Bridge Preservation
Featured Project: Identification of Bridges with Fracture-Prone Details
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. Click here to read the full report
Our Story
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.
Bridge Preservation
Sudhir Palle
Christopher Goff
Ted Hopwood
Bob Meade
Deterioration Modelling of Bridges on BrM 5.2.3
Bridge deterioration and cost models use data on bridge elements, structure age and condition, and traffic volumes to forecast future trends in condition and service. The Kentucky Transportation Cabinet (KYTC) relies on AASHTOWare Bridge Management software (BrM) to predict the future performance of structures, thereby informing future cost and resource allocation. KYTC asked KTC researchers to assist with the transition to BrM version 5.2.3 and adapt its deterioration and cost modeling features in accordance with the Cabinet’s specifications. Researchers reviewed literature for available mathematical modelling options, honed those strategies to forecast bridge and culvert element condition and performance, and verified the model’s accuracy through statistical analysis. KTC continues to work with the Cabinet to collect enough field data to continuously calibrate and validate BrM 5.2.3.
Determination of Steels in Kentucky Bridges
Over 200 bridges across Kentucky have steel superstructures of unknown composition and strength. Included among these are older bridges nearing the end of their design life. The team researched identification methods and developed a minimally invasive field test to identify steel strength and composition, making bridges easier to rehab and repair. KTC validated the test procedures and documented them for KYTC’s use. The end product was a database that classifies steels by weldability, mechanical (tensile) properties, ASTM or AASHTO steel type, and weathering properties. Click here to read the full report
Additional Research
Click on the links below to learn more:
- Inspection Training Course on Bridge Preventive Maintenance (In Progress)
- Waterproofing Options in Bridge Decks
- Longer Service Life Bridge Coatings
- Non – Destructive Technology for Bridge Evaluation
- Bridge Overcoating Materials
- Chloride Contamination Remediation on Steel Bridges