Carbon Fiber Reinforced Polymer (FRP) Composite Tubes

“ Bridge-in-a-Backpack ”in collaboration with

Who is AIT –Advanced Infrastructure Technologies?

AIT is partnered with University of Maine to commercialize “Bridge-in-a-Backpack” carbon fiber composite technologies for infrastructure construction

Designs & Manufactures FRP tubes, Headwalls, and complete Bridge Systems

Numerous Aesthetic options to beautify

Qualified Small Business Enterprise

• Product Offering– AIT designs & manufactures FRP composite tubes for construction

– Ability to supply a complete engineered bridge system

– Packages: FRP arches + composite decking, modular FRP headwalls

• Structural Design– AIT’s engineers design the composite arch bridge superstructure

– Can design the bridge substructure, internally or with consultants

– Optimization to maximize efficiency of structure

Daniel BannonStructural Engineer

Jonathan KenersonManufacturing Manager

What is “Bridge-in-a-Backpack” ? Composite + Concrete Arch Superstructure System

Image Credit – NY Times/University of Maine

“ A hybrid bridge superstructure system combining the strength and longevity of high-performance composites with durability and cost savings of cast-in-place concrete ”

National Recognition Awards for Bridge-in-a-Backpack

Engineering Excellence Award

Royal River Bridge, Auburn, ME(Along with Maine DOT & Kleinfelder | SEA)

AASHTO TIG - 2011 Focus Technology

Product featured in:

Engineering News Record,

The NY Times,

Concrete International,

Popular Science,

Popular Mechanics,

The Boston Globe

American Society of Civil Engineers

2011 Charles Pankow Award for

Innovation

2010 Award for Composites Excellence

Most Creative Application

Three Functions of the FRP Arch Tube

# 1. Stay-in-place form for concrete structures

Arches and decking are the only formwork needed to stabilize the structure

Temporary Formwork for Arches Concrete Engineers Handbook,

McGraw-Hill, 1918

Lightweight, permanent shell encases concreteEliminates need for temporary formwork

# 2. Structural reinforcement for concrete

Eliminates need for rebar installation,

Enhances concrete performance

Three Components of FRP Reinforcement Confined concrete demonstrates significant ductility over unconfined

Confined

Unconfined

Three Functions of the FRP Arch Tube

Three Functions of the FRP Arch Tube

# 3. Environmental protection for concrete

Concrete Corrosion Cycle

Steel rusts and expands causing concrete spalling

Spalling concrete exposes more reinforcement

Drastically reduces maintenance requirements & bridge life cycle costs

Buried Arch StructuresStrong, Reliable & Aesthetically Pleasing Structures

• Design Benefits– Arch efficiently carries load in compression

– Soil contributes to:

• Load distribution

• Passive restraint of structure

– Efficient soil-structure system response

– Much of structure made up of soil – a very inexpensive material

– No at-grade concrete deck to deteriorate

– No issues with icing of deck/road surface

• State of Technology– Current models neglect majority of soil restraint

– Correlation with field data confirms considerable conservatism

• Designed to exceed AASHTO HL-93 Loads

Performance Testing: Load Deflection Testing10 years of R&D at University of Maine Composites Labs

HL-93 Design Load Equivalent

Load-Deflection Response of Concrete-Filled FRP Tubular Arch

0

10

20

30

40

50

60

70

80

0 1 2 3 4 5 6 7 8 9 10

Vertical Deflection at Crown (in)

Ap

pli

ed

Lo

ad

(k

ip)

Initial Static Test to Failure Post-Failure Behavior

Performance Testing: Arch Response / Capacity TestingSafety First, Exceeds HL-93 Design Loads, Double Redundancy, No Catastrophic Failures

Failure Load (kip) COV No. Percent Diff.

InitialExperimental 72.0 2.55% 3

4.14%

Predicted 69.0 -------- --------

SecondaryExperimental 57.6 7.75% 3

1.10%

Predicted 57.0 -------- --------

Load-Deflection Response of Concrete-Filled FRP Tubular Arch

0

10

20

30

40

50

60

70

80

0 1 2 3 4 5 6 7 8 9 10

Vertical Deflection at Crown (in)

Ap

pli

ed

Lo

ad

(k

ip)

Initial Static Test to Failure Post-Failure Behavior

Experimental & Predicted Capacity

Initial hinge at crown

Subsequent hinges at shoulders

Implementation - Bridge Replacement - Maine DOT

• Neal Bridge, Maine DOT Demonstration Project in 2008

• First installation of a composite arch system

23 Arches Installed * Design enhancements allow for

wider spacing, lowering costs

Headwalls Installed,

Bridge BackfilledArches Filled with Concrete

Bridge superstructure built in less than 2

weeks

Composite Structure Cost-Competitive with Precast Concrete and

Steel Alternatives

Composites utilized for all major components in

superstructure

Joint-free, steel-free structure expected to provide 100+ years of service with very little

maintenance

Natural stream bed maintained, no

disruption to hydraulicsCraig Dilger for The New York Times

McGee Bridge ReplacementLow Bid vs. Steel, Concrete, Wood

CONSTRUCTION SEQUENCE

1. Demo. existing steel bridge

2. Excavate for footings

3. Drill bedrock, form footings

4. Arch installation

5. Pour concrete footings

6. Install composite decking

7. Fill arches with concrete

8. Erect composite headwalls

9. Pour deck concrete

10. Backfill bridge, install geogrid

11. Finish grading

12. Guardrails and cleanup

12 Days Total Construction Time

Selected Structures We’ve Done

OwnerSpan (ft) Rise (ft)

Width (ft)

# of Arches Headwall Type Foundation Type Previous Bridge Type

DOT 30.5 5.5 44.0 22FRP Panel -

Geogrid

Spread Footings, Medium Depth

Bedrock

Buried Concrete Slab/Girder

Municipal 28.0 4.5 25.0 9FRP Panel -

GeogridSpread Footings, Shallow Bedrock

Open Steel Deck on Steel Girder

DOT 38.0 9.5 38.0 13 Precast T-Wall Steel H-PileConcrete Deck on

Steel Girder

DOT 54.2 12.0 54.0 22Precast MSE

Panel

Spread Footings, Medium Depth

Bedrock

New structure

DOT 48.0 11.0 45.0 16 Precast T-WallSpread Footings, Shallow Bedrock

Buried Concrete Slab/Girder

DOT 37.6 5.6 35.8 15FRP Panel -

GeogridSpread Footings on Compacted Gravel

Buried Concrete Slab/Girder

Private 47.0 6.7 12.0 3 NoneSpread Footings on Compacted Gravel

Timber

DOT 28.5 6.0 34.4 14FRP Panel -

Through-TiedSteel H-Pile

Twin corrugated metal pipe culverts

DOT 34.3 14.0 50.0 12Precast MSE

Panel

Option of Steel H-Pile or Spread

Footings, Medium Depth Bedrock

New structure

Highly Customizable Geometries

• Spans up to 75’

• Single or Multiple Spans

• Skewed designs

• Standard geometries or customized for specific sites

• Deep soil cover (45’ and greater)

• Water/stream crossings, Roadway overpass/underpass, Railway, Pedestrian, Tunnels

Design Options – Numerous Applications

Structures We Like to Do - Speed & SavingsBetter than Traditional Materials

OwnershipBridgeType

SpanSoil

CoverHeadwall

TypeCrossing

TypeRise:Span

RatioFoundation

TypeProject/Award

Type

DOT

Municipal

Private

Other

Highway

20 ftto

75 ft

4 ftto

15 ft

FRP Panel MSE or Tied

PrecastConcrete

MSE, Tied, or Gravity

CIP Concrete Tied or Gravity

Stream

River

Roadway

Railway

Farm

Pedestrian

Utility Line

15% - 50%

Spread Footings on

bedrock

Spread Footings on

soil

Piles supported abutments

Design/Build

Detail/Build

Value Engineering

Any project in need of a

value-added design option

Rail

Pedestrian20 ft

to100 ft

Same as

above,or none

Any of the above, or

none

AIT’s product application is very adaptable and flexible to various site conditions, if your project does not fit the samples above, let our quick response team give you a price.

Range of

Rise:Span

Design Options - Headwalls

FRP Panel Walls– MSE or Through-Tied Configurations

– Compatible with skewed bridges

– Lightweight, easy to install

– Durable, and cost competitive

Multiple options to meet the Engineering, Economic, Environmental, and Aesthetic requirements of the site

Concrete – Precast or CIP– MSE, Through-Tied, or Gravity

– PC Panel, PCMG Units, Cast-in-place

– Versatile design options

– More conventional aesthetic

Summary and Quick Facts.

Innovative Product Application

Multifunction FRP composite tubes

Rapid fabrication our facility or option to fabricate at/near jobsite

Hybrid composite-concrete system improves material performance

Steel free superstructure

Reduced carbon footprint

Performance Tested

Design/tested to exceed AASHTO load requirements

Superior redundancy – safe system

Corrosion resistant materials

Field load testing indicates even greater levels of safety

Cost Effective and Fast Installation

Light weight product– reduces equipment transportation needs

Erected with a small crew, no skilled labor

Performs up to 2x lifespan of conventional materials

Accelerated Bridge Construction

Rapid design, fabrication, and delivery

Please contact us for more infowww.aitbridges.com

Daniel J. Bannon

Structural Engineer

dan@aitbridges.com

(207) 866-6526 x 126

Barry L. Raeburn

EVP - COO

barry@aitbridges.com

(207) 866-6526 x 134