Project TX 0-5566

Strategies to Improve and Preserve Flexible Pavement

at IntersectionsUTEP

- Soheil Nazarian- Imad Abdallah

Project Duration September 08 – August 10

1

ProblemRural intersections are failing early Damage to small vehicles Motorists lose control of their vehicles

2

Causes for these failures

High traffic volumes Heavy truck traffic Heat generated from vehicles waiting in

queue Repeated vehicle turning movements

and hard stops

3

Ranked Rural Issues Raised by TxDOT District Staff

4

REF: Jolanda Prozzi, Robert Harrison, Jorge A. Prozzi, (2005), “Defining and Measuring Rural Truck Traffic Needs in Texas,”Center for Transportation Research, The University of Texas at Austin, Research Report 0-4169-2

Distresses (Example 1)

5

originalprofile

weak asphalt layer

shear plane

Distresses (Example 2)

6

originalprofile

weak subgrade or underlying layer

asphalt layer

subgradedeformation

Intersections are designed as a part of the roadway but are not subjected to the same conditions

7

Bottom Line

1. Information Search

2. Understanding and Documenting

Extent of Problems and

Solutions in Texas

3. Selection of Candidate Sites

for In-Depth Evaluation

4. Thorough Forensic Study of

Candidate Sites

5. Preliminary Guideline Based on Results from

Tasks 2 through 4

6. Develop Final Design and

Construction Guideline

• A comprehensive Literature Review

• Surveying Districts• Reviewing Forensic Reports• Interviewing District Personnel and site visits• Interviewing CST Personnel

• An in depth statistical and trend analysis of results from Task 2 to categorize typical problems

• Structural and Functional evaluation of sites • Coring and Sampling • Laboratory tests of Pavement Materials • Recommending solutions • Conducting thorough structural design of the existing and recommended Solutions• Life Cycle Cost Analysis of Solutions

• Develop a Comprehensive Decision tree- to guide TXDOT personnel through the

process of field and Laboratory evaluation intersections

- to select the most appropriate rehabilitation solutions

• Incorporate the outcome of Task 5, the remaining outcome of field work and feedback from PMC in a final guideline

• A document of practices for mitigating rutting at intersections worldwide• A matrix of solutions, when they are effective, their advantages and disadvantages, their economical feasibility

• A document of typical intersections with problem• A catalog of sources of problems• A catalog of effective and ineffective solutions • A comparison of TxDOT solutions with those from other states and countries

• At least twelve sites that cover the inference space of the problems, pavement types, environmental conditions, subgrade types etc. for in depth field and laboratory evaluation

• A catalog of solutions based on the type of the problem, and the field and laboratory testing results

• A flow chart that will lead TXDOT personnel through steps necessary for selecting best rehabilitation solutions for a given intersection

• A document that can be used as a guideline by TxDOTpersonnel• An electronic version of the document with hyperlinks that provide additional information to TxDOT personnel

Task Activity Highlights Work Product

7. Develop an Expert System

• Incorporate the outcome of Task 5 and 6 in an expert system shell to readily guide TxDOTpersonnel in determining the best solution

• A software that will ask a series of simple if-then questions from users to guide them through the process of selecting the best solution, determining the most appropriate mix or mineral, and suggestions for reconstruction of the sections

8. Recommend changes to

TxDOT Policies

• Based on the outcome of all tasks, recommend changes to the TxDOT 2004 Specifications

9. Submit Reports

• a technical memorandum at the end of each task• A final report documenting all work performed, method used, and results achieved.• A Project Summary Report (PSR)

8

Revision Date:

Estimated % of Total

Project Budget

Note: A Tech Memo will be submitted to the PD & RTI at the end of each non-deliverable task.

FY 2009 FY 2010

Task 9 Submit Reports 4%

Task 6

Task 7

Task 8

Develop Final Design and Construction Guideline

Undestanding and Documenting Extent of P roblems and Solutions in Texas

7%

Selection of Candidiate Sites for In-depth Evaluation

Original Schedule

Work CompletedRevised Schedule

Task 1

Task 2

Task 3

Research Activity

Task 5

Task 4

11%

Information Search 5%

Recommend Changes to TxDOT P olicies

7%

Thorough Forensic Study of Candidate Sites

28%

P reliminary Guideline Based on Results from Task 2 through 4

4%

14%

Develop an Expert System 20%

Schedule

9

10

Outline

Problem, Schedule, Final Product Background (Review of Literature) Goal (Problem Statement) Objective Methodology Tasks

Asphalt Pavement AllianceMaryland Asphalt Association National Asphalt Pavement AssociationNational Center for Asphalt Technology Colorado Department of Transportation CanadaSouth AfricaNew ZealandIllinois DOTNevada DOTOregon DOTKansas DOT

Review of Literature (Task 1)

Common Types of Distress

Remediation

Action Plan

Most Common Distress

RuttingStructural Rutting Instability Rutting Surface/Wear Rutting

Other Common Distresses

Shoving Fatigue Cracking

Bleeding Raveling

Remediation Strategies

•Mill and Overlay with Asphalt Concrete •Rut Filling Using Spray Patching, Micro-

Surfacing •Grinding and Precision Milling •Whitetopping (Conventional and Concrete

Inlay) •Ultra-Thin Whitetopping •Thin Composite Whitetopping (TCW)•Roller Compacted Concrete (RCC)•Hot in Place Recycling (HIR)•Cold in Place Recycling (CIR)

Action Plan1. Evaluate pavement performance problems

and determine the cause of major distress.2. Ensure the pavement is structurally

adequate.3. Select and implement a cost-effective,

technically sound pavement mitigation approach with appropriate materials selection and mix designs.

4. Practice proper construction techniques with quality assurance.

Example 1 After

SUPERPAVE Mix

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Other Examples

Surface Coursedesigned toSuperpaveSpecifications

Heavy DutyBinder Course

Larger StoneBinder Course

Permeable Frictionless Coarse (PFC)

Coarse Matrix High Binder (CMHB) 18

Stone MasticAsphalt

Thin Composite Whitetopping

Stone-Matrix Asphalt (SMA)

Other Examples

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Goal To provide solutions that can be

readily and economically carried out considering: location of the project construction practices type of potential or actual damage

at intersections.

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Methodology(Expert System)

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Inference Engine(Draw Conclusions)

User Interface

Facts

Expertise

Explanation (Advice and Reasoning)

Knowledge Base (Facts and Rules)

1. Information Search

2. Understanding and Documenting

Extent of Problems and

Solutions in Texas

3. Selection of Candidate Sites

for In-Depth Evaluation

4. Thorough Forensic Study of

Candidate Sites

5. Preliminary Guideline Based on Results from

Tasks 2 through 4

6. Develop Final Design and

Construction Guideline

• A comprehensive Literature Review

• Surveying Districts• Reviewing Forensic Reports• Interviewing District Personnel and site visits• Interviewing CST Personnel

• An in depth statistical and trend analysis of results from Task 2 to categorize typical problems

• Structural and Functional evaluation of sites • Coring and Sampling • Laboratory tests of Pavement Materials • Recommending solutions • Conducting thorough structural design of the existing and recommended Solutions• Life Cycle Cost Analysis of Solutions

• Develop a Comprehensive Decision tree- to guide TXDOT personnel through the

process of field and Laboratory evaluation intersections

- to select the most appropriate rehabilitation solutions

• Incorporate the outcome of Task 5, the remaining outcome of field work and feedback from PMC in a final guideline

• A document of practices for mitigating rutting at intersections worldwide• A matrix of solutions, when they are effective, their advantages and disadvantages, their economical feasibility

• A document of typical intersections with problem• A catalog of sources of problems• A catalog of effective and ineffective solutions • A comparison of TxDOT solutions with those from other states and countries

• At least twelve sites that cover the inference space of the problems, pavement types, environmental conditions, subgrade types etc. for in depth field and laboratory evaluation

• A catalog of solutions based on the type of the problem, and the field and laboratory testing results

• A flow chart that will lead TXDOT personnel through steps necessary for selecting best rehabilita tion solutions for a given intersection

• A document that can be used as a guideline by TxDOTpersonnel• An electronic version of the document with hyperlinks that provide additional information to TxDOT personnel

Task Activity Highlights Work Product

7. Develop an Expert System

• Incorporate the outcome of Task 5 and 6 in an expert system shell to readily guide TxDOTpersonnel in determining the best solution

• A software that will ask a series of simple if-then questions from users to guide them through the process of selecting the best solution, determining the most appropriate mix or mineral, and suggestions for reconstruction of the sections

8. Recommend changes to

TxDOT Policies

• Based on the outcome of all tasks, recommend changes to the TxDOT 2004 Specifications

9. Submit Reports

• a technical memorandum at the end of each task• A final report documenting all work performed, method used, and results achieved.• A Project Summary Report (PSR)

22

1. Information Search

2. Understanding and Documenting

Extent of Problems and

Solutions in Texas

3. Selection of Candidate Sites

for In-Depth Evaluation

4. Thorough Forensic Study of

Candidate Sites

5. Preliminary Guideline Based on Results from

Tasks 2 through 4

6. Develop Final Design and

Construction Guideline

• A comprehensive Literature Review

• Surveying Districts• Reviewing Forensic Reports• Interviewing District Personnel and site visits• Interviewing CST Personnel

• An in depth statistical and trend analysis of results from Task 2 to categorize typical problems

• Structural and Functional evaluation of sites • Coring and Sampling • Laboratory tests of Pavement Materials • Recommending solutions • Conducting thorough structural design of the existing and recommended Solutions• Life Cycle Cost Analysis of Solutions

• Develop a Comprehensive Decision tree- to guide TXDOT personnel through the

process of field and Laboratory evaluation intersections

- to select the most appropriate rehabilitation solutions

• Incorporate the outcome of Task 5, the remaining outcome of field work and feedback from PMC in a final guideline

• A document of practices for mitigating rutting at intersections worldwide• A matrix of solutions, when they are effective, their advantages and disadvantages, their economical feasibility

• A document of typical intersections with problem• A catalog of sources of problems• A catalog of effective and ineffective solutions • A comparison of TxDOT solutions with those from other states and countries

• At least twelve sites that cover the inference space of the problems, pavement types, environmental conditions, subgrade types etc. for in depth field and laboratory evaluation

• A catalog of solutions based on the type of the problem, and the field and laboratory testing results

• A flow chart that will lead TXDOT personnel through steps necessary for selecting best rehabilita tion solutions for a given intersection

• A document that can be used as a guideline by TxDOTpersonnel• An electronic version of the document with hyperlinks that provide additional information to TxDOT personnel

Task Activity Highlights Work Product

7. Develop an Expert System

• Incorporate the outcome of Task 5 and 6 in an expert system shell to readily guide TxDOTpersonnel in determining the best solution

• A software that will ask a series of simple if-then questions from users to guide them through the process of selecting the best solution, determining the most appropriate mix or mineral, and suggestions for reconstruction of the sections

8. Recommend changes to

TxDOT Policies

• Based on the outcome of all tasks, recommend changes to the TxDOT 2004 Specifications

9. Submit Reports

• a technical memorandum at the end of each task• A final report documenting all work performed, method used, and results achieved.• A Project Summary Report (PSR)

Tasks

Task 2. Understanding and Documenting Extent of Problems and Solutions in Texas

Surveying TxDOT Districts Reviewing Forensic Reports Interviewing district personnel

and site visits Interviewing CST personnel

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Beaumont

Odessa

Lubbock

Amarillo

Childress

Abilene

San Angelo

Laredo

San Antonio

Austin

Pharr

Corpus Christi

Wichita Falls

Brownwood

Fort Worth

Waco

Dallas

Paris

Atlanta

Tyler

Bryan

Lufkin

El Paso

Houston

Yoakum

Texas’ Districts MapShowing Districts with Answer

Districts with high distresses at intersections

Districts with minor distresses at intersections

District: Date: Contact Person: Austin April 13th, 2009 Mike Arillano Bryan April 14th, 2009 Catherine Hejl Houston April 15th, 2009 Mike Alford Atlanta April 20th, 2009 Miles Garrison Paris April 22nd, 2009 Mykol Woodruff Lubbock April 27th, 2009 Tracy Crumby Abilene April 28th, 2009 Brian Crawford Laredo April 29th, 2009 Jo Ann Garcia

District Interviews

Task 3. Selection of Candidate Sites

A least twelve sites that cover following criteria: Type of distress observed (instability rutting vs. structural

rutting) Type of subgrade (clayey vs. sandy) Pavement structure (two-course surface treatment vs. with HMA) Traffic volume (rural vs. urban) Environmental condition (east Texas vs. west Texas)

Preference will be given to sites that are scheduled for maintenance, rehabilitation or reconstruction.

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Beaumont

Odessa

Lubbock

Amarillo

Childress

Abilene

San Angelo

Laredo

San Antonio

Austin

Pharr

Corpus Christi

Wichita Falls

Brownwood

Fort Worth

Waco

Dallas

Paris

Atlanta

Tyler

Bryan

Lufkin

El Paso

Houston

Yoakum

Texas’ Districts MapShowing Districts with Answer

Districts with high distresses at intersections

Districts with minor distresses at intersections

Site Visited

Atlanta fm 497 – fm 155 fm 149 – fm 315 US 259

Laredo fm 1472 US 83

Forensic investigation Structural strength Aggregate structure Correct Asphalt Binder grade Good construction practices

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Task 4. Forensic Study

Visited five sites and performed a thorough Investigations

Site Survey, FWD, GPR, DCP, Coring, Lab Testing

Sites Visited and Investigated

Atlanta fm 497 – fm 155 fm 149 – fm 315 US 259

Laredo fm 1472 US 83

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Task 5. Preliminary Guidelines Based on Results

Develop a Comprehensive Decision Tree

To guide TxDOT personnel through process of field and laboratory evaluation intersections

To select most appropriate rehabilitation solutions

29

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Low

Moderate

High

Low

Moderate

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Low

Moderate

High

Moisture Intrusion

Structural Rutting

MaintenanceRehabilitation

As

ph

alt

La

yer

Su

b-

gra

de

Structural Rutting

HMA Surfacing PCC

Flexible Pavement Treatment Selection Matrix

Deep Repairs

Ba

se

Shoving

Surface Rutting

Instability Rutting

Fatigue Cracking

Distress

Treatment

You might find 2 locations in the whole state for this one.

This one is brand new, we don't have a spec for it yet. There is a company that wants to show us a test strip in the near future, it'll be very good to

Remediation Alternatives

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Task 6. Develop Final Design and Construction Guidelines

A document that can be used as a guideline by TxDOT personnel

An electronic version of document with hyperlinks that provide additional information to TxDOT personnel

31

Task 7. Develop an Expert System

Incorporate an expert system shell.

With simple If-Then questions.

Guide through process of selecting best solution.

32

Use of the Expert System

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Intersection Condition

Traffic Condition

Remediation Strategies

Life Cycle Cost Analysis

Best Cost Effective

Alternative

Other Consideration

Expert SystemVariables Window

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Expert SystemLogic Block Window

Expert SystemLogic Block and Rule View

Window

Expert SystemCorvid Browser

Expert SystemCorvid Browser

Expert SystemCorvid Browser

Task 8. Recommend Changes to TxDOT Policies

Based on the outcome of all tasks, recommend changes to TxDOT 2004 Specifications, if necessary.

40

Demonstrate Prototype and Show Preliminary Guideline

41

Prototype

Guideline

Thank you

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