition of new layers strengthens the road
pavement making it capable of carrying increased traffic. It also improves riding
quality. The thickness of the asphalt resurfacing depends on the strength of the
existing pavement and the expected traffic. It is necessary to carry out a proper
design to establish the thickness of the surfacing.
59
There are two methods of resurfacing popularly used in Malaysia,
namely thick asphalt overlays with or without a prior granular overlay. The
former involves the construction of a crushed aggregate layer on the existing
pavement before laying the asphalt layer. The use of granular overlays reduces
the need for pre-treatment works.
Resurfacing without a prior granular overlay can be applied to rectify
many types of pavement failure. However, pre-treatment works such as patching
and reconstructions should be carried out at localized failed areas prior to
resurfacing can be applied on surfacing. That are cracked, rutted, polished,
raveled and those that are bleeding. Proper evaluation of the existing pavement
condition is necessary to determine the extent of pre-treatment required. The
following paragraphs describe some of the aspects that should be considered
prior to resurfacing.
3.6.1
Resurfacing on Cracked Surfaces
Cracks occur frequently on roads in Malaysia. These cracks should be
treated early to stop ingress of water into the road base layer thereby weakening
it. The common practice of overlaying the cracked pavement without prior
treatment to the cracked surface, causes the cracks to the cracked surface, causes
the cracks to reflect through the new layer as early as within 3 month depending
on the deflection of the road section and the traffic level. It is therefore very
treated before overlay. Alternatively, more expensive techniques such as using
interlayer to absorb the stresses and strains of the crack tips can be used.
One common pre-treatment method is to ‘cut and patch’ before overlay.
This results not only in delaying reflective cracking but it also gives a slight
60
increase in the strength of the pavement. The rate of progression of the cracks
reflecting through the new asphalted layer depends on the structural strength of
the pavement. Pavement with higher deflection, causing higher crack movement,
tends to be the first to crack.
Another method of reducing reflection cracks is by introducing a
separating layer to absorb the stresses from the crack movement. An example of
this stress-absorbing layer is the geosynthetic material. There are many types of
geosynthetic material available. And most of them claimed to be effective in
mitigating reflection cracks. However, the construction procedures have to be
properly looked into to ensure that the geosynthetic material is laid in
accordance to the manufacturer’s specifications.
There are basically two types of geosynthetic material available in the
market the grid and the non-woven geotextiles. When using the grid, care should
be taken to reduce the possibility of the picking up or stretching the grid by lorry
tyres. When this happens, the grids will warp and the resultant displacement of
the grids will lead to poor compaction of the asphalt layer. On the asphalt layer,
this leads to cracking. On the other hand, if the non-woven materials are used
care should be taken on the amount and type of tack coat used. If used in excess,
the non-woven material will become saturated and will lead to bleeding. If the
bitumen tack coat is too soft the material can slide at the existing road/material
interface.
Other types of Stress Absorbing Membrane Interlayer (SAMI) are also
available. These can be in the forms of aggregate interlayer (e.g. surface
dressings) or modified bitumen with or without chippings. At IKRAM studies
are being carried out on the use of some of this interlayer. Laboratory
experiments are also being carried out on the manufactures of SAMIs using
natural rubber blended bitumen.
61
Crushed aggregates have also been used as an interlayer. This method
has perform positively even with crack movement of 1.5 mm. In one of the trials
constructed by IKRAM the crushed aggregates were laid on top of segmented
concrete pavement where the movements at the joints were substantial.
Previously asphalt overlays without prior treatment would only last about 2
month. But with this method the cracks from the concrete joint have yet to come
through after a couple of years.
3.6.2
Resurfacing on Rutted Surfaces
Resurfacing on the existing pavement with surface ruts require special
considerations. Dense bituminous surfacing rut when it loses its stability
properties. These usually occur in areas where there are prolonged loading
periods of slow moving or stopped heavy vehicles namely at climbing lanes and
at intersections. The high stresses imposed on the asphalt layer causes it to
density and with the reduction in voids in the mix, the mix becomes unstable.
This layer must be removed by milling prior to overlaying it with a fresh asphalt
layer.
Bituminous mixes designed by the Marshall method have been shown to
perform poorly in high stress areas. To counter this, polymer modified bitumen
can be used in aspartic concrete on climbing lanes and junctions. The rates of
rutting of these mixes are slower than the normal aspartic mixes. However, the
use of the polymer modified bitumen can increase the cost of the asphalt to
double its normal cost.
In an effort to find cheaper solution to the above problem, IKRAM has
introduced a new mix for the surfacing, called the HCM Bituminous Surfacing.
62
The mix was tried in a trial at the Bukit Tinggi climbing lanes along the Kuala
Lumpur – Karak Highway. In the same trial, other mixes using polymers and
additives were also tried. After nearly 3 years in services, the HCM Bituminous
surfacing has performed on par to the more expensive polymer modified wearing
courses (IKRAM, 1994).
3.6.3
Resurfacing on Bleeding Surface
If the existing pavement surface which needs strengthening is suffering
from bleeding, it is advisable to consider the possibility of the excess bitumen
migrating into the new layer. The application of hot sand should be considerate.
3.6.4
Resurfacing on Corrugated Surface
If corrugations are the result of unstable surfacing materials, it should be
replaced before resurfacing. If it is due to unstable granular pavement layers then
partial reconstruction will be a better solution.
3.6.5
Resurfacing On Raveling or Weathered Surfaces
If the existing surface is experiencing raveling and loss of aggregates, no
pre- treatment is necessary. A major portion of the cost in carrying out a
63
structural resurfacing job goes to the pre-treatment works. The use of fabric
geosynthetic material would reduce the total construction cost as the fabrics mat
add about 30-40% more to the cost. Structural resurfacing can last the design life
if proper pre-treatment work is carried out. Most of the resurfacing works which
show early signs of distress are due to improper pre-treatment works.
3.7
RECONSTRUCTION
Reconstruction is the removal and rebuilding of all (including sudgrade0
or part of the road pavement using fresh material and new construction
specifications. Pavement that have failed severely are usually those where
deterioration has been allowed to occur without maintenance. The condition of
thee lower a granular layer of the pavement is best determined by destructive
testing.
There are two types of reconstruction, namely full reconstruction and
partial reconstruction. Full reconstruction is needed when the sub grade layer as
well as the pavement a layer has deteriorated beyond repair. In full
reconstruction, the rebuilding includes the sub grade. Partial reconstruction is
needed when the road base has been contaminated and it has lost its inherent
stability. In this case the rebuilding does not include the sub grade.
In the case where the failure of the road base is extensive and
conventional partial reconstruction method is uneconomical, it is advisable to
carry out recycling. Recycling of the road base is a partial reconstruction
alternative where the existing surfacing and/or part of the road base is
pulverized, and replaced as a new road base layer. The process breaks up the
existing asphalt layer into small at the same time allowing additional of road
64
base thickness. It therefore can be used to eliminate reflective cracking problems
and correct thickness deficiencies.
Among the common stabilizer suitable for base recycling are; cut-back
bitumen, cement and bitumen emulsion. The correct choice of stabilizers will
depends on the existing pavement material type, its condition and compositions.
Identify areas needing reconstruction requires evaluation of the pavement
condition. However, experience has shown that the following rule-of-thumb to
be reasonably acceptable in identifying localized reconstruction areas.
a)
Identifying full reconstruction. Full reconstruction may be needed for the
following combination of failures.
i)
Pavement surface which suffer from crocodile crack with rut
depths of more than 25 mm without shoving.
ii)
Pavement surface which suffers cracking with rut depth of more
than 15 mm and deep shoving.
b)
Identifying partial and base reconstructions. Partial reconstruction may
be needed for the following failures or combination of failures.
i)
Spalling and crocodile cracking with rut depth of less than 15 mm
ii)
Shoving with rut depth less than 15 mm
iii)
Crocodile cracking with block size less than 100 mm with
shoving.
c)
Confirmatory test using the Dynamic Cone Penetrometer (DCP). If the
site engineer is not certain of the extent of reconstruction required, the DCP can
65
be used to estimate the pavement layer strength and thus identify which material
needs to be carries to be removed. Partial reconstruction can be carried out if it is
not necessary to replace the sub grade or the sub-base.
Reconstructions requires more lane closure time than resurfacing,
since the work includes breaking up the pavement removal and rebuilding of
existing layers. The times taken for a partial reconstruction are less than that for
the full reconstruction.
Allowance should be made for the possibility of secondary
compaction of the reconstructed areas by opening them to traffic for a period of
time before applying the final overlay. Particular attention should be given to
the provision of adequate drainage when reconstructing roads with high water
table.
d)
Marking the areas to be reconstructed. Marking of the areas to be
reconstructed is best done a few days before construction. Temporary marking
can be used if construction is to follow immediately otherwise permanent
marking can be carried out. It is advisable to extend the area needing
reconstruction beyond the area over which it occurs. Marking is best carried out
by experienced personnel identifying serious pavement defects. This task is
critical in optimizing the probability of success of the rehabilitation job.
e)
Construction of base recycling. The construction of recycled stabilized
base normally requires specialized machinery. Standard contraction method may
not be suitable and be expensive. The works involved in base recycling are:-
f)
Pulverisation or ripping. Mechanical pulverisors can reduce it to uniform
sizes. The pulveris material should be inspected where all large pavement
66
chunks and organic substances should be removed. Addition of stabilizers may
be introduced at this stage.
g)
Stabiliser distribution. Cement stabilizers can be spread by a bulk
spreader or manually depending on the job size. The spread rate, water content
and mixing process is critical for efficient stabilization. Bituminous stabilizers
are mechanically spread and are seldom used for base recycling.
h)
Compaction. Compaction can be carried out using normal vibratory
rollers. The number of roller passes is critical, as over-compacting cement
stabilized base may overstress the surface. Bitumen stabilized road base do not
have this problem.
Reconstructions work done to a high construction standard will have a
life surpassing all other rehabilitation option. In fact, it can be designed to any
desired performance period. However, it is expensive and should only be carried
out where necessary (Transportation Research Board-Washington DC, 1996).
CHAPTER 4
RESEARCH METHODOLOGY
4.1
Introduction
This chapter describes the methods used in carrying out the study. A
thorough planning and scheduling had been organized on the methodology of the
study in proper sequence to ensure a smooth running of the study program from
literature review, data collection , data analysis, until the discussion of the results
and finally the suggestion and conclusion.
4.2
Determination of the Research Objectives.
Preliminary study has been carried out to determine the research objectives
and scope of the dissertation. In the process some information of the contract
documents has been investigated and some feasible methods to carry out the study
68
have also been considered. Some interviews have been carried out as the preliminary
input to evaluate the importance of the study.
After the preliminary review, some specific scopes of the study has been
determined by considering various aspects such as achievability of the study, the
time constraints, availability of the research materials and the specific scopes that
have been discussed previously in the first chapter.
4.3
Literature Review
Literature review has been carried out to establish some knowledge and to
collect information pertaining to the study area. The literature review has been
obtained from several sources such as published books, textbooks, articles in
journals and papers of some published guidance from practice in the industry and
previous maintenance and operation records. The purpose of literature review is to
gather important information related to the topic and deepen the significant of this
study.
4.4
Data Collections
There are several known modes of data collection: reading, adopting
literature review, based on observation and records of past project or personal. A
combination of analyzing of case study, reading, observation and personal interview
69
are used during field work. A part from that, the main sources of data collected are
from:
I. Engineering Drawing
II. Contract document
III. Daily report from Highway Patrolling Team
IV. Monthly report comprises of Monthly Traffic Report years 2004 to 2006,
Feedback Maintenance Report by Malaysia Highway Authorities years
2004 to 2006 and Daily Report by Traffic Surveillances Unit.
V. Minutes of Meeting, Correspondence letter and memorandum either from
client, consultant or subcontractor.
VI. Records from government department such as Malaysia Highway
Authorities, Public Works Department and Jabatan Pengairan dan Saliran.
4.5
Data Analysis
There is wide range of research design and method available. These methods
are broadly classified into qualitative and quantitative. Qualitative methods are more
committed to research in everyday setting, to allow access and to minimize
reactivity among the subjects. Qualitative methods also enable explanation by
understanding. Quantitative methods, on the other hand, involve the generation and
use of data in form of numbers, figures and illustration, usually includes physical or
statistical control to allow the testing of hypothesis and analyzing.
70
For this study, qualitative and quantitative methods will be used so that the
objectives will achieved through the selecting and analyzing data from the several of
sources and aspects. The summary of the study are then presented with the
recommendations along with the conclusion for further studies in this area.
CHAPTER 5
DATA COLLECTION AND ANALYSIS
5.1
Introduction
This chapter is concerned with analysis of data and its interpretation of the results
to answer the objectives of the study. The results of the study are discussed and analyzed
in the following table and figure to answer of the objectives mentioned in Chapter 1.
i. To determine sources of pavement distress at Kuala Lumpur Karak Highway
ii. To evaluate the effectiveness of pavement rehabilitation in term of time, quality
and cost at Kuala Lumpur Karak Highway.
72
5.2
To Determine Sources Of Pavement Distress At Kuala Lumpur Karak
Highway
The analysis of data involves the sources of flexible pavement distress obtained
during the preliminary study. These sources of damage were identified and later the data
related to the sources were collected and analyzed as water factor, diesel spillage and
climbing lane area.
5.2.1
Water Factor
The data collected includes related water factors as discussed in chapter 2.2.1.3 as
pavement infiltration, water seepage from increase of water table and water from higher
ground.
5.2.1.1 Pavement Infiltration.
Pavement infiltration has been identified as one of main sources of flexible
pavement distress , that rain factor.
Table 5.1 and Figure 5.1 shown a data rain summary at four stations in Bentong
district i.e Simpang Pelangi (3121143), Stesen Janda Baik (3318127), Stesen Ladang
Bukit Dinding (3420131) and Kuala Marong (3519125) obtained from Jabatan Pengairan
Dan Saliran, Ampang Road and compared to rain distribution in Kl Karak Hihway with
73
yearly average of 2417.83mm per year. A total four rain gauge has been set up along KL
Karak Hihgway i.e. at Km 53.80, Km 38.40, Km 61.00 and Km 76.20 where daily data
was taken by consultant.
From Table 5.1 and Figure 5.1 it is found that maximum difference value is high
1400.58mm compared to year 2006 while minimum value is -77.42mm compared to yea
1994.
Table 5.1: Comparison average between JPS and KLK
3121143
3318127
3420131
1994
956.00
2835.00
3800.00
Differences
with KLK
3519125 Average (2417.83mm)
2390.00 2495.25
-77.42
1995
1276.00
1886.00
2189.50
1747.00
1774.63
643.20
1996
1488.00
2222.50
2318.00
2180.00
2052.13
365.70
1997
1269.50
1767.50
2334.70
1801.00
1793.18
624.65
1998
1475.00
2124.00
1697.40
1811.00
1776.85
640.98
1999
1407.00
1608.00
2244.00
1657.50
1729.13
688.70
2000
1634.00
2122.50
3680.00
2041.90
2369.60
48.23
2001
2054.00
1689.00
2791.00
2324.60
2214.65
203.18
2002
1658.00
2051.00
2542.00
1624.00
1968.75
449.08
2003
1457.00
2040.00
2175.50
1669.30
1835.45
582.38
2004
1167.00
1372.00
2002.50
2140.20
1670.43
747.40
2005
244.80
969.50
1790.00
1633.00
1159.33
1258.50
2006
1126.00
758.00
1421.00
764.00
1017.25
1400.58
JPS Station
Years
74
1400.58
3000
2500
2000
1500
1000
500
-77.42
0
1500
1400
1300
1200
1100
1000
900
800
700
600
500
400
300
200
100
0
-100
1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006
Figure 5.1: Comparison graph average between JPS and KLK
5.2.1.2 Water seepage from raise of water table.
Concessionaire side has supervised water table level by constructing 26 numbers
of standpipes from east bound and 30 numbers from west bound. The result of
supervision of the 56 numbers of standpipes indicate that 39 numbers (69.64%)
standpipes always show the existence of water level from surface ranging 0.210 to
11.250, 14 numbers (25.00%) always dry and 3 numbers show water level ranging from
9.10 to dry.
75
5.2.1.3 Water seepage from higher level.
The data obtained from concessionaire show that 760 numbers horizontal drains
has been built at 35 numbers of cut slopes along Kl Karak Highway. The concessionaire
has done a test to determine the functionality of the horizontal drains by using
thermograph scanning method.
It is conducted by using infra red image that is, using thermal camera. The result
of test indicates that 537 numbers (70.65%) functioned well, 123 numbers (16.18%)
function moderately and 100 numbers did not functioned at all. In this study, function
well indicates of high water seepage.
5.2.2
Diesel Spillage Factor
Table 5.2 and Figure 5.2 below show the number of this diesel spillage were
recorded from the years 2004 to 2006 by Highway Patrolling Team. These records were
extracted from the Patrolling Daily Records.
The minor spillage usually occurred because of tank leakage and involved surface
are less than 1 meter square (1m2) while the major spillage involved more than 1m2 and
this normally caused by accident.
76
Table 5.2: Diesel spillage at Kuala Lumpur Karak Highway
years 2004-2006
2004
2005
2006
Minor Major Minor Major Minor Major
Section 1
10
5
14
3
16
5
Section 2
9
3
14
2
23
4
Section 3
3
9
Total
19
8
28
5
48
9
Section
NUMBERS OF SPILLAGE
DIESEL SPILLAGE AT KL KARAK HIGHWAY
(2004-2006)
60
48
50
40
28
30
20
2004
19
2005
8
10
5
9
2006
0
Minor
Major
CATEGORY OF SPILLAGE
Rajah 5.2: Diesel spillage at Kuala Lumpur Karak Highway years 2004-2002
As shown in Table 5.2 and Figure 5.2, it can be seen that minor spillage of 19
times (2004), 28 times (2005), 48 times (2006) had occurred. For major spillage, 8 times
occurred in year 2004, 5 times in 2005 and 9 times in year 2006.
77
5.2.3
Climbing Lane Factor.
Kuala Lumpur Karak Highway, is stretch of 16.40 km climbing lane (rate of
inclination 3%-10%) which forms of 14.00 % of the total highway. Table 5.3 and Figure
5.3 show the number of heavy vehicles which stopped and breakdown along KL Karak
Highway in comparison to those which occurred in the stretch of climbing lane at Kl
Karak Highway.
Table 5.3: Breakdown and stopped vehicle at Kl Karak Highway (2004-2006)
Years / months
January
February
March
April
May
June
July
August
September
October
November
December
TOTAL
Percentage,
(Difference)
%
2004
All Climbing
53
48
60
45
81
62
49
30
84
65
116
83
65
45
60
32
58
29
60
45
53
30
123
95
862
609
2005
All Climbing
101
85
84
65
112
79
59
45
122
102
62
49
40
35
30
18
55
45
63
57
70
60
124
103
922
743
2006
All
Climbing
136
103
116
98
65
53
80
73
179
145
70
65
68
32
91
75
52
43
31
23
56
43
86
65
1030
818
70.65%
80.59%
79.42%
78
BREAKDOWN AND STOPPED VEHICLE AT KL KARAK
HIGHWAY (2004-2006)
200
200
All '04
All '05
150
100
100
50
CLIMBING AREA
ALL AREA
150
All '06
Climbing '04
Climbing '05
50
Climbing '06
0
0
1
2
3
4
5
6
7
8
MONTHS
9
10 11 12
Figure 5.3: Breakdown and stopped vehicle at Kl Karak Highway (2004-2006)
Table 5.3 and Figure 5.3 shows 70.65% of vehicle stopped and breakdown along
this climbing lane in the year 2004, 80.39% in year 2005 and 79.42 % in year 2006.
5.3
To evaluate the effectiveness of pavement rehabilitation in term of time,
quality and cost at Kuala Lumpur Karak Highway
To evaluate the effectiveness of methods used in rehabilitation pavement, three
aspects or forms are considered, i.e. time, quality and cost. The data were collected from
different sources such as explained in chapter 4.
79
5.3.1
Time
Table 5.4 showed that time taken to complete rehabilitation pavement work.
These data where obtained from contract document.
Table 5.4: Time to complete pavement rehabilitation work.
Contractor 1
Contractor /
Section
Section 1
Section 2
Section 3
Total(
Weeks)
Original
Contract
(Weeks)
Extension
of Time
(Weeks)
36
36
Contractor 2
Original
Contract
(Weeks)
Extension
of Time
(Weeks)
32
Contractor 3
Original
Contract
(Weeks)
Extension
of Time
(Weeks)
32
44
72
64
64
108
From Table 5.4, it is formed that total time taken for pavement rehabilitation by
contractor 1 was 72 weeks, contractor 2; 64 weeks, while contractor 3 completed the
work in 108 weeks.
The main sources of delay are as follows:
1)
Rain. (As discussed on chapter 5.2.1.1)
2)
Additional scope of work such as construction of sub soil drain, median
drains and laying of ACWC with polymer.
80
3)
Changes of site conditions, such as sub-gred repair which not indicated on
drawings and bill of quantity.
4)
Design Factor. Various of inconsistence method in an area. For example,
CBM layer very short distance from one another.
5.3.2
Quality.
Data obtained from contract document, indicates that concessionaire highways
has increased specification or quality conducted during improvement work. Several
aspects have been made addendum to JKR Technical Specification. It involves two
sections i.e. section 2 (earthworks) and section 4 (flexible pavement). It is involve the
deletion of clauses and substitution of new clauses as shown in Table 5.5.
From Table 5.5, it is found that change in ACV value occurs i.e. less than 25mm
and PSV more than 49. The same is to construction methods when ACBC result must be
in the range 98-100%. For bituminous Mc Adam, road base result value was 95-100%
and ACWC 98-100%.
81
Table 5.5: Differences JKR specification with concessionaire
Item
JKR Specification
Addendum
to
concessionaire
specifications
Aggregates (4.2.4.2)
i) ACV<30 (delete)
i) ACV<25 (insert)
v) PSV>40 (delete)
v) PSV>49 (insert)
Construction method i)
(4.2.4.5)
Compaction
of
asphaltic i) Compaction of asphaltic
concrete
concrete
Binder Course 95 – 100 %
Binder Course 98 – 100 %
Bituminous
Delete clause 4.2.5.4 sub clause c Replace
Macadam (4.2.5)
– ‘Compacted Density’
with;
Required
Compacted Density :
Bound Road Base
95-
100%
Leveling Course 95-100%
Binder Course 98-100%
Wearing Course 98-100 %
(Marshall Density)
During the pavement rehabilitation works, consultant was produced 38 numbers
of non conforming records on construction contractors i.e. 7 times to contractor 1, 17
times to contractor 2 and 4 times to contractor 3. Malaysian Highway Authority has also
produced 36 numbers of non conforming records while concessionaire side produced 37
numbers. Table 5.4 shows non conforming records produced by Concessionaire,
Consultants and Malaysian Highway Authorities.
82
TOTAL OF NCR RECORDED DURING PAVEMENT
REHABILITATION
CONCESSION
AIRE, 37
,
,
Consultant, 38
,,
,
,
,
MHA, 36
Figure 5.4: Total of NCR recorded during pavement rehabilitation
Table 5.6: Types of pavement distress after rehabilitation
TYPES OF DISTRESS
CONTRACTOR
Section 1 (Contractor 1)
Section 2 (Contractor 2)
Section 3 (Contractor 3)
TOTAL
Cracks
Surface
Deformation
Surface
Defects
Patch
Pothole
1
2
3
6
1
1
5
7
3
2
6
11
2
2
2
6
1
3
4
Edge
Cracks
1
3
4
83
TOTAL OF DEFECTS RECORDED AFTER
PAVEMENT REHABILITATION
Pothole, 4
,
Edge Cracks, 4
,
,
Cracks, 6
,
Surface
Deformation, 7
Patch, 6
,
,
,
Surface
Defects, 11
Figure 5.5: Total of defects recorded after pavement rehabilitation
Table 5.6 and Figure 5.5 show damaged road surface that were recorded after
pavement rehabilitation works. There were 6 types of pavement distress after
rehabilitation works; 6 numbers of cracks, 7 numbers of surface deformation, 11 numbers
of surface defects, 4 numbers of patch, 6 numbers of pothole and 4 numbers of edge
cracks
As a whole pavement distress is not entirely from contractor defect list, but is
contributed by others factors. On analysis, improvement cost on these damaged costs to
RM 3,919,000.00 which contractor is not bear any remedial cost.
84
5.3.3
Cost
The data collected and extracted from bill of quantity, claim certificates and site
instruction. These data recorded based on financial progress up to December 2006. Table
5.7 and Figure 5.6 show cost involved based on contract document. It has been identified
overall cost were RM 86,635,467.07 which have divided for contractor 1 (30.44%),
contractor 2 (21.90%) and contractor 3 (48.16%). For variation orders, contractor 1
received the highest which amount 20.54%, contractor 2 is 1.84% and contractor 1 is
2.64%.
Table 5.7: Cost distributions on pavement rehabilitation at KLK Highway (Contract
Amount)
Contractor /
Cost
Distribution
Original Contract
Variation on Price
Variation Order
Total
Total Cost
(Overall)
Contractor 1
Contractor 2
(RM)
(RM)
(%)
(%)
Contractor 3
(RM)
(%)
24,088,962.72 27.80% 16,086,743.71 18.57% 21,575,595.90 24.90%
0.00%
852,787.00 0.98%
2,351,519.00 2.71%
2,286,701.50 2.64%
1,596,105.81 1.84% 17,797,051.43 20.54%
26,375,664.22 30.44% 18,535,636.52 21.39% 41,724,166.33 48.16%
86,635,467.07
85
5%
0%
Original Contract
Variation Order
Variation on Price
10%
Variation on Price
15%
Variation Order
20%
Variation on Price
25%
Original Contract
30%
Variation Order
Percentage
35%
Total
40%
Total
45%
Original Contract
50%
Total
Cost Distribution on Pavement Rehabilitation at KL
Karak Highway (Contract Amount)
Cost Distribution
Figure 5.6: Cost distributions on pavement rehabilitation at KLK Highway
(Contract Amount)
Table 5.8 and Figure 5.7 show cost involved based on site activity. It has been
identified the highest contribution on site activity was pavement works i.e. 25.56% for
contractor 1, 17.50% contractor 2 and 39.13% for contractor 3. Pavement works with
polymers involved 0.54% for contractor 1, 1.13% for contractor 2 and 0.96% for
contractor 3. On construction of drainage, it was involved 3.31% for contractor 11.11%
for contractor 2 and 4.33% for contractor 3.
86
Table 5.8: Cost Distribution on pavement rehabilitation at KLK Highway Based on Site
Activity
Contractor / Cost Contractor 1
Distribution
(RM)
Pavement
22,141,737.84
Pavement
469,474.80
Polymer
Drainage;
2,864,264.00
Others
(Prelim,
900,187.58
VO)
Contractor 2
Contractor 3
(%)
(RM)
(%)
(RM)
(%)
25.56% 15,164,346.87 17.50% 33,904,672.13 39.13%
0.54%
977,925.00 1.13%
834,261.00 0.96%
3.31%
961,577.65 1.11%
3,237,806.75 3.74%
1.04%
1,431,787.00 1.65%
3,747,426.45 4.33%
26,375,664.22 30.44% 18,535,636.52 21.39% 41,724,166.33 48.16%
Total
Total
(Overall)
Cost
86,635,467.07
Others (Prelim, VO)
Drainage;
Total
Others (Prelim, VO)
5%
Drainage;
10%
Pavement - Polymer
15%
Pavement
20%
Others (Prelim, VO)
25%
Drainage;
30%
Pavement - Polymer
Percentage
35%
Total
40%
Pavement
45%
Pavement - Polymer
50%
Pavement
Total
Cost Distribution on Pavement Rehabilitation at KL
Karak Highway (Activity)
0%
Cost Distribution
Figure 5.7 Cost Distributions on pavement rehabilitation at KLK Highway Based
on Site Activity
CHAPTER 6
DISCUSSION OF RESULT
6.1
INTRODUCTION
This chapter explains the results of the study given in chapter 5 based on the
objectives of study. It is also important to discuss the analysis of data in comparison
with the literature. Starting the first objectives, to determine the factor affecting
pavement distress and further discussion as the second objectives to determine the
effectiveness pavement rehabilitation that was conducted in the study.
6.2
To determine sources of pavement distress at Kuala Lumpur Karak
Highway
Based on the case study conducted, three main factors contribute towards of
flexible pavement distress at Kl Karak Hihgway. These factors are water, diesel
spillage and climbing lane area.
88
6.2.1
Water Factor
Water factor is the most important factor. This is related to three primary
sources which were discussed on literature review under chapter 2.2.1.4 and Figure
2.1. The sources are surface infiltration, lateral seepage and high ground water table.
6.2.1.1 Pavement infiltration.
From the data collected as discussed in chapter 5.2.1.1, the high rain factor at
Kl Karak Highway contributes to the damage of flexible pavement. It is found that
difference value to rain distribution is high at Kl Karak Highway compared to the
nearest station. It is shown with the highest ranging from -77.42mm to 1400.58mm. In
view of percentage it is distributes from (77.42/2417.83) 3.20% to (1400.58 /
2417.83) 57.90%.
It is show that the infiltration was high. The high of water infiltration entered
the pavement subgrade which it can weaken the layer. As a result, this weaken of
subgrade deteriorate the damage until ACWC layer. Chapter 2.4.1, 2.4.5 and 2.4.6
described clearly on this contribution to damaged pavement.
6.2.1.2 Water seepage from increase of water table
As data obtained on chapter 5.2.12, it is found that 69.64% of standpipes
indicate always show the existence of water level from surface ranging 0.210 to
11.250. This high level of water table shows that the water always penetrates until
subgred level. The sub grade refers to the soil under the pavement within depth of
approximately one meter the sub base. The strength of the subgrade layer is important
89
as the thicknesses of the upper layers are dependent on it. Any failure to the sub grade
caused more damaged and deteriorated to pavement distress.
6.2.1.3 Water Seepage from higher level.
From data collected in chapter 5.2.1.3 by using thermograph scanning method,
it is indicate that 70.65% of the total horizontal was always wet. This wet condition is
high and causes road damages easily especially on sub base. This layer serves as a
separating layer preventing contamination of the road-base by the sub grade and also
acts as a preparatory layer for road base.
This component of the pavement layers contribute to failures and caused of
primary failures of the road. Contaminated of sub base with water in flexible
pavement most commonly manifests itself as cracking (2.4.1) or deformation (2.4.2).
6.2.2
Diesel Spillage Factor
Data obtained from chapter 5.2.2 shown that either minor or major spillage
increase from year 2004 until 2006. Minor spillage increased 47.36% for year 2004
compared with year 2005, 71.42% for year 2006 compared with 2005. Major spillage
contributes decreased 37.50 % for year 2005 compared to year 2004 but increased
80.00% at year 2006 compared to year 2005.
From the result in the previous paragraph, diesel spillage is significant to
flexible pavement distress at KL Karak Highway, which has discussed on chapter
90
2.4.2.1; degradation of asphalt due to diesel spills on roads also resulted in
longitudinal cracking and rutting (Brian Balwin, Onuma Carmody and Terry Collins).
6.2.3
Climbing Lane Factors.
Kuala Lumpur Highway is strectch of 16.40 km or which forms of 14.00% the
total highway length. Gradient 3% to 10% caused further defect within a patch can be
where it is raised or depressed below the level of the pavement surface.
Refers to Figure 2.3, deflection will be rebound after the load has been
removed away from the spot. This temporary deflection is usually referred to as the
transient deflection. The bituminous surfacing also suffers from tensile strains at the
bottom and the top of the layer. The road base, the sub base and sub grade are mainly
subjected to compressive stresses. As discussed on chapter 5.2.3, 70.65% of vehicle
stopped and breakdown along this climbing lane in the year 2004, 80.39% in year
2005 and 79.42 % in year 2006. Repeatedly stopped and breakdown vehicle causes
damaged on flexible pavement such as crocodile cracks (refer to chapter 2.4.4.1),
crescent shape cracks (refer to chapter 2.4.1.5), edge cracks (refer to chapter 2.4.1.6)
and corrugations (refer to chapter 2.4.2.2).
6.3
To evaluate the effectiveness of pavement rehabilitation in term of time,
quality and cost at Kuala Lumpur Karak Highway
In order to asses the effectiveness of work that have done, several aspects
should be considered. These aspects or factors are time, quality and cost.
91
6.3.1
Time
From Table 5.4, it is found that the original schedule for pavement
rehabilitation has been changed for contractor 1 when additional or extension of time
given 100%, contractor 2 is 100% and contractor 3 up to 145%. The additional time
given causes delay in pavement rehabilitation. The main reason for delay was human
problems. As discussed on chapter 5.3.1, the main reasons for delay are rain,
additional scope of work, changes of site condition and design factors.
Clearly, having discussed earlier on chapter 3.2, it is very important to select
the appropriate procedures to execute pavement rehabilitation works. The selection
procedure heavily on engineering judgment but other factors such as costs,
construction feasibility, effects on the gridline and the road user are also be
considered as well. Because of that reasons, three stages to be followed, identifying
problems, identifying probable alternatives and selecting the preferred solution.
Consideration should be given to the problems of construction during monsoon
periods, for instance.
6.3.2
Quality
From Table 5.5, it is found that Concessionaire Company has increased
specification or quality conducted during improvement work. During the pavement
rehabilitation works, consultant was produced 38 numbers of non conforming records
during construction; Malaysian Highway Authority has also produced 36 numbers of
non conforming records while concessionaire side produced 37 numbers. There were
found 6 types of pavement distress after rehabilitation works, such as cracks, surface
deformation, surface defects, pothole and edge crack As a whole pavement distress is
92
not entirely from contractor defect list, but is contributed by others factors such as
environmental factor (water) and third party factors (diesel spillage).
Even though Concessionaire Company has increased their level of quality with
produced more on high specification and increased level of supervision and
monitoring with issuing NCR, it is found that the damaged or distress are occurred.
As recorded and agreed between Concessionaire Company and contractors, all those
costs (RM 3,919,000.00) to damaged and distress are not bear by contractor. Again,
the contribute factors to these from problems was due to high water level and diesel
spillage.
6.3.3
Cost
From Table 5.7, it is found that the total cost incurred for original contract was
RM 61,691,302.03 but this amount increased by RM 24,944,165.04. This is increase
of 40.43% and contractor 3 bear the highest increase of 82.49% from total amount. In
view of increasing price of oil world price, it is also found that, Concessionaire
Company has reimbursed variation of price to contractor amounting RM
3,204,306.00. From table 5.8, it also found that, the total cost for construction of
drainage was 8.16 % ACWC with polymer was 2.63% and construction of CBM layer
up ACWC layer was 82.19%.
With these huge of amount, it is indicated that Concessionaire Company was
highly committed to ensure all pavement rehabilitation works are done to be effective
and accordingly.
CHAPTER 7
CONCLUSION AND RECOMMENDATION
7.1
Introduction
This chapter will discuss the conclusion that can be concluded for the
research that had been studied. The achieving of the objectives and recommendation
for the future is the main point to be highlighted here.
7.2
Conclusion and Recommendation
The two main objectives of this study have been successfully achieved. The
first objective was to determine sources of pavement distress at Kuala Lumpur
Karak Highway and secondly to evaluate the effectiveness of pavement
rehabilitation in term of time, quality and cost at Kuala Lumpur Karak Highway
94
Based on this case study conducted, it has been found that there are three (3)
main factors of pavement distress at Kuala Lumpur Karak Highway. It was water
factor, diesel spillage and climbing lane. Water factors are included of water
infiltration, water seepage from increase of water table and water seepage from
higher level. As data collected and obtained, it was shown that all these factors were
significant to pavement distress on KL Karak Highway.
As the second objectives and in order to evaluate the effectiveness of
pavement rehabilitation work that has done, three aspects or factors were
successfully evaluated. These factors or aspects are time, quality and cost.
The study has shown that, during construction pavement rehabilitation
works, extension of time given to contractor was very high for all contractors which
ranging 100% to 145%. On time aspect, this analysis shown that, pavement
rehabilitation works was done is not effectively.
On cost aspect, it shown that during construction, original cost has increased
to 40.43%. The factors of increasing of this amount were contributed by variation
order and variation on price. Variation orders were occurred with reasons of to
ensure rehabilitation works was done accordingly and effectively. Unfortunately,
after rehabilitations works was done, it was founded that the damaged or distress
was occurred which not under contractor responsibilities. Estimates cost to repair
these problems was RM 3,919,000.00 or 6.35 % from the original contract. As
highlighted in previous chapter, the main factor contribute to this problems were
high water table and diesel spillage factors. Therefore, on cost aspect, this analysis
shown that, pavement rehabilitation works was done is not effectively.
Quality aspects shown that, even though three parties was supervised and
monitored, it found that the damaged and distress on flexible pavement were
reoccurred. As discussed on previous paragraph, the costs of remedial works to these
95
problems were 6.35% from the original contract. Therefore, on quality aspect, this
analysis shown that, pavement rehabilitation works was done is not effectively.
Finally, based on the findings of the study it is therefore concluded that the
objective of the study has been achieved. It is also suggested that the finding in this
study to be further digest for considering a few of recommendations.
7.3
Recommendation for Further Study
The study has somehow yielded limited performances of flexible pavement
with the whole picture of the highway. Hence to improve further the study in this
area, it is suggested that further study can be extended to as follows:
a) To expand the whole study to the whole Malaysia highways.
b) Extending the research scope to other important parameters such as
to explore the problems of design, workmanships and traffic
volumes.
c) Extending the research scope by establishing the accurate or
precise scale in determining level effectiveness of flexible
pavement rehabilitation.
d) Extending the research scope by establishing the rate of
deterioration of flexible pavement periodically.
97
REFERENCES
Skokie I.L. (1993). Pavement Rehabilitation Strategy Selection. American Concrete
Pavement Association.
Skokie I.L. (1989). Effect of Pavement Surface Type on Fuel Consumption.
American Concrete Pavement Association.
Brian Balwin, Onuma Carmody and Terry Collins (2004).Degradation of Asphalt
Due to Diesel Spills on Roads. American Concrete Pavement Association.
Caltrans S.L. (2000). Maintenance Technical Advisory Guide (TAG). American
Concrete Pavement Association.
Eaton, R.A. (1992). State of the Art Survey of Flexible Pavement Crack Sealing
Procedures. Ashcraft.
Institut Kerja Raya Malaysia (1992). A Guide to the Visual Assessments of Flexible
Pavement Surface Condition.
Institut Kerja Raya Malaysia (1994). Interim Guide to Evaluation and Rehabilitation
of Flexible Pavements.
Manual for the Long Term Pavement Performance Project Washington, DC, (1993).
Distress Identification.
Poniah, Kennepahl (1995). Crack Sealing in Flexible Pavement, A Life Cycle Cost
Analysis. Washington DC.
98
Transportation Research Board. (1996). Cost Effective Preventive Pavement
Maintenance. Washington DC.