Graduation Year

2023

Document Type

Dissertation

Degree

Ph.D.

Degree Name

Doctor of Philosophy (Ph.D.)

Degree Granting Department

Civil and Environmental Engineering

Major Professor

Christopher Alexander, Ph.D.

Committee Member

Alberto Sagues, Ph.D.

Committee Member

Michael Celestin, Ph.D.

Committee Member

Gray Mullins, Ph.D.

Committee Member

Sarah Kruse, Ph.D.

Keywords

Corrosion, Durability, Embrittlement, Post-Tensioned, Structural

Abstract

Failures in post-tensioned tendons have occurred without warning due to fractures in the high-strength steel strands. These strands are cold-drawn to increase their strength while still retaining the preferential ductile mode of fracture. Recently, a tendon failure that occurred in an upper deviation block of the I-526 James B. Edwards bridge crossing the Wando river showed signs of corrosion and potentially another method of failure, hydrogen embrittlement. One proposed source of hydrogen is through galvanic coupling that may exist between the galvanized steel duct and the steel strands. This coupling, if substantial, can promote hydrogen evolution at the steel strand's surface, which may or may not be mitigated by the condition and quality of the grout. Another proposed source of hydrogen is as a partial byproduct from a corrosion reaction that may initiate on the steel strands. Although corrosion is not likely to occur in a properly grouted tendon, voids that naturally occur in segregated grout can result in corrosion. The objectives of this work are to identify sources of hydrogen, determine conditions that promote galvanic coupling, determine conditions that initiate corrosion, quantify the amount of hydrogen produced from galvanic coupling, and quantify the amount of hydrogen produced from corrosion. The results from this work aim to inform design decisions about what factors to consider to minimize hydrogen-induced damage for future post-tensioned bridge construction.

Download

Included in

Engineering Commons

Share

COinS