Pavement_Rehabilitation_Manual.pdf

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Pavement Rehabilitation ManualApril 2012


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PAVEMENT REHABILITATIONMANUAL

Chapter 1- Overview

Issued by:

Queensland Department of Transport andMain Roads

Pavements, Materials & Geotechnical Branch

For document content enquiries: Principal Engineer (Pavement Rehabilitation)

Phone: (07) 3137 7728

Facsimile: (07) 3137 7799

For administrative enquiries: Technical Reference Centre

Engineering and Technology Division

GPO Box 1412, Brisbane, Q, 4001

Phone: (07) 3834 5488

Facsimile: (07) 3834 2612


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TRADEMARKS ACKNOWLEDGEMENT

Terms mentioned in this document that are known or understood to be trademarks, whether registered or

not, have been identified. Where trademarks have been confirmed as registered in Australia, this has been

indicated by the addition of the symbol, otherwise the symbol is used. While all care has been taken to

identify trademarks, users should rely on their own inquiries to determine trademark ownership. Use of a

term in this document as a trademark should not be regarded as affecting the validity of any trademark.

IMPORTANT INFORMATION

The requirements of this document represent Technical Policy of the department and contain Technical

Standards. Compliance with the departments Technical Standards is mandatory for all applications for the

design, construction, maintenance and operation of road transport infrastructure in Queensland by or on

behalf of the State of Queensland.

This document will be reviewed from time to time as the need arises and in response to improvement

suggestions by users. Please send your comments and suggestions to the feedback email given below.

FEEDBACK

Your feedback is welcomed. Please email it to: [email protected].

DISCLAIMER

This publication has been created for use in the design, construction, maintenance and operation of road

transport infrastructure in Queensland by or on behalf of the State of Queensland.

Where the publication is used in other than the departments infrastructure projects, the State of Queensland

and the department give no warranties as to the completeness, accuracy or adequacy of the publication or

any parts of it and accepts no responsibility or liability upon any basis whatever for anything contained in or

omitted from the publication or for the consequences of the use or misuse of the publication or any parts of it.

If the publication or any part of it forms part of a written contract between the State of Queensland and a

contractor, this disclaimer applies subject to the express terms of that contract.

COPYRIGHT

Copyright protects this publication. Except for the purposes permitted by and subject to the conditionsprescribed under the Copyright Act, reproduction by any means (including electronic, mechanical,

photocopying, microcopying or otherwise) is prohibited without the prior written permission of the

department. Enquiries regarding such permission should be directed to Pavements, Materials, and

Geotechnical Branch, Engineering and Technology Division, Queensland Department of Transport and

Main Roads.

State of Queensland (Department of Transport and Main Roads) 2012

http://creativecommons.org/licences/by-nc-nd/2.5/au

April 2012
http://creativecommons.org/licences/by-nc-nd/2.5/auhttp://creativecommons.org/licences/by-nc-nd/2.5/auhttp://creativecommons.org/licences/by-nc-nd/2.5/auhttp://creativecommons.org/licences/by-nc-nd/2.5/au


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Chapter 1- Overview


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Chapter 1Amendments April 2012

Revision Register

Issue/RevNo.

ReferenceSection

Description of RevisionAuthorised

byDate

1 First Issue. June 1992

2 Manual completely reviewed andrewritten.

See sign-offpage above.

Also PrincipalEngineer

(PavementRehabilitation)

July 2011

3 Manual checked See sign-off

page above.Also Principal

Engineer(Pavement

Rehabilitation)

April 2012

1


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Contents of Pavement Rehabilitation Manual

Chapter 1

Overview

Chapter 2

Pavement Evaluation

Chapter 3

Selection of Alternative Rehabilitation

Options

Chapter 4

Technical Details of Specific Rehabilitation

Treatments

Chapter 5

Design of Pavement Rehabilitation

Treatments: Mechanistic and Deflection

Reduction Methods

Chapter 6

Comparison of Alternative Rehabilitation

Strategies


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Pavement Rehabilitation Manual Department of Transport and Main RoadsChapter 1 Overview Pavements and Materials

Page 1-iPavement Rehabilitation ManualApril 2012

Table of Contents

Page

1.1 ................................................................................................................................ 1-1INTRODUCTION

1.2

.......................................................................................................................................... 1-1

PURPOSE

1.3 ............................................................................................................................................... 1-1SCOPE

1.3.1 ...................................................................................................................................... 1-2In scope

1.3.2 ............................................................................................................................... 1-2Out of scope

1.4 ........................................................................................................................... 1-3BASIS OF MANUAL

1.5 ............................................................................................................. 1-3DOCUMENT PRECEDENCE

1.6 ............................................................................... 1-3CURRENCY OF DOCUMENTS REFERENCED

1.7

........................................................................................................................................ 1-3

FEEDBACK

1.8 ......................................................................................................... 1-4PAVEMENT DESIGN MANUAL

1.8.1 ........................................................................................................... 1-4Pavement design system

1.9 ............................................................................................... 1-4PAVEMENT SURFACINGS MANUAL

1.10 ................................................................... 1-4AUSTROADS GUIDE TO PAVEMENT TECHNOLOGY

1.11 .................................................................... 1-6ASSET MANAGEMENT AND ASSET MAINTENANCE

1.12 ......................................................................................... 1-7PAVEMENT REHABILITATION SYSTEM

1.12.1

....................................................................................... 1-8

Step 1: Determine purpose and scope

1.12.2 .................................................................... 1-8Step 2: Evaluate existing pavement and subgrade

1.12.3 ........................................................................................ 1-8Step 3: Develop alternative strategies

1.12.4 .......................................................................................................... 1-8Step 4: Design treatments

1.12.5 ................................................................ 1-8Step 5: Select option(s) and make recommendations

1.13 ..................................................................................................... 1-8PURPOSE OF REHABILITATION

1.13.1 ....................................................................................................... 1-9Synergies and opportunities

1.14

........................................................ 1-9

TERMS, DEFINITIONS, ABBREVIATIONS AND ACRONYMS

REFERENCES............................................................................................................................................. 1-15

List of Tables

Table 1.1 The current Austroads Guide to Pavement Technology and selected TMR manuals.1-5

Table 1.2 Terms, definitions, abbreviations and acronyms and their meaning. .......................... 1-9

List of Figures

Figure 1.1 Pavement rehabilitation system ................................................................................. 1-7


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Department of Transport and Main Roads Pavement Rehabilitation ManualPavements and Materials Chapter 1 - Overview

Page 1-iiPavement Rehabilitation ManualApril 2012

List of Equations

There are no equations in this Chapter.


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Page 1-1Pavement Rehabilitation ManualApril 2012

Pavement Rehabilitation Manual

Chapter 1- Overview

1.1 INTRODUCTION

The Queensland Department of Transport and Main Roads (TMR) Pavement Rehabilitation Manual (this

manual) is written as a supplement to Part 5: Pavement Evaluation and Treatment Designof theAustroads

Guide to Pavement Technology (AGTPT)(Austroads, 2009h), hereafter referred to as the AGTPT Part 5.

The TMR Pavement Rehabilitation Manual, used in conjunction with the AGTPT Part 5 and the other

components of the TMR Pavement Design System, as outlined in the Pavement Design Manual (PDM)

(QDMR 2009), provides guidance and gives requirements for the evaluation of existing pavements and

design of rehabilitation treatments for TMR road infrastructure projects.

Designers are referred to all other relevant documents (e.g. theAGTPT) including the following TMR ones:

Pavement Surfacings Manual(PSM)(when published).

Pavement Design Manual (PDM) (QDMR 2009).

Road Planning and Design Manual (RPDM)(QDMR Various).

Road Drainage Manual (RDM) (TMR 2010).

1.2 PURPOSE

The purpose of this manual is to provide, in conjunction with AGTPT Part 5, an evaluation procedure and

range of appropriate design methods for the effective rehabilitation of the different (existing) road pavements

for which TMR is responsible. This manual reflects TMR experience.

1.3 SCOPE

For the purposes of this manual, the term pavement rehabilitation is defined as, any activity that improves

the functional or structural condition of a pavement while using some or all of its existing structure.

This manual is intended as a guide for professional, trained, experienced and knowledgeable pavement

rehabilitation designers who are required to:

work within the confines of TMR organisational policies, guidelines and road network requirements

be aware of, assess and apply risk management and budgetary constraints to the road system as a

whole and its various components

take into account local area or project specific issues and

optimise initial designs and in-service treatments to suit budget and whole-of-life cost issues.

It provides guidelines for undertaking project level rehabilitation investigations. This involves the following:

collecting and interpreting pavement condition data

evaluating the existing pavement and

developing rehabilitation treatments, if required.

If rehabilitation treatment is required, the following is also involved:

developing and designing treatment options to rehabilitate the existing pavement


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calculating the whole-of-life costs for each option

evaluating the options

providing recommendations to identify the most appropriate option(s) and how they are to be

implemented.

This manual is organised to reflect the process described above:

Chapter 1 (this Chapter) introduces the manual and provides a brief overview of pavement

rehabilitation in the TMR context.

Chapter 2 discusses the collection of pavement condition data and the evaluation of pavements.

Chapter 3 describes the typical alternative treatment options that may be used to treat various forms

of pavement distress encountered across the state-controlled road network (managed by the TMR).

Chapter 4 details how the treatment options selected are to be designed, with additional information

given in Chapter 5.

Chapter 5 gives the methodology to be used for designing pavement rehabilitation treatments usingeither the General Mechanistic Procedure (GMP) or the overlay design procedure using design charts

(i.e. deflection reduction method).

Chapter 6 provides details about how options and strategies are to be compared.

Terms, definitions, abbreviations and acronyms used, and their meaning, are outlined in Section 1.12.1.

1.3.1 In sc op e

The types of pavements to which this manual can be applied include the following:

granular pavements surfaced with bituminous chip seals or asphalt;full depth or deep strength asphalt pavements;

pavements with modified or stabilised layers; and

concrete (i.e. rigid) pavements.

This manual can be used to design a variety of pavement rehabilitation treatments including the following:

granular overlays;

asphalt overlays;

inlays;

treatments that include a cementitiously modified or stabilised layer;treatments that include a foamed bitumen (and lime) stabilised layer;

treatments that include a lime stabilised layer; and

combinations of the above.

1.3.2 Out of sco pe

This manual can not be applied to:

bridge decks

unsealed roads or


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pavements other than those subject to general road traffic (e.g. the manual can not be used to

rehabilitate pavements at container-handling yards, at ports, or for car parks).

In addition, because this manual focuses on state-controlled roads managed by the TMR and requires the

use of TMR Pavement Rehabilitation and Pavement Design Systems, it may not describe all the distress

mechanisms, treatments or other considerations that may be applicable to other roads or contexts (e.g.

roads in other states, roads in defence force bases). The user/designer must assess whether the manual is

applicable for any particular case.

1.4 BASIS OF MANUAL

The relationships between distress mechanisms and their causes are based either on the outcomes of TMR

research programmes or on the research findings of other organisations (e.g. Austroads).

The rehabilitation techniques presented in this manual are generally supported by field trials carried out by

TMR. Trials of various treatment options are part of an ongoing programme of research. This manual

presents some techniques that, even though research into them is still underway, have shown positive

indications of success. Techniques that have proven unsuccessful in trials are generally not included or

discussed except where a caution against their use is considered appropriate.

1.5 DOCUMENT PRECEDENCE

For evaluating pavements and selecting and designing pavement rehabilitation treatments (on state-

controlled roads), this manual shall take precedence over all other manuals, guidelines, etc. Where a more

recently published document conflicts with this manual, TMRs Principal Engineer (Pavement Rehabilitation)

must be contacted for clarification about what is to apply.

Refer to Sections 1.1, 1.8, 1.9and 1.10for additional guidance.

1.6 CURRENCY OF DOCUMENTS REFERENCED

This manual contains references to documents current at the time of publication. Readers, Designers and

other users of the manual must obtain the latest version and reference the later version. In particular copies

of the latest TMR Technical Publications, Standards and Guidelines (i.e. TPSGs, e.g. specifications and

technical standards) must be obtained by the reader, Designer or other user before reading, interpreting or

applying this manual.

Where a more recently published document conflicts with this manual, TMRs Principal Engineer (Pavement

Rehabilitation) must be contacted for clarification about what is to apply.

1.7 FEEDBACK

Feedback about the manual is encouraged. The feedback of users will help improve the manual (e.g. add to

content) and provide direction for future versions. By providing feedback you will also help ensure the

relevance of the manual is maintained. Feedback should be emailed to the email address nominated at

the front of this manual(i.e. the page after the front cover).


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1.8 PAVEMENT DESIGN MANUAL

The PDM (QDMR 2009) is an important reference and designers will need to refer to it to complete

pavement rehabilitation investigations and designs. This manual relies upon, but does not detail, the design

system presented in the PDM (QDMR 2009). However, this manual takes precedence over the PDM

(QDMR 2009) for the assessment of existing pavements and for other pavement rehabilitation related

matters.

In some circumstances there may be a question about which manual to apply. Following are some

guidelines about when the PDM(QDMR 2009) is to be used:

For new pavements, including those used to widen an existing pavement. For widenings, the new

pavement designs must be adjusted so that the structural integrity and service life of the new and

rehabilitated pavements are not compromised (e.g. adjust layer thicknesses of widening pavement to

allow for pavement drainage and/or provide subsurface pavement drains).

Where a pavement evaluation and/or rehabilitation investigation recommends the existing pavement

be reconstructed rather than rehabilitated.

For a single project, the total design solutions may be based, in part, on both this manual and the PDM

(QDMR 2009). For example, in the case of pavement widening and overlay, the design for the new widening

pavement must be designed using the PDM (QDMR 2009) while the overlay must be designed in

accordance with this manual.

1.8.1 Pavement desig n sys tem

The PDM(QDMR 2009) describes the TMR pavement design system and its scope and applicability (e.g.

see Sections 1.2, 1.3 and 2 of the PDM). As noted above, the system also applies to this manual except that

this manual takes precedence with respect to the assessment of existing pavements and for other pavement

rehabilitation related matters.

Reference should be made to the PDM(QDMR 2009) for further details about the pavement design system.

1.9 PAVEMENT SURFACINGS MANUAL

TMR intends to publish a Pavement Surfacings Manual in the future. In the absence of a TMR Pavement

Surfacings Manual, the Pavement Surfacings Section of the TMR Pavements and Materials Branch can

provide advice.

When published, the TMR Pavement Surfacings Manualmust be referenced by the designer to select anddesign an appropriate surfacing treatment. Where there is a conflict between the TMR Pavement Surfacings

Manualand this manual, the designer must check with TMR Pavements and Materials Branch to ascertain

which takes precedence.

Note: AGTPT Part 3(Austroads 2009a) supersedes the older Guide to the Selection of Road Surfacings

(Austroads 2003). AGTPT Part 3generally contains all relevant information, updated as required from it.

1.10 AUSTROADS GUIDE TO PAVEMENT TECHNOLOGY

Austroads has published the Austroads Guide To Pavement Technology (AGTPT). This guide is an

important reference for designers. This manual must be read in conjunction with the AGTPT. However,

the TMRs specifications, policies, manuals, etc. take precedence over theAGTPT.


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The parts of the AGTPTat the date of publication of this Chapter are given in Table 1.1. Also included in

Table 1.1are comments about each part.

Tab le 1.1 The current Aus troads Guide to Pavement Technology and selected TMR manuals

Austroads Guide toPavement Technology

PartNo.

Title

TMR manual Comments

1 Introduction toPavementTechnology

No manual The PDM(QDMR 2009) and this manual each contain anintroduction specific to them. They also provide onoverview with respect to pavement design and pavementrehabilitation in the TMR context.

AGTPT Part 1(Austroads 2005) provides a more generaloverview of pavement technology.

2 Pavement Structural

Design

Pavement

DesignManual

The PDM(QDMR 2009) is a supplement toAGTPT Part 2

(Austroads 2010). Notwithstanding this, the TMR PDM(QDMR 2009) takes precedence overAGTPT Part 2.

3 PavementSurfacings

PavementSurfacingsManual(futurepublication)

AGTPT Part 3(Austroads 2009a) provides some guidanceabout pavement surfacings.

Note: AGTPT Part 3(Austroads 2009a) supersedes theolder Guide to the Selection of Road Surfacings(Austroads 2003). AGTPT Part 3generally contains allrelevant information, updated as required from it.

TMR plans to publish a Pavement Surfacing Manualin thefuture. When published the TMR Pavement SurfacingsManualwill take precedence overAGTPT Part 3.

4andits

sub-parts

Pavement Materialswith sub-parts aboutgranular base andsub-base materials,asphalt, modified /stabilised materials,recycled materials,bituminous binders,geotextiles andgeogrids, testmethods,earthworksmaterials, aggregate

and source rock,seals, and stabilisingbinders.

No dedicatedmanual.

Refer tospecifications(MRS) andTechnicalStandards(MRTS)series.

In the first instance refer to the PDM(QDMR 2009) andthis manual for guidance about pavement materials.Similarly, once published, the TMR Pavement SurfacingsManualshould also be referenced in the first instance. AllTMR manuals, specifications, technical standards, etc takeprecedence overAGTPT Part 4 (Austroads 2006, 2007a,2007b, 2008a, 2008b, 2008c, 2008d, 2009b, 2009c,2009d, 2009e, 2009f, 2009g, 2009h). AGTPT Part 4provides additional guidance.

5 PavementEvaluation andTreatment Design

PavementRehabilitationManual

This manual is a supplement toAGTPT Part 5 (Austroads2009h). Notwithstanding this, this manual takesprecedence overAGTPT Part 5. AGTPT Part 5providesadditional guidance.

6 UnsealedPavements

No manual AGTPT Part 6(Austroads 2009i) provides guidance withrespect to unsealed road pavement technology.


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Austroads Guide toPavement Technology

PartNo.

Title

TMR manual Comments

7 PavementMaintenance

No manual Refer to TMR manuals, etc in the first instance (viz.Section 1.11). AGTPT Part 7(Austroads 2009j) providesguidance with techniques and methods for carrying out anumber of routine maintenance tasks, with emphasis on adhoc activities (not pre-programmed) such as pothole fillingand holding actions. It complementsAGTPT Part 5.

8 PavementConstruction

No dedicatedmanual.

Refer to TMRtechnicalnotes,specifications

(MRSs) andTechnicalStandards(MRTSs).

In the first instance refer to the PDM(QDMR 2009) andthis manual, which provide some guidance aboutpavement construction, and other relevant TMRdocuments (e.g. technical notes, specifications andtechnical standards). Similarly, once published, the TMRPavement Surfacings Manualshould also be referenced in

the first instance. AGTPT Part 8(Austroads 2009k)provides additional guidance on how to ensure that the asconstructed pavement layers meet the designrequirements.

9 Pavement WorkPractices

No dedicatedmanual.

Refer to TMRtechnicalnotes,specifications(MRSs) andTechnical

Standards(MRTSs).

In the first instance refer to TMR Technical Notes,Engineering Notes, Specifications, Technical Standardsand the Western Queensland Best Practice Guidelines(Kapitzke 2000). AGTPT Part 9(Austroads 2008e) is anadditional source of technical notes and similarpublications related to pavement work practices producedby Austroads, Austroads member organisations andindustry associations. Austroads and AAPA have, jointly,

published a number of work tips which are also usefulreferences.

10 SubsurfaceDrainage

No dedicatedmanual.

In the first instance refer to the PDM(QDMR 2009) andthis manual for guidance about subsurface drainage.Similarly, once published, the TMR Pavement SurfacingsManualshould also be referenced in the first instance.Also refer to the Road Drainage Manual(RDM) (TMR2010), TMR Technical Notes, Engineering Notes,Specifications, Technical Standards and the WesternQueensland Best Practice Guidelines(Kapitzke 2000).

AGTPT Part 10(Austroads 2009l) provides guidance onthe types of pavement subsurface drainage systems and

procedures to design these systems, materials used forpavement subsurface drainage and construction andmaintenance considerations for pavement subsurfacedrainage systems.

1.11 ASSET MANAGEMENT AND ASSET MAINTENANCE

Though indicators of the need for maintenance and rehabilitation may be common, and maintenance may be

required pending rehabilitation of the existing pavement being completed, this manual does not specifically

address maintenance issues. A rehabilitation technique may, however, still be applicable on a limited scale

to a maintenance task.


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1.12 PAVEMENT REHABILITATION SYSTEM

The pavement rehabilitation system on which this manual is based consists of five steps, which are depicted

in Figure 1.1.

STRUCTURAL

CA

PACITY

AN

ALYSIS

COND

ITION

ASSESSMENT

REHAB

ILITATION

DESIGN

ECONOMIC

ANALYSIS

INITIAL SITE VISIT

Collect Available

Traffic, Pavement

& Environmental

Data

Detailed

Visual

Survey

Testpit &

Laboratory

Test

Dynamic Cone

Testing

Penetrometer

Traffic

Analysis

(possible

additional

survey)

Determine Actual

Layer

Thicknesses

Mechanical

Analysis

Bowl Parameter

Analysis

Comparison

to New

Design

Requirements

General

Mechanistic

Procedure

(GMP)

Overlay Design Using Deflection

Reduction Method for flexible

Granular Pavements with thin

Surfacing and Design Traffic


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1.12.1 Step 1: Determine pu rpo se and sco pe

The purpose of the rehabilitation investigation is determined (refer to Section 1.13). To do this, questions

must be asked and answered to identify the scope and purpose, and therefore the subsequent direction, of

the investigation and design process. Such questions may be as follows:

Is work on the pavement considered necessary because of its forecast condition?

Is work on the pavement considered necessary because of its current condition?

Have increasing traffic volumes necessitated an upgrade of the roads structural capacity?

1.12.2 Step 2: Evaluate exist ing pavement and sub grade

The pavements present condition is evaluated as is the subgrades. This is described in Chapter 2.

Chapter 5 describes the overarching methodology to be used when completing Step 2 (and Step 4).

It involves firstly collecting data from a number of sources including historical records, routine or specific

condition assessments, and testing programmes. This data is then interpreted to characterise the existing

pavement (and its constituent materials) so that representative sections can be defined, pavement distress

mechanisms can be identified, the condition and serviceability of pavements assessed and the structural

capacity of pavements evaluated. The evaluation process needs to be carried out irrespective of whether

the purpose of rehabilitation is to restore the pavement to an acceptable condition or to upgrade the

structural capacity of the pavement. In all cases the present pavement condition is relevant.

1.12.3 Step 3: Develop al ternat ive strategies

A number of alternative rehabilitation strategies and options are developed. Chapter 3 describes this

process. In developing strategies the identified purpose, the pavement type and configuration, the distressmechanism(s), history of maintenance expenditure and relevant design and construction considerations are

taken into account to determine which of the wide variety of available rehabilitation treatments are

appropriate. TMR Asset Managers should be consulted to obtain some or all of this information and

determine their views about possible strategies.

1.12.4 Step 4: Design treatments

The technical details of the alternative strategies are determined, the design method(s) chosen and the

treatments designed. Chapters 4 and 5 must be used to do this. The general range of treatments is covered

in Chapter 4 while a more specific overlay design procedure is presented in Chapter 5. Chapter 5 also

describes the GMP and the overarching methodology to be used when completing Step 4 (and Step 2).

1.12.5 Step 5: Select op t ion(s) and mak e recommendat ion s

The options and strategies developed are compared and the optimal solution(s) selected. The basis of the

comparison presented in Chapter 6 is primarily economic. Design and construction considerations are taken

into account in Step 3.

1.13 PURPOSE OF REHABILITATION

The first step in carrying out a pavement rehabilitation investigation is to determine the purpose of theexercise. This may involve rectifying a pavement that has reached a state where, for the safety of road


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users, its rehabilitation cannot be delayed. Alternatively it may deal with a situation where the natural growth

in traffic has necessitated an upgrade of the pavements structural capacity, width and/or alignment.

1.13.1 Synerg ies and op po rtun i t ies

Designers must be cognisant of how the road corridor as a whole is managed. Further, they must be aware

of the synergies or opportunities presented by works being undertaken, now or in the future, whatever the

reason for them.

Where a pavement is to be rehabilitated primarily because of its current or forecast condition, consideration

should also be paid to its cross section, crossfall, superelevation (if applicable), drainage, shape and

alignment. It may be possible to upgrade/correct some or all of these characteristics concurrently for only a

marginal increase in cost. For example, where an existing substandard base gravel is to be stabilised, the

marginal cost of widening the pavement at the same time would be significantly less than carrying out the

widening at some later date.

Conversely, where action is required for reasons other than those related to the pavement, the pavement

must still be evaluated. This will provide information about whether the road pavement can function in its

present condition for the next design period and, if not, provide information enabling interventions to be

designed. The evaluation will also identify any non-critical distress mechanisms that, if addressed, can

mitigate or prevent premature failure of the pavement. In a manner similar to that described above, if works

are being carried out for reasons other than those related to the pavement (e.g. widening to improve safety,

shape correction to correct the application of superelevation, minor realignment) then it may be an opportune

time to investigate the pavement, and rehabilitate it if required. Doing this at the same time as other works

may mean the pavement can be rehabilitated at a relatively marginal increase in cost.

1.14 TERMS, DEFINITIONS, ABBREVIATIONS AND ACRONYMS

Reference is made to the Pavement Design Manual (QDMR 2009) for definitions. These apply to this

manual. Table 1.2provides additional terms, definitions, abbreviations and acronyms used in this manual.

Table 1.2 Terms, definit ion s, abbreviat ions and acron ym s and th eir meaning .

Term, definition,abbreviation or

acronymMeaning

AASHTO American Association of State Highway and Transportation Officials

AC Asphaltic Concrete.

Agricultural Lime This term refers to limestone (CaCO3) that has been ground or pulverised. This hasno engineering application, but can be used for agricultural purposes to reduce soilacidity.

AGTPT Austroads Guide to Pavement Technology

AGTPT Part 2 Austroads Guide to Pavement Technology Part 2: Pavement Structural Design.

AGTPT Part 5 Austroads Guide to Pavement Technology Part 5: Pavement Evaluation andTreatment Design.

ALD Average Least Dimension. Derived from cover aggregate used in bituminoussprayed seals. Used in the design of bituminous sprayed seals.


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acronymMeaning

ARMIS A Road Management Information System. A TMR database system that containsselected information about road infrastructure managed by the TMR.

ARRB Australian Road Research Board.

AS Australian Standard.

ASTM American Standard Test Method

BCR Benefit-Cost Ratio

C170 Class 170 bitumen that complies with MRTS17.



CBA Cost Benefit Analysis.

CBR California Bearing Ratio.

Cement Cement that complies with the relevant MRS or MRTS (e.g. MRTS07B).

Cementitious blend A cementitious blend that complies with the relevant MRS or MRTS (e.g. MRTS07B).

CF Curvature Function. Derived from surface deflections.

CIRCLY Mechanistic pavement design software from MINCAD Systems.

CTB Cementitiously Treated Base.

CTSB Cementitiously Treated Sub-Base.

CV Co-efficient of Variation.

D Surface deflection. Normally assumed to be D0. Surface deflections are measuredby various devices. Typical devices in Queensland are a FWD, a HWD, aBenkelman Beam and PAVDEF.

D0 Surface deflection measured at the point of maximum deflection (i.e. 0 mm offset).

D900 Surface deflection measured at an offset of 900 mm.

Dr Representative D.

DCP Dynamic Cone Penetrometer. Testing must comply with TMR Test Method Q114B.

DESAs Design Equivalent Standard Axles.

DG7 DGA with a maximum nominal aggregate size of 7 mm that complies with MRS30,MRTS30, MRS31 and MRTS31 as relevant.




DGA Dense Graded Asphalt that complies with MRS30, MRTS30, MRS31 and MRTS31as relevant.

Discount Rate As for Real Discount Rate.

DOS Degree of saturation.

DR Deflection Ratio. Derived from surface deflections.


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acronymMeaning

DRr Representative DR.

DVR Digital Video Road. A TMR system that records and allows viewing of images ofroad carriageways captured on roads managed by the TMR.

EFROMD3 A software package used to back analyse the pavement using deflection results. Itwas developed by, and distributed by, the ARRB. It uses CIRCLY and requires theuser to have a licensed copy of CIRCLY installed.

EVA Ethylene vinyl acetate. A polymer used to modify bitumen.

Expansion ratio (forfoamed bitumen)

The ratio of the maximum volume of foamed bitumen to the volume of un-foamedbitumen

FWD Falling Weight Deflectometer

Foamed Bitumen Bitumen, typically with a foaming agent added, foamed by the addition of water.

Foamed BitumenStabilisation

Stabilisation using at least foamed bitumen as a binder. For TMR works thisnormally requires the use of a primary binder, the foamed bitumen, and a secondarybinder, typically lime.

Foaming watercontent (for foamedbitumen)

The percentage of water added to hot bitumen to induce foaming

Foaming agent (forfoamed bitumen)

A chemical agent mixed into the bitumen to enhance its foaming characteristics.Such an additive would typically enhance the expansion ratio and/or the half-life ofthe foamed bitumen.

General mechanisticprocedure.

A pavement design procedure for non-rigid pavements. It is based on mechanisticdesign principles which take into account (some) pavement material properties and

behaviours.The procedure is as described in theAGTPT Parts 2 and 5but as modified by thismanual (viz. Chapter 5) and the Pavement Design Manual(QDMR 2009).

GAR Geotextile Absorption Rate. Used for geotextile SAMs or SAMIs.

GB cement Type GB (General Blend) cement that complies with AS3972.

Geotextile Unless otherwise described, in this manual geotextile means a paving geotextile thatcomplies with MRS57 and MRTS57.

GIMS Geospatial Information Management System. A TMR system that contains electroniccopies of many of TMR (or QDMR or QT) registered plans roads managed orformerly managed by the TMR (or by the QDMR and QT).

GMP General mechanistic procedure.

GP cement Type GP (General Purpose) cement that complies with AS3972.

GPR Ground Penetrating Radar. A technology that transmits electromagnetic signals intothe ground and receives reflections from subsurface features. The results can beinterpreted by experts to provide information about the pavement.

Half-life (for foamedbitumen)

The time taken for the maximum foamed volume of bitumen to settle to half thisvolume

HIPAR Hot in-place asphalt recycling.

HWD Heavy falling Weight Deflectometer


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acronymMeaning

Hydrated lime Calcium Hydroxide (Ca(OH)2), also known as hydrated or slaked lime, is producedby slaking or hydrating quicklime by adding water. This process can take place

immediately following quicklime manufacture at the lime kiln, on site usingconventional water trucks, or in purpose-built mixing tanks. Hydrated lime suppliedfrom the plant is typically a very fine, dry powder. By popular connotation, hydratedlime is a dry powdered hydrate, whereas slaking involves more water, producing wethydrates.

IRI International Roughness Index. A measure of road roughness.

IWP Inner wheelpath. Wheelpath in a lane that is not adjacent to a pavement edge.

Limestone A general term for carbonate-rich natural deposits composed primarily of CalciumCarbonate (CaCO3), with varying amounts of impurities.

Lime Stabilisation

Optimum

Optimum lime content determined through pH and UCS testing. An additional 1%

lime should be added in the field to allow for variations caused by losses and unevenmixing.

LSO Lime Stabilisation Optimum

MATTA MATerial Testing Apparatus. Laboratory apparatus that can test for, amongst otherthings, resilient modulus and creep.

MCA Multi-Criteria Analysis.

MRS TMR Specification. For example MRS05 refers to TMR Specification 05.

MRTS TMR Technical Standard. For example MRTS05 refers to TMR Technical Standard05.

NAASRA National Association of Australian Road Authorities. It has been replaced by

Austroads.

NPV Net Present Value. An absolute measure equal to discounted benefits (user + non-users) project less discounted costs, all calculated over the life of the project.

NSV Network Survey Vehicle owned and operated by the TMR.

OG10 OGA with a maximum nominal aggregate size of 10 mm that complies with MRS30,MRTS30, MRTS31 and MRTS31 as relevant.

OG14 OGA with a maximum nominal aggregate size of 14 mm that complies with MRS30,MRTS30, MRTS31 and MRTS31 as relevant.

OGA Open Graded Asphalt that complies with MRS30, MRTS30, MRTS31 and MRTS31as relevant.

OMC Optimum Moisture Content.

OnQ The TMR project management framework. It includes policies, principles, projectgovernance, methodology, templates, tools and project support.

OWP Outer wheelpath. Wheelpath in a lane that is closest to an edge.

PAFV Polished Aggregate Friction Value.

PAVDEF Essentially the TMRs deflectograph.

Pavementmaintenance

Routine maintenance tasks, with emphasis on ad hoc activities (not pre-programmed) such as pothole filling and holding actions.

Pavement

rehabilitation

Any activity that improves the functional or structural condition of a pavement while

using some or all of its existing structure.

PBD Polybutadiene. A polymer used to modify bitumen.


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acronymMeaning

PDM Pavement Design Manualpublished by the former QDMR.

PI Plasticity Index

PMB Polymer Modified Binder. In this manual when PMB is used it refers to a binder thatcomplies with MRTS18.

Pozzolan A pozzolan is a finely-divided siliceous and/or aluminous material that, in thepresence of water and calcium hydroxide, will form a cemented product. Thecemented products are calcium-based hydrates, which are essentially the samehydrates that form during the hydration of Portland cement.

PRM This manual (i.e. the TMR Pavement Rehabilitation Manual).

PSM TMR Pavement Surfacings Manual(future publication)

PWOC Present Worth of Costs. Future costs discounted to present costs using the real

discount rate.QDMR Queensland Department of Main Roads. (Former state department.)

QT Queensland Transport. (Former state Department of Transport.)

Quicklime Quicklime is principally comprised of Calcium Oxide (CaO) and is typically suppliedas a granular powder. Quicklime hydrates readily when in contact with water to formCalcium Hydroxide (Ca(OH)2) or hydrated lime. The hydration process results in arapid release of heat and water vapour/steam.

Heating CaCO3at elevated temperatures produces Calcium Oxide (CaO), alsoknown as burnt lime. The reaction here is: CaCO3+ heat (>1000C) gives CaO +CO2.

RAP Reclaimed Asphalt Pavement.

RDD Relative Dry Density.

Real Discount Rate The rate used to discount future costs to costs in present-day terms. This rate isexpressed in real terms (i.e. it excludes inflation). For TMR projects the discount rateshould be obtained from the Queensland Treasury Department before the analysisbegins.

Reclaimer/Stabiliser. A single-rotor mix-in-place plant of a type (i.e. plant that mixes in situ) specificallydesigned for the dual task of reclamation and stabilisation work.

Rehabilitation As for pavement rehabilitation.

RPDM Road Planning and Design Manual Chapters published by the former QDMR andthe current TMR.

RTA Roads and Traffic Authority of the state of New South Wales.

SAM Strain Alleviating Membrane.

SAMI Strain Alleviating Absorbing Membrane Interlayer.

SBR Styrene-butadiene rubber. A polymer used to modify bitumen.

SBS Styrene-butadiene-styrene. A polymer used to modify bitumen.

SMA Stone Mastic Asphaltic concrete.

Slaking (in context ofstabilisation)

The addition of water to fully hydrate a material.

Stabiliser A single-rotor mix-in-place plant (i.e. plant that mixes in situ) of a type specificallydesigned for stabilisation work.


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acronymMeaning

TBAR Total Bitumen Application Rate. Generally used for geotextile SAMs or SAMIs.

TMR Queensland Department of Transport and Main Roads.

TPSG TMR Technical Policies, Standards and Guidelines. These include specifications(MRSs), Technical Standards (MRTSs) and technical notes.

UCS Unconfined Compressive Strength.

VR Visual Rating

WH&S Workplace, Health and Safety.

WMAPT Weighted Mean Annual Average Pavement Temperature.

WOLC Whole Of Life Costs. All ownership and user costs necessary to provide aserviceable pavement over the assessment period


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REFERENCES

Austroads 2003 Guide to to the Selection of Road Surfacings (2nd

edition) (Austroads

Publication No. AP-G63/03), Austroads, Sydney

Austroads 2005 Guide to Pavement Technology Part 1: Introduction to Pavement

Technology(Austroads Publication No. AGTP01/05), Austroads,

Sydney

Austroads 2006 Guide to Pavement Technology Part 4D: Stabilised Materials

(Austroads Publication No. AGTP04D/06), Austroads, Sydney

Austroads 2007a Guide to Pavement Technology Part 4: Pavement Materials

(Austroads Publication No. AGTP04/07), Austroads, Sydney

Austroads 2007b Guide to Pavement Technology Part 4B: Asphalt(Austroads

Publication No. AGTP04B/07), Austroads, Sydney

Austroads 2008a Guide to Pavement Technology Part 4A: Granular Base and Subbase

Materials(Austroads Publication No. AGTP04A/08), Austroads,

Sydney

Austroads 2008b Guide to Pavement Technology Part 4F: Bituminous Binders

(Austroads Publication No. AGTP04F/08), Austroads, Sydney

Austroads 2008c Guide to Pavement Technology Part 4H: Test Methods(Austroads

Publication No. AGTP04H/08), Austroads, Sydney

Austroads 2008d Guide to Pavement Technology Part 4J: Aggregate and Source Rock(Austroads Publication No. AGTP04J/08), Austroads, Sydney

Austroads 2008e Guide to Pavement Technology Part 9: Pavement Work Practices


Austroads 2009a Guide to Pavement Technology Part 3: Pavement Surfacings


Austroads 2009b Guide to Pavement Technology Part 4C: Materials for Concrete Road

Pavements (Austroads Publication No. AGTP04C/09), Austroads,

Sydney

Austroads 2009c Guide to Pavement Technology Part 4E: Recycled Materials

(Austroads Publication No. AGTP04E/09), Austroads, Sydney

Austroads 2009d Guide to Pavement Technology Part 4G: Geotextiles and Geogrids

(Austroads Publication No. AGTP04G/09), Austroads, Sydney

Austroads 2009e Guide to Pavement Technology Part 4I: Earthworks Materials

(Austroads Publication No. AGTP04I/09), Austroads, Sydney

Austroads 2009f Guide to Pavement Technology Part 4K: Seals(Austroads

Publication No. AGTP04K/09), Austroads, Sydney


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Austroads 2009g Guide to Pavement Technology Part 4L: Stabilising Binders

(Austroads Publication No. AGTP04L/09), Austroads, Sydney

Austroads 2009h Guide to Pavement Technology Part 5: Pavement Evaluation and

Treatment Design(Austroads Publication No. AGTP05/09),

Austroads, Sydney

Austroads 2009i Guide to Pavement Technology Part 6: Unsealed Pavements


Austroads 2009j Guide to Pavement Technology Part 7: Pavement Maintenance


Austroads 2009k Guide to Pavement Technology Part 8: Pavement Construction


Austroads 2009l Guide to Pavement Technology Part 10: Subsurface Drainage


Austroads 2010 Guide to Pavement Technology Part 2: Pavement Structural Design


Kapitzke, J 2000 Western Queensland Best Practice Guidelines, Queensland

Department of Main Roads, Road System and Engineering, Brisbane.

QDMR 2002 Asset Maintenance Guidelines, Queensland Department of Main

Roads, Road Asset Management Branch, Brisbane.

QDMR 2008 Pavement Condition Data Collection Policy 2007/08 to 2009,

Queensland Department of Main Roads, Road Asset ManagementBranch, Brisbane.

QDMR 2009 Pavement Design Manual, Queensland Department of Main Roads,

Pavements and Materials Branch, Brisbane.

QDMR Various Road Planning and Design Manual, Queensland Department of

Main Roads, Road Planning and Design Branch, Brisbane.

TMR 2010 Road Drainage Manual, Road Planning and Design Branch,

Queensland Department of Transport and Main Roads, Brisbane.


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Chapter 2- Pavement Evaluation

Issued by:

Queensland Department of Transport andMain Roads

Pavements, Materials & Geotechnical Branch

For document content enquiries: Principal Engineer (Pavement Rehabilitation)

Phone: (07) 3137 7728

Facsimile: (07) 3137 7799

For administrative enquiries: Technical Reference Centre

Engineering and Technology Division

GPO Box 1412, Brisbane, Q, 4001

Phone: (07) 3834 5488

Facsimile: (07) 3834 2612


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TRADEMARKS ACKNOWLEDGEMENT

Terms mentioned in this document that are known or understood to be trademarks, whether registered or

not, have been identified. Where trademarks have been confirmed as registered in Australia, this has been

indicated by the addition of the symbol, otherwise the symbol is used. While all care has been taken to

identify trademarks, users should rely on their own inquiries to determine trademark ownership. Use of a

term in this document as a trademark should not be regarded as affecting the validity of any trademark.

IMPORTANT INFORMATION

The requirements of this document represent Technical Policy of the department and contain Technical

Standards. Compliance with the departments Technical Standards is mandatory for all applications for the

design, construction, maintenance and operation of road transport infrastructure in Queensland by or on

behalf of the State of Queensland.

This document will be reviewed from time to time as the need arises and in response to improvement

suggestions by users. Please send your comments and suggestions to the feedback email given below.

FEEDBACK

Your feedback is welcomed. Please email it to: [email protected].

DISCLAIMER

This publication has been created for use in the design, construction, maintenance and operation of roadtransport infrastructure in Queensland by or on behalf of the State of Queensland.

Where the publication is used in other than the departments infrastructure projects, the State of Queensland

and the department give no warranties as to the completeness, accuracy or adequacy of the publication or

any parts of it and accepts no responsibility or liability upon any basis whatever for anything contained in or

omitted from the publication or for the consequences of the use or misuse of the publication or any parts of it.

If the publication or any part of it forms part of a written contract between the State of Queensland and a

contractor, this disclaimer applies subject to the express terms of that contract.

COPYRIGHT

Copyright protects this publication. Except for the purposes permitted by and subject to the conditions

prescribed under the Copyright Act, reproduction by any means (including electronic, mechanical,

photocopying, microcopying or otherwise) is prohibited without the prior written permission of the

department. Enquiries regarding such permission should be directed to the Pavements, Materials, and

Geotechnical Branch, Engineering and Technology Division, Queensland Department of Transport and

Main Roads.

State of Queensland (Department of Transport and Main Roads) 2012

http://creativecommons.org/licences/by-nc-nd/2.5/auApril 2012
http://creativecommons.org/licences/by-nc-nd/2.5/auhttp://creativecommons.org/licences/by-nc-nd/2.5/auhttp://creativecommons.org/licences/by-nc-nd/2.5/au


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Chapter 2Amendments April 2012

Revision Register

Issue/RevNo.

ReferenceSection

Description of RevisionAuthorised

byDate

1 First Issue. June 1992

2 Manual completely reviewed andrewritten.

See sign-offpage above.

Also PrincipalEngineer

(PavementRehabilitation)

July 2011

3 Manual checked See sign-off

page above.Also Principal

Engineer(Pavement

Rehabilitation)

April 2012

2


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Contents of Pavement Rehabilitation Manual

Chapter 1

Overview

Chapter 2

Pavement Evaluation

Chapter 3

Selection of Alternative Rehabilitation

Options

Chapter 4

Technical Details of Specific Rehabilitation

Treatments

Chapter 5

Design of Pavement Rehabilitation

Treatments: Mechanistic and Deflection

Reduction Methods

Chapter 6

Comparison of Alternative Rehabilitation

Strategies


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Pavement Rehabilitation Manual Department of Transport and Main RoadsChapter 2 Pavement Evaluation Pavements and Materials

Page 2-iPavement Rehabilitation ManualApril 2012

Table of Contents

Page

2.1 ................................................................................................................................ 2-1INTRODUCTION

2.1.1

................................................................................................. 2-1

Use of data and sources of data

2.1.2 ............................................................................................................... 2-1Geometric assessment

2.1.3 .............................................................................................. 2-3The pavement evaluation concept

2.1.3.1 .................................................................................................................................. 2-3Purpose

2.1.4 ................................................................................................................ 2-3Sources of information

2.1.5 ................................................................................................................... 2-4Presentation of data

2.2 ........................................................................................................................... 2-5HISTORICAL DATA

2.2.1

................................................................................................................................. 2-5

Advantages

2.2.2 .................................................................................................... 2-5Disadvantages and limitations

2.2.3 ............................................................................................................................ 2-5Original design

2.2.4 ...................................................................................................................... 2-6Construction detail

2.2.5 ...................................................................................................................... 2-6Digital Video Road

2.2.5.1 ........................................................................................................................ 2-6Access to DVR

2.2.6 ........................................................................................................................................ 2-7ARMIS

2.2.6.1 .................................................................................................................... 2-7Access to ARMIS

2.2.6.2

........................................................................ 2-7

Interrogating ARMIS and viewing information

2.2.7 ............................................ 2-9Geospatial Information Management System: Digital Plan Room

2.2.7.1 ...................................................................................................................... 2-9Access to GIMS

2.2.8 .................................................................................................................. 2-9Maintenance records

2.2.9 ...................................................................................................................... 2-9Climatic conditions

2.2.9.1 .......................................................................................................... 2-9Rainfall and dry periods

2.2.9.2 ........................................................................................................................... 2-9Temperature

2.2.10 .......................................................................................................................................... 2-9Traffic

2.3

................................................................... 2-10

VISUAL ASSESSMENT OF PAVEMENT CONDITION

2.4 ................................................................................................. 2-10GROUND PENETRATING RADAR

2.4.1 ................................................................................................................................ 2-10Description

2.4.2 ............................................................................................................................... 2-11Advantages

2.4.3 .................................................................................................. 2-11Disadvantages and limitations

2.4.4 ................................................................................................................................. 2-11Equipment

2.4.5 ............................................................................................................................... 2-13GPR output

2.4.6

........................................................................................... 2-15

GPR and pavement investigations


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Department of Transport and Main Roads Pavement Rehabilitation ManualPavements and Materials Chapter 2 - Pavement Evaluation

Page 2-iiPavement Rehabilitation ManualApril 2012

2.4.7 ......................................................................................................................2-15Appropriate Uses

2.4.7.1 ................................................................................................................. 2-16When to use GPR

2.4.8 ....................................................................................................................2-17Inappropriate Uses

2.4.9

..................................................................................................... 2-18

Investigation Considerations

2.4.10 ............................................................................2-19Expected performance and other comments

2.4.11 .........................................................................................................................2-19Further reading

2.5 ..............................................................................................................................2-19PROJECT BRIEF

2.5.1 .............................................................................................................. 2-20Level of detail required

2.6 ........................................................................................................................2-20FUTURE PLANNING

2.7 ...................................................................................................................2-20OTHER INFORMATION

2.7.1

.........................................................................................2-20

Topography, geology and pedology2.7.2 ............................................................................................ 2-21Road geometry and cross-section

2.7.3 ....................................................................................................................2-21Project constraints

2.7.4 ...................................................................................................................................2-22Drainage

2.7.5 ........................................................................................................................2-22Utilities/services

2.7.6 ...................................................................................................................................2-23Land use

2.8 ....................................................................2-23PAVEMENT CONDITION/DISTRESS AND TESTING

2.8.1 .....................................................................................................................2-23Intervention levels

2.8.2 ...................................................................................................................2-23Investigatory levels

2.8.3 ................................................................................................... 2-23Structural condition / capacity

2.8.4 ................................................................................................................................2-23Roughness

2.8.4.1 ............................................................................................ 2-24Test procedures and measures

2.8.5 .........................................................................................................................2-26Geometric form


2.8.6 ......................................................................................................................2-27Road traffic noise


2.8.6.2 ..................................................................................................................................2-28Causes

2.8.7 ........................................................................................2-28Skid Resistance and surface texture


2.8.7.2 ..................................................................................................................................2-30Causes

2.8.8 ............................................................................................ 2-31Surface drainage and water spray

2.8.9 ......................................................................2-31Defects observable during a visual assessment

2.8.9.1 ........................................................................................................... 2-31Potholes and patches

2.8.9.2 ...................................................................................................................................2-32Rutting

2.8.9.3

................................................................................................................................2-34

Cracking2.8.9.4 .................................................................................................................................2-35Shoving


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Page 2-iiiPavement Rehabilitation ManualApril 2012

2.8.10 ................................................................................................................... 2-35Surface deflections

2.8.10.1 ................................................................................................................. 2-36Test equipment

2.8.10.2 ............................................................................................ 2-40Some testing considerations

2.8.10.3 ................................................ 2-40Granular pavements with a thin asphalt surfacing or seal

2.8.10.4

........... 2-52

Verification of pavement performance in overlay design using deflections (only)2.8.10.5 ................. 2-53Full depth asphalt, deep strength asphalt and flexible composite pavements

2.8.10.6 ............................................................................................................... 2-53Rigid pavements

2.8.11 .................................................................................................................. 2-53Materials properties

2.8.11.1 ........................................................................................................ 2-53Non-rigid pavements

2.8.11.2 ................................................................................................. 2-60Rigid pavement materials

2.9 .................................................................................................... 2-60MOISTURE CONTROL SYSTEM

2.9.1 ............................................................................................................... 2-62Moisture environment

2.9.2

................................................................ 2-64

Effects of subsurface drainage on moisture content2.9.3 .............................................................. 2-66Effects of moisture content changes on performance

2.9.4 ............................................................ 2-66Moisture control considerations in type cross Sections

2.9.5 ................................................................................................. 2-67Evaluation of drainage system

REFERENCES............................................................................................................................................. 2-69

List of Tables

Table 2.1 Pavement Surface Correction Factors (modified from QDMR 2008). 2-27

Table 2.2 Suggested terminal criteria for asphalt fatigue (crocodile) cracking. 2-34

Table 2.3 Seasonal moisture correction factors for a pavement with a thin asphalt surfacing or seal 2-51

Table 2.4 Some factors that affect the moisture condition of road pavements 2-62

Table 2.5 Typical height of capillary rise in different materials 2-64

List of Figures

Figure 2.1 Pavement evaluation process.................................................................................................... 2-2

Figure 2.2 TMRs NSV................................................................................................................................. 2-4

Figure 2.3 Example of Chartview output based on ARMIS information (thicknesses of layers shown) ..... 2-8

Figure 2.4 Example of a single-channel portable GPR control unit. .......................................................... 2-12

Figure 2.5 Example of a ground-coupled antenna with distance-measuring wheel set-up behind a vehicle 2-12

Figure 2.6 Example of an air-coupled antenna mounted on the front of a vehicle. .................................. 2-13

Figure 2.7 Example of a 2-D radargram of a road pavement (top) and corresponding layer interpretation(bottom)............................................................................................................................... 2-14

Figure 2.8 Example of 3-D radargrams of a road pavement..................................................................... 2-14

Figure 2.9 Roughness: A guide indicating the functional adequacy of the pavement. ............................ 2-25

Figure 2.10 Edge break (which can reduce seal width) ............................................................................ 2-26

Figure 2.11 Typical deflection bowl with load-deflection parameters for a Benkelman Beam test on a non-rigid pavement. ................................................................................................................... 2-36


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Page 2-ivPavement Rehabilitation ManualApril 2012

Figure 2.12 An example of a Benkelman Beam........................................................................................2-37

Figure 2.13 TMRs PAVDEF is an example of a deflectograph. ...............................................................2-37

Figure 2.14 An example of a FWD. ........................................................................................................... 2-37

Figure 2.15 Example plot of deflection results from a non-rigid pavement. ..............................................2-42

Figure 2.16 D versus CBR for Benkelman Beam, PAVDEF and normalised 40kN FWD results for agranular pavement with a thin asphalt surfacing or seal900

.....................................................2-45

Figure 2.17 Weighted Mean Annual Pavement Temperature (WMAPT) zones .......................................2-47

Figure 2.18 Temperature correction for Benkelman Beam, PAVDEF and normalised 40kN FWD deflectionsresults for a pavement with a thin asphalt surfacing or seal............................................... 2-48

Figure 2.19 Temperature correction for Benkelman Beam, PAVDEF and normalised 40kN FWD curvaturesfor a pavement with a thin asphalt surfacing or seal...........................................................2-48

Figure 2.20 Speed correction for deflections for Benkelman Beam and PAVDEF results derived for apavement with a thin asphalt surfacing or seal................................................................... 2-49

Figure 2.21 Speed correction for curvatures for Benkelman Beam and PAVDEF results derived for a

pavement with a thin asphalt surfacing or seal................................................................... 2-50

Figure 2.22 Failures as a result of boxed construction with inadequate drainage................................... 2-52

Figure 2.23 De-lamination of a seal...........................................................................................................2-59

Figure 2.24 Moisture content versus time ................................................................................................. 2-63

Figure 2.25 Relationship between CBR value and suction for soils of various plasticities (ARRB 1982). 2-65

List of Equations

Equation 2.1 - Coefficient of variation...........................................................................................................2-41

Equation 2.2 - Representative deflection......................................................................................................2-43

Equation 2.3 Deflection ratio......................................................................................................................2-44

Equation 2.4 Representative deflection ratio............................................................................................. 2-44

Equation 2.5 Curvature function. ............................................................................................................... 2-44

Equation 2.6 Representative D .900 ............................................................................................................ 2-46


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Pavement Rehabilitation Manual


2.1 INTRODUCTION

This chapter discusses the process of pavement evaluation. Chapter 3 discusses how the outcomes of a

pavement evaluation are used to identify a range of appropriate rehabilitation treatments for different

pavement types. Chapters 4 and 5 provide the specific technical detail and references relating to these

rehabilitation techniques.

This manual must be read in conjunction with the Part 5 of Austroads Guide to Pavement

Techno logy Part 5: Pavement Evaluation and Treatment Desig n (AGTPT Part 5). It should not be

assumed that this manual contains all relevant information, even where the subject or headings are the

same. For instance, the designer must refer to the visual assessment sections in both this manual and the

AGTPT Part 5to access the complete discussion.

Figure 2.1shows the pavement evaluation process. Pavement evaluation involves:

relating the symptoms of pavement distress to their causes;

explaining how the distress(es) developed (i.e. the mechanism[s] causing distress); and

detailing appropriate methods to complete an investigation and the sequencing of them.

Further, it involves assessing the functional and structural condition of the existing pavement and assessing

it against the predicted future conditions (for the required design period).

It is noted that the driver of a rehabilitation investigation may not necessarily be pavement distress (e.g.

works may be required to provide extra traffic capacity). (Refer to Chapter 1 for a discussion about

synergies and opportunities.) For example a pavement may not be showing distress (e.g. not at the end of

its design life) but will be upgraded to provide service for another design period (e.g. upgrade from four lanes

to six before the existing pavement has reached the end of its design life). In such cases, while pavement

distress may not be evident, an evaluation is still required.

2.1.1 Use of data and sou rces of data

Data should not be used in isolation. Rather the data collected from various sources should be used

together to evaluate the pavement(s). Further it is best to gather data from multiple sources rather

than rely on only one or two sources.

2.1.2 Geometric assessmen t

This Chapter focuses on the evaluation of the road pavement(s). Chapter 4 of the Road Planning and

Design Manual (RPDM) (QDMR 2005a) provides guidance about when a geometric assessment should be

undertaken. Situations where a geometric assessment is recommended include:

a full shoulder seal;

shoulder widening;

overlay and widening;

rehabilitation (e.g. stabilisation) and widening; and


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duplication of an existing carriageway.

Therefore, a geometric assessment may be warranted in parallel with a pavement rehabilitation

investigation. Refer to Section 2.7.2of this manual and the RPDMfor further guidance.

(Note: The terms rehabilitation and reconstruction, in the context of the RPDM, fall under the umbrella ofrestoration projects. Refer to Chapter 4 of the RPDMfor its definition of a restoration project.)

Figure 2.1 Pavement evaluatio n p roces s



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2.1.3.1

2.1.3 The pavement evaluation concep t

Purpose

The purpose of a pavement evaluation is primarily to determine the condition of the existing pavement so

that appropriate rehabilitation treatments may be identified (if required). A sound pavement evaluation will:

enable the designer to assess the existing pavement and determine its current condition;

identify the causes/mechanisms of any observed pavement distress, if any;

ascertain whether the existing pavement must be rehabilitated to withstand the predicted conditions

for the required design period; and

provide the foundation for identifying what treatments/interventions are required, if any.

Firstly, factors that have affected the performance of the existing pavement are investigated to determine its

functional condition (e.g. how the road satisfies the needs of road users in terms of cost, comfort,

convenience and safety) and structural condition (i.e. how it responds to load[s]). Secondly, its ability, interms of its functional and structural capacity, to withstand the traffic and other environmental conditions

expected over the required design period are determined. If rehabilitation measures are necessary, the

evaluation will also allow these to be designed so that the required life is attained.

Premature conclusions about the causes of pavement distress should be avoided as they may cause

the designer to focus on justifying them, rather than being open to all possibilities. As a result, the

designer may fail to identify the real cause(s) of the pavement distress.

2.1.4 Sources of inform ation

Information used in a pavement evaluation is available from a number of different sources. These include:

historical records;

pavement condition assessments;

an assessment of the drainage systems, including any sub-surface pavement drainage systems;

materials testing; and

the pavement's structural response to load.

The following sections provide more details about some of the abovementioned sources. While not all of the

these sources may be relevant in any particular case, the rehabilitation designer should be aware of their

potential contribution towards determining why the present conditions exist.

Pavement condition data may be collected and recorded by a variety of methods including:

as part of a formalised Visual Rating (VR) or visual condition survey;

the Department of Transport and Main Roads (TMR) Network Survey Vehicle (NSV, Figure 2.2) which

collects information such as rut depths, photographic images and roughness against (gazettal)

chainage;

pavement roughness surveys; and

deflection surveys.

Alternatively, pavement condition data may be gathered via a simple visual inspection done by the

evaluating officer.


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Fig ur e 2.2 TMR s NSV .

2.1.5 Presentatio n of data

To facilitate the effective interpretation of data, attention should be paid to how it is prepared and presented.

The designer will find the use of both data mapping and graphical techniques of considerable benefit. One

example of the output of a visual survey is shown in Figure 3.1 of Appendix A of AGTPT Part 5(Austroads,

2009).

A data map should consist of a schematic plan of the pavement under evaluation, on which some or all of

the following detail may be symbolically, diagrammatically or graphically represented:

Location, nature, extent and severity of defects including patches. (The National Association of

Australian Road Authorities (NAASRA) Guide to the Visual Assessment of Pavement Condition

provides suitable graphical conventions (NAASRA 1987). Appendix A ofAGTPT Part 5(Austroads,

2009) also contains information about the identification of visual distress. Refer to Section 2.3 for

more detail.)

Load response (e.g. deflections as recorded by FWD, HWD, PAVDEF or Benkelman Beam testing)

against chainage.

Identification of representative sections as determined by condition data (e.g. by using deflection

results).

Values that characterise representative sections (e.g. characteristic moduli derived from back

analysis).

Test results (e.g. of subgrade California Bearing Ratio [CBR])

Changes in pavement or subgrade configuration or type.

Details and extents of type cross sections.

Geometric features (e.g. longitudinal sections, superelevations/crossfalls, alignment).

Drainage features.

Topographical features (e.g. cuts, fills, cross grades).

Degrees of saturation.

Moisture contents.

Photographs (e.g. from DVR or field inspection).

The benefits of such a map include:

Assistance with identifying relationships between various observations or measured parameters.

Provision of an interim record of field observations to save repeated site inspections.



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Enabling the information to be visually appraised.

Enabling the road to be more readily divided into representative sections for analysis.

Provision of a permanent record of pavement information that may be of value in subsequent

evaluations. (Note: Once rehabilitation is completed the data may no longer be observable. A map

provides a record that may be referred to in the future.)

2.2 HISTORICAL DATA

A considerable quantity of historical data relevant to determining an appropriate rehabilitation strategy may

be available from a variety of sources.

Historical data may be available from the sources discussed in the following sections. The designer should

contact the relevant TMR regional or district office in the first instance to obtain the available, relevant

historical information.

2.2.1 Advantages

The following are some or the advantages of gathering historical data:

It can be a relatively quick process.

It can provide the pavements history.

It can help explain current distress(es).

It provides a good base for developing further investigations (e.g. testing).

However, the gathering of historical data does have some disadvantages and limitations associated with it.

2.2.2 Disadv antages and limi tation s

Gathering historical information is a useful starting point. However the designer must use this information

with care. It is not unusual for the actual (in situ) pavement to differ from that expected given the historical

information. Therefore historical information should only be used in conjunction with project specific testing.

2.2.3 Origin al desig n

Obtaining the original design data will assist the designer to determine whether the distress is caused by a

change in the design parameters, the constructed pavement or the performance expectations. (For example

there may be a difference between the [assumed] design values and the actual conditions experienced [e.g.design traffic versus actual traffic].) This information may be available from:

TMRs ARMIS database (see Section 2.2.6)

Original scheme documents (e.g. drawings/plans, specifications);

Investigation results; and

Previous design or investigation reports.

Information that may be garnered from t

Pavement_Rehabilitation_Manual.pdf

Documents

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