FHWA Bridge Preservation

Research Roadmap
PUBLICATION NO. FHWA-HRT-24-011 JANUARY 2024

Research, Development, and Technology

Turner-Fairbank Highway Research Center
6300 Georgetown Pike
McLean, VA 22101-2296
 FOREWORD

In recent years, State departments of transportation (DOTs) have established bridge preservation
programs and made significant progress in bridge preservation practice and research. More
bridge preservation technologies, planning strategies, and tools have been investigated and
adopted to extend the service life and restore serviceability of existing bridges. The concept of
using high-performance and durable materials, low-maintenance structure types, and details to
extend the maintenance-free service life of new construction has become more widely accepted.
In addition, developments in data technologies have enhanced data-driven performance
evaluation, risk-based decisionmaking, and lifecycle analysis capabilities. As more bridges in
poor condition are replaced, proactive bridge preservation is becoming increasingly important to
maintain bridge inventories in states of good repair in a cost-effective way.

In 2008, the Federal Highway Administration (FHWA) collaborated with the American
Association of State Highway and Transportation Officials (AASHTO) Transportation System
Preservation Technical Services Program and the Transportation Research Board to develop the
Transportation System Preservation Research, Development, and Implementation Roadmap.(1)
Significant advances in bridge preservation prompted FHWA to produce an updated research
roadmap reflecting the progress made and identifying current research gaps. This update was
developed by examining publications and research led by FHWA, State DOTs, and AASHTO
from 2010 to 2022 to assess accomplishments and remaining gaps. Additional research gaps
were also identified that support FHWA initiatives in sustainability, infrastructure resilience, risk
evaluation, digital twins, and data integration related to bridge preservation and management.
This roadmap is intended for use primarily by FHWA. Other agencies or organizations may also
use the roadmap in selecting and funding research in bridge preservation programs.

Jean A. Nehme, Ph.D., P.E.

Director, Office of Infrastructure
Research and Development

Notice
This document is disseminated under the sponsorship of the U.S. Department of Transportation
(USDOT) in the interest of information exchange. The U.S. Government assumes no liability for
the use of the information contained in this document.

The U.S. Government does not endorse products or manufacturers. Trademarks or

manufacturers’ names appear in this report only because they are considered essential to the
objective of the document.

Quality Assurance Statement

The Federal Highway Administration (FHWA) provides high-quality information to serve
Government, industry, and the public in a manner that promotes public understanding. Standards
and policies are used to ensure and maximize the quality, objectivity, utility, and integrity of its
information. FHWA periodically reviews quality issues and adjusts its programs and processes to
ensure continuous quality improvement.
 TECHNICAL REPORT DOCUMENTATION PAGE

1. Report No. 2. Government Accession No. 3. Recipient’s Catalog No.

FHWA-HRT-24-011
4. Title and Subtitle 5. Report Date
FHWA Bridge Preservation Research Roadmap January 2024
6. Performing Organization Code:

7. Author 8. Performing Organization Report No.

Ping Lu (ORCID: 0000-0002-9427-2415)
9. Performing Organization Name and Address 10. Work Unit No.
Office of Infrastructure Research and Development
Federal Highway Administration 11. Contract or Grant No.
6300 Georgetown Pike
McLean, VA 22101-2296
12. Sponsoring Agency Name and Address 13. Type of Report and Period Covered
Office of Infrastructure Research and Development Final Report
Federal Highway Administration 14. Sponsoring Agency Code
6300 Georgetown Pike HRDI-20
McLean, VA 22101-2296
15. Supplementary Notes
This research project was led by the Federal Highway Administration’s Office of Infrastructure Research and
Development. The point of contact was Ping Lu (HRDI-20; ORCID: 0000-0002-9427-2415).
16. Abstract
Since the publication of the Transportation System Preservation Research, Development, and Implementation
Roadmap in 2008, most State departments of transportation (DOTs) have established bridge preservation programs
and have made significant progress in the areas of bridge preservation practice and research.(1) State DOTs have
investigated, developed, and used bridge preservation technologies, materials, planning strategies, and tools to
extend the service life and restore the serviceability of existing bridges. The use of high-performance materials and
low-maintenance structure types and details to extend the maintenance-free service life of new construction has
become more widely accepted. In recent years, developments in data technologies have enhanced data-driven
performance evaluation, risk-based decisionmaking, and lifecycle analysis capabilities. As more bridges in poor
condition are replaced, proactive bridge preservation is becoming increasingly important to cost-effectively maintain
bridge inventories in states of good repair. Considering the advances mentioned, the 2008 roadmap needs to be
reevaluated to determine whether those gaps are still valid and identify new ones. The author reviewed publications
and research led by the Federal Highway Administration (FHWA), State DOTs, and the American Association of
State Highway and Transportation Officials (AASHTO) from 2010 to 2022 to assess accomplishments and
remaining gaps. Additional gaps were also identified to support FHWA initiatives in sustainability, infrastructure
resilience, risk evaluation, and big data as they relate to bridge preservation and management. The author also
investigated FHWA initiatives in climate change, infrastructure resilience, and big data related to bridge
preservation to identify new gaps. This roadmap is intended for use primarily by FHWA. Other agencies or
organizations may also use the roadmap in selecting and funding research in bridge preservation programs.
17. Key Words 18. Distribution Statement
Bridge preservation, bridge preservation No restrictions. This document is available to the public
technologies, materials, data-driven, risk-based through the National Technical Information Service,
planning, lifecycle analysis, LCCA, resilience Springfield, VA 22161.
https://www.ntis.gov.
19. Security Classif. (of this report) 20. Security Classif. (of this page) 21. No. of Pages 22. Price
Unclassified Unclassified 72 N/A
Form DOT F 1700.7 (8-72) Reproduction of completed page authorized.
 SI* (MODERN METRIC) CONVERSION FACTORS
APPROXIMATE CONVERSIONS TO SI UNITS
Symbol When You Know Multiply By To Find Symbol
LENGTH
in inches 25.4 millimeters mm
ft feet 0.305 meters m
yd yards 0.914 meters m
mi miles 1.61 kilometers km
AREA
in2 square inches 645.2 square millimeters mm2
ft2 square feet 0.093 square meters m2
yd2 square yard 0.836 square meters m2
ac acres 0.405 hectares ha
mi2 square miles 2.59 square kilometers km2
VOLUME
fl oz fluid ounces 29.57 milliliters mL
gal gallons 3.785 liters L
ft3 cubic feet 0.028 cubic meters m3
yd3 cubic yards 0.765 cubic meters m3
NOTE: volumes greater than 1,000 L shall be shown in m3
MASS
oz ounces 28.35 grams g
lb pounds 0.454 kilograms kg
T short tons (2,000 lb) 0.907 megagrams (or “metric ton”) Mg (or “t”)
TEMPERATURE (exact degrees)
5 (F-32)/9
°F Fahrenheit Celsius °C
or (F-32)/1.8
ILLUMINATION
fc foot-candles 10.76 lux lx
fl foot-Lamberts 3.426 candela/m2 cd/m2
FORCE and PRESSURE or STRESS
lbf poundforce 4.45 newtons N
lbf/in2 poundforce per square inch 6.89 kilopascals kPa
APPROXIMATE CONVERSIONS FROM SI UNITS
Symbol When You Know Multiply By To Find Symbol
LENGTH
mm millimeters 0.039 inches in
m meters 3.28 feet ft
m meters 1.09 yards yd
km kilometers 0.621 miles mi
AREA
mm2 square millimeters 0.0016 square inches in2
m2 square meters 10.764 square feet ft2
m2 square meters 1.195 square yards yd2
ha hectares 2.47 acres ac
km2 square kilometers 0.386 square miles mi2
VOLUME
mL milliliters 0.034 fluid ounces fl oz
L liters 0.264 gallons gal
m3 cubic meters 35.314 cubic feet ft3
m3 cubic meters 1.307 cubic yards yd3
MASS
g grams 0.035 ounces oz
kg kilograms 2.202 pounds lb
Mg (or “t”) megagrams (or “metric ton”) 1.103 short tons (2,000 lb) T
TEMPERATURE (exact degrees)
°C Celsius 1.8C+32 Fahrenheit °F
ILLUMINATION
lx lux 0.0929 foot-candles fc
cd/m2 candela/m2 0.2919 foot-Lamberts fl
FORCE and PRESSURE or STRESS
N newtons 2.225 poundforce lbf
kPa kilopascals 0.145 poundforce per square inch lbf/in2
*SI is the symbol for International System of Units. Appropriate rounding should be made to comply with Section 4 of ASTM E380.
(Revised March 2003)

ii
 TABLE OF CONTENTS

EXECUTIVE SUMMARY .......................................................................................................... 1

CHAPTER 1. BACKGROUND ................................................................................................... 3
CHAPTER 2. FHWA’S BRIDGE PRESERVATION PROGRAM ........................................ 5
CHAPTER 3. DEVELOPMENT APPROACH ......................................................................... 9
CHAPTER 4. ASSESSMENT OF RESEARCH GAPS FOR THE 10 TOPIC AREAS
FROM THE 2008 ROADMAP .................................................................................................. 11
Topic 1: Sensing Data in Bridge Preservation Decisionmaking ....................................... 11
Background and Originally Proposed Objective and Scope ............................................. 11
State of the Practice Based on Literature Review............................................................. 11
Related Work From the FHWA NDE Laboratory ............................................................ 13
Observed Gaps .................................................................................................................. 14
Topic 2: Effects of Bridge Preservation Activities ............................................................. 15
Background and Originally Proposed Objective and Scope ............................................. 15
State of the Practice Based on Literature Review............................................................. 15
Related Work From Long-Term Bridge Performance (LTBP) Program.......................... 16
Observed Gaps .................................................................................................................. 18
Topic 3: Best Practices for Bridge Deck Preservation ...................................................... 18
Background and Originally Proposed Objective and Scope ............................................. 19
State of Practice Based on Literature Review................................................................... 19
Observed Gaps .................................................................................................................. 20
Topic 4: Preservation of Concrete Highway Bridge Substructure .................................. 21
Background and Originally Proposed Scope and Objective ............................................. 21
State of the Practice Based on Literature Review............................................................. 21
Observed Gaps .................................................................................................................. 23
Topic 5: Corrosion Prevention and Mitigation Technologies for Concrete
Components ........................................................................................................................... 23
Background and Originally Proposed Scope and Objective ............................................. 24
State of the Practice Based on Literature Review............................................................. 24
Related Work From the FHWA Coatings and Corrosion Laboratory .............................. 25
Observed Gaps .................................................................................................................. 25
Topic 6: Deterioration Modeling Accounts for Preservation Actions and Preservation
Effects ..................................................................................................................................... 26
Background and Originally Proposed Scope and Objective ............................................. 26
State of Practice Based on Literature Review................................................................... 26
Observed Gaps .................................................................................................................. 27
Topic 7: Watertight Joints ................................................................................................... 28
Background and Originally Proposed Scope and Objective ............................................. 28
State of the Practice Based on Literature Review............................................................. 28
Observed Gaps .................................................................................................................. 29
Topic 8: Development of Bridge Maintenance Database .................................................. 30
Background and Originally Proposed Scope and Objective ............................................. 30
State of the Practice Based on Literature Review............................................................. 30

iii
 Observed Gaps .................................................................................................................. 31
Topic 9: Applying Element Data in Bridge Preservation and Management................... 32
Background and Originally Proposed Scope and Objective ............................................. 32
State of the Practice Based on Literature Review............................................................. 32
Observed Gaps .................................................................................................................. 33
Topic 10: Pile Preservation and Steel Corrosion Prevention............................................ 34
Background and Originally Proposed Scope and Objectives ........................................... 34
State of Practice Based on Literature Review................................................................... 34
Observed Gaps .................................................................................................................. 35
CHAPTER 5. RESEARCH TOPICS ........................................................................................ 37
Corrosion Evaluation, Prevention, and Mitigation for Bridge Preservation .................. 37
Data for Bridge Preservation ............................................................................................... 37
Element Data in Bridge Preservation and Management ................................................... 38
NDE/SM Data in Bridge Preservation and Management ................................................. 38
Other Data for Bridge Preservation and Management ...................................................... 38
Bridge Preservation and Management of Lifecycle Planning .......................................... 39
Cost modeling ................................................................................................................... 39
Deterioration modeling ..................................................................................................... 39
Decisionmaking ................................................................................................................ 39
Ecofriendly and Sustainable Materials and Technologies for Bridge Preservation
and Repair ............................................................................................................................. 40
Bridge Deck Preservation and Management...................................................................... 40
Preservation of Superstructure and Substructure............................................................. 41
Preservation of Bridge Piles ................................................................................................. 41
Preservation of Watertight Joints ....................................................................................... 42
CHAPTER 6. REVIEW AND RANKING ............................................................................... 45
CHAPTER 7. STATEMENT FOR SELECTED TOPICS ..................................................... 47
CHAPTER 8. CONCLUSIONS................................................................................................. 53
APPENDIX. STATEMENTS FOR OTHER TOPICS ............................................................ 55
ACKNOWLEDGMENTS .......................................................................................................... 59
REFERENCES............................................................................................................................ 61

iv
 LIST OF TABLES

Table 1. High-priority bridge preservation research topics. ..........................................................42

Table 2. Statements for the top 10 research topics. .......................................................................47
Table 3. Statements for other topics. .............................................................................................55

v
 LIST OF ABBREVIATIONS AND ACRONYMS

3D three dimensional
AASHTO American Association of State Highway and Transportation Officials
ADE Agency Developed Elements
AE acoustic emission
AI artificial intelligence
BEAST® Bridge Evaluation and Accelerated Structural Testing
BME Bridge Management Elements
BPETG Bridge Preservation Expert Task Group
BIM bridge information modeling
CFRP carbon-fiber-reinforced polymer
CGR continuously galvanized rebar
DOT department of transportation
EDC-6 Every Day Counts-6
FHWA Federal Highway Administration
FRP fiber-reinforced polymer
GFRP glass-fiber-reinforced polymer
HPMS Highway Performance Monitoring System
LCCA lifecycle cost analysis
LTBP Long-Term Bridge Performance
MFL magnetic flux leakage
MMF magnetomotive force
MSEW mechanically stabilized earth wall
NBE National Bridge Elements
NBI National Bridge Inventory
NBMD National Bridge Maintenance Database
NCHRP National Cooperative Highway Research Program
NDE nondestructive evaluation
NHI National Highway Institute
ROI return on investment
SHM structural health monitoring
SM structural monitoring
SME subject matter expert
TC3 Transportation Curriculum Coordination Council
TRB Transportation Research Board
TSP2 Transportation System Preservation Technical Services Program
UAV unmanned aerial vehicle
UHPC ultra-high performance concrete
WG working group
WIM weigh-in-motion
XML Extensible Markup Language

vi
 EXECUTIVE SUMMARY

The Federal Highway Administration (FHWA) worked with the American Association of State
Highway and Transportation Officials (AASHTO) in 2008 to develop the Transportation System
Preservation Research, Development, and Implementation Roadmap to reach consensus about
the most pressing research needs to move the preservation of roads and bridges into more
common practice.(1) Since then, most State departments of transportation (DOTs) have
established bridge preservation programs and have made significant progress in bridge
preservation practice and research. State DOTs have investigated, developed, and used bridge
preservation technologies, materials, planning strategies, and tools to extend the service life of
existing bridges in a cost-effective way. Equally important is considering bridge preservation and
service life during the planning and design stages of new construction. Adopting higher
performance materials and lower maintenance structure types and details to extend
maintenance-free service life is also an important research area for bridge preservation. In recent
years, dramatic developments in data collection, analysis, and modeling technologies have made
data-driven performance evaluation and risk-based decisionmaking more practical and efficient.
Given the promotion of bridge preservation as a cost-effective approach to maintaining bridges
in states of good repair, there is a need to reevaluate the 2008 roadmap to determine whether the
gaps are still valid and identify new gaps.

Publications and research led by FHWA, State DOTs, and AASHTO from 2010 to 2022 was
reviewed to gain useful information for the gap assessment. Research topics were identified to
cover the gaps and investigated bridge-preservation-related research topics representing
emerging technologies and new initiatives. They are ranked to show current FHWA priorities
and national interests. Data-driven planning and decisionmaking are major research areas
proposed in this roadmap. Additional gaps and research topics were also identified to support
FHWA initiatives in climate change, resilience, infrastructure digitization, AI and big data
related to bridge preservation.

This roadmap is intended for use primarily by FHWA. Local, State, and other Federal agencies
or other interested parties may also use the roadmap in selecting and funding research in bridge
preservation programs. The roadmap should be updated regularly.

1
 CHAPTER 1. BACKGROUND

In 2008, the Federal Highway Administration (FHWA), American Association of State Highway
and Transportation Officials (AASHTO), and highway preservation industries worked together
to identify the most needed research, document critical knowledge gaps in pavement and bridge
preservation, and determine the research necessary to fill those gaps.(1) This effort resulted in an
infrastructure preservation research publication called the Transportation System Preservation
Research, Development, and Implementation Roadmap. The purpose of the 2008 roadmap was to
reach consensus about the most pressing research needs to move the preservation of roads and
bridges into more common practice and to provide decision tools to assist agencies with proper
project selection, use of materials and specifications, quality construction, and appropriate
performance monitoring. The 2008 roadmap was developed when many States were in the
earliest stages of implementing preservation practices. Recently, FHWA updated and published
the pavement portion of the roadmap.(2)

In 2008, many agencies limited bridge preservation to joint repairs, preservation coatings, and
protective deck treatments. The bridge portion of the 2008 research roadmap identified
25 research topics and developed research needs statements amounting to a total estimated cost
of $12.7 million.(1) The 25 topics were distributed among six topic areas as follows:

• Asset management: 7.
• Decks and joints: 4.
• Superstructures: 5.
• Substructures: 5.
• Selection of preservation actions: 2.
• Performance of preservation actions: 2.

Since the 2008 roadmap’s publication, coupled with the Moving Ahead for Progress in the
21st Century Act(3) and the Fixing America’s Surface Transportation Act(4), significant progress
has been made in bridge preservation and management research and practice and the impact on
the performance of individual bridges and bridge networks. States recognize that maintaining an
aging bridge inventory in a state of good repair with limited budgets is challenging. A worst first
bridge management approach that focuses only on replacing poor bridges while ignoring the
preservation and maintenance needs of good- or fair-condition bridges is inefficient and cost
prohibitive in the long term.(5,6) The National Bridge Inventory (NBI) had 42,966 bridges (with a
total deck area of 217 ft2) in poor condition.(7) The replacement cost would be $49 billion based
on the replacement unit cost reported to FHWA, which was $228 per ft2 on average in 2022
(https://www.fhwa.dot.gov/bridge/nbi/sd2020.cfm).(8)

Additionally, if no preservation actions are undertaken, the total replacement cost would increase
exponentially due to the average age of existing highway bridges—which was 45.9 yr in 2022. In
contrast, delaying the need for costly rehabilitation and replacement while bridges are still in
good or fair condition through bridge preservation and, at the same time, keeping a good balance
between bridge preservation, rehabilitation, and replacement are proven effective and practical
ways to maintain and possibly improve the bridges’ overall service levels.(5,6) Using preservation

3
to maintain system conditions and extend bridge service life is a valuable tool for achieving the
asset management goals FHWA is promoting.

Currently, most State departments of transportation (DOTs) have established bridge preservation
programs to promote effective and sustainable bridge preservation practices. The success of
those programs relies not only on funding and organizational support but also on innovative
research that includes the following:

• Develop and validate cost-effective and ecofriendly bridge preservation and maintenance
techniques.

• Validate the performance of new materials (e.g., corrosion-resistant, high-strength,

high-durability, and ecofriendly materials) that extend bridge service life.

• Validate and apply early damage and deterioration detection techniques and use the data
in bridge preservation planning.

• Collect and use high-quality data—including nondestructive evaluation and structural

monitoring (NDE/SM) data—to support meaningful data-driven decisionmaking (e.g.,
lifecycle planning considering cost, performance, and risk).

• Consider resilience and sustainability in bridge preservation planning.

• Develop data modeling strategies to support innovations in decisionmaking spurred by

digital deliverables and digital twin technologies, which include bridge information
modeling (BIM) for bridge implementations.

This roadmap assesses the bridge portion of the 2008 roadmap in terms of what has been
accomplished and initiated since then, whether the gaps are still valid, and what new gaps
exist.(1) This roadmap aims to identify current research needs for bridge preservation and rank
them according to FHWA’s priority and national interest. The author’s review of publications
and research led by FHWA, State DOTs, and AASHTO from 2010 to 2022 provides useful
information for this gap assessment. The report proposes research topics to cover the gaps and
identifies research needs that represent emerging technologies. The identified research topics are
ranked to show current FHWA priority and national interests. This roadmap was developed
primarily for FHWA use because the topics discussed are broad and address national needs, but
it can also guide local, State, other Federal agencies, or other interested parties in selecting and
funding research in bridge preservation and management programs. The roadmap is expected to
be updated regularly.

4
 CHAPTER 2. FHWA’S BRIDGE PRESERVATION PROGRAM

Research conducted in response to this roadmap is intended to feed into FHWA’s broader bridge
preservation program. The following are key activities in the broader program.

FHWA’s bridge preservation program published Bridge Preservation Guide: Maintaining a

State of Good Repair Using Cost Effective Investment Strategies and Bridge Preservation Guide:
Maintaining a Resilient Infrastructure to Preserve Mobility in 2011 and 2018, respectively.(5,6)
The guides define bridge preservation terms and identify commonly practiced bridge
preservation activities. The guides also provide information for State DOTs and other bridge
owners regarding establishing or improving existing bridge preservation programs as part of an
asset management program.

In 2020, FHWA published the FHWA Bridge Preservation Expert Task Group [BPETG]
Strategic Plan FY2020–FY2024.(9) The plan identified four strategic objectives:

1. Share cost-effective bridge preservation strategies that include the following actions:

a. Develop documents on practices adopted or conducted by States or bridge owners.

b. Develop apps for mobile devices.
c. Develop case studies.
d. Determine the duration of bridge preservation treatments from a bridge condition
rating perspective.
e. Study next-generation data framework for developing data-driven preservation
performance estimates.
2. Promote bridge preservation as a component of asset and performance management that
includes the following actions:

a. Integrate bridge preservation into asset management.

b. Support the development of bridge deck preservation portals.
c. Communicate how bridge preservation extends the lives of bridges at other venues.

3. Develop educational materials on bridge preservation that include the following actions:

a. Design Web-based training.

b. Communicate the importance of bridge preservation as a component of an asset
management strategy.
c. Explore the development and deployment of curricular modules on bridge
preservation—including appropriate references to asset management and lifecycle
costs—for undergraduate and graduate courses.
d. Provide technical assistance for local agencies.
4. Foster a collaborative environment that encourages the innovation and adoption of new
technologies for bridge preservation that include the following actions:

5
 a. Explore opportunities to improve States’ qualified product list process for owners,
suppliers, and contractors that identifies new technologies, gaps, and key performance
indicators.
b. Assist other research sponsors in promoting bridge preservation research.

Since the publication of the strategic plan, BPETG has completed the following case studies:

• Case Study: Utilization of Cathodic Protection to Extend the Service Life of Reinforced
Concrete Bridges – An Overview of the Installation and Maintenance of the Cathodic
Protection Systems Protecting the Howard Frankland and Crescent Beach Bridges (in
response to a U.S. Government Accountability Office report dated September 28,
2021).(10)

• Case Study: Eliminating Bridge Joints with Link Slabs – An Overview of State
Practices.(11)

• Case Study: Response to Bridge Impacts – An Overview of State Practices.(12)

The FHWA BPETG developed many pocket guides for bridge preservation activities, which can
be found at https://tsp2bridge.pavementpreservation.org/technical/fhwa/pocket-guides/.(13)

Recently, FHWA published a report entitled Prioritizing Preservation for Locally Owned
Bridges.(14) The report highlights local agency project selection processes for bridge preservation
activities, funding sources, typical bridge preservation actions, bridge asset management
practices, and successes and challenges for funding locally owned bridge preservation programs.

In 2022, FHWA published the Reference Guide for Service Life Design of Bridges.(15) This
document is intended to act as a nonbinding “roadmap” of service life design concepts and
methods for bridge owners and designers.

For bridge preservation training, several Web-based training courses were developed and are
available through the AASHTO Transportation Curriculum Coordination Council (TC3) website
(https://transportation.org/technical-training-solutions/).(16) Examples of courses include the
following:

• TC3MN036: Bridge Preservation Guide.

• TC3MN037: Bridge Cleaning.
• TC3MN038: Thin-Polymer Bridge Deck Overlay Systems.
• TC3MN039: Removal and Replacement of Bridge Coatings.
• TC3MN042: Concrete Bridge Deck Patching.
• TC3MN043: Spot, Zone, and Overcoating Existing Bridge Coatings.
• TC3MN044: Repair of Bridge Concrete Substructure Elements.
• TC3MN049: Maintenance and Repair of Bridge Bearings.

Many National Highway Institute (NHI) training courses were also developed, including the
following examples:

6
 • FHWA-NHI-130106A: Bridge Preservation Fundamentals.(17)
• FHWA-NHI-130106B: Establishing a Bridge Preservation Program.(18)
• FHWA-NHI-130107A: Fundamentals of Bridge Maintenance.(19)
• FHWA-NHI-130107C: Maintenance of Movable Bridges.(20)
• FHWA-NHI-130107D: Maintenance of Masonry Bridge Elements.(21)
• FHWA-NHI-130108: Bridge Maintenance.(22)

FHWA’s bridge preservation program also published the following documents:

• Report on Techniques for Bridge Strengthening: Main Report.(23)

• Manual for Design, Construction, and Maintenance of Orthotropic Steel Deck

Bridges.(24) This manual covers bridge engineering topics related to orthotropic steel
decks, including analysis, design, detailing, fabrication, testing, inspection, evaluation,
and repair.

• Methodology for Analysis of Soluble Salts from Steel Substrates.(25) This report presents
the results of a laboratory study of the methodology for extraction and analysis of soluble
salts from steel substrates.

• Proceedings of the 2011 National Bridge Management, Inspection and Preservation

Conference: Beyond the Short Term.(26) The conference included tracks on bridge
management, inspection, and preservation, emphasizing how all three interrelated
disciplines can collaborate to improve the long-term performance of the Nation’s
highway bridges.

More information about FHWA’s bridge preservation and management program can be found at
the FHWA “Bridge Preservation” web page (https://www.fhwa.dot.gov/bridge/preservation/) and
“Bridge Management” web page (https://www.fhwa.dot.gov/bridge/management/).(27,28)

7
 CHAPTER 3. DEVELOPMENT APPROACH

The author identified research topics based on the assessment of existing and emerging research
and carried out five steps to fulfill the task:

Step 1. The author worked with the FHWA Research Library to conduct a literature review of
the previously mentioned 25 bridge-related topics in the 2008 roadmap, classifying the topics
into 18 groups by considering their similarities and connections.(1) Results from major databases,
AASHTO, the Transportation Research Board (TRB), FHWA publications, and FHWA- and
State-DOT-funded projects published after 2010 were documented in a spreadsheet.

Step 2. The author considered 11 of the 18 groups more suited to FHWA research due to their
fundamental research natures and current national needs. Due to ongoing research, the
weathering steel-related research was not included in further. More topics can be identified later
as necessary.

Step 3. The author further analyzed the literature research results of the 10 high-priority topics
and related FHWA research to identify the potential knowledge gaps.

Step 4. The author proposed research topics to address the knowledge gaps identified in step 3
and investigated topics for emerging technologies.

Step 5. The research topics identified in step 4 were prioritized by bridge experts of FHWA and
stakeholders and developed as project statements for selected topics.

Chapter 4 summarizes the literature review findings and gap analysis results for the 10
high-priority topics (steps 1 through 3). Based on the gap analysis, future research topics are
identified (step 4) and summarized in chapter 5. The author collected FHWA internal feedback
for the roadmap. A working group (WG) representing FHWA, TRB, AASHTO (State DOTs and
the Transportation System Preservation Technical Services Program (TSP2)), academia, and
industry was formed and provided feedback on prioritizing the topics and research statements.

9
 CHAPTER 4. ASSESSMENT OF RESEARCH GAPS FOR THE 10 TOPIC AREAS
FROM THE 2008 ROADMAP

The literature review covers 10 topic areas identified from the 2008 roadmap and an analysis of
related ongoing FHWA work.(1) The results from this effort were used to support research gap
identification.

TOPIC 1: SENSING DATA IN BRIDGE PRESERVATION DECISIONMAKING

NDE/SM technologies were developed rapidly during the past decade. However, integrating
NDE/SM data into bridge condition evaluation, preservation, and management decisionmaking
still needs more research. Artificial intelligence (AI) and big-data-based analysis approaches
show promise in applying NDE/SM data in bridge preservation decisionmaking. Early damage
detection approaches are needed to facilitate early preservation interventions. The ability to
model sensing data in the context of digital deliverables—including BIM for bridges and digital
twins—is important for the next-generation bridge preservation program.

Background and Originally Proposed Objective and Scope

Unexpected failures of prestressing strand embedded in concrete or encased in ducts have

happened. In 2008, NDE technology was inadequate to evaluate the condition of such embedded
and ducted strands for active corrosion and section loss, breakage, grout quality, etc. NDE
technologies at that time were inadequate to provide condition knowledge that could support
proactive actions to mitigate or prevent further deterioration or future unanticipated failure. Even
though NDE technologies have improved, technologies focused on determining the current
condition and identifying active corrosion or conditions favorable to corrosion are needed. This
research aims to improve the current state of inspection technologies or to develop new tools and
methodologies for assessing the current state of steel prestressing strand, ducts, cables, and
ropes. Some of the technologies will focus on determining the current condition, and others will
focus on identifying active corrosion or conditions favorable to corrosion.

State of the Practice Based on Literature Review

The literature review results showed that extensive research has been conducted in the past 10 yr
for NDE/SM techniques and their applications in corrosion and damage detection for prestressed
strand/tendon/rope, ducts, and grouting.

The studied NDE/SM techniques included acoustic emission (AE), eddy current,
fiber-optic-based sensing technologies, ground penetration radar (GPR), impact echo (IE),
impact-elastic wave, infrared and induction thermography, magnetic- and electromagnetic-based
methods, magnetic flux leakage (MFL), magnetic flux methods, magnetomotive force (MMF)
ultrasound, robot, sensor network, three-dimensional (3D) microwave camera, ultrasonic shear
wave imaging device, and x-ray image and other radiography techniques, etc.

The most used methods for corrosion detection were AE and magnetic flux. Ultrasound and
impact echo were widely used in grouting-condition evaluation. SM systems were typically used
for stress and axle force monitoring and damage detection. In addition, radiography was used to

11
measure reinforcing configuration, cable and strand or grouting-condition evaluation, and stress
levels.

Among the 315 results, 74 were from industries other than bridges. The NDE/SM techniques
used by the bridge industry and other industries were generally similar. The literature review
yielded the following results:

• Forty papers discussed AE or acoustic-based methods, and 13 focused on corrosion

detection.

• Forty-four results were related to the magnetic flux method, including MMF and MFL,
and 13 focused on corrosion detection.

• SM was used to provide real-time or near-real-time information for conditions or stresses

in cables or strands. Much of the research was about fiber-optic piezoceramic sensors and
sensor networks. Twenty-one results were about fiber-optic sensors, and 15 of them were
used to monitor stress and axial force in prestress strands or posttensioned cable. Four
results were about piezoceramic transducers used to evaluate stress level, cable condition,
and grouting condition. Sensor network was widely used in cable condition evaluation.

• For dynamic testing, nine results documented systems for cable and strand stress
evaluation and damage detection.

• Twelve results were found for radiography that measured stress level, reinforcing
configuration, cable and strand condition, grouting condition, etc.

• One result was for an ultrasonic shear wave imaging device.

• Six results were found for eddy current. The technology was used to evaluate stress level,
reinforcing configuration, wire rope condition, etc.

• Thirty-seven results were found for ultrasonic or guided ultrasonic waves. Ultrasonic
waves are widely used in grouting-condition evaluation (9 papers), corrosion detection
(9 papers), and stress-level evaluation (10 papers).

• Magnetic-based methods (28 results) were commonly used in stress-level evaluation.

• Two results were found for lethal-concentration oscillation, which is used in stress-loss
evaluation.

• Five results were found for impulse hammer, which is commonly used in condition
evaluation of posttensioned structures (e.g., grouting-condition evaluations).

• Six results were found for image-based methods, three of which were about applications
for wire rope condition evaluation.

12
 • Twenty-three results were about impact echo and impact-elastic wave, whose most
common application was grouting-condition evaluation, and 14 out of the 23 results were
about impact echo and impact-elastic wave.

• The 11 results found for robot were all applications in posttension cable condition
evaluation.

• Six papers used an AI data analysis approach.

• The impedance method, with five results, was most commonly used in grouting-condition
evaluation.

Related Work From the FHWA NDE Laboratory

FHWA’s NDE Laboratory led several research projects that are closely related to bridge
preservation and management. The scope of these projects are about general applications of
NDE/SM in bridge condition evaluation rather than only for strand, cables, ropes, and grouting
in prestressed concrete components. Following are summaries of representative products and
projects:

• The Nondestructive Evaluation [NDE] Web Manual provides knowledge that fills the gap
between highway infrastructure practitioners/asset managers dealing with highway
infrastructure performance challenges and researchers developing and refining NDE
technologies to support practitioners/asset managers’ efforts. The manual is published
through the FHWA InfoTechnology™ portal.(29)
•
Collection of Data with Unmanned Aerial Systems (UAS) for Bridge Inspection and
Construction Inspection.(30)
•
Leveraging Augmented Reality for Highway Construction.(31)

Some of the ongoing research projects led by FHWA’s NDE Laboratory aim to integrate
NDE/SM data into bridge management decisionmaking frameworks. Return-on-investment
(ROI) analysis was carried out in the following projects to justify the cost-effectiveness of using
NDE and SM techniques in bridge preservation and management decisionmaking:

• Incorporating NDE and SM Methods into Bridge Deck Preservation Strategies.(32)

This project includes efforts to identify state-of-practice preservation decisionmaking
processes, define specific NDE/SM thresholds for specific preservation actions, develop
matrices to incorporate NDE/SM methodology into bridge preservation strategies, and
examine the economics of incorporating NDE/SM into bridge preservation strategies.

• Structural Health Monitoring (SHM) Current Practice and Web Manual. A Web
manual for structural monitoring (SM) technologies will be developed and integrated into
the FHWA InfoTechnology portal.(29) ROI analysis was conducted to justify the
cost-effectiveness of using SM data in bridge management decisionmaking.

13
 • Current Practices and Policies of State Highway Agency Bridge and Tunnel Units
on the Use of Deployment-ready NDE Technologies in Complementing Visual
Bridge and Tunnel Safety Inspections.(32) The primary goal of this project is to enhance
NDE information and its use in managing bridge and tunnel assets. Project-level-analysis
and network-level-analysis tools were developed. The ROI for using NDE data in asset
management decisionmaking was evaluated.

Through the aforementioned projects, FHWA expects that standard approaches for certain SM
technologies can be established and more widely adopted. By establishing the framework for
integrating NDE/SM data into bridge management decisionmaking, the NDE/SM technologies
would have more potential to be adopted as standard practices to supplement current bridge
visual inspection.

On the data side, more work can be done for NDE/SM data governance, storage, and data
analysis and visualization and to investigate AI-based data analysis and integration for
deterioration modeling. NDE/SM-based model updating in the context of digital as-built and
digital twin is also worth more research. In addition, NDE/SM techniques that can detect early
damage and deterioration are needed to facilitate cost-effective early preservation interventions.

Observed Gaps

The literature review identified the following research gaps:

• Developing/Testing NDE/SM techniques that could detect early damage/deterioration to

facilitate cost-effective early preservation interventions.

• Integrating NDE/SM data into bridge components and elements in deterioration modeling
and remaining service life estimation to support bridge preservation planning. AI- and
big-data-based data analysis is expected to generate useful information to support
data-driven bridge preservation and management decisionmaking.

• Integrating NDE/SM data into digital as-built (BIM for bridges) and digital twin models,
which could be the next-generation data environment for bridge preservation
decisionmaking.

• Applying existing and recently completed work conducted by FHWA’s NDE Laboratory
to bridge preservation decisionmaking—such as integrating UAS, unmanned
ground-based systems such as those with data collected by NDE robot, and unmanned
water-based systems such as those with underwater sensing data—in bridge condition
and postdisaster condition evaluation. Using virtual-reality- or augmented-reality-based
bridge inspection data in model updating and data visualization would enable bridge
preservation engineers to understand bridge condition more intuitively and accurately and
thus improve preservation decisionmaking.

14
TOPIC 2: EFFECTS OF BRIDGE PRESERVATION ACTIVITIES

Understanding the effects of bridge preservation activities is important in decisionmaking.

Postaction deterioration modeling and remaining service life prediction have not been fully
studied. For many new materials and new technologies, long-term performance data can be
obtained only from accelerated laboratory testing or numerical simulation. The ability to validate
accelerated testing and numerical simulation results is important for practical applications. In
addition to performance modeling, the cost and ecoimpact of bridge preservation activities are
important in decisionmaking.

Background and Originally Proposed Objective and Scope

Bridge preservation is a systematic and proactive effort to sustainably extend the service life of a
bridge or bridge elements. Limited attempts have been made to collect high-quality data,
properly analyze the data, and draw conclusions about the costs, effectiveness, and longevity of
preservation actions. Examining such issues as how long the service life of a bridge or bridge
element is extended or the effects that various commonly used preservation actions have on the
lifecycle costs of bridges is difficult. Most of the conclusions bridge practitioners reach are based
on intuition or simple common sense backed by experience.

Collection of the data necessary to support the effectiveness and economic analysis of bridge
preservation activities should be addressed in a logical sequence, starting with short-term studies
of existing data and going on to future data collections targeting specific elements of the
performance of bridge preservation actions.

Identifying the kinds of data needed, such as which performance characteristic needs
improvement by means of which preservation techniques, is important. Experimental studies
may be needed to collect the data and evaluate the benefits of specific and commonly used
bridge preservation actions.

State of the Practice Based on Literature Review

The literature review results show that most previous research focused on bridge preservation
and maintenance optimization and planning at project and network levels. That focus involved
research into deterioration modeling based mostly on NBI and National Bridge Elements (NBE)
inventory data(33,34), cost and depreciation modeling, and decisionmaking procedures. Some
projects also studied the performance and economic impacts of bridge preservation activities.
However, researchers rarely study the postpreservation deterioration models. Collecting and
analyzing data to support the evaluation of service life extension of each intervention were not
adequately studied.

The 138 literature review results break down as follows:

• Sixteen results discussed the effects of bridge preservation and maintenance actions,
among which seven were about economic impacts, and nine were about performance
impact.

• Fifteen results discussed individual bridge preservation and maintenance decisionmaking.

15
 • Nineteen results discussed bridge network preservation and maintenance decisionmaking.

• Twenty-seven results were about maintenance prioritization and decision models.

• Sixteen results were about lifecycle planning.

• Five results were about deterioration modeling and service life prediction.

• Three results discussed cost modeling.

• Twelve results discussed performance measurements.

• Seven results were FHWA, State DOT, or AASHTO guides to bridge preservation
actions.

• Eight results discussed bridge deck preservation.

• Four papers discussed preservations of historic bridges.

• One result was about data workflow for highway assets. The paper discusses the data
sharing and information exchange for highway asset management.

• Five papers focused on other topics.

Related Work From Long-Term Bridge Performance (LTBP) Program

The LTBP Program is a long-term research effort authorized by the U.S. Congress under the
Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users(35) to
collect high-quality bridge data from a representative sample of highway bridges nationwide that
will help the bridge community to better understand bridge performance.

LTBP InfoBridge™ (https://infobridge.fhwa.dot.gov) is a comprehensive bridge performance

portal that enables researchers to develop tools and products that will enhance understanding of
the performance of highway bridge assets and will lead to more efficient design, construction,
rehabilitation, maintenance, preservation, and management of those assets.(7) The deterioration
and performance prediction models and data collected by LTBP and other research programs
published at this Web portal are expected to be very useful for bridge preservation and
maintenance planning.

The LTBP Program published the following series of reports and papers, many of them closely
related to bridge preservation, asset management, and related data needs:

• The Summary Report: Long-Term Bridge Performance Program Data Collection

Workshop describes the input received from bridge community subject matter experts
(SMEs) to assist FHWA in assessing the LTBP Program’s future data collection
efforts.(36) Previously identified high-priority performance issues were paired into five
categories (i.e., warm-weather reinforced concrete bridge decks, cold-weather reinforced
concrete decks, bridge deck joints and superstructure bearings, corrosion protection for

16
 structural steel, and pretensioned and posttensioned strands), and five WGs were formed
accordingly. The WGs consisted of SMEs from State highway departments, industry,
academia, and FHWA, who provided input during group discussions. As reported,
commonalities between certain data were found among the various WGs, such as climate
data, joint condition data, and other data. Analysis of the input received from each of the
five WGs, in addition to lessons learned from past LTBP data collection efforts, resulted
in developing two overall data collection strategies.

The first strategy identified can be termed a “desk audit” type of data collection. The
second involves collecting physical and visual data from bridges in the field.

Data collection requires extensive resources and a strategy to collect data to study the
long-term performance of bridges. Determining the value of any data and how the data
can be used when developing the LTBP Program’s future data collection approach is
imperative. The LTBP Program is currently working on executing two studies to assess
the overall value of already collected data—namely, data collected through an ongoing
accelerated testing experiment and data available through earlier LTBP data collection
efforts—to help guide the path forward.

The data collected and that will be collected by the LTBP Program constitute an
important asset for the bridge preservation community’s future research.

• The report Synthesis of National and International Methodologies Used for Bridge
Health Indices is important for bridge asset management.(37) Deterioration models based
on elements and health indexes are useful in asset management decisionmaking at both
the project and network levels. Deterioration models for bridge load ratings would be
useful tools for evaluating the bridge capacity changes over time. More research into cost
and cost modeling is needed for bridge asset management. Cost can be financial cost as
well as environmental cost. With known costs, project- and network-level bridge
preservation optimization tools can be developed.

• The Bridge Evaluation and Accelerated Structural Testing (BEAST®) laboratory is the
world’s first accelerated testing facility for full-scale bridge systems.(38) BEAST subjects
bridges to extreme environmental and traffic loading to simulate decades of deterioration
in only months. The facility produces quantitative data on material and component
performance that can be used to study bridges’ long-term performance and operation. The
current study covers concrete decking systems, prestressed concrete girders, joints,
bearings, deck drainage, latex-modified concrete overlay, and ultra-high performance
concrete (UHPC) overlay systems.

• Other LTBP Program publications can be found at

https://highways.dot.gov/research/long-term-infrastructure-performance/ltbp/long-term-
bridge-performance-ltbp-program-publications.(39)

17
Observed Gaps

The literature review identified the following research gaps:

• More research is needed to standardize the quality control and performance evaluation
procedure for bridge preservation actions.

• More research is needed for using NDE/SM data in bridge deck or other element
deterioration modeling.

• More research is needed to develop a standard data collection and governance framework
for bridge preservation and maintenance activities. A uniform data framework would
facilitate more efficient data query and sharing and establish a more meaningful data
analysis supporting bridge preservation and management decisionmaking.

• BIM data needs and model updating to represent bridge preservation and maintenance
effects is helpful for preservation decisionmaking.

• Integration of agency-collected data (e.g., Highway Performance Monitoring System

(HPMS) data, weigh-in-motion (WIM) data, pavement profile and condition data, traffic
data, friction index data, climate data, cost data, etc.) into bridge preservation planning
and postactivity performance evaluation.

• Lifecycle and network-level bridge preservation planning are more advanced than
project-level bridge preservation decisionmaking. However, research about lifecycle and
network-level planning is still in the early stages, and more research is needed.

• Research into data sharing and information exchange is needed for the entire lifecycle of
bridge projects—from planning to design, construction, operation, and management in
BIM or a digital deliverables context so that bridge preservation and management
programs can adapt to the next-generation data environment.

• More research is needed correlating accelerated testing results with field-collected

performance data for testing validation. Once validated, the tests can be designed to
simulate performance data that are rarely available or hard to collect in the field.

TOPIC 3: BEST PRACTICES FOR BRIDGE DECK PRESERVATION

Deck preservation has been widely studied during the past decade. The ongoing pooled funded
project Bridge Deck Preservation Tool (https://www.pooledfund.org/Details/Study/701) and
Proposed AASHTO Guides for Bridge Preservation Actions
(https://www.trb.org/Publications/Blurbs/181532.aspx) answered many of the previous questions
about bridge deck preservation activities and selection criteria.(40,41) However, the existing
research addressed mainly the single selected treatments of individual bridges . Research into
individual bridge lifecycle planning and network-level planning for selected bridges is still in the
early stages and deserves more research. Risk-based performance-driven decisionmaking can
potentially lead to a more sophisticated and easy-to-implement approach.

18
Evaluations of deck sealer and overlay materials, technologies, and best practices are important
in deck preservation research. Because many ongoing research projects focus on case studies and
decision tool development, these areas can be revisited later. Emerging research needs for deck
preservation research may include new materials, the impact of climate change, heavy live load,
etc.

Background and Originally Proposed Objective and Scope

In current bridge inventory, about 90 percent of bridges have concrete decks. All State DOTs
recognize the importance of concrete deck preservation. The purpose of deck preservation
treatments is to protect decks and maximize service life with limited resources. Typical
treatments include the following:

• Concrete surface and crack sealers.

• Thin overlays.
• Periodic washing.
• Electrochemical treatments.
• Cathodic protection.
• Membranes.
• Coatings.

Research is needed to establish cost-effective lifecycle preservation programs for maintaining

and preserving concrete bridge decks.

State of Practice Based on Literature Review

The 90 literature reviews yielded the following results:

• Eighteen were about manuals, guides, and specifications.

• Fourteen were about overlays (not UHPC).

• Eleven were about UHPC overlays, which is also one of the major topics of Every Day
Counts-6 (EDC-6).(42)

• Eleven were about decisionmaking.

• Seven were about waterproof membrane or asphalt overlay.

• Seven were about service life analysis.

• Six were about the preservation effect or field performance evaluation.

• Five were about lifecycle cost analysis (LCCA).

• Four were about high-performance or new materials.

19
 • Three were about cathodic protection or chloride extraction.

• Two were about deck preservation protocols and tools.

• Two were about construction methods.

• Other research included sealer, high-friction surface treatment, patching, internal curing,
cleaning, preservation of posttensioned bridges, link slab, bridge seats and bearings, and
deck-cracking control and repair.

Related Work from FHWA EDC-6 (43)

• EDC-6 work with UHPC for bridge preservation and repair lead to the publication of a
report entitled Design and Construction of UHPC-Based Bridge Preservation and Repair
Solutions.(42,43) The report contains design and construction recommendations for three
promising and fastest growing UHPC preservation and repair applications: bridge deck
overlays, link slabs, and steel beam end repair. The report also includes other key
concepts of UHPC, such as material mechanical properties and durability. The
information is valuable for all owner agencies considering the development of UHPC
materials, construction, and design specifications.

Observed Gaps

The literature review identified the following research gaps:

• Bridge deck preservation decisionmaking has been thoroughly studied at the bridge and
project levels. However, more study is needed for lifecycle and network-level planning.

• Fiber-reinforced concrete is gaining attention for bridge deck and deck overlays
construction to prevent cracking. However, research into the material characteristics and
field performance data is not yet readily available for use in decisionmaking.

• More research is needed into ecofriendly materials that can be used in bridge deck
preservation or repair.

• More research is needed into the long-term field performance of corrosion resistant rebar
(e.g. glass-fiber-reinforced polymer (GFRP), stainless steel, etc.) reinforced concrete
deck and its preservation needs.

• More research is needed into NDE/SM integration for early deck damage and
deterioration detection and preservation.

• More research is needed into collecting NDE or other sensing data from the deck bottom,
such as by using an unmanned aerial vehicle (UAV) in deck preservation and
management decisionmaking.

20
 • More research is needed into the impact of climate change that causes extreme events and
how changes in the number of snow and freeze–thaw cycles will affect bridge deck
design, deterioration, and preservation.

• More research is needed into how live loads (e.g., heavy trucks and truck platooning)
affect the deterioration of bridge decks and preservation planning.

• UHPC bridge preservation applications can be further developed and tested in the future.
Examples are UHPC shotcrete, 3D printing, and UHPC for structural strengthening and
repair.

TOPIC 4: PRESERVATION OF CONCRETE HIGHWAY BRIDGE SUBSTRUCTURE

Active corrosion is common for bridge substructures. Early prevention actions, such as applying
surface treatments prior to chlorides reaching critical concentration at rebar depth, are effective.
However, more research is needed on schedules for applying and reapplying. Once rebar
corrosion has started, preservation actions that can reduce deterioration rate are needed. In
addition to specific preservation techniques, strategic decision matrices and tools for preservation
planning are needed.

Background and Originally Proposed Scope and Objective

States need to develop guidance that highway agencies can follow in applying technologies that
prevent or delay corrosion initiation, reduce corrosion rate, extend service life, and enhance the
long-term durability of concrete bridge substructures. States need to develop strategic decision
matrices for when and what corrosion mitigation strategies to implement to prolong the service
lives of in-service highway bridge substructures because gaps still exist.

State of the Practice Based on Literature Review

The literature review results showed that in the past 10 yr, corrosion prevention and mitigation
techniques were the most studied topics for bridge substructure. Among the topics, cathodic
protection has been the most studied approach, followed by inhibitor and corrosion-resistant
rebars.

Marine and coastal environment and the application of chloride deicing agents were found to be
the two major factors that caused corrosion. Corrosion and remaining service life modeling was
widely studied. Multihazard and climate change are considered in many of the studies. Research
was also conducted into corrosion management, lifecycle assessment, and critical chloride
thresholds. The performance of corroded components was also studied in many previous
projects. Other studies included corrosion detection for girders, structural steel, steel piles, metal
culverts (pipes), and mechanically stabilized earth walls (MSEWs).

21
Following is a summary of approximately 270 literature review results:

• Corrosion mitigation (171 items):

o Cathodic protection was the most studied approach (48 items).

o Twenty-four were about inhibitors.
o Twenty were about corrosion-resistant rebar.
o Eighteen were about special concrete mixture design.
o Sixteen compared different methods or literature reviews.
o Ten were about rebar coating.
o Eight were about fiber-reinforced-polymer (FRP) external bond/wrap/jacket.
o Eight studies used multiple corrosion mitigation approaches simultaneously.
o Five results were about electrochemical chloride extraction and electrochemical
realkalization.
o Ten were about other methods.
o Four were about concrete surface coating.

• Ninety-two results were about corrosion-impacting factors:

o Sixty-six were about marine and coastal environments.

o Fourteen were about deicing salt.
o Twelve were about global warming.

• Sixty-five of the results were about modeling:

o Eight were about multihazard modeling.

o Nine were about how climate change affects corrosion initiation and propagation.
o Others focused on corrosion deterioration modeling, remaining-life prediction,
concrete cracking and diffusion, and rebar corrosion modeling.

• Corrosion detection with NDE/SM had 29 results:

o Half-cell potential was the most studied method and had seven results.
o Electrochemical-based method had six results.
o AE had three results.
o Polarization resistance had two results.
o Ground penetration radar had two results.
o Corrosion rate monitoring had four results.
o Five were about other.

• Corrosion detection for specific components: Girders (5 results), structural steel

(3 results), piles (17 results), metal pipeline (1 result), MSEW (2 results).

• Sixteen of the results were about the performance of corroded components.

• Eight of the results were about corrosion management and LCCA.

• Four of the results were about critical chloride threshold.

22
 • Six of the results were corrosion-related specifications.

• Other research included chloride permeability, chloride ponding test improvement, and
concrete cover crack propagation. Studies focused on concrete crack and rebar corrosion
modeling, diffusion modeling, cathodic protection modeling, deterioration, and
remaining-life prediction also exist.

Observed Gaps

The literature review identified the following research gaps:

• More field-collected long-term-performance data is needed for corrosion-resistant rebars

(e.g., stainless steel rebar, GFRP, carbon-fiber-reinforced polymer (CFRP), and
microcomposite multistructural formable steel rebar) embedded in concrete. These data
are critical for bridge design as well as preservation and management decisionmaking.

• More field-collected long-term-performance data for UHPC that can be used to support
preservation decisionmaking is needed.

• Many NDE/SM research projects focus on corrosion or corrosion environment detection,

but very few of them apply the NDE/SM data to bridge preservation and management
decisionmaking.

• More research is needed for integrating NDE/SM corrosion detection data into digital
twin models or BIM models for a real-time model updating that would reflect the
operational condition of bridges to support bridge preservation decisionmaking.

• More research is needed to develop an element-based data framework that supports

defect inspection.

• Much research is needed on cathodic protection. However, cathodic protection’s adoption

by State DOTs is limited, and research is lacking about the reasons cathodic protection is
not more widely accepted by States.

• More studies are needed that estimate the impact of climate-change-caused accelerated
corrosion development and how such studies would affect asset management
decisionmaking.

• More research is needed for bridge deck, superstructure, and substructure lifecycle
corrosion management planning.

TOPIC 5: CORROSION PREVENTION AND MITIGATION TECHNOLOGIES FOR

CONCRETE COMPONENTS

Corrosion prevention and mitigation are important for preserving the condition and extending the
service lives of concrete structural components. The cost and performance of available
preservation actions are essential in decisionmaking, and they are not fully studied or
documented.

23
Background and Originally Proposed Scope and Objective

This research is proposed to conduct an extensive field evaluation of the most common concrete
structure corrosion protection and mitigation technologies in use since approximately 1980. The
study should address the following parameters:

• Initial cost (difference) during construction or postconstruction application.

• Complexity of installation and construction (e.g., level of effort, training, and

environmental concerns).

• Performance since installation—and comparison, if possible, to the performance of

similar bridges in similar environments without these protective systems.

• Required maintenance (if any) performed to keep the technology functional.

• Cost of maintenance performed to keep the technology functional.

State of the Practice Based on Literature Review

Many of the results found in the previous section are also related to the state of the practice. In
addition to those results, another approximately 110 papers and reports were found from the
literature review. Most of them focused on preserving concrete bridge decks and superstructures.
The most studied corrosion prevention and mitigation approach for concrete structures is
cathodic protection, followed by concrete sealers and sealants or surface-applied inhibitors.

The approximately 110 papers and reports yielded the following results:

• Thirty-three were about cathodic protection.

• Fifteen were about concrete sealer and sealant or surface-applied inhibitors.

• Nine were about corrosion-resistant rebars.

• Eight were about inhibitors.

• Six were about concrete or asphalt overlays.

• Five were about epoxy-coated or other coating systems for rebars.

• Four were about the use of lower permeate concrete or special concrete mixtures.

• Four were focused on LCCA.

• Four compared multiple methods.

• Three were about corrosion prevention of posttension components.

24
 • Two were about performance-testing methods.

• Other results included studies of multiple impact factors, lifecycle corrosion treatment
plans and management planning, factors that affect corrosion, etc.

Related Work From the FHWA Coatings and Corrosion Laboratory

Determining the corrosion performance of coating and metal materials through laboratory
approaches is one of the tasks of the FHWA Coatings and Corrosion Laboratory. Publications by
the laboratory can be found at https://highways.dot.gov/research/laboratories/coatings-corrosion-
laboratory/corrosion-coating-publications.(44) The laboratory’s research projects have covered the
topics of coatings, corrosion of reinforcing steel, corrosion in prestressed concrete, and others.

In parallel with laboratory evaluation, field evaluation for material corrosion performance and
the effect of corrosion prevention methods is still important. More corrosion-resistant materials
and corrosion mitigation approaches need validation in the laboratory and in the field, with
exposure to realistic highway operation environments. For example, cathodic protection is one of
the most studied corrosion prevention and mitigation approaches in the literature and the
laboratory, but its application in bridge preservation practice is still limited. More laboratory
research and field performance data would be useful for further validation and future adoption.

Observed Gaps

The literature review identified the following research gaps:

• The most studied corrosion mitigation method for concrete structural components is
cathodic protection. However, its adoption by State DOTs is limited. Research into the
reasons cathodic protection is not more widely accepted by States is lacking.

• More research is needed into the live-load effect on the corrosion performance of bridge
decks.

• Research into cost information and LCCA or ROI analysis is limited.

• More research is needed into bridge deck lifecycle corrosion management planning.

• More research is needed into laboratory and field performance concerning

corrosion-resistant materials, including UHPC.

• More research is needed into how climate change and extreme events affect bridge deck
corrosion performance.

• Projects led by the FHWA Coatings and Corrosion Laboratory have provided useful
knowledge that supports bridge preservation decisionmaking. However, most of the
studies were based on material-level accelerated laboratory testing. Structure-level and
field-performance data are needed to validate the laboratory-testing data and thereby
support more accurate preservation decisionmaking and management planning.

25
TOPIC 6: DETERIORATION MODELING ACCOUNTS FOR PRESERVATION
ACTIONS AND PRESERVATION EFFECTS

Deterioration models are key in bridge preservation decisionmaking. Bridge component

deterioration modeling has been widely studied during the past decade. However, the
development of element-based deterioration models, early deterioration modeling that allows for
early preservation intervention, and postaction modeling are all in their early stages.

Background and Originally Proposed Scope and Objective

States need to study the performance of various bridge preservation actions and develop
deterioration models that account for the performance of preservation actions in bridge
management calculations.

States need to develop quantitative models of the time until onset of deterioration and become
sensitive to adherence to preventive maintenance policies. Models would be quantified for
common routine maintenance treatments, such as washing and sealing, and agencies could
extend the models for other types of preventive maintenance. Such models would be developed
according to the AASHTO Guide to Commonly Recognized (CoRe) Structural Elements and
would be compatible with their standardized condition state language for visual inspection.(45)

State of Practice Based on Literature Review

The literature review found 426 results, among which the most widely studied topics were
deterioration modeling (153 items) and bridge asset management (60 items). Transportation
Pooled Fund-5(432) Bridge Element Deterioration for Midwest States is one of the pilot
projects.(46) In the project, element deterioration models were developed using new element data
and taking a Markov chain approach. Relevant data were collected from participant States, and,
along with inventory data and collected NDE data, the collected maintenance information was
saved in a SQL database to facilitate future updates and easy data sharing. Most of the asset
management topics found from the literature review focused on maintenance and inspection
planning:

• One hundred fifty-three results were about deterioration modeling.

• Thirteen were about survival and transition analysis.

• Sixty-two were about bridge asset management: preservation or maintenance planning.

• Eighteen were about bridge inspection intervals and maintenance planning and
optimization.

• Seventy were about bridge preservation, maintenance, and repair activities.

• Eleven were about the impact of preservation and maintenance activities or the impact of
investment.

• Fifteen were about performance evaluation or new performance measurements.

26
 • Fifteen were about cost models.

• Fifteen were about bridge service life prediction or remaining service life.

• Six were about the risk and resilience of bridges.

• Thirty-eight were about lifecycle analysis.

• Ten were about BIM or digital twin or data-sharing workflow.

• Other topics included one repair of bridge approaches, three for detection of abnormal
behaviors, two for cracking predictive models, two for service life design, two for
corrosion modeling, one for seismic fragility study, one for robust modeling, one about
NBE and NBI conversions, one about the effect of climate change, three about health
index, and two about sustainability.

Observed Gaps

The literature review identified the following research gaps:

• More research is needed into deterioration modeling that considers:

o Impact of climate change.

o Impact of heavy truckload.
o Effect of bridge preservation and maintenance activities.
o Structural capacity.

• More research is needed into the environmental footprint, performance impact, and
lifecycle cost impact of bridge preservation and maintenance activities.

• More research is needed into resilience and how resilience affects bridge preservation
decisionmaking.

• More research is needed into substructure and foundation preservation and maintenance
activities.

• More research is needed into data-sharing requirements for supporting bridge operation
and asset management in BIM or digital twin environments.

• More research is needed to identify and collect data for early stage deterioration
modeling that supports preservation decisionmaking.

• More research is needed into risk-based bridge preservation planning.

27
TOPIC 7: WATERTIGHT JOINTS

Joint leakage is the major factor that caused the deterioration of adjacent decks, beam ends, and
bearings. Eliminating joints by using integral abutment and link slabs is an effective way to
avoid such maintenance issues. Joint maintenance, replacement, and repair actions and related
performance evaluations are needed for existing bridges.

Background and Originally Proposed Scope and Objective

Maintaining watertight joints is essential preserving the condition of adjacent decks,

superstructures, and substructures.

State of the Practice Based on Literature Review

The literature review extended the original scope to general joints-related research; 191 papers
were found, of which 160 or so were about bridge deck joints. The most studied topic was joint
sealant and filler. The joint maintenance, replacement, and repair of UHPC and fiber-reinforced
joints and link slabs were all studied at different levels. Some studies also involved deterioration
modeling for joints. Details of the literature review results are summarized as follows:

• Five papers discussed jointless bridges and eliminating joints on existing bridges. The
author concluded that elimination of transverse joints is a practical and cost-effective
approach to avoiding joint leakage and leakage-induced damage and corrosion of
bearings, superstructures, and substructures.

• Nine papers were about link slab studies. Materials for link slabs, link slab design and
construction, and analysis approaches were studied. Link slabs were effective in
eliminating deck joints.

• Fifteen papers were about UHPC joints, and six papers were about fiber-reinforced
concrete joints. UHPC for bridge preservation and repair is one topic of EDC-6.(42)

• Twelve papers were about longitudinal joints, which included longitudinal joints for
wider decks, joints between box girders, or joints between other adjacent concrete
members.

• Twelve papers were about expansion joints. Materials, installation procedure,

maintenance, replacement of all types of expansion joints, and sealant and filler materials
were thoroughly documented.

• Five papers discussed asphalt expansion joints (asphalt plug joints).

• Three papers discussed strip seal.

• Twenty-three papers discussed joint sealant and filler.

• Three papers discussed sealer and membranes.

28
 • Two papers discussed modular joints.

• One paper was about ribbed loop joint, and one paper was about half joint.

• Six papers were about joint design.

• Two papers were about joint cleaning.

• Five papers were about LCCA.

• Two papers were about joint management systems and asset management.

• Eight papers were about material testing.

• Eleven papers were about material standards.

• Sixteen papers were about joint maintenance, replacement, and repair.

• Four papers were about joint monitoring.

• Seven papers were about performance assessment and deterioration modeling.

• One paper was about pier cap and beam end repair caused by joint leakage.

Observed Gaps

The literature review identified the following research gaps:

• Nationwide case studies to identify and document best practices for expansion joints,
jointless bridges (including joint elimination), and associated LCCA are needed.

• The link slab concept is relatively new; more studies can achieve a better understanding
for material selection (fiber-reinforced concrete, UHPC, or regular concrete), behavior,
and performance. Such studies could lead to the development of guidelines for link slab
design, construction, monitoring, and preservation. UHPC link slab is one topic regarding
the current EDC-6 UHPC for bridge preservation.(42) The advantages of replacing
expansion joints with UHPC link slab were documented. The design of UHPC link slab
was also studied and documented. However, the long-term performance of UHPC link
slabs and their deterioration, maintenance, and preservation still need investigation. In
addition, the behavior of link slabs on bridges in seismic zones needs study.

• More work is needed on bridge deck joint deterioration modeling.

• A joint selection decision tool needs to be developed.

• The problem caused by longitudinal joints was observed, but solutions need to be fully
studied and recommended.

29
 • Maximum span length for integral abutment needs to be established at the national level.
Considering bridge preservation during design is also important.

• Replacement of stub abutments on existing bridges with semi-integral abutments can

reduce joint maintenance needs and be economical from a lifecycle point of view. LCCA
can be used to justify the cost effectiveness.

• Long-term monitoring of performance of joints is needed.

• Workflow and data sharing for joint management need to be identified as a component of
BIM for bridge maintenance and management. (No work has been done to develop data
dictionaries of joint elements).

TOPIC 8: DEVELOPMENT OF BRIDGE MAINTENANCE DATABASE

The National Bridge Maintenance Database (NBMD) was proposed and framed in National
Cooperative Highway Research Program (NCHRP) 14-15 to enable DOTs to evaluate the costs
and performance of maintenance actions, execute cost–benefit analysis, and better manage
bridge maintenance resources.(47) The data and data format suggested in the database are useful
for understanding the performance and cost of maintenance activities. It would be helpful if State
DOTs’ adoption status and update suggestions could be investigated and the system updated to
reflect current needs.

Background and Originally Proposed Scope and Objective

NCHRP 14-15 has developed a standardized data structure for reporting and sharing bridge work
accomplishment data.(47) The researchers proposed the project to gather bridge work
accomplishment data in NCHRP 14-15 format from any agency able to provide such data. The
project then quantified production functions, cost functions, and outcome functions as envisioned
in the 14-15 report. The production functions and cost models account for both direct and
indirect resource inputs.

State of the Practice Based on Literature Review

NCHRP 14-15 provided a framework for a database system—NBMD—for uniform reporting of

bridge maintenance actions.(47) The database is in a uniform and readable format for bridge
maintenance, condition, and inventory data. The database conforms with the NBI format. NBMD
collects outputs from existing DOT data systems and casts the outputs into a standard format.
The database was designed to have 13 tables presenting bridge maintenance activities along with
bridge inventory and condition data. The data formats include tab-delimited text files and
Extensible Markup Language (XML) documents, each conforming to a standard XML schema.

Instead of focusing only on topics related to NCHRP 14-15, the literature review was extended to
include general topics of cost modeling.(47) Among the 300 or so results, 171 were bridge related;
others focused more on pavement, roadway, or other infrastructure structures. The most studied
topics focused on cost estimation, probabilistic modeling, prediction modeling, and risk and
uncertainty estimation. The following is a summary of the results:

30
 • Four were about State implementation of a construction cost index.

• Fifty-six were about general cost estimation.

• Forty were about maintenance cost.

• Thirty-two were about user cost, and four about user and agency costs.

• Twenty-four were about asset management.

• Fifteen were about early cost estimation—either preconstruction cost or cost estimation
made during planning or preliminary design.

• Fourteen focused on construction cost only.

• Fourteen were about cost overrun.

• Thirteen were about work zone cost (most were user cost).

• Thirteen were about network-level analysis.

• Eight discussed cost data integration with BIM models.

• Eight were about the cost benefit of activity-based-costing.

• Five were about cost due to lane closure.

• Three were about construction material quantities and time estimation.

• Two were about network cost.

• Two were about congestion cost.

• Other topics included one about accident cost, one about night construction, one about
pay items from the design development process, one about cost and demand forecast, one
about cost comparison between using in-house staff and using a consultant, one about
incentive study, one about sustainable bridge invention strategies, one about project delay
cost, and one about asset valuation.

Observed Gaps

The literature review identified the following research gaps:

• More research is needed into adopting an NCHRP 14-15 national maintenance database
and the need for updating.(47)

• More research is needed into data frameworks and governance for cost information
collection and application.

31
 • More research is needed into lifecycle cost savings due to emerging technologies, such as
the adoption of BIM design, digital deliveries, and remote sensing and virtual reality for
construction management and truck platooning.

• More research is needed into cost impacts due to climate-change-caused bridge

preservation needs.

• More research is needed into lifecycle cost due to live-load changes: increasing average
daily truck traffic, truck weight, and truck platooning.

• More research is needed into lifecycle costs of bridge preservation activities.

• More research is needed into element-based bridge preservation costs. Data on element-
based preservation activities and costs need to be collected, and best practices established
through case studies would be helpful.

• More research is needed into the use of environmental cost or carbon footprint as an
optimization factor in bridge management.

TOPIC 9: APPLYING ELEMENT DATA IN BRIDGE PRESERVATION AND

MANAGEMENT

New AASHTO elements were adopted into bridge inspection practice in 2014, which addressed
most of the research needs identified in the 2008 roadmap.(48,1) In the current NBE data system,
element data do not provide damage location information.(34) The computed health index
considers only damage quantity, not location. Damage location information is important for
performance evaluation and preservation decisionmaking. Recent developments in project
deliverables, bridge inspection and operation, and other technologies have generated new
research requirements and opportunities for bridge elements.

Background and Originally Proposed Scope and Objective

This research will develop a recommendation to modify and supplement the current list of
elements. The proposed modified and new elements will be presented to AASHTO’s bridge
management community for adoption and integration into current and future bridge management
systems.

State of the Practice Based on Literature Review

The new AASHTO elements adopted in 2014 addressed most of the previously identified
research needs for NBE data.(48) Current bridge elements have three categories: NBE, Bridge
Management Elements (BME), and Agency Developed Elements (ADE). Regarding ADEs,
agencies can define their own elements as subsets of NBE/BME (e.g., beam ends) or
independent agency-defined elements (e.g., movable bridge components). All elements have four
fixed-condition statuses. During the 8 yr of implementation of AASHTO elements inspection,
more and more State DOTs have been creating different ADEs. Some of the created ADEs might
also be useful for other States or bridge owners. Awareness of ADE development status will help
evaluate the potential to adopt ADEs as NBE or BME.

32
Meanwhile, detailed information about bridge elements is more readily available due to the
implementation of digital deliverables. The development of a bridge data dictionary for digital
as-built, digital twin, or BIM models—along with identifying information exchange
requirements for bridge operation, inspection, and management—provides the opportunity to
include more information for current bridge elements or to identify the need for new elements for
special bridges. In addition, planning for next-generation bridge element systems within digital
deliverables and BIM frameworks can never start too early.

The literature review found 50 results. Following is a summary of the findings:

• Fourteen results were about applying element data in bridge asset management.

• Sixteen results were about element inspection manuals.

• Two results were about the UNIFORMAT II (ASTM E2103) classification of bridge
elements.(49)

• Two results were about new elements.

• Five results were about BIM, a data dictionary, and 3D modeling.

• Two results were about more information for elements.

• Two results were about element data and NBI data conversion.(33)

• One result was about definitions of bridge preservation, maintenance, and replacement.

• One result was about defining significant predictors for bridge health indexes and
defining bridges in poor condition with element data.

• Five results were about other content.

Observed Gaps

The literature review identified the following research gaps:

• More research is needed into element inspection that supports effective and systematic
defect and maintenance reporting. Development of an effective and systematic defect
inspection and maintenance activity reporting framework is needed.

• More research is needed to identify new bridge elements for special bridges (e.g.,
movable bridges) or to incorporate additional information (e.g., location or position
information like beam ends or more precise position information associated with damage
and deterioration) into existing elements. Such information is important in bridge
management decisionmaking.

• Research is needed to evaluate ADE and determine its potential for adoption as NBE or
BME.

33
 • More research is needed to develop next-generation bridge elements within digital
as-built, digital twin, or BIM frameworks. Developing a new bridge element system in
the digitalization context would never be too early.

• More research is needed to develop a risk index using inventory data and other available
information (e.g., NDE/SM data, failure probability data, and failure consequence data)
to support bridge preservation planning.

TOPIC 10: PILE PRESERVATION AND STEEL CORROSION PREVENTION

Corrosion is the most common damage and deterioration mode for steel bridge piles. The topic
covers research related to performance evaluation, corrosion prevention and mitigation, and
damage repair of steel piles.

Background and Originally Proposed Scope and Objectives

This research aims to develop one or more methods to determine the condition of and remaining
service life of in-service exposed and unexposed steel piles in environments of varying
aggressiveness and to identify methods to preserve such piles.

State of Practice Based on Literature Review

Most of the previous research focused on steel pile corrosion mitigation and repair. Among the
57 results, cathodic protection was the most widely studied algorithm, followed by FRP repair.
Some projects also studied NDE/SM techniques for corrosion and damage detection, factors that
affect corrosion development, and the performance of corroded piles. Other topics also studied
included corrosion rate and simulation, pile fatigue, coasting, coating effects on force and
deformation characteristic of steel piles, drilled shafts, sheet piles, pipe piles, foundation reuse,
durability, soil-pile interaction modeling, fragility analysis, response to bridge foundation failure,
LCCA, pile-type selection criteria, and service life of a steel structure.

The 145 literature reviews yielded the following results:

• Fifty-four were about corrosion mitigation and repair:

o Cathodic protection was the most studied technology (18 results).

o FRP repair was also very well studied (17 results).

o Other approaches included coating (seven results), metal cold-air spray (one result),
thermal spray (one result), petrolatum-based wrap (three results), UHPC (three
results), concrete jacket (three results), and bolted or welded steel shapes or plates
(one result).

• Twenty-eight were about factors affecting corrosion development:

o Four were about the environment.

o Three were about climate change.

34
 o One was about expansion joint degradation.
o One was about salt effect.
o Four were about soil properties.
o Four were about dissolved inorganic nitrogen.
o Ten were about fouling and antifouling coating or microbiologic-influenced corrosion
and deterioration.
o One was about contaminated water.

• Thirteen were about the performance of corroded piles.

• Eight were about NDE for corrosion detection:

o Two were about ultrasonic-guided waves.

o Two were about eddy currents.
o One was about sonic echo impulse response.
o Two were about pile depth estimation.
o One was about surface topography.

• Four were about repair methods and decisionmaking matrices.

• Four were about the analysis, design, and construction of steel piles.

• Two were about corrosion rate and corrosion simulation.

• Two were about steel pile fatigue.

• The remaining 30 reviews included coating effects on force and deformation

characteristics of steel piles, drilled shafts, sheet piles, pipe piles, foundation reuse,
durability, soil pile interaction modeling, fragility analysis, response to bridge foundation
failure, LCCA, pile type selection criteria, and service life of steel structures.

Observed Gaps

The literature review identified the following research gaps:

• More study of element-based steel pile deterioration modeling is needed.

• More research is needed into integrating NDE/SM data into early corrosion and
deterioration modeling and prevention decisionmaking.

• More research is needed into underwater NDE technologies (e.g., underwater inspection
robots) that can collect useful data to support pile management decisionmaking.

• More research is needed into SM for corroded piles to collect performance data to
support decisionmaking and policy making.

• More study is needed on cost data collection and modeling that supports steel pile
preservation and maintenance planning.

35
• More study is needed on how the performance of steel piles is affected by climate
change, live-load change, and extreme events and how performance, in turn, affects
preservation and management decisionmaking.

• More study is needed on why cathodic protection is not more widely accepted by bridge
owners.

• More field-collected long-term-performance data on the performance of FRP pile repair

is needed. Best practices and guidance for FRP pile repair were not established.

• More research is needed into steel pile lifecycle corrosion management planning.

• More research is needed into using special materials (e.g., corrosion-resistant and
ultra-high performance materials) for pile construction and preservation.

36
 CHAPTER 5. RESEARCH TOPICS

The author proposes the following research topics to cover the gaps identified in chapter 4.

CORROSION EVALUATION, PREVENTION, AND MITIGATION FOR BRIDGE

PRESERVATION

Based on the identified gaps, the following research topics are proposed:

• Performance and preservation needs for corrosion-resistant rebar (e.g., stainless steel,
CFRP/GFRP, chromium alloy steel, continuously galvanized rebar (CGR) and duplex
coating rebar)-reinforced bridge components and elements (e.g., decks, superstructures,
substructures, and piles) (C1 *).

• Identification of performance and preservation needs for bridge components and elements
with duplex coatings (C2*).

• Assessments of cost, performance, and service life extension of corrosion protection,

prevention, and mitigation techniques (C3*).

• Impacts of climate change on corrosion initiation and development and the effects on
bridge preservation and management decisionmaking.

• Cathodic protection for bridge decks, superstructures, substructures, and piles;

determination of best practices; and creation of guidelines.

• Live-load effects on bridge corrosion initiation and propagation and their impacts on
bridge preservation and management decisionmaking.

• Use of NDE/SM data to enhance early detection of corrosion initiation and propagation
and facilitate early corrosion prevention intervention.

• Identification of performance matrix and testing methods to measure the effectiveness of

corrosion prevention and mitigation techniques.

DATA FOR BRIDGE PRESERVATION

Based on the identified research gaps, the following research topics applying element data,
NDE/SM data, and other data in bridge preservation and management are proposed.

*
Topic identities in table 1.

37
Element Data in Bridge Preservation and Management

The following are identified topics for element data:

• Evaluation of ADE and determination of its potential for adoption as NBE or BME.

• Element-based defect-reporting framework that includes damage location information.

• Development of an element data framework to accept BIM and digital as-built data that
provide improved information for preservation and management decisionmaking (D4 *).

NDE/SM Data in Bridge Preservation and Management

Following are identified topics for NDE/SM data:

• Development of bridge preservation planning, project costs, and quantity estimations for
bridges, with and without NDE/SM data (D1*).

• Integration of construction and sensing data (e.g., light detection and ranging (LiDAR),
UAV, and NDE/SM data) into 3D bridge models or digital as-builts to facilitate more
efficient and effective bridge preservation and management decisionmaking (D2*).

• AI-based and big-data-based approaches for NDE/SM data analysis that support effective
bridge preservation and management decisionmaking.

• Use of WIM data, NDE/SM data, and inventory data to determine the live-load effect on
the performance of bridge components or elements and preservation decisionmaking.

• Use of NDE/SM data to enhance early deterioration modeling and improve preservation
and maintenance decisionmaking (D3*).

• UAV, unmanned water vehicle, and unmanned ground vehicle data in bridge preservation
and asset management decisionmaking.

• The possibility of collecting NDE or other sensing data from deck bottoms (e.g., via
UAV) and the use of such data in deck preservation and management decisionmaking.

Other Data for Bridge Preservation and Management

Following are identified topics for other data:

• Development of a bridge maintenance data collection framework to understand bridge

preservation activities (D5*).

• Evaluation of potential bridge preservation applications using currently available but

underused data (D6 *).

*
Topic identities in table 1.

38
 • Identification of data needs for post-extreme-event bridge repair or rebuild
decisionmaking (D7*).

BRIDGE PRESERVATION AND MANAGEMENT OF LIFECYCLE PLANNING

Based on identified gaps, research topics are proposed for cost modeling, deterioration modeling,
and decision making.

Cost modeling

Following are topics for cost modeling:

• Lifecycle cost savings due to adopting new materials and new technologies in bridge
preservation (P4*).

• Quantification of the effects of bridge preservation activities (P2*).

Deterioration modeling

Following are topics for deterioration modeling:

• Development of element and health-index-based deterioration modeling (P3*).

• Live-load effects on bridge performance and impacts on preservation and management

decisionmaking (P5*).

• Deterioration modeling that considers the impacts of climate change and other
environmental factors.

• Deterioration model of structural capacity (load-rating deterioration modeling).

• Bridge resilience and how it affects bridge preservation and asset management
decisionmaking.

Decisionmaking

Following are topics for decisionmaking:

• Methods to integrate risk assessment into bridge preservation and management

decisionmaking (P1*).

• Quantification of the effects of bridge preservation activities through accelerated

laboratory testing, field testing, and inventory data analysis (P2*).

• Bridge preservation decisionmaking that considers environmental costs and resilience.

*
Topic identities in table 1.

39
 • Performance-based and risk-based bridge preservation and management planning.

• Network-level and lifecycle bridge preservation and management planning.

ECOFRIENDLY AND SUSTAINABLE MATERIALS AND TECHNOLOGIES FOR

BRIDGE PRESERVATION AND REPAIR

Based on the identified gaps, the following research topics are proposed:

• Sustainable and innovative techniques and materials for bridge and tunnel preservation or
repair (S1 *).

• Consideration of environmental costs of bridge preservation and asset management

decisionmaking and planning.

• Preservation techniques to improve bridge resilience and protect bridges from natural and
man-made hazards.

BRIDGE DECK PRESERVATION AND MANAGEMENT

Based on the identified gaps, the following research topics are proposed:

• Identification of standard tests for quality assurance and performance evaluation of deck
preservation activity (B1*).

• Performance of UHPC overlays:

• Accelerated testing data.

• Field data.

• Validation and calibration of testing data with field data.

• Use of testing data to predict performance.

• LCCA.

• Bridge deck lifecycle preservation and management planning.

• Performance of fiber-reinforced concrete for bridge deck and deck overlay (B2*).

• Ecofriendly materials and techniques for bridge deck preservation and repair.

• Live-load effects on bridge deck performance and impact on preservation and

management decisionmaking.

*
Topic identities in table 1.

40
 • Impact of climate change on bridge deck performance, preservation, and improvement in
decisionmaking.

PRESERVATION OF SUPERSTRUCTURE AND SUBSTRUCTURE

Based on the identified gaps, the following research topics are proposed:

• Identification of performance matrix and testing methods to measure the effectiveness of

bridge substructure and superstructure preservation techniques.

• UHPC shotcrete for bridge superstructure and substructure preservation (B4 *).

• Case study for beam end repair of prestressed concrete beams, steel girders, and other
beams.

• Early deterioration and damage detection and treatment and prevention of deterioration
and damage of substructures.

• Fire damage monitoring, reporting, repair, and prevention (B5*).

• Vehicle and vessel collision monitoring, reporting, repair, and prevention (B5*).

• Identification of effective approaches to substructure and superstructure preservation

(B6*).

PRESERVATION OF BRIDGE PILES

Based on the identified gaps, the following research topics are proposed:

• Impact of environmental factors and live load on bridge pile performance, preservation,
and management decisionmaking.

• Bridge pile lifecycle preservation and management planning (B6*).

• Performance and preservation needs of UHPC piles and LCCA.

• Performance and preservation needs of FRP pile in marine environments and LCCA.

• Case study for FRP repair of bridge pile.

• Underwater NDE robot or SM systems for pile performance evaluation and integration of
data into pile preservation decisionmaking.

• SM for the performance of deteriorated or damaged piles and use of data in management
decisionmaking.

*
Topic identities in table 1.

41
 • Identification of performance matrix and testing methods to measure the effectiveness of
pile preservation techniques.

PRESERVATION OF WATERTIGHT JOINTS

Based on the identified gaps, the following research topics are proposed:

• Guidelines for link slab design, construction, inspection, and preservation (B3 *).

• Case study, best practices, performance measurements, deterioration modeling, and

LCCA for the following:

o Expansion joints.
o Link slab (guidelines for design, construction, and performance evaluation).
o Joint elimination (semi-integral abutment, link slab, etc.) and jointless bridges.
o Longitudinal joints.

With the comments from the FHWA internal review, the author selected high-priority topics,
which are shown in table 1.

Table 1. High-priority bridge preservation research topics.

Category Topic ID Topic

Develop methods to integrate risk assessment into bridge
P1
preservation and management decisionmaking.
P2 Quantify the effects of bridge preservation activities.
Planning P3 Develop element- and health-index-based deterioration models.
Assess LCCA and performance of new materials and new
P4
technologies in bridge preservation.
Evaluate live-load effects on bridge performance and how they
P5
affect preservation and management decisionmaking.
Develop bridge preservation planning, project costs, and quantity
D1
estimations for bridges, with and without NDE/SM data.
Integrate construction and sensing data (e.g., LiDAR, UAV, and
NDE/SM data) into 3D bridge models or digital as-builts to
D2
facilitate more efficient and effective bridge preservation and
Data management decisionmaking.
Develop methods to leverage NDE/SM data to enhance early
D3 deterioration modeling and improve preservation and maintenance
decisionmaking.
Develop an element data framework that accepts BIM and digital
D4 as-built data and provides enhanced information for preservation
and management decisionmaking.

*Topic identities in table 1.

42
 Category Topic ID Topic
D5 Develop a bridge maintenance database framework.
Identify available but underused data and evaluate the data’s
D6 potential benefit in bridge preservation and management
decisionmaking.
Identify unique data needs for post-extreme-event bridge repair or
D7
rebuild decisionmaking.
Develop or identify sustainable techniques and materials for bridge
Sustainability S1
preservation and repair.
Identify performance and preservation needs for corrosion-resistant
rebar (e.g., stainless steel, CFRP/GFRP, MMX, CGR, epoxy
C1 coated, and new textured epoxy rebar), reinforced bridge
components and elements (e.g., deck, superstructure, substructure,
Corrosion and piles).
Identify performance and preservation needs for bridge components
C2
and elements with duplex coatings.
Assess cost, performance, and service life extension of corrosion
C3
protection, prevention, and mitigation techniques.
Identify evaluation methodology (including standard tests) and data
B1 framework for quality assurance and performance evaluation for
deck preservation activities.
Evaluate the performance of fiber-reinforced concrete for bridge
B2
decks and deck overlays.
Develop guidelines for link slab design, construction, inspection,
B3
Preservation and preservation.
of bridge Assess UHPC shotcrete or other applications for bridge
B4
components preservation.
Develop methods to monitor, report, repair, and prevent fire
B5
damage and vehicle and vessel collisions.
Evaluate techniques for the preservation of bridge piles,
B6
substructures, and superstructures.
Develop performance criteria, corrective actions, and optimization
B7
for bridge approach systems.

43
 CHAPTER 6. REVIEW AND RANKING

A draft of this document went through FHWA internal and external review, and the author
collected feedback. The following describes the review and feedback collection procedure:

• The first draft of the roadmap was sent for review to engineers in FHWA’s Office of
Infrastructure Research and Development, the FHWA senior bridge preservation
engineer, the FHWA senior bridge management engineer, and all team leaders of FHWA
structure disciplines. The draft was revised to address their comments, and a list of
high-priority bridge preservation research topics was created. The updated version was
sent to the same group of FHWA personnel for further followup.

• The revised draft was sent for external review. A small WG consisting of BPETG
members was formed to conduct the first round of external review. The author received
and incorporated the WG’s input regarding topic grouping and ranking.

The third draft version was distributed to members of the TSP2 national deck
preservation WG members, the AASHTO Bridge Preservation Technical Subcommittee
(T-9), and FHWA BPETG for final external review. Presentations were given to the TRB
Bridge Preservation Committee (TRB AKT60), AASHTO T-9, the small WG, and
FHWA BPETG to collect feedback. FHWA BPETG members were asked to select their
top three topics from the high-priority project list. Fifteen responses were received.
Collective responses showed interest in the following 13 topics, in priority order:

1. P2: Quantify the effects of bridge preservation activities.

2. P1: Develop methods to integrate risk assessment into bridge

preservation/management decisionmaking.

3. D5: Develop an NBMD framework. Develop a bridge maintenance data collection

framework to understand bridge preservation activities.

4. B1: Identify evaluation methodology (including standard tests) for quality assurance
and performance evaluation for deck preservation activities.

5. P4: Assess the LCCA and performance of new materials and new technologies in
bridge preservation.

6. D3: Leverage NDE/SM data to enhance the early deterioration modeling and improve
preservation/maintenance decisionmaking.

7. C1: Identify performance and preservation needs for corrosion-resistant rebar (e.g.,
stainless steel, CFRP/GFRP, MMX, CGR, black rebar, epoxy coated, new textured
epoxy rebar)-reinforced bridge components/elements (e.g., deck, superstructure,
substructure, and piles).

45
 8. C3: Assess cost, performance, and service life extension of corrosion protection,
prevention, and mitigation techniques.

9. P5: Evaluate the live-load effects on bridge performance and how they impact
preservation and management decisionmaking.

10. B6: Evaluate techniques for preserving bridge piles, substructures, and
superstructures.

11. P3: Develop element and health-index-based deterioration models.

12. D2: Integrate construction and sensing data (e.g., LiDAR, UAV, NDE/SM data) into
3D bridge models or digital as-builts to facilitate more efficient and effective bridge
preservation and management decisionmaking.

13. D4: Develop an element data framework to accept BIM and digital as-built data that
provide improved information for preservation and management decisionmaking.

A priority score for each topic was calculated for the top three topics received in the voting, and
the preceding list shows the computed priorities. However, due to the limited number of votes
received, the rankings may not be accurate. Research with an immediate application received
more interest. Topics not receiving priority interest are typically more innovative and may be
associated with relatively higher risk. If aligned well with organizational strategic goals, an
innovative, high-risk project also could be an important component of the research portfolio.

46
 CHAPTER 7. STATEMENT FOR SELECTED TOPICS

The author developed short descriptions of the topics shown in table 1. Table 2 shows the
statements for the 10 topics that were rated higher by BPETG and other stakeholders.
Descriptions of other topics can be found in the appendix.

AASHTO made a 2024 NCHRP project selection recently. The project, called Incorporate Risk
Management in Maintenance Practice (NCHRP 23-38), may cover some aspects of topic P1.(50)
NCHRP 20-05 (Topic 55-01 State DOT Use and Policies on Implementation of Corrosion
Resistant Reinforcing Bars), covers some parts of topic C1.(51) NCHRP 20-05 originated from
topic C1 and ranked high in the stakeholders’ top 10 list. Close followup of those two NCHRP
projects is necessary to avoid duplicate research and identify new research needs as practical.

Consider the similarities and correlations between topics D2, D3, and D4, which have been
combined into a topic called Leverage Digital As-Built, Operational, and Sensing Data to Bridge
Preservation and Management. The combined project will identify data needs for bridge
management; evaluate the data source, collection costs, data management, and interface with
bridge management systems; and manage automated data integration and model updating to
optimize bridge management decisionmaking in a BIM-compatible way. The project can be part
of FHWA infrastructure digitization (e.g., digital as-built, digital twin, and BIM) efforts.

Table 2. Statements for the top 10 research topics.

Estimated
Project
ID Topic Short Statement Duration
• Conduct a survey for the state of
practice of maintenance data
collection.
• Improve the efficiency and
effectiveness of data collection,
sharing, and utilization with a
consistent data framework.
Develop a bridge
• Develop guidelines for maintenance
maintenance data
data collection by analyzing existing
D5 collection framework to 2–3 yr
State-collected data and updating the
understand bridge
NCHRP 14-15 framework to reflect
preservation activities.
new NBI and BIM requirements.(47,7)
• Develop a tiered data collection
strategy so stakeholders can collect
data at a minimum level or include
more data.
• Understand bridge preservation
activities from collected data.

47
 Estimated
Project
ID Topic Short Statement Duration
• Select activities for this study.
• Collect/acquire bridge
preservation/maintenance data and
testing data if available.
Quantify the effects of • Evaluate the benefits of the activities
P2 bridge preservation through inventory data analysis, 3 yr
activities. accelerated laboratory testing, and
field testing.
• Evaluate the lifecycle cost (in terms of
financial and environmental costs, if
possible) for each activity.
• Define the bridge asset management
workflow and data needs.
• Determine the data sources and data
collection cost associated with each
data requirement.
• Optimize the data items for bridge
Leverage digital as-built,
preservation/management
operational, and sensing
Combined decisionmaking through cost-benefit
data in bridge
D2, D3, evaluation. 3 yr
preservation and
and D4 • Make the identified data items
management
available or accessible for bridge
decisionmaking.
management systems. BIM
compatibility will also be studied.
• Automate the data-leveraging
procedure.
• Conduct a pilot case study to
demonstrate the work.
• Establish quality control procedures
and performance evaluation
Develop a quality control
procedures for bridge preservation
procedure and
activities.
B1 performance evaluation 3 yr
• Research and develop guidelines for
of bridge preservation
quality control procedures and
activities.
performance evaluation procedures
for selected preservation activities.

48
 Estimated
Project
ID Topic Short Statement Duration
• Identify new materials and new
Assess the lifecycle cost technologies for study.
and performance of new • Collect/acquire cost data for new
P4 materials and new materials and new technologies. 2–3 yr
technologies in bridge • Develop lifecycle preservation plans
preservation. that use new materials and new
technologies based on LCCA.
• Identify live-load impacts on bridge
performance, which is important due
to the ever-increasing truck weight,
next generation trucks and truck
operation.
• Investigate how WIM data can be
used to establish general and bridge
specific live load model
• Investigate how to quantify live-load
Evaluate live-load effects effect on bridge deck deterioration,
on bridge performance fatigue service life, and capacity etc.
P5 and how they affect through analysis and/or field testing 2–3 yr
preservation which may involve NDE/SM data and
decisionmaking. inventory data
• Investigate preservation activities that
are more effective for heavy load-
caused deterioration.
• Investigate preservation and
management decisionmaking
strategies considering live load
effects
• Demonstrate the work with one or two
case studies
Identify performance and • Establish a database for bridges with
preservation needs for corrosion-resistant rebar (starting with
corrosion-resistant rebar stainless steel rebar and bridge deck)
(e.g., stainless steel, and reinforced components and
CFRP/GFRP, MMX, elements. Develop a data dictionary
C1* CGR, epoxy coated, new and start populating it with data.
textured epoxy rebar) • Determine field performance from
reinforced bridge inventory data or laboratory or
components/elements field-testing data if available.
(e.g., deck, • Correlate field performance (from
superstructure, inventory or field testing) with

49
 Estimated
Project
ID Topic Short Statement Duration
substructure, and piles). accelerated laboratory-testing data, if
available, to validate the testing. After
validation, laboratory testing can be
used to predict future performance
data, which is rarely available or
expensive to collect.
• Collect cost data and perform LCCA
to show the benefit of using stainless
steel rebar, GFRP rebar, and other
corrosion-resistant rebar in bridge
deck and corrosion-prone zones.
• Recommend using the stainless-steel
rebar type in bridge deck,
superstructure, and substructure.
Investigate maintenance needs, if any.
• Quantify the benefit of using
corrosion-resistant rebar in service life
design.
• Identify effective preservation
techniques through a literature review.
Evaluate techniques for
• Conduct an indepth survey/interview
the preservation of bridge
B6 with bridge owners to document the 2–3 yr
piles, substructures, and
state-of-practice procedure.
superstructures.
• Conduct LCCA if practical.
• Identify and document best practices.
• Develop a risk evaluation framework
that includes or facilitates the
following:
o Investigate bridge
deterioration-caused risks.
o Investigate climate change (e.g.,
changes in temperature,
Develop methods to
precipitation, freeze–thaw
integrate risk assessment
cycle)-caused risks.
P1* into bridge preservation 3 yr
o Evaluate extreme events (e.g.,
and management
hurricane, wildfire, flood,
decisionmaking.
earthquake)-caused risks.
o Investigate the combined
multihazard risk.
• Investigate bridge resilience and
sustainability.
• Develop a data collection framework
for before, during, and after event

50
 Estimated
Project
ID Topic Short Statement Duration
condition evaluation. Sensing
technologies are needed in data
collection.
• Investigate and develop a risk-based
preservation and management
decisionmaking framework and
demonstration tool. AI and big-data
approaches can be used.
• Identify corrosion protection,
Assess the costs, prevention, and mitigation
performance, and service technologies (e.g., galvanic coating,
life extensions of cathodic protection) to be studied.
C3** 3 yr
corrosion protection, • Collect cost and performance data.
prevention, and • Conduct a case study to develop
mitigation techniques. practice guidelines for identified
techniques.
*Recently funded project NCHRP 23-38 is closely related to topic P1. FHWA will follow up to avoid duplicate
research and identify new needs as practical.(50)
**More specific research needs will be identified after the report on FHWA corrosion peer exchange is available.(51)

51
 CHAPTER 8. CONCLUSIONS

As State DOT bridge preservation programs mature and more bridges in poor condition get
replaced, proactive bridge preservation is becoming a cost-effective tool for maintaining the
bridge inventory in a state of good repair. In the meantime, considering service life during bridge
design and balancing bridge rehabilitation and replacement are also important preservation
decisions. Increasing knowledge of bridge preservation materials, technologies, and
decisionmaking strategies is becoming more helpful in optimizing limited funds. This roadmap
represents a strategic approach to bridge preservation research needs for FHWA and may also be
used by other agencies or organizations. In addition to addressing research gaps, this roadmap
addresses emerging technologies and innovative techniques. This roadmap is a living document
and will be updated periodically to reflect completed work and new research needs.

53
 APPENDIX. STATEMENTS FOR OTHER TOPICS

In table 3, short descriptions were developed for high-ranking topics that were not selected for
the top 10 list.

Table 3. Statements for other topics.

ID Topic Short Description

• Conduct a literature review and case study.
• Compile AASHTO element or component data from
NBI.(7)
• Develop a health index from element data (consider
Develop health-index-
including extra data).
based and risk-based
• Develop element-based and health index-based
P3 deterioration models for
deterioration models using AI and big-data approaches.
bridge preservation
decisionmaking. • Investigate if risk-based deterioration models are
practical.
• Investigate the framework for integrating NDE/SM
data into element-based deterioration modeling
(optional).
Develop methods to use
• Research NDE/SM techniques (including load testing)
NDE/SM data to enhance
that are effective for enhanced condition evaluation,
the early deterioration
especially for early damage and deterioration detection.
D3 modeling and improve
• Improve preservation and maintenance decisionmaking
preservation and
by integrating NDE/SM data into the decision
maintenance
procedure.
decisionmaking.
• Integrate bridge construction data (including cost and
sensing data) into the project information model to
Integrate construction or obtain digital as-builts.
sensing data (e.g., LiDAR, • Develop workflow and an information delivery manual
UAV, NDE/SM data) into for BIM-based bridge asset management framework.
3D bridge models or digital • Develop a process to update the project information
D2 as-builts to facilitate more model with sensing data (e.g., NDE/SM data, UAV
efficient and effective data, and LiDAR data).
bridge preservation and • Use model in preservation, management, and postevent
management decisionmaking.
decisionmaking. • Determine lifecycle cost savings due to adoption of
BIM-based design, construction, and asset
management approaches.

55
 ID Topic Short Description
Develop an element data • Develop a data framework that provides more
framework to accept BIM element-data information (e.g., report damage
and digital as-built data systematically).
that provide improved • Allow seamless BIM or digital twin model updating for
D4
information for any element data update.
preservation and
management
decisionmaking.
Develop bridge • Investigate how deterioration models can be improved
preservation planning, by NDE/SHM data.
project cost, and quantity • Investigate network-level bridge preservation planning
D1
estimation for bridges— for bridges with and without NDE/SHM data.
with and without NDE/SM • Investigate how NDE/SHM data can improve
data. preservation planning at the project level.
• Incorporate data currently collected by State DOTs or
FHWA programs or projects. Many bridge
preservation engineers are not aware of this data, and
therefore, such data are not fully used in bridge
preservation decisionmaking:
o Design and construction data (digital as-built).
Identify available but o HPMS, such as WIM data.
underused data and o Traffic data and collision data.
evaluate the data’s o Climate data.
D6 potential benefit in bridge o Other data to be identified.
preservation and • Collect bridge damage and deterioration reported by
management the public on social media sites (may consider
decisionmaking. establishing a system for the public to report this type
of finding in the future).
• Evaluate the data to determine their applications in
bridge preservation decisionmaking.
• Develop a decisionmaking tool that uses the identified
data.
• Evaluate the results and benefits.
• Investigate the data (e.g., UAV data and other
remote-sensing or image data) need for post
Identify unique data needs extreme-event bridge condition evaluation and repair,
for post-extreme-event rehabilitation, or rebuild decisionmaking.
D7 bridge repair, • Investigate the data application approaches.
rehabilitation, or rebuild • Evaluate the improvement (e.g., cost saving) by using
decisionmaking. the data.
• Develop a decision tool that involve using the
identified data.

56
 ID Topic Short Description
• Investigate sustainable materials and techniques that
Identify sustainable can be used for bridge and tunnel preservation and
techniques for bridge and repair.
S1
tunnel preservation and • Develop case studies and guidelines for applying
repair. identified materials and techniques.
• Perform LCCA and lifecycle emission analysis.
Identify performance and Investigate the field performance of the coating
•
preservation needs for systems of the 80 or so bridges in the United States
C2 bridge components and known to have duplex coatings.
elements with duplex • Identify potential maintenance needs.
coating rebar. • Perform LCCA.
• Evaluate fiber-reinforced concrete because it shows
potential in solving the problem of deck cracking, a
Evaluate the performance
common problem of bridge decks.
of fiber-reinforced concrete
B2 • Investigate the performance of fiber-reinforced
for bridge decks and deck
concrete deck or overlay.
overlays.
• Investigate the possibility to use steel fiber to facilitate
EV charging.
• Link slab has shown advantages in extending deck
Develop guidelines for link service life. A national policy or guideline has not yet
slab design, construction, been developed.
B3
inspection, and • Investigate the underused technology of link slab and
preservation. its performance.
• Perform LCCA to justify the value of the technology.
• Conduct a literature review for UHPC shotcrete
applications and interview selected early adopters.
Assess UHPC shotcrete or
• Evaluate UHPC shotcrete material characteristics and
B4 other applications for
application procedures.
bridge preservation.
• Evaluate the performance of UHPC shotcrete for
preservation of bridge components.
• Develop the data framework and reporting procedure
for fire and collision events.
Develop methods to
• Investigate sensing and prevention systems for fire and
monitor, report, repair, and
collision events.
B5 prevent fire damage and
• Investigate fire damage repair and prevention
vehicle and vessel
technologies.
collisions.
• Investigate collision damage repair and prevention
technologies.

57
 ID Topic Short Description
• Investigate current bumps at bridge entrances/ends,
which are common, especially for bridges with stub
abutments. The bumps can cause larger live-load
impact and discomfort for drivers and passengers.
Develop performance • Conduct a study for best design and construction
criteria, corrective actions, practice to reduce bump formation.
B7
and optimization for bridge • Develop the specification of performance criteria for
approach systems. bridge approaches and how to achieve the desired
performance through cost-effective design,
construction, and maintenance practices.
• Recommend early preservation intervention activities
and their effects.
*Recently funded NCHRP synthesis topic 55-01 is similar to topic C1.(52) FHWA will follow up to avoid duplicate
research and identify new needs.

58
 ACKNOWLEDGMENTS

The author appreciates the help provided by the following:

• The FHWA Research Library staff for their great efforts in providing literature review
results always ahead of schedule. AASHTO Technical Committees on Bridge
Preservation (T-9), Bridge Management, Evaluation and Rehabilitation (T-18), TSP2,
TRB Standing Committees on Bridge Preservation (AKT60), Bridge and Structures
Management (AKT50), and Structures Maintenance (AKT40) for helpful and insightful
feedback.

• FHWA BPETG and Roadmap Development WG for very helpful feedback.

• FHWA internal reviewers for spending lots of time on the draft review.

59
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 Recommended citation: Federal Highway Administration,
Recycled FHWA Bridge Preservation Research Roadmap
HRDI-20/01-24(WEB)E
Recyclable (Washington, DC: 2024) https://doi.org/10.21949/1521789