FIELD EVALUATION OF COMPOSITE MATERIALS
FOR BRIDGE STRENGTHENING

by

ALEXIS ANDRES LOPEZ-INOJOSA

A DISSERTATION
Presented to the Faculty of the Graduate School of the
UNIVERSITY OF MISSOURI-ROLLA
In Partial Fulfillment of the Requirements for the Degree

DOCTOR OF PHILOSOPHY
in
CIVIL ENGINEERING

2006

Antonio Nanni, Advisor

Genda Qhen

John Myers

Cesar Mendoza

K. Chandrashekhara

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UMI N um ber: 3229186

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PUBLICATION DISSERTATION OPTION

The present dissertation has been prepared in the form of five technical papers for
publication. The first paper “Field Validation of FRP Strengthening Technologies on Five
Reinforced Concrete Bridges,” pages 79 through 99, has been accepted for publication in
the ACI Journal Concrete International: Design and Construction. The second paper
“Validation of FRP Composite Technology Through Field Testing,” pages 100 through
115, has been published in the World Conference on Nondestructive Testing, Montreal,
Canada. August 30- September 3, 2004. The third paper “Strengthening of a Reinforced
Concrete Bridge with Externally Bonded Steel Reinforced Polymer (SRP),” pages 116
through 136, has been submitted to the Journal Composites Part B: Engineering
(Elsevier). The fourth paper “Bonded and Mechanically Fastened FRP Strengthening
Systems: A Case of Study,” pages 137 through 162, has been accepted for special
publication of ACI committee 440: 7th International Symposium on Fiber Reinforced
Polymer Reinforcement for Reinforced Concrete Structures (FRPRCS-7), to be held in
New Orleans, Louisiana, November 9, 2005. The fifth paper “Moment Redistribution in
Continuous Reinforced Concrete Slabs Strengthened with Carbon NSM Bar,” pages 163
through 187, has been submitted to the Journal Composites Part B: Engineering
(Elsevier).

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iv


ABSTRACT

This dissertation document consists on five technical papers, compiling the results
of the research done on two projects related to the uses of FRP materials on the
strengthening RC bridges structures. Four papers are related to the first project
“Validation of FRP Composite Technology Through Field Testing,” and one paper to the
second project “Moment Redistribution on Composite-Strengthened RC Slabs.”
The work of the first project focuses on field validation of five variances of FRP
techniques for strengthening of concrete bridges. Fundamental issues related to bridge
strengthening with composites are identified and studied, in particular those associated to
construction, analysis and design, load testing, load rating and monitoring.
One of the intellectual merit of the present dissertation consist of development of
materials and construction specifications, a comprehensive document developed to make
the technology of composite available to bridges owners and intended to be used in future
FRP-related projects. These specifications cover material and construction requirements
for strengthening RC bridges with composites materials and cover the phases of concrete
repairs, surface preparation, material specification, storage, handling, installation process,
for five technologies used in the project.
The work of the second project is focuses on analytical and numerical work to
discuss if moment redistribution can be neglected in Reinforced Concreted (RC) flexural
slabs strengthened with externally-bonded carbon FRP system. Two 22-ft continues slabs

were tested to validate the model.

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v

ACKNOWLEDGMENTS


The author wishes to express his sincere appreciation and gratitude to his advisor
Dr. Antonio Nanni for the opportunity to work under a high performance and
professional team. Also, to Dr. Shamsher Prakash for his appropriate and disinterested
advise.
Special thanks are given to his partner Estela Melian and to his colleagues and
friends: Dr Nestore Galati, Eli Hernandez, William Otero, Abigayle Sherman, Gayle
Spitzmiller, Jason Cox, Travis Hernandez, Silvia Rocca, Marta Matana, Jess Moss and
Wesley Merkle for their cooperation, friendship and help.
The author is grateful to the University of Missouri-Rolla (UMR) for the
opportunity to pursue PhD studies. Also, to Missouri Department of Transportation
(MoDOT), to the Center for Infrastructure Engineering Studies (CIES) at UMR and to the
University Transportation center (UTC) at UMR for their financial support.

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TABLE OF CONTENTS
Page
PUBLICATION DISSERTATION O PT IO N ..........................................................................iii
ABSTRACT

.............................................................................................................................. iv

ACKNOWLEDGMENTS............................................................................................................v
LIST OF ILLUSTRATIONS..................................................................................................... xv
LIST OF T A B LE S.................................................................................................................... xix
SECTION
1. INTRODUCTION......................................................................................................1
2. DESCRIPTION OF THE FIELD VALIDATION PR O JE C T............................. 2

2.1. BACKGROUD AND DESCRIPTION............................................................2
2.2. LOAD TESTING AND MONITORING.........................................................5
2.2.1. Load Testing............................................................................................5
2.2.2. Fiber Optic...............................................................................................6
2.2.3. Crack S ensor.......................................................................................... 7
2.2.4. Installation Criteria for FRP to be Used for Strengthening.............. 7
2.2.5. Delamination and Substrate C ondition............................................... 8
2.2.6. Microwave Near-Field N D T ................................................................ 9
3. MATERIALS AND CONSTRUCTION SPECIFICATIONS............................10
3.1. CONCRETE R E PA IR .................................................................................. 10
3.1.1. Site D em olition.................................................................................. 10
3.1.1.1. General requirem ents.......................................................... 10

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vii

3.1.1.2. Submittals................................................................................ 10
3.1.1.3. Dust and debris control......................................................... 11
3.1.1.4. Protection................................................................................11
3.1.1.5. Execution................................................................................. 11
3.1.2. Deck Repairs........................................................................................12
3.1.2.1. Description of work................................................................12
3.1.2.2. Locations................................................................................. 12
3.1.2.3. M aterials.................................................................................. 13
3.1.2.3.1. Cementitious patch material................................. 13
3.1.2.3.2. A ggregate................................................................14
3.1.2.3.3. Reinforcing b a rs.....................................................14
3.1.2.4. Equipm ent...............................................................................14

3.1.2.5. Construction m ethod............................................................. 15
3.1.2.6. Surface preparation.................................................................16
3.2. MANUAL LAY-UP CARBON/EPOXY FRP L A M IN A TE.................. 17
3.2.1. G eneral....................................................................................................18
3.2.2. Delivery, Handling and Storage..........................................................20
3.2.3. Products................................................................................................. 21
3.2.3.1. Carbon fabric.......................................................................... 21
3.2.3.2. Epoxy prim er/sealer.............................................................. 22
3.2.3.3. Epoxy putty surface/void filler.............................................22
3.2.3.4. Epoxy saturant........................................................................ 23

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viii
3.2.4. Execution...............................................................................................23
3.2.4.1. Concrete repair.......................................................................23
3.2.4.2. Surface preparation................................................................ 23
3.2.4.3. Carbon manual lay-up laminate installation.......................25
3.2.4.3.1. Application of filler/surface.................................27
3.2.4.3.2. Application of carbon fiber sheet........................ 27
3.2.5. Rework and Repairs............................................................................. 29
3.2.6. Acceptance Testing.............................................................................. 30
3.3. NEAR SURFACE MOUNTED COMPOSITE BAR SYSTEM ............. 31
3.3.1. G eneral................................................................................................... 31
3.3.2. Delivery and Storage............................................................................ 33
3.3.3. Products................................................................................................. 34
3.3.3.1. Carbon/epoxy FRP bars.........................................................34
3.3.3.2. Epoxy adhesive system..........................................................35
3.3.3.2.1. Epoxy adhesive.......................................................35

3.3.3.2.2. UV protection.........................................................36
3.3.4. Execution...............................................................................................36
3.3.4.1. Concrete repair.......................................................................37
3.3.4.2. Surface preparation................................................................ 37
3.3.4.3. Carbon bar installation............................................................. 38

3.3.5. Rework and Repairs............................................................................. 40
3.4. BONDED CARBON/EPOXY PRE-CURED LAMINATE .....................41

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ix

3.4.1. G eneral................................................................................................... 41
3.4.2. Delivery, Handling and Storage..........................................................43
3.4.3. Products.................................................................................................44
3.4.3.1. Carbon/epoxy FRP pre-cured lam inate.............................. 44
3.4.3.2. Epoxy prim er/sealer.............................................................. 45
3.4.3.3. Adhesive..................................................................................45
3.4.4. Execution...............................................................................................46
3.4.4.1. Concrete repair.......................................................................46
3.4.4.2. Surface preparation................................................................ 46
3.4.4.3. Pre-cured CFRP laminate installation.................................47
3.4.5. Rework and Repairs............................................................................. 50
3.4.6. Acceptance Testing.............................................................................. 51
3.5. STEEL REINFORCED POLYMER LAMINATES ................................52
3.5.1. G eneral................................................................................................... 52
3.5.2. Delivery and Storage............................................................................ 54
3.5.3. Products................................................................................................. 55

3.5.3.1. Steel cord lam inates.............................................................. 55
3.5.3.2. Epoxy resin............................................................................. 55
3.5.4. Execution...............................................................................................56
3.5.4.1. Concrete repairs.......................................................................... 56

3.5.4.2. Surface preparation................................................................ 56
3.5.4.3. Steel reinforced polymer laminate installation...................57

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X

3.5.5. Rework and Repairs............................................................................. 61
3.5.6. Acceptance Testing.............................................................................. 61
3.6. MECHANICALLY FASTENED FRP LA M IN A TE...............................62
3.6.1. G eneral................................................................................................... 62
3.6.2. Delivery and Storage............................................................................ 64
3.6.3. Products.................................................................................................65
3.6.3.1. FRP strip..................................................................................65
3.6.3.2. Epoxy adhesive system..........................................................65
3.6.3.3. Fasteners..................................................................................66
3.6.4. Execution...............................................................................................66
3.6.4.1. Surface preparation................................................................ 66
3.6.4.2. Mechanically fastened FRP lam inate..................................66
3.6.5. Rework and Repairs............................................................................. 68
4. DESCRIPTION OF MOMENT REDISTRIBUTION PR O JEC T.....................69
5. LAYOUT OF THE DISSERTATION.................................................................. 71
5.1. PA PER S............................................................................................................71
5.2. APPENDICES.................................................................................................. 74

6. CONCLUDING REM A RK S..................................................................................75
BIBLIOGRAPHY.......................................................................................................................77
PAPER
1. FIELD VALIDATION OF FRP STRENGTHENING TECHNOLOGIES
ON FIVE REINFORCED CONCRETE BRIDGES.............................................79
ABSTRACT...................................................................................................... 79

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xi

INTRODUCTION.............................................................................................80
DESCRIPTION OF THE PR O JEC T............................................................. 80
BRIDGE ANALYSIS AND COMPOSITE REINFORCEMENT
D ESIG N ............................................................................................................. 81
CONSTRUCTION............................................................................................84
Surface Preparation............................................................................. 87
Inspection During Construction........................................................89
LONG TERM M ONITORING.......................................................................91
NDT M ONITORING....................................................................................... 92
CONCLUSIONS...............................................................................................92
ACKNOWLEDGMENTS................................................................................94
REFERENCES.................................................................................................. 94
2. VALIDATION OF FRP COMPOSITE TECHNOLOGY THROUGH
FIELD TESTING .................................................................................................. 100
A bstract............................................................................................................ 100
Introduction......................................................................................................100
FRP M aterial....................................................................................................103
Critical Issues on FRP Strengthening........................................................... 104

Fiber Alignment................................................................................... 105
Optimal Surface Roughness................................................................106
Detection of Debonding...................................................................... 108
Strain M easurement.............................................................................110
Degree of Resin C uring...................................................................... 110

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Cracking................................................................................................ I l l
Long-term Global Performance......................................................... I l l
Results and Discussion................................................................................... 112
Conclusions......................................................................................................112
Acknowledgments...........................................................................................113
References........................................................................................................ 113
3. STRENGTHENING OF A REINFORCED CONCRETE BRIDGE WITH
EXTERNALLY BONDED STEEL REINFORCED PO L Y M ER ................... 116
ABSTRACT.....................................................................................................116
INTRODUCTION...........................................................................................116
BRIDGES DESCRIPTION .......................................................................... 118
BRIDGE ANALYSIS AND SRP REINFORCEMENT DESIGN

119

INSTALLATION OF SR P.............................................................................123
Surface preparation.............................................................................123
Reinforcement installation................................................................124
LOAD RATING.............................................................................................. 124
LONG-TERM PERFORMANCE.................................................................125
CONCLUSIONS............................................................................................. 126

ACKNOWLEDGMENTS..............................................................................126
REFERENCES................................................................................................ 127
4. BONDED AND MECHANICALLY FASTENED FRP
STRENGTHENING SYSTEMS: A CASE STUDY..........................................137
SYNOPSIS.......................................................................................................137

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INTRODUCTION...........................................................................................138
BRIDGES DESCRIPTION AND OBJECTIVES.......................................140
BRIDGE ANALYSIS AND ENTERNAL REINFORCEMENT
D ESIG N ........................................................................................................... 142
INSTALLATION OF EXTERNAL REINFORCEMENT........................ 145
Surface preparation.............................................................................145
Reinforcement installation................................................................145
LOAD RATING.............................................................................................. 146
FIELD VALIDATION AND FEM ANALYSIS.........................................147
CONCLUSIONS............................................................................................. 150
ACKNOWLEDGMENTS..............................................................................151
REFERENCES................................................................................................ 152
5. MOMENT REDISTRIBUTION IN CONTINUOUS REINFORCED
CONCRETE SLABS STRENGTHENED WITH CARBON NSM
BARS ..................................................................................................................... 163
ABSTRACT.....................................................................................................163
INTRODUCTION...........................................................................................164
VARIABLES INFLUENCING M R ............................................................. 166
MR IN THE ACI C O D E................................................................................167
ELEMENTS STRENGTHENED WITH F R P ............................................ 169
NEAR SURFACE MOUNTED CARBON FRP BAR SY STEM


171

DECREASE OF DUCTILITY DUE TO FRP REINFORCEMENT

172

NUMERICAL PREDICTION AND EXPERIMENTAL TE ST ...............173

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xiv
Test R esults.........................................................................................176
SUMMARY AND CONCLUSIONS........................................................... 176
REFERENCES................................................................................................ 178
APPENDICES
A. CONSTRUCTION REPORT: STRENGTHENING OF BRIDGE
P-0962..................................................................................................................... 188
B. DVD: INSTALLATION PROCESS FOR FIVE VARIATIONS
OF COMPOSITE MATERIALS.......................................................................... 206
V IT A .......................................................................................................................................... 208

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XV

LIST OF ILLUSTRATIONS


Figure

Page

2.1. Manual Lay-up FRP Laminates and FRP NSM B ars................................................ 3
2.2. Adhered Pre-cured FRP Laminates.............................................................................. 3
2.3. Mechanically Fastened FRP Lam inates.......................................................................4
2.4. Steel Reinforced Polym ers............................................................................................ 4
2.5. Load Testing Using Surveying E q u ip m en t................................................................ 6
2.6. Fiber Optic Sensors Installation....................................................................................6
2.7. Microwave Image of a D isbond....................................................................................9
2.8. Automated Scanner........................................................................................................ 9
6.1. Flowchart for the Organization of the D issertation...............................................76
PAPER 1
1. Approach to One of the Strengthened Bridges.............................................................97
2. Manual Lay-up FRP Laminate for Shear U -w raps..................................................... 97
3. Adhered Pre-cured FRP Laminate Installation............................................................97
4. Near Surface Mounted Bars Installation.......................................................................97
5. Mechanically Fastened FRP Laminate Installation..................................................... 98
6. Manual Lay-up SRP Laminate....................................................................................... 98
7. Surface Preparation by Sandblasting............................................................................. 98
8. Environmental Pollution C ontrol...................................................................................98
9. Load Testing Using Surveying Equipm ent.................................................................. 99
10. Longitudinal Deflection Before and After Strengthening........................................ 99

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xvi


PAPER 2
1. Representation of FRP M aterial................................................................................... 104
2. Fiber Misalignment Detection...................................................................................... 106
3. Roughness Surface.........................................................................................................108
4. Intentional Delaminations on FRP Lam inates........................................................... 109
5. Load Testing....................................................................................................................112
PAPER 3
1. Fabric Made of Steel Cords...........................................................................................129
2. Lateral View of Bridge P 0 9 6 2 ..................................................................................... 129
3. Cross Section of the Bridge...........................................................................................129
4. Truck Loads HS20-44 and 3 S 2 .................................................................................... 129
5. Internal Strain and Stress Distribution for a Rectangular Section Under
Flexural at Ultimate S tage............................................................................................130
6. Illustration of Dimensional Variables Used in Shear Strengthening....................... 130
7. Flexural SRP Strengthening Layout Detail and MomentsforInternal Girders.... 131
8. Shear SRP Strengthening Layout Detail and Shear for Internal G irders................132
9. Surface Preparation........................................................................................................133
10. Cutting the Cord T ape................................................................................................. 133
11. Application of Epoxy R esin....................................................................................... 133
12. Installation of SRP by Manual Lay-up Procedure.................................................. 134
13. Full Impregnation of S R P ...........................................................................................134
14. U-Wraps for Shear Reinforcement.............................................................................134
15. Static Load Test............................................................................................................ 135

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xvii

PAPER 4

1. Side View of the Bridge Y-0298 in Pulaski County, M O.........................................155
2. Areas of Deck with Major Concrete Deterioration on both Sides of the Bridge ..155
3. Geometry of the Bridge................................................................................................. 156
4. FRP Materials Used in Strengthening System ........................................................... 157
5. MF-FRP System for the Strengthening of the Major Deteriorated Areas.............. 157
6. Strengthening Layout of the Bridge Y-0298.............................................................. 158
7. Installation of Manual Lay-up Lam inates...................................................................158
8. Application of the MF-FRP Strengthening System .................................................. 159
9. Instrumentation to Monitor Displacements and Strains............................................160
10. FEM Model for the Bridge Y-0298........................................................................... 160
11. Composite Reinforcement in FEM M odel............................................................... 161
12. Experimental and Analytical Displacement Prior to Strengthening..................... 161
13. Experimental and Analytical Displacement after Strengthening.......................... 162
14. Strain in the MF-FRP Lam inates...............................................................................162
PAPER 5
1. Representation of Continuous Beam under Distributed L o a d .................................181
2. Idealized Moment-Curvature Relationship.................................................................181
3. Strain Diagram for Reinforced C oncrete....................................................................181
4. Moments Variation for Continuous Elements............................................................ 182
5. Permissible Moment Redistribution According ACI 3 1 8 -0 2 .................................. 182
6. Moment-Curvature Relationship for FRP-Strengthened Section.............................182
7. Moment Curvature Relation under Elastic and Nonlinear Behavior for
Strengthened and Unstrengthened FRP Sections......................................................183

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xviii

8. Ultimate Net Tensile Strain vs. Amount of Steel Reinforcement p/pb...................183

9. Decrease of Net Tensile Steel Ultimate Strain with FRP Reinforcement.............. 184
10. Geometry and Cross-section Details of the Slabs................................................... 184
11. Setup of the Specimen................................................................................................. 184
12. Applied Force vs. Displacement for Numerical Prediction and Test.................... 185
13. Negative Moment vs. Applied Force for Elastic Prediction and Test...................185
14. Moment Redistribution vs. Applied Force............................................................... 186
15. Variation of the Ratio Negative Moment over Positive Moment
for Elastic Prediction and Experim ent...................................................................... 186
16. Forces between the NSM Bar and the Adhesive......................................................187

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xix

LIST OF TABLES

Table

Page

2.1. Project Expected D eliverables......................................................................................4
3.1. Mechanical Properties for Carbon F abric................................................................. 21
3.2. Mechanical Properties for Prim er/Sealer.................................................................. 22
3.3. Mechanical Properties for Putty Surfacer................................................................. 23
3.4. Mechanical Properties for Epoxy Saturant................................................................ 23
3.5. Mechanical Properties for Epoxy A dhesive.............................................................. 35
3.6. Mechanical Properties for FRP B ars.......................................................................... 35
3.7. Epoxy Resin B inder..................................................................................................... 36
3.8. Carbon Pre-cured Laminates....................................................................................... 45

3.9 Mechanical Properties for Primer................................................................................ 45
3.10. Mechanical Properties for A dhesive........................................................................46
3.11. Mechanical Properties for Steel Cord Laminates................................................... 55
3.12. Mechanical Properties for Epoxy Resin.................................................................. 56
3.13. Fiber Composite FRP Lam inates............................................................................. 65
3.14. Mechanical Properties for Epoxy Adhesive System ...............................................66
PAPER 2
1. Bridge P-0962 in Dallas County, MO...............................................................................102
PAPER 3
1. Properties of SRP constituent m aterials...................................................................... 136
2. Design values for flexure and shear SRP reinforcement...........................................136

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PAPER 4
1. Properties of CFRP L am inate...................................................................................... 154
2. Slab Positive Moment Capacity per Foot Before and After Strengthening

154

3. Trucks Used in the Load T ests..................................................................................... 154

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1. INTRODUCTION
The presentation dissertation compiling the results of the research performed on

two research projects related to the uses of FRP materials on the strengthening RC
bridges structures. The work of the first project “Validation of FRP Composite
Technology Through Field Testing” focus on field validation of five variances of FRP
techniques for strengthening of concrete bridges. Fundamental issues related to bridge
strengthening with composites are identified and studied, in particular those associated to
analysis

and

design,

construction,

load

testing,

load

rating

and

monitoring.

Comprehensive documents were developed to make the technology of composite
available to bridges owners. For the present dissertation, two of these documents
concerning construction specifications and didactical videos and developed for Missouri
Department of Transportation are presented. They are supposed to be used in future FRPrelated projects.
The work of the second project is focuses on numerical and experimental work to

discuss if moment redistribution can be neglected in Reinforced Concreted (RC) flexural
slabs strengthened with externally-bonded carbon FRP system. Two 22-ft continues RC
slab were tested to calibrate the model. After that, a parametric numerical analysis was
performed.

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2

2. DESCRIPTION OF THE FIELD VALIDATION PROJECT
2.1. BACKGROUND AND DESCRIPTION
The overall goal of the research program “Validation of FRP Composite
Technology Through Field Testing” is to make the technology of bridge strengthening
with composites fully available to bridge owners and professionals.

It intended to

validate the use of fiber-reinforced polymer (FRP) materials as a means to strengthen
existing RC bridges considered structurally deficient. The program aims to provide
guidelines, technology transfer (software and didactical videos) and economical methods
to help with the preservation of Missouri transportation infrastructure.
For over a decade, FRP laminates have been used worldwide to strengthen, repair
or add ductility to existing bridges and buildings.

Composite materials are strong,

lightweight and not susceptible to corrosion. However, despite all their well-documented
benefits (Bakis et al. 2002), including low cost, no traffic-disruption and short-time
installation, and anticipated long-term durability, validation of this technology for bridge

retrofit applications on a large scale is required. The technology for strengthening
existing concrete bridges using fiber-reinforced polymer (FRP) materials is well founded,
with many international guides available (ACI Committee 440 1996, ACI Committee 440
2002, CAN/CSA-S806-02 2002, JSCE 1997, FIB 2001), but transfer of this technology to
bridge owners must be conducted with urgency. The project presented in this dissertation
is intended to expedite this activity in Missouri.
The research project is being conducted under a joint MODOT - University of
Missouri-Rolla (UMR) - private sector funding initiative. Five existing concrete bridges,
geographically spread over three MODOT districts, were strengthened using five

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3

different technologies that go under the name of: manual lay-up FRP laminates (Figure
2.1); adhered pre-cured FRP laminates (Figure 2.2); near surface mounted (NSM) FRP
bars (Figure 2.3); mechanically fastened FRP laminates (Figure 2.3); and, steel reinforced
polymer (SRP) (Figure 2.4).
Validation of these technologies, taking into account durability issues and cost
impact, is undertaken with a 5-year monitoring program with emphasis on non­
destructive testing (NDT).

Figure 2.1. Manual Lay-up FRP
Laminates and FRP NSM Bars

Figure 2.2. Adhered Pre-cured FRP
Laminates

Development of specifications that cover all aspects of the strengthening process,

starting from the assessment and evaluation of the candidate structure prior to
strengthening and finishing with its inspection and maintenance after strengthening are
expected at the end o f the five years (2003-2008).

The intellectual outcomes of the program consist of development of draft
specifications that head towards a national code; and development of draft guides that

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4
have the purpose of aiding MoDOT personnel and may be considered to be of an interim
nature. Table 2.1 summarizes the expected deliverables and the status of these tasks.

Figure 2.3. Mechanically Fastened FRP
Laminates

Figure 2.4. Steel Reinforced Polymers
(SRP)

Table 2.1. Project Expected Deliverables
Name
Status
Materials and Installation
Draft Completed
(See Section 3)
Didactical Videos
Draft Completed.
Development
Design

MathCAD platform
of
software for Design
Draft Specifications
Analytical Part of the
Bridge Rating
task completed
Collection of
Inspection & Maintenance
Data Continue
Draft for Cost
Selection Criteria for
And Effectiveness
Development
Candidate Bridges
Analysis
of
With Cost Estimates
Expert System is
D r a ft G u id e s
in Construction.
Life Expectancy
In Construction
Estimate

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