Anatomy of Steel Bridge Heat-Straightening Project

Abstract

Heat-straightening repair of damaged steel girders has been conducted on a number of bridges over the years. However, little documentation is available on repair methodology and response to such repairs. Such documentation for the field repair of a bridge in Iowa is provided. The Iowa Department of Transportation (IDOT) decided to train its maintenance personnel to perform heat-straightening repairs. The training program consisted of 2 days of classroom and laboratory tutorial training and a field heat-straightening project. The field project was a bridge spanning I-80 near Davenport. The repair was successfully completed and demonstrated the practicality of implementing recent advances in heat-straightening research. The response of the damaged girder to the heat-straightening process was also measured and compared with theoretical models.

Synthesis Study: Heat Treatment and Its Effects on Rehabilitating Steel Bridges in Indiana

“…It was found that the use of the jacking forces expedited the plastic rotation per heating cycle until the diaphragm offered increasing restraint to the heat straightening process. The author also noted, "If the jacking/restraining forces are too high, a fracture might occur during straightening" (Avent and Brakke 1996). Results from this field study revealed the following conclusions:…”

“…Several researchers have tested the notch toughness of steel subjected to heat straightening (Harrison 1952, Pattee 1969, Pattee et al 1970, Avent and Brakke 1996, Till 1996. Results from tests, using various grades of steel plates, have indicated that there is an insignificant change in the upper shelf energy absorption before and after application of heat straightening (FHWA 1998 (Pattee 1969).…”

What You Should Know About Heat Straightening Repair of Damaged Steel

“…Perhaps the most typical type of damage found on steel bridge members results from impact of vehicles or freight on the beams or girders of composite deck-girder bridges. Heat straightening is an attractive repair alternative because of its low cost and minimal disruption of traffic (Avent and Brakke, 1996). Typical damage includes: (1) a flexural yield zone at the impact point in the lower flange due to bending about the strong axis of the flange;…”

Fundamental Concepts of Heat-Straightening Repair for Damaged Steel Bridges

“…In recent years considerable research has been conducted to quantify the heat-straightening process (9)(10)(11)(12)(13)(14). Presented here are a comprehensive summary and evaluation of the practical aspects of the heat-straightening process.…”