20-year performance of bridge maintenance systems.ppt

7/29/2019 20-Year Performance of Bridge Maintenance Systems.ppt

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Greenman-Pedersen, Inc.Greenman-Pedersen, Inc.Coatings Group

Review of Maintenance PrioritizationReview of Maintenance Prioritization

Schemes from Three TransportationSchemes from Three Transportation

AuthoritiesAuthoritiesChristopher L. Farschon, P.E., PCS

Greenman Pedersen, Inc. Coatings Group

October 7, 2009NACE Eastern Area Conference


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Why Prioritize Bridge Painting?Why Prioritize Bridge Painting?


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Why Prioritize? PLANNINGWhy Prioritize? PLANNING

Money

Money

Money

Define an acceptable state of

existence How coating conditions affect

a bridge throughout itslifetime

Identify what funding is

needed to meet that need Justify painting budgets


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Where to Start Planning?Where to Start Planning?

Bridge typeSize

Proximity

LocationTraffic Conditions

Deck

Substructure

Future Rehabilitation

Coating and Corrosion Condition


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Goals of a Prioritization ProgramGoals of a Prioritization Program

Vary by Agency Lowest overall cost (today, life cycle, year 20?)

Define needed funding

Meet constraints

Integrate with other work Improvements TrafficAesthetics

Be adaptable

MonitorMonitor

LearnLearn

DesignDesign


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Three AuthoritiesThree Authorities

A - Toll Authority 1 Major structures only (9 facilities 26M square feet) Metropolitan area

100% self funded

B - Toll Authority 2 Major highway (hundreds of bridges focus on 16)

Urban / Metropolitan / Rural

Combination funding

C - State DOT District Over 1,000 bridges (focus on overpasses)

Metropolitan and Suburban area

Federal / state funding


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Historical - Toll Authority AHistorical - Toll Authority A

Years of as-required maintenance painting Increasing environmental concerns Increasing steel repair frequencyPainting Program was planned around 1990,

implemented 1993-1995Unofficial Program Goals

Reduce lead paint liabilities Reduce as-needed steel repairs Improve bridge appearance Define needed funding


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Program Description Toll Authority AProgram Description Toll Authority A

Based on a facility wide survey conducted in1993

Categorizes bridge areas based on paintconditions and local environments

Appropriate painting is performed in each areato minimize costsAccess costs very high = minimal contracts

One contract multiple Items multiple methods


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Program Goals Toll Authority AProgram Goals Toll Authority A

Maintain an acceptable paint condition whilemaintaining budget goals

Coordinate with Capital improvement projectsand biennial inspections

Address highest priorities within 12 years


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Define the Problem Toll Authority ADefine the Problem Toll Authority A

0%

10%

20%

30%

40%

50%

1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

Year

Coating

Deterioration

-percent


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Track Progress Toll Authority ATrack Progress Toll Authority A

0%

5%

10%

15%

20%

25%

30%

35%

40%

45%

50%

1 2 3 4 5 6 7 8 9 10

Biennial Cycle

CoatingDeterioration-percent

Line representing theoriginal program goal(10% by 2006)

Predicted trend withoutprogram (44% by 2006)

20%Deterioration Line


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$-

$2,000

$4,000

$6,000

$8,000

$10,000

$12,000

$14,000

$16,000

$18,000

$20,000

$22,000

$24,000

$26,000

$28,000

1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

$inthousands

Yearly Costs Toll Authority AYearly Costs Toll Authority A

Average = $14.9M per Year

Average = $21.4M per Year


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Types of Painting Toll Authority ATypes of Painting Toll Authority A

TBTA Painting

Cumulative SF - New Coating, Overcoat, and Total

0

2,000

4,000

6,000

8,000

10,000

12,000

14,000

16,000

18,000

20,000

1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006Year

SF

in

thousands

New - Actual / Forecast SF

New - Original Goal SF

Ovrct - Actual / Forecast SF

Ovrct - Original Goal SF

Total - New + Ovrct Act/Frcst SF

Total - New + Ovrct Orig Goals


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Unit Cost Trends Toll Authority AUnit Cost Trends Toll Authority A

Low early High middle Lower recentlyWorst corrosion addressed first Large projects (economies of scale were good)

Concurrent with some maintenance

Aesthetic areas Hold until re-paint

Combination / Rehabilitation Projects Difficult projects? Some shared costs Some additional costsMaximize shop painting


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Cost/Specification Factors- Authority ACost/Specification Factors- Authority A

Size of the projectMobilization and staging areas

Access to work- placement of equipment Lane closures, water - barge etc.

Environmental controls

Inspection requirements - warranty

Configuration or type of structure

Labor, equipment, and material costs

Bidding climate (other work, available bidders)


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Program Summary Toll Authority AProgram Summary Toll Authority A

Budgets were justifiedFunding allocated

Projects designed

Conditions were monitored with databasepopulation Influenced priorities on a biennial basis

Program is in place that relates painting needs

to available time to needed funding Needs not always driven by conditions


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Toll Authority - BToll Authority - B

Program recently enacted to prioritize paintingof major structures

Not an authority-wide plan (16 of severalhundred structures, but the most significant 16)

Works around/with major capital programs

Coordination with other maintenance work

Constructability a key factor


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Project Background Toll Authority BProject Background Toll Authority B

Program has 2 objectives: Part 1 - The investigation and assessment of the

existing coating system on 16 major bridges,development of a prioritized list of bridges requiringrepainting, and recommendations related to bridgepainting as part of a Ten Year Capital Program

Part 2 - The design and development of documentsfor two (2) Major Bridge Repainting contracts


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Budget / Financial Toll Authority BBudget / Financial Toll Authority B

Predetermined budget and timeframe anticipated value of $250M

10 year effort

Prioritize the needs based on constraints,

coordination, conditionsGenerate project specific engineers estimates

for near-term painting costs


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Bridge Surveys Toll Authority BBridge Surveys Toll Authority B

Technical Paint Condition Data Adhesion,thickness, lab tests, visual survey data for paint(peeling and corrosion)

Development of square footage quantities

Other considerations - Deck and Jointcondition, planned rehabilitations and priorpainting work


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Painting Options Toll Authority BPainting Options Toll Authority B

Total Coating Removal and ReplacementZone Coating Repair (Beam Ends, Bearings,

Weathering Steel)

Maintenance Spot Painting and Full

Overcoating


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Prioritization Toll Authority BPrioritization Toll Authority B

Rough Budget Estimates Key to project designs andevening out the workload across the program duration

Coordination with other work Use of the deckcondition study data, coordination with completeddeck/rehabilitation projects and the capital improvement

projects Prioritization factors

Condition of the existing coatings and extent of corrosion Condition of the existing deck Availability of construction staging areas Complexity of maintenance and protection of traffic Complexity of containment Environmental impacts Outside agency coordination


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Prioritization Matrix Toll Authority BPrioritization Matrix Toll Authority B

CORROSION MPT/Staging Envir/Contain Agency Deck FINAL

Bridge ID RATING Complexity Complexity Coordination Condition SCORE

1 GSP 28.0N 10 2 5 4 3 24

2 GSP 28.0S 6 2 5 4 3 20

3 GSP 31.0 8 5 3 4 3 23

4 GSP 49.0 4 3 5 4 3 19

5 GSP 51.9 4 3 3 3 3 16

6 GSP 127.2T 2 3 5 4 5 19

7 GSP 127.2S

8 GSP 158.2 4 1 2 3 3 13

9 NJT P0.00 4 1 1 1 5 12

10 NJT 84.24N

11 NJT 84.24S 4 4 5 4 3 20

12 NJT E107.88 6 5 5 4 5 25

13 NJT W107.87

14 NJT E109.83 4 5 3 4 3 19

15 NJT N2.01 4 1 0 3 3 1116 NJT W115.36

maximum ratings 10 5 5 5 10 35

= Sister weathering steel bridges


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Project Sequencing Toll Authority BProject Sequencing Toll Authority B

Projects of constructible size and duration wereappropriately prioritized / sequenced

Highest 2 priorities under design /construction

Update survey needed Project was a snapshot of conditions combined with

other available data to make the most appropriateprioritization today

Future survey will justify extending durations before

painting or accelerating certain projects


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Program Summary Toll Authority BProgram Summary Toll Authority B

Select group of bridgesProjects designed and estimated to fit available

budget

Technical data / conditions were not always the

priority driverProgram is based on a snapshot survey of

facilities

Follow-up survey will be needed


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AuthorityAuthorityCC

State Department of Transportation District1998 projectOver 1,000 bridges

Majority are highway overpasses and smaller

structuresSemi Automated database systemUsed condition data, constraints, project-

specific factors

Prioritization was based on Return onInvestment


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Technical Basis Authority CTechnical Basis Authority C

Historical data for coatings in appropriateenvironments defines degradation rates

Survey characterizes exposure conditions andtechnical paint data

Lowest cost painting option is selected using an

ROI calculation

Current coatings and corrosion condition ratings Exposure environment ratings Predicted life to next painting event

=

InvestmentofCost

InvestmentofCost-InvestmentfromGainROI


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Cost vs. Corrosion TheoreticalCost vs. Corrosion Theoretical

Cost vs. %Corrosion

0.1% 1.0% 10.0% 100.0%

% Corrosion

Cost

Spot Repair

Maintenance Repaint

Remove and Replace


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Cost vs. Corrosion ActualCost vs. Corrosion Actual

Cost vs. % Corrosion

0.1% 1.0% 10.0% 100.0%

% Corrosion

Cost

Spot Repair

Maintenance Repaint

Remove and Replace


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Program Summary Authority CProgram Summary Authority C

Database program generates a list of structuressorted by ROI

DOT organizes projects to address priorities(human factor is required)

Condition data easily attainedDegradation models and cost factors were fixed

Constraints were variable

Does not estimate budgets


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Common ThreadsCommon Threads

All prioritization programs were customAuthority constraints were custom

All used existing data sources withenhancements

All need maintenance to remain accurate

All provide a starting point for defendableanalysis


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Feedback is NeededFeedback is Needed

Programs are tools use for designatedpurpose and within limitations

MonitorMonitor

LearnLearn

DesignDesign


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Using FeedbackUsing Feedback

Painting ProgramSquare Feet per Year (actual + forecast)

-

200.000

400.000

600.000

800.000

1,000.000

1,200.000

1,400.000

1,600.000

1,800.000

2,000.000

2,200.000

2,400.000

1992

1994

1996

1998

2000

2002

2004

2006

2008

2010

2012

2014

2016

2018

2020

2022

2024

Years

SquareFeetofPaintingperYear(t

housands)

New Painting

Maintenance Painting

Estimated MaintenanceA: 11.3% (7-10 years)B: 41.1% (11-17 years)C: 47.5% (18-30 years)


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Prioritization Program ComparisonsPrioritization Program Comparisons

Authority A B C

Budget Justified thelevel of effort tosecure funding

Budget was pre-determined

Program fitpriorities tovariable funds

TechnicalData

Initial surveywith biennialupdates

Initial survey,one plannedupdate

Initial surveywith Authority /consultantupdates

Cost Data Living history of

project dataused in budgetupdates

Engineer

estimates asprojectschedulesadvance

N/A - program

ranks need,Authority buildsand estimatesprojects


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Prioritization Program CostPrioritization Program Cost

Planning/Prioritization Program Cost

0.4%

0.2% 0.2%

0.1%

1.0%

10.0%

100.0%

Toll Authority A Toll Authority B Authority C

Authority

%o

fConstructio

n


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Inspection vs. ExpectationInspection vs. Expectation


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Planning a ProjectPlanning a Project


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ConclusionsConclusions

Maintenance painting is neededAll painting can be scheduled with the most

benefit (least cost) by evaluating structures andimplementing a maintenance painting program

Numerous constraints affect a programOther work Cost trends Priorities / Goals

Program must be adaptableUse existing data or existing inspection

activities

20-year performance of bridge maintenance systems.ppt

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