S40_General and Comprehensive Framework for Design of Bridges for Service Life_LTC2013

7/29/2019 S40_General and Comprehensive Framework for Design of Bridges for Service Life_LTC2013

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Bridges for ServiceLife Beyond 100 Years:

Innovative Systems,Subsystems andComponents

SHRP 2 | Project R19A


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SHRP 2- Project (R19A)

Bridges for Service Life beyond 100 Years: Innovative Systems,Subsystems, and Components

Principal Investigator: Dr. Atorod Azizinamini, P.E.Professor and Chairperson

Florida International University

Miami, Florida

Program Officer: Dr. Monica Starnes (2007-2010)

Mark Bush, P.E., PTOE (Jan 2011- Dec 2011)

Jerry DiMaggio (Jan 2012 to present)


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Main Product

Design Guide for Bridges for Service Life,hereafter referred to as the

Guide.

Provides systematic and general approach for design

for service life is developed.

Camera ready copy of the Guide was submitted Feb 2013

Should be available by end of March 2013


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Research Team MembersFlorida International University

University of NebraskaHDR

Attkins

Celik Ozyildirim

KTAVector Corrosion

University of Delaware

Georgia Inst. Of Tech

AASHTO T-9Ralph Oesterle, CTL J ointless BridgesLloryd SterlingWater Proofing Bridge DeckMartin BurkeConsultantJ ointless BridgesCharles Roeder- University of Washington- Bearings

Six (6) Ph.D., students

Three (3) M.S. students

Three (2) Research Associates


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Strategy,

Technology and

Ranking Tables

Concrete Durability Bridge Decks

Substructures Bearings

Fatigue and

Fracture

Steel Bridges

Expansion Joints,

Joints and Jointless

Structural Steel

Protection

Concrete Bridges

Major Categories

Concrete Durability

Concrete Durability Bridge Decks

Bridge Decks

Substructures

Substructures Bearings

Bearings

Fatigue and

Fracture

Fatigue and

Fracture

Steel Bridges

Steel Bridges

Expansion Joints,


Expansion Joints,


Structural Steel

Protection

Structural Steel

Protection

Concrete Bridges

Concrete Bridges

Major Categories

Suggested Topics

Cate

gory

1

Cate

gory

2

Cate

gory

3

Suggested Topics

Cate

gory

1

Cate

gory

2

Cate

gory

3

Input of AASHTO

Sub-committeesSurvey of DOTs

Input from IndustryInput of Individuals

Outside the Team

Analysis of NBI

Data

Problematic Issues

Input of AASHTO

Sub-committees

Input of AASHTO

Sub-committeesSurvey of DOTs

Survey of DOTs

Input from Industry

Input from IndustryInput of Individuals

Outside the Team

Input of Individuals

Outside the Team

Analysis of NBI

Data

Analysis of NBI

Data

Problematic Issues

Chapter 11

Chapter 12

Chapter 13

Stand Alone Guide

Chapter 14

Chapter 15

Chapter 6

Chapter 7

Chapter 8

Chapter 9

Chapter 10

Chapter 1

Chapter 2

Chapter 3

Chapter 4

Chapter 5

Chapter 11

Chapter 11

Chapter 12

Chapter 12

Chapter 13

Chapter 13

Stand Alone Guide

Chapter 14

Chapter 14

Chapter 15

Chapter 15

Chapter 6

Chapter 6

Chapter 7

Chapter 7

Chapter 8

Chapter 8

Chapter 9

Chapter 9

Chapter 10

Chapter 10

Chapter 1

Chapter 1

Chapter 2

Chapter 2

Chapter 3

Chapter 3

Chapter 4

Chapter 4

Chapter 5

Chapter 5

Start

AASHTO

Specifications

Design Guide for

Bridges for Service Life


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Project main product

Design Guide for Bridges for Service

Life


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Guide is primarily for bridges withspans of less than 300 ft.

However, Guide provides a frame workthat could be used to address service life

design of any span bridges


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Review of bridges that have lastedmore than 100 years indicates:

1- Maintainable and well maintained over their 100-year lives due to extreme importance or high capital

replacement cost,

2- Originally over-designed

.


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Traditional Approaches

- Service life of bridges in various codes and an- Direct or indirect and isolated form,specifying the use of certain details or

properties such as cover thickness,maximum crack width, concretecompressive strength, etc.


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How to accomplish design for service

life

- At the design stage- Systematic and comprehensive- Plan should eliminate the surprise

factor for the owner


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OBJECTIVES OF THE GUIDE

The main objective of the Guide is toprovide information about, and define

procedures for systematically designing forservice life and durability for both new andexisting bridges.


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GUIDE Approach

- Provide body of knowledge to makedecision

- Establish array of solutions- Allow incorporating local experiences,practice and preferences

- Let designer and owner select theoptimum solution


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Chapters

Design Guide forBridges for Service Life


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General categories of informationincluded in each Chapter

1- Introduction2- Factors Affecting Service Life

3- Options for Enhancing Service Life4- Strategy for developing solution for

specific problem5- Management Plan

6- Examples


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Guide for Bridges for Life

Sources of Information Being Used

to Develop the Guide

Available information

in AASHTO specifications

Synthesis of state

of the knowledge

Results of R19A

research (about 40%)

Industry inputs

AASHTO and

DOT inputsInput from

other experts

Others, such as

fib C5

Commission


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Chapter 1- Design for Service Life: general

Framework

Chapter 1-This chapter provides an overview of theapproach used in the Guide for design for service life.Chapter 1, also describes terminologies used throughout the

guide and various relationships that exist between service

life of bridge element, component, subsystem and system

and bridge design life as used in AASHTO Specifications. It

provides an introduction to the different philosophies used

to predict service life. It is essential to read this chapter

before proceeding with use of the Guide.


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Chapter 2- Bridge System Selection

Chapter 2-This Chapter provides a description of variousbridge systems and factors that affect their service life.Chapter includes the description of a general strategy and

rational procedure for selecting the optimum bridge system,

subsystems, components and elements, considering specific

project limitations and requirements, such as climate,

traffic, usage and importance. The discussion includes both

existing and new bridges, with more detail provided in other

chapters


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Chapter 3- Materials

Chapter 3-This chapter provides general properties anddurability characteristics of the two most commonly usedmaterials in bridge systems, namely steel and concrete. For

each material, a general description of variables affecting

the service life is provided, followed by strategies used to

mitigate them. This chapter forms the basis for materials

used in bridge elements, components and subsystems

specifically addressed in other chapters of the Guide.


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Chapter 4- Bridge Deck

Chapter 4-This chapter provides descriptions of variousbridge deck types and essential information related to theirservice life, such as modes of deterioration and strategies to

mitigate them. The chapter concentrates on cast-in-place

and precast concrete bridge decks.


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Chapter 4- Bridge Deck

New Concepts- Self stressingWaterproofing Manual


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Chapter 5- Corrosion Protection of Concrete

Bridges

Chapter 5-This chapter provides basic mechanismscausing corrosion of reinforcement embedded in concreteand strategies for preventing corrosion of reinforcement inconcrete bridges

Chloride Contaminated

Concrete

Fe Fe2+ + 2e -

Fe2+ + 2Cl- FeCl2

2Fe(OH)2 +1/2O2 Fe2O3 + 2H2O

2e -

FeCl2 + 2OH- Fe(OH)2 + 2Cl

-

2OH-

1/2O2 + H2O + 2e- 2OH-


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Chapter 6- Corrosion Protection of Steel

Bridges

Chapter 6-This chapter provides descriptions of variouscoating systems using paint, galvanizing and metalizing,and descriptions of corrosion resistant steels along withfactors affecting their service life. Various options forpreventing corrosion of steel bridges and general

approaches that could lead to bridge coatings withenhanced service life are presented.


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Chapter 7- Fatigue and Fracture

Chapter 7-This chapter provides the basics of fatigue

and fracture and factors that cause fatigue and fracture insteel bridges. Various available options to repair observedcracking in steel bridges are also presented


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Chapter 8- Jointless Bridges

Chapter 8- This chapter provides descriptions,advantages and disadvantages of various jointless bridgesystems, and provides complete steps for design ofjointless integral abutment bridges. This chapter providesdesign procedures to extend the application of jointless

integral bridges to curved girder bridges. This chapter alsointroduces new details and integral abutment systems,where expansion joints are completely eliminated, even atthe end of approach slabs.


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Chapter 8- Jointless Bridges

Provides A to Z design of jointless bridgesProvides new details- Pin Head

Provisions to apply to curved girder bridges

Introduces seamless bridge system


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0

1

2

3

4

5

6

7

8

9

10

0 50 100 150 200

Disp.

Ca

pacity(in)

Axial Load (kips)

HP12x84-Medium Clay

Pinned-Strong

Pinned-Weak

Fixed-StrongFixed-Weak

Transition Zone


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Bridge Approach

Abutment

Transition Zone

JPCP

Secondar Slab

Small Piles


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Chapter 9- Bridge Expansion Devices

Chapter 9-The Guide encourages, eliminating the use of

expansion joints, however, expansion joints may be needed

when the total bridge length exceeds practical limits of

jointless bridges. This chapter provides description of

various expansion joints used in practice, observed modes of

failure for each and potential strategies to mitigate them.


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Chapter 10- Bridge Bearings

Chapter10-This chapter provides descriptions of

various bearing types, and lists factors that affect theirservice life with strategies to mitigate them. Newmaterials capable of providing long service life for slidingsurfaces are introduced as well as deterioration models for

sliding surfaces. The Guide emphasizes use ofelastomeric bearing pads for long service life.


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0

10

20

30

40

50

60

70

80

90

100

0.00 5.00 10.00 15.00 20.00 25.00

Travel Distance (Miles)

Thickness

(Pe

rcentofinitialthickness)

PTFE Sample #1

PTFE Sample #2

MSM Sample #1

MSM Sample #2

Fluorogold Sample #1



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0

10

20

30

40

50

60

70

80

90

100

0.00 5.00 10.00 15.00 20.00 25.00

Travel Distance (Miles)

Thickness

(Percentofinitialthickness)

PTFE Sample #1

PTFE Sample #2

MSM Sample #1

MSM Sample #2



= (,,) Eq. 1

() = 2 1 1.33 ()

365

63360 Eq. 1

() = () 365/5280 Eq. 3

() = () 1

5280 Eq. 4

(TD) Demand= () + () + ()


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Chapter 11- Life Cycle Cost Analysis

Chapter11-This chapter provides essential information

for incorporating Life Cycle Cost Analysis (LCCA) in bridgesystem, subsystem, component and element selection.This chapter concentrates on general features andelements of incorporating LCCA in the design process,

emphasizing consideration of project costs throughout itsservice life.

ProbabilityDistribution

of NPV

Uncertaintyin

ConstructionCost

Uncertaintyin Timing

Uncertaintyin RepairCosts


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Steps in Design for Service Life

Step 1-Identify the factors that influence the service life ofbridge elements, components and subsystems, such as traffic,environmental or internal defects and risk to damage.

Step 2-Identify the deterioration and damage mechanism,such as freeze/thaw cycles

Step 3-Identify modes of failures and consequences. For

instance, the corrosion of reinforcement, causing corrosioninduced cracking and loss of strength.

i i f i if


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Steps in Design for Service Life

Step 4-Identify suitable approaches for mitigating the failure modes or

assessing risk of damage, through life cycle cost analysis. For instance, useof higher performing materials for sliding surfaces in bearings or use ofmaterial prone to deterioration at lower initial cost.

Step 5-Estimate service life of the bridge element, component or

subsystem using Finite or Target Service Life Design approaches.

Step 6-Compare the service life of the bridge element, component orsubsystem to the service life of the bridge system and develop appropriatemaintenance, retrofit and/or replacement plan.

Step 7-Develop design, fabrication, construction, operation, maintenance,replacement and management plans for achieving the specified design lifefor the bridge system.

F t t St 5


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What is needed to Estimate the Service Life of

Bridge Elements, Components andSubsystems

Deterioration ModelsExamples

C C erfx

D t

x t o

c

( , )

1

2

Fatigue Design Approach in AASHTO LRFD

Footnote Step 5


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Flow Charts to Use Guide

Series of flow charts are provided, withineach chapter, that allows an engineer withminimal design experience to navigatethrough design for service life steps.

Next slide shows the main steps, withoutelaborating on the details


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Reduced Service Life of

Cast-in-Place Bridge Deck

Caused by DeficiencyCaused by

Obsolescence

Natural or Man-Made

HazardsLoad-Induced

Production/

Operation Defects


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Load-Induced

WearFatigue

System-

Dependent Loads

Differential

Shrinkage

System

Framing

Restraint

Traffic-Induced

Loads

ThermalOverload

Example Bridge Deck


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Example- Bridge Deck

Bridge Deck System Component

S l i P


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1.b: Identify Local Factors

Affecting Service Life

2: Identify Feasible Deck Alternatives Satisfying Design

Provisions of AASHTO LRFD, Operational, Site and

Bridge System Requirements

1.a: Identify Local Operational

and Site Requirements

3: For Each Alternative, Identify Factors Affecting

Service Life Following Fault Tree

Go To

A

Selection Process

Yes

No

6: Identify Maintenance Requirements

5.a: Identify Rehab

or Replacement

Requirements

Yes

7: Develop Life Cycle Costs

No5: Deck SL

System

TDSL?

8: Addl. Deck

Alternative?

9: Compare Alternatives and Select Deck System

B8.a: Go ToNext

Alternative


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2A.b: Modify Bridge

Deck Configuration

A

2A.a: Identify

Consequence and

Determine Appropriate

Strategies for

Avoidance or Mitigation

1A: Identify Individual Factor Affecting

Service Life Considering Each Branch

of Fault Tree

3A.a: Go to

Next

Factor

4A: Modified Bridge Deck Configuration for Deck

Alternative under Consideration

Go To

B

Yes

No

2A: Does

Factor Apply?

Yes

No3A: All Factors

Considered?


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Operational Category Operational Criteria to Be Specified

Traffic capacity requirements Urban arterial, 4 lanes, 40 mphTraffic volumes and required capacity 24000 ADT NB and SB

Truck volumes 10%

Special vehicle uses Overload possible

The local environment or man-made hazard category Maintain 2 existing lanes

Mixed use requirements Traffic, pedestrians, bicycle lane

Vehicle loads and special vehicle load requirements

HL 93 with typical legal and permit loadsNo special construction loadsOverload with 20 kip tire loads (HL93 truck configuration)Studded tires used in winter


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Bridge Deck Systems Advantage Disadvantage

Cast-In-Place Concrete Deck Systems

Readily available material.

Accommodates tolerances.

Low-cost.

Susceptible to cracking and corrosion.

Precast Concrete Deck Systems

Readily available material.

Typically prestressed, reducing

cracking.

Requires construction joints between

components.

Higher initial cost.

Metal Deck SystemsLightweight system.

Prefabricated system.

Requires protective coatings.

Difficult tolerance adjustments.

High cost.

Timber Deck Systems

Lightweight system.

Constructible with unskilled labor.

Low-cost.

Limited span range.

Susceptible to wear without overlays.

Susceptible to moisture degradation.

FRP Deck SystemsLightweight system.

Noncorrosive system.

High cost.Limited history.

Requires overlay for traction.


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Service Life

Issue

Corresponding Job

RequirementsSection Mitigating Strategy Advantage Disadvantage

Overload

HL93 with 20 kip

wheel load, applied

once a month

5.3.2.1.1.2 Increase deck thickness Minimizes crackingAdds weight to bridge structure,

increases cost

Minimize bar spacing for given

amount of steelImproves crack control More labor to install and higher cost

Fatigue 24000 ADT NB and SBand 10% truck volume

5.3.2.1.1.1 Design perLRFD Specifications Minimizes possibility ofreinforcement failure

May increase area of steel

Wear and

Abrasion

Studded tires on high

level of service bridge5.3.2.1.1.3

Implement concrete mix design

strategiesIdentified in Chapter 3 Identified in Chapter 3

Implement membranes and

overlays

Protects surface from direct contact

with tires

Requires periodic rehabilitation every

10 to 20 years

System

Framing

Restraint

Deck shrinkage

restraint from shear

studs

5.3.2.1.2.3 Develop accurate system modelIdentifies design criteria for

establishing stresses

Restraining force may cause cracking

in deck. Refer to Chapter 8.

Differential

Shrinkage

Use low modulus concrete mix

design for composite decks

Allows additional strain to be

accommodated up to cracking stress

Typically lower in strength and may

be subject to wear and abrasion

Use high creep concrete mixdesigned for composite decks

Reduces lockedin stressesUncommon mix design. Difficult toassess stress relief

Develop composite action after

concrete has hardened

Allows slippage between deck and

supporting members, minimizing

locked-in stresses

Little experience with experimentalsystems. Friction reduction difficult

to assess. Introduces numerous

construction joints. Grout integrity

issues in closed void systems.

Use precast deck panels

Allows slippage between deck and

supporting members, minimizinglocked-in stresses

Introduces numerous construction

joints

Reactive

Ingredients

ASR/ACR

Local aggregates arereactive

5.3.2.2.4.1 Use materials and mix designs thatare not sensitive to aggregate

Refer to Chapter 3 Refer to Chapter 3

Coastal

ClimateHumidity

RH average 70% 5.3.2.2.2.2Use materials that are not sensitiveto moisture content

Refer to Chapter 3 Refer to Chapter 3

Thermal

Climate

Freeze/Thaw

Multiple cycles of

freeze/thaw expected5.3.2.2.1.2

Refer to Chapter 3 for strategies

relating to freeze/thaw






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Overload Fatigue WearSystem

Restraint

Differential

ShrinkageDeicing

Freeze/

ThawSalt spray Humidity ASR/ACR

Increase

Deck

Thinness

Design per

AASHTO

Concrete

mix

Accurate

modeling

during

analysis of

the system

Concrete mix

Use mix with

low modulus

ImpermeableConcrete

Concrete

mix

air content

Stainlesssteel

Use

aggregate

that are not

sensitive to

humidity

Concrete

mix non-reactive

aggregate

Membrane

and overlayStainless Steel

Stay in

place metal

deck toprotect

bottom

Increasethickness

Specify non-

chloride based

deicing

Deck

bottom

sealer and

top

membrane

Membrane and

Overlay


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Before Design

for Service Life

Alt. 1

Good Mix

Alt. 2

Stainless steel


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Alt. 3

Large

cover

Alt. 4

Membrane


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Alternative Main Feature to

address corrosion

Initial cost Life cycle cost

AASHTO Base Design N/A $37,215 $774,676

1 Impermeable concreteusing silica fume

$44,645 $277,550

2 Use of 316-stainlesssteel

$152,753 $152,753

3 Increasing concretecover

$46,519 $691,114

4 Using membrane and

overlay

$109,541 $172,252


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Camera ready copy of the Guide was submitted Feb 2013Should be available by end of March 2013

Atorod [email protected]
mailto:[email protected]:[email protected]

S40_General and Comprehensive Framework for Design of Bridges for Service Life_LTC2013

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