University of Southern Queensland

Faculty of Health, Engineering and Sciences

An Analysis of Roadbase Materials used in Foamed Bitumen Stabilisation

A dissertation submitted by

Mr Adam O’Callaghan

In fulfilment of the requirements of

Bachelor of Engineering (Civil)

ENG4111/ENG4112 Research Project

October 2014
 University of Southern Queensland

Faculty of Health, Engineering and Sciences

ENG4111/ENG4112 Research Project

Limitations of Use

The Council of the University of Southern Queensland, its Faculty of Health, Engineering &
Sciences, and the staff of the University of Southern Queensland, do not accept any
responsibility for the truth, accuracy or completeness of material contained within or associated
with this dissertation.

Persons using all or any part of this material do so at their own risk, and not at the risk of the
Council of the University of Southern Queensland, its Faculty of Health, Engineering &
Sciences or the staff of the University of Southern Queensland.

This dissertation reports an educational exercise and has no purpose or validity beyond this
exercise. The sole purpose of the course pair entitled “Research Project” is to contribute to the
overall education within the student’s chosen degree program. This document, the associated
hardware, software, drawings, and other material set out in the associated appendices should
not be used for any other purpose: if they are so used, it is entirely at the risk of the user.

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Abstract

Foamed bitumen Stabilisation is an insitu stabilisation process which uses foamed, or

expanded, bitumen as a binding agent. The process produces a bound pavement which acts
as a flexible pavement. The process can be used for improvement of both road base and sub-
base materials. The reconstruction of a road pavement can be complete within a day and the
road can be reopened to traffic after the final compaction is complete with no detrimental
effects on the pavement.

The application of foamed bitumen stabilisation is not limited to use on good quality
pavement materials. The purpose of this project is to examine the material properties of road
base materials used in foamed bitumen stabilisation, the effects on the pavement strength
and the serviceability of the pavement.

The methodology used to complete this project involved a detailed analysis of road base
materials used in foamed bitumen stabilisation from various sites in New South Wales,
Queensland and Victoria. This analysis involved conducting a number of tests on samples
from different sites along Eastern Australia and using some historical data from testing
conducted over the last 15 years.

The key outcomes of this project are to determine the effects of variations in material
properties, bitumen content and if marginal materials can be successfully used in in foamed
bitumen stabilisation.

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Candidates Certification

I certify that the ideas, designs and experimental work, results, analysis and conclusions set
out in dissertations are entirely my own efforts, except where otherwise indicated and
acknowledged.

I further certify that the work is original and has not been submitted for assessment in any
other course or institution, except where specifically stated.

Adam O’Callaghan

0050049644

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Acknowledgements

I would like to thank my supervisors Soma Somasundaraswaran and Peter Sheen for their
advice and guidance, Coffey Pty. Ltd., the staff of the Concord West laboratory and their
clients, for their time, training, use of equipment, and access to historical test data. Finally I
would like to thank my wife and family for their support and understanding throughout this
project without their support and encouragement I may not have completed this project.

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Table of Contents
Limitations of use ………………………………………………………………………………………..…………………..… i
Abstract ………………………………………………………………………………………………………..………………...… ii
Candidates Certification……………………………………………………………………………………………………... iii
Acknowledgements………………………………………………………………………………………………….……...... iv
Abstract ...................................................................................................................................... ii
Candidates Certification............................................................................................................ iii
Acknowledgements................................................................................................................... iv
Table of Contents ....................................................................................................................... v
1 Introduction ........................................................................................................................ 1
2 Background and Literature Review .................................................................................... 2
2.1 History of Foamed Bitumen ........................................................................................ 2
2.2 What is Pavement Stabilisation .................................................................................. 2
2.3 Foamed Bitumen ......................................................................................................... 4
2.4 Foamed Bitumen Stabilisation .................................................................................... 6
2.5 Material Properties ..................................................................................................... 9
2.5.1 Material Testing ........................................................................................................... 9
2.5.2 Material Requirements .............................................................................................. 10
2.5.3 Moisture Content of the Pavement Material ............................................................ 12
2.5.4 Bitumen Moisture Content ........................................................................................ 12
2.5.5 Secondary Binders ..................................................................................................... 13
2.5.6 Bitumen ..................................................................................................................... 14
2.5.7 Ideal Materials ........................................................................................................... 14
2.5.8 Marginal Materials..................................................................................................... 15
2.5.9 Recycled Materials ..................................................................................................... 15
2.5.10 Secondary Binders ..................................................................................................... 16
2.6 Pavement Design....................................................................................................... 18
2.6.1 Pavement Design Specifications ................................................................................ 21
2.6.2 Pavement Service Life ................................................................................................ 24
2.7 Testing Program and Data Analysis ........................................................................... 25
2.7.1 Testing Methods ........................................................................................................ 25
2.7.2 Equipment Requirements .......................................................................................... 26
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2.7.3 Proposed Data Analysis ............................................................................................. 27
2.8 Sustainable ................................................................................................................ 27
2.9 Safety and Risk Assessment ...................................................................................... 29
3 Testing Methodology ........................................................................................................ 31
3.1 Standards and Specifications .................................................................................... 31
3.2 Sample Preparation ................................................................................................... 31
3.3 Testing ....................................................................................................................... 32
3.3.1 Particle size Distribution ............................................................................................ 32
3.3.2 Plasticity Index ........................................................................................................... 32
3.3.3 Moisture Content ...................................................................................................... 33
3.3.4 Maximum Dry Density and Optimum Moisture Content .......................................... 33
3.3.5 Foamed Bitumen Mix and Briquette Manufacture ................................................... 34
3.3.6 Resilient Modulus Testing.......................................................................................... 36
4 Test Samples ..................................................................................................................... 38
4.1 Sample Locations....................................................................................................... 38
4.2 Summary of Samples ................................................................................................. 38
4.2.1 North Queensland ..................................................................................................... 38
4.2.2 The Sunshine Coast .................................................................................................... 39
4.2.3 Southern Queensland ................................................................................................ 39
4.2.4 New South Wales Mid-North Coast........................................................................... 39
4.2.5 Sydney ........................................................................................................................ 40
4.2.6 Central Western New South Wales ........................................................................... 40
4.2.7 South Coast New South Wales .................................................................................. 41
4.2.8 Australian Capital Territory ....................................................................................... 41
4.2.9 Victoria ....................................................................................................................... 41
5 Data Analysis..................................................................................................................... 42
5.1 Analysis Parameters .................................................................................................. 42
5.2 Test Results Data ....................................................................................................... 43
5.3 Effects of Particle Size Distribution on a Foamed Bitumen Stabilised Pavement..... 43
5.3.1 Particle Size Distribution ............................................................................................ 43
5.4 Effects of Varying the Binders in a Foamed Bitumen Trial Mix ................................ 45
5.4.1 What the Bitumen does ............................................................................................. 45
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5.4.2 Bitumen Content ....................................................................................................... 45
5.5 Effects of Particle Size Distribution on the Bitumen Content of a Foamed
Bitumen Stabilised Pavement ............................................................................... 48
5.5.1 Particle Size Distribution and Bitumen Content ........................................................ 48
5.6 Effects of Marginal Materials on a Foamed Bitumen Stabilised Pavement ............. 49
5.6.1 Marginal Materials..................................................................................................... 49
5.6.2 Marginal Materials by Particle Size Distribution ....................................................... 50
5.6.3 Marginal Material by Material Quality ...................................................................... 54
6 Conclusions ....................................................................................................................... 59
7 Further Research .............................................................................................................. 62
8 Reference List ................................................................................................................... 63
Appendix A. Project Specification ....................................................................................... 66
Appendix B. Test Data ........................................................................................................ 68
B.1. Test Data Location: Northern Queensland ............................................................... 68
B.2. Northern Queensland (Whitsunday Coast) ............................................................... 73
B.3. Sunshine Coast .......................................................................................................... 76
B.4. Southern Queensland ............................................................................................... 80
B.5. NSW Mid North Coast ............................................................................................... 82
B.6. Sydney ....................................................................................................................... 84
B.7. Western NSW ............................................................................................................ 86
B.8. Central NSW .............................................................................................................. 88
B.9. Southern NSW ........................................................................................................... 90
B.10. ACT ............................................................................................................................ 92
B.11. Victoria ...................................................................................................................... 94
Appendix C. CIRCLY Output ................................................................................................ 97
C.1. 3% Bitumen 1% Lime 6% finer than 75µm ................................................................ 97
C.2. 3% Bitumen 1.5% Lime 2% finer than 75µm ............................................................. 97
C.3. 3% Bitumen 1.5% Lime 6% finer than 75µm ............................................................. 98
C.4. 3% Bitumen 1.5% Lime 10% finer than 75µm ........................................................... 98
C.5. 3% Bitumen 1.5% Lime 13% finer than 75µm ........................................................... 99
C.6. 3% Bitumen 1.5% Lime 15% finer than 75µm ........................................................... 99
C.7. 3.5% Bitumen 1.5% Lime 2% finer than 75µm ........................................................ 100

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 C.8. 3.5% Bitumen 1.5% Lime 6% finer than 75µm ........................................................ 100
C.9. 3.5% Bitumen 1.5% Lime 10% finer than 75µm ...................................................... 101
C.10. 3.5% Bitumen 1.5% Lime 15% finer than 75µm ...................................................... 101
C.11. 3.5% Bitumen 1.5% Lime 20% finer than 75µm ...................................................... 102
C.12. 2% Bitumen 2% Lime 2% finer than 75µm .............................................................. 102
C.13. 2% Bitumen 2% Lime 10% finer than 75µm ........................................................... 103
C.14. 3% Bitumen 2% Lime 2% finer than 75µm .............................................................. 103
C.15. 3% Bitumen 2% Lime 6% finer than 75µm.............................................................. 104
C.16. 3% Bitumen 2% Lime 10% finer than 75µm ............................................................ 104
C.17. 3% Bitumen 2% Lime 15% finer than 75µm ............................................................ 105
C.18. 3% Bitumen 2% Lime 20% finer than 75µm ............................................................ 105
C.19. 3% Bitumen 2% Lime 24% finer than 75µm ............................................................ 106
C.20. 3.5% Bitumen 2% Lime 2% finer than 75µm ........................................................... 106
C.21. 3.5% Bitumen 2% Lime 6% finer than 75µm ........................................................... 107
C.22. 3.5% Bitumen 2% Lime 10% finer than 75µm ......................................................... 107
C.23. 3.5% Bitumen 2% Lime 15% finer than 75µm ......................................................... 108
C.24. 3.5% Bitumen 2% Lime 20% finer than 75µm ......................................................... 108
C.25. 3.5% Bitumen 2% Lime 25% finer than 75µm ......................................................... 109
C.26. 3.5% Bitumen 2% Lime 30% finer than 75µm ......................................................... 109
C.27. Mackay 1 (2%) ......................................................................................................... 110
C.28. Mackay 1 (3%) ......................................................................................................... 110
C.29. Mackay 1 (4%) ......................................................................................................... 111
C.30. Marginal Material – Sandstone ............................................................................... 112
Appendix D. Typical Service Life Calculations ................................................................... 114
Appendix E. Summary of Service Life Data ...................................................................... 118

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Table of Figures

Figure 2-1: Characteristics of Pavement Materials.......................................................................3

Figure 2-2: The manufacture of foamed bitumen .......................................................................5
Figure 2-3: Typical plot of moisture content vs. expansion ratio and half-life.............................5
Figure 2-4: Bitumen foaming properties schematics. ..................................................................7
Figure 2-5: Foamed bitumen aggregate and binder bond ...........................................................8
Figure 2-6: Flexible and Rigid pavements .....................................................................................8
Figure 2-7: Foamed Bitumen grading envelopes ........................................................................11
Figure 2-8: Optimum Foamant Water Content ..........................................................................13
Figure 2-9: Direct injection spreading and mixing of lime ..........................................................16
Figure 2-10: Influence of Lime on MATTA Results ......................................................................17
Figure 2-11: Mechanistic pavement design model ....................................................................21
Figure 2-12: Optimum bitumen content determination ...........................................................23
Figure 3-1: Preferred Grading Envelope .....................................................................................32
Figure 3-2: Maximum Dry Density and Optimum Moisture Content .........................................34
Figure 3-3: WLB10 Laboratory scale foamed bitumen machine ...............................................35
Figure 3-4: Roadbase material before (left) and after (right) addition of foamed bitumen. .....36
Figure 3-5: Foamed bitumen briquette ......................................................................................37
Figure 5-1: Effect of % material finer than 75µm on resilient modulus – 3% Bitumen with 2%
Lime .....................................................................................................................44
Figure 5-2: Effect of the percentage passing 4.75mm on resilient modulus - 3% Bitumen 2%
Lime .....................................................................................................................45
Figure 5-3: Bitumen Content vs. Resilient Modulus and Ratio of Retained Modulus ................47
Figure 5-4: Effect on modulus from variations in bitumen content ...........................................48
Figure 5-5 Effect of particle size distribution on Bitumen Content ............................................49
Figure 5-6: Marginal materials by Particle Size Distribution ......................................................50
Figure A-1: North Queensland grading profiles - Townsville and Gladstone .............................71
Figure A-2: North Queensland grading profiles - Mackay ..........................................................72
Figure A-3: North Queensland grading profiles - Whitsunday Coast .........................................75
Figure A-4: Sunshine Coast grading profiles (1-8) ......................................................................78
Figure A-5: Sunshine Coast grading profiles (10-14) ..................................................................79
Figure A-6: Southern Queensland grading profiles ....................................................................81
Figure A-7: NSW Mid North Coast grading profiles ....................................................................83
Figure A-8: Sydney grading profiles ............................................................................................85
Figure A-9: Western NSW grading profiles .................................................................................87
Figure A-10: Central NSW grading profiles .................................................................................89
Figure A-11: Southern NSW grading profiles ..............................................................................91
Figure A-12: ACT grading profiles ...............................................................................................93
Figure A-13: Victoria grading profiles .........................................................................................96

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List of Tables
Table 2-1: Preferred Particle Size Distribution for material for foamed bitumen stabilisation 11
Table 2-2: Residual bitumen classes ..........................................................................................14
Table 2-3: Mechanistic design procedure: input requirements ................................................19
Table 2-4: Mechanistic design procedure: analysis ...................................................................20
Table 2-5: Mechanistic design procedure: interpertation of results .........................................20
Table 2-6: Foamed bitumen - Initial modulus design limits ......................................................21
Table 2-7: Foamed bitumen pavement cured design limits ......................................................22
Table 2-8: Optimal bitumen content ranges ..............................................................................23
Table 2-9: Bitumen content by particle size ..............................................................................24
Table 2-10: Bitumen content and secondary binder by particle size and plasticity index ........24
Table 5-1: Preferred grading limits .............................................................................................42
Table 5-2: Design modulus limits ................................................................................................42
Table 5-3: Trial design Content ..................................................................................................46
Table 5-4: Material for Grading Profile 1 ....................................................................................51
Table 5-5: Material for Grading Profile 2 ....................................................................................52
Table 5-6: Material for Grading Profile 3 ....................................................................................52
Table 5-7: Material for Grading Profile 5 ....................................................................................53
Table 5-8: Material for Grading Profile 6 ....................................................................................53
Table 5-9: Material for Grading Profile 7 ....................................................................................54
Table 5-10: Grading Profile 8 Material .......................................................................................54
Table 5-11: Summary of "Sydney 1" Modulus Testing ...............................................................55
Table 5-12: Summary of Modulus testing for "ACT 1” and "ACT 2" ...........................................55
Table 5-13: Summary of Modulus testing for "Victoria 1” and "Victoria 2" ...............................56
Table 5-14: Summary of Modulus testing for "Sydney 5” and "Sydney 6" ................................57
Table 5-15: Summary of Modulus testing for "Bega 4”, "Bega 5" and "Bega 6" ........................57
Table 5-16: Summary of Modulus testing for "Tamworth" ........................................................58
Table 5-17: Summary of Modulus testing for "Bega 1” and "Bega 2" ........................................58
Table A-1: Northern Queensland roadbase test data Table (A) .................................................68
Table A-2: Northern Queensland roadbase test data Table (B) .................................................69
Table A-3: Northern Queensland roadbase test data Table (C) .................................................70
Table A-4: Northern Queensland (Whitsunday Coast) roadbase test data Table (A) ................73
Table A-5: Northern Queensland (Whitsunday Coast) roadbase test data Table (B) ................74
Table A-6: Sunshine Coast roadbase test data (Table A) ............................................................76
Table A-7: Sunshine Coast roadbase test data Table B ..............................................................77
Table A-8: Southern Queensland roadbase test data.................................................................80
Table A-9: NSW Mid North Coast roadbase test data ................................................................82
Table A-10: Sydney roadbase samples testing data ...................................................................84
Table A-11: Western NSW roadbase test data ...........................................................................86
Table A-12: Central NSW roadbase test data .............................................................................88

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Table A-13: Southern NSW roadbase test data ..........................................................................90
Table A-14: ACT roadbase test data ...........................................................................................92
Table A-15: Victoria roadbase test data Table (A) ......................................................................94
Table A-16: Victoria roadbase test data Table (B) ......................................................................95
Table D-1: Service life data - Variations in Grading, Bitumen content and lime content (1) .. 118
Table D-2: Service life data - Variations in Grading, Bitumen content and lime content (2) .. 119
Table D-3: Service life data - Variations in bitumen content ................................................... 119
Table D-4: Service life data - Marginal material (Sandstone) .................................................. 119

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List of Equations

Equation 2-1: Asphalt fatigue .......................................................................................................7

Equation 2-2: Hydration reaction of Quicklime ..........................................................................16
Equation 2-3: Damage Index.......................................................................................................25
Equation 3-1: Plasticity Index......................................................................................................33
Equation 3-2: Moisture Content .................................................................................................33
Equation 5-1: Bitumen Content ..................................................................................................46

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The purpose of this project is to examine the material properties of road base materials used
in foamed bitumen stabilisation, the effects on the pavement strength and the serviceability
of the pavement. To achieve this purpose I plan to

- Research foamed bitumen and foamed bitumen stabilisation, the properties of

materials used for foamed bitumen stabilisation and the design methods,
requirements and specification of foamed bitumen stabilisation.

- Analyse road base materials used in foamed bitumen stabilisation from various sites in
New South Wales, Queensland and Victoria

- Evaluate the effect that the material properties have on the pavement strength and
the expected design life in ESA’s

- Analyse the effect of changes in the material properties of road base materials on the
resilient modulus through laboratory testing

- Analyse the effect of bitumen content on marginal materials used in foamed bitumen
stabilisation
-
- If “marginal materials” can be used in foamed bitumen stabilisation and still provide a
serviceable pavement comparable to a pavement produced using ideal materials. If
marginal material can be used satisfactorily then foamed bitumen stabilisation can be
performed in a wider range of situations.

- The effect variations in material properties have on the strength of a foamed bitumen
stabilised pavement to identify what material properties are most critical to a foamed
bitumen stabilisation and the sensitivity of variation on these properties.

- If the air void content of the compacted stabilised material has an effect on the
strength and what impact this will have on the thickness of the design pavement.

- If variations in bitumen content effects the strength and air voids content of the
compacted stabilised material what impact this will have on the thickness of the
design pavement.

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1 Introduction
Australia has the one of the most kilometres of sealed road pavement per capita in the
world making innovation in pavements rehabilitation of critical importance. Motorsports
and driving are integral parts of the broader Australian culture, increasing volumes road
traffic (both light and heavy vehicles) along with an ever increasing reliance on road
transport; the quality and strength of pavements will need to improve to ensure sufficient
pavement performance and life.

The rehabilitation of a road pavement involves extending the life of an existing road by
improving or modifying the material by one form or another. One method of doing this is
through pavement stabilisation, or the addition of a binder to improve the pavement
material. Foamed bitumen is one way of achieving this goal. To be able to successfully use
foamed bitumen we first need to understand how the different pavement materials and
properties respond to this form of stabilisation.

In this age of sustainability renewable resources are of growing importance. Foamed

bitumen stabilisation reuses the old pavement material reducing the drain on ever
dwindling resources. However guidelines and specifications put limits on the quality of the
material that can be used in this process. If “marginal” or “unsuitable” materials could be
used to some extent this could make this rehabilitation process used in a wider range of
situations.

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2 Background and Literature Review
Foamed bitumen is an insitu stabilisation process which uses expanded bitumen as a binding
agent. The process produces a bound pavement which acts as a flexible pavement. The
process can be used for improvement of both road base and sub-base materials.

The application of foamed bitumen stabilisation is not limited to use on good quality
pavement materials. Foamed bitumen stabilisation is used all around the world but is most
prolific in South Africa, America, New Zealand and Australia. The design processes and
application of foamed bitumen between these countries varies quite extensively while the
process remains the same.

2.1 History of Foamed Bitumen

The ability to use Foamed bitumen as a binder was first trialled at the Iowa State
University’s Engineering Experiment Station by Dr Ladi Csanyi in 1956. Csanyi original
concept involved injecting steam into hot bitumen to cause the bitumen to foam. This
process was ideal for use in asphalt plants however it was not practical for insitu
stabilisation.

In the late 1960’s Mobile bought the rights to the foamed bitumen process and brought it to
Australia. At this time the steam was replaced with cold water making the process more
transportable and practical for both plant production and insitu stabilisation.

During the 1980’s the application of foamed bitumen in insitu stabilisation in Australia fell
away. With the introduction of more modern technologies and more specialised
stabilisation plant in the late 1990’s foamed bitumen stabilisation underwent resurgence.
Today the use of foamed bitumen is continually increasing. The author has noticed that this
increase is not limited to insitu stabilisation of roads but extended to application in airports
and port facilities.

2.2 What is Pavement Stabilisation

Pavement stabilisation process is a of insitu pavement recycling, where the pavement

materials are improved through mechanical, or chemical processes. Mechanical
stabilisation involves the incorporation of a better quality material, typically an imported
quarry gravel, to improve the physical properties of the pavement layer. Chemical
stabilisation involves the addition of a binding agent which chemically alters the pavement
material. Chemical stabilisation includes the use of cementitious binders, polymers and
bitumen.
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Pavement stabilisation can occur in new road pavements or as a way of rehabilitating an old
road pavement. Wilmot and Vorobieff (1997) note that there are a number of reasons for
pavement stabilisation, these are to;

- Correct mechanical defects in unbound pavements. i.e. imported gravel to improve

grading deficiencies
- Improvement of the strength characteristics of weaker pavement materials by
increasing the pavements compressive strength.
- Increases the bearing capacity of the pavement
- Reduce constructions cost by recycling the old pavement
- Reduce the moisture sensitivity and permeability of the pavement to reduce the risk
of strength loss in the materials.
- Improve weak or reactive subgrades materials for construction.
- Improve compaction of an unbound pavement

In mechanical stabilisation the physical properties of the pavement materials is improves by

incorporating a material with the required properties. Andrews (2006) notes that quality
gravel is usually mixed in to the pavement to increase the strength by improving the
mechanical interlock of the pavement.

Figure 2-1: Characteristics of Pavement Materials. Asphalt Academy (2009)

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More commonly used stabilisation processes use cementitious binders such as cement,
lime, fly ash, ground granulated blast furnace slag and blends of these. Cementitious
binders used in pavement stabilisation produce a ridge pavement. In cementitious
stabilisation, the cementitious binder hydrates with the addition of water and cement the
particles together as it cures. During the curing process, the strength of the pavement
increases gradually over time. Vorobieff (2012) notes that cementitious bound pavements
have a limited working life, a time period by which the material can be worked before the
point where proper compaction is able to be achieved. Bound pavements using
cementitious binders can have strengths up to that of lean mix concrete. Pavements
stabilised using cementitious binders are prone to shrinkage cracking and erosion.

More commonly stabilisation involves a mix of mechanical and chemical stabilisation. This
occurs when the contractor undertakes either cross blending or lateral blending of the
existing pavement where extensive patching has happened previously, or when they mill
the into the subgrade prior to the addition of a binder to the pavement.

2.3 Foamed Bitumen

Foamed bitumen is process by which hot bitumen is caused is mixed with air and cold water.
This causes the mixture to rapidly expand. To manufacture foamed bitumen, the bitumen is
heated to a temperature of 160 to 190C and combined with air and water at 15 to 20C in
the expansion chamber and forced out through the foaming nozzle. Uncontrolled this can
result in an explosive situation, but in the proportions used for foamed bitumen , 98%
bitumen, 1% water and 1% air, a rapid volume expansion of greater than 10 results.

The amount of water used in the foaming process will affect the characteristics of the foam
produced. As more water is added to the bitumen the expansion ratio increases while the
half-life of the foam decreases. The expansion ratio refers to the rate of volume increase of
the bitumen. The half-life of the foam is the time for the bitumen foam to collapse to half
its expanded volume.

Ramanujam, Jones and Janosevic (2009) suggest a good foamed bitumen mix has an
minimum expansion ratio of 10 times and a half-life of at least 20 seconds, which can
typically be achieved with a moisture content of 2.5%. If the expansion ration of the
foamed bitumen is <10 times the bitumen may not create enough volume to coat the fine
particles in the pavement and result in the formation of bitumen lumps, dags and strings. If
the half-life is too short the bitumen may not hold up for long enough to be mixed into the
pavement before if collapses, resulting in insufficient mixing through the pavement
material, causing the formation of bitumen lumps, dags and strings.

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Figure 2-2: The manufacture of foamed bitumen (Ramanujam, Jones & Janosevic 2009)

Figure 2-3: Typical plot of moisture content vs. expansion ratio and half-life (Ramanujam, Jones & Janosevic 2009)

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Leek and Jameson (2011) identifies that foamed bitumen is characterised by:

 The expansion ratio – The ratio of the maximum expanded volume of the foamed
bitumen to the volume of the non-foamed bitumen, taken either before foaming or
after the foam has completely collapsed. The greater the expansion ratio the further
the bitumen will be spread through the pavement. The expansion ratio is influenced
by two factors, temperature and bitumen water content. By increasing the
temperature of the bitumen or increasing the amount of water to cause the bitumen
to foam will increase the expansion of the foam. A minimum of 10 times expansion
is recommended by most sources while 15 times expansion is mostly preferred.
However, as the expansion ratio gets larger the stability of the foam decreases,
resulting in a decreased half-life of the foam.

 The half-life – The time taken for the expanded foamed bitumen to collapse to half
the maximum expanded volume. A minimum half-life of 20 – 40 seconds is usually
preferred, to ensure sufficient for the foamed bitumen to be mixed in to the
pavement material. The half-life can be increased by using a more viscous class of
bitumen (i.e. C320 bitumen), lower water bitumen content, decreased bitumen
temperature, or the addition of a foaming agent (i.e. Teric). The using of a higher
class of bitumen is not common except in hot climates. The use of a foaming agent
will result in more stable foam with a longer half-life and higher expansion ratio.

Figure 2-4 demonstrates these properties and the order in which they occur during the
foaming process. The initial rapid expansion, followed by the exponential decay as the foam
collapses back to its unexpanded volume.

2.4 Foamed Bitumen Stabilisation

Foamed Bitumen stabilisation is an insitu stabilisation process used predominantly in road

construction and pavement improvement. This involves the mixing of foamed bitumen into
a pavement material. Andrews (2006) notes that, in its foamed state, bitumen is suited to
mixing with fine material as the large surface area will readily bond with the fine particles.
This is the primary concept behind foamed bitumen stabilisation. The bitumen coats the
fine particles, and once the foam collapses and the material is compacted, the fine particles
bind the coarser particles together. The bitumen coats the particles <75µm size. The
Asphalt Academy (2009) describes foamed bitumen as “producing ‘spot welds’ of a mastic
of bitumen droplets and fines”. This can be seen in Figure 2-5: Foamed bitumen aggregate

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and binder bond where the bitumen coats the fine particles and form droplets which bind
the larger aggregate.

Figure 2-4: Bitumen foaming properties schematics. (Leek & Jameson 2011)

Foamed bitumen stabilisation produces a pavement which is a flexible pavement. The

pavement is not prone to shrinkage cracking as a cementitious bound pavement is.
Austroads (2012) suggests that the predominant performance relationship is that used for
asphalt fatigue. Asphalt fatigue is the result of repeated tensile failure.

( )
[ ]

Equation 2-1: Asphalt fatigue

Where;
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 ( )

( )
( )
( )

Figure 2-5: Foamed bitumen aggregate and binder bond (Asphalt Academy 2009)

Figure 2-6: Flexible and Rigid pavements (Sharp 2009)

As shown in Figure 2-6 the loading of a flexible pavement is quite a bit different to that of a
ridged pavement.

Vorobieff (2012) notes that the advantages of foamed bitumen stabilisation are:

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  Cost reductions – transport are reduces in that the amount of water required for the
foaming process in minimal (typically 2% of the bitumen used), and binder costs are
reduced because standard bitumen is used.
 Duration of road closure is reduced – the road can be opened to traffic immediately
after the mixing and compaction is complete.
 Workability – foamed bitumen does not have a “working life’ in the same way that a
cementitious stabilised pavement does, and remains workable for some time. The
process can continue during adverse weather and not suffer from the usual
problems like aggregate washout.

2.5 Material Properties

2.5.1 Material Testing

2.5.1.1 Particle Size Distribution

The particle Size distribution of a material is a means by sieving a material to determine the
distribution of particle sizes of a material. From this distribution a physical classification can
be determined.

The PDS is determined by a sieve analysis, or mechanical analysis, where the material is put
through a nest of sieves of decreasing coarseness. Particles are retained on the sieves they
are unable to pass through.

2.5.1.2 Plasticity Index

The plasticity index is a measure of the plasticity of a material. The plasticity index is found
by first determining the “Plastic Limit” and the “Liquid Limit”. The plastic limit is the
moisture content where the material stops behaving elastically and starts to behave
plastically. The liquid limit is the moisture content where the material enters a liquid phase.

The Plasticity Index is the difference between the moisture content at the Liquid Limit and
the moisture content at the Plastic Limit. The higher the plasticity index the more reactive
to moisture the fines will be.

2.5.1.3 Compaction, or Proctor Test

This test is used to determine the maximum dry density and optimum moisture content of a
material. The material is compacted in to a mould with a specified number of blows from a
drop hammer of specific weight and drop. This is then repeated at different moisture.
When the dry density of the compacted material is plotted against the moisture content at
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each determination the maximum dry density a peak of the graph, and the optimum
moisture content is the corresponding moisture content.

2.5.1.4 Moisture Content

The amount of water relative to the dry mass of solids expressed as a percentage.

2.5.2 Material Requirements

The requirements for pavement material to be stabilised with foamed bitumen has slight
variations between some of the different state authorities, national road associations and
between different countries. In Australia most state road authorities follow the guidelines
set by Austroads, while the Queensland Department of Transport and Main Roads have
their own specifications based on their own research. More recently, In NSW, the Roads
and Maritime Services have set out to define their own material specifications. The main
debate has been around which specification to adopt, The Queensland model, the
Austroads model, the South African model, or develop their own.

Austroads (2011a), Asphalt Academy (2009) and TMR (2012) identify the following material
properties as being critical to a being important to an ideal material for foamed bitumen
stabilisation. Some of these properties have had limits specified while others are notes for
consideration when selecting material for stabilisation. These properties are:

 Particle Size Distribution

Austroads and the Asphalt Academy have similar grading envelopes for suitable materials
while the Queensland TMR envelope tends to be finer as shown in Figure 2-7.

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Figure 2-7: Foamed Bitumen grading envelopes (Leek & Jameson 2011)

Table 2-1: Preferred Particle Size Distribution for material for foamed bitumen stabilisation (Leek & Jameson 2011)

 Plasticity

The plasticity relates the clay content of the material and how readily the soil will lose shear
strength as the moisture content of the soil increases. The plasticity of the pavement
material is inversely proportional to the shear strength, as plasticity increases the shear
strength of the pavement material increases. As the shear strength of a pavement
decreases the chance of the pavement failing by rutting or shoving increases. This in turn
means that the stabilised pavement may have a reduced design.

Typically the material should have a plasticity index (PI) of less than 12. Materials with a PI
greater than 12 will usually require treatment with a cementitious binder, typically lime
prior to the application of the foam bitumen.

 Aggregate Angularity

Aggregate angularity relates to the shape of the aggregate pieces and the degree of
angularity or roundness of these pieces. The more angular the aggregate the better the
aggregate will interlock to form a stronger pavement. Rounded particles do not tend the

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interlock but are more inclined to slide past each other, leading to early rutting and
pavement failure.

Leek and Jameson (2011) identify aggregate angularity, especially the fine aggregate, as
“an excellent indicator of suitability for foamed bitumen”. The angularity of the aggregate
and the degree of aggregate interlock influences the stability of foamed asphalt. The
Asphalt Academy (2009) has a recommended particle index of greater than 10 to prevent
premature rutting of the pavement.

 Aggregate Durability

The durability of the aggregate is an important factor in the strength of the pavement.
Asphalt Academy (2009) identifies the durability of the untreated aggregate as being one of
the most important factors relating to the suitability for a successful pavement. The
durability relates to the in service breakdown of the untreated aggregate as well as
moisture susceptibility of the stabilised pavement. Breakdown of the aggregate, both in
service and during mixing, can result in the formation of plastic and non-plastic fines.

2.5.3 Moisture Content of the Pavement Material

The moisture content of the material is critical to producing successful test specimens and a
successful stabilised pavement. Foley (2002) recommends a moisture of the pavement
material, prior to the addition of foam bitumen, to be between 70% and 90% of the
optimum moisture content of the parent material. TMR (2012) identifies that the material
should be 70% of the optimum moisture content for the material unless the insitu moisture
content of the pavement is >70% OMC and cannot be dried out then the laboratory testing
should be at the filed moisture content. Asphalt Academy(2009) has the pavement material
is tested at 80% the unmodified OMC and suggests that this moisture content facilities
compaction process.

2.5.4 Bitumen Moisture Content

Two things are required to successfully create foamed bitumen; hot bitumen and water.
The bitumen moisture content relates to the amount of water required to achieve the
required expansion of the bitumen. As illustrated in Figure 2-8,Figure 2-3 with an increasing
water addition rate to the foam, greater expansion results, i.e. increased expansion ratio,
while the foam is less stable and decays quicker, i.e. shorter half-life (Asphalt Academy
(2009)).

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Figure 2-8: Optimum Foamant Water Content (Asphalt Academy (2009))

Ramanujam, Jones and Janosevic (2009) suggest that 2.5% is a typical addition rate for the
foamant water to achieve the required expansion ratio. The TMR (2012) agree with this
addition rate and recommend that laboratory testing undertaken to confirm this rate each
time minor variations in the foamant water rate can have serious effects on the expansion
ratio and half-life.

The Asphalt Academy (2009) identifies the influence of the application rate of the foamant
water of equal importance to the bitumen temperature on the quality of the foamed
bitumen produces.

2.5.5 Secondary Binders

Secondary binders are commonly used in Australia for a number of reasons. Andrews (2006)
has noted the following uses for secondary binders;

- To stiffen the bitumen

- Act as an anti-stripping agent – Typically lime is used
- Assist in the dispersion of the bitumen through the mix
- Improve early stiffness
- Improve rut resistance
- Reduce moisture sensitivity of the stabilised pavement
- Increase the % of material passing the 75µm size
- Decrease the plasticity of the material – Lime is usually used

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The most commonly used secondary binders are quicklime and cement, either General
Purpose (GP) or General Blend (GB) cement. Cement tends to stiffen the bitumen more
than the lime and can make the pavement slightly more ridged as it usually increases the
strength of the pavement material. Andrews also notes that the secondary binder is added
the pavement material at the same time as the foamed bitumen to ensure the performance
of the mix.

2.5.6 Bitumen
Bitumen comes is different classes. These classes, or classification, are related to the
viscosity of the bitumen at 60°C (Standards Australia. (1997). The different classes of
bitumen are:

Viscosity at 60°C
Class
(Pa.s)

C50 50 to 60
C170 140 to 200
C320 260 to 380
C600 500 to 700
Table 2-2: Residual bitumen classes (Standards Australia(1997))

Each different class of bitumen is stiffer than the previous class. Class C170 bitumen is
typically used for it for foamed bitumen. Other classes of bitumen can be used, however
the foam produced is either more expansive but less stable (shorter half-life) or less
expansive and more stable (longer half-life). For example C50 bitumen will have a greater
expansion than C170 bitumen but the half-life of the C50 bitumen is less than that of the
C170 and as such produces a less stable foam. Likewise, C320 bitumen will have a longer
half-life and sore stable foam, than the C170 bitumen but the C320 will not have the same
expansion but will have more stable foam. Additives used in bitumen production can have
an effect on the ability of the bitumen to foam.

2.5.7 Ideal Materials

A material is considered to be ideal for foamed bitumen stabilisation if it complies with one
of the grading envelopes shown in Figure 2-7. Materials are preferred to have a PI of less
than 12; materials with a PI greater than 12 may require treatment with a secondary binder
like quicklime.

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Asphalt Academy (2009) identifies the following material types as being suitable for foamed
bitumen stabilisation;

 Crushed stone – any type of sound quarried stone

 Untreated natural gravels – including basalt, granite, limestone, dolerite, dolomite,

quartz and sandstone gravels,

 Reclaimed asphalt – blended with a crushed stone or gravel

 Reclaimed pavement materials – consisting of sound road base graves and crushed
stone and previously stabilised pavements.

In Australia, the suitability of the material is based primarily on the particle size distribution
of the material. Leek and Jameson (2011) note that while the particle size distribution of a
material may indicate suitability there is no guarantee of producing a pavement with
sufficient strength.

2.5.8 Marginal Materials

Materials that have a higher content of sand size or finer particles are considered to be a
marginal material, i.e. materials that tend to be on the finer side of the grading envelopes in
Figure 2-7: Foamed Bitumen grading envelope. Materials that have undergone some form
of breakdown as a result of the weathering process or prone to breakdown during
construction may also be considered as marginal materials. This is due to the increase the
proportions of the fine material (Asphalt Academy 2009).

These marginal materials may not need to be excluded from the foamed bitumen process,
and may make suitable stabilised pavements; however further testing of the material for
modulus is required to ensure the success of the pavement.

Materials where breakdown during construction is prone to occur may not be suitable for
foamed bitumen stabilisation. If the material produces excess fine material as a result of
compaction than pockets of unstabilised materials may occur resulting in areas of localised
weakness and site of potential future failure.

2.5.9 Recycled Materials

Collings and Thompson (2007) note that the most common application of foamed bitumen
stabilisation is in pavement rehabilitation and insitu stabilisation using recycled pavements.
Also, for recycled pavement materials to be successfully used, sufficient investigation into
the existing pavement must be undertaken. They observe that little can be done with the

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road recycler to vary the nature of the material in the pavement except to change the
grading, so areas on similar material need to be identified and where the pavement quality
drops, cross-blending should be considered to reduce variation in the pavement.

2.5.10 Secondary Binders

Secondary binders are commonly used in foamed bitumen stabilisation. The most
commonly used binders are lime and cement. The secondary binder is mixed into the
pavement prior to the introduction of the foamed bitumen. Each has a different effect on
the pavement and influence on the foamed bitumen. Asphalt Academy (2009) comments
that it is impossible to determine which secondary binder will be suitable without first
completing laboratory trials.

2.5.10.1 Lime
Lime is a commonly used secondary binder used in foamed bitumen stabilisation. Of the
three types of lime available (agricultural lime, hydrated lime and quicklime) quicklime is the
preferred form of lime for stabilisation, while hydrated lime can be used it is more
expensive as 30% more hydrated lime is required when compared to quicklime. Quicklime
needs to be slaked prior to mixing into the pavement resulting in the following reaction;

( )

Equation 2-2: Hydration reaction of Quicklime

Figure 2-9: Direct injection spreading and mixing of lime (Ramanujam, Jones & Janosevic 2009)

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Lime can be added at different times prior to the introduction of the foamed bitumen. If
the lime is mixed and left for a period of time, prior to the foamed bitumen stabilisation, its
purpose is to reduce the plasticity in highly plastic pavement materials and subgrades. If the
lime is immediately before the foamed bitumen, Andrews (2006) notes the following effects
on the pavement and the stabilisation process;

- A stiffening of the bitumen

- The lime will act as an anti-stripping agent
- Assistance in moving the bitumen through the material
- A reduction in moisture sensitivity of the material after stabilisation
- An improved early stiffness and early rut resistance allowing an immediate return of
traffic to the road.

Quicklime is used in the stabilisation process while in the laboratory testing hydrated lime is
used. Hydrated lime is a safer option during the laboratory design trial because quicklime is
highly corrosive to the skin.

Figure 2-10: Influence of Lime on MATTA Results (TMR (2012))

Quicklime has 1.32 times the equivalent ( ) ⁄ of hydrated lime, so when

hydrated lime is used in the laboratory testing the quantity of quicklime used in the field
needs to be reduced accordingly. The addition of lime to the pavement will increase in the
modulus, as illustrated in Figure 2-10 where the modulus is shown to increase with
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increasing lime content. TMR (2012) indicates that lime will also reduce the moisture
sensitivity of the pavement. However Andrews (2006) and the Asphalt Academy(2009)
recommend testing to confirm the ideal lime addition rate and warn against the addition of
excessive amounts of lime, 1.5% Asphalt Academy (2009) and 2%(TMR 2012), as the
flexibility of the mix may be significantly compromised. Kendal et al. (1999) observed an
increased number of voids in samples that where treated with 3% lime, and attribute this to
the effect of the lime as it reduces the plasticity of the materials, resulting in an open
structure in the stabilised material.

2.5.10.2 Cement
Cement as a secondary binder is not as common as lime. Both Andrews (2006) and the
Asphalt Academy (2009) note that the use of cement as a secondary binder will increase the
stiffness of the mix while significantly reducing the flexibility of the material. Andrews and
the Asphalt Academy both comment that the percentage of cement used should be limited
to 1% by dry mass the benefits of using the foamed bitumen is lost.

2.6 Pavement Design

When planning a pavement design where foamed bitumen is to be used Ramanujam, Jones
and Janosevic (2009) describe a process of “trench investigation, testing and mechanistic
pavement design”. During the trench investigation of the pavement importance should be
places on;

- pavement profile, including classification of the material and moisture condition of

the pavement, and layer thickness
- determining the type and cause of any failure in the existing pavement
- determining the condition of the subgrade, including moisture condition and
location of ground water (if possible), and the strength of the subgrade by dynamic
cone penetrometer

After the pavement investigation laboratory testing of samples taken, including particle size
distribution and plasticity index to determine the pavement materials suitability for foamed
bitumen stabilisation. Leek and Jameson (2011) suggest that if the grading curves of
materials taken from the same section of pavement vary by <10% for fraction greater than
2.36mm or <5% for the material passing 2.36mm, than then the materials should be
combined and treated as a single pavement material. If the material is found to be suitable
than MATTA testing should commence for design assessment.

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In Australia, no pavement design process specific to foamed bitumen stabilisation exists.
The pavement design process is based on the ‘Guide to Pavement Technology: Part 2 -
Pavement Structural Design’ (Austroads 2012) and for stabilised materials the ‘Guide to
Pavement Technology Part 4D: Stabilised Materials’ (Andrews 2006). These are either used
directly or are adapted by local council or state authorities to suit local and regional
conditions. Commonly state authorities produce a supplementary document to assist
designers, like in NSW the Roads and Maritime Service produces the “RMS Austroads Guide
Supplement to Austroads Guide to Pavement Technology: Part 2 – Pavement Structural
Design” (Tamsett 2013). These supplementary guides are intended to assist designers by;

- Recommending practices which are intended to enhance the Austroads guide

- Offering materials and practices which are intended to complement the Austroads
guide
- Identify where practices depart from the Austroads guide.

The closest to a specific foamed bitumen pavement design process was an “interim design
method” in the appendix of “Review of structural design procedures for foamed bitumen
pavements” Austroads (2011b) Austroads (2011b) Austroads (2011b) Austroads (2011b)
Austroads (2011b) Austroads (2011b) Austroads (2011b) Austroads (2011b) Austroads
(2011b) Austroads (2011b) which is based on the Austroads 2012 method. Most Australian
Road Authorities use the design procedure outlined in 2012 Austroads Pavement Design
Guide Part 2.

Step Activity
1 Set pavement profile and project reliability
2 Determine insitu subgrade elastic properties
( )
3 Determine the elastic properties of the top sublayer of subgrade
4 Determine the elastic parameters and thickness of the other granular sub-
layers
5 Determine the elastic parameters for cemented materials, pre and post
fatigue cracking
6 Determine elastic parameters of asphalt
7 Adopt the subgrade strain criteria
8 Determine fatigue criteria for cemented materials
9 Determine fatigue criteria for asphalt
10 Determine design number of Standard Axle Repetitions (SAR) for each
distress mode
Table 2-3: Mechanistic design procedure: input requirements (Austroads, 2012)

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 11 Approximate the Standard Axle wheel Loadings as four uniformly loaded
areas at centre-to-centre spacing of 330mm, 1470mm and 330mm; vertical
load of 20kN is applied to each circular area at a vertical stress of 750kPa.
Radius for each load is 92.1mm for highway traffic. , where
R=radius (mm) and p=vertical stress (kPa)
12 Determine critical locations in the pavement for the calculation of strains as
follows:
 Bottom of each asphalt or cemented layer, and
 Top of in situ subgrade and the top of selected subgrade materials
For load configurations see
13 Input the above values into the linear elastic model (i.e. CIRCLY) and
determine maximum critical strains at each location
Table 2-4: Mechanistic design procedure: analysis (Austroads, 2012)

14 Determine the allowable number of Standard Axle Repartitions for each

distress mode.
If post-cracking phase of cemented material life is being considered, calculate
the total allowable loading of the pre-cracking and post-cracking phase of life.
In this case the total allowable loading is expressed in terms of ESA rather
than Standard Axle Repartitions.
15 For each distress mode, compare allowable number of Standard Axle
Repartitions with the design number of Standard Axles
16 If, for all distress modes, the allowable number of Standard Axle Repartitions
exceeds the design number of Standard Axle Repartitions, the pavement is
acceptable. If not, it is unacceptable.
17 If the pavement is unacceptable or additional pavement configurations are
required, select a new trial pavement, return to Step 1 and repeat Steps 1 to
16
18 Compare alternate acceptable design
Table 2-5: Mechanistic design procedure: interpertation of results (Austroads, 2012)

Austroads (2012) describes two design procedures for designing a flexible pavement. These
procedures are by;

 Empirical Design – This procedure is based around a design chart figure 8.4 in
Austroads (2012) “Part 2: Structural Pavement Design”. This design procedure
allows for rutting and shape loss but does not take into account fatigue of the
asphalt surfacing and is only intended for use on unbound granular pavements with
up to 40mm asphalt or bituminous seal. This design method is inappropriate for this
type of pavement.

 Mechanistic Design – The Mechanistic design uses structural analysis of the various
pavement layers under standard road loadings. Critical strains are determined at so
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 the life of the pavement can be determined for the various failure modes. Figure
2-11 illustrates the locations where the critical strains are determined in the
pavement. Due to the complexity of the calculations computer programs like CIRCLY
are used.

Figure 2-11: Mechanistic pavement design model (Austroads 2012)

2.6.1 Pavement Design Specifications

Various road authorities around the world have different design specifications for foamed
bitumen stabilisation. In Australia the different state authorities have their own
specifications which are based on the Austroads specification. The Austroads specification
is part of the Austroads Pavement Technology Series, the Guide to Pavement Technology
Part 4D: Stabilised Materials (2006).

In Australia, the design specifications are based on initial, unsoaked (dry) and soaked
resilient modulus of the pavement and the retained modulus ratio. These values are based
on the average daily ESA’s in the year of opening.

The TMR mix design limits are;

Average daily ESA’s in the year of opening Minimum initial modulus (MPa)
<100 500
≥100 700
Table 2-6: Foamed bitumen - Initial modulus design limits (TMR 2012)

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 Minimum Unsoaked
Average daily ESA’s Minimum Soaked
‘Dry’ cured MATTA Minimum retained
in the year of ‘Wet’ cured MATTA
modulus modulus ratio
opening modulus (MPa)
(MPa)
<100 2,500 1,500 0.4
100 – 1,000 3,000 1,800 0.45
>1,000 4,00 2,000 0.5
Table 2-7: Foamed bitumen pavement cured design limits (TMR 2012)

These different amounts of curing relate to different life stages of the pavement (Austroads
2011a).

 Initial Modulus – The modulus obtained within 3 hours of mixing. This is the
modulus relating to the pavement strength for when the road is initially reopened to
traffic.

 Unsoaked or ‘Dry’ Modulus – the modulus obtained after the test specimens have
been cured for 72 hours at 40°C. This dry cured condition is indicative of the
strength of the pavement 6 months after stabilisation.

 Soaked or ‘Wet’ Modulus – The modulus obtained after the test specimens have
been cured for the dry modulus and then soaked for 24 hours at 20°C. The results of
the wet modulus give an indication to the materials moisture sensitivity.

 Retained Modulus Ratio – This is the ratio of the ‘Wet’ modulus to the ‘Dry’ modulus.
The purpose of this is to relate the effects of soaking on the strength of the
pavement, and demonstrate how much strength is retained after the effect of
moisture on the cured pavement.

TMR (2012) suggests that the modulus of the pavement should be determined over a range
of additive contents (Table 2-10), of both the bitumen and secondary binder, to determine
the optimum proportions for the additives. This should be conducted for both the bitumen
and the lime or cement as small variations in the additives can result in variations in the
properties of the material. Figure 2-12 demonstrated how the optimum bitumen content
can be determined. This optimum bitumen content should be used providing it meets the
modulus limits as shown in Table 2-6 and Table 2-7.

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Figure 2-12: Optimum bitumen content determination (TMR 2012)

Soil Type Binder (%) Further Additives

Well graded clean sand 2.0 – 2.5%
Well graded marginally clayey/silty 2.0 – 2.5%
gravel
Poorly graded marginally clayey/silty 2.0 – 2.5%
gravel
Clayey gravel 4.0 – 6.0% Lime modification
Well graded clean sand 4.0 – 5.0% Filler
Well graded marginally silty sand 2.5 – 4.0%
Poorly graded marginally silty sand 3.0 – 4.5% Low penetration of bitumen and
filler
Poorly graded clean sand 2.5 – 5.0% Filler
Silty sand 2.5 – 4.5%
Silty clayey sand 4.0% Possibly lime
Clayey sand 3.0 – 4.0% Lime modification
Table 2-8: Optimal bitumen content ranges (Kendall et al. 2001)

Bowering and Martin (cited in Kendall et al. 2001), Table 2-8, give some guidance on what
percentage bitumen binder should be used based on the different material classifications.
Also guidance is given relating to pre-treatment that may be required to make the material
suitable for the foamed bitumen process. Muthen (1998) offers a series of bitumen
contents based on the material grading,

Table 2-9. It is also noted that these bitumen content proposed is suitable for most
materials, depending on the parent material. TMR (2012) suggests similar bitumen contents
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based on the grading of the material, but also recommends testing the material with
bitumen contents ±0.5% of the target bitumen content.

Table 2-9: Bitumen content by particle size (Muthen 1998)

Table 2-10: Bitumen content and secondary binder by particle size and plasticity index (Leek and Jameson (2011))

2.6.2 Pavement Service Life

The pavement service life can be determined by the procedure outlined in Austroads
(2011b) and shown in Table 2-3, Table 2-4 and Table 2-5 above. This procedure is based on
the asphalt fatigue relationship (Equation 2-1).

Once a pavement profile has been selected the required parameters can be entered in to
CIRCLY (Wardle 2004) to determine the critical strains. The critical strains can then be

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entered into the fatigue equation and the allowable repetitions calculated. This is then
converted into Equivalent Standard Axles using the relationship;

Equation 2-3: Damage Index (Austroads 2012)

2.7 Testing Program and Data Analysis

2.7.1 Testing Methods

As a part of this project some testing and analysis is required. The following testing has
been planned to be undertaken.

 AS1289.3.6.1, Particle Size Distribution – Mechanical analysis of a variety of different

materials from around New South Wales, Queensland and Victoria to determine
suitability for foamed bitumen stabilisation

 AS1289.3.1.1, 3.2.1, 3.3.1, Liquid Limit, Plastic Limit and Plasticity Index –
Determination of the plasticity of materials from around New South Wales,
Queensland and Victoria, where foamed bitumen testing has been performed to see
the effect plasticity has on the modulus of the stabilised material.

 AS1289.5.1.1, Proctor compaction (Standard compactive effort ) – For the

determination of Maximum Dry Density (MDD) determination and Optimum
Moisture Content (OMC) of the material before and after the addition of lime and
foamed bitumen

 RMS T150, Density-Moisture relationship for mixtures of road materials and

bituminous materials -

 RMS T153, The half-life and expansion ratio of foamed bitumen – To determine the
bitumen moisture content to give a half-life of 20-40 seconds and minimum

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 expansion ratio of 10 to ensure satisfactory foaming for mixing in to the pavement
materials for testing

 RMS T154, Resilient modulus of road construction materials stabilised by foamed

bitumen - Including the foaming, mixing and manufacture of test briquettes for the
determination of the resilient modulus

2.7.2 Equipment Requirements

To complete the practical component of this project I will need to use an amount of testing
equipment. The following items have been identified and permission to use this equipment
with suitable guidance has been given.

 Nest of sieves – Sieves for sample preparation and sample analysis.

o 37.5mm, 26.5mm, 19mm and 13.2mm sieves used bulk sample preparation,
2.36mm and 4.35µm sieves used for plasticity index sample preparation
o AS sizes nest of sieves ranging from 37.5mm to 75µm for particle size
distribution of the sample.

 Compaction Moulds – a variety of different mould sizes may be required for this
project. The following sizes are expected to be used;
o 1L/2L/2.4L mould – These moulds will be used for maximum dry density and
optimum moisture content determination.
o Foam Bitumen Briquette mould – a custom made mould with a diameter of
150mm and height of 85mm for the manufacture of the MATTA test
specimens.

 Compaction hammers – Two different compaction hammers will be used.

o Standard Proctor hammer – A drop hammer with a 2.7kg falling weight and a
300mm drop, where the energy is passes directly into the sample.
o Marshall hammer – A drop hammer consisting of a sliding 4.5 kg weigh on to
a tamping foot with a drop of 450mm, typically used for compacting asphalt
samples

 Thermostatically Controlled Oven with a temperature range up to 110°C

o Drying Oven – An oven thermostatically controlled for the range of 105°C to
110°C
o Curing Oven – An oven thermostatically controlled for the range of 40°C to
45°C

 Casagrande Cup and grooving tool

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  MATTA (MATerials Testing Apparatus) Universal Testing Machine – The MATTA is
used to test the resilient modulus of the cured briquettes.

 Expansion Ratio Apparatus – A calibrated bucket and dip stick

 Stop watch

 Wirtgen WLB10 Laboratory scale foamed bitumen machine and Hobart mixer

I will have access to most of this equipment through the Coffey Testing laboratory located in
Concord West. I will be able to access a MATTA universal testing machine through the RMS
laboratory located in Russell Vale. The equipment for the void content testing will be
accessed from the STS laboratory in Macquarie Park. I have a private arrangement with
each of these testing facilities to access the equipment required to complete the necessary
testing.

2.7.3 Proposed Data Analysis

As a part of this project I will be performing analysis on data obtained from testing
performed by myself and from historical data obtained over the last 15 years. As a part of
this analysis I will perform the following analysis on the data;

 Particle Size Distribution data – from the PSD data, materials will be grouped into
ideal, marginal and unsuitable. This will categorise materials by physical properties.
At present the PSD is the predominant method used for determining the suitability
of the material for foamed bitumen stabilisation.

 Plasticity – Data on the plasticity of the materials will be used to help categorise the
material and determine the influence of

 MATTA Testing data – Modulus data obtained from the MATTA test will determine
the strength of the stabilised material and the compliance with published minimum
design requirements. This data in conjunction with the PSD data will be analysed to
determine the effect of PSD and plasticity on the modulus of the pavement material.
If possible

2.8 Sustainable
Foamed bitumen stabilisation, like other forms of pavement stabilisation, is a sustainable
pavement construction process resulting in social, environmental and direct cost benefit.
Being an insitu stabilisation process the existing pavement is reused needing little or no
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material required to be brought to site and very little waste material needing disposal. This
in turn speeds up the construction by shortening the duration of road closures, decreasing
the number of heavy vehicle movements and the reducing amount of greenhouse emissions
produces.

Foamed bitumen stabilisation is an insitu stabilisation process and consequentially reduces

the time of road closures. The reconstruction of a road pavement can be complete within a
day and the road can be reopened to traffic after the final compaction is complete with no
detrimental effects on the pavement. The speed of the reconstruction means that work on
the pavement can begin at the completion of the morning peak and be complete for the
afternoon peak meaning less inconvenience to road users and residents.

Foamed bitumen is predominantly an insitu stabilisation process, as such, less heavy

vehicles are required during the construction process as little or no material requires
disposal off site and the only materials coming onto site is the binders which is about 2% to
3% of the quantity of the material to be stabilised. With less heavy vehicles movements the
roads around the construction are less congested making the surrounding roads safer. The
environment benefits from less noise and exhaust emissions being produces.

Old pavement materials are recycled in to a new revitalised pavement makes the process
sustainable for the future by reducing the amount of waste going to landfill normally
required for the construction of the new pavement and reduces the reliance on imported
quarry materials. The existing pavement can be used as a linear quarry so material does not
need to be imported making construction suitable for remote areas where importing a
quarried material is financially prohibitive and reduces the environmental impact of opening
sites to find new material sources. Less waste and import material reduces the cost of
constructing the pavement and less waste material goes into landfill sites putting less strain
on these facilities.

By recycling the existing pavement foamed bitumen stabilisation is a greener option when
compared to full reconstruction of the pavement. With the pavement material is being
recycled little to no material is required to be brought on to site and material is not being
sent to landfill so less trucks hauling material to and from site reduced carbon footprint
comes of the construction. Also material is not being sourced from quarry sites so
quarrying works are not required for the construction, because of this work is not required
to locate and quarry quality road base gravel further reducing the environmental impact
and cost of the construction.

The ability to use marginal recycled materials for foamed bitumen stabilisation is a
sustainable and ethical decision for road construction and rehabilitation. The use of
recycled and marginal material has all of the social, environmental and cost benefits listed
above.

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2.9 Safety and Risk Assessment
With this project there are a number of inherent safety risks. These have been identified as;

- Working with hot materials

- Working with lime
- Exposure to dust
- Working with moving parts
- Exposure to potentially hazardous materials.

The most obvious hazard is working with hot materials. To be able to use the bitumen I will
need to soften the solid bitumen to get into the kettle of the foamed bitumen machine,
during this process the bitumen needs to be heated to about 130 - 140°C. While decanting
the bitumen in to the kettle on the WLB10 extreme care must be taken as there is a risk of
spilling or splashing the bitumen which may result in serious burns. While determining the
bitumen flow rate, the half-life and the expansion ratio of the bitumen hot bitumen is
expelled from the foaming chamber of the WLB10. At this time the bitumen is at about
180°C and any contact will cause serious burns. Protective gloves, long sheaves and face
shield are required while handling hot bitumen or then there is a chance of exposure to
protect against any bitumen splash or spills that may occur.

Lime is used as a secondary binder in the foamed bitumen process. In insitu stabilisation
quicklime is used for economic reasons, however quicklime is too hazardous to use in a
laboratory situation so hydrated lime is used. Hydrated lime, while not as hazardous as
quick lime, is a potentially hazardous material. While working with lime there is a chance of
exposure by direct contact while mixing the lime into the samples and by contact and
inhalation of airborne lime resulting from the mixing process. Exposure to hydrated lime
can cause skin and respiratory irritation.

Generally working there should not be too much dust, except for the lime, encountered as
the materials for testing are kept in a moist state. The only occasions where dust may be an
issue are in preparation of the Plasticity Index test as the material needs to be air dried and
ground to pass through a 425µm sieve and any waste materials not cleaned up while
working. This dust can be a slip hazard if it is left on the ground in walkways. It can also be
a respiratory hazard if breathed in. Breathing in dust can result in respiratory irritation and,
if silicon is present in the dust, silicosis. To prevent this, spills should be cleaned up and not
left, where the chance of dust becoming airborne is present then dust masks or other
respiratory protection should be used.

When mixing the lime and bitumen into the bulk sample a Hobart mixer is used. This has a
planetary mixer which can move at variable speeds. While using this piece of equipment
care should be taken to ensure hands and all loose items are clear of the mixing bowl prior

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to operation. If it is necessary to check the consistency or moisture content of the mixed
material during the mixing process the mixer should be turned off and unplugged until the
inspection of the material is complete.

Some potentially hazardous materials and additives are used in the foamed bitumen
process. Some of the materials and additives are bitumen, lime, cement and foaming
agents. Prior to using these substances, Material Safety Data Sheets (MSDS) should be
sourced from the relevant manufactures. The MSDS has details about any potential
hazards, toxicology and methods of disposal.

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3 Testing Methodology

3.1 Standards and Specifications

 AS 1289.3.1.1

 AS 1289.3.2.1

 AS 1289.3.3.1

 AS 1289.3.6.1

 AS 2891.13.1 – Determination of the resilient modulus of asphalt – Indirect tensile

method

 RMS T111 – Dry density/moisture relationship of road construction materials

 RMS T153 – The half-life and expansion ratio of foamed bitumen

 RMS T154 – Resilient modulus of road construction materials stabilised by foamed

bitumen (blended in the laboratory)

3.2 Sample Preparation

Representative samples were submitted for testing from a number of different locations in
each of the areas. The samples consisted of materials representing the of a profile
pavement of the existing granular base and bituminous/asphaltic seal layers of the
pavement, in some samples a granular material was added to improve deficiencies in the
material to assist in making it suitable for stabilisation. These samples were prepared for
testing by combining different the different layers of the pavement proportional to the
thickness of the layers. Conglomerations of granular material were broken down to discreet
particles or 19mm size. The bituminous seal or asphaltic concrete it be incorporated was
broken down to 19.0mm size to simulate the effects of milling and mixing on the material.
The combined composite samples were sieved on a 26.5mm sieve and particles retained on
this sized sieve were broken down to simulate the action of the milling and mixing
encounter in the stabilisation process. Samples were than mixed and subsampled for
testing.

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Some samples were not suitable for testing and had to have quality imported gravel
blended to improve the material. Some of these samples had too much fines or not enough
coarse material for to produce a satisfactory pavement.

3.3 Testing

3.3.1 Particle size Distribution

An AS1289.3.6.1 washed soil grading was conducted to determine the suitability of the
material for testing. Samples were washed, dried and sieved on a standard set of AS sieves.
The results of these grading were plotted on to the preferred grading envelope. The grading
was performed on the material passing 26.5mm

100.0
90.0
80.0
70.0
60.0
% Passing

50.0
40.0
30.0
20.0
10.0
0.0
0.01

0.10

1.00

10.00
6.7
9.5
0.075

0.15

0.300
0.425
0.600

1.18

2.36

4.75

13.2
19.0
26.5
37.5
53
AS Sieve Sizes

Austroads Upper Limit Austroads Lower Limit

Austroads >100 ESA/day - Upper Limit Austroads >100 ESA/day - Lower Limit

Figure 3-1: Preferred Grading Envelope

3.3.2 Plasticity Index

Each material was tested to AS1289.3.1.1, 3.2.1, and 3.3.1 to determine the plasticity index
of the material. A subsample from each location was air dried and ground in a mortar and
pestle to break particles down into discreet particles. The material was then sieved on a
sieve. A portion of the material was wet up to test for the plastic limit, while the
rest wet up to be able to be used to determine the liquid limit. Once the liquid limit and
plastic limit portions had been prepared they were left of a minimum of 24 hours to cure
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and allow the moisture in the respective portions to fully penetrate the material. After the
curing was completed, the material was tested for the plastic limit (PL), the moisture
content where a material enters a plastic phase, and liquid limit (LL), the moisture content
where a material enters the liquid phase.

The Plastic Limit (PL) is determined by rolling the material to be tested into a thread, the
moisture content of the material when this thread just starts to crumble at a diameter of
3mm id the plastic limit. The Liquid Limit (LL) is determined by determined using a
Casagrande Cup and grooving tool. The Plasticity Index is the difference in moisture
content between the Liquid Limit and the Plastic Limit

Equation 3-1: Plasticity Index

3.3.3 Moisture Content

Secondary binders are added on a dry mass basis so the moisture content of the material is
required to determine the dry mass of the material to be tested. By using this moisture
content and the optimum moisture content of the material we were able to adjust the
moisture in the material ready for the foaming process, as the ideal moisture ratio for the
material for foaming is 70 -80% of the optimum moisture content. The method used was
AS1289.1.2.1

Equation 3-2: Moisture Content

3.3.4 Maximum Dry Density and Optimum Moisture Content

The Maximum Dry Density and Optimum Moisture Content of the material were
determined by either a “Standard” Proctor Compaction, RMS T111. In the standard
compaction the material is compacted into a mould using a drop hammer, the number of
blows is proportional to the size of the mould. 25 blows for a 1L mould and 50 blows for a
2L mould. The mould size is determined by the size of the larger particles in the material
being testes, a 1L mould is used for material less the 19mm and a 2L mould for material
where there is material retained on the 19mm sieve and all material passing the 26.5mm
sieve is included. The optimum moisture content determination was conducted on the

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unstabilised material, the material prior to any modification by the secondary binders; this
was to assist the contractor with the moisture content they should use in the field.

The maximum dry density is required to assist in moulding the test specimens. The
briquettes are usually moulded at 100%-102% of the maximum dry density. The maximum
dry density for moulding the briquettes has been conducted on the material after the
foaming process has been completed.

1.953

Maximum Dry Density

1.933

1.913
Dry Density (t/m3)

1.893

Optimum Moisture Content

1.873

1.853

1.833
10.9 11.9 12.9 13.9 14.9 15.9
Moisture Content (%)

Figure 3-2: Maximum Dry Density and Optimum Moisture Content

3.3.5 Foamed Bitumen Mix and Briquette Manufacture

Mixing the foamed bitumen into the roadbase gravel we had to use some specialised
equipment. To create the foamed bitumen we used a Wirtgen WLB10 Laboratory scale
foamed bitumen machine. This machine is of one of the foaming jets the stabiliser used for
stabilising in the field and consists of a;

 Heating kettle – used for heating the bitumen to 170-185°C

 Pressure vessel – for supplying pressure to the water used in the foaming, injecting
air into the foaming process and operating the pneumatic solenoids for releasing the
bitumen and water

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  Bitumen pump – for supplying the bitumen for foaming and to keep the bitumen in
the kettle moving

 Expansion chamber and foaming jet – where the air and water is injected into the
hot bitumen

Prior to mixing the foamed bitumen into the roadbase material, the flow rate of the
bitumen, the half-life and expansion ratio had to be determined. When the bitumen is
released for foaming it is controlled by an automated timer so the flow rate of the
bitumen was determined to enable accurate timing for the addition of the bitumen to
be mixed into the roadbase. Next the half-life and expansion of the foam needed to be
determined. This is because a half-life of 20 to 40 seconds is required and an expansion
of 10 to 15 times. The half-life and expansion is checked at a number of different water
addition rates to achieve the required half-life and expansion of the foamed bitumen,
typically a foaming agent is added to the bitumen to assist in the foaming. The half-life
and expansion was conducted as per the RMS T153 method.

Figure 3-3: WLB10 Laboratory scale foamed bitumen machine (Kendall et al. 2001)

The briquettes of the road material after the foaming process were compacted using an
internal testing method for most of the testing due to the lack of any standardised
compaction method. This compaction method involved the material being compacted in
two layers using a modified compaction hammer, scarifying the first layer first layer prior to
placing the second layer. More recently, with the publication of RMS T154, the method of
compaction changed to the use of a Marshall Compaction hammer, where the briquettes
have been moulded in one layer and compacted from either end. Typically three briquettes

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were produced for testing, an additional three briquettes may be produced if the initial
modulus of the mix was required but this was not commonly required.

The briquettes were typically moulded into a mould 150mm diameter, or 100mm for
samples where all the material is passing the 19mm sieve, and compacted to give the
briquettes a height of 80mm±5mm.

3.3.6 Resilient Modulus Testing

The resilient modulus of the briquettes was tested by the RMS laboratory in Russel Vale. In
testing the resilient modulus the briquettes were tested after ‘dry’ and ‘wet’ curing. The dry
curing consisted of sealing the briquettes in a plastic bag and curing in an oven at 40°C for
72 hours prior to testing. The ‘Wet’ curing is then conducted where the briquettes are
immersed in water at 23°C for 24 hours and towel dried prior to testing. The resilient
modulus was determined by RMS T154 and AS 2891.13.1. The average of the modulus after
each conditioning was taken as the modulus for the mix.

Figure 3-4: Roadbase material before (left) and after (right) addition of foamed bitumen.

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Figure 3-5: Foamed bitumen briquette

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4 Test Samples

4.1 Sample Locations

Material has been test from locations across New South Wales, Queensland and Victoria.
The test samples have been grouped into geographic regions for comparison, these regions
are:

- North Queensland – encompassing Townsville, Mackay and Gladstone

- The Sunshine Coast – including Maroochydore and Slippy Downs
- Southern Queensland – Logan City and Surrounds
- New South Wales Mid-North Coast – Tamworth, Port Macquarie and Mulbring
- Sydney – Greater Sydney Region
- Central and Western New South Wales – Bathurst and Parks areas
- Southern New South Wales – Bega district
- ACT
- Victoria

4.2 Summary of Samples

For all samples there was a grading, plasticity index, moisture content and maximum dry
density/optimum moisture content tests were performed to classify the materials, assist in
determining the required bitumen content and any adjustments that may be required to the
sample prior to foaming. Following is a summary of the foamed bitumen mix testing
conducted on the samples from each of the different sampling locations.

4.2.1 North Queensland

Samples were taken from 9 locations around Townsville, Gladstone, Mackay and the
Whitsunday Coast. Of these samples there was;

 2 samples tested with one bitumen content and one lime content
 1 sample tested where the lime content was varied and the bitumen content was
kept constant, 1 bitumen content and 2 different lime contents
 2 sample tested where the bitumen content was varied, 2 different bitumen
contents and 1 lime content, and 3 different bitumen contents and 1 lime content
 4 samples tested where the bitumen content was varied and cement was added, 3
different bitumen contents and 1 cement content including one of these samples
tested with 1 bitumen content and 1 lime content

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4.2.1.1 Material Descriptions
The material from the samples around Townsville and Mackay were typically well graded
sandy gravels with some plasticity predominantly existing roadbase gravels with some
asphaltic concrete included. The samples from the Whitsunday Coast were quality existing
roadbase gravel with no plasticity. The Gladstone sample was an imported roadbase gravel
classified as a 2.1 roadbase as per the TMR specifications.

4.2.2 The Sunshine Coast

Samples were tested from 13 from locations around the Sunshine Coast Region. From these
samples the following mixes were tested;

 13 samples tested with one bitumen content and one lime content

4.2.2.1 Material Descriptions

The Sunshine Coast samples were all existing roadbase gravel samples, they mostly clayey
gravels and well graded. Being existing roadbase samples they all had some asphalt seal in
them. While most of the samples had some plasticity, three of the samples had little or no
plasticity at all.

4.2.3 Southern Queensland

Samples were tested from 3 from locations around Southern Queensland southwest of
Brisbane. From these samples the following mixes were tested;

 2 samples were tested with one bitumen content and one lime content
 1 sample was tested where the bitumen content was varied, 2 different bitumen
contents and 1 lime content

4.2.3.1 Material Description

The Southern Queensland samples were all existing roadbase and all but one had an
imported quarry gravel blended with it to improve the grading of the materials. One sample
was tested as two different blends on the imported roadbase. The original roadbase
materials were all silty roadbase gravels.

4.2.4 New South Wales Mid-North Coast

Samples were tested from 3 from locations around the New South Wales mid-North
Coast/Hunter. From these samples the following mixes were tested;

 2 samples were tested with one bitumen content and one lime content
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  1 sample was tested where the bitumen content was varied, 2 different bitumen
contents and 1 lime content

4.2.4.1 Material Description

The sample from the Tamworth region was silty sandy gravel with some bituminous seal,
this sample was well graded with no too may fines and non-plastic, this sample showed
signs of previous cementitious stabilisation, a CBR test was performed on this material prior
to foaming and was found to be CBR 50. The sample from the Hunter region was a blended
sample of 60% decomposed granite and 40% 20/5mm concrete aggregate. The Port
Macquarie sample was clayey roadbase gravel with some asphalt seal.

4.2.5 Sydney
Samples were tested from 6 from locations around the greater Sydney region. From these
samples the following mixes were tested;

 samples were tested with one bitumen content and one lime content

4.2.5.1 Material Description

The samples taken from Sydney were all existing roadbase samples. Sample #4 from Sydney
consisted of 80% existing roadbase gravel and asphaltic concrete and 20% crusher dust,
Samples #5 & #6 were a blend of the existing pavement. Sample #5 was 22% Asphalt, 52%
roadbase which had been previously cementitiously stabilised and 26% unmodified
roadbase gravel. Sample #6 was 52% Asphalt, 22% roadbase which had been previously
cementitiously stabilised and 26% unmodified roadbase gravel.

4.2.6 Central Western New South Wales

Samples were tested from 12 from locations around Central Western New South Wales.
From these samples the following mixes were tested;

 12 samples were tested with one bitumen content and one lime content

4.2.6.1 Material Description

The Central Western New South Wales samples were all existing roadbase samples. The
material was silty sandy gravel and well graded with varying degrees of plasticity.

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4.2.7 South Coast New South Wales
Samples were tested from 6 from locations around the South Coast of New South Wales.
From these samples the following mixes were tested;

 6 samples were tested with one bitumen content and one lime content

4.2.7.1 Material Description

The samples from the South Coast of New South Wales were all existing roadbase samples,
all showed signs of previous stabilisation, some cementitious others with Polyroad. Sample
#4, #5 and #6 are all gravelly silty sands which show signs of previous cementitious
stabilisation. Samples #1 and #2 are graded roadbase gravels which had been previously
treated with Polyroad.

4.2.8 Australian Capital Territory

Samples were tested from 2 from locations around the South Coast of New South Wales.
From these samples the following mixes were tested

 2 samples were tested with one bitumen content and one lime content

4.2.8.1 Material Description

The samples from the ACT were all existing roadbase samples. These samples were blended
with 7% recycled Asphalt Pavement.

4.2.9 Victoria
Samples were tested from 8 from locations around the South Coast of New South Wales.
From these samples the following mixes were tested

 8 samples were tested with one bitumen content and one lime content, of this two
samples were tested which had near identical grading profiles and as could be
treated as the same material and were tested at different bitumen content

4.2.9.1 Material Description

The samples from Victoria were existing roadbase and blends of existing roadbase and
imported materials. Sample #1 and 2 were a 60/40 composite of Sandstone gravel and
20mm imported quarries aggregate. Sample #3 and #4 were a composite blend of the
existing road pavement with a fine crushed rock. Sample #4 was a composite blend of the
existing roadbase gravel.

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5 Data Analysis

5.1 Analysis Parameters

The data gained from the testing is to be analysed with the following parameters,

 Particle Size Distribution – Compared with the Austroads preferred grading and the
>100 ESA’s/day grading envelope for suitability

 Modulus – ‘Dry’ cured, ‘Wet’ cured and retained

Austroads Limits
AS Sieve Sizes (mm) <100 ESA’s /day >100 ESA’s /day
26.5 73 100 100 100
19.0 64 100 80 100
9.5 44 75 55 90
4.75 29 55 40 70
2.36 23 45 30 55
1.18 18 38 22 45
0.600 14 31 16 35
0.425 -- -- 12 30
0.300 10 27 10 24
0.150 8 24 8 19
0.075 5 20 5 15
Table 5-1: Preferred grading limits

Average Daily Minimum Dry Minimum Maximum Minimum

ESA Modulus Soaked Modulus Soaked Modulus retained
(MPa) (MPa) (MPa) modulus Ratio
(%)
<100 2500 1500 2500 40%
100 – 1000 3000 1800 2500 45%
>1000 4000 2000 2500 50%
Table 5-2: Design modulus limits

Due to the nature of the material some variability is to be expected in the modulus results.
As a result of this an average of the modulus results for comparison and determination of
the retained modulus ratio, on occasion outliers have been experienced and Vorobieff

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(2005) notes that when a result varies from the average by more than 30% it should be
discarded and the average of the remaining results used.

5.2 Test Results Data

The results of the particle size distribution and resilient modulus testing can be found in
Appendix A.

5.3 Effects of Particle Size Distribution on a Foamed Bitumen

Stabilised Pavement

The particle size distribution, or grading, of pavement material is a key factor in foam
bitumen stabilisation. The grading of the material is used to determine the suitability of the
material for foam bitumen stabilisation and as an indicator of the percentage of bitumen to
use in the mix design. Materials with different particle size distribution will affect the
resulting stabilised pavement in different ways.

5.3.1 Particle Size Distribution

The Particle Size Distribution is a means by which a soil or aggregate can be classified by the
sizes of the discreet and cemented particles. The material is passed through a set of sieves
of decreasing mesh sizes, the percentage of the material retained on each sieve, by dry
mass, is determined, from this a grading profile or particle size distribution is determined.

5.3.1.1 Effects of Particle Size Distribution on Resilient Modulus

When examining the results of the resilient modulus for the samples tested there is a trend
relating the particle size distribution to the modulus. This trend can be found in both the
wet cured and the dry cured modulus results.

When the results for the resilient modulus, for fixed bitumen content, are compared to the
percentages of material finer than 75µm, a distinct trend was found as shown in Figure 5-1.
As the percentage of material finer than 75µm increased so did the modulus until a
maximum was reached. After this point the modulus tended to decrease.

On samples where there is a lower percentage of material passing the 75µm sieve the
resilient modulus is relatively low. As this percentage of material passing increases so does

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the modulus. This increases to a point where a maximum occurs and there appears
insufficient bitumen to bind the particles together.

This effect is seen in both the dry cured and the wet cured results; however the rate the
modulus peaks for each of the curing conditions is different. The curve for the modulus of
the wet conditioned specimens is much flatter than that of the dry conditioned specimens.
As the percentage of material finer than 75µm increases, or decreases, away from the
maximum the difference in the wet and the dry conditioned modulus becomes less.

10000 100%

9000 90%

8000 80%

Retained Modulus Ratio (%)

7000 70%
Modulus (Mpa)

6000 60%

5000 50%

4000 40%

3000 30%

2000 20%

1000 10%

0 0%
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
% Passing 75um
Dry Modulus Wet Modulus Ratio

Figure 5-1: Effect of % material finer than 75µm on resilient modulus – 3% Bitumen with 2% Lime

In specimens with low percentages of fines, there is more bitumen coating the fine particles,
the modulus tends to be lower because the bitumen will provide some lubrication between
the particles. The retained modulus of these materials with low percentages of fines tends
to be high, 80% or higher, this is due to the lubrication of the particles and in the wet cured
specimens the bitumen coats more of the particles, waterproofing the material to some
extent so the soaking has less of an effect.

Design specifications use the percentage of material passing 4.75mm as a significant in

determining bitumen content. When the modulus results are split into results with <50%
material finer than 4.75mm and >50% material finer than 4.75mm and plotted against the
percentage of material finer than 75µm the same trends are observed as before. As the
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percentage of material finer than 4.75mm increases the peek modulus shifts to a higher
percentage of material finer than 75µm (Figure 5-2).

10000

9000

8000
Resiliant Modulus (Mpa)

7000

6000

5000

4000

3000

2000

1000

0
0 2 4 6 8 10 12 14 16 18
% Passing 75um

<50% passing 4.75mm (Dry) >50% Passing 4.75mm (Dry)

<50% Passing 4.75mm (Wet) >50% Passing 4.75mm (Wet)

Figure 5-2: Effect of the percentage passing 4.75mm on resilient modulus - 3% Bitumen 2% Lime

5.4 Effects of Varying the Binders in a Foamed Bitumen Trial Mix

5.4.1 What the Bitumen does

The bitumen is used in the foamed bitumen stabilisation process as the primary binder;
typically Class C170 bitumen is used. The bitumen is used to bind the granular particles of
the roadbase gravel together to improve the strength of the stabilised pavement. The
bitumen enables the pavement to gain strength while retaining a flexible pavement.

5.4.2 Bitumen Content

The bitumen content for foamed bitumen is the percentage of bitumen based on the
amount of bitumen to be used as a percentage of the dry aggregate in the pavement.

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Equation 5-1: Bitumen Content

5.4.2.1 How is the Bitumen Content Determined for a Mix?

The bitumen content for a design mix is based on design specification guidelines. Table 5-3
illustrates recommendations for the starting percentage of bitumen and Jones and
Ramanujam (2008) suggests conducting trials at 0.5% either side of the starting content to
determine the optimum bitumen content for the resulting pavement.

Passing 4.75mm Sieve Passing 0.075mm Sieve Foamed Bitumen Content

(%) (%) (% of Dry Aggregate)
5.0 – 7.5 3.0
<50 7.5 – 15.0 3.5
15.0 – 20.0 4.0
5.0 – 7.5 3.5
>50 7.5 – 15.0 4.0
15.0 – 20.0 4.0
Table 5-3: Trial design Content (Jones & Ramanujam 2008)

The percentage of bitumen is typically dependant on the grading of the pavement material.
The higher the percentage of the fine material the more bitumen is required to sufficiently
coat these fine particles.

5.4.2.2 The effect of Varying the Bitumen Content

As a part of the testing conducted different samples were tested to different percentages of
bitumen.

One sample was tested with three different percentages of bitumen. This sample has 46%
passing 4.75mm and 10% passing 75µm and a plasticity index of 5%, the sample was tested
with 2.0%, 3.0% and 4.0%, and 2.0% hydrated lime. Figure 5-3 indicates that the bitumen
content was past the optimum bitumen content for the material tested. The dashed lines
are extrapolations of the curves based on the three points tested. This extrapolation
indicates optimum bitumen content at the maximum modulus is achieved.

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Figure 5-4 illustrates how the maximum modulus varies with different bitumen contents. As
the bitumen content increases the percentage of material finer than 75µm where the
maximum modulus increases and the maximum modulus decreases.

12000 89%

Retained Modulus - Ratio of Wet to Dry Modulus (%)

11000 86%

10000 83%
Resilient Modulus (Mpa)

9000 80%

8000 77%

7000 74%

6000 71%

5000 68%

4000 65%
0.0% 0.5% 1.0% 1.5% 2.0% 2.5% 3.0% 3.5% 4.0%
Bitumen Content (%)

Dry Modulus (Mpa) Wet Modulus (Mpa) Retained Modulus (%)

Figure 5-3: Bitumen Content vs. Resilient Modulus and Ratio of Retained Modulus

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 12000

10000
Resilient modulus (Mpa)

8000

6000

4000

2000

0
0 2 4 6 8 10 12 14 16
% Passing 75um

3% Bitumen 1.5% Lime 3.5% Bitumen 1.5% Lime

3% Bitumen 1.5% Lime - Wet 3.5% Bitumen 1.5% Lime - Wet

Figure 5-4: Effect on modulus from variations in bitumen content

5.5 Effects of Particle Size Distribution on the Bitumen Content of a

Foamed Bitumen Stabilised Pavement

5.5.1 Particle Size Distribution and Bitumen Content

The particle size distribution of the material is used to determine the suitability of the
material for foam bitumen stabilisation and as an indicator of the percentage of bitumen to
use in the mix design. Materials with different percentages of fine material will be affected
by the resulting stabilised pavement in different ways.

5.5.1.1 Effect of Particle Size Distribution of Bitumen Content

In all the design guides there is a sliding scale for the percentage of bitumen to use in design
trial mixes. Typically the design guides indicate increasing bitumen content with increasing
material passing. The data collected from the testing conducted appears to support this
information. As the percentage of material finer than 75µm increases the pavement
material is able to take a greater bitumen content.

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 12000

10000
Resilient modulus (Mpa)

8000

6000

4000

2000

0
0 2 4 6 8 10 12 14 16
% Passing 75um

3% Bitumen 1.5% Lime 3.5% Bitumen 1.5% Lime

Figure 5-5 Effect of particle size distribution on Bitumen Content

5.6 Effects of Marginal Materials on a Foamed Bitumen Stabilised

Pavement

A material can be defined as marginal based on the particle size distribution of the material,
the type and quality of the material in the pavement, and if the pavement has been
previously stabilised. Material which are considered marginal or unsuitable for use in foam
bitumen stabilisation are usually discarded prior to testing as these materials are commonly
thought to be unusable. The effect of these materials on the pavement can vary from an
unsatisfactory to a successful pavement.

5.6.1 Marginal Materials

5.6.1.1 Particle Size Distribution

If the particle size distribution of the pavement material is at the edge, or outside, the
preferred grading envelopes for foamed bitumen than it may be considered a marginal
material (Figure 2-7). Some specifications give actual limits where the material is
considered unsuitable and marginal. As previously discussed I am using the preferred
grading envelope from Austroads (2012) and considering material at the outer edge of the
grading envelope marginal
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5.6.1.2 Material Quality
The quality of the material can make a pavement a marginal material. If the material is has
too much clayey material or particles which will breakdown under compaction. Materials
which breakdown under compaction will make excess fines and these will not be coated in
bitumen making pockets of unstabilised material in the pavement. This is likely to occur in
materials containing excess amounts of sandstone, RAP, or highly weathered aggregates.

5.6.1.3 Previously Stabilised Pavement

As discussed earlier there are four different methods of stabilisation, mechanical,
cementitious, bituminous, and chemical. A road pavement in need of rehabilitation may
have been previously stabilised by any one of these methods. A pavement previously
stabilised by mechanical means may be difficult to identify, and due to the fact that foam
bitumen stabilised pavements have not reached the repair and rehabilitation phase of their
life cycle these two types of previously stabilised pavements are beyond the scope of this
report.

5.6.2 Marginal Materials by Particle Size Distribution

Most of the materials tested fall outside the preferred grading envelope at some point,
while very few samples were mostly or completely out of the grading envelope.

100

90

80

70

60
% Passing

50

40

30

20

10

0
0.01

0.10

1.00

10.00
6.7
0.075

0.150

0.300

0.600

1.18

2.36

4.75

19.0
26.5

AS Sieve Sizes (mm)

Profile 1 Profile 2 Profile 3 Profile 4 Profile 5

Profile 6 Profile 7 Profile 8

Figure 5-6: Marginal materials by Particle Size Distribution

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Materials where the grading goes above and to the left the grading envelope are too fine.

Sample ID Bitumen Dry Cured Wet Cure

Lime Content
Content Modulus (MPa) Modulus (MPa)
3.5% 2.0% 5385 2016
Mackay 4
4.5% 2.0% 4525 2090
Southern
3.5% 1.5% 8413 6479
Queensland 1
Sydney 1 3.5% 1.5% 2389 1561
Bega 3 3.5% 1.5% 5867 3254
Bega 4 3.5% 1.5% 4089 2275
Victoria 3 3.5% 1.5% 3164 1738
Victoria 6 3.0% 1.5% 4469 3525
Victoria 7 3.0% 1.5% 5631 4063
Victoria 8 3.5% 1.5% 5657 4553
Table 5-4: Material for Grading Profile 1

Material like Grading Profile 1, are deficient in coarse and medium gravel sizes, material
greater than 4.75mm; this material will not benefit from the mechanical interlock of the
coarse aggregate. Most of the materials tested achieved sufficient resilient modulus to for a
high traffic road (>1000 ESA/day). These samples are mostly silty or sandy gravels, where
there is and excess amount of material in the sandy or silty sizes. While the results for the
testing conducted on the sample Sydney 1 indicate will not produce a pavement suitable to
carry low traffic counts (<100 ESA/day). This sample contained a high percentage of R.A.P.
and is further explored in section 5.6.3.1.

In profile 2 the material has an excess amount of medium/fine gravel to coarse sand sizes,
material sized from 4.75mm to 600µm size; this type of material is gap graded in one size in
this range. Most of the samples tested have resilient modulus results to indicate a
satisfactory pavement can be produced. A number of the samples have high dry modulus
and low wet modulus results. This indicates that the pavement materials are susceptible to
loss of strength resulting from the ingress of moisture. Most of the samples consisted of
silty or sandy gravels, and being gap or poorly graded had the potential to have an increased
amount of voids for the moisture to get in. The samples Victoria 1 & 2 had high quantities
of sandstone and will be discussed in section later in section 5.6.3.2 .

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Sample ID Bitumen Dry Cured Wet Cure
Lime Content
Content Modulus (MPa) Modulus (MPa)
3.5% 2.0% 5385 4525
Mackay 4
4.5% 2.0% 2016 2090
Sunshine Coast
3.0% 2.0% 1490 1417
12
Sunshine Coast
3.0% 2.0% 4367 1300
13
Byron Regional
3.0% 2.0% 4014 1890
Council
Parkes 2 3.5% 1.5% 5270 1388
Parkes 3 3.5% 1.5% 4153 2676
Parkes 4 3.5% 1.5% 5647 3446
Parkes 5 3.5% 1.5% 4326 1489
Parkes 6 3.5% 1.5% 7030 3882
Bathurst 1 3.5% 1.5% 2749 1381
Bathurst 5 3.5% 1.5% 5847 3730
Bega 5 3.5% 1.5% 4524 2835
ACT 2 3.5% 2.0% 7604 7044
Victoria 1 3.0% 1.5% 5629 301
Victoria 2 3.5% 1.5% 5715 718
Table 5-5: Material for Grading Profile 2

In profile 3 the material has excess silty or clay materials. This material will require more
bitumen to coat all the fine material. The sample Mackay 3 consisted of silty gravel and the
fine end of the grading is on the upper grading limit. Increases in the bitumen content
indicate some improvement, however the bitumen content required to improve the
material may make the process too expensive to be a viable option.

Sample ID Dry Cured Wet Cure

Bitumen Content Lime Content
Modulus (MPa) Modulus (MPa)
3.5% 2.0% 2955 1088
Mackay 3
4.0% 2.0% 2792 1141
Table 5-6: Material for Grading Profile 3

On the underside of the grading envelope the grading profiles are too coarse in size.
Material in profile 4, tend to be very bony, with an excess amount of coarse gravel. No
samples were tested with this grading.

Profile 5 is material where there is an excess in the medium and coarse gravel size and
deficiency in the sand and silt sizes. While there may be sufficient material passing the

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75µm size to indicate a successful foam bitumen mix there may not be sufficient material in
the fractions above to bind the material properly. The sample Bega 4 was a material which
had been previously stabilised and this may account for the high modulus results.

Sample ID Bitumen Dry Cured Wet Cure

Lime Content
Content Modulus (MPa) Modulus (MPa)
Bega 1 3.5% 1.5% 3984 2932
Table 5-7: Material for Grading Profile 5

Profile 6 is material with insufficient fine material especially the passing 75µm. Material like
this will, when mixed with foam bitumen, most probably result in bitumen stringers or dags
and lumps of bitumen encrusted in coarse aggregate; to prevent this reduced bitumen
contents may be required. This material will benefit from bending in another material with
fine material prior to stabilisation. While the samples Sydney 5 & 6 and Victoria 4 & 5 both
have insufficient material finer than 75µm to be considered for treatment with foamed
bitumen the modulus results were satisfactory to produce pavements for moderate to high
traffic counts. This may be the result of the samples ‘Sydney 5’ and ‘Sydney 6’ being
previously stabilised, (see section 5.6.3.3.1) and in the case of the Victoria samples,
sufficient material finer than 4.75mm to improve the material.

Sample ID Lime Dry Cured Wet Cure

Bitumen Cement
Content Modulus Modulus
Content Content
(MPa) (MPa)
2.0% 0.0% 1.0% 1689 1140
Whitsunday
3.0% 0.0% 1.0% 1648 1117
Coast 3
4.0% 0.0% 1.0% 1420 1008
Sydney 5 3.5% 2.5% 0.0% 3762 2759
Sydney 6 3.5% 2.5% 0.0% 3892 3314
Victoria 4 3.0% 1.5% 0.0% 5427 2842
Victoria 5 3.0% 1.5% 0.0% 7194 4995
Table 5-8: Material for Grading Profile 6

Profile 7 consists of materials which are deficient in the coarse fractions and have an excess
amount of fine fractions. These materials are generally too fine and tend to have high clay
and silt contents and are more likely to be gravelly clays. An example of this type of
material is ‘Mackay 5’.

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Sample ID Bitumen Dry Cured Wet Cure
Lime Content
Content Modulus (MPa) Modulus (MPa)
3.5% 2.0% 4624 892
Mackay 5
4.5% 2.0% 4028 1107
Table 5-9: Material for Grading Profile 7

This material had a high dry modulus and a very low wet modulus. This shows the materials
highly sensitive to loss of strength due to moisture, this is probably due to the excess
amount of fine material. The effect of moisture is reduced with increased bitumen however
the dry modulus is seen to decrease more rapidly. While higher bitumen content may
improve the wet modulus, higher bitumen content may result in making the treatment too
expensive to be serviceable.

Sample ID Bitumen Lime Content Dry Cured Wet Cure

Content Modulus (MPa) Modulus (MPa)
Mackay 2 2.0% 2.0% 3191 2270
Table 5-10: Grading Profile 8 Material

Grading Profile 8 is representative of a material which is deficient in fine material and

considered to be “bony”. This material poorly graded containing and excess amount of
coarse material. ‘Mackay 2’ is a material fitting this profile. The stabilised material
indicated it may make a suitable pavement and may be suitable for traffic loading of up to
1000 ESA’s/day.

5.6.3 Marginal Material by Material Quality

Most specifications identify a number of material qualities as indications on marginal or
unsuitable materials. Excessive bitumen in the pavement material, materials prone to
breakdown and previously stabilised materials are all seen as being undesirable.

5.6.3.1 Recycled Asphalt Pavement (RAP) Blend

Sample: Sydney 1

The sample ‘Sydney 1’ was a good example of a material with a high percentage of RAP,
with the sample containing a blend 55% RAP. The modulus for this material was poor with
the cured modulus not making the minimum requirement for a road with less than 100
ESA’s /day while the soaked and the retained were satisfactory for this category of traffic.

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In the sample ‘Sydney 1’ the pavement material contained 55% Recycled asphaltic
pavement and 45% crusher dust. This material blend was tested with 3.0% bitumen and 2%
lime. A summary of the results of the modulus testing is shown in Table 5-11.

Sample ID ‘Dry’ Cured Modulus ‘Wet’ Cured Modulus Retained Modulus

(MPa) (MPa) Ratio (%)
Sydney 1 2389 1561 65%
Table 5-11: Summary of "Sydney 1" Modulus Testing

This shows that the pavement may have too much total bitumen in the mix. The bitumen
content of the RAP has an effect of the bitumen content of the stabilised material. This
sample has a low dry cured modulus and a relatively high wet cured modulus as indicated by
the retained modulus ratio. This may suggest that the bitumen is causing some lubrication
of the particles allowing movement in the pavement material, while decreasing the
susceptibility of the material to moisture.

Sample: ACT 1 & ACT 2

The samples ‘ACT 1’ and ‘ACT 2’ both had a low percentage of RAP in the blend; the sample
consisted of a blend on 93% existing pavement and 7% RAP. These modulus results
exceeded the minimum design requirements of a road to carry more than 1000 ESA’a/day in
the year of opening.

Sample ID ‘Dry’ Cured Modulus ‘Wet’ Cured Modulus Retained Modulus

(MPa) (MPa) Ratio (%)
ACT 1 8357 5861 70%
ACT 2 7604 7044 93%
Table 5-12: Summary of Modulus testing for "ACT 1” and "ACT 2"

The ACT samples had considerable less RAP blended into the material than the Sydney
sample. This suggests that increasing percentage of RAP blended into pavement material
results in a decrease in the resilient modulus of the test specimens. There may be an
optimum percentage of RAP which can be blended in to the pavement material before the
modulus of the test specimens is effected, this may be an area for consideration for future
study.

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5.6.3.2 Material Prone to Breakdown during Compaction
Sample: Victoria 1 & Victoria 2

In samples Victoria 1 & 2, the pavement consisted of 60% sandstone and 40% 20mm
aggregate. The blended material was tested with 3.0 and 3.5% bitumen and 1.5% lime. A
summary of the results of the modulus testing is shown in

Sample ID ‘Dry’ Cured Modulus ‘Wet’ Cured Modulus Retained Modulus

(MPa) (MPa) Ratio (%)
Victoria 1 5629 301 5%
Victoria 2 5715 718 13%
Table 5-13: Summary of Modulus testing for "Victoria 1” and "Victoria 2"

Both of the these samples show a high dry cured modulus indicating that there is the
material has good dry strength while the wet strength is very low which suggests that the
bulk of the material in the pavement has a relatively low wet strength of the pavement will
be prone to breakdown with increased moisture.

5.6.3.3 Previously Stabilised Materials

5.6.3.3.1 Pavements previously treated with cementitious binders

Previously stabilised materials are considered unsuitable for foamed bitumen stabilisation.
This is because pavement materials previously treated by cementitious stabilisation have a
tendency not to produce many fines. This is due to the binder cementing the fine particles
together and the pavement shattering during milling which does not produce fine material.
Another problem that occurs is that the particles produced are not likely be to be discreet
particles but cemented conglomerations of coarse medium and fine sizes. These particles
may be prone to breakdown during stabilisation, compaction and or service. As these
particles breakdown they will produce fine material which will in turn make for weak
treated pockets in the pavement which may result in the pavement blowing out or washing
out.

Sample: Sydney 6 & Sydney 7

The samples taken from the locations ‘Sydney 6’ and ‘Sydney 7’ contained examples of
heavy bound pavement which, when prepared for testing, still had very high strength bound
aggregation and as such most of the fine particles were still bound together. From the
particle size distributions of these samples it can be seen that both of these materials have
4% less than 75µm size and 30% and 26% respectively less than 4.25mm size. These
aggregations, at the time of testing, were not prone to breakdown and with the previous

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cementitious stabilisation and the foamed bitumen restricting the ingress of moisture the
material was able to retain a higher wet cured modulus. The modulus results for these
materials would indicate design traffic of 100-1000 ESA/day

Sample ID ‘Dry’ Cured Modulus ‘Wet’ Cured Modulus Retained Modulus

(MPa) (MPa) Ratio (%)
Sydney 5 3762 2754 73%
Sydney 6 3892 3314 85%
Table 5-14: Summary of Modulus testing for "Sydney 5” and "Sydney 6"

Sample: Bega 4, Bega 5 & Bega 6

The samples ‘Bega 4’ and ‘Bega 5’ both show results suitable for design traffic of greater
than 1000 ESA/day. More fines were present in these materials with 11% and 12%
materials less than 75µm size and 77% and 78% less than 4.75mm respectively. These
samples have shown some potential for breakdown during milling, producing enough fine
material for successful foamed bitumen stabilisation. The retained modulus ratio of ‘Bega 4’
and ‘Bega 5’ were not as high as that of ‘Sydney 5’ and ‘Sydney 6’, but the dry strength was
higher indicating that ‘Bega 4’ and ‘Bega 5’ were more susceptible to the effects of moisture

The results for ‘Bega 6’ show a pavement suited to less than 100 ESA/day. This material had
more coarse material produced during milling and similar percentages of material finer than
75µm as ‘Bega 4’ and ‘Bega 5’ and less material finer than 4.75mm. The dry modulus is
considerably lower than ‘Bega 4’ and ‘Bega 5’ and the wet modulus is similar to ‘Bega 4’.
This indicates that some breakdown of the coarse particles may have occurred during
compaction resulting in the lower dry modulus.

Sample ID ‘Dry’ Cured Modulus ‘Wet’ Cured Modulus Retained Modulus

(MPa) (MPa) Ratio (%)
Bega 4 4089 2275 56%
Bega 5 4524 2835 63%
Bega 6 2849 2162 76%
Table 5-15: Summary of Modulus testing for "Bega 4”, "Bega 5" and "Bega 6"

Sample: Tamworth

The particle size distribution for the ‘Tamworth’ sample is within the ideal grading envelope,
this suggests that this material should be suited to foamed bitumen stabilisation. The
materials description indicating that the material has been previously stabilised indicates
that it is not suited to foamed bitumen stabilisation. The modulus results indicate that the
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pavement material should not be used for foamed bitumen stabilisation. This results for
this sample show that some of the coarse particles may be breaking down during
compaction leaving pockets of unstabilised material.

Sample ID ‘Dry’ Cured Modulus ‘Wet’ Cured Modulus Retained Modulus

(MPa) (MPa) Ratio (%)
Tamworth 2147 1058 49%
Table 5-16: Summary of Modulus testing for "Tamworth"

5.6.3.3.2 Pavements Previously Treated with Polyroad

Polyroad is a polymer based stabilising agent which preserves the dry strength of the
pavement material. Polyroad works by having an insoluble polymer coating an inert carrier
which coats the particles in the pavement material, Polyroad also uses lime to cause clay
particles to flocculate aiding the coating process.

Sample: Bega 1 & Bega 2

The sample ‘Bega 1’ and ‘Bega 2’ are samples which were previously treated with a Polyroad
stabilising agent. The test specimens for these locations performed quite well. Both
samples achieved the minimum wet cured requirements for a road to carry more than 1000
ESA’s/day in the year of opening. The ‘Bega 1’ sample was only just low of this minimum
dry cured requirement for while the Bega 2 sample achieved the minimum requirement.
The retained modulus for these samples was 74% and 55% respectively; this indicated that
the ‘Bega 1’ sample has potentially received greater residual benefits from the previous
application of the Polyroad product.

Sample ID ‘Dry’ Cured Modulus ‘Wet’ Cured Modulus Retained Modulus

(MPa) (MPa) Ratio (%)
Bega 1 3984 2932 74%
Bega 2 5867 3254 55%
Table 5-17: Summary of Modulus testing for "Bega 1” and "Bega 2"

Road pavements previously treated with Polyroad may have some residual effects of the
treatment. Polyroad preserves the strength of the pavement material by waterproofing the
particles. Waterproofing the fine particles of the pavement material is a secondary effect of
the foam bitumen process. As a result pavements previously treated by Polyroad may have
wet cured modulus much higher than usual for the bitumen content.
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6 Conclusions

In the process of conducting this project, I have assessed materials from a number of
locations across Eastern Australia through Queensland, New South Wales and Victoria.
Materials were tested to determine their properties prior to stabilisation and the resilient
modulus of the post stabilised material. The material properties tested prior to stabilisation
were particle size distribution and plasticity. Via visual assessment the material description
and quality was ascertained to assist in categorising the pavement material. The materials
were subjected to foamed bitumen stabilisation and tested for the resulting resilient
modulus after a period of dry curing and then retested after wet curing. From this, data was
assessed to determine the effects of the particle size distribution, percentage of bitumen
and material quality on the modulus and how the service life of the resultant pavement may
be affected.

When examining the pavement materials, it was found, that the particle size distribution
had an influence on the post stabilised materials. Due to the complexity of the particle size
distributions the percentage of material finer than 75µm and 4.75mm were used when
determining the influence of the particle size distribution on the resilient modulus and
bitumen content of the stabilised pavement. The resilient modulus of the stabilised
materials was initially found to increase as the percentage of material finer than 75µm
increased, for a given bitumen content. This continued till a maximum modulus was
achieved, after this point increasing amounts of material finer than 75µm results in
decreasing modulus, as the amount of fine material exceeds the point where the bitumen
can satisfactorily bind the particles in the pavement. When examining the effect of the
percentage of material finer than 4.75mm, it was found that when the material had less
than 50% finer than 4.75mm there was a higher peak modulus coinciding with a lower
percentage of material finer than 75µm when compared to a material with more than 50%
finer than 4.75mm. This demonstrates that there is an optimum percentage of material
finer than 75µm the percentage of bitumen used in stabilisation process.

Similar results were obtained when different percentages of bitumen were used. When the
bitumen content was increased while the optimum percentage of material finer than 75µm
increased. The rate the resilient modulus increased and decreased was less severe,
reducing the how sensitive the modulus is to changes in the particle size distribution. This
indicates that there is an optimum percentage of material finer than 75µm for each
different percentage of bitumen used. The amount of bitumen used in the foamed bitumen
stabilisation process was found to affect the service life of the pavement. As the modulus of
the pavement increases so does the service life of the pavement. When the bitumen
content is increased, the service life increases more rapidly with smaller increments in the
resilient modulus.

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The effect of the roadbase material quality was assessed with mixed results. Roadbase
materials where the particle size distribution was marginal or non-compliant with respect to
the Austroads preferred limits indicated that the main contributing factor was the
percentage of material finer than 75µm and 4.75mm. The resilient modulus of pavements
with very low percentages (less than 5% finer than 75µm) of fine material required small
quantities of foamed bitumen and are very sensitive to fluctuations in the amount of
bitumen used. While pavements, with high to very high percentages (more than 20% finer
than 75µm) of fine material, require high quantities of foamed bitumen and the resilient
modulus is less sensitive to small variations in the amount of bitumen added. These
materials do not have a tendency to to achieve the prescribed modulus limits. Blending
with other materials to improve the particle size distribution may be required for successful
foamed bitumen stabilisation. Pavements where the percentage of material finer than
4.75mm is satisfactory yet the coarse fractions are marginal or non-compliant, the modulus
has the tendency to be satisfactory however foamed bitumen mix testing to confirm the
materials suitability still be conducted on a case by case basis.

Roadbase materials which were considered marginal because of material quality were
tested. The testing included materials containing Recycled Asphaltic Pavement (RAP),
materials likely to breakdown during compaction, and material from previously stabilised
pavements. When a high proportion of RAP was blended into the pavement material it was
found to be detrimental to the resilient modulus of the stabilised pavement. However,
small quantities of RAP in the pavement material had little effect on the modulus of the
pavement. Further testing is needed to determine the upper limiting content of RAP which
can be blended into a pavement material for foamed bitumen stabilisation.

Pavements containing material prone to breakdown were tested, these pavement typically
contained sandstone. When a material is mixed with the foamed bitumen the fine particles
are coated with the bitumen. With these materials, during compaction some of the larger
particles and aggregations may breakdown, producing more fine material. This newly
produced fine material has had little or no exposure to the foamed bitumen so pockets of
untreated material form. Testing on these samples showed high dry cured resilient modulus
while the wet cured resilient modulus was very low showing high sensitivity to moisture.
This indicates that while dry these pockets of untreated materials can maintain some
strength however when wet these untreated particles are allowed to slide over each other
resulting in a lower resilient modulus. From this it should be recommended that roadbase
materials prone to break down during compaction are unsuitable for foamed bitumen
stabilisation.

The suitability for, foamed bitumen stabilisation, of pavement materials that were
previously stabilised was inconclusive. Pavements which were previously stabilised using
cementitious binders cement the particles together. When the pavement is milled a
reduced amount of fine material may be produced as the cemented pavement tends to

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shatter and the fine particles remain bound together. Some previously stabilised pavement
material, due to fatigue or loss of strength, may breaks down during compaction. As a
result the material will not be suitable for foamed bitumen stabilisation. If enough fine
materials is produced and the previously stabilised material has a high residual strength it
may prove satisfactory. Pavements previously treated with products like PolyRoad may
have a higher retained modulus ratio than the material would normally have. This is due to
the PolyRoad product waterproofing the material. If the previous PolyRoad treatment is still
serviceable in the pavement it may help increase the wet cured modulus of an otherwise
unsuitable material.

When looking at the service life of a foamed bitumen stabilised pavement with respect to
the particle size distribution, similar trends were found. Maximum service life coincided
with the optimum percentage of material finer than 75µm for maximum modulus and the
service life dropped off on either side of this point. The service life of the pavement was
found to be very sensitive to increases in the amount of material finer than 75µm and the
percentage of bitumen used in the pavement. As a result of this sensitivity care must be
taken to ensure accuracy in the delivery and the quantity of bitumen added to stabilise the
pavement. Accuracy in sampling and testing is also important as variations in the particle
size distribution can result in significant differences in strength and service life impacting on
the design of the pavement.

In conclusion, particle size distribution and bitumen content does have a significant effect
on a foamed bitumen stabilised roadbase material, influencing both the modulus and
service life of the resulting pavement. Some marginal materials may be used in foamed
bitumen stabilisation. Materials with insufficient or excess fine materials typically will not
be suited. Where the quality of the material is poor, the material again may not be suited.
Where material quality is in question testing should be conducted to determine if the
material can be used.

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7 Further Research
From this study, a number of areas of further exploration can be identified.

 The sensitivity of the modulus of foamed bitumen stabilised roadbase materials to

changes in the particle size distribution can be a critical issue for foamed bitumen
stabilisation pavement design. From this, examination of the effects of different
field sampling methods for collecting laboratory test samples and heavy plant used
in pavement stabilisation on the particle size distribution of a road pavement
material.

 Blending RAP into a pavement to improve it for foamed bitumen stabilisation may
become an environmentally beneficial way to dispose of a waste product resulting
from road pavement rehabilitation and remediation. This study has indicated that
the ratio of RAP to roadbase material may have an influence on the resulting
pavement. Assessment of the quantity of RAP which can be blended into a roadbase
pavement for to produce serviceable foamed bitumen stabilised pavements.

 The briquettes for this work was conducted using Marshall hammer, an alternate
method of compaction is using a servopac gyratory compactor. These compaction
methods compact the material in completely different way, and the method of
compaction for the foamed bitumen specimens may have an effect on the modulus.
How do these compaction methods affect the modulus and how will the compaction
method affect the pavement design. This is issue is currently up for debate in the
industry.

 Another area for further research could be focused around the debate of whether
foamed bitumen stabilisation should be treated as asphalt. The void content of
asphalt is critical in the design of an asphalt pavement. Does the void content of a
foamed bitumen stabilised pavement affect the resilient modulus and serviceability
of the pavement.

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8 Reference List
Asphalt Academy, A, Technical guideline: bitumen stabilised matrials, TG2, 2009,
Asphalt Academy, CSIR Build Environment, Pretoria, South Africa.

Andrews, B 2006, Guide to pavement technology part 4D: Stabilised Materials,

Austroads.

Australia., SAo 1997, Residual bitumen for pavements, Standards Australia,

Sydney.

Austroads 2011a, Review of Foamed Bitumen Stabilisation Mix Design Methods,

Austroads Inc., Sydney.

Austroads 2011b, Review of structural design procedures for foamed bitumen

pavements, Austroads, Sydney Australia.

Austroads 2012, Guide to Pavement Technology: Part 2 - Pavement Structural

Design, Austroads, Sydney.

Austroads. 2002, Bitumen sealing safety guide, 2nd edn, Austroads, Sydney.

Collings, D & Thompson, H 2007, 'A Critical Appraisal of the Performance of

Foamed Bitumen and Bitumen Emulsion Treated Materials', in Proceedings of the
9th Conference on Asphalt Pavements for Southern Africa (CAPSA’07):
proceedings of theProceedings of the 9th Conference on Asphalt Pavements for
Southern Africa (CAPSA’07) p. 5.

Foley, G 2002, Mix design for stabilised pavement materials, Austroads, Sydney.

Jones, J & Ramanujam, I, Design of Foamed Bitumen Stabilised Pavements, 2008,

PMB Department of Main Roads, Road & Delivery Performance Division,
Queensland Department of Main Roads, Herston Queensland.

Kendal, M, Baker, B, Evans, P & Ramanujam, I 1999, 'Foamed Bitumen

Stabilisation', in Foamed Bitumen Stabilisation - Southern Region Symposium:
proceedings of theFoamed Bitumen Stabilisation - Southern Region Symposium
Queensland Department of Main Roads & transport.

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An Analysis of Roadbase Materials used in Foamed Bitumen Stabilisation
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Kendall, M, Baker, B, Evans, P & Ramanujan, J 2001, 'FOAMED BITUMEN
STABILISATION–THE QUEENSLAND EXPERIENCE', in 20th australian road
research conference: proceedings of the20th australian road research conference.

Leek, C & Jameson, G 2011, Review of foamed bitumen stabilisation mix design
methods, 1921709774, Austroads.

Muthen, K 1998, 'Foamed asphalt mixes-mix design procedure', Transportation

Research Record, vol. 898, pp. 290-6.

Ramanujam, J, Jones, J & Janosevic, M 2009, 'Design, construction and

performance of insitu foamed bitumen stabilised pavements', QUEENSLAND
ROADS, no. 7.

Sharp, K 2009, Guide to pavement technology: part 1: introduction to pavement

technology.

Tamsett, P, RMS Austroads Supplement for Guide to Pavement Technology - Part 2:

Pavement Structural Design, 2013, RPaG Engineering, Roads and Maritime
Services.

TMR 2012, Pavement Rehabilitation Manual, Queensland Government

Department of Transport and Main Roads.

Vorobieff, G 2005, 'Design of foamed bitumen layers for roads', in AustStab

workshop on road stabilisation in Queensland, Australia: proceedings of
theAustStab workshop on road stabilisation in Queensland, Australia.

Vorobieff, G 2012, Insitu Stabilisation, vol. CPE602/658, Centre for Pavement

Engineering Education, Box Hill North, Victoria, Australia.

Wardle, L 2004, CIRCLY 5.0, 5.0, MINICAD Systems Pty. Ltd., Richmond South,
Victoria.

Wilmot, T & Vorobieff, G 1997, 'Is road recycling a good community policy', in
Ninth National Local Government Engineering Conference: proceedings of
theNinth National Local Government Engineering Conference.

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 65
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Appendix A. Project Specification

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 Faculty of Health, Engineering and Sciences
ENG4111/ENG4112 Research Project Part 1 & 2
PROJECT SPECIFICATION

FOR: Adam O’Callaghan (0050049644)

TOPIC: AN ANALYSIS OF ROAD PAVEMENT MATERIALS USED IN FOAMED BITUMEN

STABILISATION

SUPERVISORS: Soma Somasundaraswaran

Peter Sheen, Coffey Pty. Ltd.

PROJECT AIMS: This project seeks to examine the material properties of road base materials used in foamed
bitumen stabilisation and the effect on the pavements strength and serviceability

SPONSORSHIP: Coffey Pty. Ltd.

PROGRAM:
1. Research the,
a. background of foamed bitumen stabilisation,
b. ideal material properties,
c. design requirements for foamed bitumen stabilisation.

2. Analysis the properties of materials used in foamed bitumen stabilisation from sites in New South Wales,
Queensland and Victoria.

3. Evaluate the influence of material properties on pavement strength and expected design life in ESAs

4. Analyse the effects of changes in the material properties of road base materials on resilient modulus
through laboratory testing.

5. Analysis the effect of bitumen content in marginal road base materials used in foamed bitumen.

If Time Permits

6. Evaluate the effects of air voids on pavement strength

7. The influence of varying the bitumen content on air voids and pavement strength.

Note: A Preliminary plan for material testing (proposed by the student)

Elements of this project will involve a variety of laboratory testing. I will need to learn and perform a number of
standard and specialised test methods. Some of the specialised testing equipment I will need to use including a
Wirtgen WLB10 laboratory scale foamed bitumen plant, located at the Coffey materials testing laboratory in
Concord West NSW, and MATTA testing equipment at the RMS laboratory in Bellambi NSW. I have access,
through my employer, to all the laboratory testing equipment I may require. I have been in contact with trained
and experienced technicians who are willing to guide me through the testing I will need to perform.

USQ collects personal information to assist the University in providing tertiary education and related ancillary services and to be able to contact you regarding enrolment, assessment and associated USQ
services. Personal information will not be disclosed to third parties without your consent unless required by law.

ENG4111 PROJECT PROPOSAL FORM VALID AT: 30 OCTOBER 2014 ISSUED 11/09/12
Appendix B. Test Data

B.1. Test Data Location: Northern Queensland

Sample ID Townsville Mackay 1 Mackay 2 Mackay 3
Material Existing Existing Roadbase Gravel Existing Existing Roadbase
Description Roadbase Roadbase Gravel
Gravel Gravel

26.5 100 100 100 100

% Material Passing AS Sieve Size (mm)

19.0 90 91 96 98
13.2 78 77 55 81
9.5 68 63 51 72
6.7 58 53 33 63
4.75 49 46 20 54
2.36 35 37 9 40
1.18 26 31 6 32
0.600 20 24 5 29
0.300 15 19 3 27
0.150 12 14 2 24
0.075 10 10 2 20
Binders
Bitumen 3.5% 3.5% 3.5% 3.5% 3.0% 3.0% 3.0%
Hyd. Lime 2.0% 1.5% 1.5% 1.5% 2.0% 2.0% 2.0%
Resilient Modulus (MPa)
7020 10755 9050 6365 3421 3409 2820
6630 10241 9206 6729 3511 2970 3041
7466 11053 9480 5427 2640 2485 2514
Dry Cured 7039 10683 9245 6174 3191 2955 2792
4819 8761 7185 4500 2279 1195 963
4100 8727 7452 4625 2569 1232 1335
4811 7987 6274 3854 1963 837 1125
Wet Cured 4577 8492 6970 4326 2270 1088 1141
Retained
Modulus 65% 79% 75% 70% 71% 37% 41%
Ratio
Table B-1: Northern Queensland roadbase test data Table (A)

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 Sample ID Mackay 4 Mackay 5 Mackay 6
Material Existing Roadbase Gravel Existing Roadbase Gravel Existing Roadbase Gravel
Description
26.5 100 100 100
% Material Passing AS Sieve Size (mm)

19.0 98 95 87
13.2 92 91 71
9.5 85 85 60
6.7 76 79 54
4.75 63 72 49
2.36 42 59 40
1.18 31 50 32
0.600 27 46 25
0.300 24 41 19
0.150 21 37 15
0.075 16 32 11
Binders
Bitumen 3.5% 4.5% 3.5% 4.5% 3.5% 4.0%
Hyd. Lime 2.0% 2.0% 2.0% 2.0% 2.0% 2.0%
Resilient Modulus (MPa)
5439 4690 4657 4209 -- 3963
5234 4135 4427 3770 6256 3462
5482 4750 4789 4106 4744 3916
Dry Cured 5385 4525 4624 4028 5500 3780
2231 1963 1025 1208 -- 2319
2039 2088 855 1033 4936 2367
1777 2219 796 1079 3274 2661
Wet Cured 2016 2090 892 1107 4105 2449
Retained
Modulus 37% 46% 19% 27% 75% 65%
Ratio
Table B-2: Northern Queensland roadbase test data Table (B)

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 Sample ID Mackay 7 Mackay 8 Mackay 9
Material Existing Roadbase 20mm Roadbase Gravel Existing Roadbase
Description Gravel Gravel

26.5 100 100 100

% Material Passing AS Sieve Size (mm)

19.0 96 95 83
13.2 81 83 73
9.5 70 71 64
6.7 60 61 56
4.75 51 53 49
2.36 37 38 38
1.18 27 29 30
0.600 21 23 23
0.300 17 18 17
0.150 14 14 13
0.075 9 11 10
Binders
Bitumen 3.5% 4.5% 3.5% 4.0% 3.5% 4.5%
Hyd. Lime 2.0% 2.0% 2.0% 2.0% 2.0% 2.0%
Resilient Modulus (MPa)
7512 5631 5898 4586 3292 3316
7315 4093 5804 5125 3419 4290
6552 7045 3915 3305 3932 3081
Dry Cured 7126 5590 5206 4339 3548 3562
5186 4832 4222 3161 1042 2108
5859 3178 3769 3211 1093 2102
6037 5851 2923 1692 2108 3687
Wet Cured 5694 4620 3638 2688 1414 2632
Retained
Modulus 80% 83% 70% 62% 40% 74%
Ratio
Table B-3: Northern Queensland roadbase test data Table (C)

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 Grading Profiles: Northern Queensland
100

90

80

70

60
% Passing

50

40

30

20

10

0
0.0

0.1

1.0

10.0
6.7
0.075

0.15

0.300

0.425

0.600

1.18

2.36

4.75

13.2

19.0

26.5

37.5
AS Sieve Sizes (mm)

Townsville Gladstone Upper Limit Austroads Lower Limit Austroads

Figure B-1: North Queensland grading profiles - Townsville and Gladstone

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 Grading Profiles: Northern Queensland (Mackay)
100

90

80

70

60
% Passing

50

40

30

20

10

0
0.0

0.1

1.0

10.0
0.15

1.18

2.36

4.75

6.7

13.2

19.0

26.5

37.5
0.075

0.300

0.425

0.600
AS Sieve Sizes (mm)

Makay 1 Makay 2 Makay 3 Upper Limit Austroads

Mackay 4 Mackay 5 Mackay 6 Lower Limit Austroads
Mackay 7 Mackay 8 Mackay 9

Figure B-2: North Queensland grading profiles - Mackay

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B.2. Northern Queensland (Whitsunday Coast)
Sample ID Whitsunday Coast 1 Whitsunday Coast 2
Material Existing AC & Roadbase Existing AC & Roadbase
Description
26.5 100 100
% Material Passing AS Sieve Size (mm)

19.0 98 98
13.2 83 84
9.5 68 70
6.7 55 58
4.75 46 49
2.36 33 35
1.18 23 26
0.600 15 18
0.300 10 13
0.150 7 9
0.075 6 7
Binders
Bitumen 2.0% 3.0% 4.0% 3.0% 2.0% 3.0% 4.0%
GP Cement 1.0% 1.0% 1.0% 0.0% 1.0% 1.0% 1.0%
Hyd. Lime 0.0% 0.0% 0.0% 1.0% 0.0% 0.0% 0.0%
Resilient Modulus (MPa)
2358 1621 1448 2193 3314 2047 897
2093 1761 1196 1915 4156 1838 1231
1997 1518 933 2463 3486 1695 920
Dry Cured 2149 1633 1192 2190 3652 1860 1016
1475 1134 1217 1985 1545 969 1021
1422 1214 853 1649 1912 923 931
1300 1041 783 1916 1684 964 497
Wet Cured 1399 1130 951 1850 1714 952 816
Retained
Modulus 65% 69% 80% 84% 47% 51% 80%
Ratio
Table B-4: Northern Queensland (Whitsunday Coast) roadbase test data Table (A)

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 Sample ID Whitsunday Coast 3 Whitsunday Coast 4
Material Existing AC & Roadbase Existing AC & Roadbase
Description
26.5 100 100
% Material Passing AS Sieve Size (mm)

19.0 97 97
13.2 78 84
9.5 62 71
6.7 47 61
4.75 38 52
2.36 27 40
1.18 19 29
0.600 13 19
0.300 8 12
0.150 6 8
0.075 4 6
Binders
Bitumen 3.5% 3.5% 3.5% 3.5% 3.5% 3.5%
GP Cement 1.0% 1.0% 1.0% 1.0% 1.0% 1.0%
Resilient Modulus (MPa)
1832 1832 1637 1999 1687 1264
1883 1453 1290 2297 1489 1419
1353 1660 1332 1858 1625 1228
Dry Cured 1689 1648 1420 2051 1600 1304
1200 1167 1246 1630 1038 967
1324 949 796 1183 1009 1060
896 1234 983 1450 1001 874
Wet Cured 1140 1117 1008 1421 1016 967
Retained
Modulus 67% 68% 71% 69% 63% 74%
Ratio
Table B-5: Northern Queensland (Whitsunday Coast) roadbase test data Table (B)

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 Grading Profiles: Northern Queensland (Whitsunday Coast)
100

90

80

70

60
% Passing

50

40

30

20

10

0
0.0

0.1

1.0

10.0
6.7
0.075

0.15

0.300

0.425

0.600

1.18

2.36

4.75

13.2

19.0

26.5

37.5
AS Sieve Sizes (mm)
Whitsunday Coast 1 Whitsunday Coast 2 Upper Limit Austroads
Whitsunday Coast 3 Whitsunday Coast 4 Lower Limit Austroads

Figure B-3: North Queensland grading profiles - Whitsunday Coast

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B.3. Sunshine Coast
Sample ID Sunshine Sunshine Sunshine Sunshine Sunshine Sunshine Sunshine
Coast 1 Coast 2 Coast 3 Coast 4 Coast 5 Coast 6 Coast 7

Material Clayey Clayey Sandy Clayey Clayey Clayey Clayey

Description gravel gravel Clayey Gravel Gravel Gravel Gravel
with with gravel with with with with
Bitumen Bitumen with Bitumen Bitumen Bitumen Bitumen
seal seal Bitumen Seal Seal Seal Seal
seal

26.5 100 100 100 100 100 100

% Material Passing AS Sieve Size (mm)

19.0 84 96 82 91 86 95 100
13.2 70 81 65 79 68 81 89
9.5 60 68 56 64 52 67 74
6.7 52 57 47 52 39 56 61
4.75 44 49 41 45 32 47 52
2.36 34 37 30 34 23 34 39
1.18 28 26 26 27 18 25 31
0.600 24 20 21 22 14 18 25
0.300 19 15 16 18 11 13 18
0.150 13 12 12 14 7 10 13
0.075 10 9 10 12 6 8 11
Binders
Bitumen 3.5% 3.0% 3.5% 3.5% 3.5% 3.0% 3.5%
Hyd. Lime 1.5% 1.5% 1.5% 2.0% 2.0% 2.0% 1.5%
Resilient Modulus (MPa)
-- -- 6367 6139 5992 4949 2642
-- -- 5602 7001 7114 4802 3481
-- -- 6103 6403 5960 4738 2993
Dry Cured 7339 5836 6024 6514 6355 4830 3039
-- -- 3749 4919 -- 2031 1687
-- -- 3194 5583 -- 2225 1669
-- -- 3310 5309 -- 2528 1571
Wet Cured 5786 3372 3418 5270 3889 2261 1642
Retained
Modulus 79% 58% 57% 81% 61% 47% 54%
Ratio
Table B-6: Sunshine Coast roadbase test data (Table A)

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 Sunshine Sunshine Sunshine Sunshine Sunshine Sunshine Sunshine
Sample ID Coast 8 Coast 9 Coast 10 Coast 11 Coast 12 Coast 13 Coast 14

Material Clayey Clayey Clayey Clayey Existing Existing Roadbase

Description gravel with gravel with Gravel with
Gravel Roadbase Roadbase Gravel
some some Bituminous
with Bituminous Bituminous seal
Gravel Gravel
Bitumen seal seal

Seal

26.5 100 100 100 100 100 100 100

% Material Passing AS Sieve Size (mm)

19.0 91 96 93 84 97 95 97
13.2 79 81 79 72 85 84 86
9.5 64 68 65 62 76 74 77
6.7 53 57 51 51 71 66 63
4.75 45 49 41 45 65 60 51
2.36 33 37 30 36 50 47 38
1.18 24 26 23 26 37 35 31
0.600 17 20 19 21 27 26 25
0.300 12 15 15 16 18 19 19
0.150 9 12 11 13 13 12 12
0.075 7 9 9 10 10 9 6
Binders
Bitumen 3.5% 3.5% 3.5% 3.5% 3.0% 3.0% 3.0%
Hyd. Lime 2.0% 1.5% 1.5% 1.5% 2.0% 2.0% 2.0%
Resilient Modulus (MPa)
2453 5611 7338 9829 1050 4220 1510
2795 6061 6930 4691 1860 4060 2311
2876 -- 7879 5116 1560 4820 2194
Dry Cured 2708 5836 7382 6545 1490 4367 2005
1091 3742 5903 2492 520 4870 714
1411 3001 5331 2092 1850 3770 1200
1248 -- 6322 2037 1880 4260 1049
Wet Cured 1250 3372 5852 2207 1417 4300 988
Retained
Modulus 46% 58% 79% 34% 95% 98% 49%
Ratio
Table B-7: Sunshine Coast roadbase test data Table B

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 Grading Profiles: Sunshine Coast (1)
100

90

80

70

60
% Passing

50

40

30

20

10

0
0.0

0.1

1.0

10.0
0.15

1.18

2.36

4.75

6.7

13.2

19.0

26.5

37.5
0.075

0.300

0.425

0.600
AS Sieve Sizes (mm)
Sunshine Coast 1 Sunshine Coast 2 Sunshine Coast 3 Upper Limit - Austroads
Sunshine Coast 4 Sunshine Coast 5 Sunshine Coast 6 Lower Limit - Austroads
Sunshine Coast 7 Sunshine Coast 8

Figure B-4: Sunshine Coast grading profiles (1-8)

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 Grading Profiles: Sunshine Coast (2)
100.0

90.0

80.0

70.0

60.0
% Passing

50.0

40.0

30.0

20.0

10.0

0.0
0.0

0.1

1.0

10.0
6.7
0.075

0.15

0.300

0.425

0.600

1.18

2.36

4.75

13.2

19.0

26.5

37.5
AS Sieve Sizes (mm)

Upper Limit - Austroads Sunshine Coast 10 Sunshine Coast 11 Sunshine Coast 12

Lower Limit - Austroads Sunshine Coast 13 Sunshine Coast 14

Figure B-5: Sunshine Coast grading profiles (10-14)

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An Analysis of Roadbase Materials used in Foamed Bitumen Stabilisation
Adam O’Callaghan - 0050049644
B.4. Southern Queensland
Sample ID Southern Southern Southern Southern Southern
Queensland Queensland Queensland Queensland Queensland
1 2 3 4 5
Material Silty Roadbase Roadbase Blended Roadbase
Description Roadbase Gravel + 10% Gravel + 10% Roadbase Gravel -
Gravel FH2.3 FH2.3 Gravel imported

26.5 100 100 100 100

% Material Passing AS Sieve Size

19.0 100 95 95 95 97
13.2 94 76 85 87 86
9.5 84 62 74 76 73
6.7 72 52 63 68 61
(mm)

4.75 62 46 54 60 50
2.36 46 38 41 49 35
1.18 34 30 31 41 26
0.600 27 21 25 35 20
0.300 21 15 20 28 16
0.150 16 12 18 21 12
0.075 12 11 17 17 9
Binders
Bitumen 3.5 3.5 3.5 3 3.5
Hyd. Lime 1.5 1.5 1.5 2 2.5
Resilient Modulus (MPa)
8214 6166 7078 7333 7256
7872 5549 -- 6888 --
9154 5986 7640 7383 --
Dry Cured 8413 5900 7359 7201 7256
6770 3124 5140 2599 3686
6436 2674 2163 3604 --
6231 2586 5292 2883 3385
Wet Cured 6479 2795 5216 2741 3536
Retained
Modulus 77% 47% 71% 38% 49%
Ratio
Table B-8: Southern Queensland roadbase test data

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 Grading Profiles: Southern Queensland
100.0

90.0

80.0

70.0

60.0
% Passing

50.0

40.0

30.0

20.0

10.0

0.0
0.0

0.1

1.0

10.0
6.7
0.075

0.15

0.300

0.425

0.600

1.18

2.36

4.75

13.2

19.0

26.5

37.5
AS Sieve Sizes (mm)

Upper Limit - Austroads Southern Queensland 1 Southern Queensland 2 Southern Queensland 3

Lower Limit - Austroads Southern Queensland 4 Southern Queensland 5

Figure B-6: Southern Queensland grading profiles

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An Analysis of Roadbase Materials used in Foamed Bitumen Stabilisation
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B.5. NSW Mid North Coast
Sample ID Tamworth Mulbring 1 Mulbring 2 Port Richmond Byron Byron
Macquarie River Region Region
Material Sandy Silty 60% 60% Clayey Existing Roadbase Existing
gravel with Decomposed Decomposed
Description Granite Granite Roadbase Roadbase Gravel, Roadbase
some
bituminous
40% 20/5mm 40% 20/5mm Gravel Gravel Sandy Gravel
Concrete Concrete Silty with
seal - aggregate aggregate
Cemented some AC
lumps
Polyroad
26.5 100 100 100 100 100 100 100
% Material Passing AS Sieve Size (mm)

19.0 89 89 89 99 84 90 94
13.2 81 68 68 89 71 88 82
9.5 71 60 60 76 59 84 73
6.7 58 56 56 54 51 73 63
4.75 46 52 52 52 43 61 55
2.36 31 44 44 37 34 50 43
1.18 21 37 37 29 29 43 34
0.600 15 29 29 22 24 37 26
0.300 11 18 18 17 22 30 15
0.150 8 12 12 14 19 24 10
0.075 6 9 9 11 12 17 8
Binders
Bitumen 3.5% 3.0% 3.5% 3.5% 3.5% 3.0% 3.5%
Hyd. Lime 1.5% 1.5% 1.5% 2.0% 2.0% 2.0% 1.5%
Resilient Modulus (MPa)
2194 7469 8567 5190 2926 -- 4125
1687 7802 9521 5224 3317 3897 4199
2560 6690 9093 4843 2650 4131 3978
Dry Cured 2147 7320 9060 5086 2964 4014 4101
1070 2819 4721 3446 1850 2365 2300
863 3284 4855 2496 2005 1476 2263
1241 2733 4034 2651 1547 1829 2357
Wet Cured 1058 2945 4537 2864 1801 1890 2307
Retained
Modulus 49% 40% 50% 56% 61% 47% 56%
Ratio
Table B-9: NSW Mid North Coast roadbase test data

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 Grading Profiles: NSW Mid North Coast
100

90

80

70

60
% Passing

50

40

30

20

10

0
0.01

0.1

10
6.7
0.15

1.18

2.36

4.75

13.2

19.0

26.5

37.5
0.075

0.300

0.425

0.600
AS Sieve Sizes (mm)

Tamworth Mulbring Port Macquarie Upper Limit - Austroads

Richmond River Council BRC1 TB032 Lower limit - Austroads

Figure B-7: NSW Mid North Coast grading profiles

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An Analysis of Roadbase Materials used in Foamed Bitumen Stabilisation
Adam O’Callaghan - 0050049644
B.6. Sydney
Sample ID Sydney 1 Sydney 2 Sydney 3 Sydney 4 Sydney 5 Sydney 6
Material 55%RAP Roadbase Roadbase 80% 22% AC 52% AC
Description 43% Gravel and Gravel and Roadbase 52% Red 22% Red
Crusher Asphalt Asphalt Gravel & Stabilised Stabilised
Dust seal seal AC Roadbase Roadbase
20% 26% 26%
Crusher Roadbase Roadbase
Dust Gravel Gravel
26.5 100 100 100 100 100
% Material Passing AS Sieve Size

19.0 99 100 97 87 71 79
13.2 99 91 84 74 56 57
9.5 96 79 69 58 44 43
6.7 85 65 54 46 35 33
(mm)

4.75 80 52 44 36 30 26
2.36 53 35 31 21 21 17
1.18 31 23 22 12 15 13
0.600 19 16 15 7 11 11
0.300 11 11 11 4 8 9
0.150 7 8 8 3 5 6
0.075 5 7 6 2 4 4
Binders
Bitumen 3.5% 3.5% 3.5% 3.0% 3.5% 3.5%
Hyd. Lime 1.5% 1.5% 1.5% 2.0% 2.5% 2.5%
Resilient Modulus (MPa)
2941 2125 1915 -- 4358 3814
2057 2654 1816 1299 3682 3710
2170 2663 1679 1357 3245 4153
Dry Cured 2389 2481 1803 1328 3762 3892
2011 1054 902 1729 2992 3433
1396 1142 984 1280 2796 2745
1276 1142 1090 1302 2488 3763
Wet Cured 1561 1272 992 1291 2759 3314
Retained
Modulus 65% 51% 55% 97% 73% 85%
Ratio
Table B-10: Sydney roadbase samples testing data

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An Analysis of Roadbase Materials used in Foamed Bitumen Stabilisation
Adam O’Callaghan - 0050049644
 Location: Sydney
100

90

80

70

60
% Passing

50

40

30

20

10

0
0.01

0.10

1.00

10.00
6.7
0.075

0.15

0.300

0.425

0.600

1.18

2.36

4.75

13.2

19.0

26.5

37.5
AS Sieve Sizes (mm)
Sydney 1 Sydney 2 Upper Limit Austroads
Sydney 3 Sydney 4 Lower Limit Austroads

Figure B-8: Sydney grading profiles

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An Analysis of Roadbase Materials used in Foamed Bitumen Stabilisation
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B.7. Western NSW
Sample ID Parkes 1 Parkes 2 Parkes 3 Parkes 4 Parkes 5 Parkes 6
Material Silty Sandy Silty Sandy Silty Sandy Silty Sandy Silty Sandy Silty Sandy
Description Gravel Gravel Gravel Gravel Gravel Gravel
26.5 100 100 100 100
% Material Passing AS Sieve Size (mm)

19.0 98 97 98 99 100 100

13.2 92 91 97 96 98 98
9.5 83 84 91 91 94 95
6.7 71 78 83 83 86 89
4.75 59 71 72 74 77 82
2.36 42 57 52 57 61 66
1.18 31 43 37 43 48 51
0.600 21 33 24 30 37 37
0.300 14 24 15 20 28 27
0.150 11 19 10 14 21 20
0.075 9 15 7 10 16 16
Binders
Bitumen 3.5% 3.5% 3.5% 3.5% 3.5% 3.5%
Hyd. Lime 1.5% 1.5% 1.5% 1.5% 1.5% 1.5%
Resilient Modulus (MPa)
7673 5219 4284 5220 4071 5916
6627 5417 4223 5880 4599 8344
7835 5174 3951 5871 4309 6830
Dry Cured 7378 5270 4153 5657 4326 7030
4171 1369 2711 3220 1353 3559
3387 1380 2683 3360 1551 4238
4242 1415 2633 3759 1564 3848
Wet Cured 3933 1388 2676 3446 1489 3882
Retained
Modulus 53% 26% 64% 61% 34% 55%
Ratio
Table B-11: Western NSW roadbase test data

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 Grading Profiles: Western NSW
100

90

80

70

60
% Passing

50

40

30

20

10

0
AS Sieve Sizes (mm)
0.0

0.1

1.0

10.0
0.15

1.18

2.36

4.75

6.7

13.2

19.0

26.5

37.5
0.075

0.300

0.425

0.600

Parkes 1 Parkes 2 Parkes 3 Upper Limit Austroads

Parkes 4 Parkes 5 Parkes 6 Lower Limit Austroads

Figure B-9: Western NSW grading profiles

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An Analysis of Roadbase Materials used in Foamed Bitumen Stabilisation
Adam O’Callaghan - 0050049644
B.8. Central NSW
Sample ID Bathurst 1 Bathurst 2 Bathurst 3 Bathurst 4 Bathurst 5 Bathurst 6
Material Silty Sandy Silty Sandy Silty Sandy Silty Sandy Silty Sandy Silty Sandy
Description Gravel Gravel Gravel Gravel Gravel Gravel
26.5 100 100 100 100 100 100
% Material Passing AS Sieve Size (mm)

19.0 97 96 99 99 99 96
13.2 90 90 89 89 97 86
9.5 83 83 76 76 92 77
6.7 77 72 64 64 83 65
4.75 72 63 52 52 73 56
2.36 65 47 37 37 58 42
1.18 53 36 29 29 45 33
0.600 42 27 22 22 32 23
0.300 33 20 17 17 23 16
0.150 26 15 14 14 16 12
0.075 20 11 11 11 11 9
Binders
Bitumen 3.5% 3.5% 3.5% 3.5% 3.5% 3.5%
Hyd. Lime 1.5% 1.5% 1.5% 1.5% 1.5% 1.5%
Resilient Modulus (MPa)
2659 4466 3584 3642 5915 5386
2891 4059 2862 3227 6239 6188
2696 3863 2612 2718 5388 5949
Dry Cured 2749 4129 3019 3196 5847 5841
1350 3124 1463 2122 3746 2264
1508 2861 1970 2017 4117 4412
1284 2893 1970 2035 3328 4426
Wet Cured 1381 2959 1801 2058 3730 4419
Retained
Modulus 50% 72% 60% 64% 64% 76%
Ratio
Table B-12: Central NSW roadbase test data

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An Analysis of Roadbase Materials used in Foamed Bitumen Stabilisation
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 Grading Profiles: Central NSW (Bathurst)
100

90

80

70

60
% Passing

50

40

30

20

10

0
0.0

0.1

1.0

10.0
6.7
0.075

0.15

0.300

0.425

0.600

1.18

2.36

4.75

13.2

19.0

26.5

37.5
AS Sieve Sizes (mm)

Bathurst 1 Bathurst 2 Bathurst 3 Upper Limit - Austroads

Bathurst 4 Bathurst 5 Bathurst 6 Lower Limit - Austroads

Figure B-10: Central NSW grading profiles

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An Analysis of Roadbase Materials used in Foamed Bitumen Stabilisation
Adam O’Callaghan - 0050049644
B.9. Southern NSW
Sample ID Bega 1
Bega 3 Bega 2
Bega 4 Bega 5 Bega 6
Material Gravelly Gravelly Roadbase Gravelly Gravelly Roadbase
Description Silty Sand Silty Sand Gravel Silty Sand Silty Sand Gravel
with with previously with with previously
Bituminous Bituminous stabilised Bituminous Bituminous stabilised
Seal Seal Seal Seal
with with
Polyroad Polyroad
26.5 100 100 100 100 100 100
% Material Passing AS Sieve Size (mm)

19.0 93 97 87 94 95 96
13.2 77 90 62 90 91 89
9.5 67 80 48 88 87 81
6.7 57 68 37 83 84 75
4.75 51 59 30 77 78 69
2.36 41 45 21 64 66 55
1.18 39 33 15 33 50 39
0.600 36 26 11 25 35 26
0.300 25 20 8 18 24 17
0.150 17 15 6 14 17 11
0.075 10 11 5 11 12 7
Binders
Bitumen 3.5% 3.5% 3.5% 3.5% 3.5% 3.5%
Hyd. Lime 1.5% 1.5% 1.5% 1.5% 1.5% 1.5%
Resilient Modulus (MPa)
2717 -- 3553 3652 3943 5439
2888 -- 4216 4031 4518 6364
2942 -- 4184 4584 5111 5799
Dry Cured 2849 5875 3984 4089 4524 5867
2200 -- 3165 1969 2549 2735
2159 -- 2826 2370 2929 3485
2127 -- 2804 2487 3027 3543
Wet Cured 2162 4586 2932 2275 2835 3254
Retained
Modulus 76% 78% 74% 56% 63% 55%
Ratio
Table B-13: Southern NSW roadbase test data

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An Analysis of Roadbase Materials used in Foamed Bitumen Stabilisation
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 Location: Southern NSW
100

90

80

70

60
% Passing

50

40

30

20

10

0
0.01

0.10

1.00

10.00
AS Sieve Sizes (mm)

6.7
0.15

1.18

2.36

4.75

13.2

19.0

26.5

37.5
0.075

0.300

0.425

0.600

Bega 1 Bega 2 Bega 3 Upper Limit Austroads

Bega 4 Bega 5 Bega 6 Lower Limit Austroads

Figure B-11: Southern NSW grading profiles

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An Analysis of Roadbase Materials used in Foamed Bitumen Stabilisation
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B.10. ACT
Sample ID ACT 1 ACT 2
Material 93% Roadbase 93% Roadbase
Description 7% RAP 7% RAP
26.5 100 100
% Material Passing AS Sieve Size (mm)

19.0 99 96
13.2 88 90
9.5 76 83
6.7 67 75
4.75 59 66
2.36 45 52
1.18 32 42
0.600 23 34
0.300 17 28
0.150 13 24
0.075 10 20
Binders
Bitumen 3.0% 3.5%
Hyd. Lime 2.0% 2.0%
Resilient Modulus (MPa)
7662 7735
8862 7366
8547 7710
Dry Cured 8357 7604
4304 7215
6485 7051
6794 6866
Wet Cured 5861 7044
Retained
Modulus 70% 93%
Ratio
Table B-14: ACT roadbase test data

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An Analysis of Roadbase Materials used in Foamed Bitumen Stabilisation
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 Grading Profiles: ACT
100

90

80

70

60
% Passing

50

40

30

20

10

0
0.0

0.1

1.0

10.0
6.7
0.075

0.15

0.300

0.425

0.600

1.18

2.36

4.75

13.2

19.0

26.5

37.5
AS Sieve Sizes (mm)

ACT 1 ACT 2 Upper Limit - Austroads Lower Limit - Austroads

Figure B-12: ACT grading profiles

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An Analysis of Roadbase Materials used in Foamed Bitumen Stabilisation
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B.11. Victoria
Sample ID Victoria 1 Victoria 2 Victoria 3 Victoria 4 Victoria 5 Victoria 6
Material 60% 60% 57% Composite 50% Roadbase
Description Sandstone Sandstone Composite Roadbase Composite Gravel and
40% 20mm 40% 20mm 43% Gravel 50% Bitumen
aggregate aggregate Hillview Hillview seal
Class 2 FCR Class 1 FCR
26.5 100 100 100 100
% Material Passing AS Sieve Size (mm)

19.0 96 96 100 98 91 100

13.2 64 64 94 86 82 98
9.5 53 55 89 77 71 92
6.7 51 52 85 65 62 78
4.75 49 50 80 56 52 63
2.36 47 47 67 42 39 50
1.18 45 44 47 27 27 41
0.600 42 40 34 16 17 35
0.300 23 25 24 8 11 30
0.150 14 17 18 3 8 23
0.075 11 13 14 1 2 14
Binders
Bitumen 3.0% 3.5% 3.5% 3.0% 3.0% 3.0%
Hyd. Lime 1.5% 1.5% 1.5% 1.5% 1.5% 1.5%
Resilient Modulus (MPa)
6548 6738 3263 4455 7291 4830
5630 5220 2941 5646 8507 3900
4709 5187 3289 6179 5785 4676
Dry Cured 5629 5715 3164 5427 7194 4469
336 803 1776 2286 5687 4016
313 752 1684 3140 5926 3259
255 598 1754 3100 3373 3299
Wet Cured 301 718 1738 2842 4995 3525
Retained
Modulus 5% 13% 55% 52% 69% 79%
Ratio
Table B-15: Victoria roadbase test data Table (A)

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An Analysis of Roadbase Materials used in Foamed Bitumen Stabilisation
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 Sample ID Victoria 7 Victoria 8 Victoria 9 Victoria 10 Victoria 11
Material Roadbase Roadbase Roadbase Roadbase Roadbase Gravel
Description Gravel Gravel Gravel Gravel
and
Bitumen
seal
26.5 100 100 100 100
% Material Passing AS Sieve Size (mm)

19.0 99 97 89 100 96
13.2 91 88 75 86 86
9.5 81 80 61 68 73
6.7 71 72 49 56 61
4.75 62 56 41 48 53
2.36 51 41 32 35 41
1.18 40 29 26 24 30
0.600 31 21 21 17 23
0.300 25 14 17 13 17
0.150 18 10 12 10 13
0.075 13 8 8 7 9
Binders
Bitumen 3.0% 3.5% 3.0% 3.0% 3.0%
Hyd. Lime 1.5% 1.5% 2.0% 2.0% 2.0%
Resilient Modulus (MPa)
5258 5248 6139 5236 5454
6262 5455 6845 -- 5753
5372 6268 5521 4744 5104
Dry Cured 5631 5657 6168 4990 5437
4248 4244 3365 2697 3196
3511 4490 3667 1720 2496
4431 4924 2782 2256 3117
Wet Cured 4063 4553 3271 2224 2936
Retained
Modulus 72% 80% 53% 45% 54%
Ratio
Table B-16: Victoria roadbase test data Table (B)

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An Analysis of Roadbase Materials used in Foamed Bitumen Stabilisation
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 Grading Profiles: Victoria
100

90

80

70

60
% Passing

50

40

30

20

10

0
0.0

0.1

1.0

10.0
0.15

1.18

2.36

4.75

6.7

13.2

19.0

26.5

37.5
0.075

0.300

0.425

AS Sieve Sizes (mm) 0.600

Victoria 1 Victoria 2 Victoria 3 Victoria 5 Upper Limit - Austroads

Victoria 4 Victoria 6 Victoria 7 Victoria 8 Lower Limit - Austroads
Victoria 9 Victoria 10 Victoria 11

Figure B-13: Victoria grading profiles

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An Analysis of Roadbase Materials used in Foamed Bitumen Stabilisation
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Appendix C. CIRCLY Output

C.1. 3% Bitumen 1% Lime 6% finer than 75µm

Service Life

3% Bitumen 1% Lime 6% Passing 0.075mm

Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .20476E+00 -0.19022E-03

Maximum of total damage= 0.2047636

Subgrade, CBR=5,Aniso
Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .72427E-04 0.46000E-03

Maximum of total damage= 7.2427443E-05

C.2. 3% Bitumen 1.5% Lime 2% finer than 75µm

Service Life

3% Bitumen 1.5% Lime 2% Passing 0.075mm

Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .20783E-01 -0.79627E-04

Maximum of total damage= 2.0782905E-02

Subgrade, CBR=5,Aniso
Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .60702E-06 0.23232E-03

Maximum of total damage= 6.0702411E-07

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An Analysis of Roadbase Materials used in Foamed Bitumen Stabilisation
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C.3. 3% Bitumen 1.5% Lime 6% finer than 75µm
Service Life

3% Bitumen 1.5% Lime 6% Passing 0.075mm

Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .11443E-01 -0.63723E-04

Maximum of total damage= 1.1442849E-02

Subgrade, CBR=5,Aniso
Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .18672E-06 0.19631E-03

Maximum of total damage= 1.8671868E-07

C.4. 3% Bitumen 1.5% Lime 10% finer than 75µm

Service Life

3% Bitumen 1.5% Lime 10% Passing 0.075mm

Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .14074E-01 -0.69564E-04

Maximum of total damage= 1.4074348E-02

Subgrade, CBR=5,Aniso
Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .29638E-06 0.20970E-03

Maximum of total damage= 2.9637530E-07

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C.5. 3% Bitumen 1.5% Lime 13% finer than 75µm
Service Life

3% Bitumen 1.5% Lime 13% Passing 0.075mm

Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .35343E-01 -0.97110E-04

Maximum of total damage= 3.5343062E-02

Subgrade, CBR=5,Aniso
Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .17611E-05 0.27050E-03

Maximum of total damage= 1.7611352E-06

C.6. 3% Bitumen 1.5% Lime 15% finer than 75µm

Service Life

3% Bitumen 1.5% Lime 15% Passing 0.075mm

Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .17260E+00 -0.17792E-03

Maximum of total damage= 0.1725960

Subgrade, CBR=5,Aniso
Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .49719E-04 0.43593E-03

Maximum of total damage= 4.9719143E-05

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C.7. 3.5% Bitumen 1.5% Lime 2% finer than 75µm
Service Life

3.5% Bitumen 1.5% Lime 2% Passing 0.075mm

Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .39097E+00 -0.31540E-03

Maximum of total damage= 0.3909675

Subgrade, CBR=5,Aniso
Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .12974E-02 0.69467E-03

Maximum of total damage= 1.2974023E-03

C.8. 3.5% Bitumen 1.5% Lime 6% finer than 75µm

Service Life

3.5% Bitumen 1.5% Lime 6% Passing 0.075mm

Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .30711E-01 -0.11659E-03

Maximum of total damage= 3.0711215E-02

Subgrade, CBR=5,Aniso
Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .47595E-05 0.31178E-03

Maximum of total damage= 4.7594940E-06

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C.9. 3.5% Bitumen 1.5% Lime 10% finer than 75µm
Service Life

3.5% Bitumen 1.5% Lime 10% Passing 0.075mm

Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .16530E-01 -0.92316E-04

Maximum of total damage= 1.6529826E-02

Subgrade, CBR=5,Aniso
Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .13402E-05 0.26015E-03

Maximum of total damage= 1.3402429E-06

C.10. 3.5% Bitumen 1.5% Lime 15% finer than 75µm

Service Life

3.5% Bitumen 1.5% Lime 15% Passing 0.075mm

Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .19165E-01 -0.97599E-04

Maximum of total damage= 1.9164797E-02

Subgrade, CBR=5,Aniso
Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .18096E-05 0.27155E-03

Maximum of total damage= 1.8095545E-06

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C.11. 3.5% Bitumen 1.5% Lime 20% finer than 75µm
Service Life

3.5% Bitumen 1.5% Lime 20% Passing 0.075mm

Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .93744E-01 -0.17891E-03

Maximum of total damage= 9.3743533E-02

Subgrade, CBR=5,Aniso
Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .51306E-04 0.43789E-03

Maximum of total damage= 5.1305753E-05

C.12. 2% Bitumen 2% Lime 2% finer than 75µm

Service Life

2% Bitumen 2% Lime 2% Passing 0.075mm

Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .47720E+00 -0.14361E-03

Maximum of total damage= 0.4772003

Subgrade, CBR=5,Aniso
Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .15025E-04 0.36743E-03

Maximum of total damage= 1.5025473E-05

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C.13. 2% Bitumen 2% Lime 10% finer than 75µm
Service Life

2% Bitumen 2% Lime 10% Passing 0.075mm

Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .40097E-01 -0.56660E-04

Maximum of total damage= 4.0096771E-02

Subgrade, CBR=5,Aniso
Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .10095E-06 0.17980E-03

Maximum of total damage= 1.0094633E-07

C.14. 3% Bitumen 2% Lime 2% finer than 75µm

Service Life

3% Bitumen 2% Lime 2% Passing 0.075mm

Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .11782E+01 -0.38477E-03

Maximum of total damage= 1.178222

Subgrade, CBR=5,Aniso
Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .40893E-02 0.81847E-03

Maximum of total damage= 4.0893313E-03

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C.15. 3% Bitumen 2% Lime 6% finer than 75µm
Service Life

3% Bitumen 2% Lime 6% Passing 0.075mm

Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .58090E-01 -0.11718E-03

Maximum of total damage= 5.8090344E-02

Subgrade, CBR=5,Aniso
Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .48941E-05 0.31302E-03

Maximum of total damage= 4.8940792E-06

C.16. 3% Bitumen 2% Lime 10% finer than 75µm

Service Life

3% Bitumen 2% Lime 10% Passing 0.075mm

Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .27400E-01 -0.88289E-04

Maximum of total damage= 2.7399695E-02

Subgrade, CBR=5,Aniso
Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .10545E-05 0.25139E-03

Maximum of total damage= 1.0545166E-06

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C.17. 3% Bitumen 2% Lime 15% finer than 75µm
Service Life

3% Bitumen 2% Lime 15% Passing 0.075mm

Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .25283E-01 -0.85686E-04

Maximum of total damage= 2.5282897E-02

Subgrade, CBR=5,Aniso
Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .89820E-06 0.24569E-03

Maximum of total damage= 8.9819582E-07

C.18. 3% Bitumen 2% Lime 20% finer than 75µm

Service Life

3% Bitumen 2% Lime 20% Passing 0.075mm

Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .57651E-01 -0.11685E-03

Maximum of total damage= 5.7651374E-02

Subgrade, CBR=5,Aniso
Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .48182E-05 0.31233E-03

Maximum of total damage= 4.8181951E-06

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C.19. 3% Bitumen 2% Lime 24% finer than 75µm
Service Life

3% Bitumen 2% Lime 24% Passing 0.075mm

Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .11192E+01 -0.37668E-03

Maximum of total damage= 1.119193

Subgrade, CBR=5,Aniso
Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .36164E-02 0.80423E-03

Maximum of total damage= 3.6164462E-03

C.20. 3.5% Bitumen 2% Lime 2% finer than 75µm

Service Life

3.5% Bitumen 2% Lime 2% Passing 0.075mm

Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .32453E-01 -0.11914E-03

Maximum of total damage= 3.2452766E-02

Subgrade, CBR=5,Aniso
Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .53582E-05 0.31710E-03

Maximum of total damage= 5.3582157E-06

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C.21. 3.5% Bitumen 2% Lime 6% finer than 75µm
Service Life

3.5% Bitumen 2% Lime 6% Passing 0.075mm

Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .25167E-01 -0.10815E-03

Maximum of total damage= 2.5167475E-02

Subgrade, CBR=5,Aniso
Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .31577E-05 0.29403E-03

Maximum of total damage= 3.1577397E-06

C.22. 3.5% Bitumen 2% Lime 10% finer than 75µm

Service Life

3.5% Bitumen 2% Lime 10% Passing 0.075mm

Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .21213E-01 -0.10135E-03

Maximum of total damage= 2.1213247E-02

Subgrade, CBR=5,Aniso
Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .22196E-05 0.27959E-03

Maximum of total damage= 2.2196064E-06

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C.23. 3.5% Bitumen 2% Lime 15% finer than 75µm
Service Life

3.5% Bitumen 2% Lime 15% Passing 0.075mm

Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .18766E-01 -0.96814E-04

Maximum of total damage= 1.8765554E-02

Subgrade, CBR=5,Aniso
Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .17323E-05 0.26986E-03

Maximum of total damage= 1.7322736E-06

C.24. 3.5% Bitumen 2% Lime 20% finer than 75µm

Service Life

3.5% Bitumen 2% Lime 20% Passing 0.075mm

Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .18161E-01 -0.95602E-04

Maximum of total damage= 1.8160792E-02

Subgrade, CBR=5,Aniso
Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .16184E-05 0.26725E-03

Maximum of total damage= 1.6183669E-06

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C.25. 3.5% Bitumen 2% Lime 25% finer than 75µm
Service Life

3.5% Bitumen 2% Lime 25% Passing 0.075mm

Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .19123E-01 -0.97472E-04

Maximum of total damage= 1.9122604E-02

Subgrade, CBR=5,Aniso
Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .17969E-05 0.27128E-03

Maximum of total damage= 1.7969185E-06

C.26. 3.5% Bitumen 2% Lime 30% finer than 75µm

Service Life

3.5% Bitumen 2% Lime 25% Passing 0.075mm

Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .19123E-01 -0.97472E-04

Maximum of total damage= 1.9122604E-02

Subgrade, CBR=5,Aniso
Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .17969E-05 0.27128E-03

Maximum of total damage= 1.7969185E-06

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C.27. Mackay 1 (2%)
Service Life

Foam Bitumen Stabilised 2% Bitumen (Mackay 1)

Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .40097E-01 -0.56660E-04

Maximum of total damage= 4.0096771E-02

Subgrade, CBR=5,Aniso
Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .10095E-06 0.17980E-03

Maximum of total damage= 1.0094633E-07

C.28. Mackay 1 (3%)

Service Life

Foam Bitumen Stabilised - 3% Bitumen (Mackay 1)

Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .24968E-02 -0.63451E-04

Maximum of total damage= 2.4968218E-03

Subgrade, CBR=5,Aniso
Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .18257E-06 0.19568E-03

Maximum of total damage= 1.8257163E-07

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C.29. Mackay 1 (4%)
Service Life

Foamed Bitumen Stabilised - 4% Bitumen (Mackay 1)

Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .58860E-03 -0.86813E-04

Maximum of total damage= 5.8859552E-04

Subgrade, CBR=5,Aniso
Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .96334E-06 0.24816E-03

Maximum of total damage= 9.6334134E-07

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C.30. Marginal Material – Sandstone
3% Bitumen 1.5% Lime

Dry Modulus
Service Life

Marginal Materials Sandstone (5629MPa)

Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .15255E+00 -0.93220E-04

Maximum of total damage= 0.1525498

Subgrade, CBR=5,Aniso
Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .14125E-05 0.26211E-03

Maximum of total damage= 1.4125047E-06

Wet Modulus
Service Life

Marginal Material SS (301 MPa)

Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .45613E+02 -0.83646E-03

Maximum of total damage= 45.61252

Subgrade, CBR=5,Aniso
Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .36311E+00 0.15536E-02

Maximum of total damage= 0.3631113

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4% Bitumen 1.5% Lime

Dry Modulus
Service Life

Marginal Material SS (5715 MPa)

Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .67795E-02 -0.92135E-04

Maximum of total damage= 6.7794663E-03

Subgrade, CBR=5,Aniso
Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .13262E-05 0.25976E-03

Maximum of total damage= 1.3261762E-06

Wet Modulus
Service Life

Marginal Material SS (301 MPa)

Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .45613E+02 -0.83646E-03

Maximum of total damage= 45.61252

Subgrade, CBR=5,Aniso
Maximum damage values for each vehicle type
-------------------------------------------
Vehicle Type Damage Factor Critical Strain
------------ ------------- ---------------
ESA750-Full .36311E+00 0.15536E-02

Maximum of total damage= 0.3631113

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Appendix D. Typical Service Life Calculations
Step 1

Layer Material Type Thickness (mm)

Sealing Layer Spray Seal Surface --
Basecourse Foamed Bitumen Stabilised 260
Material

Subgrade Existing Subgrade Semi-Infinite

For Foamed bitumen stabilisation the project reliability is

Step 2

( )

Step 3

Not relevant – No granular subgrade layers

Step 4

Not relevant – No granular subgrade layers

Step 5

Not relevant – No granular subgrade layers

Step 6

No sublayering

Resilient modulus = 2190MPa

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Heavy Vehicle traffic speed = 100km/hr

( ( ))
( )

Elastic properties of all materials

Material Material Elastic Modulus Poisson’s Ratio f Value

Type Thickness Ev Eh vv vh
(mm)
Spray Seal - - - - - -
Foamed
260 1953 1953 0.40 0.40 1395
bitumen
Semi
Subgrade 50 25 0.45 0.45 34.5
infinint

Step 7

( )

Step 8

Not relevant

Step 9

Foamed bitumen fatigue

( )
( )

Step 10

Not relevant

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Step 11

Standard axle load represented as

Tyre-pavement contact stress=750kPa

Load radius=92.1mm

Four circular area separated centre-to-centre 330mm, 1470mm and 330mm

Step 12

Critical location of calculated strains

 Bottom of Foamed Bitumen layer

 Top of Subgrade layer

The strains are calculated beneath one of the loaded wheels and mid-way between the
loaded wheels

Step 13

Critical strains from CIRCLY

Step 14

Calculated Allowable Traffic Loading

 Foamed Bitumen

( )
( )
( )

Converting Standard Axle Repartitions to ESA using

 Subgrade

( )

Converting Standard Axle Repartitions to ESA using

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Step 15

Allowable Traffic Loading = Service Life

 Foamed Bitumen
 Subgrade

Step 16

Not relevant – No design traffic

Step 17

Not relevant – No design traffic

Step 18

Not relevant – No design traffic

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Appendix E. Summary of Service Life Data

Bitumen Content (%) Corrected Dry

Lime Content % Finer than Dry Modulus Critical Strain Service Life
Modulus
by dry weight By Volume (%) (MPa) ( ) (ESA)
(MPa)
2.0 4.0% 2.0 2 3191 2845 143.6
2.0 4.0% 2.0 10 10683 9535 56.66
3.0 6.0% 1.0 6 2190 1953 190.2
3.0 6.0% 1.5 2 6905 6156 79.6
3.0 6.0% 1.5 6 9195 8198 63.7
3.0 6.0% 1.5 10 8217 7326 63.6
3.0 6.0% 1.5 13 5338 4759 97.1
3.0 6.0% 1.5 15 2397 2137 177.9
3.0 6.0% 2.0 2 818 729 384.8
3.0 6.0% 2.0 6 4174 3722 117.2
3.0 6.0% 2.0 10 6041 5386 88.3
3.0 6.0% 2.0 15 6279 5599 85.7
3.0 6.0% 2.0 20 4190 3736 116.9
3.0 6.0% 2.0 24 843 753 376.7
3.5 7.0% 1.5 2 1089 971 315.4
3.5 7.0% 1.5 6 4203 3747 116.6
3.5 7.0% 1.5 10 5701 5083 92.3
3.5 7.0% 1.5 15 5302 4728 97.6
3.5 7.0% 1.5 20 2379 2121 178.9
Table E-1: Service life data - Variations in Grading, Bitumen content and lime content (1)

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 Bitumen Content (%) Corrected Dry
Lime Content % Finer than Dry Modulus Critical Strain Service Life
Modulus
by dry weight By Volume (%) (MPa) ( ) (ESA)
(MPa)
3.5 7.0% 2.0 2 4084 3642 119.1
3.5 7.0% 2.0 6 4637 4135 108.2
3.5 7.0% 2.0 10 5047 4501 101.4
3.5 7.0% 2.0 15 5359 4778 96.8
3.5 7.0% 2.0 20 5447 4857 95.6
3.5 7.0% 2.0 25 5412 4736 97.5
3.5 7.0% 2.0 30 4953 4416 102.8
Table E-2: Service life data - Variations in Grading, Bitumen content and lime content (2)

Bitumen Content (%) Corrected Dry

Lime Content Dry Modulus Critical Strain Service Life
Modulus
by dry weight By Volume (%) (MPa) ( ) (ESA)
(MPa)
2.0 4.0% 2.0 10683 9525 56.7
3.0 6.0% 2.0 9245 8243 63.5
4.0 8.0% 2.0 6174 5505 86.8
Table E-3: Service life data - Variations in bitumen content

Bitumen Content (%) Corrected

Lime Content % Finer than Curing Dry Modulus Critical Strain Service Life
Dry Modulus
by dry weight By Volume (%) Condition (MPa) ( ) (ESA)
(MPa)
Dry 5629 5019 93.2
3.0 6.0% 1.5 11
Wet 301 268 836.5
Dry 5715 5096 92.1
4.0 8.0% 1.5 13
Wet 718 640 420.3
Table E-4: Service life data - Marginal material (Sandstone)

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