Hot News: Damaged steel bridge girders can be repaired

By Tom Hein, Wichita Public Affairs Manager

In December 2018, a large load struck the underside of a KDOT bridge on K-96 near Maize.

 Extensive damage to steel girders was obvious but the distortions were deemed repairable.

In December 2018, damage to the underside of a bridge on K-96 near Maize occurred.  

In January, a contractor was hired to use a heat straightening process to repair the damaged girders. Steel has a memory and generally wants to go back to its original shape. 

Contractors were hired to repair the underside of the bridge by using a heat straightening process. 

By heating in the right place and at the right temperature, as the steel cools from brief heating process, the metal shrinks and pushes back to its original shape.

Along with using the heat straightening process, other tools like clamps and hydraulic jacks are used to fix the bridge. 

Besides judiciously placed heatings, clamps and hydraulic jacks are used to help influence the return of the steel to its former shape.

The bridge on K-96 is now repaired. 

After seven days of the heat straightening process, the bridge damage has been reversed. 

In a 2008 report, The Federal Highway Administration cited that heat straightening can be traced to the early days of welding. Experiments to reverse distortions by heating steel in specific patterns were successful. Originally considered more art form than a scientific process, the techniques eventually generated wide-spread acceptance through engineering evaluation and research. Today, heat straightening is considered an accepted science and will continue to be used when necessary.