10.1.1.199.5112

AUSTROADS FRAMEWORK FOR SPECIFYING ASPHALT

Austroads Framework for Specifying Asphalt First Published 2002

© Austroads Inc. 2002 This work is copyright. Apart from any use as permitted under the Copyright Act 1968, no part may be reproduced by any process without the prior written permission of Austroads.

National Library of Australia Cataloguing-in-Publication data: Austroads Framework for Specifying Asphalt ISBN 0 85588 624 2 Austroads Project No T&E.P.C.020 Austroads Publication No. AP–T18/02 Project Manager Allan Armistead, Commonwealth Department of Transport and Regional Development Prepared by Austroads Pavement Reference Group Published by Austroads Incorporated Level 9, Robell House 287 Elizabeth Street Sydney NSW 2000 Australia Phone: +61 2 9264 7088 Fax: +61 2 9264 1657 Email: [email protected] www.austroads.com.au

Austroads believes this publication to be correct at the time of printing and does not accept responsibility for any consequences arising from the use of information herein. Readers should rely on their own skill and judgement to apply information to particular issues.

AUSTROADS FRAMEWORK FOR SPECIFYING ASPHALT

Sydney 2002

AUSTROADS PROFILE Austroads is the association of Australian and New Zealand road transport and traffic authorities. Austroads contributes to the achievement of improved Australian and New Zealand transport related outcomes by: ♦ ♦ ♦ ♦ ♦ ♦

developing and promoting best practice for the safe and effective management and use of the road system providing professional support to member organisations and national and international bodies acting as a common vehicle for national and international action fulfilling the role of the Australian Transport Council’s Road Modal Group undertaking performance assessment and development of Australian and New Zealand standards developing and managing the National Strategic Research Program for roads and their use.

Within this ambit, Austroads aims to provide strategic direction for the integrated development, management and operation of the Australian and New Zealand road system — through the promotion of national uniformity and harmony, elimination of unnecessary duplication, and the identification and application of world best practice.

AUSTROADS MEMBERSHIP Austroads membership comprises the six State and two Territory road transport and traffic authorities and the Commonwealth Department of Transport and Regional Services in Australia, the Australian Local Government Association and Transit New Zealand. It is governed by a council consisting of the chief executive officer (or an alternative senior executive officer) of each of its eleven member organisations: ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦ ♦

Roads and Traffic Authority New South Wales Roads Corporation Victoria Department of Main Roads Queensland Main Roads Western Australia Transport South Australia Department of Infrastructure, Energy and Resources Tasmania Department of Infrastructure, Planning and Environment Northern Territory Department of Urban Services Australian Capital Territory Commonwealth Department of Transport and Regional Services Australian Local Government Association Transit New Zealand

The success of Austroads is derived from the synergies of interest and participation of member organisations and others in the road industry.

AUSTRALIAN ASPHALT PAVEMENT ASSOCIATION LIMITED (AAPA) AAPA is a non-profit organisation formed to promote the economic use of asphalt based on sound technical grounds. The Association’s Mission Statement for Research and Development is to ensure the attainment of the optimum level of quality and long-term performance in flexible pavement design, construction and maintenance. The AAPA CART Committee manages the AAPA Program for Asphalt Research and Technology and works in close cooperation with the Austroads Pavement Reference Group. The research programs are coordinated and complementary.

NEW ZEALAND PAVEMENT AND CONTRACTORS ASSOCIATION The New Zealand Pavement and Contractors Association is an independent organisation representing the major road contractors in New Zealand. Members include roading contractors, bitumen suppliers and associates such as equipment suppliers and road controlling authorities. The Association promotes the interests of bitumen, pavement maintenance and construction contractors and specifiers by taking a constructive professional proactive approach to developing and using best practice in New Zealand.

ACKNOWLEDGEMENTS Austroads Pavement Reference Group Members Mr Ian Reeves, Queensland Department of Main Roads (Austroads Program Manager) Mr Philip Rankine, Queensland Department of Main Roads (Austroads Program Executive) Mr Bruce Hansen, Australian Local Government Association (Convenor) Mr John Bethune, Australian Asphalt Pavement Association Mr Steve Brown, VicRoads, Victoria Mr David Dash, Roads and Traffic Authority, NSW Mr Peter Douglas, Department of Transport, Tasmania Mr Gareth Evans, Transport, South Australia Mr John Fischer, Main Roads Department, Western Australia Mr Paul Hambleton, Transit New Zealand Mr Allan Jones, Department of Main Roads, Queensland Mr Leslie Leung, Department of Urban Services, ACT Mr Scott Matthews, Cement & Concrete Association of Australia Mr Chris Olsen, NZ Pavements & Bitumen Contractors’ Association Mr Robert Pemble, Department of Transport and Works, Northern Territory Mr Kieran Sharp, ARRB Transport Research Ltd Mr George Vorobieff, Australian Stabilisation Industry Association Mr Garry Wickham, Federal Airports Corporation Liaison Officers Mr Laurie Dowling, AMRG Corresponding Officer Mr Ashok Mehta, Department of Transport & Regional Services, Canberra Ms Julie Chia, ARRB Transport Research Ltd, APRG Secretariat Mr David Jones, CSIR Transportek, South Africa Mr Rod Addis, Federation of European Highway Research, Belgium Mr Roy Mumu, Department of Works and Transport, PNG Secretary Mr Shane Tepper, ARRB Transport Research Ltd Project Steering Committee Mr Allan Armistead, Commonwealth Department of Transport and Regional Development Mr John Bethune, Australian Asphalt Pavement Association Mr Mike Butcher, Transport, South Australia Mr David Dash, Roads and Traffic Authority, NSW Mr Bruce Hansen, Australian Local Government Association Mr Michael Haydon, NZ Pavements & Bitumen Contractors’ Association Mr Bill Hooker, VicRoads, Victoria Mr Allan Jones, Department of Main Roads, Queensland Mr Brian Norris, Main Roads Department, Western Australia Mr Chris Olsen, NZ Pavements & Bitumen Contractors’ Association Mr Ken Wonson, Boral Asphalt Technical Writer Mr John Rebbechi

FOREWORD Austroads and the Australian Asphalt Pavement Association (AAPA) have jointly prepared this specification framework, with input from the New Zealand Pavement and Bitumen Contractors Association (BCA), to promote national uniformity and good practice in the specification and use of asphalt throughout Australasia. The document is in three parts. Part A provides a general introduction to application of asphalt specifications to variations in contracting environment. Part C is a series of specification clauses that may be used directly in contract documentation or as a framework for the preparation of individual specifications or quality plans. When used in contract documentation, the user must select the appropriate asphalt mix type, thickness and any special requirements that reflect the particular application. Part B is a set of “Notes for Implementation and Use” that are provided as a guide to interpretation of the specification clauses and the selection of alternatives appropriate to particular applications or jurisdictions. The specification clauses are applicable to component materials, design and manufacture and placement of dense graded asphalt. Further documents are proposed that will extend the scope to other mix types such as open graded asphalt and stone mastic asphalt. It is intended for application to most uses of dense graded asphalt although some specialist uses such as heavy-duty, off-road applications (airfields, container terminals), major freeways and other non-road applications may require further specific requirements. Individual road agencies may use the specification framework in tailoring standard specifications for agency use. Such agency specifications may vary from the format of the specification framework to reflect individual agency requirements in respect of style, contracting environment, asphalt mix requirements for particular applications, and the management of quality assurance, acceptance testing, and risks associated with long term performance of heavily trafficked pavements. The specification clauses are based on a quality system approach, with asphalt being specified in terms of performance-related mix design criteria as well as manufacture and construction standards. In this format it is targeted at a contracting environment where the principal accepts the long term performance risks associated with selection of design and construction criteria, and acceptance and payment of works is made after a defects liability period that is generally no more than 12 months. Where works are specified in terms of functional performance over a longer period of time, the detailed requirements of this specification framework may be used as a code of practice to assist in the preparation of quality plans or subcontract agreements. Over recent years there has been considerable interest by some parties to move towards more performancebased specifications. Although much work is required to achieve this, Part A of this framework contains the basic generic requirements for a performance-based specification for roads surfaced with asphalt. This part will act as a platform for determining further research necessary for the development of such specifications.

AUSTROADS 2002 —i—

AUSTROADS 2002 — ii —

TABLE OF CONTENTS PART A — CONTRACTING ENVIRONMENT ............................................................………….....1 1

INTRODUCTION ................................................................................................................................................. 1

2

PERFORMANCE SPECIFICATIONS ............................................................................................................... 1

3

OWNERSHIP OF RISK IN ASPHALT SERVICE DELIVERY ..................................................................... 3 3.1 3.2 3.3 3.4 3.5 3.6 3.7

4

GENERAL .......................................................................................................................................................... 3 QUALITY SYSTEMS ........................................................................................................................................... 4 PAVEMENT DESIGN AND SELECTION OF ASPHALT TYPE ................................................................................... 4 SELECTION OF COMPONENT MATERIALS AND ASPHALT MIX DESIGN .............................................................. 5 MANUFACTURE ................................................................................................................................................ 5 PLACING ........................................................................................................................................................... 5 MONITORING OF PERFORMANCE....................................................................................................................... 5

SPECIFICATION FRAMEWORK ..................................................................................................................... 6 4.1 4.2

BACKGROUND .................................................................................................................................................. 6 FRAMEWORK FOR SELECTION FOR SPECIFICATION CLAUSES ............................................................................ 6

PART B — NOTES FOR IMPLEMENTATION AND USE OF SPECIFICATION CLAUSES..…....10 1

GENERAL............................................................................................................................................................ 10 1.1 1.2

2

MATERIALS ....................................................................................................................................................... 11 2.1 2.2 2.3 2.4

3

SCOPE ............................................................................................................................................................. 10 QUALITY SYSTEMS ......................................................................................................................................... 10 AGGREGATE ................................................................................................................................................... 11 MINERAL FILLER ............................................................................................................................................ 11 BINDER ........................................................................................................................................................... 11 RECLAIMED ASPHALT PAVEMENT (RAP)....................................................................................................... 11

MIX DESIGN....................................................................................................................................................... 12 3.1 3.2 3.3 3.4 3.5

GENERAL ........................................................................................................................................................ 12 AGGREGATE GRADING AND BINDER CONTENT .............................................................................................. 13 MIX PROPERTIES: SELECTION OF MIX TYPE, BINDER TYPE, AND TESTING REQUIREMENTS.......................... 13 DESIGN AND MANUFACTURE OF ASPHALT MIXES INCORPORATING RECLAIMED ASPHALT PAVEMENT (RAP)15 APPROVAL OF JOB MIX................................................................................................................................... 15

4

MANUFACTURE AND STORAGE.................................................................................................................. 17

5

SAMPLING AND TESTING OF ASPHALT PRODUCTION ....................................................................... 18 5.1

GENERAL ........................................................................................................................................................ 18

6

DELIVERY .......................................................................................................................................................... 20

7

PLACING ............................................................................................................................................................. 21 7.1 7.2 7.3 7.4 7.5

PREPARATION OF SURFACE............................................................................................................................. 21 TACK COATING .............................................................................................................................................. 21 SPREADING ..................................................................................................................................................... 21 COMPACTION .................................................................................................................................................. 22 JOINTS ............................................................................................................................................................ 22

8

PRODUCTION AND CONSTRUCTION TRIAL ........................................................................................... 23

9

FINISHED PAVEMENT PROPERTIES.......................................................................................................... 24

10

MEASUREMENT AND PAYMENT................................................................................................................. 25

11

APPENDIX (SCHEDULE OF JOB DETAILS) ............................................................................................... 26

AUSTROADS 2002 — iii —

TABLE OF CONTENTS (CONTINUED) PART C — SPECIFICATION CLAUSES ..........................................…………...............…...........21 1

GENERAL............................................................................................................................................................ 27 1.1 SCOPE........................................................................................................................................................... 27 1.2 REFERENCES .............................................................................................................................................. 27 1.3 DEFINITION OF TERMS ............................................................................................................................ 28 1.3.1 Asphalt Mix Types..................................................................................................................................... 28 1.4 QUALITY SYSTEM..................................................................................................................................... 28 1.5 TESTING....................................................................................................................................................... 28

2

MATERIALS ....................................................................................................................................................... 29 2.1 AGGREGATE............................................................................................................................................... 29 2.1.1 General ..................................................................................................................................................... 29 2.1.2 Coarse Aggregate ..................................................................................................................................... 29 2.1.3 Fine Aggregate ......................................................................................................................................... 30 2.2 MINERAL FILLER....................................................................................................................................... 30 2.3 BINDER ........................................................................................................................................................ 31 2.3.1 Bitumen ..................................................................................................................................................... 31 2.3.2 Other Binders............................................................................................................................................ 31 2.3.4 Additives ................................................................................................................................................... 31 2.3.4 Rejuvenating Agent................................................................................................................................... 31 2.4 RECLAIMED ASPHALT PAVEMENT ...................................................................................................... 32

3

MIX DESIGN....................................................................................................................................................... 33 3.1 GENERAL..................................................................................................................................................... 33 3.2 AGGREGATE GRADING AND BINDER CONTENT .............................................................................. 33 3.3 MIX PROPERTIES ....................................................................................................................................... 34 3.4 DESIGN OF ASPHALT MIXES INCORPORATING RECLAIMED ASPHALT PAVEMENT (RAP) ... 35 3.4.1 General ..................................................................................................................................................... 35 3.4.2 Asphalt mixes containing not more than 15% of RAP by mass of total mix ............................................. 35 3.4.3 Asphalt mixes containing more than 15% but not more than 30% of RAP by mass of total mix. ............ 35 3.4.4 Asphalt mixes containing more than 30% of RAP .................................................................................... 35 3.5 APPROVAL OF JOB MIX ........................................................................................................................... 36 3.5.1 General ..................................................................................................................................................... 36 3.5.2 Submission of Samples.............................................................................................................................. 36 3.5.3 Approval to Use Previously Designed Mix............................................................................................... 37

4

MANUFACTURE AND STORAGE.................................................................................................................. 38 4.1 4.2 4.3 4.4 4.5 4.6

5

GENERAL..................................................................................................................................................... 38 MIXING TEMPERATURES ........................................................................................................................ 38 MOISTURE CONTENT ............................................................................................................................... 38 PRODUCTION TOLERANCES................................................................................................................... 38 ASPHALT MIXES INCORPORATING POLYMER MODIFIED BINDERS............................................ 38 ASPHALT MIXES INCORPORATING RECLAIMED ASPHALT PAVEMENT (RAP) ......................... 39

SAMPLING AND TESTING OF ASPHALT PRODUCTION ....................................................................... 40 5.1 5.2 5.3

GENERAL..................................................................................................................................................... 40 FREQUENCY OF SAMPLING AND TESTING......................................................................................... 40 PROCESS CONTROL .................................................................................................................................. 41

6

DELIVERY .......................................................................................................................................................... 42

7

PLACING ............................................................................................................................................................. 42 7.1 7.2 7.3

PREPARATION OF SURFACE................................................................................................................... 42 PROTECTION OF SERVICES .................................................................................................................... 42 TACK COATING ......................................................................................................................................... 42

AUSTROADS 2002 — iv —

TABLE OF CONTENTS (CONTINUED) 7.4 SPREADING................................................................................................................................................. 42 7.4.1 General ..................................................................................................................................................... 42 7.4.2 Ambient Conditions for Placing ............................................................................................................... 42 7.4.3 Layer Thickness ........................................................................................................................................ 43 7.4.4 Level Control ............................................................................................................................................ 43 7.4.5 Spreading.................................................................................................................................................. 43 7.5 COMPACTION............................................................................................................................................. 43 7.6 JOINTS.......................................................................................................................................................... 43 7.6.1 General ..................................................................................................................................................... 43 7.6.2 Longitudinal Joints ................................................................................................................................... 43 7.6.3 Transverse Joints ...................................................................................................................................... 44 8

PRODUCTION AND CONSTRUCTION TRIAL ........................................................................................... 45 8.1 8.2 8.3 8.4

9

GENERAL..................................................................................................................................................... 45 MANUFACTURE......................................................................................................................................... 45 PLACING, COMPACTION AND FINISHING ........................................................................................... 45 TESTING OF TRIAL SECTION .................................................................................................................. 45

FINISHED PAVEMENT PROPERTIES.......................................................................................................... 46 9.1 LEVEL........................................................................................................................................................... 46 9.2 ALIGNMENT ............................................................................................................................................... 46 9.3 THICKNESS ................................................................................................................................................. 46 9.4 SHAPE........................................................................................................................................................... 46 9.4.1 Surface ...................................................................................................................................................... 46 9.4.2 Ride Quality .............................................................................................................................................. 46 9.5 DENSITY ...................................................................................................................................................... 47

10

MEASUREMENT AND PAYMENT................................................................................................................. 49 10.1 10.2 10.3 10.4

11

GENERAL..................................................................................................................................................... 49 MEASUREMENT BY MASS....................................................................................................................... 49 MEASUREMENT BY AREA AND THICKNESS ...................................................................................... 49 NON COMPLYING MATERIALS .............................................................................................................. 49

APPENDIX (SCHEDULE OF JOB DETAILS) ............................................................................................... 50 11.1 11.2

ASPHALT MIX REQUIREMENTS............................................................................................................. 50 MEASUREMENT AND PAYMENT ........................................................................................................... 50

AUSTROADS 2002 —v—

AUSTROADS 2002 — vi —

Framework for Specifying Asphalt

PART A — CONTRACTING ENVIRONMENT 1

INTRODUCTION

The contracting environment under which road agencies operate is a dynamic situation. Contract documents have evolved from largely method-based specifications to a range of options involving various end result and performance outcomes. Evolution has also included changes to increase the levels of accountability for contractor performance and transfer of service delivery and performance risk from the public to the private sector. The private sector is also becoming more involved in management of road system elements through design and construct contracts, design construct and maintain contracts, and performance specified maintenance contracts. Advances in asphalt technology have also brought changes in criteria applied to the selection of asphalt mix types and design requirements for particular applications. This part of the specification framework aims to indicate where the different elements involved in the service delivery of asphalt pavements and surfacings relate to different forms of contracting environment with particular reference to the current status of performance-related asphalt specifications.

2

PERFORMANCE SPECIFICATIONS

While there is no generally agreed terminology for describing different forms of performance specification and performance contracts, the following distinctions are used in this document. Method specification - Method and materials, or prescription elements are used where the characteristics of the completed work are not measurable or no practical or timely acceptance test is available. Traditional specifications evolved from the transfer of construction activity from direct labour to contractors and thus used to describe the work in the same manner as conveying information to employees. Some prescriptive elements, particularly related to materials factors still remain in many roadmaking specifications. Performance-related specification - One that describes the desired level of materials and construction (M&C) factors that have been found to correlate with fundamental engineering properties that predict performance. These factors are amenable to acceptance testing at the time of construction. The specification clauses included in this document have been built around a performance-related model using performancerelated design standards and verification that the designed material is manufactured and placed to appropriate standards. Performance-based specification – One that describes desired levels of fundamental engineering properties (e.g. resilient modulus, deformation resistance, fatigue) that are predictors of performance and can be used in models to predict pavement performance or distress from the combination of those properties in association with external factors such as traffic, environment and underlying materials. Generally these properties are not amenable to timely acceptance testing. In the accompanying specification, fundamental engineering properties are applied as optional asphalt design requirements. Further options are also provided for verification of design properties on manufactured asphalt. Performance specification - One that describes how the finished product should perform over time. A distinction is made here between a performance specification and an end product specification. An end product specification describes how a product should perform at the completion of the contract (i.e. it does not have an extended contract period to reflect the life of the product). End product criteria may include performance measures such as ride quality or surface characteristics. Other end product measures may also be included in all specification types but recognition must still be given to limitations in current technology for predicting long term performance (e.g. skid resistance, durability, rutting or structural performance). Continued improvement in performance prediction models is an important element of R&D for both road agencies and contractors. AUSTROADS 2002 —1—

Framework for Specifying Asphalt

Performance contract – A contract that defines obligations and outcomes in terms of performance indicators for the product or service and is of sufficient duration to enable measurement of the contractor’s performance over time and provide assurance of the quality and longevity of the product or service. The key requirements desirable for performance contracts are: ♦ ♦ ♦ ♦

♦

A partnership approach Creation of an economic framework that encourages the contractor to meet long term performance objectives Selection of appropriate key performance indicators (KPIs) An understanding of sharing of risk, including: o effectiveness of design/performance prediction models o variations in predicted traffic volumes o variations in climatic conditions o performance of underlying pavement or subgrade Application of Quality Systems

Requirements for Key Performance Indicators include: ♦ Safety o Surface texture o Skid resistance o Conspicuity o Water spray ♦ Ride Quality o Roughness o Surface defects (cracking, patching, etc.) o Rutting ♦ Environmental o Noise o Environmental sustainability (recycling, etc) ♦ User Costs o Response times for remedial work o Vehicle delays o Appearance o Effectiveness of remedial work ♦ Future Agency costs o Remaining life of surfacing o Future maintenance and rehabilitation costs Distinctions between each of the above different forms of specification are not precise, as contract documentation for different elements within a particular project may include various features of method, performance-related, performance-based and end result criteria as outlined in the following discussion. Care must be exercised to ensure that a mixture of specification elements does not introduce conflict.

AUSTROADS 2002 —2—

Framework for Specifying Asphalt

3

OWNERSHIP OF RISK IN ASPHALT SERVICE DELIVERY

3.1

GENERAL

The implementation of performance measures in asphalt contracts involves a shift of risk from the public to the private sector. An appreciation of the management of risk for the various elements involved in the service delivery of asphalt surfacing is an important factor in the development of performance specification requirements. The elements of asphalt service delivery are broadly categorised as: ♦ Pavement design/Selection of asphalt mixes ♦ Selection of component materials and asphalt mix design ♦ Manufacture ♦ Placement ♦ Monitoring of pavement performance Asphalt must also be supplied in a Quality Systems environment. Application of the above elements to the allocation of risk to variations in contracting environment is shown broadly in Figure 1.

Element of asphalt service delivery

Ownership of risk* (Type of contract)

Methodology

Method Pavement design/ asphalt mix selection

Use established design models/ past performance to select products/ treatments expected to meet long term performance requirements

Asphalt mix design/ component materials

Use established design procedures/ standards of component materials to support selection assumptions

Manufacture

Use established processes and undertake acceptance testing of manufactured materials

Placement

Use established processes and undertake acceptance testing of completed work

Monitoring of performance

Monitor performance using defined criteria

Performance -related

Performance -based

*Ownership of risk Principal

Figure 1 — Ownership of Risk

AUSTROADS 2002 —3—

Contractor

Performance

Framework for Specifying Asphalt

3.2

QUALITY SYSTEMS

A major change in contract documentation in Australia came with the introduction of Quality Systems in the late 1980s. Under Quality Assured contracts, many of the prescription and procedural elements were removed from specifications on the basis that these would form part of the Contractor’s Quality System and Quality Plan. Specification elements were changed to emphasise design and/or end result standards and acceptance testing criteria. All contracts for road works in Australia are now undertaken under some form of Quality Assurance contract. A general outline of the application of Quality Assurance in roadworks contracts is provided in Austroads Quality Assurance in Contracts, 1994, Publication No. AP-115/94. Further guidance to contract surveillance activity is provided in Austroads Guide to Field Surveillance of Quality Assurance Contracts, 1995, Publication No. AP-38/95. In practice, the state road authorities have instituted detailed procedures for the management of QA Contracts. These can include one or more of the following: ♦ ♦ ♦ ♦ ♦

Prequalification of Contractors Detailed technical audit of Contractors’ Quality Systems and Quality Plans Surveillance of contract activity Audit/verification of quality of materials and testing Selection of test lots and random sampling schemes

Specific guidelines for the above activities are not provided in this document, as procedures will vary between road agencies, type and size of project, and approach to management of risk. 3.3

PAVEMENT DESIGN AND SELECTION OF ASPHALT TYPE

For new and reconstructed pavements, structural design is undertaken using established design models. Selection of rehabilitation treatments is generally based on the condition of the existing pavement, level of improvement required and expectations of performance based on experience and performance models. In all cases, selection of wearing course is based on the surface characteristics required (texture, noise, water spray etc.), traffic, and operating environment. Guidelines for pavement design, selection of rehabilitation treatments and selection of surfacing types is provided in a range of manuals, guides and publications such as the Austroads Pavement Design Guide and Austroads Guide to the Selection of Pavement Surfacings. An Austroads Rehabilitation Guide is in the course of preparation. Apart from performance contracts, the risks associated with long term performance arising from pavement design models and selection of type and thickness of asphalt mix are accepted by the Principal. In the case of a design and construct contract, the Principal may pass some of the risk associated with interpretation of design criteria to the designer but will still generally specify or approve the design models to be used. Under performance contracts, the Principal may require the contractor to accept the risks associated with design and selection of treatment but must also be satisfied that the contractor is capable of providing the performance required. Management of that risk is undertaken through procedures for contractor prequalification, contract acceptance and auditing and surveillance of quality systems.

AUSTROADS 2002 —4—

Framework for Specifying Asphalt

3.4

SELECTION OF COMPONENT MATERIALS AND ASPHALT MIX DESIGN

Established design procedures, engineering properties and quality standards for component materials are used to support the assumptions made in structural design models. The basis for quality standards of components is largely covered by Australian Standards or Austroads Guides. These cover issues of durability and certain performance attributes, e.g. resistance to polishing of aggregates, performance attributes of polymer modified binders. Selection of component material types and specification standards are generally defined by the Principal although some scope may be provided for selection by the contractor where certain performance-based design criteria must be met. Similarly mix design procedures and design criteria are generally specified by the Principal to satisfy the structural design and other assumptions relating to prediction of long term performance. Under contracts established on performance-related and performance-based specification criteria, asphalt mix design is almost always undertaken by the contractor, but the Principal generally accepts the risks associated with selection of design models and may undertake verification or checking of design data prior to commencing works under the contract. 3.5

MANUFACTURE

Under method specifications, the only manufacturing risks carried by the contractor are those associated with efficiency of organisation and adherence to procedures. Under quality assured contracts, the contractor must ensure that procedures are adequate to meet the performance-based and/or performance-related acceptance testing criteria defined by the Principal. The contractor is responsible for selection of the processes and management of control procedures to meet those criteria while the Principal generally accepts that the specified acceptance testing criteria correlate with the engineering properties required. Under performance contracts that responsibility and risk shifts to the contractor. 3.6

PLACING

As with manufacture, contractor risk under method specifications is largely confined to efficiency of organisation and adherence to procedures, although some end result criteria may also be included. Quality assured specifications are largely based on acceptance testing of end result criteria, primarily compacted density and geometric standards. End result criteria may also be applied to ride quality and some performance-related/performance-based criteria. In this form of contract, the contractor is responsible for both selection of processes and their control. 3.7

MONITORING OF PERFORMANCE

Monitoring of performance is generally only applicable to performance contracts although it may also be applied to verification and refinement of assumptions used in design models and selection criteria.

AUSTROADS 2002 —5—

Framework for Specifying Asphalt

4

SPECIFICATION FRAMEWORK

4.1

BACKGROUND

The specification framework incorporates performance-related design criteria developed through the research programs of Austroads, AAPA and ARRB Transport Research. There has been significant world-wide technological development in the characterisation of asphalt in the last decade. Austroads has invested heavily in development of asphalt testing equipment, research and methods. Leadership and funding has come from Austroads, with support from AAPA, ARRB and the PBCA. There is now a desire to convert the investment into tangible specifications that move towards a performance specified contract framework. An outcome of the initiatives to move towards performance specifications has been publication of the provisional guide to mix design and selection; APRG Report No 18 – Selection and Design of Asphalt Mixes. This report is a milestone in Australian asphalt technology. It implements outcomes of the Austroads R&D program and sets out procedures for the rational characterisation of asphalt performance properties in place of the empirical requirements on which most Australasian asphalt specifications have been based. The most significant change it promotes is the adoption of gyratory compaction methods to replace Marshall and Hubbard-Field compaction techniques for the determination of volumetric properties. Another significant change is the use of performance-based tests (modulus, creep, wheel tracking, fatigue, etc) to replace Marshall or Hubbard-Field parameters for pavements in more heavily trafficked situations. The intent of this specification is to provide a document that reflects the current status taking into account advances made by both road agencies and industry. It has been drafted in the knowledge that we are in a transition stage from method-based to more performance-related specifications. In recognition of the transition phase it caters for gyratory compaction as well as the Marshall method of compaction of asphalt samples for determination of volumetric properties. By the introduction of new requirements for the selection of materials and design and testing of asphalt mixes, it supersedes the relevant sections of AS 2150 – 1995, Hot Mix Asphalt. In due course it is expected that these procedures will be incorporated in AS 2150. Other sections of AS 2150 relating to requirements for manufacturing plant, storage and delivery of asphalt are referred to in the specification framework and remain relevant. 4.2

FRAMEWORK FOR SELECTION FOR SPECIFICATION CLAUSES

Figure 2 depicts a framework of asphalt specification clauses related to variations in contracting environment. It highlights the specification clauses contained in Part C of this document, optional clauses related to method specifications or performance-based specifications, and relationship to other forms of specification clauses that are not used here. A more detailed guide to interpretation and application of specification provisions is provided in Part B. The main elements of the framework are: Contracting environment Contracting environment has been described in the previous sections. Although four distinct forms of specification are shown, variations in contracting environment will result in some hybridisation in application of specification clauses to different forms of contract.

AUSTROADS 2002 —6—

Framework for Specifying Asphalt

Scope Scope in this context refers to pavement design and selection of asphalt type and layer thickness as described in Section 3.3 of this part. This is generally determined by the Principal based on pavement design requirements or type of rehabilitation treatment, in conjunction with surface characteristics required and operating environment. Quality systems Depending on project type and performance risk, the Principal may undertake an audit of a Contractor’s Quality System and/or Quality Plan as part of prequalification or contract acceptance procedures. Method specifications rely on detailed specification of equipment and all stages of the process including quality of component materials, asphalt mix design, manufacturing processes and placing procedures, together with detailed inspection and supervision to ensure that procedures are adhered to. Materials Quality requirements for materials used in asphalt manufacture are generally included in all specification types as being relevant to durability and other long term performance characteristics. Asphalt Mix Design Asphalt mix design may be specified at a number of levels, varying from prescriptive, through basic volumetric criteria, to detailed performance characterisation. The specification clauses in Part C include provision for optional performance characterisation tests as well as traditional Marshall mix design criteria. In some cases the Principal may require details of mix designs to be submitted for approval prior to commencing work (this may be a specification hold point) or provision of samples for audit or verification. The specification makes provision for such options. The output of the asphalt mix design process is a job mix (or job mix formula) to be used as the manufacturing target. Manufacture Method specifications contain detailed requirements for mixing plants and mixing procedures. In QA specifications these form part of the Contractor’s Quality System. Basic requirements are included in Part 3 by reference to AS 2150 – Hot Mix Asphalt. Assessment of asphalt manufacture may be at several levels: ♦ ♦ ♦

Verification that the asphalt has been produced in accordance with the job mix (i.e. use of correct materials, grading and binder content) Confirmation that the manufactured mix meets basic volumetric criteria on laboratory compacted samples of manufactured asphalt. Confirmation that manufactured asphalt achieves other mix design performance criteria.

Optional clauses are provided for all three levels of testing. In addition, the use of statistical process control techniques for assessment of asphalt production are strongly recommended as outlined in Part B of this framework.

AUSTROADS 2002 —7—

Framework for Specifying Asphalt

Placing Placing involves: ♦ ♦ ♦ ♦ ♦ ♦

Delivery of asphalt. Use of appropriate equipment and procedures. In QA specifications this forms part of the Contractor’s Quality System. A production and placing trial may be used for major projects, particularly for newly established project plants. Achievement of geometric standards (shape and thickness). Achievement of an appropriate standard of compacted density. Acceptance on the basis of rolling procedures may be applied to some minor works. Measurement of ride quality and other finished surface characteristics (e.g. texture, segregation) may be included where appropriate.

Performance Monitoring Measurement and monitoring of performance criteria (e.g. ride quality, rutting, cracking, surface texture or skid resistance) is generally only applied to contracts involving performance specified maintenance although some criteria can be applied to defects occurring within the contract defects liability period. Measurement and Payment Measurement and payment is included in the basic specification clauses although some agencies may have more detailed requirements.

AUSTROADS 2002 —8—

Framework for Specifying Asphalt

CONTRACTING ENVIRONMENT

SCOPE

Method

Quality Assured Performance-related

Performance

Performance standards or improvement required

Asphalt mix type(s) and layer thickness

Quality system requirements

QUALITY SYSTEM

MATERIALS

Performance-based

Audit of Quality System and Quality Plans

Materials Asphalt mix design - basic requirements Performance related mix design criteria

MIX DESIGN Mix design data submitted to principal Mix design data verified by principal Basic requirements for asphalt mixing plants and storage of materials Description of manufacturing procedures

MANUFACTURE

Verification that manufacture conforms to job mix (grading and binder content) Verification of design properties of manufactured asphalt Statistical process control Delivery Basic placing requirements

PLACING

Major projects

Description of placing plant and procedures

Production & placing trial

MONITORING PAYMENT

Minor works

Geometric standards and layer thickness Compacted density

Measurement of performance criteria, e.g. Ride quality Rutting Cracking Surface texture (skid resistance)

Ride quality Monitoring performance

Measurement and payment Basic specification clauses (Part C)

Optional clauses (Part B)

Figure 2 — Specification Framework AUSTROADS 2002 —9—

Not used in this specification

Framework for Specifying Asphalt

PART B — NOTES FOR IMPLEMENTATION AND USE OF SPECIFICATION CLAUSES 1

GENERAL

1.1

SCOPE

The specification has been prepared for the manufacture, supply and placing of dense graded hot mix asphalt (also referred to as asphaltic concrete or AC) for roadworks and related applications. Different criteria apply to quality of components and asphalt mix design according to the application and the nominal size and types of mixes to be used should be specified in the Schedule of Job Details. A guide to the selection of mixes is given in the notes to Section 3. The intended use of the materials may also involve the application of different construction requirements and these should also be nominated in the Schedule of Job Details. Guidelines for the application of such requirements are given in the notes to the relevant specification clauses. Careful consideration of the Schedule of Job Details is required to ensure that asphalt is fit for purpose, of the appropriate type and quality, and provided in a cost effective manner. This specification will normally be used as contract documentation in conjunction with a standard General Conditions of Contract such as AS 2124. Contract documentation may also include other works. The terms used in the specification guidelines are generally consistent with AS 2124, and include Principal, Superintendent, and Superintendent’s Representative. Where these terms are in conflict with those otherwise used, a general interpretation clause should be inserted in the contract documents. 1.2

QUALITY SYSTEMS

For discussion on the application of Quality Systems, prequalification, technical audit, surveillance and audit testing refer to the introduction in Part A of this Guide. Where required, this specification may be used in conjunction with general clauses or project specific clauses for such details.

AUSTROADS 2002 — 10 —

Framework for Specifying Asphalt

2

MATERIALS

2.1

AGGREGATE

The specification refers to AS 2758.5, which requires the user to select from a number of options for determination of aggregate hardness and soundness. These options tend to have been developed around the tests considered to provide the most suitable characterisation of the various stone types found in different localities. As a general rule, the standards are applied on a State by State basis as follows: Soundness based on Los Angeles Abrasion and Unsound Stone Content (Table 2.1.1) – Victoria and Western Australia. Soundness based on Ten Percent Fines Value and Wet/Dry Strength Variation (Table 2.1.2) – All other States. Minimum values of polishing resistance (PSV or PAFV) are provided as default values for general application. Surface friction requirements will vary according to the risks associated with operating environment or particular sites, which will also influence the choice of type of asphalt mix and other design factors associated with surface texture. This may lead to the adoption of higher or lower minimum polishing values for some applications. 2.2

MINERAL FILLER

Some asphalt specifications show confusion over the role and specification of filler in asphalt mixes. This specification adopts a simple definition that filler is that mineral matter passing the 75 micron sieve and includes filler sized particles derived from aggregates as well as added fine materials such as lime, fly ash, etc. Effectiveness of filler materials has been found to correlate with fineness and particle size distribution and can influence both asphalt mix stiffness and moisture sensitivity. The measure of voids in dry compacted filler is the simplest test for the characterisation of filler particle size distribution. The minimum value of 38% voids in dry compacted filler should give adequate asphalt mix performance for most applications. This generally requires the use of an added filler to achieve the minimum level. Where additional filler properties are desired for particular applications, they should be specified as special clauses. 2.3

BINDER

A guide to selection of binder type is provided in the notes to Section 3. 2.4

RECLAIMED ASPHALT PAVEMENT (RAP)

A guide to the application of design and manufacturing requirements for RAP in asphalt is provided in the notes to Section 3.

AUSTROADS 2002 — 11 —

Framework for Specifying Asphalt

3

MIX DESIGN

3.1

GENERAL

This specification has been prepared to incorporate performance-based design criteria developed through the national research programs of AAPA, AUSTROADS and ARRB Transport Research. The outcome of that research program has been published as AUSTROADS Pavement Research Group Report No. 18 - Selection and Design of Asphalt Mixes: Australian Provisional Guide. The provisional status of the Guide reflects the tentative nature of aspects of the performance criteria and the requirement for some test data to be reported rather than meet particular limits. Guidelines for application of performance tests are given in the notes to Section 3.3. The APRG 18 mix design procedure has two main elements: ♦ ♦

Gyratory compaction for preparation of laboratory samples in place of Marshall or Hubbard Field. Performance-related tests on compacted materials.

The general volumetric requirements for asphalt mixes remain largely unchanged (requirements for component materials, grading limits, binder content, and voids relationships) so that asphalt mixes should therefore not change greatly from those previously used, particularly where there is a satisfactory record of performance. The new procedures should, however, provide greater reliability and prediction of performance behaviour. Gyratory compaction enables ready selection of different compaction levels to match expected service conditions as well as being able to simulate long term heavy traffic loadings by compaction to “refusal density”. Gyratory compaction is also considered to achieve particle alignment that is a better representation of field compaction of asphalt. The specification does, however, provide for the use of Marshall compaction where that method of compaction is more expedient. It is important that only one set of criteria are applied, either Marshall or gyratory compaction. In due course it is expected that gyratory compaction will become more common than Marshall. The mechanical properties of Marshall and Hubbard Field ‘Stability’ and ‘Flow’ do not directly measure fundamental properties but provide empirical relationships that have been found to correlate with asphalt mixes that provide suitable levels of field performance. The new mix design procedures provide for a range of tests on performance-based properties that include: ♦ ♦ ♦ ♦ ♦

Resilient modulus of laboratory compacted samples or cores using MATTA indirect tensile test. Dynamic creep, using MATTA, on laboratory compacted samples or cores. Users should note, however, that this test is undergoing further development. Moisture sensitivity (Modified Lottman test) of gyratory compacted samples. Wheel tracking of laboratory compacted slabs. Fatigue testing and flexural stiffness of beams cut from laboratory compacted slabs or field samples.

The Provisional Guide provides for three levels of design depending on the intended application. In summary, the major test requirements for each level are shown in Table 3.3.1.

AUSTROADS 2002 — 12 —

Framework for Specifying Asphalt Table 3.3.1 — Laboratory Mix Design Levels Design level 1 2 3

3.2

Standard tests Gyratory compaction, density and voids determinations Resilient modulus Dynamic creep 

Optional tests  Moisture sensitivity Fatigue Wheel tracking Compaction to maximum gyratory cycles

AGGREGATE GRADING AND BINDER CONTENT

The aggregate grading and binder content ranges shown in Tables 3.2.1 and 3.2.2 of the specification are targets for design purposes. Application of production tolerances may result in actual production being outside those limits. Table 3.2.1 restricts the proportion of finer materials in order to provide good texture for wearing course mixes for medium and heavy traffic and increased deformation resistance in heavier trafficked applications. Table 3.2.2 allows increased proportions of finer materials for all lesser trafficked applications. The Superintendent may approve the use of asphalt mixes with a design target outside the ranges shown, where it can be shown that all the other performance requirements can be adequately met. 3.3

MIX PROPERTIES: SELECTION OF MIX TYPE, BINDER TYPE, AND TESTING REQUIREMENTS

The principal factors influencing the performance characteristics of asphalt mixes are the selection and quality of components, and the volumetric properties of the mix (nominal size, grading, binder content and voids relationships). The specification provides for different criteria for aggregate quality and voids relationships (Level 1 of APRG 18 design procedure) based on traffic categories. A guide to selection of traffic category is shown in the Table 3.3.1 below. The relevant traffic category should be nominated in the Schedule of Job Details. The nominal mix size and binder type should also be nominated in the Schedule of Job Details. The nominal size may be determined as a function of the layer thickness or the layer thickness selected on the basis of the nominal size required for a particular application. A guide to selection of layer thickness and nominal size is shown in Table 3.3.2. Guides to selection of binder types for wearing and base course applications are shown in Tables 3.3.3 and 3.3.4. It should be noted that the design air voids targets for gyratory compaction are different to those for Marshall compaction. The limits for gyratory compaction are based on different compactive effort (cycles) for different traffic applications whereas the design air void targets for Marshall compaction are based on a single 50 blow compactive effort. The use of 50 blow compaction enables mixes of different applications and voids targets to be selected from the one set of laboratory test data. If mixes are to be designed for different compactive effort, the target air voids and VMA should be reduced by up to about 1% for 75 blow compaction and increased by up to about 1% for 35 blow compaction. Where different design air voids criteria are required, a special clause should be inserted in the schedule of details.

AUSTROADS 2002 — 13 —

Framework for Specifying Asphalt Table 3.3.1 — Guide to Traffic Category Indicative Traffic Volume Commercial Structural design level vehicles/lane/day < 100 100 – 500 500 – 1000 > 1000

< 5x105 ESAs 5x105 - 5x106 ESAs 5x106 - 2x107 ESAs > 2x107 ESAs

Traffic Category Free flowing vehicles Stop/start OR climbing lane OR slow moving Light Medium Medium Heavy Heavy Very Heavy Very heavy Very Heavy

Table 3.3.2 — Guide to Selection of Nominal Size Nominal size (mm) 5 7

Typical Layer thickness (mm) 15 –20 20 – 25

10 14

25 – 35 35 – 45

20 28

> 50 > 60

40

> 100

Typical Use Very thin surfacing layer with fine surface texture. May not be available in all locations Commonly used for surfacing residential streets and foot traffic areas where thin layers and fine surface texture are required. General purpose wearing course in light and medium traffic applications Wearing course mix for heavier traffic applications. Also some intermediate course applications depending on layer thickness General purpose base and intermediate course mix for wide range of use. Base and intermediate course but less commonly used than 20 mm. Control of segregation can sometimes be an issue. Occasionally used as heavy duty base. Control of segregation can be a significant issue.

Table 3.3.3 — Selection of binder type for wearing course applications Traffic Category Light Medium Heavy

Very Heavy

Binder Class/Type 170 320 170 320 320 600, Multigrade or PMB 320 600, Multigrade or PMB

Recommended use Residential streets, car parks and foot traffic Alternative to 170, particularly in warmer climates Normal conditions and lower traffic ranges, particularly in cooler conditions Good general purpose mix for wide range of applications General purpose mix for heavily trafficked applications. Higher performance mixes for more critical traffic applications or where elastomeric polymers are required to improve flexibility. Stiffer binders require strong, stiff base. Heavily trafficked intersections and slow moving traffic Special applications such as very heavily trafficked intersections and heavy duty industrial pavements.

Table 3.3.4 — Selection of binder type for intermediate and base course applications Traffic Category Light and Medium Medium/ Heavy (high fatigue base) Heavy Very Heavy

Binder Class/Type 170 320 320 320 600, 320,600, Multigrade or PMB

Recommended use General purpose mixes for cooler conditions General purpose mixes for most light and medium traffic applications Special high bitumen content sub-base layer providing high fatigue resistance. To avoid rutting, this mix should not be used within 125 mm of surface. The layer thickness should not generally exceed 70 mm or one third of the structural pavement depth. General purpose mix for heavy traffic applications. High stiffness base for use in heavy duty pavements. Special applications such as heavy duty industrial pavements and hard standing areas.

AUSTROADS 2002 — 14 —

Framework for Specifying Asphalt

3.4

DESIGN AND MANUFACTURE OF ASPHALT MIXES INCORPORATING RECLAIMED ASPHALT PAVEMENT (RAP)

As a general rule, no special requirements need apply to the use of RAP in hot mix asphalt where the percentage of RAP does not exceed 15% of the total mix, provided that separate designs are prepared for such mixes, the proportions used in manufacture are not substantially altered from that used in design, and that the Quality Plan includes a reasonable management plan for monitoring incoming RAP materials. Where RAP is to be added in proportions greater than 15%, but not more than 30% of the total mix, the use of bitumen binder of one class softer than that otherwise specified will generally provide suitable compensation for the influence of hardened binder in the RAP and produce asphalt mixes of comparable stiffness, fatigue resistance and deformation resistance to mixes manufactured with virgin materials. Alternative procedures include the use of rejuvenators or a softer class of binder tailored to tests on actual penetration or viscosity of binders recovered from stockpiled RAP materials. The latter approach is appropriate where it is believed that accurate prediction of binder stiffness is critical to the long term performance of the asphalt. e.g. Heavy traffic base applications and Very Heavy traffic base and wearing course applications. A further option is to accept the material without adjustment to the grade of fresh binder. In such cases the asphalt may have slightly higher flexural stiffness that could reduce fatigue resistance in thin surfacing applications when the proportion of RAP approaches 25 or 30%. The specifier may also restrict use of more than 15% RAP to particular mix types or project applications. Mixes that are not permitted to contain more than 15% RAP should be listed in the Schedule of Job Details. The use of RAP in proportions greater than 15% should not be allowed where polymer modified binders are specified but should be satisfactory for use with multigrade binder and most applications with standard classes of bitumen binder. The use of RAP in proportions greater than 30% of the total mix should only be permitted where the Contractor can demonstrate suitable manufacturing plant and quality control procedures. Manufacture should only be carried out in asphalt plants specifically designed to handle such proportions of RAP without overheating and damage to binder in the RAP or new mix. The quality plan should indicate the procedures for monitoring the consistency of grading and binder properties of incoming RAP materials, the use of softer binders or rejuvenating agents to achieve a binder of comparable performance to that otherwise specified, and testing to validate the properties of the manufactured asphalt. A guide to blending of binders or rejuvenating agents to achieve a target binder viscosity is provided in the Austroads Asphalt Recycling Guide (AP-44/97) and Austroads Framework Specifications for Asphalt Recycling (AP-T02). Caution must be used in determining targets for blending of binders as fresh binder or rejuvenator may not be fully combined with the aged binder during the asphalt manufacture process. Consequently, mix performance characteristics imparted by binder stiffness, particularly fatigue and rutting resistance, may be somewhat intermediate between that of the fresh binder and that predicted from the stiffness or viscosity calculated or determined by extraction and testing of the blended binder. 3.5

APPROVAL OF JOB MIX

In addition to the tests listed in Table 3.5.1 of the specification that are required to be reported from a production trial batch, the Contractor may also be required to report the results of Moisture Sensitivity Testing. A typical minimum value for the Moisture Sensitivity test is a Tensile Strength Ratio of 80%. Further application of APRG 18 Level 2 and Level 3 testing should not be required for most routine asphalt applications as these tests are largely used in the development of design models and confirmation of the selection of Level 1 criteria and binder type.

AUSTROADS 2002 — 15 —

Framework for Specifying Asphalt

A guide to applications where Level 2 and Level 3 tests may be relevant is provided in Table 3.5.1. Some of these tests are expensive and only capable of being performed in a limited number of research laboratories. Specifiers should therefore consider the balance between the cost of providing test data and the use to which the information is to be put. Where testing is required, the tests should be nominated in the Schedule of Details and a separate schedule item provided for the cost of testing. Table 3.5.1 — Guide to applications where Level 2 and Level 3 Mix Design tests may be considered

Traffic Category

Light Medium Heavy Very Heavy

Mix Type Application Wearing and base Wearing and base High fatigue base Wearing and base High fatigue base Wearing and base

Resilient Modulus at 25°C

Dynamic Creep at 50°C

Moisture Sensitivity

Yes Yes Yes Yes Yes Yes

No No No Yes No Yes

No No No Yes No Yes

AUSTROADS 2002 — 16 —

Fatigue Life at 20°C and 400 micro strain No No No Yes Yes Yes

Wheel Tracking Test at 60°C No No No Yes No Yes

Framework for Specifying Asphalt

4.

MANUFACTURE AND STORAGE

Reference is made to AS 2150 that outlines the requirements applicable to most common mixing plant types. Guidance for binder storage and mixing temperatures may be obtained by reference to AAPA Advisory Note 7: Guide to the Heating and Storage of Binders for Sprayed Sealing and Hot Mixed Asphalt. The length of time that manufactured asphalt may be held in hot storage bins will vary according to the type of mix, type of binder and construction of storage bins. Maximum storage times (24h) are applicable to standard dense graded asphalt mixes, standard bitumen binder and well insulated bins that may also include supplementary heating. Shorter storage periods apply to high binder content mixes, polymer modified binders and poorly insulated bins. Guidelines for storage of polymer modified binders at elevated temperatures is generally provided by the manufacturers of polymer modified binders. Other potential deleterious influences of extended storage may be assessed by monitoring mix temperature variation and segregation.

AUSTROADS 2002 — 17 —

Framework for Specifying Asphalt

5.

SAMPLING AND TESTING OF ASPHALT PRODUCTION

5.1

GENERAL

The purpose of inspection and testing is to provide reasonable assurance to the purchaser that the quality of component materials comply with the standards specified, and that the manufactured asphalt is in accordance with the designated job mix design. Manufacturing compliance may be assessed at two levels: ♦ ♦

Verification that the job mix has been replicated, i.e. use of conforming components and combination in the design proportions to achieve the job mix grading and binder content. Verification that the design targets have been met, i.e. testing of compacted samples for volumetric properties and other design properties.

For many applications, compliance with the job mix grading and binder content is adequate. If production is controlled within the tolerances specified, it is neither necessary nor cost effective to perform further testing for conformity to mix design criteria as a routine measure of quality. In fact, the variability inherent in such sampling and testing may lead to misleading interpretation of quality variation where no such variation really exists. Where confirmation of volumetric properties is required, an additional clause should be inserted to require compaction of samples taken from production to be compacted using the same procedures as that specified for the design of the relevant mix. The sampling frequency should be the same as that applied to testing of grading and binder content and the tolerance on air voids should be ± 1.5% of the design target. Compacted samples may also be assessed for other design properties such as Marshall stability and flow or resilient modulus. The Marshall test properties should meet the specified design criteria. At this stage there are no accepted minimum standards to be applied to resilient modulus and other asphalt performance criteria testing but some agencies are collecting this information on a routine basis in order to establish limits for future application. The manufacturer should not rely solely on the sampling and testing done for compliance purposes as the measures of process quality control. The specification provides an incentive to the manufacturer to undertake suitable measures to improve the level of conformity and consistency of manufactured product by reducing the frequency of testing for compliance purposes where the manufacturer is using a suitable statistical process control system and where the results of compliance tests show an appropriate level of consistency in meeting the specification requirements. A guide to statistical process control systems is provided in AAPA Implementation Guide IG-3: Asphalt Plant Process Control Guide. Further guidance to the application of statistical techniques is provided in Australian Standards AS 3940 – Quality control – Guide to the use of control charts including Cusum techniques and AS 3942 Quality control – Variables charts – Guide. A typical statistical process control system that would be suitable for this application is one that incorporates the following elements: Process control charts for the compliance tests for grading (one sieve below mix nominal size, 2.36 mm and 0.075 mm sieves), binder content, and maximum density.

AUSTROADS 2002 — 18 —

Framework for Specifying Asphalt

Process charts should show: (a) Actual individual sample test results plotted against the target value and specified tolerances. (b) Five point rolling mean, with the target value, warning and control limits. (c) Five point rolling range (the maximum of five points) Corrective action should be taken when any of the following occur: (a) One point lies outside the control limits (b) Two out of three points lie outside the warning limits. Investigation of possible assignable causes, and need for corrective action, should be undertaken if: (a) Five consecutive points in the rolling mean are above or below the target (b) Five consecutive increasing points occur in the range (c) Two out of three points lie outside the warning limits The use of statistical process control measures are strongly encouraged as a means of reducing the uncertainties associated with interpretation of test results from single samples. The use of risk assessment procedures to define where variation may occur is also recommended.

AUSTROADS 2002 — 19 —

Framework for Specifying Asphalt

6

DELIVERY

Reference is made to AS 2150. The rate of delivery should be matched to paving output to maintain consistent spreading to achieve good ride quality and uniform compaction and to avoid unnecessary delays in spreading operations and loaded asphalt being held on site for long periods. Asphalt should arrive on site at a suitable temperature for spreading. A guide to asphalt temperature at the time of spreading is shown in the following table. Table 6.1 — Asphalt Spreading Temperatures Road surface temperature1 (°C)

5 - 10 10 – 15 15 – 25 > 25

Range of mix temperature3 (°C)

Minimum mix temperature2 (°C) Thickness of layer, mm < 30 See note 4 150 150 150

30 - 40 See note 4 145 145 145

41 -100 145 140 135 130

> 100 135 - 150 130 – 145 125 – 140 120 – 135

Notes: 1 2 3 4

Surface temperature should be generally that applicable to the coolest area of the pavements, e.g. shade areas, if applicable Mix temperatures apply to Class 170 and 320 bitumen binder. Use of Class 600, Multigrade, or PMBs may require minimum temperatures 5°C to 10°C higher than those shown. Maximum temperatures apply when placing thick layers, to avoid excessive displacement under rolling. Placing asphalt in thin layers under cool conditions may adversely affect the result due to the increased difficulty in achieving proper compaction, effective joints and good surface finish. Additional attention should be paid to issues of mix workability, asphalt temperature, compaction techniques and any influence from additional cooling due to wind or moisture.

AUSTROADS 2002 — 20 —

Framework for Specifying Asphalt

7

PLACING

7.1

PREPARATION OF SURFACE

Road surfaces must be clean to ensure good bond between new asphalt and the existing surface. 7.2

TACK COATING

Bitumen emulsion used for tack coating may be diluted to assist uniform coverage, provided that the residual binder application rate is achieved. The type of bitumen emulsion should suit the conditions of use. Generally, rapid setting cationic emulsion is used in cooler regions where damp conditions may be encountered. In warmer or drier conditions, slower setting cationic emulsions and anionic emulsions may combine easier handling with satisfactory performance. Tack coating is generally not necessary when placing over clean, freshly applied primed surfaces or newly placed, untrafficked asphalt. Crushed rock and gravel surfaces should be primed with a suitable application of primer, prior to placing asphalt, particularly where the total thickness of asphalt is 50 mm or less. Priming the surface assists in: • Achieving a strong bond between asphalt and granular layers. • Reducing the permeability of the surface of the granular layer. • Stabilising the pavement moisture content and assisting in the curing of cement stabilised layers. • Preserving the integrity of the granular surface after completion of preparation and before placing asphalt. If priming is required, it must be included as a separate specification and schedule item. 7.3

SPREADING

The specification provides for asphalt to be placed when pavement surface temperatures are as low as 5°C. Placing in cool conditions increases the difficulty in obtaining good standards of work and, where practicable, work involving thin layers (40 mm or less) or PMB binders should be programmed to be done when such conditions are less likely to occur. The selection and use of automatic level control for asphalt paving should normally be determined by the Contractor, taking into account the applicability to site conditions and the geometric requirements of the finished result. Where the Superintendent requires a particular form of level control, it may be specified in the Schedule of Job Details. Typical applications of automatic controls are as follows: Joint Matcher. Suitable for use on most classes of work to reduce manual effort Travelling Beam (Generally 9.0 m). Assists in removing minor irregularities within the length of the beam. Suitable for a wide range of work, except for short runs and restricted working space. Improved shape correction may involve increased quantities of asphalt. Cross-fall. Limited applications where a set crossfall is desired from a reference on one side of the paver. Computerised Electronic Control (e.g. “Paveset”). Enables paver to operate to predetermined profile. Needs accurate survey and well maintained equipment.

AUSTROADS 2002 — 21 —

Framework for Specifying Asphalt

Fixed Stringline. Enables paver to operate to set profile. Requires accurate survey and additional personnel for setting up and maintaining lines. Presence of stringlines can severely restrict movement of spreading vehicles. 7.4

COMPACTION

Selection of compaction equipment is the responsibility of the Contractor, provided that it is capable of achieving the required standards of compacted density, surface shape and finish. 7.5

JOINTS

Joints are the weakest part of the pavement. Cold joints should be minimised by planning of works to achieve a minimum number of construction joints and, where practicable, maximum use of hot or warm joints.

AUSTROADS 2002 — 22 —

Framework for Specifying Asphalt

8.

PRODUCTION AND CONSTRUCTION TRIAL

A production and construction trial is usually only applicable to major projects where a transportable plant is specifically set up for the project. Preliminary trials may also be called for on major project works to be supplied from fixed plants, where a plant has not been used to supply that class of work or where the use of new sources of materials and mix designs are involved. A separate schedule item should be included for payment for production and construction trials.

AUSTROADS 2002 — 23 —

Framework for Specifying Asphalt

9.

FINISHED PAVEMENT PROPERTIES

For general asphalt work, the application of shape standards as specified in Clause 9.4.1, together with the use of good placing practices as outlined in the notes to Section 7, should provide adequate surface smoothness and ride quality. Additional measures of pavement smoothness may be applicable to high class facilities where the importance of the resulting ride quality justifies both the cost of testing and (where high standards are to be applied) the additional cost of work procedures that may be required to achieve the specified result. The standard of ride quality that can be achieved will depend on the roughness of the surface on which the asphalt layer is to be placed, and the extent of shape correction and additional asphalt layers that may be applied prior to the final layer. Typical applications of ride quality measures are Freeways and major arterial roads where the posted speed limit is 80 km/h or more. The following are some guidelines to applicable standards. New Work: A value of 40 NAASRA roughness counts is generally applicable to new works where the Contractor has control of the shape of base and wearing course layers. Higher standards are achievable but the cost of obtaining higher ride standards through the use of special techniques and equipment needs to be balanced against the benefit likely to be derived from the attainment of that higher standard of pavement smoothness. Resurfacing: The standard of ride quality achievable will be influenced by the shape of the existing surface and the number of layers, or extent of any regulation and shape correction, prior to placing the wearing course layer. As a general guide, a suitable target for improvement for each layer is to achieve a NAASRA roughness count of 60% of the existing conditions plus 5. For example, for an existing roughness count of 80, Target = 0.60 x 80 + 5 = 53. An alternative to NAASRA roughness counts (NRM) is the use of International Roughness Index (IRI). Values may be converted using the formula 1 NRM = 0.03925 IRI.

AUSTROADS 2002 — 24 —

Framework for Specifying Asphalt

10.

MEASUREMENT AND PAYMENT

Payment is normally on the basis of mass determined from an approved weighing system. Alternatively, on new works where asphalt is being placed to a specified thickness, the mass may be determined on the basis of measured area, thickness and density. Additional clauses may also be inserted to apply a scheduled rate of reduction in payment for failure to comply with manufacturing targets, compacted density and ride quality requirements to compensate for reduced service life.

AUSTROADS 2002 — 25 —

Framework for Specifying Asphalt

11.

APPENDIX (SCHEDULE OF JOB DETAILS)

ASPHALT MIX REQUIREMENTS (Clause 1.3.1, 2.3, 3.2, 3.3) Insert type/traffic category of mix, binder type, nominal size and thickness, where applicable. MEASUREMENT AND PAYMENT (Clause 10.1) Indicate the method of measurement applicable. SPECIAL JOB REQUIREMENTS Where required, special clauses should be prepared and inserted in the schedule of job details for the following. Design Criteria (Clause 3.3) Insert any special design requirements, if applicable. Reporting Of Level 2 & 3 Design Tests (Clause 3.3) Insert reporting requirements for mix design tests other than standard volumetric data. A separate schedule item should be provided for the cost of such testing. Use of Reclaimed Asphalt Pavement (RAP) (Clause 3.4) Insert any particular conditions or restrictions to mix types or applications of RAP in asphalt. Submission of Samples (Clause 3.5.2) Insert details for delivery of samples (if relevant) Automatic Paver Level Control (Clause 7.4.4) Insert any special requirements for use of automatic paver control, if applicable. Production and Construction Trial (Clause 8) Insert requirements for production and construction trial, if applicable. A separate schedule item is also required for the cost of such trial. Measurement of Ride Quality (Clause 9.4.2) Insert special requirements for measurement of ride quality, if applicable. A separate schedule item should be provided for the cost of testing, where testing is to be provided by the Contractor. Non Complying Materials (Clause 10.4) Insert special requirements for payment for non complying materials, if applicable.

AUSTROADS 2002 — 26 —

Framework for Specifying Asphalt

PART C — SPECIFICATION CLAUSES 1

GENERAL

1.1

SCOPE

This specification covers dense graded hot mix asphalt for roads and related applications. The areas covered by this specification include: ♦ ♦ ♦ ♦ ♦

Asphalt materials Asphalt mix design requirements Process control in manufacture and placement of asphalt Acceptance criteria for asphalt Quality systems, minimum process standards, plant requirements and sampling and testing frequencies.

This section is to be read in conjunction with the Appendix (Schedule of Job Details). Where there is conflict between the requirements of this section and the Appendix, the requirements of the Appendix shall apply. 1.2

REFERENCES

APRG Report No.18 – Selection and Design of Asphalt Mixes: Australian Provisional Guide, AUSTROADS, 1997. Austroads Specification Framework for Polymer Modified Binders, AP-T04 Austroads Provisional Specification for Multigrade Binders AP-T01 Austroads Manual of Test Procedures Standards Australia

AS 1141 Methods for Sampling and Testing Aggregates AS 1160 Bituminous Emulsions for Construction and Maintenance of Pavements AS 1289 Methods of Testing Soils for Engineering Purposes AS 1672.1 Limes and Limestones – Lime for Buildings AS 2008 Residual Bitumen for Pavements AS 2150 Hot Mix Asphalt AS 2758.5 Aggregates and Rock for Engineering Purposes, Part 5: Asphalt Aggregates AS 2891 Methods of Sampling and Testing Asphalt AS 3582.1 Supplementary Cementitious Materials for use with Portland Cement, Part 1 – Fly Ash AS 3582.2 Supplementary Cementitious Materials for use with Portland Cement, Part 2 – Slag – Ground Granulated Iron Blast-Furnace. AS/NZS ISO 9002 Quality Systems – Model for Quality Assurance in Production, Installation and Servicing for Production and Installation AS 3972 Portland and Blended Cements

AUSTROADS 2002 — 27 —

Framework for Specifying Asphalt

1.3

DEFINITION OF TERMS

1.3.1

Asphalt Mix Types

For the purposes of this specification asphalt mixes have been classified in terms of wearing course and base and four traffic categories of Light, Medium, Heavy and Very Heavy. The particular mixes to be used shall be nominated in the Appendix or, if not otherwise specified, selected in accordance with the traffic category guidelines given in APRG 18. Dense graded hot mix asphalt is also known as asphaltic concrete and designated by the abbreviation AC. 1.4

QUALITY SYSTEM

The Contractor shall establish, implement and maintain a Quality System in accordance with this Specification and the requirements of AS/NZS ISO 9002, or a recognised equivalent. Where required in the Contract general clauses, the Contractor shall submit a Quality Plan prior to commencement of any works. The Quality Plan shall take into account the specific requirements for inspection and testing, acceptance/rejection criteria, details of proposed methods and other quality requirements that are contained in the Contract Documents. No part of the Quality System shall be used to pre-empt or otherwise negate the technical requirements of the Contract Documents. 1.5

TESTING

All testing of properties required by the Specification shall be undertaken in a laboratory registered by the National Association of Testing Authorities (NATA) for the appropriate tests and performed in accordance with procedures contained in the relevant Australian Standard or Austroads Manual of Test Procedures. Where there is no applicable Australian Standard or Austroads Test Method, or where the Standard/Manual provides a choice of procedures, the method to be adopted shall be that endorsed by the relevant State Road Authority in the State in which the work is being undertaken.

AUSTROADS 2002 — 28 —

Framework for Specifying Asphalt

2

MATERIALS

2.1

AGGREGATE

2.1.1

General

All materials shall be obtained from established sources and have established properties. Each individual component of coarse and fine aggregate shall be obtained from the same sources as materials in design of the Job Mix. Stockpiles of all aggregates from different sources or of different sizes shall be separated. Where requested, the source of all materials shall be subject to inspection and approval by the Superintendent and only material from a nominated quarry face or location shall be used. 2.1.2

Coarse Aggregate

Coarse aggregate is comprised of particles that are retained on the 4.75 mm sieve. Coarse aggregate shall comply with Australian Standard AS 2758 Part 5 with the application of those test properties specified in Tables 2.1.1, 2.1.2 and 2.1.3 as appropriate except that the Superintendent may approve the use of non complying materials from sources of proven performance. Tables 2.1.1 and 2.1.2 provide alternative combinations of hardness and durability and only one combination shall apply. The particular hardness and durability combination to be used shall be selected by the Contractor unless specified in the Schedule of Job Details. Table 2.1.1 — Coarse Aggregate Requirements for Hardness and Durability Based on Los Angeles Abrasion Loss (LA) and Unsound and Marginal Stone Content Test value Test property Los Angeles Abrasion Loss (% maximum)

Unsound stone content (%) Marginal and unsound stone content (%)

Heavy/Very Heavy Traffic Mix Types Rock type LA All 25

3 maximum 8 maximum

Other Mix types Rock type Acid Igneous: Granitic rocks Others Intermediate igneous Basic igneous Metamorphic Sedimentary Dense metallurgical slags 5 maximum 10 maximum

LA

Table 2.1.2 — Coarse Aggregate Requirements for Hardness and Durability Based on Wet Strength and Wet/Dry Strength Variation Test property Ten Percent Fines Value (Wet) (kN) Wet/Dry Strength Variation (%)

Test value Heavy/Very Heavy Traffic Mix Types 150 minimum 35 maximum

AUSTROADS 2002 — 29 —

Other Mix types 100 minimum 35 maximum

35 30 30 30 30 25 30

Framework for Specifying Asphalt Table 2.1.3 — Other Coarse Aggregate Requirements

Test property Flakiness Index (% maximum) Weak particles (% maximum) Water absorption (% maximum) Polished Stone Value or Polished Aggregate Friction Value

2.1.3

Test value Heavy/Very Heavy Traffic Mix Types 25 1 2 48 minimum

Other Mix types 35 1 2.5 45 minimum

Fine Aggregate

Fine aggregate shall consist of crushed rock particles finer than the 4.75 mm sieve and manufactured from an approved source complying with the requirements of Section 2.1.2, clean sand, or both. The fine aggregate shall be clean, hard, durable and free from lumps of clay and other aggregations of fine materials, organic material and any other deleterious material. Fine aggregate consisting of crushed rock particles shall have a minimum Degradation Factor, Crusher Fines of 60 when tested in accordance with AS 1141.25.3. Natural sands shall have a Sand Equivalent (AS 1289.3.7.1) of not less than 60. 2.2

MINERAL FILLER

Mineral filler is that portion of mineral matter passing a 75 micron sieve, and includes rock dust derived from coarse and fine aggregates used in the production of asphalt in accordance with this specification, and any other materials added to supplement the quantity and properties of filler in the mix. The total filler component in the combined job mix for medium, heavy and very heavy traffic mix types shall have a value of dry compacted voids (AS 1141.17) not less than 38%. Filler shall be consistent in mineral composition and dry compacted air voids. It shall be dry, and free from lumps, clay, organic matter or other material deleterious to asphalt. Added filler (material not derived from the aggregate components) shall comply with the relevant standards listed in Table 2.2.1. The Superintendent may approve materials other than those listed provided that the Contractor supplies evidence of the quality and effect of the proposed materials on the properties of the asphalt mix. Rock dust that is not derived from the aggregate components may also be used as added filler provided that it is derived from materials that meet the requirements of Clause 2.1. Table 2.2.1 — Standards for Materials Used as Added Filler. Material Hydrated lime Fly Ash Cement Kiln Dust Slag Ground Limestone Cement

Standard – See note 1 AS 1672.1 Limes and Limestones – Lime for Building AS 3582.1 Fly Ash Table 1, Fine Grade. See note 2 AS 3582.2 Slag – Ground Granulated Iron Blast-Furnace See note 3 AS 3972 Portland and Blended Cements

Notes: 1 Provision of test certificates for compliance with the relevant Australian Standard and this specification shall be limited to those tests listed in Table 2.2.3. 2 Cement kiln dust shall be solid material extracted from the flue gases in the manufacture of Portland cement, having a maximum water soluble fraction of 20% by mass and complying with the grading limits specified in Table 2.2.2 3 Ground limestone shall consist of rock dust derived from the grinding of sound limestone and complying with the grading limits specified in Table 2.2.2.

AUSTROADS 2002 — 30 —

Framework for Specifying Asphalt Table 2.2.2 — Grading Limits for Ground Limestone and Cement Kiln Dust Materials for Use as Added Filler Sieve Size AS (mm) 0.600 0.300 0.075

Percentage passing sieve size (by mass) 100 95 – 100 75 - 100

Materials for use as added filler shall meet the test requirements specified in Table 2.2.3. Table 2.2.3 — Test Requirements for Materials for Use as Added Filler Filler type All All All Fly ash Cement kiln dust

2.3

BINDER

2.3.1

Bitumen

Test type Grading (AS 0.600 mm, 0.300 mm and 0.075 mm sieves) Voids dry compacted filler Moisture content Loss on ignition Water soluble fraction

Test requirements Report Report 3% max. 4% max. 20% max.

Standard Classes of bitumen shall comply with the requirements of AS 2008. Multigrade bitumen shall comply with the Austroads Provisional Specification for Multigrade Binders. 2.3.2

Other Binders

Polymer modified binder shall comply with the Austroads Specification Framework for Polymer Modified Binders. 2.3.4

Additives

The type and proportion of additives to be used in the mix, other than those specified elsewhere in this specification, shall be in accordance with an approved specification. An approved specification may be a manufacturer’s recommendation, purchaser’s specification or as agreed between the parties. 2.3.4

Rejuvenating Agent

Rejuvenating agent, if required in mixes incorporating recycled asphalt, shall be a low volatility oil capable of combining with bitumen to counteract hardening and produce a lower viscosity grade of binder. Rejuvenating agent shall comply with recognised standards for such materials.

AUSTROADS 2002 — 31 —

Framework for Specifying Asphalt

2.4

RECLAIMED ASPHALT PAVEMENT

Reclaimed asphalt pavement (RAP) shall be obtained from milling or excavation of existing asphalt. RAP shall be crushed and screened as necessary to ensure a maximum size no greater than the maximum size of asphalt being produced and to achieve a reasonably well graded, free flowing, and consistent product. RAP shall be free of foreign material such as unbound granular base, broken concrete, crumbed rubber or other contaminants. Asphalt containing tar shall not be used. RAP shall be placed in separate stockpiles prior to use.

AUSTROADS 2002 — 32 —

Framework for Specifying Asphalt

3

MIX DESIGN

3.1

GENERAL

The Contractor shall provide all mix designs. Where specified, the Contractor’s mix design shall be assessed by the Superintendent for compliance with the requirements of this specification. In such cases, the mix design shall be approved by the Superintendent prior to its use. The types of mixes shall be as listed in the schedule of job requirements, or as shown on drawings. 3.2

AGGREGATE GRADING AND BINDER CONTENT

Unless otherwise specified, asphalt mixes shall be designed with a target grading and binder content complying with the limits given in Table 3.2.1 for Medium, Heavy and Very Heavy Traffic Wearing Course and Heavy and Very Heavy Traffic Base Course mix types, or Table 3.2.2 for all other mix types. Bitumen content shall be expressed as a percentage by mass of the total mix. Table 3.2.1 — Combined Aggregate Grading (Including Filler) for Medium, Heavy and Very Heavy Traffic Heavy Wearing Course and All Base Course Mix Types. Sieve Size AS (mm)

37.5 26.5 19.0 13.2 9.5 6.7 4.75 2.36 1.18 0.600 0.300 0.150 0.075 Total Binder Content (% by mass)

AC10

100 90 - 100 68 - 82 50 - 70 32 – 51 22 – 40 15 – 30 10 – 22 6 – 14 4-7 100 4.5 – 6.5

Mix designation AC14 AC20 AC28 Percentage passing sieve size (by mass)

100 90 - 100 72 – 83 54 – 71 43 – 61 28 – 45 19 – 35 13 – 27 9 – 20 6 – 13 4-7 100 4.0 – 6.0

100 90 – 100 71 – 86 58 – 75 46 – 64 37 – 55 24 – 42 15 – 32 10 – 24 7 – 17 4 – 12 3–6 100 3.8 – 5.8

100 90 - 100 73 – 88 58 – 76 47 – 67 37 – 58 30 – 50 20 – 37 13 – 28 9 – 22 6 – 16 4 – 10 3-6 100 3.5 – 5.5

Notes: 1 The range of binder content for high fatigue base course mixes shall be increased by I percentage point.

AUSTROADS 2002 — 33 —

AC40 100 90 – 100 72 – 87 58 – 76 38 – 58 27 – 43 16 – 33 11 – 26 7 – 20 5 – 14 4 – 10 3–6 100 3.0 – 5.0

Framework for Specifying Asphalt Table 3.2.2 — Combined Aggregate Grading (Including Filler) for Light Traffic Wearing Course Mix Types. Sieve Size AS (mm)

Mix designation AC7 AC10 AC14 Percentage passing sieve size (by mass) 100 100 90 - 100 100 90 - 100 72 – 89 85 - 100 68 – 87 54 – 79 70 – 87 50 – 76 43 – 69 44 – 65 32 – 57 28 – 53 29 – 48 22 – 42 19 – 40 19 – 35 15 – 31 13 – 30 12 – 25 10 – 23 9 – 22 8 – 16 6 – 14 6 – 15 5-8 4-7 4-7 100 100 100 5.0 – 7.0 4.5 – 6.5 4.3 – 6.3

19.0 13.2 9.5 6.7 4.75 2.36 1.18 0.600 0.300 0.150 0.075 Total Binder Content (% by mass)

3.3

MIX PROPERTIES

Where laboratory preparation and compaction of asphalt mixes is undertaken using gyratory compaction, asphalt mixes shall comply with the target volumetric design criteria listed in Tables 3.3.1 and Voids Mineral Aggregate (VMA) requirements listed in Table 3.3.3, provided that alternative design targets may be specified or agreed for particular applications. Where laboratory preparation and compaction of asphalt mixes is undertaken using the Marshall method, asphalt mixes shall comply with the target design criteria listed in Tables 3.3.2 and VMA requirements in Table 3.3.3 provided also that alternative design targets may be specified or agreed. The design criteria shall apply to only one method of compaction. The method of compaction shall be nominated by the Contractor unless otherwise specified. Table 3.3.1. — Level 1 Design and Refusal Density Requirements for Asphalt Mixes Prepared Using Gyratory Compaction Mix Type Traffic Category

Application

Light Medium

Wearing and base Wearing and base High fatigue base Wearing and base High fatigue base Wearing and base

Heavy Very Heavy

Laboratory Compaction Level (cycles) 50 80 80 120 80 120

Design Air Voids - Target (%) 4.0 4.0 3.0 4.0 3.0 5.0

Air Voids at 250 cycles - min (%)      2.0

Table 3.3.2 — Design Requirements for Asphalt Mixes Compacted by the Marshall Method (50 Blow Compaction1) Mix Type Traffic Category Light Medium Heavy Very Heavy

Application Wearing and base Wearing and base High fatigue base Wearing and base High fatigue base Wearing and base

Design Air Voids (%) 4.0 5.0 3.0 5.0 5.0 6.0

Stability - min (kN) 5.5 6.5 6.5 6.5 6.5 7.0

Notes: 1 Where 75 blow Marshall compaction is used, the air voids targets shall be reduced by 1 percentage point.

AUSTROADS 2002 — 34 —

Flow (mm) 2-4 2–4 2–4 2–4 2–4 2-4

Framework for Specifying Asphalt

Table 3.3.3 — Voids Mineral Aggregate (VMA) Mix Nominal Size (mm)

7 10 14 20 28 40

Gyratory Compaction 17 16 15 14 13 12

VMA (% minimum) Marshall Compaction (50 blow1) Heavy/Very Heavy Traffic Wearing Other Mix Types Course Mixes 17 17 16 16 15 14 13 12

Notes: 1 Where 75 blow Marshall compaction is used, the VMA targets shall be reduced by 1 percentage point.

All mixes shall be designed to have a minimum effective binder film thickness of 7.5 microns with the exception of high fatigue base that shall have a minimum effective design binder film thickness of 10 microns. 3.4

DESIGN OF ASPHALT MIXES INCORPORATING RECLAIMED ASPHALT PAVEMENT (RAP)

3.4.1

General

Separate mix designs shall be prepared for all mixes containing RAP. Binder in RAP shall be included as binder in the total mix. Alterations to the proportion of RAP shall constitute a design change. Mixes shall generally comply with the design and manufacture requirements specified elsewhere in this specification with the additional requirements specified in Clause 2.4 and the following sub-clauses. 3.4.2

Asphalt mixes containing not more than 15% of RAP by mass of total mix

Unless otherwise specified, RAP in proportions up to 15% by mass of the total mix shall be permitted in all mixes. 3.4.3

Asphalt mixes containing more than 15% but not more than 30% of RAP by mass of total mix.

RAP in proportions greater than 15%, but not exceeding 30%, may be used in asphalt mixes except for Heavy and Very Heavy Duty Wearing Course Mixes, mixes containing polymer modified binder, or where excluded in the Schedule of Job Details. In addition to the requirements specified in Clause 3.4.1, allowance may be made for increase in binder stiffness due to hardened binder in RAP by adoption of bitumen binder one class lower in viscosity than that otherwise specified. 3.4.4

Asphalt mixes containing more than 30% of RAP

Asphalt mixes containing more than 30% of RAP shall only be accepted where the Contractor can demonstrate suitable manufacturing plant and quality control procedures to ensure consistent production of hot mix asphalt of a standard not less than that otherwise specified.

AUSTROADS 2002 — 35 —

Framework for Specifying Asphalt

3.5

APPROVAL OF JOB MIX

3.5.1

General

Where approval of the job mix is required by the Superintendent, the Contractor shall provide the information listed in Table 3.5.1 at least seven (7) days prior to commencement of production. Each mix design shall be identified by a unique number system allocated by the Contractor or Superintendent in accordance with the accepted practice of the Principal and shall be designated the Job Mix. Table 3.5.1 — Information to be Submitted by Contractor for Approval of Job Mix 1

Details of constituent materials required under this Specification including aggregates, filler, binder, additives (if used) and source of materials

2

The nominated grading, binder content, design air voids and proportion of each component in the mix

3

Test results verifying constituent material properties and test results of trial mixes made at varying binder contents to arrive at the design mix

4

Test results in accordance with the design requirements specified in Section 3.3.

5

The following test results performed on a batch of each mix proposed to be used, and produced from the mixing plant from which the asphalt is to be supplied: • Grading • Binder Content • Maximum density • Air voids at laboratory design compaction level • Air voids at 250 cycles gyratory compaction (Heavy and Very Heavy Traffic Category mixes only)

Where specified in the Schedule of Job Details, the Contractor shall also report the results of the nominated performance tests conducted in accordance with the Level 2 and Level 3 Mix Design procedures described in APRG 18. 3.5.2

Submission of Samples

Where specified in the Schedule of Job Details, or on request by the Superintendent, the Contractor shall provide samples of the constituent materials used in the proposed mix design. The samples shall be provided at the Contractor’s expense and delivered to the address specified in the Schedule of Job Details. The quantity of samples shall be in accordance with Table 3.5.2, or as directed by the Superintendent. Table 3.5.2. — Sample Quantities of Constituent Materials Material Each coarse and fine aggregate component RAP (if used) Added Mineral Filler Binder Additives

AUSTROADS 2002 — 36 —

Sample Quantity 50 kg 50 kg 5 kg 8 litres As appropriate

Framework for Specifying Asphalt

3.5.3

Approval to Use Previously Designed Mix

The Superintendent may accept a Job Mix used by the Contractor under other Contracts for the supply of asphalt of the particular type and nominal size specified subject to the following conditions: (a) The project work is undertaken within a two-year period of mix design work for the Job Mix. (b) The type, quality and sources of all constituent materials remain unchanged. (c) The proportions of aggregates and filler are not varied by more than 20% of the proportion of that component in the original Job Mix. (d) The in-service performance of the Job Mix materials has been satisfactory.

AUSTROADS 2002 — 37 —

Framework for Specifying Asphalt

4

MANUFACTURE AND STORAGE

4.1

GENERAL

Plants used for the manufacture and storage of asphalt shall comply with AS 2150, Section 7. 4.2

MIXING TEMPERATURES

Bitumen binder shall not be heated to more than 185°C. Multigrade and Polymer Modified binders shall not be heated or stored contrary to the temperature and time combinations specified by the manufacturer’s written instructions. Temperature of bitumen and aggregates at the mixing plant, and the temperature of asphalt as it is discharged from the asphalt plant, shall not exceed the limits specified in Table 4.2.1 Table 4.2.1 — Temperatures Material Class 170, Class 320 Bitumen delivered into mixer Class 600 Bitumen delivered into mixer Aggregates before mixing with binder Asphalt at discharge from asphalt plant

4.3

Maximum Temperature (°C) 165 175 200 175

MOISTURE CONTENT

After completion of mixing the moisture content of the mix shall not exceed 0.5.%. 4.4

PRODUCTION TOLERANCES

Production tolerances on grading and binder content shall comply with Table 4.4.1 Table 4.4.1 — Production Tolerances Description

Maximum Tolerance on Job Mix Percentage

Grading: Sieve size one size larger than nominal size 4.75 mm sieve and larger 2.36 mm sieve 1.18 mm sieve 0.600 mm sieve 0.300 mm sieve 0.150 mm sieve 0.075 mm sieve Binder Content: Percent by mass

4.5

Nil ±7 ±5 ±5 ±4 ±4 ± 2.5 ± 1.5 ± 0.3

ASPHALT MIXES INCORPORATING POLYMER MODIFIED BINDERS

Asphalt with polymer modified binders shall not be stored in plant silos for a longer period than that recommended by the manufacturer of the polymer modified binder.

AUSTROADS 2002 — 38 —

Framework for Specifying Asphalt

4.6

ASPHALT MIXES INCORPORATING RECLAIMED ASPHALT PAVEMENT (RAP)

RAP shall only be used from stockpiles that have been tested for consistency in grading and binder content with materials used in mix design. In batch mixing plants, the RAP shall be either: ♦ ♦ ♦

Metered into the asphalt plant after heating and drying of aggregates Added directly to the weigh hopper with the other aggregate materials, for each batch. Weighed separately and added direct to the pugmill.

Batch mixing time shall be increased, if necessary, to ensure adequate heat transfer and dispersion of RAP. In drum mix plants, RAP shall be protected from excessive temperatures by a combination of entry point to the drum and shielding from direct flame contact.

AUSTROADS 2002 — 39 —

Framework for Specifying Asphalt

5

SAMPLING AND TESTING OF ASPHALT PRODUCTION

5.1

GENERAL

The Contractor shall arrange for all relevant testing. Samples for process control testing shall be randomly selected (random sampling) by a recognised statistical technique from fresh production asphalt at the asphalt plant. Samples shall not be mixed. In addition, each loaded truck shall be visually inspected for segregation, uncoated particles, excess bitumen or overheating, before dispatch from the plant. Production asphalt shall be tested for the following: (a) Grading (b) Binder content (c) Maximum density (d) Temperature 5.2

FREQUENCY OF SAMPLING AND TESTING

Frequency of sampling and testing shall be not less than that shown in Table 5.2.1 and 5.2.2. Table 5.2.1 provides for two levels of minimum frequency. The reduced frequency may only be adopted where the process is demonstrated to be under statistical control as specified in Section 5.3. Where a non-conformance occurs in any test requirement, the frequency of sampling and testing for that particular property shall be increased to the normal level until conforming results have been obtained on five consecutive samples. Table 5.2.1 — Frequency of Sampling and Testing of Production Asphalt Test Grading Binder Content Maximum density Temperature

Normal Minimum Frequency One test per 300 t of asphalt plant production One test per 300 t of asphalt plant production One test per 300 t of asphalt plant production Each loaded truck

Reduced Minimum Frequency One test per 500 t of asphalt plant production One test per 500 t of asphalt plant production One test per 500 t of asphalt plant production Lesser of each loaded truck or one per 15 minutes

Table 5.2.2 — Frequency of Testing of Component Materials Test Los Angeles Abrasion (where applicable) Unsound and marginal stone content (where applicable) Wet Strength (where applicable) Wet/Dry Variation (where applicable) Flakiness index of coarse aggregate Dry compacted voids of combined filler Added filler (Tables 2.2.2 and 2.2.3) Binder viscosity RAP grading and binder content

AUSTROADS 2002 — 40 —

Minimum Frequency 3 Monthly 3 Monthly 3 Monthly 3 Monthly Monthly Monthly Certification of each delivery Certification of each delivery One test per 500 t of RAP.

Framework for Specifying Asphalt

5.3

PROCESS CONTROL

The Contractor shall implement suitable measures for control of the asphalt process. Process control measures may include the use of statistical process control charts for some, or all, of the tests required in Section 5.2 and suitable decision rules for determining that the process is under statistical control and therefore subject to reduced minimum frequency of test. Elements of the process control system that incorporate the application of statistical process control shall be included in the Contractor’s Quality Plan.

AUSTROADS 2002 — 41 —

Framework for Specifying Asphalt

6

DELIVERY

Delivery of asphalt shall comply with AS 2150, Section 8.

7

PLACING

7.1

PREPARATION OF SURFACE

Prior to tack coating and placing of asphalt, the surface shall be free of all deleterious material. Where required, the Contractor shall sweep clean the area on which asphalt is to be placed. 7.2

PROTECTION OF SERVICES

The Contractor shall prevent tack coat, binder, aggregate, asphalt or other material used on the work from entering, adhering or obstructing gratings, hydrants, valve boxes, inspection pit covers, kerbs and other road fixtures. 7.3

TACK COATING

Tack coat shall be applied to the cleaned surface prior to placing asphalt. Tack coat shall consist of bituminous emulsion complying with AS 1160. The type and breaking rate shall be suitable to the climatic and surface conditions of use such that it is fully broken, free of surface water and intact before the commencement of asphalt spreading. Unless otherwise directed, tack coat shall be applied to provide a uniform application rate of residual binder of between 0.10 and 0.20 litres/m2. Tack coat shall be applied by spray bar fitted to a mechanical sprayer. Hand spraying shall be carried out only in those areas where it is impracticable to use a spray bar. Precautions shall be taken to protect kerbs, channels, adjoining structures, traffic and parked vehicles from tack coat spray. Where asphalt is to be spread over clean, freshly placed asphalt, over a clean primed surface, or where the depth of layer exceeds 50 mm, the Superintendent may direct the Contractor to omit the tack coat. 7.4

SPREADING

7.4.1

General

Unless otherwise specified, self-propelled mechanical pavers shall be employed to place asphalt except for areas where the use of a paver is impracticable. 7.4.2

Ambient Conditions for Placing

The surface on which the asphalt is to placed shall be essentially dry and free from puddles. Asphalt shall not be placed when the pavement surface temperature is less than 5°C.

AUSTROADS 2002 — 42 —

Framework for Specifying Asphalt

Wearing course asphalt shall not be placed when the pavement surface temperature is less than 10°C except that placing at lower temperatures may be permitted subject to agreement on procedures used to compensate for rapid cooling of asphalt materials. 7.4.3

Layer Thickness

Asphalt shall be spread in layers at the compacted thickness shown on the drawings, or as specified. 7.4.4

Level Control

The method of paver level control shall be as specified in the Schedule of Job Details. If no method is specified in the Schedule of Job Details, the Contractor shall apply suitable automatic or manual screed level controls to achieve the standards specified in Clause 9. 7.4.5

Spreading

Asphalt shall be spread without tearing or segregation. The Contractor shall conduct spreading operations to ensure that the paver speed matches the rate of supply so that the number of paving stops is minimised. The paver shall not be left stationary for prolonged periods with the screed box in contact with either the previously placed asphalt or loose asphalt in front of the screed. 7.5

COMPACTION

Asphalt shall be uniformly compacted to the standards specified in Clause 9.5 as soon as the asphalt has cooled sufficiently to support the rollers without undue displacement. Compaction shall be achieved using suitable sized steel wheeled or vibratory rollers or combination of steel wheeled or vibratory rollers and pneumatic tyred rollers. 7.6

JOINTS

7.6.1

General

Joints shall be provided as follows: (a) Longitudinally, if the width of the pavement is such that more than one paving run is necessary. (b) Transversely, after the completion of a day’s paving operations, or where a delay in paving operation allows asphalt to cool and adversely affect placing, and elsewhere if a break in a longitudinal run is required. The location of joints shall be planned before work commences. The number of joints shall be minimised by adopting good asphalt paving practices. All joints shall be well constructed and comply with the shape requirements specified in Clause 9. 7.6.2

Longitudinal Joints

Longitudinal joints in the wearing course shall coincide with traffic lane lines unless otherwise specified or agreed. Longitudinal joints shall be offset from layer to layer by not less than 150 mm provided that no joint is placed directly below a trafficked wheel path. AUSTROADS 2002 — 43 —

Framework for Specifying Asphalt

Where asphalt is placed against the edge of a preceding lane that has not cooled below 100°C it shall be considered a hot joint. Hot joints shall be constructed by leaving a 150 mm strip of asphalt unrolled along the free edge until the adjoining lane is placed and then compacting the unrolled strip simultaneously with the material in the adjoining lane. Where asphalt is placed against the edge of a preceding lane that has not cooled below 60°C it shall be considered a warm joint. Warm joints shall be constructed by rolling the full width of the first lane being placed, prior to placing the adjoining lane. Where asphalt is placed against the edge of a preceding lane that has cooled below 60°C it shall be considered a cold joint. Asphalt placed against a cold edge should overlap the previous edge by 25 mm to 50 mm. The overlap should be pushed back using lutes, immediately after spreading, to form a slight ridge that is compacted with the steel wheel roller. 7.6.3

Transverse Joints

Transverse joints shall be offset by not less than 2 m in adjoining paver runs and from layer to layer.

AUSTROADS 2002 — 44 —

Framework for Specifying Asphalt

8

PRODUCTION AND CONSTRUCTION TRIAL

8.1

GENERAL

Where a production and construction trial is specified in the Schedule of Job Details, and not less than two days before the site work is due to commence, all the Contractor’s plant and personnel proposed for use on the job shall be subjected to a production and construction trial in the presence of the Superintendent. If more than one asphalt mix is specified, each mix shall be subjected to the trial not less than 24 hours before the proposed commencement of production of that mix. Asphalt manufactured in the production trial may also be used in the construction trial provided that it meets the requirements of the specification. 8.2

MANUFACTURE

The mixing plant shall be operated at approximately the rate intended for full scale production to produce the following minimum quantities: 7 or 10 mm nominal size mix: 20 to 30 t. 14, 20 or 28 nominal size mix: 50 to 100 t. The Contractor shall sample and test the asphalt in accordance with Clause 5. If the tests on the samples indicate that the asphalt does not conform to the Specification, the Contractor shall make such alterations in the procedures or adjustments to the plant and equipment as necessary to produce asphalt in accordance with this Specification. The mixing trial shall be repeated as necessary until asphalt of the quality specified is being consistently produced. 8.3

PLACING, COMPACTION AND FINISHING

The Contractor shall subject all of the placing, compaction and finishing equipment and operating personnel, proposed for use in the works, to a trial using the construction procedures proposed for the work. The trial shall consist of at least two adjacent lanes 3 metres wide and at least 50 metres long and shall be constructed in the designated area, in accordance with all the requirements of this Specification, or as directed. The joint between the lanes shall be a warm joint where the temperature of mix at the first run edge is greater than 60°C. Otherwise the joint is a cold joint and is to be treated as detailed in Clause 7.6.2. 8.4

TESTING OF TRIAL SECTION

The Contractor shall test the trial section for the finished pavement properties of this Specification. In the event that the tests indicate that the asphalt in the test section does not conform to the specification requirements, the Contractor shall make any necessary adjustments and, if necessary, repeat the production and construction trials, as specified above, until the Superintendent is satisfied that asphalt of uniform quality is being consistently produced, placed, compacted and finished in accordance with the requirements of this Specification. A hold point shall be designated in the Contractor’s Quality System at the conclusion of the trial and the Contractor shall not commence full scale production of any asphalt for the works until the hold point has been lifted.

AUSTROADS 2002 — 45 —

Framework for Specifying Asphalt

9

FINISHED PAVEMENT PROPERTIES

9.1

LEVEL

The level at the top of each course of asphalt shall not differ from the specified level by more than 10 mm, except that where asphalt is placed against kerb and channel, the surface at the edge of the wearing course shall be flush with, or not more than 5 mm above, the lip of the channel, unless otherwise specified or shown on the Drawings. 9.2

ALIGNMENT

The horizontal location of any point on the pavement shall not vary by more than ±50 mm from the corresponding points shown on the documents, except where alignment with an existing pavement structure is necessary, when the new work shall be joined to the existing work or structure in a smooth manner. 9.3

THICKNESS

The average total compacted thickness of the combined asphalt courses shall be not less than the specified thickness. The average thickness of any individual asphalt course shall be not less than the specified thickness by more than 10 mm. Where confirmation of asphalt thickness is required, it shall be determined by coring to a recognised random sampling plan. 9.4

SHAPE

9.4.1

Surface

No point on the finished surface shall deviate below a 3 m straightedge, measured between any two points, by more than the tolerances specified in Table 9.4.1. Table 9.4.1 — Permissible tolerances in surface shape

Layer

Wearing course Intermediate and base

9.4.2

Freeways and Highways With High Speed Traffic Parallel to Transverse to centreline centreline 3 5 6 10

Deviations below 3 m straightedge, mm Heavy and Very heavy Traffic Roads Parallel to centreline 5 8

Transverse to centreline 7 12

Medium and Light Traffic Roads Parallel to centreline 7 12

Transverse to centreline 10 16

Ride Quality

Where ride quality is specified in the Schedule of Job Details it shall be determined from the average of three replica runs with a calibrated roughness car, laser profiler or ARRB TR Walking Profiler. Each lane shall be divided into homogenous sections 100 m long. Any length less than 100 m shall be included with the section immediately preceding it, and an average roughness determined for the section. Start and finish joints of the entire work, and bridge expansion joints, shall not be included in any section. Roundabouts shall not be measured under Clause 9.4.

AUSTROADS 2002 — 46 —

Framework for Specifying Asphalt

9.5

DENSITY

Compliance testing of asphalt shall be undertaken on a lot-by-lot basis. A pavement lot shall be an essentially homogeneous section of completed pavement, not greater than 500 t in size or a shift production, whichever is the lesser, unless otherwise specified in the Schedule of Job Details. Density testing shall not be performed on lots of less than 30 t, layers with a nominal thickness less than 30 mm, or layers with a nominal thickness less than 2.5 times the nominal mix size. The location of each insitu density test shall be chosen by a method of random stratified sampling. For core sample tests, the layer thickness is the mean thickness of the core samples and for nuclear gauge tests, the layer thickness is the nominal thickness. All core holes shall be repaired by an appropriate method that is compatible with the layer from which cores have been taken. Density testing shall be carried out as soon as practicable after completion of work. Relative compaction is the percentage ratio of the insitu density of the compacted asphalt and the reference density of the asphalt of a particular lot. The reference density shall be the mean of the five most recent maximum density measurements of the same mix, provided that: (a) The tests have been completed within the previous 4 weeks (b) The binder content of samples tested is within ±0.3% of the job mix binder content (c) There has been no change in the mix components or proportions. Where 5 tests complying with the above conditions are not available, the Contractor shall carry out a minimum of 5 tests in order to establish the reference density. The characteristic value of relative compaction is calculated as Mean – K x S where, Mean

= The mean of the relative compaction results.

S

= The sample standard deviation of the relative compaction results

K

= A factor that depends on the number of tests as shown in Table 9.5.1 Table 9.5.1 — Acceptance Constant Number of Tests or Measurements 6 7 8 9 10

Acceptance Constant (K) 0.719 0.755 0.783 0.808 0.828

The work represented by a lot shall be assessed as the characteristic value of insitu voids where: Characteristic value of insitu air voids (%) = 100 – Characteristic relative compaction The value of characteristic voids shall comply with the maximum characteristic values specified in Table 9.5.2 and 9.5.3.

AUSTROADS 2002 — 47 —

Framework for Specifying Asphalt Table 9.5.2 — Characteristic Value of Insitu Air Voids for Wearing Course Asphalt Asphalt Type and Thickness (mm) All heavy and very heavy traffic asphalt wearing courses All medium and light traffic wearing courses.

Maximum Characteristic Value (%) 8 9

Table 9.5.3 — Characteristic Value of Insitu Air Voids for Base Asphalt Asphalt Type and Thickness (mm) Heavy and very heavy traffic mixes in layers ≤ 40 mm Medium and light traffic mixes in layers ≤ 40 mm Heavy and very heavy traffic (except high fatigue base) mixes in layers > 40 mm Medium and light traffic mixes in layers > 40 mm High fatigue base

AUSTROADS 2002 — 48 —

Maximum Characteristic Value (%) 8 9 7 8 6

Framework for Specifying Asphalt

10

MEASUREMENT AND PAYMENT

10.1

GENERAL

Payment for tack coat shall be included in payment for asphalt. Payment for asphalt shall be by mass for quantities determined in accordance with Clause 10.2 or 10.3 as appropriate. Measurement for payment will include all works shown on the plans or as specified but will not include asphalt lost in transit, works not shown on the plans and variations in quantities due to variations in actual thickness exceeding the specified tolerances. 10.2

MEASUREMENT BY MASS

Unless otherwise specified in the Schedule of Job Details, the quantity of asphalt shall be measured by mass. The quantity of asphalt shall be determined from dockets supplied by the Contractor and issued at a certified weighing system unless measurement by batch weights using certified scales is approved by the Superintendent. Separate pay items shall be included in the Schedule of Rates for each nominal course thickness and each nominal size and type of asphalt specified. 10.3

MEASUREMENT BY AREA AND THICKNESS

Where specified in the Schedule of Job Details, the quantity of asphalt shall be determined from measurement of area and thickness. The area and thickness shall be determined from the dimensions on the plans or as specified for the work being measured. The density of asphalt in a lot shall be taken as the arithmetic mean of the insitu densities of the lot. Separate pay items shall be included in the Schedule of Rates for each nominal course thickness and each nominal size and type of asphalt specified. 10.4

NON COMPLYING MATERIALS

In the event that the material supplied is not within the tolerances and standards defined for manufacture or placing of asphalt, the Superintendent may direct: •

The removal of non complying material; or,

•

That the reduced service life arising from the non complying material is offset by reducing payment for the non complying material by the method defined in the Schedule of Job Details; or,

•

With the consent of the Contractor, any other remedial treatment that is expected to provide the required level of service.

AUSTROADS 2002 — 49 —

Framework for Specifying Asphalt

11

APPENDIX (SCHEDULE OF JOB DETAILS)

11.1

ASPHALT MIX REQUIREMENTS (Clause 1.3.1, 2.3, 3.2, 3.3) Item

11.2

Layer/Course

Asphalt Mix Type/ Traffic Category

Binder Class/Type

MEASUREMENT AND PAYMENT (Clause 10.1)

Measurement and payment shall be by: Mass/ Area and Thickness

AUSTROADS 2002 — 50 —

Nominal Size

Layer Thickness

INFORMATION RETRIEVAL

Austroads (2002), Framework for Specifying Asphalt, Sydney, A4, 64pp, AP-T18/02.

KEYWORDS: Asphalt; Pavements; Mixing/Asphalt; Paving/Recycling/Construction ABSTRACT: This framework for specifying asphalt has been prepared by Austroads and the Australian Asphalt Pavement Association, with input from the New Zealand Pavement and Bitumen Contractors Association (BCA) to promote national uniformity and good practice in the specification and use of asphalt throughout Australia. The document is in three parts. Part A provides a general introduction to application of asphalt specifications to variations in contracting environment. Part B provides guidance to the application of model specification clauses provided in Part C. Part C is a series of specification clauses that may be used directly in contract documentation or as a framework for the preparation of individual specifications or quality plans.

AUSTROADS PUBLICATIONS Austroads publishes a large number of guides and reports. Some of its publications are: AP-1/89 Rural Road Design AP-8/87 Visual Assessment of Pavement Condition Guide to Traffic Engineering Practice AP-11.1/88 Traffic Flow AP-11.2/88 Roadway Capacity AP-11.3/88 Traffic Studies AP-11.4/88 Road Crashes AP-11.5/88 Intersections at Grade AP-11.6/93 Roundabouts AP-11.7/88 Traffic Signals AP-11.8/88 Traffic Control Devices AP-12/91 AP-13/91 AP-14/91 AP-15/96 AP-17/92 AP-18/00 AP-22/95 AP-23/94 AP-26/94 AP-29/98 AP-30/94 AP-34/95 AP-36/95 AP-38/95 AP-40/95 AP-41/96 AP-42/96 AP-43/00 AP-44/97 AP-45/96 AP-46/97 AP-47/97 AP-48/97 AP-49/97 AP-50/97 AP-51/98 AP-52/97 AP-53/97 AP-54/97 AP-55/98 AP-56/98 AP-57 & 58/98 AP-59/98 AP-60/98 AP-61/99 AP-62/99 AP-63/00 AP-64/00 AP-65/02 AP-66/02 AP-67/02 AP-G68/01 AP-G69/02

AP-11.9/88 AP-11.10/88 AP-11.11/88 AP-11.12/88 AP-11.13/95 AP-11.14/99 AP-11.15/99

Arterial Road Traffic Management Local Area Traffic Management Parking Roadway Lighting Pedestrians Bicycles Motorcycle Safety

Road Maintenance Practice Bridge Management Practice Guide to Bridge Construction Practice Australian Bridge Design Code Pavement Design RoadFacts 2000 Strategy for Pavement Research and Development Waterway Design, A Guide to the Hydraulic Design of Bridges, Culverts & Floodways Strategy for Structures Research and Development Austroads Strategic Plan 1998–2001 Road Safety Audit Design Vehicles and Turning Path Templates Adaptions and Innovations in Road & Pavement Engineering Guide to Field Surveillance of Quality Assurance Contracts Strategy for Ecological Sustainable Development Bitumen Sealing Safety Guide Benefit Cost Analysis Manual National Performance Indicators Asphalt Recycling Guide Strategy for Productivity Improvements for the Road Transport Industry Strategy for Concrete Research and Development Strategy for Road User Cost Australia at the Crossroads, Roads in the Community — A Summary Roads in the Community — Part 1: Are they doing their job? Roads in the Community — Part 2: Towards better practice Electronic Toll Collection Standards Study Strategy for Traffic Management Research and Development Strategy for Improving Asset Management Practice Austroads 1997 Bridge Conference Proceedings — Bridging the Millennia Principles for Strategic Planning Assessing Fitness to Drive Cities for Tomorrow — Better Practice Guide & Resource Document Cities for Tomorrow — CD Guide to Stabilisation in Roadworks Australia Cycling 1999-2004 — The National Strategy e-transport — The National Strategy for Intelligent Transport Systems Guide to the Selection of Road Surfacings Austroads 4th Bridge Conference Proceedings — Bridges for the New Millenium Guide for Road Condition Monitoring: Part 1 — Pavement Roughness Asphalt guide Travel Demand Management: A Resource Book Guide to Heritage Bridge Management Guide to the Geometric Design of Major Urban Roads

These and other Austroads publications may be obtained from: ARRB Transport Research Ltd 500 Burwood Highway VERMONT SOUTH VIC 3131 Australia

Telephone: Fax: Email: Website:

+61 3 9881 1547 +61 3 9887 8144 [email protected] www.arrb.org.au

or from road authorities, or their agent in all States and Territories; Standards New Zealand; Standards Australia & Bicycle New South Wales.