Plenary Lecture

Corrosion, Fracture, and Failure Issues for Post-tensioned Concrete Bridge Structures

William H. Hartt, PhD, PE, F-NACE
Professor Emeritus, Department of Ocean Engineering, Florida Atlantic University-SeaTech Campus

Monday, April 19
8 – 9 a.m.

Dr. Hartt received a Bachelor of Science degree from Virginia Tech in 1961 and PhD from the University of Florida in 1966, both in metallurgical engineering. Subsequent to two years at the Army Materials and Mechanics Research Center, he joined the Department of Ocean Engineering at Florida Atlantic University, where he served as Director of the Center for Marine Materials and is now Professor Emeritus. Dr. Hartt has been a member of NACE International for 51 years and has chaired what was the Cathodic Protection in Sea Water and Corrosion in Concrete Materials Committees. He has published more than 200 papers in either journals or conference proceedings and has been designated a NACE International Fellow and recipient of the Frank Speller Award. Dr. Hartt continues to serve as a consultant to government and private sector entities.

The inception of post-tensioned (PT) concrete dates to less than one century ago, and the technology has subsequently evolved in response to integrity issues as these have been identified. While individual high-strength steel wires or threaded bars are sometimes employed, spiral wound seven wire strand conforming to ASTM A416 in plastic duct is more common. The focus here is upon PT in concrete bridge structures where there is an array of ducts within concrete segments, each with multiple strands that, subsequent to stressing, are grouted. This results in compressive stresses in the concrete at locations that otherwise would be in tension and subject to cracking. Particular attention is given to causes and occurrences of wire and strand corrosion and resultant tendon failure. Such corrosion most commonly occurs from bleed water, water entry through grouting ports or deck drains, or the presence of what has been termed “soft grout;” that is, grout that is segregated and moist with the presence of free water and relatively high sulfate concentrations. Tendon failures in the latter case have been reported as soon as two years post-construction. In response to this, a modeling approach that projects the onset and subsequent rate of wire and strand fractures and tendon failures, given statistics for individual wire/strand corrosion rate, is described along with the role of influential factors. A foremost challenge moving forward is the development of technologies for, first, identifying and quantifying corrosion damage and, second, controlling any ongoing corrosion. Approaches for accomplishing this are described.

Willis Rodney Whitney Award Lecture

Robert G. Kelly

Tuesday, April 20
11 - 11:30 a.m.

The Whitney Award recognizes public contributions to the science of corrosion.

Kelly has been conducting research on the corrosion of metals for the past 35 years. He holds a Ph.D. from Johns Hopkins University and spent two years at the Corrosion and Protection Centre at the University of Manchester as a Fulbright Scholar and as an NSF/NATO Post-doctoral Fellow. His experience includes work on the corrosion of metals and alloys, nonaqueous and mixed solvents, as well as studies of the electrochemical and chemical conditions in localized corrosion sites in various alloy systems. He has graduated over 25 Ph.D. students and co-authored over 120 papers. Kelly is also a Fellow of NACE International and has won several teaching awards during his career. He is currently a professor with the University of Virginia.

Frank Newman Speller Award Lecture

Jose Maria Bastidas

Wednesday, April 21
11 - 11:30 a.m.

The Speller Award Lecture recognizes contributions to the practice of corrosion engineering.

For over four decades, Professor Jose-Maria Bastidas has contributed in many aspects of corrosion, electrochemical methods applied to corrosion assessment, and materials characterization. He has devoted his career to elucidate the mechanisms of electrochemical corrosion by studying several technological applications in energy generation, transport systems, aerospace, automotive, and food industries. Bastidas has championed over 60 research projects in corrosion, produced over 450 original articles, and supervised over 30 Ph.D. theses at different universities of Spain, Colombia, Mexico, and Venezuela.