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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




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

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

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

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