Bridge-in-a-BackpackConcrete Bridges. Concrete Savings.

Wednesday, April 19, 2023

Composite Arch “Bridge-in-a-Backpack” System

Image Credit:NY Times, University of Maine

Secretary of Transportation Ray LaHood Speaks about innovations such as Bridge-in-a-Backpack at Univ. Maine

“Corrosion-free bridge using high-

performance composites with cast-

in-place concrete”

2011 Charles Pankow Award for Innovation

2011 Engineering Excellence Grand Award

AASHTO TIG2011 Focus Technology

2010 Award for Composites ExcellenceMost Creative Application

Also recently featured in: ENR, Concrete International, Popular Science, Popular Mechanics, NY Times…

National Recognition for Bridge-in-a-Backpack

Advanced Infrastructure Technologies

• Product – 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– Local manufacturing and installation

• Carbon Fiber Bridge Superstructures – Safe, Fast, Designed with Redundant Strength Characteristics

Concrete Bridges Concrete Savings

Summary & Opportunities

• Bridge-in-a-Backpack– Innovative system for short- to medium-span

bridge construction– All Bridges designed for AASHTO LRFD Specs– Fast and simple to construct– Minimal transportation and equipment needs– Durable – long life and minimal maintenance– Enhanced material performance makes for

safe, efficient, economical structure

• Advanced Infrastructure Technologies offers:– An engineered bridge superstructure system– Full superstructure design– Limited substructure design– Optimization to ensure efficient design

www.aitbridges.com

“Bridge-in-a-Backpack” Composite Arches

• FRP Composite tubes– Carbon & Glass Fibers– Marine Grade Vinylester Resin

• All Bridges designed for AASHTO LRFD Specs• Fully Manufactured in USA, Maine– Ability to manufacture locally

Composite Arch Manufacturing Process

• 4 -6 week standard lead times• Can rush delivery in under 20 days

when necessary

Manufacturing of a 15” diameter 48’ span composite arch

1. Carbon Tubes assembled and Inflated

2. Bend to required arch geometry

3. Infused with durable vinyl ester resin

Arch delivery/unloading

Arrives ready for Install - No heavy equipment needed

Stay-in-place form for concrete 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

Functions of the FRP Arch Tube

Environmental protection Reduces bridge maintenance requirements

Concrete Corrosion Cycle

Steel rusts and expands causing concrete spalling

Spalling concrete exposes more reinforcement

Functions of the FRP Arch Tube

Constructability and Concrete Filling

• Arches placed in one day• Fill with Self Consolidating

Concrete (SCC)– No rodding/vibration required– AIT provides standard specifications

for concrete mix

Pumping concrete into archesAttach decking on hollow arches

McGee Bridge Replacement

CONSTRUCTION SEQUENCE

1. Demo. existing steel bridge2. Excavate for footings3. Drill bedrock, form footings4. Arch installation5. Pour concrete footings6. Install composite decking7. Fill arches with concrete8. Erect composite headwalls9. Pour deck concrete10. Backfill bridge, install geogrid11. Finish grading12. Guardrails and cleanup

12 Days Total Construction Time

Headwalls, Wingwalls, & Backfill

After arches are filled with SCC, headwalls and wingwalls are erected, and the bridge is backfilled

Arch End Treatments – Headwall Options

• FRP Panel Walls– MSE or Through-Tied– Compatible with skewed bridges– Lightweight, easy to install– Durable, and cost competitive

• Concrete – Precast or CIP– MSE, Through-Tied, or Gravity– PC Panel, PCMG Units, Cast-in-place– Versatile design options– More conventional aesthetic

Multiple options to meet any Engineering, Cost, or Aesthetic Needs

Benefits – Save time, Save Money, Last Longer All Bridges designed for AASHTO LRFD Specs

Bridge superstructure

built in less than 2 weeks

Replaces all Concrete, Precast

Concrete and Steel Alternatives

Composites utilized for all major

components in superstructure

Joint-free, steel-free structure

Natural stream bed maintained,

bottomless, no disruption to

hydraulics

Craig Dilger for The New York Times

Provides 100+ years of service with very little maintenance

Design of a Buried Composite Arch Bridge

• Cast in place, buried concrete arch bridge• AASHTO LRFD, Section 12 – Buried Structures• AASHTO LRFD, Section 5 – Concrete Structures• AASHTO LRFD, Section 3 – Loads & Load Factors

– Dead Loads (DC, DW), Soil Loads (EV, EH)– Live Load (HL-93)

Design of Concrete-Filled FRP Tubular Arches All Bridges designed for AASHTO LRFD Specs

• Proposed AASHTO LRFD Guide Specifications for Design of Concrete-Filled FRP Tubes for Flexural and Axial Members

• Closed-form, simplified method for design of Concrete-Filled FRP Tubes (CFFT’s)– Bending (φMn), Axial (φPn) , Shear (φVn)

– Combined Axial and Bending (interaction diagrams)

– Connection detailing

• Generic in nature – applies to all CFFT’s• Presented to AASHTO’s T-6 (FRP) Committee

in May 2011, currently under review

Projects Completed & Underway

Status Bridge Location/NameDescription

Const.Year Key Stats

Complete(9)

Pittsfield, ME – Neal BridgePilot Project with University of Maine

2008 29.0’ Span

Anson, ME – McGee BridgeMunicipal Design/Build Project

2009 28.0’ Span

Bradley, ME – Jenkins Bridge 2010 28.5’ Span

Auburn, ME – Royal River Bridge 2010 38.0’ Span

Belfast, ME – Perkins Bridge 2010 48.0’ Span

Hermon, ME – Tom Frost Memorial BridgeSnowmobile/Pedestrian Bridge

2010 44.5’ Span3 Arches

Fitchburg, MAMA DOT Accelerated Bridge Program

2011 37.5’ Span

Caribou, ME – Farm Access Overpass 2011 54.0’ Span

Pinkham’s Grant, NHDOT State Bridge Program

2011 24.5’ Span6 Arches

Awarded Harbor Beach, MIDOT State Bridge Program, FHWA Grant

2012 38.0’ Span

Ellsworth, MEState Bridge Program

2012 34.0’ Span11 Arches

Upcoming LaGrange, ME; Weston, CT; VT, RI, VA, CO, UT 2012

Bradle

yBelfast

Fitchburg

Caribo

u

Opportunities – Anywhere a concrete bridge is needed

Useful for a wide range of bridge geometries/site conditions

Single-radius arches with

rise/span from 15%-50%

Variable radius arches up to 48’

span

Single and multi-span,Including highly skewed bridges

Auburn, MaineProject Details• Year: 2010• Span: 38'-0"• Rise: 9'-6"• Width: 38'• Skew: 15°• Arches: 12" diameter• Headwall: cast-in-place concrete and

precast modular gravity wall• Owner: MaineDOT• Engineer: Kleinfelder •SEA

Highlights Replaced steel beam Widened river opening Selected as a national 2011 Engineering

Excellence Grand Award winner by the American Council of Engineering Companies (ACEC).

Before:

After:

Concrete Bridges. Concrete Savings.

www.aitbridges.com

Bradley, MaineProject Details• Year: 2010• Span: 28'-6"• Rise: 6'-0"• Width: 34'• Skew: 19°• Arches: 12" diameter• Headwall: FRP composite wall panels with

through ties• Owner: MaineDOT• Engineer: Kleinfelder •SEA

Highlights Replaced pipe culverts Widened opening, clear span Out of the water Reduced permitting needs / time Full FRP bridge – superstructure +

headwalls Corrosion resistant means of

construction and soil retention

Before:

After:

Concrete Bridges. Concrete Savings.

www.aitbridges.com

Belfast, MaineProject Details• Year: 2010• Span: 47'-7"• Rise: 11'-0"• Width: 45'• Skew: 0°• Arches: 15" diameter• Headwall: cast-in-place concrete and

precast modular gravity wall• Owner: MaineDOT• Engineer: Kleinfelder •SEA

Highlights Replaced concrete T-beam Widened opening 50 yards from Belfast Reservoir dam Constructed with 15" diameter tubes.

With only 25% more carbon fiber than their 12" alternatives these arches provide twice the bending strength

Before:

After:

Concrete Bridges. Concrete Savings.

www.aitbridges.com

Fitchburg, MassachusettsProject Details• Year: 2011• Span: 37'-7"• Rise: 5'-7"• Width: 36'• Skew: 30°• Arches: 12" diameter• Headwall: Composite panels + MSE wall

with geo grid reinforcement• Owner: MassDOT• Engineer: Greenman-Pedersen

Highlights Replaced concrete T-beam Clear span, pier removed Arches carried into place by 5 workers Accelerated Bridge Program for the

replacement of the Scott Reservoir Outlet bridge

Composite headwall system with MSE walls

Before:

After:

Concrete Bridges. Concrete Savings.

www.aitbridges.com

Gov. Deval Patrick Of MA & Local Officials

Advancing US Technology

Anson, MaineProject Details• Year: 2009• Span: 27'-7"• Rise: 4'-5"• Width: 25'• Skew: 15°• Arches: 12" diameter• Headwall: corrugated composite panels +

MSE wall with geo grid reinforcement• Owner: Town of Anson, Maine• Engineer: AIT

Highlights Replaced steel beam $90,000 total project cost, $5,000

better than lowest alternative bid Municipal owner, local contractor Superstructure placed in 8 hours Was replaced start to finish in twelve

working days

Before:

After:

Concrete Bridges. Concrete Savings.

www.aitbridges.com

Pinkham's Grant, New HampshireProject Details• Year: 2011• Span: 23'-8"• Rise: 6'-0"• Width: 26'• Skew: 0°• Arches: 12" diameter• Headwall: composite sheet pile with

through ties• Owner: NHDOT• Engineer: NHDOT / AIT

Highlights Replaced steel beam No heavy equipment used Near the base of Mt. Washington Exposed to extreme conditions, flash

flooding and huge snow fall levels Was replaced start to finish less than

27 working days

Before:

After:

Concrete Bridges. Concrete Savings.

www.aitbridges.com

Option A – Precast Concrete Arch: Square Alignment (~2870 sq.ft.)

Option B (Chosen) – AIT Arch Bridge: Skewed Alignment Savings (~1775 sq. ft.)

Ellsworth Maine -- Maine DOTSkew Bridge Example

38% footprint reduction compared to precast concrete

Concrete Bridges. Concrete Savings.

www.aitbridges.com

Summary and Quick Facts on CFFT Arch BridgesInnovative Product Application

• 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

CONCRETE BRIDGES - CONCRETE SAVINGS.

Concrete Bridges. Concrete Savings.

www.aitbridges.com

Inspection and Maintenance

• AIT provides owners with an inspection manual to augment existing inspection programs and procedures

• Includes guidance for identifying damage and maintenance needs with composite materials

• Covers system specific considerations when inspecting a Bridge-in-a-Backpack™ structure• Arches• Decking • Headwalls

• Maintenance and repair with composites is an established science. Composite technicians have been successfully repairing composites in marine and aviation applications for decades.

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Composite Arch “Bridge-in-a-Backpack” System

Image Credit:NY Times,

University of Maine

Advanced Infrastructure Technologies

• Product – 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– Local manufacturing and installation

• Carbon Fiber Bridge Superstructures – Safe, Fast, Designed with Redundant Strength Characteristics

Concrete Bridges Concrete Savings