International Concrete Abstracts Portal

Professor Carolyn Hansson’s remarkable journey began in England, during the turbulence of the Second World War. Despite the hardships of wartime and the limitations imposed by rationing, Carolyn was raised in a nurturing environment by parents who instilled in her a deep respect for learning and perseverance. These values would guide her through an exceptional academic and professional life. As the sole woman at the Royal School of Mines, Carolyn studied metallurgy at Imperial College, where she later earned her PhD, focusing on superconductivity and crystal structures at liquid helium temperatures. Her postdoctoral path led her from industrial research at Martin Marietta Laboratories to academic positions at Columbia University and the State University of New York at Stony Brook, and later to Bell Laboratories in 1976. Her pivotal shift into corrosion science began in 1980 at the Danish Corrosion Centre, where she worked on a new type of cement and corrosion of steel in concrete. From Denmark to Canada, Professor Hansson continued her research at Queen’s University and later at the University of Waterloo, building an enduring legacy in the field of steel corrosion in concrete structures. Over the decades, Carolyn’s contributions to corrosion research have shaped and guided generations of engineers and scientists. Her pioneering studies—on electrical resistivity of concrete, quantifying reinforcement corrosion rates, and understanding the complex role of chlorides—remain foundational in the field. Her investigations into corrosion inhibitors, electrochemical chloride extraction, effects of concrete cracking on reinforcement corrosion, and corrosion-resistant steels continue to influence global practices in infrastructure resilience. This Special Publication celebrates more than 60 years of Professor Hansson’s contributions as a scientist, educator, and mentor. The papers collected here, presented at the 2025 Spring Convention in Toronto, reflect not only the lasting relevance of her work but also its future promise. Her vision stands as both a mirror to the past and a beacon for innovations yet to come in corrosion-resistant construction. O. Burkan Isgor David Tepke Ceki Halmen Neal Berke

A review of corrosion literature on corrosion of steel in concrete clearly shows that Carolyn Hansson’s work and vision mirrors the exponentially increasing interest on the subject since 1980s. During the time Dr. Hansson has been contributing to the scientific community, significant advancements have occurred in understanding and controlling corrosion of metals in concrete. This paper discusses some of the key advancements over the last six decades as Dr. Hansson was making her mark on the industry. The recognition of the role of corrosive environments, development and roles of committees in providing forums for experts, service-life modeling, electrochemical control, and other topics are discussed. Finally, a perspective on where the industry may be going in the future years is offered.

The increased use of alternative deicers to rock salt and introduction of anti-icing prior to winter events using concentrated brines has, in some cases, been associated with deterioration of concrete, especially at joints in pavements. While many commercial products are being used, most either are sodium, calcium, or magnesium chlorides, or mixtures of chlorides. In this study, the effects of different concentrations of calcium and magnesium chlorides on concrete are compared to that of sodium chloride. This study, completed in 2009, found that highly concentrated calcium and magnesium chloride brines caused damage to concrete exposed to low-temperature and freezing temperature cycles by formation of expansive oxychlorides. These results were confirmed by subsequent extensive research performed by others. This paper focusses on concrete performance when exposed to the different forms of chlorides.

It is well known that the steel–concrete interface (SCI) influences corrosion of steel in concrete. Numerous factors related to the SCI have been hypothesized to affect the mechanism of corrosion initiation and propagation, including steel surface characteristics, interfacial concrete properties (voids, cracks, etc.), and conditions related to the exposure (e.g., SCI moisture state). This contribution offers an overview of current knowledge on these aspects. Additionally, recent advances toward a fundamental understanding of corrosion-related processes occurring at the SCI are highlighted, including a novel experimental methodology for studying the steel surface behavior, imaging of the SCI moisture state, and the impact of macroscopic voids. Finally, perspectives for future research are given.

The electrical properties of concrete are being increasingly used to assess concrete resistance to fluid transport. Electrical measurements are strongly dependent on sample conditioning, which includes the degree of saturation. This paper presents an analytical approach for interpreting electrical measurements in partially saturated concrete. Previous approaches have used a power law to describe the influence of saturation. This paper proposes a saturation function that accounts for the contributions of the entrained air voids, the capillary pores, and the gel pores (the GCA function). The proposed approach is demonstrated for high performance, internally cured concrete mixtures tested between the ages of 30 d and 120 d. The power function had a greater measured uncertainty than the GCA function, which performed better at both high and low degrees of saturation. The resistivity of specimens submersed in simulated pore solution was measured as was the resistivity of sealed specimens. The sealed specimens have a degree of saturation that is similar to those at the nick point (matrix saturation), with an offset consistently only due to the self-desiccation of the binder.