AGGREGATE AND BINDER APPLICATION RATE WITH DIFFERENT
NUMBER OF PASSES FOR SURFACE DRESSING PERFORMANCE
ASHRIF MASOUD A.SAAD
A project report submitted in partial fulfillment of the
requirements for the award of the degree of Master of Engineering
(Civil – Transportation and Highway)
Faculty of Civil Engineering
Universiti Teknologi Malaysia
NOVEMBER 2009
iii
“To my beloved father Masoud Elsaiti and mother,
my lovely brother and my dearest sisters.
For their eternal love, support and encouragement…”
iv
ACKNOWLEDGEMENT
In the name of Allah, Most Gracious, and Most Merciful
Praise be to Almighty Allah (Subhanahu Wa Ta’ala) who gave me the
courage and patience to carry out this work. Pease and blessing of Allah be upon his
last prophet Mohammed (Sallulaho-Alaihe Wassalam) and all his companions
(Sahaba), (Razi-Allaho-Anhum) who devoted their lives towards the prosperity and
spread of Islam.
With utmost respect and pleasure, I would like to express my sincere thanks
and appreciation to my academic supervisor, Dr.Haryati Binti Yaacob, who
continuously guided me throughout every step of my thesis work and generously
shared his time and knowledge with me. I am greatly indebted to him for his
encouragement and incessant help to achieve more than I expected of myself.
My special thanks must be extended to technical staff members at the
Highway & transportation engineering laboratory at UTM for their collaboration.
I would like to express special great words of thanks to my family, who
tirelessly encouraged and supported me in countless ways to pursue my Master's
Degree. Without their sacrifices, understanding and endless care, I would not have
had the opportunity to study in Malaysia and I could never have reached where I am
today.
v
ABSTRACT
Surface dressing is a very useful and cost effective process for restoring skid
resistance to a road surface that is structurally sound. In the new roads adequate
surface texture is designed in the running surface by specifying requirements for both
aggregate properties and texture depth. The objective of this study is look on the
effect of aggregate application rate, binder application rate and number of passes on
surface dressing performance. This study involves 6, 10, and 14mm size of
aggregates. All the aggregates were laid with penetration grade 80-100 bitumen. Skid
resistance and texture depth were measured by British Pendulum Test (BPT) and
Sand Patch Test (SPT). Results were analyzed using analysis of variance (ANOVA)
using (Minitab15) to justify the objectives. The result showed that 14mm generated
higher skid resistance and texture depth.
vi
ABSTRAK
Penggunaan material seperti kain untuk menutup permukaan sangat berguna
dan ini merupakan salah satu kos yang sangat
berkesan untuk memulihkan
runtuhan/regangan yang berlaku terhadap permukaan jalan yang disebabkan oleh
gegaran ke atas struktur binaan . Dalam pembinaan jalan baru, tekstur permukaan
yang cukup baik direka dalam pembinaan permukaan iaitu dengan menetapkan
keperluan untuk kedua-dua agregat pembangunan dan tekstur dalaman. Objektif
daripada kajian ini adalah untuk melihat kesan bagi aplikasi nilai agregat, tahap
aplikasi pengikat dan jumlah keberkesanan atas penggunaan lapisan permukaan.
Kajian ini melibatkan 6, 10, dan saiz 14mm agregat. Semua agregat telah dibebankan
dengan tingkat tekanan 80-100 bitumen. Regangan yang berlawanan dan tekstur
kedalaman diukur oleh British Pendulum Test (BPT) dan Sand Patch Test (SPT).
Keputusan dianalisis dengan menggunakan analisis varians (ANOVA) dengan
menggunakan (Minitab15) untuk mengesahkan tujuan dan objektif kajian. Keputusan
kajian menunjukkan bahawa regangan 14mm yang dihasilkan lebih tinggi dari kalis
regangan dan tekstur kedalaman.
vii
TABLE OF CONTENTS
TITLE
PAGE
CHAPTER
I
II
DECLARATION
ii
DEDICATION
iii
ACKNOWLEDGEMENT
iv
ABSTRACT
v
ABSTRAK
vi
TABLE OF CONTENTS
vii
LIST OF TABLES
x
LIST OF FIGURES
xi
LIST OF SYMBOLS
xiii
LIST OF APPENDICES
xiv
INTRODUCTION
1
1.1
Introduction
1
1.2
Problem Statement
3
1.3
Objectives of Study
4
1.4
Scope of Study
4
1.5
Importance of Study
5
LITERATURE REVIEW
6
2.1
6
2.2
Conventional Bitumen
Surface Dressing
7
viii
2.2.1 Types of Surface Dressing
2.3
9
2.2.1.1 Single Surface Dressing
9
2.2.1.2 Double Surface Dressing
10
2.2.1.3 Inverted Double Surface Dressing
10
2.2.1.4 Sandwich Surface Dressing
11
2.2.1.5 Raked-in Surface Dressing
11
The Advantages and Disadvantages of Surface
12
Dressing
2.3.1 Advantages of Surface Dressing
12
2.3.2 Disadvantages of Surface Dressing
13
Components of Surface Dressing
13
2.4.1 Aggregate
13
2.4.2 Bitumen
15
2.5
Aggregate and Binder Application Rate
16
2.6
Skid Resistance Test
16
2.7
Surface Texture and Skid Resistance
17
2.8
Sand Patch Test
18
2.4
III
METHODOLOGY
20
3.1
Introduction
20
3.2
Material Selection
22
3.2.1 Aggregate
22
3.2.2 Bitumen
23
Wheel Track Test
24
3.3.1 Track Preparation
25
3.3.2 Specimens Preparation
28
3.3
3.3.2.1 Procedure Preparing Surface
28
3.4
Load Applied onto the Track
30
3.5
Skid Resistance Test
31
3.5.1 Procedure of Skid Resistance Test
32
3.5.2 Calculations for Pendulum Test Value
33
Sand Patch Test
34
3.6.1 Procedure of Sand Patch Test
35
3.6
ix
3.7
IV
3.6.2 Calculation for Texture Depth
36
Analysis of Variance (ANOVA) Using Minitab
37
RESULTS AND DISCUSION
38
4.1
Introduction
38
4.2
Pendulum Test Value
39
4.2.1 The effect of Aggregate Application Rate
40
on Pendulum Test Value
4.2.2
The effect of Binder Application Rate
44
on Pendulum Test Value
4.2.3
The effect of Nmber of Passes on
46
Pendulum Test Value
4.3
Sand Patch Test
49
4.3.1
50
The effect of Aggregate Application
Rate on Texture Depth
4.3.2 The effect of Binder Application Rate on
52
Texture Depth
4.3.3
The effect of Number of Passes on
54
Texture Depth
4.4
V
Analysis of Variance (ANOVA) using Minitab
56
CONCLUSION
63
5.1
Conclusion
63
5.2
Recommendations
64
REFERENCES
65-66
APPENDICES
67
x
LIST OF TABLES
TITLE
PAGE
Gradation Limits for Bituminous Surface Dressing (JKR,
15
TABLE NO.
2.1
2008)
3.1
Gradation Limits for Bituminous Surface Dressing (JKR,
22
2008)
3.2
Rates of Application of Cover Aggregate (JKR, 2008)
23
3.3
Rates of Application of Penetration Graded Bitumen
23
(JKR, 2008)
3.4
Spraying Temperature for Bituminous (JKR, 2008)
23
4.1
Pendulum Test Values for 14mm, 10mm and 6mm
40
4.2
Summary of equation obtained from PTV vs aggregate
43
application rate
4.3
Summary of equation obtained from PTV vs binder
46
application rate
4.4
Summary of equation obtained from PTV vs number of
49
passes
4.5
Sand Patch Test Values for 14mm, 10mm and 6mm
50
4.6
ANOVA Table for PTV (14mm)
57
4.7
ANOVA Table for PTV (10mm)
58
4.8
ANOVA Table for PTV (6mm)
59
4.9
ANOVA Table for Texture Depth (14mm)
60
4.10
ANOVA Table for Texture Depth (10mm)
61
4.11
ANOVA Table for Texture Depth (6mm)
62
xi
LIST OF FIGURES
TITLE
FIGURE NO.
PAGE
2.1
Single Surface Dressing (TRL, 2002)
10
2.2
Double Surface Dressing (TRL, 2002)
10
2.3
Inverted Double Surface Dressing (TRL, 2002)
11
2.4
Sandwich Surface Dressing (TRL, 2002)
11
2.5
Racked-in Surface Dressing (TRL, 2002)
12
2.6
Pendulum Skid Resistance Tester
17
2.7
Microtexture and Macrotexture
18
2.8
The apparatus and element used on Sand Patch Test
19
2.9
Sand-patch method of measuring texture depth
19
3.1
Laboratory Test Flow Chart
21
3.2
Shows Wheel Track Makmal Pengangkutan,
24
Universiti Teknologi Malaysia, Skudi
3.3
Shows dial gauge for speed
25
3.4
Shows single wheel track with variable imposed
25
load range from 80 kg to 180 kg
3.5
Shows marking are made at the edges of the track
26
3.6
ACW14 is obtained from the batching plant
27
3.7
Premix is laid manually using a wheelbarrow
27
3.8
Compaction is carried out using a compactor
28
3.9
The Coarse Aggregates (14, 10,6mm)
29
3.10
Divide the wheel track path to 27 samples
29
(80cmx100cm)
3.11
The aggregates are spread on the penetration
30
xii
bitumen
3.12
Steel Roller Compactor
30
3.13
Portable Skid Resistance Tester
32
3.14
The apparatus and elements used on Sand Patch Test
34
3.15
Spreading the sand into circle shape
35
4.1
PTV vs Aggregate Application Rate for 14mm
41
4.2
PTV vs Aggregate Application Rate for 10mm
42
4.3
PTV vs Aggregate Application Rate for 6mm
43
4.4
PTV vs Binder Application Rate for 14mm
44
4.5
PTV vs Binder Application Rate for 10mm
45
4.6
PTV vs Binder Application Rate for 6mm
45
4.7
PTV vs Number of Passes for 14mm
47
4.8
PTV vs Number of Passes for 10mm
48
4.9
PTV vs Number of Passes for 6mm
48
4.10
MTD vs Aggregate Application Rate for 14mm
51
4.11
MTD vs Aggregate Application Rate for 10mm
51
4.12
MTD vs Aggregate Application Rate for 6mm
52
4.13
MTD vs Binder Application Rate for 14mm
53
4.14
MTD vs Binder Application Rate for 10mm
53
4.15
MTD vs Binder Application Rate for 6mm
54
4.16
MTD vs Number of Passes for 14mm
55
4.17
MTD vs Number of Passes for 10mm
55
4.18
MTD vs Number of Passes for 6mm
56
xiii
LIST OF SYMBOLS AND ABBREVIATIONS
ACW14
-
Asphalt Concrete Wearing Course with Nominal
Maximum Aggregate size of 14mm
AASHTO
-
American
Association
of
Transportation Officials
JKR
-
Jabatan Kerja Raya
HMA
-
Hot Mix Asphalt
UTM
-
Universiti Teknologi Malaysia
BPT
-
British Pendulum Tester
BPN
-
British Pendulum Number
PTV
-
Pendulum Test Value
SRV
-
Skid Resistance Value
SPT
-
Sand Patch Test
MTD
-
Mean Texture Depth
ANOVA
-
Analysis of Variance
State
Highway
and
xiv
LIST OF APPENDICES
APPENDIX
TITLE
PAGE
1
Sand Density and Volume Calculation
68
2
Analysis of Variance using Minitab 15
69
3
Pictures of Laboratory Testing
87
CHAPTER I
INTRODUCTION
1.1 Introduction
Bitumen has been use for various purposes including road making, however,
Gorman et al., (2004) (8) traced the use of bitumen in a range of applications,
including mummifying the dead and as a waterproofing agent, to over 5000 years.
Now, the main use of bitumen is in the road making industry for construction and
maintenance. In road making, bitumen products are typically applied with mineral
aggregate. The strong adhesion that occurs between the bitumen and mineral
aggregate enables the bitumen to act as a binder, with the mineral aggregate
providing mechanical strength for the road. Bitumen is difficult to work with at
ambient temperatures since it is a highly viscous material under these conditions. It
can, however, be transformed into a workable state by either applying heat (hot
mixes), by blending with petroleum solvents (cutback mixes) or by emulsification
with a surfactant in water to form a bitumen emulsion.
Surface dressing is still one of the most economical and versatile surfacing
options, and properly applied using advanced binders, a highly cost-effective
2
solution. It is potentially suitable for all classes of road. Though it cannot strengthen
the highway or correct its profile, surface dressing does seal the surface against
ingress of water, while its chippings provide a skid-resistant surface. Using naturalcoloured aggregates, such as gravels, provides an attractive finish.
Surface dressing is an established, proven process. It is the most cost-effective
surface maintenance treatment when properly designed, specified and executed.
Developments in surface dressing materials, techniques and equipment mean
that problems of which it is often accused can be minimized or eliminated. Unless
the amount of surface dressing is increased our roads will continue to deteriorate.
This will result from the lack of sealing of the surface and less roads being treated
because of higher alternative costs and financial constraints on budgets (United
Kingdom Road dressing Association, 2005).
United Kingdom Road dressing Association, (2005) stated the following reasons for
which Surface Dressing is done
i.
To seal the road surface against ingress of water.
ii.
To arrest the deterioration of the road surface.
iii.
To provide a skid resistant road surface with the resultant benefits of
reduction in accidents.
iv.
To reduce spray.
v.
To maximize the cost effectiveness of limited highway maintenance funds.
Surface dressing if required before the road surface deteriorates to the stage at
which expensive major patching and/or reconstruction is required. It is also required
before surface skidding levels fall below the nationally accepted level for the class of
road in question. All classes of road, from single track, unclassified roads and
footpaths to national high speed motorways can and have been successfully treated
Regarding the Environmental consideration, Surface dressing minimizes the use of
3
scarce national aggregate resources - all the stone used is in direct contact with the
tyre of the motorist, not buried below the road surface, Accident levels will be
reduced, and proper attention to detail can minimize the surface use noise (United
Kingdom Road dressing Association, 2005).
Normally, surface dressing requires a high quality of workmanship and materials.
Binder is heated in and applied by a distributor. Good quality chippings, in terms of
grading, shape, cleanliness and hardness, are applied by a purpose made spreading
device. However, surface dressing can be done by labour based methods but it is
usually not of high quality. It can be relatively expensive unless suitable gravel,
which can be easily screened, is available locally. For the trials, locally available
hand-crushed rock could be easily screened to give two nominal sizes of aggregate.
Dust in the smaller sized chippings was removed by manual segregation. Washing
with river water could have been carried out had this been necessary (Akpokodje and
Hudec 1992) (4).
1.2 Problem Statement
Surface dressing is one of the oldest and most widely used forms of treatment
used in highway surfacing. In its simplest form it involves spraying a coat of bitumen
to seal the existing road surface from the ingress of water followed by the application
of aggregate to provide a texture surface for wet skid resistance. This simple process
has steadily evolved over the years with the use of conventional binders and differing
applications of aggregate sizes. A growing number of performance expectations now
influence the choice of surfacing materials. However, because the decorative
aggregate is just the depth of a single layer of stones, any loose aggregate might be
flicked out by wear or trafficking. Aggregate should not be so small that they are
rapidly embedded into the underlying surface or too large that may they be dislodged
by traffic. They should have strength characteristics and resistance to polishing
4
appropriate to the road being surface dressed. The problem statement is thus what
effect does size of aggregate and binder application rate of the performance of
surface dressing.
1.3 Objectives of Study
The objectives of this study are as follows:i.
To look on the effect of aggregate application rate, binder application rate and
number of passes on skid resistance and Texture Depth,
ii.
To select and recommend the best application rate of aggregate and binder.
1.4 Scope of Study
This research will focus on three sizes of aggregate, 14mm 10mm and 6mm
aggregate. Study on types of such aggregate is outside the scope of this research.
Among the types of binders available, the research will use conventional 80/100
penetration grade bitumen binder and the surface dressing to be applied will be in
accordance with JKR/SPJ/2008(15). The entire test is conducted at Makmal
Pengangkutan, UTM Skudai.
5
1.5 Importance of Study
Both laboratory and field studies have shown that laterite aggregates are not
inert. During construction and in service, laterite gravels are subject to mechanical
degradation and to chemical and mineralogical changes under adverse drainage
and/or environmental conditions. Like most other geologic materials, the mechanical
strength and durability of concretionary laterite gravels depend on a combination of
several complex factors, the most important ones being texture, structure, hardness,
and chemical/mineralogical composition. Although some general statements on the
relations between these factors and the strength/durability of concretionary laterite
gravels have been made, the relative importance of each factor has not been properly
defined (Akpokodje and Hudec 1992) (4).
The research will contribute to the body of knowledge in relation to the effect of
size of aggregate to the application rate of binder in single surface dressing.
CHAPTER II
LITERATURE REVIEW
2.1 Conventional Bitumen
Bitumen or asphalt is obtained by the distillation of crude petroleum using
different refining techniques. The main use of bitumen is as a binder in the
production of Hot Mix Asphalt (HMA) which is used in the construction of
bituminous roads or more commonly known as flexible pavement. Currently,
bituminous surfacing in Malaysia use primarily the conventional 80/100 penetration
grade bitumen binder. The bitumen is normally mixed with hot aggregates to produce
the Hot Mix Asphalt.
Bituminous surfacing in Malaysia is exposed to hot and humid climate
throughout the year. High pavement temperatures and moisture level pose big
challenges to road engineers to design and construct good, safe and long lasting road.
Premature failures of pavements associated with cracking and rutting are very serious
problems not only to highway authorities in terms of maintenance but also to road
user in terms of safety and comfort. Traffic growth in Malaysia continues to be very
high, leading to increased demands on road surfacing. Higher traffic volume and axle
loads emphasize the need for binders with improved performance. One of the ways to
7
enhance the performance of bituminous binders is to incorporate a suitable additive
such as polymeric materials into the plain bitumen (Petronas.com).
Binder An adhesive used to hold aggregate together in a coherent mass or, as in a
surface dressing, to stick chippings to a road surface or to coat chippings used in
surface dressing or scattered on the surface of a wearing course. Bitumen A product
of the oil refinery process that is usually stored at approximately 150°C to maintain it
in a liquid form. Used in asphalt and spray seal applications.
2.2 Surface Dressing
Surface dressing is a treatment process used to protect and extend the life of our
roads, bitumen, usually in the form of an emulsion, is sprayed onto the road surface
at an appropriate rate from the spray bar at the rear of a large tanker containing the
bitumen emulsion, or cutback bitumen. Chippings of an appropriate size are
immediately applied to the bitumen by a large spreader which usually tows behind it
a lorry containing the chippings. The lorry being backed onto the spreader hopped.
Surface dressing is the renewal of the surface of a minor road by the spreading of
chippings on to a film of bitumen coating the previous surface; it is a Wearing
Surface consisting of a layer of chippings or gravel on a thin layer of fresh road tar or
bitumen. The object of surface dressing is to create a stable mosaic of chippings
securely attached to the road surface. This is achieved by spraying the correct amount
of bitumen onto the road surface followed by the appropriate amount of the correct
size of chippings.
8
For a structurally–sound road, one of the most cost effective ways to restore its
skid resistance is the application of surface dressing. Surface dressing consist of
spraying a thin film of binder onto the road followed by the application of one or two
layers of stone aggregates.
The aggregate are then rolled to promote contact between the aggregate and
binders and to initiate the formation of an interlocking mosaic. The factors which
influence the performance and the service life of a surface dressing are traffic,
existing road surface, size and type of aggregate, binder, rate of application and
environmental condition.
The function of binder is to seal crack and bind the aggregate to the underlying
surface. The viscosity of the binder must be such that it can wet the aggregate
adequately at the time of application. Dislodgment of aggregate must be prevented
when the road is open to traffic and become brittle during period of prolonged low
temperature and function effectively for its design life.
The rate of spread of binder has to be such that there is sufficient binder to retain
aggregate during early life of dressing, without filling a proportion of the void in the
layer of aggregate in excess of the required to ensure adequate surface texture depth
during the life of the dressing (Hunter and Telford, 1994) (11).
The hardness of the road surface affects the extent to which the applied aggregate
becomes embedded into the road surface during the dressing. Choice of aggregate is
directly related to road hardness. The use of aggregate which are too small will result
in early embedment of the aggregate in to the surface leading to a rapidly loss of
texture depth and the worst case fatting up of binders over the entire surface of the
road. The use of aggregate which are too large may result in immediate failure to the
treatment due to the stripping of the aggregate under the applied stress of the traffic
9
and can also result in excessive surface texture and consequent noise. The hardness
of the surface also influences the rate of application of binder required for a given
size of aggregate; the rate of application must be decreased where the road surface is
shift to compensate for the greater penetration of the aggregate into the surface under
the action of traffic (Hunter and Telford, 1994) (11).
2.2.1
Types of Surface Dressing
There are several types of surface dressing systems which vary according to
the number of layers of chippings and binders applied (O'Flaherty and Boyle, 2002)
(2):
2.2.1.1 Single Surface Dressing
The single surface dressing system is still the most widely used and cheapest
type of surface dressing. It consists of a single application of a binder followed by a
single application of chipping. Its advantages are that it has the least number of
operations, uses the least amount of material and is sufficiently robust for minor
roads and some main roads where excessive braking and acceleration are unlikely to
occur and where speeds are unlikely to exceed 100km/h.
10
Figure 2.1: Single Surface Dressing (TRL, 2002)
2.2.1.2 Double Surface Dressing
This is similar to the single system, but uses two applications of binders and
chippings. The first application contains large chippings while the second contains
smaller one. It is used on main roads as an alternative to the racked-in system to
provide a mechanically strong dressing with a texture that is marginally less than a
racked-in dressing, and therefore quieter. The method is also suitable for minor roads
that have become very, dry and lean in binder.
Figure 2.2: Double Surface Dressing (TRL, 2002)
2.2.1.3 Inverted Double Surface Dressing
This is essentially a single surface dressing system with small (usually 6mm)
size chipping. It is usually applied to porous, hungry, hard or uneven roads to
produce a more uniform surfacing which can be subsequently surfaced dressed. This
technique is appropriate for use on minor concrete roads where chipping embedment
does not occur and surface texture is not an important issue or on sections of road
that have been widely patched.
11
Figure 2.3: Inverted Double Surface Dressing (TRL, 2002)
2.2.1.4 Sandwich Surface Dressing
Sandwich surface dressing is used in situations where the road surface
condition is very rich in binder. Sandwich dressings can be considered as double
dressings in which the first binder film has already been applied. The degree of
binder richness at the surface has to be sufficient to hold the first layer of chippings
in place until the remainder of the operation has been completed. The sizes of the
chippings must be chosen such that they are appropriate for the quantity of excess
binder on the surface and the rate of application of the second coat of binder.
Figure 2.4: Sandwich Surface Dressing (TRL, 2002)
2.2.1.5 Racked-in Surface Dressing
Where the existing road surface is very hard or porous with high or variable
macro-texture, a first dressing using small chippings (6mm) can be made to provide a
uniform softer surface to which the main dressing is applied.
12
Figure 2.5: Racked-in Surface Dressing (TRL, 2002)
2.3 The Advantages and Disadvantages of Surface Dressing
There are a lot of advantages and disadvantages of surface dressing
2.3.1
Advantages of Surface Dressing
i.
Restores a good resistance to skidding on smooth or slippery roads.
ii.
Prevents water from seeping into the road foundation and weakening it,
reducing the chances of potholes developing and delaying the need for
complete rebuilding of a road.
iii.
Up to ten times cheaper than other methods of restoring road surfaces.
iv.
Traffic can be allowed to run on the new surface almost immediately,
avoiding lengthy closures and disruption.
v.
The speed with which it can be laid reduces delays to traffic.
13
2.3.2
Disadvantages of Surface Dressing
1. Drivers need to travel very slowly on the newly laid surface to prevent
chippings being dislodged.
2. Inconsiderate drivers travelling above the recommended speed cause
chippings to be thrown up which can damage other vehicles and property.
2.4 Components of Surface Dressing
There are two types of materials used for surface dressing which are
aggregate and bitumen
2.4.1
Aggregates
Although surfacing aggregate account for only a small proportion of the total
road construction, they form a significant part of the total cost. Should they fail
prematurely, the engineer is left with a road which, although may be structurally
sound, has a surface not capable of providing the necessary level of performance to
ensure adequate safety for the public. To limit their premature failure, specifications
impose more stringent than for any other layer. Generally, surfacing aggregate are
required to be clean, hard and durable, posses properties which provide the minimum
level of skid and abrasion-resistance and provide an adhesive bond with bitumen
(Nicholls, 1998) (1).
14
For single bituminous surface dressing the cover aggregate shall be nominal
14mm, 10mm and 6mm size chippings. Cover aggregate shall be screened, crushed
stone and shall comprise clean, dry, hard, tough, sound, angular and cubical
chippings free from vegetative and other organic matter, clay and other deleterious
substances, and containing few, if any, flaky or elongated particles. Dusty chipping
shall be washed clean, all to the satisfaction of the S.O. Cover aggregates shall
conform to the following physical and mechanical requirements:
i.
Using the type of bituminous material to be used in the works, treated with
additive if so required, the coated area in coating and stripping test for
bitumen aggregate mixtures, AASHTO Test Method T 182, shall not be less
than 95%;
ii.
The aggregate crushing value when tested in accordance with M.S.30 shall be
not more than 30;
iii.
The weighted average loss of weight in the sodium sulphate soundness test
(5cycle) when tested in accordance with AASHTO Test Method T 104 shall
be not more than 12%;
iv.
The flakiness index when tested in accordance with M.S>30 shall be not more
than 25;
v.
The polished stone value when tested in accordance with M.S. 30 shall be not
less than 40;
vi.
The gradation shall conform to the appropriate envelope shown in Table 2.1.
15
Table 2.1: Gradation Limits for Bituminous Surface Dressing (JKR, 2008)
B.S.
Sieve Size
2.4.2
% Passing By Weight
Nominal
Nominal
Nominal
14 mm
10 mm
6 mm
Chipping
Chipping
Chipping
20.0 mm
100
-
-
14.0 mm
85 – 100
100
-
10.0 mm
0 – 20
85 – 100
100
6.3 mm
-
0 – 20
85 – 100
4.75 mm
0–5
0 – 10
0 – 25
2.36 mm
0-2
0-2
0 - 10
Bitumen
Bituminous binder for bituminous surface dressing shall be penetration
graded bitumen, or cut-back bitumen, or bitumen emulsion
i.
Penetration graded bitumen shall be 80-100 grade conforming to M.S.
124 (JKR, 2008) (15).
ii.
Cut-back bitumen shall be grade RC-70 or MC-70 conforming to M.S.
159 (JKR, 2008) (15).
iii.
Bitumen emulsion shall be rapid setting of grade RS-1, RS-1K, RS-2,
RS-2K or RS-3K conforming to M.S. 161. The grade of emulsion
selected shall be anionic or cationic as appropriate to the type of rock
from which the cover aggregate is derived, and shall be approved by
the S.O. (JKR, 2008) (15).
16
2.5 Aggregate and Binder Application Rate
Large size aggregate require additional binder to achieve the optimum
embedment. The design binder application rate is calculated after considering a
number of correction features or allowance to the basic binder application rate.
Typical adjustments are based on traffic characteristics, surface texture, aggregate
absorption characteristics and surface hardness. Typically, binder application rate are
reduce where large traffic volume are expected to considerably reorient and embed
the aggregate after final rolling. The binder application rate may also be adjusted
depending on the exiting surface texture. It is necessary to increase the application
rate on pocked, porous, or oxidized surface because such texture will absorb more
binder (Gransberg et al., 2005) (3).
2.6 Skid Resistance Test
The resistance of wet road surfaces to skidding can be checked by means of a
Portable Skid-resistance Tester (Portable Pendulum Tester). This apparatus is used to
measure the frictional resistance between a rubber slider (mounted on the end of a
pendulum arm) and the road surface. This method provides a measure of frictional
property, microtexture of surfaces, either in the field or in the laboratory.
17
Figure 2.6: Pendulum Skid Resistance Tester
2.7 Surface Texture and Skid Resistance
The skidding resistance of a road surface is determined by two basic
characteristics, the microtexture and macrotexture, as shown in Fig. 2.7. Microtexture
is the surface texture of the aggregate. A significant level of microtexture is
necessary to enable vehicle tyres to penetrate thin films of water and thus achieve dry
contact between the tyre and the aggregate on the carriageway. Macrotexture is the
overall texture of the road surface. An adequate value of macrotexture is necessary to
provide drainage channels for the removal of bulk water from the road surface.
18
Figure 2.7: Microtexture and Macrotexture
2.8 Sand Patch Test
This test method is suitable for field tests to determine the average macrotexture
depth of a pavement surface. The knowledge of pavement macrotexture depth serves
as a tool in characterizing the pavement surface texture. It uses a volumetric
approach of measuring pavement macrotexture. In this study a known volume of
glass beads is spread evenly over the pavement surface to form a circle, thus filling
the surface voids with glass beads. The diameter of the circle is measured on four
axes and the value averaged. This value is then used to calculate the mean texture
depth (MTD).
19
Figure 2.8: The apparatus and element used on Sand Patch Test
Figure 2.9: Sand-patch method of measuring texture depth
CHAPTER III
METHODOLOGY
3.1 Introduction
Research methodology is very important to look on the effect of different
aggregate and binder application rate on surface dressing performance with
difference sizes of aggregates. A sample from 14mm aggregate with an application
rate of aggregate 12 kg/𝑚𝑚2 with binder application 1.5 liters/𝑚𝑚2 will be made; it will
be followed by another sample of 10mm aggregate with an application rate 8 kg/𝑚𝑚2
with 1..3 liters/𝑚𝑚2 . The same procedure will be repeated for 6mm with application of
5 kg/𝑚𝑚2 with 1.1 liters/𝑚𝑚2 . Such as:
i.
Prepared 27 specimens with different size of aggregates in each specimen;
ii.
British Pendulum Test is used to measure the skid resistance; and
iii.
Sand Patch Test is used to measure the texture depth.
21
Track Preparation
AC14 used for the base (5cm)
Divide the wheel track path to 27
Specimens (80cm * 100cm)
Prepared Single Surface Dressing 27 Specimens with (6, 10 and 14 mm) size of
aggregate with binder (pen 80/100), surface dressing design to be used (JKR/SPJ/2008)
14 mm
10 mm
6 mm
Appl. of Aggregate 12–18
kg/ 𝑚𝑚2
Appl. of Binder 1.5–1.7
liters/𝑚𝑚2
Appl. of Aggregate 8–12
kg/ 𝑚𝑚2
Appl. of Binder 1.3–1.5
liters/𝑚𝑚2
Appl. of Aggregate 5–8
kg/ 𝑚𝑚2
Appl. of Binder 1.1–1.3
liters/𝑚𝑚2
No of passes 50, use self weight of the wheel 80 kg and use Dial Gauge 6
British Pendulum Test is used to
measure the skid resistance (PTV)
Sand Patch Test is used to measure the
texture depth (MTD)
This procedure continued till
250 passes
Data Analysis
Conclusion and Recommendation
Figure 3.1:
Laboratory Test Flow Chart
22
3.2 Material
There are two types of materials used to produce the road surface dressing
specimens in the laboratory. The materials used are:
i.
Aggregate; and
ii.
Bitumen.
3.2.1
Aggregate
The size of aggregates used to construct the sample specimens in the
laboratory are 14 mm, 10mm and 6 mm. all of the aggregates will be laid with
penetration grade bitumen 80/100. Table 3.1 shows the gradation limits for
bituminous surface dressing and 3.2 shows the rates of application of cover aggregate
cover (JKR, 2008) (15).
Table 3.1: Gradation Limits for Bituminous Surface Dressing (JKR, 2008)
B.S.
Sieve Size
% Passing By Weight
Nominal
Nominal
Nominal
14 mm
10 mm
6 mm
Chipping
Chipping
Chipping
20.0 mm
100
-
-
14.0 mm
85 – 100
100
-
10.0 mm
0 – 20
85 – 100
100
6.3 mm
-
0 – 20
85 – 100
4.75 mm
0–5
0 – 10
0 – 25
2.36 mm
0-2
0-2
0 - 10
23
Table 3.2: Rates of Application of Cover Aggregate (JKR, 2008)
Nominal Size of Aggregate (mm)
Rate of Application
14
12 – 18 kg/𝑚𝑚2
10
6
3.2.2
8 – 12 kg/𝑚𝑚2
5 – 8 kg/𝑚𝑚2
Bitumen
The bitumen for laid aggregates is penetration bitumen used is grade 80/100.
Table 3.3 shows the rates of application of Penetration Graded Bitumen. The
temperature of the bituminous material shall be maintained during spraying
operations within the appropriate range given in table 3.4 (JKR, 2008) (15).
Table 3.3: Rates of Application of Penetration Graded Bitumen (JKR, 2008)
Nominal Size of Aggregate (mm)
Rate of Application of Penetration
Graded
14
10
6
1.5 – 1.7 liters/𝑚𝑚2
1.3 – 1.5 liters/𝑚𝑚2
1.1 – 1.3 liters/𝑚𝑚2
Table 3.4: Spraying Temperature for Bituminous (JKR, 2008)
Bituminous Material
Spraying Temperature
80 – 100 penetration grade bitumen
150 ∁° to 165 ∁°
Cut-back bitumen grade RC-70 or MC70
Bitumen emulsions
50 ∁° to 65 ∁°
25 ∁° to 45 ∁°
24
The type of surface dressing used in this research was the Single Surface
Dressing. And Surface dressing design to be used is JKR / SPJ / 2008(15). ACW14
used for the base.
Three types of test will be conducted on each of the 6, 10, and 14mm aggregate.
The types of test to be conducted are:-
3.3 Wheel Track Test
Wheel track used in this study has a width of 919 mm and a total length of 22.6
m .Calibration work is carried out to obtain speed for each dial number with variable
imposed load. The imposed load implied varies from 80 kg (self weight of the wheel)
to 180 kg.
Figure 3.2: Shows Wheel Track Makmal Pengangkutan,
Universiti Teknologi Malaysia, Skudi
25
Figure 3.3: Shows dial gauge for speed
Figure 3.4: Shows single wheel track with variable imposed
load range from 80 kg to 180 kg
3.3.1
Track Preparation
Design mixes is used in this study namely ACW14. 100% of this track was
laid with ACW14. Marking were made to the entire track so that the premix can be
laid uniformly. Uncompacted premix height was 60mm at all straight stretches of the
track whereas at corners the uncompacted premix height varies from 60mm to 70mm
26
to take consideration of superelevation. Final thickness of the pavement was 50mm
at straight stretches whereas at the corners the pavement thickness varies from 50mm
to 60mm. ACW14 was obtained from the batching plant. Premix laying was carried
out manually and a compactor machine was used to achieve proper compaction of
the asphalt.
Figure 3.5: Shows marking are made at the edges of the track
27
Figure 3.6: ACW14 is obtained from the batching plant
Figure 3.7: Premix is laid manually using a wheelbarrow
28
Figure 3.8: Compaction is carried out using a compactor
3.3.2
Specimens Preparation
27 specimens are prepared where each of the specimens is consisted of
different size of aggregates, different aggregate and binder application rate. The area
of each sample is 80cm x 100cm so that it is easier to conduct the skid resistance and
texture depth test.
3.3.2.1 Procedure Preparing Surface Dressing Specimen
i.
The aggregates are placed in the oven 24 hours.
ii.
Prepared pen 80/100 bitumen and placed it in the oven and hated it until 150
iii.
∁° - 165 ∁° .
The hot aggregates are then removed from the oven.
iv.
The mould is made up of wheel track with area 80cm x 100cm.
v.
After that the aggregates are spread on the penetration bitumen and rolled
with steel roller.
29
vi.
The procedure is repeated with difference size of aggregates.
Figure 3.9: The Coarse Aggregates (14, 10,6mm)
Figure 3.10: Divide the wheel track path to 27 samples
(80cmx100cm)
30
Figure 3.11: The aggregates are spread on the penetration bitumen
Figure 3.12: Steel Roller Compactor
3.4 Load Applied onto the Track
Load imposed by the wheel track on the pavement is as follows:
Total weight imposed on the pavement = 80kg
The weight is converted to KN as follows;
𝑚𝑚
(80kg/1000)∗ 10 𝑠𝑠 2 = 0.8 𝐾𝐾𝐾𝐾/𝑡𝑡𝑡𝑡𝑡𝑡𝑡𝑡
(Equation 3.1)
31
3.5 Skid Resistance Test
The portable Skid Resistance Tester SRT (also known as the "Pendulum Tester")
gives information on the pavement grip of the examined surfaces through checking
the resistance to skidding of wet road surface. This test is based on BS EN 130364:2003.
This apparatus is used to measure the Polished Stone Value (PSV, which is a
value of an individual aggregate, found by subjecting the aggregate to a standard
polishing process and then testing the aggregate with SRT) and the Skid Resistance
Value (SRV, which is the value obtained from the actual road surface, measured
using the SRT). This method provides a measure of the frictional property, and the
microtexture of surfaces, either in the field or in the laboratory.
The measurement of the frictional resistance occurs between a rubber slider
(mounted at the end of a pendulum arm) and the surface of the specimen (piece to be
inspected). Figure 3.13 shows the Portable Skid Resistance Tester which will be
used in this study.
32
Figure 3.13: Portable Skid Resistance Tester
3.5.1
Procedure of Skid Resistance Test
Following are the procedure to perform the Pendulum Test Value:
i.
Firstly the test surface shall be brushed free of loose particles and flushed
clean with water. Make sure also the surface shall be free of any particle.
ii.
Place the Pendulum Tester upon a firm surface with the pendulum swinging
in the direction of traffic.
iii.
Measure the temperature of the wetted test surface and the slider to the
nearest whole number. If the surface temperature is outside the range 1 ∁° to
iv.
40 ∁° the test cannot carried out.
v.
Then raise the axis of suspension of the pendulum for the arm swings freely.
Adjust the leveling screws to make the pendulum support column in vertical.
Adjust the friction in the pointer mechanism until the pointer arrive zero
position on the test scale.
vi.
Adjust the height of the pendulum arm so that in traversing the surface the
rubber slider is in contact with it over the whole width of the slider and over
33
the length below. A pointer fixed to the foot of the assembly and a permarked gauge shall be used.
vii.
The surface and the slider is wet with a clean water and be careful not to
disturb the slider from its set position.
viii.
Then using the holding button, the pointer and the pendulum released from
horizontal position. Catch the pendulum arm on the early portion of the return
swing and record the position of the pointer on the scale to the nearest whole
number. The pendulum and pointer returned to the release position by raising
the slider using the lifting handle.
ix.
This procedure performs for five times and re-wetting the surface copiously
just before releasing the pendulum.
x.
3.5.2
The reading recorded.
Calculations for Pendulum Test Value
Calculate the PTV as the mean of five swings using the formula:
PTV =
∑(V1 + V2 + V3 + V4 + V5 )�
5
Where:
𝑉𝑉1 to 𝑉𝑉5 are individual values for each swing.
(Equation 3.2)
34
3.6 Sand Patch Test
The sand patch test is a quick on-site method to measure the texture depth of any
surface to ensure skid resistance is achieved. This test will be based on British
Standards (BS EN 13036-1:2002).On coated macadam the choice of material in
relation to aggregate size and grading helps to achieve the texture depth required.
On asphalt surfaces using finer graded materials the texture depth is achieved by
application the test is carried out on a dry surface by pouring a known quantity of
sand onto the surface and spreading it with the wooden disc in a circular area. When
the sand spreads no further all the voids are filled and the dividers used to measure
the diameter of the circle to the nearest millimeter. The mean average is then
calculated and the tables provided used to determine texture depth. A texture depth
of about 1.5mm is normally required for heavily trafficked areas.
Figure 3.14: The apparatus and elements used on Sand Patch Test
35
Figure 3.15: Spreading the sand into circle shape
3.6.1
Procedure of Sand Patch Test
i.
The first step is inspecting the pavement surface to be measured and
select a dry and homogeneous area. The area must be no having any
cracks and joints.
ii.
Then clean the test surface using the stiff wire brush first and followed by
soft bristle brush to remove any residue, debris or loosely bonded
aggregate particles from the surface.
iii.
The portable windshield must be place around the surface area.
iv.
The cylinder filled with the known volume of dry material and gently taps
the base of the cylinder several times on a rigid surface. Add more
materials to fill the cylinder to the top, and level with a straightedge. If a
laboratory balance is available, determine the mass of material in the
cylinder and use this mass of materials sample for each measurement.
v.
The sand in the cylinder poured to the cleaned test surface. Then spread
the materials carefully into a circular patch, with the disc tool, rubber –
covered side down, filling the surface voids flush with the aggregates
particle tips. Use a slight pressure on the hand, just enough to ensure that
36
the disc will spread out the materials so that the disc touches the surface
aggregate particle tips.
vi.
The diameter of the circular area covered with the sand is measured and
recorded with a minimum of four equally spaced locations around the
sample circumference.
vii.
3.6.2
The average diameter is calculated and recorded.
Calculation for Mean Texture Depth
Calculate the internal volume of the sample cylinder as follows:
2
𝑉𝑉 = 𝜋𝜋d h�4
(Equation 3.3)
Where:
V is the internal cylinder volume (𝑚𝑚𝑚𝑚3 );
d is the internal cylinder diameter (𝑚𝑚𝑚𝑚);
h is the cylinder height (𝑚𝑚𝑚𝑚).
Calculate the mean texture depth, MTD, using the following equation:
MTD = 4V�πD2
Where:
MTD is the mean texture depth (𝑚𝑚𝑚𝑚);
(Equation 3.4)
37
V is the sample volume (𝑚𝑚𝑚𝑚3 );
D is the average diameter of the area covered by the sand.
3.7 Analysis of Variance (ANOVA) Using Minitab 15
Analysis of Variance (ANOVA) is a means of evaluating the effect of factors on
a process. The purpose of ANOVA is to test for significant differences between
means. Elementary Concepts provides a brief introduction into the basics of
statistical significance testing. For example, you can use ANOVA to find the optimal
settings for manufacturing equipment, the factor or combination of factors
accounting for production errors, and more.
Minitab's collection of ANOVA capabilities include procedures for choosing
ANOVA models, for fitting MANOVA models (multiple response), and ANOM
models (analysis of means). It also includes graphs for testing equal variances,
confidence interval plots, and graphs of main effects and interactions.
CHAPTER IV
RESULTS AND DISCUSSIONS
4.1
Introduction
The analysis process of all data obtained by the laboratory work has been
discussed in this chapter. British Pendulum Test and Sand Patch Test were carried
out on the specimens to determine skid resistance and the texture depth of the
samples. After the successfull completion of tests, the data was collected and
analyzed which is based on the objectives of this study.
Analysis of this study is focused on the relationship of three different factors
affecting skid resistance and texture depth. The relationship of aggregate application
rate, binder application rate and number of passes are obtained to evaluate the effect
of those three factors on PTV and Texture Depth. Besides that, analysis of variance
(ANOVA) using Minitab 15 is carried out to determine the significant factors for
PTV and Texture Depth.
39
4.2
Pendulum Test Value
The pendulum Test Value is determined by three different independent
variables. The variables are the Aggregate Application Rate, the Binder Application
Rate and the Number of Passes. The Pendulum Test Value is obtained through three
different types of aggregates which were 14mm, 10mm and 6mm. The procedures of
measuring PTV follow the BS standard (BS 13036:2003).
The highest value of Pendulum Test is 117 for the aggregate of 14mm at
application rate of 18 𝑘𝑘𝑘𝑘/𝑚𝑚2 . Binder application rate 1.7 𝑙𝑙/𝑚𝑚2 has been recorded
with 50 passes while the lowest Pendulum Test Value of 81 recorded for 6mm at
aggregate application rate 5 𝑘𝑘𝑘𝑘/𝑚𝑚2 . The binder application rate is 1.2 𝑙𝑙/𝑚𝑚2 with 250
passes. Due to new surface dressing the PTV was reported high ranged at 81 to 117.
The results of skid resistance on the samples are shown in table 4.1.
40
Table 4.1: Pendulum Test Values for 14mm, 10mm and 6mm
Sizes of
Aggregates
(mm)
14
10
6
Application
of Aggregate
(𝑘𝑘𝑘𝑘/𝑚𝑚2 )
12
12
12
15
15
15
18
18
18
8
8
8
10
10
10
12
12
12
5
5
5
7
7
7
8
8
8
Application
of Binder
(𝑙𝑙/𝑚𝑚2 )
1.5
1.6
1.7
1.5
1.6
1.7
1.5
1.6
1.7
1.3
1.4
1.5
1.3
1.4
1.5
1.3
1.4
1.5
1.1
1.2
1.3
1.1
1.2
1.3
1.1
1.2
1.3
No. of Passes
100 150 200
Pendulum Test Value
112
111 109 108
112
111 110 107
111
110 109 107
114
112 111 109
114
113 112 110
113
112 110 110
115
114 113 111
117
116 114 112
117
116 115 113
97
96.8 94
93
97
96
95
92
96
95
93
92
98
97.4 95
94
97.2
97
96
94
98
97
95
93
98
96
95
93
99
97
94
94
99
98
97
95
88
87
85
84
88
86
84
83
87
86
85 84.4
89
89 86.6 85
90
89
86 84.7
91
90
86
85
92
91
87
86
93
91
89
87
93
92
90
88
50
250
106
105
104
107
109
108
109
111
111
91
90
91
92
93
91
92.4
93
93.3
82
81
81.2
83
84
83
84
85.7
86
4.2.1 The effect of Aggregate Application Rate on Pendulum Test Value
Figure 4.1 to Figure 4.3 shows the Pendulum Test Value increase as the
aggregate application rate increase for 14mm, 10mm and 6mm aggregates. The
Pendulum Test Value of the Portable Skid Resistance Tester will increase due to the
increase in microtexture. More so, when the aggregate application rate increases, the
friction area between the slider and road surface of the Pendulum Test Value
increases.
41
The figure below shows the relationship that exists between the Pendulum
Test Value and Aggregate Application Rate which will give a clear picture on the
increases for 14mm.
Figure 4.1: PTV vs Aggregate Application Rate for 14mm
PTV
PTV vs Aggregate Application Rate
(1.7 liters/m^2, 50 passes)
118
117
116
115
114
113
112
111
110
y = 1.25x + 98.667
R² = 0.9643
Series1
Linear (Series1)
0
5
10
15
20
Aggregate Application Rate (kg/m^2)
Figure 4.1 shows that for 14mm the equation is y = 1.25x + 98.667 and 𝑅𝑅 2 =
0.9643, therefore the Pendulum Test Value is directly proportional to the aggregate
application rate. The larger aggregate application rate is reported as 18 𝑘𝑘𝑘𝑘/𝑚𝑚2 with
1.7 𝑙𝑙/𝑚𝑚2 binder application rate have the higher Pendulum Test Value 117.
In the figure below, the relationship that exists between the Pendulum Test
Value and Aggregate Application Rate shows a clear picture on the increases for
10mm.
42
Figure 4.2: PTV vs Aggregate Application Rate for 10mm
PTV
PTV vs Aggregate Application Rate
(1.5 liters/m^2, 50 passes)
99.5
99
98.5
98
97.5
97
96.5
96
95.5
y = 0.9375x + 90.167
R² = 0.9643
Series1
Linear (Series1)
0
5
10
15
Aggregate Application Rate (kg/m^2)
Figure 4.2 shows that for value of 10mm, the equation is y = 0.9375x +
90.167 and 𝑅𝑅 2 = 0.9643, therefore the Pendulum Test Value is directly proportional
to the aggregate application rate. In this case the larger aggregate application rate is
given as 12 𝑘𝑘𝑘𝑘/𝑚𝑚2 with the binder application rate of 1.5 𝑙𝑙/𝑚𝑚2 . It can be seen has the
higher Pendulum Test Value 99.
The figure below shows the relationship that exists between the Pendulum
Test Value and Aggregate Application Rate which will give a clear picture on the
increases for 6mm.
43
Figure 4.3: PTV vs Aggregate Application Rate for 6mm
PTV
PTV vs Aggregate Application Rate
(1.3 liters/m ^2, 50 passes)
94
93
92
91
90
89
88
87
86
y = 2.5x + 77
R² = 1
Series1
Linear (Series1)
0
2
4
6
8
Aggregate Application Rate (kg/m^2)
Figure 4.3 shows that for the value of 6mm the equation is y = 2.5x + 77 and
𝑅𝑅 2 = 1, therefore the Pendulum Test Value is directly proportional to the aggregate
application rate. The larger aggregate application rate is noted as 8 𝑘𝑘𝑘𝑘/𝑚𝑚2 with
binder application rate of 1.3 𝑙𝑙/𝑚𝑚2 have also the higher Pendulum Test Value which
is 93.
Table 4.2: Summary of equation obtained from PTV vs aggregate application rate
•
Size of aggregate (mm)
Linear Equation Obtained
14
y = 1.25x + 98.667
10
y = 0.9375x + 90.167
6
y = 2.5x + 77
Y is Pendulum Test Value dependent to X, the aggregate application rate.
44
4.2.2 The effect of Binder Application Rate on Pendulum Test Value
The binder application rate does not have a clear impact on Pendulum Test
Value due to the binder application rates values for 14mm that were 1.5-1.7 𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙/
𝑚𝑚2 . For 10mm the values were 1.3-1.5𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙/𝑚𝑚2 and finally for 6mm these values
were 1.1-1.3 𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙/𝑚𝑚2 . This shows that no big distinction between the different
binder application rates. The number of passes is not enough to show the effect of
binder application rate on PTV.
The figure below shows the relationship that exists between the Pendulum
Test Value and Binder Application Rate which will give a clear picture on the
increases for 14mm.
Figure 4.4: PTV vs Binder Application Rate for 14mm
PTV vs Binder Application Rate
(18 kg/m^2, 50 passes)
117.5
117
y = 12.5x + 100.33
R² = 0.75
PTV
116.5
116
Series1
115.5
Linear (Series1)
115
114.5
1.15
1.2
1.25
1.3
1.35
1.4
Binder Application Rate (litres/m^2)
The figure below shows the relationship that exists between the Pendulum
Test Value and Binder Application Rate which will give a clear picture on the
increases for 10mm.
45
Figure 4.5: PTV vs Binder Application Rate for 10mm
PTV
PTV vs Binder Application Rate
(12 kg/m^2, 50 passes)
99.4
99.2
99
98.8
98.6
98.4
98.2
98
97.8
y = 6.25x + 91.667
R² = 0.75
Series1
Linear (Series1)
1
1.05
1.1
1.15
1.2
1.25
Binder Application Rate (litres/m^2)
The figure below shows the relationship that exists between the Pendulum
Test Value and Binder Application Rate which will give a clear picture on the
increases for 6mm.
Figure 4.6: PTV vs Binder Application Rate for 6mm
PTV
PTV vs Binder Application Rate
(8 kg/m^2, 50 passes)
93.4
93.2
93
92.8
92.6
92.4
92.2
92
91.8
y = 6.25x + 86.667
R² = 0.75
Series1
Linear (Series1)
0.85
0.9
0.95
1
1.05
Binder Application Rate (litres/m^2)
46
Table 4.3: Summary of equation obtained from PTV vs binder application rate
•
Size of aggregate (mm)
Linear Equation Obtained
14
y = 12.5x + 100.33
10
y = 6.25x + 91.667
6
y = 6.25x + 86.667
Y is Pendulum Test Value dependent to X, the binder application rate.
4.2.3 The effect of Number of Passes on Pendulum Test Value
From figure 4.7 to 4.9, the Pendulum Test Value decrease as the number of
passes increase for 14mm, 10mm and 6mm of the aggregate respectively. The
Pendulum Test Value decrease due the decrease in microtexture value. Skidresistance decreases when the road surface is polished by the traffic. Traffic plays a
very important in the performance of a good surface dressing. The number of wheel
passes has a considerable effect upon the embedment of chipping as shown in the
figure below.
47
Figure 4.7: PTV vs Number of Passes for 14mm
PTV vs Number of Passes
(18 kg/m^2, 1.7 liters/m^2)
118
117
y = -0.03x + 118.9
R² = 0.9698
PTV
116
115
114
113
Series1
112
Linear (Series1)
111
110
0
50
100
150
200
250
300
Number of Passes
The figure above indicates the increase in number of passes which result
to decrease in PTV for 14mm.
In the following figures, the relationship between PTV and Number of
Passes shows the increase in Number of Passes and decrease in PTV for 10mm as
well as 6mm.
48
Figure 4.8: PTV vs Number of Passes for 10mm
PTV vs Number of Passes
(12 kg/m^2, 1.5 liters/m^2)
100
99
y = -0.0288x + 100.78
R² = 0.9766
98
PTV
97
96
95
Series1
94
Linear (Series1)
93
92
0
50
100
150
200
250
300
Number of Passes
Figure 4.9: PTV vs Number of Passes for 6mm
PTV vs Number of Passes
(8 kg/m^2, 1.3 liters/m^2)
94
93
y = -0.034x + 95.1
R² = 0.9633
92
PTV
91
90
89
Series1
88
Linear (Series1)
87
86
85
0
50
100
150
200
Number of Passes
250
300
49
Table 4.4: Summary of equation obtained from PTV vs number of passes
•
4.3
Size of aggregate (mm)
Linear Equation Obtained
14
y = -0.03x + 118.9
10
y = -0.0288x + 100.78
6
y = -0.034x + 95.1
Y is Pendulum Test Value dependent to X, the number of passes.
Sand Patch Test
After the completion of Sand Patch Test, the highest Texture Depth for 14mm
is 4.85mm, for 10mm is 3.8mm and for 6mm it is 3.59mm. This proves that the
macrotexture for 14mm is bigger and rougher than macrotexture of 10mm followed
by macrotexture of 6mm. These results for the Sand Patch Test are also shown in
table 4.2. The sand density and volume calculation was given in Appendix 1.
50
Table 4.5: Sand Patch Test Values for 14mm, 10mm and 6mm
Sizes of
Aggregates
(mm)
14
10
6
Application
of Aggregate
(𝑘𝑘𝑘𝑘/𝑚𝑚2 )
12
12
12
15
15
15
18
18
18
8
8
8
10
10
10
12
12
12
5
5
5
7
7
7
8
8
8
Application
of Binder
(𝑙𝑙/𝑚𝑚2 )
1.5
1.6
1.7
1.5
1.6
1.7
1.5
1.6
1.7
1.3
1.4
1.5
1.3
1.4
1.5
1.3
1.4
1.5
1.1
1.2
1.3
1.1
1.2
1.3
1.1
1.2
1.3
No. of Passes
50
100 150 200 250
Mean Texture Depth (mm)
4.08
4.01 3.94 3.85 3.77
4.01
3.94 3.92 3.77 3.77
4.1
4.1 4.03 3.94 3.85
4.5
4.3 4.12 4.12 4.03
4.4
4.2 4.03 4.12 3.94
4.62
4.3 4.31 4.22 4.03
4.74
4.4 4.42 4.32 4.21
4.74
4.6 4.53 4.32 4.32
4.85
4.75 4.75 4.64 4.42
3.23
3.2 2.88 2.88 2.77
3.4
3.2 3.18 3.06 2.94
3.3
3.2 3.18 3.12 2.94
3.6
3.4 3.25 3.18 3.06
3.6
3.4 3.32 3.18 3.12
3.7
3.52 3.46 3.32 3.18
3.7
3.6 3.46 3.38 3.38
3.8
3.6 3.53 3.38 3.25
3.8
3.85 3.7 3.6 3.53
2.61
2.57 2.49 2.4 2.36
2.66
2.66 2.53 2.4 2.36
2.82
2.71 2.67 2.58 2.49
2.87
2.76 2.78 2.67 2.63
2.93
2.82 2.78 2.63 2.58
3.05
3.05 2.88 2.78 2.72
3.3
3.12 2.94 2.83 2.78
3.44
3.17
3
2.94 2.83
3.59
3.37 3.06 2.94 2.78
4.3.1 The effect of Aggregate Application Rate on Texture Depth
Figure 4.10 to Figure 4.12 shows the Texture Depth increase as the aggregate
application rate increase for 14mm, 10mm and 6mm. Texture Depth increase due to
the increase in macrotexture.
.
51
Figure 4.10: MTD vs Aggregate Application Rate for 14mm
MTD
MTD vs Aggregate Application Rate
(1.7 liters/m^2, 50 passes)
5
4.9
4.8
4.7
4.6
4.5
4.4
4.3
4.2
4.1
4
y = 0.1563x + 2.6483
R² = 0.9525
Series1
Linear (Series1)
0
5
10
15
20
Aggregate Application Rate (kg/m^2)
Figure 4.10, for 14mm the equation was y = 0.1563x + 2.6483 and 𝑅𝑅 2 =
0.9525, therefore, the Texture Depth is directly proportional to the aggregate
application rate. The larger aggregate application rate 18 𝑘𝑘𝑘𝑘/𝑚𝑚2 with 1.7 𝑙𝑙/𝑚𝑚2
binder application rate has the Texture Depth 4.85mm.
Figure 4.11: MTD vs Aggregate Application Rate for 10mm
MTD vs Aggregate Application Rate
(1.5 liters/m^2, 50 passes)
3.9
3.8
y = 0.1562x + 2.35
R² = 0.8929
MTD
3.7
3.6
3.5
Series1
3.4
Linear (Series1)
3.3
3.2
0
2
4
6
8
10
Aggregate Application Rate (kg/m^2)
12
52
Figure 4.11 shows that for 10mm, the equation is y = 0.1562x + 2.35 and 𝑅𝑅 2
= 0.8929, therefore the Texture Depth is directly proportional to the aggregate
application rate. The larger aggregate application rate 12 𝑘𝑘𝑘𝑘/𝑚𝑚2 with 1.5 𝑙𝑙/𝑚𝑚2
binder application rate has the Texture Depth 3.8mm.
Figure 4.12: MTD vs Aggregate Application Rate for 6mm
MTD vs Aggregate Applicaion Rate
(1.3 liters/m^2, 50 passes)
4
3.5
y = 0.2955x + 1.5771
R² = 0.8348
MTD
3
2.5
2
Series1
1.5
Linear (Series1)
1
0.5
0
0
2
4
6
8
Aggregate Application Rate (kg/m^2)
Figure 4.12 shows that for 10mm the equation is y = 0.2955x + 1.5771 and
𝑅𝑅 2 = 0.8348, therefore the Texture Depth is directly proportional to the aggregate
application rate. The larger aggregate application rate 8 𝑘𝑘𝑘𝑘/𝑚𝑚2 with 1.3 𝑙𝑙/𝑚𝑚2 binder
application rate has the Texture Depth of 3.59mm.
4.3.2 The effect of Binder Application Rate on Texture Depth
The binder application rate does not have a clear impact on Texture Depth
due to the binder application rates values. The values for 14mm are 1.5-1.7 𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙/
53
𝑚𝑚2 . For 10mm these values are 1.3-1.5 𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙/𝑚𝑚2 and for 6mm the values are 1.11.3 𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙/𝑚𝑚2 . This means that no big different between the different binder
application rates. The number of passes is not enough to show the effect of binder
application rate on Texture Depth.
Figure 4.13: MTD vs Binder Application Rate for 14mm
MTD vs Binder Application Rate
(18 kg/m^2, 50 passes)
4.86
y = 0.6875x + 3.8967
R² = 0.75
4.84
MTD
4.82
4.8
4.78
Series1
4.76
Linear (Series1)
4.74
4.72
4.7
1.15
1.2
1.25
1.3
1.35
1.4
Binder Application Rate (litres/m^2)
Figure 4.14: MTD vs Binder Application Rate for 10mm
MTD vs Binder Application Rate
(12 kg/m^2, 50 passes)
3.84
3.82
y = 0.625x + 3.0667
R² = 0.75
MTD
3.8
3.78
3.76
3.74
Series1
3.72
Linear (Series1)
3.7
3.68
1
1.05
1.1
1.15
1.2
Binder Application Rate (kg/m^2)
1.25
54
Figure 4.15: MTD vs Binder Application Rate for 6mm
MTD vs Binder Application Rate
(8 kg/m^2, 50 passes)
3.65
3.6
y = 1.8125x + 1.7033
R² = 0.9996
MTD
3.55
3.5
3.45
Series1
3.4
Linear (Series1)
3.35
3.3
3.25
0.85
0.9
0.95
1
1.05
Binder Application Rate (litres/m^2)
4.3.3 The effect of Number of Passes on Texture Depth
Figure 4.16 to 4.18 shows that the Texture Depth decrease as the number of
passes increase for 14mm, 10mm and 6mm. The Texture Depth decrease due the
macrotexture was decrease. Macrotexture decreases when the road surface is
polished by the traffic.
Surface dressing have very good surface texture, but much of this is lost in
the first few passes of wheel. This is due more to re-orientation of the applied
chippings than to embedment.
55
Figure 4.16: MTD vs Number of Passes for 14mm
MTD vs Number of Passes
(18 kg/m^2, 1.7 liters/m^2)
4.9
y = -0.0019x + 4.973
R² = 0.8722
4.8
MTD
4.7
4.6
Series1
4.5
Linear (Series1)
4.4
4.3
0
50
100
150
200
250
300
Number of Passes
Figure 4.17: MTD vs Number of Passes for 10mm
MTD vs Number of Passes
(12 kg/m^2, 1.5 liters/m^2)
3.9
3.85
y = -0.0016x + 3.933
R² = 0.8751
MTD
3.8
3.75
3.7
Series1
3.65
Linear (Series1)
3.6
3.55
3.5
0
50
100
150
200
Number of Passes
250
300
56
Figure 4.18: MTD vs Number of Passes for 6mm
MTD vs Number of Passes
(8 kg/m^2, 1.3 liters/m^2)
4
3.5
MTD
3
y = -0.0041x + 3.763
R² = 0.9749
2.5
2
Series1
1.5
Linear (Series1)
1
0.5
0
0
50
100
150
200
250
300
Number of Passes
4. 4
Analysis of Variance (ANOVA) using Minitab 15
ANOVA is carried out to determine the factors affecting PTV and Texture
Depth differs or otherwise according to the variables. The summary of ANOVA
results on each factor is shown in Table 4.3 to Table 4.8 below. The complete
analysis of ANOVA is attached in Appendix 2.
In determining the statistical significance which is the number, called a pvalue that tells you the probability of your result being observed, given that a certain
statement (the null hypothesis) is true. If this p-value is sufficiently small, the
experimenter can safely assume that the null hypothesis is false. Therefore for
p<0.05., all the factors were to be significant and if the F value has the highest value
indicates the most significant for both the size of aggregate (14mm, 10mm and
6mm).
57
The tables below show the ANOVA table from Minitab 15 that indicate
whether a factor is significant or not.
Table 4.6: ANOVA Table for PTV (14mm)
Source
DF
Seq SS
Adj SS
No. of Passes
4
340.889
340.889
85.222
348.64
p
0.000
Aggregate Application
2
275.356
275.356
137.678
563.23
0.000
2
19.756
19.756
9.878
40.41
0.000
8
18.311
18.311
2.289
9.36
0.000
8
12.578
12.578
1.572
6.43
0.000
4
20.644
20.644
5.161
21.11
0.000
16
19.022
19.022
1.189
4.86
0.000
Adj MS
F
Rate
Binder Application
Rate
No. of
Passes*Aggregate
Application Rate
No. of Passes*Binder
Application Rate
Aggregate Application
Rate*Binder
Application Rate
No. of
Passes*Aggregate
Application
Rate*Binder
Application Rate
Table 4.6 shows PTV of 14mm. It can be seen that all the factors are
significant i-e number of passes, aggregate application rate and binder application
rate, but the most significant factor is the aggregate application rate
58
Table 4.7: ANOVA Table for PTV (10mm)
Source
DF
Seq SS
Adj SS
No. of Passes
4
382.336
382.336
95.584
577.74
p
0.000
Aggregate Application
2
32.616
32.616
16.308
98.57
0.000
2
3.698
3.698
1.849
11.17
0.000
8
11.463
11.463
1.433
8.66
0.000
8
5.241
5.241
0.655
3.96
0.001
4
16.535
16.535
4.134
24.99
0.000
16
16.116
16.116
1.007
6.09
0.000
Adj MS
F
Rate
Binder Application
Rate
No. of
Passes*Aggregate
Application Rate
No. of Passes*Binder
Application Rate
Aggregate Application
Rate*Binder
Application Rate
No. of
Passes*Aggregate
Application
Rate*Binder
Application Rate
Table 4.7 shows PTV of 10mm. Here all the factors were significant. The
number of passes, aggregate application rate and binder application rate, but the most
significant the number of passes.
59
Table 4.8: ANOVA Table for PTV (6mm)
Source
DF
Seq SS
Adj SS
No. of Passes
4
578.615
578.615
144.654
695.08
p
0.000
Aggregate Application
2
180.623
180.623
90.311
433.96
0.000
2
13.436
13.436
6.718
32.28
0.000
8
15.945
15.945
1.993
9.58
0.000
8
2.332
2.332
0.291
1.40
0.223
4
22.771
22.771
5.693
27.35
0.000
16
15.484
15.484
0.968
4.65
0.000
Adj MS
F
Rate
Binder Application
Rate
No. of
Passes*Aggregate
Application Rate
No. of Passes*Binder
Application Rate
Aggregate Application
Rate*Binder
Application Rate
No. of
Passes*Aggregate
Application
Rate*Binder
Application Rate
Table 4.8 shows PTV of 6mm all the factors were significant, number of
passes, aggregate application rate and binder application rate, but the most significant
the number of passes.
60
Table 4.9: ANOVA Table for Texture Depth (14mm)
Source
DF
Seq SS
Adj SS
No. of Passes
4
1.57710
1.57710
0.39428
846.89
p
0.000
Aggregate Application
2
5.24110
5.24110
2.62055
5628.86
0.000
2
0.50798
0.50798
0.25399
545.57
0.000
8
0.14168
0.14168
0.01771
38.04
0.000
8
0.03083
0.03083
0.00385
8.28
0.000
4
0.10092
0.10092
0.02523
54.20
0.000
16
0.11006
0.11006
0.00688
14.78
0.000
Adj MS
F
Rate
Binder Application
Rate
No. of
Passes*Aggregate
Application Rate
No. of Passes*Binder
Application Rate
Aggregate Application
Rate*Binder
Application Rate
No. of
Passes*Aggregate
Application
Rate*Binder
Application Rate
Table 4.9 shows Texture Depth of 14mm all the factors were significant,
number of passes, aggregate application rate and binder application rate, but the most
significant the aggregate application rate.
61
Table 4.10: ANOVA Table for Texture Depth (10mm)
Source
No. of Passes
DF
4
Seq SS
1.98269
Adj SS
1.98269
Adj MS
0.49567
F
626.55
p
0.000
Aggregate Application
2
3.89847
3.89847
1.94923
2463.92
0.000
2
0.45718
0.45718
0.22859
288.95
0.000
8
0.05859
0.05859
0.00732
9.26
0.000
8
0.10354
0.10354
0.1294
16.36
0.000
4
0.11269
0.11269
0.02817
35.61
0.000
16
0.12122
0.12122
0.00758
9.58
0.000
Rate
Binder Application
Rate
No. of
Passes*Aggregate
Application Rate
No. of Passes*Binder
Application Rate
Aggregate Application
Rate*Binder
Application Rate
No. of
Passes*Aggregate
Application
Rate*Binder
Application Rate
Table 4.10 shows Texture Depth of 10mm all the factors were significant,
number of passes, aggregate application rate and binder application rate, but the most
significant the aggregate application rate.
62
Table 4.11: ANOVA Table for Texture Depth (6mm)
Source
DF
Seq SS
Adj SS
No. of Passes
4
2.08437
2.08437
0.52109
2151.30
p
0.000
Aggregate Application
2
4.11699
4.11699
2.05849
8498.37
0.000
2
0.38249
0.38249
0.19124
789.54
0.000
8
0.34410
0.34410
0.04301
177.58
0.000
8
0.5074
0.5074
0.00634
26.18
0.000
4
0.02507
0.02507
0.00627
25.87
0.000
16
0.06291
0.06291
0.00393
16.23
0.000
Adj MS
F
Rate
Binder Application
Rate
No. of
Passes*Aggregate
Application Rate
No. of Passes*Binder
Application Rate
Aggregate Application
Rate*Binder
Application Rate
No. of
Passes*Aggregate
Application
Rate*Binder
Application Rate
Table 4.11 shows Texture Depth of 6mm all the factors were significant,
number of passes, aggregate application rate and binder application rate, but the most
significant the aggregate application rate.
CHAPTER V
CONCLUSION AND RECOMMENDATIONS
5.1
Conclusion
1) Study on the performance of surface dressing, skid resistance test and sand
patch test has shown that, surface dressing with 14mm higher skid resistance
and texture depth,
2) The PTV and Texture Depth increase as the aggregate application rate
increase,
3) The binder application rate does not have a clear impact on PTV and Texture
Depth,
4) The PTV and Texture Depth decrease as the number of passes increase,
5) From ANOVA table for PTV all the factors are significant. While for PTV
(14mm) the most significant is the application of aggregate and for 10mm
and 6mm the most significant is the number of passes respectively,
6) From ANOVA table for Texture Depth all the factors are significant and the
most significant for Texture Depth 14mm, 10mm and 6mm is the application
of aggregate,
7) The best application rate of aggregate and binder for 14mm is (18
𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙
1.7
𝑚𝑚 2
), for 10mm is (12
𝑘𝑘𝑘𝑘
𝑚𝑚 2
𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙
, 1.5
𝑚𝑚 2
) and for 6mm is (8
𝑘𝑘𝑘𝑘
𝑚𝑚 2
𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙𝑙
, 1.3
𝑚𝑚 2
𝑘𝑘𝑘𝑘
𝑚𝑚 2
).
,
64
5.2
Recommendations
Based on the limited study, a few recommendations for future work are as
follows;
1) Increase the tyre loads and decrease the number of passes,
2) Decrease the wheel speed,
3) Construct a double layer surface dressing.
REFERENCES
1. Cliff Nicholls, (1998) Asphalt surfacing: a guide to asphalt surfacing and
treatments used for the surface course of road pavements, Taylor & Francis,
pp 1-405.
2. Coleman A. O'Flaherty, A. Boyle (2002) Highways: The Location, Design,
Construction and Maintenance of Road Pavements, 4th Edition, ButterworthHeinemann, pp. 1-553.
3. Douglas D. Gransberg, David M. B. James (2005) Chip seal best practices,
National Cooperative Highway Research Program, National Research
Council (U.S.). Transportation Research Board, pp. 1-111.
4. Enuvie G. Akpokodje1 and Peter P. Hudec (1992) Factors Controlling
Properties and Durability of Concretionary Laterite Gravel Aggregates,
Journal of Materials in Civil Engineering, 4 (1), February, pp. 1-13, No. 412.
5. Bila, J. A. L (1980) Bitumen-its origin, use and performance characteristics,
Road and Bridge Engineering, 3, p.117.
6. Bremner,
A.J.
(1985).
Bitumen
emulsions
in
road
construction,
Techemoleum, 8, Emoleum Australia Ltd.
7. Barth, E.J. (1962). Asphalt Science and Technology, Gordon and Breach,
New York, p.284.
8. Jacinta, L. Gorman., Rusell, J. Crawford., and Ian, H. Harding (2004)
Bitumen emulsions in road construction - A review, Road & Transport
research, Nunawading, 13 (1) p. 1-25.
9. Loeber, L., Muller, G., Morel, J. and Sutton, O (1998) Bitumen in colloid
science: a Chemical, structural and rheological approach, Fuel, 77(13),
p.1443.
10. Poirier, J.E., Bourrel, M., Castillo, P., Chambu, C. and Kbala, M (1989)
Asphalt emulsions: Experimental study of cationic surfactant adsorption at
the asphalt water interface, programme of Colloid Polymer Science, 79,p.106.
66
11. Robert, N. Hunter and Thomas Telford (1994) Bituminous Mixture in Road
construction Bituminous Mixtures in Road Construction, Thomas Telford, pp.
1-441.
12. Salou, M., Siffert, B. and Jada, A (1998) Interfacial characteristics of
petroleum bitumen in contact with acid water, Fuel, 77(4), p.343.
13. Shell Bitumen (1990) The Shell B bitumen Handbook, Shell Bitumen UK,
p.13.
14. Staples, P.R (1997) Cold emulsion macadam performance trials for footway
surfacing in Leicestershire, Proceedings of the Institution of Civil Engineers Transport, 123, p.174.
15. Kerajaan Malaysia Jabatan Kerja Raya Malaysia JKR/SPJ/2008 (Standard
Specification for Road Works) Section 4: Flexible Pavement.