Pavement Design good ref.

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Document Number: AD-D-09

First Edition - May 2013

PAVEMENT DESIGN MANUAL

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PAVEMENT DESIGN MANUAL

C

OMMENTARY REPORT

B

Y

P

ARSONS

I

NTERNATIONAL LIMITED

D

OCUMENT

N

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:

AD-D-09

F

IRST

E

DITION

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Document No: AD-D-09 First Edition

May 2013

Department of Transport PO Box 20

Abu Dhabi, United Arab Emirates

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Page i Contents Approval and Amendment Record

This report has been issued and amended as follows:

Issue Revision Description Lead Author Lead Reviewer

Date

1.0 0 Report to accompany draft

final of Pavement Design Manual submitted to Review Committee Mohamed Elbasyouny (PIL) Mohamed Elbasyouny (PIL) 6/05/2013

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Page ii

T

ABLE OF

C

ONTENTS

List of Figures ... iii

List of Tables ... iii

Executive Summary ... 1

1 Introduction ... 2

2 methodology ... 3

3 background and history ... 4

4 base documents ... 5

4.1 1993 AASHTO Empirical method ... 5

4.2 Austroads Mechanistic-empirical method ... 5

4.3 Abu Dhabi Municipality Pavement Design Manual ... 7

5 scope of manual ... 8

5.1 Application of this manual ... 8

5.2 Content and format ... 8

6 Document development ... 10 6.1 Progress meetings ... 10 6.2 Consultation meetings ... 10 6.3 Formal submission ... 10 6.4 Workshop ... 11 6.5 Comment Review ... 11 6.6 Final submission ... 11 7 Acknowlegment ... 13

Appendix A: compiled comments from Dot/ stakeholders ... 15

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Page iii

L

IST OF

F

IGURES

Figure 1 Mechanistic-Empirical Design Method Flowchart ... 7

L

IST OF

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ABLES

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Page 1

EXECUTIVE SUMMARY

In 2010, the Department of Transport commenced with the “Unifying and Standardizing of Road Engineering Practices” Project. The objective of the project was to enhance the management, planning, design, construction, maintenance and operation of all roads and related infrastructures in the Abu Dhabi Emirate and ensure a safe and uniform operational and structural capacity throughout the road network.

To achieve this objective a set of 36 standards, specifications, guidelines and manuals were developed in consultation with all relevant authorities in the Abu Dhabi Emirate. In future, all authorities or clients involved in roads and road infrastructures in the Emirate shall exercise their functions and responsibilities in accordance with these documents.

One of these 36 manuals is the Pavement Design Manual (PDM). The PDM focuses on the material characterization, traffic estimation and climatic influence for the structural design of the pavements structural layers. Combining conditions and resources from different international manuals, while including ways to use sustainable and economical materials, this manual is highly applicable to Abu Dhabi.

This manual provides comprehensive information needed to develop complete structural pavement designs for both flexible (asphalt) and rigid (concrete) pavements. Topics covered in PDM include required traffic and climatic data for pavement design, material characterization, new pavement design, rehabilitation techniques, pavement maintenance, pavement management, low volume roads, evaluation of existing pavements condition and life cycle cost (LCC) analysis. This manual also covers the empirical and the mechanistic-empirical (M-E) design methods. Using the information in this manual, a designer can apply several design methods and select a final design based on a life cycle cost analysis.

In coordination with DoT and Aurecon (Project Manager), following process was identified and followed:

• Get comprehensive brief from DoT Staff to understand their requirements.

• Submit Preliminary report to confirm DoT’s requirements.

• Review the existing International pavement design manuals.

• Conduct an initial workshop to discuss the draft contents and methodology to be adopted.

• Prepare and submit a first draft Manual for comments and review by DoT.

• Receive comments from DoT and improve the draft.

• Submit a second draft for DoT / Stakeholders review.

• All agencies to attend a workshop to receive comment and thereby improve the draft.

• Collect comments from the workshop outcome and prepare a final manual.

All the Chapters and Appendices of the PDM were developed in complete co-ordination with DoT. Several chapters were submitted individually for DoT review during the development process. However, the first complete draft of the PDM was delivered for review in April 2012. The document has been subject to further rigorous review during several meetings with DoT lead reviewer. The second full draft of the document was delivered for review in September 2012. In November 2012 a workshop was held for all agencies to present the draft final and collect their comments. In mid December 2012 after meeting with DoT and other manuals developer a new chapter was requested to be added. Finally, in February 2013 the final draft manual was submitted.

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1 INTRODUCTION

Pavement design, an integral and critical part of the transportation system, focuses on thickness design of pavement layers. In general, pavement design requires knowledge about the materials in any existing pavement layers, the foundation upon which the pavement will reside, traffic levels, and climatic conditions. Selecting a final design, however, depends on the availability of materials, funding, and local experience.

The manual’s approach is consistent with DoT’s objective to upgrade the existing pavement design methodology by incorporating advanced technology and pavement design procedures. This manual provides comprehensive information needed to develop complete structural pavement designs for asphalt and concrete pavements. Topics include required data, material characterization, new pavement design, rehabilitation techniques, pavement maintenance, pavement management, low volume roads, and life cycle cost (LCC) analysis. This manual also covers the empirical and the mechanistic-empirical (M-E) design methods.

Several pavement design methods are currently used by different agencies and countries. These methods vary somewhat for differing local conditions and resources. The procedures range from empirical to M-E approaches. New M-E pavement design analysis procedures developed over the last 20 years focus on the design and construction of high quality, long-lasting and well-performing highways that accommodate the increase in traffic volumes and loads in ways that exceed the empirical methods. These new approaches are challenging in that they require advanced analysis methods and material characterization. In response to these technical advances and increasingly easy computation, DoT has incorporated the newer and more fundamental mechanistic-empirical design approaches in this new manual.

Combining conditions and resources from different international manuals, while including ways to use sustainable and economical materials, this manual is highly applicable to Abu Dhabi. It covers different options for obtaining traffic count and loads, environmental factors, and advanced material characterizations that apply to Abu Dhabi. Brief descriptions for some pavement design topics are given since other DoT manuals cover such topics in more details.

This report supports the PDM manual, as it summarizes the approach followed in developing the PDM. The report also, provides the activities undertaken and communications with DoT to develop the PDM in its final version.

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2 METHODOLOGY

The method followed to develop the pavement design manual was set from the start of the project with the DoT and Aurecon (Project Manager). The following process was identified and followed:

1. Get comprehensive brief from DoT Staff to understand their requirements. 2. Submit Preliminary report to confirm DoT’s requirements.

3. Review the existing International pavement design manuals.

4. Conduct an initial workshop to discuss the draft contents and methodology to be adopted. 5. Prepare and submit a first draft Manual for comments and review by DoT.

6. Receive comments from DoT and improve the draft. 7. Submit a second draft for DoT / Stakeholders review.

8. All agencies to attend a workshop to receive comment and thereby improve the draft. 9. Collect comments from the outcome of the workshop and prepare a final manual.

These steps were followed as practical as possible to develop the manual. Since the pavement design manual is special design manual consultation with stakeholders were conducted mainly during the workshops that was held during the project. Also, meetings with consultants developing other manual were held to coordinate the interaction between the pavement design manual and the other manuals.

The DoT instructions from the beginning were to incorporate a mechanistic-empirical method in the new design manual, include new material characterization and add sections for pavement maintenance and life cycle cost analysis. All the Chapters and Appendices of the PDM were developed in complete co-ordination with DoT. An initial table of contents of the topics that expected to be covered in the manual was given by the DoT. Some changes were introduced on the table of content. However, all topics were covered in the developed manual.

The DoT requirements were included in a preliminary report that was submitted to DoT in March 2011. Following this submission a workshop was held in March 2011 to the DoT /Stakeholders. The purpose of this workshop was to present the updated topics and table of contents that will be incorporated in the manual as well as address comments received on the preliminary report.

Once the general outline was set from the workshop the manual development started. All the Chapters and Appendices of the PDM were developed in complete co-ordination with DoT. Several chapters were submitted individually for DoT review during the development process. The following sections will cover the document development and the consultation with the DoT.

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3 BACKGROUND AND HISTORY

Historically, pavement design had been based on empirical models formulated from pavement test tracks or lab testing. These empirical methods use nomographs and simple equations to obtain the layers thickness. While these nomographs were developed using limited data, the issue that had faced many agencies is when the conditions extend beyond the nomograph limits, is the resulting thickness acceptable from an economical and safety viewpoints or not.

There had been a huge advance in the technology which led to the easiness to perform complicated computations using computer. At the same time, there had been a significant increase in the traffic loads, traffic counts, advance in material characterization and better modelling of the environmental factors. Accordingly, agencies started looking into using mechanistic – empirical (M-E) methods that is based on fundamental properties and advanced material characterization to better design economical pavement structure.

Countries around the World either use a method that was developed locally or adopt an international method but modify it to the country local condition. The manuals that were considered for the pavement design manual were the following:

1. A Guide to Structural Design of Road Pavements – Austroads – Australia and New Zealand.

2. South African Mechanistic Pavement Design Method – South Africa

3. American Association of State Highway and Transportation Officials. Mechanistic-Empirical Pavement Design Guide (MEPDG) – USA.

4. Asphalt Institute Thickness Design Guide – MS-1 5. Shell Oil Methodology – UK.

6. American Association of State Highway and Transportation Officials. Guide for Design of Pavement Structures (1993) – USA.

7. Abu Dhabi Municipality (ADM) pavement design manual 8. Dubai Pavement Design Manual

9. Saudi Arabia Pavement Design Manual 10. Qatar Pavement Design Manual

The first 4 methods are mechanistic-empirical methods that are based on fundamental material characterization and mechanistic analysis of pavement structure. While the remaining methods are empirical methods developed from test tracks and lab testing analysis. Qatar PDM provides a catalog type of pavements design manual in which a pavement section can be selected based upon allowable traffic and foundation conditions.

These listed manuals were studied and evaluated for the Abu Dhabi. ME methods are based on similar concepts with different models development. Accordingly, it was decided to rely on only one empirical method and one ME method. The 1993 AASHTO was selected for the empirical method because all agencies and clients are familiar with this method. 1993 ASSHTO guide has been used for long time in Abu Dhabi as the base for Abu Dhabi Municipality Roadway Design Manual. While, Austroads was selected for the M-E method because the models used in Austroads were developed for similar climatic conditions to Abu Dhabi. In addition to these two main manuals Abu Dhabi Municipality Roadway Design Manual referenced to obtain inputs that was set for Abu Dhabi and is common to all pavement designers.

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4 BASE DOCUMENTS

The three manuals selected for the new Abu Dhabi pavement design manual were:

1. A Guide to Structural Design of Road Pavements – Austroads – Australia and New Zealand.

2. American Association of State Highway and Transportation Officials. Guide for Design of Pavement Structures (1993) – USA.

3. Abu Dhabi Municipality (ADM) pavement design manual This section gives a general overview and summary to these manual.

4.1 1993 AASHTO Empirical method

The 1993 American Association of State Highway and Transportation Officials (AASHTO) Guide for Design of Pavement Structures is based on empirical method. Most countries around the world use the 1993 AASHTO guide with some modification to reflect local experience and conditions. Abu Dhabi Municipality Roadway Design Manual, which is based on the 1993 AASHTO guide, is an example.

To develop the Guide for Design of Pavement Structures, AASHTO compiled results from road tests conducted from 1958 to 1960 in Ottawa, Illinois, U.S.A. Data from these tests reflect one climatic condition, one foundation type, and one million equivalent single axle loads (ESALs). From 1960 to 1993, AASHTO added several enhancements, such increased reliance on traffic data and a limiting layer approach.

Covering both flexible and rigid pavement design, The 1993 AASHTO Guide describes material characterization, equivalent traffic estimation, life cycle costs, and existing pavement evaluation. It applies an ESAL as the basic unit for traffic estimation. Its material characterizations use an empirical factor to reflect layer stiffness.

Pavement designers around the world have used this guide successfully for many years. Reasons for designers’ success with this guide include the following:

1. Pavement designers can easily use the Nomograph or software.

2. Inputs defined by the guide are simple, many of which can be assumed easily. 3. Designers are very familiar with the methodology.

4.2 Austroads Mechanistic-empirical method

Advances in technology have encouraged the pavement community to start shifting from the empirical method to the M-E method, which is based on fundamental material properties and actual traffic loads.

Applying the fundamental stresses and strains of the materials in different layers at different depths of the pavement structure, the mechanistic method enables designers to evaluate the validity of proposed layer thicknesses. Designers calculate stresses and strains using either linear elastic analysis or a more complicated model that focuses on finite elements under actual traffic loads. Analysis using the mechanistic method also depends on detailed material characterizations, which vary based on temperature (for hot mix asphalt layers), ground water table depth, and moisture

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content (for granular layers). All M-E methods involve using a software package to analyse and design the pavement structure.

Austroads, the association of Australian and New Zealand road transport and traffic authorities, has developed an M-E pavement design guide, Guide to Pavement Technology, Part 2: Pavement Structural Design. This manual contains ten different sections that cover all aspects of pavement design, including structural design, surfacing, materials, pavement evaluation and treatment, maintenance, construction work practices, and drainage. Austroads also has a software package for pavement analysis.

According to the Austroads guide, engineers apply structural analysis of the trial pavement configuration to quantify critical strains and stresses that are caused by traffic loads. They can vary the method to consider pavement layers as either fully elastic (viscoelastic), uniform in lateral extent, or variable, with either full friction or no friction between the layers. By using these variations, engineers attempt to establish theoretical estimates that agree with observed reactions to traffic loading.

In addition, engineers can analyse pavement designs based on varying traffic loads, from a single vertical load with uniform tire contact stress to multiple loads with multi-directional components and non-uniform stress distribution. They can also vary traffic speeds to further assess potential traffic loads. Engineers must be careful, however, to ensure that the sophistication of the analysis method is compatible with the quality of the input data. Otherwise, they need to make too many assumptions to fill the gaps, resulting in misleading, if not worthless, analysis.

Austroads states that engineers can reliably obtain required input for analysis based on the M-E method. Results from such analysis provide predictions of pavement performance that reasonably match pavement performance in Australasian.

Upon completing the structural analysis, engineers can use the results to estimate the allowable loading of the pavement configuration. Austroads states that, in the M-E method, most performance criteria assigned to pavement materials and to the subgrade relate the level of strain induced by a standard single axle load and the number of such loads that exceed the pavement’s tolerance level, based on material characteristics.

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Figure 1 Mechanistic-Empirical Design Method Flowchart

4.3 Abu Dhabi Municipality Pavement Design Manual

Abu Dhabi Municipality (ADM) pavement Design Manual was developed based on the 1993 AASHTO Guide for Design of Pavement Structures. The inputs required for the pavement design had been tailored for local conditions. ADM follows deep strength concept in pavement design. Using inputs from ADM manual in the 1993 AASHTO guide will provide pavement structure with thicker asphalt concrete layers. ADM also imposed minimum layer thickness for each road category to meet the standard specifications and mixture requirements available locally.

Traffic Foundation Climate Material Properties

Trial Section Pavement Analysis Performance Criteria Project Reliability Comparison of Designs Viable Design Select Design Inputs Analysis Selection Accept No Yes

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5 SCOPE OF MANUAL

5.1 Application of this manual

Information in this manual focuses on structural pavement design, with methods for determining layer thickness and pavement structural capacity. This manual is intended for use by pavement engineers conducting structural design for either existing or new pavement structures.

Structural calculations for pavement design require knowledge of existing traffic flow, predictions of anticipated future traffic, and environmental factors at the road’s location. Pavement designers must also obtain information about the properties of the materials (such as asphalt, Portland cement, or granular road base) that will be used in each pavement layer. Designs must account for these material properties in conjunction with the material specifications and asphalt mixture designs, as detailed in the Abu Dhabi DoT Standard Specifications for Road Works manual.

Completing the pavement design process involves using either the 1993 AASHTO nomograph or Austroads software to determine the required layer thickness. After generating several design options using different methods, a pavement engineer shall conduct an LCC analysis to compare the designs for cost effectiveness. For details about LCC analysis, refer to Chapter 9, Life-cycle Cost Analysis, in this manual, as well as the Abu Dhabi DoT’s Project Cost Estimating and Standard Bill of Quantities manuals.

Pavement design requires not only designing new pavements, but also evaluating existing pavement. Ensuring that existing pavement facilities have sufficient functional capacity and ride quality involves maintenance, possibly including the construction of additional layers. Optional methods for maintaining existing pavements include chip sealing, fog sealing, slurry sealing, and crack sealing. Such maintenance or rehabilitation requires accessing the pavement condition surveys database, which is part of the Abu Dhabi DoT’s pavement management system, to get information about the condition of the existing pavement. Refer to Chapter 10, Pavement Management Systems, in this manual for information about the pavement management system and Chapter 11 for the existing pavement evaluation and pavement condition surveys.

Evaluating existing pavements requires significant engineering judgement and effective application of the backcalculation procedure. Based on the pavement design guidelines in this manual, design engineers apply their own methodologies and experienced judgment to arrive at final rehabilitation methods.

This manual provides guidelines for the design of new and rehabilitation of asphalt and concrete pavements. The concrete pavement design guidelines are given in less detail. Applicable international standards for concrete pavement design are followed in the manual.

5.2 Content and format

This manual includes sections detailing inputs such as traffic, climate, and material properties, as well as sections on maintenance, rehabilitation, and LCC analysis. It also provides appropriate charts and nomographs. The section on low-volume roads is particularly relevant for rural areas. Because different design methodologies deal with inputs in different ways, this manual advises designers on how to estimate these inputs and how to obtain valid condition inputs for Abu Dhabi. It also includes ways to ensure that pavement designs support sustainability.

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Page 9 This manual includes the following chapters:

• Chapter 1 – Introduction: Outlines the purpose, scope, intended users, and application of this manual.

• Chapter 2 – Pavement design components: Describes elements, such as environmental and traffic factors, that must be considered in pavement design, and provides instructions on how to determine such factors.

• Chapter 3 – Pavement material characterization: Identifies properties of pavement materials and provides instructions on how to determine such properties through tests of the use of models.

• Chapter 4 – Pavement rehabilitation: Details the rehabilitation of flexible and rigid pavement structures.

• Chapter 5 – Rigid pavement design: Details the design of new flexible and rigid pavement structures.

• Chapter 6 – Low-volume roads: Covers the design of low-volume roads.

• Chapter 7 – Drainage design: Focuses on the design of granular drainage layer in a pavement structure.

• Chapter 8 – Flexible pavement maintenance: Offers different maintenance options. • Chapter 9 – Life-cycle cost analysis: Details LCC analysis for pavement structures. • Chapter 10 – Pavement management systems: Provides an overview of the Abu Dhabi

PMS and summarises related concepts.

• Chapter 11 - Existing Pavement Evaluation: Provides overview of different methods to conduct pavement condition surveys and how to analysis the collected distress data.

The appendices of this manual provide supplementary charts and tables for the design on the rigid pavements.

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6 DOCUMENT DEVELOPMENT

The development of the manual document required progress meeting with DoT and Aurecon, submission of separate chapters for early review, and meetings with DoT and other consultants. The Table below includes the dates of meetings and presentations held during the progress of the manual development.

The overall Schedule for Parsons International Limited’s completion of the Pavement design manual is shown on the schedule included in PIL’s Project Management Plan (PMP). The key milestone dates for the delivery of the Pavement Design manual are as follows.

• Preliminary Study and List of Contents: 10 March 2011

• First workshop 14 March 2011

• Completion of Stakeholder Review: 31 March 2011

• Delivery of First Draft Document: April 2012

• Completion of DOT Reviews July 2012

• Submission of Draft Document: September 2012

• Second Workshop: 12 November 2012

• Final Comments: 01 December 2012

• Final Draft Document: February 2013

• Final Document: 01 May 2013

6.1 Progress meetings

Monthly progress meetings were being held with DoT and Aurecon to update on the progress of the manual development. The progress meeting were attended by the Parsons Project Director. Progress and information presented in these meeting were collected from each manual lead developer.

6.2 Consultation meetings

The progress meeting were mainly on the project management level not on the technical level. Several technical meetings were held with the DoT pavement design manual lead reviewer (Dr. Salim Sulaiman). Also, meetings were held with other consultants (TrafQuest and Halcrow) developing other manual to discuss interaction between the pavement design manual and these manual. The manuals that had interaction with pavement design manual were the Geotechnical Investigation and Design Guidelines developed by Halcrow and the Road Performance Manual by TrafQuest.

In mid December 2012, a meeting was held at the DoT with DoT, Aurecon and the Getechnical investigation manual developer (Halcrow). The outcome of this meeting was to add a new section in the pavement design manual to cover the evaluation of the existing pavement structures.

6.3 Formal submission

All the Chapters and Appendices of the PDM were developed in complete co-ordination with DoT. The initial plan was to submit chapter by chapter to the DoT lead reviewer. This plan was followed for the first few chapters that were submitted individually for DoT review. However, due to the interaction between different chapters and complication of the manual, all chapters were submitted together as a first complete draft.

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The first complete draft of the PDM was delivered for review in April 2012. The document has been subject to rigorous review during several meetings with DoT lead reviewer and DoT reviewer panel. The comments obtained from this first review were addressed in a second draft.

The second full draft of the document was delivered for review in September 2012. The second draft was distributed to the Stakeholders for their review. Initial comments from Aurecon reviewers were send on the second draft. Comments that were received for the Pavement Design Manual are listed in Appendix A.

In November 2012 a workshop was held for all agencies to present the draft final and collect their comments. After the presentation additional comments were received from the Stakeholders mainly Al-Ain Municipality. All comments were addressed and included in the final document. In mid December 2012 after meeting with DoT and other manuals developer a new chapter on the evaluation of the existing pavement structures was requested to be added. Initially, this new section was added as an appendix and in February 2013 the final draft manual was submitted. Then the DoT requested that it should be added as a new chapter to the main text which was done in the final version that was submitted in beginning of May 2013.

6.4 Workshop

Two workshops were given during the project; the first was given in March 2011 to discuss the

initial outline of the manual. The second workshop was given on November 12th 2012. The

second workshop presented the final developed manual. The workshop discussed the new features and methods described in the pavement design. A design example using the empirical and the M-E method was presented to compare the two methods. The presentation given during the second workshop is included in Appendix B.

6.5 Comment Review

The comments received from the DoT / Stakeholders were reviewed carefully. Most of the comments incorporated in the pavement design manual. None of the comments was major due to the coordination with the DoT lead reviewer throughout the manual development.

The few comments that were not included require the standardization of certain inputs to the design process. The standardization of certain inputs would disagree with one of the main requirement of the manual that it should be applicable to all clients and projects. The standardization can be done individually by local agencies to accommodate their local requirements.

6.6 Final submission

The final document was updated with the final format that was request by the project manager (Aurecon). The cover and back pages were added to the PDF file. A final version was submitted in May 2013.

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The following table list the technical meeting held during the development of the PDM.

Table 1 Technical Meetings Information

Date Title Agenda Attendees

20-Feb-11 PDM Preliminary

report

Discussion of the Preliminary report and manual outline

Dr. Salim Suliman (DOT), Dr. Rasin Mufti (PIL), Dr. Walid

Nassar (PIL)

10-March-11 PDM Preliminary

report

Discussion of the Preliminary report and preparation for the

first workshop

Parviz Djahani (DoT), Dr. Salim Suliman (DOT), Willie Victor (Aurecon), Dr. Rasin Mufti (PIL),

Mohamed Elbasyouny (PIL)

05-April-11 PDM Workshop

comments

Updated outline, schedule and the comments received

on the PDM during the workshop

Dr. Salim Suliman (DOT), Dr. Rasin Mufti (PIL), Mohamed

Elbasyouny (PIL)

08-June-11 PDM progress

meeting

Discuss comments on Chapters 1,2,and 3

Elbasyouny (PIL)

14-June-11 PDM and RPMS

Manual

Discuss interaction between PDM and RPMS Manual

Rob Hranac (TrafQuest), Mohamed El-Basyouny (PIL),

Ahmed Abdel Dayem, (Trafquest) 15- September-11 PDM progress meeting Progress in PDM

Elbasyouny (PIL)

06-June-12 PDM Review Comments of PDM First Draft

Dr. Salim Suliman (DOT), Dr. Nabil Salman (DoT), Dr. Rasin

Mufti (PIL), Mohamed Elbasyouny (PIL)

12-June-12 PDM Review Comments of PDM First Draft Dr. Salim Suliman (DOT),

Mohamed Elbasyouny (PIL)

19- December-12 Meeting on Pavement Condition Survey

Discuss location and content of Pavement Condition

Survey

Parviz Djahani (DoT), Dr. Salim Suliman (DOT), Jihad Sawan

(DoT), Abdulla Al Shaibani (DoT), Willie Victor (Aurecon),

Andrew Harley (Halcrow), Mohamed Elbasyouny (PIL)

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7 ACKNOWLEGMENT

This document was developed by Parsons International Limited. The document consultants would like to express their personal thanks and gratitude to:

Dr Parviz Djahani: For overall leading and steering of the project.

Dr. Salim Sulaiman (DoT Review Committee Lead): For his clear and thoughtful guidance

throughout the development of PDM.

Willie Victor, For his time and support during the project progress.

Members of the DoT review Committee For their time and input to aid the development of the

PDM.

All remaining stakeholders :For having shared their thoughts, comments and ideas to develop

the PDM.

Parsons Staff:

• Dr. Rasin Mufti, Project Director

• Dr. Mohamed Elbasyouny, manual lead author • Eng. Sohila Bemanian, maintenance author • Eng. Keith Hixson, drainage author

• Dr. Walid Nassar, peer reviewer

• Eng. Ramesh Vishwakarma, rigid pavement author • Gaylin Gardette, editor

• Ron Manns, editor

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A

PPENDIX

A:

COMPILED COMMENTS FROM

D

OT

/

STAKEHOLDERS

This appendix provides the comments received for the Pavement Design Manual draft final version by December 2012.

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A14 Document Title: Deliverable

Ref: A14.12

Title of Interim

Deliverable: Second Draft Document

MAN-000540 Revision No: 3 Dated: #################### ACONEX Document No. of Approved Content Outline:

Geometry #################### Due Date for Initial Responses:

Priorities: High Priority (H): Medium Priority (M): Low Priority (L): Priority (H,M,L)

1 Bus stops Bus stop pavement area should be laid with bitumen modified red colored asphalt wearing course.

M DOT-Public Transport

Division

Added to Roads Specification manual

2 Par 1.4 Content and Format Page 3 Chapter 8 - Flexible pavement maintenance: Change "offers" to "Offers"

L Johan Calitz Aurecon Docment Reviewer

Corrected

3 Par 1.5.1Flexible pavements Page 4 In second paragraph change "contactors" to "contractors" L Johan Calitz Aurecon Docment Reviewer

Corrected

4 Par 2.1 Overview Page 9 First paragraph. Careful study and characterization of these factors is … Change "is" to "are"

Corrected

5 Par 2.2 Environment Page 9 Environment includes a many variables…. Omit "a". L Johan Calitz Aurecon Docment Reviewer

Corrected

6 Figure 2-2 Page 12 Cannot read some rainfall figures H Johan Calitz Aurecon Docment Reviewer

Corrected

7 Table 2-1 Page 12 Start table on next page to fit the whole table on 1 page M Johan Calitz Aurecon Docment Reviewer

Corrected

8 Paragraph 2.3.2 Vehicle classification

Page 16 Vehicle classifications on paragraph 3 should start with numbering 1 and not 7 to be similar to numbering in Figure 2-4 on page 17

M Johan Calitz Aurecon Docment Reviewer

Corrected

9 Paragraph 2.3.10 Truck factor and Paragraph 2.3.11 Equivalent axle load factor

Page 21 and Page 22 These paragraps should be changed around because the method to calculate EALF used in equation 2-9 in paragraph 2.3.10 is only provided in paragraph 2.3.11

Corrected

10 Paragraph 2.3.11 Page 22 Last sentence of first paragraph: "As an alternative method, can apply .." Add "designers" before "can apply"

Corrected

11 Chapter 3 Pavement Materials Page 25 Second paragraph. Add "a" to "Pavement is composed of .." L Johan Calitz Aurecon Docment Reviewer

Corrected

DDC Response

Observations such as typographical errors which may be corrected during next revision.

No Subject Page / Section No Reviewer’s Comment Reviewer Reviewer's Organization Sub-Package Name: Geometry 2

Comments that will cause the document to be unacceptable.

Comments which require the document to be revised and resubmitted.

Package Name: Consolidated Comments Submitted to DDC:

Pavement Design Manual

ACONEX Document No. of Interim Deliverable Reviewed:

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Ref: A14.12

Priorities: High Priority (H): Medium Priority (M): Low Priority (L): Priority (H,M,L) DDC Response

12 Par 3.2.1 Empirical design for granular base and subbase materials

Page 28 Add "The AASHTO Road Test basis of these correlations is" to the second sentence of the second paragraph reading "A granular base of has a layer …" Refer to page II-17 and II-20 of 1993 AASHTO Guide for Design of Pavement Structures

Corrected

13 Figure 3-1 Page 29 This figure copied from the AASHTO manual page II-19 should be revised so that the footers which include AASHTO manual references are not shown.

Corrected

14 Figure 3-1 page 29 The title of this figure is on the page following the figure and should be moved to the bottom of the figure on page 29

Corrected

15 Par 3.2.1 Empirical design for granular base and subbase materials

page 30 Add "In the AASHTO Road Test the basis of these correlations is" to the second sentence of the paragraph reading " Granular subbase has a base layer …" Refer to page II-20 of 1993 AASHTO Guide for Design of Pavement Structures

Corrected

17 Par 3.2.2 Mechanistic design for granular base and subbase materials

Page 32 Change the last sentence of the third paragraph to: "The top half of Table 3-2 is applicable for granular material that has a CBR greater than 30%." Refer Table 6.4 on page 52 of Austroads manual.

Corrected

18 Par 3.3 modified granular materials Page 33 Last sentence of first paragraph : Change "stabilised" to "modified" in the sentence "Austroads specifies that stabilised granular materials …". Refer page 53 Autroads Manual

Corrected

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Ref: A14.12

Corrected

21 Par 3.5.1 Empirical design for asphalt concrete materials

Page 38 Change the second paragraph to the following: "The structural coefficient of AC varies between 0.2 and 0.44 and AC with a layer coefficient of 0.44 (per inch), corresponds to an AC resiient modulus of 3.1 Gpa (450,000 psi)" Reference AASHTO manual page II-17

Corrected

22 Par 3.5.2 Mechanistic design for asphalt concrete materials

Page 41 First bullet "… modulus of the bitumen…" Second bullet. "…percentage bitumen in the asphalt.." Directly from Austroads manual page 71. This is the convention used in AAHTO and Austroads design manuals. In this design manual the authors used aphalt binder and asphalt concrete.

Corrected

23 Figure 3-7 Page 42 Change "asphalt" in title to "asphalt concrete". Refer Austroads figure 6.10 page 71

Corrected

24 Figure 4-3 Page 55 Change "Foundatio" to "Foundation" and "Climat" to "Climate". Refer Austroads page 97.

Corrected

25 Par 4.2.2.3Determination of a granular base layer's elastic parameters

Page 58 First paragraph. Change "because" to "Because" L Johan Calitz Aurecon Docment Reviewer

Corrected

26 Par 4.3.2 Empirical pavement design Page 61 Second parapraph. Reference is made to Appendix C for design traffic calculation procedure. Appendix C on page 202 contains AASHTO slab thickness design tables. Correct reference.

H Johan Calitz Aurecon Docment Reviewer

Corrected

27 Par 4.3.3.2Determine required structural design

Page 67 First paragraph. "Refer to section X.". Provide correct reference H Johan Calitz Aurecon Docment Reviewer

Corrected

28 Par 4.3.3.2Determine required structural design

Page 67 - 69 Please provide reference to the design figures: Figure 6, Figure 4-7, Figure 4-8 and Figure 4-9. Could not be found in AASHTO or Austroads Design manuals

Corrected

(27)

Ref: A14.12

29 Par 4.3.4 Joint details Page 70 Change "joint" to "joints" in first paragraph L Johan Calitz Aurecon Docment Reviewer

Corrected

30 Par4.3.5.1Rigid pavement types Page 72 Third sentence of first paragraph. Change "LPCP" to "JPCP" L Johan Calitz Aurecon Docment Reviewer

Corrected

31 Equation 4-10 Page 73 Provide details for the symbols used in equation as in Austroads manual page 127. Note that according to Austroads manual the maximum value for subgrade CBR determined according to this method is 15%.

Corrected

32 Equation 4-11 Page 74 Change "Designers shall use Equation 4-12.." to "Designers shall use equation 4-11.." in the line below the equation. Refer Austroads Manual page 130, equation 9.2

Corrected

33 Equation 4-12 Page 74 Change title of Equation 4.12 to "Allowable axle load repitions when stress (Sr) is between 0.45 and 0.55." Refer Autroads manual page 130 equation 9.3

Corrected

34 Equation 4-12 Page 75 Change "designers shall use Equation 4-13.." to "designers shall use equation 4-12.." in the line below the eqation. Refer Austroads Manual page 130, equation 9.3

Corrected

35 Equation 4-13 Page 75 Change title of Equation 4-13 to: "Equivalent Stress for use in equations 4-11 and 4-12". Refer Austroads manual page 130

Corrected

36 Par 4.4.3 Construction procedure Page 78 Recommend that the use of stabilised layers beneath interlock paver blocks be mentioned. Also bedding sand layer thickness of 50 mm might be changed to 25 to 50 mm.

Added

37 Par 4.4.4.1 Design factors Page 79 Change "The Four .." to "The four …" in the first paragraph L Johan Calitz Aurecon Docment Reviewer

Corrected

38 Par 5.4.2 Functional evaluation of existing pavement

Page 93 In the third bullet change "Refer to table 4-1 .." to "Refer to Table 5-1 .."

Corrected

(28)

Ref: A14.12

39 Par 5.5.6 Mechanistic design Page 102 Reference should be made to Austroads Guide to Pavement Technology Part 5: Pavement Evaluation and Treatment Design

Corrected

40 Par 8.4 Pavement preservation treatments

Page 144 Recommend that paragraph 8.5 Preservation Treatments be placed before Paragraph 8.4 Pavement preservation treatments. The reason being that the individual treatments mentioned in paragraph 8.4 are discussed in detail in paragraph 8.5.

Corrected

41 Table 8-2: Pavement treatments and Table 8-3 Pavement treatment cost and expected life

Page 147 and page 148

Abbreviation "CIR" for cold in place recycling is used in comparison with pages 136, 137 and 155 where the abreviation "CIPR" is used. Recommend change to "CIPR" in these tables.

Corrected

42 Profile milling, cold in place recycling, Hot-in -place asphalt recycling, Full-depth asphalt repair (patching)

page 155 to page 157 These paragraphs should be numbered 8.5.2.6 ; 8.5.2.7; 8.5.2.8; 8.5.2.9 respectively

Corrected

43 Hot -in-place asphalt recycling page 156 In the third paragraph mention is made of adding "bitumen". This is the Australian and American thermodology which is used worlwide. In this manual "bitumen" is called "asphalt".

Corrected

44 Par 9.4 LCCA example page 171 The first line reads:"Figure 9-5 shows a step- by -step process…" This is not correct because Figure 9-5 is a photo of a highway.

Corrected

45 Appendix A: Developing Effective Modulus of Subgrade Reaction

page 185 The first paragraph says "This appendix provides an excerp from the 1993 American Association of State …" This exerp is not as on page ii-37 par 3.2.1 of the 1993 AASHTO manual. The reference should be corrected

Corrected

46 Cited References page 220 Add Austroads: Guide to Pavement Technology, Part 5: Pavement Evaluation and Treatment Design. Synney Australia: Austroads Incorporated, 2008. 978-1-921551-22-2

Added

47 Glossary Glossary to be added M Johan Calitz Aurecon Docment

Reviewer

Added

(29)

Ref: A14.12

1 Traffic Projections /2.3.6

Please include rational growth rate for major town (example Al Ain, Abu Dhabi, western region, any other major city area) based on the latest studies (steam model 2015etc) conducted by the transport agencies to enable the designer to have fair assumption to predict future traffic.

L Al Ain

Municipality Al Ain Municipality

This is included in the traffic manual

2 Equivlent Axle load factor /2.3.11

IT will be better if we used Standard axel load from GCC truck manufacturing specification, or the truck weight that adopted by DOT to defined standard axel load that used in UAE. Also consider different type of busses and their standard axle load factor for each one seperately

L Al Ain

PDM is general manual however, clients need to include local axles.

3 Modified granular material /3.3

Provide extract of the specification for modified granular material, percentage of cement, lime to be added, expected stiffness, indirect tensile strength, other properties etc.

M Al Ain

added

4 Stabilized material /3.4.2

Provide Figure showing the relationship between indirect tensile strength, field stiffness of stabilized material with layer coefficient.

M Al Ain

There are many relationships and none is recommended

(30)

Ref: A14.12

5 Recycled Material /3.8

There is no Design guide line provided in the manual for the use of recycled pavement material for rehabilitation of pavement structure. In fact most part of the world these techniques have been adopted long ago. As the Abu Dhabi Emirates mandates to use sustainable design technique, the manual should have more emphasized on these techniques by providing design guideline, design example. Furthermore this chapter should be expanded by taking into consideration of case studies.

M Al Ain

Added but more information is included in the specification manual

6 Recycled Material /3.9.4 Include Methodology for Cold In situ Recycling with

form bitumen, foamed asphalt mixes. M

Al Ain

Added in the maintenance chapter

7 Interlocking Pavers Design

The manual does not provide guideline for heavy duty interlocking pavers design. The information provided under this section is bare minimum.

M Al Ain

PDM is not entended for heavy duty such as in airport. General guideline for regular interlocking pavers is given

8 Interlocking Pavers Design

Layer coefficient for, Concrete paver, sand bedding considered in the example (section 4.4.4.1, paragraph 3) is incorrect as per the table 4-3.Layer coefficient for sand bedding cannot be the same as Asphalt and table 4-3 does not provide layer coefficient for concrete paver as well.

H Al Ain

reference added. However, this is an approximation that was recommended by ICPI

(31)

Ref: A14.12

9 Unbound Granular material /6.3.2

The last paragraph of the above section states that the minimum CBR for the sub base is 65%.But sub base, CBR 60% material used in Al AIn , Similarly, Sub-base with CBR 30% used in Dubai. Therefore please provide reference to the above requirement to justify.

L Al Ain

added

10 Pavement treatment cost and expected life The Manual should use the cost inputs based on the

local condition rather than referring to US condition. M

Al Ain

Modified as possible

11 Pavement treatment cost and expected life The envinmental impact should be considered for the

cases, Alternatives 1 &2 L

Al Ain

The proposed method does not include the envirnmental effect.

12 Cited references General Comment

The manual is more biased towards American Standards. The author did not refer important design guidelines adopted in the other developed countries standards. The Author should also refer other standards as well while compiling comprehensive documents. Example .For heavy duty paving block design Author should refer BS 7533-1:2001 which provide comprehensive design guideline. Similarly, Recycle Asphalt pavement design (Cold in situ recycling/ Hot in place recycling as stated in the life cycle cost example) no design guideline provided. Author could have referred other standards adopted in the developed countries

M Al Ain

The manual covers Austrailian as well as American standards

(32)

Ref: A14.12

13 Pavement Design Check list General Comment

Provide check list sheet that include requirements information for the pavement design to assess designer in revising pavement design documents

L Al Ain

This would differ from one client to the other and each should have his own requirements.

14

Emperical Pavement Design Example /4.5 Provide detailed example for pavement design using

M-E method M

Al Ain

Provided and added to chapter 4.

1 Pavement Design Manual

Traffic requires more details on Traffic count and axle configurations

Dr.Salim/ Dr.

Nabel DOT

addressed in the final version

Add Examples Dr.Salim/ Dr.

Nabel DOT

added

3 Pavement Design Manual Techniques for Stabilization and Material selection

Dr.Salim/ Dr.

Nabel DOT

added

4 Pavement Design Manual More details on Pavement Management Systems

Dr.Salim/ Dr.

Nabel DOT

This would be covered in the management manual

Maintenance chapter need to include diagnostic and methods

Dr.Salim/ Dr.

Nabel DOT

added chapter on pavement evaluation

Graphics throughout the manual need to be improved and made clearer.

Dr.Salim/ Dr.

Nabel DOT

All graphs are fixed

Add Chapter on over-weighted trucks and up-normal loads damage to pavement

Dr.Salim/ Dr.

Nabel DOT

Add section on analysis and data interpretation of Falling Weight Deflectometer (FWD) testing

Dr.Salim/ Dr.

Nabel DOT

Added reference but no specific method is added since it will depend on the software used for the backcalcualtions.

Add section on Paver interlocking blocks design – use UK

Dr.Salim/ Dr.

Nabel DOT

Added

10 Pavement Design Manual Add sketches for axle types

Dr.Salim/ Dr.

Nabel DOT

Added

Adjust design lane, % of trucks and other traffic factors.

Dr.Salim/ Dr.

Nabel DOT

Corrected

12 Pavement Design Manual Check equation 2.9 and add example

Dr.Salim/ Dr.

Nabel DOT

Corrected

(33)

Ref: A14.12

Add more details to page 23 and describe “traffic wander” and other factors listed.

Dr.Salim/ Dr.

Nabel DOT

Corrected

14 Pavement Design Manual Include CBR power model

Dr.Salim/ Dr.

Nabel DOT

Added

Emphasize that better quality material should be at the top for empirical design.

Dr.Salim/ Dr.

Nabel DOT

text is added

Add more details on the Geo-grids functionality and description

Dr.Salim/ Dr.

Nabel DOT

Geo-grids specification is added in the specification manual. Geogird impact in pavement design is not proven

yet

Comment on reliability and its impact on structure design

Dr.Salim/ Dr.

Nabel DOT

Text updated

Adjust the drainage coefficient to include 1.2 for drainage layers.

Dr.Salim/ Dr.

Nabel DOT

Corrected

Adjust Road Classes to reflect Highway classes (Truck route, freeway, expressway, collector and local).

Dr.Salim/ Dr.

Nabel DOT

Corrected

(34)

Page 26

A

PPENDIX

B:

WORKSHOP PRESENTATION

This appendix provides the slides for the presentation given by PIL on the pavement design manual draft final version during the second workshop on 12 November 2012.

(35)

1

UNIFYING AND STANDARDIZATION OF UNIFYING AND STANDARDIZATION OF UNIFYING AND STANDARDIZATION OF UNIFYING AND STANDARDIZATION OF UNIFYING AND STANDARDIZATION OF UNIFYING AND STANDARDIZATION OF UNIFYING AND STANDARDIZATION OF UNIFYING AND STANDARDIZATION OF HIGHWAY ENGINEERING PRACTICES HIGHWAY ENGINEERING PRACTICES HIGHWAY ENGINEERING PRACTICES HIGHWAY ENGINEERING PRACTICES HIGHWAY ENGINEERING PRACTICES HIGHWAY ENGINEERING PRACTICES HIGHWAY ENGINEERING PRACTICES HIGHWAY ENGINEERING PRACTICES

Pavement Design Manual

Workshop on 12 November 2012

Unifying and Standardization of Highway Engineering Practices Manuals Developed by Parsons

Geometry 2

Roads and Highway Drainage Manual

Road Landscape Manual

Pavement Design Manual

Construction

Standard Specification for Roads and Structures Works

Volume 1 – Road Works

Volume II – Structure Works Standard Bill of Quantities Project Cost Estimating Manual

(36)

2 Overall Objectives

Unify the approach for preparing BoQ and Cost Estimation for all

Road Projects in the Emirates

Update to recent international standards and practices

Inclusive for all conditions and types of road construction within

the Emirate

Produce high quality manuals and documents that are most applicable for the longest term possible

Customize Manuals for Abu Dhabi environment utilizing Parson’s local work experience

Objective of Pavement Design Manual

Provides detailed guidelines for Pavement Structural

Design, that includes:

Structure Design of Flexible and Rigid Pavements, New and rehabilitation of pavement structures Low Volume Roads

Life Cycle Cost analysis

Pavement Maintenance strategy

More details and analysis that require the Engineers

involvement and understanding of traffic, material,

environment and

pavement structural design to

provide a sustainable and economical design.

(37)

3 Preparation Approach and Methodology

Mechanistic Pavement

Design based on Guide to Pavement Technology – Part 2, Austroads, 2008, Australia.

Empirical Pavement Design

based on AASHTO Guide for Design of Pavement Structures, 1993, USA.

4

Organization of the Pavement Design Manual The PD manual is divided into ten different Chapters:

1. Introduction

2. Pavement Components 3. Pavement Materials 4. New Pavement Design 5. Rehabilitation Design 6. Low Volume Roads 7. Drainage Design 8. Pavement Maintenance 9. Life Cycle Cost Analysis

10.Pavement Management System.

Chapter 2 Pavement Components

Environmental

Empirical design – correct subgrade modulus using

Relative Damage (U

_f

)

ME design – rainfall for subgrade modulus and

temperature for asphalt modulus

Traffic Analysis

(39)

5 Chapter 2 Pavement Components

Rainfall 56.3 mm

Chapter 2 Pavement Components

Weighted mean annual air temperature 45.0° C to 38.7° C,

(40)

6 Chapter 2 Pavement Components

Traffic

Design life

Vehicle classification

Axle group configuration

Tire pressure Vehicle count Traffic projections Design lanes Directional factor Percentage of trucks Truck factor

Equivalent axle load factor

ESAL calculation

Chapter 2 Pavement Components

Axle Group type Load (kN)

Single axle, single tire 53 Single axle, dual tire 80 Tandem axle, single tire 90 Tandem axle, dual tire 135 Tridem axle, dual tire 181 Quad axle, dual tire 221

Design Method

Load Damage Exponent (m)

Empirical 4

Mechanistic – Control Fatigue 5 Mechanistic – Control Rutting 7