| The focus areas in concrete
research are High Performance Concrete, and Corrosion Protection of Concrete
Structures. High Performance Concrete (HPC) is a major FHWA Structures Technology
Program initiative. The Program is being led by the HPC Bridge-Technology
Delivery Team (TDT) that was formally established in May 1997. A goal of
the HPC Bridge TDT is to implement this proven technology through having
at least one HPC bridge project in every State by the Year 2002. The HPC
Bridge TDT consists of FHWA staff from Research and Development, Office
of Technology Applications, Office of Engineering, FHWA field offices, plus
academia and the private sector. The HPC Bridge TDT works with the AASHTO
HPC Lead States Team and the concrete industry's National Concrete Bridge
Council to implement HPC around the Nation. The second focus area 'Corrosion
Protection of Concrete Structures' is aimed at developing improved corrosion
protection systems for bridge steels used in reinforced, pretensioned, and
postensioned concrete structures. The FHWA contacts for Area 1, High
Performance Concrete - Bridges from Research & Development are Susan
N. Lane, & Marcia Simon, unless noted; and for Area 11, Corrosion
Protection of Concrete Structures is Dr. Yash Paul Virmani. Studies
which do not fit neatly into the above two areas are grouped under Area
111. FHWA contacts for Area III are noted after each study description.
Area I. High Performance
Concrete - Bridges
1. The FHWA has initiated of number of high performance concrete
(HPC) bridge projects. A number of participating states have selected
one or more bridges as demonstration HPC sites where improvements in concrete
durability and/or strength can be made. Each project includes some degree
of research, design, instrumentation, construction, and technology transfer.
The FHWA shares funding for the HPC bridge with the individual State where
the project is located. Some projects have also been partially funded
by a group of 10 states which combined their research funds into a "pooled-fund"
effort. Current projects are listed below; others are under negotiation.
- Alabama- The Alabama
Highway 199 Bridge over Uphapee Creek in Macon County, GA is currently
under construction. It will have HPC in the deck, Bulb-Tee girders and
substructure.
- Colorado- The Interstate
25 Bridge over the Yale River in Denver, Co has been constructed. It
contains HPC box beams, as well as an HPC deck and substructure. A Showcase
for FHWA Region 8 states was held in February, 1998.
Publications:
- Cooke, Daniel P.; Shing,
Benson; and Frangopol, Dan. "Colorado Study on Transfer and Development
Length of Prestressing Strand in High Performance Concrete Box Girders,"
University of Colorado at Boulder, April 1998.
- Georgia- The Georgia
HPC bridge on State Route 920, Jonesboro Road, in Henry County, GA has
been designed. Construction of the bridge is scheduled to begin in 1999.
Publications:
- Saber, Aziz. "High Performance
Concrete: Behavior, Design, and Materials in Pretensioned AASHTO
and NU Girders", a Ph.D. dissertation, Georgia Institute of Technology,
Atlanta, GA, 1998.
- Champney, Mark. "Development
of High Performance Concrete for Precast Prestressed Bridges", a
Masters Thesis, Georgia Institute of Technology, Atlanta, GA, 1998.
- Nebraska- The 120' Street
and Giles Road Bridge was completed in 1996 in Sarpy County,NE. This
bridge incorporates HPC in the deck and girders. A Showcase was held
for FHWA Region 7 states in November, 1996.
Publications:
- Kebraei, Mahmound; Luedke,
Jim; and Azizinamini, Atorod. "High Performance Concrete in 120'
and Giles Bridge, Sarpy County, Nebraska," Volumes I and 11, August
1997.
- SHRP High Performance
Concrete Bridge Showcase -Nebraska
- New Hampshire- The Route
104 Bridge crossing the Newfound River at Bristol, NH was completed
in 1996. This bridge also incorporates HPC into the deck and girders.
A Showcase for FHWA Region I states was held in September 22-23, 1997.
A second HPC bridge, the Route 3A Bridge over the Newfound River at
Bristol, NH is under construction.
Publications:
- SHRP High Performance
Concrete Bridge Showcase -New Hampshire
- New Mexico- Up to
two bridges on Interstate 10 will be designed and constructed with HPC.
The bridges are currently in the design phase.
- North Carolina- The
U.S. 401 Bridge over the Neuse River in Wake County, NC is currently
under design.
- Ohio- The State Route
22 Bridge at Mile Post 6.57 in Guernsey County, Ohio is currently under
construction. Structural experimentation on HPC box beams was conducted
during 1997 and 1998. A Showcase for surrounding states will be held
February 23-24 1999.
- South Dakota- HPC
is being used in new bridge decks on two bridges in Sioux Falls, one
bridge with steel girders and one bridge with prestressed concrete girders.
HPC girders and decks will also be used in a pair of bridges on 1-29
over a railroad near Sioux Falls.
- Tennessee- A new
bridge is under construction which utilizes HPC in the deck and girders.
- Texas- The Louetta
Road Overpass near Houston, TX and the San Angelo Bridge in San Angelo,
TX are both HPC bridges. Both incorporate HPC in the deck, girders and
substructure. A Showcase was held in Houston, TX during March 1996 to
transfer this technology to a regional and national audience. Construction
was completed on the San Angelo Bridge in 1997 and on the Louetta Road
Overpass in 1998. Live load tests were conducted for both bridges to
document performance and create a baseline for future measurements.
Publications are being prepared by TX DOT and the University of Texas
researchers on the bridge projects. The Louetta Road Overpass won a
design award in 1998 from the Precast[Prestressed Concrete Institute.
Publications:
- SHRP High Performance
Concrete Bridge Showcase -Texas
- Farrington, Erik; Bums,
Ned; and Carrasquillo, Ramon. "Creep and Shrinkage of High Performance
Concrete", FHWA/TX-98/580-5, February 1996.
- Gross, Shawn; Byle,
Kenneth; and Burns, Ned. "Camber of Long-Span High Performance Concrete
Girders", Technical Memorandum No. 1, University of Texas at Austin,
June 1996.
- Virginia- The Virginia
DOT plans to build 14 bridges utilizing HPC in the deck and/or the superstructure.
A number of these bridges have been completed. The Richlands Bridge
near Bristol, VA will be the first one in Virginia to utilize the 0.6-in
diameter prestressing strands in the HPC girders. A Showcase to transfer
this technology for FHWA Region 3 states was held 'in June 24-26, 1997.
(FHWA contact: Sheila R. Duwadi).
Publications:
- SHRP High Performance
Concrete Bridge Showcase -Virginia.
-
Washington- The Eastbound
State Route 18 Bridge over State Route 516 in King County, WA has been
constructed. A Showcase for FHWA Region 10 states was held in August
18-20, 1997. (FHWA contacts: Sheila R. Duwadi & Barry Brecto)
Publications:
- SHRP High Performance
Concrete Bridge Showcase -Washington.
- Barr, P.; Fekete, E.;
Eberhard, M.; Stanton, J.; Khaleghi, B.; Hsieh, J.C. "High Performance
Concrete in Washington State - SR516 Overcrossing, Eastbound Bridge
No. 18/25S - Interim Report on Girder Monitoring", (Draft) Washington
State Transportation Center, & Washington State Department of Transportation,
June 98.
- Fekete, E.; Barr, P.;
Stanton, J.; Eberhard, M.; Janssen, D. "High Performance Concrete
in Washington State - SR516 Overcrossing, Eastbound Bridge No. 18/25S
- Interim Report on Materials Tests", (Draft) Washington State Transportation
Center, June 98.
2. Optimized Sections for
High Strength Concrete Bridge Girders -Construction Technology Laboratories,
Inc. and Henry Russell, Inc. Phase 1: This phase analyzed the
feasibility of using high-strength concrete with current prestressed
concrete girder cross-sections. Sections included Bulb-Tee sections,
AASHTO Type VI sections, the Texas U-Beam, the Nebraska NU girder, and
modified sections from Florida, Washington, and Colorado. The analyses
indicated that using concrete compressive strengths up to 10,000 psi
allowed longer span lengths and more economical structures. The researchers
also identified possible modifications to current practice which would
allow high-strength concrete to he used more cost-effectively. The final
report for this phase has been published. Phase 2: This phase
evaluated the effect of using high performance concrete (HPC) in bridge
decks. It concentrated on the structural effects of using HPC rather
than on the durability effects. The effect of using HPC in the deck
on the flexural strength, ductility, prestress losses and long-term
deflections of the superstructure were evaluated. Cost analyses were
also performed. The draft final report for this phase has been completed
and is currently under review.
Publications:
- Russell, H.; Volz, J.;
and Bruce, R. "Optimized Sections for High- Strength Concrete Bridge
Girders", FHWA-RD-95-180, August 1997.
3. High Performance Concrete
State-of-the Art Report - North Carolina State University. This
effort is an update of the Strategic Highway Research Program (SHRP)
report No. SHRP-C/FR-91-103, "High Performance Concretes: A State-of-the-Art
Report." A final report has been published and is available on FHWA's
web site. (FHWA Contacts: Lou Colucci & Susan N. Lane).
4. Fatigue of High-Strength
Concrete Bridge Girders - University of Minnesota. This study
is a continuation of a study funded by Minnesota DOT; the continuation
of the study is funded by a "pooled-fund" research effort of nine
State DOTS. It examines the fatigue performance of high-strength prestressed
concrete girders. Draft final reports are under review.
5. Investigation of
Development Length of Uncoated and Epoxy- Coated Prestressing Strand
- The objective of this staff study is to investigate validity of
AASHTO Equation 9-32 for predicting both the transfer length and development
length for fully-bonded, uncoated and epoxy-coated prestressing strand.
Toward this end, the effects of strand diameter (3/8, 0.5, and 0.6
in), concrete strength, and strand coating (uncoated or epoxy coated)
on development length will be evaluated.
Phase 1: Fifty
rectangular prestressed concrete specimens were fabricated in the
FHWA Structures Laboratory beginning in September, 1990. These specimens
ranged in size from: 4"x"xl2'-O"to 14"xl4"x28'-O". Experimentation
to determine transfer length for these specimens was conducted for
one year. Development length experimentation followed and was completed
in Fall 1992. Analysis and report writing followed.
Phase 2: Sixty-four
full-size prestressed concrete 1-girders and deck panels were fabricated
during February through May 1994 at Shockey Bros. precast concrete
plant in Winchester, VA. The members were constructed with either
normal strength (fc= 5000 psi) or high strength (f c =10,000 psi)
concrete. Transfer and development length experimentation on these
members began in May 1994 and was completed in June 1995. New transfer
and development length equations for use in pretensioned beams and
piles have been developed with assistance from Construction Technology
Laboratories, Inc. The equations have been submitted to the AASHTO
Technical Committee for Concrete (T- IO) for consideration for inclusion
in the AASHTO Bridge Specifications.
Publications:
- Lane, Susan. "A New
Development Length Equation for Pretensioned Strands in Bridge Beams
and Piles", FHWA-RD-98-1 16; 1998.
- Tabatabai, Habib; and
Dickson, Timothy. "The History of the Prestressing Strand Development
Length Equation", FHWA-RD-93-076; Feb 1995.
6. Prediction of Chloride
Penetration in Concrete
- University of Toronto (Dr. Hooton and Dr. Thomas). The broad objective
of this research is to develop a new method or methods for predicting
chloride ion penetration into portland cement concrete contained in
bridges and pavements, and to correlate the results from this new
test or tests with a long-term ponding test. The new method(s) will
be utilized for predicting resistance of concrete to chloride ion
penetration for use in evaluating new mixes, accepting or rejecting
new concrete according to specifications, and evaluating in-place
concrete. This study began in September, 1997. (FHWA Contacts: Susan
N. Lane & Marcia Simon).
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