Date of Completion

4-17-2015

Embargo Period

4-17-2015

Keywords

Corrosion, Ultra-High Strength Concrete, Rehabilitation, Finite Element Modeling

Major Advisor

Arash Zaghi

Associate Advisor

Kay Wille

Associate Advisor

Jeong-Ho Kim

Field of Study

Civil Engineering

Degree

Doctor of Philosophy

Open Access

Open Access

Abstract

The end corrosion in steel girders at the bearings due to joint leakage is a significant problem in many of the old bridges around the nation. This critical damage impairs the shear and bearing capacities of girders. Research has been conducted investigating a novel method for retrofitting the corroded ends of steel bridge girders using ultra-high performance concrete (UHPC) encasings. The repair involves casting thin UHPC panels on each side of girder web. Shear studs welded to undamaged portion of the web and flange engage the UHPC panels and provide an alternate load path. This repair method is expected to be superior to the current practice of attaching steel cover plates. It can be easier to design and install, reduce obstruction to traffic during the repair, prevent future corrosion to the girder end, and reduce the total cost of repair. To investigate the effectiveness of the repair in recovering the capacity of the corrosion damaged girders, three large-scale experiments were performed on the undamaged, damaged and repaired rolled girders. It was found that a 1 3/4-in. thick UHPC panel cast two-third of the height of the girder effectively restores the bearing capacity. A high fidelity finite element model was created from the results of the large-scale experiments. This model was then used to design eight repair techniques for full size plate and rolled girders with heavy corrosion damage. This innovative repair method may offer the bridge design community a superior alternative retrofit method for large scale application on the nation’s aging bridge infrastructure.

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