Of the 1,100 steel bridges in Kentucky, several make use of steel girders with weld details that, once exposed to service stresses, are prone to constraint-induced fractures (CIFs). Once a crack initiates, a brittle fracture can develop and severely damage or sever parts of the girders. KTC researchers evaluated welded girder bridges across the state by first reviewing KYTC’s bridge inventory. Based on this work, KTC found 45 bridges that have potentially problematic CIF details and another 55 steel span bridges labeled as being of a different material type, warranting up-close inspection. Researchers developed arm’s length inspection criteria which KYTC inspectors can use to determine whether the 55 steel span bridges have CIF details and if they are problematic enough to require repairs. Additionally, KTC devised a prioritization method for bridges, including specifics about fatigue and fracturing along with the recommended retrofit or mitigation action.
Featured Project: Identification of Bridges with Fracture-Prone Details
With the bridge inventory of the United States rapidly aging, and departments of transportation lacking the financial resources to replace these structures, it is critical to identify and implement novel bridge preservation strategies. KTC’s Bridge Preservation research group works on questions related to the techniques and materials used to repair, reinforce, and preserve the structural elements of bridges. They have worked on numerous projects for the Kentucky Transportation Cabinet, National Cooperative Highway Research Program (NCHRP), and the Federal Highway Administration. Key research topics include the effectiveness of protective coatings for concrete and steel, spot painting techniques, remediating chloride damage on steel bridges, the use of nondestructive technologies to inspect bridges, and holistic bridge maintenance and preservation strategies to prolong service lives.
Research in Progress
- Inspection Training Course on Bridge Preventive Maintenance
- Spot, Zone, and Overcoat Painting of Steel Bridges
- Steel Bridge Coating Inventory 2021
- Assessment of Deteriorated Structural Concrete to Provide Durable Repairs
- Deterioration Modelling of Bridges on AASHTOWare Bridge Management software (BrM)