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The ABCs of Heat-Straightening Repair for Steel Bridges
A number of calamities
can cause damage to steel bridges, including vehicle impact, earthquake,
and fire. While the procedure of heat-straightening has been used sporadically
over the past 50 years as a way of correcting this damage, the technique
had never been well-documented. To provide guidance to State highway
agencies and contractors, the Federal Highway Administration (FHWA)
released a two CD-ROM set, Heat-Straightening Repair for Damaged
Steel Bridges: An Interactive Guide, in 2000 and will be offering
specialized training through a series of 2-day seminars. FHWA has also
published a manual, Heat-Straightening Repairs of Damaged Steel Bridges:
A Technical Guide and Manual of Practice.
Heat-straightening is a repair process in which a limited amount of
heat is applied in specific patterns to the deformed regions of damaged
steel in repetitive heating and cooling cycles to produce a gradual
straightening of the material. A benefit of using the process is that
the repairs generally don't require the temporary shoring of the bridge.
Another benefit is that the process can eliminate or greatly curtail
the need for traffic detours. When done properly, the heat-straightening
technique is an effective and economical approach that can be used in
many damage cases. The same principle can also be applied to the fabrication
of new bridges for curving or cambering a girder.
The Manual of Practice and CD-ROM provide information on the management
and design of heat-straightening repair projects, as well as techniques
for using the procedure. The CD also presents a detailed case study
of a heat-straightening project on a bridge near Lake Charles, Louisiana.
The two-lane bridge crossing on I-10 had been damaged when equipment
on a flatbed tractor-trailer impacted a bridge beam. The repair was
designed by a team from Louisiana State University and implemented in
conjunction with the Louisiana Department of Transportation and Development.
Seminars will be held in Little Rock, Arkansas, on November 27-28, 2001,
and in Crawfordsville, Indiana, on December 10-11. Additional workshops
will also be scheduled over the next 2 years. The training programs
will cover:
An overview of heat straightening
How to conduct various heating patterns
How to repair various damage types
How to inspect and supervise repairs
How to estimate the time required to straighten a beam
How to set up technical specifications
A step-by-step description of how heat-straightening was used
in Lake Charles, Louisiana.
Workshops
were previously held this year in Topeka, Kansas, and Atlanta, Georgia.
The Topeka workshop drew more than 50 attendees, while the Atlanta course
attracted nearly 70 participants. "Very useful information was
provided in a format that could be understood and applied to what I
do at work," said attendee Steve Vaughn of the Georgia Department
of Transportation (DOT). "It was one of the best FHWA courses that
we have had," noted Paul Liles, Jr., of the Georgia DOT. Don Whisler
of the Kansas DOT says, "The materials provided will be great tools
to use in the future."
For more information on the workshops or scheduling a training session
in your area, or to obtain a copy of the CD-ROM, contact Krishna Verma,
Senior Welding Engineer at FHWA, 202-366-4601 (fax: 202-366-3077;
email: krishna.verma@fhwa.dot.gov).
More information, including a link for downloading the heat-straightening
manual, can also be found on the Web at www.fhwa.dot.gov/bridge/heat.htm.
![men welding](images/welding1.jpg) |
![men welding](images/welding2.jpg) |
![men welding](images/welding3.jpg) |
![man welding](images/welding4.jpg) |
The
nearly 70 attendees at FHWA's heat-straightening repair workshop
in Atlanta got a hands-on introduction to the technique. |
Other articles in this issue:
From Arizona to Alaska: Maintaining
access and mobility on federal lands highways
Cold in-place recycling a success
in the badlands
New data collection tools get a tryout
in Denali
Combatting pavement roughness with ROSAN
How well do you know your asphalt
mix design?
The ABCs of heat-straightening repair for steel bridges
Highway technology calendar
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