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NC STATE UNIVERSITY
Extending the Useful Life of Prestressed Concrete Bridges Using Mechanically-Fastened Fiber-Reinforced Polymer
Lt. Col. Brad C. McCoy, Ph.D., P.E., ENV SP
Presented to:NCDOT Research and Innovation Summit
May 7th, 2019
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NC STATE UNIVERSITY
Problem Statement Background Research Objective Literature Review Topics Retrofit Concept
Small-scale Testing Results
Full-scale Testing and Results Retrofit Design Full-scale tests Installation optimization
Conclusions
Future Research
Agenda
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NC STATE UNIVERSITY
Deteriorated Prestressed Concrete Superstructures
Sectional capacity vs. Concrete tensile stress
C-channel girder – Bridge No. 380093
Partial loss of prestressing and concrete cover
Complete loss of prestressing and concrete cover
Hollow core slab – North Wake Co.
Problem Statement
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NC STATE UNIVERSITY
Primary Research Objective
Life cycle of 3 – 5 years until permanent repair or replacement
Time and cost of retrofit installation Capability to monitor and maintain Durability of solution
Additional Considerations
Development of a methodology: address common load rating challenges for deteriorated
prestressed concrete bridge superstructures optimized to maximize efficiency of the system and
minimize installation time and resources Bridge remains open without load posting
Installation and inspection capable with DOT personnel
Cost of alternate solutions: Closures, detours, delays, etc.
Problem Statement
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NC STATE UNIVERSITY
Implementation Observations of bridge
inspections and maintenance procedures NCDOT crew capabilities
Optimization installation time skill level
Quantifiable impact of detours for posted candidate bridges travel time $$$
Design Small-scale material testing:
with and without holes hole pattern analysis hole spacing analysis fastener bearing analysis
Connection post-tensioning concrete splitting
Full-scale testing undamaged / damaged with / without retrofit retrofit efficiency
Implementation Road Map
Design Guide
Installation &Maintenance
Lit. Review Topics MF-FRP In-place concrete strength Concrete splitting behavior Vehicle operating cost Digital Image Correlation (DIC) Bridge load rating considerations
Current State of Practice
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NC STATE UNIVERSITY
0125 in.
4 in.
Continuous-strand glass mat top and bottom
Polyester surfacingveil-perimeter
Carbon tows and fiberglass rovings in vinyl ester resin
FRP Plate
Problem Statement
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NC STATE UNIVERSITY
Retrofit Concept Sketch
C-channel beam:
Problem Statement
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NC STATE UNIVERSITY Problem Statement
Retrofit Concept Sketch
FRP
Mechanical fasteners to substrate
Mechanical fasteners to connector plate
Prestressing mechanism
Live-endDead-end
Hollow core slab:
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NC STATE UNIVERSITY
Initial Small-Scale Material Testing
Specimen ID No. of
Replicates Treatment Description ASTM T 8 No holes D3039
S-OH 6 Single open hole centered in gauge length D57661
DBL4-OH-1.5 6 4 open holes; 2-by-2; 1.5 in. transverse spacing; 4 in. longitudinal spacing D57661
DBL4-OH-2.0 6 4 open holes; 2-by-2; 2.0 in. transverse spacing; 4 in. longitudinal spacing D57661
STG4-OH-1.5 6 4 open holes; staggered with 2.0 in. offset; 1.5 in. transverse spacing; 4.0 in. longitudinal spacing D57661
STG4-OH-2.0 6 4 open holes; staggered with 2.0 in. offset; 2.0 in. transverse spacing; 4.0 in. longitudinal spacing D57661
S-B-X-1.5 6 Single bolt bearing with 1.5 in. edge distance excluding threads D5961 S-B-N-1.5 6 Single bolt bearing with 1.5 in. edge distance including threads D5961 S-B-X-4.0 6 Single bolt bearing with 4.0 in. edge distance excluding threads NA S-B-N-4.0 6 Single bolt bearing with 4.0 in. edge distance including threads NA
DBL16-B-1.5 6 16 bolts; 0.5 in. diameter; 2-by-2; 1.5 in. transverse spacing; 4.0 in. longitudinal spacing NA
DBL18-B-1.5 6 18 bolts; 0.5 in. diameter; 2-by-2; 1.5 in. transverse spacing; 4.0 in. longitudinal spacing NA
DBL20-B-1.5 6 20 bolts; 0.5 in. diameter; 2-by-2; 1.5 in. transverse spacing; 4.0 in. longitudinal spacing NA
DBL22-B-1.5 6 22 bolts; 0.5 in. diameter; 2-by-2; 1.5 in. transverse spacing; 4.0 in. longitudinal spacing NA
Material Testing
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NC STATE UNIVERSITY
0.5 in. Diameter Multi-Bolt
Mean multi-bolt load-displacement curves (DBL series)
Maximum prestress level
FRP with holes
Material Testing
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NC STATE UNIVERSITY
Full-Scale C-channel TestingSpecimen ID Specimen Description
U Undamaged Control D Damaged (deteriorated) Control
MF-FRP-U1 Undamaged with first version retrofit (MF-FRP 1.0) installed on both stems MF-FRP-U2 Undamaged with improved retrofit (MF-FRP 2.0) installed on both stems MF-FRP-D1 Damaged with MF-FRP 1.0 installed on both stems MF-FRP-D2 Damaged with MF-FRP 2.0 installed on both stems
Test set-up
Full-scale Testing
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NC STATE UNIVERSITY
MF-FRP 1.0 Design
Dead-end
Live-end
Full-scale Testing
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NC STATE UNIVERSITY
MF-FRP 1.0 Design
Dead-end
Live-end
Full-scale Testing
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NC STATE UNIVERSITY
Control Specimen D
MF-FRP-D1
MF-FRP-U1
Control Specimen U
MF-FRP 1.0 Results
Original Inventory LoadDamaged Inventory Load
MF-FRP-D Inventory Load
Original Operating Load
Damaged Operating Load
≈ MF-FRP-D Operating Load
Full-scale Testing
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NC STATE UNIVERSITY
MF-FRP 1.0 Results
In-plane moment developed in FRP plate at dead-end
Longitudinal splitting initiated at dead-end
Full-scale Testing
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NC STATE UNIVERSITY
MF-FRP 2.0 Design
Dead-end and
Live-end
FRP PlateFRP Connector Plate
Fixed Plate
Pin Connection
Fixed PlatePin Connection
TB Connector Plate
Turnbuckle (TB)
Dead-end Live-end
Full-scale Testing
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NC STATE UNIVERSITY
MF-FRP 2.0 Design
Dead-end
Live-end
Full-scale Testing
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NC STATE UNIVERSITY
Control Specimen D
MF-FRP-D1
MF-FRP-U1
Control Specimen U
MF-FRP-U2
MF-FRP-D2
MF-FRP 2.0 Results
Original Inventory LoadDamaged Inventory Load
MF-FRP-D Inventory Load
Original Operating Load
Damaged Operating Load
≈ MF-FRP-D Operating Load
Full-scale Testing
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NC STATE UNIVERSITY
MF-FRP 2.0 Results
FRP plate post-testing: minor longitudinal splitting
Live-end Dead-end
PFRP = 30 kips
Recall MF-FRP 1.0 FRP failure
Full-scale Testing
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NC STATE UNIVERSITY
MF-FRP 2.0 ResultsFull-scale Testing
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NC STATE UNIVERSITY
Installation Time (labor-hrs.)
MF-FRP 1.0 MF-FRP 2.0 Task W C NW TOTAL W C NW TOTAL
Locate steel 0.3 0.1 0 0.4 0.2 0.1 0 0.3 Drill live-end 0.8 0.5 0.8 2.0 0.5 0.5 0.3 1.3 Drill dead-end 1.0 1.0 1.0 3.0 0.5 0.5 0.3 1.3 Attach live-end 0.5 0.3 0.2 1.0 0.3 0.2 0 0.4 Attach dead-end 0.2 0.3 0 0.7 0.2 0.1 0 0.3 Post-tension FRP 0.4 0.5 0.4 1.2 0.3 0.3 0.0 0.7
TOTAL 3.1 2.7 2.5 8.3 1.9 1.7 0.5 4.1 Percent of Total, % 37.7 32.7 29.6 100 46.9 40.8 12.2 100
Installation OptimizationFull-scale Testing
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NC STATE UNIVERSITY
Key Conclusions For a complete retrofit solution to meet both inventory and operating
ratings, it must restore prestress losses and strength due to deterioration. [ASCE Journal of Performance of Constructed Facilities; under review]
The FRP plate examined in this research is capable of restoring prestress losses due to moderate deterioration in prestressed concrete bridge superstructures with sufficient residual capacity for strength restoration. Further, the FRP plate can be mechanically fastened with sufficient optimization for ultimate capacity, bearing stress, and anchor length. [ASCE Journal of Composites in Construction; in press]
MF-FRP methodology is capable of sufficiently restoring prestressed concrete superstructure with moderate deterioration such that the bridge is capable of supporting original inventory and operating loads. Further, MF-FRP 2.0 is optimized for rapid installation.[ASCE Journal of Performance of Constructed Facilities; under review]
Conclusions
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NC STATE UNIVERSITY Future Research
NC Bridge: 340080
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NC STATE UNIVERSITY
Planned
Investigation to quantify installation and maintenance costs of the MF-FRP retrofit solution to aid in complete life-cycle-cost analysis.
Investigation of alternative composite systems to replace steel components in MF-FRP connections.
Military applications to increase Military Load Classification of bridges in forward theaters of operation
Future Research
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NC STATE UNIVERSITY
Acknowledgements
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NC STATE UNIVERSITY
Questions
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4D MODELING AND DISCRETE EVENT SIMULATION FOR PHASING HIGHWAY RECONSTRUCTION PROJECTS
Mohammed Mawlana, Ph.D.
05-07-2019
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Outline Introduction
Proposed Method
Implementation
Case Study
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Introduction
Transportation developments are shifting from the construction of new
highways to the reconstruction of existing facilities.
The most important factor in the reconstruction of urban highway projects is
the duration of the project.
The duration of reconstruction projects not only impacts the users of highways,
but also affects the whole community around the project area.
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Introduction
Simulation is a powerful tool that can be used to mimic the behavior of real-
world systems over time.
Usage:
» planning and resource allocation
» comparing alternative construction methods
» analyzing earthmoving operations bridge construction operations
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Proposed Method
A two-stage method that can be used in planning the phasing of
elevated urban highway reconstruction projects:
» Phasing Plan Assessment: Generates a clash-free reconstruction phasing plan that meets the imposed traffic and construction constraints.
» Stochastic Spatiotemporal Clash Detection: Captures the uncertainty in the durations of the reconstruction work, detects stochastic spatiotemporal
clashes and calculates their probabilities if they exist.
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Phasing Plan Assessment
Generate All Possible Plans
3D ModelAvailable
Contractors
Traffic
Management Plan
Generate Deterministic 4D
Model
Time-based Clash Detection
Eliminate Infeasible Plans
Constraints of
Construction/
Demolition Methods
Constraints
Eliminate Infeasible Plans
Select Optimum Feasible Plan
Calculate Productivity Rates
and Costs of the Contractors
Rank Feasible Plans
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Stochastic Spatiotemporal Clash Detection
Apply Stochastic Simulation at
those Locations
Identify Potential Stochastic
Spatiotemporal Clashes
Calculate Clash Probability
Select the Starting Date of the
Determinant Segment Causing
the Clash
Time-based Clash Detection
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Implementation Schematic Diagram
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Case Study
Existing Interchange Proposed Interchange
The case study is inspired by the Turcot Interchange reconstruction project in Montreal, Canada
• Built in the 1960s
• Interconnect the three main highways 20, 15, and 720
• Several bridge structures located on three different levels
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Case Study - Constraints
Two contractors available for constructing segment E, F, and G of the
proposed interchange.
One contractor responsible for the demolition of segment F’ of the existing
interchange.
The existing segment F’ cannot be demolished before either segment E or
segment F of the proposed interchange is ready for traffic operation.
Construction of segments G and E can only start from the west and south
ends, respectively.
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Case Study
Existing interchange with marked segment F'
Segment E, F, and G of proposed Interchange
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Construction & Demolition Methods
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Prototype System- Input of segments and contractors
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System output of plans
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System output of plans after applying traffic constraints
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System output of plans after ranking
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C2
C 1
Conflict
Under
Construction
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1st Scenario: conflict
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C 2
C 1
Ready for Traffic
Demolition Start
No Conflict
Replay
2nd Scenario: no conflict
Demolition Start
No Conflict
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Combined probability
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Total clash probability
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Questions?
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Traffic Circulations
E
GF
F'
E'
G'
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E
GF
F'
E'
G'
Trolley
www.colossaltransport.com
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E
GF
F'
E'
G'
Span Pick-up
www.cec.com.tw
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E
GF
F'
E'
G'
Span Placing
www.sdi-intl.com
BMcCoyMcCoy Presentation v. 1.0Extending the Useful Life of Prestressed Concrete Bridges Using Mechanically-Fastened Fiber-Reinforced PolymerSlide Number 2Slide Number 3Slide Number 4Slide Number 5Slide Number 6Slide Number 7Slide Number 8Slide Number 9Slide Number 10Slide Number 11Slide Number 12Slide Number 13Slide Number 14Slide Number 15Slide Number 16Slide Number 17Slide Number 18Slide Number 19Slide Number 20Slide Number 21Slide Number 22Slide Number 23Slide Number 24Slide Number 25Slide Number 26
MMawlanaNCDOT Summit 2019 - NCAT Mawlana