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Highways for LIFE

Arrow Iowa Demonstration Project: Accelerated Bridge Construction on US 6 over Keg Creek

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Draft Final Report July 2012

Table of Contents

Iowa Demonstration Project: Accelerated Bridge Construction on US 6 over Keg Creek
Figure 1. Map. Project location (source: Google Maps)
Figure 2. Photos. Existing bridge
Figure 3. Photos. Newly reconstructed bridge
Figure 4. Photo. Temporary supports used for the bridge modules during fabrication
Figure 5. Photo. View during the modular section pour
Figure 6. Diagram. Modular section plan and cross section
Figure 7. Diagram. Cross section of a typical exterior module
Figure 8. Photo. Lifting an exterior module into place
Figure 9. Photo. Aerial view showing placement of bridge modules
Figure 10. Photos. Drilled shafts next to existing bridge (left) and workers positioning rebar
Figure 11. Diagram. Cap to column detail
Figure 12. Diagram. Detail of the drilled shaft to column connection
Figure 13. Diagram. Suspended backwall detail
Figure 14. Photo. Suspended backwall of an interior module (source: HNTB Corp.)
Figure 15. Photo. Workers spread granular backfill behind an abutment
Figure 16. Photo. Water is applied to consolidate the fully-contained flooded backfill
Figure 17. Diagram. Approach slab cross section
Figure 18. Photo. Pier joint reinforcement
Figure 19. Photo. Workers place UHPC in a longitudinal joint
Figure 20. Diagram. Post-tension retrofit design
Figure 21. Photo. Post-tension retrofit installation
Figure 22. Map. Detour route with travel time nodes (source: Google Maps)
Figure 23. Photo. OBSI dual probe system and the SRTT
Figure 24. Graph. Mean A-weighted SI frequency spectra before and after construction
Figure 25. Photo. High-speed inertial profiler mounted behind the test vehicle
Figure 26. Graph. Mean IRI values computed at 20-ft intervals before and after construction
Figure 27. Photo. Sandra Larson gives opening remarks at the showcase
Figure 28. Photo. Showcase participants discuss UHPC
Table 1. Detour route travel times
Table 2. Bid results
Table 3. Capital cost calculation table
Abbreviations and Symbols
AADT annual average daily traffic
AASHTO American Association of State Highway and Transportation Officials
ABC accelerated bridge construction
ADT average daily traffic
dB(A) A-weighted decibel
DOT department of transportation
EDC Every Day Counts
FHWA Federal Highway Administration
HfL Highways for LIFE
HPC high performance concrete
HPS high performance steel
IRI International Roughness Index
ITS intelligent transportation system
OBSI onboard sound intensity
OSHA Occupational Safety and Health Administration
PBES prefabricated bridge elements and systems
PCC portland cement concrete
SAFETEA-LU Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users
SAVER Safety Analysis, Visualization, and Exploration Resource
SCC self-consolidating concrete
SHRP 2 Strategic Highway Research Program
SI sound intensity
SRTT standard reference test tire
TRB Transportation Research Board
UHPC ultra high performance concrete
VOC vehicle operating cost


The purpose of the Highways for LIFE (HfL) pilot program is to accelerate the use of innovations that improve highway safety and quality while reducing congestion caused by construction. LIFE is an acronym for Longer–lasting highway infrastructure using Innovations to accomplish the Fast construction of Efficient and safe highways and bridges.

Specifically, HfL focuses on speeding up the widespread adoption of proven innovations in the highway community. "Innovations" is an inclusive term used by HfL to encompass technologies, materials, tools, equipment, procedures, specifications, methodologies, processes, and practices used to finance, design, or construct highways. HfL is based on the recognition that innovations are available that, if widely and rapidly implemented, would result in significant benefits to road users and highway agencies.

Although innovations themselves are important, HfL is as much about changing the highway community's culture from one that considers innovation something that only adds to the workload, delays projects, raises costs, or increases risk to one that sees it as an opportunity to provide better highway transportation service. HfL is also an effort to change the way highway community decisionmakers and participants perceive their jobs and the service they provide.

The HfL pilot program, described in Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (SAFETEA–LU) Section 1502, includes funding for demonstration construction projects. By providing incentives for projects, HfL promotes improvements in safety, construction–related congestion, and quality that can be achieved through the use of performance goals and innovations. This report documents one such HfL demonstration project.

Additional information on the HfL program is at


This document is disseminated under the sponsorship of the U.S. Department of Transportation in the interest of information exchange. The U.S. Government assumes no liability for its contents or use thereof. This report does not constitute a standard, specification, or regulation.

The U.S. Government does not endorse products or manufacturers. Trade and manufacturers' names appear in this report only because they are considered essential to the object of the document.

1. Report No. 2. Government Accession No. 3. Recipient's Catalog No.
4. Title and Subtitle
Iowa Demonstration Project: Accelerated Bridge Construction on US 6 over Keg Creek
5. Report Date
July 2012
6. Performing Organization Code
7. Author(s)
Paul Littleton, P.E and Jagannath Mallela
8. Performing Organization Report No.
9. Performing Organization Name and Address
Applied Research Associates, Inc.
100 Trade Centre Drive, Suite 200
Champaign, IL 61820
10. Work Unit No.(TRAIS) C6B
11. Contract or Grant No.
12. Sponsoring Agency Name and Address
Office of Infrastructure
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590

13. Type of Report and Period Covered

Final Report

August 2011 —July 2012

14. Sponsoring Agency Code
15. Supplementary Notes
Contracting Officers Technical Representatives: Byron Lord, Mary Huie
16. Abstract

As part of a national initiative sponsored by the Federal Highway Administration (FHWA) under the Highways for LIFE program, the Iowa Department of Transportation (DOT) was awarded a $400,000 grant to demonstrate the use of proven, innovative accelerated bridge construction (ABC) technologies to deliver this $2.7 million project in less time than conventional construction. This project represents a cooperative effort among the FHWA, Iowa DOT, and the Strategic Highway Research Program (SHRP 2) project R04 research team to demonstrate the latest advances in ABC methods.

This report details the ABC innovations used to replace the US 6 bridge over Keg Creek featuring prefabricated superstructure and substructure systems, high- and ultra-high-performance concrete, self-consolidating concrete, and fully contained flooded backfill. The new bridge was completely prefabricated off-site and installed into placeā€”a first in Iowa and in the United States. The ABC approach and innovations in this project increased safety, enhanced quality, and allowed the contractor to replace the bridge during a 16-day road closure instead of 6 months, as would have been required under traditional construction methods.

Using prefabricated bridge systems and innovative materials nearly doubled the initial bridge construction cost compared to traditional construction. However, a comprehensive economic analysis including user cost savings shows that the project saved road users about $0.44 million (or about 29 percent less than conventional construction). The experience gained on this successful project will help the Iowa DOT implement these innovations more routinely on future projects.

17. Key Words
Highways for LIFE, prefabricated bridge systems, innovative construction, high-performance materials, UHPC, fully contained flooded backfill, self-consolidating concrete, economic analysis
18. Distribution Statement

No restriction. This document is available to the public through the Highways for LIFE website:

19. Security Classif. (of this page)
20. No. of Pages
21. Price

Form DOT F 1700.7 (8–72) Reproduction of completed page authorized

Symbol When You Know Multiply By To Find Symbol Symbol When You Know Multiply By To Find Symbol
in inches 25.4 millimeters mm mm millimeters 0.039 inches in
ft feet 0.305 meters m m meters 3.28 feet ft
yd yards 0.914 meters m m meters 1.09 yards yd
mi miles 1.61 kilometers km km kilometers 0.621 miles mi
in2 square inches 645.2 square millimeters mm2 mm2 square millimeters 0.0016 square inches in2
ft2 square feet 0.093 square meters m2 m2 square meters 10.764 square feet ft2
yd2 square yards 0.836 square meters m2 m2 square meters 1.195 square yards ac
ac acres 0.405 hectares ha ha hectares 2.47 acres mi2
mi2 square miles 2.59 square kilometers km2 km2 square kilometers 0.386 square miles
fl oz fluid ounces 29.57 milliliters ml ml milliliters 0.034 fluid ounces fl oz
gal gallons 3.785 liters l l liters 0.264 gallons gal
ft3 cubic feet 0.028 cubic meters m3 m3 cubic meters 35.71 cubic feet ft3
yd3 cubic yards 0.765 cubic meters m3 m3 cubic meters 1.307 cubic yard yd3
NOTE: Volumes greater than 1000 l shall be shown in m3
oz ounces 28.35 grams g g grams 0.035 ounces oz
lb pounds 0.454 kilograms kg kg kilograms 2.202 pounds lb
T short tons (2000 lb) 0.907 megagrams Mg Mg megagrams 1.103 short tons (2000 lb) T
TEMPERATURE (exact degrees) TEMPERATURE (exact degrees)
°F Fahrenheit 5(F–32)/9 or (F–32)/1.8 Celcius °C °C Celsius 1.8C +32 Fahrenheit °F
fc foot–candles 10.76 lux l lx lux 0.0929 foot–candles fc
fl foot–Lamberts 3.426 candela/m2 cd/m2 cd/m2 candela/m2 0.2919 foot–Lamberts fl
lbg pounds 4.45 newtons N N newtons 0.225 poundforce lbf
lb/in2 pound per square inch 6.89 kilopascals kPa kPa kilopascals 0.145 poundforce per square inch ib/in2(psi)
k/in2 klps per square inch 6.89 megaPascals mPa MPa megaPascals 0.145 klps per square inch k/in2(ips)
ib/ft3(pcf) pounds per cubic foot 16.02 kilograms per cubic meter kg/m3 kg/m3 pounds per cubic foot 0.062 kilograms per cubic meter ib/ft3(pcf)


The project team would like to acknowledge the invaluable insights and guidance of Federal Highway Administration (FHWA) Highways for LIFE Team Leader, Byron Lord, and Program Coordinators Mary Huie and Kathleen Bergeron, as well as the Strategic Highway Research Program 2 Senior Program Officer, Dr. Monica Starnes, who served as the technical panel on this demonstration project. Their vast knowledge and experience with the various aspects of construction, technology deployment, and technology transfer helped immensely in developing both the approach and the technical matter for this document. The team also is indebted to Iowa Department of Transportation Engineers, Ahmad Abu-Hawash and Bruce Flippin, and FHWA Engineers Andrew Wilson and Benjamin Beerman for their assistance during this project. Thanks to Mike LaViolette of HNTB Corporation for sharing photographs and valuable insights into the lessons learned from the design and construction process.

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Mary Huie
Highways for LIFE

Updated: 12/21/2012

United States Department of Transportation - Federal Highway Administration